Wet-strength of wet glass fiber mats by treatment with anionic polyelectrolytes

Claim 1

In the manufacture of glass fiber mat products by the wet-laid process at a high rate of production wherein an aqueous dispersion of individual glass fibers is formed from bundles of glass fibers of about 1/4 to 3 inches in length and an amine oxide dispersant or cationic quaternary ammonium dispersant compound having the formula: ##STR4## where R 1 , R 2 , R 3 and R 4 are selected from the group consisting of aliphatic and aromatic hydrocarbon radicals, straight chain or branched, or two or more form a cyclic group, saturated or unsaturated, substituted or unsubstituted, at least two of said radicals containing at least 10 carbon atoms each, being the same or different, the sum of the carbon atoms in R 1 , R 2 , R 3 and R 4 being at least 22 and less than about 48, and X is an anion at a concentration of about 5-500 ppm and at a fiber consistency of about 0.001 to 3%, which dispersion is passed through a mat-forming screen to form a freshly-prepared wet-mat of said fibers, the improvement which comprises: applying to said freshly-prepared wet mat an anionic polyelectrolyte having the structural formula: ##STR5## wherein each R can be the same or different and is selected from the group consisting of hydrogen, lower alkoxy, hydroxy, lower alkylcarbonyloxy, hydroxy lower alkyl, lower alkyl, phenyl, carboxy, lower alkoxycarbonyl, lower alkylcarbonyloxy lower alkyl, amido and carbamyl, with the proviso that only one R can be lower alkyl or phenyl; wherein X, Y and Z can be the same or different and are each selected from the group consisting of hydrogen, lower alkyl, carboxy, lower alkoxycarbonyl, with the proviso that at least one of X, Y and Z be selected from the group consisting of carboxy and lower alkoxycarbonyl, and, when X and Y are each lower alkoxycarbonyl, Z is carboxy or lower alkoxycarbonyl, with the further proviso that only one of X, Y and Z can be lower alkyl; a is 0 to less than 1 and a+b=1; and n is a whole integer which ranges from about 5 to about 10,000 thereby to improve the wet-strength properties of said freshly-prepared wet-mat so that it can be readily handled and transferred during other steps in said process, including the drying and binder application units of the production line for said process, into a finished glass fiber mat product.