The present application claims priority to European patent application 17195099.1, filed Oct. 6, 2017, which is incorporated herein by reference.
The present invention relates to aqueous dispersions containing silicon dioxide and trimethyl-1,6-hexamethylenediamine, to a process for the production thereof and to the use thereof in lacquer preparations.
Silicon dioxide is often used for adjusting rheological properties in liquid systems. Thus, for example, silicon dioxide particles may be used in solvent-based paints and lacquers to prevent running thereof before curing on vertical surfaces or to counter settling of the pigments in such lacquers. Such rheological effects are based on the formation of hydrogen bonds between silanol groups and the adjacent silica particles. Hydrophilic silica has the largest thickening and thixotroping effect in nonpolar liquids, i.e. liquids having a small amount of inherent hydrogen bonds. The inherent hydrogen bonds of a liquid medium can disrupt the formation of hydrogen bonds between silanol groups of the silica and reduce the thickening effect. In moderately polar systems such as a number of epoxy resins, the thickening effect is still quite strong. WO 2009/068379 A1 discloses hydrophilic precipitated silicas exhibiting an elevated thickening effect in nonpolar and moderately polar systems, for example UPE formulations. However, in highly polar systems such as systems containing low molecular weight alcohols or water, hydrophilic silica is often inefficient for thickening and generating thixotropy.
In aqueous systems such as for example emulsions and dispersions, the hydrophilic silicas are usually inefficient when a relatively low concentration of silicon dioxide is employed as a thickener. However, the thickening effect of the silica may be significantly enhanced by using special additives.
It is known that a very wide variety of amines can be adsorbed at the surface of pyrogenic silicon dioxide in aqueous dispersions (Archiv der Pharmazie, 1987, volume 320, pages 1-15). This effect is used for producing highly-filled, ammonia-stabilized aqueous dispersions having a low viscosity. Thus, WO 2012/062559 A1 discloses such aqueous dispersions containing inter alia hydrophobized silicon dioxide particles and amino alcohols having low viscosities at relatively high solids loadings.
WO 2016/095196 discloses aqueous lacquer preparations comprising colloidal silicon dioxide and a very wide variety of amines. On page 23, reference is made to table 4 and it is noted that diamines such as JEFFAMINE D203, isophoronediamine (IPD) and N,N′-diethyl-1,3-propanediamine bring about a greater thickening (viscosity increase) in the aqueous dispersions compared to monoamines. The lacquer preparation of comparative example M here contains for example 7.6% by weight of SiO2 and 0.4% by weight of IPD (SiO2/amine=53.9 mol/mol; SiO2/water=0.04 mol/mol).
The problem addressed by the present invention is that of providing a water-containing system having a relatively high viscosity compared to the known systems at a relatively low solids content.
This problem, among others, was solved by an aqueous dispersion comprising silicon dioxide and 2,2,4-trimethyl-1,6-hexamethylenediamine and/or 2,4,4-trimethyl-1,6-hexamethylenediamine.
It has now been found that, surprisingly, compared to the other structurally very similar diamines, the abovementioned amines exhibit a much higher viscosity so of the aqueous dispersion at a relatively low content of silicon dioxide.
Any ranges mentioned herein below include all values and subvalues between the lowest and highest limit of this range.
One embodiment relates to an aqueous dispersion, comprising: silicon dioxide and at least one of 2,2,4-trimethyl-1,6-hexamethylenediamine and 2,4,4-trimethyl-1,6-hexamethylenediamine
The dispersion according to the invention contains silicon dioxide, preferably in amorphous form. This silicon dioxide may include one or more commonly known types of silicas, such as the so-called aerogels, xerogels, perlites, precipitated silicas, fumed silicas. It is preferable when the dispersion according to the invention contains silicon dioxide from the group consisting of pyrogenic silicon dioxide, precipitated silicon dioxide, silicon dioxide produced by a sol-gel process and mixtures thereof.
The silicon dioxide prepared by precipitation (precipitated silica) is formed for example in the reaction of water glass solutions (water-soluble sodium silicates) with mineral acids. It is also possible here to generate in the solution of sodium silicate a colloidal silicon dioxide (silica sol) which provides dispersions having very small particle sizes and very good dispersion stability. A disadvantage, particularly in the polishing of semiconductor substrates, is the proportion of impurities introduced via the sodium silicate starting material.
Pyrogenic silicon dioxide, also known as fumed silica, is produced by means of flame hydrolysis or flame oxidation. This involves oxidizing or hydrolysing hydrolysable or oxidizable starting materials, generally in a hydrogen/oxygen flame. Starting materials that may be used for pyrogenic so methods include organic and inorganic substances. Particularly suitable therefor is silicon tetrachloride. The hydrophilic silica thus obtained is amorphous. Fumed silicas are generally in aggregated form. “Aggregated” shall be understood to mean that so-called primary particles initially formed during genesis form strong bonds with one another in the further course of the reaction to form a three-dimensional network. The primary particles are very substantially free of pores and have free hydroxyl groups on their surface. Pyrogenic silicon dioxide exhibits a very high purity and a primary particle size comparable to colloidal silicon dioxide. However, these primary particles undergo aggregation and agglomeration to form relatively hard particles. Dispersion of the aggregates and agglomerates has proven difficult; the dispersions are less stable and have a propensity for sedimentation or else gelation.
A further silicon dioxide source suitable for producing the dispersions according to the invention is a silicon dioxide produced by a sol-gel process, for example an aerogel, a xerogel or similar materials. Starting materials for an SiO2 sol synthesis are often silicon alkoxides. The hydrolysis of such precursors and the condensation between the thus formed reactive species are the essential fundamental reactions in the sol-gel process. Suitable silicon sources include in particular the tetraalkyl orthosilicates, for example tetramethyl orthosilicate or tetraethyl orthosilicate. Removal of the alcohol formed in the hydrolysis of tetraalkyl orthosilicates is carried out under supercritical conditions (for methanol, temperature >239.4° C.; pressure >80.9 bar) and results in the formation of highly porous SiO2 aerogels.
Compared to the typical precipitated silicas, a pyrogenic silica is more efficient in increasing viscosity, provides a better suspension stability in low-viscosity resins and results in better clarity. The advantages of precipitated silica compared to pyrogenic silica include faster and shear-independent dispersion, lower costs, better flow of the coating or of the glaze, lower porosity in gelcoats. Consequently, a mixture of pyrogenic silica and precipitated silica is used in numerous cases to obtain the advantages of both silica types.
However, it is very particularly preferable when one or more pyrogenic silicas are used in the dispersion according to the invention.
The dispersion according to the present invention may contain from 1% to 50% by weight, particularly preferably from 1% to 30% by weight, of silicon dioxide. The molar ratio of SiO2 to water in the dispersion according to the invention here is preferably from 0.001 to 0.5, particularly preferably from 0.005 to 0.2, very particularly preferably from 0.01 to 0.1.
The silicon dioxide present in the dispersion according to the invention is preferably hydrophilic.
The term “hydrophilic” in the context of the present invention relates to the particles having a relatively high affinity for polar media such as water and having a relatively low hydrophobicity. Such hydrophobicity may typically be achieved by application of appropriate nonpolar groups to the silica surface. The extent of the hydrophobicity of a silica may be determined via parameters including its methanol wettability, as more particularly described in WO2011/076518 A1, pages 5-6, for example. In pure water, a hydrophobic silica separates completely from the water and floats on the surface thereof without being wetted with the solvent. In pure methanol, by contrast, a hydrophobic silica is distributed throughout the solvent volume; complete wetting takes place. Measurement of methanol wettability determines a maximum content of methanol in a methanol/water test mixture at which wetting of the silica still does not take place, i.e. after contact with the test mixture 100% of the employed silica separates from the test mixture. This methanol content in the methanol/water mixture in % by weight is called methanol wettability. The higher such a methanol wettability, the more hydrophobic the silica. The lower the methanol wettability, the lower the hydrophobicity and the higher the hydrophilicity of the material.
The silicon dioxide employed in the dispersion according to the invention has a methanol wettability of less than 20%, preferably from 0% to 15%, particularly preferably from 0% to 10%, very particularly preferably from 0% to 5%, by weight of methanol in a methanol/water mixture.
The silicon dioxide employed in the dispersion according to the invention may have a hydroxyl density of 1.2 to 5.4 OH/nm2, preferably of 1.5 to 3.0 OH/nm2, particularly preferably of 1.8 to 2.5 OH/nm2. The hydroxyl density may be determined by the method published by J. Mathias and G. Wannemacher in Journal of Colloid and Interface Science 125 (1988) by reaction with lithium aluminium hydride. As is explained in the abovementioned publication, the surface of the untreated silicon dioxide powder produced by flame hydrolysis has a hydroxyl density of about 1.8 to 2.5 OH/nm2. WO 2004/020334 A1 for example discloses how silicas having an elevated hydroxyl density of 2.5 to 5.4 OH/nm2 may be obtained. A hydroxyl density lower than 1.8 OH/nm2 may be achieved for example by partial hydrophobizing of the free silanol groups with a suitable hydrophobizing agent. The hydrophobizing agent may be a silicon-containing compound preferably selected from the group consisting of halosilanes, alkoxysilanes, silazanes or siloxanes.
Such a silicon-containing compound is particularly preferably a liquid compound having at least one alkyl group and a boiling point of less than 200° C. It is preferably selected from the group consisting of CH3SiCl3, (CH3)2SiCl2, (CH3)3SiCl, C2H5SiCl3, (C2H5)2SiCl2, (C2H5)3SiCl, C3H8SiCl3, CH3Si(OCH3)3, (CH3)2Si(OCH3)2, (CH3)3SiOCH3, C2H5Si(OCH3)3, (C2H5)2Si(OCH3)2, (C2H5)3SiOCH3, C8H15Si(OC2H5)3, C8H15Si(OCH3)3, (H3C)3SiNHSi(CH3)3 and mixtures thereof. Particular preference is given to (H3C)3SiNHSi(CH3)3 and (CH3)2SiCl2.
The dispersion of the present invention is preferably basic and has a pH of more than 8, preferably of 9 to 13, particularly preferably of 10 to 12.
The dispersion according to the present invention may contain from 0.01% to 10% by weight, particularly preferably from 0.1% to 7% by weight, very particularly preferably from 0.5% to 5% by weight, of 2,2,4-trimethyl-1,6-hexamethylenediamine and/or 2,4,4-trimethyl-1,6-hexamethylenediamine.
In a particularly preferred embodiment of the invention, the dispersion according to the invention contains both 2,2,4-trimethyl-1,6-hexamethylenediamine and 2,4,4-trimethyl-1,6-hexamethylenediamine, wherein the molar ratio of 2,2,4-trimethyl-1,6-hexamethylenediamine to 2,4,4-trimethyl-1,6-hexamethylenediamine is from 0.5 to 1.5, particularly preferably from 0.8 to 1.2, very particularly preferably from 0.9 to 1.1. It is particularly preferable to produce the dispersion according to the invention using an isomer mixture of 2,2,4-trimethyl-1,6-hexamethylenediamine and 2,4,4-trimethyl-1,6-hexamethylenediamine which has virtually identical proportions of about 50% by weight of both amines and is obtainable for example under the name VESTAMIN® TMD from Evonik Resource Efficiency GmbH.
It has proven particularly advantageous when the molar ratio of silicon dioxide to 2,2,4-trimethyl-1,6-hexamethylenediamine and/or 2,4,4-trimethyl-1,6-hexamethylenediamine in the dispersion according to the invention is from 1 to 1000, particularly preferably from 5 to 200, very particularly preferably from 10 to 100.
It has further proven advantageous when silicon dioxide particles in the dispersion according to the invention have a numerical average particle size d50 of not more than 300 nm. A range of 100 to 250 nm is particularly preferred. A numerical average particle size may be determined according to ISO13320:2009 by laser diffraction particle size analysis.
Employable hydrophilic pyrogenic silicon dioxides are hydrophilic pyrogenic silicon dioxides having a BET surface area of 20 to 500 m2/g, preferably of 30 to 400 m2/g. It is particularly preferable to employ hydrophilic pyrogenic silicon dioxides having a BET surface area of 200±25, 300±30 or 380±30 m2/g. The specific surface area, also referred to simply as BET surface area, is determined according to DIN 9277:2014 by nitrogen adsorption in accordance with the Brunauer-Emmett-Teller method.
The silicon dioxide employed in the dispersion according to the invention may have a tamped density of up to 400 g/L, preferably of 20 to 300 g/L, particularly preferably of 30 to 200 g/L, very particularly preferably of 40 to 100 g/L. Tamped densities of various pulverulent or coarse-grain granular materials may be determined according to DIN ISO 787-11:1995 “General methods of test for pigments and extenders—Part 11: Determination of tamped volume and apparent density after tamping”. This involves measuring the bulk density of a bulk material after agitation and tamping.
The dispersion according to the invention may contain not only water, silicon dioxide and trimethyl-1,6-hexamethylenediamine but also other constituents, for example solvents and a very wide variety of additives. The proportion of water in the aqueous dispersion according to the invention may be from 50% to 99% by weight, particularly preferably from 60% to 90% by weight.
The dispersion according to the invention may contain up to 10% by weight of at least one organic solvent, with the exception of N-methyl pyrrolidone. The solvent is preferably selected from the group consisting of aliphatic, cycloaliphatic and aromatic hydrocarbons, alcohols, glycols, glycol ethers, ketones, esters and ethers. Explicit mention may be made of n-hexane, n-heptane, cyclohexane, toluene, xylene, ethylbenzene, cumene, styrene, dichloromethane, 1,2-dichlorethane, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, isobutanol, 2-ethylhexanol, cyclohexanol, diacetone alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, mesityl oxide, isophorone, methyl acetate, methyl acetate, butyl acetate, butyl ether, ethyl acetate, butyl acetate, isobutyl acetate, methyl glycol acetate, butyl glycol acetate, ethyl diglycol acetate, butyl diglycol acetate, methoxypropyl acetate, ethoxypropyl acetate, ethylene carbonate, propylene carbonate, diethyl ether, methyl tert-butyl ether, tetrahydrofuran, dioxane, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-isopropoxy-2-propanol, 1-isobutoxy-2-propanol, ethyl glycol, propyl glycol, butyl glycol, ethyl diglycol, butyl diglycol, methyl dipropylene glycol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol, hexanediol, octanediol and triethylene glycol. Employable with particular preference are diethylene glycol, dipropylene glycol and tripropylene glycol.
The dispersion according to the invention is preferably very largely free from colour pigments and binders employed in the lacquer industry. In a preferred embodiment of the invention, the proportion of silicon dioxide is at least 90% by weight, particularly preferably at least 98% by weight, of the solids content of the dispersion. Very particular preference is given to an embodiment in which the solid phase of the dispersion consists entirely of silicon dioxide.
The dispersion according to the invention may additionally contain up to 1% by weight of N-methyl pyrrolidone.
In a particular embodiment of the invention, from 5% to 20% by weight, preferably from 8% to 15% by weight, in each case based on the proportion of silicon dioxide, of an alcohol alkoxylate of general formula R1O((CH2)mO)nH are employed in the dispersion according to the invention. The best lacquering results are obtained for one or more compounds of general formula R1O((CH2)mO)nH where R1═CH3(CH2)xCH2O where x=8-18, m=1-4 and n=15-25. Explicit mention may be made of CH3(CH2)10CH2O[(CH2)2O]18H, CH3(CH2)12CH2O[(CH2)2O]18H, CH3(CH2)14CH2O[(CH2)2O]18H, CH3(CH2)16CH2O[(CH2)2O]18H, CH3(CH2)10CH2O[(CH2)2O]20H; CH3(CH2)12CH2O[(CH2)2O]20H, CH3(CH2)14CH2O[(CH2)2O]20H, CH3(CH2)16CH2O[(CH2)2O]20H, CH3(CH2)10CH2O[(CH2)2O]23H, CH3(CH2)12CH2O[(CH2)2O]23H, CH3(CH2)14CH2O[(CH2)2O]23H and CH3(CH2)16CH2O[(CH2)2O]23H.
The dispersion according to the invention may further contain amines and/or amino alcohols other than trimethyl-1,6-hexamethylenediamine. The proportion thereof is preferably from 3% to 20% by weight, particularly preferably from 5% to 15% by weight, in each case based on the proportion of silicon dioxide. The term amino alcohol is to be understood as meaning a compound containing at least one amino group and at least one hydroxyl group. The molecular weight of the amino alcohol for use in the present invention is preferably from 50 to 500 g/mol, particularly preferably from 100 to 250 g/mol. Suitable amino alcohols are 2-aminoethanol, 1-aminoethanol, 3-amino-1-propanol, 2-amino-1-propanol, 1-amino-2-propanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-hydroxymethyl-1,3-propanediol, 2-(2-aminoethoxy)ethanol, 2-amino-1-butanol, 4-amino-1-butanol, 1-amino-2-butanol, 1-amino-3-butanol, 3-amino-1-butanol, 2-amino-1-cyclohexanol, 3-amino-1-cyclohexanol, 4-amino-1-cyclohexanol, 2-amino-1-(hydroxymethyl)cyclopentane, 2-amino-1-hexanol, 6-amino-1-hexanol, 2-amino-3-methyl-1-butanol, 1-(aminomethyl)cyclohexanol, 6-amino-2-methyl-2-heptanol, 2-amino-3-methyl-1-pentanol, 2-amino-4-methyl-1-pentanol, 2-amino-1-pentanol, 5-amino-1-pentanol, 1-amino-2,3-propanediol, 2-amino-1,3-propanediol, 2-amino-1,3-propanediol, 2-((3-aminopropyl)methylamino)ethanol or mixtures thereof.
Amino alcohols of the type (CH3)2NCHR1CHR2—O—[CHR3—CHR4—O]nH, in which R1, R2, R3 and R4 may each represent H, CH3 or C2H5 and n may be 1-5, wherein R1, R2, R3 and R4 may each be identical or different, may also be a constituent of the dispersion according to the invention. Examples include 1-(2-dimethylaminoethoxy)2-propanol, 1-(1-dimethylamino-2-propoxy)-2-propanol, 2-(1-dimethylamino-2-propoxy)ethanol, 2-(2-dimethylaminoethoxy)ethanol and 2-[2-(2-dimethylaminoethoxy)ethoxy]ethanol.
N,N-dialkylalkanolamines such as N,N-dimethylethanolamine and N,N-dimethylisopropanolamine are particularly preferred.
The dispersion according to the invention may further contain from 0.1% to 1.5% by weight of at least one polyethylene glycol and/or polypropylene glycol. Preference is given to polypropylene glycols having an average molecular weight (mass-average) of 100 g/mol or more, particularly preferably of 150 to 6000 g/mol. It has proven advantageous when the dispersion according to the invention further contains from 0.1% to 1% by weight, based on the proportion of silicon dioxide, of at least one copolymer of general formula I
where Z=
where
Preferably used as monovalent or divalent metal cation M are sodium, potassium, calcium and magnesium ions. Preferably employed as organic amine radicals are substituted ammonium groups derived from primary, secondary or tertiary C1- to C20-alkylamines, C1- to C20-alkanolamines, C6- to C8-cycloalkylamines and C6- to C14-arylamines. Examples of corresponding amines are methylamine, dimethylamine, trimethylamine, ethanolamine, diethanolamine, triethanolamine, cyclohexylamine, dicyclohexylamine, phenylamine, diphenylamine in the protonated (ammonium) form.
X may represent —OMa or —O—(CpH2pO)q—R1 where R1═H, an aliphatic hydrocarbon radical having 1 to 20 carbon atoms, a cycloaliphatic hydrocarbon radical having 5 to 8 carbon atoms, an aryl radical having 6 to 14 carbon atoms, which may optionally also be substituted. p may be from 2 to 4, q=0 to 100, wherein in a preferred embodiment p=2 or 3 and thus derives from polyethylene oxide or polypropylene oxide. Alternatively, X may also represent —NHR2 and/or —NR22 where R2═R1 or —CO—NH2, which corresponds to the monosubstituted or disubstituted monoamides of the corresponding unsaturated carboxylic acid. Y may represent O (acid anhydride) or NR2 (acid imide).
Employable with preference is a copolymer of general formula Ia or Ib, wherein A1 is an ethylene radical, m is 10 bis 30, n is 5 to 20, k is 10 to 30 and wherein the sum of m+k is in the range from 20 to 40.
Also employable with preference are compounds of general formula Ia or Ib in which R represents an optionally branched, optionally multiply bonded, optionally hydroxyl-containing alkyl radical having 8 to 18 carbon atoms, A represents an ethylene radical, M=H or an alkali metal, a is 1 to 30, b is 1 or 2.
A dispersion which has proven particularly suitable for lacquering applications contains at least one alcohol alkoxylate of general formula R1O((CH2)mO)nH, at least one polypropylene glycol having an average molecular weight of 100 to 6000 g/mol and at least one copolymer of general formula I. The alcohol alkoxylate/polypropylene glycol/copolymer weight ratios here are preferably 50-70/15-30/10-20, where these sum to 100.
The dispersion according to the invention may finally also have defoaming agents and preservatives added to it. The proportion thereof in the dispersion is generally below 1% by weight.
The invention further provides a lacquer preparation containing the dispersion according to the invention.
Suitable binders here may be the resins customary in lacquer and coating technology, such as are described for example in “Lackharze, Chemie, Eigenschaften and Anwendungen, Editors D. Stoye, W. Freitag, Hanser Verlag, Munich, Vienna 1996”.
Examples include inter alia polymers and copolymers of (meth)acrylic acid and their esters, optionally bearing further functional groups, with further unsaturated compounds, such as for example styrene, polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols and epoxy resins and also any desired mixtures of these polymers, and also fatty-acid-modified alkyd resins produced by polycondensation.
Also employable as polymer components are organic hydroxyl-bearing compounds, for example polyacrylate, polyester, polycaprolactone, polyether, polycarbonate and polyurethane polyols and hydroxy-functional epoxy resins and also any desired mixtures of these polymers. Employed in particular are aqueous or solvent-containing or solvent-free polyacrylate and polyester polyols and any desired mixtures thereof.
Polyacrylate polyols are copolymers of hydroxyl-containing monomers with other olefinically unsaturated monomers, for example esters of (meth)acrylic acid, styrene, alpha-methylstyrene, vinyltoluene, vinylesters, maleic and fumaric monoalkyl and dialkyl esters, alpha-olefins and other unsaturated oligomers and polymers.
The lacquer preparation according to the invention may further contain colour pigments and/or inactive fillers.
The colour pigments may be organic or inorganic in nature. Examples include lead oxides, lead silicates, iron oxides, phthalocyanine complexes, titanium dioxides, zinc oxides, zinc sulfide, bismuth vanadate, spinel mixed oxides, for example titanium-chromium, titanium-nickel or tin-zinc spinel or mixed oxides, platelet-shaped metallic or interference pigments and carbon blacks.
The lacquer preparation according to the invention may further contain inactive fillers. “Inactive fillers” shall be understood to mean fillers known to those skilled in the art which have only an insignificant effect, if any, on the rheological properties of the preparation. Examples include calcium carbonate, diatomaceous earth, mica, kaolin, chalk, quartz and talc.
Color pigments and/or inactive fillers are typically present in proportions which sum to 10% to 70% by weight, preferably from 30% to 50% by weight, based on the total solids content of the preparation.
The total solids content of the lacquer preparation which is composed of silicon dioxide particles, binders and optionally colour pigments and inactive fillers is preferably from 10% to 80% by weight, particularly preferably from 20% to 70% by weight, very particularly preferably from 30% to 60% by weight, based on the total mass of the lacquer preparation.
The invention further provides for the use of the dispersion according to the invention as an additive to hydrofillers in the automotive industry, as a coating constituent in can- and coil-coating processes and as an additive in water-based UV-curable formulations.
The invention further provides a process for producing the dispersion according to the invention by stirring the mixture comprising silicon dioxide, water and 2,2,4-trimethyl-1,6-hexamethylenediamine and/or 2,4,4-trimethyl-1,6-hexamethylenediamine.
The process according to the invention may be performed in a dispersing apparatus for example. Apparatuses suitable as such a dispersing apparatus for producing the dispersion according to the invention include all apparatuses capable of bringing about intensive wetting of the pulverulent or granular silicon dioxide with the aqueous phase. The lacquer industry typically uses so-called dissolvers for this purpose, the relatively simple construction of which allows for a low-maintenance and easy-clean mode of production. However, depending on the required viscosity or else fill level of the aqueous dispersion to be generated, intensive dispersing or post-milling is still necessary. Post-milling may be carried out in an agitator bead mill for example. However, intensive shearing using rotor/stator machines is often sufficient. An expedient combination of wetting and dispersing facility is provided by the rotor/stator machines from Ystral which allow the powder to be aspirated and, after closing the powder aspiration opening, dispersed by intensive shearing.
The process of the present invention is preferably performed at a stirrer speed of more than 500 rpm (revolutions per minute), particularly preferably of 1000 to 10000 rpm, very particularly preferably of 2000 to 8000 rpm.
Especially when using rotor/stator machines where aspiration of air and thus foam formation can occur, it has proven advantageous to initially charge only a portion of the required water and the additives and to incorporate a portion of the silicon dioxide. Above a particular amount of silicon dioxide of about 25-30% by weight, based on the entirety of the silicon dioxide to be incorporated, the defoaming effect thereof is apparent. Only after addition of the entire amount of powder are the remaining proportions of water subsequently added. This reserves a sufficient volume in the make-up vessel for the initial foam formation at commencement of the powder addition.
Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.
Production of all dispersions from comparative examples 1-4 and inventive examples 1-3 was carried out by initially incorporating the silicon dioxide into the water by stirring with a dissolver (ATP DISPERMILL Vango 100) at 4000 rpm over 30 min to obtain a 25% SiO2 dispersion. This 25% aqueous SiO2 dispersion was mixed with water and amine according to the desired end composition and subjected to further dispersion with a Polytron PT 6100 rotor-stator disperser from Kinematica AG at 6000 rpm for 30 min.
The dynamic viscosity (shear viscosity) of the obtained dispersions was determined using a rheometer (Anton Paar MCR100) at a rotational speed of sec−1 (1 revolution per second).
The employed amounts and proportions of SiO2 and respective amines, the pH of the resulting dispersions and the viscosity thereof are summarized in table 1 which follows:
1)DMAE = N,N-dimethylaminoethanol [CAS No 108-01-0, Mw = 89.1 g/mol]
2)HMDA = 1,6-hexamethylenediamine [CAS No 124-09-4, Mw = 116.2 g/mol]
3)IPD = isophoronediamine [CAS No 2855-13-2, Mw = 170.3 g/mol]
4)TMD = isomer mixture of approximately equal parts (50% by weight/50% by weight) of 2,2,4-trimethyl-1,6-hexamethylenediamine and 2,4,4-trimethyl-1,6-hexamethylenediamine [Mw = 158.3 g/mol] obtainable from Evonik Resource Efficiency GmbH under the name VESTAMIN ® TMD.
5)SiO2 = pyrogenic silicon dioxide AEROSIL ® 200 (BET = 200 m2/g) from Evonik Resource Efficiency GmbH.
6)The term “amine” relates to the amines employed in each case (DMAE, HMDA, IPD and TMD).
7)Viscosity of the mixture cannot be measured because it solidifies.
Inventive examples 1-3 clearly show that, utterly surprisingly, TMD exhibits a much greater thickening effect than the structurally very similar 1,6-hexamethylenediamine (comparative example 2) and isophoronediamine (comparative examples 3 and 4) given otherwise identical other constituents of the dispersions and identical test conditions.
Numerous modifications and variations on the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
Number | Date | Country | Kind |
---|---|---|---|
17195099 | Oct 2017 | EP | regional |
Number | Name | Date | Kind |
---|---|---|---|
5372905 | Deusser et al. | Dec 1994 | A |
5384194 | Deusser et al. | Jan 1995 | A |
5415936 | Deusser et al. | May 1995 | A |
5419928 | Deusser et al. | May 1995 | A |
5429873 | Deusser et al. | Jul 1995 | A |
5501933 | Deusser et al. | Mar 1996 | A |
5736407 | Hennig et al. | Apr 1998 | A |
5746347 | Riedemann et al. | May 1998 | A |
6436715 | Michael et al. | Aug 2002 | B1 |
7235298 | Katusic et al. | Jun 2007 | B2 |
7282236 | Michael et al. | Oct 2007 | B2 |
7361777 | Herrwerth et al. | Apr 2008 | B2 |
7365101 | Kroll et al. | Apr 2008 | B2 |
7374743 | Katusic et al. | May 2008 | B2 |
7438836 | Michael et al. | Oct 2008 | B2 |
7442666 | Herrwerth et al. | Oct 2008 | B2 |
7465431 | Katusic et al. | Dec 2008 | B2 |
7553465 | Katusic et al. | Jun 2009 | B2 |
7598334 | Ferenz et al. | Oct 2009 | B2 |
7605284 | Brückner et al. | Oct 2009 | B2 |
7718261 | Katusic et al. | May 2010 | B2 |
7722714 | Michael et al. | May 2010 | B2 |
7727599 | Döhler et al. | Jun 2010 | B2 |
7759402 | Venzmer et al. | Jul 2010 | B2 |
7834122 | Ferenz et al. | Nov 2010 | B2 |
7893128 | Busch et al. | Feb 2011 | B2 |
7925479 | Zielinski et al. | Apr 2011 | B2 |
7964694 | Ferenz et al. | Jun 2011 | B2 |
8030366 | Ferenz et al. | Oct 2011 | B2 |
8038788 | Michael et al. | Oct 2011 | B2 |
8084633 | Herrwerth et al. | Dec 2011 | B2 |
8138372 | Herrwerth et al. | Mar 2012 | B2 |
8152916 | Meyer et al. | Apr 2012 | B2 |
8153098 | Meyer et al. | Apr 2012 | B2 |
8163080 | Meyer et al. | Apr 2012 | B2 |
8172936 | Herrwerth et al. | May 2012 | B2 |
8211972 | Meyer et al. | Jul 2012 | B2 |
8466248 | Meyer et al. | Jun 2013 | B2 |
8597789 | Schulz et al. | Dec 2013 | B2 |
8617529 | Herrwerth et al. | Dec 2013 | B2 |
8631787 | Benitez et al. | Jan 2014 | B2 |
8642525 | Herrwerth et al. | Feb 2014 | B2 |
8685376 | Czech et al. | Apr 2014 | B2 |
8778319 | Herrwerth et al. | Jul 2014 | B2 |
8841400 | Henning et al. | Sep 2014 | B2 |
8882901 | Michael et al. | Nov 2014 | B2 |
8993792 | Hartung et al. | Mar 2015 | B2 |
9073818 | Herrwerth et al. | Jul 2015 | B2 |
9138385 | Dahl et al. | Sep 2015 | B2 |
9221945 | Alzer et al. | Dec 2015 | B2 |
9353289 | De Gans et al. | May 2016 | B2 |
9616007 | Herrwerth et al. | Apr 2017 | B2 |
9617390 | Hinzmann et al. | Apr 2017 | B2 |
9663622 | Hinzmann et al. | May 2017 | B2 |
20010055639 | Moritz et al. | Dec 2001 | A1 |
20020037936 | Michael et al. | Mar 2002 | A1 |
20030101659 | Katusic et al. | Jun 2003 | A1 |
20030124051 | Servaty et al. | Jul 2003 | A1 |
20030206854 | Gutsch et al. | Nov 2003 | A1 |
20040024070 | Michael et al. | Feb 2004 | A1 |
20040038745 | Ahlqvist | Feb 2004 | A1 |
20050069506 | Katusic et al. | Mar 2005 | A1 |
20050074610 | Kroll et al. | Apr 2005 | A1 |
20050136269 | Doehler et al. | Jun 2005 | A1 |
20050182174 | Michael et al. | Aug 2005 | A1 |
20060003166 | Wissing | Jan 2006 | A1 |
20060041097 | Herrwerth et al. | Feb 2006 | A1 |
20060073092 | Katusic et al. | Apr 2006 | A1 |
20060155089 | Ferenz et al. | Jul 2006 | A1 |
20060210495 | Meyer et al. | Sep 2006 | A1 |
20070003779 | Katusic et al. | Jan 2007 | A1 |
20070048205 | Katusic et al. | Mar 2007 | A1 |
20070059539 | Doehler et al. | Mar 2007 | A1 |
20070100153 | Brueckner et al. | May 2007 | A1 |
20070123599 | Eilbracht et al. | May 2007 | A1 |
20070172415 | Zimmermann et al. | Jul 2007 | A1 |
20070175362 | Gutsch et al. | Aug 2007 | A1 |
20070190306 | Herrwerth et al. | Aug 2007 | A1 |
20070202030 | Michael et al. | Aug 2007 | A1 |
20070287765 | Busch et al. | Dec 2007 | A1 |
20070299231 | Doehler et al. | Dec 2007 | A1 |
20080027202 | Ferenz et al. | Jan 2008 | A1 |
20080064782 | Doehler et al. | Mar 2008 | A1 |
20080076842 | Ferenz et al. | Mar 2008 | A1 |
20080166289 | Meyer et al. | Jul 2008 | A1 |
20080216708 | Herrwerth et al. | Sep 2008 | A1 |
20080305065 | Ferenz et al. | Dec 2008 | A1 |
20090007483 | Hansel et al. | Jan 2009 | A1 |
20090024374 | Zielinski et al. | Jan 2009 | A1 |
20090054521 | Herrwerth et al. | Feb 2009 | A1 |
20090071467 | Benitez et al. | Mar 2009 | A1 |
20090093598 | Venzmer et al. | Apr 2009 | A1 |
20090120328 | Michael et al. | May 2009 | A1 |
20090136672 | Panz et al. | May 2009 | A1 |
20100031852 | Herrwerth et al. | Feb 2010 | A1 |
20100034765 | Herrwerth et al. | Feb 2010 | A1 |
20100081763 | Meyer et al. | Apr 2010 | A1 |
20100126387 | Meyer et al. | May 2010 | A1 |
20100152350 | Meyer et al. | Jun 2010 | A1 |
20100210445 | von Rymon Lipinski et al. | Aug 2010 | A1 |
20100236451 | Michael et al. | Sep 2010 | A1 |
20100266651 | Czech et al. | Oct 2010 | A1 |
20100276626 | Seitzer | Nov 2010 | A1 |
20110030578 | Schulz et al. | Feb 2011 | A1 |
20110070175 | Herrwerth et al. | Mar 2011 | A1 |
20110091399 | Meyer et al. | Apr 2011 | A1 |
20110206623 | Wenk et al. | Aug 2011 | A1 |
20120015893 | Herrwerth et al. | Jan 2012 | A1 |
20120021960 | Wenk et al. | Jan 2012 | A1 |
20120027704 | Henning et al. | Feb 2012 | A1 |
20120152151 | Meyer et al. | Jun 2012 | A1 |
20120294819 | Herrwerth et al. | Nov 2012 | A1 |
20130071343 | Herrwerth et al. | Mar 2013 | A1 |
20130078208 | Herrwerth et al. | Mar 2013 | A1 |
20130171087 | Herrwerth et al. | Jul 2013 | A1 |
20130204021 | Hartung et al. | Aug 2013 | A1 |
20130259821 | Henning et al. | Oct 2013 | A1 |
20130267403 | von Rymon Lipinski et al. | Oct 2013 | A1 |
20130303673 | Michael et al. | Nov 2013 | A1 |
20130331592 | Hartung et al. | Dec 2013 | A1 |
20140134125 | Dahl et al. | May 2014 | A1 |
20150073069 | De Gans et al. | Mar 2015 | A1 |
20150094419 | Alzer et al. | Apr 2015 | A1 |
20160185918 | Hinzmann et al. | Jun 2016 | A1 |
20160222169 | Hinzmann et al. | Aug 2016 | A1 |
20180100071 | Duerr et al. | Apr 2018 | A1 |
Number | Date | Country |
---|---|---|
103261335 | Feb 2015 | CN |
104893242 | Sep 2015 | CN |
105111987 | Dec 2015 | CN |
105602310 | May 2016 | CN |
107099209 | Aug 2017 | CN |
25 24 309 | Dec 1976 | DE |
199112204 | Aug 1991 | WO |
199418277 | Aug 1994 | WO |
2004020334 | Mar 2004 | WO |
2009068379 | Jun 2009 | WO |
2011076518 | Jun 2011 | WO |
2012062559 | May 2012 | WO |
2016095196 | Jun 2016 | WO |
Entry |
---|
U.S. Pat. No. 5,429,873, Oct. 7, 1992, U.S. Appl. No. 07/957,362, Hans Deusser, et al. |
U.S. Pat. No. 5,384,194, Jan. 28, 1993, U.S. Appl. No. 08/012,163, Hans Deusser, et al. |
U.S. Pat. No. 5,419,928, Oct. 26, 1993, U.S. Appl. No. 08/141,083, Hans Deusser, et al. |
U.S. Pat. No. 5,501,933, May 19, 1994, U.S. Appl. No. 08/245,620, Hans Deusser, et al. |
U.S. Pat. No. 5,415,936, Jan. 28, 1993, U.S. Appl. No. 08/012,160, Hans Deusser, et al. |
U.S. Pat. No. 5,372,905, Oct. 26, 1993, U.S. Appl. No. 08/141,084, Hans Deusser, et al. |
U.S. Pat. No. 5,736,407, Jan. 8, 1997, U.S. Appl. No. 08/780,450, Thomas Hennig, et al. |
U.S. Pat. No. 5,746,347, Sep. 3, 1996, U.S. Appl. No. 08/697,857, Thomas Riedemann, et al. |
U.S. Pat. No. 6,436,715, Jun. 30, 2000, U.S. Appl. No. 09/607,952, Günther Michael, et al. |
U.S. Appl. No. 09/810,517, filed Mar. 19, 2001, 2001-0055639, Tassilo Moritz , Freiberg, et al. |
U.S. Appl. No. 09/740,039, filed Dec. 20, 2000, 2002-0037936, Güther Michael, et al. |
U.S. Pat. No. 7,282,236, Jul. 18, 2003, 2004-0024070, Günther Michael, et al. |
U.S. Appl. No. 11/741,381, filed Apr. 27, 2007, 2007-0202030, Günther Michael, et al. |
U.S. Appl. No. 10/417,137, filed Apr. 17, 2003, 2003-0206854, Andreas Gutsch, et al. |
U.S. Appl. No. 11/733,998, filed Apr. 11, 2007, 2007-0175362, Andreas Gutsch, et al. |
U.S. Appl. No. 10/175,142, filed Jun. 20, 2002, 2003-0124051, Sabine Servaty, et al. |
U.S. Pat. No. 7,465,431, Aug. 6, 2002, 2003-101659, Stipan Katusic, et al. |
U.S. Pat. No. 7,374,743, Aug. 22, 2005, 2007-0003779, Stipan Katusic, et al. |
U.S. Pat. No. 7,718,261, Aug. 24, 2004, 2005-0069506, Stipan Katusic, et al. |
U.S. Pat. No. 7,235,298, Feb. 1, 2005, 2006-0073092, Stipan Katusic, et al. |
U.S. Appl. No. 10/568,992, filed Feb. 21, 2006, 2006-0210495, Jürgen, Meyer,et al. |
U.S. Appl. No. 10/433,837, filed Jun. 9, 2003, 2004-0038745, Stein G. Ahlqvist, et al. |
U.S. Pat. No. 7,365,101, Sep. 15, 2004, 2005-0074610, Michael Kroll , et al. |
U.S. Appl. No. 11/013,639, filed Dec. 16, 2004, 2005-0136269, Hardi Döhler,et al. |
U.S. Pat. No. 7,438,836, Jan. 24, 2005, 2005-1082174, Günther Michael, et al. |
U.S. Pat. No. 8,153,098, Oct. 15, 2007, 2008-0166289, Jürgen, Meyer,et al. |
U.S. Pat. No. 7,442,666, Aug. 17, 2005, 2006-0041097-A1, Sascha Herrwerth, et al. |
U.S. Appl. No. 11/612,112, filed Dec. 18, 2006, 2007-0172415, Guido Zimmermann, et al. |
U.S. Pat. No. 7,553,465, Aug. 11, 2006, 2007-0048205, Stipan Katusic, et al. |
U.S. Pat. No. 7,598,334, Jan. 6, 2006, 2006-0155089, Michael Ferenz, et al. |
U.S. Appl. No. 11/530,562, filed Sep. 11, 2006, 2007/0059539, Hardi Doehler, et al. |
U.S. Pat. No. 7,605,284, Oct. 26, 2006, 2007/00100153, Arndt Brückner, et al. |
U.S. Appl. No. 11/593,733, filed Nov. 7, 2006, 2007/0123599, Christian Eilbracht, et al. |
U.S. Pat. No. 7,772,714, Oct. 30, 2008, 2009/0120328, Günther Michael,et al. |
U.S. Pat. No. 8,163,080, Oct. 27, 2009, 2010/0126387, Jügen Meyer, et al. |
U.S. Appl. No. 13/409,715, filed Mar. 1, 2012, 2012/0152151, Jürgen Meyer, et al. |
U.S. Pat. No. 7,759,402, Aug. 30, 2007, 2009/0093598, Joachim Venzmer,et al. |
U.S. Pat. No. 7,893,128, May 11, 2007, 2007/0287765, Stefan Busch, et al. |
U.S. Pat. No. 7,964,694, Jul. 27, 2007, 2008/0305065, Michael Ferenz, et al. |
U.S. Pat. No. 8,030,366, Sep. 6, 2007. 2008/0076842, Michael Ferenz,et al. |
U.S. Pat. No. 7,834,122, Jul. 27, 2007, 2008/0027202, Michael Ferenz,et al. |
U.S. Pat. No. 7,727,599, Sep. 4, 2007, 2008/0064782, Hardi Döhler,et al. |
U.S. Pat. No. 7,361,777, Feb. 12, 2007, 2007/0190306, Sascha Herrwerth, et al. |
U.S. Pat. No. 8,152,916, Nov. 17, 2009, 2010/0152350, Jürgen Meyer, et al. |
U.S. Appl. No. 12/165,735, filed Jul. 1, 2008, 2009/0007483, René Hänsel,et al. |
U.S. Pat. No. 8,631,787, Sep. 8, 2008, 2009/071467, Pablo Benitez, et al. |
U.S. Pat. No. 8,138,372, Jun. 12, 2008, 2009/0054521, Sascha Herrwerth,et al. |
U.S. Pat. No. 7,925,479, Jul. 20, 2007, 2009/0024374, Kurt Zielinski,et al. |
U.S. Appl. No. 12/674,831, filed May 9, 2011, 2011/0206623, Hans Henning Wenk,et al. |
U.S. Pat. No. 8,038,788, May 5, 2010, 2010/0236451, Güther Michael, et al. |
U.S. Pat. No. 8,084,633, Mar. 7, 2008, 2008/0216708, Sascha Herrwerth, et al. |
U.S. Appl. No. 12/370,733, filed Feb. 13, 2009, 2010/0210445, Tadeusz von Rymon Lipinski. |
U.S. Appl. No. 13/855,273, filed Apr. 2, 2013, 2013/0267403, Tadeusz von Rymon Lipinski. |
U.S. Pat. No. 8,617,529, Nov. 15, 2010, 2011/0070175, Sascha Herrwerth, et al. |
U.S. Pat. No. 8,466,248, Nov. 5, 2010, 2011/0091399, Jürgen Meyer, et al. |
U.S. Appl. No. 12/536,146, filed Aug. 5, 2009, 2010/0034765, Sascha Herrwerth, et al. |
U.S. Pat. No. 8,172,936, Aug. 5, 2009, 2010/0031852, Sascha Herrwerth, et al. |
U.S. Pat. No. 8,211,972, Sep. 11, 2009, 2010/0081763, Jürgen Meyer, et al. |
U.S. Pat. No. 8,642,525, Sep. 22, 2011, 2012/0015893, Sascha Herrwerth, et al. |
U.S. Pat. No. 8,685,376, Apr. 16, 2010, 2010/0266651, Karin Czech, et al. |
U.S. Appl. No. 13/260,657, filed Sep. 27, 2011, 2012/0021960, Hans Henning Wenk, et al. |
U.S. Pat. No. 8,841,400, Oct. 4, 2011, 2012/0027704, Frauke Henning, et al. |
U.S. Pat. No. 8,597,789, Aug. 5, 2010, 2011/0030578, Katharina Scchulz, et al. |
U.S. Pat. No. 8,778,319, Jul. 17, 2012, 2012/0294819, Sascha Herrwerth, et al. |
U.S. Pat. No. 9,073,818, Dec. 3, 2012, 2013/0078208, Sascha Herrwerth, et al. |
U.S. Appl. No. 13/701,737, filed Dec. 3, 2012, 2013/0071343, Sascha Herrwerth, et al. |
U.S. Pat. No. 8,882,901, Jul. 23, 2013, 2013/0303673, Günther Michael, et al. |
U.S. Pat. No. 9,616,007, Mar. 11, 2013, 2013/0171087, Sascha Herrwerth, et al. |
U.S. Appl. No. 13/992,311, filed Jun. 7, 2013, 2013/0259821, Frauke Henning, et al. |
U.S. Appl. No. 14/001,382, filed Aug. 23, 2013, 2013/0331592, Christian Hartung, et al. |
U.S. Pat. No. 9,138,385, Dec. 19, 2013, 2014/0134125, Verena Dahl, et al. |
U.S. Pat. No. 8,993,792, Feb. 4, 2013, 2013/0204021, Christian Hartung, et al. |
U.S. Pat. No. 9,663,622, Feb. 10, 2016, 2016/0185918, Dirk Hinzmann, et al. |
U.S. Pat. No. 9,617,390, Mar. 10, 2016, 2016/0222169, Dirk Hinzmann, et al. |
U.S. Pat. No. 9,353,289, Aug. 25, 2014, 2015/0073069, Berend-Jan De Gans, et al. |
U.S. Pat. No. 9,221,945, Sep. 24, 2014, 2015/0094419, Heiko Alzer, et al. |
Sep. 14, 2017, 2018/0100071, Georg Dürr, et al. |
European Search Report issued in EP 17 19 5099, dated Dec. 19, 2017. |
Database WPI Week 201776 Thomas Scientific, London, GB; AN 2017-61076W, XP002776361, 3 pages. |
Database WPI Week 201662 Thomas Scientific, London, GB; AN 2016-34980T, XP002776362, 2 pages. |
Database WPI Week 201662 Thomas Scientific, London, GB; AN 2015-80045U, XP002776363, 2 pages. |
Anonymous: “Evonik for composites; Products for efficiency and performance”, Apr. 1, 2008 (Apr. 1, 2008), Seiten 1-28, XP055042093, Gefunden im Internet: URL:http://composites.evonik.com/sites/dc/Downloadcenter/Evonik/Product/Composites/Composites_ 16_03_ 10_Doppel.pdf [gefunden am Oct. 24, 2012) 28 pages. |
M. Ettlinger, et al., Archiv der Pharmazie, Jan. 1987, vol. 320, 8 pages. |
J. Mathias and G. Wannemacher, Journal of Colloid and Interface Science vol. 125 Sep. 1988, 8 pages. |
Number | Date | Country | |
---|---|---|---|
20190106581 A1 | Apr 2019 | US |