Composite particles, method for producing the same, composition, and molded body

Abstract

To provide composite particles that make it possible to impart excellent wear resistance to a non-fluorine thermoplastic resin.SOLUTION: Composite particles comprise a polymer A and a polymer B. The polymer A contains 99.5 mol% or more of units based on tetrafluoroethylene. The polymer B contains 90.0 mol% or more and less than 99.5 mol% of units based on tetrafluoroethylene, has a melting point of 260°C or more, is melt-moldable, and has at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, an amide group, an amino group, and an isocyanate group. The mass ratio represented by polymer A / polymer B is 55 / 45 to 99 / 1. There are two or more melting points in the range of 150°C or more and less than 500°C. One peak is observed in a volume-based frequency distribution curve determined by laser diffraction / scattering particle size distribution measurement.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a composite particle, a method for producing the same, a composition, and a molded article. [Background technology]

[0002] From the viewpoint of improving fuel efficiency and reducing noise, there is a demand for reducing friction in resin parts for automobiles, aircraft, etc. One method known for reducing friction in non-fluorinated thermoplastic resins such as polyamide is to add polytetrafluoroethylene (PTFE) to impart sliding properties.

[0003] However, since PTFE has no melt flowability and low affinity with non-fluorinated thermoplastic resins, poor dispersion and falling off of PTFE may occur, particularly when highly filled. Therefore, a resin composition has been proposed that contains a non-fluorinated thermoplastic resin, PTFE, and a polymer containing 40.0 mol % or more and less than 99.5 mol % of units based on tetrafluoroethylene in specific ratios (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-37656 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the resin composition of Patent Document 1, PTFE does not disperse sufficiently in the non-fluorinated thermoplastic resin, and the abrasion resistance provided by PTFE may not be fully exhibited. The present invention provides composite particles capable of imparting excellent abrasion resistance to a non-fluorinated thermoplastic resin, a method for producing the same, and a composition having excellent abrasion resistance and a molded article thereof. [Means for solving the problem]

[0006] The present invention has the following aspects. [1] A polymer comprising a polymer A and a polymer B, The polymer A contains 99.5 mol % or more of units based on tetrafluoroethylene, the polymer B contains 90.0 mol % or more and less than 99.5 mol % of units based on tetrafluoroethylene, has a melting point of 260° C. or more, is melt-moldable, and has at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, an amide group, an amino group, and an isocyanate group; The mass ratio of the polymer A to the polymer B is 55 / 45 to 99 / 1, It has two or more melting points within the range of 150°C or more and less than 500°C, Composite particles that have one peak on the volume-based frequency distribution curve obtained by laser diffraction / scattering particle size distribution measurement. [2] The composite particle according to [1], wherein the polymer B contains units based on at least one comonomer selected from the group consisting of perfluoro(alkyl vinyl ether), hexafluoropropylene, and fluoroalkylethylene. [3] A method for producing the composite particles according to [1] or [2], A method for producing composite particles, comprising the steps of: combining a powder of the polymer A and a powder of the polymer B, which satisfy the following formula 1, by a mechanofusion method. D50 A / D50 B ≧1.1 ···Equation 1 However, D50 A indicates the average particle size (μm) of the powder of the polymer A, and D50 B indicates the average particle size (μm) of the powder of the polymer B. [4] The manufacturing method according to [3] above, wherein when the powder of the polymer A and the powder of the polymer B are composited, the surface temperatures of the powders are set to be lower than the glass transition temperature of the polymer B. [5] A composition comprising the composite particles according to [1] or [2] above and a non-fluorinated thermoplastic resin. [6] The composition according to [5], wherein the non-fluorinated thermoplastic resin is at least one selected from the group consisting of polyamide, polyetherimide, thermoplastic polyimide, polyamideimide, aromatic polyester, semi-aromatic polyester, polyarylene sulfide, polyarylene sulfone, polyarylene ether ketone, polyacetal, and polycarbonate. [7] A molded article comprising the composition according to [5] or [6]. Effect of the Invention

[0007] According to the present invention, there can be provided composite particles capable of imparting excellent abrasion resistance to a non-fluorinated thermoplastic resin, a method for producing the same, and a composition having excellent abrasion resistance and a molded article thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The meanings and definitions of the terms used in the present invention are as follows. "Non-fluorine" means not containing fluorine atoms. "Melting point" is the temperature corresponding to the maximum of the melting peak as measured by differential scanning calorimetry (DSC). By "melt-formable" it is meant that the material exhibits melt flowability. The term "exhibiting melt fluidity" means that there exists a temperature at least 20° C. higher than the melting point of the polymer, at which the melt flow rate is 0.1 to 1,000 g / 10 min. The "melt flow rate" is the melt mass flow rate (MFR) defined in JIS K 7210-1:2014 (corresponding international standard ISO 1133-1:2011). Hereinafter, the melt flow rate will also be referred to as MFR. The term "carbonyl group-containing group" refers to a group having a carbonyl group (-C(=O)-) in its structure. The "glass transition temperature" is the temperature corresponding to the maximum value of the tan δ peak measured by dynamic mechanical analysis (DMA). Hereinafter, the glass transition temperature is also referred to as Tg. "Average particle size" refers to the particle size at the 50% point on a cumulative distribution curve where the total volume of the particle size distribution calculated on a volume basis is 100%, that is, the volume-based cumulative 50% diameter (D50). The particle size distribution is obtained by laser diffraction / scattering particle size distribution measurement. Hereinafter, the average particle size will also be referred to as D50. The term "unit based on a monomer" is a general term for an atomic group formed directly by polymerization of one monomer molecule, and an atomic group obtained by chemically converting a part of the atomic group. The symbol "~" indicating a range of numerical values ​​means that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0009] [Composite particles] The composite particle according to one embodiment of the present invention (hereinafter also referred to as the present composite particle) contains a polymer A and a polymer B. Polymer A contains 99.5 mol % or more of units based on tetrafluoroethylene (hereinafter also referred to as TFE) (hereinafter also referred to as TFE units). Polymer B contains 90.0 mol % or more and less than 99.5 mol % of TFE units, has a melting point of 260° C. or more, is melt-moldable, and has at least one functional group (hereinafter also referred to as functional group G) selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, an amide group, an amino group, and an isocyanate group. Polymer A and Polymer B will be described in detail later.

[0010] In the present composite particle, the mass ratio represented by polymer A / polymer B is 55 / 45 to 99 / 1. When the polymer A / polymer B is 55 / 45 or more, the effect of improving the abrasion resistance by polymer A is sufficiently exhibited, and when it is 99 / 1 or less, the effect of improving the dispersibility by polymer B is sufficiently exhibited. Therefore, when the polymer A / polymer B is within the above range, the composite particle is well dispersed in the non-fluorinated thermoplastic resin, and excellent abrasion resistance is obtained. The mass ratio represented by polymer A / polymer B is preferably from 70 / 30 to 99 / 1, and more preferably from 80 / 20 to 95 / 5.

[0011] The total content of polymer A and polymer B is preferably 50% by mass or more, more preferably 80% by mass or more, and may be 100% by mass, based on the total mass of the present composite particle.

[0012] The composite particle may further contain, as necessary, components other than the polymer A and the polymer B, to the extent that the effects of the present invention are not impaired. Examples of components other than the polymer A and the polymer B include carbon-based fillers, heat stabilizers containing metal oxides or phenol group-containing compounds, pigments, and synthetic polymers such as polyphenylene sulfide (PPS) and polyimide (PI).

[0013] The present composite particle has two or more melting points within the range of 150° C. or more and less than 500° C. In other words, when the present composite particle is subjected to DSC, two or more melting peaks are observed within the range of 150° C. or more and less than 500° C. In addition, the present composite particle has one peak in a volume-based frequency distribution curve obtained by laser diffraction / scattering particle size distribution measurement. Having two or more melting points indicates that the composite particle contains a portion made of polymer A and a portion made of polymer B. Also, having a single peak in the frequency distribution curve indicates that the composite particle is not a mixture of powder of polymer A and powder of polymer B. Therefore, having two or more melting points and having a single peak in the frequency distribution curve indicates that the composite particle is a group of particles that contains a portion made of polymer A and a portion made of polymer B in one particle.

[0014] The composite particles are typically obtained by compounding powders of polymer A and polymer B by the mechanofusion method. In the mechanofusion method, when different types of particles are mixed, mechanical energy (shear force, friction force, impact energy, etc.) is applied to the particles to cause a mechanochemical reaction. As a result, the different types of particles are surface fused together and compounded. The method for producing the composite particles by the mechanofusion method will be described in detail later.

[0015] The composite particles have a D50 of preferably 0.1 to 800 μm, more preferably 1 to 500 μm, and even more preferably 10 to 100 μm. When the composite particles have a D50 of not less than the lower limit, the abrasion resistance is superior, and when the D50 is not more than the upper limit, the dispersibility in other materials is superior.

[0016] (Polymer A) Polymer A contains 99.5 mol % or more of TFE units based on all units constituting polymer A. Polymer A may be a homopolymer of TFE, or a copolymer of TFE and another monomer copolymerizable with TFE (hereinafter also referred to as "comonomer"). Examples of the comonomer include perfluoro(alkyl vinyl ether) (hereinafter also referred to as "PAVE"), hexafluoropropylene (hereinafter also referred to as "HFP"), and fluoroalkyl ethylene (hereinafter also referred to as "FAE"). PAVE, HFP, and FAE are collectively referred to as PAE.

[0017] For example, CF 2 =CFOCF 3 (hereinafter referred to as "PMVE"), CF 2 =CFOCF 2 CF 3 , C.F. 2 =CFOCF 2 CF 2 CF 3 (hereinafter referred to as "PPVE"), CF 2 =CFOCF 2 CF 2 CF 2 CF 3 , C.F. 2 =CFO(CF 2 ) 8 Among these, PMVE or PPVE is preferable. FAEs include, for example, CH 2 =CH(CF 2 ) 2 F, C.H. 2 =CH(CF 2 ) 3 F, C.H. 2 =CH(CF 2 )4 F, C.H. 2 =CF(CF 2 ) 3 H, C.H. 2 =CF(CF 2 ) 4 Among these, CH 2 =CH(CF 2 ) 4 F or CH 2 =CH(CF 2 ) 2 F is preferred.

[0018] As the polymer A, from the viewpoints of a large effect of improving abrasion resistance and easy availability, a homopolymer of TFE, a copolymer of TFE and PAVE, a copolymer of TFE and HFP, or a copolymer of TFE and FAE is preferred, and a homopolymer of TFE or a copolymer of TFE and FAE is particularly preferred.

[0019] When polymer A is a copolymer, the content of the units based on the comonomer relative to all units constituting polymer A is preferably from 0.001 to 1.0 mol %, more preferably from 0.005 to 0.1 mol %.

[0020] The melting point of polymer A is preferably from 310 to 390°C, more preferably from 320 to 380°C.

[0021] (Polymer B) Polymer B is a copolymer of TFE and a comonomer, and contains TFE units in an amount of 90.0 mol % or more and less than 99.5 mol % based on all units constituting Polymer B. Examples of the comonomer include PAVE, HFP, FAE, ethylene, propylene, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene, and monomers having a functional group G described below.

[0022] From the viewpoint of heat resistance, polymer B preferably contains units based on at least one comonomer selected from the group consisting of PAVE, HFP and FAE. Polymer B may further contain units based on comonomers other than PAVE, HFP and FAE.

[0023] The content of the units based on the comonomer is more than 0.5 mol % and not more than 10.0 mol % based on the total units of the polymer B. When the comonomer is ethylene, the content of the units based on ethylene is preferably 0.5 to 3.0 mol %. When the comonomer is PAE, the content of the units based on PAE is preferably 0.5 to 3.0 mol %.

[0024] The polymer B has a functional group G. This allows the polymer A and the polymer B to be satisfactorily composited. In addition, the dispersibility in a non-fluorinated thermoplastic resin is improved.

[0025] Of the functional groups G, examples of the carbonyl-containing group include a group having a carbonyl group between the carbon atoms of a hydrocarbon group, a carbonate group, a carboxy group, a haloformyl group, an alkoxycarbonyl group, and an acid anhydride group (-C(=O)-OC(=O)-). Examples of the hydrocarbon group in the group having a carbonyl group between carbon atoms of the hydrocarbon group include an alkylene group having 2 to 8 carbon atoms. Here, the number of carbon atoms in the alkylene group is the number of carbon atoms not including the carbon that constitutes the carbonyl group. The alkylene group may be linear or branched. The haloformyl group is represented by -C(=O)-X (wherein X is a halogen atom). Examples of the halogen atom in the haloformyl group include a fluorine atom and a chlorine atom, and a fluorine atom is preferred. That is, the haloformyl group is preferably a fluoroformyl group (also called a carbonyl fluoride group). The alkoxy group in the alkoxycarbonyl group may be linear or branched. The alkoxy group in the alkoxycarbonyl group is preferably an alkoxy group having 1 to 8 carbon atoms, and particularly preferably a methoxy group or an ethoxy group.

[0026] The functional group G is preferably an acid anhydride group, a cyclic acetal group, a 1,2-dicarboxylic acid residue, a 1,2-diol residue or a 1,3-diol residue, and more preferably a cyclic acid anhydride group, because they have an excellent effect of improving dispersibility in non-fluorinated thermoplastic resins.

[0027] The functional group G may be contained in a unit based on a monomer having the functional group G (hereinafter also referred to as a G unit) or in a polymer end group, and is preferably contained in the former. The functional group G may be a group formed by modifying a polymer having a group capable of forming a functional group. The functional group G contained in the polymer end group can be obtained by adjusting the components (polymerization initiator, chain transfer agent, etc.) used in the polymerization of the polymer.

[0028] As the monomer having the functional group G, a monomer having an acid anhydride group, a monomer having a cyclic acetal group, a monomer having a 1,2-dicarboxylic acid residue, a monomer having a 1,2-diol residue, or a monomer having a 1,3-diol residue is preferred, and a monomer having a cyclic acid anhydride group is particularly preferred. Examples of monomers having a cyclic acid anhydride group include itaconic anhydride (hereinafter also referred to as IAH), citraconic anhydride (hereinafter also referred to as CAH), 5-norbornene-2,3-dicarboxylic anhydride (hereinafter also referred to as NAH), and maleic anhydride.

[0029] The G unit may be of one type or of two or more types. The proportion of G units relative to all units constituting the polymer B is preferably from 0.01 to 3.0 mol %, more preferably from 0.05 to 1.5 mol %.

[0030] Polymer B has a melting point of 260° C. or higher. When the melting point of Polymer B is 260° C. or higher, high heat resistance can be obtained. The melting point of Polymer B is preferably 275° C. or higher, and more preferably 290° C. or higher. The melting point of the polymer B is preferably not more than 350° C., more preferably not more than 330° C. When the melting point of the polymer B is not more than the upper limit, the polymer B has excellent moldability. The melting point of polymer B can be adjusted by the proportion of TFE units, the proportion of comonomer units, etc. For example, the melting point tends to increase as the proportion of TFE units increases.

[0031] The MFR of polymer B is preferably 1 to 100 g / 10 min, more preferably 3 to 50 g / 10 min. When the MFR is not less than the lower limit, the moldability is superior, and when it is not more than the upper limit, the strength is superior. The MFR of Polymer B is a value at a temperature of 372° C. and a load of 49 N.

[0032] (Method of manufacturing composite particles) The present composite particle can be produced, for example, by a method in which powders of polymer A and polymer B are combined by mechanofusion.

[0033] It is preferable that the powder of polymer A and the powder of polymer B satisfy the following formula 1. D50 A / D50 B ≧1.1 ···Equation 1 However, D50 A indicates the average particle size (μm) of the powder of polymer A, and D50 B indicates the average particle size (μm) of the powder of polymer B.

[0034] D50 A / D50 B If D50 is 1.1 or more, the compounding by the mechanofusion method is easy to proceed. A / D50 B is preferably 2 or more, and more preferably 5 or more. Also, the D50 A / D50 B From the viewpoint of the homogeneity of the composite particles, the value is preferably 200 or less, and more preferably 50 or less.

[0035] D50 A D50 is preferably 5 to 800 μm, and more preferably 10 to 600 μm. A Within the above range, the D50 of the resulting composite particles is likely to fall within the above-mentioned preferred range.

[0036] In the compounding by the mechanofusion method, for example, powder of polymer A and powder of polymer B are dry-mixed while applying mechanical energy such as shear force. In addition to the mechanical energy, other energy such as plasma or a high magnetic field may be applied. The composite can be carried out using a known composite device, such as "Nobilta", "Nanocura" or "Mechanofusion" manufactured by Hosokawa Micron Corporation.

[0037] In the composite formation, it is preferable that the surface temperatures of the powder of polymer A and the powder of polymer B are each lower than the Tg of polymer B. If the surface temperature of each powder is lower than the Tg of polymer B, each powder is in a hard state, and it is easy to impart mechanical energy such as shear force to each powder. The surface temperature of each of the powder of polymer A and the powder of polymer B is preferably Tg of polymer B-5°C or lower, and more preferably Tg of polymer B-10°C or lower. The lower limit of each of the powder of polymer A and the powder of polymer B is not particularly limited, but is, for example, -200 to 50°C.

[0038] [Composition] A composition according to one embodiment of the present invention (hereinafter also referred to as the present composition) contains the present composite particles and a non-fluorinated thermoplastic resin (hereinafter also referred to as the non-fluorinated thermoplastic resin).

[0039] In the present resin composition, the content of the present composite particles is preferably 1 to 45 mass %, more preferably 5 to 40 mass %, and even more preferably 10 to 30 mass %, based on the total mass of the present composite particles and the non-fluorinated thermoplastic resin. When the content of the present composite particles is equal to or more than the lower limit, the abrasion resistance is superior, and when the content is equal to or less than the upper limit, the excellent properties (mechanical properties, etc.) of the non-fluorinated thermoplastic resin are easily exhibited.

[0040] The total mass of the present composite particle and the non-fluorinated thermoplastic resin is preferably 50 mass % or more, more preferably 80 mass % or more, and may be 100 mass % based on the total mass of the present composition.

[0041] The present composition has a wear amount measured on a molded body (hereinafter also referred to as molded body M) formed into a plate shape of the present composition of 2.5×10 -3 cm 3 It is preferable that the value is less than 2.0×10 -3 cm 3 If the wear amount is equal to or less than the above upper limit, the material is useful in applications where wear resistance is required. The amount of wear is measured by the Matsubara friction measuring method in accordance with JIS K 7218. Details are as described in the examples below.

[0042] (Non-fluorinated thermoplastic resin) Examples of non-fluorinated thermoplastic resins include polyamide, polyetherimide, thermoplastic polyimide, polyamideimide, aromatic polyester, semi-aromatic polyester, polyarylene sulfide (e.g., PPS), polyarylene sulfone, polyarylene ether ketone, polyacetal, and polycarbonate. These non-fluorinated thermoplastic resins may be used alone or in combination of two or more.

[0043] Among the above, the non-fluorinated thermoplastic resin is preferably at least one selected from the group consisting of polyamide, polyamideimide, polyarylene ether ketone, and polyarylene sulfide, and more preferably polyamide, in terms of low friction and superior abrasion resistance of the composition.

[0044] Examples of polyamides include aliphatic polyamides such as polyamide 6 (PA6), polyamide 11 (PA11), polyamide 12 (PA12), polyamide 46 (PA46), polyamide 66 (PA66), polyamide 610 (PA610), polyamide 612 (PA612), polyamide 1010 (PA1010), polyamide 6 / 66 copolymer (PA6 / 66), and polyamide 6 / 66 / 610 copolymer (PA6 / 66 / 610); semi-aromatic polyamides such as polyamide 6T, polyamide 9T, polyamide 10T, polyamide 11T, polyamide MXD6 (MXD6), and polyamide 6 / 6T copolymer; and aromatic polyamides. Note that T means terephthalic acid. These polyamides may be used alone or in combination of two or more. Among these, from the viewpoint of heat resistance, semi-aromatic polyamide resins are preferred, and at least one selected from the group consisting of PA9T, PA10T and PA6T is more preferred.

[0045] In view of the heat resistance of the composition, the melting point of the non-fluorinated thermoplastic resin is preferably 150° C. or higher, more preferably 240° C. or higher. The upper limit of the melting point of the non-fluorinated thermoplastic resin is not particularly limited, but is, for example, 420° C.

[0046] The composition may contain materials other than the composite particles and the non-fluorinated thermoplastic resin, as long as the effects of the present invention are not impaired. Examples of the materials include fillers, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, brighteners, colorants, conductive agents, release agents, surface treatment agents, and flame retardants.

[0047] As the other material, a filler is preferable. As the filler, an inorganic filler is preferable from the viewpoint of increasing the strength of the composition, and among them, carbon fiber and glass fiber are preferable, and glass fiber is particularly preferable.

[0048] (Production method of the composition) The composition can be produced, for example, by melt-kneading the composite particles and a raw material containing a non-fluorinated thermoplastic resin. The raw material may contain other materials. The melt kneading can be carried out using a known melt kneader such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, a kneader, etc. The composite particles and raw materials such as the non-fluorinated thermoplastic resin may be mixed in advance using a mixer such as a tumbler or a Henschel mixer, or may be directly charged into the melt kneader. The melt-kneading temperature is, for example, 160 to 450° C. The melt-kneading time is, for example, 0.2 to 60 minutes.

[0049] The present composition described above contains the present composite particles and a non-fluorinated thermoplastic resin, and therefore has excellent abrasion resistance. The reason for the excellent abrasion resistance is believed to be that the composite of polymer A and polymer B improves the dispersibility of polymer A in the non-fluorinated thermoplastic resin compared to conventional products.

[0050] [Molded body] A molded article according to one embodiment of the present invention (hereinafter also referred to as the present molded article) contains the present composition. The present molded article can be obtained, for example, by molding the present composition by a method such as compression molding (hot molding method, free baking method, etc.), injection molding, transfer molding, or other general method.

[0051] The molded article has excellent abrasion resistance and is therefore useful as an article requiring abrasion resistance, such as a sliding member, a seal, a tube, an insulating coating material for electric wires (wires, cables, etc.), a film, a sheet, etc. Other examples include gears, actuators, pistons, bearings, housings, aircraft interior materials, hoses, tanks, wires, bottles, fibers, etc. Examples of applications of the tubes, hoses, tanks, seals, and wires include those described in International Publication No. 2015 / 182702. Examples of applications of the tubes and hoses include tubes for drilling for energy resources such as petroleum, natural gas, and shale oil. The insulating coating material for electric wires can be used as an insulating coating material for electric wires or rectangular copper wires for motor coils, particularly rectangular conductors in drive motors for hybrid electric vehicles (HEVs) and electric vehicles (EVs). The insulating coating material for rectangular conductors is preferably in the form of a film. The insulating coating material for electric wires can be used as an insulating coating material for downhole cables for drilling energy resources (oil, natural gas, shale oil, etc.). Applications of the films and sheets include speaker diaphragms, plates for trauma or fractures, various electrical insulating adhesive tapes and other insulating paper (e.g., insulating paper for motors), sealing tapes for oil or natural gas pipes, and release films for molding thermosetting and thermoplastic composite materials. EXAMPLES

[0052] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. "Parts" refers to "parts by mass." Examples 1 to 3 are working examples, and Examples 4 to 6 are comparative examples.

[0053] [Measurement method] (Melting Point) The temperature corresponding to the maximum value of the melting peak measured by differential scanning calorimetry (DSC) was taken as the melting point.

[0054] (particle size distribution) As a pretreatment of the composite particles, the composite particles were mixed with water containing 1% by mass of neutral detergent and subjected to ultrasonic treatment for 2 minutes. The particle size distribution of the obtained dispersion was measured on a volume basis using a laser diffraction / scattering particle size distribution analyzer (Microtrac, manufactured by Microtrac Corporation), and the average particle size (D50) and the number of peaks in the frequency distribution curve were obtained.

[0055] (Wear resistance) The press plate was cut into a test piece measuring 30 mm x 30 mm x 1 mm thick. The test specimens were subjected to a friction and wear test using an Orientec friction and wear tester, using the Matsubara friction measurement method (cylindrical flat type, O-ring type) in accordance with JIS K 7218, and the wear amount (cm 3The test was performed at room temperature (23±1°C) in a non-lubricated system, with the test piece attached to a ring (material: S45Cs (1.5S), contact area: 2 cm 2 ) were brought into contact under the following conditions: test load: 150N, rotation speed: 0.5m / sec, test time: 100min. From the measured wear amount, the specific wear amount was calculated according to the following formula. Specific wear rate (mm 3 / N·km) = wear amount (mm 3 ) / (Test load (N) x Test time (sec) x Test speed (km / sec))

[0056] [Materials used] Powder A-1: ​​Powder of a polymer containing 99.5 mol% or more of TFE units, melting point 333°C, Tg: 110°C, D50: 22 μm. Powder A-2: Powder of a polymer containing 99.5 mol% or more of TFE units, melting point: 327°C, Tg: 110°C, D50: 500 μm. Powder B-1: Polymer powder containing 97.9 mol% TFE units, 0.1 mol% NAH units, and 2.0 mol% PPVE units, melting point: 300°C, Tg: 94°C, D50: 3 μm. Polyamide 9T: Manufactured by Kuraray, product name: Genestar N1000A, melting point 300°C.

[0057] [Examples 1 to 3] (Production of Composite Particles) Powder A-1 and powder B-1 were mixed in the ratios shown in Table 1 using a composite processing device (Nobilta NOB-130 manufactured by Hosokawa Micron Corporation) that applies shear force to composite particles, under conditions of a product temperature of less than 50°C, a load power of 3±0.5 kW, and a rotor rotation speed of 4000±500 rpm, to obtain composite particles. The product temperature is the surface temperature of the powder during mixing, and was measured with a temperature sensor. The melting point, D50, and number of peaks in the frequency distribution curve of the obtained composite particles were determined. The results are shown in Table 1.

[0058] (Production of the composition) The obtained composite particles and polyamide 9T were dry-blended by hand shaking in the ratio shown in Table 1, and then charged into a batch mixer (Labo Plastomill manufactured by Toyo Seiki Seisaku-sho), and melt-kneaded under the conditions of resin discharge rate: 2.0 kg / hour, screw rotation speed: 200 rpm, set resin temperature: 310°C, and kneading time: 15 minutes to obtain a composition.

[0059] (Press plate production and evaluation) The composition obtained in Example 1 was press molded using a melt hot press machine (manufactured by Tester Sangyo Co., Ltd.) under the conditions of temperature: 300°C, preheating: 5 minutes, pressure: 10 MPa, and press time: 5 minutes to obtain a pressed plate with a thickness of 2.5 mm. The abrasion resistance of the obtained press plate was evaluated, and the results are shown in Table 1.

[0060] [Examples 4 to 6] Powder A-1 or A-2, Powder B-1 and Polyamide 9T were dry-blended by hand shaking in the ratios shown in Table 1, and then charged into a batch mixer (Labo Plastomill manufactured by Toyo Seiki Seisaku-sho), and melt-kneaded under the conditions of resin discharge rate: 2.0 kg / hour, screw rotation speed: 200 rpm, set resin temperature: 310°C, and kneading time: 15 minutes to obtain a composition. For the obtained compositions, press plates were produced and the abrasion resistance was evaluated in the same manner as in Examples 1 to 3. The results are shown in Table 1. However, in Example 6, gelation and fibrillation occurred during the production of the press plate, resulting in poor molding, and therefore the abrasion resistance was not evaluated.

[0061] [Table 1]

[0062] The composition of Example 1 was superior to the compositions of Examples 4 and 5 in abrasion resistance. [Industrial Applicability]

[0063] According to the composite particles of the present invention, a composition is obtained from which a molded article having excellent abrasion resistance can be easily produced.

Claims

1. Contains polymer A and polymer B, The polymer A contains 99.5 mol % or more of units based on tetrafluoroethylene, the polymer B contains 90.0 mol % or more and less than 99.5 mol % of units based on tetrafluoroethylene, has a melting point of 260° C. or more, is melt-moldable, and has at least one functional group selected from the group consisting of a carbonyl group-containing group, a hydroxy group, an epoxy group, an amide group, an amino group, and an isocyanate group; a mass ratio of the polymer A / the polymer B is 55 / 45 to 99 / 1; Has two or more melting points within the range of 150°C or more and less than 500°C, Composite particles having one peak on a volume-based frequency distribution curve obtained by laser diffraction / scattering particle size distribution measurement.

2. 2. The composite particle according to claim 1, wherein the polymer B contains units based on at least one comonomer selected from the group consisting of perfluoro(alkyl vinyl ether), hexafluoropropylene, and fluoroalkylethylene.

3. A method for producing the composite particle according to claim 1 or 2, comprising the steps of: A method for producing composite particles, comprising: combining a powder of the polymer A and a powder of the polymer B that satisfy the following formula 1 by a mechanofusion method. D50 Ａ / D50 Ｂ ≧1.1 ……Formula 1 However, D50 Ａ indicates the average particle size (μm) of the powder of the polymer A, and D50 Ｂ indicates the average particle size (μm) of the powder of the polymer B.

4. The method according to claim 3 , wherein when the powder of the polymer A and the powder of the polymer B are composited, the surface temperatures of the powders are set to be lower than the glass transition temperature of the polymer B.

5. A composition comprising the composite particles according to claim 1 or 2 and a fluorine-free thermoplastic resin.

6. The composition according to claim 5, wherein the non-fluorinated thermoplastic resin is at least one selected from the group consisting of polyamide, polyetherimide, thermoplastic polyimide, polyamideimide, aromatic polyester, semi-aromatic polyester, polyarylene sulfide, polyarylene sulfone, polyarylene ether ketone, polyacetal and polycarbonate.

7. A molded article comprising the composition of claim 5 .

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