CPC B27N 3/002 (2013.01) [C08G 18/3206 (2013.01); C08G 18/348 (2013.01); C08G 18/4277 (2013.01); C08G 18/672 (2013.01); C08G 18/73 (2013.01); C08G 18/755 (2013.01); C08G 18/758 (2013.01); C08L 75/06 (2013.01); C09J 175/06 (2013.01); C08L 2201/54 (2013.01)] | 18 Claims |
1. A no-added formaldehyde composite wood product binder, comprising agent A and agent B, wherein the agent A is an isocyanate binder, and the agent B is an aqueous dispersion of a polyester-based aliphatic polyurethane and/or a modified polyester-based aliphatic polyurethane;
wherein the modified polyester-based aliphatic polyurethane is the polyester-based aliphatic polyurethane modified with a polymerizable vinyl monomer based polymer, which is obtained by chemically bonding of the polyester-based aliphatic polyurethane with a polymer of polymerizable vinyl monomers;
wherein the isocyanate binder as agent A is a polymethylene polyphenyl polyisocyanate and/or a derivative thereof, and has a NCO value of 20-33%, a functionality of 2.1-3.3, and a viscosity of 50-2000 cp (25° C.); the derivative of the polymethylene polyphenyl polyisocyanate is obtained by reacting a polymethylene polyphenyl polyisocyanate with a polyol;
wherein the polyester-based aliphatic polyurethane in the aqueous dispersion of a polyester-based aliphatic polyurethane as agent B has a number average molecular weight of 50000 to 500000 Dalton, and a glass transition temperature of −30° C.-5° C.;
wherein the weight ratio of agent A to agent B is 1-5:1;
wherein the aqueous dispersion of a polyester-based aliphatic polyurethane and/or a modified polyester-based aliphatic polyurethane as agent B has a solid content of 20 to 60 wt %.
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