Bicomponent strengthening system for paper

Abstract

The present invention is directed to a bicomponent strengthening system and the paper webs produced with the bicomponent strengthening system. Through use of the strengthening system, paper webs may be produced in which the strength characteristics of the web may be specifically tailored. The first component of the system comprises a polymer having at least about 1.5 m-eq primary amine functionality per gram of polymer and a molecular weight of at least about 10,000 Daltons. The second component may be either a polymeric anionic compound or a polymeric aldehyde functional compound. For example, the polyamine polymer component may be a polyvinylamine or polysaccharide having primary amine functionality. In one embodiment, the second component may be a cationic polymeric aldehyde functional compound. For example, the second component may be a cationic glyoxylated polyacrylamide. In another embodiment, the second component may be a polymeric anionic compound comprising carboxy functionality.

Description

BACKGROUND OF THE INVENTION [0001] In the art of tissue making and papermaking in general, many additives have been proposed for specific purposes, such as increasing wet strength, improving softness, or control of wetting properties. For instance, in the past, wet strength agents have been added to paper products in order to increase the strength or otherwise control the properties of the product when contacted with water and / or when used in a wet environment. For example, wet strength agents are added to paper towels so that the paper towel may be used to wipe and scrub surfaces after being wetted without the towel disintegrating. Wet strength agents are also added to facial tissues to prevent the tissues from tearing when contacting fluids. In some applications, wet strength agents are also added to bath tissues to provide strength to the tissues during use. When added to bath tissues, however, the wet strength agents should not prevent the bath tissue from disintegrating when dr...

AI Technical Summary

Benefits of technology

[0014] The bicomponent strengthening system of the present invention may be adjusted so as to provide either temporary or permanent wet strength to a paper web. For instance, the bicomponent strengthening system may provide temporary wet strength to a paper web such that the paper web may have less than about 70% of the initial wet tensile index remaining after soaking in water for about one hour. In one embodiment, the paper web may have less than about 60% of the initial wet tensile index remaining after soaking in water for about one hour. For example, in one embodiment, the bicomponent strengthening system of the present invention can act as a temporary wet strength agent and the paper web thus produced may have a wet tensile index after soaking in water for about one hour of less than about 2 Nm / g.

[0015] In an alternative embodiment, the bicomponent strengthening system may provide permanent wet strength to a paper web such that the paper web may have more than about 70% of the initial wet tensile index remaining after soaking in water for about one hour. In one embodiment, the paper web may have more than about 80% of the initial wet tensile index remaining after soaking in water for about one hour.

[0022] In one embodiment, the present invention is directed to a method for decreasing the amount of low molecular weight organic chlorinated compounds in the waste stream of a paper manufacturing process. In this embodiment, the invention includes eliminating the addition of chlorinated strengthening agents to a paper manufacturing process, and replacing the chlorinated strengthening agents with the bicomponent strengthening system of the present invention. For example, in one embodiment, the bicomponent strengthening system of the present invention can replace polyamide epichlorohydrin strengthening agents in a paper manufacturing process. Definitions and Test Methods

Problems solved by technology

When added to bath tissues, however, the wet strength agents should not prevent the bath tissue from disintegrating when dropped in a commode and flushed into a sewer line.

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