Paper and paper-like products including water insoluble fibrous carboxyalkyl cellulose
AssigneeWeyerhaeuser Company
InventorsRichard A. Jewell, David W. Park
Life of this patent
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Abstract
The invention relates to paper and similar products made with at least a portion of the papermaking furnish being essentially water insoluble carboxyethyl cellulose fibers. A cationic additive material, such as a polyamide epichlorohydrin wet strength resin or cationic starch, is also required. From 2-100% of the modified fiber is used in conjunction with a usual papermaking fiber. The D.S. of the carboxyethylated fiber is in the range of about 0.01-0.3, preferably about 0.025-0.10. A notable feature of paper products made with the fiber/cationic additive system is an improved ratio of wet to dry tensile and burst strengths compared with sheets made from unmodified fiber.
Claims10
A paper or paper-like product which comprises:
- a fibrous, essentially water insoluble carboxyalkyl cellulose in which the alkyl group is at least two carbon atoms in length and the D.S. is in the range of 0.01-0.3 used in an amount of 2-100% of the dry weight of the fibers present;
- unsubstituted cellulose fibers in an amount of 98-0% of the dry weight of the fibers present;
- and
- a cationic additive selected from the group consisting of polyethyleneimine, cationic starch, and polyamide-epichlorohydrin resins, said additive being present in an amount of 0.1-4.0% based on total fiber.
A paper or paper-like product having an improved wet to dry burst strength ratio which comprises:
- a fibrous, essentially water insoluble carboxyethyl cellulose having a D.S. in the range of 0.01-0.3 in an amount of 2-100% of the dry weight of the fibers present;
- unsubstituted cellulose fibers in an amount of 98-0% of the dry weight of the fibers present;
- and
- a polyamide-epichlorohydrin resin present in an amount of 0.1-4.0% based on total fiber.
Dependencies are inferred from the claim text.