Pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet

Patent metadata

Field	Value
Publication number	US-9902886-B2
Application number	US-201314385194-A
Country	US
Kind code	B2
Filing date	Mar 7, 2013
Priority date	Mar 16, 2012
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A polyester-based pressure-sensitive adhesive composition which can be produced even from plant-derived raw materials with no need of using a costly silicone-based pressure-sensitive adhesive or the like and which is usable for producing a pressure-sensitive adhesive sheet excellent in wettability to an adherend, light peelability (removability), anti-staining property (little adhesive residues), and workability, and to provide a pressure-sensitive adhesive sheet using the composition. A polyester-based pressure-sensitive adhesive composition comprising a polyester obtained by condensation polymerization of at least a carboxylic acid component and a diol component, and a crosslinking agent, wherein the carboxylic acid component contains a dicarboxylic acid having a side chain in an amount of 50 to 90% by weight and a tricarboxylic acid having a side chain in an amount of 10 to 50% by weight, and wherein the polyester has a weight average molecular weight of 5000 to 150000.

First claim

The invention claimed is:

1. A polyester-based pressure-sensitive adhesive composition comprising a polyester and a crosslinking agent, wherein
the polyester is obtained by condensation polymerization of only a carboxylic acid component and a diol component,
the carboxylic acid component contains only a dicarboxylic acid having a side chain and a tricarboxylic acid having a side chain,
the carboxylic acid component contains a dicarboxylic acid having a side chain in an amount of 60 to 85% by weight and a tricarboxylic acid having a side chain in an amount of 15 to 40% by weight, and
the polyester has a weight average molecular weight of 10000 to 150000.

2. The polyester-based pressure-sensitive adhesive composition according to claim 1 , wherein the diol component contains an aliphatic diol having 3 to 10 carbon atoms.

3. The polyester-based pressure-sensitive adhesive composition according to claim 1 , further comprising a polyether polyol.

4. A pressure-sensitive adhesive sheet comprising a support and a pressure-sensitive adhesive layer obtained by crosslinking the polyester-based pressure-sensitive adhesive composition according to claim 1 and formed on at least one surface of the support, wherein
the pressure-sensitive adhesive layer has a gel fraction of 70 to 98% by weight.

5. The pressure-sensitive adhesive sheet according to claim 4 , which has an adhesive strength to glass of 0.5 N/25 mm or less.

6. The pressure-sensitive adhesive sheet according to claim 4 , which is used for surface protection.

Assignees

• Nitto Denko Corp

Inventors

• Yoshie Satomi
• Ishiguro Shigeki
• Senda Hiroki

Classifications

• C08G18/4233

  derived from polymerised higher fatty acids or alcohols · CPC title

• C09J167/08

  Polyesters modified with higher fatty oils or their acids, or with natural resins or resin acids · CPC title

• C09J2467/00

  Presence of polyester · CPC title

• C09J171/02 Primary

  Polyalkylene oxides · CPC title

• C08G18/4018

  Mixtures of compounds of group C08G18/42 with compounds of group C08G18/48 · CPC title