JPH07742B2 - Polyphenylene sulfide resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyphenylene sulfide resin composition having excellent slidability and mechanical properties and giving a better appearance, and more specifically, it is specified. The present invention relates to a polyphenylene sulfide resin composition having high lubricity, abrasion resistance and mechanical properties, and further improved appearance by improving the dispersibility of polytetrafluoroethylene as a lubricant by containing the organosilane compound. .

[Problems to be Solved by Prior Art and Invention]

Polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) has extremely high heat resistance, chemical resistance, electrical properties, and combustion resistance, and is excellent by strengthening it with a reinforcing filler. It is known to give mechanical strength, rigidity and dimensional stability, and is widely used for various molding applications such as electric / electronic parts, automobile parts, mechanical parts and sliding mechanism parts such as gears, bearings and cams. ing.

When PPS resin is used as a sliding member for bearings, etc., this resin has superior heat resistance and mechanical strength compared to sliding members such as polytetrafluoroethylene, polyamide, polyacetal, polybutylene terephthalate, etc. Therefore, a high load capacity that can withstand use under high speed and high load conditions can be expected, and many studies have already been made for such applications.

However, since PPS resin itself is poor in self-lubricating property, molybdenum disulfide, graphite, polytetrafluoroethylene, mineral oil, etc. were added as a lubricant for the purpose of imparting slidability, and a reinforcing filler was compounded if necessary. Compositions are known, for example, polytetrafluoroethylene type (Japanese Patent Laid-Open No. 50-119040), graphite, polytetrafluoroethylene, lubricating oil type (Japanese Patent Publication No. 56-50124), polybutene disulfide, carbon. Fiber type (Japanese Patent Publication No. 57-135)
No. 86 bulletin).

However, even when the lubricant is added, the affinity between the PPS resin and the lubricant is poor and the lubricity is not sufficiently expressed due to poor dispersion of the lubricant, and the mechanical strength is greatly reduced, and the appearance is poor. There are problems and it is hard to say that it is enough.

Especially polytetrafluoroethylene (hereinafter abbreviated as PTFE)
In the case of, it has long been known as an excellent lubricant for imparting slidability to PPS resin, but it cannot be said that it has sufficient affinity with PPS resin, especially at 330 ° C, which exceeds the melting point of PTFE.
At the above melting temperature, PTFE re-aggregates and remarkably deteriorates the appearance of the molded product at the time of injection molding.Furthermore, due to poor dispersion of PTFE, mechanical strength is drastically reduced and sufficient circulation is not exhibited, especially at high temperatures.・ Under severe conditions such as high-speed injection molding, there were many defects such as this phenomenon becoming more prominent.

[Means for solving problems]

The object of the present invention is to improve the dispersibility of PTFE with respect to a PPS resin containing PTFE as a lubricant and reinforced with a reinforcing filler, and having a high degree of lubricity and mechanical properties and a good appearance, especially at high temperature and high speed. An object of the present invention is to provide a composition capable of retaining its excellent properties even under severe conditions such as injection molding.

As a result of intensive studies by the present inventors, PTFE was used as a lubricant.
By adding a specific organic silane compound to a PPS resin that is reinforced with a reinforced filler that contains, a resin composition having extremely excellent dispersibility of PTFE, high lubricity and mechanical properties, and a good appearance is obtained. It was found that the object of the present invention is achieved by this.

That is, the present invention relates to (A) polyphenylene sulfide resin 100 parts by weight, (B) reinforcing filler 3 to 150 parts by weight, (C) polytetrafluoroethylene (PTFE) 1 to 80
Parts by weight and (D) general formula It is formed by mixing 0.01 to 10 parts by weight of the organosilane compound represented by. The present invention provides a polyphenylene sulfide resin composition having enhanced lubricity and mechanical properties with improved PTFE dispersibility and good appearance.

The greatest feature of the resin composition of the present invention is that the dispersibility of PTFE is extremely enhanced and reaggregation of PTFE is not observed even under severe injection conditions such as high temperature and high speed injection molding, and PTFE is stably and uniformly dispersed. Especially. That is, since the PTFE is stably and uniformly dispersed, the resin composition of the present invention has an extremely good appearance and a high degree of lubricity and wear resistance.

Even more surprisingly, the resin composition of the present invention is extremely excellent in mechanical properties, in particular, weld strength, mechanical strength in a resin flow direction of a molded product and a direction perpendicular to the flow, and elongation at break.

In general, PPS resin reinforced with a reinforced filler such as glass fiber is apt to be incompletely fused at the weld part, which is the confluence point of materials, in the molding die during injection molding, so that the molded product is subject to thermal stress. It has a drawback that it is broken from the weld portion by mechanical stress or mechanical stress, that is, the so-called weld strength is low, and this tendency becomes particularly remarkable when a fluororesin such as PTFE is contained.

Furthermore, PPS reinforced with reinforced filler such as glass fiber
Resin has a large anisotropy in strength and the like, and there is a large difference in strength and breaking elongation between the resin flow direction of the injection molded product and the direction perpendicular to the flow, and despite being extremely tough in the resin flow direction, It has the drawback of being brittle in the direction perpendicular to the flow.

However, in the composition of the present invention, a specific organic silane compound is further added to the PPS resin which contains PTFE as a lubricant and is reinforced with a reinforcing filler, which greatly improves the weld strength and further improves the resin flow direction and flow. The strength and the elongation at break are significantly improved in both the right and left directions.

The composition of the present invention, as described above, PTFE as a lubricant is stably and uniformly dispersed even under severe injection molding conditions, and further has mechanical properties, particularly weld strength and resin flow direction and strength perpendicular to the flow direction, Although it is excellent in the balance of breaking elongation, although the reason for this is not clear, the affinity at the interface between the matrix phase PPS resin and the dispersed phase PTFE is large due to the presence of the organosilane compound of the present invention. It is thought that this is due to the improvement.

That is, when PTFE having a very low critical surface tension γc itself disperses in the PPS resin, γc at the PTFE dispersed phase interface increases due to the presence of a specific organic silane compound at the interface, and as a result, It is considered that the "wetness" with PTFE was improved and the affinity at the interface was greatly improved.

The PPS resin used in the present invention has the general formula It is preferable that the content of the structural unit represented by the formula is 90 mol% or more. If the amount is less than 90 mol%, it is difficult to obtain a composition having excellent properties. This polymer can be polymerized by polymerizing P-dichlorobenzene in the presence of sulfur and sodium carbonate, in the presence of sodium sulfide or sodium hydroxide and sodium hydroxide or hydrogen sulfide and sodium hydroxide in a polar solvent. Polymerization with P-chlorothiophenol, self-condensation of P-chlorothiophenol, N-methylpyrrolidone,
A suitable method is to react sodium sulfide with P-dichlorobenzene in an amide solvent such as dimethylacetamide or a sulfone solvent such as sulfolane. At this time, it is a preferable method to add an alkali metal salt of carboxylic acid or sulfonic acid or to add an alkali hydroxide in order to adjust the degree of polymerization. If less than 10 mol% as a copolymerization component, meta bond Ether bond Sulfone bond Biphenyl bond Substituted phenyl sulfide bond ( Where R represents an alkyl, nitro, phenyl or alkoxy group) trifunctional phenyl sulfide bond Although it does not matter if it contains such a compound as long as it does not significantly affect the crystallinity of the polymer, preferably the content of the copolymerization component is 5 mol% or less. When the above is selected, 3 mol% or less is preferable, and 1 mol% or less is more preferable.

Such a PPS resin is produced by a general method, for example, (1) a reaction between a halogen-substituted aromatic compound and an alkali sulfide (US Pat. No. 2513188, JP-B-44-27671 and JP-B-Sho 4).
5-3368) (2) Condensation reaction of thiophenols in the presence of an alkali catalyst or a copper salt (US Pat. No. 3,274,274)
165, see British Patent No. 1160660) (3) Synthesis of aromatic compounds by condensation reaction with sulfur chloride in the presence of Lewis acid catalyst (see Japanese Examined Patent Publication No. 46-27255, Belgian Patent No. 29437), etc. However, it can be arbitrarily selected according to the purpose.

The reinforcing filler in the composition of the present invention is a fibrous reinforcing agent such as glass fiber, carbon fiber, potassium titanate, asbestos, silicon carbide, ceramic fiber, metal fiber or silicon nitride; barium sulfate, calcium sulfate, kaolin, clay, pyro. Fluorite, bentonite, sericite, zeolite, mica, mica, nepheline sinite, talc, attarpulgite, wollastonite, PMF, ferrite, calcium silicate, calcium carbonate, magnesium carbonate, dolomite, ammonium trioxide, zinc oxide , Inorganic oxides such as titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide, graphite, gypsum, glass beads, glass balloons, quartz powder, etc., especially excellent strength when filled with glass fiber or carbon fiber. , Rigidity, heat resistance and dimensional stability are demonstrated.

The glass fiber can be any of roving glass, chopped strand glass, milled glass, etc., and the glass fiber diameter is 0.005 to 0.02 m.
The range of m is 0.01 to 10 mm, preferably 0.05
A range of up to 1 mm is suitable.

The compounding ratio of the reinforcing filler in the composition of the present invention is PPS resin 1
It is 3 to 150 parts by weight, preferably 5 to 100 parts by weight, relative to 00 parts by weight.

When the compounding ratio of the reinforcing filler is less than 3 parts by weight, the reinforcing effect by the reinforcing filler is small, and when it exceeds 150 parts by weight, the moldability of the composition is remarkably reduced, which is not preferable.

The PTFE in the present invention is a resin in the form of differential powder, which is generally commercially available as a solid lubricant, such as those obtained by emulsion polymerization, suspension polymerization, etc., or pulverized products of baked molded products.

Commercially available products of such PTFE are "Lubron L-5" (made by Daikin Industries), "Fluon L-169J" (made by Asahi Glass),
"TLP-10" (Mitsui Fluorochemical), "Polymist" (Allied Chemical), "Fluon Lubricant" (ICI), etc. The molecular weight of PTFE is preferably 1
It is, 000,000 or less, particularly preferably 300,000 or less. Also, the particle size is 100 μm or less, especially 50 μm in consideration of dispersibility.
Most preferably, it is m or less.

The compounding ratio of PTFE in the composition of the present invention is 1 to 80 parts by weight, preferably 5 to 60 parts by weight, relative to 100 parts by weight of PPS resin, and when the PTFE compounding ratio is less than 1 part by weight, lubricity is obtained. Is insufficient, and when it exceeds 80 parts by weight, the strength, rigidity, heat resistance and abrasion resistance of the composition are deteriorated, which is not preferable.

The specific organosilane compound used in the composition of the present invention is represented by the following general formula.

Among the organic silane compounds represented by the general formula, if a specific example of a particularly preferred silane compound in the present invention is shown,
Vinyltrichlorosilane, vinyltriethoxysilane,
Vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N Examples include -β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane and γ-chloropropyltrimethoxysilane.

The compounding ratio of the organosilane compound in the composition of the present invention is
0.01 to 10 parts by weight with respect to 100 parts by weight of PPS resin, preferably 0.
If the amount of the organic silane compound is less than 0.01 parts by weight, the desired effect of the present invention will not be exhibited, and if it exceeds 10 parts by weight, the appearance will be deteriorated and the moldability will be deteriorated. Therefore, it is not preferable.

The composition of the present invention can be prepared by various known methods.

For example, PPS resin, PTFE and organic silane compound are mixed in advance with a Henschel mixer or a tumbler, and then a reinforcing filler is further mixed, or after all raw materials are mixed together, uniaxial or biaxial extrusion is performed. Supply to machines 26
It can be obtained in the form of pellets by melt-kneading at 0 ° C to 360 ° C.

INDUSTRIAL APPLICABILITY The composition of the present invention is applied to various sliding parts such as electric / electronic device parts, machine / device parts, automobile parts and the like, and the piston ring is excellent in its sliding property and mechanical property. , Bearings, compressor vanes,
It is useful as an industrial material for thrust washers, rotary insulation sleeves, printer parts, etc.

〔The invention's effect〕

The resin composition of the present invention is extremely excellent in PTFE dispersibility as a lubricant, has a high degree of lubricity, wear resistance, mechanical properties, and even a good appearance, and particularly under severe conditions such as high temperature / high speed injection molding. Also in the above, the excellent properties can be exhibited and maintained.

〔Example〕

 The present invention will be further described with reference to examples.

The parts shown in the examples mean parts by weight unless otherwise specified.

Reference Example I (Synthesis of PPS resin) A 50-scale autoclave was charged with N-methylpyrrolidone in a molar ratio of 70, sodium sulfide nonahydrate of 0.99, sodium benzoate of 0.60, and sodium hydroxide of 0.15 mol in a molar ratio (50 (Mole scale) In a nitrogen stream, the temperature was raised to 210 ° C and dehydration was performed to a dehydration rate of 110%. After cooling the system to 160 ° C
The mixture was charged with P-dichlorobenzene at a molar ratio of 1.0, sealed, and then pressurized with nitrogen to an internal pressure of 2.5 kg / cm ² . The heat generated by the polymerization was controlled while controlling the temperature rise, and the temperature was raised to 270 ° C., and the polymerization was carried out with stirring for 5 hours. The internal pressure had risen to 17 kg / cm ² . Next, the system was cooled and then depressurized, and the contents were poured into a large amount of water to recover a flake-like polymer. The polymer was repeatedly washed with hot water and acetone, and finally 70%.
It was in the form of white flakes with a yield of.

Put this PPS resin powder into the ribbon blender and
Stir while blowing air at ℃, PPS in powder state
Was partially crosslinked and heat-treated until the intrinsic viscosity finally reached 0.3.

Examples 1 to 8 and Comparative Examples 1 to 4 Using the PPS resin synthesized in Reference Example 1, the raw materials shown in Table 1 were uniformly premixed at the compounding ratio in the table, and then at 65 ° C at 330 ° C at 330 ° C. Melt kneading was performed to obtain pellets. Using an in-line screw type 3 ounce injection molding machine (manufactured by Toshiba Machine), the pellets were heated at a cylinder temperature of 330 ° C. and a mold temperature of 150.
℃, injection pressure 1000kg / cm ² , injection speed at a medium speed to mold the test piece, (PTFE dispersibility test cylinder temperature
Molding at 350 ℃, mold temperature 150 ℃, injection pressure 1000kg / cm ² , injection speed high speed) Sliding characteristics, mechanical characteristics (weld strength, bending strength in resin flow direction and direction perpendicular to flow, bending elongation at break) And the PTFE dispersibility were evaluated.

The results are shown in Table 1.

Examples 9 to 12 and Comparative Example 5 Using the PPS resin synthesized in Reference Example 1, the raw materials shown in Table 2 were uniformly premixed at the compounding ratio in the table, and then melt-kneaded at 330 ° C. in a 65 mm extruder. And pellets were obtained. The pellets were injection-molded in the same manner as in the above-mentioned Examples and Comparative Examples, and then the respective properties were evaluated.

The results are shown in Table 2.

Claims (1)

[Claims] 1. A polyphenylene sulfide resin (A) 10
(B) 3 to 150 parts by weight, (C) 1 to 80 parts by weight of a polytetrafluoroethylene resin,
And (D) 0.01 to 10 organosilane compound represented by the following general formula
A polyphenylene sulfide resin composition comprising parts by weight.