JP2001300977A - Insert molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insert molding of a polyarylene sulfide resin which is improved in high/low temperature impact properties. SOLUTION: In the molding obtained by the insert injection molding of a resin composition mainly containing the polyarylene sulfide resin at a mold temperature of 40-130 deg.C with metal or an inorganic solid, the calorific value after cold crystallization is at least 0.5 J/g (polyarylene sulfide resin).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insert molded product obtained by insert molding a polyarylene sulfide resin composition and a metal or inorganic solid, and more particularly to an insert molded product having improved high and low temperature impact characteristics. It is about.

[0002]

2. Description of the Related Art The insert molding method is based on the characteristics of resin and metal or inorganic solid (hereinafter, referred to as "solid").
(May be abbreviated as metal, etc.) This is a molding method that embeds metal, etc. in resin in order to make use of the characteristics of the material, and is applied to a wide range of fields such as automobile parts, electric / electronic parts, and OA equipment parts. Is one of the general molding methods. However, since the expansion rate and the shrinkage rate (so-called linear expansion coefficient) of resin and metal due to temperature change are extremely different, the resin part of the molded product is thin, or there is a portion having a large change in wall thickness and metal. In some cases, such as those having sharp corners, cracks occur immediately after molding, or cracks due to temperature changes during use. For this reason,
At present, the use and the shape of the molded product are considerably restricted.

[0003] Recently, in the field of automobiles, resinization around the engine has been advanced, and insert molded products have become important parts. In particular, for ignition systems and distributor parts, polyphenylene sulfide (hereinafter referred to as PP) together with metal products such as aluminum, copper, iron, and brass
Insert molded products wrapped with polyarylene sulfide (hereinafter sometimes abbreviated as PAS) resin typified by a resin have been studied, but this is because the structure of the insert molded product is complicated. In addition to the fact that there are many portions where the thickness of the resin varies, and because the location where the resin is used is near the engine, the change in high and low temperature is large, the performance required for the insert molded product is also high. Therefore, from these facts, recently, there has been a strong demand for a resin that can withstand long-term high-low temperature changes, that is, a resin having excellent high-low temperature impact characteristics.

[0004] PAS resins have high heat resistance, mechanical properties,
Because of its chemical resistance, dimensional stability, and flame retardancy, it is widely used in electrical and electronic equipment parts materials, automotive equipment parts materials, chemical equipment parts materials, etc. It is poor and brittle, and has the disadvantage that the reliability of the insert molded product against long-term high / low temperature changes is low. As a method of improving this, a method of adding various elastomers to a PAS resin has been proposed.
There are problems that the inherent strength of the resin is lowered and that the amount of gas generated during molding is too large to be practically used.

[0005]

Means for Solving the Problems In view of the above-mentioned problems, the present inventors have conducted intensive studies to obtain insert molded products having improved high and low temperature impact characteristics, and as a result, have specially developed a resin composition mainly composed of PAS resin. High-low temperature impact characteristics of insert molded products without changing the original characteristics of PAS resin by insert injection molding under special conditions (especially when the resin part is thin or metal etc. has sharp corners) Was found to be able to be significantly improved, and the present invention was completed.

That is, the present invention relates to a molded article obtained by insert injection molding a resin composition mainly composed of a polyarylene sulfide resin at a mold temperature of 40 to 130 ° C., wherein the calorific value of the cold crystallization is 0.5. The present invention relates to an insert-molded product obtained by insert-molding a metal or an inorganic solid having J / (polyarylene sulfide resin) g or more.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The PAS resin used in the present invention has a repeating unit
-(Ar-S)-(where Ar is an arylene group). 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'-diphenylene ether group, p, p ' -A diphenylenecarbonyl group, a naphthalene group or 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 a heterogeneous repeating unit from the viewpoint of processability of the composition Is sometimes preferred. As the homopolymer, one having a p-phenylene sulfide group as a repeating unit using a p-phenylene group as an arylene group is particularly preferably used. Further, as the copolymer, among the arylene sulfide groups consisting of the above-described arylene groups, two or more different combinations can be used. Among them, a combination containing a p-phenylene sulfide group and an m-phenylene sulfide group is particularly preferably used. Can be Among them, those containing a p-phenylene sulfide group in an amount of 70 mol% or more, preferably 80 mol% or more are suitable in terms of physical properties such as heat resistance, fluidity (moldability), and mechanical properties.

Among these PAS resins, a high molecular weight polymer having a substantially linear structure obtained by condensation polymerization from a monomer mainly comprising a bifunctional halogen aromatic compound can be particularly preferably used. PAS with linear structure
In addition to the resin, when polycondensation is performed, a polymer having a partially branched or cross-linked structure can be used by using a small amount of a monomer such as a polyhalo aromatic compound having three or more halogen substituents, A polymer having a relatively low molecular weight linear structure polymer heated at a high temperature in the presence of oxygen or an oxidizing agent to increase the melt viscosity by oxidative crosslinking or thermal crosslinking and to improve the moldability can also be used.

[0009] The PAS resin is a linear PAS (3
The viscosity at 10 ° C. and a shear rate of 1200 sec ⁻¹ is 10
300 Pa · s) and a part (1 to 30% by weight, preferably 2 to 25% by weight) of which has a relatively high viscosity (3
00 to 3000 Pa · s, preferably 500 to 2000 Pa
A mixed system with the branched or crosslinked PAS resin of s) may be used. Further, the PAS resin used in the present invention is, after polymerization, washed with an acid, washed with hot water, washed with an organic solvent (or a combination thereof).
It is preferable to remove and purify by-product impurities and the like by carrying out the above.

The resin composition used in the present invention may contain various reinforcing materials for improving the performance such as mechanical strength, heat resistance, dimensional stability (deformation resistance, warpage), and electrical properties. For this purpose, a fibrous, powdery or plate-like filler is used depending on the purpose. As the fibrous filler, glass fiber,
Asbestos fiber, carbon fiber, silica fiber, silica
Examples include inorganic fibrous substances such as alumina fibers, zirconia fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, and metal fibrous materials such as stainless steel, aluminum, titanium, copper, and brass. Particularly typical fibrous fillers are glass fibers and carbon fibers. In addition, a high-melting organic fibrous substance such as polyamide, fluororesin, and acrylic resin can also be used. On the other hand, powdered and granular fillers include carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, silicates such as wollastonite, and oxides. 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, boron nitride, silicon nitride; Various metal powders are included. Examples of the plate-like filler include mica, glass flake, various metal foils, and the like. These fillers can be used alone or in combination of two or more.

In using these fillers, if necessary, a sizing agent or a surface treatment agent may be used as long as the effects of the present invention are not impaired. This example is a functional compound such as an epoxy compound, an isocyanate compound, a silane compound and a titanate compound. These compounds may be used after being subjected to a surface treatment or a convergence treatment in advance, or may be added simultaneously with the preparation of the material.

The amount of the reinforcing material used is preferably from 5 to 300 parts by weight, more preferably from 50 to 20 parts by weight, per 100 parts by weight of the PAS resin.
0 parts by weight are used.

It is also preferable to incorporate various elastomer components into the resin composition used in the present invention in order to further improve the high / low temperature impact characteristics. Examples of such an elastomer component include polyolefin elastomers, polyester elastomers, fluorine elastomers, silicone elastomers, butadiene elastomers, polyamide elastomers, polystyrene elastomers, urethane elastomers, and various particle elastomers having a crosslinked structure at the center. And one or more kinds can be used. These elastomers are used to improve dispersibility.
It may be modified with a monomer having a functional group such as an acid anhydride, a glycidyl group and an isocyanate group. The use amount of these elastomers is preferably 5 to 100 parts by weight per 100 parts by weight of the PAS resin.

The resin composition used in the present invention may also contain a silane compound for the purpose of improving burrs and the like as long as the effects of the present invention are not impaired. Examples of the silane compound include various types such as vinyl silane, methacryloxy silane, epoxy silane, amino silane, and mercapto silane, for example, vinyl trichlorosilane, γ-
Examples include, but are not limited to, methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like.

Further, the resin composition used in the present invention may be used in combination with a small amount of another thermoplastic resin depending on the purpose. The other plastic resin used here may be any thermoplastic resin that is stable at high temperatures. For example, aromatic polyesters, polyamides, polycarbonates, and aromatic polyesters comprising an aromatic dicarboxylic acid such as polyethylene terephthalate and polybutylene terephthalate and a diol or an oxycarboxylic acid.
BS, polyphenylene oxide, polyalkyl acrylate, polysulfone, polyether sulfone, polyether imide, polyether ketone, fluororesin, polyethylene, polypropylene, olefin copolymer, glycidyl methacrylate / olefin copolymer, etc. it can. These thermoplastic resins can be used as a mixture of two or more kinds.

Further, the resin composition used in the present invention contains known substances which are generally added to a thermoplastic resin, such as a flame retardant, a coloring agent such as a dye or a pigment, a lubricant, a crystallization accelerator, and a nucleating agent. In addition, various antioxidants, heat stabilizers, weathering stabilizers and the like can be appropriately added according to required performance.

[0017] The resin composition of the present invention can be prepared by equipment and a method generally used for preparing a synthetic resin composition. Generally, necessary components are mixed, melt-kneaded using a single-screw or twin-screw extruder, and extruded to form molding pellets.

According to the present invention, the resin composition mainly composed of the PAS resin as described above is subjected to insert injection molding at a mold temperature (actually measured temperature of the mold surface) of 40 to 130 ° C. Characterized in that it is a metal or inorganic solid insert molded product having a heat value of 0.5 J / (polyarylene sulfide resin) g or more in cold crystallization. Normal,
PAS resin has a mold temperature above 130 ° C., preferably 15 ° C.
Molding conditions at a mold temperature of 0 ° C. or higher and sufficiently high crystallinity are recommended. At lower mold temperatures,
It has been said that sufficient crystallization does not proceed and desired characteristics cannot be obtained. However, 130 ° C for insert molded products
It has been found that, when molding is performed at a higher mold temperature, the residual stress generated around the insert component when the resin solidifies and shrinks in the mold is large, and the high / low temperature impact characteristics are remarkably deteriorated. On the other hand, as in the present invention, insert injection molding is performed at a mold temperature of 40 to 130 ° C., and the calorific value of cold crystallization of this molded product is 0.5 J / (polyarylene sulfide resin) g.
In the above cases, it was found that the residual stress in the molded article was small, and the high-low temperature impact characteristics were remarkably improved.

The preferred mold temperature is between 40 and 130 ° C.
More preferably, it is 80 to 120 ° C. When the mold temperature is lower than 40 ° C., the strength is remarkably low, and the releasability from the mold is deteriorated, so that the mold is not practical.

Further, there is a concern that a PAS resin molded product molded by a low-temperature mold may have a reduced strength due to insufficient crystallinity. To solve this problem, an annealing treatment is generally used in which heat treatment is performed after molding. It has been found that when this annealing treatment is performed, the original characteristics of a PAS resin that has been sufficiently crystallized can be obtained, and at the same time, excellent high-low temperature impact characteristics are maintained. A preferred annealing temperature is 15
0-220 ° C. is used, and the treatment time is preferably about 0.5-3.0 hours.

The material to be inserted into the resin is used for the purpose of taking advantage of its characteristics and compensating for the defects of the resin, so that the material whose shape is not deformed or melted is used. For this reason, metals such as aluminum, copper, iron, brass, and alloys thereof, and inorganic solids such as glass and ceramics, which are previously formed into rods, plates, pins, screws, etc., are used.

[0022]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
The specific substances of each component used in Examples and Comparative Examples are as follows. (A) Polyphenylene sulfide (PPS) resin Fortron KPS made by Kureha Chemical Industry Co., Ltd. (B) Reinforcing material B-1 Glass fiber; 13 μm φ, chopped strand B-2 Calcium carbonate; Average particle size 0.7 μm (C) Elastomer C-1 Ethylene / glycidyl methacrylate copolymer C-2 Copolymer obtained by grafting methyl methacrylate / butyl acrylate copolymer to ethylene / glycidyl methacrylate copolymer C-3 Polyester elastomer; Liteflex 655 manufactured by TICONA Examples 1 to 8 and Comparative Examples 1 to 7 (Preparation of resin pellets) (A), (B), and
The component (C) was mixed with a Henschel mixer for 5 minutes, and the mixture was charged into a twin-screw extruder having a cylinder temperature of 320 ° C (glass fiber B-1 was separately added from a side feed section of the extruder) and melt-kneaded. Then, pellets of the resin composition were prepared. (Preparation of insert molded products and evaluation of high / low temperature impact characteristics) Using the above resin composition pellets, resin temperature 320 ° C, injection time
40 seconds, cooling time 60 seconds, metal pin (14mm × 14mm × 24m
In m), insert injection molding was performed so that the minimum thickness of the resin portion was 1 mm, to produce an insert molded product. The mold temperature is measured by measuring the mold surface temperature during continuous molding with a surface thermometer.
Mold temperature. The processing conditions for the annealed molded article in Example 8 are 200 ° C. for 1 hour.

The obtained insert molded product was heated at 180 ° C. for 2 hours using a thermal shock tester, and then at −40 ° C.
After cooling for 2 hours, the process of raising the temperature to 180 ° C. was performed as one cycle, and a high / low temperature impact test was performed. The number of cycles until cracks were formed in the molded product was measured, and the high / low temperature impact characteristics were evaluated. . (Heat generation value of cold crystallization) Sample: 10 ± 1 mg of molded product Measurement temperature range: 50 to 150 ° C Temperature rise rate: 10 ° C / min Atmosphere: Nitrogen Measuring instrument: PERKIN ELMER Thermal Differential Scanner DSC7 100 to above under the above conditions The calorific value of the secondary crystallization peak that appeared during 130 ° C was measured. After measurement, the calorific value was 1 g of PAS resin.
The calorific value per unit was converted.

The results are shown in Tables 1 and 2.

[0025]

[Table 1]

[0026]

[Table 2]

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Claims (4)

[Claims] 1. A molded article obtained by insert injection molding of a resin composition mainly composed of a polyarylene sulfide resin at a mold temperature of 40 to 130 ° C., the calorific value of cold crystallization being 0.5 J / ( (Polyarylene sulfide resin) g or more, an insert molded product obtained by insert molding a metal or inorganic solid. 2. The insert-molded article according to claim 1, wherein the resin composition is a polyarylene sulfide resin composition in which 5 to 300 parts by weight of a reinforcing agent is blended with respect to 100 parts by weight of the polyarylene sulfide resin. 3. A resin composition comprising 100 parts by weight of a polyarylene sulfide resin and one or more elastomer components.
The insert molded article according to claim 1, which is a polyarylene sulfide resin composition containing 5 to 100 parts by weight of at least one kind. 4. An insert molded product obtained by subjecting the insert molded product according to claim 1 to an annealing treatment at 150 ° C. or more.