US 5,633,300 AGranted

Enhancement of paper dry strength by anionic and cationic guar combination

AssigneeHercules Incorporated

InventorSunil P. Dasgupta

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Abstract

A process for making paper to enhance the dry strength of the paper produced without substantially reducing its softness comprising adding to a bleached pulp furnish, separately or together, (1) an anionic polymer selected from the group consisting of carboxymethyl guar, carboxymethyl bean gum, carboxymethyl hydroxyethyl guar, and a carboxymethyl hydroxypropyl guar, with (2) a cationic polymer selected from the group consisting of a cationic guar, a cationic acrylamide copolymer, a cationic bean gum, a cationic amineepichlorohydrin wet strength resin, and both a cationic wet strength resin and at least one of the other said cationic polymers, a composition for adding to a paper-making pulp slurry comprising the said polymers, a method for making the said composition, and a paper product containing the said composition, are disclosed.

Claims17

Dependent claims

A composition comprising:

(1) an anionic polymeric component selected from the group of polymers consisting of carboxymethyl guar, carboxymethyl bean gum, carboxymethyl hydroxyethyl guar, and a carboxymethyl hydroxypropyl guar, end (2) a cationic polymeric component selected from the group of polymers consisting of cationic wet strength resin and cationic wet strength rein combined with additional cationic polymer selected from the group consisting of cationic guar, a cationic acrylamide copolymer, and a cationic bean gum, the cationic wet strength resin being an amine polymer-epichlorohydrin resin selected from the group consisting of a polyamide-epichlorohydrin (PAE) resin, a polyalkylenepolyamine-epichlorohydrin (PAPAE) resin, and an amine polymer-epichlorohydrin (APE) resin, in which amine groups have been alkylated with epichlorohydrin to produce a polyamine-epichlorohydrin resin that has azetidinium or epoxide functionality.

Dependencies are inferred from the claim text.

Facts

Application: 08/483,616Filed 7 Jun 1995 · continuation
Priority: 23 Dec 1991
Granted: 27 May 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

D21H 21/18
Characterised by function or properties in or on the paper: reinforcing agents
C08G 73/022
Preparatory process: from polyamines and epihalohydrins
C08G 73/0293
Polyamidoamines: quaternisation of polyamidoamines
C08L 5/14
Compositions of polysaccharides or of their derivatives not provided for in groups C08L1/00 or C08L3/00: hemicellulose; Derivatives thereof

Family

Serial812,534Parent of this continuation-in-part · filed 23 Dec 1991
Serial202,417Parent of this continuation · filed 28 Feb 1994
US 5,502,091 AParent of this continuation
US 5,338,407 AParent of this continuation-in-part
US 5,633,300 AThis patent

From the US filing history. Foreign family members aren’t listed.