Method for strengthening cellulosic substrates, cellulosic nonwoven wipes, and paper filter stock
AssigneeRohm and Haas Company
InventorsCharles Thomas Arkens, Scott Lind Egolf, Robert David Gleim, Oscar Hsien-Hsiang Hsu, Kenneth John Wiesinger
Life of this patent
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Abstract
This invention relates to a method for strengthening a cellulosic substrate by treating the substrate with a formaldehyde-free curable aqueous composition and curing the composition. The cellulosic substrates include, for example, paper oil- and air-filter stock, rayon nonwoven wipes, cellulosic laminating stock, cotton woven fabrics, and wood flakes suitable to be consolidated into flakeboard.
Claims5
A method for strengthening a cellulosic substrate comprising contacting said substrate with a formaldehyde-free curable aqueous composition comprising (a) a polyacid containing at least two carboxylic acid groups, anhydride groups, or the salts thereof;
- and (b) a phosphorous-containing accelerator, wherein said carboxyl groups, anhydride groups, or salts thereof are neutralized to an extent of less than about 35% with a fixed base;
- and heating said composition.
A method for increasing the solvent- and water-wet strength and dry strength of a cellulosic nonwoven wipe comprising contacting said nonwoven with a formaldehyde-free curable aqueous composition comprising (a) a polyacid containing at least two carboxylic acid groups, anhydride groups, or the salts thereof;
- and (b) a phosphorous-containing accelerator, wherein said carboxyl groups, anhydride groups, or salts thereof are neutralized to an extent of less than about 35% with a fixed base;
- and heating said composition.
A method for increasing the solvent- and water-wet strength and dry strength of paper oil- and air-filter stock comprising contacting said stock with a formaldehyde-free curable aqueous composition comprising (a) a polyacid containing at least two carboxylic acid groups, anhydride groups, or the salts thereof;
- and (b) a phosphorous-containing accelerator, wherein said carboxyl groups, anhydride groups, or salts thereof are neutralized to an extent of less than about 35% with a fixed base;
- and heating said composition.
Dependencies are inferred from the claim text.