Salt-sensitive vinyl acetate binder compositions and fibrous article incorporating same
AssigneeCelanese International Corporation
InventorsRajeev Farwaha, Steven P. Pauls, Sr., Pavneet S. Mumick
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Abstract
A salt sensitive polymeric binder for use in fibrous webs, where the binder contains a copolymer incorporating the residue of vinyl acetate, a carboxylic acid, and a vinyl ester of a saturated aliphatic monocarboxylic acid having between 6 and 18 carbon atoms in the carboxylic acid moiety. The copolymer is neutralized at least to the extent that it is water soluble. The binders are particularly suitable for strengthening non-woven fibrous webs in disposable articles such as wet-wipes, personal care products, diapers, and the like.
Claims40
A binder solution for a fibrous web, said solution comprising:
- (a) an aqueous solvent medium;
- and
- (b) a binder composition comprising a salt sensitive copolymer that incorporates the residue of:
- (i) from about 60 to about 90 weight percent of vinyl acetate;
- (ii) from about 2 to about 20 weight percent of a carboxylic acid monomer;
- and
- (iii) from about 5 to about 30 percent vinyl ester of the formula:
- where R1 and R2 are alkyl groups collectively having between 3-14 carbon atoms,
- wherein said copolymer is neutralized with base at least to the point where it is water soluble,
- and wherein said binder composition has a characteristic wet strength of at least about 75 gf/in in a 10% NaCl solution, and a characteristic wet strength of less than 50 gf/in in deionized water.
A method of producing a disposable fibrous web, said method comprising the steps of:
- (a) preparing a salt sensitive binder polymer by copolymerizing fromabout 60-90 weight percent vinyl acetate, from about 2-20 weight percent of a carboxylic acid monomer, and from about 5 to about 30 percent of a vinyl ester having the formula,
- where R1 and R2 are alkyl groups collectively having between 3-14 carbon atoms;
- (b) neutralizing the polymer with base at least to the point where it is water soluble;
- (c) dissolving said binder polymer into an aqueous solution;
- and
- (d) applying said solution to the fibrous web,
- wherein the binder has a characteristic wet strength of at least about 75 gf/in in an aqueous solution of 10 wt. % NaCl, and has less than 50 gf/in in deionized water.
A disposable article comprising a fibrous web which is provided with a salt sensitive binder composition, wherein the binder composition includes a copolymer that incorporates the residue of:
- (a) from about 60 to about 90 weight percent of vinyl acetate;
- (b) from about 2 to about 20 weight percent of carboxylic acid;
- and
- (c) from about 5 to about 30 percent of a vinyl ester having the formula
- wherein R1 and R2 are alkyl groups collectively having between 3-14 carbon atoms,
- wherein said copolymer is neutralized with base at least to the point where it is water soluble,
- and wherein the binder composition has a characteristic wet strength of at leastabout 75 gf/in in an aqueous solution of 10 wt. % NaCl, and a characteristic wet strength of less than 50 gf/in in deionized water.
Dependencies are inferred from the claim text.