Powder molding process using a thermoplastic elastomer powder
AssigneeSumitomo Chemical Company, Limited
InventorsToshio Sasaki, Takeshi Ebara, Toshio Igarashi, Masayuki Tatsumi, Kazuki Wakamatsu
Life of this patent
Estimating the term…
Abstract
This invention provides a thermoplastic elastomer powder produced by a gas polymerization process by the use of a specified catalyst system which is excellent in powder fluidity, retains a high fluidity even in a state where no substantial forming pressure is applied and can be formed by powder molding process, as well as a powder molding process using said elastomer powder and a molded product of said molding process.
Claims11
A powder molding process comprising the forming of a propylene based prepolymer by one method selected from the group consisting of:
- a method comprising carrying out a polymerization in liquified propylene,
- a method comprising carrying out a polymerization in liquified propylene and thereafter carrying out a polymerization in gas phase, and
- a method comprising carrying out a polymerization in gas phase,
- to obtain a propylene-base prepolymer and thereafter carrying out a random copolymerization of ethylene and .alpha.-olefin to make an ethylene/.alpha.-olefin random copolymer portion in the presence of the propylene-based prepolymer in gas phase by the use of a catalyst system consisting of:
- (A) a solid catalyst component comprising a porous carrier and a polymerization accelerator comprising titanium, magnesium and halogen supported on the porous carrier,
- (B) an organoaluminum compound, and
- (C) an electron donative compound,
- to form elastomer powder;
- the elastomer powder having a melt flow rate (MFR) of 15-200 g/10 min, an intrinsic viscosity [.eta]sub.T of 1.25-1.70, a content of ethylene in the ethylene/.alpha.-olefin random copolymer portion of 20-85% by mole, and a complex dynamic viscosity .eta.* (1) at a frequency of 1 radian/second of 1.5.times.10.sup.5 poises or below as determined by dynamic viscoelastic measurement at 250.degree. C., and having a Newtonian viscosity index n of 0.67 or below as calculated from the following equation:
- ti n={log .eta.* (1)-log .eta.* (100)}/2
- wherein .eta.* (1) is the complex dynamic viscosity at frequency of 1 radian/second and .eta.* (100) is a complex dynamic viscosity at a frequency of 100 radians/second, and forming a molded article from said elastomer powder.
Dependencies are inferred from the claim text.