| abstract |
The invention provides a process for the preparation of a thermoplastic elastomeric resin composition comprising melt kneading n (a) 100 parts by weight of a block copolymer consisting of at least two polymeric blocks (A) composed mainly of a vinyl aromatic compound and at least one polymeric block (B) composed mainly of a conjugated diene compound, and/or a hydrogenated block copolymer obtained by hydrogenating said block copolymer, n (b) 40 to 240 parts by weight of a non-aromatic softening agent for rubber, n (c) 5 to 300 parts by weight of polyethylene or a copolymer composed mainly of ethylene, and n (d) 5 to 60 parts by weight of polypropylene or a copolymer composed mainly of propylene, n characterized in that the process comprises the following steps: n (I) melt kneading the whole amounts of components (a), (b) and (d) and a part of component (c), and, at the same time or subsequently, melt kneading these with (f) an organic peroxide, and n (II) melt kneading the product obtained from step (I) with the remaining part of component (c), n and component (c) is one which has been prepared using a single site catalyst. n The obtained composition is soft and excellent in heat deformation resistance and mechanical strength, moldability and processability. The present invention also provide a thermoplastic elastomeric resin composition comprising the above components (a), (c) and (d) in an amount of 100 parts by weight, 5 to 150 parts by weight and 5 to 80 parts by weight, respectively. The composition is soft and excellent in heat deformation resistance and mechanical strength, moldability and processability and shows good results in the extraction tests. |