BACKREST DEVICE FOR CHAIR

摘要

PROBLEM TO BE SOLVED: To provide an inner shell body 9 of a composition the function of which as a lumber support in a backrest section for a chair is optimal. SOLUTION: The inner shell body 9 is formed of a composition wherein a composition containing a polyolefin based thermoplastic elastomer and a hydrogenated butadiene rubber is made to contain a metallocene polyethylene or a random polypropylene. The bending elasticity of the composition is set in a range of 20 to 250 MPa.