ADHESIVE COMPOSITION

• US 20110034614A1
• Filed: 04/10/2009
• Published: 02/10/2011
• Est. Priority Date: 04/14/2008
• Status: Active Grant

• Current Assignee: Asahi Kasei Chemicals Corporation (Asahi Kasei Corporation), Japan Elastomer Co.,Ltd. (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei Chemicals Corporation (Asahi Kasei Corporation), Japan Elastomer Co.,Ltd. (Asahi Kasei Corporation)
• Inventors: Nakamichi, Yukinori, Nakajima, Shigeo
• Granted Patent: US 8,563,646 B2
• Time in Patent Office: Days
• US Class Current: 524/505
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 53/025 modified
• CPC Class Codes: C09J 153/025 modified

Abstract

An adhesive composition having good balance in tackiness properties such as tack strength and retentivity, low melt viscosity, high processability, and high stability in melt viscosity under high temperature heating is provided. An adhesive composition containing two hydrogenated block copolymers and a predetermined tackifier is provided, the two hydrogenated block copolymers each having a different structure obtained by controlling the degree of hydrogenation of a block copolymer of a conjugated diene compound and a vinyl aromatic hydrocarbon in a particular range.

Claims

1. An adhesive composition comprising 100 parts by mass of (1) a hydrogenated block copolymer and 20 to 400 parts by mass of (2) a tackifier, the hydrogenated block copolymer having 30 to 90% by mass of (1-A) below and 70 to 10% by mass of (1-B) below:

(1-A) a hydrogenated block copolymer that comprises a polymer block mainly composed of a vinyl aromatic hydrocarbon and a polymer block mainly composed of a conjugated diene compound, and satisfies requirements (a) to (c) below;

(a) a total degree of hydrogenation H (%) of unsaturated double bonds based on the conjugated diene compound is 10 to 80%,

(b) a content of the vinyl aromatic hydrocarbon is 20 to 60% by mass, and

(c) a peak molecular weight is 30,000 to 60,000; and

(1-B) a hydrogenated block copolymer that comprises a polymer block mainly composed of not less than two vinyl aromatic hydrocarbons and a polymer block mainly composed of a conjugated diene compound, and satisfies requirements (d) to (f) below;

(d) a total degree of hydrogenation H (%) of unsaturated double bonds based on the conjugated diene compound is 10 to 80%,

(e) a content of the vinyl aromatic hydrocarbons is 20 to 60% by mass, and

(f) a peak molecular weight is more than 60,000 and less than 100,000.

2. The adhesive composition according to claim 1, wherein

the (1-A) hydrogenated block copolymer is a hydrogenated block copolymer of a block copolymer comprising a polymer block mainly composed of a vinyl aromatic hydrocarbon and a polymer block mainly composed of a conjugated diene compound, and having 10 to 80% of a vinyl bond amount V (%) based on the conjugated diene compound,

a degree of hydrogenation S (%) of vinyl bonds in conjugated diene before hydrogenation is not less than 82%, and

the total degree of hydrogenation H (%) of unsaturated double bonds based on the conjugated diene compound satisfies a relationship of V≦

H≦

2×

V+10 (wherein 10≦

H≦

80); and

the (1-B) hydrogenated block copolymer is a hydrogenated block copolymer of a block copolymer having 10 to 80% of a vinyl bond amount V (%) based on the conjugated diene compound,

a degree of hydrogenation S (%) of vinyl bonds in conjugated diene before hydrogenation is not less than 82%, and

the total degree of hydrogenation H (%) of unsaturated double bonds based on the conjugated diene compound satisfies a relationship of V≦

H≦

2×

V+10 (wherein 10≦

H≦

80); and

the peak molecular weight is 65,000 to 95,000.

3. The adhesive composition according to claim 1, further comprising a softener.

4. The adhesive composition according to claim 2, further comprising a softener.