Foam gasket and bonding tape based on polyurethane dispersions

Patent metadata

Field	Value
Publication number	US-2017334103-A1
Application number	US-201715668330-A
Country	US
Kind code	A1
Filing date	Aug 3, 2017
Priority date	Jun 13, 2013
Publication date	Nov 23, 2017
Grant date	—

Abstract

A polymer sheet includes a polyurethane core. The polyurethane core has a first major surface and a second major surface opposite the first major surface. The polymer sheet can have at least one functional layer overlying a major surface. The polymer sheet has a thickness t PS . The polyurethane core has a thickness t PC . In embodiments t PC can be at least 0.3 t PS . The polyurethane core can have at least one of the following property:
(i) a Scratch Resistance Rating, as further described herein, of not greater than about 10 wt %, (ii) an elongation at break of at least 200%, (iii) a tensile strength at break of at least 0.3 MPa, (iv) a loss of tensile strength of not greater than about 30% when exposed to UV light according to standard SAE J1960 (Rev. August 2003).

The polymer sheet can be used for gaskets or bonding tapes.

First claim

1 . A polymer sheet comprising:
a polyurethane core, having a first major surface and a second major surface opposite the first major surface; and at least one functional layer, wherein the polymer sheet has a thickness t PS and the polyurethane core has a thickness t PC , wherein t PC is at least 0.3 t PS , wherein the polyurethane core comprises polyurethane polymer, wherein the polyurethane core a Scratch Resistance Rating of not greater than about 10 wt %.

2 . The polymer sheet according to claim 1 , wherein the polymer sheet has a primary aspect ratio of at least about 400.

3 . The polymer sheet according to claim 1 , wherein the functional layer is selected from the group of a permanent liner, a release liner, a topcoat, an adhesive, or any combination thereof.

4 . The polymer sheet according to claim 3 , wherein the permanent liner includes a thermoplastic selected from polyethylene, polyester, polyimide, or any combination thereof.

5 . The polymer sheet according to claim 4 , wherein the polyethylene includes ultra-high molecular weight polyethylene.

6 . The polymer sheet according to claim 3 , wherein the permanent liner, the release liner, or the adhesive layer has a thickness of in a range of about 0.01 mm to about 0.1 mm.

7 . The polymer sheet according to claim 3 , wherein the release liner includes a polyester, polyethylene, polypropylene, paper, or any combination thereof.

8 . The polymer sheet according to claim 3 , wherein the topcoat as thickness in a range of from 0.001 mm to about 0.01 mm.

9 . The polymer sheet according to claim 3 , wherein the adhesive is a pressure sensitive adhesive selected from an acrylic adhesive, a silicon adhesive, a rubber hot melt adhesive, an acrylic copolymer, a rubber acrylic copolymer, or any combination thereof.

10 . The polymer sheet according to claim 1 , wherein the polymer sheet is in form of a roll.

11 . The polymer sheet according to claim 1 , wherein the polyurethane core has a thickness in a range of about 0.2 mm to about 3.0 mm.

12 . The polymer sheet according to claim 1 , wherein the loss of tensile strength when exposed to UV light according to standard SAE J1960 (Rev. August 2003) is not greater than about 25%.

13 . The polymer sheet according to claim 1 , wherein the polyurethane core has at least one of the following performance data:
(i) a compression force deflection at 25% compression of at least 3 kPa; (ii) a force to compress at 25% compression of at least 6 kPa and; (iii) a recovery time of not greater than 5 seconds according to ASTM D3574 (iv) a compression set of not greater than 10% after compression of 50% at room temperature for 22 hours according to ASTM D3574.

14 . The polymer sheet according to claim 1 , wherein the polyurethane core has a discoloration ΔE of not greater than 4.0.

15 . The polymer sheet according to claim 1 , wherein the polyurethane core has a yellowing Δb of not greater than 2.

16 . The polymer sheet according to claim 1 , wherein the polyurethane core is essentially free of pigment.

17 . The polymer sheet according to claim 1 , wherein the polyurethane core has an elongation at break of at least 200%.

18 . The polymer sheet according to claim 1 , wherein the polyurethane core has a tensile strength at break of at least 0.3MPa.

19 . An assembly comprising:
a first member and a second member; and a gasket compressed between the first member and the second member, wherein the gasket includes a polyurethane core, having a first major surface and a second major surface opposite the first major surface; and the gasket is compressed between the first and the second member at a compression of at least about 10%, wherein the polyurethane core comprises a polyurethane polymer, wherein the polyurethane core has a Scratch Resistance Rating of not greater than about 10 wt %.

20 . The assembly according to claim 19 , wherein the assembly is an electronic device and the first member and the second member are components of the electronic device.

Assignees

• Saint Gobain Performance Plastics Corp

Inventors

• Guan Jing
• Dong Yue
• Moineau Georges

Classifications

• B29C39/203 Primary

  Making multilayered articles · CPC title

• Y10T428/1457

  Silicon · CPC title

• Y10T428/1462

  Polymer derived from material having at least one acrylic or alkacrylic group or the nitrile or amide derivative thereof [e.g., acrylamide, acrylate ester, etc.] · CPC title

• B29C39/18

  incorporating preformed parts or layers, e.g. casting around inserts or for coating articles {(B29C39/206 takes precedence)} · CPC title

• B29L2007/002

  Panels; Plates; Sheets · CPC title