GRAFT COPOLYMERS

摘要

1489725 Co-crosslinked starch/polyamide polymer products NATIONAL STARCH & CHEMICAL CORP 28 Jan 1976 [3 Feb 1975] 03354/76 Heading C3U [Also in Division D2] A copolymer for use as a paper wet strength additive is obtained by the condensation of (a) a polyamideamine substrate of total amine to carboxylic equivalent ratio of 1À75 : 1 to 3À0 : 1 and a reduced viscosity in methanol at 1% w./v. of 0À05 to 0À20 dl./gm., the substrate being the reaction product of a polyalkylene polyamine, a difunctional acid or ester and optionally an alkyl lactam, acrylic or methacrylic ester, or beta-lactone, (b) a water dispersible starch and (c) as condensing agent-epichlorohydrin, epibromohydrin, 1,3 - dichloropropanol, 1,2 - dichloroethane, 1,4 - dichloro - 2 - butene, divinyl sulphone, methylene bis-acrylamide, glyoxal and divinyl ether, the wt. ratio of starch to polyamideamine being from 1 : 9 to 9 : 1 and the amount of condensing reagent being 0À75 to 2À0 moles per equivalent of amine in the substrate. The starch may be dextrinized, oxidized, thin boiling or an ether or ester derivative. The preferred reagents are a polyalkylene polyamine of formula NH 2 -[-(CH 2 ) n -NR] m -H, where R is H, -CH 3 , or CH 2 CH 3 , n is 2-6 and m is 1-6, a dibasic acid or ester where R1 is (CH 2 ) p and p is 2-9 or and R11 is H or -CH 3 and optionally an alkyl lactam of formula where R 1 is a divalent alkylene radical containing 3-12 C atoms and R 2 is H or an alkyl radical containing 1-6 C atoms; an acrylic or methacrylic ester of formula where R 3 is H or -CH 3 and R 4 is a 1-4 C alkyl radical; and beta lactones of formula where R 5 is H or -CH 3 . The most preferred condensing agents are epichlorohydrin or 1,2- dichloroethane.