Resin Composition for Seamless Air Bag Covers, and Seamless Air Bag Covers or Seamless Instrument Panels with Air Bag Covers, Made by Using the Composition

Abstract

A resin composition for a seamless air bag cover or a resin composition for a seamless instrument panel having an air bag cover which comprises (A) 50 to 90% by mass of polypropylene, (B) 0 to 20% by mass of a thermoplastic elastomer and (C) 10 to 30% by mass of talc having an average particle diameter of 15 to 25 μm and a distribution of a particle diameter such that the content of particles having a diameter of 5 μm or smaller is 10% by mass or smaller and the content of particles having a diameter exceeding 40 μm is 10% by mass or smaller. The resin composition exhibits sufficient properties when an instrument panel is molded. A seamless instrument panel having an air bag cover can be obtained as an integrally molded product, which can be treated as a single article in recycling.

1 . A resin composition for a seamless air bag cover or a resin composition for a seamless instrument panel having an air bag cover which comprises (A) 50 to 90% by mass of polypropylene, (B) 0 to 20% by mass of a thermoplastic elastomer and (C) 10 to 30% by mass of talc, wherein the talc has an average particle diameter of 15 to 25 μm and a distribution of a particle diameter such that a content of particles having a diameter of 5 μm or smaller is 10% by mass of smaller and a content of particles having a diameter exceeding 40 μm is 10% by mass or smaller. 
     
     
         2 . A resin composition for a seamless air bag cover or a resin composition for a seamless instrument panel having an air bag cover according to  claim 1 , wherein the thermoplastic elastomer of component (B) is an ethylene-α-olefin copolymer elastomer. 
     
     
         3 . A resin composition for a seamless air bag cover or a resin composition for a seamless instrument panel having an air bag cover according to any one of  claims 1  and  2 , wherein the resin composition has (1) an Izod impact strength of 15 to 40 kJ/m 2  as measured in accordance with a method of ASTM D256 at 23° C. with a notch, (2) a flexural modulus of 1,600 to 3,000 MPa as measured in accordance with a method of ASTM D790 at 23° C. and (3) a melt flow rate (MFR) of 5 to 40 g/10 minutes as measured in accordance with a method of JIS K7210 at 230° C. under a load of 21.2 N (2.16 kgf). 
     
     
         4 . A seamless air bag cover comprising a resin composition described in  claim 1 . 
     
     
         5 . A seamless instrument panel having an air bag cover which is obtained by integrally molding a seamless air bag cover comprising a resin composition described in  claim 1  and an instrument panel comprising the resin composition.