Vinylidene fluoride resin composition, molded article and laminate

Abstract

The present invention addresses the problem of providing: a vinylidene fluoride-based resin composition having excellent heat resistance, wear resistance and solvent resistance; a molded article; and a multilayer body. The present invention provides a vinylidene fluoride-based resin composition comprising 60 to 95% by mass of a vinylidene fluoride-based resin (A) and 5 to 40% by mass of a methacrylic copolymer (B), in which the methacrylic copolymer (B) comprises 50 to 93% by mass of a methyl methacrylate unit, 7 to 30% by mass of an α-methylstyrene unit, and 0 to 20% by mass of another monomer unit that is copolymerizable with the methyl methacrylate unit and the α-methylstyrene unit.

Description

[Technical Field]

[0001] This application claims priority to Japanese Patent Application No. 2021-093731, filed on June 3, 2021, the entire disclosure of which is incorporated herein by reference. The present invention relates to a vinylidene fluoride resin composition, a molded article, and a laminate. [Background technology]

[0002] Fluoropolymers have excellent properties such as weather resistance, flame retardancy, heat resistance, stain resistance, smoothness, and chemical resistance, making them suitable as materials for items exposed to outdoor environments. Among fluoropolymers, vinylidene fluoride resins, particularly polyvinylidene fluoride (hereinafter referred to as "PVDF"), have a large difference between their melting point and decomposition temperature, making them suitable for molding and processing. However, PVDF crystals tend to grow to sizes larger than the wavelength of visible light, scattering part of the visible light and reducing transparency. Therefore, films made from PVDF crystallize during film formation, resulting in high haze and opacity.

[0003] As a technique for reducing the haze of a film made of PVDF, there is a technique of mixing PVDF with a methacrylic resin to reduce the crystallinity of PVDF (see, for example, Patent Documents 1 to 3).

[0004] However, methacrylic resins are inferior to PVDF in heat resistance, abrasion resistance, and solvent resistance. Furthermore, resin compositions of PVDF and methacrylic resins tend to form β-type crystals, making it difficult to form α-type crystal structures with high heat resistance. Therefore, films of resin compositions containing PVDF and methacrylic resins may have insufficient heat resistance, abrasion resistance, and solvent resistance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 43-12012 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-19051 [Patent Document 3] WO2016 / 199829 A1 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above circumstances, an object of the present invention is to provide a vinylidene fluoride resin composition, a molded article and a laminate having excellent heat resistance, abrasion resistance and solvent resistance. [Means for solving the problem]

[0007] As a result of investigations conducted to achieve the above object, the present invention has been completed, including the following aspects. [1] A resin composition containing 60 to 95 mass% of a vinylidene fluoride resin (A) and 5 to 40 mass% of a methacrylic copolymer (B), A vinylidene fluoride resin composition, wherein the methacrylic copolymer (B) comprises 50 to 93 mass % of methyl methacrylate units, 7 to 30 mass % of α-methylstyrene units, and 0 to 20 mass % of other monomer units copolymerizable therewith. [2] The vinylidene fluoride resin composition according to [1], wherein the copolymerizable other monomer unit is formed of at least one monomer selected from the group consisting of an unsaturated dicarboxylic acid anhydride monomer, an acrylic acid ester monomer, an aromatic vinyl monomer, and a vinyl cyanide monomer. [3] The vinylidene fluoride resin composition according to [1] or [2], wherein the copolymerizable other monomer unit is formed from at least one selected from the group consisting of maleic anhydride, methyl acrylate, ethyl acrylate, styrene, and acrylonitrile. [4] The vinylidene fluoride resin composition according to any one of [1] to [3], wherein the vinylidene fluoride resin (A) is a homopolymer of vinylidene fluoride. [5] The vinylidene fluoride resin composition according to any one of [1] to [4], wherein the crystal structure determined from absorbance in an infrared absorption spectrum has a proportion of α-type crystals of 40% or more, where the total of α-type crystals and β-type crystals is taken as 100%. [6] The vinylidene fluoride resin composition according to any one of [1] to [5], which has a crystalline fusion enthalpy of 15 J / g or more and 40 J / g or less as measured by a differential scanning calorimeter. [7] A molded article obtained by molding the vinylidene fluoride resin composition according to any one of [1] to [6]. [8] The molded article according to [7], which is a film having a thickness of 350 μm or less. [9] A laminate having a layer containing the vinylidene fluoride resin composition according to any one of [1] to [6] and a layer containing another thermoplastic resin. [Effects of the Invention]

[0008] According to the present invention, by using a resin composition containing a vinylidene fluoride resin and a methacrylic copolymer, it is possible to obtain a film and a laminate having excellent heat resistance, abrasion resistance, and solvent resistance. DETAILED DESCRIPTION OF THE INVENTION

[0009] The vinylidene fluoride resin composition of the present invention contains a vinylidene fluoride resin (A) and a methacrylic copolymer (B). The content of the vinylidene fluoride resin (A) in the vinylidene fluoride resin composition is 60 to 95 mass%, preferably 65 to 90 mass%, and more preferably 70 to 85 mass%. When the vinylidene fluoride resin (A) content is 60 mass% or more, the vinylidene fluoride resin composition of the present invention exhibits excellent heat resistance, abrasion resistance, and solvent resistance, and when the content is 95 mass% or less, the transparency is improved.

[0010] (Vinylidene fluoride resin (A)) In the present invention, the term "vinylidene fluoride resin" refers to a polymer containing vinylidene fluoride units as a main component. The content of vinylidene fluoride units is 50% by mass or more, preferably 75% by mass or more, and more preferably 85% by mass or more, based on 100% by mass of the polymer. The polymer may be a 100% by mass homopolymer (PVDF).

[0011] The weight-average molecular weight (hereinafter referred to as "Mw") of the vinylidene fluoride resin is preferably 50,000 to 350,000, more preferably 60,000 to 300,000, and even more preferably 70,000 to 250,000. Having an Mw of 50,000 or more ensures the mechanical strength of a film made from the vinylidene fluoride resin composition of the present invention. Furthermore, having an Mw of 350,000 or less makes it easier to obtain a melt viscosity suitable for molding.

[0012] The weight average molecular weight (Mw) is a value calculated by converting a chromatogram measured by gel permeation chromatography into the molecular weight of standard polystyrene.

[0013] The vinylidene fluoride resin of the present invention may contain structural units derived from fluorine-containing monomers in addition to structural units derived from vinylidene fluoride. The structural units derived from fluorine-containing monomers may be of one type or two or more types.

[0014] Examples of the fluorine-containing monomer include hexafluoropropylene (HFP), trifluoroethylene, chlorotrifluoroethylene (CTFE), tetrafluoroethylene (TFE), and perfluoroalkyl vinyl ether. Among these, hexafluoropropylene, chlorotrifluoroethylene, and tetrafluoroethylene are preferred from the viewpoint of transparency.

[0015] From the viewpoint of transparency, the content of the structural units derived from the fluorine-containing monomer in the vinylidene fluoride resin is preferably 2% by mass or more, more preferably 4% by mass or more, and even more preferably 6% by mass or more.

[0016] From the viewpoint of high crystallinity, the content is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less. Improved crystallinity of the vinylidene fluoride resin leads to improved physical properties of a film formed from the resin composition.

[0017] The vinylidene fluoride resin may further contain other structural units in addition to the structural units derived from vinylidene fluoride and the structural units derived from the fluorine-containing monomer, as long as the effects of the present embodiment are obtained. Such other structural units may be one or more types, and examples thereof include ethylene, unsaturated dibasic acid derivatives (e.g., monomethyl maleate, dimethyl maleate), and vinyl acetate.

[0018] The polymerization method for synthesizing the vinylidene fluoride resin may be any method based on known polymerization methods, such as suspension polymerization and emulsion polymerization.

[0019] In emulsion polymerization, vinylidene fluoride alone or vinylidene fluoride with a comonomer such as hexafluoropropylene is emulsified in an aqueous medium using a chemically stable fluorine-based emulsifier. Polymerization is then carried out using a polymerization initiator such as an inorganic peroxide, an organic peroxide, or an organic percarbonate compound. After emulsion polymerization, the resulting submicron-sized latex is precipitated and agglomerated using a flocculant, allowing the vinylidene fluoride resin to be recovered as particles of an appropriate size.

[0020] In the suspension polymerization method, vinylidene fluoride or vinylidene fluoride and a comonomer are suspended in an aqueous medium using a suspending agent such as methyl cellulose. For example, an organic percarbonate that is active at low temperatures is used as a polymerization initiator to initiate polymerization at a temperature below the critical temperature of vinylidene fluoride to produce primary polymer particles, and the temperature is increased as necessary to continue the polymerization reaction and produce secondary polymer particles.

[0021] The vinylidene fluoride resins may be used alone or in combination of two or more. As the vinylidene fluoride resin, it is preferable to use a vinylidene fluoride homopolymer (PVDF) alone because it is easily crystallized.

[0022] The vinylidene fluoride resin may be a commercially available product, and examples of suitable products include "Kynar 720 (trade name)" and "Kynar 710 (trade name)" manufactured by Arkema K.K., "KF#850 (trade name)" and "KF#1100 (trade name)" manufactured by Kureha Corporation, and "Solef 1006 (trade name)" and "Solef 1008 (trade name)" manufactured by Solvay Specialty Polymers Japan, Ltd.

[0023] (Methacrylic copolymer (B)) The content of the methacrylic copolymer (B) in the vinylidene fluoride resin composition of the present invention is 5 to 40 mass%, preferably 10 to 35 mass%, and more preferably 15 to 30 mass%. When the content of the methacrylic copolymer (B) is in the range of 5 to 40 mass%, the vinylidene fluoride resin composition of the present invention has excellent transparency.

[0024] The methacrylic copolymer (B) according to the present invention contains methyl methacrylate units and α-methylstyrene units, and may further contain other monomer units copolymerizable with methyl methacrylate and / or α-methylstyrene.

[0025] The methacrylic copolymer (B) according to the present invention has a ratio of methyl methacrylate units of 50 to 93 mass%, preferably 55 to 85 mass%, more preferably 65 to 80 mass%, based on the total structural units. From the viewpoint of increasing both the total light transmittance and heat resistance of the resulting methacrylic copolymer, it is preferable that the ratio of methyl methacrylate units is within this range.

[0026] The methacrylic copolymer (B) according to the present invention has an α-methylstyrene unit content of 7 to 30 mass%, preferably 8 to 27 mass%, and more preferably 11 to 25 mass%, based on the total structural units. From the viewpoints of improving the heat resistance and polymerizability of the resulting methacrylic copolymer, thereby leading to high productivity, it is preferable that the α-methylstyrene unit content be within this range.

[0027] The methacrylic copolymer (B) according to the present invention may contain structural units other than methyl methacrylate units and α-methylstyrene units. The structural units are other monomer units copolymerizable with methyl methacrylate units and / or α-methylstyrene units, such as unsaturated dicarboxylic acid anhydride monomer units, acrylic acid ester monomer units, aromatic vinyl monomer units, vinyl cyanide monomer units, and other monomer units. The monomer units copolymerizable with methyl methacrylate units and / or α-methylstyrene units may be used alone or in combination of two or more.

[0028] In the methacrylic copolymer (B) according to the present invention, the proportion of other monomer units is 0 to 20% by mass, preferably 0 to 15% by mass, and more preferably 0 to 10% by mass, based on the total structural units. From the viewpoint of increasing the heat resistance and rigidity of the resulting methacrylic copolymer, the proportion of structural units other than methyl methacrylate units and α-methylstyrene units is preferably 20% by mass or less.

[0029] The unsaturated dicarboxylic acid anhydride used as a raw material for the unsaturated dicarboxylic acid anhydride monomer unit is not particularly limited, but from the viewpoints of heat resistance, heat stability, productivity, etc., maleic acid anhydride, itaconic acid anhydride, citraconic acid anhydride, and aconitic acid anhydride are preferred, and maleic acid anhydride is more preferred. One or more types of unsaturated dicarboxylic acid anhydride monomer unit can be used.

[0030] The acrylic acid ester monomer serving as the raw material for the acrylic acid ester monomer unit is not particularly limited, but from the viewpoints of heat resistance, fluidity, heat stability, productivity, etc., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, cyclohexyl acrylate, phenyl acrylate, etc. are preferred, more preferably methyl acrylate, ethyl acrylate, and n-butyl acrylate, and from the viewpoint of productivity, even more preferably methyl acrylate and ethyl acrylate. One or more types of acrylic acid ester monomer units can be used.

[0031] The aromatic vinyl monomer used as the raw material for the aromatic vinyl monomer unit is not particularly limited, but from the viewpoints of heat resistance, fluidity, heat stability, productivity, etc., styrene (St), o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, o-ethylstyrene, p-tert-butylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 1,1-diphenylethylene, isopropenyltoluene, isopropenylethylbenzene, isopropenylpropylbenzene, isopropenylpropylbenzene, isopropenylbutylbenzene, isopropenylbenzylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene, etc. are preferred, and from the viewpoint of productivity, styrene is more preferred. The aromatic vinyl monomer unit can be used alone or in combination of two or more types.

[0032] The vinyl cyanide monomer used as a raw material for the vinyl cyanide monomer unit is not particularly limited, but from the viewpoints of heat resistance, flowability, heat stability, productivity, etc., acrylonitrile (AN), methacrylonitrile, vinylidene cyanide, etc. are preferred, and among these, acrylonitrile is preferred from the viewpoints of easy availability and chemical resistance. One or more types of vinyl cyanide monomer units can be used.

[0033] The other monomer units are not particularly limited, and examples thereof include amides such as acrylamide and methacrylamide; ethylene glycols such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate, or oligomers thereof, in which both terminal hydroxyl groups are esterified with acrylic acid or methacrylic acid; neopentyl glycol di(meth)acrylate, di(meth)acrylate, and other compounds in which two alcohol hydroxyl groups are esterified with acrylic acid or methacrylic acid; polyhydric alcohol derivatives such as trimethylolpropane and pentaerythritol esterified with acrylic acid or methacrylic acid; and polyfunctional monomers such as divinylbenzene.

[0034] Among the monomers constituting the other monomer units described above, at least one selected from the group consisting of maleic anhydride, methyl acrylate (MA), ethyl acrylate, styrene, and acrylonitrile is preferred from the viewpoint of availability.

[0035] The methacrylic copolymer (B) according to the present invention has a weight-average molecular weight (Mw) of preferably 30,000 to 200,000, more preferably 40,000 to 180,000, and even more preferably 50,000 to 160,000. When Mw is 30,000 or more, the strength and toughness of the film and laminate according to the present invention are improved. When Mw is 200,000 or less, the flowability of the methacrylic copolymer according to the present invention is improved, and molding processability is improved.

[0036] The methacrylic copolymer (B) according to the present invention has a glass transition temperature of preferably 110°C as a lower limit, more preferably 115°C, and even more preferably 120°C, and although there is no particular limitation, the upper limit is preferably 140°C.

[0037] In this specification, the "glass transition temperature (Tg)" is measured in accordance with JIS K7121. Specifically, the temperature is raised once to 230°C, then cooled to room temperature, and then the DSC curve is measured under conditions of raising the temperature from room temperature to 230°C at a rate of 10°C / min. The midpoint of the DSC curve measured during the second temperature rise is determined as the "glass transition temperature (Tg)."

[0038] The method for producing the methacrylic copolymer (B) according to the present invention comprises the steps of continuously supplying a reaction raw material containing a monomer mixture containing 50 to 93 mass % of methyl methacrylate, 40 to 7 mass % of α-methylstyrene, and 0 to 20 mass % of other monomers copolymerizable therewith, a radical polymerization initiator, and, if necessary, a chain transfer agent, to a tank reactor; bulk polymerizing the monomer mixture in the tank reactor to a polymerization conversion rate of 30 to 60 mass % to obtain a reaction product; and removing the monomer mixture from the reaction product to obtain a polymer, each of which can be carried out by a known technique.

[0039] (Vinylidene fluoride resin composition) In the vinylidene fluoride resin composition of the present invention, the mass ratio of the vinylidene fluoride resin (A) to the methacrylic copolymer (B) is 95 / 5 to 40 / 60, preferably 90 / 10 to 45 / 55, and more preferably 80 / 20 to 50 / 50, from the viewpoints of heat resistance, chemical resistance, and abrasion resistance.

[0040] The vinylidene fluoride resin composition of the present invention preferably has an α-type crystal ratio of 40% or more, more preferably 50% or more, and even more preferably 60% or more. When the α-type crystal ratio is 40% or more, the vinylidene fluoride resin composition of the present invention has excellent heat resistance.

[0041] It is known that PVDF has three types of crystal structures: α type (also called "type II"), β type (also called "type I"), and γ type (also called "type III"). Resin compositions containing vinylidene fluoride resin and methacrylic resin are known to have a predominant β type crystal structure, but the vinylidene fluoride resin composition of the present invention is characterized in that the proportion of the α type crystal structure is 40% or more.

[0042] The α-crystal ratio of a vinylidene fluoride resin composition (hereinafter referred to as the α-crystal ratio) can be confirmed by an infrared absorption spectrum measured by a transmission method using an infrared spectrophotometer. Specifically, the characteristic absorption of α-crystals at a wave number of 765 cm can be confirmed from the obtained spectrum. -1 The absorption intensity of the β-type crystal is -1 The absorption intensity is calculated using the following formula: α crystal ratio %={765cm -1 Absorption intensity / (765cm -1 Absorption intensity of +840cm -1 absorption intensity) × 100

[0043] The vinylidene fluoride resin composition of the present invention preferably has a crystalline fusion enthalpy measured by a differential scanning calorimeter in the range of 15 to 40 J / g, more preferably in the range of 17 to 35 J / g, and even more preferably in the range of 20 to 30 J / g. The crystalline fusion enthalpy depends on the content of the vinylidene fluoride resin (A) in the vinylidene fluoride resin composition. Therefore, increasing the content of the methacrylic resin (B) to improve transparency decreases the value. From the viewpoint of achieving both a high crystal content and transparency, a value of 15 to 40 J / g is preferred. In the present invention, the crystalline fusion enthalpy refers to the crystalline fusion enthalpy measured in accordance with JIS K7121.

[0044] The vinylidene fluoride resin composition of the present invention may contain a filler, if necessary, within a range that does not impair the effects of the present invention. Examples of fillers include calcium carbonate, talc, carbon black, titanium oxide, silica, clay, barium sulfate, and magnesium carbonate. The amount of filler that can be contained in the resin composition of the present invention is preferably 3% by mass or less, and more preferably 1.5% by mass or less.

[0045] The vinylidene fluoride resin composition of the present invention may contain other polymers as long as the effects of the present invention are not impaired. Other polymers include polyolefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene-based ionomers; styrene-based resins such as polystyrene, styrene-maleic anhydride copolymer, high-impact polystyrene, AS resin, ABS resin, AES resin, AAS resin, ACS resin, and MBS resin; methyl methacrylate-styrene copolymers; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamides such as nylon 6, nylon 66, and polyamide elastomers; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacetal, polyurethane, phenoxy resin, modified polyphenylene ether, polyphenylene sulfide, and silicone-modified resins; silicone rubber; acrylic multilayer copolymer elastomers; acrylic thermoplastic elastomers such as diblock and triblock copolymers of methyl methacrylate polymer block and n-butyl acrylate polymer block; styrene-based thermoplastic elastomers such as SEPS, SEBS, and SIS; and olefin-based rubbers such as IR, EPR, and EPDM. The amount of other polymers that can be contained in the resin composition of the present invention is preferably 10% by mass or less, more preferably 5% by mass or less, and most preferably 0% by mass.

[0046] The vinylidene fluoride resin composition of the present invention may contain additives such as antioxidants, heat degradation inhibitors, ultraviolet absorbers, light stabilizers, lubricants, release agents, polymer processing aids, antistatic agents, flame retardants, dyes and pigments, light diffusing agents, organic dyes, matting agents, and fluorescent materials, as long as the effects of the present invention are not impaired.

[0047] The antioxidant is effective in preventing oxidative degradation of the resin by itself in the presence of oxygen. Examples include phosphorus-based antioxidants, hindered phenol-based antioxidants, and thioether-based antioxidants. These antioxidants can be used alone or in combination of two or more. Among these, from the viewpoint of the effect of preventing degradation of optical properties due to coloring, phosphorus-based antioxidants and hindered phenol-based antioxidants are preferred, and a combination of a phosphorus-based antioxidant and a hindered phenol-based antioxidant is more preferred.

[0048] When a phosphorus-based antioxidant and a hindered phenol-based antioxidant are used in combination, their ratio is not particularly limited, but the mass ratio of phosphorus-based antioxidant / hindered phenol-based antioxidant is preferably 1 / 5 to 2 / 1, and more preferably 1 / 2 to 1 / 1.

[0049] Examples of phosphorus-based antioxidants include 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite (manufactured by ADEKA Corporation; trade name: Adeka STAB HP-10), tris(2,4-di-t-butylphenyl) phosphite (manufactured by Ciba Specialty Chemicals Corporation; trade name: IRUGAFOS168), and 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (manufactured by ADEKA Corporation; trade name: Adeka STAB PEP-36).

[0050] Examples of hindered phenol antioxidants include pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (manufactured by Ciba Specialty Chemicals; trade name IRGANOX 1010) and octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate (manufactured by Ciba Specialty Chemicals; trade name IRGANOX 1076).

[0051] A thermal degradation inhibitor is a compound that can prevent thermal degradation of a resin by capturing polymer radicals that are generated when the resin is exposed to high heat in a substantially oxygen-free state. Examples of such an inhibitor include 2-t-butyl-6-(3'-t-butyl-5'-methyl-hydroxybenzyl)-4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd.; trade name: Sumilizer GM) and 2,4-di-t-amyl-6-(3',5'-di-t-amyl-2'-hydroxy-α-methylbenzyl)phenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd.; trade name: Sumilizer GS).

[0052] An ultraviolet absorber is a compound that has the ability to absorb ultraviolet rays and is said to have the function of converting light energy into heat energy.

[0053] Examples of ultraviolet absorbers include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalic anilides, malonic acid esters, and formamidines. These may be used alone or in combination of two or more. Among these, benzotriazoles, triazines, or compounds having a maximum molar absorption coefficient ε at a wavelength of 380 to 450 nm are preferred. max 1200dm 3 mol -1 cm -1 The following ultraviolet absorbers are preferred:

[0054] Light stabilizers are compounds that are said to have the function of capturing radicals generated mainly by oxidation due to light, and examples thereof include hindered amines such as compounds having a 2,2,6,6-tetraalkylpiperidine skeleton.

[0055] Examples of the lubricant include stearic acid, behenic acid, stearamidic acid, methylene bisstearamide, hydroxystearic acid triglyceride, paraffin wax, ketone wax, octyl alcohol, and hydrogenated oil.

[0056] The mold release agent is a compound that functions to facilitate the release of a molded product from a mold, and examples thereof include higher alcohols such as cetyl alcohol and stearyl alcohol; glycerin higher fatty acid esters such as stearate monoglyceride and stearate diglyceride; etc. The use of glycerin higher fatty acid esters can cause gel-like foreign matter, so it is preferable to use higher alcohols.

[0057] The polymer processing aid is a compound that is effective in achieving thickness accuracy and thinning when molding a vinylidene fluoride resin composition. The polymer processing aid can usually be produced by emulsion polymerization. The polymer processing aid is preferably polymer particles having a particle size of 0.05 to 0.5 μm.

[0058] The polymer particles may be single-layer particles made of a polymer with a single composition ratio and a single intrinsic viscosity, or may be multi-layer particles made of two or more polymers with different composition ratios or intrinsic viscosities. Among these, preferred are particles with a two-layer structure having an inner polymer layer with a low intrinsic viscosity and an outer polymer layer with a high intrinsic viscosity of 5 dL / g or more. The polymer processing aid preferably has an intrinsic viscosity of 3 to 6 dL / g. From the viewpoint of improving the moldability and the melt fluidity of the acrylic resin composition, the intrinsic viscosity is preferably within the above range.

[0059] Examples of the antistatic agent include alkyl sulfonates such as sodium heptyl sulfonate, sodium octyl sulfonate, sodium nonyl sulfonate, sodium decyl sulfonate, sodium dodecyl sulfonate, sodium cetyl sulfonate, sodium octadecyl sulfonate, sodium diheptyl sulfonate, potassium heptyl sulfonate, potassium octyl sulfonate, potassium nonyl sulfonate, potassium decyl sulfonate, potassium dodecyl sulfonate, potassium cetyl sulfonate, potassium octadecyl sulfonate, potassium diheptyl sulfonate, lithium heptyl sulfonate, lithium octyl sulfonate, lithium nonyl sulfonate, lithium decyl sulfonate, lithium dodecyl sulfonate, lithium cetyl sulfonate, lithium octadecyl sulfonate, and lithium diheptyl sulfonate.

[0060] Examples of the flame retardant include metal hydrates having a hydroxyl group or crystal water, such as magnesium hydroxide, aluminum hydroxide, hydrated aluminum silicate, hydrated magnesium silicate, and hydrotalcite; phosphate compounds, such as polyamine phosphate and phosphate esters; and silicon compounds. Of these, preferred are phosphate ester-based flame retardants, such as trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, dimethylethyl phosphate, methyldibutyl phosphate, ethyldipropyl phosphate, and hydroxyphenyldiphenyl phosphate.

[0061] Examples of dyes and pigments include red organic pigments such as Para Red, Fire Red, Pyrazolone Red, Thioindiko Red, and Perylene Red; blue organic pigments such as Cyanine Blue and Indanthrene Blue; and green organic pigments such as Cyanine Green and Naphthol Green. One or more of these can be used.

[0062] As the organic dye, a compound having a function of converting ultraviolet light into visible light is preferably used.

[0063] Examples of light diffusing agents and matting agents include glass particles, polysiloxane-based crosslinked particles, crosslinked polymer particles, talc, calcium carbonate, and barium sulfate.

[0064] Examples of the fluorescent substance include fluorescent pigments, fluorescent dyes, fluorescent white dyes, fluorescent brighteners, and fluorescent bleaches.

[0065] These additives may be used alone or in combination of two or more. These additives may be added to the polymerization reaction solution during the production of the vinylidene fluoride resin (A) or the methacrylic copolymer (B), or to the vinylidene fluoride resin (A) or the methacrylic copolymer (B) produced, or may be added during the preparation of the vinylidene fluoride resin composition of the present invention. From the viewpoint of suppressing defects in the appearance of molded articles, the total amount of additives contained in the vinylidene fluoride resin composition of the present invention is preferably 7% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less, based on the vinylidene fluoride resin composition.

[0066] The method for preparing the vinylidene fluoride resin composition of the present invention is not particularly limited. Examples include a method in which a monomer mixture containing methyl methacrylate or the like is polymerized in the presence of a vinylidene fluoride resin (A) to produce a methacrylic copolymer (B), and a method in which the vinylidene fluoride resin (A) and the methacrylic copolymer (B) are melt-kneaded. During melt-kneading, other polymers and additives may be added as needed. Alternatively, the vinylidene fluoride resin (A) may be mixed with other polymers and additives and then mixed with the methacrylic copolymer (B). Alternatively, the methacrylic copolymer (B) may be mixed with other polymers and additives and then mixed with the vinylidene fluoride resin (A). Other methods are also acceptable. Kneading can be performed using known mixing or kneading devices, such as a kneader-ruder, extruder, mixing roll, or Banbury mixer. Among these, a twin-screw extruder is preferred.

[0067] The vinylidene fluoride resin composition of the present invention can be made into a form such as pellets in order to improve convenience in storage, transportation, and molding.

[0068] (molded product) The molded article of the present invention comprises the vinylidene fluoride resin composition of the present invention. The method for producing the molded article of the present invention is not particularly limited. Examples include melt molding methods such as the T-die method (lamination method, coextrusion method, etc.), inflation method (coextrusion method, etc.), compression molding, blow molding, calendar molding, vacuum molding, and injection molding (insert method, two-color method, press method, core-back method, sandwich method, etc.), as well as solution casting. Among these, the T-die method, inflation method, and injection molding are preferred from the standpoints of productivity and cost. While there are no limitations on the type of molded article, films (flat molded articles with a thickness of 5 μm to 250 μm) and sheets (flat molded articles with a thickness of more than 250 μm) are preferred. Among these, films are particularly preferred due to their excellent transparency.

[0069] Generally, the thinner the film, the more likely it is that a film with higher transparency will be obtained, and therefore the thickness of the film of the present invention is preferably 350 μm or less, more preferably 250 μm or less, and even more preferably 100 μm or less.

[0070] If the film surface is rough, external haze occurs due to light scattering on the film surface, resulting in reduced transparency. Therefore, the arithmetic mean roughness (Ra) of the film is preferably 50 nm or less, and more preferably 40 nm or less.

[0071] A laminate can be obtained by laminating a layer containing the vinylidene fluoride resin composition of the present invention with another material (for example, a layer containing another thermoplastic copolymer). Examples of other materials that can be used in the laminate include steel, plastics (for example, other thermoplastic resins), wood, and glass. The laminate obtained by the present invention can be suitably used for wallpaper, automobile interior surfaces, automobile exterior surfaces such as bumpers, mobile phone surfaces, furniture surfaces, personal computer surfaces, vending machine surfaces, and bathroom surfaces such as bathtubs.

[0072] Examples of other thermoplastic resins that can be used in layers containing other thermoplastic copolymers include olefin-based resins such as methacrylic resin, polycarbonate, polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene-based ionomers; styrene-based resins such as polystyrene, styrene-maleic anhydride copolymer, high-impact polystyrene, AS resin, ABS resin, AES resin, AAS resin, ACS resin, and MBS resin; methyl methacrylate-styrene copolymer; ester-based resins such as polyethylene terephthalate and polybutylene terephthalate; amide-based resins such as nylon 6, nylon 66, and polyamide elastomer; polyphenylene sulfide, polyether ether ketone, polysulfone, polyphenylene oxide, polyimide, polyetherimide, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacetal, and phenoxy-based resins, with methacrylic resin and polycarbonate being preferred.

[0073] A laminate comprising a layer containing the vinylidene fluoride resin composition of the present invention and a layer containing a methacrylic resin, which is one form of the laminate, has high chemical resistance and heat resistance and is suitable for decorative applications, and is suitable for use as an automobile interior / exterior material, etc. Other applications include metal decorative sheets, vehicle glazing, machine tool covers, security sheets, and shatterproof sheets.

[0074] When a laminate comprising a layer containing the vinylidene fluoride resin composition of the present invention and a layer containing a methacrylic resin, which is one form of the laminate, is used as an automobile interior / exterior material, the layer containing the vinylidene fluoride resin composition of the present invention may be laminated on only one side of the layer containing the methacrylic resin, or may be laminated on both sides. The thickness of the layer containing the vinylidene fluoride resin composition is preferably in the range of 2 to 15%, more preferably in the range of 3 to 12%, and even more preferably in the range of 4 to 10% of the thickness of the laminate. [Example]

[0075] The present invention will now be described in more detail with reference to examples, although the present invention is not limited to these examples. Measurements of physical properties etc. were carried out by the following methods.

[0076] (Weight average molecular weight) The weight-average molecular weight (Mw) of the resin obtained in the production examples was determined by GPC (gas chromatography). A sample solution was prepared by dissolving 4 mg of the target resin in 5 mL of tetrahydrofuran. The column oven temperature was set to 40°C, and 20 μL of the sample solution was injected into the instrument at an eluent flow rate of 0.35 mL / min. Chromatograms were then measured. Ten standard polystyrene samples with molecular weights ranging from 400 to 5,000,000 were measured by GPC, and a calibration curve showing the relationship between retention time and molecular weight was created. The Mw of the target resin was determined based on this calibration curve. The value corresponding to the molecular weight of the standard polystyrene from the chromatogram measured by GPC (gel permeation chromatography) was taken as the molecular weight of the copolymer. Apparatus: Tosoh GPC HLC-8320 Separation column: TSKguardcolumSuperHZ-H, TSKgelHZM-M, and TSKgelSuperHZ4000 manufactured by Tosoh Corporation connected in series Eluent: tetrahydrofuran Eluent flow rate: 0.35 ml / min Column temperature: 40℃ Detection method: Refractive index (RI)

[0077] (Composition of each unit in the copolymer) 13 The carbon ratios of the phenyl group of the α-methylstyrene unit, the methoxy group of the methyl methacrylate unit, the phenyl group of the styrene unit, and the carbonyl group of the maleic anhydride unit were determined by C-NMR, and the composition of each unit was calculated from this.

[0078] (glass transition temperature; Tg) The resin obtained in the Production Examples was measured for its DSC curve in accordance with JIS K7121 using a differential scanning calorimeter (Shimadzu Corporation, DSC-50 (product number)) by heating it once to 250°C, then cooling it to room temperature, and then heating it from room temperature to 200°C at a rate of 10°C / min. The midpoint glass transition temperature determined from the DSC curve measured during the second heating was taken as the glass transition temperature in the present invention.

[0079] (crystal fusion enthalpy (ΔH), melting point) The resin compositions obtained in the examples and comparative examples were measured using a differential scanning calorimeter (TA Instruments, Q-20 (product number)) in accordance with JIS K7121. The DSC curve was measured under conditions in which the temperature was raised to 200°C once, then cooled from 200°C to -50°C at 5°C / min, and then raised from -50°C to 200°C at 10°C / min. The crystalline melting enthalpy (ΔH) was calculated from the area of ​​the crystalline melting peak observed during the second heating. The melting point was determined as the value at the peak top of the crystalline melting peak.

[0080] (α crystal ratio) The resin compositions obtained in the examples and comparative examples were placed in a mold frame and heated at 230°C and 50 kg / cm 2 Pressed at 50kg / cm 2 Each test piece was subjected to a transmission method using an FT-IR spectrometer (Nicolet iz10 (product number) manufactured by Thermo Fisher Scientific). The infrared absorption spectrum obtained showed a wave number of 765 cm, which is the characteristic absorption of the α-type crystal. -1 The absorption intensity of the β-type crystal is -1 The absorption intensity of the α-type crystals was measured, and the proportion of α-type crystals (α-crystal ratio) was calculated using the following formula. α crystal ratio (%)={765cm -1 Absorption intensity / (765cm -1 Absorption intensity of +840cm -1 absorption intensity) × 100

[0081] (Heat resistance; Vicat softening point temperature (VST)) The resin compositions obtained in the examples and comparative examples were placed in a mold frame and heated at 230°C and 50 kg / cm 2 Pressed at 50kg / cm 2 Test pieces with a thickness of 4 mm were prepared by water cooling at 100°C. The Vicat softening temperature (VST) of each test piece was measured using an HDT tester (Toyo Seiki Seisakusho, Ltd., 3M-2 (product number)) in accordance with the method described in the B50 method of JIS K7206.

[0082] (scratch resistant; steel wool resistant) The resin compositions obtained in the examples and comparative examples were placed in a mold frame and heated at 230°C and 50 kg / cm 2 Pressed at 50kg / cm 2 Each test piece was rubbed 200 times using a reciprocating abrasion tester (manufactured by Toyo Seiki Seisakusho) with a load of 900 g of steel wool #0000. The difference in haze value before and after rubbing was evaluated. Haze was measured using a spectrophotometer (Nippon Denshoku Industries Co., Ltd., "SE5000") in accordance with JIS-K7361.

[0083] (Chemical resistance; dimethyl carbonate resistance) The resin compositions obtained in the examples and comparative examples were placed in a mold frame and heated at 230°C and 50 kg / cm 2 Pressed at 50kg / cm 2 Each test piece was immersed in dimethyl carbonate at 23°C and a relative humidity of 50% for 168 hours, and the weight change before and after immersion was measured.

[0084] <Examples of various materials> The vinylidene fluoride resin (A) used in the present invention was the material shown below. KF Polymer #1100 (product name, manufactured by Kureha Corporation), 100% by mass of vinylidene fluoride units (homopolymer of vinylidene fluoride), Mw = 280,000, glass transition temperature = -35°C

[0085] (Methacrylic copolymer (B)) Manufacturing Examples 1 to 4 Purified methyl methacrylate (MMA), α-methylstyrene (αMSt), maleic anhydride (Mah), styrene (St), 2,2'-azobis(2-methylpropionitrile) (AIBN), and n-octyl mercaptan (n-OM) were charged into an autoclave equipped with a stirrer in the proportions listed in Table 1 and dissolved uniformly to obtain the polymerization raw material (raw material liquid). Nitrogen gas was blown into the polymerization raw material to remove dissolved oxygen to 3 ppm. The atmosphere in a continuous-flow tank reactor equipped with a brine cooling condenser was then purged with nitrogen gas. The polymerization raw material was continuously fed into the tank reactor at a constant flow rate to achieve the average residence time listed in Table 1, and bulk polymerization was carried out at the polymerization temperature listed in Table 1. A liquid containing the methacrylic copolymer was continuously discharged from the tank reactor. The pressure inside the tank reactor was adjusted using a pressure control valve connected to the brine cooling condenser. The polymerization conversion was the value listed in Table 1. The liquid discharged from the reactor was then heated to 230°C and fed to a twin-screw extruder controlled at 240°C. In the twin-screw extruder, volatile components, primarily unreacted monomers, were separated and removed, and the methacrylic copolymer was extruded as strands. The strands were cut with a pelletizer to obtain methacrylic copolymers (B-1) to (B-4). The weight-average molecular weight Mw, the proportion of each monomer unit, and the glass transition temperature of the resulting methacrylic copolymers were measured. The results are shown in Table 1.

[0086] Production Example 5 An MS resin (a copolymer of methyl methacrylate (MMA) and styrene (St)) was polymerized according to the method for producing copolymer (A) described in the Examples section of JP 2003-231785 A. By varying the mass ratio of MMA and St charged into an autoclave, a methacrylic copolymer (B-5) with Mw=95,000, Tg=115°C, and a styrene monomer unit content of 20% by mass was obtained.

[0087] [Table 1]

[0088] Example 1 90 parts by mass of vinylidene fluoride resin (A) and 10 parts by mass of methacrylic copolymer (B-1) were mixed and melt-kneaded at 230°C for 3 minutes in a Laboplastomill (manufactured by Toyo Seiki Co., Ltd.) to obtain a vinylidene fluoride resin composition. The evaluation results are shown in Table 2.

[0089] Examples 2 to 5 A vinylidene fluoride resin composition was obtained in the same manner as in Example 1, except for the formulation shown in Table 2. The evaluation results are shown in Table 2.

[0090] Comparative Examples 1 to 6 A vinylidene fluoride resin composition was obtained in the same manner as in Example 1, except for the formulation shown in Table 2. The evaluation results are shown in Table 2.

[0091] [Table 2]

[0092] As shown in Table 2, the vinylidene fluoride resin composition of the present invention, despite containing a methacrylic copolymer, is highly crystalline and has a high proportion of α crystals, resulting in an excellent balance of heat resistance, scratch resistance, and chemical resistance. Due to these characteristics, the vinylidene fluoride resin composition of the present invention can provide molded articles and laminates that are excellent in heat resistance, scratch resistance, and chemical resistance. [Industrial Applicability]

[0093] The molded article and laminate of the present invention have excellent heat resistance, scratch resistance and chemical resistance, and are suitable for use as covers and housings for display devices, window materials and covers for the interior and exterior of vehicles, and the like.

Claims

1. A resin composition containing 60 to 95 mass% of a vinylidene fluoride resin (A) and 5 to 40 mass% of a methacrylic copolymer (B), A vinylidene fluoride resin composition, wherein the methacrylic copolymer (B) comprises 50 to 93 mass% of methyl methacrylate units, 7 to 30 mass% of α-methylstyrene units, and 0 to 20 mass% of other monomer units copolymerizable therewith.

2. 2. The vinylidene fluoride resin composition according to claim 1, wherein the copolymerizable other monomer unit is formed from at least one monomer selected from the group consisting of an unsaturated dicarboxylic acid anhydride monomer, an acrylic acid ester monomer, an aromatic vinyl monomer (excluding α-methylstyrene), and a vinyl cyanide monomer.

3. 2. The vinylidene fluoride resin composition according to claim 1, wherein the copolymerizable other monomer unit is formed by at least one selected from the group consisting of maleic anhydride, methyl acrylate, ethyl acrylate, styrene, and acrylonitrile.

4. 2. The vinylidene fluoride resin composition according to claim 1, wherein the vinylidene fluoride resin (A) is a homopolymer of vinylidene fluoride.

5. 2. The vinylidene fluoride resin composition according to claim 1, wherein the crystal structure determined from absorbance in an infrared absorption spectrum has a proportion of α-type crystals of 40% or more, where the total of α-type crystals and β-type crystals is 100%.

6. 2. The vinylidene fluoride resin composition according to claim 1, wherein the crystalline fusion enthalpy measured by a differential scanning calorimeter is 15 J / g or more and 40 J / g or less.

7. A molded article obtained by molding the vinylidene fluoride resin composition according to claim 1.

8. 8. The molded article according to claim 7, which is a film having a thickness of 350 μm or less.

9. A laminate comprising a layer containing the vinylidene fluoride resin composition according to claim 1 and a layer containing another thermoplastic resin.

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