JP2002179915A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyphenylene sulfide resin composition wherein balance of fluidity and a mechanical property is improved with a low incidence rate of flash. SOLUTION: A polyphenylene sulfide resin composition comprises: (A) a polyphenylene sulfide wherein melt viscosity measured in 500 sec-1 of a shear rate at 300 deg.C is 100-2,000 poise; (B) a polyphenylene ether; and (C) a glass fiber, in which the ratio of a total amount of component (A) and component (B) to component (C) is 75/25-30/70 based on a weight ratio of [(A)+(B)]/(C) and a ratio of component (A) to component (B) is 75/25-97/3 based on a weight ratio of (A)/(B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyphenylene sulfide resin composition, and more particularly to a polyphenylene sulfide resin composition suitable for injection molding.

[0002]

2. Description of the Related Art Polyphenylene sulfide has fluidity,
It is known as an engineering plastic having excellent mechanical strength and heat resistance, as well as good electrical properties and high rigidity, and is widely used as various materials such as materials for electronic and electric equipment parts. However, since the glass transition temperature is not so high, the rigidity of the molded article at a high temperature is greatly reduced. On the other hand, polyphenylene ether is an engineering plastic having excellent heat resistance, dimensional stability, electrical properties, and the like, but has a problem that melt flowability is poor and molding workability is poor. Therefore,
Both compositions have been proposed as molding materials that complement the drawbacks while maintaining the advantages of both (Japanese Patent Publication No. 56-3 / 1981).
No. 4032). However, this resin composition is
Although the moldability is slightly improved, there is a drawback that the fluidity is poor and burrs are frequently generated. for that reason,
Japanese Patent Application Laid-Open No. 7-278432 discloses that the use of a high-viscosity polyphenylene sulfide and a low-viscosity polyphenylene sulfide improves the fluidity of a melt during molding of a composition and can suppress the burr generation rate. Is disclosed. However, this method has a problem that the balance between the burr generation rate and the mechanical properties of the molded product having fluidity of the melt is insufficient.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a polyphenylene sulfide resin composition having a low burr generation rate and an improved balance between fluidity and mechanical properties. The purpose is to do.

[0004]

Means for Solving the Problems The present inventors have found that a resin composition which solves the above problems can be obtained by adding polyphenylene ether at a specific ratio. The present invention has been completed based on such findings. That is, the present invention relates to (A) 300 ° C., shear rate 5
(A) a polyphenylene sulfide having a melt viscosity of 100 to 2000 poise measured at 00 sec ^-1 , (B) polyphenylene ether and (C) glass fiber;
The total amount of the component and the component (B) and the ratio of the component (C) are 75/25 to 3 in a weight ratio of [(A) + (B)] / (C).
The present invention provides a polyphenylene sulfide resin composition wherein the ratio of the component (A) to the component (B) is 75/25 to 97/3 by weight of (A) / (B).

As described above, the polyphenylene sulfide resin composition of the present invention comprises the components (A), (B) and (C). Here, the component (A) is 300
Melt viscosity measured at 500 ° C. and a shear rate of 500 sec ⁻¹ is 10
Polyphenylene sulfide having a size of 0 to 2000 poise. If the melt viscosity is less than 100 poise, there is a disadvantage that the mechanical strength is reduced and burrs are increased.
If it exceeds 00 poise, there is a problem that the fluidity is reduced. Further, the polyphenylene sulfide used in the present invention preferably has a crystallization temperature of 225 ° C. or higher. If the crystallization temperature is lower than 225 ° C., the burr length may increase. In the present invention, polyphenylene sulfide (hereinafter, may be abbreviated as PPS) has, for example, the structural formula -Ph-S- (where Ph is a phenylene group)
Is a polymer containing 70 mol% or more of the repeating unit represented by. The typical one is represented by the following general formula (I)

[0006]

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[Wherein, R ¹ represents an alkyl group having 6 or less carbon atoms, an alkoxy group, a phenyl group, a carboxylic acid / metal salt,
A substituent selected from an amino group, a nitro group, a halogen atom such as fluorine, chlorine, and bromine; m is an integer of 0 to 4; n indicates an average degree of polymerization; A polyphenylene sulfide having at least 70 mol% of a repeating unit represented by the following general formula (II):

[0008]

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Wherein n is the same as above. ] Can be mentioned. PPS is generally classified into a PPS having a substantially linear structure having no branched or crosslinked structure and a PPS having a branched or crosslinked structure depending on the production method. In the present invention, any of these types may be used. PPS
As a repeating unit, a paraphenylene sulfide unit is 70 mol% or more, more preferably 80 mol%.
A homopolymer or copolymer containing the above is exemplified. Examples of the copolymerization structural unit, for example, a metaphenylene sulfide unit, an orthophenylene sulfide unit,
p, p'-diphenylene ketone sulfide unit, p,
p′-diphenylene sulfone sulfide unit, p, p ′
-Biphenylene sulfide unit, p, p'-diphenylene ether sulfide unit, p, p'-diphenylene methylene sulfide unit, and p, p'-diphenylene cumenyl sulfide unit. Further, as the polyphenylene sulfide used in the present invention, in addition to the above-mentioned substantially linear polymer, a branched or cross-linked polyphenylene sulfide polymerized using a small amount of a monomer having three or more functional groups as a part of the monomer, Further, a blended polymer obtained by blending this with the above-mentioned linear polymer can also be used.

The polyphenylene ether (hereinafter sometimes abbreviated as PPE) used as the component (B) in the resin composition of the present invention is represented by the following general formula (III):

[0011]

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[Wherein, R ² and R ³ each independently represent an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 8 carbon atoms, a halogen atom or a hydrogen atom, and x represents 50 to 5;
00, preferably an integer of 100 to 450. ].

Specific examples of such a polyphenylene ether include poly (2,6-dimethyl-1,4-phenylene) ether; poly (2,6-diethyl-1,4-phenylene) ether; Methyl-6-ethyl-
1,4-phenylene) ether; poly (2-methyl-6)
-Isopropyl-1,4-phenylene) ether; poly (2-methyl-1,4-phenylene) ether; poly (2,6-dichloro-1,4-phenylene) ether;
Poly (2-ethyl-6-bromo-1,4-phenylene)
Ether; poly (2-phenyl-1,4-phenylene)
Ether and the like. Of these, poly (2,6-dimethyl-1,4-phenylene) ether is particularly preferred.

The molecular weight of polyphenylene ether is 0.25 to 1.0 dl / chloroform at an intrinsic viscosity of 30 ° C.
g, preferably 0.3 to 0.7 dl / g. 0.2
If it is less than 5 dl / g, the mechanical strength decreases, and
/ G, the fluidity decreases. The glass fiber used as the component (C) in the present invention is not particularly limited, and may be any of alkali glass, low alkali glass and non-alkali glass, and the fiber length is preferably 0.1 to 8
mm, more preferably 0.3 to 6 mm, the fiber diameter is preferably 7 μm or more, more preferably 7 to 20 μm,
Particularly preferably, it is 9 to 13 μm. Fiber length is 0.1m
If it is smaller than m, the reinforcing effect is low, and if it is larger than 8 mm, the fluidity decreases. When the fiber diameter is less than 7 μm, the fluidity decreases, and when the fiber diameter exceeds 20 μm, the strength decreases. Further, the form of the glass fiber is not particularly limited, and examples thereof include various types such as roving, milled fiber, and chopped strand. These glass fibers may be used alone or in combination of two or more. In order to enhance the affinity with the resin, the glass fiber may be a silane coupling agent such as an aminosilane, an epoxysilane, a vinylsilane or a methacrylsilane, or a titanate such as tetramethylorthotitanate or tetraethylorthotitanate. It may be one that has been surface-treated with a system coupling agent, a chromium complex compound, a boron compound, or the like.

The resin composition of the present invention contains the components (A), (B) and (C) as described above, and the total amount of the components (A) and (B) is (C) )) Is 75/25 by weight ratio of [(A) + (B)] / (C).
３０30/70. When the total amount of the components (A) and (B), that is, the total amount of PPS and PPE exceeds 75% by weight, the rigidity is insufficient. Lacks sex. If the glass fiber (C) component is less than 25% by weight, the rigidity is insufficient, and if it exceeds 70% by weight, the strength and the fluidity are insufficient. In the resin composition of the present invention, the ratio of the component (A) to the component (B) is 75/2 in a weight ratio of (A) / (B).
5 to 97/3. When the component (B), that is, PPE exceeds 25% by weight, the fluidity and strength decrease, and PP
When E is less than 3% by weight, the effect of reducing burr is small.

The resin composition of the present invention comprises the above (A),
In addition to the components (B) and (C), fillers, antioxidants, heat stabilizers, lubricants, plasticizers, release agents, coupling agents, and conductivity-imparting agents are provided as long as the objects of the present invention are not impaired. , Colorant,
Additives such as pigments can be included. The method for preparing the resin composition of the present invention is not particularly limited, but the above components (A), (B) and (C) and additives used as necessary are blended, and a tumbler blender, Henschel mixer is used. The mixture can be prepared by melt-kneading and granulating using a single screw extruder or a multi-screw extruder, or by melt-kneading and granulating using a kneader or a Banbury mixer. The resin composition of the present invention can be suitably used for producing various molded articles by an injection molding method, an extrusion molding method, or the like.

[0017]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In addition, the raw materials used in the following Examples and Comparative Examples are as follows. PPS-1; melt viscosity 1800 poise, crystallization temperature 23
1 ° C polyphenylene sulfide (Tosoh Corporation, # 16
0) PPS-2; melt viscosity 340 poise, crystallization temperature 238
℃ polyphenylene sulfide (manufactured by Tosoh Corporation, # 14
0) PPS-3; melt viscosity 300 poise, crystallization temperature 216
℃ polyphenylene sulfide (manufactured by Toprene, T-
1) PPE; manufactured by Mitsubishi Engineering Plastics,
Poly (2,6-dimethyl-1,4-phenylene ether), intrinsic viscosity 0.40 dl / g (30 ° C., in chloroform) Glass fiber GF-1; Asahi Fiberglass Co., Ltd., CS03JAF
T591, fiber diameter 10 μm GF-2; manufactured by Asahi Fiberglass Co., Ltd., CS03DEF
T104, fiber diameter 6μm

Examples 1 to 8 and Comparative Examples 1 to 4 The components were uniformly mixed at the mixing ratios shown in Table 1 and then melt-kneaded at a cylinder temperature of 320 ° C. by a twin-screw extruder to obtain pellets. Using the obtained pellets, test specimens were produced by the following method, the occurrence of burrs was evaluated, the fluidity and the crystallization temperature were measured, and the results are shown in Table 1.

Production of Test Pieces Injection molding was performed at a cylinder temperature of 320 ° C. and a mold temperature of 135 ° C. Burr evaluation method A 50-ton injection molding machine (manufactured by Nippon Steel Co., Ltd.) was used as the injection molding machine, with a thickness of 3.2 mm, a width of 12.4 mm, and a length of 1.
A 26 mm molded product is injection molded at a cylinder temperature of 320 ° C. and a mold temperature of 135 ° C. at an injection pressure of 1.1 times the minimum filling pressure. Was measured. Fluidity As an injection molding machine, a 30-ton injection molding machine (manufactured by Toshiba Machine Co., Ltd.) was used.
Molded with Pa, length (spiral flow length; SFL)
Was measured. Measurement of Crystallization Temperature Using a differential scanning calorimeter (DSC) manufactured by PerkinElmer, the raw material powder or the composition pellet of PPS is held at 50 ° C. for 1 minute in a nitrogen atmosphere, and then at a rate of 20 ° C./min. After holding at 320 ° C. for 5 minutes, the temperature is lowered at a rate of 20 ° C./min, and the exothermic peak is read from the obtained DSC chart to obtain the crystallization temperature. PPS-1 to PPS-1
The crystallization temperature of PPS-3 was measured by this method. Flexural strength The test specimen was measured according to ASTM D790. Flexural Modulus The test specimen was measured according to ASTM D790. Notched Izod Strength The test pieces were measured according to ASTM D256. Notched Izod Strength The test specimen was measured according to ASTM D256.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

As is clear from the results shown in Table 1,
Comparative Example 1 has a small amount of PPE and therefore has many burrs, Comparative Example 2 has a large amount of PPE and therefore has a low strength, and Comparative Example 3 has a small number of glass fibers, and therefore has low physical properties and large burrs. Low flowability due to high glass fiber content.

[0024]

According to the present invention, by blending a specific amount of polyphenylene ether with polyphenylene sulfide, excellent low burr can be realized without impairing fluidity and physical properties. That is, according to the present invention, it is possible to provide a polyphenylene sulfide resin composition suitable for injection molding, having a low burr generation rate and an improved balance between fluidity and mechanical properties.

Claims (2)

[Claims] 1. (A) 300 ° C., shear rate 500 sec.
^The composition is composed of polyphenylene sulfide, (B) polyphenylene ether and (C) glass fiber having a melt viscosity of 100 to 2000 poise as measured at ^-1 and the total amount of the components (A) and (B) and the ratio of the component (C). Is [(A) +
(B)] / (C) in a weight ratio of 75/25 to 30/70, and the ratio of the component (A) to the component (B) is (A) / (B).
A polyphenylene sulfide resin composition having a weight ratio of 75/25 to 97/3. 2. The polyphenylene sulfide as the component (A) has a crystallization temperature of 225 ° C. or higher, and the polyphenylene ether as the component (B) is poly (2,6-dimethyl-1,4-phenylene ether). The glass fiber of the component (C) has a fiber diameter of 7 μm or more,
The polyphenylene sulfide resin composition according to claim 1, wherein the ratio of the component (A) to the component (B) is 90/10 to 97/3 by weight ratio of (A) / (B).