Patent ID: 9080075
Filing Date: 2015-07-14
Classification: C08J,C08K,C08L,C09D,D21H,Y10T

Abstract:
1. A water- and oil-repellent paper sheet having improved fold resistance, said paper sheet comprising a paper substrate and a water- and oil-repellent, releasable silicone resin layer on at least one surface of the paper substrate, said paper sheet including a planar portion normally and a folded portion when folded, the planar portion exhibiting an oil resistance which is at least 9 in Kit value and the folded portion exhibiting an oil resistance which is at least 8 in Kit value, both as measured at 20° C. and a humidity 50% by J. TAPPI paper/pulp test No. 41-83, and the planar portion exhibiting a water repellency which is at least R8 and the folded portion exhibiting a water repellency which is at least R7, both as measured by J. TAPPI paper/pulp test No. 68:2000, said silicone resin layer us formed by coating a water- and oil-repellent composition on the surface of the paper substrate, said composition primarily comprising an aqueous silicone resin emulsion comprising: (a) 100 parts by weight of an organopolysiloxane containing at least two-silicon-bonded hydroxyl groups in a molecule, (b) 0.5 to 20 parts by weight of dicarboxylic acid base curing agent, (c) 1 to 50 parts by weight of silica, (d) 2 to 4 parts by weight of an organopolysiloxane containing long-chain alkyl and alkoxy groups, but free of hydroxyl; groups, and having the average compositional formula (3): wherein Q is each independently selected from hexyl, octyl, decyl, and dodecyl, Z is each independently selected from methoxy, ethoxy and —C (e) a surfactant in an effective amount to keep components (a)-(d) in emulsion form.