Patent ID: 8334334
Filing Date: 2012-12-18
Classification: C08K,C08L,Y10T

Abstract:
1. A method for preparing a thermoplastic polymeric material, which comprises incorporating into said thermoplastic polymeric material a silica (S) as an inorganic filler, said silica having a BET specific surface area of at least 60 m 2 /g, and which is obtained according to a method (P) comprising reacting a silicate with an acidifying agent, thereby obtaining a silica suspension, then separating and drying the suspension, wherein the reaction of the silicate with the acidifying agent is performed according to the following consecutive steps: (i) forming an aqueous starter having a pH of between 2 and 5; (ii) adding silicate and acidifying agent simultaneously to said starter in such a way that the pH of the reaction medium is kept between 2 and 5; (iii) stopping the addition of the acidifying agent while continuing the addition of silicate to the reaction medium until a pH value of the reaction medium of between 7 and 10 is obtained; (iv) adding silicate and acidifying agent simultaneously to the reaction medium in such a way that the pH of the reaction medium is kept between 7 and 10; and (v) stopping the addition of the silicate while continuing the addition of the acidifying agent to the reaction medium until a pH value of the reaction medium of less than 6 is obtained, wherein the inorganic filler increases the rigidity of the thermoplastic polymeric material while maintaining or improving its impact resistance, and wherein the thermoplastic polymeric material comprises at least 90% by mass of: a homopolyolefin selected from the group consisting of a polyethylene, a polypropylene, a polybutylene and a poly(methylpentene); a copolymeric polyolefin formed from at least two different members selected from the group consisting of ethylene, propylene, butylene and methylpentene units; or a mixture of two or more of said homopolyolefins and/or said copolymeric polyolefins, and the remainder of the material is a silica (S) and optionally one or more additives and/or inorganic fillers.