JPH03229760A - Polyarylene sulfide resin composition and its preparation method - Google Patents

Abstract

PURPOSE:To obtain a resin composition which is prevented from forming gases during molding, is lowly discolored and has high whiteness and stable quality by mixing a polyarylene sulfide resin with an inorganic filler surface-coated with an organic stabilizer. CONSTITUTION:A process for preparing a polyarylene sulfide resin composition by mixing a polyarylene sulfide resin with an inorganic filler, wherein 100 pts.wt. polyarylene sulfide resin (e.g. one comprising p-phenylene sulfide groups) is mixed with 5-400 pts.wt. inorganic filler (e.g. glass or carbon fiber) surface- coated with 0.01-2.5wt.% (based on the inorganic filler) organic stabilizer [e.g. tri(nonylphenyl)phosphite]. According to the above process, the title composition which is prevented from causing discoloration and has high whiteness because the oxidative deterioration of the resin is small during the production of the composition and which has stable quality and moldability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyarylene sulfide resin composition containing an inorganic filler and a method for preparing the same. More specifically, the present invention relates to a polyarylene sulfide resin composition that exhibits little oxidative deterioration of the resin during composition production, suppresses discoloration, has high whiteness, and has stable quality and moldability, and a method for preparing the same.

[Conventional technology and its issues]

Polyarylene sulfide (PAS) resins, typified by polyphenylene sulfide (PPS) resins, are often used as compositions containing inorganic fillers and have excellent mechanical properties, high heat resistance, chemical resistance, and flame retardancy. In addition, due to its high processing productivity and cost performance, demand has been increasing in recent years as it fits well with market needs as electrical/electronic equipment parts materials, automobile equipment parts materials, and chemical parts materials. .

In the past, it was difficult to obtain molded products with high whiteness without discoloration because PAS resin was actively heated and reacted with oxygen during production to thicken it, but in recent years PAS resin
The polymerization method of AS resin has shown remarkable progress, and it has become possible to obtain a resin with high whiteness at the end of polymerization.

However, this resin composition is inherently susceptible to the effects of oxygen at high temperatures, and during the subsequent process of kneading and extrusion with fillers, discoloration progresses due to the effects of heat and oxygen, and the degree of whiteness decreases. The problem remained that the hue fluctuated.

Further, there are also problems such as the additive components decomposing during melt-kneading with the filler, generating gas, or adhering to molds etc. during molding.

Furthermore, in the electrical and electronic parts industry, which is one of the main demand destinations for this resin, surface mount technology (S!JT) is used to attach components to wiring boards for the purpose of downsizing equipment, rationalizing production, and stabilizing production. During this process, severe heating such as soldering is often required when attaching parts, and under such processing conditions, it is particularly desirable to suppress discoloration and decomposition.

As a means to solve these problems, conventionally it has been proposed to add stabilizers such as antioxidants to membranes during polymerization or extrusion processing, but many stabilizers do not work on their own due to the high processing temperature of PAS resin. is undesirable because it decomposes or changes color. Patent application No. 1-164310 and No. 1-1 proposed by the inventors
Stabilizers such as 64311 are relatively effective but may not be sufficient.

[Means to solve the problem]

The inventors of the present invention have aimed at maintaining the excellent heat resistance, solvent resistance, flame retardance, mechanical properties, and crystallinity of PAS resin compositions, especially PPS resin compositions, and suppressing gas generation during molding. In order to obtain a resin composition with little discoloration, high whiteness, and stable quality, we conducted extensive studies, and since the discoloration is most noticeable during melt extrusion with fillers, we decided to use inorganic fillers in this process. Since there is a large amount of oxygen (air) brought in by the filler, there is a possibility that the filler will react at the interface where it comes into contact with the high-temperature resin, causing discoloration.Furthermore, fillers such as glass fiber are generally used with various types of fillers to increase their affinity (adhesiveness) with the resin. It is treated with an organic surface treatment agent, and is sized with various organic substances as a binder for handling reasons, so we assume that these deposits may decompose under high temperatures and cause problems such as discoloration. It was predicted that the discoloration prevention effect would be doubled if stabilizers such as antioxidants were concentrated at the interface of the filler, and as a result of adding the stabilizer by attaching it to the surface of the filler, Compared to adding a stabilizer to the blend raw materials, even if the amount of stabilizer added is reduced, it has a sufficient stabilizing effect, and the discoloration property is significantly improved.
Furthermore, the present inventors have discovered that the generation of decomposed gas and the resulting buildup of deposits on molding molds, etc. can be improved, and that molded products with high whiteness can be obtained, leading to the completion of the present invention.

That is, in the present invention, in preparing a composition in which a polyarylene sulfide resin is blended with an inorganic filler, 0.0 parts by weight of an organic stabilizer is added to the reserved surface of 100 parts by weight of the polyarylene sulfide resin. A method for preparing a polyarylene sulfide resin composition characterized by blending 5 to 400 parts by weight of an inorganic filler attached in an amount of 25% by weight (based on the inorganic filler), and a resin composition obtained by such a preparation method. It is related to.

The base resin used in the composition of the present invention is mainly composed of PAS resin, and the repeating unit → ^r-5+ (however, Ar
is mainly composed of arylene groups.

Examples of the arylene group include p-phenylene group, m
-phenylene group, 0-)unicine group, substituted phenylene group, p, p'-diphenylene sulfone group, p, ρ''-biphenylene group, p, p''-diphenylene ether group, p
, p'-diphenylenecarbonyl group, naphthalene group, etc. can be used.

In this case, among the arylene sulfide groups composed of the above-mentioned arylene groups, a polymer using the same repeating units, that is, a homopolymer, can be used, or from the viewpoint of processability of the composition, different repeating units can be used. Copolymers containing copolymers may be preferred.

As the homopolymer, one in which a p-phenylene group is used as an arylene group and a p-phenylene sulfide group is used as a repeating unit is particularly preferably used.

As a copolymer, a combination of two or more different types of arylene sulfide groups consisting of the above-mentioned arylene groups can be used, and among them, a combination containing a p-phenylene sulfide group and an m-phenylene sulfide group is particularly preferably used. Among these, p-phenylene sulfide group is 50 mol% or more, preferably 7
Those containing 0 mol % or more are suitable from the viewpoint of physical properties such as heat resistance, moldability, and mechanical properties.

In addition, m-phenylene sulfide group is 5 to 50 mol%,
In particular, a copolymer containing 10 to 25 mol% is preferable. In this case, components in which the repeating units are contained in blocks (for example, those described in JP-A-61-14228) have better processability than those in random shapes;
In addition, it has excellent heat resistance and mechanical properties, so it can be preferably used.

Moreover, among these, a polymer having a substantially linear structure obtained by condensation polymerization from a polymer mainly composed of a difunctional halogen aromatic compound can be particularly preferably used.

In addition to polymers with a linear structure, when performing condensation polymerization, 3
Polymers in which a partially crosslinked structure is formed by using a small amount of a crosslinking agent such as a polyhaloaromatic compound having halogen substituents or more can also be used, or the above-mentioned linear structured polymer is heated at high temperature in the presence of oxygen. Polymers whose melt viscosity is increased and moldability is improved can also be used.

However, since the crosslinked polymer heated at high temperature in the presence of oxygen is colored brown, a resin composition with high whiteness, which is one of the objects of the present invention, cannot be obtained.

However, since it has a resin stabilizing effect, it is effective in reducing gas generation during molding, deposits on molds, etc., and obtaining a resin composition with less deterioration in physical properties.

Melt viscosity of polyarylene sulfide resin as the base resin used in the present invention (temperature 310°C, shear rate 1
200/sec) is preferably 10 to 10,000 poise. Among them, those in the range of 50 to 5000 poise are
It is particularly preferred because it has an excellent balance between mechanical properties and fluidity. If the melt viscosity is less than 10 poise, it is not preferable because the mechanical strength is insufficient. Also, the melt viscosity is 100
If it exceeds 0.00 poise, the fluidity of the resin composition during injection molding becomes poor, making the molding operation difficult, which is not preferable.

Furthermore, as the base resin of the present invention, in addition to the polyarylene sulfide resin, it is also possible to use a small amount of other thermoplastic resin as an auxiliary amount, within a range that does not impede the purpose.

The other thermoplastic resin used here may be any thermoplastic resin that is stable at high temperatures. For example, polyolefin (co)polymers, aromatic polyesternope polyamide polymers made of aromatic dicarboxylic acids and diols or oxycarboxylic acids such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, ABS, polyphenylene oxides, and polyalkyl acrylates. , polyacetal, polysulfone, polyethersulfone, polyetherimide, polyetherketone, fluororesin, and the like.

Moreover, two or more types of these thermoplastic resins can also be used in combination.

The inorganic filler used in the composition of the present invention can be any filler commonly used for thermoplastic resins, and fibrous, powdery, or plate-like fillers are used.

Among these, fibrous fillers include glass fiber, asbestos fiber, carbon fiber, silica fiber, silica/alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, stainless steel,
Examples include inorganic sacrificial fibrous materials such as moldy fibrous materials of metals such as aluminum, titanium, copper, and brass. Particularly typical fibrous fillers are glass fibers or carbon fibers. Note that high melting point organic fibrous substances such as polyamide, fluororesin, and acrylic resin can also be used.

On the other hand, silicates such as carbon black, silica, quartz powder, glass peas, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, and wollastonite can be used as particulate fillers. Metal oxides such as iron oxide, titanium oxide, zinc oxide, alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, and other silicon carbide and nitride. Examples include silicon, boron nitride, and various metal powders.

Further, 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.

The amount of inorganic filler used is 5 to 400 parts by weight, preferably 10 to 200 parts by weight, per 100 parts by weight of polyarylene sulfide resin. If it is smaller than 5-fold N part, the weaving strength will not be sufficient, and if it is too large, the forming operation will be difficult.

These fillers are preferably used after surface treatment or convergence treatment with a functional compound such as an epoxy compound, an isocyanate compound, a silane compound, a titanate compound, or a polymer.

A feature of the present invention is that an organic stabilizer is attached to the inorganic filler in advance and added to the resin.

As the organic stabilizer attached to the surface of the inorganic filler, phenol-based, amine-based, sulfur-based, and phosphorus-based organic compounds, which are generally used to prevent oxidation of resins and rubbers, are used.

Among these, organic phosphorus stabilizers and phenolic antioxidants are particularly preferred because they have excellent discoloration inhibiting effects, generate less gas during molding, and are well balanced.

As the organic phosphorus stabilizer, for example, Japanese Patent Application No. 1-1643
No. 10, No. 1-164311, phosphite-based and phosphonite-based organic compounds are preferred, such as triallylphosphites such as triphenylphosphite and tri(nonylphenyl)phosphite, and distearylpentalylphosphite. Erythritol diphosphite, cyclic neopentane tetrayl bis(
2,4-di-t-butylphenyl-phosphite),
Di(2,6-di-t-butyl-4-methylphenyl)
Heat-resistant phosphites deprived of pentaerythritol siphosphite, tetrakis(2,4-di-t-butylphenyl)-4,4-biphenylenefunasphonite, etc. 7
Typical examples include osphonite compounds.

However, inorganic phosphorous compounds, such as hypophosphorous acid or its salts, have a low heat resistance and are easily decomposed, and the ions they contain tend to affect the crystallinity of PAS and lower the degree of crystallinity, so they are not preferred. ).

Furthermore, as phenolic antioxidants, a series of phenol derivatives generally referred to as hindered phenols are effective. Among them, high-molecular-weight compounds with particularly high heat resistance have a good balance between moldability and resin stabilization. Examples of this type of compound include pentaerythritr-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] and triethylene glycol-bisC3-(3t-phthyl-5-methyl- 4
-hydroxyphenyl)propionate] is cited as a representative example.

To attach these organic stabilizers to the surface of an inorganic filler, a solution in which the stabilizer is dissolved or dispersed in a solvent is sprayed and stirred onto the inorganic filler in a Henschel mixer, and then the solvent is removed. Any method can be applied as long as it can be uniformly adhered to the surface of the inorganic filler, including evaporation, a method of incorporating a stabilizer into the sizing agent when consolidating the inorganic filler, and attaching it at the same time as the sizing process. However, the method of attachment is not limited.

The amount of stabilizer attached to the surface of the inorganic filler is 0.01~
It is appropriate to set the amount to 2.5% by weight, preferably 0.02 to 1% by weight, and if the amount is less than this, the effect of improving whiteness, which is the objective of the present invention, will not be sufficient and the amount will be too much. During processing, odor and gas are generated, which is undesirable.

Moreover, the organic stabilizers of the present invention can also be used in combination of two or more kinds.

The compositions of the present invention may further contain known substances commonly added to thermoplastics and thermosets, namely antistatic agents, flame retardants, colorants such as dyes and pigments, lubricants and crystallization promoters. , a crystal nucleating agent, etc. can also be added as appropriate depending on the required performance.

The polyarylene sulfide resin composition of the present invention can be prepared using equipment and methods generally used for preparing synthetic resin compositions.

In other words, the necessary ingredients can be mixed, kneaded using a single- or twin-screw extruder, and extruded to form pellets for molding.In particular, during the melt extrusion process, the inorganic filler is melted while the resin component is being melted. The method in which the fibrous filler is added causes less damage to the fibrous filler, and the effects of the present invention are fully exhibited.

〔Example〕

The present invention will be specifically explained below using Examples, but the present invention is not limited thereto.

Examples 1 to 15 and Comparative Examples 1 to 13 The commercially available organic stabilizers shown in Table 1.2.3 were added to the inorganic filler and sized by incorporating the commercially available organic stabilizers shown in Tables 1 to 1. As shown in 3, polyphenylene sulfide resin (manufactured by Kureha Chemical Industry Co., Ltd., product name:
30 in a blender with Fortron KPS J)
Mixed for seconds. This mixture is then heated to a cylinder temperature of 31
The mixture was melt-kneaded in an extruder at 0°C to produce pellets of a polyphenylene sulfide resin composition.

Using this pellet, the cylinder temperature was 32°C in an injection molding machine.
Mold the STM test piece at 0°C and mold temperature of 150°C,
Tensile strength and tensile elongation were measured.

In addition, the gas generated from the nozzle during extrusion and molding was detected from the odor and visual observation during molding, and the degree of deposits was determined from the surface condition of the mold after repeated molding.

Also, under the same molding conditions, a flat plate of 8 axes m x 80 mm x 3 m + n was molded using a color difference meter 2-1001 manufactured by Nippon Heavy Industries Co., Ltd.
The hue (whiteness value) of the flat plate was measured using a DP type. The results are shown in Table 1.2.3.

For comparison, similar tests were also conducted in the absence of a stabilizer and on extruded pellets, etc., in which the same amount of the same stabilizer was mixed with the resin in a conventional manner without adhering to the filler. The results are also shown in Table 1.2.3.

〔Effect of the invention〕

As is clear from the above description and examples, the PAS resin composition prepared by the preparation method of the present invention has little discoloration during processing such as extrusion and molding, and can stably obtain molded products with high whiteness. There is less gas generation during the process, and the generation of deposits on the mold tends to be suppressed, and since it is effective even in a small amount compared to the usual method of using stabilizers, it is less expensive even if expensive stabilizers are used. It also has the advantage of minimizing the increase in carbon dioxide, making it promising as a material for various functional parts, especially electronic parts assembled using surface mount technology.

Claims (1)

[Claims] 1. In preparing a composition in which an inorganic filler is blended with a polyarylene sulfide resin, 0.0% of an organic stabilizer is added to the surface of 100 parts by weight of the polyarylene sulfide resin in advance.
A method for preparing a polyarylene sulfide resin composition, which comprises blending 5 to 400 parts by weight of an inorganic filler deposited in an amount of 01 to 2.5% by weight (based on the inorganic filler). 2. The method for preparing a polyarylene sulfide resin composition according to claim 1, wherein the organic stabilizer is a phosphite-based and/or phosphonite-based organic compound. 3. The method for preparing a polyarylene sulfide resin composition according to claim 1, wherein the organic stabilizer is a phenolic antioxidant. 4. The method for preparing a polyarylene sulfide resin composition according to any one of claims 1 to 3, wherein the inorganic filler is glass fiber. 5. A resin composition obtained by the preparation method according to any one of claims 1 to 4.