Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-03-29
2002-10-22
Wilson, D. R. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S494000, C524S505000, C525S070000, C525S071000, C525S089000, C525S09200D, C525S098000, C525S099000
Reexamination Certificate
active
06469081
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a syndiotactic, polystyrenic resin composition. More precisely, it relates to a syndiotactic, polystyrenic resin composition which can be formed into an article having improved heat resistance, an increased modulus of elasticity and greatly improved toughness, and in addition, the peeling of the surface layer of the article to be formed from the composition is retarded.
BACKGROUND OF THE INVENTION
Articles formed from a styrene-based polymer having a syndiotactic configuration (hereinafter referred to as SPS) have excellent heat resistance and chemical resistance but have poor impact resistance. Therefore, the polymer has heretofore been used in limited ranges. In order to improve the impact resistance of SPS articles, it has been proposed to add rubber-like elastic substances and other thermoplastic resins to SPS (see Japanese Patent Application Laid-Open Nos. 257950/1987, 146944/1989, 182344/1989, 279944/1989, and 64140/1990).
Concretely, a composition comprising SPS and, as a rubber-like elastic material, a component containing a styrenic compound (see Japanese Patent Application Laid-Open No. 146944/1989), and a composition comprising a mixture of SPS and a thermoplastic resin and/or a rubber-like polymer except SPS, and, as a miscibility-improving agent, a styrenic chain-containing, block or graft copolymer (see Japanese Patent Application Laid-open No. 279944/1989) have been proposed.
These compositions contain, as a miscibility-improving agent, a polystyrenic chain-containing, block or graft polymer, in order to improve the miscibility of a rubber component with immiscible SPS and to improve the dispersibility of the rubber component and the interfacial strength between the constitutive components. However, the effect of the miscibility-improving agent therein is not satisfactory. Therefore, the articles formed from these compositions are not satisfactorily tough and the peeling of the surface layers from the articles could not be retarded sufficiently.
SUMMARY OF THE INVENTION
Given the situations, it is an object of the present invention to provide a syndiotactic, polystyrenic resin composition which can be formed into an article having an increased modulus of elasticity, high heat resistance and greatly improved toughness, and additionally having high impact resistance while retarding the peeling of the surface layer from the article.
We, the inventors of the present invention have assiduously studied so as to develop a syndiotactic, polystyrenic resin composition having the above-mentioned favorable properties and, as a result, have found that the intended object can be attained by a composition comprising a styrene-based polymer having a syndiotactic configuration and a polyolefin and, as a miscibility-improving agent for these, a particular styrene-olefin copolymer, in predetermined ratios. In addition, we have found that, when a small amount of a polyphenylene ether is added to the composition, the toughness of an article to be formed from the resulting composition can be more effectively improved. Moreover, we have further found that, when a particular styrene-based copolymer and/or a particular oil or wax are/is added thereto, the toughness of the article can be much more effectively improved. Furthermore, we have found that, when an inorganic filler, or a combination of an inorganic filler and a particular polymer having a polar group is added to the composition in predetermined ratios, the heat resistance and the modulus of elasticity of the article can be much more increased. On the basis of these findings, we have completed the present invention.
Specifically, the present invention provides;
(1) a syndiotactic, polystyrenic resin composition comprising resin components of (A) 100 parts by weight of a component composed of (a) from 10 to 98% by weight of a styrene-based polymer having a syndiotactic configuration and (b) from 2 to 90% by weight of a polyolefin, and (B) from 0.5 to 50 parts by weight of a styrene-olefin copolymer having a styrene content of from 40 to 85% by weight;
(2) a syndiotactic, polystyrenic resin composition comprising resin components of (A) 100 parts by weight of a component composed of (a) from 10 to 98% by weight of a styrene-based polymer having a syndiotactic configuration and (b) from 2 to 90% by weight of a polyolefin, (B) from 0.5 to 50 parts by weight of a styrene-olefin copolymer having a styrene content of from 40 to 85% by weight, and (C) from 0.5 to 10.0 parts by weight, relative to 100 parts by weight of the component (a) of (A), of a polyphenylene ether (having an intrinsic viscosity in chloroform at 25° C. of 0.4 dl/g or higher);
(3) a syndiotactic, polystyrenic resin composition of the above-mentioned (1) or (2), which further contains (D) from 0 to 200 parts by weight, relative to 100 parts by weight of the component (b) of (A), of a styrene-olefin copolymer having a styrene content of from 5 to 35% by weight;
(4) a syndiotactic, polystyrenic resin composition of the above-mentioned (1) or (2), which further contains (E) from 0 to 200 parts by weight, relative to 100 parts by weight of the component (b) of (A), of a paraffinic oil, a paraffinic wax, a mineral oil and/or a siloxanic oil; and
(5) a syndiotactic, polystyrenic resin composition of the above-mentioned (1) or (2), which further contains (D) from 0 to 200 parts by weight, relative to 100 parts by weight of the component (b) of (A), of a styrene-olefin copolymer having a styrene content of from 5 to 35% by weight, and (E) from 0 to 200 parts by weight, relative to 100 parts by weight of the component (b) of (A), of a paraffinic oil, a paraffinic wax, a mineral oil and/or a siloxanic oil.
Preferred embodiments of the present invention are;
(6) the syndiotactic, polystyrenic resin composition of any of the above-mentioned (1) to (5), which further contains (F) from 0.5 to 350 parts by weight, relative to 100 parts by weight of the resin components, of an inorganic filler, and
(7) the syndiotactic, polystyrenic resin composition of any of the above-mentioned (1) to (5), which further contains (F) from 0.5 to 350 parts by weight, relative to 100 parts by weight of the resin components, of an inorganic filler, and (G) from 0.1 to 10 parts by weight, relative to the same, of a polymer which is miscible with or has an affinity for the component (a) of (A) and which has a polar group.
DETAILED DESCRIPTION OF THE INVENTION
The resin composition of the present invention comprises, as the component (a) of (A), a styrene-based polymer having a syndiotactic configuration. The syndiotactic configuration in the styrene-based polymer as referred to herein indicates that the stereochemical structure of the polymer is syndiotactic or, that is, such that the phenyl groups or substituted phenyl groups which are in the side chains of the polymer are located alternately in opposite directions relative to the main chain of the polymer that consists of carbon-carbon bonds. The tacticity of the polymer is quantitatively determined through nuclear magnetic resonance thereof using a carbon isotope (
13
C-NMR). The tacticity as determined through
13
C-NMR can be represented by the proportions of the structural units as continuously connected to each other, for example, in terms of diad for two structural units, triad for three structural units and pentad for five structural units. The styrene-based polymer having a syndiotactic configuration as referred to herein includes, for example, polystyrene, poly(alkylstyrene), poly(halogenostyrene), poly(halogenoalkylstyrene), poly(alkoxystyrene), poly(vinyl benzoate), hydrogenated polymers of these, mixtures of these, and copolymers consisting essentially of these, which have generally 75% or more, preferably 85% or more of syndiotacticity of racemic diad, or have generally 30% or more, preferably 50% or more of syndiotactcity of racemic pentad. The poly(alkylstyrene) includes, for example, poly(methylstyrene), poly(ethylstyrene), poly(isopropylstyrene), poly(tert-butylstyrene), poly(p
Chino Shinji
Okada Akihiko
Satoh Nobuyuki
Idemitsu Petrochemical Co. Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Wilson D. R.
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