The invention relates to a composition and method for manufacture of paper, board, tissue or the like. The composition comprises an amphoteric polymer component, which has a weight average molecular weight of at least 600 000 g/mol, preferably at least 1 000 000 g/mol, more preferably at least 2 000 000 g/mol, and at least one synthetic cationic polymer component, which is a copolymer of a polyamidoamine and has a weight average molecular weight ≤550 000 g/mol, preferably ≤500 000 g/mol, more preferably ≤400 000 g/mol and dispersity index more than 15, preferably more than 20, more preferably more than 25.

The present disclosure generally relates to glyoxalated polyacrylamide (GPAM) compositions, methods of preparation and methods of use thereof, particularly in the paper industry. Moreover, the present disclosure generally pertains to cationic GPAM compositions, methods of preparation and methods of use thereof in papermaking applications and in products such as paper-based products, wherein the cationic GPAM compositions may provide increased wet and/or dry strength to the paper-based products, and wherein such cationic GPAM compositions optionally require a reduced volume of an aqueous carrier for storage or transport compared to a volume of an aqueous carrier needed for conventional GPAMs used in papermaking.

The invention relates to a process for manufacturing wet strength resins, which process comprises a polyamide reactor (11) for amidation, an EHH reactor (12) for epihalohydrin addition, a maturing tank (15) for maturing, a ring-closure and cross-linking reactor (16) for polymerization, and in the process a reaction mixture containing at least EHH and at least polyaminoamide epihalohydrin adduct is manufactured. The process further comprises between the maturing tank (15) and the ring-closure and cross-linking reactor (16) a membrane unit (20) comprising a membrane by dividing the reaction mixture stream from the membrane unit (20) into two streams: a permeate stream (202) comprising un-reacted epi-halohydrin and a reject stream (201) comprising EHH/PAIM adduct guided to the ring-closure and cross-linking reactor (16).

The invention relates to a process for manufacturing wet strength resins, which process comprises a polyamide reactor (11) for amidation, an EHH reactor (12) for epihalohydrin addition, a maturing tank (15) for maturing, a ring-closure and cross-linking reactor (16) for polymerization, and in the process a reaction mixture containing at least EHH and at least polyaminoamide epihalohydrin adduct is manufactured. The process further comprises between the maturing tank (15) and the ring-closure and cross-linking reactor (16) a membrane unit (20) comprising a membrane by dividing the reaction mixture stream from the membrane unit (20) into two streams: a permeate stream (202) comprising un-reacted epi-halohydrin and a reject stream (201) comprising EHH/PAIM adduct guided to the ring-closure and cross-linking reactor (16).

An aramid-based paper comprising at least 90 wt. % of aramid material, the aramid material including at least one of aramid shortcut and aramid fibrid, the paper including at most 40 wt. % aramid pulp, calculated on the total amount of aramid material, wherein the paper includes 0.1-10 wt. % of polyamido-amine epichlorohydrin (PAE). It has been found that the incorporation of 0.1-10 wt. % of polyamido-amine epichlorohydrin (PAE) into an aramid-based paper including at least 90 wt. % of aramid material calculated on the weight of the paper not including the PAE, the aramid material including at least one of aramid shortcut and aramid fibrid, the paper including at most 40 wt. % aramid pulp, leads to a surprising improvement of the z-strength and the tear strength of the paper.

An aramid-based paper comprising at least 90 wt. % of aramid material, the aramid material including at least one of aramid shortcut and aramid fibrid, the paper including at most 40 wt. % aramid pulp, calculated on the total amount of aramid material, wherein the paper includes 0.1-10 wt. % of polyamido-amine epichlorohydrin (PAE). It has been found that the incorporation of 0.1-10 wt. % of polyamido-amine epichlorohydrin (PAE) into an aramid-based paper including at least 90 wt. % of aramid material calculated on the weight of the paper not including the PAE, the aramid material including at least one of aramid shortcut and aramid fibrid, the paper including at most 40 wt. % aramid pulp, leads to a surprising improvement of the z-strength and the tear strength of the paper.

Resin systems and methods for making and using same are provided. The method for making a paper product can include contacting a plurality of pulp fibers with a resin system. The resin system can include a first polyamidoamine-epihalohydrin resin and a second resin that can include a second polyamidoamine-epihalohydrin resin, a urea-formaldehyde resin, or a mixture thereof to produce a paper product. The first resin and the second resin can be sequentially or simultaneously contacted with the plurality of pulp fibers. The period for sequential addition between the first resin and the second resin is about 1 second to about 1 hour.

Resin systems and methods for making and using same are provided. The method for making a paper product can include contacting a plurality of pulp fibers with a resin system. The resin system can include a first polyamidoamine-epihalohydrin resin and a second resin that can include a second polyamidoamine-epihalohydrin resin, a urea-formaldehyde resin, or a mixture thereof to produce a paper product. The first resin and the second resin can be sequentially or simultaneously contacted with the plurality of pulp fibers. The period for sequential addition between the first resin and the second resin is about 1 second to about 1 hour.

The invention provides a polyamide resin composition (1) containing a polyamide (A) and a free volume modifier (B), and having a free volume, as measured according to a positron annihilation method, of 0.0545 nm.sup.3 or less. The invention also provides a polyamide resin composition (2) prepared by adding from 0.005 to 1.200 parts by mass of a polysilsesquioxane (B) whose main chain is comprised of siloxane bonds, to 100 parts by mass of a polyamide (A) that contains a diamine unit including an aromatic diamine unit represented by the following general formula (I) in an amount of 70 mol % or more and a dicarboxylic acid unit including at least one of a linear aliphatic dicarboxylic acid unit represented by the following general formula (II-1) and an aromatic dicarboxylic acid unit represented by the following general formula (II-2) in a total amount of 50 mol % or more: ##STR00001##
wherein n in the general formula (II-1) indicates an integer of from 2 to 18, and Ar in the general formula (II-2) represents an arylene group.

The present disclosure provides for a paper product. The paper product has: (a) from about 20% to about 90% by weight of the dry fiber basis of the paper product of a refined soft wood pulp fiber mixture, (b) pulp fibers selected from the group consisting of hard wood fibers, non-wood fibers, recycled fibers, synthetic polymer fibers, bleached eucalyptus kraft fibers, and combinations thereof; and, (c) not more than about 10% by weight moisture.