Composition and surface protection film

Patent metadata

Field	Value
Publication number	US-9873788-B2
Application number	US-201515129991-A
Country	US
Kind code	B2
Filing date	Apr 7, 2015
Priority date	Apr 8, 2014
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A composition comprising: a hydrogenated block copolymer (1) comprising a block A mainly comprising a vinyl aromatic compound monomer unit and a block B mainly comprising a conjugated diene monomer unit, wherein the conjugated diene monomer unit has an amount of vinyl bonds of 50% or more before hydrogenation; and a hydrogenated copolymer (2) comprising a block C randomly comprising a vinyl aromatic compound monomer unit and a conjugated diene monomer unit, and having a degree of hydrogenation of double bonds based on the conjugated diene monomer unit of 90% or more.

First claim

The invention claimed is:

1. A surface protection film comprising:
a substrate film, and
a tackifier layer comprising a composition comprising:
a hydrogenated block copolymer (1) comprising a block A mainly comprising a vinyl aromatic compound monomer unit and a block B mainly comprising a conjugated diene monomer unit, wherein the conjugated diene monomer unit has an amount of vinyl bonds of 50% or more before hydrogenation; and
a hydrogenated copolymer (2)
(i) comprising a block C randomly comprising a vinyl aromatic compound monomer unit and a conjugated diene monomer unit,
(ii) having a content of the vinyl aromatic compound monomer unit of 40 mass % or more,
(iii) having a degree of hydrogenation of double bonds based on the conjugated diene monomer unit of 90% or more, and
(iv) excluding a block mainly comprising a conjugated diene monomer unit,

wherein a mass ratio of the hydrogenated block copolymer (1) to the hydrogenated copolymer (2) is 95:5 to 15:85.

2. The surface protection film according to claim 1 , wherein
the hydrogenated block copolymer (1) has a content of the vinyl aromatic compound monomer unit of 5 to 30 mass %, and
the hydrogenated copolymer (2) has a content of the vinyl aromatic compound monomer unit of 40 to 80 mass %.

3. The surface protection film according to claim 1 , wherein the hydrogenated block copolymer (1) has a degree of hydrogenation of double bonds based on the conjugated diene monomer unit of 90% or more.

4. The surface protection film according to claim 1 , wherein the hydrogenated copolymer (2) has a degree of hydrogenation of double bonds based on the conjugated diene monomer unit of 93% or more.

5. The surface protection film according to claim 1 , wherein the hydrogenated block copolymer (1) has a melt flow rate (g/10 min) of 1.0 to 30 at a temperature of 230° C. under a load of 2.16 kg.

6. The surface protection film according to claim 1 , wherein the hydrogenated copolymer (2) further comprises a block A mainly comprising a vinyl aromatic compound monomer unit.

7. The surface protection film according to claim 6 , wherein the hydrogenated copolymer (2) has a block A content of 5.0 to 30 mass %.

8. The surface protection film according to claim 1 , wherein the conjugated diene monomer unit of the hydrogenated copolymer (2) has an amount of vinyl bonds of less than 50% before hydrogenation.

9. The surface protection film according to claim 1 , wherein the conjugated diene monomer unit of the hydrogenated copolymer (2) has an amount of vinyl bonds of 20% or more and less than 50% before hydrogenation.

10. The surface protection film according to claim 1 , wherein the hydrogenated copolymer (2) has only one loss tangent peak top in a range of −70 to 50° C. in a dynamic viscoelasticity spectrum.

11. The surface protection film according to claim 1 , wherein the hydrogenated block copolymer (1) has a weight average molecular weight of more than 100,000.

12. The surface protection film according to claim 1 , further comprising a hydrogenated copolymer (3) having a weight average molecular weight 0.30 to 0.70 times that of the hydrogenated copolymer (2).

13. The surface protection film according to claim 12 , wherein a conjugated diene monomer unit of the hydrogenated copolymer (3) has an amount of vinyl bonds of less than 50% before hydrogenation.

14. The surface protection film according to claim 2 , wherein the hydrogenated block copolymer (1) has a degree of hydrogenation of double bonds based on the conjugated diene monomer unit of 90% or more.

15. The surface protection film according to 3, wherein the hydrogenated copolymer (2) has a degree of hydrogenation of double bonds based on the conjugated diene monomer unit of 93% or more.

16. The surface protection film according to claim 1 , wherein a thickness of the tackifier layer is 1.0 μm or more and 100 μm or less.

Assignees

• Asahi Chemical Ind

Inventors

• Kamei Yuta
• Hoshina Toshikazu

Classifications

• C08L2203/16

  used for films · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L53/025 Primary

  modified · CPC title

• C08F297/04 Primary

  polymerising vinyl aromatic monomers and conjugated dienes · CPC title

• C08F297/044

  using a coupling agent · CPC title