Polymer and molded article

Abstract

To provide a polymer having excellent alkali resistance.SOLUTION: Provided is a polymer that includes a segment A and a segment B. The segment A has a glass transition temperature of 25°C or lower and contains a 2,3,3,3-tetrafluoropropene unit and a fluorine-containing monomer unit (excluding a 2,3,3,3-tetrafluoropropene unit and a trifluoroethylene unit). The segment B has a melting point of 50°C or higher.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to polymers and molded articles. [Background technology]

[0002] Patent Document 1 describes a method for producing a fluorine-containing multi-segmented polymer, characterized in that, in the presence of a radical generating source and an iodide compound having iodine bonded to carbon, at least two kinds of monomers having a radically polymerizable unsaturated bond are radically polymerized, and monomers constituting the respective polymer chain segments are sequentially polymerized so as to form at least two kinds of polymer chain segments between the carbon-iodine bonds of the iodide compound, to obtain a multi-segmented polymer in which at least one of the polymer chain segments is a fluorine-containing polymer chain segment.

[0003] Patent Document 2 describes a polymerizable composition comprising a chain consisting of two or three types of polymer chain segments, an iodine atom present at one end of the chain, and a residue obtained by removing at least one iodine atom from an iodide compound present at the other end of the chain, one kind (when the chain is composed of two kinds of polymer chain segments) or one or two kinds (when the chain is composed of three kinds of polymer chain segments) of the polymer chain segments is an elastomeric polymer chain segment having a molecular weight of 30,000 to 1,200,000 selected from (1) vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene (molar ratio of 45 to 90: 5 to 50: 0 to 35) polymer and (2) perfluoro(alkyl vinyl ether) (alkyl group has 1 to 3 carbon atoms) / tetrafluoroethylene / vinylidene fluoride (molar ratio of 15 to 75: 0 to 85 (excluding 0): 0 to 85) polymer, the remainder of the polymer segment is a non-elastomeric polymer chain segment having a molecular weight of 3,000 to 400,000 selected from (3) vinylidene fluoride / tetrafluoroethylene (molar ratio 0 to 100: 0 to 100) polymer and (4) ethylene / tetrafluoroethylene (molar ratio 40 to 60: 40 to 60) polymer, The weight ratio of the elastomeric polymer chain segment to the non-elastomeric polymer chain segment is 40-95:5-60. Fluorine-containing segmented polymers are described.

[0004] Patent Document 3 states: a first step of copolymerizing a first monomer component mainly composed of tetrafluoroethylene and propylene at a polymerization temperature of 0 to 50°C in the presence of a radical polymerization initiator and an iodine compound represented by general formula RI2 (wherein R is an alkylene group or a fluoroalkylene group having 3 or more carbon atoms) to produce a tetrafluoroethylene / propylene-based segment; The document describes a method for producing a fluorine-containing block copolymer, which comprises a second step of copolymerizing a second monomer component mainly composed of tetrafluoroethylene and ethylene in the presence of the tetrafluoroethylene / propylene-based segment, and bonding the tetrafluoroethylene / ethylene-based segment to the tetrafluoroethylene / propylene-based segment.

[0005] Patent Document 4 describes thermoplastic block copolymers having trifluoroethylene units and further units different from vinylidene fluoride; or only trifluoroethylene units and vinylidene fluoride units; or trifluoroethylene units and vinylidene fluoride units and further units, and having xanthate or trithiocarbonate or monoiodized end groups. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 53-3495 [Patent Document 2] Special Publication No. 61-49327 [Patent Document 3] JP 2014-070206 A [Patent Document 4] Special Publication No. 2015-514854 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present disclosure is to provide a polymer that can be easily molded and has excellent alkali resistance. [Means for solving the problem]

[0008] According to the present disclosure, there is provided a polymer comprising segment A and segment B, wherein segment A has a glass transition temperature of 25° C. or less and contains 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units (excluding 2,3,3,3-tetrafluoropropene units and trifluoroethylene units), and segment B has a melting point of 50° C. or more. Effect of the Invention

[0009] According to the present disclosure, it is possible to provide a polymer that can be easily molded and has excellent alkali resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Specific embodiments of the present disclosure will be described in detail below, but the present disclosure is not limited to the following embodiments.

[0011] (First polymer) The first polymer of the present disclosure includes a segment A and a segment B. The first polymer may be a block polymer including a segment A and a segment B.

[0012] Conventionally, known block polymers are those that are composed of an elastomeric polymer chain segment and a non-elastomeric polymer chain segment, such as the fluorine-containing segmented polymer described in Patent Document 2. Patent Document 2 describes that the fluorine-containing segmented polymer composed of these segments has properties that are sufficiently durable for practical use as a thermoplastic rubber, and that, like fluorine-containing thermoplastic resins, it can be molded directly by compression or other methods without vulcanization, and that the molded product has desirable elastomeric properties almost to the same extent as vulcanized rubber.

[0013] However, no polymer is known that exhibits excellent flexibility, can be molded by molding methods applied to general thermoplastic resins, and has excellent alkali resistance.

[0014] The polymer is composed of two or more segments, At least one segment has a glass transition temperature of 25° C. or less and is composed of 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units (excluding 2,3,3,3-tetrafluoropropene units and trifluoroethylene units); At least one segment shall have a melting point of 50°C. It has been found that the polymer obtained thereby exhibits excellent flexibility, can be molded by a molding method applied to a general thermoplastic resin, and exhibits excellent alkali resistance. The first polymer of the present disclosure has been completed based on this finding.

[0015] The first polymer includes a segment A and a segment B. The first polymer will be described in detail below. As long as the first polymer includes a segment A and a segment B, it may include another segment having a structure different from that of the segments A and B.

[0016] (Segment A) Segment A has a glass transition temperature of 25° C. or lower. The glass transition temperature of segment A is preferably 0° C. or lower, more preferably −5° C. or lower, and even more preferably −10° C. or lower, and although there is no lower limit, may be −40° C. or higher. Since the first polymer contains segment A having a glass transition temperature, it has excellent flexibility.

[0017] The glass transition temperature can be determined by obtaining a DSC curve using a differential scanning calorimeter (DSC822e, Mettler Toledo, or X-DSC7000, Hitachi High-Tech Science) by cooling 10 mg of a sample to -75°C and then heating at 20°C / min, and determining the glass transition temperature as the temperature at the intersection of an extension of the baseline before and after the second-order transition of the DSC curve and a tangent to the inflection point of the DSC curve.

[0018] The heat of fusion of segment A is preferably less than 5 J / g, more preferably less than 3 J / g, and even more preferably less than 2 J / g, because this allows further improvement in flexibility.

[0019] The heat of fusion can be calculated from the magnitude of the melting peak (ΔH) of the endothermic curve obtained by heating a sample from 30° C. to 220° C. at a rate of 10° C. / min using a differential scanning calorimetry (DSC) device. When a polymer does not show a clear melting peak, the polymer has no heat of fusion, that is, the heat of fusion of the polymer is 0 J / g.

[0020] Segment A may be a segment that does not exhibit a distinct melting point.

[0021] Segment A contains 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units (excluding 2,3,3,3-tetrafluoropropene units and trifluoroethylene units). The first polymer has a glass transition temperature and contains segment A containing 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units, and therefore has excellent flexibility and alkali resistance. In addition, since segment A contains 2,3,3,3-tetrafluoropropene units, the solubility of the polymer in solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide can be improved.

[0022] The fluorine-containing monomer that can constitute segment A is not particularly limited as long as it is a monomer other than 2,3,3,3-tetrafluoropropene and trifluoroethylene and contains a fluorine atom, and examples of the fluorine-containing monomer include vinylidene fluoride [VdF], tetrafluoroethylene [TFE], hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), chlorotrifluoroethylene, hexafluoroisobutene, and vinyl fluoride.

[0023] As the fluorine-containing monomer that can constitute the segment A, at least one selected from the group consisting of VdF, TFE, hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), and chlorotrifluoroethylene is preferred, at least one selected from the group consisting of VdF and TFE is more preferred, and VdF is even more preferred. By containing VdF units in the segment A, the glass transition temperature of the segment A can be easily adjusted within a desired range, and flexibility can be further improved. In addition, by containing VdF units in the segment A, the solvent solubility of the polymer in solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide can be improved.

[0024] The content of 2,3,3,3-tetrafluoropropene units in Segment A is preferably 1 to 85 mol%, more preferably 6 mol% or more, even more preferably 12 mol% or more, still more preferably 18 mol% or more, particularly preferably 20 mol% or more, more preferably 78 mol% or less, even more preferably 50 mol% or less, still more preferably 40 mol% or less, and particularly preferably 30 mol% or less, based on all monomer units constituting Segment A.

[0025] The content of the fluorine-containing monomer unit in Segment A is preferably 99 to 15 mol%, more preferably 94 mol% or less, even more preferably 88 mol% or less, still more preferably 82 mol% or less, particularly preferably 78 mol% or less, more preferably 22 mol% or more, even more preferably 50 mol% or more, still more preferably 60 mol% or more, and particularly preferably 70 mol% or more, based on all monomer units constituting Segment A.

[0026] The content of VdF units in segment A is preferably 99 to 15 mol%, more preferably 94 mol% or less, even more preferably 88 mol% or less, still more preferably 82 mol% or less, particularly preferably 78 mol% or less, more preferably 22 mol% or more, even more preferably 50 mol% or more, still more preferably 60 mol% or more, and particularly preferably 70 mol% or more, based on all monomer units constituting segment A.

[0027] Segment A may further contain a non-fluorine-containing monomer unit. Examples of the non-fluorine-containing monomer include ethylene, propylene, and alkyl vinyl ether. The content of the non-fluorine-containing monomer unit is preferably 0 to 50 mol%, more preferably 0 to 10 mol%, and even more preferably 0 to 1 mol%, based on the total monomer units constituting segment A, and may be 0 mol%.

[0028] Segment A may further contain units based on a monomer having a reactive group such as a cyano group, a carboxyl group, an alkoxycarbonyl group, I, Br, -CHOH, a carbon-carbon double bond, etc. The content of units based on a monomer having a reactive group is preferably 0 to 50 mol %, more preferably 0 to 10 mol %, and even more preferably 0 to 1 mol %, relative to all monomer units constituting segment A, and may be 0 mol %.

[0029] In the present disclosure, the content of each monomer unit can be measured by NMR.

[0030] In one embodiment, segment A may be formed by a 2,3,3,3-tetrafluoropropene / VdF copolymer or a 2,3,3,3-tetrafluoropropene / VdF / TFE copolymer.

[0031] In the 2,3,3,3-tetrafluoropropene / VdF copolymer, the composition (mol %) of 2,3,3,3-tetrafluoropropene units / VdF units is preferably (18 to 40) / (82 to 60), and more preferably (20 to 30) / (80 to 70).

[0032] In the 2,3,3,3-tetrafluoropropene / VdF / TFE copolymer, the composition (mol %) of 2,3,3,3-tetrafluoropropene units / VdF units / TFE units is preferably (18 to 40) / (81 to 25) / (1 to 35), and more preferably (20 to 40) / (75 to 30) / (5 to 30).

[0033] In one embodiment, segment A contains 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units (excluding 2,3,3,3-tetrafluoropropene units and trifluoroethylene units), and the content of monomer units other than 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units is preferably 0 to 10 mol%, more preferably 0 to 2 mol%, even more preferably 0 to 1 mol%, still more preferably 0 to 0.1 mol%, and particularly preferably 0 mol%, based on the total monomer units constituting segment A. The content of 2,3,3,3-tetrafluoropropene units and the content of fluorine-containing monomer units may be within the above-mentioned ranges.

[0034] In one embodiment, segment A contains 2,3,3,3-tetrafluoropropene units and VdF units, and the content of monomer units other than 2,3,3,3-tetrafluoropropene units and VdF units is preferably 0 to 10 mol%, more preferably 0 to 2 mol%, even more preferably 0 to 1 mol%, still more preferably 0 to 0.1 mol%, and particularly preferably 0 mol%, based on the total monomer units constituting segment A. The content of 2,3,3,3-tetrafluoropropene units and the content of VdF units may be within the above-mentioned ranges.

[0035] (Segment B) Segment B has a melting point of 50°C or higher. The melting point of segment B is preferably 90°C or higher, more preferably 140°C or higher, preferably 240°C or lower, more preferably 220°C or lower, and even more preferably 200°C or lower. Since the first polymer contains segment B having a melting point in addition to segment A having a glass transition temperature, it has excellent flexibility and can be molded by a molding method applied to general thermoplastic resins. In the present disclosure, the phrase "the polymer can be easily molded" means that it can be molded by a molding method applied to general thermoplastic resins, such as extrusion molding, injection molding, and compression molding.

[0036] The melting point can be determined by using a differential scanning calorimetry (DSC) device to raise the temperature of a sample from 30° C. to 220° C. at a rate of 10° C. / min, and measuring the temperature at the peak of the endothermic curve obtained.

[0037] Typically, the melting point of segment B is the same as the melting point of the first polymer. Therefore, by measuring the melting point of the first polymer, the melting point of segment B in the first polymer can be determined.

[0038] The heat of fusion of segment B is preferably 5 J / g or more, more preferably 10 J / g or more, even more preferably 30 J / g or more, still more preferably 35 J / g or more, and preferably 90 J / g or less, more preferably 60 J / g or less, and even more preferably 55 J / g or less.

[0039] The heat of fusion can be calculated from the magnitude of the melting peak (ΔH) of the endothermic curve obtained by heating a sample from 30° C. to 220° C. at a rate of 10° C. / min using a differential scanning calorimetry (DSC) device.

[0040] As long as segment B is formed from a polymer having a melting point, it may contain a fluorine-containing monomer unit or a non-fluorine-containing monomer unit. From the viewpoint of further improving the alkali resistance of the first polymer, segment B preferably contains a fluorine-containing monomer unit, and more preferably contains a fluorine-containing monomer unit (excluding trifluoroethylene units).

[0041] Examples of fluorine-containing monomers include vinylidene fluoride [VdF], tetrafluoroethylene [TFE], hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), chlorotrifluoroethylene, hexafluoroisobutene, and vinyl fluoride.

[0042] The fluorine-containing monomer is preferably at least one selected from the group consisting of VdF, TFE, hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), and chlorotrifluoroethylene, more preferably at least one selected from the group consisting of VdF and TFE, and even more preferably VdF.

[0043] When segment B has a VdF unit as a fluorine-containing monomer unit, the first polymer exhibits excellent flexibility and can be molded by a molding method applied to general thermoplastic resins, and also exhibits excellent alkali resistance and excellent solubility in solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide.

[0044] Segment B may contain, in addition to VdF units, other monomer units other than VdF. The other monomers may be either fluorine-containing or non-fluorine-containing monomers, and are preferably fluorine-containing monomers (excluding trifluoroethylene) or non-fluorine-containing monomers.

[0045] Examples of fluorine-containing monomers that can form segment B together with VdF include TFE, hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), chlorotrifluoroethylene, hexafluoroisobutene, vinyl fluoride, and 2,3,3,3-tetrafluoropropene.

[0046] Examples of the fluorine-free monomer that can form the segment B together with VdF include ethylene and propylene.

[0047] Segment B may further contain a unit based on a monomer having a polar group, such as a carbonyl group-containing group, an epoxy group, a hydroxy group, a sulfonic acid group, a sulfate group, a phosphate group, an amino group, an amide group or an alkoxy group.

[0048] Examples of monomers having a polar group include hydroxyalkyl (meth)acrylates such as hydroxyethyl acrylate and 2-hydroxypropyl acrylate; unsaturated monobasic acids such as (meth)acrylic acid, crotonic acid, vinyl acetic acid (3-butenoic acid), 3-pentenoic acid, 4-pentenoic acid, 3-hexenoic acid, and 4-heptenoic acid; unsaturated dibasic acids such as maleic acid, maleic anhydride, citraconic acid, and citraconic anhydride; alkylidene malonic acid esters such as dimethyl methylidene malonate; and vinyl carboxyalkyl ethers such as vinyl carboxymethyl ether and vinyl carboxyethyl ether. carboxyalkyl (meth)acrylates such as 2-carboxyethyl acrylate and 2-carboxyethyl methacrylate; (meth)acryloyloxyalkyl dicarboxylate esters such as acryloyloxyethyl succinate, methacryloyloxyethyl succinate, acryloyloxyethyl phthalate, acryloyloxypropyl succinate, and methacryloyloxyethyl phthalate; monoesters of unsaturated dibasic acids such as maleic acid monomethyl ester, maleic acid monoethyl ester, citraconic acid monomethyl ester, and citraconic acid monoethyl ester; and the like.

[0049] As the other monomer capable of constituting segment B together with VdF, at least one selected from the group consisting of TFE, hexafluoropropylene, 2,3,3,3-tetrafluoropropene, and (meth)acrylic acid is particularly preferred.

[0050] The content of VdF units in segment B is preferably 60 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and even more preferably 99 mol % or more, and may be 100 mol % or less, based on all monomer units constituting segment B, because this further improves the solubility in solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide.

[0051] The content of other monomer units in Segment B is preferably 40 mol % or less, more preferably 10 mol % or less, even more preferably 5 mol % or less, still more preferably 1 mol % or less, and may be 0 mol % or more, based on the total monomer units constituting Segment B, because this further improves the solubility in solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide.

[0052] In one embodiment, segment B can be formed by a VdF homopolymer containing only VdF units, or a copolymer containing VdF units and at least one other monomer unit selected from the group consisting of TFE units, hexafluoropropylene units, 2,3,3,3-tetrafluoropropene units, and (meth)acrylic acid units.

[0053] In a copolymer containing VdF units and other monomer units, the composition (mol %) of VdF units / other monomer units is preferably 97.0 to 99.9 / 3.0 to 0.1.

[0054] The first polymer may contain a segment C having a structure different from that of the segments A and B, so long as the first polymer contains the segments A and B.

[0055] The first polymer may be a block polymer containing a chain structure represented by any of the following general formulas: General formula:AB General formula: ABA General formula: BAB General formula: ABC General formula: BAC (wherein A represents segment A, B represents segment B, and C represents segment C).

[0056] The first polymer preferably contains a chain structure represented by general formula (1) or general formula (2), since this can further improve alkali resistance and is easy to produce. General formula (1):ABA General formula (2): BAB (In the formula, A represents segment A and B represents segment B.)

[0057] In the first polymer, the mass ratio (A / B) of segment A to segment B is preferably 40 / 60 to 95 / 5, more preferably 50 / 50 or more, even more preferably 60 / 40 or more, and more preferably 90 / 10 or less, from the viewpoint of a balance between excellent flexibility and excellent alkali resistance.

[0058] The number average molecular weight (polystyrene equivalent) of the first polymer is preferably 20,000 to 1,500,000, more preferably 40,000 or more, even more preferably 70,000 or more, particularly preferably 140,000 or more, more preferably 1,400,000 or less, even more preferably 1,200,000 or less, and particularly preferably 1,100,000 or less. The number average molecular weight can be measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent.

[0059] The weight average molecular weight (polystyrene equivalent) of the first polymer is preferably 50,000 to 3,000,000, more preferably 80,000 or more, even more preferably 100,000 or more, still more preferably 200,000 or more, particularly preferably 500,000 or more, more preferably 2,400,000 or less, even more preferably 2,200,000 or less, and particularly preferably 2,000,000 or less. The weight average molecular weight can be measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent.

[0060] The first polymer of the present disclosure can be, for example, (1) A method of preparing a polymer for forming segment B by polymerizing a monomer for forming segment B in the presence of a bromine compound or an iodine compound as a chain transfer agent, and preparing a polymer for forming segment A by polymerizing a monomer for forming segment A in the presence of the polymer for forming segment B; (2) A method of preparing a polymer for forming segment A by polymerizing a monomer for forming segment A in the presence of a bromine compound or an iodine compound as a chain transfer agent, and preparing a polymer for forming segment B by polymerizing a monomer for forming segment B in the presence of the polymer for forming segment A; The composition can be produced by the above-mentioned production method.

[0061] When method (1) is used, a polymer is obtained in which segment A is bonded to both ends of a polymer chain forming segment B, that is, a polymer containing a chain structure represented by general formula (1): ABA.

[0062] Furthermore, when method (2) is used, a polymer that forms segment B bonded to both ends of a polymer chain that forms segment A, that is, a polymer containing a chain structure represented by general formula (2): BAB, is obtained.

[0063] In the methods (1) and (2), a bromine compound or an iodine compound is used as a chain transfer agent. By using a bromine compound or an iodine compound, an iodine atom or a bromine atom is introduced into the polymer chain end forming one segment, and serves as a binding site for another segment.

[0064] The polymerization method using a bromine compound or an iodine compound includes, for example, a method in which emulsion polymerization is carried out in an aqueous medium under pressure in the presence of a bromine compound or an iodine compound in a substantially oxygen-free state (iodine transfer polymerization method). Representative examples of the bromine compound or iodine compound to be used include, for example, General formula: R 8 Ix Br y (In the formula, x and y are each an integer of 0 to 2, and 1≦x+y≦2 is satisfied; R 8 is a saturated or unsaturated fluorohydrocarbon group or chlorofluorohydrocarbon group having 1 to 16 carbon atoms, or a hydrocarbon group having 1 to 3 carbon atoms, which may contain an oxygen atom).

[0065] Examples of iodine compounds include 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3-diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5-diiodo-2,4-dichloroperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2-diiodoethane, 1,3-diiodo-n-propane, CF2Br2, BrCF2CF2Br, CF3CFBrCF2Br, CFClBr2, BrCF2CFCl Br, CFBrClCFClBr, BrCF2CF2CF2Br, BrCF2CFBrOCF3, 1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluorobutene-1, 2-bromo-4-iodoperfluorobutene-1, monoiodomonobromo-substituted benzene, diiodomonobromo-substituted benzene, and (2-iodoethyl) and (2-bromoethyl)-substituted benzene. These compounds may be used alone or in combination with each other.

[0066] Among these, it is preferable to use 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, and 2-iodoperfluoropropane in terms of polymerization reactivity, crosslinking reactivity, availability, and the like.

[0067] In the above-mentioned production method, the polymerization of the monomer is preferably carried out by emulsion polymerization. In one embodiment, the polymerization of the monomer is carried out in the presence of a polymerization initiator, a surfactant and a solvent.

[0068] The polymerization initiator may be an oil-soluble radical polymerization initiator or a water-soluble radical initiator.

[0069] The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, for example, dialkyl peroxycarbonates such as diisopropyl peroxydicarbonate and disec-butyl peroxydicarbonate, peroxyesters such as t-butyl peroxyisobutyrate and t-butyl peroxypivalate, dialkyl peroxides such as di-t-butyl peroxide, and the like. In addition, di(ω-hydro-dodecafluoroheptanoyl) peroxide, di(ω-hydro-tetradecafluorooctanoyl) peroxide, di(ω-hydro-hexadecafluorononanoyl) peroxide, di(perfluorobutyryl) peroxide, di(perfluparyl) peroxide, di(perfluorohexanoyl) peroxide, di(perfluoroheptanoyl) peroxide, di(perfluorooctanoyl) peroxide, di(perfluorononanoyl) peroxide, di(ω-chloro- Representative examples of the perfluoro(or fluorochloro)acyl]peroxides include di(ω-chlorohexafluorobutyryl) peroxide, di(ω-chloro-decafluorohexanoyl) peroxide, di(ω-chloro-tetradecafluorooctanoyl) peroxide, ω-hydro-dodecafluoroheptanoyl-ω-hydrohexadecafluorononanoyl-peroxide, ω-chloro-hexafluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydrododecafluoroheptanoyl-perfluorobutyryl-peroxide, di(dichloropentafluorobutanoyl) peroxide, di(trichlorooctafluorohexanoyl) peroxide, di(tetrachloroundecafluorooctanoyl) peroxide, di(pentachlorotetradecafluorodecanoyl) peroxide, and di(undecachlorodotriacontafluorodocosanoyl) peroxide.

[0070] The water-soluble radical polymerization initiator may be a known water-soluble peroxide, such as ammonium salts, potassium salts, or sodium salts of persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, or percarbonic acid, t-butyl permaleate, or t-butyl hydroperoxide, etc. A reducing agent such as sulfites may also be contained, and the amount used may be 0.1 to 20 times that of the peroxide.

[0071] The amount of the polymerization initiator to be added is not particularly limited, but may be added all at once, stepwise, or continuously in an amount (for example, several ppm relative to water concentration) at least to the extent that the polymerization rate does not drop significantly. The upper limit is within the range in which the heat of polymerization reaction can be removed from the equipment side.

[0072] The surfactant may be a nonionic surfactant, an anionic surfactant, a cationic surfactant, etc. The amount added (relative to the solvent) is preferably 10 ppm by mass to 20% by mass, more preferably 10 ppm by mass to 10% by mass, further preferably 10 to 5000 ppm by mass, and particularly preferably 50 to 5000 ppm by mass.

[0073] A polymerizable emulsifier may also be used as the surfactant. The polymerizable emulsifier is not particularly limited as long as it is a compound having at least one unsaturated bond and at least one hydrophilic group, and examples thereof include CH2=CFCF2OCF(CF3)CF2OCF(CF3)COONH4, CH2=CFCF2CF(CF3)OCF2CF2COONH4, and CF2=CFOCF2CF(CF3)OCF(CF3)COONH4. The amount of the emulsifier added (relative to the solvent) is preferably 10 to 5000 ppm by mass, more preferably 50 to 5000 ppm by mass.

[0074] The solvent is preferably a solvent that does not have chain transfer properties, and examples of the solvent include water, a mixture of water and a water-soluble organic solvent, and a mixture of water and a water-insoluble organic solvent.

[0075] In the polymerization of the monomer, the polymerization temperature, polymerization pressure and polymerization time may vary depending on the type of solvent and polymerization initiator, but may be -15 to 150°C, atmospheric pressure to 12 MPa, and 1 to 24 hours. When an oil-soluble radical polymerization initiator is used as the polymerization initiator, the polymerization temperature is preferably 30 to 95°C. When a water-soluble radical polymerization initiator is used as the polymerization initiator, the polymerization temperature is preferably 0 to 100°C, and more preferably 10 to 95°C.

[0076] When the polymerization of the monomer is carried out by emulsion polymerization, an aqueous dispersion containing the polymer is obtained. In the above-mentioned production method, the polymer in the aqueous dispersion is coagulated, washed with water, dehydrated, and dried to obtain a powder of the polymer. The coagulation can be carried out by adding an inorganic salt such as aluminum sulfate or an inorganic acid to the dispersion, by applying a mechanical shear force to the dispersion, or by freezing the dispersion.

[0077] The first polymer can also be produced by using at least 2,3,3,3-tetrafluoropropene as a monomer according to the methods described in JP-A-53-3495 and JP-B-61-49327.

[0078] (Second Polymer) The second polymer of the present disclosure is a polymer having a glass transition temperature and a melting point, containing 2,3,3,3-tetrafluoropropene units, and having a tetrahydrofuran extractable amount of 5% by mass or less at 25° C. The second polymer does not include polymers containing trifluoroethylene units.

[0079] As described above, no polymer is known that exhibits excellent flexibility, can be molded by molding methods applied to general thermoplastic resins, and has excellent alkali resistance.

[0080] Selecting a polymer configuration such that the polymer has a glass transition temperature and a melting point; Introducing 2,3,3,3-tetrafluoropropene units into the polymer, The polymer composition is selected so that the amount of tetrahydrofuran extractable from the polymer at 25°C is 5% by mass or less. It has been found that the resulting polymer exhibits excellent flexibility, can be molded by a molding method applied to general thermoplastic resins, and exhibits excellent alkali resistance. The second polymer of the present disclosure has been completed based on this finding.

[0081] The glass transition temperature of the second polymer is preferably 25° C. or lower, more preferably 0° C. or lower, even more preferably −5° C. or lower, and even more preferably −10° C. or lower, and although there is no lower limit, may be −40° C. or higher. Since the second polymer has a glass transition temperature, it has excellent flexibility.

[0082] The glass transition temperature can be determined by obtaining a DSC curve using a differential scanning calorimeter (DSC822e, Mettler Toledo, or X-DSC7000, Hitachi High-Tech Science) by cooling 10 mg of a sample to -75°C and then heating at 20°C / min, and determining the glass transition temperature as the temperature at the intersection of an extension of the baseline before and after the second-order transition of the DSC curve and a tangent to the inflection point of the DSC curve.

[0083] The melting point of the second polymer is preferably 50° C. or higher, more preferably 90° C. or higher, even more preferably 140° C. or higher, and preferably 240° C. or lower, more preferably 220° C. or lower, and even more preferably 200° C. or lower. The second polymer has a melting point in addition to having a glass transition temperature, and therefore has excellent flexibility, and furthermore can be molded by a molding method applied to general thermoplastic resins.

[0084] The melting point can be determined by using a differential scanning calorimetry (DSC) device to raise the temperature of a sample from 30° C. to 220° C. at a rate of 10° C. / min, and measuring the temperature at the peak of the endothermic curve obtained.

[0085] The amount of tetrahydrofuran extracted from the second polymer is 5% by mass or less, preferably 4% by mass or less, and more preferably 3% by mass or less. By making the amount of tetrahydrofuran extracted within the above numerical range, the polymer can be given flexibility and excellent moldability. The lower limit of the amount of tetrahydrofuran extracted is not particularly limited, but may be 1% by mass or more or 2% by mass or more.

[0086] The amount of tetrahydrofuran extractables can be measured by a method in which a polymer is immersed in tetrahydrofuran at 25° C., and the filtered solution is dried and solidified.

[0087] The second polymer contains 2,3,3,3-tetrafluoropropene units. The second polymer has a glass transition temperature and a melting point, and since it contains 2,3,3,3-tetrafluoropropene units, it has excellent flexibility and excellent alkali resistance.

[0088] The second polymer preferably contains a fluorine-containing monomer unit (excluding 2,3,3,3-tetrafluoropropene unit and trifluoroethylene unit). By introducing the fluorine-containing monomer unit into the polymer, the glass transition temperature and melting point of the polymer can be easily adjusted, and the flexibility and alkali resistance can be further improved.

[0089] The fluorine-containing monomer that can constitute the second polymer is not particularly limited as long as it is a monomer other than 2,3,3,3-tetrafluoropropene and trifluoroethylene and contains a fluorine atom, and examples of the fluorine-containing monomer include vinylidene fluoride [VdF], tetrafluoroethylene [TFE], hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), chlorotrifluoroethylene, hexafluoroisobutene, and vinyl fluoride.

[0090] The fluorine-containing monomer that can constitute the second polymer is preferably at least one selected from the group consisting of VdF, TFE, hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), and chlorotrifluoroethylene, more preferably at least one selected from the group consisting of VdF and TFE, and even more preferably VdF.

[0091] The content of 2,3,3,3-tetrafluoropropene units in the second polymer is preferably 1 to 65 mol%, more preferably 5 mol% or more, even more preferably 9 mol% or more, still more preferably 12 mol% or more, particularly preferably 14 mol% or more, more preferably 62 mol% or less, still more preferably 40 mol% or less, still more preferably 32 mol% or less, and particularly preferably 24 mol% or less, based on all monomer units constituting the second polymer.

[0092] The content of the fluorine-containing monomer unit in the second polymer is preferably 99 to 35 mol %, more preferably 95 mol % or less, even more preferably 91 mol % or less, still more preferably 88 mol % or less, particularly preferably 86 mol % or less, more preferably 38 mol % or more, still more preferably 60 mol % or more, still more preferably 68 mol % or more, and particularly preferably 76 mol % or more, based on all monomer units constituting the second polymer.

[0093] When the second polymer contains a VdF unit as a fluorine-containing monomer unit, the second polymer exhibits excellent flexibility and can be molded by a molding method applied to general thermoplastic resins, and also exhibits better alkali resistance and better solubility in solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide.

[0094] The content of VdF units in the second polymer is preferably 99 to 35 mol %, more preferably 95 mol % or less, even more preferably 91 mol % or less, still more preferably 88 mol % or less, particularly preferably 86 mol % or less, more preferably 38 mol % or more, even more preferably 60 mol % or more, still more preferably 68 mol % or more, and particularly preferably 76 mol % or more, based on all monomer units constituting the second polymer, in order to further improve the solvent solubility.

[0095] The second polymer may further contain a non-fluorine-containing monomer unit. Examples of the non-fluorine-containing monomer include ethylene, propylene, and alkyl vinyl ether. The content of the non-fluorine-containing monomer unit is preferably 0 to 40 mol%, more preferably 0 to 8 mol%, and even more preferably 0 to 1 mol%, and may be 0 mol%, based on the total monomer units constituting the second polymer.

[0096] The second polymer may further contain units based on a monomer having a reactive group such as a cyano group, a carboxyl group, an alkoxycarbonyl group, I, Br, -CHOH, a carbon-carbon double bond, etc. The content of the units based on a monomer having a reactive group is preferably 0 to 10 mol %, more preferably 0 to 2 mol %, and even more preferably 0 to 1 mol %, relative to all monomer units constituting the second polymer, and may be 0 mol %.

[0097] The second polymer may further contain units based on monomers having polar groups such as carbonyl group-containing groups, epoxy groups, hydroxy groups, sulfonic acid groups, sulfate groups, phosphate groups, amino groups, amide groups, and alkoxy groups.

[0098] Examples of monomers having a polar group include hydroxyalkyl (meth)acrylates such as hydroxyethyl acrylate and 2-hydroxypropyl acrylate; unsaturated monobasic acids such as (meth)acrylic acid, crotonic acid, vinyl acetic acid (3-butenoic acid), 3-pentenoic acid, 4-pentenoic acid, 3-hexenoic acid, and 4-heptenoic acid; unsaturated dibasic acids such as maleic acid, maleic anhydride, citraconic acid, and citraconic anhydride; alkylidene malonic acid esters such as dimethyl methylidene malonate; and vinyl carboxyalkyl ethers such as vinyl carboxymethyl ether and vinyl carboxyethyl ether. carboxyalkyl (meth)acrylates such as 2-carboxyethyl acrylate and 2-carboxyethyl methacrylate; (meth)acryloyloxyalkyl dicarboxylate esters such as acryloyloxyethyl succinate, methacryloyloxyethyl succinate, acryloyloxyethyl phthalate, acryloyloxypropyl succinate, and methacryloyloxyethyl phthalate; monoesters of unsaturated dibasic acids such as maleic acid monomethyl ester, maleic acid monoethyl ester, citraconic acid monomethyl ester, and citraconic acid monoethyl ester; and the like.

[0099] The content of units based on monomers having a polar group is preferably 0 to 10 mol %, more preferably 0 to 2 mol %, and even more preferably 0 to 1 mol %, relative to all monomer units constituting the second polymer, and may be 0 mol %.

[0100] In one embodiment, the second polymer contains 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units (excluding 2,3,3,3-tetrafluoropropene units and trifluoroethylene units), and the content of monomer units other than 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units is preferably 0 to 10 mol%, more preferably 0 to 2 mol%, even more preferably 0 to 1 mol%, still more preferably 0 to 0.1 mol%, and particularly preferably 0 mol%, based on the total monomer units constituting the second polymer. The content of 2,3,3,3-tetrafluoropropene units and the content of fluorine-containing monomer units may be within the above-mentioned ranges.

[0101] In one embodiment, the second polymer contains 2,3,3,3-tetrafluoropropene units and VdF units, and the content of monomer units other than 2,3,3,3-tetrafluoropropene units and VdF units is preferably 0 to 10 mol%, more preferably 0 to 2 mol%, even more preferably 0 to 1 mol%, still more preferably 0 to 0.1 mol%, and particularly preferably 0 mol%, based on the total monomer units constituting the second polymer. The content of 2,3,3,3-tetrafluoropropene units and the content of VdF units may be within the above-mentioned ranges.

[0102] The number average molecular weight (polystyrene equivalent) of the second polymer is preferably 20,000 to 1,500,000, more preferably 40,000 or more, even more preferably 70,000 or more, particularly preferably 140,000 or more, more preferably 1,400,000 or less, even more preferably 1,200,000 or less, and particularly preferably 1,100,000 or less. The number average molecular weight can be measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent.

[0103] The weight average molecular weight (polystyrene equivalent) of the second polymer is preferably 50,000 to 3,000,000, more preferably 80,000 or more, even more preferably 100,000 or more, still more preferably 200,000 or more, particularly preferably 500,000 or more, more preferably 2,400,000 or less, even more preferably 2,200,000 or less, and particularly preferably 2,000,000 or less. The weight average molecular weight can be measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent.

[0104] The heat of fusion of the second polymer is preferably 1 J / g or more, more preferably 3 J / g or more, even more preferably 5 J / g or more, even more preferably 8 J / g or more, and preferably 40 J / g or less, more preferably 30 J / g or less, even more preferably 20 J / g or less.

[0105] In one embodiment, the second polymer contains two or more segments. By forming the polymer from two or more segments, the glass transition temperature and melting point of the polymer can be easily imparted and easily adjusted, and flexibility and alkali resistance can be further improved.

[0106] When the second polymer contains two or more segments, the configuration of each segment can be the same as the configuration of each segment of the first polymer. That is, the second polymer can contain segment A and segment B like the first polymer, and can have the same configuration as the first polymer. The first polymer can also have the same configuration as the second polymer.

[0107] The second polymer of the present disclosure can be produced, for example, by the method described above as the method for producing the first polymer of the present disclosure.

[0108] The composition may be prepared by mixing the first polymer of the present disclosure or the second polymer of the present disclosure (hereinafter, the first polymer and the second polymer may be simply referred to as the "polymer of the present disclosure") with other components. Examples of the other components include fillers, plasticizers, processing aids, release agents, pigments, flame retardants, lubricants, light stabilizers, weather stabilizers, conductive agents, antistatic agents, UV absorbers, antioxidants, foaming agents, fragrances, oils, softeners, dehydrofluorination agents, etc.

[0109] In addition, other polymers different from the polymers of the present disclosure can be used as the other components. Examples of the other polymers include fluororesins, fluororubbers, and non-fluorine-containing polymers.

[0110] The polymers of the present disclosure or the compositions described above can also be molded to obtain molded articles.

[0111] The polymer of the present disclosure or the above-mentioned composition can be molded by molding methods generally applied to thermoplastic resins, such as injection molding, extrusion molding, compression molding, blow molding, transfer molding, roto-molding, roto-lining molding, etc.

[0112] In one embodiment of the polymer of the present disclosure, the polymer exhibits good solvent solubility. For example, the polymer of the present disclosure is well soluble in solvents such as nitrogen-containing organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and dimethylformamide; ketone-based solvents such as acetone, methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; ester-based solvents such as ethyl acetate and butyl acetate; and ether-based solvents such as dioxane.

[0113] When the polymer of the present disclosure exhibits good solvent solubility, the polymer of the present disclosure can also be dissolved in a solvent and used as a coating material.

[0114] The polymer of the present disclosure or the above-described composition can also be used as a binder for forming an electrode of a battery.

[0115] Molded articles containing the polymers of the present disclosure have excellent flexibility and alkali resistance, and can therefore be used in a variety of applications.

[0116] The molded article can be used, for example, as a tube, a hose, a film, a coating material for electric wires, a roll, a flexible joint, a rubber sheet, a belt, a damper, a valve, a valve seat, a valve body, a chemical-resistant coating material, a laminating material, a lining material, and the like.

[0117] The molded articles can also be used as various sealing materials such as rings, packings, gaskets, diaphragms, oil seals, bearing seals, lip seals, plunger seals, door seals, face seals, gas delivery plate seals, wafer support seals and barrel seals.

[0118] In particular, molded articles containing the polymer of the present disclosure have excellent flexibility and alkali resistance, and therefore can be suitably used for various components used in chemical solution supply equipment for semiconductor manufacturing and food processing equipment, such as piping, tubes, joints, valves, tanks, containers, chemical solution bags, pumps, filters, etc.

[0119] Molded articles containing the polymers of the present disclosure are also suitable for use as molded articles that come into contact with the human body.

[0120] Molded articles that come into contact with the human body do not need to be in constant contact like a watch strap, but may be in contact only when in use like a smartphone case. Also, the entire surface of the molded article does not need to come into contact with the human body, but only a part of it may. Specific uses of such molded articles include the following:

[0121] (1) Interior parts for automobiles, motorcycles, ships, aircraft, bicycles, etc. Steering wheels, armrests, shift levers, seat covers, etc. (2) Wearables Smart watches, smart bands, smart glasses, VR (Virtual Reality) devices, body-attached devices, others (clothing-attached devices, ring-type devices), etc. (3) Eyeglass parts Nose pads, vines, etc. (4) Health products Magnetic necklaces, magnetic bracelets, magnetic bandages such as PIP ELEKIBAN (registered trademark), pelvic belts, supports, healing dolls, etc. (5) Sporting goods Mats, shoes, underwater masks, snorkels, diving equipment, fishing equipment, golf club grips, etc. (6) Earphone parts, headphone parts Cables, ear hooks, ear pieces, ear pads, etc. (7) Electronic equipment cover Smartphone covers, tablet covers, keyboard covers, etc. (8) Kitchen supplies Spatulas, spatulas, bowls, steamers, baking molds, lunch cups, rubber aprons for infants and caregivers, baby bottles, pacifiers (containers, mouthpieces), water bottles, mugs, handles for pots and kettles, etc. (9) Pet supplies Toilet tray, food dish, collar, etc. (10) Office supplies Pen grips, mice, mouse pads, etc. (11) Decorations Boots, rubber boots, shoe insoles, hats, hair bands, raincoats, umbrella and walking stick grips, etc. (12)Other Buttons, wheelchair foil socks, bags, eyelash curlers, hearing aids, rubber accessories, non-magnetic rubber accessories for fashion use, robot exteriors, robot (flexible) cables, bathhouse locker keys, etc.

[0122] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims.

[0123] <1> According to a first aspect of the present disclosure, A polymer comprising a segment A and a segment B, Segment A is Has a glass transition temperature of 25°C or less, Contains 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units (excluding 2,3,3,3-tetrafluoropropene units and trifluoroethylene units), Segment B is Has a melting point of 50°C or higher A polymer is provided. <2> According to a second aspect of the present disclosure, According to a first aspect there is provided a polymer comprising a chain structure of general formula (1) or general formula (2). General formula (1):ABA General formula (2): BAB (In the formula, A represents segment A and B represents segment B.) <3> According to a third aspect of the present disclosure, There is provided a polymer according to the first or second aspect, wherein said fluorine-containing monomer units of segment A are vinylidene fluoride units. <4> According to a fourth aspect of the present disclosure, There is provided a polymer according to any one of the first to third aspects, in which the content of 2,3,3,3-tetrafluoropropene units in segment A is 18 mol % or more based on all monomer units constituting segment A. <5> According to a fifth aspect of the present disclosure, There is provided a polymer according to any one of the first to fourth aspects, in which segment B contains vinylidene fluoride units, and the content of the vinylidene fluoride units in segment B is 90 mol % or more based on all monomer units constituting segment B. <6> According to a sixth aspect of the present disclosure, Segment B is Contains only vinylidene fluoride units, or Contains vinylidene fluoride units and at least one monomer unit selected from the group consisting of tetrafluoroethylene units, hexafluoropropylene units, 2,3,3,3-tetrafluoropropene units, and (meth)acrylic acid units. According to any one of the first to fifth aspects, there is provided a polymer. <7> According to a seventh aspect of the present disclosure, There is provided a polymer according to any one of the first to sixth aspects, wherein a mass ratio of segment A to segment B is 40 / 60 to 95 / 5. <8> According to an eighth aspect of the present disclosure, Contains a chain structure represented by general formula (1) or general formula (2), General formula (1):ABA General formula (2): BAB (In the formula, A represents segment A and B represents segment B.) Segment A is It has a glass transition temperature of -10°C or less, containing 2,3,3,3-tetrafluoropropene units and vinylidene fluoride units, the content of the 2,3,3,3-tetrafluoropropene units in segment A being 18 to 30 mol % relative to all monomer units constituting segment A, and the content of the vinylidene fluoride units in segment A being 70 to 82 mol % relative to all monomer units constituting segment A; Segment B is It has a melting point of 140 to 200°C. Segment B contains vinylidene fluoride units, and the content of the vinylidene fluoride units in Segment B is 95 mol % or more based on all monomer units constituting Segment B; a mass ratio (A / B) of segment A to segment B in the polymer is 50 / 50 to 90 / 10; The weight average molecular weight of the polymer is 500,000 to 2,000,000. According to any one of the first to seventh aspects, there is provided a polymer. <9> According to a ninth aspect of the present disclosure, Provided is a polymer (excluding polymers containing trifluoroethylene units) which has a glass transition temperature and a melting point, contains 2,3,3,3-tetrafluoropropene units, and has a tetrahydrofuran extractable amount of 5% by mass or less at 25° C. <10> According to a tenth aspect of the present disclosure, Further provided is a polymer according to a ninth aspect which contains vinylidene fluoride units. <11> According to an eleventh aspect of the present disclosure, There is provided a polymer according to the ninth or tenth aspect which comprises two or more segments. <12> According to a twelfth aspect of the present disclosure, The glass transition temperature is -10°C or lower, The melting point is 140 to 200°C. The polymer contains 2,3,3,3-tetrafluoropropene units and vinylidene fluoride units, the content of the 2,3,3,3-tetrafluoropropene units being 12 to 24 mol % based on all monomer units constituting the polymer, and the content of the vinylidene fluoride units being 76 to 88 mol % based on all monomer units constituting the polymer, The amount of tetrahydrofuran extractable at 25°C is 2 to 4% by mass, The weight average molecular weight is 500,000 to 2,000,000. According to any one of the ninth to eleventh aspects, there is provided a polymer. <13> According to a thirteenth aspect of the present disclosure, There is provided a molded article comprising a polymer according to any one of the first to twelfth aspects. EXAMPLES

[0124] Next, embodiments of the present disclosure will be described with reference to examples, but the present disclosure is not limited to these examples.

[0125] (Polymerization method) Polymers were prepared by the polymerization methods described in the following Synthesis Examples. The polymers obtained were evaluated based on the following criteria.

[0126] (THF extraction amount) In each Example, 9 g of tetrahydrofuran (THF) was added to 1 g of the polymer obtained, and the mixture was stirred using a stirrer at 25° C. After 24 hours, the solid content was filtered, the solution was dried, and the weight of the dried product was measured to calculate the amount of extraction.

[0127] (solvent soluble) In each Example, 1 g of the polymer obtained was added to 9 g of N-methyl-2-pyrrolidone (NMP) and stirred using a stirrer. After 24 hours, it was confirmed that there was no residue remaining, and the results were evaluated according to the following criteria. 〇: No remains ×: Remains were found

[0128] (Alkaline resistance) The polymer obtained in each example was compression molded to obtain a sheet-like molded product having a thickness of 2 mm. When the polymer had a melting point, compression molding was performed at a temperature 20 to 40°C higher than the melting point of the polymer. When the polymer did not have a melting point, compression molding was performed at 100°C. The molded product was immersed in 1% by volume ammonia water at 90°C for 72 hours, and then the weight was measured. The weight change rate before and after immersion was calculated according to the following formula and evaluated according to the following criteria. Weight change rate (%) = [(weight of molded product after immersion) - (weight of molded product before immersion)] / (weight of molded product before immersion) x 100 ○: Weight change rate was 10% or less ×: The weight change rate was more than 10%.

[0129] (composition analysis) The polymer composition was determined by solution NMR. Measurement equipment: Varian VNMRS400 Resonance frequency: 376.04 (Sfrq) Pulse width: 30°

[0130] (Weight average molecular weight (Mw)) Based on the results of measurement by GPC, the molecular weight was calculated using standard polystyrene as the standard. GPC device: TOSOH HLC-8320GPC Columns: 1 SuperAW-H, 3 SuperAWM-H Developing solvent: Dimethylformamide (DMF) Sample concentration: 0.05% by mass Measurement temperature: 40℃

[0131] (glass transition temperature) Using a differential scanning calorimeter X-DSC7000 (Hitachi High-Tech Science Corporation), a DSC curve was obtained by heating 10 mg of a sample at 20°C / min. The glass transition temperature was determined as the temperature indicating the intersection between the extension of the baseline before and after the second-order transition of the DSC curve and the tangent to the inflection point of the DSC curve.

[0132] (Melting Point) Using a differential scanning calorimeter X-DSC7000 (Hitachi High-Tech Science Corporation), a DSC curve was obtained by heating 10 mg of a sample at 10°C / min. The temperature at the peak of the obtained endothermic curve was identified as the melting point, and the heat of fusion was calculated from the magnitude of the melting peak (ΔH) of the endothermic curve.

[0133] Example 1 (Preparation of BAB block polymer (wherein A represents segment A and B represents segment B)) (Process 1) In a 6L stainless steel autoclave, add 4000ml of pure water, 0.8001g of CH2=CFCF2OCF(CF3)CF2OCF(CF3)COONH450% aqueous solution, and C5F 1124.021g of COONH450% aqueous solution was added and replaced with nitrogen, then slightly pressurized with VdF, and the temperature was adjusted to 80°C while stirring at 400 rpm. VdF was pressed in up to 1.64 MPa, and further a mixed monomer solution of VdF and 2,3,3,3-tetrafluoropropene (R1234yf) with a molar ratio of 77.2 / 22.8 was pressed in up to 2.001 MPa. 0.16g of ammonium persulfate dissolved in 4ml of pure water was pressed in with nitrogen to start polymerization. When the mixed monomer solution reached 24g, 1.009g of 1,4-diiodoperfluorobutane was added. When the pressure dropped to 1.98MPa, the mixed monomer solution was raised to 2.01MPa, and this was repeated until 1020g was charged, after which the gas in the autoclave was released to 0.05MPa, and heat treatment was performed for 3 hours. A 10 g sample of the dispersion in the autoclave was taken and dried to obtain a polymer with a molar ratio of VdF / R1234yf=77.6 / 22.4, a glass transition temperature of -12.5°C, and no heat of fusion.

[0134] (Process 2) After the heat treatment in step 1, the autoclave was kept at 80°C and pressurized to 2.003MPa with VdF, and 0.08g of ammonium persulfate dissolved in 4ml of pure water was pressed in with nitrogen to start polymerization. When the pressure dropped to 1.98MPa, it was increased to 2.01MPa with VdF, and this was repeated until 180g was charged, at which point the gas in the autoclave was released and cooled, and 5270g of dispersion was recovered. The solid content of the dispersion was 23.83wt%.

[0135] Aluminum sulfate was added to this dispersion to cause coagulation, and then it was dried to obtain 1250g of polymer. The composition of the obtained block polymer was VdF / R1234yf=82.0 / 18.0 in molar ratio, and the content of segment B calculated from the composition was 17.2wt%. The weight average molecular weight Mw was 1,266,000, the glass transition temperature was -12.9℃, the melting point was 160.3℃, and the heat of fusion was 8.2mJ / mg.

[0136] Example 2 (Preparation of BAB block polymer (wherein A represents segment A and B represents segment B)) The same procedure as in Example 1 was followed except that the amount of the mixed monomer charged in step 1 was changed from 1020 g to 900 g, and the amount of VdF charged in step 2 was changed from 180 g to 300 g, and 5236 g of a dispersion was recovered. The solid content of the dispersion was 24.10 wt%.

[0137] Aluminum sulfate was added to this dispersion to cause coagulation, and then the mixture was dried to obtain 1257g of polymer. The composition of the obtained block polymer was VdF / R1234yf=84.2 / 15.8 in molar ratio, and the content of segment B calculated from the composition was 28.1wt%. The weight average molecular weight Mw was 1,206,000, the glass transition temperature was -11.0℃, the melting point was 161.1℃, and the heat of fusion was 11.0mJ / mg.

[0138] Example 3 (Preparation of BAB block polymer (wherein A represents segment A and B represents segment B)) The same procedure as in Example 1 was followed except that the amount of the mixed monomer charged in step 1 was changed from 1020 g to 780 g, and the amount of VdF charged in step 2 was changed from 180 g to 420 g, and 5252 g of a dispersion was recovered. The solid content of the dispersion was 23.74 wt%.

[0139] Aluminum sulfate was added to this dispersion to cause coagulation, and then the mixture was dried to obtain 1250g of polymer. The composition of the obtained block polymer was VdF / R1234yf=85.9 / 14.1 in molar ratio, and the content of segment B calculated from the composition was 36.0wt%. The weight average molecular weight Mw was 1.614 million, the glass transition temperature was -11.2℃, the melting point was 161.4℃, and the heat of fusion was 17.1mJ / mg.

[0140] Example 4 (Preparation of ABA block polymer (wherein A represents segment A and B represents segment B)) (Process 1) In a 6L stainless steel autoclave, add 4000ml of pure water, 0.8003g of CH2=CFCF2OCF(CF3)CF2OCF(CF3)COONH450% aqueous solution, and C5F 11 24.014g of COONH450% aqueous solution was added and replaced with nitrogen, then VdF was slightly pressurized, and the temperature was adjusted to 80°C while stirring at 400 rpm, and VdF was pressed in until it reached 2.00 MPa. 0.16g of ammonium persulfate dissolved in 4ml of pure water was pressed in with nitrogen to start polymerization. When the pressure reached 24g of VdF, 1.009g of 1,4-diiodoperfluorobutane was added. When the pressure dropped to 1.98MPa, it was increased to 2.01MPa with VdF, and this was repeated until 300g was charged, after which the gas in the autoclave was released to 0.05MPa, and heat treatment was performed for 3 hours. 10g of the dispersion in the autoclave was sampled and dried to obtain a polymer. The glass transition temperature of the obtained polymer was not observed. The melting point was 161.1°C, and the heat of fusion was 44.8mJ / mg.

[0141] (Process 2) After the heat treatment in step 1, the autoclave was kept at 80°C, and the pressure was increased to 1.64MPa with VdF and 2.001MPa with a mixed monomer solution of VdF and R1234yf with a molar ratio of 77.5 / 22.5. Polymerization was started by injecting 0.08g of ammonium persulfate dissolved in 4ml of pure water with nitrogen. When the pressure dropped to 1.98MPa, the mixed monomer solution was increased to 2.01MPa, and this was repeated until 900g was charged. The gas in the autoclave was released and cooled, and 5271g of dispersion was recovered. The solid content of the dispersion was 23.80wt%.

[0142] Aluminum sulfate was added to this dispersion to cause coagulation, and then the mixture was dried to obtain 1248g of polymer. The composition of the resulting block polymer was VdF / R1234yf=82.7 / 17.3 in molar ratio, and the content of segment B calculated from the composition was 24.1wt%. The weight average molecular weight Mw was 1,426,000, the glass transition temperature was -10.4℃, the melting point was 160.8℃, and the heat of fusion was 10.8mJ / mg.

[0143] Comparative Example 1 (Preparation of BAB block polymer (wherein A represents segment A and B represents segment B)) (Process 1) In a 6L stainless steel autoclave, add 4000ml of pure water, 0.8001g of 450% aqueous solution of CH2=CFCF2OCF(CF3)CF2OCF(CF3)COONH, and C5F 11 24.021g of COONH450% aqueous solution was added and replaced with nitrogen, then slightly pressurized with hexafluoropropene (HFP), and the temperature was adjusted to 80°C while stirring at 400 rpm. HFP was injected up to 0.68 MPa, and a mixed monomer solution with a molar ratio of VdF and HFP of 78.3 / 21.7 was further injected up to 2.001 MPa. 0.16g of ammonium persulfate dissolved in 4ml of pure water was injected with nitrogen to start polymerization. When the mixed monomer solution reached 24g, 1.003g of 1,4-diiodoperfluorobutane was added. When the pressure dropped to 1.98MPa, the mixed monomer solution was increased to 2.01MPa, and this was repeated until 1020g was charged. The gas in the autoclave was released to 0.05MPa, and then heat treatment was performed for 3 hours. A 10 g sample of the dispersion in the autoclave was taken and dried to obtain a polymer having a molar ratio of VdF / HFP=78.6 / 21.4.

[0144] (Process 2) After the heat treatment in step 1, the autoclave was kept at 80°C and pressurized to 2.003MPa with VdF, and 0.08g of ammonium persulfate dissolved in 4ml of pure water was pressed in with nitrogen to start polymerization. When the pressure dropped to 1.98MPa, it was increased to 2.01MPa with VdF, and this was repeated until 180g was charged, at which point the gas in the autoclave was released and cooled, and 5275g of dispersion was recovered. The solid content of the dispersion was 23.81wt%.

[0145] Aluminum sulfate was added to this dispersion to cause coagulation, and then the mixture was dried to obtain 1245g of polymer. The composition of the obtained block polymer was VdF / HFP=82.5 / 17.5 in molar ratio, and the content of segment B calculated from the composition was 14.8wt%. The weight average molecular weight Mw was 1,150,000, the glass transition temperature was -18.7℃, the melting point was 160.1℃, and the heat of fusion was 8.0mJ / mg.

[0146] Comparative Example 2 According to the production method described in Example 12 of JP2013-216915A, a fluoroelastomer having a molar ratio of VdF and R1234yf of 78.6 / 21.4 was obtained.

[0147] For Examples 1 to 4 and Comparative Examples 1 and 2, the results of alkali resistance, solvent solubility, and THF extraction tests are summarized in Table 1.

[0148] [Table 1]

Claims

1. A polymer comprising a segment A and a segment B, Segment A is having a glass transition temperature of 25° C. or less; Contains 2,3,3,3-tetrafluoropropene units and fluorine-containing monomer units (excluding 2,3,3,3-tetrafluoropropene units and trifluoroethylene units); Segment B is Has a melting point of 50°C or higher polymer.

2. 2. The polymer according to claim 1, which contains a chain structure represented by general formula (1) or general formula (2). General formula (1): ABA General formula (2): B-A-B (In the formula, A represents segment A and B represents segment B.)

3. 3. The polymer according to claim 1, wherein the fluorine-containing monomer unit of segment A is a vinylidene fluoride unit.

4. 3. The polymer according to claim 1, wherein the content of 2,3,3,3-tetrafluoropropene units in segment A is 18 mol % or more based on all monomer units constituting segment A.

5. 3. The polymer according to claim 1, wherein segment B contains vinylidene fluoride units, and the content of the vinylidene fluoride units in segment B is 90 mol % or more based on all monomer units constituting segment B.

6. Segment B is Contains only vinylidene fluoride units, or Contains vinylidene fluoride units and at least one monomer unit selected from the group consisting of tetrafluoroethylene units, hexafluoropropylene units, 2,3,3,3-tetrafluoropropene units and (meth)acrylic acid units.

3. The polymer of claim 1 or 2.

7. 3. The polymer according to claim 1, wherein the mass ratio of segment A to segment B is from 40 / 60 to 95 / 5.

8. Contains a chain structure represented by general formula (1) or general formula (2), General formula (1): ABA General formula (2): B-A-B (In the formula, A represents segment A and B represents segment B.) Segment A is It has a glass transition temperature of −10° C. or less, containing 2,3,3,3-tetrafluoropropene units and vinylidene fluoride units, the content of the 2,3,3,3-tetrafluoropropene units in segment A being 18 to 30 mol % based on all monomer units constituting segment A, and the content of the vinylidene fluoride units in segment A being 70 to 82 mol % based on all monomer units constituting segment A; Segment B is It has a melting point of 140 to 200°C, Segment B contains vinylidene fluoride units, and the content of the vinylidene fluoride units in Segment B is 95 mol % or more based on all monomer units constituting Segment B; The mass ratio (A / B) of segment A to segment B in the polymer is 50 / 50 to 90 / 10; The weight average molecular weight of the polymer is 500,000 to 2,000,000.

3. The polymer of claim 1 or 2.

9. A polymer having a glass transition temperature and a melting point, containing 2,3,3,3-tetrafluoropropene units, and having a tetrahydrofuran extractable amount of 5 mass % or less at 25° C. (excluding polymers containing trifluoroethylene units).

10. The polymer of claim 9 further comprising vinylidene fluoride units.

11. 11. The polymer of claim 9 or 10 comprising two or more segments.

12. The glass transition temperature is −10° C. or lower, The melting point is 140 to 200°C, The polymer contains 2,3,3,3-tetrafluoropropene units and vinylidene fluoride units, the content of the 2,3,3,3-tetrafluoropropene units being 12 to 24 mol % based on all monomer units constituting the polymer, and the content of the vinylidene fluoride units being 76 to 88 mol % based on all monomer units constituting the polymer, The amount of tetrahydrofuran extractable at 25° C. is 2 to 4% by mass, The weight average molecular weight is 500,000 to 2,000,000.

11. The polymer of claim 9 or 10.

13. 11. A molded article comprising the polymer of claim 1, 2, 9 or 10.

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