# US 2020/0399508 A1 · Viscoelastic foam with slow recovery time

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- Number: US 2020/0399508 A1
- Document ID: US20200399508A1
- Status: Published application
- Kind: A1
- Application number: 16/979,302
- Filed: 2019-03-08
- Published: 2020-12-24
- Earliest claimed: 2018-03-13
- Assignees: Dow Global Technologies LLC; Rohm and Haas Company
- Applicants: Dow Global Technologies LLC; Rohm and Haas Company
- Inventors: Kaoru Aou; William A. Koonce; Qinghao Meng; Christopher Thiede; William Griffith, Jr.
- Web page: https://patentgrep.com/patent/US20200399508A1

## CPC

- C08J 9/42: with macromolecular compounds
- C09J 7/385: {Acrylic polymers}
- C09J 7/26: Porous or cellular plastics
- C08G 2110/0008: flexible
- C08G 2110/005: < 50kg/m3
- C08G 2110/0058: ≥50 and <150kg/m3
- C08J 2205/05: Open cells, i.e. more than 50% of the pores are open
- C08J 2205/06: Flexible foams
- C08J 2333/04: esters
- C08J 2375/04: Polyurethanes
- C09J 2301/302: the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
- C09J 2400/243: in the substrate
- C09J 2433/00: Presence of (meth)acrylic polymer
- C09J 2475/006: in the substrate
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

Recovery times of flexible polyurethane foams are increased by treatment with a pressure sensitive adhesive. An emulsion or dispersion of the adhesive in an aqueous carrier liquid is impregnated into the foam, with subsequent removal of the carrier. This invention is of special interest when the glass transition temperature of the starting foam is 16° C. or lower.

## Claims

### Claim 1

A viscoelastic foam comprising a) an open-celled flexible polyurethane foam having internal surfaces coated with b) a pressure sensitive adhesive having a glass transition temperature of at most 0° C., wherein the pressure sensitive adhesive constitutes 1.5 to 35% of the combined weights of a) and b).

### Claim 2 (depends on 1)

The viscoelastic foam of claim 1 wherein the pressure sensitive adhesive constitutes up to 25% of the combined weights of a) and b).

### Claim 3 (depends on 2)

The viscoelastic foam of claim 2 wherein the open-celled flexible polyurethane foam has a glass transition temperature of at most 16° C.

### Claim 4 (depends on 4)

The viscoelastic foam of claim 4 wherein the open-celled flexible polyurethane foam has an airflow of at least 0.944 L/s, a density of 32 to 64 kg/m3 and a resilience of no more than 20%.

### Claim 5 (depends on 4)

The viscoelastic foam of claim 4 wherein the open-celled flexible polyurethane foam has a recovery time of up to 2 seconds.

### Claim 6 (depends on 4)

The viscoelastic foam of claim 4 wherein the pressure sensitive adhesive is not isocyanate-based.

### Claim 7 (depends on 4)

The viscoelastic foam of claim 4 wherein the pressure sensitive adhesive is an acrylic polymer having a glass transition temperature of no higher than −20° C.

### Claim 8 (depends on 4)

The viscoelastic foam of claim 4 which has a recovery time at least 200% of the recovery time of the open-celled flexible polyurethane foam.

### Claim 9

A method of reducing the recovery time of an open-celled polyurethane foam, comprising
(1) impregnating a starting flexible polyurethane foam with a solution or emulsion of a pressure sensitive adhesive in a liquid carrier, the pressure sensitive adhesive having a glass transition temperature of no greater than 0° C., to wet internal surfaces of the foam and form an impregnated foam, and
(2) removing the liquid carrier from the impregnated foam to produce a coated foam having a coating of the pressure sensitive adhesive on the internal surfaces of the flexible polyurethane foam.

### Claim 10 (depends on 9)

The method of claim 9 wherein the pressure sensitive adhesive is not isocyanate-based.

### Claim 11 (depends on 10)

The method of claim 10 wherein the pressure sensitive adhesive is an acrylic polymer having a glass transition temperature of no higher than −20° C.

### Claim 12 (depends on 9)

The method of claim 9 wherein step (1) is performed by steps including:
(1-A) immersing the starting flexible polyurethane foam into the solution or emulsion of the pressure sensitive adhesive and/or by applying the solution or emulsion of the pressure sensitive adhesive to a surface of the starting flexible polyurethane foam and allowing it to penetrate into the starting flexible polyurethane foam; and
1-B) mechanically compressing the foam while immersed or otherwise in contact with the solution or emulsion.

### Claim 13 (depends on 9)

The method of claim 9 wherein the coating of the pressure sensitive adhesive constitutes 1.5 to 35% of the weight of the coated foam.

### Claim 14 (depends on 9)

The method of claim 9 wherein the recovery time of the coated foam is at least 200% of the recovery time of the starting flexible polyurethane foam.

### Claim 15 (depends on 9)

A flexible polyurethane foam made according to the method of claim 9.