JP2946539B2 - Polyphenylene sulfide resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a polyphenylene sulfide resin composition excellent in heat resistance, impact resistance, extrusion stability and slidability.

<Prior art> Polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) is known as an engineering plastic having excellent heat resistance, chemical resistance, flame retardancy, dimensional stability, and the like. Widely used in fields such as automotive parts and films. In addition, improvements in low impact resistance, which is a drawback of PPS resins, have been actively studied in recent years.For example, Japanese Patent Application Laid-Open No. 58-154757 discloses α-olefins and α-olefins as epoxy group-containing olefin polymers. A composition prepared by blending an olefin copolymer comprising a glycidyl ester of a β-unsaturated acid is disclosed in
-153343, JP-A-62-153344 and JP-A-153344
JP-A-62-153345 discloses a composition obtained by blending an olefin copolymer composed of a glycidyl ester of an α-olefin and an α, β-unsaturated acid into a PPS resin subjected to a specific treatment. .

<Problems to be Solved by the Invention> However, in the above-mentioned conventional PPS resin and a composition of an olefin-based copolymer comprising an α-olefin and a glycidyl ester of an α, β-unsaturated acid, both are melt-kneaded. In such a case, there is a problem that a glycidyl group in the olefin-based copolymer causes an undesirable side reaction to increase the viscosity, or a gel is generated particularly at the time of abnormal retention during kneading. In addition, although the resin composition produced by kneading has high impact resistance, there is also a problem that the resin composition is severely worn when applied to sliding parts such as bearings and gears.

Therefore, the present invention provides a PPS having good impact resistance, improved extrusion characteristics, and also excellent sliding characteristics.
It is an object to obtain a resin composition.

<Means for Solving the Problem> The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that a resin comprising a copolymer of a PPS resin, an α-olefin and an α, β-unsaturated glycidyl ester is used. By adding a small amount of silicone oil to the composition, the above-mentioned problems can be solved at once, and a PPS resin composition having good impact resistance, extrusion processability, and sliding characteristics can be obtained. Heading reached the present invention.

That is, the present invention provides an olefin comprising (A) 50 to 95% by weight of a PPS resin and (B) 60 to 99% by weight of an α-olefin and 1 to 40% by weight of a glycidyl ester of an α, β-unsaturated carboxylic acid. It is intended to provide a polyphenylene sulfide resin composition characterized by mixing 0.05 to 10 parts by weight of silicone oil with respect to 100 parts by weight of a composition comprising 5 to 50% by weight of a copolymer.

Furthermore, the present invention is a sliding component material comprising the above polyphenylene sulfide resin composition as an essential component, and a sliding component comprising the same.

The PPS resin used in the present invention has a structural formula At least 70 mol%, more preferably
A polymer containing at least 90 mol%, wherein the repeating unit is 70
If it is less than mol%, heat resistance is impaired, which is not preferable.

PPS resin is generally a polymer having a relatively small molecular weight obtained by a production method represented by JP-B-45-3368 and an essentially linear polymer obtained by a production method represented by JP-B-52-12240. In the polymer obtained by the method described in JP-B-45-3368, the polymer is heated in an oxygen atmosphere after polymerization or crosslinked with peroxide or the like. It is also possible to increase the degree of polymerization by adding the agent and heating, and in the present invention, the PP obtained by any method
Although it is possible to use S resin, the essential effects obtained by the production method represented by the above-mentioned Japanese Patent Publication No. 52-12240 are because the effects of the present invention are remarkable and the toughness of the PPS resin itself is excellent. A linear and relatively high molecular weight polymer is more preferably used.

Further, the PPS resin can constitute less than 30 mol% of the repeating unit with a repeating unit having the following structural formula.

The melt viscosity of the PPS resin used in the present invention is not particularly limited as long as a molded product can be obtained.However, the PPS resin has a toughness of 100 poise or more in terms of toughness, and a moldability of 10,000 poise. The following are more preferably used.

It is preferable that the PPS resin used in the present invention has been subjected to an acid treatment, an acid water treatment or a washing with an organic solvent after being produced through the above-mentioned polymerization step.

The case of performing the acid treatment is as follows. PPS in the present invention
The acid used for the acid treatment of the resin is not particularly limited as long as it does not have an action of decomposing the PPS resin, and examples thereof include acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid, and propyl acid. And hydrochloric acid are more preferably used, but those which decompose and degrade PPS resin such as nitric acid are not preferred.

Examples of the acid treatment method include a method in which a PPS resin is immersed in an acid or an aqueous solution of an acid, and stirring or heating can be performed as needed. For example, when acetic acid is used, a sufficient effect can be obtained by immersing the PPS resin powder in a pH 4 aqueous solution heated to 80 to 90 ° C. and stirring for 30 minutes. The acid-treated PPS resin needs to be washed several times with water or hot water in order to physically remove the remaining acid or salt.

The water used for washing is preferably distilled water or deionized water in the sense that the effect of the preferred chemical modification of the PPS resin by the acid treatment is not impaired.

 The case of performing hot water treatment is as follows.

In the hot water treatment of the PPS resin used in the present invention, the temperature of the hot water is 100 ° C. or higher, more preferably 120 ° C. or higher, still more preferably 150 ° C. or higher, and particularly preferably 170 ° C.
It is important to make the above, and if the temperature is lower than 100 ° C., the effect of the preferred chemical modification of the PPS resin is small, which is not preferable.

The water used is preferably distilled water or deionized water in order to exhibit the preferable chemical modification effect of the PPS resin by the hot water washing of the present invention. The operation of hot water treatment
Usually, this is performed by charging a predetermined amount of PPS resin into a predetermined amount of water, and heating and stirring in a pressure vessel. As for the ratio of the PPS resin and water, it is preferable that the amount of water is large.
On the other hand, a bath ratio of 200 g or less of the PPS resin is selected.

In addition, since the decomposition of the terminal group is not preferable in the atmosphere of the treatment, it is desirable to use an inert atmosphere in order to avoid this. Further, the PPS resin after the hot water treatment operation is preferably washed several times with warm water to remove the remaining components.

 Washing with an organic solvent is as follows.

The organic solvent used for washing the PPS resin in the present invention is not particularly limited as long as it does not have an action of decomposing the PPS resin, for example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, 1,3-dimethylimidazo. Nitrogen-containing polar solvents such as lydinone, hexamethylphosphoramide, and piperazinones; sulfoxide-sulfone solvents such as dimethyl sulfoxide, dimethyl sulfone, and sulfolane; ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, and acetophenone; dimethyl ether; Propyl ether, dioxane, ether solvents such as tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene chloride, perchlorethylene, monochloroethane, dichloroethane,
Halogen solvents such as tetrachloroethane, perchloreethane, and chlorobenzene; alcohol and phenol solvents such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, and polypropylene glycol; Examples include aromatic hydrocarbon solvents such as benzene, toluene, and xylene. Among these organic solvents, it is particularly preferable to use N-methylpyrrolidone, acetone, dimethylformamide, chloroform and the like, and these organic solvents are used alone or in a mixture of two or more.

As a method of washing with an organic solvent, PP in an organic solvent is used.
There are methods such as immersing the S resin, and if necessary, stirring or heating can be appropriately performed.

The washing temperature when washing the PPS resin with an organic solvent is not particularly limited, and an arbitrary temperature from ordinary temperature to about 300 ° C. can be selected. Although the cleaning efficiency tends to increase as the cleaning temperature increases, a sufficient effect is usually obtained at a cleaning temperature of room temperature to 150 ° C.

It is also possible to wash under pressure at a temperature equal to or higher than the boiling point of the organic solvent in a pressure vessel. There is no particular limitation on the cleaning time. Although depending on the washing conditions, in the case of batch washing, a sufficient effect is usually obtained by washing for 5 minutes or more. It is also possible to wash in a continuous manner.

It is sufficient to wash the PPS resin produced by the polymerization with an organic solvent, but it is preferable to combine the washing with water or washing with warm water in order to further exert the effects of the present invention. When a high-boiling water-soluble organic solvent such as N-methylpyrrolidone is used, it is preferable to wash the organic solvent and then wash it with water or warm water because the remaining organic solvent can be easily removed. The water used for these washings is preferably distilled water or deionized water.

In addition, the PPS resin composition used in the present invention, within a range that does not impair the effects of the present invention, antioxidants, heat stabilizers, lubricants, crystal nucleating agents, ultraviolet additives, ordinary additives such as coloring agents and A small amount of other polymer can be added, and further, for the purpose of controlling the degree of crosslinking of the PPS resin, a conventional peroxide and a metal salt of thiophosphinic acid described in JP-A-59-131650. Crosslinking accelerator or JP-A-58-
It is also possible to add a crosslinking inhibitor such as dialkyltin dicarboxylate and aminotriazole described in JP-A-204045 and JP-A-58-20406.

Next, the olefin copolymer used in the present invention is α-
A copolymer comprising an olefin and a glycidyl ester of an α, β-unsaturated acid. Examples of the α-olefin include ethylene, propylene, and butene-1, and among them, ethylene is preferably used. The glycidyl ester of α, β-unsaturated acid is (R represents a hydrogen atom or a lower alkyl group). Specific examples thereof include glycidyl acrylate, glycidyl methacrylate, and glycidyl ethacrylate. Among them, glycidyl methacrylate is preferably used. . The copolymerization amount of the glycidyl ester of α, β-unsaturated acid in the olefin copolymer is 0.
5 to 40% by weight, especially 3 to 30% by weight, preferably 0.5% by weight
If it is less than 40%, the effect of improving impact properties cannot be obtained. If it exceeds 40% by weight, gelation occurs during melt-kneading with the PPS resin, and extrusion stability, moldability and mechanical properties are undesirably reduced.

The olefin-based copolymer may contain up to 40% by weight or less and other copolymerizable unsaturated monomers such as vinyl ether, vinyl acetate, vinyl propionate, and acrylic acid within a range not to impair the object of the present invention. Methyl, methyl methacrylate, acrylonitrile, styrene and the like may be copolymerized.

If the content of the olefin copolymer is less than 5% by weight in the mixing ratio of the PPS resin and the olefin copolymer, the effect of improving the impact characteristics is not easily obtained, and if it exceeds 50% by weight, the PPS is not obtained.
Not only may the strength, rigidity and heat resistance of the resin be impaired, but also gelling occurs during melt-kneading, extruding stability,
Since the moldability tends to be impaired, PPS resin 50-95
The olefin polymer is preferably 50 to 5% by weight, more preferably 60 to 95% by weight of the PPS resin.
Olefin copolymer 40 to 5% by weight, especially PPS resin 70 to 9
The range of 30 to 10% by weight of the olefin polymer can be selected with respect to 0% by weight.

In the present invention, an ethylene / propylene copolymer, an ethylene / butene copolymer, a copolymer of ethylene / (meth) acrylic acid and a derivative thereof, and styrene /
An elastomer component such as a hydrogenated butadiene / styrene block copolymer can also be used in combination with the olefin-based copolymer.

The silicone oil used in the present invention is a polyorganosiloxane represented by polydimethylsiloxane and an epoxy group, a carboxyl group, an amino group, a part of a side chain and / or a terminal methyl group of polydimethylsiloxane.
It is a modified polyorganosiloxane into which a reactive substituent such as a hydroxyl group or a mercapto group has been introduced.

The viscosity of the silicone oil is not particularly limited, and those having a viscosity at 25 ° C. in the range of 10 to 100,000 CS can be used, but those having a viscosity in the range of 100 to 50,000 CS from the viewpoint of the handleability and the effect of improving the molding characteristics. Is particularly preferred.

The amount of the silicone oil is 0.05% with respect to 100 parts by weight of the PPS resin composition containing the olefin copolymer.
A suitable range is from 10 to 10 parts by weight, preferably from 0.1 to 7 parts by weight. If the amount is less than 0.05 part by weight, the desired effect of improving the sliding properties and extrusion stability cannot be obtained, and if it exceeds 10 parts by weight, the impact strength of the composition is undesirably reduced.

In the present invention, the fibrous and / or granular reinforcing agent is not an essential component, but if necessary, is added in an amount not exceeding 300 parts by weight with respect to the total 100 parts by weight of the PPS resin and the olefin-based copolymer. It is possible, usually 10-300
It is possible to improve strength, rigidity, heat resistance, dimensional stability and the like by blending in the range of parts by weight.

Examples of the fiber reinforcing material include glass fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber,
Examples include inorganic fibers such as stone fibers and metal fibers, and carbon fibers.

Examples of the granular reinforcing material include silicates such as walasteinite, sericite, kaolin, mica, clay, bentonite, asbestos, talc, and alumina silicate, and metal oxides such as alumina, silicon chloride, magnesium oxide, zirconium oxide, and titanium oxide. Substances, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, boron nitride, silicon carbide and silica, and may be hollow. Two or more of these reinforcing materials can be used in combination, and if necessary, can be used after being pretreated with a silane-based or titanium-based coupling agent.

The means for preparing the composition of the present invention is not particularly limited.
Resins, olefin polymers and silicone oils,
Further, if necessary, a method is known in which a reinforcing material is melt-kneaded in an extruder at a temperature not lower than the melting point of the PPS resin and then pelletized.

The melt-kneading temperature is generally 280 ° C. or higher to sufficiently melt the composition, and is usually 340 ° C. or lower, that is, 280 to 340 ° C., from the viewpoint of preventing thermal degradation and gelation of the olefin copolymer. preferable.

The PPS resin composition thus obtained is excellent in heat resistance, impact resistance, extrusion stability and sliding properties in a balanced manner,
It is particularly suitable as a material for sliding parts and useful as a sliding part.

Hereinafter, the present invention will be described in more detail with reference to Examples.

<Examples> Reference Example 1 (Polymerization of PPS resin) 3.26 kg of sodium sulfide (25 mol, including 40% of water of crystallization), 4 g of sodium hydroxide, 1.36 kg (about 10 mol) of sodium acetate trihydrate in autoclave 7.9 kg of N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) was charged, the temperature was gradually raised to 205 ° C. while stirring, and 1.5 parts of distillate containing 1.36 kg of water was removed. Add 4.75 kg (25.5 mol) of 4-dichlorobenzene and 2 kg of NMP, and add
Heated for hours. The reaction product is washed 5 times with 70 ° C. hot water,
Dry under reduced pressure at 80 ° C for 24 hours to obtain a melt viscosity of about 2,500 poise (3
About 2 kg of a powdery PPS resin having a shear rate of 1,000 seconds- ¹ ) at 20 ° C was obtained.

 The same operation was repeated and used for the examples described below.

Examples 1 to 4 About 2 kg of the PPS resin powder obtained in Reference Example 1 was put into an aqueous acetic acid solution 20 of pH 4 heated to 90 ° C., and the mixture was stirred for about 30 minutes. The powder was washed with deionized water at about 90 ° C. to 7 and dried under reduced pressure at 120 ° C. for 24 hours to obtain a powder.

After dry-blending the PPS resin powder, ethylene-glycidyl methacrylate (88/12 weight ratio) copolymer (hereinafter abbreviated as olefin copolymer) and silicone oil in the composition shown in Table 1, 290- Set to 320 ° C
The mixture was supplied to a 40 mmφ single screw extruder and melt-kneaded to obtain PPS resin composition pellets. In addition, at the time of melt-kneading, the presence or absence of generation of a gel-like substance due to abnormal stagnation was determined by visually observing the surface appearance of the extrusion gut.

Cylinder temperature 300 ~ 320 ℃, mold temperature
The test piece was supplied to an injection molding machine set at 150 ° C. to form a test piece. The Izod impact strength and sliding properties of the above resin composition were measured according to the following methods, and the results are shown in Table 1.

A. Izod impact strength: ASTM D256 B. Sliding characteristics (dynamic friction coefficient and wear coefficient) Suzuki type thrust wear tester Load 15kgf / cm ² speed 30m / min Counterpart material SCM 21 As evident from Table 1 It can be seen that the PPS resin composition of the present invention is a material having high Izod impact strength and excellent sliding characteristics with extremely low dynamic friction coefficient and wear coefficient.

Comparative Example 1 Example 1 was repeated except that the olefin copolymer was not blended.
And the results are shown in Table 1. Although the coefficient of kinetic friction and the coefficient of wear were small, the material had a low Izod impact strength.

Comparative Example 2 The same procedure as in Example 1 was carried out except that no silicone oil was added, and the results are shown in Table 1. Many foreign substances were found in the extrusion gut of this composition, and the molded product was a material having a high Izod impact strength but a large dynamic friction coefficient and a high wear coefficient.

Comparative Example 3 Example 1 except that 12 parts by weight of silicone oil was blended.
And the results are shown in Table 1. Izod impact strength is significantly reduced.

<Effect of the Invention> Since the PPS resin composition of the present invention is excellent in heat resistance, impact resistance, extrusion stability and sliding characteristics in balance, it is practically used as a sliding material for heat insulating sleeves, gears, tubes and the like. Very large value.

Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08L 81/00-81/02 C08L 23/00-23/02 C08L 83/04

Claims (4)

(57) [Claims] 1. A polyphenylene sulfide resin (A)
Glycidyl ester of α, β-unsaturated carboxylic acid with 95% by weight and (B) 60 to 99% by weight of α-olefin and 1 to 40%
A polyphenylene sulfide resin composition characterized by comprising 0.05 to 10 parts by weight of silicone oil with respect to 100 parts by weight of a composition consisting of 5 to 50% by weight of an olefin copolymer containing 5% by weight as an essential component. 2. A polyphenylene sulfide resin is treated with an acid,
2. The polyphenylene sulfide resin composition according to claim 1, which has been subjected to hot water treatment or washing with an organic solvent. 3. A material for a sliding part comprising the polyphenylene sulfide resin composition according to claim 1 as an essential component. 4. A sliding component comprising the sliding component material according to claim 3.