JP2000198924A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyphenylene sulfide resin compsn. having good molding processability, mechanical strength, and dimensional accuracy, and never or rarely producing fins during molding. SOLUTION: This compsn. is prepared by compounding 0.3-5 pts.wt. epoxy silane compd.(B), 10-400 pts.wt. fibrous filler, an inorg. filler, or their mixture (C), to 100 pts.wt. resin compsn. (A) prepared by compounding 60-95 wt.% polyphenylene sulfide resin and 40-5 wt% polyphenylene ether resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyphenylene sulfide resin composition having good moldability such as injection molding, no or very little burr during molding, and excellent mechanical strength and heat resistance. It is about things.

[0002]

2. Description of the Related Art Conventionally, metals such as aluminum die-cast and zinc die-cast have been used for precision parts such as optical parts, electronic / electric parts, and automobile parts. However, since the cost of processing into a predetermined shape with high dimensional accuracy leads to an increase in the cost of the product, in recent years, the use of thermoplastic resins, mainly engineering plastics, has been increasing. This is because even a complicated shape can be mass-produced continuously by injection molding, so that the production cost of parts can be reduced, and the number of parts can be reduced by integrating a plurality of parts. Among the thermoplastic resins, polyphenylene sulfide resin (hereinafter abbreviated as PPS) is used for these applications because of its excellent heat resistance, dimensional stability, chemical resistance, flame retardancy, and moldability. In particular, in applications where rigidity and dimensional stability are strictly required, PPS filled with a high concentration of a fibrous, plate-like, granular or other inorganic filler is used.

However, a disadvantage of PPS is that burrs are easily generated during molding. This is due to the fact that the melt viscosity of PPS has a low dependency on the shear rate, and the melt viscosity is relatively low even at locations where the shear rate of the resin is low, such as at the end of a cavity or a minute clearance portion of a mold. . As for molded products using PPS, burrs are currently removed by blasting, such as by spraying fine nylon beads at a high speed, and the man-hours involved are not negligible. Also, as a recent trend, switching to the integral molding method with other metal foils etc. has been actively promoted for the purpose of further reducing the cost of parts. Since the situation is inevitable, there is a strong demand for non-validating PPS used for this purpose.

Various methods have been studied to reduce burrs in PPS. For example, to improve the flow characteristics of PPS, PPS is added to polyamide or liquid crystal polymer,
There are other methods such as adding a specific polyester compound. However, the definitive burr has not been reduced, and the rigidity of the material has been significantly reduced at that time. There are fatal problems such as impaired dimensional stability. On the other hand, there has been proposed a composition (for example, JP-A-7-53865) in which polyphenylene ether (hereinafter abbreviated as PPE) is added to PPS. Although it is possible to reduce burrs by adding PPE, it is necessary to increase the blending amount of PPE in order to extremely suppress burrs or prevent burrs from occurring. There is a problem that properties and mechanical strength are significantly reduced.

[0005]

[Problems to be solved by the present invention]
An object of the present invention is to provide a PPS resin composition which has excellent dimensional accuracy and does not generate burrs at the time of molding or has extremely small burrs.

[0006]

According to the present invention, there are provided (A) 100 parts by weight of a resin composition containing 60 to 95% by weight of a polyphenylene sulfide resin and 40 to 5% by weight of a polyphenylene ether resin. It is a polyphenylene sulfide resin composition comprising 0.3 to 5 parts by weight of an epoxy silane compound and 10 to 400 parts by weight of (C) a fibrous filler, an inorganic filler, or a mixture thereof. The present invention also relates to (A) polyphenylene sulfide resin
0 to 95% by weight, 40 to 40% by weight of polyphenylene ether resin
(B) based on 100 parts by weight of a mixture containing 5% by weight
0.3 to 5 parts by weight of an epoxy silane compound, (C) 10 to 40 parts of a fibrous filler, an inorganic filler, or a mixture thereof.
0 parts by weight (D) average particle diameter 0.05 μm or more and 0.5 μm
The following kaolin, average particle size 0.02 μm or more and 0.2 μm
m or less of attapulgite or a mixture thereof
It is a polyphenylene sulfide resin composition mixed with 50 parts by weight. Preferably, the polyphenylene sulfide resin is 3 ° C. at 300 ° C. and a shear rate of 500 sec ⁻¹ .
It has a melt viscosity of 00 to 3000 poise and a polyphenylene ether resin at 300 ° C. and a shear rate of 500 sec ⁻¹
Is a polyphenylene sulfide resin composition having a melt viscosity of 500 to 50,000 poise. More preferably, the resin composition has a melt viscosity of less than 2000 poise at 290 ° C. to 350 ° C. and a shear rate of 6000 sec ⁻¹ , and a shear rate of 6000 sec ⁻¹ and 20 s.
A polyphenylene sulfide resin composition having a melt viscosity ratio at ec ^-1 of 10 or more.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The PPS resin used in the present invention has a general formula

Embedded image Preferably, the composition contains at least 70 mol% of the structural unit represented by the formula. If the amount is less than 70 mol%, it is difficult to obtain a composition having excellent properties. As a polymerization method of the PPS resin, a method of reacting sodium sulfide with p-dichlorobenzene in an amide solvent such as N-methylpyrrolidone or dimethylacetamide or a sulfone solvent such as sulfolane is suitable.
At this time, an alkali metal salt of a carboxylic acid or a sulfonic acid is added to adjust the degree of polymerization, or an alkali hydroxide, an alkali metal carbonate, or an alkaline earth metal oxide is added. If the amount of the copolymer component is less than 30 mol%, a meta bond, an ortho bond, an ether bond, a sulfone bond, a biphenyl bond, a substituted phenylene sulfide bond (where the substituent is an alkyl group, a nitro group, a phenyl group, an alkoxy group) Carboxylic acid group, metal base of carboxylic acid), 3
Even if it contains a functional bond or the like, it may be in a range that does not significantly affect the crystallinity of the polymer, but preferably the copolymer component is 10 mol% or less.

[0008] The PPS resin is generally used in the presence of oxygen in the range of 200 to
It is used after thermal crosslinking at a temperature of 250 ° C. to adjust the melt viscosity. Desirable melt viscosity of the PPS used in the present invention is 300 to 3 at 300 ° C. and a shear rate of 500 sec ⁻¹ .
000 poise, more preferably in the range of 600 to 2500 poise. If the melt viscosity is less than 300 poise, burrs are likely to occur, and if it exceeds 3000 poise, moldability deteriorates. When compounding filler at a high concentration,
It is desirable to use a material having a relatively low viscosity within the above range in consideration of extrusion processability and moldability.

The PPE resin used in the present invention has a general formula

Embedded image (In the formula, at least one of R1 and R2 is a linear or primary or secondary branched alkyl group having 1 to 4 carbon atoms, an aryl group, and a halogen atom. May be the same or different from each other), a homopolymer comprising a repeating unit represented by the general formula (1),

Embedded image (In the formula, R3, R4, R5, and R6 each represent a linear or primary or secondary branched alkyl group having 1 to 4 carbon atoms, an aryl group, a halogen atom, a hydrogen atom, or the like. And R3 and R4 may not be hydrogen atoms at the same time, although they may be the same or different from each other). Graft copolymers in which styrene is graft-polymerized to copolymers or copolymers.

Representative examples of homopolymers of PPE include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether and poly ( 2,6-diethyl-1,4-phenylene) ether, poly (2-ethyl-6-n-propyl-1,4-phenylene) ether, poly (2,6-di-n-propyl-1,4-) (Phenylene) ether, poly (2-methyl-6-n-butyl-1,4-phenylene)
Ether, poly (2-ethyl-6-isopropyl-1,
4-phenylene) ether, poly (2-methyl-6-chloro-1,4-phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether, poly (2-methyl-6) -Chloroethyl-1,4-
Homopolymers such as phenylene) ether are exemplified. The PPE copolymer is o-cresol or a general formula

Embedded image (Wherein R 3, R 4, R 5, R 6 have the same meaning as described above), and mainly comprises a polyphenylene ether structure obtained by copolymerization with an alkyl-substituted phenol such as 2,3,6-trimethylphenol. Polyphenylene ether copolymers. The desirable melt viscosity of the PPE used in the present invention is 300 ° C., and the shear rate is 500 sec ^−1.
5000 to 50,000 poise, more preferably 10
It is in the range of 000-30000 poise. When it is less than 5,000 poise, the effect of reducing burr is small, and when it exceeds 50,000 poise, moldability deteriorates. PPS and PPE
The mixing ratio of PPS is 60-95% by weight of PPS
40 to 5% by weight, more preferably 70 to 90% by weight of PPS, and 30 to 10% by weight of PPE. When PPE is less than 5% by weight, the effect of reducing burr is small, and when it exceeds 40% by weight, moldability and mechanical strength are reduced.

The epoxy silane compound used in the present invention is necessary for improving mechanical strength and reducing burrs. Although there are various epoxy silane compounds, γ-glycidoxylopropyltrimethoxysilane is preferable. The compounding amount of the epoxy silane compound is PPS
The amount is 0.3 to 5 parts by weight, preferably 0.5 to 3 parts by weight based on 100 parts by weight of the resin composition obtained by mixing the resin and the PPE resin. If the amount is less than 0.3 part by weight, the effects of improving mechanical strength and reducing burrs will not be sufficiently exhibited, and if it exceeds 5 parts by weight, the moldability of the composition will decrease.

The kaolin used in the present invention is a fine white clay mineral and generally has an average particle diameter represented by a composition formula of 2SiO ₂ .Al ₂ O ₃ .2H ₂ O of 0.05 μm to 0.5 μm.
m, preferably 0.1 μm or more and 0.4 μm or less. If the average particle diameter is less than 0.05 μm, a problem of moldability occurs, and if it exceeds 0.5 μm, the effect of reducing burrs is reduced. The attapulgite used in the present invention is a very fine needle-like filler and generally has a composition formula of Si ₈ O ₂₀ Mg ₅ (O
H ₂₎ (OH ₂₎ Average particle diameter 0.02 represented by 4H ₂ O
It is not less than μm and not more than 0.2 μm, preferably not less than 0.05 μm and not more than 0.1 μm. Average particle size is 0.02μ
If it is less than m, a problem of moldability occurs, and if it exceeds 0.2 μm, the effect of reducing burr is reduced. Kaolin and attapulgite may be used alone or in combination. The compounding amount is 10 to 150 parts by weight, more preferably 20 to 130 parts by weight, based on 100 parts by weight of the resin composition obtained by mixing the PPS resin and the PPE resin. If the amount is less than 10 parts by weight, the effect of reducing burr is small, and
When the amount is more than the weight part, the moldability is reduced. If the material requires smoothness, it is better to use kaolin alone.

The fibrous filler used in the present invention includes glass fiber, carbon fiber, asbestos fiber, silica fiber, silica-alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, Inorganic fibrous substances such as potassium titanate fibers and fibrous materials of metals such as stainless steel, aluminum, titanium, copper, brass and the like. Other inorganic fillers include carbon black, silica, quartz powder, glass beads, glass powder, glass flake, calcium silicate, aluminum silicate, talc, clay, mica, diatomaceous earth, wollastonite and other silica fillers. Metal oxides such as acid salts, iron oxides, titanium oxides, zinc oxides, and aluminas; metal carbonates such as calcium carbonate and magnesium carbonate; metal sulfates such as calcium sulfate and barium sulfate; and other materials such as silicon carbide and silicon nitride , Boron nitride, various metal powders, and the like. Two or more of these fillers can be used in combination. In use, it is desirable to modify the particle surface with a surface treatment agent. Examples of the surface treatment agent include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, titanate compounds, and the like. The filler may be surface-treated with these compounds in advance or used at the same time as mixing the materials. The mixing amount of these fillers is (A) component 10
It is 10 to 400 parts by weight, more preferably 50 to 300 parts by weight, based on 0 parts by weight. When the amount is less than 10 parts by weight, the effect of improving various properties is small, and when it exceeds 400 parts by weight, the moldability is significantly reduced.

Further, the composition of the present invention may contain known substances generally added to thermoplastic resins and thermosetting resins, that is, stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents and flame retardants. Colorants such as dyes and pigments, lubricants, and the like can be appropriately added as necessary.

Although the method for producing the composition of the present invention is not limited, for example, it is also possible to weigh each component, mix it with a blender, a mixer, etc. and melt-knead it with an extruder to form pellets. Alternatively, the glass fiber may be kneaded and pelletized by being supplied in a fixed amount by a side feeder. The pellet-shaped molding material thus obtained is
It is usually molded into a desired shape by a widely used thermoplastic resin molding machine, injection molding machine, injection compression molding machine or the like and used.

The PPS resin composition obtained according to the present invention has a shear rate of 6000 sec ^-1 at 290 ° C. to 350 ° C.
Is preferably less than 2000 poise and the ratio of the melt viscosity at a shear rate of 6000 sec ^{-1 to} the melt viscosity at 20 sec ^-1 is 10 or more in order to obtain a large effect in reducing burrs during injection molding. In order to reduce burrs, it is desirable that the flow be good immediately after injection, that is, at a high shear rate, and that the flow be difficult to reach at the end of the mold, that is, at a low shear rate. Therefore, the burr can be reduced as the viscosity ratio in the low shear rate region and the high shear rate region is increased, and as the viscosity in the high shear rate region is lowered. PP
At a general molding temperature of 290 ° C. to 350 ° C., the melt viscosity at a shear rate of 6000 sec ⁻¹ is less than 2000 poise, and the ratio of the melt viscosity at a shear rate of 6000 sec ^{−1 to} the melt viscosity at 20 sec ⁻¹ is 10 If it is above, there is a great effect in reducing burrs.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

The components used in the examples and comparative examples are as shown below. PPS resin (PPS-1): trade name, manufactured by Topren Co., Ltd. LV-3 Melt viscosity 1000, at 300 ° C., 500Sec ^-1 PPS resin (PPS-2): trade name, manufactured by Toprene Co., Ltd. T-1 melt viscosity 300 Wheels (at 300 ° C, 500sec- ¹ ) PPE resin (PPE): Melt viscosity 18000 Wheels (at 300 ° C, 500sec ^{- 1} ) Silane compound: γ-glycidoxylopropyltrimethoxysilane compound Nippon Unicar Co., Ltd. -187 Kaolin: ENGELHARD (US) brand name ASP200 Average particle size 0.4 μm Attapulgite: ENGELHARD (US) brand name ATTAGEL # 50 Average particle size 0.1 μm Glass fiber: Nippon Sheet Glass product name RES03- TP29 Calcium carbonate: manufactured by Shiraishi Calcium Co., Ltd. Product name Whiten P-30

The above components were blended in the compositions shown in Tables 1 to 6, melt-kneaded with a twin-screw kneader, and pelletized. After the obtained molding material was dehumidified and dried at 140 ° C. for 5 hours, the cylinder temperature was 300 ° C., the injection pressure was 1200 kg / cm ² , the injection speed was medium speed, and the mold temperature was 140 ° C. using an injection molding machine (TOSHIBA MACHINE IS80EPN). , And various test pieces were prepared. Using each test piece, the tensile strength, tensile elongation, bending strength, flexural modulus Izod impact strength, and molding shrinkage were measured according to the ASTM test method. The burrs were evaluated by actually measuring the length of burrs generated in a clearance portion (width: 5 mm, depth: 20 μm) provided around the cavity when molded at the minimum filling speed. Further, the melt viscosity of the material was measured with a capillograph (manufactured by Toyo Seiki) (310 ° C., shear rate 20-600).
0sec ^-1 ). The results are shown in Tables 1 to 6. In addition, the melt viscosity ratio in the table is a shear rate of 20 sec ^-1 and 6000 sec ^-1
Is the ratio of the melt viscosity at.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

[0023]

[Table 5]

[0024]

[Table 6]

[0025]

According to the present invention, it is possible to provide a PPS resin composition which has good moldability, mechanical strength, and dimensional accuracy, and has little or no burr during molding. Such a resin composition can be used for electric / electronic parts such as connectors and electronic sealing parts, and precision parts such as optical parts for optical pickups.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // (C08L 81/02 71:12)

Claims (5)

[Claims] (A) 60 to 95% by weight of a polyphenylene sulfide resin and 4% of a polyphenylene ether resin.
0.3 to 5 parts by weight of the epoxy silane compound (B) per 100 parts by weight of the resin composition mixed with 0 to 5% by weight;
(C) fibrous filler, inorganic filler, or a mixture thereof
A polyphenylene sulfide resin composition comprising 0 to 400 parts by weight. 2. A polyphenylene sulfide resin (A) of 60 to 95% by weight and a polyphenylene ether resin of 4% by weight.
0.3 to 5 parts by weight of the epoxy silane compound (B) per 100 parts by weight of the mixture obtained by mixing 0 to 5% by weight;
(C) fibrous filler, inorganic filler, or a mixture thereof
0 to 400 parts by weight (D) 10 to 150 parts by weight of kaolin having an average particle diameter of 0.05 μm to 0.5 μm, attapulgite having an average particle diameter of 0.02 μm to 0.2 μm, or a mixture thereof. A polyphenylene sulfide resin composition comprising: 3. A polyphenylene sulfide resin comprising:
300-3000 at 00 ° C, shear rate 500 sec ^-1
3. The polyphenylene sulfide resin composition according to claim 1, which has a poise melt viscosity. 4. The polyphenylene ether resin is 300
° C., according to claim 1, 2 or 3 polyphenylene sulfide resin composition as claimed having a melt viscosity of 500 to 50,000 poise at a shear rate of 500 sec ^-1. 5. The method according to claim 1, wherein the resin composition has a temperature of 290 ° C. to 350 ° C.
And the melt viscosity at a shear rate of 6000 sec ^-1 is 20.
Less than 00 poise and shear rate 6000 sec ^-1
5. The polyphenylene sulfide resin composition according to claim 1, wherein the ratio of the melt viscosity at 20 sec ^{-1 to} the melt viscosity is 10 or more.