Pressure-sensitive adhesive/adhesive and block copolymer suitable for use therein
View Patent ↗The present invention provides an adhesive composition containing a block copolymer, wherein the block copolymer has a polymer block (A) which is principally composed of a α-methyl styrene unit, and a polymer block (B) which is principally composed of a conjugated diene unit and of which at least part of carbon-carbon unsaturated double bonds may be hydrogenated, and having a good holding power at high temperatures.
1. An adhesive composition containing a block copolymer, wherein said block copolymer has a polymer block (A) which is principally composed of an α-methyl styrene unit, and a polymer block (B) which is principally composed of a conjugated diene unit and of which at least part of the carbon-carbon unsaturated double bonds are hydrogenated, and wherein the cohesion at 60° C. (holding power (min.)) of the adhesive composition is in the range of 24 to 83 minutes.
2. The adhesive composition according to claim 1 , wherein said block copolymer is a straight chain form.
3. The adhesive composition according to claim 1 , wherein the conjugated diene unit in the polymer block (B) is principally a 1,3-butadiene unit.
4. The adhesive composition according to claim 1 , wherein at least part of the carbon-carbon unsaturated double bonds of the polymer block (B) are hydrogenated.
5. The adhesive composition according to claim 4 , wherein the degree of hydrogenation of the carbon-carbon unsaturated double bonds resulting from the conjugated dienes in the block copolymer is not less than 50%.
6. The adhesive composition according to claim 2 , wherein at least part of the carbon-carbon unsaturated double bonds of the polymer block (B) are hydrogenated.
7. The adhesive composition according to claim 6 , wherein the degree of hydrogenation of the carbon-carbon unsaturated double bonds resulting from the conjugated dienes in the block copolymer is not less than 50%.
8. The adhesive composition according to claim 3 , wherein at least part of the carbon-carbon unsaturated double bonds of the polymer block (B) are hydrogenated.
9. The adhesive composition according to claim 8 , wherein the degree of hydrogenation of the carbon-carbon unsaturated double bonds resulting from the conjugated dienes in the block copolymer is not less than 50%.
10. An adhesive composition containing a block polymer, wherein said block copolymer has a polymer block (A) which is principally composed of an α-methyl styrene unit, and a polymer block (B) which is principally composed of a conjugated diene unit and of which at least part of the carbon-carbon unsaturated double bonds are hydrogenated, and wherein the cohesion at 80° C. (holding power (min.)) of the adhesive composition is in the range of 47 to 240 minutes.