Method for producing a vinylidene fluoride-based resin multilayered film

The present invention relates to a vinylidene fluoride-based resin film and a vinylidene fluoride-based resin multilayer film having excellent transparency.

Vinylidene fluoride resin, which has excellent weather resistance and chemical resistance and can be melt-molded, can be used as a surface protective film for tents and truck hoods in simple warehouses, as well as for illuminated signboards, building materials, and automobile exteriors. Widely used as a protective film for films. In recent years, a method of decorating a film in which a vinylidene fluoride resin and an acrylic resin are laminated on the surface of a plastic molded product has attracted attention as an alternative to painting. Since the protective film and the decorative film are used by being adhered to the surface of the base material, transparency is required so that the prints and patterns applied to the surface of the base material can be clearly seen. However, since the vinylidene fluoride resin is a crystalline resin and has a high crystallization rate, it is very difficult to satisfy the transparency.

So far, methods such as thinning the film (see Patent Document 1), copolymerizing other monomers with vinylidene fluoride resin (see Patent Document 2), mixing with methacrylic resin (see Patent Document 3), and the like. However, the films obtained by these methods do not satisfy the required transparency.

Furthermore, by controlling the molding conditions (for example, discharge rate, take-up rate, residence time, difference between die temperature and refrigerant temperature, etc.) during processing of vinylidene fluoride resin film, the spherulite radius of polyvinylidene fluoride can be determined. A method of reducing the size and improving the transparency (see Patent Document 4) has been proposed, but it is difficult to suppress the average spherulite radius to less than 0.5 μm due to the limitation of the apparatus, and further improvement of the transparency can be achieved. I was asked.

On the other hand, vinylidene fluoride-based resin multilayer films coextruded with a methacrylic resin composition are of great interest in the market. Specific examples include a protective film that is laminated on various materials such as plastic, metal, and wood to prevent deterioration of the base material and maintain its aesthetic appearance, as well as painting and plating alternatives that are laminated on automobile interior and exterior parts. Examples include the use of film. Furthermore, since it is predicted that regulations on harmful substances emitted from the painting and plating processes will be tightened due to environmental problems, films are attracting attention as alternatives to these. Bending crack resistance and moldability are listed as required properties for these films.<patcit num="1"><text>JP-A-57-187248</text></patcit><patcit num="2"><text>Special Publication No. 64-8665</text></patcit><patcit num="3"><text>Japanese Unexamined Patent Publication No. 5-50566</text></patcit><patcit num="4"><text>Japanese Unexamined Patent Publication No. 6-80794</text></patcit>

<p> Therefore, a vinylidene fluoride-based resin film and a vinylidene fluoride-based resin multilayer film having excellent transparency, weather resistance, chemical resistance, bending crack resistance, and moldability have been required.</p><p> Therefore, as a result of diligent studies, the present inventors have found that by sandwiching the melt-extruded vinylidene fluoride resin between rolls or metal belts, the transparency is significantly improved by cooling while pressurizing. It led to the invention.</p>

<p> Of the present invention<u style="single">Fluoridene-based resin film is</u>Vinylidene fluoride in a molten state<u style="single">system</u>Resin<u style="single">The surface layer is a melted methacrylic resin composition as the base layer, and the temperature is 10 to 100 ° C.</u>A vinylidene fluoride resin film in which the average spherulite diameter of polyvinylidene fluoride is less than 0.1 μm when observed with a transmission electron microscope by sandwiching it between rolls or a metal belt and cooling and molding it.<u style="single">Characterized by</u>。 </p><p><u style="single">In the present invention</u>Cloud value is less than 1%<u style="single">Is preferable.</u></p><p><u style="single">Further, in the present invention,</u>Roll or metal belt<u style="single">The temperature is preferably 10 to 100 ° C.</u></p><p><u style="single">Also,</u>The vinylidene fluoride resin is a composition comprising 50 to 99.9 parts by weight of the vinylidene fluoride resin (D) and 0.1 to 50 parts by weight of the methacrylic resin composition (C).<u style="single">Is preferable</u>。 </p><p><u style="single">Also,</u>Form a surface layer<u style="single">Any of the above</u>A vinylidene fluoride resin multilayer film composed of a vinylidene fluoride resin layer and a methacrylic resin composition (C) layer.<u style="single">Is preferable</u>。 </p><p><u style="single">Also,</u>The vinylidene fluoride resin layer and the methacrylic resin composition (C) are coextruded.<u style="single">Is preferable.</u></p><p><u style="single">Also,</u>The methacrylic resin composition (C) is a methacrylic resin composition obtained by polymerizing a methacrylic acid ester polymer (A) in the presence of acrylic acid ester crosslinked elastic particles (B). (1) The methacrylic acid ester-based polymer (A) is obtained by polymerizing a monomer mixture containing 50 to 100% by weight of an alkyl methacrylate ester and 0 to 50% by weight of an alkyl acrylate ester. (2) Monomer mixture (b) in which acrylic acid ester-based crosslinked elastic particles (B) contain 50 to 100% by weight of acrylic acid alkyl ester and 50 to 0% by weight of methacrylic acid alkyl ester, and 2 per molecule. Obtained by copolymerizing polyfunctional monomers having more than one non-conjugated double bond, (3) The content of acrylic ester-based crosslinked elastic particles (B) is 5 to 45% by weight. And, (4) Methacrylic resin composition A methacrylic resin composition characterized by copolymerizing 0.01 to 30 parts by weight of an ultraviolet absorber represented by the general formula (1) with 100 parts by weight of (C). is there<u style="single">Is preferable.</u></p><p><chemistry num="1"><img file="JP4958552B2_D0001.tif" /></chemistry></p><p>(In the formula, X is H or halogen, R₁Is an H, methyl or t-alkyl group with 4-6 carbon atoms, R₂Is a linear or branched alkylene group having 2 to 10 carbon atoms, R₃Is H or methyl. )</p><p><u style="single">Also,</u>It is a laminated product in which any of the above-mentioned vinylidene fluoride-based resin films or vinylidene fluoride-based resin multilayer films are laminated.<u style="single">Is preferable. Further, the laminated product is preferably manufactured by injection molding.</u></p>

<p> The vinylidene fluoride-based resin film and the vinylidene fluoride-based resin multilayer film of the present invention are sandwiched between rolls or metal belts and cooled while pressurizing.<u style="single">Obtained, this film</u>While solving the problem of transparency, it is excellent in weather resistance, chemical resistance, bending crack resistance and moldability, which are the required properties of the film.</p>

The average spherulite diameter of polyvinylidene fluoride is<u style="single">The detection limit is less than 0.1 μm when observed with a transmission electron microscope.</u>Is. The average spherulite diameter of polyvinylidene fluoride<u style="single">0.1</u>If it is μm or more, the transparency of the obtained vinylidene fluoride resin film tends to be unsatisfactory.

The average spherulite diameter D of polyvinylidene fluoride in the present invention.₀Is a value measured by a transmission electron microscope observation method or a laser small-angle scattering method.

In the over-type electron microscope observation method in the present invention, a vinylidene fluoride resin film is sample-prepared by a frozen ultrathin section method, and then a transmission electron microscope (JEM-1200EX, manufactured by JEOL Ltd.) is used. , The crystal diameter of polyvinylidene fluoride when observed at 10000 times at an acceleration voltage of 80 kV was measured (detection limit: 0.1 μm). For the average crystal diameter, 50 spherulites in the electron microscopic observation photograph were measured using a caliper, and the average value was adopted.

In the laser small-angle scattering method in the present invention, eight polyvinylidene fluoride resin films are shifted by 45 degrees to prepare a measurement sample, and then a He-Ne gas laser (Neoarc Co., Ltd., NEO-15MS; Small-angle light scattering measurements were performed using a 15 mV, 632.8 nm) and a PDA detector (photodiode array S6494-128, manufactured by Hamamatsu Photonics Co., Ltd.). Scattering vector obtained-In the scattering intensity chart, the scattering vector Q with the maximum scattering intensity_max(nm^-1) From curve fitting, R₀= 4.09 / Q_maxAverage spherulite radius R by the formula of₀Was calculated. In this case, the average spherulite diameter is R.₀Is doubled.

Regarding the vinylidene fluoride-based resin multilayer film described later, the acrylic resin composition (C) layer is dissolved by immersing in chloroform, the vinylidene fluoride-based resin layer (film) is taken out, and small-angle light scattering is performed. Of measurement<u style="single">sample</u>And said.

The vinylidene fluoride resin film in the present invention has a cloudiness value of 1% or less. It is preferably 0.9% or less, more preferably 0.8% or less. If the cloudiness value of polyvinylidene fluoride exceeds 1%, the transparency of the obtained vinylidene fluoride resin film tends to be unsatisfactory. The cloudiness value is a value measured under the conditions of a temperature of 23 ° C ± 2 ° C and a humidity of 50% ± 5% in accordance with JIS K6714. In the multilayer film with the methacrylic resin composition (C), the cloudiness value of all layers of the film was almost the same as the cloudiness value of the polyvinylidene fluoride resin layer, so the cloudiness value was measured for all layers of the film.

The vinylidene fluoride-based resin film in the present invention is obtained by a method of forming a vinylidene fluoride resin in a molten state immediately after being discharged from an extruder by sandwiching it between rolls or a metal belt and cooling it while pressurizing it. Is. Simply contact the molten vinylidene fluoride resin with a roll or metal belt without sandwiching it, and when cooled, the average spherulite diameter will be increased.<u style="single">0.1</u>It cannot be less than μm, and the transparency of the obtained film cannot be satisfied. Further, by sandwiching the molten vinylidene fluoride resin between rolls or metal belts and molding the resin, not only the average spherulite diameter can be reduced, but also the surface can be smoothed.

In the sandwich molding with the roll or metal belt of the present invention, the temperature of the roll or metal belt is preferably maintained at 10 ° C to 100 ° C, more preferably 20 ° C to 60 ° C. If the temperature of the roll or metal belt exceeds 100 ° C, the transparency of the obtained film tends to deteriorate, and if it is less than 10 ° C, problems such as wrinkles in the film during winding may occur. is there.

When the vinylidene fluoride resin composition and the methacrylic resin composition (C) are coextruded, the temperature of the roll or the metal belt is 10 ° C to 80 ° C on the vinylidene fluoride resin composition side. In addition, it is preferable to keep the methacrylic resin composition (C) side at 10 ° C to 100 ° C. Furthermore, by providing a difference in the temperature of the roll or metal belt on the vinylidene fluoride resin composition side and the methacrylic resin composition (C) side, the transparency of the vinylidene fluoride resin (D) and the methacrylic resin can be obtained. It is possible to improve both defects during winding of the composition (C).

In the sandwich molding with the roll or the metal belt of the present invention, the distance from the lip of the die of the extruder to the contact with the roll or the metal belt is preferably 300 mm or less, more preferably 250 mm or less. By setting the distance to contact to 300 mm or less, the time until the molten resin is sandwiched can be shortened, and the effect of sandwiching can be enhanced.

The surface roughness of the roll or metal belt used in the present invention is preferably 0.5 μm or less, and more preferably 0.2 μm or less as the average surface roughness. When the average surface roughness of the roll or metal belt is 0.5 μm or less, the obtained film is smoothed and the transparency can be further increased.

The material of the roll used in the present invention is not particularly limited, but is preferably silicon or metal.

The vinylidene fluoride resin (D) in the present invention may be a vinylidene fluoride homopolymer, a copolymer containing 70 mol% or more of vinylidene fluoride as a constituent unit, or a mixture of these polymers. Absent. Examples of the monomer copolymerized with vinylidene fluoride include ethylene, propylene, ethylene tetrafluoride, propylene hexafluoride, ethylene trifluoride, ethylene trifluoride, vinyl fluoride, and the like. The weights may be used alone or in combination of two or more.

The melting point of these vinylidene fluoride resins is in the range of 145 to 180 ° C, but the vinylidene fluoride resin (D) in the present invention is preferably 165 ° C or higher. When the melting point of the vinylidene fluoride resin (D) is 165 ° C or higher, it is possible to prevent deterioration of transparency after secondary processing such as insert molding, in-mold molding, and lamination molding by thermal roll.

The vinylidene fluoride-based resin film in the present invention may be formed only of the vinylidene fluoride-based resin (D), but has transparency and adhesiveness to the methacrylic resin composition (C) or the object to be laminated. From the point of view, it is preferable that the composition is composed of 50 to 99.9 parts by weight of vinylidene fluoride resin (D) and 0.1 to 50 parts by weight of methacrylic resin composition (C). More preferably 60 to 99.9 parts by weight of vinylidene fluoride resin (D) and 0.1 to 40 parts by weight of methacrylic resin composition (C), more preferably 70 to 99.9 parts by weight of vinylidene fluoride resin (D) and methacrylic resin. Resin composition (C) 0.1 to 30 parts by weight. By containing 0.1 part by weight or more of the methacrylic resin composition (C), transparency and adhesiveness can be improved. If the amount of vinylidene fluoride resin (D) is less than 50 parts by weight, the chemical resistance tends to decrease.

The methacrylic resin composition (C) in the present invention is not particularly limited, but polymerizes the methacrylic acid ester-based polymer (A) in the presence of the acrylic acid ester-based crosslinked elastic body particles (B). The multilayer structure polymer obtained by the above is preferable. Further, the methacrylic acid ester-based polymer (A) and the acrylic acid ester-based crosslinked elastic particle (B) are more preferably in the following range in composition.

The methacrylic acid resin composition (C) in the present invention is a methacrylic acid ester-based polymer (A), an acrylic acid ester-based crosslinked elastic particle (B), and a methacrylic acid ester-based polymer (A) in a stepwise manner. It may be a three-layer structure polymer that polymerizes.

The methacrylic acid ester-based polymer (A) in the present invention comprises polymerizing a monomer mixture containing 50 to 100% by weight of an alkyl methacrylate ester and 0 to 50% by weight of an acrylic acid alkyl ester in at least one stage. It is a thing. More preferably, the methacrylic acid alkyl ester is 60 to 100% by weight, and the acrylic acid alkyl ester is 0 to 40% by weight. If the acrylic acid alkyl ester exceeds 50% by weight, the heat resistance and surface hardness of the film that can be formed from the obtained methacrylic resin composition tend to decrease.

The methacrylic acid alkyl ester constituting the methacrylic acid ester-based polymer (A) in the present invention preferably has an alkyl group having 1 to 12 carbon atoms from the viewpoint of polymerization reactivity and cost, and is branched even if it is linear. It may be in the form. Specific examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate and the like. These monomers may be used alone or in combination of two or more.

The acrylic acid alkyl ester constituting the methacrylic acid ester-based polymer (A) in the present invention preferably has an alkyl group having 1 to 12 carbon atoms from the viewpoint of polymerization reactivity and cost, and is linear or branched. But it may be. Specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, -2-ethylhexyl acrylate, n-octyl acrylate and the like. can give. These monomers may be used alone or in combination of two or more.

In the methacrylic acid ester-based polymer (A) of the present invention, an ethylene-based unsaturated monomer copolymerizable with the methacrylic acid alkyl ester and the acrylic acid alkyl ester may be copolymerized, if necessary. .. Examples of these copolymerizable ethylene-based unsaturated monomers include vinyl halides such as vinyl chloride and vinyl bromide, vinyl cyanide such as acryliconitrile and methacrylic acid, vinyl formate, vinyl acetate, and vinyl propionate. Vinyl esters such as styrene, vinyl toluene, aromatic vinyl derivatives such as α-methylstyrene, vinylidene halide such as vinylidene chloride, acrylic acid such as acrylic acid, sodium acrylate, calcium acrylate and salts thereof, β-acrylic acid. -Acrylic acid alkyl ester derivatives such as hydroxyethyl, dimethylaminoethyl acrylate, glycidyl acrylate, acrylamide, N-methylolacrylamide, methacrylic acid such as methacrylic acid, sodium methacrylate, calcium methacrylic acid and salts thereof, methacrylic acid. Examples thereof include methacrylic acid alkyl ester derivatives such as amide, β-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, and glycidyl methacrylate. These monomers may be used alone or in combination of two or more.

The acrylic acid ester-based crosslinked elastic particles (B) in the present invention are a monomer mixture (b) containing 50 to 100% by weight of an acrylic acid alkyl ester and 50 to 0% by weight of a methacrylic acid alkyl ester, and 2 per molecule. A mixture composed of polyfunctional monomers having a plurality of non-conjugated double bonds is copolymerized in at least one step or more. The monomer mixture (b) is more preferably 60 to 100% by weight of the acrylic acid alkyl ester and 40 to 0% by weight of the methacrylic acid alkyl ester. When the methacrylic acid alkyl ester exceeds 50% by weight, the bending and cracking resistance of the film that can be formed from the obtained methacrylic resin composition tends to decrease.

In the acrylic acid ester-based crosslinked elastic body particles (B) of the present invention, an ethylene-based unsaturated monomer copolymerizable with the methacrylic acid alkyl ester and the acrylic acid alkyl ester may be copolymerized, if necessary. Absent.

The acrylic acid ester-based crosslinked elastic particles (B) in the present invention are obtained because polyfunctional monomers having two or more non-conjugated reactive double bonds per molecule are copolymerized. The coalescence exhibits cross-linking elasticity. In addition, one of the reactive functional groups (double bond) remaining unreacted during the polymerization of the acrylic ester-based crosslinked elastic body particles (B) serves as a graft crossing point, and a certain proportion of the methacrylic acid ester-based copolymer weight is used. The coalescence (A) is grafted onto the acrylic ester-based crosslinked elastic particles (B). As a result, the acrylic acid ester-based crosslinked elastic particles (B) are discontinuously and uniformly dispersed in the methacrylic acid ester-based copolymer (A).

Examples of the polyfunctional monomer used in the present invention include allyl methacrylate, allyl acrylate, triallyl cyanuret, triallyl isocyanurate, diallyl phthalate, diallyl malete, and divinyl adipate. Divinylbenzene ethylene glycol dimethacrylate, divinylbenzeneethylene glycol-lujiacryllate, diethyleneglycoldimethacrylate, diethyleneglycol-ludiacrylet, triethyleneglycoldimethacrylate, triethyleneglycol-ludiacrylate, trimethylolpropane Trimethyllate, Trimethylol Propane Triacryllate, Tetramethylol Methantetramethylate, Tetramethylol Methantetraacryllate, Dipropylene Glycol Dimethacrylate and Dipropylene Glyco-Ludiacrylate And so on. These may be used alone or in combination of two or more.

The amount of the polyfunctional monomer added to the acrylic acid ester-based crosslinked elastic particles (B) of the present invention is preferably 0.05 to 20 parts by weight, preferably 0.1 parts by weight, based on 100 parts by weight of the monomer mixture (b). ~ 10 parts by weight is more preferable. If the amount of the polyfunctional monomer added is less than 0.05 parts by weight, the impact resistance and bending crack resistance of the film that can be formed from the methacrylic resin composition tend to decrease, and even if it exceeds 20 parts by weight. , Impact resistance and bending crack resistance tend to decrease.

This acrylic acid alkyl ester used in the acrylic ester cross-linked elastic particles (B) of the invention, the alkyl methacrylate and copolymerizable with these ethylene examples of alkylene unsaturated monomer, the methacrylic acid Examples thereof include those used for the ester-based polymer (A).

The content of the acrylic acid ester-based crosslinked elastic particle (B) in the present invention is preferably 5 to 45% by weight, preferably 10 to 40% by weight, when the entire methacrylic resin composition (C) is 100% by weight. Is more preferable, and 15 to 35% by weight is further preferable. When the content of the acrylic acid ester-based crosslinked elastic body particles (B) is less than 5% by weight, the impact resistance and bending crack resistance of the film that can be formed from the obtained methacrylic resin composition tend to decrease. If it exceeds 45% by weight, the hardness and moldability of the film tend to decrease.

The methacrylic resin composition (C) in the present invention is more preferably a methacrylic resin composition obtained by copolymerizing an ultraviolet absorber represented by the general formula (1).

<chemistry num="2"><img file="JP4958552B2_D0002.tif" /></chemistry>

(In the formula, X is H or halogen, R₁Is an H, methyl or t-alkyl group with 4-6 carbon atoms, R₂Is a linear or branched alkylene group having 2 to 10 carbon atoms, R₃Is H or methyl. )

The ultraviolet absorber represented by the general formula (1) in the present invention is 2- (2'-hydroxy-5'-methacryloyloxyethylphenyl) -2H-benzotriazoles and 2- (2'-hydroxy-5'. -Acryloyloxyethylphenyl) -2H-benzotriazole, 2- (2'-hydroxy-5'-methacryloyloxyethylphenyl) -2H-benzotriazole, 2- (2'-hydroxy-5'-methacryloyloxyethylphenyl) -5-Chloro-2H-benzotriazole, 2- (2'-hydroxy-5'-methacryloyloxypropylphenyl) -2H-benzotriazole, 2- (2'-hydroxy-5'-methacryloyloxyethyl-3'- t-butylphenyl) -2H-benzotriazole and the like can be mentioned. More preferably, it is 2- (2'-hydroxy-5'-methacryloyloxyethylphenyl) -2H-benzotriazole from the viewpoint of cost and handleability.

The copolymerization ratio of the ultraviolet absorber represented by the general formula (1) in the present invention is preferably 0.01 to 30 parts by weight, more preferably 0.01 to 25 parts by weight, based on 100 parts by weight of the methacrylic resin composition (C). , 0.01 to 20 parts by weight is more preferable, and 0.05 to 20 parts by weight is particularly preferable. If the copolymerization ratio of the ultraviolet absorber represented by the general formula (1) is less than 0.01 parts by weight, the weather resistance of the film that can be formed from the obtained methacrylic resin composition tends to decrease, and if it exceeds 50 parts by weight, it tends to decrease. The impact resistance and bending crack resistance of the film tend to decrease.

The copolymerization of the ultraviolet absorber represented by the general formula (1) in the present invention may be copolymerized in any layer of the methacrylic resin composition (C), but is a methacrylic acid ester-based copolymer (A). ), It is preferable that the acrylic acid ester-based crosslinked elastic body particles (B) are copolymerized, and it is more preferable that the ultraviolet absorber is uniformly copolymerized over the entire methacrylic resin composition (C). .. The method for producing the methacrylic resin composition (C) in the present invention is not particularly limited, and a known emulsion polymerization method, emulsification-suspension polymerization method, suspension polymerization method, massive polymerization method or solution polymerization method can be applied. However, the emulsion polymerization method is particularly preferable.

The method for copolymerizing the ultraviolet absorber represented by the general formula (1) in the present invention is not particularly limited, and it is preferable to copolymerize the methacrylic resin composition (C) during production. As the copolymerization method, known emulsion polymerization methods, emulsification-suspension polymerization methods, suspension polymerization methods, massive polymerization methods or solution polymerization methods can be applied, but the emulsion polymerization method is particularly preferable.

As the initiator in the polymerization of the acrylic acid ester-based crosslinked elastic body particles (B) of the present invention, known initiators such as organic peroxides, inorganic peroxides, and azo compounds can be used. Specifically, for example, t-butyl hydropaoxide, 1,1,3,3-tetramethylbutyl hydropaoxide, succinic acid peroxide, pa-oxymaleic acid t-butyl ester, cumene hydroper. Organic peroxides such as oxides and benzoyl peroxides, inorganic peroxides such as potassium persulfate and sodium persulfate, and oil-soluble initiators such as azobisisobutyronitrile are also used. These may be used alone or in combination of two or more. These initiators are reducing agents such as sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, hydroxyacetone acid, ferrous sulfate, ferrous sulfate and disodium ethylenediamine tetraacetate. It may be used as a combined usual redox-type initiator.

The organic peroxide can be added by a known addition method such as a method of adding it as it is to a polymerization system, a method of adding it by mixing it with a monomer, or a method of dispersing it in an aqueous emulsifier solution. From the viewpoint of transparency, a method of mixing with a monomer and adding the mixture or a method of dispersing the mixture in an aqueous emulsifier solution and adding the mixture is preferable.

In addition, the organic peroxide may be an inorganic reducing agent such as a divalent iron salt and / or a sodium formaldehyde sulfoxylate, a reducing sugar, ascorbic acid, etc. from the viewpoint of polymerization stability and particle size control. It is preferably used as a redox-based initiator in combination with an organic-based reducing agent.

The surfactant used for the emulsion polymerization is not particularly limited, and any ordinary surfactant for emulsion polymerization can be used. Specifically, for example, anionic surfactants such as sodium alkylsulfonate, sodium alkylbenzenesulfonate, sodium dioctylsulfosuccinate, sodium lauryl sulfate, and sodium fatty acid, alkylphenyls, and aliphatic alcohols. Nonionic surfactants such as reaction products of succinates with propylene oxide and ethylene oxide are shown. These surfactants may be used alone or in combination of two or more. Further, if necessary, a cationic surfactant such as an alkylamine salt may be used.

The obtained methacrylic resin composition (C) latex is separated and recovered by a normal coagulation, washing and drying operation, or by a treatment such as spray-drying and freeze-drying.

The vinylidene fluoride resin composition (vinylidene fluoride resin (D) or vinylidene fluoride resin (D) and methacrylic resin composition (C)) of the present invention may contain an inorganic pigment or an inorganic pigment for coloring. Organic dyes, antioxidants, heat stabilizers, UV absorbers, UV stabilizers, etc., or antibacterial, deodorant, lubricants, etc., alone or in combination to further improve stability to heat and light. The above may be added in combination.

The vinylidene fluoride-based resin composition of the present invention (vinylidene fluoride-based resin (D) or vinylidene fluoride-based resin (D) and methacrylic resin composition (C)) is, if necessary, polyglutarimide. , Anhydrous glutarate polymer, lactone cyclized methacrylic resin, methacrylic resin, polyethylene terephthalate resin, polybutylene terephthalate resin and the like can also be blended. The blending method is not particularly limited, and a known method can be used.

The thickness of the vinylidene fluoride resin film of the present invention is preferably 1 to 300 μm, more preferably 5 to 200 μm. If the thickness of the film is less than 1 μm, the processability of the film tends to decrease, and if it exceeds 300 μm, the transparency of the obtained film tends to decrease.

The vinylidene fluoride-based resin film of the present invention can be laminated and molded or modified by biaxial stretching, depending on the intended purpose.

The vinylidene fluoride resin film of the present invention is formed of a vinylidene fluoride resin (a vinylidene fluoride resin (D) or a composition composed of a vinylidene fluoride resin (D) and a methacrylic resin composition). However, from the viewpoint of weather resistance (particularly UV protection ability), cost, moldability, and adhesion to the object to be laminated, the vinylidene fluoride resin layer forming the surface layer and the methacrylic film are used. A vinylidene fluoride-based resin multilayer film composed of a resin composition (C) layer is preferable.

The method for producing a vinylidene fluoride-based resin multilayer film composed of the vinylidene fluoride-based resin layer forming the surface layer in the present invention and the methacrylic resin composition (C) layer is not particularly limited, but is usually laminated. The method can be applied. Specific examples of the laminating method include, for example, (i) a method of laminating the vinylidene fluoride resin film and a methacrylic resin composition (C) film separately produced by melt extrusion or the like using an adhesive. , A method of heating and then crimping the laminated surfaces of both films, and the like, (ii) a method of co-extruding a vinylidene fluoride resin layer and a methacrylic resin composition (C) layer, and the like.

Among these, the coextrusion method of the vinylidene fluoride resin composition and the methacrylic resin composition (C) ensures the adhesiveness between the vinylidene fluoride resin layer and the methacrylic resin composition (C) layer. This is preferable from the viewpoint of ease of controlling the thermal history of the film during the production of the multilayer film.

In the present invention, in the case of the vinylidene fluoride resin multilayer film composed of the vinylidene fluoride resin and the methacrylic resin composition (C), the thickness of the vinylidene fluoride resin layer is 1 to 50 μm, and the methacrylic resin composition (C). ) The thickness of the layer is preferably 20 to 200 μm. If the thickness of the vinylidene fluoride resin layer is less than 1 μm, sufficient weather resistance tends not to be obtained, and if it exceeds 50 μm, it tends to be disadvantageous in terms of cost. If the thickness of the methacrylic resin composition (C) layer is less than 20 μm, wrinkles tend to occur easily when the film is wound, and if it exceeds 200 μm, secondary processability tends to be difficult.

Also in the vinylidene fluoride resin multilayer film of the present invention, the average spherulite diameter of polyvinylidene fluoride is<u style="single">Observing with a transmission electron microscope</u>Detection limit<u style="single">below</u>It is less than 0.1 μm. The average spherulite diameter of polyvinylidene fluoride<u style="single">0.1</u>If it is μm or more, the transparency of the obtained vinylidene fluoride-based resin multilayer film tends to be unsatisfactory.

Also in the vinylidene fluoride resin multilayer film of the present invention, the cloudiness value is 1% or less, preferably 0.9% or less, and more preferably 0.8% or less. If the cloudiness value of the polyvinylidene fluoride resin multilayer film exceeds 1%, the transparency of the obtained vinylidene fluoride resin multilayer film tends to be unsatisfactory.

The vinylidene fluoride-based resin film or the vinylidene fluoride-based resin multilayer film obtained from the vinylidene fluoride-based resin composition of the present invention can reduce the gloss of the film surface by a known method, if necessary. For example, it can be carried out by a method of kneading an inorganic filler or crosslinkable polymer particles into the methacrylic resin composition (C). It is also possible to reduce the gloss on the film surface by embossing the obtained film.

The vinylidene fluoride resin film or multilayer film of the present invention can be used by laminating it on a metal, plastic or the like. Film laminating methods include wet laminating, dry laminating, and extrusion (extrusion), which include laminating molding, applying an adhesive to a metal plate such as a steel plate, and then placing the film on the metal plate, drying it, and pasting it together. ) Lamine, hot melt lamine, etc.

As a method of laminating a film on a plastic part, the film is placed in a mold, insert molding or laminate injection press molding in which resin is filled by injection molding, or placement in the mold after preforming the film. However, in-mold molding in which resin is filled by injection molding can be mentioned.

The film laminated product obtained from the methacrylic resin composition of the present invention can be used as a coating substitute for automobile interior materials, automobile exterior materials, etc., building materials such as window frames, bathroom equipment, wallpaper, floor materials, daily miscellaneous goods, etc. It can be used for furniture and housings for electrical equipment, housings for OA equipment such as facsimiles, and parts for electrical or electronic equipment. Molded products include lighting lenses, automobile headlights, optical lenses, optical fibers, optical fibers, light guide plates for liquid crystals, liquid crystal films, medical supplies requiring sterilization, microwave oven cooking containers, housings for home appliances, etc. It can be used for toys or recreational items.

Next, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

The methods for measuring the physical properties measured in the following examples and comparative examples are as follows.

(Evaluation of crystallinity by electron microscope observation) When the obtained film was sample-prepared by the frozen ultrathin section method and then observed at a magnification of 10000 at an acceleration voltage of 80 kV using a transmission electron microscope (JEM-1200EX, manufactured by JEOL Ltd.). The crystal diameter of vinylidene fluoride was measured &lt;detection limit is 0.1 μm&gt;. The crystal diameter was measured using a caliper for 10 spherulites in the electron microscopic observation photograph, and the average value was taken as the average spherulite diameter.

(Evaluation of crystallinity by laser small-angle scattering method) The obtained film was immersed in chloroform, the base resin layer was dissolved, and the obtained polyvinylidene fluoride film was shifted by 45 degrees and eight sheets were laminated to prepare a measurement sample, and then a He-Ne gas laser (He-Ne gas laser) was used as a laser light source. Small-angle light scattering measurements were performed using NeoArc Co., Ltd., NEO-15MS; 15 mV, 632.8 nm) and a PDA detector (photodiode array S6494-128, manufactured by Hamamatsu Photonics Co., Ltd.). Scattering vector Q with maximum scattering intensity_max(nm^-1) Is obtained from curve fitting, and the average spherulite radius R is calculated from the following equation.₀Was calculated. R₀(Average spherulite radius) = 4.09 / Q_max

(Evaluation of polymerization conversion rate) The obtained methacrylic resin composition (C) latex was dried in a hot air dryer at 120 ° C. for 1 hour to determine the amount of solid component, and the polymerization conversion rate (%) = 100 × amount of solid component / charged single. The polymerization conversion rate (%) was calculated by the formula of the monomer.

(Evaluation of transparency) For the transparency of the obtained film, the cloudiness value (haze) was measured under the conditions of a temperature of 23 ° C ± 2 ° C and a humidity of 50% ± 5% according to JIS K6714.

(Evaluation of chemical resistance) A drop of xylene was dropped on the film and the change in the film was visually evaluated. : No change is observed. X: Drop marks are observed.

(Evaluation of bending and cracking resistance) The obtained film was bent 180 degrees once, and the change in the bent portion was visually evaluated. : No cracks are found ×: Cracks are observed.

(Evaluation of moldability) Film molding was performed continuously for 3 hours, the operating condition was observed, and evaluation was made according to the following criteria. : The film has a uniform thickness and can be molded without cutting. X: The film thickness is uneven or the film breaks.

(Evaluation of bleeding property of UV absorber) Film molding was carried out continuously for 3 hours, the state of adhesion to the cooling roll was observed, and evaluation was made according to the following criteria. : No adhesion to the cooling roll is observed. X: Adhesion to the cooling roll is observed.

In addition, "parts" in Production Examples, Examples and Comparative Examples represent parts by weight, and "%" represents% by weight. In addition, the abbreviations represent the following substances, respectively. PVDF-1: SOLEF1010 (SOLVAY, PVDF homopolymer) PVDF-2: SOLEF1008 (SOLVAY, PVDF homopolymer) PVDF-3: SOLEF11010 (SOLVAY, PVDF copolymer) BA: Butyl acrylate MMA: Methyl methacrylate CHP: Cumene hydroperoxide tDM: Tasha Dodecyl Mercaptan AlMA: allyl methacrylate RUVA: 2- (2'-Hydroxy-5'-methacryloyloxyethylphenyl) -2-H-benzotriazole (manufactured by Otsuka Chemical Co., Ltd., RUVA-93)

(Production Example 1) Production of methacrylic resin composition The following substances were charged into an 8L polymerization device with a stirrer. 200 copies of deionized water Sodium dioctyl succinate 0.25 part Sodium Formaldehyde Sulfoxylate 0.15 copies Ethylenediaminetetraacetic acid-2-sodium 0.001 part Ferrous sulfate 0.00025 parts

After sufficiently replacing the inside of the polymerization machine with nitrogen gas to make it substantially oxygen-free, the internal temperature was set to 60 ° C., and the monomer mixture (B) shown in Table 1 (1) (that is, BA90%) was set. And 100 parts of the monomer mixture consisting of 10% MMA, 30 parts of the monomer mixture consisting of 1 part of AlMA and 0.2 parts of CHP, and 0.6 parts of RUVA) were continuously added at a ratio of 10 parts / hour. After completion, the polymerization was continued for another 0.5 hour to obtain acrylic ester-based crosslinked elastic particles (B). The polymerization conversion rate was 99.5%.

Then, after charging 0.05 part of sodium dioctyl succinate, the internal temperature was adjusted to 60 ° C, and the monomer mixture (A) shown in (1) in Table 1 &lt;that is, a simple substance consisting of 10% BA and 90% MMA. 70 parts of a monomer mixture consisting of 0.5 parts of tDM and 0.5 parts of CHP and 1.4 parts of RUVA&gt; were continuously added at a ratio of 10 parts / hour to 100 parts of the body mixture, and polymerization was further carried out for 1 hour. Subsequently, a methacrylic resin composition (C) was obtained. The polymerization conversion rate was 98.5%. The obtained latex was salted out with calcium chloride, coagulated, washed with water and dried to obtain a resin powder (1). In addition, 40 mm<u style="single">Diameter (φ)</u>Using a single-screw extruder with a vent (HV-40-28, manufactured by Tabata Industrial Machinery Co., Ltd.), the cylinder temperature was set to 240 ° C and melt-kneading was performed to pelletize.

<tables num="1"><img file="JP4958552B2_D0003.tif" /></tables>

(Manufacturing examples 2 to 7) Polymerization was carried out in the same manner as in Production Example 1 except that the monomer composition of the monomer mixture (B) or the monomer mixture (A) was changed as shown in Table 1, and the resin powder was coagulated, washed with water, and dried. (2) to (7) were obtained, and further melt-kneaded and pelletized. However, in Production Example (4), since the latex aggregated during the polymerization, the resin powder (4) could not be obtained, pelletization and film formation could not be performed, and the film physical characteristics could not be evaluated.

Further, in the production example (3), two parts of tinubin P (manufactured by Ciba Special Chemical Co., Ltd.) represented by the structural formula (2) are blended with the obtained resin powder (3) as an ultraviolet absorber, and then melt-kneaded. , Pelletized.

<chemistry num="3"><img file="JP4958552B2_D0004.tif" /></chemistry>

(Manufacturing example 8) 98 parts of PVDF-1 and 2 parts of resin powder (1) prepared in Production Example (1) are blended with a Henschel mixer and 40 mm.<u style="single">Diameter (φ)</u>Using a single-screw extruder with a vent (HV-40-28, manufactured by Tabata Industrial Machinery Co., Ltd.), the cylinder temperature was set to 240 ° C and melt-kneading was performed to pelletize.

(Manufacturing example 9) Production example except for changing to 45 parts of PVDF-1 and 55 parts of resin powder (1) prepared in production example (1).<u style="single">8</u>Blend with a Henschel mixer in the same way as, 40 mm<u style="single">Diameter (φ)</u>Using a single-screw extruder with a vent (HV-40-28, manufactured by Tabata Industrial Machinery Co., Ltd.), the cylinder temperature was set to 240 ° C and melt-kneading was performed to pelletize.

(Manufacturing example 10) Production example except that it was changed to 98 parts of PVDF-1 and 2 parts of resin powder (2) prepared in production example (2).<u style="single">8</u>Blend with a Henschel mixer in the same way as, 40 mm<u style="single">Diameter (φ)</u>Using a single-screw extruder with a vent (HV-40-28, manufactured by Tabata Industrial Machinery Co., Ltd.), the cylinder temperature was set to 240 ° C and melt-kneading was performed to pelletize.

(Manufacturing example 11) Two parts of Tinubin P (manufactured by Ciba Special Chemical Co., Ltd.) represented by the structural formula (2) are blended as an ultraviolet absorber with 45 parts of PVDF-1 and 55 parts of the resin powder (3) prepared in Production Example (3). Then, as in Production Example 10, blend with a Henschel mixer and 40 mm.<u style="single">Diameter (φ)</u>A cylinder temperature was set to 240 ° C. using a single-screw extruder with a vent, and melt-kneading was performed to pelletize.

(Examples 1 to 8, Comparative Examples 1 to 4) The methacrylic resin composition obtained in Production Example (1) is used as the base resin, and the resin composition shown in Table 2 is used as the surface layer resin. The film was molded at a die temperature of 240 ° C. and sandwiched between metal rolls controlled under the temperature conditions shown in Table 2 to obtain a film having a thickness of 60 μm (base resin layer 53 μm and surface resin layer 7 μm).

Various characteristics of the obtained film were evaluated, and the results are shown in Table 2.

<tables num="2"><img file="JP4958552B2_D0005.tif" /></tables>

Observation photographs (10000 times) of Example 1 and Comparative Example 1 with a transmission electron microscope are shown in FIGS. 1 and 2.

Regarding Example 1 and Comparative Example 1, the average crystal radius R of polyvinylidene fluoride obtained by the small-angle laser scattering method was used.₀However, in Example 1, the scattering intensity was weak and was not detected, and no spherulite formation was observed, but in Comparative Example 1, R was observed.₀= 1.48 μm (average spherulite diameter was 2.96 μm).

(Examples 9 to 13) Extruder with 2 types 2 layer T die (feed block method) (2 60mm extruders) using the methacrylic resin composition shown in Table 3 obtained in the production example as the base resin and PVDF-1 as the surface layer resin. Was molded at a die temperature of 240 ° C. and sandwiched between rolls under the temperature conditions shown in Table 3 to obtain a film having a thickness of 60 μm (base resin layer 53 μm and surface resin layer 7 μm).

Various characteristics of the obtained film were evaluated, and the results are shown in Table 3.

<tables num="3"><img file="JP4958552B2_D0006.tif" /></tables>

By sandwiching it with a roll, a film having excellent transparency could be obtained. Further, when the monomer composition ratio of the methacrylic resin composition (C) and the content of the acrylic acid ester-based crosslinked elastic particles (B) are out of the scope of the present invention, the obtained film is resistant to bending and cracking. It was found that the property and moldability were reduced.

<figref num="1"><u style="single">FIG. 1 shows the present invention.</u>Transmission electron microscope observation photograph of Example 1 (magnification 10000 times); The layer that looks black (surface layer) is a vinylidene fluoride resin layer, and the spherulite structure as seen in FIG. 2 is not observed (detection). Limit 0.1 μm).</figref><figref num="2"><u style="single">Figure 2 shows</u>Transmission electron microscope observation photograph of Comparative Example 1 (magnification 10000 times); The layer (surface layer) that looks black is a vinylidene fluoride resin layer, and spherulites with an average diameter of 3.0 μm are observed throughout.</figref>

Code description

1 Vinylidene fluoride resin layer 2 Methacrylic resin composition layer