Patent Grant
8557493
The present disclosure relates to toner compositions and toner processes, such as emulsion aggregation processes and toner compositions formed by such processes. More specifically, the present disclosure relates to emulsion aggregation processes utilizing a bio-based polyester resin.
Numerous processes are within the purview of those skilled in the art for the preparation of toners. Emulsion aggregation (EA) is one such method. Emulsion aggregation toners may be used in forming print and/or electrophotographic images. Emulsion aggregation techniques may involve the formation of a polymer emulsion by heating a monomer and undertaking a batch or semi-continuous emulsion polymerization, as disclosed in, for example, U.S. Pat. No. 5,853,943, the disclosure of which is hereby incorporated by reference in its entirety. Emulsion aggregation/coalescing processes for the preparation of toners are illustrated in a number of patents, such as U.S. Pat. Nos. 5,290,654, 5,278,020, 5,308,734, 5,344,738, 6,593,049, 6,743,559, 6,756,176, 6,830,860, 7,029,817, and 7,329,476, and U.S. Patent Application Publication Nos. 2006/0216626, 2008/0107989, 2008/0107990, 2008/0236446, and 2009/0047593. The disclosures of each of the foregoing patents are hereby incorporated by reference in their entirety.
Polyester EA ultra low melt (ULM) toners have been prepared utilizing amorphous and crystalline polyester resins as illustrated, for example, in U.S. Patent Application Publication No. 2008/0153027, the disclosure of which is hereby incorporated by reference in its entirety.
Many polymeric materials utilized in the formation of toners are based upon the extraction and processing of fossil fuels, leading ultimately to increases in greenhouse gases and accumulation of non-degradable materials in the environment. Furthermore, current polyester based toners may be derived from a bisphenol A monomer, which is a known carcinogen/endocrine disruptor.
Bio-based polyester resins have been utilized to reduce the need for this carcinogenic monomer. An example, as disclosed in co-pending U.S. Patent Application Publication No. 2009/0155703, includes a toner having particles of a bio-based resin, such as, for example, a semi-crystalline biodegradable polyester resin including polyhydroxyalkanoates, wherein the toner is prepared by an emulsion aggregation process.
In order to emulsify conventional and bio-based polymers utilized in the EA process, the acid functionality of the polyester is often increased, as measured by acid value. This is done by adding a polyfunctional monomer, such as trimellitic anhydride (TMA), post polymerization, so that the hydroxyl (OH) terminal groups are converted into carboxylated (COOH) groups. For example, isosorbide-based polyesters have limited reactivity at the isosorbide end groups, thereby restricting the conversion of OH groups into carboxylated end groups. The addition of a non-bio-based monomer, such as TMA, post-polyesterification, can enhance functionality of the polyesters so that emulsion-aggregation chemistry can be carried out.
Notwithstanding the foregoing, alternative, cost-effective, environmentally friendly toners remain desirable.
The present disclosure provides toners and processes for making these ton ers. In embodiments, a toner of the present disclosure includes an acidified bio-based resin including at least one bio-based amorphous polyester resin in combination with at least one bio-based acid; and optionally, one or more ingredients selected from the group consisting of crystalline resins, colorants, waxes, and combinations thereof, wherein the acidified bio-based resin has an acid value of from about 2 mg KOH/g of resin to about 200 mg KOH/g of resin.
In other embodiments, a toner of the present disclosure includes an acidified bio-based resin including at least one bio-based amorphous polyester resin in combination with at least one multi-functional bio-based acid such as citric acid, citric acid anhydride, and combinations thereof; at least one crystalline polyester resin; and optionally, one or more ingredients such as colorants, waxes, and combinations thereof, wherein the bio-based acid is present in an amount of from about 0.1% by weight to about 20% by weight of the bio-based amorphous resin, and wherein the acidified bio-based resin has an acid value of from about 2 mg KOH/g of resin to about 200 mg KOH/g of resin.
A process for producing a toner in accordance with the present disclosure may include, in embodiments, contacting at least one bio-based amorphous polyester resin with at least one bio-based acid to form an acidified bio-based resin having an acid value of from about 2 mg KOH/g of resin to about 200 mg KOH/g of resin; contacting the acidified bio-based resin with at least one crystalline resin, at least one colorant, at least one surfactant, and an optional wax to form an emulsion possessing small particles; aggregating the small particles to form a plurality of larger aggregates; coalescing the larger aggregates to form toner particles; and recovering the particles.
Various embodiments of the present disclosure will be described herein below with reference to the figures wherein:
The present disclosure provides processes for the preparation of resins suitable for use in toner compositions, as well as toners produced by these processes. In embodiments, toners may be produced by a chemical process, such as emulsion aggregation, wherein amorphous, crystalline, and/or bio-based latex resins are aggregated, optionally with a wax and a colorant, in the presence of a coagulant, and thereafter stabilizing the aggregates and coalescing or fusing the aggregates to provide toner size particles.
In embodiments, an unsaturated polyester resin may be utilized as a latex resin which, in turn, may be used in the formation of toner particles. The latex resin may be either crystalline, amorphous, or a mixture thereof. Thus, for example, the toner particles can include a crystalline latex polymer, a semi-crystalline latex polymer, an amorphous latex polymer, or a mixture of two or more latex polymers. In embodiments, toner particles of the present disclosure may also possess a core-shell configuration.
In embodiments, an amorphous resin used herein to form a toner may be a bio-based resin. Bio-based resins or products, as used herein, in embodiments, include commercial and/or industrial products (other than food or feed) that may be composed, in whole or in significant part, of biological products or renewable domestic agricultural materials (including plant, animal, or marine materials) and/or forestry materials as defined by the U.S. Office of the Federal Environmental Executive.
In embodiments, the present disclosure provides a resin composition where the OH-terminal of bio-based polyesters are modified with a multi-functional bio-based acid, in embodiments citric acid (CA) and/or citric acid anhydride, thereby providing acid-functionalized polyesters, sometimes referred to herein, in embodiments, as “acidified” resins, which can be readily emulsified for EA toner fabrication. Citric acid is a polyfunctional monomer which is produced commercially via fermentation, and therefore is a sustainable alternative for trimellitic anhydride. The reaction of citric acid with the bio-based resin described herein may be controlled so that only one of the three carboxylic acid groups from citric acid reacts with the polyester OH chain ends. The remaining two carboxylic acid groups of the CA may thus be utilized to stabilize the polyester emulsion and can ultimately react in the EA process to form toner particles. Depending on the time and temperature of the reaction of the resin with citric acid, the resulting bio-based polycarboxylic acid resin can be end-functionalized, chain extended and/or cross-linked. The resulting polycarboxylic acid resin can thus also be used as a cross-linker and/or chain extender upon reaction with other resins utilized to form a toner particle.
Bio-based Resins
Resins utilized in accordance with the present disclosure include bio-based amorphous resins. As used herein, a bio-based resin is a resin or resin formulation derived from a biological source such as plant-based feed stocks, in embodiments vegetable oils, instead of petrochemicals. As renewable polymers with low environmental impact, their advantages include that they reduce reliance on finite resources of petrochemicals, and they sequester carbon from the atmosphere. A bio-resin includes, in embodiments, for example, a resin wherein at least a portion of the resin is derived from a natural biological material, such as animal, plant, combinations thereof, and the like.
In embodiments, bio-based resins may include natural triglyceride vegetable oils (e.g. rapeseed oil, soybean oil, sunflower oil), or phenolic plant oils such as cashew nut shell liquid (CNSL), combinations thereof, and the like. Suitable bio-based amorphous resins include polyesters, polyamides, polyimides, and polyisobutyrates, combinations thereof, and the like.
Examples of amorphous bio-based polymeric resins which may be utilized include polyesters derived from monomers including a fatty dimer acid or diol of soya oil, D-isosorbide, and/or amino acids such as L-tyrosine and glutamic acid as described in U.S. Pat. Nos. 5,959,066, 6,025,061, 6,063,464, and 6,107,447, and U.S. Patent Application Publication Nos. 2008/0145775 and 2007/0015075, the disclosures of each of which are hereby incorporated by reference in their entirety.
Suitable bio-based polymeric resins which may also be utilized include polyesters derived from monomers including a fatty dimer acid or diol, D-isosorbide, naphthalene dicarboxylate, a dicarboxylic acid such as, for example, azelaic acid, cyclohexanedioic acid, and combinations thereof, and optionally ethylene glycol. In embodiments, a suitable bio-based polymeric resin may be based on D-isosorbide, dimethyl naphthalene 2,6-dicarboxylate, cyclohexane-1,4-dicarboxylic acid, a dimer acid such as EMPOL 1061®, EMPOL 1062®, EMPOL 1012® and EMPOL1016®, from Cognis Corp., or PRIPOL 1009®, PRIPOL 1012®, PRIPOL 1013® from Croda Ltd., a dimer diol such as SOVERMOL 908 from Cognis Corp. or PRIPOL 2033 from Croda Ltd., and combinations thereof. Combinations of the foregoing bio-based resins may be utilized, in embodiments.
In embodiments, a suitable amorphous bio-based resin may have a glass transition temperature of from about 40° C. to about 90° C., in embodiments from about 45° C. to about 75° C., a weight average molecular weight (Mw) as measured by gel permeation chromatography (GPC) of from about 1,500 to about 100,000, in embodiments of from about 2,000 to about 90,000, a number average molecular weight (Mn) as measured by gel permeation chromatography (GPC) of from about 1,000 to about 50,000, in embodiments from about 2,000 to about 25,000, a molecular weight distribution (Mw/Mn) of from about 1 to about 20, in embodiments from about 2 to about 15, and a carbon/oxygen ratio of from about 2 to about 6, in embodiments of from about 3 to about 5. In embodiments, the combined resins utilized in the latex may have a melt viscosity from about 10 to about 100,000 Pa*S at about 130° C., in embodiments from about 50 to about 10,000 Pa*S.
The amorphous bio-based resin may be present, for example, in amounts of from about 10 to about 90 percent by weight of the toner components, in embodiments from about 20 to about 80 percent by weight of the toner components.
In embodiments, the amorphous bio-based polyester resin may have a particle size of from about 40 nm to about 800 nm in diameter, in embodiments from about 75 nm to 225 nm in diameter.
In embodiments the amorphous bio-based polyester resin may possess hydroxyl groups at the terminal ends of the resin. It may be desirable, in embodiments, to convert these hydroxyl groups to acid groups, including carboxylic acid groups, and the like.
In embodiments, the hydroxyl groups at the terminal ends of the amorphous bio-based polyester resin may be converted to carboxylic acid groups by reacting the amorphous bio-based polyester resin with a multi-functional bio-based acid. Such acids include, for example, citric acid, citric acid anhydride, combinations thereof, and the like. The amount of acid to be reacted with the amorphous bio-based polyester resin will depend on the amorphous bio-based polyester resin, the desired amount of conversion of hydroxyl groups to carboxylic acid groups, and the like.
In embodiments, the amount of acid added to the amorphous bio-based polyester resin may be from about 0.1% by weight to about 20% by weight of the resin solids, in embodiments from about 0.5% by weight to about 10% by weight of the resin solids, in embodiments from about 1% by weight to about 7.5% by weight of the resin solids.
In embodiments, citric acid may be reacted with the amorphous bio-based polyester resin. Citric acid can be used as the bio-based acid for the functionalization of polyester resins, as it is commercially available and relatively inexpensive. It can be produced via fermentation where cultures of Aspergillus niger are fed glucose or sucrose-containing medium, such as those obtained from sources such as corn steep liquor, molasses, and/or or hydrolyzed corn starch. For reference, the structure of citric acid is provided below.
The structure of CA shows two reactive primary acid groups, as well as a less reactive tertiary carboxylic acid group and a sterically hindered tertiary hydroxyl group. In embodiments, only one of CA's carboxylic acid groups may react with the polyester chain ends, thus leaving two remaining carboxylic acids. Where the resulting acidified bio-based amorphous resin is used to form a latex which, in turn, is used to form a toner, these additional carboxylic acids will be available to enhance the chemical and mechanical stability of the latex particles in water prior to the EA process, and to provide the final polymer product with sites for post-polymerization reactions, in particular aggregation reactions with cationic species such as Al2(SO4)3.
In embodiments, CA will also form a reactive anhydride intermediate above its melting temperature of 153° C., which will also readily react with OH groups from the polyester chains to form ester bonds.
The CA may also form an assymetric cyclic anhydride followed by esterification of the OH end groups of the bio-based polymer resin at about 170° C., without any degradation of the CA or polymer chains.
Where a bio-based acid such as citric acid is used for end-capping or acid functionalization of the chain ends of an amorphous bio-based resin, the reaction temperature may be from about 150° C. to about 170° C., in embodiments from about 155° C. to about 165° C., so that the isosorbide or another diol may still be reactive in the esterification with the bio-based acid. The reaction may take place for a period of time of from about 30 minutes to about 480 minutes, in embodiments from about 60 minutes to about 180 minutes. In embodiments, the temperature and time of reaction may be adjusted to help control the rate of water removal from the system, to ensure that only one acid functionality of a single multi-functional bio-based acid, in embodiments CA, reacts with the bio-based resin.
If chain extension, cross-linking, or branching is desired, then more water should be evaporated from the system to ensure that one multi-functional bio-based acid, in embodiments CA, will react with two, or even three, polyester hydroxyl end groups. This can be accomplished, in embodiments, by applying a vacuum, for example, a vacuum at from about 600 Torr ((1 Torr=1 mm HgA)) to about 0.001 Torr, in embodiments from about 1 Torr to about 0.01 Torr. The esterification of the acid groups, in embodiments CA groups, can easily be tracked by 13C NMR (for the COOH of CA) and/or 1H NMR (for the OH of the polyester resin), if desired.
In embodiments, the resulting acidified bio-based amorphous resin, having been reacted with a bio-based acid, may have an acid value, sometimes referred to herein, in embodiments, as an acid number, from about 2 mg KOH/g of resin to about 200 mg KOH/g of resin, in embodiments from about 5 mg KOH/g of resin to about 50 mg KOH/g of resin, in embodiments from about 10 mg KOH/g of resin to about 30 mg KOH/g of resin. The acid containing resin may be dissolved in tetrahydrofuran solution. The acid value may be detected by titration with a KOH/methanol solution containing phenolphthalein as the indicator. The acid value (or neutralization number) is the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of the resin.
In embodiments, the weight average molecular weight (Mw) of the acidified amorphous bio-based resin may be from about 2,000 Daltons to about 150,000 Daltons, in embodiments from about 2,500 Daltons to about 100,000 Daltons, in embodiments from about 3,000 Daltons to about 50,000 Daltons, depending on the degree of chain extension, cross-linking, branching, etc.
Reacting a bio-based amorphous resin with a multi-functional bio-based acid such a citric acid to produce an acidified resin may allow one to modify the rheological properties of the resin. These modified rheological properties, in turn, can affect properties of a toner possessing the acidified resin including, but not limited to, image fusing, image gloss, image document hot offset, image document cold offset, combinations thereof, and the like. In embodiments, the resins utilized in the core, including the amorphous bio-based resin, optionally in combination with a crystalline resin, may have a melt viscosity of from about 10 to about 1,000,000 Pa*S at about 140° C., in embodiments from about 50 to about 100,000 Pa*S.
In accordance with the present disclosure, the esterification and/or cross-linking of a multi-functional bio-based acid with a bio-based amorphous resin can be influenced by various reaction parameters noted above including, for example, reaction temperature, reaction time, the application of a vacuum, the order of addition of the bio-based acid and other monomers, the amount of bio-based acid added to the formulation, and combinations thereof.
In embodiments, the resin may be formed by condensation polymerization methods. In other embodiments, the resin may be formed by emulsion polymerization methods.
Other Resins
The above bio-based resins may be used alone or may be used with any other resin suitable in forming a toner.
In embodiments, the resins may be an amorphous resin, a crystalline resin, and/or a combination thereof. In further embodiments, the polymer utilized to form the resin may be a polyester resin, including the resins described in U.S. Pat. Nos. 6,593,049 and 6,756,176, the disclosures of each of which are hereby incorporated by reference in their entirety. Suitable resins may also include a mixture of an amorphous polyester resin and a crystalline polyester resin as described in U.S. Pat. No. 6,830,860, the disclosure of which is hereby incorporated by reference in its entirety.
In embodiments, the resin may be a polyester resin formed by reacting a diol with a diacid in the presence of an optional catalyst.
Examples of diacids or diesters including vinyl diacids or vinyl diesters utilized for the preparation of amorphous polyesters include dicarboxylic acids or diesters such as terephthalic acid, phthalic acid, isophthalic acid, fumaric acid, trimellitic acid, dimethyl fumarate, dimethyl itaconate, cis, 1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, maleic acid, succinic acid, itaconic acid, succinic acid, cyclohexanoic acid, succinic anhydride, dodecylsuccinic acid, dodecylsuccinic anhydride, glutaric acid, glutaric anhydride, adipic acid, pimelic acid, suberic acid, azelaic acid, dodecanediacid, dimethyl naphthalenedicarboxylate, dimethyl terephthalate, diethyl terephthalate, dimethylisophthalate, diethylisophthalate, dimethylphthalate, phthalic anhydride, diethylphthalate, dimethylsuccinate, dimethylfumarate, dimethylmaleate, dimethylglutarate, dimethyladipate, dimethyl dodecyl succinate, and combinations thereof. The organic diacids or diesters may be present, for example, in an amount from about 40 to about 60 mole percent of the resin, in embodiments from about 42 to about 52 mole percent of the resin, in embodiments from about 45 to about 50 mole percent of the resin.
Examples of diols which may be utilized in generating the amorphous polyester include 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, pentanediol, hexanediol, 2,2-dimethylpropanediol, 2,2,3-trimethylhexanediol, heptanediol, dodecanediol, bis(hydroxyethyl)-bisphenol A, bis(2-hydroxypropyl)-bisphenol A, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, xylenedimethanol, cyclohexanediol, diethylene glycol, bis(2-hydroxyethyl)oxide, dipropylene glycol, dibutylene, and combinations thereof. The amount of organic diols selected can vary, and may be present, for example, in an amount from about 40 to about 60 mole percent of the resin, in embodiments from about 42 to about 55 mole percent of the resin, in embodiments from about 45 to about 53 mole percent of the resin.
Polycondensation catalysts which may be utilized in forming either the crystalline or amorphous polyesters include tetraalkyl titanates, dialkyltin oxides such as dibutyltin oxide, tetraalkyltins such as dibutyltin dilaurate, and dialkyltin oxide hydroxides such as butyltin oxide hydroxide, aluminum alkoxides, alkyl zinc, dialkyl zinc, zinc oxide, stannous oxide, or combinations thereof. Such catalysts may be utilized in amounts of, for example, from about 0.01 mole percent to about 5 mole percent based on the starting diacid or diester used to generate the polyester resin.
Examples of amorphous resins which may be utilized include alkali sulfonated-polyester resins, branched alkali sulfonated-polyester resins, alkali sulfonated-polyimide resins, and branched alkali sulfonated-polyimide resins. Alkali sulfonated polyester resins may be useful in embodiments, such as the metal or alkali salts of copoly(ethylene-terephthalate)-copoly(ethylene-5-sulfo-isophthalate), copoly(propylene-terephthalate)-copoly(propylene-5-sulfo-isophthalate), copoly(diethylene-terephthalate)-copoly(diethylene-5-sulfo-isophthalate), copoly(propylene-diethylene-terephthalate)-copoly(propylene-diethylene-5-sulfoisophthalate), copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfo-isophthalate), copoly(propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenol A-5-sulfo-isophthalate), copoly(ethoxylated bisphenol-A-fumarate)-copoly(ethoxylated bisphenol-A-5-sulfo-isophthalate), and copoly(ethoxylated bisphenol-A-maleate)-copoly(ethoxylated bisphenol-A-5-sulfo-isophthalate), wherein the alkali metal is, for example, a sodium, lithium or potassium ion.
In embodiments, the resin may be a crosslinkable resin. A crosslinkable resin is a resin including a crosslinkable group or groups such as a C═C bond. The resin can be crosslinked, for example, through a free radical polymerization with an initiator.
In embodiments, as noted above, an unsaturated amorphous polyester resin may be utilized as a latex resin. Examples of such resins include those disclosed in U.S. Pat. No. 6,063,827, the disclosure of which is hereby incorporated by reference in its entirety. Exemplary unsaturated amorphous polyester resins include, but are not limited to, poly(propoxylated bisphenol co-fumarate), poly(ethoxylated bisphenol co-fumarate), poly(butyloxylated bisphenol co-fumarate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-fumarate), poly(1,2-propylene fumarate), poly(propoxylated bisphenol co-maleate), poly(ethoxylated bisphenol co-maleate), poly(butyloxylated bisphenol co-maleate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-maleate), poly(1,2-propylene maleate), poly(propoxylated bisphenol co-itaconate), poly(ethoxylated bisphenol co-itaconate), poly(butyloxylated bisphenol co-itaconate), poly(co-propoxylated bisphenol co-ethoxylated bisphenol co-itaconate), poly(1,2-propylene itaconate), and combinations thereof.
In embodiments, a suitable amorphous resin may include alkoxylated bisphenol A fumarate/terephthalate based polyester and copolyester resins. In embodiments, a suitable polyester resin may be an amorphous polyester such as a poly(propoxylated bisphenol A co-fumarate) resin having the following formula (I):
wherein m may be from about 5 to about 1000, although the value of m can be outside of this range. Examples of such resins and processes for their production include those disclosed in U.S. Pat. No. 6,063,827, the disclosure of which is hereby incorporated by reference in its entirety.
An example of a linear propoxylated bisphenol A fumarate resin which may be utilized as a latex resin is available under the trade name SPARII from Resana S/A Industrias Quimicas, Sao Paulo Brazil. Other propoxylated bisphenol A fumarate resins that may be utilized and are commercially available include GTUF and FPESL-2 from Kao Corporation, Japan, and EM181635 from Reichhold, Research Triangle Park, N.C., and the like.
For forming a crystalline polyester, suitable organic diols include aliphatic diols with from about 2 to about 36 carbon atoms, such as 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethylpropane-1,3-diol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol and the like; alkali sulfo-aliphatic diols such as sodio 2-sulfo-1,2-ethanediol, lithio 2-sulfo-1,2-ethanediol, potassio 2-sulfo-1,2-ethanediol, sodio 2-sulfo-1,3-propanediol, lithio 2-sulfo-1,3-propanediol, potassio 2-sulfo-1,3-propanediol, mixture thereof, and the like, including their structural isomers. The aliphatic diol may be, for example, selected in an amount from about 40 to about 60 mole percent, in embodiments from about 42 to about 55 mole percent, in embodiments from about 45 to about 53 mole percent, and a second diol can be selected in an amount from about 0 to about 10 mole percent, in embodiments from about 1 to about 4 mole percent of the resin.
Examples of organic diacids or diesters including vinyl diacids or vinyl diesters selected for the preparation of the crystalline resins include oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, dimethyl fumarate, dimethyl itaconate, cis, 1,4-diacetoxy-2-butene, diethyl fumarate, diethyl maleate, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexane dicarboxylic acid (sometimes referred to herein, in embodiments, as cyclohexanedioic acid), malonic acid and mesaconic acid, a diester or anhydride thereof; and an alkali sulfo-organic diacid such as the sodio, lithio or potassio salt of dimethyl-5-sulfo-isophthalate, dialkyl-5-sulfo-isophthalate-4-sulfo-1,8-naphthalic anhydride, 4-sulfo-phthalic acid, dimethyl-4-sulfo-phthalate, dialkyl-4-sulfo-phthalate, 4-sulfophenyl-3,5-dicarbomethoxybenzene, 6-sulfo-2-naphthyl-3,5-dicarbomethoxybenzene, sulfo-terephthalic acid, dimethyl-sulfo-terephthalate, 5-sulfo-isophthalic acid, dialkyl-sulfo-terephthalate, sulfoethanediol, 2-sulfopropanediol, 2-sulfobutanediol, 3-sulfopentanediol, 2-sulfohexanediol, 3-sulfo-2-methylpentanediol, 2-sulfa-3,3-dimethylpentanediol, sulfo-p-hydroxybenzoic acid, N,N-bis(2-hydroxyethyl)-2-amino ethane sulfonate, or mixtures thereof. The organic diacid may be selected in an amount of, for example, in embodiments from about 40 to about 60 mole percent, in embodiments from about 42 to about 52 mole percent, in embodiments from about 45 to about 50 mole percent, and a second diacid can be selected in an amount from about 0 to about 10 mole percent of the resin.
Specific crystalline resins may be polyester based, such as poly(ethylene-adipate), polypropylene-adipate), poly(butylene-adipate), poly(pentylene-adipate), poly(hexylene-adipate), poly(octylene-adipate), poly(ethylene-succinate), poly(propylene-succinate), poly(butylene-succinate), poly(pentylene-succinate), poly(hexylene-succinate), poly(octylene-succinate), poly(ethylene-sebacate), poly(propylene-sebacate), poly(butylene-sebacate), poly(pentylene-sebacate), poly(hexylene-sebacate), poly(octylene-sebacate), poly(decylene-sebacate), poly(decylene-decanoate), poly(ethylene-decanoate), poly(ethylene dodecanoate), poly(nonylene-sebacate), poly(nonylene-decanoate), copoly(ethylene-fumarate)-copoly(ethylene-sebacate), copoly(ethylene-fumarate)-copoly(ethylene-decanoate), copoly(ethylene-fumarate)-copoly(ethylene-dodecanoate), copoly(2,2-dimethylpropane-1,3-diol-decanoate)-copoly(ethylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(octylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(octylene-adipate), alkali copoly(5-sulfoisophthaloyl)-copoly(ethylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(propylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(butylenes-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(pentylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(hexylene-succinate), alkali copoly(5-sulfoisophthaloyl)-copoly(octylene-succinate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(octylene-sebacate), alkali copoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(propylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(butylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkali copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipatenonylene-decanoate), poly(octylene-adipate), wherein alkali is a metal like sodium, lithium or potassium. Examples of polyamides include poly(ethylene-adipamide), poly(propylene-adipamide), poly(butylenes-adipamide), poly(pentylene-adipamide), poly(hexylene-adipamide), poly(octylene-adipamide), poly(ethylene-succinimide), and poly(propylene-sebecamide). Examples of polyimides include poly(ethylene-adipimide), poly(propylene-adipimide), poly(butylene-adipimide), poly(pentylene-adipimide), poly(hexylene-adipimide), poly(octylene-adipimide), poly(ethylene-succinimide), poly(propylene-succinimide), and poly(butylene-succinimide).
The crystalline resin may be present, for example, in an amount from about 1 to about 85 percent by weight of the toner components, in embodiments from about 2 to about 50 percent by weight of the toner components, in embodiments from about 5 to about 15 percent by weight of the toner components. The crystalline resin can possess various melting points of, for example, from about 30° C. to about 120° C., in embodiments from about 50° C. to about 90° C., in embodiments from about 60° C. to about 80° C. The crystalline resin may have a number average molecular weight (Mn), as measured by gel permeation chromatography (GPC) of, for example, from about 1,000 to about 50,000, in embodiments from about 2,000 to about 25,000, and a weight average molecular weight (Mw) of, for example, from about 2,000 to about 100,000, in embodiments from about 3,000 to about 80,000, as determined by Gel Permeation Chromatography using polystyrene standards. The molecular weight distribution (Mw/Mn) of the crystalline resin may be, for example, from about 2 to about 6, in embodiments from about 3 to about 4.
Suitable crystalline resins which may be utilized, optionally in combination with an amorphous resin as described above, include those disclosed in U.S. Patent Application Publication No. 2006/0222991, the disclosure of which is hereby incorporated by reference in its entirety.
In embodiments, a suitable crystalline resin may include a resin formed of ethylene glycol and a mixture of dodecanedioic acid and fumaric acid co-monomers with the following formula:
wherein b is from about 5 to about 2000 and d is from about 5 to about 2000.
Examples of other suitable resins or polymers which may be utilized in forming a toner include, but are not limited to, poly(styrene-butadiene), poly(methylstyrene-butadiene), poly(methyl methacrylate-butadiene), poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene), poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene), poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene), poly(butyl acrylate-butadiene), poly(styrene-isoprene), poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene), poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene), poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene), poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene), poly(butyl acrylate-isoprene); poly(styrene-propyl acrylate), poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid), poly(styrene-butadiene-methacrylic acid), poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid), poly(styrene-butyl acrylate-acrylonitrile), and poly(styrene-butyl acrylate-acrylonitrile-acrylic acid), and combinations thereof. The polymer may be block, random, or alternating copolymers.
Toner
The resins described above may be utilized to form toner compositions. One, two, or more resins may be used. In embodiments, where two or more resins are used, the resins may be in any suitable ratio (e.g., weight ratio) such as for instance of from about 1% (first resin)/99% (second resin) to about 99% (first resin)/1% (second resin), in embodiments from about 4% (first resin)/96% (second resin) to about 96% (first resin)/4% (second resin). Where the resin includes a crystalline resin and a bio-based amorphous resin, the weight ratio of the resins may be from 1% (crystalline resin): 99% (bio-based amorphous resin), to about 10% (crystalline resin): 90% (bio-based amorphous resin).
Toner compositions may also include optional colorants, waxes, coagulants and other additives, such as surfactants. Toners may be formed utilizing any method within the purview of those skilled in the art. The toner particles may also include other conventional optional additives, such as colloidal silica (as a flow agent).
The resulting latex formed from the resins described above may be utilized to form a toner by any method within the purview of those skilled in the art. The latex emulsion may be contacted with a colorant, optionally in a dispersion, and other additives to form an ultra low melt toner by a suitable process, in embodiments, an emulsion aggregation and coalescence process.
Surfactants
In embodiments, colorants, waxes, and other additives utilized to form toner compositions may be in dispersions including surfactants. Moreover, toner particles may be formed by emulsion aggregation methods where the resin and other components of the toner are placed in one or more surfactants, an emulsion is formed, toner particles are aggregated, coalesced, optionally washed and dried, and recovered.
One, two, or more surfactants may be utilized. The surfactants may be selected from ionic surfactants and nonionic surfactants. Anionic surfactants and cationic surfactants are encompassed by the term “ionic surfactants.” In embodiments, the use of anionic and nonionic surfactants help stabilize the aggregation process in the presence of the coagulant, which otherwise could lead to aggregation instability.
In embodiments, the surfactant may be added as a solid or as a solution with a concentration from about 5% to about 100% (pure surfactant) by weight, in embodiments, from about 10% to about 95 weight percent. In embodiments, the surfactant may be utilized so that it is present in an amount from about 0.01 weight percent to about 20 weight percent of the resin, in embodiments, from about 0.1 weight percent to about 16 weight percent of the resin, in other embodiments, from about 1 weight percent to about 14 weight percent of the resin.
Anionic surfactants which may be utilized include sulfates and sulfonates, sodium dodecylsulfate (SDS), sodium dodecylbenzene sulfonate, sodium dodecylnaphthalene sulfate, dialkyl benzenealkyl sulfates and sulfonates, acids such as abitic acid available from Aldrich, NEOGEN R™, NEOGEN SC™ obtained from Daiichi Kogyo Seiyaku, combinations thereof, and the like. Other suitable anionic surfactants include, in embodiments, DOWFAX™ 2A1, an alkyldiphenyloxide disulfonate from The Dow Chemical Company, and/or TAYCA POWER BN2060 from Tayca Corporation (Japan), which are branched sodium dodecylbenzene sulfonates. Combinations of these surfactants and any of the foregoing anionic surfactants may be utilized in embodiments.
Examples of the cationic surfactants, which are usually positively charged, include, for example, alkylbenzyl dimethyl ammonium chloride, dialkyl benzenealkyl ammonium chloride, lauryl trimethyl ammonium chloride, alkylbenzyl methyl ammonium chloride, alkyl benzyl dimethyl ammonium bromide, benzalkonium chloride, cetyl pyridinium bromide, C12, C15, C17 trimethyl ammonium bromides, halide salts of quaternized polyoxyethylalkylamines, dodecylbenzyl triethyl ammonium chloride, MIRAPOL™ and ALKAQUAT™, available from Alkaril Chemical Company, SANIZOL™ (benzalkonium chloride), available from Kao Chemicals, and the like, and mixtures thereof.
Examples of nonionic surfactants that can be utilized include, for example, polyvinyl alcohol, polyacrylic acid, methalose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, dialkylphenoxy poly(ethyleneoxy) ethanol, available from Rhone-Poulenc as IGEPAL CA210™, IGEPAL CA520™, IGEPAL CA720™, IGEPAL CO-890™, IGEPAL CO720™, IGEPAL CO290™, IGEPAL CA210™, ANTAROX890™ and ANTAROX 897™ (alkyl phenol ethoxylate). Other examples of suitable nonionic surfactants include a block copolymer of polyethylene oxide and polypropylene oxide, including those commercially available as SYNPERONIC PE/F, in embodiments SYNPERONIC PE/F 108.
Colorants
As the colorant to be added, various known suitable colorants, such as dyes, pigments, mixtures of dyes, mixtures of pigments, mixtures of dyes and pigments, and the like, may be included in the toner. The colorant may be included in the toner in an amount of, for example, about 0.1 to about 35 percent by weight of the toner, or from about 1 to about 15 weight percent of the toner, or from about 3 to about 10 percent by weight of the toner, although the amount of colorant can be outside of these ranges.
As examples of suitable colorants, mention may be made of carbon black like REGAL 330® (Cabot), Carbon Black 5250 and 5750 (Columbian Chemicals), Sunsperse Carbon Black LHD 9303 (Sun Chemicals); magnetites, such as Mobay magnetites M08029™, M08060™; Columbian magnetites; MAPICO BLACKS™ and surface treated magnetites; Pfizer magnetites CB4799™, CB5300™, CB5600™, MCX6369™; Bayer magnetites, BAYFERROX 8600™, 8610™; Northern Pigments magnetites, NP604™, NP608™; Magnox magnetites TMB-100TH, or TMB-104TH; and the like. As colored pigments, there can be selected cyan, magenta, yellow, red, green, brown, blue or mixtures thereof. Generally, cyan, magenta, or yellow pigments or dyes, or mixtures thereof, are used. The pigment or pigments are generally used as water based pigment dispersions.
In general, suitable colorants may include Paliogen Violet 5100 and 5890 (BASF), Normandy Magenta RD-2400 (Paul Uhlrich), Permanent Violet VT2645 (Paul Uhlrich), Heliogen Green L8730 (BASF), Argyle Green XP-111-S (Paul Uhlrich), Brilliant Green Toner GR 0991 (Paul Uhlrich), Lithol Scarlet D3700 (BASF), Toluidine Red (Aldrich), Scarlet for Thermoplast NSD PS PA (Ugine Kuhlmann of Canada), Lithol Rubine Toner (Paul Uhlrich), Lithol Scarlet 4440 (BASF), NBD 3700 (BASF), Bon Red C (Dominion Color), Royal Brilliant Red RD-8192 (Paul Uhlrich), Oracet Pink RF (Ciba Geigy), Paliogen Red 3340 and 3871K (BASF), Lithol Fast Scarlet L4300 (BASF), Heliogen Blue D6840, D7080, K7090, K6910 and L7020 (BASF), Sudan Blue OS (BASF), Neopen Blue FF4012 (BASF), PV Fast Blue B2G01 (American Hoechst), Irgalite Blue BCA (Ciba Geigy), Paliogen Blue 6470 (BASF), Sudan II, III and IV (Matheson, Coleman, Bell), Sudan Orange (Aldrich), Sudan Orange 220 (BASF), Paliogen Orange 3040 (BASF), Ortho Orange OR 2673 (Paul Uhlrich), Paliogen Yellow 152 and 1560 (BASF), Lithol Fast Yellow 0991K (BASF), Paliotol Yellow 1840 (BASF), Novaperm Yellow FGL (Hoechst), Permanent Yellow YE 0305 (Paul Uhlrich), Lumogen Yellow D0790 (BASF), Sunsperse Yellow YHD 6001 (Sun Chemicals), Suco-Gelb 1250 (BASF), Suco-Yellow D1355 (BASF), Suco Fast Yellow D1165, D1355 and D1351 (BASF), HOSTAPERM PINK E™ (Hoechst), Fanal Pink D4830 (BASF), CINQUASIA MAGENTA™ (DuPont), Paliogen Black L9984 (BASF), Pigment Black K801 (BASF), Levanyl Black A-SF (Miles, Bayer), combinations of the foregoing, and the like.
Other suitable water based colorant dispersions include those commercially available from Clariant, for example, Hostafine Yellow GR, Hostafine Black T and Black TS, Hostafine Blue B2G, Hostafine Rubine F6B and magenta dry pigment such as Toner Magenta 6BVP2213 and Toner Magenta EO2 which may be dispersed in water and/or surfactant prior to use.
Specific examples of pigments include Sunsperse BHD 6011X (Blue 15 Type), Sunsperse BHD 9312X (Pigment Blue 15 74160), Sunsperse BHD 6000X (Pigment Blue 15:3 74160), Sunsperse GHD 9600X and GHD 6004X (Pigment Green 7 74260), Sunsperse QHD 6040X (Pigment Red 122 73915), Sunsperse RHD 9668X (Pigment Red 185 12516), Sunsperse RHD 9365X and 9504X (Pigment Red 57 15850:1, Sunsperse YHD 6005X (Pigment Yellow 83 21108), Flexiverse YFD 4249 (Pigment Yellow 17 21105), Sunsperse YHD 6020X and 6045X (Pigment Yellow 74 11741), Sunsperse YHD 600X and 9604X (Pigment Yellow 14 21095), Flexiverse LFD 4343 and LFD 9736 (Pigment Black 7 77226), Aquatone, combinations thereof, and the like, as water based pigment dispersions from Sun Chemicals, HELIOGEN BLUE L6900™, D6840™, D7080™, D7020™, PYLAM OIL BLUE™, PYLAM OIL YELLOW™, PIGMENT BLUE 1™ available from Paul Uhlich & Company, Inc., PIGMENT VIOLET 1™, PIGMENT RED 48™, LEMON CHROME YELLOW DCC1026™, E.D. TOLUIDINE RED™ and BON RED C™ available from Dominion Color Corporation, Ltd., Toronto, Ontario, NOVAPERM YELLOW FGL™, and the like. Generally, colorants that can be selected are black, cyan, magenta, or yellow, and mixtures thereof. Examples of magentas are 2,9-dimethyl-substituted quinacridone and anthraquinone dye identified in the Color Index as CI-60710, CI Dispersed Red 15, diazo dye identified in the Color Index as CI-26050, CI Solvent Red 19, and the like. Illustrative examples of cyans include copper tetra(octadecyl sulfonamido) phthalocyanine, x-copper phthalocyanine pigment listed in the Color Index as CI-74160, CI Pigment Blue, Pigment Blue 15:3, and Anthrathrene Blue, identified in the Color Index as CI-69810, Special Blue X-2137, and the like. Illustrative examples of yellows are diarylide yellow 3,3-dichlorobenzidene acetoacetanilides, a monoazo pigment identified in the Color Index as CI-12700, CI Solvent Yellow 16, a nitrophenyl amine sulfonamide identified in the Color Index as Foron Yellow SE/GLN, CI Dispersed Yellow 33 2,5-dimethoxy-4-sulfonanilide phenylazo-4′-chloro-2,5-dimethoxy acetoacetanilide, and Permanent Yellow FGL.
In embodiments, the colorant may include a pigment, a dye, combinations thereof, carbon black, magnetite, black, cyan, magenta, yellow, red, green, blue, brown, combinations thereof, in an amount sufficient to impart the desired color to the toner. It is to be understood that other useful colorants will become readily apparent based on the present disclosures.
In embodiments, a pigment or colorant may be employed in an amount of from about 1 weight percent to about 35 weight percent of the toner particles on a solids basis, in other embodiments, from about 5 weight percent to about 25 weight percent of the toner particles on a solids basis.
Wax
Optionally, a wax may also be combined with the resin and a colorant in forming toner particles. The wax may be provided in a wax dispersion, which may include a single type of wax or a mixture of two or more different waxes. A single wax may be added to toner formulations, for example, to improve particular toner properties, such as toner particle shape, presence and amount of wax on the toner particle surface, charging and/or fusing characteristics, gloss, stripping, offset properties, and the like. Alternatively, a combination of waxes can be added to provide multiple properties to the toner composition.
When included, the wax may be present in an amount of, for example, from about 1 weight percent to about 25 weight percent of the toner particles, in embodiments from about 5 weight percent to about 20 weight percent of the toner particles.
When a wax dispersion is used, the wax dispersion may include any of the various waxes conventionally used in emulsion aggregation toner compositions. Waxes that may be selected include waxes having, for example, a weight average molecular weight from about 500 to about 20,000, in embodiments from about 1,000 to about 10,000. Waxes that may be used include, for example, polyolefins such as polyethylene including linear polyethylene waxes and branched polyethylene waxes, polypropylene including linear polypropylene waxes and branched polypropylene waxes, polyethylene/amide, polyethylenetetrafluoroethylene, polyethylenetetrafluoroethylene/amide, and polybutene waxes such as commercially available from Allied Chemical and Petrolite Corporation, for example POLYWAX™ polyethylene waxes such as commercially available from Baker Petrolite, wax emulsions available from Michaelman, Inc. and the Daniels Products Company, EPOLENE N-15™ commercially available from Eastman Chemical Products, Inc., and VISCOL 550-P™, a low weight average molecular weight polypropylene available from Sanyo Kasei K. K.; plant-based waxes, such as carnauba wax, rice wax, candelilla wax, sumacs wax, and jojoba oil; animal-based waxes, such as beeswax; mineral-based waxes and petroleum-based waxes, such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax such as waxes derived from distillation of crude oil, silicone waxes, mercapto waxes, polyester waxes, urethane waxes; modified polyolefin waxes (such as a carboxylic acid-terminated polyethylene wax or a carboxylic acid-terminated polypropylene wax); Fischer-Tropsch wax; ester waxes obtained from higher fatty acid and higher alcohol, such as stearyl stearate and behenyl behenate; ester waxes obtained from higher fatty acid and monovalent or multivalent lower alcohol, such as butyl stearate, propyl oleate, glyceride monostearate, glyceride distearate, and pentaerythritol tetra behenate; ester waxes obtained from higher fatty acid and multivalent alcohol multimers, such as diethylene glycol monostearate, dipropylene glycol distearate, diglyceryl distearate, and triglyceryl tetrastearate; sorbitan higher fatty acid ester waxes, such as sorbitan monostearate, and cholesterol higher fatty acid ester waxes, such as cholesteryl stearate. Examples of functionalized waxes that may be used include, for example, amines, amides, for example AQUA SUPERSLIP 6550™, SUPERSLIP6530™ available from Micro Powder Inc., fluorinated waxes, for example POLYFLUO190™, POLYFLUO 200™, POLYSILK 19™, POLYSILK 14™ available from Micro Powder Inc., mixed fluorinated, amide waxes, such as aliphatic polar amide functionalized waxes; aliphatic waxes consisting of esters of hydroxylated unsaturated fatty acids, for example MICROSPERSION 19™ also available from Micro Powder Inc., imides, esters, quaternary amines, carboxylic acids or acrylic polymer emulsion, for example JONCRYL 74™, 89™, 130™, 537™, and 538™, all available from SC Johnson Wax, and chlorinated polypropylenes and polyethylenes available from Allied Chemical and Petrolite Corporation and SC Johnson wax. Mixtures and combinations of the foregoing waxes may also be used in embodiments. Waxes may be included as, for example, fuser roll release agents. In embodiments, the waxes may be crystalline or non-crystalline.
In embodiments, the wax may be incorporated into the toner in the form of one or more aqueous emulsions or dispersions of solid wax in water, where the solid wax particle size may be from about 100 nm to about 300 nm.
Toner Preparation
The toner particles may be prepared by any method within the purview of one skilled in the art. Although embodiments relating to toner particle production are described below with respect to emulsion aggregation processes, any suitable method of preparing toner particles may be used, including chemical processes, such as suspension and encapsulation processes disclosed in, for example, U.S. Pat. Nos. 5,290,654 and 5,302,486, the disclosures of each of which are hereby incorporated by reference in their entirety. In embodiments, toner compositions and toner particles may be prepared by aggregation and coalescence processes in which small-size resin particles are aggregated to the appropriate toner particle size and then coalesced to achieve the final toner particle shape and morphology.
In embodiments, toner compositions may be prepared by emulsion aggregation processes, such as a process that includes aggregating a mixture of an optional colorant, an optional wax, an optional coagulant, and any other desired or required additives, and emulsions including the resins described above, optionally in surfactants as described above, and then coalescing the aggregate mixture. A mixture may be prepared by adding a colorant and optionally a wax or other materials, which may also be optionally in a dispersion(s) including a surfactant, to the emulsion, which may be a mixture of two or more emulsions containing the resin(s). For example, emulsion/aggregation/coalescing processes for the preparation of toners are illustrated in the disclosure of the patents and publications referenced hereinabove.
The pH of the resulting mixture of resins, colorants, waxes, coagulants, additives, and the like, may be adjusted by an acid such as, for example, acetic acid, sulfuric acid, hydrochloric acid, citric acid, trifluoro acetic acid, succinic acid, salicylic acid, nitric acid or the like. In embodiments, the pH of the mixture may be adjusted to from about 2 to about 5. In embodiments, the pH is adjusted utilizing an acid in a diluted form of from about 0.5 to about 10 weight percent by weight of water, in other embodiments, of from about 0.7 to about 5 weight percent by weight of water.
Additionally, in embodiments, the mixture may be homogenized. If the mixture is homogenized, homogenization may be accomplished by mixing at a speed of from about 600 to about 6,000 revolutions per minute. Homogenization may be accomplished by any suitable means, including, for example, an IKA ULTRA TURRAX T50 probe homogenizer.
Following the preparation of the above mixture, an aggregating agent may be added to the mixture. Any suitable aggregating agent may be utilized to form a toner. Suitable aggregating agents include, for example, aqueous solutions of a divalent cation or a multivalent cation material. The aggregating agent may be, for example, polyaluminum halides such as polyaluminum chloride (PAC), or the corresponding bromide, fluoride, or iodide, polyaluminum silicates such as polyaluminum sulfosilicate (PASS), and water soluble metal salts including aluminum chloride, aluminum nitrite, aluminum sulfate, potassium aluminum sulfate, calcium acetate, calcium chloride, calcium nitrite, calcium oxylate, calcium sulfate, magnesium acetate, magnesium nitrate, magnesium sulfate, zinc acetate, zinc nitrate, zinc sulfate, zinc chloride, zinc bromide, magnesium bromide, copper chloride, copper sulfate, and combinations thereof. In embodiments, the aggregating agent may be added to the mixture at a temperature that is below the glass transition temperature (Tg) of the resin.
Suitable examples of organic cationic aggregating agents include, for example, dialkyl benzenealkyl ammonium chloride, lauryl trimethyl ammonium chloride, alkylbenzyl methyl ammonium chloride, alkyl benzyl dimethyl ammonium bromide, benzalkonium chloride, cetyl pyridinium bromide, C12, C15, C17 trimethyl ammonium bromides, halide salts of quaternized polyoxyethylalkylamines, dodecylbenzyl triethyl ammonium chloride, combinations thereof, and the like.
Other suitable aggregating agents also include, but are not limited to, tetraalkyl titinates, dialkyltin oxide, tetraalkyltin oxide hydroxide, dialkyltin oxide hydroxide, aluminum alkoxides, alkyl zinc, dialkyl zinc, zinc oxides, stannous oxide, dibutyltin oxide, dibutyltin oxide hydroxide, tetraalkyl tin, combinations thereof, and the like.
Where the aggregating agent is a polyion aggregating agent, the agent may have any desired number of polyion atoms present. For example, in embodiments, suitable polyaluminum compounds have from about 2 to about 13, in other embodiments, from about 3 to about 8, aluminum ions present in the compound.
The aggregating agent may be added to the mixture utilized to form a toner in an amount of, for example, from about 0.1 to about 10 weight percent, in embodiments from about 0.2 to about 8 weight percent, in other embodiments from about 0.5 to about 5 weight percent, of the resin in the mixture. This should provide a sufficient amount of agent for aggregation.
The particles may be permitted to aggregate until a predetermined desired particle size is obtained. A predetermined desired size refers to the desired particle size to be obtained as determined prior to formation, and the particle size being monitored during the growth process until such particle size is reached. Samples may be taken during the growth process and analyzed, for example with a Coulter Counter, for average particle size. The aggregation thus may proceed by maintaining the elevated temperature, or slowly raising the temperature to, for example, from about 40° C. to about 100° C., and holding the mixture at this temperature for a time from about 0.5 hours to about 6 hours, in embodiments from about hour 1 to about 5 hours, while maintaining stirring, to provide the aggregated particles. Once the predetermined desired particle size is reached, then the growth process is halted.
The growth and shaping of the particles following addition of the aggregation agent may be accomplished under any suitable conditions. For example, the growth and shaping may be conducted under conditions in which aggregation occurs separate from coalescence. For separate aggregation and coalescence stages, the aggregation process may be conducted under shearing conditions at an elevated temperature, for example from about 40° C. to about 90° C., in embodiments from about 45° C. to about 80° C., which may be below the glass transition temperature of the resin(s) utilized to form the toner particles.
As noted above, the acidified bio-based resin of the present disclosure may, in embodiments, have additional free carboxylic acids thereon, which are capable of reacting with coagulants and other cationic species such as Al2(SO4)3.
Once the desired final size of the toner particles is achieved, the pH of the mixture may be adjusted with a base to a value from about 3 to about 10, and in embodiments from about 5 to about 9. The adjustment of the pH may be utilized to freeze, that is to stop, toner growth. The base utilized to stop toner growth may include any suitable base such as, for example, alkali metal hydroxides such as, for example, sodium hydroxide, potassium hydroxide, ammonium hydroxide, combinations thereof, and the like. In embodiments, ethylene diamine tetraacetic acid (EDTA) may be added to help adjust the pH to the desired values noted above.
Shell Resin
In embodiments, after aggregation, but prior to coalescence, a resin coating may be applied to the aggregated particles to form a shell thereover. Any resin described above may be utilized as the shell. In embodiments, a polyester amorphous resin latex as described above may be included in the shell. In embodiments, the polyester amorphous resin latex described above may be combined with a different resin, and then added to the particles as a resin coating to form a shell.
In embodiments, resins which may be utilized to form a shell include, but are not limited to, the amorphous resins described above in combination with the acidified bio-based amorphous resin as described above. In yet other embodiments, the bio-based resin described above may be combined with another resin and then added to the particles as a resin coating to form a shell.
The shell resin may be applied to the aggregated particles by any method within the purview of those skilled in the art. In embodiments, the resins utilized to form the shell may be in an emulsion including any surfactant described above. The emulsion possessing the resins may be combined with the aggregated particles described above so that the shell forms over the aggregated particles. In embodiments, the shell may have a thickness of up to about 5 microns, in embodiments, of from about 0.1 to about 2 microns, in other embodiments, from about 0.3 to about 0.8 microns, over the formed aggregates.
The formation of the shell over the aggregated particles may occur while heating to a temperature from about 30° C. to about 80° C., in embodiments from about 35° C. to about 70° C. The formation of the shell may take place for a period of time from about 5 minutes to about 10 hours, in embodiments from about 10 minutes to about 5 hours.
The shell may be present in an amount from about 1 percent by weight to about 80 percent by weight of the toner particles, in embodiments from about 10 percent by weight to about 40 percent by weight of the toner particles, in other embodiments from about 20 percent by weight to about 35 percent by weight of the toner particles.
Coalescence
Following aggregation to the desired particle size and application of any optional shell, the particles may then be coalesced to the desired final shape, the coalescence being achieved by, for example, heating the mixture to a temperature from about 45° C. to about 100° C., in embodiments from about 55° C. to about 99° C., which may be at or above the glass transition temperature of the resins utilized to form the toner particles, and/or reducing the stirring, for example to from about 100 rpm to about 1,000 rpm, in embodiments from about 200 rpm to about 800 rpm. The fused particles can be measured for shape factor or circularity, such as with a Sysmex FPIA 2100 analyzer, until the desired shape is achieved.
Coalescence may be accomplished over a period from about 0.01 to about 9 hours, in embodiments from about 0.1 to about 4 hours.
After aggregation and/or coalescence, the mixture may be cooled to room temperature, such as from about 20° C. to about 25° C. The cooling may be rapid or slow, as desired. A suitable cooling method may include introducing cold water to a jacket around the reactor. After cooling, the toner particles may be optionally washed with water, and then dried. Drying may be accomplished by any suitable method for drying including, for example, freeze-drying.
Additives
In embodiments, the toner particles may also contain other optional additives, as desired or required. For example, the toner may include positive or negative charge control agents, for example in an amount from about 0.1 to about 10 weight percent of the toner, in embodiments from about 1 to about 3 weight percent of the toner. Examples of suitable charge control agents include quaternary ammonium compounds inclusive of alkyl pyridinium halides; bisulfates; alkyl pyridinium compounds, including those disclosed in U.S. Pat. No. 4,298,672, the disclosure of which is hereby incorporated by reference in its entirety; organic sulfate and sulfonate compositions, including those disclosed in U.S. Pat. No. 4,338,390, the disclosure of which is hereby incorporated by reference in its entirety; cetyl pyridinium tetrafluoroborates; distearyl dimethyl ammonium methyl sulfate; aluminum salts such as BONTRON E84™ or E88™ (Orient Chemical Industries, Ltd.); combinations thereof, and the like. Such charge control agents may be applied simultaneously with the shell resin described above or after application of the shell resin.
There can also be blended with the toner particles external additive particles after formation including flow aid additives, which additives may be present on the surface of the toner particles. Examples of these additives include metal oxides such as titanium oxide, silicon oxide, aluminum oxides, cerium oxides, tin oxide, mixtures thereof, and the like; colloidal and amorphous silicas, such as AEROSIL®, metal salts and metal salts of fatty acids inclusive of zinc stearate, calcium stearate, or long chain alcohols such as UNILIN 700, and mixtures thereof.
In general, silica may be applied to the toner surface for toner flow, triboelectric charge enhancement, admix control, improved development and transfer stability, and higher toner blocking temperature. TiO2 may be applied for improved relative humidity (RH) stability, triboelectric charge control and improved development and transfer stability. Zinc stearate, calcium stearate and/or magnesium stearate may optionally also be used as an external additive for providing lubricating properties, developer conductivity, triboelectric charge enhancement, enabling higher toner charge and charge stability by increasing the number of contacts between toner and carrier particles. In embodiments, a commercially available zinc stearate known as Zinc Stearate L, obtained from Ferro Corporation, may be used. The external surface additives may be used with or without a coating.
Each of these external additives may be present in an amount from about 0.1 weight percent to about 5 weight percent of the toner, in embodiments from about 0.25 weight percent to about 3 weight percent of the toner, although the amount of additives can be outside of these ranges. In embodiments, the toners may include, for example, from about 0.1 weight percent to about 5 weight percent titania, from about 0.1 weight percent to about 8 weight percent silica, and from about 0.1 weight percent to about 4 weight percent zinc stearate.
Suitable additives include those disclosed in U.S. Pat. Nos. 3,590,000, and 6,214,507, the disclosures of each of which are hereby incorporated by reference in their entirety. Again, these additives may be applied simultaneously with the shell resin described above or after application of the shell resin.
In embodiments, toners of the present disclosure may be utilized as ultra low melt (ULM) toners. In embodiments, the dry toner particles having a core and/or shell may, exclusive of external surface additives, have one or more the following characteristics:
(1) Volume average diameter (also referred to as “volume average particle diameter”) of from about 3 to about 25 μm, in embodiments from about 4 to about 15 μm, in other embodiments from about 5 to about 12 μm.
(2) Number Average Geometric Size Distribution (GSDn) and/or Volume Average Geometric Size Distribution (GSDv): In embodiments, the toner particles described in (1) above may have a narrow particle size distribution with a lower number ratio GSD of from about 1.15 to about 1.38, in other embodiments, less than about 1.31. The toner particles of the present disclosure may also have a size such that the upper GSD by volume in the range of from about 1.20 to about 3.20, in other embodiments, from about 1.26 to about 3.11. Volume average particle diameter D50v, GSDv, and GSDn may be measured by means of a measuring instrument such as a Beckman Coulter Multisizer 3, operated in accordance with the manufacturer's instructions. Representative sampling may occur as follows: a small amount of toner sample, about 1 gram, may be obtained and filtered through a 25 micrometer screen, then put in isotonic solution to obtain a concentration of about 10%, with the sample then run in a Beckman Coulter Multisizer 3.
(3) Shape factor of from about 105 to about 170, in embodiments, from about 110 to about 160, SF1*a. Scanning electron microscopy (SEM) may be used to determine the shape factor analysis of the toners by SEM and image analysis (IA). The average particle shapes are quantified by employing the following shape factor (SF1*a) formula:
SF1*a=100πd2/(4A), (IV)
where A is the area of the particle and d is its major axis. A perfectly circular or spherical particle has a shape factor of exactly 100. The shape factor SF1*a increases as the shape becomes more irregular or elongated in shape with a higher surface area.
(4) Circularity of from about 0.92 to about 0.99, in other embodiments, from about 0.94 to about 0.975. The instrument used to measure particle circularity may be an FPIA-2100 manufactured by SYSMEX, following the manufacturer's instructions.
The characteristics of the toner particles may be determined by any suitable technique and apparatus and are not limited to the instruments and techniques indicated hereinabove.
In embodiments, the toner particles may have a weight average molecular weight (Mw) of from about 1,500 Daltons to about 60,000 Daltons, in embodiments from about 2,500 Daltons to about 18,000 Daltons, a number average molecular weight (Mn) of from about 1,000 Daltons to about 18,000 Daltons, in embodiments from about 1,500 Daltons to about 10,000 Daltons, and a MWD (a ratio of the Mw to Mn of the toner particles, which is a measure of the polydispersity of the polymer) of from about 1.7 to about 10, in embodiments from about 2 to about 6. For cyan and yellow toners, the toner particles can exhibit a weight average molecular weight (Mw) of from about 1,500 Daltons to about 45,000 Daltons, in embodiments from about 2,500 Daltons to about 15,000 Daltons, a number average molecular weight (Mn) of from about 1,000 Daltons to about 15,000 Daltons, in embodiments from about 1,500 Daltons to about 10,000 Daltons, and a MWD of from about 1.7 to about 10, in embodiments from about 2 to about 6. For black and magenta, the toner particles, in embodiments, can exhibit a weight average molecular weight (Mw) of from about 1,500 Daltons to about 45,000 Daltons, in embodiments from about 2,500 Daltons to about 15,000 Daltons, a number average molecular weight (Mn) of from about 1,000 Daltons to about 15,000 Daltons, in embodiments from about 1,500 Daltons to about 10,000 Daltons, and a MWD of from about 1.7 to about 10, in embodiments from about 2 to about 6.
Further, the toners, if desired, can have a specified relationship between the molecular weight of the latex resin and the molecular weight of the toner particles obtained following the emulsion aggregation procedure. As understood in the art, the resin undergoes crosslinking during processing, and the extent of crosslinking can be controlled during the process. The relationship can best be seen with respect to the molecular peak values (Mp) for the resin which represents the highest peak of the Mw. In the present disclosure, the resin can have a molecular peak (Mp) of from about 5,000 to about 30,000 Daltons, in embodiments from about 7,500 to about 29,000 Daltons. The toner particles prepared from the resin also exhibit a high molecular peak, for example, in embodiments, of from about 5,000 to about 32,000, in other embodiments, from about 7,500 to about 31,500 Daltons, indicating that the molecular peak is driven by the properties of the resin rather than another component such as the colorant.
Toners produced in accordance with the present disclosure may possess excellent charging characteristics when exposed to extreme relative humidity (RH) conditions. The low-humidity zone (C zone) may be about 12° C./15% RH, while the high humidity zone (A zone) may be about 28° C./85% RH. Toners of the present disclosure may possess a parent toner charge per mass ratio (Q/M) of from about −2 μC/g to about −50 μC/g, in embodiments from about −4 μC/g to about −35 μC/g, and a final toner charging after surface additive blending of from −8 μC/g to about −40 μC/g, in embodiments from about −10 μC/g to about −25 μC/g.
Developer
The toner particles may be formulated into a developer composition. For example, the toner particles may be mixed with carrier particles to achieve a two-component developer composition. The carrier particles can be mixed with the toner particles in various suitable combinations. The toner concentration in the developer may be from about 1% to about 25% by weight of the developer, in embodiments from about 2% to about 15% by weight of the total weight of the developer (although values outside of these ranges may be used). In embodiments, the toner concentration may be from about 90% to about 98% by weight of the carrier (although values outside of these ranges may be used). However, different toner and carrier percentages may be used to achieve a developer composition with desired characteristics.
Carriers
Illustrative examples of carrier particles that can be selected for mixing with the toner composition prepared in accordance with the present disclosure include those particles that are capable of triboelectrically obtaining a charge of opposite polarity to that of the toner particles. Accordingly, in one embodiment the carrier particles may be selected so as to be of a negative polarity in order that the toner particles that are positively charged will adhere to and surround the carrier particles. Illustrative examples of such carrier particles include granular zircon, granular silicon, glass, silicon dioxide, iron, iron alloys, steel, nickel, iron ferrites, including ferrites that incorporate strontium, magnesium, manganese, copper, zinc, and the like, magnetites, and the like. Other carriers include those disclosed in U.S. Pat. Nos. 3,847,604, 4,937,166, and 4,935,326.
The selected carrier particles can be used with or without a coating. In embodiments, the carrier particles may include a core with a coating thereover which may be formed from a mixture of polymers that are not in close proximity thereto in the triboelectric series. The coating may include polyolefins, fluoropolymers, such as polyvinylidene fluoride resins, terpolymers of styrene, acrylic and methacrylic polymers such as methyl methacrylate, acrylic and methacrylic copolymers with fluoropolymers or with monoalkyl or dialkylamines, and/or silanes, such as triethoxy silane, tetrafluoroethylenes, other known coatings and the like. For example, coatings containing polyvinylidenefluoride, available, for example, as KYNAR 301F™, and/or polymethylmethacrylate, for example having a weight average molecular weight of about 300,000 to about 350,000, such as commercially available from Soken, may be used. In embodiments, polyvinylidenefluoride and polymethylmethacrylate (PMMA) may be mixed in proportions of from about 30 weight % to about 70 weight %, in embodiments from about 40 weight % to about 60 weight % (although values outside of these ranges may be used). The coating may have a coating weight of, for example, from about 0.1 weight % to about 5% by weight of the carrier, in embodiments from about 0.5 weight % to about 2% by weight of the carrier (although values outside of these ranges may be obtained).
In embodiments, PMMA may optionally be copolymerized with any desired comonomer, so long as the resulting copolymer retains a suitable particle size. Suitable comonomers can include monoalkyl, or dialkyl amines, such as a dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, diisopropylaminoethyl methacrylate, or t-butylaminoethyl methacrylate, and the like. The carrier particles may be prepared by mixing the carrier core with polymer in an amount from about 0.05 weight % to about 10 weight %, in embodiments from about 0.01 weight % to about 3 weight %, based on the weight of the coated carrier particles (although values outside of these ranges may be used), until adherence thereof to the carrier core by mechanical impaction and/or electrostatic attraction.
Various effective suitable means can be used to apply the polymer to the surface of the carrier core particles, for example, cascade roll mixing, tumbling, milling, shaking, electrostatic powder cloud spraying, fluidized bed, electrostatic disc processing, electrostatic curtain, combinations thereof, and the like. The mixture of carrier core particles and polymer may then be heated to enable the polymer to melt and fuse to the carrier core particles. The coated carrier particles may then be cooled and thereafter classified to a desired particle size.
In embodiments, suitable carriers may include a steel core, for example of from about 25 to about 100 μm in size, in embodiments from about 50 to about 75 μm in size (although sizes outside of these ranges may be used), coated with about 0.5% to about 10% by weight, in embodiments from about 0.7% to about 5% by weight (although amounts outside of these ranges may be obtained), of a conductive polymer mixture including, for example, methylacrylate and carbon black using the process described in U.S. Pat. Nos. 5,236,629 and 5,330,874.
The carrier particles can be mixed with the toner particles in various suitable combinations. The concentrations are may be from about 1% to about 20% by weight of the toner composition (although concentrations outside of this range may be obtained). However, different toner and carrier percentages may be used to achieve a developer composition with desired characteristics.
Imaging
Toners of the present disclosure may be utilized in electrophotographic imaging methods, including those disclosed in, for example, U.S. Pat. No. 4,295,990, the disclosure of which is hereby incorporated by reference in its entirety. In embodiments, any known type of image development system may be used in an image developing device, including, for example, magnetic brush development, jumping single-component development, hybrid scavengeless development (HSD), and the like. These and similar development systems are within the purview of those skilled in the art.
Imaging processes include, for example, preparing an image with an electrophotographic device including a charging component, an imaging component, a photoconductive component, a developing component, a transfer component, and a fusing component. In embodiments, the development component may include a developer prepared by mixing a carrier with a toner composition described herein. The electrophotographic device may include a high speed printer, a black and white high speed printer, a color printer, and the like.
Once the image is formed with toners/developers via a suitable image development method such as any one of the aforementioned methods, the image may then be transferred to an image receiving medium such as paper and the like. In embodiments, the toners may be used in developing an image in an image-developing device utilizing a fuser roll member. Fuser roll members are contact fusing devices that are within the purview of those skilled in the art, in which heat and pressure from the roll may be used to fuse the toner to the image-receiving medium. In embodiments, the fuser member may be heated to a temperature above the fusing temperature of the toner, for example to temperatures of from about 70° C. to about 160° C., in embodiments from about 80° C. to about 150° C., in other embodiments from about 90° C. to about 140° C. (although temperatures outside of these ranges may be used), after or during melting onto the image receiving substrate.
The following Examples are being submitted to illustrate embodiments of the present disclosure. These Examples are intended to be illustrative only and are not intended to limit the scope of the present disclosure. Also, parts and percentages are by weight unless otherwise indicated. As used herein, “room temperature” refers to a temperature from about 20° C. to about 25° C.
A 1 Liter Parr reactor, equipped with a mechanical stirrer, bottom drain valve and distillation apparatus, was charged with about 219.26 grams (about 897.74 mmoles, 0.325 eq.) of Dimethyl 2,6-Naphthalenedicarboxylate (NDC), about 215 grams (about 1471.19 mmoles, 0.5326 eq.) of D-isosorbide (IS), and about 81.97 grams (about 610.93 mmoles, 0.22 eq.) of dipropylene glycol (DPG), followed by about 0.625 grams of a butylstannoic acid catalyst (FASCAT® 4100, commercially available from Arkema). The reactor was blanketed with nitrogen and the temperature of the reactor was slowly raised to about 210° C. with stirring (once the solids melted).
This reaction mixture was maintained under nitrogen overnight while methanol was continuously collected in a collection flask. At this point, approximately 66 ml of methanol was distilled. The reactor was opened and about 49.94 grams (about 290.04 mmoles, 0.105 eq.) of 1,4-Cyclohexanedicarboxylic acid (CHDA) and about 58.37 grams (about 103.31 mmoles, 0.0374 eq.) of a dimer diacid, commercially available as PRIPOL® 1012 from Croda, were added to the prepolymer mixture. The temperature of the reaction mixture was decreased to about 190° C. and left stirring under nitrogen overnight, before increasing the temperature, to about 205° C. Once the temperature reached 205° C., a low vacuum (>10 Torr) was applied for about 40 minutes. The vacuum was switched to a higher vacuum (<0.1 Torr). During this time, glycol distilled off (about 40 grams) and a low molecular weight polymer was formed. The high vacuum was applied in 3 intervals of about 4 hours each over about 2 days. Once the softening point reached about 119° C., the temperature was lowered to about 195° C. and the contents were discharged onto a polytetrafluoroethylene (TEFLON) pan. The acid value of this resin was about 0.92 mg KOH/g.
A 1 Liter Parr reactor, equipped with a mechanical stirrer, bottom drain valve and distillation apparatus, was charged with about 146.11 grams of the resin from Comparative Example 1 (acid value of about 0.92 mg KOH/g) and about 1.47 grams citric acid (about 1% by weight). The reactor was blanketed with nitrogen and the temperature of the reactor was slowly raised to about 170° C. and held there for about 2.5 hours. The polymer melt was sampled three times (A, B, and C) within the first 2.5 hours, at 1 hour, 1.75 hours, and 2.5 hours. The polymer melt was processed for another hour under low vacuum (>10 Torr) and sample D was taken at that time (a total of 3.5 hours from the start of reaction). Finally the vacuum was switched to high (<0.1 Torr) for 1 hour (one sample, E was taken at that time (a total of 4.5 hours from the start of reaction)) before discharging from the reactor and allowed to cool. The acid value of this acidified resin was about 4.61 mg KOH/g.
The same process was followed as described above in Example 1, except about 100.86 grams of the resin from Comparative Example 1 (acid value of about 0.92 mg KOH/g) and about 2.02 grams of citric acid (about 2% by weight) were combined to form the acidified resin. The polymer melt was sampled three times (A, B, and C) within the first 2.5 hours, at 1 hour, 1.75 hours, and 2.5 hours. The polymer melt was processed for another hour under low vacuum (>10 Torr) and sample D was taken at that time (a total of 3.5 hours from the start of reaction). Finally the vacuum was switched to high (<0.1 Torr) for 2 hours (two samples, E and F, were taken at that time (a total of 5.5 hours from the start of reaction)) before being discharged from the reactor and allowed to cool. The acid value of this acidified resin was about 6.77 mg KOH/g.
About 10.09 grams of the acidified resin from Example 1 was measured into a 500 milliliter beaker containing about 100.9 grams of dichloromethane. The mixture was stirred at about 300 revolutions per minute at room temperature to dissolve the resin in the dichloromethane.
About 0.07 grams of sodium bicarbonate, and about 0.43 grams of DOWFAX™ 2A1, an alkyldiphenyloxide disulfonate from The Dow Chemical Company (about 46.75 wt % solids), were measured into a 500 milliliter Pyrex glass beaker containing about 57.33 grams of deionized water. Homogenization of the water solution occurred in an IKA ULTRA TURRAX T18 homogenizer operating at about 5,000 revolutions per minute.
The resin solution was then slowly poured into the water solution as homogenization of the mixture continued; the homogenizer speed was increased to about 8,000 revolutions per minute and homogenization was carried out for about 30 minutes. Upon completion of homogenization, the glass reactor and its contents were placed on a heating mantle and connected to a distillation device. The mixture was stirred at about 260 revolutions per minute and the temperature of the mixture was increased to about 50° C. at a rate of about 1° C. per minute to distill off the dichloromethane from the mixture. Stirring of the mixture continued at about 50° C. for about 180 minutes followed by cooling at about 2° C. per minute to room temperature.
The product was screened through a 25 micron sieve. The resulting resin emulsion included about 25% by weight solids in water, with an average particle size of about 913 nm, as determined by dynamic light scattering with a Nanotrac Particle Size Analyzer.
About 9.93 grams of the acidified resin from Example 2 was measured into a 500 milliliter beaker containing about 99.3 grams of dichloromethane. The mixture was stirred at about 300 revolutions per minute at room temperature to dissolve the resin in the dichloromethane. Then, about 0.10 grams of sodium bicarbonate and about 0.42 grams of DOWFAX™ 2A1, an alkyldiphenyloxide disulfonate from The Dow Chemical Company (about 46.75 wt % solids), were measured into a 500 milliliter Pyrex glass beaker containing about 56.42 grams of deionized water. Homogenization of the water solution occurred with an IKA ULTRA TURRAX T18 homogenizer operating at about 5,000 revolutions per minute.
The resin solution was then slowly poured into the water solution as homogenization of the mixture continued; the homogenizer speed was increased to about 8,000 revolutions per minute and homogenization was carried out for about 30 minutes. Upon completion of homogenization, the glass reactor and its contents were placed on a heating mantle and connected to a distillation device. The mixture was stirred at about 250 revolutions per minute and the temperature of the mixture was increased to about 50° C. at a rate of about 1° C. per minute to distill off the dichloromethane from the mixture. Stirring of the mixture continued at about 50° C. for about 180 minutes, followed by cooling at about 2° C. per minute to room temperature.
The product was screened through a 25 micron sieve. The resulting resin emulsion included about 25% by weight solids in water, with an average particle size of about 762 nm, as determined by dynamic light scattering with a Nanotrac Particle Size Analyzer.
Table 1 below summarizes the weight average molecular weight (Mw), number average molecular weight (Mn), onset glass transition temperature (Tg (on)), softening point (Ts), and acid value (AV) of the bioresins of Comparative Example 1, and multiple samples of Examples 1 and 2, both before and after citric acid (CA) treatment.
As can be seen from Table 1 above, citric acid was used as an acid functionality enhancer without causing a significant increase in Mw and/or Mn when compared to the untreated starting resin (Comparative Example 1). By controlling reaction time, temperature and vacuum, the reactivity of CA was controlled so that no, or minimal, branching and/or cross-linking occurred.
A 1 Liter Parr reactor equipped with a mechanical stirrer, bottom drain valve, and distillation apparatus, was charged with about 231 grams (about 944 mmoles, 0.3 eq.) of Dimethyl 2,6-Naphthalenedicarboxylate (NDC), about 248 grams (about 1700 mmoles, 0.54 eq.) of D-isosorbide (IS), and about 86 grams (about 157 mmoles, 0.05 eq.) of a dimer diol, commercially available as SOVERMOL 908 from Cognis Corporation, followed by the addition of about 0.631 grams of a butylstannoic acid catalyst (FASCAT® 4100, commercially available from Arkema). The reactor was blanketed with nitrogen and the temperature of the reactor was slowly raised to about 205° C. with stirring (once the solids melted). This reaction mixture was maintained under nitrogen overnight at about 195° C. while methanol was continuously collected in a collection flask. At this point, approximately 49 ml of methanol was distilled.
The following day, the reactor was opened and about 66.5 grams (about 346 mmoles, 0.11 eq.) citric acid (CA) was added to the prepolymer mixture. The temperature of the reaction mixture was increased to about 200° C. and left stirring under nitrogen until the setpoint of 200° C. was reached. A low vacuum (>10 Torr) was then applied for about 64 minutes. The vacuum was switched to a higher vacuum (<0.1 Torr). During this time a low molecular weight polymer was formed. High vacuum was applied for about 93 minutes; another 23 grams of distillate was collected. Once the softening point reached about 108.5° C., the temperature was lowered to about 195° C. and the product was discharged onto a polytetrafluoroethylene (TEFLON) pan. The properties of the acidified resin (not acidified via citric acid)—cut/paste from ID and paragraph
The resin of Example 5 was compared with: a low softening point (Ts) biobased resin having a Mw of about 4243 Daltons, including Dimethyl 2,6-Naphthalenedicarboxylate (NDC) with D-isosorbide (IS), succinic acid and azelaic acid co-mononers (hereinafter “Low Tg Biobased Resin”); a high molecular weight amorphous resin having a Mw of about 63,400 Daltons including alkoxylated bisphenol A with terephthalic acid, trimellitic acid, and dodecenylsuccinic acid co-monomers (hereinafter “High MW Amorphous Resin”); a lower molecular weight amorphous resin having a Mw of about 16,100 including an alkoxylated bisphenol A with terephthalic acid, fumaric acid, and dodecenylsuccinic acid co-monomers (hereinafter “Low MW Amorphous Resin”); and a commercially available bio-based resin, BIOREZ 64-113, from Advanced Image Resources. The results are summarized in Table 2 below.
The above resin was also compared with a propoxylated bisphenol A polyester based resin (Non-biobased Control 1). The results are also plotted in
A 2 Liter Büchi reactor equipped with a mechanical stirrer, bottom drain valve and distillation apparatus, was charged with about 527.36 grams of Dimethyl 2,6-Naphthalenedicarboxylate (NDC), about 113.9 grams of D-isosorbide (IS), about 158.09 grams of azelaic acid (AzA) and about 396 grams of propylene glycol (PG), followed by about 1.5 grams of a butylstannoic acid catalyst (FASCAT® 4100, commercially available from Arkema). The reactor was blanketed with nitrogen and the temperature of the reactor was slowly raised to about 210° C. with stirring (once the solids melted). This reaction mixture was maintained under nitrogen overnight at about 210° C. while water and methanol were continuously collected in a collection flask. At this point, approximately 115 grams of distillate was collected.
The following day, the temperature of the reaction mixture was increased to about 215° C. and left stirring under nitrogen until the set point was reached. Low vacuum (>10 Torr) was then applied for about 15 minutes. The vacuum was then switched to a higher vacuum (<0.1 Torr). During this time a low molecular weight polymer was formed. High vacuum was applied for about 6 hours until the softening point was about 116.8° C. The reaction was left over night at about 165° C. so that additional polymerization was avoided, after which about 14 grams of citric acid (about 1.5% by weight) was added to the reactor. The temperature was then increased to about 185° C. and low vacuum was applied for about 15 minutes. The reaction mixture was switched to a higher vacuum (<0.1 Torr) for about 2 hours before discharging onto a polytetrafluoroethylene (TEFLON) pan. The final softening point of the resin was about 117.4° C. with an acid value of about 12.77 mg KOH/g.
A 1 Liter Parr reactor equipped with a mechanical stirrer, bottom drain valve and distillation apparatus, was charged with 370 grams of the resin of Example 6 having an acid value of about 12.77 mg KOH/g. The temperature of the reactor was slowly raised to about 200° C. and held there for about 2.5 hours. A low vacuum (>10 Torr) was applied for about 20 minutes, followed by a high vacuum (<0.1 Torr) for about 2.5 hours, until the softening point was about 121° C. The polymer melt was processed under vacuum for another 5 hours, to enable cross-linking and further reaction of the citric acid with the polymer chains. At this point the resin was discharged from the reactor and allowed to cool. The acid value of the resulting resin was about 8.36 mg KOH/g.
A 1 Liter Pan reactor equipped with a mechanical stirrer, bottom drain valve and distillation apparatus, was charged with about 263.68 grams of Dimethyl 2,6-Naphthalenedicarboxylate (NDC), about 56.95 grams D-isosorbide (1S), about 79.05 grams Azelaic acid (AzA), and about 198 grams propylene glycol (PG), followed by about 0.75 grams of a butylstannoic acid catalyst (FASCAT 4100, commercially available from Arkema). The reactor was blanketed with nitrogen and the temperature of the reactor was slowly raised to about 190° C. with stirring (once the solids melted). This reaction mixture was maintained under nitrogen overnight at about 190° C. while water and methanol was continuously collected in a collection flask. At this point, approximately 77 grams of distillate was collected.
The following day, the temperature of the reaction mixture was increased to about 205° C. and left stirring under nitrogen until the set point was reached. A low vacuum (>10 Torr) then was applied for about 15 minutes. The vacuum was then switched to a higher vacuum (<0.1 Torr), and a low molecular weight polymer began to form. The high vacuum was applied for about 9 hours until a softening point of from about 110 to about 115° C. was reached. The reaction was left over night at about 160° C. so that additional polymerization was avoided. The following day, the temperature was increased to about 200° C. and high vacuum (<0.1 Torr) was applied for about 3.5 hours. The temperature was then reduced to about 185° C. and about 6 grams of citric acid (about 1.5% by weight) was added to the reactor and allowed to react under the nitrogen blanket for about 100 minutes before discharging onto a polytetrafluoroethylene (TEFLON) pan. The final softening point of the resin was about 123.9° C. with an acid value of 9.34 mg KOH/g.
A comparative resin was made except the resin was treated with about 5 grams of trimellitic anhydride (TMA) instead of citric acid. A 1 Liter Parr reactor equipped with a mechanical stirrer, bottom drain valve and distillation apparatus, was charged with Dimethyl 2,6-Naphthalenedicarboxylate (NDC, 0.37 equivalents (eq.)), D-isosorbide (IS, 0.11 eq.), Azelaic acid (AzA, 0.13 eq.) and propylene glycol (PG, 0.39 eq.), followed by about 0.75 grams of FASCAT 4100 catalyst. The reactor was blanketed with nitrogen and the temperature of the reactor was slowly raised to about 190° C. with stirring (once the solids melted). This reaction mixture was maintained under nitrogen overnight at about 190° C. while water and methanol were continuously collected in a collection flask. At this point, approximately 77 grams of distillate was collected.
Next day, the reaction mixture was increased to about 205° C. and left stirring under nitrogen until the set point was reached. Low vacuum was then applied for about 15 minutes. The vacuum was switched to a higher vacuum (<0.1 Torr). During this time a low molecular weight polymer was formed. High vacuum was applied for about 9 hours until softening point reached about 110-115° C. The reaction was left over night again at about 160° C. so that polymer would not polymerize any further. Next day, the temperature was increased to about 200° C. and high vacuum was applied for about 3.5 hours. The temperature was then reduced to about 185° C. and about 5.2 grams of trimellitic anhydride was added to the reactor and allowed to react under a nitrogen blanket for about 100 minutes before discharging onto a polytetrafluoroethylene (Teflon) pan. The final softening point of the resin was about 119.7° C. with an acid value of about 9.5 mg KOH/g.
Table 3 below demonstrates the materials and properties of bio-based resins treated with citric acid (CA) instead of trimellitic anhydride (TMA).
About 120 grams of the resin from Example 6 was measured into a 1 liter beaker containing about 923 grams of ethyl acetate. The mixture was stirred at about 500 revolutions per minute at room temperature to dissolve the resin in the ethyl acetate.
About 2.24 grams of sodium bicarbonate and about 5.11 grams of DOWFAX™ 2A1, an alkyldiphenyloxide disulfonate from The Dow Chemical Company (about 47 wt % solids), were measured into a 2 liter Pyrex glass reactor containing about 681.8 grams of deionized water. Homogenization of the water solution occurred with an IKA ULTRA TURRAX T50 homogenizer operating at about 5,000 revolutions per minute.
The resin solution was then slowly poured into the water solution; as the mixture continued to be homogenized, the homogenizer speed was increased to about 8,000 revolutions per minute and homogenization occurred for about 30 minutes. Upon completion of homogenization, the glass reactor and its contents were placed on a heating mantle and connected to a distillation device. The mixture was stirred at about 300 revolutions per minute and the temperature of the mixture was increased to about 83° C. at a rate of about 1° C. per minute to distill off the ethyl acetate from the mixture. Stirring of the mixture continued at about 83° C. for about 180 minutes, followed by cooling at a rate of about 2° C. per minute to room temperature. The product was screened through a 25 micron sieve. The resulting resin emulsion included about 17 percent by weight solids in water, with an average particle size of about 109 nm as determined by dynamic light scattering with a Nanotrac Particle Size Analyzer.
The process of Example 9 was repeated, except that in this Example, about 120 grams of the resin of Example 7, and about 1.47 grams of sodium bicarbonate, were used in the process. The resulting resin emulsion included about 13 percent by weight solids in water, with an average particle size of about 125 nm.
Examples 9 and 10 demonstrate that stable emulsions, with particle sizes from about 100 nm to about 150 nm, were obtainable.
Notwithstanding the above disclosure and examples, the emulsification of citric acid-based polyesters can also be practiced via phase inversion emulsification (PIE) and solvent-less/solvent-free emulsification.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. Unless specifically recited in a claim, steps or components of claims should not be implied or imported from the specification or any other claims as to any particular order, number, position, size, shape, angle, color, or material.
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