Crosslinkable stabilized composition for a nonwoven substrate and process for preparing the same

Patent metadata

Field	Value
Publication number	US-2025066963-A1
Application number	US-202218719297-A
Country	US
Kind code	A1
Filing date	Jan 5, 2022
Priority date	Jan 5, 2022
Publication date	Feb 27, 2025
Grant date	—

Abstract

A crosslinkable stabilized composition for a nonwoven substrate includes an aqueous dispersion of vinyl acetate-ethylene copolymers, a polyvinyl alcohol dispersion stabilizer, and a copolymer comprising maleic anhydride units or a copolymer comprising maleic acid units. The composition exhibits a free formaldehyde content of 5 ppm or less.

First claim

1 . A crosslinkable stabilized composition for a nonwoven substrate, comprising:
an aqueous dispersion of vinyl acetate-ethylene copolymers, a polyvinyl alcohol dispersion stabilizer, and a copolymer comprising maleic anhydride units or a copolymer comprising maleic acid units, wherein the composition exhibits a free formaldehyde content of 5 ppm or less.

2 . The crosslinkable stabilized composition of claim 1 , wherein the composition exhibits a viscosity of 4000 mPa-s or less when measured at 23° C. and using a no. LV-3 spindle at 60 revolutions per minute.

3 . The crosslinkable stabilized composition of claim 1 , wherein the copolymer further comprises ethylene units.

4 . The crosslinkable stabilized composition of claim 1 , wherein the composition does not comprise N-methylol acrylamide.

5 . The crosslinkable stabilized composition of claim 1 , wherein composition comprises the copolymer in an amount of 0.5 wt % or more based on the total weight of monomers in the aqueous dispersion.

6 . The crosslinkable stabilized composition of claim 1 , wherein the polyvinyl alcohol dispersion stabilizer comprises a partially hydrolysed polyvinyl acetate having an average degree of hydrolysis of 80 to 96 mol %.

7 . The crosslinkable stabilized composition of claim 2 , wherein the composition exhibits a viscosity of 200 to 4000 mPa-s when measured at 23° C. and using a no. LV-3 spindle at 60 revolutions per minute.

8 . The crosslinkable stabilized composition of claim 2 , wherein the viscosity exhibited by the composition does not undergo a change of more than 60% after 75 days at 20° C.

9 . The crosslinkable stabilized composition of claim 3 , wherein the copolymer comprises ethylene maleic anhydride polymers.

10 . The crosslinkable stabilized composition of claim 8 , wherein the viscosity exhibited by the composition does not undergo a change of more than 25% after 75 days at 20° C.

11 . Process for preparing a crosslinkable stabilized composition for a nonwoven substrate, comprising:
providing a copolymer comprising maleic anhydride units or a copolymer comprising maleic acid units; providing vinyl acetate and ethylene; polymerizing vinyl acetate and ethylene in the presence of a polyvinyl alcohol dispersion stabilizer to form vinyl acetate-ethylene copolymers; and forming a composition comprising the vinyl acetate-ethylene copolymers and that has a formaldehyde level of 5 ppm or less.

12 . The process of claim 11 , wherein the vinyl acetate-ethylene copolymers are provided in an aqueous dispersion that is formed by emulsion polymerization.

13 . The process of claim 11 , wherein the copolymer is mixed with the polyvinyl alcohol dispersion stabilizer prior to forming the vinyl acetate-ethylene copolymers.

14 . The process of claim 11 , wherein the copolymer is provided in an amount of 0.5 wt % or more based on total weight of monomers in the aqueous dispersion.

15 . The process of claim 11 , wherein the composition exhibits a viscosity of 50 to 4000 mPa-s when measured at 23° C. and using a no. LV-3 spindle at 60 revolutions per minute.

16 . The process of claim 11 , wherein the copolymer further comprises ethylene units.

17 . The process of claim 12 , further comprising mixing the copolymer with the aqueous dispersion to form the composition.

18 . The process of claim 14 , wherein the copolymer is provided in an amount of 0.5 to 5 wt % based on total weight of monomers in the aqueous dispersion.

19 . A nonwoven product, comprising:
a nonwoven substrate treated with the composition of claim 1 , wherein the nonwoven product exhibits a wet tensile strength that is 25% or more of a dry tensile strength exhibited and a formaldehyde content of 1.5 ppm or less.

20 . The nonwoven product of claim 19 , wherein the copolymer and vinyl acetate-ethylene copolymers are crosslinked.

Assignees

• Wacker Chemie Ag

Inventors

• Sagl Dennis
• Boylan John
• Plummer Jennifer

Classifications

• D06M15/263

  of unsaturated carboxylic acids; Salts or esters thereof · CPC title

• D06M15/233

  aromatic, e.g. styrene · CPC title

• D04H1/64

  the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions · CPC title

• D04H1/587 Primary

  characterised by the bonding agents used · CPC title