Air drying process

A hydrophilic polymer having the formula ##STR13## where n is an integer from 2 to 6, m is an integer from 4 to 10, M is either absent or a group capable of activating the adjacent double bond, and R.sub.1 and R.sub.2 are each hydrogen or C.sub.1 -C.sub.4 alkyl groups.

A hydrophilic polymer having the empirical formula ##STR14## wherein n is an integer from 2 to 6, m is an integer from 6 to 10 and Q is a moiety with the empirical formula ##STR15## wherein g is a fraction up to 0.5, Y is a halogen or a quaternary ammonium, sulfonium or phosphonium radical and R.sub.1 and R.sub.2 are each hydrogen or C.sub.1 to C.sub.4 alkyl groups.

A process for enhancing inter-fiber bonding in a fibrous substrate which comprises applying to the substrate a hydrophilic polymer having a backbone comprising at least one segment with the formula ##STR16## wherein A is a moiety terminating in the residue of an active hydrogen-containing group selected from the group consisting of alcoholic hydroxyl, amide, carboxylic acid and secondary amine with an active hydrogen atom removed, E is a moiety containing a radical having an activated olefinic unsaturation either .alpha.,.beta. or .beta.,.gamma. to the activating group, n is the number of adjacent, (as the term is hereinbefore defined), segments in the polymer having this formula, m is an integer, and m and n are at least one provided that where either is less than 4, the other is at least 4;

• and curing the polymer in the presence of oxygen.

A process for improving the wet strength of a paper substrate which comprises treating the substrate with from 15 to 30 kilograms per metric ton of substrate of a composition comprising a hydrophilic polymer having the formula ##STR20## wherein A is a moiety terminating in the residue of an active hydrogen-containing group selected from the group consisting of alcoholic hydroxyl, amide, carboxylic acid and secondary amine with the active hydrogen atom removed, E is a moiety containing a radical having an activated olefinic unsaturation either .alpha.,.beta. or .beta.,.gamma. to the activating group, n is the number of adjacent, (as the term is hereinbefore defined), segments in the polymer having this formula;

• m is an integer, and m and n are at least one provided that where either is less than 4, the other is at least 4;
• said composition comprising the polymer and a methanol/water solvent in which the volume ratio of methanol to water is from 95:5 to 40:60 and the weight ratio of polymer to solvent is from 0.5:99.5 to 20:80.

A process for improving the wet strength of a paper substrate which comprises treating the substrate with from 15 to 30 kilos per metric ton of a hydrophilic polymer having the empirical formula ##STR21## wherein n is an integer from 1 to 6, m is an integer from 6 to 10 and Q is a moiety with the empirical formula ##STR22## wherein g is a fraction up to 0.5, Y is a halogen or a quaternary ammonium radical and R.sub.1 and R.sub.2 are each hydrogen or C.sub.1 to C.sub.4 alkyl groups;

• said polymer being added in the form of a composition comprising from 0.5 to 20% by weight of the polymer and from 99.5 to 80% by weight of a solvent comprising from 80 to 50% by volume of methanol and correspondingly from 20 to 50% by volume of water, said composition further containing from 0.001 to 0.01% by weight of a carboxylic acid salt of a metal selected from cobalt and manganese.