Patent ID: 9739008
Date: 2017-08-22
CPC Classifications: B05D,C09J,D06M

Claim:
1. A method for treating a filament or yarn comprising: (a) exposing the filament or yarn to a first mixture of reagents comprising first multi-functional isocyanate oligomers and first multi-functional epoxy oligomers, wherein the ratio of total isocyanate groups to total epoxy groups in the first mixture is in the range of from 0.8 to 1.2, (b) heating the exposed filament or yarn at a temperature of at least 100 degrees C. whereby the first epoxy oligomers and first isocyanate oligomers crosslink and form a network on the surface of the filament or yarn, (c) exposing this treated filament or yarn to a second mixture of reagents comprising second multi-functional isocyanate oligomers and second multi-functional epoxy oligomers wherein the ratio of total isocyanate groups to total epoxy groups in the second mixture is in the range of from 0.8 to 1.2, and (d) heating the exposed filament or yarn of at a temperature of at least 100 degrees C. whereby the second epoxy oligomers and the second isocyanate oligomers crosslink and form a network on the outer surface of the network formed by the first epoxy and first isocyanate oligomers, with the proviso that double bonds present in the second epoxy and second isocyanate oligomers do not participate in the crosslinking reaction, wherein the first and second multi-functional isocyanate oligomers of the first and second mixtures are different.