Silane-containing binder for composite materials
View Patent ↗The present invention relates to a binder for composite materials comprising cellulose- or lignocellulose-containing materials, which is based on the components (i) at least one binder from the series consisting of organic resins, isocyanates, natural or near-natural binders and (ii) at least one composition based on an aminoalkylsilane. The invention furthermore relates to a composite material which is at least based on a cellulose- or lignocellulose-containing material and the abovementioned binder, a process for the production of such a composite material and the use of the binder system according to the invention for the production of wood-based materials.
1. A binder for a composite material comprising cellulose- or lignocellulose-containing material, the binder comprising an aqueous solution of:
(i) 5-50% by weight of a natural binder selected from the group consisting of a wheat protein, a tannin, and potato pulp, and
(ii) 0.1 to 10% by weight of a substantially alcohol-free hydrolysis product of a cocondensate consisting of one or more aminoalkylsilanes of formula (I)
R 1 R 2 N(CHR 4 ) a Si(R 3 ) r (OR) 3-r (I),
wherein
R 1 and R 2 are each independently H or an optionally substituted linear, branched or cyclic C 1 - to C 20 -alkyl group or an aryl group or an aminocarbyl group,
R 3 is H or a linear or branched C 1 -C 8 -alkyl group, groups
R 4 are each independently H or methyl,
a is from 1 to 10, groups
R are each independently a linear or branched C 1 - to C 8 -alkyl group, and
r is 0 or 1 or 2,
wherein
the amino functions are neutralized with from 0.9 to 3.6 mol of HCOOH or H 3 CCOOH per mole of amino group, and
a content of (i) and (ii) in the aqueous binder solution is from 1 to 80% by weight.
2. The binder according to claim 1 , further comprising a component selected from the group consisting of a paraffin- or wax-based water repellent, a flameproofing agent, a biocidal substance and a fragrance.
3. The binder according to claim 1 , wherein the natural binder is a wheat protein.
4. The binder according to claim 3 , wherein the amount of wheat protein is 8-15% by weight and the amount of the aminoalkylsilane cocondensate is 1-6% by weight.
5. The binder according to claim 1 , wherein the natural binder is a tannin.
6. The binder according to claim 1 , wherein the natural binder is a potato pulp.
7. A composite material comprising at least one cellulose- or lignocellulose-containing material and the binder according to claim 1 .
8. A composite material according to claim 7 , comprising at least one natural or near-natural cellulose- or lignocellulose-containing material from the series consisting of industrial wood, forestry industry timber, used or recycled wood, wood particles, woodchips, wood fibers, wood wool, wood dust, sawdusts, planing chips, cutting chips, slabs, veneer wastes, splinters, particle material from annual plants, or a mixture of at least two of the abovementioned materials.
9. A composite material according to claim 7 , the cellulose- or lignocellulose-containing fiber material originating from hardwood, softwood, palm fibers and annual plants.