JPS6047059A - Polyphenylene ether resin composition - Google Patents

Abstract

PURPOSE:To provide the titled resin compsn. having excellent impact resistance and good moldability, by blending a rubber-modified polystyrene resin, a hydrogenated block copolymer elastomer and a specified styrene oligomer. CONSTITUTION:10-90pts.wt. polyphenylene ether resin [e.g. poly(2,6-dimethyl-1,4- phenylene)ether], 0-85wt% rubber-modified polystyrene resin (a resin obtd. by dispersing 3-30wt% rubbery random copolymer or polybutadiene in the matrix of polystyrene), 2-10wt% hydrogenated A-B-A type block copolymer elastomer (wherein A is a polymer block of an arom. vinyl hydrocarbon and B is a polymer block of a conjugated diene hydrocarbon) and 1-15wt% low-molecular resin (selected from alpha-methylstyrene oligomer, styrene oligomer and a styrene/acrylic oligomer) are blended together.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel resin composition, particularly a polyphenylene ether m resin, a -f m modified polystyrene resin, a hydrogenated block copolymer elastomer, and a particularly selected low molecular weight resin. The present invention relates to a polyphenylene ether resin composition having impact properties and improved moldability.

Polyphenylene ether is a well-known resin and is a high-performance industrial plastic with relatively high melt viscosity and softening point. However, polyphenylene ether resin itself is inferior to certain resins in terms of impact strength.
Furthermore, due to the high melt viscosity, it is commercially inappropriate to mold the resin itself while melting. This is because high temperatures are required to melt the resin, which causes various undesirable problems such as discoloration and oxidative deterioration. In order to solve this problem, a resin composition of polyphenylene ether and rubber-modified polystyrene resin has been proposed in US Pat.
No. 683.455. Although this resin composite acid improves the moldability of polyphenylene ether, it cannot be said to have sufficient impact resistance at a practical level.

In order to improve the impact resistance of a resin composition of polyphenylene ether and rubber-modified polystyrene resin, several methods have been proposed for blending an elastomer (rubber-like elastic body). For example, Japanese Patent Publication No. 57-56.941 discloses that a composition comprising 10 to about 9 D% of polyphenylene ether resin and rubber-modified polystyrene resin has A composed of a polymerized noalkenyl aromatic hydrocarbon block, and B
A resin composition is disclosed in which a hydrogenated block copolymer of the ABA type is blended with a polymerized diene block whose degree of unsaturation is reduced to 10% or less of the initial degree of unsaturation. Furthermore, the trap disclosed in JP-A-53-73248 is (a) a combination of polyphenylene ether and styrene resin.
(b) A self-extinguishing thermoplastic molding composition comprising a hydrogenated A-B-A block copolymer and a (cl aromatic phosphate ester compound) is disclosed.
Although the -B-A type block copolymer can be contained in an amount of 5% by weight or more, it contains an aromatic phosphoric acid ester compound as an essential component to impart self-extinguishing properties.

In order to improve the impact resistance of compositions of polyphenylene ether and rubber-modified polystyrene resin, attempts have been made to incorporate elastomers (rubber-like elastic bodies) into the compositions, but in general, blending in small amounts does not improve the impact resistance. less effective,
On the other hand, if a large amount is blended, unfavorable phenomena such as poor appearance and deterioration of melt flow characteristics due to poor dispersion of the elastomer will occur.

The inventor of the present invention has conducted intensive studies on methods for improving the impact resistance of a resin composition of polyphenylene ether and rubber-modified polystyrene resin without impairing moldability or product appearance. I found that the purpose was achieved.

That is, the resin composition of the present invention comprises - (al polyphenylene ether resin, (b) rubber-modified polystyrene resin, (c) hydrogenated A-B-Affi block copolymer, and (yama α-methylstyrene oligomer, - , styrene oligomer, sesame, and styrene acrylate co-oligomer.

The polyphenylene ether resin used in the present invention includes homopolymers or copolymers having the structural units shown in the following formula as repeating units, and graft copolymers obtained by graft polymerizing styrene to these polymers. Examples of polyphenylene ethers having repeating units include poly(2,6-
dimethyl-1,4-phenylene)nythyl, poly(2-
Methyl-6ethyl-1,4-phenylene) ether, poly(2-methyl-6propyl-1,4-phenylene)
Ether, poly (2-de-chiru 6-brobi-ru 12.
4-phenylene) ether, a copolymer derived from 2,6-dimethylphenol and 2.3.6-')limethylphenol, 2-methyl-6ethylphenol and 2
．． Examples include copolymers derived from 3.6-)trimethylphenol, and styrene-grafted polyphenylene ether, which is obtained by graft polymerizing styrene to Bo11 (2,6-dimethyl-1,4-phenylene) ether. Suitable polyphenylene ethers include poly(2,6-dimethyl-1,4-phenylene) ether, copolymers of 2,6-dimethylphenol and 2,5,6-)limethylphenol, styrene-grafted poly(2,6-dimethyl-1,4-phenylene) ether, ,6-cymethyl-1
．． 4-phenylene) ether. These polyphenylene ethers are obtained by polycondensing one or more alkylphenols in a manner known per se.

The rubber-modified polystyrene resin used in the present invention is one in which 6 to 60% by weight of polybutadiene or a rubbery random copolymer is dispersed in a polystyrene matrix, and usually 7% by weight is dispersed in the polybutadiene. The grafted rubber phase to which tyrene is grafted is present in an amount of 5 to 40% by weight. Such rubber-modified polystyrene resins are easily available on the market as impact-resistant polystyrenes or high-impact polystyrenes. A preferred rubber-modified polystyrene resin contains 6-8% by weight of polybutadiene;
It contains 7 to 22% by weight as a glazed rubber phase, and the intrinsic viscosity of polystyrene-q) lithics, measured in chloroform at 25°C, is 0-56-e/lr ~ 1, Od.
, 13/lr.

The hydrogenated block copolymer elastomer used in the present invention is A-
It has a B-A type structure, where λ and B each represent a polymer block, and the central block B is made of a polymer of a conjugated diene hydrocarbon compound, usually butadiene,
Before hydrogenation, it is a polybutadiene block.Due to hydrogenation, the double bonds in polybutadiene are converted into saturated hydrocarbons, and the terminal block A is a heavy vinyl aromatic hydrocarbon block. It represents a coalescing block, preferably a block made of polystyrene. The molecular weight of the end blocks is 4,000-115,000, preferably 5,000-15,000, and the molecular weight of the central block B is 20,000-450,000. Preferably 2
It is desirable that it is 5,000 to 100,000. Such hydrogenated block copolymer elastomer is easily available on the market, for example, "Krayton G1650J" from Shell Chemical Co., Ltd.
,'r Clayton G1652J, 'Clayton G16
It is commercially available under trade names and grade names such as 57J.

Next, among the low molecular weight resins used in the present invention, α-methylstyrene oligomer is α-methylstyrene oligomer represented by the following general formula.
- A pomopolymer of methylstyrene, with a molecular weight of 5
00-1000.

This oligomer is commercially available from Amoco Chemicals as "Resin-18" and is easily available on the market.
The weight average molecular weight due to C is about 3. ODD~25,000
It is a pale yellow transparent lumpy resin, and is commercially available from Sanyo Chemical Co., Ltd. under the trade name "Hi-f-3TJ."In addition, styrene-acrylic cooligomer has a weight average molecular weight of about 10,000 to 60,000 by GPC. Preferably, it means a copolymer of 15,000 to 50,000 styrene and acrylic acid, and this polymer can be obtained from Sanyo Chemical Co., Ltd. under the trade name [Himer SBMJ].

In the composition of the present invention, the above-mentioned components should be selected from the following ranges so as to significantly exhibit the effects of the present invention: (a) Polyphenylene ether resin 10 to 90% by weight , preferably 20 to 60% by weight, (b) rubber-modified polystyrene resin 0 to 85% by weight, preferably 20 to 7% by weight
5% by weight, (cl hydrogenated A-B-A type book copolymer 2-10
% by weight, and (cl) one or more low molecular weight resins selected from the group consisting of α-methylstyrene oligomers, styrene oligomers, and styrene acrylic co-oligomers, preferably 1 to 15% by weight, preferably 1 to 10% deuterium 96 There are no particular restrictions on the method for producing the composition, and conventional compounding techniques may be used as appropriate. In addition, various additives and fillers such as pigments, heat stabilizers, ultraviolet absorbers, etc. may be added to the composition of the present invention as desired, and this mixture is kneaded in an extruder, extruded, and then Cut into sized berets.

Examples are shown below, and unless otherwise specified in the examples, all parts and percentages are based on weight.

Examples 1 to 3 and Comparative Examples 1a to 6b Intrinsic viscosity measured in chloroform at 25°C is o, 5
Copolymer (2
,3I 6-drimethylphenol content fi5 mol%
monomer Jul) (PPE), rubber-modified polystyrene (gel content 16% by weight, intrinsic viscosity of the polystyrene matrix in chloroform at 25 °C o, 9 o d4
/gr) (HIPS), styrene-butadiene-
Hydrogenated block copolymer of styrene (manufactured by Shell Chemical Co., trade name "Krayton G 1650J") and α-methylstyrene oligomer [average molecular weight 685, softening point 99°
C (ASTM-E-28 ring and ball method) manufactured by Amoff Chemicals, trade name "Resin 18"] was mechanically mixed with the composition shown in Table 1, and then in a twin screw extruder manufactured by Ikegai Iron Works. Pellets were obtained by extrusion, and then various test pieces were molded using an injection molding machine manufactured by Meiki Seisakusho. The physical properties of the molded test piece are shown in the lower column of Table 1.

For comparison, the physical property values of compositions lacking some of the compositional components of the present invention are also listed in Table 1.

In Table 1, melt-to-rate is 265℃, load 3.8
The heat distortion temperature was measured at 264 psi at 3 inch thickness, the Izod impact value was measured at 3 inch thickness with a notch, and the tensile strength was measured at 3 inch thickness and yield point strength.

Example 4 A composition was manufactured according to the same steps as in Example 1 using the following composition components.

Ingredients Polyphenylene ether (same as Example 1) 38 parts Rubber modified polystyrene (Same as Example 1) 51.5 parts Hydrogenated A-B-A type block copolymer (Same as Example 1) 7.5 parts Styrene oligomer CG , p:c weight average molecular weight approximately 5000, softening point 95°C (ring and ball method)] 66 parts titanium oxide 2 parts hydrogenated bisphenol A phosphite polymer 04 parts 2.2'-methylenebis(4, methyl-6-characteristic melt Flow rate: 91?'/10 minutes Heat deformation temperature: 110 °C Notched Izot impact strength: 19-6 kl?・crn/am Tensile strength: 508 hours The resin composition obtained with the same composition as in Example 4 except that the weight average molecular weight by method was about 40,000, the softening point was 120 ° C. (ring and ball method), the melt flow rate was 6-3 Ir/10 minutes, Thermal deformation temperature was 116 DEG C. (IJ Izot impact strength was 21.4 to 9.~), and the tensile strength was 518 degrees per hour.

Patent applicant: Mitsubishi Gas Chemical Co., Ltd. Representative Kazuyoshi Nagano

Claims (1)

[Claims] France) Polyphenylene ether resin 10 to 90% by weight (b) Comb modified polystyrene resin 0 to 85% by weight (c) Hydrogenated A-B-A type block copolymer elastomer 2 to 1
0% by weight, and 1 to 15% by weight of one or more low molecular weight resins selected from the group consisting of α-methylstyrene oligomer, styrene □ oligomer, and styrene-acrylic co-oligomer. Polyphenylene ether 'rth4 fat Mi JK product (here,
AI'! , a polymer block of vinyl aromatic hydrocarbons,
B means a polymer block of a conjugated diene hydrocarbon compound 1)