JP2005162886A - Polyarylene sulfide resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyarylene sulfide resin composition markedly improved in impact resistance at a low temperatures without impairing its injection moldability. <P>SOLUTION: The polyarylene sulfide resin composition is obtained by compounding (A) 100 pts.wt. of a polyarylene sulfide resin with (B) 1-30 pt(s). wt. of an olefin copolymer with an α-olefin and an α, β-unsaturated acid glycidyl ester as the main components and (C) 10-50 pts.wt. of an olefin copolymer of ethylene and a ≥5C α-olefin having a melt index of ≤5 g/10min determined in accordance with ASTM D-1238 and a specific gravity of ≤0.9. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyarylene sulfide resin composition having excellent impact resistance at low temperatures and suitable for injection molding.

  Polyarylene sulfide (hereinafter abbreviated as PAS) resin represented by polyphenylene sulfide (hereinafter abbreviated as PPS) resin has high heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame retardancy. For this reason, it is widely used for electrical / electronic equipment parts materials, automotive equipment parts materials, chemical equipment parts materials, and the like. However, PAS resins have a fundamental drawback that they have poor toughness and are fragile, and have insufficient mechanical properties represented by impact resistance. As a conventional method for solving this problem, it is known to blend various elastomers. In particular, olefin copolymers mainly composed of α-olefin and glycidyl ester of α, β-unsaturated acid are excellent in compatibility with PAS resin as shown in Patent Documents 1 to 3 and the like. Improves impact resistance. However, recently, with respect to the above-mentioned electrical / electronic equipment component materials and automotive equipment component materials, the demand for impact resistance characteristics has become stricter, and particularly, excellent impact resistance characteristics under a low temperature use environment are required. However, the impact resistance improvement effect at low temperatures was insufficient.

On the other hand, methods for blending an olefin copolymer of ethylene and an α-olefin having 5 or more carbon atoms have been proposed for the purpose of further improving impact resistance (Patent Documents 4 to 7). However, sufficient impact resistance in a low temperature use environment is not necessarily obtained.
JP 58-154757 A JP 59-152953 A JP 59-189166 Japanese Patent Publication No. 4-24388 JP-A-5-230370 JP-A-7-157660 JP 11-49952 A

  The object of the present invention is to solve the above-mentioned problems of the prior art and to provide a PAS resin composition having improved impact resistance under a low temperature use environment.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a PAS resin contains an olefin copolymer mainly composed of an α-olefin and a glycidyl ester of an α, β-unsaturated acid and a specific ethylene-olefin. It has been found that the impact resistance at low temperatures can be greatly improved without impairing the injection moldability by blending the copolymer together, and the present invention has been completed.

That is, the present invention
(A) For 100 parts by weight of polyarylene sulfide resin,
(B) 1-30 parts by weight of an olefin copolymer based on α-olefin and α, β-unsaturated glycidyl ester
(C) 10-50 parts by weight of an olefin copolymer of ethylene and an α-olefin having 5 or more carbon atoms, having a melt index of 5 g / 10 minutes or less and a specific gravity of 0.9 or less, measured according to ASTM D-1238 Is a polyarylene sulfide resin composition comprising

  Hereinafter, the constituent components of the present invention will be described in detail. The PAS resin as the component (A) used in the present invention is mainly composed of — (Ar—S) — (wherein Ar is an arylene group) as a repeating unit. Examples of the arylene group include p-phenylene group, m-phenylene group, o-phenylene group, substituted phenylene group, p, p'-diphenylene sulfone group, p, p'-biphenylene group, p, p'-di A phenylene ether group, p, p′-diphenylenecarbonyl group, naphthalene group, and the like can be used. In this case, among the arylene sulfide groups composed of the above-mentioned arylene groups, in addition to a polymer using the same repeating unit, that is, a homopolymer, a copolymer containing different repeating units from the viewpoint of processability of the composition May be preferred.

  As the homopolymer, those having a p-phenylene sulfide group as a repeating unit and using a p-phenylene group as an arylene group are particularly preferably used. In addition, as the copolymer, among the arylene sulfide groups comprising the above-mentioned arylene groups, two or more different combinations can be used, and among them, a combination containing a p-phenylene sulfide group and an m-phenylene sulfide group is particularly preferably used. It is done. Among these, those containing 70 mol% or more, preferably 80 mol% or more of p-phenylene sulfide groups are suitable from the viewpoint of physical properties such as heat resistance, moldability and mechanical properties.

  Further, among these PAS resins, a high molecular weight polymer having a substantially linear structure obtained by condensation polymerization from a monomer mainly composed of a bifunctional halogen aromatic compound can be particularly preferably used. In addition to the PAS resin with a structure, when polycondensation is used, a polymer in which a branched structure or a crosslinked structure is partially formed by using a small amount of a monomer such as a polyhaloaromatic compound having 3 or more halogen substituents is also used. It is also possible to use a polymer in which a low molecular weight linear structure polymer is heated at a high temperature in the presence of oxygen or an oxidant to increase the melt viscosity by oxidative crosslinking or thermal crosslinking, thereby improving the molding processability.

The PAS resin as component (A) is mainly composed of the above-mentioned linear PAS (310 ° C., viscosity at 1200 sec ^{−1 at} 10 to 300 Pa · s), and a part thereof (1 to 30% by weight, preferably Also suitable is a mixed system with a branched or crosslinked PAS resin having a relatively high viscosity (300 to 3000 Pa · s, preferably 500 to 2000 Pa · s).

  In addition, the PAS resin used in the present invention is preferably one obtained by purifying by-product impurities and the like by performing acid cleaning, hot water cleaning, organic solvent cleaning (or a combination thereof) after polymerization.

  Next, an olefin copolymer mainly composed of an α-olefin and a glycidyl ester of α, β-unsaturated acid as components (B) used in the present invention is an α-olefin and an α, β-unsaturated acid. A glycidyl ester of a glycidyl ester or a glycidyl ester of an α-olefin, an α, β-unsaturated acid, and a compound copolymerizable therewith, one of the copolymerizable compounds Or 2 or more types can be used. Furthermore, a graft copolymer in which one or two or more polymers or copolymers are chemically bonded in a branched or crosslinked structure to the above-mentioned copolymer can also be used.

  Here, examples of the α-olefin include ethylene, propylene, butylene and the like, and ethylene is preferable. Examples of the glycidyl ester of α, β-unsaturated acid include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and the like, and glycidyl methacrylate is preferred.

  A copolymer of an α-olefin and a glycidyl ester of an α, β-unsaturated acid can be obtained by copolymerization by a generally well-known radical polymerization reaction. The ratio of the α-olefin to the glycidyl ester of the α, β-unsaturated acid is preferably 70 to 99% by weight of the α-olefin and 1 to 30% by weight of the glycidyl ester of the α, β-unsaturated acid.

  The amount of component (B) is 1 to 30 parts by weight, preferably 3 to 20 parts by weight, per 100 parts by weight of (A) polyarylene sulfide resin. If the amount of the component (B) is too small, the effect of improving the impact resistance cannot be obtained. If the amount is too large, mechanical properties such as rigidity are impaired, which is not preferable.

  Next, in the present invention, as component (C), an olefin copolymer of ethylene and an α-olefin having 5 or more carbon atoms is blended as an essential component. Specific examples of the component (C) include ethylene-pentene copolymer, ethylene-hexene copolymer, ethylene-heptene copolymer, ethylene-octene copolymer, ethylene-nonene copolymer, ethylene-decene. Examples thereof include olefin copolymers, and preferred is an olefin copolymer of ethylene and an α-olefin having 6 to 12 carbon atoms, such as an ethylene-octene copolymer. These copolymers are usually prepared by well-known radical polymerization. These copolymers are preferably polymerized using a metatheron catalyst as a polymerization catalyst for the purpose of obtaining a narrow molecular weight distribution and uniform copolymer.

  One of the features of the present invention is that the component (C) has a melt index measured according to ASTM D-1238 of 5 g / 10 min or less and a specific gravity of 0.9 or less, preferably 0.89 or less, more preferably 0. The point is to selectively use an olefin copolymer of ethylene and an α-olefin having 5 or more carbon atoms, which is .88 or less. When the melt index is greater than 5 and the specific gravity is greater than 0.9, it is difficult to obtain the effect of improving impact resistance at low temperatures, which is the object of the present invention. That is, when the melt index is greater than 5, the olefin copolymer is not easily dispersed in the PAS resin, and when the specific gravity is greater than 0.9, the flexibility of the olefin copolymer is poor. This is not preferable because the effect of improving the impact resistance is not obtained.

  The amount of component (C) is 10 to 50 parts by weight, preferably 20 to 40 parts by weight, per 100 parts by weight of (A) polyarylene sulfide resin. If the amount of component (C) is too small, the effect of improving impact resistance at low temperatures cannot be obtained, and if it is too large, mechanical properties such as rigidity are impaired, which is not preferable.

  The resin composition of the present invention can be blended with an inorganic filler for the purpose of improving performance such as mechanical strength, heat resistance, dimensional stability (deformation resistance, warpage), and electrical properties. Depending on the case, fibrous, granular and plate-like fillers are used. Examples of the fibrous filler include glass fiber, asbestos fiber, carbon fiber, silica fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, boron fiber, potassium titanate fiber, stainless steel, aluminum, titanium, copper, brass, etc. Examples thereof include inorganic fibrous materials such as metal fibrous materials. Particularly typical fibrous fillers are glass fibers or carbon fibers. High melting point organic fiber materials such as polyamide, fluororesin and acrylic resin can also be used. On the other hand, as the granular filler, carbon black, silica, quartz powder, glass beads, glass powder, calcium oxalate, aluminum oxalate, kaolin, talc, clay, diatomaceous earth, wollastonite and oxidation Metal oxides such as iron, titanium oxide, zinc oxide and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, other silicon carbide, silicon nitride, boron nitride, Various metal powders are mentioned. Examples of the plate-like filler include mica, glass flakes, and various metal foils. These inorganic fillers can be used alone or in combination of two or more. In using these fillers, it is desirable to use a sizing agent or a surface treatment agent if necessary. Examples of this are functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds. These compounds may be used after being subjected to surface treatment or convergence treatment in advance, or may be added at the same time as material preparation. The amount of the inorganic filler used is 10 to 300 parts by weight per 100 parts by weight of the component (A) PAS resin. If it is less than 10 parts by weight, the mechanical strength is slightly inferior, and if it is too large, the molding operation is difficult. In addition, there is a problem with the mechanical strength of the molded product.

  Moreover, the silane compound can be mix | blended with the resin composition of this invention in order to improve a burr | flash etc. in the range which does not impair the effect of this invention. The silane compound includes various types such as vinyl silane, methacryloxy silane, epoxy silane, amino silane, mercapto silane, etc., for example, vinyl trichloro silane, γ-methacryloxy propyl trimethoxy silane, γ-glycidoxy propyl trimethoxy silane. , Γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like, but are not limited thereto.

  The resin composition of the present invention can be used in combination with a small amount of other thermoplastic resins in addition to the above components depending on the purpose. The other thermoplastic resin used here may be any thermoplastic resin that is stable at high temperatures. For example, aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate, and aromatic polyesters composed of diol or oxycarboxylic acid, polyamide, polycarbonate, ABS, polyphenylene oxide, polyalkyl acrylate, polysulfone, polyethersulfone, polyetherimide , Polyether ketone, fluororesin and the like. These thermoplastic resins can also be used as a mixture of two or more.

  Furthermore, as a molded article composition used in the present invention, known substances generally added to thermoplastic resins, that is, stabilizers such as antioxidants, flame retardants, colorants such as dyes and pigments, lubricants and crystallization Accelerators, crystal nucleating agents, and the like can be appropriately added according to the required performance.

  The resin composition of the present invention can be prepared by facilities and methods generally used for preparing a synthetic resin composition. In general, necessary components can be mixed, melt-kneaded using a single-screw or twin-screw extruder, and extruded to form pellets for molding. The resin temperature during this melt-kneading is preferably 360 ° C. or lower in order to prevent thermal degradation of the olefin copolymer. It is also a preferred method to melt-extrude the resin component and add and mix an inorganic component such as glass fiber in the middle. The material pellets thus obtained can be molded using generally known thermoplastic resin molding methods such as injection molding, extrusion molding, vacuum molding, compression molding, etc., but injection molding is most preferred. .

Next, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these. The specific substances (A), (B) and (C) used in Examples and Comparative Examples are as follows.
(A) Polyphenylene sulfide (PPS) resin, Kureha Chemical Industry Co., Ltd., Fortron KPS (viscosity at 310 ° C., shear rate of 1200 sec ⁻¹ 140 Pa · s)
(B) Olefin copolymer based on α-olefin and α, β-unsaturated glycidyl ester
B-1; Ethylene / glycidyl methacrylate copolymer
B-2: Copolymer obtained by grafting methyl methacrylate / butyl acrylate copolymer to ethylene / glycidyl methacrylate copolymer
(C) Olefin copolymer
C-1; ethylene-hexene copolymer (melt index = 3 g / 10 min, specific gravity = 0.85)
C-2; ethylene-octene copolymer (melt index = 1.6 g / 10 min, specific gravity = 0.897)
C-3: ethylene-octene copolymer (melt index = 1 g / 10 min, specific gravity = 0.857)
C-4; ethylene-octene copolymer (melt index = 5 g / 10 min, specific gravity = 0.870)
C′-1; ethylene-hexene copolymer (melt index = 8 g / 10 min, specific gravity = 0.880)
C′-2; ethylene-octene copolymer (melt index = 3.5 g / 10 min, specific gravity = 0.910)
Examples 1-7, Comparative Examples 1-9
The components (A), (B), and (C) shown in Tables 1 and 2 are mixed for 5 minutes with a Henschel mixer, and the mixture is put into a twin screw extruder with a cylinder temperature of 320 ° C. and melt kneaded at a resin temperature of 350 ° C. And pellets of the resin composition were made.

  Next, an Izod impact test piece was molded in accordance with ASTM D-256 at a cylinder temperature of 320 ° C. and a mold temperature of 150 ° C. with an injection molding machine, and the notch side impact strength was measured. Moreover, after leaving it to stand at -30 degreeC atmosphere for 2 hours or more, the notch side impact strength was measured. The results are shown in Tables 1-2.

Claims (1)

(A) For 100 parts by weight of polyarylene sulfide resin,
(B) 1-30 parts by weight of an olefin copolymer based on α-olefin and α, β-unsaturated glycidyl ester
(C) 10-50 parts by weight of an olefin copolymer of ethylene and an α-olefin having 5 or more carbon atoms, having a melt index of 5 g / 10 minutes or less and a specific gravity of 0.9 or less, measured according to ASTM D-1238 A polyarylene sulfide resin composition comprising: