Pressure sensitive adhesive products and the method for preparation of the same

• US 4,425,176 A
• Filed: 03/19/1982
• Issued: 01/10/1984
• Est. Priority Date: 11/09/1978
• Status: Expired due to Term

• Current Assignee: Lintec Corporation
• Original Assignee: Sanyo-Kokusaku Pulp Company Limited
• Inventors: Kobayashi, Tadashi, Shibano, Tomishi, Maruchi, Sachio, Akimoto, Saburo, Yakan, Koji
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): BUFFALOW, EDITH
• Application Number:
  US06/360,002
• Time in Patent Office: 662 Days
• Field of Search: 428/352, 428/500, 428/516, 428/520, 428/515, 428/518, 156/289, 156/334, 156/344, 156/244.11
• US Class Current: 156/244.11
• CPC Class Codes: C09J 2400/283 in the substrate
• CPC Class Codes: C09J 2423/005 in the release coating
• CPC Class Codes: C09J 2423/165 in the release coating
• CPC Class Codes: C09J 2433/00 Presence of (meth)acrylic polymer
• CPC Class Codes: C09J 7/201 characterised by the release coating composition on the carrier layer
• CPC Class Codes: C09J 7/21 Paper; Textile fabrics
• CPC Class Codes: Y10T 156/1168 Gripping and pulling work apart during delaminating
• CPC Class Codes: Y10T 156/1195 Delaminating from release surface
• CPC Class Codes: Y10T 428/1452 Polymer derived only from ethylenically unsaturated monomer
• CPC Class Codes: Y10T 428/2839 with release or antistick coating
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31913 Monoolefin polymer
• CPC Class Codes: Y10T 428/31928 Ester, halide or nitrile of addition polymer

Abstract

Pressure sensitive adhesive products or articles having one or more release layers and a pressure sensitive adhesive layer, said one or more release layer comprising a polyolefinic elastomer having a shearing modulus of less than 2.0×10⁸ dyne/cm² and surface wettability expressed in terms of an equilibrium contact angle of more than 55° with respect to a standard liquid, and said adhesive layer being composed mainly of a polyacrylate. To increase the adhesion between the release layer and a backing substrate, a reinforcing interlayer may be used. As the release layer, a mixture of the polyolefinic elastomer and polyethylene may be used. The release layer is then kept in contact with the adhesive layer over a given area to form a composite or integral layer thereof as by extrusion coating.

Claims

1. A method of preparing pressure sensitive adhesive products having one or more release layer and poly acrylate-based pressure sensitive adhesive layer, which comprises co-extruding a release layer consisting of a polyolefinic elastomer having a shearing modulus of less than 2.0×

10⁸ dyne/cm² according to JIS K 7213 test and surface wettability expressed in terms of an equilibrium contact angle of more than 55°

with respect to a standard liquid having a surface tension of 50 dyne/cm and used in JIS K 6768 test under the conditions of 20±

1°

C. and 65±

5% RH and olefinic resin forming a reinforcing interlayer for increasing the adhesion between a backing substrate and said release layer such that said elastomer is coated to a thickness of at least 1 micron, said elastomer forming said release layer being bonded to said substrate through said reinforcing interlayer, and said elastomer forming said release layer is kept in contact with said pressure sensitive adhesive layer over a given area to form a composite or integral layer thereof.

2. The method as recited in claim 1, in which said resin forming said reinforcing interlayer is a low-density polyethylene or its derivative.

3. The method as recited in claim 2, in which said polyolefinic elastomer is extruded at a temperature of 180°

to 290°

C. prevailing at the outlet of die lips, and said resin forming said reinforcing interlayer extruded at a temperature of 260°

to 330°

C. prevailing at the outlet of die lips.

4. A method of preparing pressure sensitive adhesive products having one or more release layer and a poly acrylate-based pressure sensitive adhesive layer, which comprises co-extruding a release layer composed of a resin mixture of a polyolefinic elastomer having a shearing modulus of less than 2.0×

10⁸ dyne/cm² according to JIS K 7213 test and surface wettability expressed in terms of an equilibrium contact angle of more 55°

with respect to a standard liquid having a surface tension of 50 dyne/cm and used in JIS K 6768 test under the conditions of 20±

1°

C. and 65±

5% RH and a polyethylene added thereto and olefinic resin forming a reinforcing interlayer for increasing the adhesion between a backing substrate and said release layer such that said resin mixture is coated to a thickness of at least 1 micron, said resin mixture forming said release layer being bonded to said substrate through said resin forming said interlayer, and said release layer consisting of said resin mixture being in contact with said adhesive layer over a given area to form a composite or integral layer thereof.

5. The method is recited in claim 4, in which said resin forming said reinforcing interlayer is a low-density polyethylene or its derivative.

6. The method as recited in claim 5, in which said resin mixture is extruded at a temperature of 200°

to 290°

C. prevailing at the outlets of die lips, and said resin extruded at a temperature of 260°

to 330°

C. prevailing at the outlets of die lips.