Polyvinyl alcohol stabilized acetate ethylene copolymer dispersions as adhesives for creped webs

Patent metadata

Field	Value
Publication number	US-10968569-B2
Application number	US-201716097018-A
Country	US
Kind code	B2
Filing date	Apr 21, 2017
Priority date	Apr 28, 2016
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

A crepe process includes applying an adhesive composition to a nonwoven web, drying, and creping the nonwoven web on a creping drum. The improvement includes using an adhesive composition that includes an aqueous copolymer dispersion obtained by emulsion polymerization of a monomer mixture including 65 to 94.5% by weight of vinyl acetate, 5 to 30% by weight of ethylene, (meth)acrylamide, and 0.1 to 4% by weight of an N-methylol functional monomer. The N-methylol functional monomer constitutes from 25 to 85% by weight of the combined amounts of acrylamide and N-methylol functional monomer, which combined amounts constitute from 0.5 to 5% by weight of the monomer mixture. The emulsion polymerization is performed in the presence of 1 to 10% by weight of polyvinyl alcohol, based on the total weight of all monomers used for the polymerization. The adhesive composition does not include alkylphenol ethoxylates, phosphate ester surfactants, or sodium laureth sulfate.

First claim

The invention claimed is:

1. In a crepe process comprising applying an adhesive composition to a nonwoven web, drying, and creping the nonwoven web on a creping drum, the improvement comprising applying an adhesive composition comprising an aqueous copolymer dispersion obtained by emulsion polymerization of a monomer mixture comprising 65 to 94.5% by weight of vinyl acetate, 5 to 30% by weight of ethylene, (meth)acrylamide, and 0.1 to 4% by weight of an N-methylol functional monomer, wherein the N-methylol functional monomer constitutes from 25 to 85% by weight of the combined amounts of (meth)acrylamide and N-methylol functional monomer, said combined amounts constituting from 0.5 to 4% by weight of the monomer mixture;
wherein the emulsion polymerization is performed in the presence of 1 to 10% by weight of polyvinyl alcohol, based in each case on the total weight of all monomers used for the polymerization;
wherein the adhesive composition does not comprise any of the following types of surfactant:
alkylphenol ethoxylate, phosphate ester, or sodium laureth sulfate, and wherein the polyvinyl alcohol has a degree of hydrolysis in a range from 86% to 89 mol %, wherein the polyvinyl alcohol is present in an amount of from 2.5 to 10% by weight.

2. The process of claim 1 , wherein the polyvinyl alcohol is present in an amount of from 3 to 10% by weight.

3. In a crepe process comprising applying an adhesive composition to a nonwoven web, drying, and creping the nonwoven web on a creping drum, the improvement comprising applying an adhesive composition comprising an aqueous copolymer dispersion obtained by emulsion polymerization of a monomer mixture comprising 65 to 94.5% by weight of vinyl acetate, 5 to 30% by weight of ethylene, (meth)acrylamide, and 0.1 to 4% by weight of an N-methylol functional monomer, wherein the N-methylol functional monomer constitutes from 25 to 85% by weight of the combined amounts of (meth)acrylamide and N-methylol functional monomer, said combined amounts constituting from 0.5 to 4% by weight of the monomer mixture;
wherein the emulsion polymerization is performed in the presence of 1 to 10% by weight of polyvinyl alcohol, based in each case on the total weight of all monomers used for the polymerization;
wherein the adhesive composition does not comprise any of the following types of surfactant:
alkylphenol ethoxylate, phosphate ester, or sodium laureth sulfate, and wherein the polyvinyl alcohol has a degree of hydrolysis in a range from 86% to 89 mol %, wherein the adhesive composition contains no ethoxylated secondary alcohols and no ethoxylated branched primary alcohols as emulsifiers.

Assignees

• Wacker Chemie Ag
• Boylan John Richard
• Sagl Dennis

Inventors

• Boylan John Richard
• Sagl Dennis

Classifications

• B31F1/12 Primary

  Crêping · CPC title

• D21H21/146

  Crêping adhesives · CPC title

• D04H1/587

  characterised by the bonding agents used · CPC title

• D04H1/74

  the fibres being orientated, e.g. in parallel {(anisotropic fleeces)} · CPC title

• C08L29/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title