Patent Application
20190257078
The present invention relates to composite products manufactured using a binder composition which comprises a carbohydrate component, possibly a crosslinker, possibly reaction product of carbohydrate component and crosslinker; it also relates to such binders obtained from said binder composition.
While known carbohydrate based binders and composite material made therewith show interesting mechanical properties, there always is a need to further improve said properties, more specifically under humid or wet conditions.
In accordance with one of its aspects, the present invention provides a binder composition as defined in claim 1. Further aspects are defined in other independent claims. The dependent claims define preferred or alternative embodiments.
The term “binder composition” as used herein means all ingredients applied to the matter to be bound and/or present on the matter to be bound, notably prior to curing, (other than the matter and any moisture contained within the matter) including reactants, solvents (including water), any carbohydrate component, any crosslinker and any additives.
The term “binder” is used herein to designate a thermoset binder resin obtained from the “binder composition”.
The term “cured” means that the components of the binder composition have been subjected to conditions that lead to chemical change, such as covalent bonding, hydrogen bonding and chemical crosslinking, which may increase the cured product's durability and solvent resistance, and result in thermoset material.
The term “dry weight of the binder composition” as used herein means the weight of all components of the binder composition other than any water that is present (whether in the form of liquid water or in the form of water of crystallization).
The term “carbohydrate component” as used herein means a carbohydrate or derivative thereof, including monosaccharides, disaccharides, oligosaccharides and polysaccharides. Examples are glucose, fructose, xylose, sucrose, maltose, trehalose, sorbitol, dextrines, maltodextrins, amylose, amylopectine, starch, modified starches, cellulose, hemicellulose, and pectins, hydrolysis products thereof, precursors thereof that form the relevant carbohydrates or derivatives thereof in situ, and mixtures thereof. The carbohydrate component may be a reducing sugar reactant or a non-reducing sugar that generates a reducing sugar in situ.
The term “crosslinker” as used herein comprises compounds that are capable of reacting with the carbohydrate component to form ramifications or reticulations of the said carbohydrate component.
Phenalkamines are known as curing agents and may be obtained by the reaction of an alkylphenol with aliphatic polyamines and formaldehyde. The polyamine advantageously is an amine having two or more primary amine functionalities, possibly substituted with additional secondary amine functionalities.
A preferred phenalkamine shows the general formula below
wherein
R1 is a straight or branched, saturated or unsaturated alkyl group comprising 12 to 24 C-atoms
R2 and R3 are linear or branched alkanediyl having 2 to 20 C-atoms, cycloaliphatic groups or contain aromatic groups and
x is an integer ranging from 0 to 5 and y is an integer ranging from 1 to 5.
Suitable polyamines for reaction with alkylphenol and formaldehyde show the general formula
H2N—((—R2—NH—)x—R3—)y—NH2
wherein R2 and R3 are linear or branched alkanediyl having 2 to 20 C-atoms, cycloaliphatic groups or contain aromatic groups, and x is an integer ranging from 0 to 5 and y is an integer ranging from 1 to 5.
Examples of polyamines include, but are not limited to: ethyleneamines such as 1,2-ethanediamine (EDA), N-(2-aminoethyl)-1,2-ethanediamine (DETA), N,N-bis(2-amino-ethyl)-I,2-ethanediamine (TETA), N-(2-aminoethyl)-N′-[(2-amino-ethyl)amino-ethyl]-I,2-ethanediamine (TEPA), aminoethylpiperazine, and higher polyethylenepolyamines, 1,3-benzenedimethanamine (MXDA—metaxylylene diamine); 1,3-cyclohexanedimethanamine (1,3-BAC); 1,2-diaminocyclohexane (DACH); norbornanediamine; isophorone diamine; 5-amino-I,3,3-trimethylcyclo-hexanemethanamine (IPDA); trimethylhexamethylenediamine (TMD); 1,3-pentanediamine; 2-methyl-I,5-pentanediamine; 1,6-hexanediamine (HMDA) and 4,4′-diaminodicyclohexylmethane (PACM).
The binder composition may be used in the manufacturing of composite products, such as wood boards, for example wood particle boards, medium density fibreboard (MDF), chip boards or orientated strand board (OSB), and plywood. The binder may be used to bond abrasive particles together and/or onto a backing sheet or to bond fibers, such as woven and non-woven natural, synthetic, textile or mineral fibers, for instance glass fibers or mineral wool fibers. Such bonded mineral fibers, for instance mineral glass wool or stone wool fibers, may be used in the manufacturing of thermal and/or acoustic insulating materials.
A wood particle board is a composite material manufactured from wood particles, for example wood chips, sawmill shavings and/or saw dust at varying particle sizes held together by a binder and used especially for the manufacture of furniture, such as cabinets, kitchens and bathroom furniture. Generally, wood particle board (which is sometimes referred to as “chipboard”) is produced by mixing wood particles and a binder composition, e.g. a thermo-curable resin, subsequently forming the resulting mixture into a sheet or mat and compressing said sheet or mat under elevated temperatures.
Plywood is a composite sheet material manufactured from thin layers of wood glued together by a binder, adjacent wood layers having their wood grain rotated by approx. 90 degrees to one another.
When used as a binder in wood boards, such as plywood, particle boards, fiber boards, the solid content of the aqueous binder composition may range from 50 to 95 w %, preferably 50 to 90 w %, more preferably 55 to 85 w % or even 60 to 80 w %, based upon the weight of the total aqueous binder composition.
The binder may also be used to bond synthetic or natural fibers, for instance mineral fibers, such as glass fibers, glass wool or stone wool. In view of the manufacture of a fiber mat, such as for insulating products, for instance, an aqueous binder composition is applied onto the fibers, e.g. by spraying, and the binder impregnated mineral fibers are deposited as a mat and subsequently subjected to heat for curing of the binder composition, hence forming an assembly of bonded fibers.
When used in the manufacture of a fiber based composite, the solid content of the invention aqueous binder composition may range from 5 to 95 w %, advantageously from 8 to 90 w %, preferably from 10 to 85 w %, based on the weight of the total aqueous binder composition. More specifically, when used as a binder for mineral wool insulation, the solid content of the aqueous binder composition may be in the range from 5 to 25 w %, preferably from 8 to 20 w %, more preferably from 10 to 20 w % or even 12 to 18 w %, based on the weight of the total aqueous binder composition.
In preferred embodiments, the present invention provides improved product and/or binder performance, notably mechanical performance, under wet or humid conditions. This makes the binders particularly suitable where sensitivity to water or humidity is an important criteria, for example wood boards.
It has been found that the phenalkamine component reacts with the carbohydrate component and/or the cross-linker and confers water-resistance properties to the binder through its hydrophobic groups, and hence to the composite product incorporating said binder. As a result, the binder composition of the invention may be used to form a water-resistant silicone-free binder and composite incorporating said binder.
The crosslinker may advantageously be selected from mono- or polycarboxylic acids, including monomeric and polymeric polycarboxylic acids, such as polyacrylates, and nitrogenous components. The nitrogenous component may be selected from NH3, an inorganic amine or an organic amine comprising at least one primary amine group, as well as salts thereof. It may comprise NH3 used as such (e.g. in form of an aqueous solution), or an inorganic or organic ammonium salt, for example ammonium sulfate (AmSO4), ammonium phosphate, e.g. diammonium phosphate, ammonium chloride, ammonium nitrate or ammonium citrate. The nitrogenous component may also be a polyamine, that is any organic compound having two or more amine groups, which may independently be substituted or unsubstituted. For example, the polyamine may be a primary polyamine. As used herein, a “primary polyamine” is an organic compound having two or more primary amine groups (—NH2). Within the scope of the term primary polyamine are those compounds which can be modified in situ or isomerize to generate a compound having two or more primary amine groups (—NH2). The primary polyamine may be a molecule having the formula H2N-Q-NH2, wherein Q is an alkanediyl, cycloalkanediyl, heteroalkanediyl, or cycloheteroalkanediyl, each of which may be optionally substituted. For example, Q may be an alkanediyl group selected from —C2-C24—, an alkanediyl group selected from —C2-C9—, or an alkanediyl group selected from —C3-C7—. According to a preferred embodiment, Q is a C6 alkanediyl. According to another embodiment, Q may be a cyclohexanediyl, cyclopentanediyl or cyclobutanediyl, or a divalent benzyl radical. In this context, it should be noted that certain authors prefer using the term “alkyl” instead of the chemically more correct “alkanediyl” nomenclature; the same chemical group is meant. As used herein, the term “alkanediyl” means a chain of carbon atoms, which may optionally be branched, preferably of limited length, including —C1-C24—, —C1-C12—, —C1-C8—, —C1-C6—, and —C1-C4—. Shorter alkanediyl groups may add less lipophilicity to the compound and accordingly will have different reactivity towards the reducing sugar reactant and/or solubility.
As used herein, the term “cycloalkanediyl” means a chain of carbon atoms, which may optionally be branched, where at least a portion of the chain is cyclic and also includes polycyclic structures, for example, cyclopropanediyl, cyclopentanediyl, cyclohexanediyl, 2-methylcyclopropanediyl, 2-ethylcyclopentanediyl, adamantanediyl. Furthermore, the chain forming cycloalkanediyl is advantageously of limited length, including —C3-C24—, —C3-C12—, —C3-C8—, —C3-C6—, and —C5-C6—. Shorter alkanediyl chains forming cycloalkanediyl may add less lipophilicity to the compound and accordingly will have a different behaviour.
As used herein, the term “heteroalkanediyl” means a chain of atoms that includes both carbon and at least one heteroatom, and is optionally branched. Examples of such heteroatoms include nitrogen, oxygen, and sulfur. In certain variations, said hetero-atoms also include phosphorus, and selenium. In one embodiment, the heteroalkanediyl is a polyether. As used herein, the term “cycloheteroalkanediyl”, includes a chain of atoms that includes both carbon and at least one heteroatom, such as heteroalkanediyl, and may optionally be branched, where at least a portion of the chain is cyclic. Particularly, examples of cycloheteroalkanediyl include divalent tetrahydrofuryl, pyrrolidinyl, tetrahydropyranyl, piperidinyl, morpholinyl, piperazinyl, homopiperazinyl, quinuclidinyl.
“Optionally substituted” means the replacement of one or more hydrogen atoms with other functional groups. Such other functional groups may include amino, hydroxyl, halo, thiol, alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl, nitro, sulfonic acids and derivatives thereof, carboxylic acids and derivatives thereof.
The primary polyamine may be a diamine, triamine, tetramine, or pentamine, for example: a triamine selected from a diethylenetriamine, 1-piperazineethanamine, or bis(hexamethylene)triamine; triethylenetetramine; or tetraethylenepentamine. One feature of the primary polyamine is that it may possess low steric hindrance. For example, 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,12-diaminododecane, 1,4-diaminocyclohexane, 1,4-diaminobenzene, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1-piperazine-ethanamine, 2-methyl-pentamethylenediamine, 1,3-pentanediamine, and bis(hexamethylene)triamine, as well as 1,8-diaminooctane have low steric hindrance.
Preferably, the nitrogenous component comprises or consists of 1,6-diaminohexane (hexamethylenediamine, HMDA) or 1,5-diamino-2-methylpentane (2-methyl-pentamethylenediamine.
In another embodiment, the nitrogenous component comprises or consists of a polyether-polyamine, which may be a diamine or a triamine, for example a trifunctional primary amine having an average molecular weight of 440 known as Jeffamine T-403 Polyetheramine (e.g. Huntsman Corporation). In yet another embodiment, the nitrogenous component may comprise or consist of a polymeric polyamine, for example chitosan, polylysine, polyethylene imine, poly(N-vinyl-N-methyl amine), polyaminostyrene, polyvinyl amine (which can be a homopolymer or a copolymer). Proteins, such as whey protein or soy protein, may also be used.
The binder composition may comprise a binder composition as described in any of WO 2007/014236, WO 2009/019232, WO 2009/019235, WO 2011/138458, WO 2011/138459 or WO 2013/150123, each of which is hereby incorporated by reference.
In the binder composition, the carbohydrate component is advantageously present in an amount ranging from 30%, preferably from 40%, preferably from 50%, more preferably from 60%, more preferably from 70%, even more preferably from 80% by dry weight of the binder composition, to less than 97% more preferably less than 95% by dry weight of the binder composition.
The crosslinker may make up:
less than 50% or 40%, preferably less than 30%, more preferably less than 25% by dry weight of the binder composition; and/or
at least 2.5%, preferably at least 5%, more preferably at least 10% by dry weight of the binder composition.
The binder composition may comprise at least 25%, and preferably at least 40%, at least 50% or at least 60% by dry weight of: (a) carbohydrate component and crosslinker and/or (b) curable reaction product(s) of carbohydrate component and crosslinker.
When the carbohydrate is a reducing sugar and the crosslinker is an amino compound, the ratio of carbonyl groups in the reducing sugar reactant(s) to reactive amino groups in the nitrogen-containing reactant(s) may be in the range of 5:1 to 1:2. For example, the ratio of carbonyl groups to reactive amino groups may be in the range of 5:1 to 1:1.8, 5:1 to 1:1.5, 5:1 to 1:1.2, 5:1 to 1:1, 5:1 to 1:0.8 and 5:1 to 1:0.5. Further examples include ratios such as 4:1 to 1:2, 3.5:1 to 1:2, 3:1 to 1:2, 2.5:1 to 1:2, 2:1 to 1:2 and 1.5:1 to 1:2. In this context, the term “reactive amino group” means any amino group in the crosslinker which is capable of reacting with the carbohydrate component. Specifically, examples of such reactive amino groups include primary and secondary amino groups, amide groups, imine and imide groups, as well as cyanate and isocyanate.
The crosslinker and the reducing sugar reactant(s) (or their reaction product(s)) may be Maillard reactants that react to form Maillard reaction products, notably melanoidins when cured. Curing of the binder composition may comprise or consist essentially of Maillard reaction(s). The cured binder is preferably a thermoset binder and is preferably substantially water insoluble.
The reducing sugar reactant may comprise: a monosaccharide, a monosaccharide in its aldose or ketose form, a disaccharide, a polysaccharide, a triose, a tetrose, a pentose, xylose, an hexose, dextrose, fructose, a heptose, a sugar, molasses, starch, starch hydrolysate, cellulose hydrolysates, reaction product(s) thereof or mixtures thereof as well as non-reducing sugars and derivatives thereof that generate a reducing sugar in situ, like sucrose or molasses. The reducing sugar reactant(s), or carbohydrate reactant(s) that yield the reducing sugar reactant(s) may have a dextrose equivalent of at least about 50, at least about 60, at least about 70, at least about 80 or at least about 90. The reducing sugar reactant may comprise or consist of high fructose corn syrup (HFCS).
The binder composition may comprise one or more adjuvants, for example waxes, dyes, dedusters, release agents and formaldehyde scavengers (notably urea, tannins, quebracho extract, ammonium phosphate bisulfite). It may further comprise, if so desired, appropriate catalysts that catalyse the reaction between carbohydrate component and crosslinker. Such catalysts may be selected from known catalysts, such phosphorous containing salts or acids. Examples are sodium hypophosphite, phosphates etc.
The binder composition is preferably free of, or comprises no more than 5 wt % or no more than 10 wt % urea formaldehyde (UF), melamine urea formaldehyde (MUF) and/or phenol formaldehyde.
The binder composition preferably does not comprise any added formaldehyde. It may be “substantially formaldehyde free”, that is to say that it liberates less than 5 ppm formaldehyde as a result of drying and/or curing (or appropriate tests simulating drying and/or curing); more preferably it is “formaldehyde free”, that is to say that it liberates less than 1 ppm formaldehyde in such conditions.
The binder composition of the invention may be applied to wood particles, abrasive particles, sheet material, or fibers, which may then be subjected to heat and/or pressure to cure the components of the binder composition in order to form a cured thermoset binder resin which holds the particles, sheet or fibers together in a composite material.
The binders of the invention may be used to bond a collection of non or loosely assembled matter. The collection of matter includes any collection of matter which comprises fibers selected from mineral fibers, slag wool fibers, stone wool fibers, glass fibers, aramid fibers, ceramic fibers, metal fibers, carbon fibers, polyimide fibers, polyester fibers, rayon fibers, and cellulosic fibers. Further examples of collection of matter include particulates such as coal, sand, cellulosic fibers, wood shavings, saw dust, wood pulp, ground wood, wood chips, wood strands, wood layers, other natural fibers, such as jute, flax, hemp, straw, wood veneers, facings and other particles, woven or non-woven materials. According to a specific embodiment of the invention, the collection of matter is selected from wood particles and mineral fibers.
In one illustrative embodiment, the binder composition of the invention may be used to make thermal insulation products, comprising mineral fibers. In such an application, the fibers are bonded together such that they become organized in a fiberglass mat which may then be processed into an insulation product. In such an application, the fibers are generally present in an amount ranging from 70 to 99% by total weight of the insulation product, notably from 80 to 99% or from 85 to 99%.
According to another embodiment of the invention, the binder may be used to bond cellulosic particles, such as cellulosic fibers, wood shavings, wood pulp and other materials commonly used to manufacture composite wood boards, including fiber boards, particle boards, oriented strand boards, plywood etc. Such wood boards show nominal thicknesses ranging from 6 to 30 mm and a modulus of Elasticity of at least about 1000 N/mm2, bending strength of at least about 5 N/mm2 and/or an internal bond strength of at least 0.10 N/mm2. In such applications, the binder content in the final wood board may range from about 5 to 30% wt with respect to the total weight of the wood board notably from 9 to 20%.
The aqueous binder composition may be applied onto the fiber or particulate material by spray application. Other possible techniques include roll application or mixing and/or tumbling the collection of matter with the binder composition. As water evaporates the binder composition may form a gel that bonds the particulate material together when arranged into a desirable assembly. When curing, the polyphenolic macromolecular compound and the polyamine functional compound are caused to react to form an essentially water insoluble macromolecular binder. Curing thus imparts increased adhesion, durability and water resistance as compared to uncured binder. Curing may be effected at temperatures between ambient and up to 280° C.
The invention will be described here below with reference to examples and Figures.
In the Figures:
As mentioned earlier, the phenalkamine component appears to confer water-resistance properties to the binder incorporating it and to composite materials made with the invention binder. The advantageous properties of invention binder compositions and composite materials will be shown in more details herein below.
Glucose and ammonium sulphate were dissolved in water individually and combined at ambient temperature under stirring such as to obtain a glucose:ammonium sulphate ratio of 85:15 wt %, based on dry weight. A fraction of the obtained composition was retained as control (control 1). Another fraction was withdrawn and 3 wt % of polydimethylsiloxane based water repellent (Basildon Chemicals BC2631 which is a co-emulsion of blended reactive polydimethylsiloxanes for use on glass wool and mineral substrates) were added (based on dry weight) to form control 2. A further fraction of the initial binder composition was withdrawn and 3 wt % phenalkamine (RAC950 supplied by Royce International) were added as a 10% dispersion in water (B1). To a further fraction, 1.5 wt % BC2631 and 1.5 wt % RAC950 as a 10% aqueous dispersion were added (B2).
The binder compositions were applied onto a glass microfiber Whatman GF/A filter as follows: the glass filter was completely submerged for 5 seconds into a binder composition, fixed with a wire. The glass filter was then withdrawn and suspended in a frame placed in a drying oven at 200° C. for 10 min. After curing, the filter was weighted. The obtained composite product (bonded glass filter) was placed into a 400 ml beaker and 200 ml water were added. A glass rod was placed on top of the filter and the filter was left submerged in water for 1 hour. After 1 hour, the filter was withdrawn and water allowed to drip for 2 minutes. Excess water was removed using absorbent paper. The filter was weighted again. Water absorption (%) is calculated as 100×(mass wet filter−mass dry filter)/mass dry filter. The test results are summarized in
As can be seen, and as expected, the addition of siloxane based water-repellent additive significantly reduces water uptake (compare control 1 and control 2). The addition of phenalkamine even further reduces water uptake (compare B1 and control 1). The combination of silicon based water repellent and phenalkamine performs similarly to the sole phenalkamine additive (see B2).
The compositions Control 1 and B1 were subjected to dry and wet tensile strength tests as follows: suitable strips of impregnated and cured glass veils were placed onto a testometric machine (M350-10CT) and tested using a 50 kg load cell at an automated test speed of 10 mm/min controlled by winTest Analysis software. Various parameters such as maximum load at peak, stress at peak and modulus (stiffness) were evaluated by the software, and data presented as an average of 8 samples with standard deviation. The average maximum load at peak or stress at peak defined as the bond strength. For the wet test, the cured veil samples were placed in an autoclave (J8341, Vessel: PV02626 with associated safety valve, door interlock and integrated pipework) system. Samples were treated at 90% humidity and at a temperature ranging from 40° C. to 110° C. (full cycle), at a pressure of up to 2.62 bar, for 3 hours. The samples were dried completely in order to ensure no moisture remains onto the veils. The autoclave treated samples were tested for bond strength by means of testometric machine (M350-10CT) described here above, and the results were compared with those of untreated samples. The test results are summarized in
The same experiment was repeated with a binder composition comprising glucose and HMDA (hexamethylenediamine) in 85/15 ratio (B4) and a binder composition comprising glucose and HMDA (hexamethylenediamine) in 85/15 ratio plus 3 wt % phenalkamine (RAC950) added (B5) as a 10% aqueous dispersion. The results are shown in
Example 1 was repeated with a binder composition comprising glucose and ammonium sulphate in a ratio of 85:15 wt %, based on dry weight. A fraction of the obtained composition was retained as control. Another fraction was withdrawn and 1 wt % of polydimethylsiloxane based water repellent (Basildon Chemicals BC2631 which is a co-emulsion of blended reactive polydimethylsiloxanes for use on glass wool and mineral substrates) were added (based on dry weight) to form a second control. A further fraction of the initial binder composition was withdrawn and 0.5 wt % phenalkamine (RAC950 supplied by Royce International) were added as a 10% dispersion in water together with 0.5 wt % of the above polydimethylsiloxane.
The water pick-up results are shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 1610063.8 | Jun 2016 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/063147 | 5/31/2017 | WO | 00 |
