Impact-resistant polystyrene resin composition

• Main Authors: SUZUKI, MICHINORI, WADA, TAKASHI, ASAKURA, YOSHIO, TSUJIMOTO, NOBUHIRO, AKAHORI, KEIICHI
• Format: Patent
• Language: English; French; German
• Published: 13.05.1998
• Edition: 6
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

A rubber-modified impact-resistant polystyrene resin composition is disclosed, which contains dispersed particles comprising a rubber-like polymer in amount of from 1 to 25% by weight, the rubber-like polymer being a high-cis high-vinyl polybutadiene which comprises from 65 to 95% cis-1,4-structures and from 30 to 4% 1,2-structures, and in which when the relationship between the 1,4-structures and 1,2-structures of the rubber-like polymer is represented by the expression beta =P1,2-1,4/(2xP1,2xP1,4) (wherein P1,2 represents the content of 1,2-structures, P1,4 represents the content of 1,4-structures, and P1,2-1,4 represents the content of 1,2-structure/1,4-structure diads in all diads), then 1.0< beta ≤1.43. The relationship between the viscosity of a 5% styrene solution of the rubber-like polymer as measurement at 25 DEG C (5% SV) and the Mooney viscosity (ML1+4) of the polymer preferably satisfies the expression 2.0≤(5% SV)/ML1+4≤7.0. Another rubber-modified impact-resistant polystyrene resin composition is disclosed, which contains dispersed particles comprising a rubber-like polymer in an amount of from 3 to 15% by weight, the rubber-like polymer being a high-cis high-vinyl polybutadiene which comprises from 65 to 95% cis-1,4-structures and from 30 to 4% 1,2-structures, and in which when the relationship between the tensile elongation (E) of the rubber-modified impact-resistant polystyrene resin composition and the dispersed-particle diameter (X1) and amount (X2) of the rubber-like polymer is represented by the expression E=-17.8X1+5.6X2+38.5, then 20%<E<90%. The compositions have a well balanced combination of improved properties such as reactivity with styrene monomer, impact resistance, low-temperature properties, gloss, tensile strength, and tensile elongation.