Low viscosity hot melt pressure sensitive ashesive compositions

A hot melt pressure sensitive adhesive composition comprising a mixture of:

• a) 100 parts by weight of a thermoplastic elastomer having the structure (S-I).sub.n-1 S, wherein S is a polystyrene block, I is a polyisoprene block and n is an integer of from 2 to 10 and wherein the content of polystyrene in said thermoplastic elastomer ranges from about 10 to 20% by weight and wherein the number average molecular weight of said thermoplastic elastomer ranges from about 50,000 to about 175,000, said thermoplastic elastomer containing less than 0.1 weight percent diblock S-I;
• b) from about 70 to about 150 parts by weight of a petroleum resin tackifier having a softening point in the range of from about 8.5.degree. C. to about 105.degree. C., said resin being a Friedel Crafts copolymer comprising:
• i) a petroleum feed comprising C.sub.5 olefins and diolefins or a mixture of C.sub.5 and C.sub.6 olefins and diolefins, said feed being obtained from the cracking of petroleum feedstock, copolymerized with
• ii) from about 5 to 15% by weight, based on component (b) of one or a mixture of monovinyl aromatic compounds having 8-9 carbon atoms;
• said composition characterized as having a melt viscosity at 175.degree. C. of from about 35,000 to less than about 100,000 mPa.s as measured by ASTM-D3236.