JP4747634B2 - Polyarylene sulfide resin composition - Google Patents

Description

  The present invention relates to a polyarylene sulfide resin composition capable of obtaining a molded article excellent in flatness, slidability and mechanical properties.

  Among thermoplastic resins, sliding materials using polyphenylene sulfide resin have excellent heat resistance, rigidity, and moldability, and also have excellent flame resistance, chemical resistance, dimensional stability, and sliding properties. Therefore, it is attracting attention as a high-performance, high-performance engineering plastic.

  However, materials using polyarylene sulfide resin also have some drawbacks. For example, in a polyphenylene sulfide resin composition that does not use a reinforcing material, it is necessary to use a lubricant because the strength is insufficient and the range in which the reinforcing material is used is limited, or planarity decreases when using a reinforcing material, When the effect of the lubricant is lost, problems such as performance degradation have been pointed out, and there is a demand for component supply with a resin material having excellent flatness and slidability and improved mechanical properties.

  In general, it is known to use a lubricant such as graphite or molybdenum disulfide in a polyphenylene sulfide resin composition reinforced with glass fibers in order to impart slidability (see Patent Document 1). However, when used in a fluid, there is a problem that the lubricant present on the surface falls off and the lubrication effect falls.

  Also known is a method for increasing flatness with a resin composition having an aspect ratio of 3 or less or a spherical filler (see Patent Document 2). However, there is a problem that it cannot be applied to parts that require strength.

Furthermore, a method for enhancing the lubrication effect by using a polyphenylene sulfide resin composition containing graphite or talc (see Patent Document 3) is known. However, it was found that the composition using plate-like fillers such as graphite and talc has a problem that the amount of wear is large, the product is easily worn away, the performance cannot be maintained, and the fallen powder is clogged. .
JP 2001-132757 (2nd page) JP2001-152515 (2nd page) JP 2003-14141 (2nd page)

  Accordingly, it is an object of the present invention to provide a polyarylene sulfide resin composition that is excellent in flatness, slidability, and mechanical properties and is particularly suitable for sliding parts.

The present invention can solve the above problems by blending a polyarylene sulfide resin and a polyphenylene ether resin, a fluororesin, a fibrous reinforcing material, and calcium carbonate by the following method. That is, the present invention
(1) The ratio [(B) / (A)] (weight ratio) of (A) polyarylene sulfide resin and (B) polyphenylene ether resin to (A) component of (B) component is 0.2-0. 7 and (C) the fluororesin is blended at a ratio of ([C) / (A)] (weight ratio) to the component (A) of 0.2 to 0.6 , and (A), (B) and ( A polyarylene sulfide resin composition obtained by blending 0.01 to 80 parts by weight of (D) fibrous reinforcing material and (E) 0.01 to 80 parts by weight of calcium carbonate with respect to 100 parts by weight of the total amount of C). ,
( 2 ) The polyarylene sulfide resin composition according to the above (1), wherein the fluororesin is a tetrafluoroethylene resin,
( 3 ) The polyarylene sulfide resin composition according to the above (1), wherein the fibrous filler is at least one selected from glass fibers and carbon fibers,
( 4 ) The polyarylene sulfide resin composition according to any one of (1) to ( 3 ), which is for a sliding component.

  If the polyarylene sulfide resin composition of the present invention configured as described above is used, it is possible to improve all of slidability, flatness, and mechanical properties, and a sliding part with extremely excellent practicality can be obtained. Can give. In particular, a molded article using the polyarylene sulfide resin composition of the present invention is excellent in flatness, so that fluid can be sealed by sliding the molded article in combination. This molded product is useful for sliding parts that require flatness.

  (A) As a polyarylene sulfide resin used by this invention, the polyphenylene sulfide resin which has a repeating unit shown by the following structural formula is mentioned preferably.

  A polyphenylene sulfide resin containing 70 mol% or more, particularly 90 mol% or more of the repeating unit represented by the above structural formula is more preferable from the viewpoint of heat resistance. Further, the polyphenylene sulfide resin may comprise less than 30 mol% of the repeating units composed of repeating units having the following structure.

  The method for producing the polyarylene sulfide resin is not particularly limited, and is usually produced by a known method such as the method described in Japanese Patent Publication No. 45-3368 or the method described in Japanese Patent Publication No. 52-12240. it can. In the present invention, the polyarylene sulfide resin obtained as described above is used after being heat-treated in an inert gas atmosphere such as nitrogen or under reduced pressure, and washed with an organic solvent, hot water, an acid aqueous solution or the like. It is also possible. In the case of washing with an organic solvent, the organic solvent to be used is not particularly limited as long as it does not have an action of decomposing the polyarylene sulfide resin, and N-methylpyrrolidone, dimethylformaldehyde, dimethylacetaldehyde, and 1,3-dimethylimidazolide. Nitrogen-containing polar solvents such as nonone, hexamethylphosphorus amide and piperazinones, sulfoxide and sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone and sulfolane, ketone solvents such as acetone, methyl ethyl ketone, dimethyl ketone and acetophenone, dimethyl ether and dipropyl Ether solvents such as ether, dioxane, tetrahydrafuran, chloroform, methylene chloride, trichloroethylene, methylene chloride, perchlorethylene, monochloroethylene, monochloro Halogen-based solvents such as luethane and chlorobenzene, alcohol / phenolic solvents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, polypropylene glycol, and benzene, toluene, Examples thereof include aromatic hydrocarbon solvents such as xylene, among which N-methylpyrrolidone and acetone are preferable. The washing temperature is not particularly limited, and is usually selected from room temperature to about 300 ° C. In the case of washing with an acid aqueous solution, the acid used is not particularly limited as long as it does not have an action of decomposing the polyarylene sulfide resin, and examples thereof include acetic acid, hydrochloric acid, phosphoric acid, silicic acid, carbonic acid, and propyl acid. .

In the present invention, the blending amount of (A) polyarylene sulfide resin and (B) polyphenylene ether resin is such that the ratio [(B) / (A)] (weight ratio ) of component (B) to component (A ) is 0.00. it is good preferable to be 2 to 0.7. When [(B) / (A)] is less than 0.2 , the effect of improving the flatness is not sufficient, and when [(B) / (A)] exceeds 0.7 , the fluidity deteriorates. In a thin molded product, the moldability is poor due to poor filling, and the flatness is deteriorated.

  Examples of (C) fluororesin used in the present invention include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), Polychlorotrifluoroethylene (PCTFE) chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), titafluoroethylene-hexafluoropropylene-bar fluoroalkyl vinyl ether ether copolymer (EPE), etc. Can be mentioned. Among them, PTFE is preferable, and both baked and unfired PTFE can be used, but a baked powder is more preferable. Moreover, it is preferable that an average particle diameter is PTFE of 1 micrometer-50 micrometers. Here, the average particle diameter is a weight average particle diameter measured using a laser diffraction / scattering method (MICOTRAC method).

In the present invention, the blending amount of the (A) polyarylene sulfide resin and the (C) fluororesin is such that the ratio ((C) / (A)) (weight ratio ) of the (C) component to the (A) component is 0.2. it is good preferable to 0.6. If [(C) / (A)] is less than 0.2 , the effect of slidability is not sufficient, and if [(C) / (A)] exceeds 0.6 , the fluidity deteriorates. A thin molded product is not preferable because moldability deteriorates due to poor filling and flatness deteriorates.

  Examples of the (D) fibrous reinforcing material used in the present invention include glass fiber, carbon fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, gypsum fiber, metal fiber, and the like. Whiskers such as potassium whisker, aluminum borate whisker, wollastonite, sericite, and kaolin can also be used. More preferably, the average fiber diameter is 5 to 14 μm, the length of the fiber is not particularly limited, and short fibers, roving glass fibers, and carbon fibers are used.

  The (E) calcium carbonate used in the present invention is not particularly limited as long as it is not fibrous, but preferably has an average particle size of 0.1 to 10 μm. In addition, the average particle diameter here is a specific surface area diameter calculated by ((6 × 10) / true specific gravity × specific surface area) using the specific surface area measured by the air permeation method and the true specific gravity measured by JIS-5101. .

  In the present invention, other non-fibrous fillers can be further blended within a range that does not impair the effects of the present invention. Such a non-fibrous reinforcing material is other than the above (E) calcium carbonate, and specific examples include silicates such as mica, clay, bentonite, asbestos, talc, alumina silicate, alumina, Examples thereof include metal compounds such as silicon chloride, magnesium oxide, zirconium oxide and titanium oxide, carbonates such as magnesium carbonate and dolomite, sulfates such as barium sulfate and potassium sulfate, glass beads, boron nitride, silicon carbide and silica. As such a non-fibrous filler, those having a ratio of the major axis L to the minor axis D (L / D) of 10 or less are particularly preferable.

  In the present invention, a release agent, a crystal nucleating agent, and the like can be further blended in an amount that does not impair the effects of the present invention. Examples of the release agent include polyolefins such as polyethylene and polypropylene, or montanic acid waxes, or fatty acid amide polycondensates such as ethylenediamine / stearic acid polycondensate, ethylenediamine / stearic acid / sebacic acid polycondensate, and stearic acid. Examples thereof include metal soaps such as lithium and aluminum stearate.

  Examples of the crystal nucleating agent include polyether-terketone resin, nylon resin, talc, kaolin and the like.

  In addition, additives such as modifiers, anti-coloring agents, plasticizers, anticorrosives, antioxidants, heat stabilizers, thirstants, ultraviolet absorbers, coloring agents, flame retardants, antistatic agents, foaming agents, etc. It can add in the range which does not impair the effect of invention.

  Although there is no restriction | limiting in particular in the manufacturing method of the polyarylene sulfide resin composition of this invention, The mixture of a raw material is supplied to normally well-known melt mixers, such as a twin-screw extruder, a Banbury mixer, a kneader, and a mixing roll, 280 degreeC-380 A typical example is a method of melt kneading at a temperature of ° C. In addition, there is no particular limitation on the mixing order of the raw materials, and the above-mentioned melt mixing with or without dry blending polyarylene sulfide resin, amorphous resin, fluororesin, fibrous reinforcing material, calcium carbonate and optional additives in advance. A method of blending by supplying to a machine is preferred.

  The polyarylene sulfide resin composition of the present invention thus obtained is generally molded by a known thermoplastic resin molding method such as injection molding, extrusion molding, compression molding, blow molding, injection compression molding, transfer molding, vacuum molding and the like. Of these, injection molding is preferred.

  The polyarylene sulfide resin composition of the present invention thus formed has a flatness of a mold surface of 1 μm and a molded product having a flatness of 20 μm or less when molded under an injection pressure of 125 MPa, and the amount of wear is extremely low. A molded product having few mechanical properties can be obtained. The flatness is represented by the sum of the maximum height and the maximum height of the surface of the molded product. The flatness can be measured by measuring the height of the surface of the molded product using a shape measuring machine (for example, Contracer (CA41) manufactured by Mitutoyo).

  The polyarylene sulfide resin composition of the present invention is a resin composition excellent in flatness, sliding properties and mechanical properties, and is a sliding component utilizing such properties, particularly a sliding component requiring flatness. Can be suitably used. It is particularly useful for sliding parts that can seal fluid by combining and sliding molded products obtained from the polyarylene sulfide resin composition of the present invention, excellent in mechanical properties, and inexpensively mass-produced. Is extremely useful since

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention concretely, this invention is not restrict | limited at all by these.

  The flatness, wear amount, tensile strength, and bending strength in the examples were measured according to the following methods.

<Flatness>
For the measurement of flatness, a cylinder plate having a film gate of 30 mm in length, 30 mm in width, and 3 mm in thickness is used with an injection molding machine having a clamping force of 55 ton, a cylinder temperature of 320 ° C., a mold temperature of 130 ° C., Molding was performed under the conditions of a flatness of 1 μm and an injection pressure of 125 MPa. Using a shape measuring machine (Contractor (CA41) manufactured by Mitutoyo), the highest value from the reference line with reference to the line connecting the arbitrarily selected start point (test piece center) and end point (test piece end) The test was conducted with the sum of the lowest values as the flatness.

<Abrasion amount>
For measuring the wear amount, a cylindrical test piece having an inner diameter of 20 mm and an outer diameter of 24 mm having a side gate was molded using an injection molding machine having a clamping force of 55 tons at a cylinder temperature of 320 ° C. and a mold temperature of 130 ° C. A wear test was conducted according to ASTM-D1894 under conditions of a pressure of 5.75 kg / cm ² , a rotation speed of 46 rpm, and a test time of 4 hours. The amount of wear was measured using an Orientec friction and wear tester (EFM-III-EN), and the weight change before and after the test was calculated to determine the amount of wear.

<Measurement of tensile strength>
In the tensile strength test, an ASTM No. 1 dumbbell piece having a gate on one side was molded using an injection molding machine with a clamping force of 100 ton at a cylinder temperature of 320 ° C. and a mold temperature of 130 ° C., and a tensile strain rate of 10 mm / min. A tensile strength test was performed according to ASTM-D638 under the condition of a distance between fulcrums of 114 mm.

<Measurement of bending strength>
In the bending strength test, a 1/4 inch (6 mm) thickness with a gate on one side and a 1/2 inch (12 mm) inch bending test piece was used at a cylinder temperature of 320 ° C. and a mold using an injection molding machine with a clamping force of 100 ton. Molding was performed at a temperature of 130 ° C., and bending strength was tested according to ASTM-D790 under conditions of a bending strain rate of 3 mm / min and a distance between fulcrums of 100 mm.

<Sealability>
A square plate having a diameter of 24 mm is formed in a square plate having a length of 30 mm, a width of 30 mm, and a thickness of 3 mm used for measuring the flatness, and the square plate having no holes is brought into close contact therewith. Furthermore, water was poured into the holes, and the presence or absence of water leakage from the mating surfaces of the square plates was observed.

Examples 1-5, Comparative Examples 6-12
The prepared PPS-1, amorphous resin, fluororesin, fiber reinforcing material and calcium carbonate were dry blended with the composition shown in Table 1. PPS-1, PPO-1, PTFE-1, glass fiber, calcium carbonate, and graphite used are shown below.
(PPS-1)
Torelina polyphenylene sulfide resin L4230 manufactured by Toray Industries, Inc.
(Amorphous resin, PPO-1)
GE PLASTICS Co., Ltd. Polyphenylene ether resin SA120
(Fluororesin, PTFE-1)
PTFE SG-1000 manufactured by Sanko Fine Material Co., Ltd.
Average particle diameter of 32 μm (weight average particle diameter measured using laser diffraction / scattering method (MICOTRAC method))
(Fiber reinforcement)
Glass fiber T747GH manufactured by Nippon Electric Glass Co., Ltd.
Fiber length 3 mm, fiber diameter 10.0 mm (measurement method: JIS R3420)
(Calcium carbonate)
Hayashi Kasei Co., Ltd. calcium carbonate KSS-1000
Average particle size 2.2 μm (Calculated using the specific surface area measured by the air permeation method using a powder specific surface area measuring machine manufactured by Shimadzu Corporation and the true specific gravity measured by JIS-5101 (6 × 10) / true specific gravity × ratio) Specific surface area diameter)
(graphite)
Scalar graphite manufactured by Nippon Graphite Co., Ltd. Graphite CP (granular)
Average particle size of 7.0 μm (weight average particle size measured according to JIS M8511)

  The dry blend mixture thus obtained was melt kneaded and pelletized by a twin screw extruder (Toshiba TEM-50) set at a cylinder temperature of 320 ° C. to obtain a polyphenylene sulfide resin composition. The obtained polyphenylene sulfide resin composition was injection molded under conditions of a cylinder temperature of 320 ° C. and a mold temperature of 130 ° C., and the flatness, wear amount, tensile strength, and bending strength were measured.

As is apparent from Table 1, Comparative Examples 1, 3, and 5 are cases where the strength is low, Comparative Examples 2 and 6 are cases where the flatness is poor, and Comparative Examples 4 and 7 are cases where the amount of wear is poor. It can be seen that Examples 1 to 5 are excellent in all of flatness, slidability, and mechanical properties.
Comparative Examples 8 and 9 correspond to known examples, in which the slidability is poor and the strength is low.

Claims (4)

(A) The polyarylene sulfide resin and the (B) polyphenylene ether resin are 0.2 to 0.7 in a ratio [(B) / (A)] (weight ratio) of the component (B) to the component (A), and (C) The fluororesin is blended in a ratio [(C) / (A)] (weight ratio) to the component (A) at a ratio of 0.2 to 0.6 , and (A), (B) and (C) A polyarylene sulfide resin composition comprising (D) 0.01 to 80 parts by weight of a fibrous reinforcing material and (E) 0.01 to 80 parts by weight of calcium carbonate with respect to 100 parts by weight of the total amount. The polyarylene sulfide resin composition according to claim 1, wherein the fluororesin is a tetrafluoroethylene resin. The polyarylene sulfide resin composition according to claim 1, wherein the fibrous filler is at least one selected from glass fibers and carbon fibers. The polyarylene sulfide resin composition according to any one of claims 1 to 3 , which is used for sliding parts.