Patent ID: 7994256
Filing Date: 2011-08-09
Classification: C08F,C08L

Abstract:
1. A method for preparing an elastosol, comprising the steps of: (a) mixing 5 to 50 parts by weight of a block copolymer and 95 to 50 parts by weight of a benzoate ester having a melting point between about 70° C. and about 170° C. at a mixing temperature above the melting point of the ester, wherein said block copolymer is a solid selectively hydrogenated block copolymer having the general configuration A-B-A, (A-C) (i) prior to hydrogenation each A block is a mono alkenyl arene polymer block and each B block and C block is a conjugated diene block having a vinyl content between 30 weight percent and 70 weight percent; (ii) subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced; (iii) each A block having a number average molecular weight between about 25,000 and about 35,000; each B block having a number average molecular weight between about 100,000 and about 150,000; and each C block having a number average molecular weight between about 50,000 and about 75,000; and (iv) the total amount of mono alkenyl arene in the hydrogenated block copolymer is about 30 percent weight to about 35 percent weight; (b) cooling the block copolymer/benzoate ester mixture below the melting point of the ester and turning it into a powder having a particle size of less than 800 micron; (c) mixing the block copolymer/benzoate ester powder with an oil and a tackifying resin at room temperature to form a dispersion wherein the percent weight of the block copolymer/benzoate ester powder mixture is between 15 and 50 wt. %, the weight percent of oil is between zero and 30 wt. %, and the weight percent of tackifying resin is between 85 and 30 wt. %; (d) heating the dispersion of the block copolymer/benzoate ester powder to a temperature higher than the melting point of the ester to form a hot fluid mixture; and (e) cooling the fluid mixture to form a solid elastic composition.