JPWO1997015623A1 - Resin composition, molded article using same, and method for producing same - Google Patents

Abstract

(57) [Abstract] Provided are a resin composition that can maintain the excellent heat resistance, chemical resistance, surface properties (non-stickiness, low friction), electrical insulation, etc. of fluorine-containing polymers and further provide molded articles with excellent mechanical properties and abrasion resistance, as well as a molded article using the same, and a method for producing the same. The resin composition comprises (A-1) a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol % based on the total amount of monomers of at least one fluorine-containing monomer having either a hydroxyl group, a carboxyl group or a carboxylate group, a carboxy ester group, or an epoxy group, and (B-1) an inorganic filler or a pre-insolubilized organic filler, the resin composition comprising 1 to 99.5 wt % of (A-1) and 0.5 to 99 wt % of (B-1).

Description

[Detailed Description of the Invention] Resin composition, molded article using the same, and method for producing the same Technical Field The present invention relates to a novel resin composition comprising a specific fluorine-containing ethylenic polymer having functional groups and a filler. More specifically, it relates to a resin composition comprising a fluorine-containing ethylenic polymer having functional groups mixed with an inorganic filler or a pre-insolubilized organic filler, which has improved mechanical properties and sliding properties and can be suitably used in a variety of applications described below.

The present invention further relates to a molded article having improved mechanical properties and sliding properties obtained by heat treating a molded article made from the above resin composition, and to a method for producing the same.

BACKGROUND ART Fluorocarbon resins generally have heat resistance, chemical resistance and a low coefficient of friction, and attempts have been made to compound inorganic or organic fillers with them in order to further improve their mechanical properties and abrasion resistance.

However, fluoropolymers themselves have low surface energy and disperse poorly when mixed with fillers, so their addition has only a limited effect on mechanical properties. Furthermore, the interfacial adhesion between the fluoropolymer and filler in the mixture is poor. For example, when used as a sliding material, the filler in the molded product is prone to falling off from the sliding surface, resulting in insufficient wear resistance and a long-life sliding material.

In order to improve the interfacial adhesion between the fluororesin and the filler, attempts have been made to mix fillers that have been previously surface-treated with organic compounds.

For example, a hydrolyzable non-fluorine siloxane compound having an amine terminal group is used for the surface treatment of glass fiber (U.S. Pat. No. 3,787,281), and a silane coupling agent having a silicon-bonded methyl group is used for the surface treatment of a filler (Japanese Patent Laid-Open No. 7-53780). Various surface treatment agents using silane compounds have been disclosed, such as a fluorine-containing silane coupling agent (JP-A-4-272973).

Other examples include the use of fluorine-containing acid chlorides for surface treatment of glass fibers and carbon fibers (Japanese Patent Laid-Open Publication No. 4-345691), and the use of fluoropolyethers having terminal functional groups such as siloxane groups, alkoxytitanium groups, epoxy groups, and isocyanate groups for surface treatment of reinforcing agents (Japanese Patent Publication No. 7-64973).

Since these surface treatment agents are structurally fundamentally different from the base fluorine-containing ethylenic polymer, the interfacial adhesion between the fluorine-containing polymer and the filler in compositions or molded articles containing fillers that have been surface-treated by the above-mentioned methods is insufficient, and the effects of imparting mechanical properties and abrasion resistance to the molded articles are insufficient.

Furthermore, these surface treatment agents generally lack sufficient heat and chemical resistance, causing foaming and discoloration due to decomposition during mixing and molding of the fluororesin and surface-treated filler. Furthermore, when used in structural and sliding materials that require thermal durability in fields such as automobiles, industrial machinery, office automation equipment, and home appliances, prolonged use can cause the leaching of surface treatment agents and their decomposition products, resulting in a decline in initial performance (mechanical properties and abrasion resistance).

The object of the present invention is to solve the above-mentioned conventional problems and to provide a resin composition that maintains the excellent heat resistance, chemical resistance, surface properties (non-tackiness, low friction), electrical insulation, and other properties of fluoropolymers, while also imparting excellent mechanical properties and abrasion resistance to molded articles; a molded article using the same; and a method for producing the same.

DISCLOSURE OF THE INVENTION The present invention relates to a resin composition comprising (A-1) a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol % based on the total amount of monomers of at least one fluorine-containing ethylenic monomer having either a hydroxyl group, a carboxyl group, a carboxylate group, a carboxylate ester group, or an epoxy group, and (B-1) an inorganic filler or a pre-insolubilized organic filler, wherein the resin composition comprises 1 to 99.5% by weight of component (A-1) and 0.5 to 99% by weight of component (B-1).

The fluorine-containing ethylenic polymer (A-1) is preferably a fluorine-containing ethylenic polymer having a crystalline melting point of 120°C or higher.

The fluorine-containing ethylenic polymer (A-1) is represented by (a-1) formula (1): (wherein Y represents _—CH2OH , —COOH, a carboxylate, a carboxy ester group or an epoxy group; X and X are the same or different and represent a hydrogen atom or a fluorine atom; and R represents a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms containing an ether bond or a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms containing an ether bond), and (b-1) 70 to 99.95 mol % of at least one ethylenic monomer copolymerizable with said component (a-1).

The functional group-containing fluorine-containing ethylenic monomer (a-1) is preferably a fluorine- ^{containing monomer represented by formula (2): CH2=CFCF2-Rf1-Y1} _{( 2 )} ^[ wherein ^Y1 represents _-CH2OH , -COOH, a carboxylate, a carboxy ester group or an epoxy group, ^and _Rf1 represents a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms or _-ORf2 ( ^Rf2 represents a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms or _a divalent fluorine-containing alkylene group having 1 ^to 39 carbon atoms and containing an ether bond)].

At least one of the ethylenic monomers (b-1) is preferably a fluorine-containing ethylenic monomer.

The fluorine-containing ethylenic monomer (b-1) is preferably tetrafluoroethylene.

^The fluorine-containing ethylenic monomer (b-1) is preferably a mixture of 85 to 99.7 mol % of tetrafluoroethylene and 0.3 to 15 mol % of a monomer represented by formula ( ³ ): _CF2 =CF- _Rf2 ^{( 3} ) [ _Rf2 represents _-CF3 or _ORf3 ( _Rf3 is a perfluoroalkyl group having 1 to 5 carbon atoms)].

The fluorine-containing ethylenic monomer (b-1) is preferably a mixture of 40 to 80 mol % of tetrafluoroethylene or chlorotrifluoroethylene, 20 to 60 mol % of ethylene, and 0 to 15 mol % of other monomers.

The filler (B-1) is preferably carbon fiber.

The filler (B-1) is preferably a whisker.

The filler (B-1) is preferably a glass-based filler.

The filler (B-1) is preferably an inorganic filler having shearing properties.

The filler (B-1) is preferably a pre-insolubilized organic fiber.

The filler (B-1) is preferably carbon fiber.

The filler (B-1) is preferably aluminum borate whiskers.

The filler (B-1) is preferably glass fiber.

The filler (B-1) is preferably molybdenum disulfide.

The filler (B-1) is preferably bronze.

The filler (B-1) is preferably an aramid fiber.

The present invention also relates to a resin composition comprising (A-2) a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol %, based on the total amount of monomers, of at least one fluorine-containing ethylenic monomer having either a hydroxyl group, a carboxyl group, a carboxylate group, a carboxylate ester group, or an epoxy group; (B-2) an inorganic filler or a pre-insolubilized organic filler; and (C) a fluorine-containing ethylenic polymer not containing functional groups in its side chains, wherein the resin composition comprises 1 to 50 wt % of component (A-2), 0.5 to 80 wt % of component (B-2), and the remainder being component (C), with the proviso that the sum of (A-2) and (C) is 20 to 99.5 wt %, and (C)/((A-2) + (C)) ≥ 0.4.

The fluorine-containing ethylenic polymer (C) having no functional group in its side chain is preferably a fluorine-containing ethylenic polymer having a crystalline melting point of 120°C or higher.

The fluorine-containing ethylenic polymer (C) having no functional groups in its side chains is preferably polytetrafluoroethylene, a tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer or an ethylene-tetrafluoroethylene copolymer.

The present invention also relates to a resin composition comprising (A-3) a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol %, based on the total amount of monomers, of at least one fluorine-containing ethylenic monomer having either a hydroxyl group, a carboxyl group, a carboxylate group, a carboxy ester group, or an epoxy group, the fluorine-containing ethylenic polymer having a crystalline melting point of 120°C or higher, and (B-3) an inorganic filler or a pre-insolubilized organic filler, the resin composition comprising 1 to 99.5 wt % of component (A-3) and 0.5 to 99 wt % of component (B-3), and the resulting molded article being heat-treated at a temperature not lower than 100°C and not higher than the crystalline melting point of the fluorine-containing ethylenic polymer (A-3).

The fluorine-containing ethylenic polymer (A-3) is represented by formula (a-2) (1): (wherein Y represents _-CH2OH , -COOH, a carboxylate or carboxy ester group or an epoxy group; X and ^X1 are the same or different and represent a hydrogen atom or a fluorine atom; and _Rf represents a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms containing an ether bond or a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms containing an ether bond) with 70 to 99.95 mol % of at least one ethylenic monomer copolymerizable with (b-2) and (a-2).

At least one of the ethylenic monomers (b-2) is preferably a fluorine-containing ethylenic monomer.

The fluorine-containing ethylenic monomer (b-2) is preferably tetrafluoroethylene.

^The fluorine-containing ethylenic monomer (b-2) is preferably a mixture of 85 to 99.7 mol % of tetrafluoroethylene and 0.3 to 15 mol % of a monomer represented by formula ( ³ ): _CF2 =CF- _Rf2 ^{( 3} ) [ _Rf2 represents _-CF3 or _ORf3 ( _Rf3 is a perfluoroalkyl group having 1 to 5 carbon atoms)].

The fluorine-containing ethylenic monomer (b-2) is preferably a mixture of 40 to 80 mol % of tetrafluoroethylene, 20 to 60 mol % of ethylene, and 0 to 15 mol % of other monomers.

The filler (B-3) is preferably carbon fiber.

The filler (B-3) is preferably a whisker.

The filler (B-3) is preferably aluminum borate whiskers.

The filler (B-3) is preferably a glass-based filler.

The filler (B-3) is preferably an inorganic filler having cleavage properties.

The filler (B-3) is preferably a pre-insolubilized organic fiber.

The present invention further relates to a method for producing the above-mentioned molded article, which comprises heat-treating a molded article obtained by molding the above-mentioned resin composition at a temperature of 100°C or higher and not higher than the crystalline melting point of the fluorine-containing ethylenic polymer (A-1).

It is preferable to heat-treat a molded article obtained by molding the resin composition at a temperature of 200°C or higher and not higher than the crystalline melting point of the fluorine-containing ethylenic polymer (A-1).

It is preferable that the molded article obtained by melt molding the resin composition is heat-treated at a temperature of 200° C. or higher and not higher than the crystalline melting point of the fluorine-containing ethylenic polymer (A-1).

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining a reciprocating sliding type friction tester used in the friction test in the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION The functional group-containing fluorine-containing ethylenic polymer (A-1) used in the resin composition of the present invention is a polymer obtained by copolymerizing at least one fluorine-containing ethylenic monomer having a hydroxyl group, a carboxyl group or a carboxylate group, a carboxy ester group or an epoxy group in an amount of 0.05 to 30 mol % based on the total amount of the monomer components.

The functional group of the functional group-containing fluorine-containing polymer (A-1) in the resin composition of the present invention is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a carboxylate or carboxy ester group, and an epoxy group. The type of functional group is appropriately selected depending on the type of filler (B-1) in the composition, the purpose, and the application. However, when the composition is used for molded articles, molded parts, etc. that require heat resistance at high temperatures, fluorine-containing polymers containing hydroxyl groups are particularly preferred.

The fluorine-containing ethylenic polymer (A-1) used in the composition of the present invention can be selected from a variety of resinous and elastomeric polymers. However, when the composition itself is to be used for molding, such as for sliding materials and molded parts, (A-1) is preferably a fluorine-containing polymer having a crystalline melting point of 120°C or higher, more preferably 150°C or higher.

The fluorine-containing ethylenic polymer used in the resin composition of the present invention is specifically a fluorine-containing ethylenic monomer having a functional group represented by formula (1) (a-1): [X, ^X1 , _Rf and Y are the same as in formula (1)] A fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol % of (a-1) component (a-1) with 70 to 99.95 mol % of an ethylenic monomer copolymerizable with the component (a-1).

Specifically, the functional group-containing fluorine-containing ethylenic monomer (a-1) is represented by the formula (4): _CF2 =CF- _Rf4 ^- Y (4) (wherein Y is the same as Y in formula (1), _Rf4 ^represents a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms or _-ORf5 ( ^{Rf5 is} a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms or _a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms and containing an ether bond)), formula (5): _CF2 = _CFCF2 - _ORf6 ^- Y (5) (wherein Y is the same as Y in formula (1), _-Rf6 represents a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms or a divalent fluorine-containing alkylene group having 1 ^to 39 carbon atoms and containing an ether bond), formula (6): _CH2 = _CFCF2 - _Rf ⁷ -Y (6) [wherein Y is the same as Y in formula (1), _-Rf7 ^represents a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms, or _-ORf8 ( _{wherein -Rf8} ^{is a} divalent fluorine-containing alkylene group having 1 to 39 carbon atoms or a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms and containing an ether bond)] or those represented by formula (7): _CH2 =CH- _Rf9 - ^Y (7) [wherein Y is the same as Y in formula (1), _Rf9 represents a divalent fluorine-containing alkylene group having 1 ^to 40 carbon atoms].

The functional group-containing fluorine-containing ethylenic monomers of formulas (4) to (7) are preferred because they have relatively good copolymerizability with the fluorine-containing ethylenic monomer (b-1) and do not significantly reduce the heat resistance of the copolymer obtained by copolymerization.

Among these, compounds of formula (4) and formula (6) are preferred in terms of copolymerizability with other fluorine-containing ethylenic monomers and the heat resistance of the resulting polymer, and compound of formula (6) is particularly preferred.

The functional group-containing fluorine-containing monomer represented by formula (4) is more specifically Examples of the functional group-containing fluorine-containing monomer represented by formula (5) include: Examples of the functional group-containing fluorine-containing monomer represented by formula (6) include: Examples of the functional group-containing fluorine-containing monomer represented by formula (7) include: Examples include:

others Other examples include:

The ethylenic monomer to be copolymerized with the functional group-containing fluorine-containing ethylenic monomer (a-1) can be appropriately selected from known monomers. However, in order to impart heat resistance, chemical resistance, and low friction to the copolymer, it is preferable to select from fluorine-containing ethylenic monomers or fluorine-free ethylenic monomers having 1 to 5 carbon atoms.

Specific examples of the fluorine-containing ethylenic monomer include tetrafluoroethylene, chlorotrifluoroethylene, vinyl fluoride, vinylidene fluoride, hexafluoropropylene, hexafluoroisobutene, (wherein each X is selected from H, Cl, and F, and each n is an integer of 1 to 5), and perfluoro(alkyl vinyl ethers).

Examples of the fluorine-free ethylenic monomer include ethylene, propylene, 1-butene, 2-butene, vinyl chloride, and vinylidene chloride.

In terms of heat resistance, chemical resistance, and low friction, it is preferable that at least one of the monomers in (b-1) is a fluorine-containing monomer.

The content of functional groups in the fluorine-containing ethylenic polymer in the resin composition of the present invention is 0.05 to 30 mol % of the total amount of monomers in the polymer. This content can be appropriately selected depending on the type of filler (B-1) in the composition, the compositional ratio of component (A-1) to component (B-1), the purpose of the composition, and the like, but is preferably 0.05 to 20 mol %, and particularly preferably 0.1 mol % to 10 mol %.

If the content of the functional group is 0.05 mol % or less, the dispersibility and interfacial adhesion between the fluoropolymer (A-1) and the filler (B-1) in the composition are not sufficiently achieved. Furthermore, if the content is 30 mol % or more, the heat resistance of the fluoropolymer is reduced, which reduces the heat resistance of the resin composition and molded articles made therefrom, and is likely to result in reduced mechanical properties and coloration.

A preferred example of the fluorine-containing ethylenic polymer (A-1) used in the resin composition of the present invention is a copolymer of 0.05 to 30 mol % of a functional group-containing fluorine-containing ethylenic monomer (a-1) and 70 to 99.95 mol % of tetrafluoroethylene (so-called functional group-containing polytetrafluoroethylene (functional group-containing PTFE)), which contains 0.05 to 30 mol % of the fluorine-containing ethylenic monomer (a-1) based on the total amount of monomers, and further contains 85 to 99.7 mol % of tetrafluoroethylene and 0.3 to 15 mol % of a monomer represented by the above formula (3) ^: _CF2 =CF- _Rf2 (3) [ _Rf2 is _—CF3 , _ORf3 ( ^Rf3 is a perfluoroalkyl group having 1 to 5 carbon atoms)] based on ^the total amount of monomers excluding (a-1)] (functional group-containing tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (functional group-containing PTFE) A) or a functional group-containing tetrafluoroethylene-hexafluoropropylene copolymer (functional group-containing FEP)), a copolymer containing 0.05 to 30 mol % of a fluorine-containing ethylenic monomer (a-1) based on the total amount of monomers, and further containing 40 to 80 mol % of tetrafluoroethylene or chlorotrifluoroethylene, 20 to 60 mol % of ethylene, and 0 to 15 mol % of other copolymerizable monomers based on the total amount of monomers excluding monomer (a-1) (functional group-containing ethylene-tetrafluoroethylene copolymer (functional group-containing ETFE) or functional group-containing ethylene-chlorotrifluoroethylene copolymer (functional group-containing ECTFE)).

Other copolymerizable monomers that can be used in copolymerization of tetrafluoroethylene or chlorofluoroethylene having this functional group with ethylene include hexafluoropropylene, hexafluoroisobutene, CH (wherein X is H, Cl or F, and n is an integer of 1 to 5) and perfluoro(alkyl vinyl ethers).

These exemplified fluorine-containing ethylenic polymers are particularly excellent among fluorine-containing polymers in heat resistance, chemical resistance, mechanical properties and low friction, and when combined with filler (b-1), are particularly excellent as heat-resistant sliding materials.

The inorganic filler or pre-insolubilized organic filler used as component (B-1) in the resin composition of the present invention is thermally stable, does not decompose or melt at the processing temperatures of typical fluorine-containing polymers, and when mixed with the filler, can impart mechanical properties, abrasion resistance, and other functions to molded articles.

Specific examples of inorganic fillers include metals such as stainless steel, iron, nickel, lead, copper, gold, and silver; aluminum, molybdenum, rare earth cobalt, and boron fibers; and metal fibers; carbons such as carbon black, graphite, carbon fiber, activated carbon, hollow carbon spheres, graphite, and coke; oxides such as silica, alumina, titanium oxide, iron oxide, zinc oxide, magnesium oxide, tin oxide, and antimony oxide; hydroxides such as aluminum hydroxide and magnesium hydroxide; carbonates such as calcium carbonate, magnesium carbonate, and zinc carbonate; sulfates such as calcium sulfate, gypsum fiber, barium sulfate, magnesium sulfate, and MOS (fibrous basic magnesium sulfate); glass, hollow glass spheres, and glass fiber. Examples include silicates such as talc, mica, kaolin, calcium silicate, wollastonite, xonotlite, PMF (a type of slag fiber, a mixture of calcium aluminosilicate and magnesium oxide), and mica; borates such as aluminum borate, magnesium borate, and calcium borate; titanates such as potassium titanate and barium titanate; nitrides such as aluminum nitride and silicon nitride; carbides such as silicon carbide and titanium carbide; sulfides such as molybdenum disulfide, molybdenum trisulfide, tungsten disulfide, zinc sulfide, and cadmium sulfide; phosphates such as calcium phosphate and iron phosphate; ferrites such as barium ferrite, calcium ferrite, and strontium ferrite.

The inorganic fillers may be in the form of fibers, whiskers, needles, powders, granules, beads, or the like.

The pre-insolubilized organic filler is an organic substance, excluding fluoropolymers, that is highly heat-resistant and does not decompose or melt at the temperatures used to produce the resin composition of the present invention or to process the composition into molded articles, and that can impart mechanical properties, abrasion resistance, or other functions to the molded articles.

The organic filler is specifically an organic substance having a melting point of 400°C or higher, or, if insoluble, a decomposition temperature of 400°C or higher. Specific examples include organic fibers such as aramid fiber, polyarylate fiber, and phenol fiber, polyimide, and thermosetting resins such as COPNA resin.

The type (composition, shape) of the filler in the composition of the present invention can be selected depending on the intended function and application of the composition and the molded article using it.

Among these, carbon fibers are preferred, as they significantly improve mechanical properties (especially strength and modulus of elasticity), dimensional stability, and abrasion resistance, and can also provide electrical conductivity. Glass-based fillers maintain insulation and significantly improve mechanical properties, dimensional stability, and abrasion resistance. Whiskers maintain the flexibility and sealing properties of fluororesin and provide surface smoothness to molded products, improving mechanical strength, dimensional stability, and abrasion resistance. Inorganic fillers with cleavage properties are self-lubricating, providing lubrication to compositions and molded products and reducing the coefficient of friction. Organic fibers have low hardness, making them less likely to scratch mating materials (such as soft metals) on the sliding surface, especially when the composition is used in sliding parts, and can also provide molded products with mechanical properties, dimensional stability, and abrasion resistance.

More specific examples of the glass-based fillers include glass fiber, glass beads, glass powder, and glass hollow spheres, with glass fiber being particularly preferred in terms of improving mechanical properties and abrasion resistance.

Whiskers are needle-like single crystal materials, specifically, single crystals with a cross-sectional area of 8×10 ⁻⁵ in ² or less and a length of 10 times or more the average cross-sectional diameter, and are distinguished from polycrystalline continuous fibers.

Specific examples of the whiskers include silicon carbide whiskers, silicon nitride whiskers, potassium titanate whiskers, aluminum borate whiskers, zinc oxide whiskers, basic magnesium sulfate whiskers, graphite whiskers, magnesium oxide whiskers, magnesium borate whiskers, titanium diboride whiskers, and calcium sulfate whiskers.

In the present invention, the term "cleavable filler" refers to a filler that has self-lubricating properties and can impart lubricity to a molded product. Specific examples of cleavable fillers include layered crystalline materials such as graphite, molybdenum disulfide, tungsten disulfide, hexagonal boron nitride, talc, and mica, with graphite and molybdenum disulfide being preferred.

Examples of organic fibers include aramid fibers, polyarylate fibers, and phenolic fibers, with aramid fibers being preferred.

The first resin composition of the present invention is a composition comprising (A-1) a fluorine-containing ethylenic polymer obtained by copolymerizing at least one fluorine-containing ethylenic monomer having a hydroxyl group, a carboxyl group, a carboxylate group, a carboxy ester group, or an epoxy group in an amount of 0.05 to 30 mol %, based on the total amount of monomers, and (B-1) an inorganic filler or a pre-insolubilized organic filler.

In the resin composition of the present invention comprising the two components, component (A-1) and component (B-1), the fluorine-containing ethylenic polymer (A-1) may be the same as the functional group-containing fluorine-containing ethylenic polymer described above, but the concentration of the functional group in the fluorine-containing ethylenic polymer (A-1) is 0.05 to 30 mol %, preferably 0.1 to 10 mol %, and particularly preferably 0.1 to 5 mol %, based on the total monomers used in the fluorine-containing ethylenic polymer (A-1).

If the functional group concentration is too low, the dispersibility and affinity between the fluorine-containing ethylenic polymer (A-1) and the filler (B-1) will not be sufficiently improved. On the other hand, if the functional group concentration is too high, the heat resistance and mechanical properties will be reduced.

In the resin composition of the present invention comprising the two components, component (A-1) and component (B-1), the filler (B-1) may be the same inorganic or organic filler as described above.

Although other components may be added to the two essential components, component (A-1) and component (B-1), it is preferable that the resin composition essentially consist of only components (A-1) and (B-1) in order to improve the mechanical properties and wear resistance without compromising the excellent heat resistance, chemical resistance, and low friction properties of the fluoropolymer.

The composition ratio of component (A-1) to component (B-1) in the two-component resin composition of the present invention can be within the range of 1 to 99.5 wt % for (A-1) and 0.5 to 99 wt % for (B-1). However, in the case of a composition consisting essentially of only two components, the ratios, expressed by volume (vol %), are 20 to 99.5 vol % for (A-1) and 0.5 to 80 vol % for (B-1), preferably 40 to 99 vol % for (A-1) and 1 to 60 vol % for (B-1), and particularly preferably 50 to 98 vol % for (A-1) and 2 to 50 vol % for (B-1).

The two-component resin composition of the present invention can be used for a variety of purposes and applications. However, when used as a sliding material, which requires heat resistance in particular, specific examples of preferred resin compositions are as follows:

i) A composition comprising (A-1) at least one selected from the fluorine-containing polymer (functional group-containing PTFE) of claim 6, the fluorine-containing polymer (functional group-containing FEP or PFA) of claim 7, and the fluorine-containing polymer (functional group-containing ETFE) of claim 8, and (B-1) carbon fiber, wherein a resin composition comprising 60 to 95 wt % of (A-1) and 5 to 40 wt % of (B-1) is preferred in that it exhibits significant improvements in mechanical properties and abrasion resistance and can impart electrical conductivity to the composition.

ii) A composition comprising (A-1) at least one selected from the polymer of claim 6 (functional group-containing PTFE), the fluoropolymer of claim 7 (functional group-containing FEP or PFA), and the fluoropolymer of claim 8 (functional group-containing ETFE), and (B-1) glass fiber, wherein a resin composition obtained by mixing 60 to 95 wt % of (A-1) and 5 to 40 wt % of (B-1) is preferred because it can significantly improve mechanical properties and abrasion resistance while maintaining electrical insulation, and the filler itself is inexpensive and therefore economically advantageous.

iii) A composition comprising (A-1) at least one polymer selected from the group consisting of the polymer (functional group-containing FEP or PFA) according to claim 7 and the polymer (functional group-containing ETFE) according to claim 8, and (B-1) aluminum borate whiskers, wherein the resin composition is a mixture of 70 to 98 wt % of (A-1) and 2 to 30 wt % of (B-1). This resin composition is preferred as a sliding material that has excellent sealing properties while maintaining the flexibility of the fluororesin and the smoothness of the surface of the molded article.

iv) A composition comprising (A-1) at least one selected from the polymer of claim 6 (functional group-containing PTFE), the polymer of claim 7 (functional group-containing FEP or PFA), and the polymer of claim 8 (functional group-containing ETFE), and (B-1) molybdenum disulfide. A resin composition obtained by mixing 70 to 98 wt % of (A-1) and 2 to 30 wt % of (B-1) is preferred in that it can impart self-lubricating properties to a molded article and further reduce the surface friction coefficient.

v) A composition comprising (A-1) at least one selected from the polymer of claim 6 (functional group-containing PTFE), the polymer of claim 7 (functional group-containing FEP or PFA), and the polymer of claim 8 (functional group-containing ETFE), and (B-1) bronze, wherein a resin composition obtained by mixing 40 to 95 wt % of (A-1) and 5 to 60 wt % of (B-1) is preferred in that it can impart self-lubricating properties and surface smoothness to a molded article and stably reduce the coefficient of surface friction.

vi) A composition comprising (A-1) at least one polymer selected from the group consisting of the polymer (functional group-containing FEP or PFA) according to claim 7 and the polymer (functional group-containing ETFE) according to claim 8, and (B-1) aramid fiber, wherein a resin composition obtained by mixing 60 to 95 wt % of (A-1) and 5 to 40 wt % of (B-1) is preferred because it has improved mechanical properties and wear resistance, and is particularly resistant to damaging soft metals when used as a sliding material.

These exemplary resin compositions i) to vi) have active sites such as OH groups on the surface of the filler (B-1) in the composition, which have good reactivity or affinity with the functional groups in the fluorine-containing ethylenic polymer (A-1) in the resin composition of the present invention. As a result, molded articles obtained using the composition can have better mechanical properties and abrasion resistance.

The second resin composition of the present invention is a resin composition comprising: (A-2) a fluorine-containing ethylenic polymer obtained by copolymerizing at least one fluorine-containing monomer having a hydroxyl group, a carboxyl group, or a carboxylate, or a carboxyester group, or an epoxy group, in an amount of 0.05 to 30 mol % based on the total amount of monomers; (B-2) an inorganic filler or a pre-insolubilized organic filler; and (C) a fluorine-containing ethylenic polymer not containing a functional group in the side chain.

In other words, in a resin composition consisting of the three components (A-2), (B-2), and (C), the functional group-containing fluorine-containing ethylenic polymer (A-2) in the composition adheres to or has affinity with the surface of the filler (B-2), modifying the surface properties of (B-2), thereby improving the interfacial affinity and dispersibility between the general fluorine-containing ethylenic polymer (C) that does not contain functional groups and the filler, thereby imparting good mechanical properties and abrasion resistance to molded articles.

In the three-component resin composition of the present invention, the functional group-containing fluorine-containing ethylenic polymer (A-2) can be the same as the functional group-containing fluorine-containing ethylenic polymers described above, and the functional group concentration is 0.05 to 30 mol %, preferably 0.1 to 10 mol %, based on the total monomers used in (A-2). If the functional group concentration is too low, sufficient effects on the dispersibility and affinity between the fluorine-containing ethylenic polymer (C) and the filler (B-2) will not be achieved.

In the three-component resin composition of the present invention, the filler (B-2) may be the same inorganic or organic filler as described above.

In the resin composition consisting of three components of the present invention, the fluorine-containing ethylenic polymer (C) not containing functional groups excludes polymers in which functional groups have been intentionally introduced into the side chains of the polymer, and includes those having functional groups that are generated at the molecular end of the polymer in general fluorine-containing polymer polymerization methods (for example, -COF groups and _-CH2OH groups at the molecular end of PFA).

The fluorine-containing ethylenic polymer (C) may be selected from the above-mentioned polymers depending on the purpose and use of the composition. When the composition is used for molding, such as for sliding materials and molded parts, (C) is preferably a resinous fluorine-containing ethylenic polymer having a crystalline melting point of 120°C or higher, more preferably 150°C or higher.

Among these, PTFE, PFA, FEP, and ETFE are particularly preferred, as they have excellent heat resistance, chemical resistance, and low friction, and can impart similar properties to the composition.

The three-component resin composition of the present invention contains (A-2), (B-2), and (C) as essential components, and other components may also be added. However, in order to improve the mechanical properties and wear resistance without reducing the excellent heat resistance, chemical resistance, and low friction properties of the fluorine-containing ethylenic polymer, it is desirable for the resin composition to consist essentially of only the three components (A-2), (B-2), and (C).

In the three-component resin composition of the present invention, the preferred composition ratios of (A-2), (B-2), and (C) are 1 to 50 wt% (A-2), 0.5 to 80 wt% (B-2), and the remainder (C), where the total of (A-2) and (C) is 20 to 99.5 wt% and the composition ratio is (C)/((A-2) + (C)) ≥ 0.4. It is even more preferred that (A-2) is 1 to 40 wt%, (B-2) is 2 to 70 wt%, and (C) is the remainder, where the total of (A-2) and (C) is 30 to 98 wt% and the composition ratio is (C)/((A-2) + (C)) ≥ 0.5.

If the amount of filler (B-2) is less than 2% by weight, the effects on mechanical strength and abrasion resistance become insufficient, and if the total amount of filler (A-2) and filler (C) is less than 30% by weight, the resin composition will not exhibit sufficient chemical resistance or low friction.

In the three-component resin composition of the present invention, it is particularly preferred that the functional group-containing fluorine-containing ethylenic polymer (A-2) in the composition has a structure that is sufficiently compatible with the non-functional group-containing fluorine-containing ethylenic polymer (C), in terms of the affinity and dispersibility of the components of the composition.

For example, in a composition consisting of three components, the following are most preferred: a composition consisting of (A-2) the fluorine-containing ethylenic polymer according to claim 6 or 7 (functional group-containing PTFE or FEP, PFA), (B-2) a filler, and (C) PTFE; a composition consisting of (A-2) the fluorine-containing ethylenic polymer according to claim 7 (functional group-containing PFA, FEP), (B-2) a filler, and (C) PFA or FEP; and a composition consisting of (A-2) the fluorine-containing ethylenic polymer according to claim 8 (functional group-containing ETFE), (B-2) a filler, and (C) ETFE.

In the resin composition of the present invention, a two-component composition consisting of a functional group-containing fluorine-containing ethylenic polymer (A-1) and a filler (B-1) or a three-component composition consisting of (A-2), (B-2), and a non-functional fluorine-containing ethylenic polymer (C) can be produced by a method conventionally used for mixing filled PTFE, for example, in the case of a composition primarily consisting of PTFE or a PTFE-type copolymer. The resulting composition can be used as a molding material for compression molding or the like. Furthermore, compositions primarily consisting of a melt-processible fluorine-containing polymer are preferably produced by melt mixing. Examples of melt mixing equipment include a mixing roll, a Banbury mixer, a Brabender mixer, and an extruder. Among these, an extruder is preferred because of its greater mixing power, which can be expected to further improve dispersion when blended with a filler, and because of its favorable productivity during the production of the composition. The extruder may be one having a single screw or two or more screws. However, the use of a twin-screw extruder is particularly preferred because it provides a greater kneading force, resulting in a composition with better dispersibility, and the kneading force can be freely controlled.

By melt mixing, the composition is generally formed into pellets and used as a molding material for injection molding.

The second aspect of the present invention relates to a molded article comprising (A-3) a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol % of at least one fluorine-containing ethylenic monomer having a hydroxyl group, a carboxyl group, a carboxylate group, a carboxylate ester group, or an epoxy group, based on the total amount of monomers, the fluorine-containing ethylenic polymer having a crystalline melting point of 120°C or higher, and (B-3) an inorganic filler or a pre-insolubilized organic filler, the molded article being obtained by molding a composition consisting of 1 to 99.5 wt % of (A-3) and 0.5 to 99 wt % of (B-3), and heat-treating the molded article at a temperature above 100°C and below the crystalline melting point of the fluorine-containing ethylenic polymer (A-3).

That is, the molded article of the present invention is a molded article obtained by molding the above-described resin composition of the present invention into a certain shape by a commonly used molding method, and then heat-treating it at a temperature of 100°C or higher but below the crystalline melting point of the fluorine-containing ethylenic polymer in the resin composition.

Therefore, in the molded article before heat treatment used for the molded product of the present invention, the functional group-containing fluorine-containing ethylenic polymer (A-1) contained therein is the functional group-containing fluorine-containing ethylenic polymer (A-1) in the above-mentioned resin composition of the present invention, which has a crystalline melting point of 120°C or higher.

Specifically, functional group-containing PTFE (the polymer described in claim 6), functional group-containing PFA or FEP (the polymer described in claim 7), and functional group-containing ETFE (the polymer described in claim 8) are preferred examples because they themselves have excellent heat resistance, chemical resistance, mechanical properties, and low friction. Furthermore, by heat treating molded articles made using these polymers and fillers, the mechanical properties and wear resistance can be more effectively improved.

The filler (B-3) contained in the molded article before heat treatment used for the molded article of the present invention is the same as the filler used in the above-described resin composition of the present invention.

Specific examples of the filler include carbon fibers, whiskers, glass-based fillers, cleavable inorganic fillers, and pre-insolubilized organic fibers.

Among these, carbon fiber, aluminum borate whisker, glass fiber, molybdenum disulfide, and aramid fiber are preferred.

The aforementioned resin composition of the present invention is a composition comprising a functional group-containing fluorine-containing ethylenic polymer (A-1) and a filler (B-1), and the functional groups of (A-1) effectively improve adhesion to (B-1), interfacial affinity, and mutual dispersibility.

Furthermore, in the case of a molded article obtained by molding the composition of the present invention and then heat-treating the molded article, the following effects can be obtained by the heat treatment.

1. Heat treatment further promotes the reaction and adsorption between the functional group-containing fluorine-containing ethylenic polymer (A-3) and the filler (B-3) in the molded product, further improving interfacial adhesion. As a result, removal of the filler (B-3) from the sliding surface during a sliding test is suppressed, further improving wear resistance.

2. Heat treatment causes partial reaction between the functional groups of the functional group-containing fluorine-containing ethylenic polymer (A-3) in the molded article, resulting in self-crosslinking and a high molecular weight, which can impart further improvements to the mechanical properties, heat resistance, abrasion resistance, and creep resistance of the molded article.

The molded article of the present invention is a molded article that can provide the above-mentioned effect 1 or 2, or a combination of effects 1 and 2.

The third aspect of the present invention relates to a method for producing a molded article, which comprises molding a resin composition comprising a fluorine-containing ethylenic polymer (A-3) having a functional group and a crystalline melting point of 120°C or higher and a filler (B-3), and then heat-treating the molded article at a temperature of 100°C or higher and below the crystalline melting point of (A-3).

The method for producing the molded article of the present invention involves molding a resin composition of the functional group-containing fluorine-containing ethylenic polymer (A-3) and the filler (B-3) into the desired shape by various conventional molding methods depending on the purpose and application, and then heat-treating the molded article at a temperature of 100°C or higher but not higher than the melting point of the fluorine-containing ethylenic polymer (A-3). Such heat treatment can result in a molded article with improved mechanical properties, heat resistance, and abrasion resistance.

If the heat treatment temperature is too low, sufficient improvements in mechanical properties, heat resistance, and abrasion resistance will not be achieved. Furthermore, if the heat treatment is performed at a temperature above the melting point of (A-3), the molded product will not be able to maintain its intended shape during the heat treatment. Furthermore, if the temperature is too high, prolonged heat treatment may result in thermal degradation.

Heat treatment is preferably carried out for 5 hours or more. If the heat treatment time is too short, it is difficult to obtain sufficient mechanical properties, heat resistance, and wear resistance. Heat treatment may also be carried out in an inert gas such as nitrogen gas or in air.

The fluorine-containing polymer in the molded article to be heat-treated in the present invention is a functional group-containing fluorine-containing ethylenic polymer (A-3) having a crystalline melting point of 120°C or higher. Among these, those having a crystalline melting point of 200°C or higher are preferred because they have good heat resistance, can be heat-treated at high temperatures, and therefore can more easily achieve a sufficient heat-treatment effect.

Among these, functional group-containing PTFE-type polymers (polymers described in claim 6), functional group-containing PFA and FEP-type polymers (polymers described in claim 7), and functional group-containing ETFE-type polymers (polymers described in claim 8) are preferred, as they are particularly excellent in heat resistance, chemical resistance, and low friction. When these polymers are heat-treated, the heat treatment temperature is preferably 180°C or higher and below the crystalline melting point of the fluorine-containing ethylenic polymer, and more preferably 200°C or higher and below the crystalline melting point of the fluorine-containing ethylenic polymer.

The molded article obtained by the heat treatment of the present invention can be processed into a desired shape by various molding methods, such as compression molding, transfer molding, or injection molding, before the heat treatment. It can also be molded into a film, rod-shaped pipe, or tube by extrusion molding. Furthermore, the molded articles obtained by these methods can be machined into the desired shape.

Among these molding methods, melt molding, especially injection molding, is preferred because it allows for the production of molded products in a variety of shapes, allows for precision molding, has good productivity, can be automated, and reduces processing costs.

Among the resin compositions of the present invention, those using melt-processable fluorine-containing ethylenic polymers ((A) and (C)) are generally injection moldable, whereas compositions using a PTFE-type polymer as the primary component are generally difficult to melt-process. For example, resin compositions using functional group-containing PFA or FEP-type polymers (polymers of claim 7) and ETFE-type polymers (polymers of claim 8) are melt-processable. The molded articles obtained in this manner have good heat resistance and abrasion resistance under normal conditions, but, compared with molded articles obtained from compositions using functional group-containing PTFE-type polymers (polymers of claim 6), the molded articles inevitably soften at high temperatures and change shape or are destroyed on friction surfaces. By heat-treating these melt-molded molded articles according to the method of the present invention, the fluorine-containing ethylenic polymers in the molded articles self-crosslink with each other, resulting in higher molecular weight and increased melt viscosity. This imparts greater heat resistance and abrasion resistance to the molded articles, resulting in molded articles with a high limiting PV value and a wide operating temperature range.

In other words, when a resin composition using a functional group-containing PFA or FEP-type polymer (the polymer described in claim 7) or an ETFE-type polymer (the polymer described in claim 8) is used, melt molding is possible, and by heat treating the resulting molded article, a molded article with heat resistance and abrasion resistance (particularly the limiting PV value) comparable to that of a molded article made from a PTFE-based polymer can be obtained.

The resin composition of the present invention and the molded articles obtained therefrom can be used as sliding materials because, in addition to the heat resistance and low friction coefficient of the fluoropolymer, the filler imparts mechanical properties and wear resistance to the composition.

Specifically, it can be used in automotive bearings, mechanical shaft seals, piston rings, segment rings, rider rings, V-packings, sliding pads, oil seals, automatic seal rings, and shock absorber piston rings; in office automation equipment, such as copiers, printers, and fax machines, as well as parts such as fuser unit bearings, separation pawls, fuser rolls, discharge rollers, transmission gears, liner toner transport roll gears, and wire guides; in air conditioning compressor seals, such as scroll compressor chip seals and other gears and bearings; in industrial machinery, bearings, packings, and seals for pumps; and in sliding components for construction machinery, loading and unloading machinery, food processing machinery, and agricultural machinery. In addition to sliding applications, the heat resistance, electrical insulation, and chemical resistance of fluoropolymers can be utilized to make electrical and electronic components that require dimensional stability, heat resistance, and electrical properties, such as connector chips, carriers, sockets, printed wiring boards, and wire coating materials; semiconductor-related products that require chemical resistance, particularly large wafer baskets, which are difficult to manufacture using fluoropolymers alone due to their lack of moldability and strength; and materials and molded products such as valves and chemical pump parts.

EXAMPLES The present invention will now be described with reference to the following examples, but the present invention is not limited to these examples.

The tests in the examples were carried out by the following methods.

(1) Tensile Test Measurements were performed at room temperature at a crosshead speed of 10 mm/min using a Type 5 dumbbell, in accordance with ASTM D638, using a Tensilon universal testing machine manufactured by Orientec Co., Ltd.

(2) Bending test: Measurements were performed at room temperature at a bending speed of 2 mm/min using a Tensilon universal testing machine manufactured by Orientec Co., Ltd., in accordance with JIS K-6911.

(3) Deflection Temperature Under Load: Measurement was carried out using a heat distortion tester manufactured by Yasuda Seiki Seisakusho Co., Ltd. in accordance with JIS K 7207 under conditions of a N ₂ gas flow, a load of 18.6 kgf/cm ² and a temperature rise rate of 2° C./min.

(4) Thrust Friction and Wear Test A Suzuki-Matsubara friction and wear tester manufactured by Orientec Co., Ltd. was used, and aluminum die-cast (ADC12) was used as the mating material. The test was conducted in air at room temperature at a speed of 42 m/min, and the limiting PV value was measured.

The limit PV value was measured under these fixed conditions by increasing the load by 2.5 kg/cm ² for each 1 km of sliding distance, and the limit PV value was determined to be the value immediately before wear began to progress rapidly.

(5) Reciprocating sliding friction test A reciprocating sliding friction tester as shown in Figure 1 was used, and carbon steel (S45C) was used as the mating material. Measurements were conducted in air at room temperature, under unlubricated conditions, with a load of 10 kg (surface pressure of 50 kg/ ^cm2 ), a stroke of 5 cm, and a speed of 200 cpm, up to 10,000 cycles.

Reference Example 1 (Synthesis of Functional Group-Containing PFA) A 6-liter glass-lined autoclave equipped with a stirrer, valve, pressure gauge, and thermometer was charged with 1,500 ml of pure water, thoroughly purged with nitrogen gas, and then evacuated. Then, 1,500 g of 1,2-dichloro-1,1,2,2-tetrafluoroethane (R-114) was added.

Then, perfluoro-(1,1,9,9-tetrahydro-2,5-bistrifluoromethyl-3,6-dioxa-8-nonenol) 5.0 g of the above, 130 g of perfluoro(propyl vinyl ether) (PPVE), and 180 g of methanol were injected using nitrogen gas, and the temperature inside the system was maintained at 35°C.

While stirring, tetrafluoroethylene gas (TFE) was injected so that the internal pressure became 8.0 kgf/cm ² G. Then, 0.5 g of a 50% methanol solution of di-n-propyl peroxydicarbonate was injected using nitrogen to initiate the reaction.

As the polymerization reaction proceeded, the pressure decreased, and when it dropped to 7.5 kgf/cm ² G, it was re-pressurized to 8.0 kgf/cm ² with tetrafluoroethylene gas, and the pressure was repeatedly increased and decreased.

While continuing to supply tetrafluoroethylene, 2.5 g of the hydroxyl group-containing fluorine-containing ethylenic monomer (the compound represented by formula (4)) was injected nine times (total of 22.5 g) every time approximately 60 g of tetrafluoroethylene gas was consumed from the start of polymerization, and polymerization was continued. When approximately 600 g of tetrafluoroethylene had been consumed from the start of polymerization, the supply was stopped, the autoclave was cooled, and the unreacted monomer and R-114 were released.

The resulting copolymer was washed with water and methanol, and then vacuum dried to obtain 710 g of a white solid. The composition of the resulting copolymer was ^determined by F-NMR and IR analyses to be TFE/PPVE/(hydroxyl group-containing fluorine-containing ethylenic monomer represented by formula (8)) = 97.0/2.0/1.0 mol %. The infrared spectrum showed a characteristic -OH absorption at 3620-3400 ^cm .

DSC analysis revealed a Tm of 305°C, and DTGA analysis revealed a 1% thermal decomposition temperature, Td, of 375°C. The melt flow rate was measured using a Koka flow tester with a nozzle of 2 mm diameter and 8 mm length at 372°C for 5 minutes, and was found to be 32 g/10 min.

Reference Example 2 (Synthesis of PFA without Functional Groups) The synthesis was carried out in the same manner as in Reference Example 1, except that perfluoro(1,1,9,9-tetrahydro-2,5-bistrifluoromethyl-3,6-dioxa-8-nonenol) (the compound represented by formula (8)) was not used and 240 g of methanol was used. 597 g of PFA without functional groups was obtained.

The resulting PFA was analyzed in the same manner as in Reference Example 1. TFE/PPVE = 98.2/1.8 mol% Tm = 310°C Td = 469°C Melt flow rate = 24 g/10 min

Example 1 (Blend of Functional Group-Containing Fluorine-Containing Ethylenic Polymer and Carbon Fiber) The functional group-containing PFA obtained in Reference Example 1 and carbon fiber (Kureka Chop M-207S, manufactured by Kureha Chemical Industry Co., Ltd.) were homogeneously blended in a rocking mixer at a weight ratio of 80:20. The blend was then kneaded and extruded in a twin-screw extruder (Labo Plastomill, manufactured by Toyo Seiki Co., Ltd.) at 350-370°C to produce pellets. These pellets were then molded into test specimens in an injection molding machine (Minimat M26/15B, manufactured by Sumitomo Heavy Industries, Ltd.) at a cylinder temperature of 360-390°C and a mold temperature of 200°C.

The obtained test pieces were subjected to a tensile test, a bending test, a deflection temperature under load test, and a thrust friction and wear test. The results are shown in Table 1.

Example 2 (Heat Treatment of Molded Articles Composed of Functional Group-Containing Fluorine-Containing Ethylenic Polymer and Carbon Fiber) The test specimens obtained in Example 1 were heat-treated at 280°C for 24 hours in a hot-air circulating thermostatic chamber.

The heat-treated molded articles were tested in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 (Blend of PFA without functional groups and carbon fiber) Test specimens were obtained by compounding, extrusion, and molding in the same manner as in Example 1, except that the functional group-containing PFA obtained in Reference Example 1 was replaced with the functional group-free PFA obtained in Reference Example 2. Tests were then conducted using the obtained test specimens in the same manner as in Example 1. The results are shown in Table 1.

Example 3 (Blend of functional group-containing fluorine-containing ethylenic polymer and aluminum borate whiskers) The functional group-containing PFA obtained in Reference Example 1 and aluminum borate whiskers (Arbolex Y, manufactured by Shikoku Chemical Industry Co., Ltd.) were uniformly blended in a weight ratio of 92:8 using a rocking mixer, and then the blend was kneaded and extruded at 350 to 370°C using a twin-screw extruder (Labo Plastomill, manufactured by Toyo Seiki Co., Ltd.) to prepare pellets.

These pellets were used to prepare test specimens in an injection molding machine (Minimat M26/15B, manufactured by Sumitomo Heavy Industries, Ltd.) at a cylinder temperature of 360-390°C and a mold temperature of 200°C. The obtained test specimens were used to perform tensile tests, bending tests, deflection temperature under load tests, and reciprocating sliding friction tests.

The results are shown in Table 2.

Comparative Example 2 (Blend of Functional Group-Free PFA and Aluminum Borate Whiskers) Test specimens were obtained by kneading, extrusion, and molding in the same manner as in Example 3, except that the functional group-free PFA obtained in Reference Example 2 was used instead of the functional group-containing PFA obtained in Reference Example 2. Tests similar to those in Example 3 were performed using the obtained test specimens. The results are shown in Table 2.

Example 4 (Heat Treatment of Molded Articles Composed of Functionalized Fluorine-Containing Ethylenic Polymer and Aluminum Borate Whiskers) The test specimens obtained in Example 3 were heat-treated at 280°C for 24 hours in a hot-air circulating thermostatic chamber. The heat-treated molded articles were tested in the same manner as in Example 3.

The results are shown in Table 2.

INDUSTRIAL APPLICABILITY The present invention can provide a molded article that maintains properties such as heat resistance, chemical resistance, surface properties (non-stickiness, low friction), and electrical insulation, and also has excellent mechanical properties and abrasion resistance, a resin composition for obtaining the same, and a method for producing the molded article.

───────────────────────────────────────────────────── Continued from the front page (72) Inventor: Masami Kato 1-1 Nishiichitsuya, Settsu City, Osaka Prefecture Daikin Industries Co., Ltd., Yodogawa Plant (72) Inventor: Masaji Komori 1-1 Nishiichitsuya, Settsu City, Osaka Prefecture Daikin Industries Co., Ltd., Yodogawa Plant (72) Inventor: Taketo Kato 1-1 Nishiichitsuya, Settsu City, Osaka Prefecture Daikin Industries Co., Ltd., Yodogawa Plant (72) Inventor: Tetsuo Shimizu 1-1 Nishiichitsuya, Settsu City, Osaka Prefecture Daikin Industries Co., Ltd., Yodogawa Plant (Note) This publication is based on the publication published internationally by the International Bureau of International Patent Office (WIPO). Please note that the effect of the international publication of the Japanese-language patent application (Japanese-language utility model registration application) related to this publication arises pursuant to Article 184-10, Paragraph 1 of the Patent Act (Article 48-13, Paragraph 2 of the Utility Model Act), and is unrelated to this publication.

Claims (1)

[Claims] 1. A resin composition comprising (A-1) a fluorine-containing ethylenic polymer obtained by copolymerizing at least one fluorine-containing ethylenic monomer having either a hydroxyl group, a carboxyl group, a carboxylate group, a carboxylate ester group, or an epoxy group, in an amount of 0.05 to 30 mol % based on the total amount of monomers, and (B-1) an inorganic filler or a pre-insolubilized organic filler, wherein the component (A-1) comprises 1 to 99.5 wt % and the component (B-1) comprises 0.5 to 99 wt %. 2. A resin composition according to claim 1, wherein the fluorine-containing ethylenic polymer (A-1) is a fluorine-containing ethylenic polymer having a crystalline melting point of 120°C or higher. 3. The fluorine-containing ethylenic polymer (A-1) is a fluorine-containing ethylenic polymer represented by (a-1) formula (1): (wherein Y represents _-CH2OH , -COOH, a carboxylate, a carboxy ester group or an epoxy group; X and ^X1 are the same or different and each represents a hydrogen atom or a fluorine atom; and _Rf represents a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms containing an ether bond or a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms containing an ether bond), and (b-1) 70 to 99.95 mol % of at least one ethylenic monomer copolymerizable with said component (a-1). 3. The resin composition according to claim 1, which is a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol % of at least one fluorine-containing ethylenic monomer having a functional group represented by the formula (wherein Y represents -CH2OH, -COOH, a carboxylate, a carboxy ester group or an epoxy group; X and X1 are the same or different and each represents a hydrogen atom or a fluorine atom; and Rf represents a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms containing an ether bond or a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms 4. A resin composition according to claim ^{3, wherein the functional group-containing fluorine-containing ethylenic monomer (a-1) is a fluorine-containing monomer represented by formula (2): CH2=CFCF2-Rf1-Y1} _{( 2 )} ^{( wherein} _Y1 ^{represents -CH2OH} _, -COOH, a carboxylate, a carboxy ester group or an epoxy group, and _Rf1 represents a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms or ^-ORf2 ( _Rf2 represents a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms or a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms and containing an ether bond). 5. A resin composition according to claim 3, wherein at least one of the ethylenic monomers (b-1) is a fluorine-containing ethylenic monomer. 6. A resin composition according to claim 5, wherein the fluorine-containing ethylenic monomer (b-1) is tetrafluoroethylene. 7. 7. The resin composition of claim ⁵ , wherein the fluorine-containing ethylenic monomer (b-1) is a mixture of 85 to 99.7 mol% of tetrafluoroethylene and ^0.3 to 15 mol% of a monomer represented by formula ₍ ³ ): _CF2 =CF- _Rf2 (3) [ _Rf2 represents _-CF3 or _ORf3 ( ^Rf3 is a perfluoroalkyl group having 1 to 5 carbon atoms)]. 8. The resin composition of claim 5, wherein the fluorine-containing ethylenic monomer (b-1) is a mixture of 40 to 80 mol% of tetrafluoroethylene or chlorotrifluoroethylene, 20 to 60 mol% of ethylene, and 0 to 15 mol% of other monomers. 9. The resin composition of claim 2, wherein the filler (B-1) is carbon fiber. 10. The resin composition of claim 2, wherein the filler (B-1) is whiskers. 11. The resin composition according to claim 2, wherein the filler (B-1) is a glass-based filler. 12. The resin composition according to claim 2, wherein the filler (B-1) is a cleavable inorganic filler. 13. The resin composition according to claim 2, wherein the filler (B-1) is a pre-insolubilized organic fiber. 14. The resin composition according to claim 6, 7, or 8, wherein the filler (B-1) is a carbon fiber. 15. The resin composition according to claim 7 or 8, wherein the filler (B-1) is an aluminum borate whisker. 16. The resin composition according to claim 6, 7, or 8, wherein the filler (B-1) is a glass fiber. 17. The resin composition according to claim 6, 7, or 8, wherein the filler (B-1) is molybdenum disulfide. 18. The resin composition according to claim 6, 7, or 8, wherein the filler (B-1) is bronze. 19. 20. A resin composition according to claim 7 or 8, wherein the filler (B-1) is aramid fiber. 21. A resin composition comprising: (A-2) a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol % based on the total amount of monomers of at least one fluorine-containing ethylenic monomer having either a hydroxyl group, a carboxyl group, a carboxylate group, a carboxy ester group, or an epoxy group, (B-2) an inorganic filler or a pre-insolubilized organic filler, and (C) a fluorine-containing ethylenic polymer not containing a functional group in the side chain, wherein the resin composition contains 1 to 50 wt % of the (A-2) component, 0.5 to 80 wt % of the (B-2) component, and the remainder is the (C) component (provided that the total of (A-2) and (C) is 20 to 99.5 wt % and (C)/((A-2)+(C))≧0.4). 21. The resin composition according to claim 20, wherein the fluorine-containing ethylenic polymer (C) having no functional groups in its side chains is a fluorine-containing ethylenic polymer having a crystalline melting point of 120° C. or higher. 22. The resin composition according to claim 21, wherein the fluorine-containing ethylenic polymer (C) having no functional groups in its side chains is polytetrafluoroethylene, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, tetrafluoroethylene-hexafluoropropylene copolymer or ethylene-tetrafluoroethylene copolymer. 23. 24. A molded article comprising a resin composition comprising: (A-3) a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol % based on the total amount of monomers of at least one fluorine-containing ethylenic monomer having either a hydroxyl group, a carboxyl group, a carboxylate group, a carboxy ester group, or an epoxy group, the fluorine-containing ethylenic polymer having a crystalline melting point of 120°C or higher; and (B-3) an inorganic filler or a pre-insolubilized organic filler, the molded article being obtained by molding a resin composition comprising 1 to 99.5 wt % of the (A-3) component and 0.5 to 99 wt % of the (B-3) component, and heat-treating the molded article at a temperature of 100°C or higher and not higher than the crystalline melting point of the fluorine-containing ethylenic polymer (A-3). 25. A molded article comprising: (A-3) a fluorine-containing ethylenic polymer represented by the formula (1) (a-2): 24. A molded article according to claim ^{23, which is a fluorine-containing ethylenic polymer obtained by copolymerizing 0.05 to 30 mol % of at least one functional group-containing fluorine-containing ethylenic monomer represented by the formula (wherein Y represents —CH2OH, —COOH, a carboxylate or carboxy ester group, or an epoxy group; X and X1} _{are the} same or different and represent a hydrogen atom or a fluorine atom; and Rf represents a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms, a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms containing an ether bond, or a divalent fluorine-containing oxyalkylene group having 1 to 40 carbon atoms containing an ether bond), with 70 to 99.95 mol % of at least one ethylenic monomer copolymerizable with (b-2)(a-2). 25. A molded article according to claim 24, wherein at least one of the ethylenic monomers (b-2) is a fluorine-containing ethylenic monomer. 26. A molded article according to claim 25, wherein the fluorine-containing ethylenic monomer (b-2) is tetrafluoroethylene. 27. A molded article according to claim 25, wherein the fluorine-containing ethylenic monomer ( ^b -2) is a mixture of 85 to 99.7 mol % of tetrafluoroethylene and 0.3 to ¹⁵ mol % of a monomer represented by formula ( ³ ): _CF2 =CF- _Rf2 ( ³ ) [ _Rf2 represents _-CF3 or _ORf3 ( _Rf3 represents a perfluoroalkyl group having 1 to 5 carbon atoms)]. 28. 29. A molded article according to claim 23, wherein the fluorine-containing ethylenic monomer (b-2) is a mixture of 40 to 80 mol % of tetrafluoroethylene, 20 to 60 mol % of ethylene, and 0 to 15 mol % of other monomers. 29. A molded article according to claim 23, wherein the filler (B-3) is carbon fiber. 30. A molded article according to claim 23, wherein the filler (B-3) is whiskers. 31. A molded article according to claim 30, wherein the filler (B-3) is aluminum borate whiskers. 32. A molded article according to claim 23, wherein the filler (B-3) is a glass-based filler. 33. A molded article according to claim 23, wherein the filler (B-3) is a cleavable inorganic filler. 34. A molded article according to claim 23, wherein the filler (B-3) is a pre-insolubilized organic fiber. 35. 36. A process for producing a molded article according to claim 26, 27 or 28, characterized in that a molded article obtained by molding the resin composition according to claim 6, 7 or 8 is heat-treated at a temperature of 200°C or higher and the crystalline melting point of the fluorine-containing ethylenic polymer (A-1). 37. A process for producing a molded article according to claim 27 or 28, characterized in that a molded article obtained by melt-molding the resin composition according to claim 7 or 8 is heat-treated at a temperature of 200°C or higher and the crystalline melting point of the fluorine-containing ethylenic polymer (A-1).