Double coated pressure sensitive adhesive tape

Abstract

A double coated pressure sensitive adhesive tape comprising pressure sensitive adhesive layers which comprise an acrylic ester-based copolymer having a weight-average molecular weight of 700,00 or greater and a content of a butyl acrylate unit of 90% by mass or greater and 40 to 60% by mass of a tackifier as main components and are disposed on both faces of a core material, wherein the thickness of the entire tape including the core material and the adhesive layers is 30 μm or smaller, and the thickness of the adhesive layer on each face is 2 to 10 μm. The tape is transparent and thin, is advantageously used for fixing members of portable terminals such as portable telephones and PDA and thin film displays, laminating substrates in optical disks and fixing polarizing plates and exhibits excellent adhesive strength and holding power at high temperatures.

Description

Claims

1. A double coated pressure sensitive adhesive tape comprising a core material and pressure sensitive adhesive layers which comprise an acrylic ester-based copolymer having a weight-average molecular weight of 700,00 or greater and a content of a butyl acrylate unit of 90% by mass or greater and a tackifier as main components, have a content of the tackifier of 40 to 60% by mass and are disposed on both faces of the core material, wherein a thickness of the entire tape including the core material and the pressure sensitive adhesive layers disposed on both faces of the core material is 30 μm or smaller, and a thickness of the pressure sensitive adhesive layer on each face is 2 to 10 μm.

2. The double coated pressure sensitive adhesive tape according to claim 1, wherein, when a thickness of the pressure sensitive adhesive layer on one face is represented by a (μm), and an adhesive strength of the pressure sensitive adhesive layer is represented by c (N/25 mm), the pressure sensitive adhesive layer on each face has a value of c/a in a range of 1.3 to 5.0.

3. The double coated pressure sensitive adhesive tape according to claim 1, wherein a holding power of the pressure sensitive adhesive layers at both faces at 120° C. is 5 mm or smaller.

4. The double coated pressure sensitive adhesive tape according to claim 2, wherein a holding power of the pressure sensitive adhesive layers at both faces at 120° C. is 5 mm or smaller.

5. The double coated pressure sensitive adhesive tape according to claim 1, wherein a release film released under a greater force is attached to the pressure sensitive adhesive layer on one face of the core material and a release film released under a smaller force is attached to the pressure sensitive adhesive layer on the other face of the core material.

6. The double coated pressure sensitive adhesive tape according to claim 2, wherein a release film released under a greater force is attached to the pressure sensitive adhesive layer on one face of the core material and a release film released under a smaller force is attached to the pressure sensitive adhesive layer on the other face of the core material.

7. The double coated pressure sensitive adhesive tape according to claim 3, wherein a release film released under a greater force is attached to the pressure sensitive adhesive layer on one face of the core material and a release film released under a smaller force is attached to the pressure sensitive adhesive layer on the other face of the core material.

8. The double coated pressure sensitive adhesive tape according to claim 4, wherein a release film released under a greater force is attached to the pressure sensitive adhesive layer on one face of the core material and a release film released under a smaller force is attached to the pressure sensitive adhesive layer on the other face of the core material.

9. The double coated pressure sensitive adhesive tape according to claim 5, wherein the release film released under a greater force has a thickness of 30 to 100 μm.

10. The double coated pressure sensitive adhesive tape according to claim 6, wherein the release film released under a greater force has a thickness of 30 to 100 μm.

11. The double coated pressure sensitive adhesive tape according to claim 7, wherein the release film released under a greater force has a thickness of 30 to 100 μm.

12. The double coated pressure sensitive adhesive tape according to claim 8, wherein the release film released under a greater force has a thickness of 30 to 100 μm.