Adhesive sheet

Patent metadata

Field	Value
Publication number	US-9593270-B2
Application number	US-201013513409-A
Country	US
Kind code	B2
Filing date	Nov 30, 2010
Priority date	Dec 3, 2009
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

The present invention provides a pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer that contains a polyester resin as a main component, in which the pressure-sensitive adhesive layer having a laminate structure that contains at least one layer LA where a polyester resin E A having Mw of from 4×10 4 to 12×10 4 is crosslinked and at least one layer LB where a polyester resin E B having Mw of from 0.2×10 4 to 1×10 4 is crosslinked, and at least one surface of the pressure-sensitive adhesive layer is constituted by the layer LA.

First claim

The invention claimed is:

1. A pressure-sensitive adhesive sheet provided with a pressure-sensitive adhesive layer that comprises a polyester resin as a main component thereof,
wherein the pressure-sensitive adhesive layer has a laminate structure containing: at least one layer LA, which has a gel fraction of from 30 to 65%, and which is formed by crosslinking a polyester resin E A having a weight-average molecular weight of from 4×10 4 to 12×10 4 ; and at least one layer LB, which has a gel fraction of from 70 to 90%, and which is formed by crosslinking a polyester resin E B having a weight-average molecular weight of from 0.2×10 4 to 1×10 4 , and
at least one surface of the pressure-sensitive adhesive layer is constituted by the layer LA.

2. The pressure-sensitive adhesive sheet according to claim 1 , wherein the pressure-sensitive adhesive layer comprises at least two layers LA, and one surface and the other surface of the pressure-sensitive adhesive layer are constituted by the first layer LA and the second layer LA, respectively.

3. The pressure-sensitive adhesive sheet according to claim 1 , wherein
the layer LA constituting at least one surface of the pressure-sensitive adhesive layer has a thickness T LA of from 5 μm to 100 μm.

4. The pressure-sensitive adhesive sheet according to claim 1 , wherein the layer LB is laminated on the back of the layer LA that constitutes at least one surface of the pressure-sensitive adhesive layer, and the layer LB has a thickness T LB of from 10 μm to 2000 μm.

5. The pressure-sensitive adhesive sheet according to claim 1 , wherein at least one surface of the pressure-sensitive adhesive layer is constituted by the layer LA having the thickness of T LA , the layer LB having the thickness of T LB is laminated on the back of the layer LA, and T LA and T LB satisfy a relation of the following formula: 1<T LB /T LA ≦50.

6. The pressure-sensitive adhesive sheet according to claim 1 , wherein at least one of the polyester resin E A and the polyester resin E B is crosslinked with a tri- or more-functional isocyanate.

7. The pressure-sensitive adhesive composition according to claim 1 , wherein each of the polyester resin E A and the polyester resin E B contains a polycarboxylic acid component and a polyalcohol component, and the combination of the polycarboxylic acid component and the polyalcohol component constituting the polyester resin E A is the same as the combination of the polycarboxylic acid component and the polyalcohol component constituting the polyester resin E B .

8. The pressure-sensitive adhesive sheet according to claim 1 , wherein each of the polyester resin E A and the polyester resin E B contains a polycarboxylic acid component and a polyalcohol component, and at least one polycarboxylic acid of the polycarboxylic acid component constituting the polyester resin E A and the polycarboxylic acid component constituting the polyester resin E B is an aliphatic dicarboxylic acid having a dimerized structure of an unsaturated fatty acid.

9. The pressure-sensitive adhesive sheet according to claim 1 , wherein each of the polyester resin E A and the polyester resin E B contains a polycarboxylic acid component and a polyalcohol component, and at least one polyalcohol of the polyalcohol component constituting the polyester resin E A and the polyalcohol component constituting the polyester resin E B is an aliphatic diol having a structure where an aliphatic dicarboxylic acid of a dimerized unsaturated fatty acid is subjected to hydrogenation.

10. The pressure-sensitive adhesive sheet according to claim 1 , wherein each of the polyester resin E A and the polyester resin E B is a polycondensate of a dimer acid with a dimer diol.

11. The pressure-sensitive adhesive sheet according to claim 1 , which comprises 1 to 3 sheets of layers LA and 1 or 2 sheets of layers LB.

12. The pressure-sensitive adhesive sheet according to claim 1 , wherein the weight-average molecular weight of the polyester resin E A is larger by 9 times or more than the weight-average molecular weight of the polyester resin E B .

13. The pressure-sensitive adhesive sheet according to claim 1 , wherein the layer LA has a gel fraction G LA and the layer LB has a gel fraction G LB , satisfying G LB /G LA ≧1.2.

14. The pressure-sensitive adhesive sheet according to claim 1 , wherein the layer LB is formed by crosslinking only a polymer composition containing the polyester resin E B .

15. The pressure-sensitive adhesive sheet according to claim 1 , wherein the layer LB is formed by crosslinking only a polyester resin composition containing the polyester resin E B .

16. The pressure-sensitive adhesive sheet according to claim 1 , wherein the layer LB is formed by crosslinking only the polyester resin E B .

Assignees

• Tanimura Miki
• Takahira Hitoshi
• Yoshie Satomi
• Nitto Denko Corp

Inventors

• Tanimura Miki
• Takahira Hitoshi
• Yoshie Satomi

Classifications

• C09J167/00

  Adhesives based on polyesters obtained by reactions forming a carboxylic ester link in the main chain (based on polyester-amides C09J177/12; based on polyester-imides C09J179/08); Adhesives based on derivatives of such polymers · CPC title

• C09J2467/00

  Presence of polyester · CPC title

• Y10T428/264

  Up to 3 mils · CPC title

• Y10T428/2852

  Adhesive compositions · CPC title

• Y10T428/2495

  Thickness [relative or absolute] · CPC title