Polymer and molded product

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 Art

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

[0003] Patent Document 2 discloses a chain composed of two or three 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 polymer chain segments) or one or two kinds (when the chain is composed of three polymer chain segments) of the polymer chain segments are elastomeric polymer chain segments having a molecular weight of 30,000 to 1,200,000, selected from (1) vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene (molar ratio 45 to 90:5 to 50:0 to 35) polymers and (2) perfluoro(alkyl vinyl ether) (alkyl group having 1 to 3 carbon atoms) / tetrafluoroethylene / vinylidene fluoride (molar ratio 15 to 75:0 to 85 (excluding 0):0 to 85) polymers. 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, wherein the weight ratio of the elastomeric polymer chain segment to the non-elastomeric polymer chain segment is 40 to 95:5 to 60, A fluorine-containing segmented polymer is described.

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

[0005] In Patent Document 4, a thermoplastic block copolymer having trifluoroethylene units and further units different from vinylidene fluoride; or only trifluoroethylene units and vinylidene fluoride units; or trifluoroethylene units, vinylidene fluoride units and further units, and having a xanthate or trithiocarbonate or a monoiodinated end group is described.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[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 Problems

[0008] According to the present disclosure, there is provided a polymer including segment A and segment B, wherein segment A has a glass transition temperature of 25°C or lower 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 higher. [Advantages 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. [Modes for Carrying Out the Invention

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

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

[0012] Conventionally, as a block polymer, for example, a polymer 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, is known. Patent Document 2 describes that a fluorine-containing segmented polymer composed of these segments has properties that can sufficiently withstand practical use as a thermoplastic rubber, and like the case of a fluorine-based thermoplastic resin, it can be formed by direct compression or other methods without vulcanization, and the formed product has elastomeric properties almost as desirable as those of vulcanized rubber.

[0013] However, there is no known polymer that exhibits excellent flexibility, can be formed by a molding method applicable to general thermoplastic resins, and is excellent in 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 lower, and further, 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 has a melting point of 50°C As a result, it has been found that the resulting polymer exhibits excellent flexibility, can be formed by a molding method applicable to general thermoplastic resins, and exhibits excellent alkali resistance. The first polymer of the present disclosure has been completed based on this finding.

[0015] The first polymer includes segment A and segment B. Hereinafter, the first polymer will be described in detail. The first polymer may include other segments having different structures from segment A and segment B as long as it includes segment A and segment 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, still more preferably -10°C or lower, and the lower limit is not limited but may be -40°C or higher. Since the first polymer contains Segment A having a glass transition temperature, it is excellent in flexibility.

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

[0018] The heat of fusion of Segment A is preferably less than 5 J / g, more preferably less than 3 J / g, still more preferably less than 2 J / g, since it can further improve flexibility.

[0019] The heat of fusion can be calculated from the magnitude of the melting peak (ΔH) of the endothermic curve obtained by using a differential scanning calorimetry (DSC) apparatus and heating the sample from 30°C to 220°C at a rate of 10°C / min. When the polymer does not show a distinct 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 show 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, so it is excellent in flexibility and also excellent in alkali resistance. Further, since segment A contains 2,3,3,3-tetrafluoropropene units, the solvent solubility of the polymer in solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide can be improved.

[0022] The fluorine-containing monomers that can constitute segment A are monomers other than 2,3,3,3-tetrafluoropropene and trifluoroethylene, and are not particularly limited as long as they are monomers containing fluorine atoms. Examples thereof include vinylidene fluoride [VdF], tetrafluoroethylene [TFE], hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), chlorotrifluoroethylene, hexafluoroisobutene, vinyl fluoride, and the like.

[0023] The fluorine-containing monomers that can constitute segment A are 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 still more preferably VdF. By segment A containing VdF units, the glass transition temperature of segment A can be easily adjusted within a desired range, and the flexibility can be further improved. Further, by segment A containing VdF units, 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, still more preferably 12 mol% or more, yet more preferably 18 mol% or more, particularly preferably 20 mol% or more, more preferably 78 mol% or less, still more preferably 50 mol% or less, yet more preferably 40 mol% or less, and particularly preferably 30 mol% or less, based on all the monomer units constituting segment A.

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

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

[0028] Segment A may further contain units based on monomers having reactive groups such as cyano groups, carboxyl groups, alkoxycarbonyl groups, I, Br, -CH2OH, and carbon-carbon double bonds. The content of the units based on the monomers having reactive groups is preferably 0 to 50 mol%, more preferably 0 to 10 mol%, still more preferably 0 to 1 mol%, and may be 0 mol% with respect to all the monomer units constituting Segment A.

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

[0030] In one embodiment, Segment A can be formed from 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), 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), 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%, still more preferably 0 to 1 mol%, yet still more preferably 0 to 0.1 mol%, and particularly preferably 0 mol% with respect to all 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 - described 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%, still more preferably 0 to 1 mol%, yet still more preferably 0 to 0.1 mol%, and particularly preferably 0 mol% with respect to all 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 - described 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 still more preferably 200°C or lower. Since the first polymer includes segment B having a melting point in addition to segment A having a glass transition temperature, it has excellent flexibility and can be further molded by a molding method applicable to general thermoplastic resins. In the present disclosure, being able to easily mold a polymer means that it can be molded by a molding method applicable to general thermoplastic resins such as an extrusion molding method, an injection molding method, and a compression molding method.

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

[0037] Generally, the melting point of segment B is the same as that 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 grasped.

[0038] The heat of fusion of segment B is preferably 5 J / g or more, more preferably 10 J / g or more, still more preferably 30 J / g or more, yet still more preferably 35 J / g or more, preferably 90 J / g or less, more preferably 60 J / g or less, and still 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 the sample from 30°C to 220°C at a rate of 10°C / min using a differential scanning calorimetry (DSC) apparatus.

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

[0041] 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, vinyl fluoride, and the like.

[0042] As the fluorine-containing monomer, 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 preferable, at least one selected from the group consisting of VdF and TFE is more preferable, and VdF is even more preferable.

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

[0044] In addition to the VdF unit, segment B may contain other monomer units other than VdF. The other monomer may be either a fluorine-containing monomer or a non-fluorine-containing monomer, and a fluorine-containing monomer (excluding trifluoroethylene) or a non-fluorine-containing monomer is preferable.

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

[0046] Examples of the non-fluorine-containing monomer that can constitute segment B together with VdF include ethylene, propylene, and the like.

[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 sulfuric acid group, a phosphoric acid group, an amino group, an amide group, and an alkoxy group.

[0048] Examples of the monomer 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, vinylacetic 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 methylidenemalonate; 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 dicarboxylic acid esters such as acryloyloxyethyl succinic acid, methacryloyloxyethyl succinic acid, acryloyloxyethyl phthalic acid, acryloyloxypropyl succinic acid, and methacryloyloxyethyl phthalic acid; monoesters of unsaturated dibasic acids such as monomethyl maleate, monoethyl maleate, monomethyl citraconate, and monoethyl citraconate; and the like.

[0049] As another monomer that can form 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 preferable.

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

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

[0052] In one embodiment, segment B can be formed of 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 the 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 another segment C having a different structure from segments A and B as long as it contains segments A and B.

[0055] Examples of the first polymer include block polymers containing a chain structure represented by any of the following general formulas. General formula: A-B General formula: A-B-A General formula: B-A-B General formula: A-B-C General formula: B-A-C (In the formula, A represents segment A, B represents segment B, and C represents segment C).

[0056] Since the first polymer can further improve the alkali resistance and is easy to manufacture, it preferably contains a chain structure represented by general formula (1) or general formula (2). General formula (1): A - B - A General formula (2): B - A - B (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, still more preferably 60 / 40 or more, and even more preferably 90 / 10 or less, from the viewpoint of the 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, still more preferably 70,000 or more, particularly preferably 140,000 or more, more preferably 1,400,000 or less, still more preferably 1,200,000 or less, and particularly preferably 1,100,000 or less. The above 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, still more preferably 100,000 or more, even more preferably 200,000 or more, particularly preferably 500,000 or more, more preferably 2,400,000 or less, still more preferably 2,200,000 or less, and particularly preferably 2,000,000 or less. The above 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 is, for example, (1) In the presence of a bromine compound or an iodine compound as a chain transfer agent, a monomer capable of forming segment B is polymerized to prepare a polymer forming segment B, and in the presence of the polymer forming segment B, a monomer capable of forming segment A is polymerized to prepare a polymer forming segment A. (2) In the presence of a bromine compound or an iodine compound as a chain transfer agent, a monomer capable of forming segment A is polymerized to prepare a polymer forming segment A, and in the presence of the polymer forming segment A, a monomer capable of forming segment B is polymerized to prepare a polymer forming segment B. It can be produced by production methods such as these.

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

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

[0063] In method (1) and method (2), a bromine compound or an iodine compound is used as the 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 functions as a bonding site for the other segment.

[0064] Examples of the polymerization method carried out using a bromine compound or an iodine compound include, for example, a method of carrying out emulsion polymerization in an aqueous medium while applying 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 (wherein x and y are each an integer from 0 to 2 and satisfy 1 ≦ x + y ≦ 2, and 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). Examples of the compound include those represented by the following formula:

[0065] Examples of the iodine compound include 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3-diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5-diiodo-2,4-dichloroperfluoropentane, 1,6-diiodoperfluorhexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2-diiodoethane, 1,3-diiodo-n-propane, CF2Br2, BrCF2CF2Br, CF3CFBrCF2Br, CFClBr2, BrCF2CFClBr, 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 substitution products of benzene, diiodomonobromo substitution products, and (2-iodoethyl) and (2-bromoethyl) substitution products. These compounds may be used alone or in combination with each other.

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

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

[0068] Examples of the polymerization initiator include 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 peroxydicarbonates such as diisopropyl peroxydicarbonate and di-sec-butyl peroxydicarbonate, peroxy esters such as t-butyl peroxyisobutyrate and t-butyl peroxypivalate, dialkyl peroxides such as di-t-butyl peroxide, etc. Also, di(ω-hydroxy-dodecafluorooctanoyl) peroxide, di(ω-hydroxy-tetradecafluorononanoyl) peroxide, di(ω-hydroxy-hexadecafluorodecanoyl) peroxide, di(perfluorobutyryl) peroxide, di(perfluorovaleryl) peroxide, di(perfluorohexanoyl) peroxide, di(perfluoroheptanoyl) peroxide, di(perfluorooctanoyl) peroxide, di(perfluorononanoyl) peroxide, di(ω-chloro-hexafluorobutyryl) peroxide, di(ω-chloro-decafluorohexanoyl) peroxide, di(ω-chloro-tetradecafluorononanoyl) peroxide, ω-hydroxy-dodecafluorooctanoyl-ω-hydroxy-hexadecafluorodecanoyl-peroxide, ω-chloro-hexafluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydroxy-dodecafluorooctanoyl-perfluorobutyryl-peroxide, di(dichloropentafluorobutanoyl) peroxide, di(trichlorooctafluorononanoyl) peroxide, di(tetrachloroundecafluorooctanoyl) peroxide, di(pentachlorotetradecafluorodecanoyl) peroxide, di(undecachlorodotriacontapentafluorodocosanoyl) peroxide, etc., di[perfluoro(or fluorochloro)acyl] peroxides, etc., are mentioned as typical ones.

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

[0071] The addition amount of the polymerization initiator is not particularly limited, but it may be added all at once, sequentially, or continuously at the initial stage of polymerization in an amount such that the polymerization rate does not significantly decrease (for example, several ppm relative to the water concentration) or more. The upper limit is within the range where the heat of polymerization reaction can be removed from the equipment surface.

[0072] As the surfactant, nonionic surfactants, anionic surfactants, cationic surfactants, etc. can be used. The addition amount (relative to the solvent) is preferably 10 mass ppm to 20 mass%, more preferably 10 mass ppm to 10 mass%, still more preferably 10 to 5000 mass ppm, and particularly preferably 50 to 5000 mass ppm.

[0073] Also, a polymerizable emulsifier may be used as the surfactant. The polymerizable emulsifier is not particularly limited as long as it is a compound having one or more unsaturated bonds and hydrophilic groups. For example, CH2 = CFCF2OCF(CF3)CF2OCF(CF3)COONH4, CH2 = CFCF2CF(CF3)OCF2CF2COONH4, CF2 = CFOCF2CF(CF3)OCF(CF3)COONH4 may be mentioned. The addition amount (relative to the solvent) is preferably 10 to 5000 mass ppm, more preferably 50 to 5000 mass ppm.

[0074] The solvent preferably has no chain transferability. Examples of the solvent include water, a mixture of water and a water-soluble organic solvent, or a mixture of water and a water-insoluble organic solvent.

[0075] In the polymerization of monomers, the polymerization temperature, polymerization pressure, and polymerization time 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 using an oil-soluble radical polymerization initiator as the polymerization initiator, the polymerization temperature is preferably 30 to 95 °C. When using a water-soluble radical polymerization initiator 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 an emulsion polymerization method, an aqueous dispersion containing the polymer can be obtained. In the above production method, the polymer in the aqueous dispersion can be coagulated, washed with water, dehydrated, and dried to obtain a polymer powder. Coagulation can be carried out by adding an inorganic salt or inorganic acid such as aluminum sulfate to the dispersion, applying a mechanical shearing force to the dispersion, or freezing the dispersion.

[0077] In addition, 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, contains 2,3,3,3-tetrafluoropropene units, and has a tetrahydrofuran extraction amount at 25 °C of 5% by mass or less. The second polymer does not include a polymer containing trifluoroethylene units.

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

[0080] Select the polymer configuration so that the polymer has a glass transition temperature and a melting point, Introduce 2,3,3,3-tetrafluoropropene units into the polymer, Select the polymer structure so that the amount of tetrahydrofuran extracted from the polymer at 25 °C is 5% by mass or less. By doing so, it has been found that the obtained polymer exhibits excellent flexibility, can be molded by a molding method applicable 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, still more preferably -5 °C or lower, yet still more preferably -10 °C or lower. The lower limit is not limited, but it may be -40 °C or higher. Since the second polymer has a glass transition temperature, it is excellent in flexibility.

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

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

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

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

[0086] The tetrahydrofuran extraction amount can be measured by a method in which the polymer is immersed in tetrahydrofuran at 25°C and the filtered solution portion is dried to dryness.

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

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

[0089] Examples of the fluorine-containing monomer that can constitute the second polymer include monomers other than 2,3,3,3-tetrafluoropropene and trifluoroethylene, and any monomer containing a fluorine atom is not particularly limited, but vinylidene fluoride [VdF], tetrafluoroethylene [TFE], hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), chlorotrifluoroethylene, hexafluoroisobutene, vinyl fluoride, etc. can be mentioned.

[0090] As the fluorine-containing monomer that can constitute the second polymer, 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 preferable, at least one selected from the group consisting of VdF and TFE is more preferable, and VdF is even more preferable.

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

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

[0093] When the second polymer contains VdF units as fluorine-containing monomer units, the second polymer exhibits excellent flexibility, can be molded by a molding method applicable to general thermoplastic resins, shows even more excellent alkali resistance, and moreover, shows even more excellent solvent 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, still more preferably 91 mol% or less, yet 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, yet still more preferably 68 mol% or more, and particularly preferably 76 mol% or more, based on all the monomer units constituting the second polymer, since the solvent solubility is further improved.

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

[0096] The second polymer may further contain units based on monomers having reactive groups such as a cyano group, a carboxyl group, an alkoxycarbonyl group, I, Br, -CH2OH, and a carbon-carbon double bond. The content of the units based on the monomers having reactive groups is preferably 0 to 10 mol%, more preferably 0 to 2 mol%, still more preferably 0 to 1 mol%, and may be 0 mol%, based on all the monomer units constituting the second polymer.

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

[0098] Examples of the monomer 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, vinylacetic 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 methylidenemalonate; 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 dicarboxylic acid esters such as acryloyloxyethyl succinic acid, methacryloyloxyethyl succinic acid, acryloyloxyethyl phthalic acid, acryloyloxypropyl succinic acid, and methacryloyloxyethyl phthalic acid; monoesters of unsaturated dibasic acids such as monomethyl maleate, monoethyl maleate, monomethyl citraconate, and monoethyl citraconate; and the like.

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

[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%, still more preferably 0 to 1 mol%, yet still more preferably 0 to 0.1 mol%, and particularly preferably 0 mol%, based on all 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-specified 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%, still more preferably 0 to 1 mol%, yet still more preferably 0 to 0.1 mol%, and particularly preferably 0 mol%, based on all 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-specified 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, still more preferably 70,000 or more, particularly preferably 140,000 or more, more preferably 1,400,000 or less, still more preferably 1,200,000 or less, and particularly preferably 1,100,000 or less. The above number average molecular weight can be measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent.

[0103] The weight average molecular weight (polystyrene conversion) of the second polymer is preferably from 50,000 to 3,000,000, more preferably 80,000 or more, still more preferably 100,000 or more, yet still more preferably 200,000 or more, particularly preferably 500,000 or more, more preferably 2,400,000 or less, still more preferably 2,200,000 or less, and particularly preferably 2,000,000 or less. The above 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, still more preferably 5 J / g or more, yet still more preferably 8 J / g or more, preferably 40 J / g or less, more preferably 30 J / g or less, and still more preferably 20 J / g or less.

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

[0106] When the second polymer contains two or more segments, the constitution of each segment can be the same as that 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 constitution as the first polymer. Also, the first polymer can have the same constitution as the second polymer.

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

[0108] A 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 polymers of the present disclosure") with other components. Examples of other components include fillers, plasticizers, processing aids, release agents, pigments, flame retardants, lubricants, light stabilizers, weather stabilizers, conductive agents, antistatic agents, ultraviolet absorbers, antioxidants, foaming agents, fragrances, oils, softeners, dehydrofluorinating agents, and the like.

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

[0110] A molded article can also be obtained by molding the polymer of the present disclosure or the above composition.

[0111] The polymer of the present disclosure or the above composition can be molded by a molding method applicable to general thermoplastic resins. Examples of molding methods include, for example, injection molding, extrusion molding, compression molding, blow molding, transfer molding, rotational molding, rotomolding, and the like.

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

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

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

[0115] Since the molded article containing the polymer of the present disclosure is excellent in flexibility and alkali resistance, it can be used for various applications.

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

[0117] The molded article 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, barrel seals, etc.

[0118] In particular, since the molded article containing the polymer of the present disclosure is excellent in flexibility and alkali resistance, it can be suitably used for various members used in chemical liquid supply facilities and food equipment for semiconductor manufacturing, such as pipes, tubes, joints, valves, tanks, containers, chemical liquid bags, pumps, filters, etc.

[0119] It is also suitable to use the molded article containing the polymer of the present disclosure as a molded article that comes into contact with the human body.

[0120] The molded article that comes into contact with the human body does not necessarily need to be in constant contact like a watch band, and it may be one that comes into contact only during use like a smartphone case. Also, it is not necessary for the entire surface of the molded article to come into contact with the human body, and a part may be sufficient. Specific applications of such molded articles include the following.

[0121] (1) Interior parts of automobiles, motorcycles, ships, airplanes, bicycles, etc. Handles, armrests, shift levers, seat covers, etc. (2) Wearables Smartwatches, smart bands, smart glasses, VR (Virtual Reality) devices, body-attached types, others (clothes-attached types, ring types), etc. (3) Eyewear parts Nose pads, vines, etc. (4) Health goods Magnetic necklaces, magnetic bracelets, magnetic band-aid types such as Pip Electro Band (registered trademark), pelvic belts, supporters, healing dolls, etc. (5) Sports equipment Mats, shoes, underwater masks, snorkels, diving equipment, fishing equipment, golf club grips, etc. (6) Earphone parts, headphone parts Cables, ear hooks, earpieces, ear pads, etc. (7) Electronic device covers Smartphone covers, tablet covers, keyboards (covers), etc. (8) Kitchen utensils Spatulas, frying pans, bowls, steamers, cookie baking molds, bento cups, rubber aprons for infants and nursing care, baby bottles, pacifiers (containers, sucking mouths), water bottles, mugs, handles of pots and kettles, etc. (9) Pet supplies Toilet trays, food dishes, collars, etc. (10) Office supplies Pen grips, mice, mouse pads, etc. (11) Ornaments Boots, long boots, shoe insoles, hats, hair bands, raincoats, grips of umbrellas and walking sticks, etc. (12) Others Buttons, wheelchair wheel socks, bags, lighters, hearing aids, rubber accessories, rubber accessories for non-magnetic fashion uses, robot exteriors, robot (flexible) cables, public bath 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 segment A and segment B, where segment A has a glass transition temperature of 25°C or lower, 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 higher a polymer is provided. <2> According to a second aspect of the present disclosure, a polymer according to the first aspect containing a chain structure represented by general formula (1) or general formula (2) is provided. General formula (1): A - B - A General formula (2): B - A - B (In the formula, A represents segment A and B represents segment B.) <3> According to a third aspect of the present disclosure, a polymer according to the first or second aspect, wherein the fluorine - containing monomer unit of segment A is a vinylidene fluoride unit, is provided. <4> According to a fourth aspect of the present disclosure, a polymer according to any one of the first to third aspects, 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, is provided. <5> According to a fifth aspect of the present disclosure, a polymer according to any one of the first to fourth aspects, wherein segment B contains vinylidene fluoride units and the content of vinylidene fluoride units in segment B is 90 mol% or more based on all monomer units constituting segment B, is provided. <6> According to a sixth aspect of the present disclosure, segment B contains only vinylidene fluoride units, or Containing a vinylidene fluoride unit and at least one monomer unit selected from the group consisting of a tetrafluoroethylene unit, a hexafluoropropylene unit, a 2,3,3,3-tetrafluoropropene unit, and a (meth)acrylic acid unit A polymer according to any one of the first to fifth aspects is provided. <7> According to a seventh aspect of the present disclosure, A polymer according to any one of the first to sixth aspects, in which the mass ratio of segment A to segment B is from 40 / 60 to 95 / 5, is provided. <8> According to an eighth aspect of the present disclosure, Containing a chain structure represented by general formula (1) or general formula (2), General formula (1): A - B - A General formula (2): B - A - B (In the formula, A represents segment A and B represents segment B.) Segment A is having a glass transition temperature of -10°C or lower, containing a 2,3,3,3-tetrafluoropropene unit and a vinylidene fluoride unit, the content of the 2,3,3,3-tetrafluoropropene unit in segment A being 18 to 30 mol% based on all the monomer units constituting segment A, and the content of the vinylidene fluoride unit in segment A being 70 to 82 mol% based on all the monomer units constituting segment A, Segment B is having a melting point of 140 to 200°C, containing a vinylidene fluoride unit, the content of the vinylidene fluoride unit in segment B being 95 mol% or more based on all the monomer units constituting segment B, the mass ratio (A / B) of segment A to segment B in the polymer being from 50 / 50 to 90 / 10, the weight average molecular weight of the polymer being from 500,000 to 2,000,000 A polymer according to any one of the first to seventh aspects is provided. <9> According to a ninth aspect of the present disclosure, A polymer is provided that has a glass transition temperature and a melting point, contains 2,3,3,3-tetrafluoropropene units, and has a tetrahydrofuran extraction amount at 25 °C of 5% by mass or less (however, excluding polymers containing trifluoroethylene units). <10> According to a tenth aspect of the present disclosure, Furthermore, a polymer according to the ninth aspect containing vinylidene fluoride units is provided. <11> According to an eleventh aspect of the present disclosure, A polymer according to the ninth or tenth aspect containing two or more segments is provided. <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, It contains 2,3,3,3-tetrafluoropropene units and vinylidene fluoride units, the content of 2,3,3,3-tetrafluoropropene units is 12 to 24 mol% based on all monomer units constituting the polymer, and the content of vinylidene fluoride units is 76 to 88 mol% based on all monomer units constituting the polymer, The tetrahydrofuran extraction amount at 25 °C is 2 to 4% by mass, The weight average molecular weight is 500,000 to 2,000,000 A polymer according to any of the ninth to eleventh aspects is provided. <13> According to a thirteenth aspect of the present disclosure, A molded article containing a polymer according to any of the first to twelfth aspects is provided.

Examples

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

[0125] (Polymerization method) Polymers were polymerized by a polymerization method according to each of the following synthesis examples. The obtained polymers were evaluated based on the following evaluation criteria.

[0126] (THF extraction amount) For 1 g of the polymer obtained in each example, 9 g of tetrahydrofuran (THF) was added, and the mixture was stirred at 25 °C using a stirrer. After 24 hours, the solid content was filtered, the solution was dried, and the extraction amount was calculated by measuring the weight of the dried product.

[0127] (Solvent solubility) To 1 g of the polymer obtained in each example, 9 g of N-methyl-2-pyrrolidone (NMP) was added and stirred using a stirrer. After 24 hours, it was confirmed that there was no residue, and evaluation was carried out according to the following criteria. 〇: No residue ×: There was a residue

[0128] (Alkali resistance) By compression molding the polymer obtained in each example, a sheet-shaped molded product having a thickness of 2 mm was obtained. When the polymer had a melting point, compression molding was carried out at a temperature 20 to 40 °C higher than the melting point of the polymer. When the polymer had no melting point, compression molding was carried out at 100 °C. The molded product was immersed in 1% by volume aqueous ammonia solution 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 the molded product after immersion) - (weight of the molded product before immersion)] / (weight of the molded product before immersion) × 100 〇: The weight change rate was 10% or less ×: The weight change rate exceeded 10%

[0129] (Composition analysis) The polymer composition was measured by solution NMR method. Measuring device: VNMRS400 manufactured by Varian Resonance frequency: 376.04 (Sfrq) Pulse width: 30°

[0130] (Weight average molecular weight (Mw)) Based on the results measured by GPC method, the molecular weight was calculated based on standard polystyrene. GPC device: TOSOH HLC-8320GPC Column: 1 SuperAW-H, 3 SuperAWM-H Developing solvent: Dimethylformamide [DMF] Sample concentration: 0.05 mass% Measurement temperature: 40 °C

[0131] (Glass transition temperature) Using a differential scanning calorimeter X-DSC7000 (manufactured by Hitachi High-Technologies Corporation), a DSC curve was obtained by heating 10 mg of the sample at 20 °C / min. The temperature indicated by the intersection of the extension of the baseline before and after the second transition of the DSC curve and the tangent line at the inflection point of the DSC curve was defined as the glass transition temperature.

[0132] (Melting point) Using a differential scanning calorimeter X-DSC7000 (manufactured by Hitachi High-Technologies Corporation), a DSC curve was obtained by heating 10 mg of the sample at 10 °C / min. The temperature corresponding to the peak of the obtained endothermic curve was specified 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 (Production of B-A-B block polymer (wherein A represents segment A and B represents segment B.)) (Step 1) In a 6 L stainless steel autoclave, 4000 ml of pure water, 0.8001 g of a 50% aqueous solution of CH2=CFCF2OCF(CF3)CF2OCF(CF3)COONH4, C5F 1124.021 g of 50% aqueous ammonium carboxylate was placed, and the system was purged with nitrogen. While maintaining a slightly increased pressure with VdF and stirring at 400 rpm, the temperature was adjusted to 80 °C. VdF was then pressured in up to 1.64 MPa, and further a mixed liquid monomer with a molar ratio of VdF to 2,3,3,3-tetrafluoropropene (R1234yf) of 77.2 / 22.8 was pressured in up to 2.001 MPa. A solution prepared by dissolving 0.16 g of ammonium persulfate in 4 ml of pure water was pressured in with nitrogen to initiate polymerization. When 24 g of the mixed liquid monomer was reached, 1.009 g of 1,4-diiodoperfluorobutane was added. When the pressure dropped to 1.98 MPa, the pressure was increased to 2.01 MPa with the mixed liquid monomer, and this was repeated. When 1020 g was charged, after releasing the gas in the autoclave to 0.05 MPa, heat treatment was performed for 3 hours. 10 g of the dispersion in the autoclave was sampled and dried, and the composition of the resulting polymer was VdF / R1234yf = 77.6 / 22.4 in molar ratio, the glass transition temperature was -12.5 °C, and there was no heat of fusion.

[0134] (Step 2) While maintaining the autoclave at 80 °C after the heat treatment in Step 1, VdF was pressured in up to 2.003 MPa, and a solution prepared by dissolving 0.08 g of ammonium persulfate in 4 ml of pure water was pressured in with nitrogen to initiate polymerization. When the pressure dropped to 1.98 MPa, the pressure was increased to 2.01 MPa with VdF, and this was repeated. When 180 g was charged, the gas in the autoclave was released and cooled, and 5270 g of the dispersion was recovered. The solid content of the dispersion was 23.83 wt%.

[0135] Aluminum sulfate was added to this dispersion for coagulation, and 1250 g of the polymer was obtained by drying. The composition of the resulting block polymer was VdF / R1234yf = 82.0 / 18.0 in molar ratio, and the content ratio of segment B determined from the composition was 17.2 wt%. The weight average molecular weight Mw was 1.266 million, the glass transition temperature was -12.9 °C, the melting point was 160.3 °C, and the heat of fusion was 8.2 mJ / mg.

[0136] Example 2 (Production of B-A-B block polymer (wherein A represents segment A and B represents segment B.)) The procedure was the same as in Example 1 except that the monomer charge in the mixed solution in Step 1 was changed from 1020 g to 900 g and the VdF charge in Step 2 was changed from 180 g to 300 g. 5236 g of the dispersion was recovered. The solid content of the dispersion was 24.10 wt%.

[0137] Aluminum sulfate was added to this dispersion for coagulation, and after drying, 1257 g of the polymer was obtained. The composition of the obtained block polymer was VdF / R1234yf = 84.2 / 15.8 in molar ratio, and the content ratio of segment B determined from the composition was 28.1 wt%. The weight-average molecular weight Mw was 1.206 million, the glass transition temperature was -11.0 °C, the melting point was 161.1 °C, and the heat of fusion was 11.0 mJ / mg.

[0138] Example 3 (Production of B-A-B block polymer (wherein A represents segment A and B represents segment B.)) The procedure was the same as in Example 1 except that the monomer charge in the mixed solution in Step 1 was changed from 1020 g to 780 g and the VdF charge in Step 2 was changed from 180 g to 420 g. 5252 g of the dispersion was recovered. The solid content of the dispersion was 23.74 wt%.

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

[0140] Example 4 (Production of A-B-A block polymer (wherein A represents segment A and B represents segment B.)) (Step 1) Into a 6 L stainless steel autoclave, 4000 ml of pure water, 0.8003 g of a 50% aqueous solution of CH2=CFCF2OCF(CF3)CF2OCF(CF3)COONH4, and 11 24.014 g of a 50% aqueous solution of C5F 11 COONH4 were added, and the autoclave was purged with nitrogen. Slightly pressurized with VdF, the temperature was adjusted to 80 °C while stirring at 400 rpm, and VdF was injected until the pressure reached 2.00 MPa. A solution prepared by dissolving 0.16 g of ammonium persulfate in 4 ml of pure water was injected with nitrogen to start the polymerization. When 24 g of VdF was reached, 1.009 g of 1,4-diiodoperfluorobutane was added. When the pressure dropped to 1.98 MPa, the pressure was increased to 2.01 MPa with VdF, and this was repeated. When 300 g was charged, the gas in the autoclave was released to 0.05 MPa, and then heat treatment was carried out for 3 hours. 10 g of the dispersion in the autoclave was sampled and dried to obtain a polymer. The glass transition temperature of the obtained polymer was not visible. The melting point was 161.1 °C, and the heat of fusion was 44.8 mJ / mg.

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

[0142] Aluminum sulfate was added to this dispersion for coagulation and drying to obtain 1248 g of a polymer. The composition of the obtained block polymer was VdF / R1234yf = 82.7 / 17.3 in molar ratio, and the content ratio of segment B determined from the composition was 24.1 wt%. The weight average molecular weight Mw was 1.426 million, the glass transition temperature was -10.4 °C, the melting point was 160.8 °C, and the heat of fusion was 10.8 mJ / mg.

[0143] Comparative Example 1 (Production of B - A - B block polymer (wherein A represents segment A and B represents segment B.)) (Step 1) Into a 6L stainless steel autoclave, add 4000 ml of pure water, 0.8001 g of a 50% aqueous solution of CH2 = CFCF2OCF(CF3)CF2OCF(CF3)COONH4, and 24.021 g of a 50% aqueous solution of C5F 11 COONH4. Replace the air with nitrogen, slightly pressurize with hexafluoropropene (HFP), adjust the temperature to 80 °C while stirring at 400 rpm, press in HFP until 0.68 MPa, and then press in a mixed monomer solution with a molar ratio of VdF to HFP of 78.3 / 21.7 until 2.001 MPa. A solution prepared by dissolving 0.16 g of ammonium persulfate in 4 ml of pure water was pressed in with nitrogen to start the polymerization. When 24 g of the mixed monomer was reached, 1.003 g of 1,4 - diiodoperfluorobutane was added. When the pressure dropped to 1.98 MPa, the pressure was increased to 2.01 MPa with the mixed monomer, and this was repeated. After charging 1020 g, the gas in the autoclave was released to 0.05 MPa, and then heat treatment was carried out for 3 hours. A 10 g sample of the dispersion in the autoclave was sampled and dried, and the composition of the polymer obtained was VdF / HFP = 78.6 / 21.4 in molar ratio.

[0144] (Step 2) After the heat treatment in Step 1, while maintaining the autoclave at 80 °C, VdF was pressed in until 2.003 MPa, and a solution prepared by dissolving 0.08 g of ammonium persulfate in 4 ml of pure water was pressed in with nitrogen to start the polymerization. When the pressure dropped to 1.98 MPa, the pressure was increased to 2.01 MPa with VdF, and this was repeated. After charging 180 g, the gas in the autoclave was released and cooled, and 5275 g of the dispersion was recovered. The solid content of the dispersion was 23.81 wt%.

[0145] Aluminum sulfate was added to this dispersion to cause coagulation, and the mixture was dried to obtain 1245 g of a polymer. The composition of the obtained block polymer was VdF / HFP = 82.5 / 17.5 in terms of molar ratio, and the content ratio of segment B determined from the composition was 14.8 wt%. The weight average molecular weight Mw was 1.15 million, the glass transition temperature was -18.7°C, the melting point was 160.1°C, and the heat of fusion was 8.0 mJ / mg.

[0146] Comparative Example 2 According to the production method described in Example 12 of JP-A-2013-216915, a fluoroelastomer in which VdF and R1234yf were in a molar ratio of 78.6 / 21.4 was obtained.

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

[0148]

Table 1

Claims

1. A polymer comprising segment A and segment B, containing a chain structure represented by General Formula (1) or General Formula (2), General Formula (1): A - B - A General Formula (2): B - A - B (In the formula, A represents segment A and B represents segment B.) Segment A has a glass transition temperature of 25°C or lower, 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 (excluding 2,3,3,3 - tetrafluoropropene units and trifluoroethylene units) in segment A is 0 to 2 mol% based on all monomer units constituting segment A, Segment B has a melting point of 50°C or higher, contains vinylidene fluoride units, and the content of vinylidene fluoride units in segment B is 90 mol% or more based on all monomer units constituting segment B Polymer.

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

3. The polymer according to Claim 1 or 2, 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.

4. Segment B 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 The polymer according to Claim 1 or 2.

5. The polymer according to Claim 1 or 2, wherein the mass ratio of segment A to segment B is 40 / 60 to 95 / 5.

6. Segment A has a glass transition temperature of - 10°C or lower, Containing 2,3,3,3 - tetrafluoropropene units and vinylidene fluoride units, the content of 2,3,3,3 - tetrafluoropropene units in segment A is 18 to 30 mol% based on all monomer units constituting segment A, and the content of vinylidene fluoride units in segment A is 70 to 82 mol% based on all monomer units constituting segment A, Segment B is having a melting point of 140 to 200 °C, containing vinylidene fluoride units, and the content of 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 The polymer according to claim 1 or 2.

7. A molded article containing the polymer according to claim 1 or 2.

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