JP5473309B2 - Acrylic resin film for covering bathroom interior materials - Google Patents

Description

  The present invention relates to an acrylic resin film for covering bathroom interior materials, and more particularly, the present invention is suitable for forming a protective layer on a surface that is integrated with various base materials by laminating, etc. The present invention relates to an acrylic resin film for covering a bathroom interior material that can withstand long-term warm water.

  Taking advantage of the excellent characteristics of acrylic resin film such as transparency, flexibility, and workability, a coating film for bathroom interior materials that has a deep appearance is used by laminating a specific acrylic resin film on the surface. ing.

  In addition, the acrylic resin film can be printed on a surface other than the surface that is in direct contact with hot water, and can be laminated on various base materials to enhance the design of the base material surface. However, acrylic resin films for covering bathroom interior materials have been required to have excellent warm water whitening resistance because they are in contact with warm water. A method for controlling the amount of calcium remaining in the acrylic resin film within a specific range in response to such a request (for example, see Patent Document 1), or a method for setting the water-soluble substance in the acrylic resin film to 200 ppm or less (for example, , See Patent Document 2).

  However, even acrylic resin films obtained by these methods have not been able to withstand recent demands for hot water whitening resistance.

JP 2000-191804 A JP 2003-277528 A

  One object of the present invention is to provide an acrylic resin film for covering a bathroom interior material having better hot water whitening resistance.

  According to one aspect of the present invention, there is provided a rubber-containing polymer (B) having an acrylic thermoplastic polymer (A) of 70.5 to 94.5% by mass and a weight average particle diameter of 0.08 to 0.18 μm. ) For covering a bathroom interior material, containing 5.5 to 29.5% by mass, having a thickness of 25 to 300 μm, and having a haze value of 3% or less after being immersed in warm water at 80 ° C. for 240 hours It is an acrylic resin film.

  The acrylic resin film for covering a bathroom interior material according to the present invention, which has good initial transparency and good long-term warm water resistance, can change the design (color, design, etc.) of the bathroom interior material covered with the film. Can be suppressed.

  Such acrylic resin films for covering bathroom interior materials are particularly suitable for applications such as bathroom interior wall materials, bathtub lids, kitchens, washrooms and toilets, humidifiers, dishwashers, etc. can do.

Hereinafter, the present invention will be described in detail, but this is to explain preferred embodiments of the present invention, and the present invention is not limited to only these embodiments.
Below, the preferable acrylic resin film in this invention is demonstrated.

<Acrylic resin film>
The acrylic resin film of the present invention contains 70.5 to 94.5% by mass of an acrylic thermoplastic polymer (A) and 5.5 to 29.5% by mass of a rubber-containing polymer (B). When the content of the acrylic thermoplastic polymer (A) is 70.5% by mass or more, the long-term warm water whitening resistance is good, and when it is 94.5% by mass or less, the film forming property is obtained. Becomes better.

<Acrylic thermoplastic polymer (A)>
The acrylic thermoplastic polymer (A) contains 50 to 100% by mass of an alkyl methacrylate unit having an alkyl group having 1 to 4 carbon atoms and a unit derived from another vinyl monomer copolymerizable therewith. A homopolymer or copolymer consisting of ˜50% by mass (a total of 100% by mass of the above-mentioned alkyl methacrylate and other copolymerizable vinyl monomers).

  As the alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, methyl methacrylate is most preferable.

  When the acrylic thermoplastic polymer (A) is a copolymer, other vinyl monomers copolymerizable with alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms include, for example, methyl acrylate, ethyl acrylate, butyl Alkyl acrylates such as acrylate, propyl acrylate and 2-ethylhexyl acrylate; alkyl methacrylates such as butyl methacrylate, propyl methacrylate, ethyl methacrylate and methyl methacrylate; aromatic vinyl compounds such as styrene, α-methylstyrene and paramethylstyrene; acrylonitrile, methacrylate Examples thereof include vinylcyan compounds such as ronitrile.

  Two or more kinds of the above-mentioned alkyl methacrylate, alkyl acrylate, and other monomers can be used as necessary.

  The acrylic thermoplastic polymer (A) preferably has a heat distortion temperature of 90 ° C. or higher. When this heat distortion temperature is low, the hot water resistance of the resulting film is inferior, which is not preferable for practical use. The acrylic thermoplastic polymer having this heat distortion temperature can be obtained by appropriately selecting the type and ratio of the monomer, the amount of chain transfer agent, and the like. Although depending on the type of other monomers to be copolymerized, it is preferable to use 92% by mass or more of methyl methacrylate as the monomer. The “thermal deformation temperature” is a value measured based on ASTM D648.

The acrylic thermoplastic polymer (A) can be produced by polymerizing the above-described monomer component by a generally known method such as a suspension polymerization method, an emulsion polymerization method, or a bulk polymerization method. It is preferable that 0.1 g of acrylic thermoplastic polymer (A) is dissolved in 100 ml of chloroform and the reduced viscosity η _SP / C measured at 25 ° C. is 0.075 liter / g or less. When the reduced viscosity η _SP / C is 0.075 liter / g or less, the film forming property is good. In order to make the reduced viscosity within a predetermined range, specifically, a chain transfer agent may be used in the monomer component for obtaining the acrylic thermoplastic polymer (A). As the chain transfer agent, various conventionally known ones can be used, and mercaptans are particularly preferable. What is necessary is just to determine suitably the usage-amount of a chain transfer agent with the kind and composition of a monomer. Generally, when a large amount of chain transfer agent is used, the value of reduced viscosity becomes small.

  As an acrylic thermoplastic polymer (A), what is industrially available as Mitsubishi Rayon Co., Ltd. Dianal BR series and Mitsubishi Rayon Co., Ltd. acrylpet can be used, for example.

<Rubber-containing polymer (B)>
In one embodiment, the rubber-containing polymer (B) used in the present invention is a monomer or monomer containing 50% by mass or more of alkyl methacrylate in the presence of an elastic polymer containing 50% by mass or more of alkyl acrylate. It is a polymer obtained by polymerizing a monomer mixture.

  Further, the amount of the elastic polymer used in the rubber-containing polymer (B) is preferably 70% by mass or less. The monomer or monomer mixture polymerized in the presence of the elastic polymer may be polymerized in one stage, or may be polymerized in two stages or three stages.

  The elastic polymer in the rubber-containing polymer (B) may be linear or branched consisting of 50% by mass or more of alkyl acrylate. Specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate and the like. These can be used alone or in admixture of two or more. Of these, n-butyl acrylate is preferred. These can be used alone or in admixture of two or more. Among these, n-butyl acrylate is preferable. It is preferable to use a polyfunctional monomer as a part of the monomer constituting the elastic polymer. As the polyfunctional monomer, for example, alkylene glycol dimethacrylate such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and propylene glycol dimethacrylate is preferably used. In addition, polyvinyl benzene such as divinylbenzene and trivinylbenzene, triallyl cyanurate, triallyl isocyanurate, and the like can also be used. These can be used individually by 1 type or in combination of 2 or more types. The amount of the polyfunctional monomer used is preferably 0.1 to 10% by mass in the total monomers.

  Specific examples of the preferred rubber-containing polymer (B) include the following polymers (I), (II), and (III).

  In the present invention, the “rubber-containing polymer” refers to a polymer having a glass transition temperature (Tg) of less than 25 ° C. of a monomer homopolymer or a monomer mixture copolymer constituting the polymer. Tg can be calculated from the FOX equation using values described in the Polymer Handbook [Polymer HandBook (J. Brandrup, Interscience, 1989)].

  The polymer (I) as a specific example of the rubber-containing polymer (B) used in the present invention is an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms. In the presence of a rubber polymer obtained by polymerizing the monomer (IA) having at least a graft crossing agent as a constituent component, at least an alkyl methacrylate having a C 1-4 alkyl group as a constituent component It is a polymer obtained by polymerizing the monomer (IB). Here, when each of the monomers (IA) and (IB) is polymerized, they can be polymerized in a lump or in two or more stages.

  Further, the polymer (II) as a specific example of the rubber-containing polymer (B) used in the present invention includes (1) an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl having 1 to 4 carbon atoms. (2) having an alkyl group having 1 to 8 carbon atoms in the presence of a polymer obtained by polymerizing a monomer (II-A) comprising at least an alkyl methacrylate having a group and a graft crossing agent as a constituent component A monomer having a composition different from that of the monomer (II-A), comprising at least constituents of an alkyl acrylate and / or an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent (II-B) To obtain a rubber polymer, and in the presence thereof, (3) an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms is used as at least a constituent component. It is a polymer obtained by polymerizing the dimer (II-C).

  Further, the polymer (III) as a specific example of the rubber-containing polymer (B) used in the present invention is (1) an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and / or an alkyl having 1 to 4 carbon atoms. A monomer (III-A) comprising at least an alkyl methacrylate having a group and a graft crossing agent as a constituent component to obtain a polymer, and in the presence thereof, (2) having an alkyl group having 1 to 8 carbon atoms A monomer (III-B) comprising at least an alkyl acrylate and a graft crossing agent as a constituent component is polymerized to obtain a rubber polymer, and in the presence thereof, (3) an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms. And / or a monomer (II) comprising at least an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and a graft crossing agent as constituents -C) was polymerized, a further (4) comprising at least as constituents alkyl methacrylate having an alkyl group of 1 to 4 carbon atoms monomer (III-D) polymer obtained by polymerizing.

  The amount of the monomer or monomer mixture containing 50 parts by mass or more of alkyl methacrylate used in the rubber-containing polymer (B) used in the present invention is determined from the viewpoint of transparency of the acrylic resin film. It is preferable that it is 40 mass parts or more with respect to 100 mass parts of unification (B). When the amount is less than 40 parts by mass, the dispersibility of the rubber-containing polymer (B) decreases, and the transparency of the resulting film tends to decrease. More preferably, it is 80 parts by mass or more, and the upper limit is 900 parts by mass or less from the viewpoint of film formability and laminating properties of the film.

  The alkyl acrylate having an alkyl group having 1 to 8 carbon atoms may be either linear or branched. Specific examples thereof include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate and the like. These can be used alone or in admixture of two or more. Of these, n-butyl acrylate is preferred.

  The alkyl methacrylate having 1 to 4 carbon atoms may be either linear or branched. Specific examples thereof include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate and the like. These can be used alone or in admixture of two or more. Of these, methyl methacrylate is preferred.

  Along with the alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and the alkyl methacrylate having 1 to 4 carbon atoms, a vinyl monomer or a polyfunctional monomer copolymerizable therewith may be used as necessary. it can.

  Examples of the copolymerizable vinyl monomer include acrylic monomers such as lower alkoxy acrylate, cyanoethyl acrylate, acrylamide, acrylic acid, and methacrylic acid, styrene, alkyl-substituted styrene, acrylonitrile, methacrylonitrile, and the like. . These can be used alone or in combination of two or more.

  A polyfunctional monomer is defined as a monomer having two or more copolymerizable double bonds in one molecule. Preferable specific examples thereof include alkylene glycol dimethacrylates such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and propylene glycol dimethacrylate. In addition, polyvinylbenzene such as divinylbenzene and trivinylbenzene can be used. Of these, 1,3-butylene glycol dimethacrylate is preferred. The graft crossing agent is defined as a monomer having two or more different copolymerizable double bonds in one molecule. Specific examples thereof include allyl, methallyl, or crotyl ester of copolymerizable α, β-unsaturated carboxylic acid or dicarboxylic acid. In particular, acrylic acid, methacrylic acid, maleic acid, or acrylic ester of fumaric acid is preferable. Of these, allyl methacrylate is preferable because of its excellent effect. In addition, triallyl cyanurate, triallyl isocyanurate and the like are also effective. In the graft crossing agent, the conjugated unsaturated bond of the ester mainly reacts and bonds much faster than the allyl group, methallyl group, or crotyl group. A substantial portion of the allyl, methallyl, or crotyl group works effectively during the polymerization of the next layer polymer to provide a graft bond between adjacent two layers.

  Moreover, although it does not specifically limit, a chain transfer agent can be used at the time of superposition | polymerization of the monomer or monomer mixture containing 50 mass% or more of alkyl methacrylate, and the molecular weight of the polymer obtained can be adjusted. This chain transfer agent is preferably selected from those usually used for radical polymerization, and specific examples thereof include alkyl mercaptans having 2 to 20 carbon atoms, mercapto acids, thiophenol, carbon tetrachloride, and the like. These can be used alone or in admixture of two or more. The content of the chain transfer agent is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the monomer or monomer mixture. More preferably, it is 0.2 mass part or more, Most preferably, it is 0.3 mass part or more.

<Method for producing rubber-containing polymer (B)>
As the method for producing the rubber-containing polymer (B), the sequential polymerization method is the most suitable polymerization method. The production is not particularly limited to this, and for example, it can be carried out by an emulsion suspension polymerization method in which after emulsion polymerization, the polymer is converted into a suspension polymerization system at the time of polymerization of each polymer.

  As the surfactant used when preparing the emulsion, an anionic, cationic or nonionic surfactant can be used, and an anionic surfactant is particularly preferable. Examples of the anionic surfactant include rosin soap; potassium oleate, sodium stearate, sodium myristate, sodium N-lauroyl sarcosinate, dipotassium alkenyl succinate, and the like; sulfate salts such as sodium lauryl sulfate Sulfonic acid salts such as sodium dioctylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium alkyldiphenyl ether disulfonate; phosphate esters such as polyoxyethylene alkylphenyl ether sodium phosphate; polyoxyethylene alkyl ether phosphate Examples thereof include sodium phosphate salts and the like. Of these, phosphate esters such as polyoxyethylene alkyl ether sodium phosphates are preferable from the viewpoint of ecological protection from endocrine disrupting chemicals, which have become a problem in recent years.

  Preferred specific examples of the surfactant include NC-718 manufactured by Sanyo Chemical Industries, phosphanol LS-529, phosphanol RS-610NA, phosphanol RS-620NA, and phospha Nord RS-630NA, Phosphanol RS-640NA, Phosphanol RS-650NA, Phosphanol RS-660NA, Latemu P-0404, Latemulu P-0405, Latemulu P-0406, Latemulu P-0407 manufactured by Kao Corporation Is mentioned.

  Moreover, as a method for preparing an emulsion, a method in which a monomer is charged in water and then a surfactant is added, a method in which a surfactant is charged in water and then a monomer is charged, a monomer Examples thereof include a method in which water is added after a surfactant is charged therein. Among these methods, the method of charging the surfactant after charging the monomer into water and the method of charging the monomer after charging the surfactant into water are the methods for obtaining the rubber-containing polymer (B). preferable.

  In addition, as a mixing device for preparing an emulsion prepared by mixing the monomer that gives the first-stage polymer constituting the rubber-containing polymer (B) with water and a surfactant, stirring is performed. Stirrers equipped with blades; various forced emulsifiers such as homogenizers and homomixers; membrane emulsifiers and the like.

  Further, the emulsion to be prepared may have either a W / O type or an O / W type dispersion structure, and in particular, an O / W type in which monomer oil droplets are dispersed in water. The diameter is preferably 100 μm or less.

  A well-known thing can be used as a polymerization initiator. As the addition method, a method of adding to one or both of the aqueous phase and the monomer phase can be adopted. Particularly preferred polymerization initiators include peroxides, azo initiators, or redox initiators in which an oxidizing agent / reducing agent is combined. Among these, a redox initiator is more preferable, and a sulfoxylate initiator combined with ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, longalite, and hydroperoxide is particularly preferable.

  The rubber-containing polymer (B) can be produced by recovering the rubber-containing polymer from the polymer latex produced by the above-described method. The method for recovering the rubber-containing polymer (B) from the polymer latex is not particularly limited, and examples thereof include salting out or acid precipitation coagulation, spray drying, freeze drying, and the like, and the powder is recovered in a powder form.

<Weight average particle diameter of rubber-containing polymer (B)>
The weight average particle diameter of the rubber-containing polymer (B) used in the present invention is 0.08 to 0.18 μm. From the viewpoint of warm water resistance of the acrylic resin film for covering a bathroom interior material, it is preferably 0.18 μm or less, more preferably 0.15 μm or less. If it is 0.08 μm or less, the flexibility of the acrylic resin film may be impaired. As will be described later, the particle size of the rubber-containing polymer (B) is measured by a dynamic light scattering method.

<Amount of use of rubber-containing polymer (B)>
In this invention, a rubber containing polymer (B) can be used in the range which does not impair the warm water resistance of the acrylic resin film for coating | covering a bathroom interior material. The rubber-containing polymer (B) is contained in an amount of 5.5% by mass or more, and more preferably in an amount of 10% by mass or more, from the viewpoint of the film production process, the slitting process, and the laminate property. The amount of the rubber-containing polymer (B) is 29.5% by mass or less. When the amount of the rubber-containing polymer (B) is 30% by mass or more, long-term warm water resistance tends to be lowered.

<Recovery method of rubber-containing polymer (B)>
The rubber-containing polymer (B) can be produced by recovering the rubber-containing polymer from the polymer latex produced by the above-described method. The method for recovering the rubber-containing polymer from the polymer latex is not particularly limited, and examples thereof include salting out or acid precipitation coagulation, spray drying, freeze drying and the like. By such a recovery method, the rubber-containing polymer is recovered in powder form.

<Ultraviolet absorber>
The acrylic resin film of this invention may contain various additives, such as a ultraviolet absorber, as needed. The ultraviolet absorber to be added is not particularly limited, but the types of ultraviolet absorbers that can be used in the present invention are listed as follows.
Examples include benzotriazole-based UV absorbers, benzophenone-based UV absorbers, benzoate-based UV absorbers, cyanoacrylate-based UV absorbers, and triazine-based UV absorbers. Examples of commercially available products of these compounds and compositions containing these compounds include, for example, trade names: Tinuvin 234, Tinuvin 1577, manufactured by Ciba Specialty Chemicals Co., Ltd., trade names: Adeka Stub LA manufactured by Adeka Corporation -31, Adekastab LA-32, Adekastab LA-46, manufactured by BASF, Uvinul 3035.

  The molecular weight of the ultraviolet absorber is preferably 300 or more, more preferably 400 or more. When a UV absorber having a molecular weight of 300 or more is used, volatilization of the UV absorber when the pressure in the extrusion process and the film forming process is reduced can be suppressed, and adhesion to various rolls in the film forming process due to such volatilization. Can be prevented. In addition, an ultraviolet absorber having a higher molecular weight is generally less prone to long-term bleed out from the acrylic resin film, and is preferable from the viewpoint of maintaining the appearance over a long period of time.

  The amount of the ultraviolet absorber added to the acrylic resin film is preferably 0 to 2 parts by mass with respect to a total of 100 parts by mass of the acrylic thermoplastic polymer (A) and the rubber-containing polymer (B). More preferably, it is 0.2-1.8 mass parts.

  When the amount of the ultraviolet absorber is less than 0.1 parts by mass, the weather resistance of the article protected by the acrylic resin film is poor and the deterioration is rapid. On the other hand, in order to give sufficient weather resistance, when the amount of the UV absorber is more than 5 parts by weight, the long-term warm water resistance is lowered, and the appearance quality due to bleeding in the film forming process is impaired. There is a problem that the laminate roll is soiled during lamination.

<Other additives>
Acrylic resin film, especially in terms of protection of components that are directly exposed to sunlight, to provide weather resistance, if necessary, in combination with UV absorbers, such as light stabilizers such as hindered amine radical scavengers An additive may be included. As a commercial item of the composition containing these hindered amine type radical scavengers, for example, trade names manufactured by Ciba Specialty Chemicals: Chimassorb 119FL, 2020FDL, 944FD, 944LD, Tinuvin 123S, 765, 770, Sankyo Product names manufactured by Co., Ltd .: Sanol LS-770, LS-765, LS-292, product names manufactured by Adeka Co., Ltd .: ADK STAB LA-57, LA-62, LA-67, LA-68, etc. Can do.
Moreover, in order to prevent the design fall by mold | fungi, an antibacterial agent, mold prevention agent, etc. can also be included.

<Processing aid>
Moreover, when shape | molding the acrylic resin film of this invention, a processing aid can also be added from the point of film forming stabilization. For example, the processing aid is obtained by polymerizing 50 to 100% by mass of methyl methacrylate and 0 to 50% by mass of another vinyl monomer copolymerizable therewith, and its reduced viscosity (polymer 0). 0.1 g is dissolved in 100 ml of chloroform and measured at 25 ° C.) is 0.2-2 L / g acrylic polymer. A preferred reduced viscosity is 0.2 to 1.2 L / g, and a particularly preferred reduced viscosity is 0.2 to 0.8 L / g. The processing aid is commercially available as Metablene P manufactured by Mitsubishi Rayon Co., Ltd.

  The blending amount of the processing aid is preferably 0 to 2.0 parts by mass with respect to 100 parts by mass in total of the acrylic thermoplastic polymer (A) and the rubber-containing polymer (B). If the blending amount exceeds 2.0 parts by mass, the long-term hot water resistance of the acrylic resin film tends to decrease. A more preferable blending amount is 0.5 to 1.5 parts by mass.

<Compound>
As a method of adding a compounding agent such as a processing aid, a composition containing an acrylic thermoplastic polymer (A) and a rubber-containing polymer (B) in a molding machine when the acrylic resin film of the present invention is molded. There are a method of supplying a compound together with a product, and a method of kneading and mixing a mixture containing a rubber-containing polymer (B) and a mixture in which a compounding agent is previously added to an acrylic thermoplastic polymer (A). . Examples of the kneader used in the latter method include ordinary single screw extruders, twin screw extruders, Banbury mixers, roll kneaders, and the like.

<Method for producing acrylic resin film>
The acrylic resin film of this invention can be used as a multilayer resin molded product by laminating | stacking with a resin molded product etc. as mentioned later. The method for producing the acrylic resin film used for the surface layer of the multilayer resin molded product of the present invention is not particularly limited. Examples of the production method include known melt extrusion methods such as a melt casting method, a T-die method, and an inflation method. Of these, the T-die method is most preferable in terms of economy.

  The thickness of the acrylic resin film of the present invention for laminating a bathroom interior material, particularly an interior wall material, is not particularly limited, but is, for example, 25 to 300 μm in terms of film properties and processability. preferable. Moreover, since it becomes moderate rigidity as it is 40-150 micrometers, lamination property, secondary workability, etc. become favorable, and also film forming property becomes stable and manufacture of a film becomes easy.

<Transparency and resistance to warm water whitening>
It is preferable that the haze value of the acrylic resin film of the present invention measured in accordance with JIS K 7136 (ISO14782) is 3% or less. The haze value is preferably 1% or less.

Further, in the acrylic resin film of the present invention, the haze value after being immersed in warm water at 80 ° C. for 240 hours is required to be 3% or less. In order to obtain such a film, it is achieved by controlling the type of acrylic thermoplastic polymer (A), the particle size and content of the rubber-containing polymer (B), the type and amount of additives, etc. can do. For example, as described above, when an acrylic thermoplastic polymer having a low heat distortion temperature is used, when an acrylic thermoplastic polymer having a high molecular weight (high reduction viscosity) is used, a large amount of processing aid is used. In some cases, when the particle size of the rubber-containing polymer is large, or when the amount of the rubber-containing polymer used is large, the haze value after being immersed in warm water at 80 ° C. for 240 hours may exceed 3%.
Accordingly, an acrylic thermoplastic polymer having a high heat distortion temperature, an acrylic thermoplastic polymer having a low molecular weight (low reduced viscosity), or the like, and a rubber-containing polymer (B) having a specific particle size range are used. An acrylic resin film having a haze value of 3% or less after being immersed in warm water at 80 ° C. for 240 hours can be obtained.

<Lamination method>
The acrylic resin film of the present invention can be laminated using a coextrusion method such as a coextrusion T-die method or a coextrusion lamination method. Moreover, an acrylic resin film can be laminated | stacked on shaping | molding resin by utilizing well-known methods, such as a dry lamination, a heat lamination, and a film lamination method suitably. Of course, any method applicable to the present invention other than these methods can be adopted. Of these, the coextrusion method and the film lamination method are preferred, and the film lamination method is particularly preferred because the apparatus can be easily obtained and a laminated sheet having a stable quality can be easily obtained.

<Laminated resin>
The type of the molding resin used in the present invention is not particularly limited, and any resin that can be injection molded can be used. Examples of such molding resins include polyethylene resins, polypropylene resins, polybutene resins, polymethylpentene resins, ethylene-propylene copolymer resins, ethylene-propylene-butene copolymer resins, and olefin thermoplastics. Olefin resins such as elastomers, polystyrene resins, ABS (acrylonitrile / butadiene / styrene copolymers) resins, AS (acrylonitrile / styrene copolymers) resins, acrylic resins, urethane resins, unsaturated polyesters And general-purpose thermoplastic or thermosetting resins such as epoxy resins and epoxy resins. Also, general engineering resins such as polyphenylene oxide / polystyrene resins, polycarbonate resins, polyacetal resins, polycarbonate modified polyphenylene ether resins, polyethylene terephthalate resins, polysulfone resins, polyphenylene sulfide resins, polyphenylene oxide resins, polyethers Super engineering resins such as imide resins, polyimide resins, liquid crystal polyester resins, and polyallyl heat resistant resins can also be used. Furthermore, reinforcing materials such as glass fibers and inorganic fillers (talc, calcium carbonate, silica, mica, etc.), composite resins to which modifiers such as rubber components are added, and various modified resins can also be used.

Examples of the present invention will be described below, but the present invention is not limited thereto. In the examples and comparative examples, “part” represents “part by mass”, and “%” represents “% by mass”. Abbreviations in the reference examples are as follows.
Methyl methacrylate MMA
Methyl acrylate MA
n-butyl acrylate n-BA
Styrene ST
Allyl methacrylate AMA
1,3-butylene glycol dimethacrylate 1,3BD
t-Butyl hydroperoxide t-BH
Cumene hydroperoxide CHP
n-octyl mercaptan n-OM
Azobisisobutyronitrile AIBN
Ethylenediaminetetraacetic acid disodium EDTA
Emulsifier (1): Sodium mono-n-dodecyloxytetraoxyethylene phosphate Product name: Phosphanol RS-610NA, manufactured by Toho Chemical Co., Ltd.]
Moreover, evaluation of the rubber-containing polymer (B) prepared in Examples and Comparative Examples and measurement of various physical properties of the acrylic film were carried out by the following test methods.

<Evaluation and measurement method>
(1) Weight average particle diameter of rubber-containing polymer (B) Using a light scattering photometer DLS-700 manufactured by Otsuka Electronics Co., Ltd., the polymer latex of the rubber-containing polymer (B) obtained by emulsion polymerization, It was determined by measuring with a dynamic light scattering method.

(2) Gel content of rubber-containing polymer (B) The weighed rubber-containing polymer (B) was subjected to extraction treatment under reflux in an acetone solvent, and this extraction treatment liquid was fractionated by centrifugation. Subsequently, after drying the obtained solid content, mass measurement (mass after extraction) was carried out, and it calculated | required with the following formula | equation.
Gel content rate (%) = (mass before extraction (g) −mass after extraction (g)) / mass before extraction (g)

(3) Measurement of haze value of acrylic resin film Haze value was measured according to JIS K7136 (ISO 14782) using a haze computer (Suga Test Instruments Co., Ltd., model: HGM-2DP).

(4) Measurement of heat distortion temperature of acrylic thermoplastic polymer (A) Heat distortion temperature (HDT): Each pellet was molded by injection molding into a heat distortion temperature measurement specimen based on ASTM D648, and 4 at 60 ° C. After time annealing, it was measured according to ASTM D648 at high load (1.8 MPa).

(5) Warm water resistance test of acrylic resin film The acrylic resin film is immersed in ion exchange water at 80 ° C., taken out from the warm water after 240 hours, water drops adhering to the film surface are removed, and the film is 25 ° C./50%. After holding at RH for 24 hours, the haze is measured according to JIS K7136 (ISO 14782).

(6) Film-formability ○: Appropriate elongation occurs when the film raw material resin is melted, and the film-formability is good.
(Triangle | delta): The film thickness precision of a film is inferior and the surface smoothness of a film is bad.
X: The film is fragile and breaks the film during film formation.

Example 1
(1) <Production of Acrylic Thermoplastic Polymer (A) (a-1)>
<D) Production of acrylic thermoplastic polymer (a-1)>
(I) Production of Anionic Polymer Compound Aqueous Solution (A1) as Dispersion Stabilizer In a polymerization apparatus equipped with a stirrer, 58 parts by mass of 2-sulfoethyl sodium methacrylate, an aqueous potassium methacrylate solution (potassium methacrylate content 30% by mass) ) A monomer mixture consisting of 31 parts by mass and 11 parts by mass of methyl methacrylate and 900 parts by mass of deionized water were added and dissolved by stirring. Thereafter, the mixture was heated to 60 ° C. with stirring under a nitrogen atmosphere, and kept at 60 ° C. with stirring for 6 hours to obtain an aqueous anionic polymer compound solution. At this time, after the temperature reached 50 ° C., 0.1 part by mass of ammonium persulfate was added as a polymerization initiator, and 11 parts by mass of methyl methacrylate weighed separately was continuously added to the above reaction system over 75 minutes. It was dripped in.
Let the anionic polymer compound aqueous solution obtained by the above-mentioned manufacturing method be (A1).

<(Ii) Production of Anionic Polymer Compound Aqueous Solution (A2) as Dispersion Stabilizer>
A mixture obtained by adding 68 parts by mass of an aqueous potassium hydroxide solution (potassium hydroxide content: 17.1% by mass) and 32 parts by mass of methyl methacrylate to a polymerization apparatus equipped with a stirrer is stirred. After completion of the saponification reaction, the temperature of the mixture was raised to 80 ° C. and kept at 80 ° C. while stirring for 4 hours to obtain an aqueous anionic polymer compound solution. At this time, after the temperature reached 72 ° C., 0.1 part by mass of ammonium persulfate was added as a polymerization initiator. Thereafter, 1000 parts by mass of deionized water was dividedly charged into a polymerization apparatus equipped with a stirrer, and at the same time, an aqueous anionic polymer compound solution was transferred and collected in a container equipped with a stirrer. Let the anionic polymer compound aqueous solution obtained by the above-mentioned manufacturing method be (A2).

<(Iii) Suspension polymerization method>
In a separable flask having an internal volume of 10 liters equipped with a stirrer, 6000 ml of deionized water was added, and 4 g of the anionic polymer compound aqueous solution (A1) obtained in (i) above as a dispersion stabilizer, obtained in (ii) above. 1 g of the resulting aqueous anionic polymer compound (A2) and 9 g of sodium sulfate as a dispersion stabilizing aid were added and stirred and dissolved. Also, to a monomer mixture of MMA 2940 g and MA 60 g prepared in a separate container equipped with a stirrer, add 3 g of AIBN as a polymerization initiator, n-OM 6.6 g as a chain transfer agent, and 6 g of S100A as a release agent, and stir and dissolve. It was. This monomer mixture was put into a separable flask having an internal volume of 10 L provided in the stirrer and stirred for 15 minutes at a rotation speed of 300 rpm of the stirrer while purging with nitrogen. Thereafter, the polymerization was started by heating to 80 ° C., and after completion of the polymerization exothermic peak, a heat treatment was performed at 95 ° C. for 60 minutes to complete the polymerization.

  The polymer-containing aqueous solution obtained by this suspension polymerization method was dehydrated, washed with water, and dried, and then a powdery acrylic thermoplastic polymer (a-1) was recovered. This acrylic thermoplastic polymer (a-1) was dissolved in 0.1 g of chloroform (100 ml), and the reduced viscosity was measured at 25 ° C. As a result, it was 0.06 liter / g. The heat distortion temperature (measured based on ASTM D648) was 105 ° C.

(2) <Preparation of rubber-containing polymer (I)>
Under a nitrogen atmosphere, 310 parts of deionized water was placed in a reaction vessel equipped with a reflux condenser, and the temperature was raised to 80 ° C. Then, after adding the following (A) and continuously adding the following raw material (B) while stirring, polymerization was further performed for 120 minutes to obtain a latex of a rubber polymer.
Subsequently, 10 parts of deionized water and 0.15 part of sodium formaldehyde sulfoxylate were added to the latex and held for 15 minutes. Then, while stirring at 80 ° C. in a nitrogen atmosphere, the following raw materials (c) were continuously added over 100 minutes, and then held at 80 ° C. for 60 minutes to complete the polymerization.

The average particle diameter of the rubber-containing polymer (I) measured after polymerization was 0.12 μm.
The obtained copolymer latex was subjected to coagulation, aggregation and solidification using calcium acetate, filtered, washed with water, and dried to obtain a rubber-containing polymer (I).
(I)
Sodium carbonate 0.05 part Sodium formaldehyde sulfoxylate 0.6 part Ferrous sulfate 0.0002 part EDTA 0.0006 part Emulsifier (1) 1.0 part

(B)
n-BA 81.0 parts ST 19.0 parts AMA 1.0 parts t-BH 0.25 parts

(C)
MMA 57.0 parts MA 3.0 parts n-OM 0.2 parts t-BH 0.1 parts Emulsifier (1) 0.5 parts Filtration is a vibration type with a stainless steel (SUS) mesh attached as a filter medium. It filtered using the filtration apparatus. This was added to a 3% saline solution, salted out and dehydrated, washed with water and dried to obtain a powdery rubber-containing polymer (I).

(3) Production of acrylic resin film:
90 parts of an acrylic thermoplastic polymer (a-1) as an acrylic resin was added to 10 parts of the rubber-containing polymer (I), and then mixed using a Henschel mixer. Next, the obtained mixture was supplied to a degassing extruder (PCM-30 manufactured by Ikekai Tekko Co., Ltd.) heated to 230 ° C. and kneaded to obtain pellets.

The pellets produced by the above method were dried at 80 ° C. all day and night, and the dried pellets were fed to a 40 mmφ non-vent screw type extruder (L / D = 26) equipped with a 300 mm wide T-die and 350 μm thick. An acrylic film was prepared. The conditions at that time were a cylinder temperature of 200 to 240 ° C., a T die temperature of 250 ° C., and a cooling roll temperature of 95 ° C.
Table 1 below shows the evaluation results of the haze before and after the hot water test, including the film-forming property, regarding the hot water resistance of the acrylic resin film produced by the above method.

(Example 2)
An acrylic resin film was obtained in the same manner as in Example 1 except that the rubber-containing polymer (I) was 16 parts and the acrylic thermoplastic polymer (a-1) was 84 parts. Table 1 below shows the evaluation results of the haze before and after the hot water test, including the film-forming property, regarding the hot water resistance of the acrylic resin film.

(Example 3)
(1) Preparation of rubber-containing polymer (II) 195 parts of ion-exchanged water was charged into a reaction vessel equipped with a cooler, the temperature was raised to 70 ° C., and further, In addition, the prepared mixture was added all at once. Next, while stirring under nitrogen, a first monomer mixture (Tg: −13 ° C.) consisting of (b) shown below was dropped into the reaction vessel over 8 minutes, and then the reaction was continued for 15 minutes. A rubber polymer was obtained.
Subsequently, a second monomer mixture (C) (Tg is −40 ° C.) is dropped into the reaction vessel over 90 minutes, and then the reaction is continued for 60 minutes to contain a rubber containing a crosslinked elastic polymer. A polymer was obtained.
Then, after dripping the 3rd monomer mixture which consists of (d) over 30 minutes in reaction container, reaction was continued for 60 minutes and the polymer was obtained.
Next, a fourth monomer mixture (Tg 94 ° C.) consisting of (e) was dropped into the reaction vessel over 130 minutes, and then the reaction was continued for 60 minutes to obtain a rubber polymer (II) latex. It was. Here, the mass average particle diameter measured after polymerization was 0.09 μm.

(I)
Sodium formaldehyde sulfoxylate 0.10 parts Ferrous sulfate 0.0002 parts EDTA 0.0006 parts

(B)
MMA 2.3 parts n-BA 2.13 parts ST 0.37 parts 1,3-BD 0.2 parts CHP 0.01 parts Emulsifier (1) 1.3 parts

(C)
n-BA 24.54 parts ST 4.26 parts BD 1.2 parts AMA 0.225 parts

(D)
MMA 6 parts n-BA 3.28 parts ST 0.72 parts AMA 0.15 parts CHP 0.02 parts

(E)
MMA 52.25 parts n-BA 2.26 parts ST 0.49 parts n-OM 0.193 parts t-BH 0.055 parts

  The polymer latex of the rubber-containing polymer (II) thus obtained was filtered using a vibration type filtration device in which a stainless steel (SUS) mesh (average opening 62 μm) was attached to the filter medium, and 3 parts of calcium acetate was then added. Salting out was carried out in an aqueous solution containing water, recovered by washing, and then dried to obtain a powdery rubber-containing polymer (II). The gel content of the rubber-containing polymer (II) was 72%.

  An acrylic resin film was obtained in the same manner as in Example 1 except that the rubber-containing polymer (II) was 16 parts and the acrylic thermoplastic polymer (a-1) was 84 parts. Regarding the warm water resistance of this acrylic resin film, the evaluation results for the haze values before and after the hot water test, including the film forming property, are shown in Table 1 below.

Example 4
An acrylic resin film was obtained in the same manner as in Example 2, except that a benzotriazole-based ultraviolet absorber (manufactured by Adeka Co., Ltd., Adeka Stub LA-31RG) was added as the ultraviolet absorber in a mass part shown in Table 1. Regarding the warm water resistance of this acrylic resin film, the evaluation results for the haze values before and after the hot water test, including the film forming property, are shown in Table 1 below.

(Comparative Example 1)
(1) Preparation of rubber-containing polymer (III):
In a nitrogen atmosphere, put 320 parts of deionized water in a reaction vessel equipped with a reflux condenser, raise the temperature to 80 ° C., add (a) shown below, and stir the following raw material (b) (polymer) 1/10 of the mixture of (III-A) raw material) and charged for 15 minutes. Thereafter, the remaining raw material (b) was continuously added at an increase rate of 8% / hour of the monomer mixture with respect to water. Thereafter, it was kept for 1 hour to obtain a latex of polymer (III-A).
Subsequently, 0.2 parts of sodium formaldehyde sulfoxylate was added to this latex and held for 15 minutes. While stirring at 80 ° C. in a nitrogen atmosphere, the following raw materials (c) were mixed with monomer in water. Was continuously added at an increase rate of 4% / hour. Thereafter, the rubber polymer was polymerized by holding the polymer for 2 hours to obtain a rubber polymer latex.
Subsequently, 0.2 parts of sodium formaldehyde sulfoxylate was added to this latex, and the mixture was held for 15 minutes and stirred at 80 ° C. in a nitrogen atmosphere. Was continuously added at an increase rate of 10% / hour. Thereafter, the mixture was held for 1 hour for polymerization to obtain a latex of the rubber-containing polymer (III). The rubber-containing polymer (III) had an average particle size of 0.28 μm.
The rubber-containing polymer (III) latex was subjected to coagulation, aggregation and solidification using calcium acetate, filtered, washed with water and dried to obtain a rubber-containing polymer (III).

(I)
Sodium formaldehyde sulfoxylate 0.4 part Ferrous sulfate 0.00004 part EDTA 0.00012 part

(B)
MMA 22.0 parts n-BA 15.0 parts ST 3.0 parts AMA 0.4 parts 1,3BD 0.14 parts t-BH 0.18 parts Emulsifier (1) 1.0 part

(C)
n-BA 49.5 parts ST 10.5 parts AMA 1.05 parts 1,3BD 0.15 parts CHP 0.17 parts Emulsifier (1) 0.96 parts

(D)
MMA 57.0 parts MA 3.0 parts n-OM 0.18 parts t-BH 0.1 parts

  The polymer latex of the rubber-containing polymer (III) thus obtained was filtered using a vibration type filtration device equipped with a stainless steel (SUS) mesh (average opening 150 μm) as a filter medium, and then 3 parts of calcium acetate. The solution was poured into an aqueous solution containing water, salted out, washed with water, separated and recovered, and dried to obtain a powdery rubber-containing polymer (III). The gel content of the rubber-containing polymer (III) was 89%.

(2) Production of acrylic resin film:
Next, an acrylic resin film was obtained in the same manner as in Example 1 except that the rubber-containing polymer (I) of Example 1 was changed to 10 parts of the rubber-containing polymer (III).
Regarding the warm water resistance of this acrylic resin film, the evaluation results for the haze values before and after the hot water test, including the film forming property, are shown in Table 1 below.

(Comparative Example 2)
An acrylic resin film was obtained in the same manner as in Example 1 except that the rubber-containing polymer (I) and the acrylic thermoplastic polymer (a-1) were blended in the proportions shown in Table 1.
Regarding the warm water resistance of this acrylic resin film, the evaluation results for the haze values before and after the hot water test, including the film forming property, are shown in Table 1 below.

(Comparative Example 3)
An acrylic resin film was obtained in the same manner as in Example 1 except that the rubber-containing polymer (I) and the acrylic thermoplastic polymer (a-2) shown below were blended in the proportions shown in Table 1.
The obtained film had uneven thickness in the width direction of the film during extrusion film formation, and the surface smoothness was inferior. The warm water resistance of this acrylic resin film is shown in Table 1 below for the evaluation results of the haze values before and after the hot water test.

<E) Production of acrylic thermoplastic polymer (a-2)>
Of the production method of d) acrylic thermoplastic polymer (a-1) used in Example 1, MMA2820g and MA180g were changed to the same except that n-OM3.0g as a chain transfer agent was used. The suspension polymerization method was carried out. As a result of dissolving 0.1 g of this acrylic thermoplastic polymer (a-2) in 100 ml of chloroform and measuring the reduced viscosity at 25 ° C., it was 0.09 liter / g. The heat distortion temperature (measured based on ASTM D648) was 96 ° C.

(Comparative Example 4)
An acrylic resin film was obtained in the same manner as in Example 1 except that the rubber-containing polymer (I) and the acrylic thermoplastic polymer (a-3) shown below were blended in the proportions shown in Table 1.
Regarding the warm water resistance of this acrylic resin film, the evaluation results for the haze values before and after the hot water test, including the film forming property, are shown in Table 1 below.

<F) Production of acrylic thermoplastic polymer (a-3)>
The same suspension polymerization method was carried out except that the d) acrylic thermoplastic polymer (a-1) used in Example 1 was changed to MMA 2700 g and MA 300 g. As a result of dissolving 0.1 g of this acrylic thermoplastic polymer (a-3) in 100 ml of chloroform and measuring the reduced viscosity at 25 ° C., it was 0.06 liter / g. The heat distortion temperature (measured based on ASTM D648) was 89 ° C.

(Comparative Example 5)
An acrylic resin film was obtained in the same manner as in Example 4 except that metablene P (manufactured by Mitsubishi Rayon Co., Ltd.) was used as a high molecular weight acrylic thermoplastic polymer as an additive and compounded at a ratio shown in Table 1.
Regarding the warm water resistance of this acrylic resin film, the evaluation results for the haze values before and after the hot water test, including the film forming property, are shown in Table 1 below.

(Comparative Example 6)
Compounding was carried out at the ratio shown in Table 1, using Irganox 1076 (manufactured by Ciba Specialty Chemicals) as an additive as the ultraviolet absorber (D-2) and antioxidant (D-3) used in Example 4. Except for the above, an acrylic resin film was obtained in the same manner.
Regarding the warm water resistance of this acrylic resin film, the evaluation results for the haze values before and after the hot water test, including the film forming property, are shown in Table 1 below.

(Comparative Example 7)
An acrylic resin film was obtained in the same manner except that the rubber-containing polymer (II) and the acrylic thermoplastic polymer (a-1) were compounded in the ratio shown in Table 1.
From the examples and comparative examples described above, the following became clear.
Regarding the warm water resistance of this acrylic resin film, the evaluation results for the haze values before and after the hot water test, including the film forming property, are shown in Table 1 below.

  When a rubber-containing polymer having a rubber particle diameter of 0.2 μm or more is used as in Comparative Example 1, the haze value of the film before the hot water test is also higher than in the Examples, and the proportion of the rubber-containing polymer is low. The haze value after the hot water test was as high as 3% or more. This shows that there is a possibility of damaging the design when used for the skin of a bathroom interior wall material.

  In Comparative Example 2, the ratio of the acrylic thermoplastic polymer (A) and the rubber-containing polymer (B) does not satisfy the requirements of the present invention, and the cloudiness after the warm water test of the acrylic resin film as in Comparative Example 1 The value is as high as 3% or more, and the fog value after the warm water test of the acrylic resin film is as high as 3% or more as in Comparative Example 1, and the design may be damaged when used for the skin of the bathroom interior wall material. I understand that. In Comparative Example 3, since an acrylic thermoplastic polymer having a high molecular weight (high reduced viscosity) was used, the film-forming property was poor, and the haze value after being immersed in warm water at 80 ° C. for 240 hours was 3% or more. It has become. In Comparative Example 4, since an acrylic thermoplastic polymer having a low heat distortion temperature was used, the haze value after being immersed in warm water at 80 ° C. for 240 hours is 3% or more. In Comparative Example 5, since a processing aid is used, the haze value after being immersed in warm water at 80 ° C. for 240 hours is 3% or more. In Comparative Example 6, since the ultraviolet absorber and the antioxidant were used, the haze value after being immersed in warm water at 80 ° C. for 240 hours is 3% or more.

When the amount of the rubber polymer added is small as in Comparative Example 7, when the film is thinned during film formation, the film is frequently cut off from the end of the film, which causes a problem in film productivity.
In the acrylic resin film laminated body using the acrylic resin film of these comparative examples, the above problems occur, and the industrial utility value is low.

  As described in detail above, the acrylic resin film of the present invention has a low initial haze value and excellent long-term hot water resistance, so that the acrylic resin film of the present invention and the laminate composed of these are of high quality. Can be maintained for a long time, and is particularly suitable for bathroom interior materials, for example, bathroom interior wall materials. Moreover, compared with the case where an equivalent external appearance is obtained by conventional clear coating, there is no design deterioration due to coating unevenness, construction is simple, and a product can be obtained at low cost.

(Aspect 1)
Acrylic thermoplastic polymer (A) 70.5-94.5% by mass and rubber-containing polymer (B) 5.5-29.5% by mass with a weight average particle size of 0.08-0.18 μm. An acrylic resin film for covering a bathroom interior material, having a thickness of 25 to 300 μm and a haze value of 3% or less after being immersed in warm water at 80 ° C. for 240 hours.
(Aspect 2)
The rubber-containing polymer (B) was obtained by polymerizing 40 to 900 parts by mass of a monomer or monomer mixture containing 50% by mass or more of alkyl methacrylate in the presence of 100 parts by mass of the rubber-containing polymer. The acrylic resin film for covering a bathroom interior material according to aspect 1, which is a polymer.
(Aspect 3)
Reduced viscosity η measured at 25 ° C. by dissolving 0.1 g of acrylic thermoplastic polymer (A) in 100 ml of chloroform _SP The acrylic resin film for covering a bathroom interior material according to aspect 1 or 2, wherein / C is 0.075 liter / g or less and the heat distortion temperature (measured based on ASTM D648) is 90 ° C or higher.

Claims (2)

Acrylic thermoplastic polymer (A) 70.5-94.5% by mass and rubber-containing polymer (B) 5.5-29.5% by mass with a weight average particle size of 0.08-0.18 μm. DOO contain a thick 25～300Myuemu, and 80 ° C. warm water for 240 hours soaked haze after the Ri der 3%
0.1 g of the acrylic thermoplastic polymer (A) is dissolved in 100 ml of chloroform, the reduced viscosity η _SP / C measured at 25 ° C. is 0.075 liter / g or less, and the heat distortion temperature. An acrylic resin film for covering a bathroom interior material (measurement based on ASTM D648) is 90 ° C. or higher .   The rubber-containing polymer (B) was obtained by polymerizing 40 to 900 parts by mass of a monomer or monomer mixture containing 50% by mass or more of alkyl methacrylate in the presence of 100 parts by mass of the rubber-containing polymer. The acrylic resin film for covering a bathroom interior material according to claim 1, which is a polymer.