JP2003277528A - Acrylic resin film having excellent resistance to hot water whitening and interior wall covering material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acrylic resin film having improve resistance to hot water whitening, and furthermore an acrylic resin film laminated interior wall covering material having a feeling of deep transparency and the resistance to hot water whitening required for the interior wall covering material which is frequently brought into contact with hot water with the use of the acrylic film while enabling reduction of production steps. <P>SOLUTION: The acrylic resin film is composed of an acrylic resin obtained by dispersing rubber particles into a methacrylic resin, and has a content of water soluble substances of ≤200 ppm, a cloudiness after dipping in hot water of 80°C for one hour of ≤5%, and a thickness of 50 μm to 600 μm. The acrylic resin film is laminated on a base material to produce the indoor interior wall covering material for a bathroom, a kitchen, a lavatory, a toilet and the like which are frequently brought into contact with hot water. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an interior wall material for indoor use, such as bathrooms, kitchens, washrooms, and toilets, which often come into contact with hot water, and prevents the whitening of hot water by laminating a specific acrylic film. And an acrylic resin film used for the application.

[0002]

2. Description of the Related Art Conventionally, ceramic tiles, vinyl chloride steel plates, molded panels made of fiber reinforced resin (FRP), etc. have been used as wall materials for bathrooms, kitchens, washrooms, toilets and the like. A clear layer is generally formed on the outermost surface of these wall materials by a thermosetting resin such as a diallyl phthalate resin or a polyester resin, or by coating. On the other hand, recently, along with the widespread use of system buses and the like, there is an increasing need for interior wall materials that are affordable, easy to handle, and have excellent design.

The conventional interior wall material having a clear layer used in bathrooms, kitchens, washrooms, toilets and the like has the following problems.

(1) The design which is the basis of the design is under the clear layer and is printed directly on the base material or a special printing paper is attached to the substrate. However, since direct printing adopts a batch method, the cost is high, while the form in which special printing paper is attached to a substrate is not suitable for places where high water resistance is required, such as a bathroom. In addition, the number of steps, such as adding a pattern before placing the clear layer, also leads to high cost.

(2) The thermosetting resin-based clear layer does not necessarily have high transparency. Also, the clear layer has a thickness of at most about 0.1 to 0.2 mm in one layer, and several layers of overcoating are required to obtain a deep view. Even when a clear layer is formed by coating, the maximum coating thickness is as thin as 0.1 mm, and multiple coating is required to obtain a deep view. When obtaining a mirror surface, the surface must be finally polished.

On the other hand, JP-A-2000-191804 discloses a specific acrylic resin as a solution to the above problems in the conventional interior wall material having a thermosetting resin or a clear layer formed by coating. Proposals have been made to make a bathroom interior wall material with a deep appearance by laminating a film on the surface. Interior wall materials for indoor use, such as bathrooms, kitchens, washrooms, and toilets, which often come into contact with hot water, are in direct contact with water or hot water during use, and therefore require hot water whitening resistance. Although the 2000-191804 publication describes that the amount of calcium remaining in the acrylic resin film is within a predetermined range, it is excellent in hot water whitening resistance, but in addition to that, specific hot water whitening resistance is good. The method of obtaining the film is not disclosed.

[0007]

An object of the present invention is to provide an acrylic resin film having improved hot water whitening resistance by a means different from the above-mentioned Japanese Patent Laid-Open No. 2000-191804. Provided is an acrylic resin film laminated interior wall material having a deep transparency and having a warm water whitening resistance required as an interior wall material for indoors which has a lot of opportunities to come into contact with hot water while enabling a shortening of the manufacturing process. Especially.

[0008]

Means for Solving the Problems In view of the above-mentioned prior art, the inventors of the present invention have conducted diligent research to develop an acrylic resin film excellent in hot water whitening resistance, and as a result, rubber particles were found in methacrylic resin. In the film made of the dispersed acrylic resin, the amount of the water-soluble substance remaining in the film due to the emulsifier used in the manufacturing process, particularly the manufacturing process of the methacrylic resin and the rubber particles, can be reduced to a specific amount or less. It was found that an acrylic resin film having good resistance to warm water whitening can be obtained. Based on this knowledge,
The present invention has been completed through various further studies.

That is, the present invention comprises an acrylic resin in which rubber particles are dispersed in a methacrylic resin, has a water-soluble substance content of 200 ppm or less, and has a haze value of 5 after being immersed in warm water at 80 ° C. for 1 hour. % Or less and 50 μm or more 60
Provided is an acrylic resin film having a thickness of 0 μm or less and excellent in hot water whitening resistance. The present invention also provides an interior wall material in which this acrylic resin film is laminated on a base material.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In the present invention, a film is formed of an acrylic resin in which rubber particles are dispersed in a methacrylic resin, and the amount of the water-soluble substance contained therein is 200 ppm or less. This film contains rubber particles, which are usually
It is produced by emulsion polymerization, but the water-soluble substance remains in the film due to the emulsifier used at that time. When the methacrylic resin, which is the base resin of the film, is produced by emulsion polymerization or suspension polymerization, the emulsifier and suspension stabilizer used there are also mixed in the film. Then, it was found that when the remaining amount of the water-soluble substance mainly composed of such an emulsifier or suspension stabilizer becomes large, the film is likely to be whitened when it comes into contact with warm water.

Therefore, in the present invention, the amount of the water-soluble substance contained in the acrylic resin film is set to 200 ppm or less. By suppressing the amount of the water-soluble substance to this extent, it is possible to suppress whitening during contact with warm water.
The haze value after soaking in warm water of ℃ for 1 hour becomes 5% or less, and good designability can be maintained. The water-soluble substance in the acrylic resin film is preferably 100 ppm or less. The water-soluble substance in the acrylic resin film can be quantified using a general extraction method. As a specific example of the quantitative method, the method described in Examples described later can be mentioned.

In order to reduce the amount of water-soluble substance contained in the acrylic resin film, the rubber particles may be washed sufficiently with water after the production of the rubber particles described later. Further, when emulsion polymerization or suspension polymerization is used in the production of the methacrylic resin as the mother phase, the methacrylic resin after the polymerization also needs to be sufficiently washed with water. By repeating washing with water, it is possible to reduce the amount of the water-soluble substance, and the smaller the amount, the more preferable. However, increasing the number of times of washing increases the manufacturing process and increases the cost. It is well tolerated that the water-soluble substance is present in an amount of about 20 ppm or more, or about 50 ppm or more.

The acrylic resin film is 50
The thickness is not less than μm and not more than 600 μm. By setting the thickness of the film in this range, it is possible to obtain excellent surface smoothness, high designability and excellent surface hardness. If the film thickness is less than 50 μm, sufficient surface hardness cannot be obtained. On the other hand, when the thickness exceeds 600 μm, it is difficult to form a stable film as a film, and the rigidity is increased, which causes a problem that it becomes difficult to perform lamination processing with a substrate. This acrylic resin film also has good transparency and is superior to polyvinyl chloride films and polyester films in terms of depth of view and a sense of quality.

The methacrylic resin constituting the acrylic resin film is a polymer mainly containing methacrylic acid ester, and may be a homopolymer of methacrylic acid ester or a copolymer mainly containing it. As the methacrylic acid ester, an alkyl ester of methacrylic acid is usually used, and the alkyl group may have about 1 to 4 carbon atoms. In the case of using a copolymer, acrylic acid esters, aromatic vinyl compounds, vinyl cyan compounds, etc., which are known to be advantageous as a copolymerization component of methacrylic resin, are used.

More specifically, the methacrylic resin is
50 to 100% by weight of an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, and an acrylic acid ester of 0 to 50
It is preferably a thermoplastic polymer obtained by polymerizing a monomer composed of 0 wt% and 0 to 49 wt% of at least one other vinyl monomer copolymerizable therewith. Here, the acrylic acid ester is more preferably 0.1 to 5
0% by weight, more preferably 0.5 to 50% by weight
Therefore, a more preferable copolymerization ratio of alkyl methacrylate is in the range of 50 to 99.9% by weight, and a further preferable copolymerization ratio is in the range of 50 to 99.5% by weight. In the present specification, the term “monomer” is not limited to the case of being composed of one kind of a monomer, but also includes a state in which a plurality of monomers are mixed, that is, a so-called monomer mixture. To do.

Examples of the alkyl methacrylate constituting the above-mentioned thermoplastic polymer include methyl methacrylate,
Examples thereof include ethyl methacrylate and butyl methacrylate, with methyl methacrylate being particularly preferred. As the acrylic acid ester, an alkyl ester of acrylic acid is usually used, and the alkyl group may have about 1 to 8 carbon atoms. For example, methyl acrylate, ethyl acrylate, butyl acrylate, etc. may be mentioned. As the other vinyl monomer copolymerizable with the alkyl methacrylate and / or the acrylic ester, various monomers conventionally known in the field of methacrylic resin can be used, and examples thereof include styrene. Examples thereof include aromatic vinyl compounds and vinyl cyan compounds such as acrylonitrile.

As mentioned above, the methacrylic resin has 1 carbon atoms.
~ Alkyl methacrylate having an alkyl group of ~ 50 ~
100% by weight, more preferably 50-99.9% by weight
And 0 to 50% by weight of acrylic acid ester, more preferably 0.1 to 50% by weight, and 0 to 49% by weight of at least one other vinyl monomer copolymerizable therewith. Polymers obtained by polymerizing the above are suitable, and polymers falling within this range can be used alone or as a mixture of two or more polymers. The methacrylic resin preferably has a glass transition temperature of 40 ° C. or higher, and more preferably has a glass transition temperature of 60 ° C. or higher. If the glass transition temperature of the methacrylic resin is less than 40 ° C, the heat resistance of the obtained film will be low, which is not preferable in practice. The glass transition temperature can be appropriately set by changing the type and amount of other monomers copolymerized with the methacrylic acid ester. The glass transition temperature of a homopolymer of methyl methacrylate is about 106 ° C., and therefore, when methyl methacrylate is used as the methacrylic acid ester, the glass transition temperature of the obtained methacrylic resin is usually 106 ° C. or lower.

The method for polymerizing the methacrylic resin is not particularly limited, and it can be carried out by a usual method such as suspension polymerization, emulsion polymerization, bulk polymerization and the like. Among these, the bulk polymerization method, in which a water-soluble component such as a surfactant or a suspension stabilizer is not present in the polymerization system, is preferably adopted. Further, it is preferable to use a chain transfer agent during the polymerization in order to obtain a suitable glass transition temperature or a viscosity showing suitable moldability for a film. The amount of the chain transfer agent may be appropriately determined according to the type and composition of the monomer. When suspension polymerization or emulsion polymerization using a water-soluble component such as a surfactant or a suspension stabilizer is adopted, it is washed sufficiently with water after completion of the polymerization to reduce the amount of the water-soluble component in the resin. I need to put it.

The rubber particles are dispersed in such a methacrylic resin. The rubber particles preferably have an average particle diameter in the range of 0.2 μm or more and 0.4 μm or less. When the average particle diameter of the rubber particles is within this range, a film having high impact resistance, excellent surface hardness and a smooth surface can be obtained. A more preferable average particle diameter of the rubber particles is 0.25 μm or more and 0.35 μm or less. If the average particle size of the rubber particles is too small, the surface hardness of the film decreases and the film becomes brittle. On the other hand, if the average particle size is too large, the surface smoothness of the film is impaired, which is not preferable.

The rubber particles are preferably acrylic particles, and more specifically, alkyl acrylate 50
To 99.9% by weight, at least one other vinyl monomer copolymerizable therewith 0 to 49.9% by weight, and a copolymerizable crosslinkable monomer 0.1 to 10% by weight. A polymer 100 having a layer of an elastic copolymer obtained by polymerizing a monomer comprising
In the presence of parts by weight, methacrylic acid ester 50-100
% By weight, 0 to 50% by weight of acrylic acid ester, and at least one other vinyl monomer copolymerizable therewith 0
By polymerizing 10 to 400 parts by weight of a monomer consisting of ˜49% by weight, at least one polymerized layer of the latter monomer is bonded to the surface of the elastic copolymer. The average particle size of the polymer layer is 0.2 μm or more and 0.4 μm
Polymers containing rubbers up to m are advantageously used. During this polymerization, the reaction conditions are adjusted so that the average particle diameter of the elastic copolymer layer is 0.2 μm or more and 0.4 μm or less.

The rubber particles are obtained, for example, by polymerizing the above-mentioned components for the elastic copolymer by at least one step reaction by an emulsion polymerization method or the like to obtain an elastic copolymer, and in the presence of the elastic copolymer, The methacrylic acid ester-containing monomer can be produced by polymerizing at least one step reaction by an emulsion polymerization method or the like. By such multi-step polymerization, the monomer containing the methacrylic acid ester used in the latter step is graft-copolymerized with the elastic copolymer, and a crosslinked elastic copolymer having a graft chain is produced. That is, the rubber particles are a graft copolymer having a multilayer structure containing alkyl acrylate as a main component of rubber. When the polymerization of the elastic copolymer is carried out in two or more steps, or when the subsequent polymerization of the monomer containing the methacrylic acid ester as the main component is carried out in two or more steps, each is a unit amount of each step. It is sufficient that the monomer composition as a whole, not the body composition, is within the above range.

In the above rubber particles, examples of the alkyl acrylate used for forming the elastic copolymer include those having an alkyl group having 1 to 8 carbon atoms. Of these, alkyl groups having 4 to 8 carbon atoms such as butyl acrylate and 2-ethylhexyl acrylate are preferable.

Other vinyl monomers, which are optionally used to form elastic copolymers and are copolymerizable with alkyl acrylate, include one polymerizable carbon-carbon double bond in one molecule. A monofunctional compound having, specifically, methyl methacrylate, butyl methacrylate, a methacrylate ester such as cyclohexyl methacrylate, an aromatic vinyl compound such as styrene, a vinyl cyanide compound such as acrylonitrile, and the like, It can be mentioned as a suitable one.

The copolymerizable crosslinkable monomer used to form the elastic copolymer may be one having at least two polymerizable carbon-carbon double bonds in one molecule, and examples thereof include ethylene. Unsaturated carboxylic acid diesters of glycols such as glycol dimethacrylate and butanediol dimethacrylate, alkenyl esters of unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, allyl cinnamate, diallyl phthalate, diallyl maleate. Examples thereof include polyalkenyl esters of polybasic acids such as triallyl cyanurate and triallyl isocyanurate, unsaturated carboxylic acid esters of polyhydric alcohols such as trimethylolpropane triacrylate, and divinylbenzene. Among them, alkenyl ester of unsaturated carboxylic acid and polyalkenyl ester of polybasic acid are preferable. These crosslinkable monomers may be used alone or in combination of two or more, if necessary.

The elastic copolymer obtained by polymerizing the monomer mainly containing alkyl acrylate as described above includes
A monomer comprising 50 to 100% by weight of a methacrylic acid ester, 0 to 50% by weight of an acrylic acid ester, and 0 to 49% by weight of at least one other copolymerizable vinyl monomer is grafted thereto. . The methacrylic acid ester which is the main component of the monomer to be grafted to the elastic copolymer is preferably an alkyl ester of methacrylic acid, and examples thereof include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and methacrylic acid. Examples thereof include cyclohexyl acid. Examples of the acrylic acid ester which is optionally used include alkyl esters of acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate and cyclohexyl acrylate, and methacrylic acid ester and / or acrylic acid ester. Other vinyl monomers copolymerizable with and optionally used include, for example, aromatic vinyl compounds such as styrene and vinyl cyan compounds such as acrylonitrile.

The monomer to be grafted is preferably 10 to 400 parts by weight, more preferably 20 parts by weight or more, and even more preferably 100 parts by weight of the polymer having the layer of the elastic copolymer as the surface. Is used in an amount of 200 parts by weight or less, and the polymerization can be carried out in a reaction of one step or more. Here, when the amount of the monomer to be grafted is 10 parts by weight or more, aggregation of the elastic copolymer is less likely to occur, and unevenness of the surface is less likely to occur when the film is formed. Further, when the amount of the monomer to be grafted is too large, the fluidity of the entire resin in which the rubber particles are dispersed is lowered,
Since film formation tends to be difficult, per 100 parts by weight of the polymer having the layer of the elastic copolymer as the surface,
It is preferably 400 parts by weight or less, more preferably 200 parts by weight or less.

It is also possible to provide a hard polymer layer containing methacrylic acid ester as a main component inside the elastic copolymer layer to obtain rubber particles having a multilayer structure composed of at least three layers. In this case, the monomer of the hard layer constituting the innermost layer is first polymerized, and in the presence of the hard polymer obtained, the monomer constituting the elastic copolymer is polymerized to obtain further. In the presence of the elastic copolymer to be grafted, the above-mentioned methacrylic acid ester is mainly used and the monomer to be grafted may be polymerized. Such rubber particles having at least a three-layer structure in which the innermost layer is a hard polymer layer are more preferable in terms of elastic modulus and surface hardness when formed into a film.

Here, the innermost hard polymer layer is formed by polymerizing a monomer consisting of 70 to 100% by weight of methacrylic acid ester and 0 to 30% by weight of another vinyl monomer copolymerizable therewith. Those that have been allowed are preferred. As the methacrylic acid ester, an alkyl ester of methacrylic acid, particularly methyl methacrylate is advantageous. Other vinyl monomers optionally used include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, acrylate esters such as cyclohexyl acrylate, aromatic vinyl compounds such as styrene, and acrylonitrile. Examples thereof include vinyl cyan compounds. It is also effective to use a copolymerizable crosslinkable monomer as one of the other vinyl monomers. As the crosslinkable monomer, a compound having at least two polymerizable carbon-carbon double bonds in one molecule can be used, which is similar to the components exemplified above as the component constituting the elastic copolymer. Rubber particles having such a three-layer structure are disclosed, for example, in Japanese Examined Patent Publication No. 55-27576 (= USP 3,79).
3,402). Particularly, the one described in Example 3 of the publication is one of the preferable compositions.

When the rubber particles having a multi-layered structure composed of at least three layers as described above are used, the amount of the methacrylic acid ester-based monomer to be grafted as the outermost layer is 10 to 400 parts by weight. A total of 100 parts by weight of the elastic copolymer serving as the intermediate layer may be used as a reference.

By the above polymerization reaction, rubber particles are obtained in a latex state. The emulsifier used for the polymerization remains as a water-soluble component in the rubber particles and is taken into the film as it is. Therefore, it is necessary to sufficiently wash after the polymerization to remove such water-soluble components. The method of washing is not particularly limited, for example, in the step of recovering the polymer (rubber particles) from the polymer latex, a method of repeating washing with water when aggregating the polymer by salting out or acidification, A method of spray-drying or freeze-drying to make a powder and then washing with water can be adopted.

In the present invention, the average particle diameter of the rubber particles is 0.2 μm or more and 0.4 or more by controlling the addition amount of the emulsifier in the emulsion polymerization and the charging amount of the monomers.
It may be set to an appropriate value within the range of μm or less. By using the rubber having such a particle diameter, it is possible to satisfy the quality required as an interior wall material for an interior, such as a bathroom, a kitchen, a washroom, and a toilet, which is often exposed to hot water. By blending a predetermined amount of such rubber particles, a film excellent in stain resistance, chemical resistance, surface hardness, etc. can be obtained.

The average particle size of the rubber particles was determined by mixing the rubber particles with a methacrylic resin to form a film, dyeing the rubber component with ruthenium oxide on the cross section, and observing the dye with an electron microscope. It can be determined from the diameter of the particle outer layer portion. That is, when rubber particles containing an elastic copolymer layer containing alkyl acrylate as a main component are mixed with methacrylic resin and the cross section thereof is dyed with ruthenium oxide, the methacrylic resin of the mother phase is not dyed, and the outermost layer of the rubber particles is not dyed. If there is a hard layer mainly composed of methacrylic acid ester, the hard layer is also not mixed with the base resin to be dyed, and only the elastic copolymer layer containing alkyl acrylate as a main component is dyed. The particle diameter can be determined from the diameter of the portion observed in an electron microscope in a substantially circular shape. When a hard polymer layer exists inside the elastic copolymer layer, the innermost hard polymer is not dyed, and the outer elastic polymer layer is observed in a dyed two-layer structure. However, the average particle diameter of the rubber particles in this case may be considered outside the two-layer structure, that is, the outer diameter of the elastic copolymer layer.

The rubber particles are dispersed in the methacrylic resin to form an acrylic resin film. The ratio of both is such that the methacrylic resin is used in the range of 50 to 95 parts by weight and the rubber particles are used in the range of 5 to 50 parts by weight. Is preferred. If the amount of rubber particles is too small, it becomes difficult to form a film, and if the amount is too large, it becomes difficult to obtain an appropriate surface hardness.

In this rubber particle, the above-mentioned elastic copolymer mainly composed of acrylic acid ester occupies 10 parts in total of all components, that is, methacrylic resin and rubber particle.
The amount is preferably 3 to 35 parts by weight, based on 0 parts by weight. Furthermore, it is more preferable that the elastic copolymer is 5 parts by weight or more and 25 parts by weight or less based on 100 parts by weight of the total of the methacrylic resin and the rubber particles. When the amount of the elastic copolymer is 3 parts by weight or more per 100 parts by weight of the total of the methacrylic resin and the rubber particles, the film does not become brittle and the film forming property can be improved. On the other hand, when the amount of the elastic copolymer is too large, the transparency and surface hardness of the film tend to be lost.

The acrylic resin film in which rubber particles are dispersed in methacrylic resin is used as a usual additive, for example, an ultraviolet absorber, an organic dye, a pigment, an inorganic dye, an antioxidant,
200 pp of water-soluble components such as antistatic agents and surfactants
You may contain in the range which does not exceed the density | concentration of m. Among them, the ultraviolet absorber is preferably used for improving weather resistance. Examples of the UV absorber include benzotriazole-based UV absorbers, 2-hydroxybenzophenone-based UV absorbers and salicylic acid phenyl ester-based UV absorbers that are commonly used. Specific examples of the benzotriazole-based ultraviolet absorber include 2,2′-
Methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl)
Phenol], 2- (5-methyl-2-hydroxyphenyl) -2H-benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2 -(3,5-Di-tert-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole , 2- (3,5-di-tert-butyl-
2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-tert-amyl-2-
Hydroxyphenyl) -2H-benzotriazole, 2
Examples thereof include-(2'-hydroxy-5'-tert-octylphenyl) -2H-benzotriazole. Two
Specific examples of the -hydroxybenzophenone ultraviolet absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-. Chlorobenzophenone,
Examples include 2,2'-dihydroxy-4-methoxybenzophenone and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone. Further, as a salicylic acid phenyl ester-based ultraviolet absorber, specifically, p-te
Examples include rt-butylphenyl salicylate and p-octylphenyl salicylate.

These ultraviolet absorbers may be used alone or in admixture of two or more. When compounding the ultraviolet absorber, the amount thereof is usually 0.1 part by weight or more, preferably 0.3 part by weight or more, and more preferably 2 parts by weight, based on the total 100 parts by weight of the methacrylic resin and the rubber particles. Below the section.

The acrylic resin film for decorating according to the present invention, which is used for indoor interior wall materials which are often exposed to hot water, preferably has a pencil hardness of H or higher, that is, H or higher. . When the pencil hardness is H or more, it can be suitably used as an interior wall material for an interior such as a bathroom, a kitchen, a washroom, and a toilet, which is often exposed to hot water. Pencil hardness is displayed by the pencil scratch value specified in JIS K 5400. The pencil hardness of the film can be adjusted to an appropriate value by changing the type of the methacrylic resin that serves as the mother phase and the type and amount of the rubber particles dispersed therein. If the pencil hardness is H or higher, operations such as cross-linking for increasing the surface hardness are not required, workability such as stretching and bending is excellent, and processing such as lamination in the secondary processing step is performed. The property is also good.

An acrylic resin film is produced by mixing the methacrylic resin and the rubber particles described above, and forming a mixture containing other additives, if necessary, into a film. As a method for producing the film, any method such as a melt casting method, a melt extrusion method such as a T-die method or an inflation method, or a calender method may be used.
Among them, the method of melt-extruding the mixture from, for example, a T-die and bringing at least one surface of the obtained film-like material into contact with a roll or a belt to form a film is preferable in that a film having a good surface property can be obtained. In particular, from the viewpoint of improving the surface smoothness and surface gloss of the film, a method of forming a film by bringing both surfaces of a film-like product obtained by melt extrusion of the mixture into contact with the roll surface or the belt surface is preferable. The rolls or belts used at this time are preferably made of metal. The roll preferably has a mirror surface.
Therefore, as a preferable mode, after melt-extruding the acrylic resin containing the methacrylic resin and the rubber particles from the T die, it is brought into contact with at least one mirror surface roll, and more preferably, brought into contact with two mirror surface rolls. A method of forming a film in the sandwiched state may be mentioned.

The acrylic resin film may be colored. As a coloring method, a method in which a pigment or a dye is contained in a mixture itself of a methacrylic resin and rubber particles to color the resin itself before film formation, a dyeing method in which an acrylic resin film is dipped in a liquid in which the dye is dispersed for coloring However, the method is not particularly limited. This acrylic resin film can also be formed with a design layer by printing a pattern or the like or providing a coloring layer on at least one surface thereof. These design layers are preferably provided on the side in contact with the base material forming the interior wall material in order to provide a deep appearance.

This acrylic resin film may have at least one layer made of another thermoplastic resin laminated on one side thereof. When the acrylic resin film has a design layer for printing or coloring on one side, another resin is laminated on that side. As a laminated integral molding method with another thermoplastic resin, for example, a method in which the acrylic resin film and the thermoplastic resin are separately formed in advance into a film shape and continuously laminated between heating rolls,
A method of thermocompression bonding with a press, a method of simultaneously laminating under pressure or vacuum molding, a method of laminating with an adhesive layer interposed (wet lamination), and a method of pre-molding one resin film on the other side melt-extruded from a T-die. Examples thereof include a method of laminating a resin. When these methods are used, the acrylic resin formed into a film may be subjected to corona treatment or the like on the surface on the side to be bonded to the other thermoplastic resin substrate, for example. Layers may be provided. Also, another printed thermoplastic resin film can be laminated. A resin film having a high compatibility with an acrylic resin such as a polyvinyl chloride resin may be directly laminated with the acrylic resin film.
Further, since a resin that is incompatible with the acrylic resin, such as a polyolefin resin, requires an adhesive with the acrylic resin film, a method such as dry lamination may be used. In addition, if the other thermoplastic resin laminated on one surface is colored, and the acrylic resin film remains colorless and transparent, the base material of the interior wall material is pasted on the colored resin side to form a composite,
It is possible to provide an excellent decorative member that exhibits a deep colored state.

The thermoplastic resin suitable for lamination with the acrylic resin film is, for example, polycarbonate resin,
Polyethylene terephthalate resin, polyethylene resin,
Examples thereof include polypropylene resin, polystyrene resin, polyvinyl chloride resin, other (meth) acrylic resins, and ABS (acrylonitrile-butadiene-styrene copolymerization) resin. Among these, ABS (acrylonitrile-butadiene-styrene copolymer) resin is one of the preferable ones.

By laminating the above-described acrylic resin film of the present invention on a substrate, a bathroom, a kitchen, a washroom,
It is possible to obtain an acrylic laminated interior wall material that is effective for indoors where there is a lot of opportunity to come into contact with hot water, such as a toilet. In order to impart a design property such as a color pattern to the interior wall material, by preparing a decorated acrylic resin film in advance, the number of steps for producing the interior wall material can be shortened and the interior wall material can be deepened. A sense of transparency can be achieved. For example, a method of printing on one side of an acrylic resin film and laminating it on a substrate on the printed side with or without an adhesive layer, a method of printing on one side of an acrylic resin film Laminate the film of, through the adhesive layer, or without, a method of laminating to the substrate on the side of another printed film, coating on one side of the acrylic resin film, through the adhesive layer,
Alternatively, a method of laminating the coated surface side on the base material without intervention may be employed.

The base material constituting the interior wall material is rock wool board, calcium silicate board, plastic board,
Various conventionally known materials such as a steel plate and a sandwich material having a structure in which urethane foam is sandwiched between steel plates can be used.

The interior wall material thus obtained has a state in which the acrylic resin film of the present invention is laminated on the outermost surface thereof, and is excellent in warm water whitening resistance, and also has a deep feeling, surface hardness, surface smoothness, etc. It also has excellent properties.

[0045]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the examples,% and parts indicating the content or the amount used are based on weight unless otherwise specified.

Example 1 (A) Methacrylic resin 97.8% methyl methacrylate and methyl acrylate 2.
Resin pellets (glass transition temperature 103 ° C.) obtained by a bulk polymerization method from a monomer composition of 2% were used.

(B) Production of Rubber Particles A reaction vessel was charged with the total amount of the medium raw material (a) and half of the innermost layer hard body raw material (b) shown below and charged under a nitrogen atmosphere.
Polymerization was carried out at 80 ° C. for 60 minutes while stirring. afterwards,
The other half of the innermost layer hard body material (b) was continuously added at the same temperature for 90 minutes, and further aged for 30 minutes at the same temperature while stirring to obtain a hard polymer latex.
To this hard polymer latex, the following additional initiator raw material (c) was added and stirred, and then the intermediate layer elastic body raw material (d) shown below was continuously added at 80 ° C. for 90 minutes, Then, the mixture was aged for 90 minutes at the same temperature while stirring to obtain a latex having a structure having a hard layer as an inner layer and a rubber elastic layer on the outer side. The following additional initiator raw material (e) was added to this latex and stirred, and then the outermost layer hard body raw material (f) shown below was added at 60 ° C. to 60
It was continuously added over a period of 30 minutes, and then aged for 30 minutes at the same temperature while stirring.

[Medium raw material (a)] Ion-exchanged water 150 parts Sodium carbonate 0.1 part [Innermost layer hard body material (b)] 62 parts of methyl methacrylate Methyl acrylate 4 parts Allyl methacrylate 0.1 part Deionized water 15 parts Sodium dodecylbenzene sulfonate 0.3 parts Potassium persulfate 0.03 parts [Additional initiator raw material (c)] Sodium dodecylbenzene sulfonate 0.3 parts Deionized water 5 parts Potassium persulfate 0.1 part [Intermediate layer elastic material (d)] Butyl acrylate 70 parts Styrene 15 parts Allyl methacrylate 2 parts [Additional initiator raw material (e)] Deionized water 5 parts 0.05 parts of potassium persulfate [Outermost layer hard body material (f)] Methyl methacrylate 30 parts Methyl acrylate 2 parts

Thus, the innermost layer is methyl methacrylate /
Spherical three-layer structure composed of methyl acrylate / allyl methacrylate hard crosslinked polymer, intermediate layer of butyl acrylate / styrene / allyl methacrylate soft elastic copolymer, and outermost layer of methyl methacrylate / methyl acrylate hard polymer Obtained a latex. The average particle size of this latex measured by the laser light scattering diffraction method is 0.28.
It was μm.

To this latex was added 1.5 times by weight of ion-exchanged water, and the mixture was stirred, heated to 80 ° C., and then, with vigorous stirring, sulfuric acid in an amount corresponding to 2% based on the solid content in the latex. Magnesium was added to coagulate the polymer particles. The polymer particles were then isolated by filtration. The polymer particles were washed by pouring them into ion-exchanged water heated to 80 ° C., which is 20 times the weight, stirred, and filtered. This washing operation was repeated 5 times in total and then dried by a vacuum dryer set at 80 ° C. to obtain rubber particles. The average particle diameter of the elastic copolymer layer in the rubber particles was measured by the following method and was found to be 0.26 μm.

[Measurement of Average Particle Size of Elastic Copolymer Layer of Rubber Particles] Rubber particles were mixed with methacrylic resin to form a film, the obtained film was cut into an appropriate size, and a piece was cut with 0.5% tetraoxidation. The rubber particle portion (elastic copolymer portion) is dyed by immersing in a ruthenium aqueous solution at room temperature for 15 hours.
Further, after cutting the sample to a thickness of about 80 nm using a microtome, a photograph is taken with a transmission electron microscope.
After randomly selecting 100 dyed rubber particle parts from this photograph and calculating the particle size of each, the average value is taken as the average particle size.

(C) Production of acrylic resin film 80 parts of methacrylic resin pellets and rubber particles 2 shown above
0 part was mixed with a super mixer and melt-kneaded with a twin-screw extruder to obtain pellets. Next, the pellets were extruded through a T-shaped die with a preset temperature of 275 ° C. using a 65 mmφ uniaxial extruder manufactured by Toshiba Machine Co., Ltd., and cooled so that both sides were completely in contact with two polishing rolls. An acrylic resin film having a thickness of 0.5 mm was obtained. With respect to the obtained film, the surface hardness, the amount of residual water-soluble substance and the resistance to warm water whitening were evaluated by the following methods, and the results are shown in Table 1.

[Surface Hardness] The pencil scratch value is measured according to JIS K 5400.

[Quantification of Water-Soluble Substance] Approximately 100 g of the acrylic resin film was dried in a vacuum dryer set at 100 ° C. for 24 hours in advance, and then precisely weighed to obtain the weight W ₁ (g). This is dissolved in about 500 ml of chloroform, and then the chloroform solution is added little by little to about 5 liters of ion-exchanged water and stirred. The precipitated insoluble matter is allowed to settle with a centrifuge, and the supernatant is collected. This supernatant is allowed to stand for 24 hours to remove only chloroform separated below. By concentrating the remaining liquid with an evaporator equipped with a cooling tube, and finally evaporating the medium completely,
The water-soluble component dissolved in the liquid is isolated. The isolated water-soluble component was accurately weighed to a unit of 0.01 mg using a semi-micro electronic balance manufactured by Shimadzu Corporation, and the weight W ₂
Calculate (mg). The content of the water-soluble substance in the film is calculated from the following formula. Content of water-soluble substance (ppm) = W ₂ ÷ W ₁ × 1,000

[Hot water whitening resistance] Sample film 80
After being immersed in ion-exchanged water at ℃ for 1 hour, it is taken out from the warm water to remove the water droplets adhering to the film surface, and the haze value is measured according to JIS K 7105 while the film is at room temperature.

(D) On the back surface of the hard acrylic resin transparent film obtained in the production of the decorative sheet,
A decorative pattern sheet was formed by printing a stone pattern layer with a thickness of 10 μm by silk printing.

(E) Preparation of interior wall material A vinyl acetate-based adhesive was applied to the surface of rockwool board which had been sanded in advance for the purpose of improving surface smoothness and water resistance, and was prepared as described above. After attaching the decorative sheet on the printing layer side, heat press at 15
A bathroom interior wall material was produced by crimping at a set pressure of kgf / cm ² . The resulting wall material was evaluated for design property after contact with hot water by the following method, and the results are shown in Table 1.

[Designability after Contact with Hot Water as Interior Material] The interior wall material having an acrylic resin film arranged on the surface is immersed in ion-exchanged water at 80 ° C., and after 1 hour, taken out from the hot water and visually observed. The appearance is judged according to the following criteria. It is transparent and maintains excellent designability .... ○ Whitening occurs, resulting in poor designability ....... ×

Example 2 The procedure of Example 1 is repeated, except that when an acrylic resin film is produced, a film having a film thickness of 0.125 μm is produced, and no decoration such as printing is performed on the film, and the film is kept transparent. Used as interior wall material. The physical properties of this acrylic resin film were evaluated in the same manner as in Example 1. Further, an interior wall material was produced in the same manner as in (E) of Example 1 except that this acrylic resin film was used and an aluminum steel plate having crushed stone powder on the surface layer was used as a base material of the interior wall material. And evaluated.
The results are shown in Table 1.

Comparative Example 1 An acrylic resin film was prepared in the same manner as in Example 1 except that the latex was used without washing and filtering in the production of the rubber particles, and the acrylic resin film was used as in Example 1. By the same operation, a decorative film and an interior wall material were produced. The evaluation results are shown in Table 1.

[0061]

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━           Acrylic resin film  Interior wall material            Thickness Water-soluble substance Surface 80 ℃ warm water immersion After hot water immersion                    Content Hardness Haze after pickling Designability ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 1 500 μm 70 ppm H 3.6% ○   〃 2 125 μm 70 ppm H 3.0% ○ ───────────────────────────── Comparative Example 1 500 μm 300 ppm H 20.5% × ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0062]

INDUSTRIAL APPLICABILITY The acrylic resin film of the present invention is useful as a surface material for indoor interior wall materials, such as bathrooms, kitchens, washrooms and toilets, which often come into contact with hot water, and the resin film is laminated on a substrate. The interior wall material as described above does not cause whitening due to contact with water, maintains a glossy and excellent design property, and satisfies the quality required as the interior wall material for a long period of time. Further, compared with the case where the surface is formed by clear painting, the process can be simplified and the product can be manufactured at low cost.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 51:04) F term (reference) 2E110 AA01 AA12 AA64 AB23 AB42 AB43 BA02 BA12 BB02 BB03 GA02W GA32W GB45W GB55W 4F071 AA33 AA33X AA77 AF25Y AF30Y AH03 BA01 BB06 BC12 4F100 AK21B AK21J AK25B AK25J AK25K AL01B AL05B AN00B AT00A BA02 CA23B DE01B GB08 HB31B JB07 JK12B JN30B YY00B 4J002 GF061GL00122

Claims (9)

[Claims] 1. A methacrylic resin made of an acrylic resin in which rubber particles are dispersed, and having a water-soluble substance content of 200 pp.
Haze value of 5 or less after immersion in warm water at 80 ℃ for 1 hour
% Or less and a thickness of 50 μm or more and 600 μm or less, an acrylic resin film excellent in hot water whitening resistance. 2. A methacrylic resin is an alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms in an amount of 50 to 100% by weight.
And 0 to 50% by weight of acrylic acid ester, and at least one kind of other vinyl monomer copolymerizable with them 0 to 49
The acrylic resin film according to claim 1, which is a thermoplastic polymer obtained by the polymerization of a monomer consisting of 10 wt%. 3. The acrylic resin film according to claim 1, wherein the rubber particles have an average particle size of 0.2 μm or more and 0.4 μm or less. 4. Rubber particles are alkyl acrylate 50-9.
9.9% by weight, at least one other vinyl monomer copolymerizable therewith 0 to 49.9% by weight, and a copolymerizable crosslinkable monomer 0.1 to 10% by weight In the presence of 100 parts by weight of a polymer having a layer of an elastic copolymer obtained by the polymerization of the following monomer, 50 to 100% by weight of a methacrylic acid ester and 0 to 50% by weight of an acrylic acid ester, At least one other polymerizable vinyl monomer 0 to 4
By polymerizing 10 to 400 parts by weight of the monomer composed of 9% by weight, at least one polymerized layer of the latter monomer is bonded to the surface of the elastic copolymer, The acrylic resin film according to claim 3, which is a rubber-containing polymer having an average particle diameter of the coalescence layer of 0.2 µm or more and 0.4 µm or less. 5. The acrylic resin film according to claim 4, wherein the rubber particles have a multi-layer structure including a hard polymer layer inside the elastic copolymer layer. 6. A rubber composition containing 50 to 95 parts by weight of methacrylic resin and 5 to 50 parts by weight of rubber particles, and the amount of the elastic copolymer in the rubber particles is 10 in total of the methacrylic resin and the rubber particles.
The acrylic resin film according to claim 4, which is 3 to 35 parts by weight per 0 parts by weight. 7. The acrylic resin film according to claim 1, wherein the surface has a pencil hardness of H or a value harder than H. 8. An interior wall material comprising an acrylic resin film according to any one of claims 1 to 7 laminated on a base material. 9. The acrylic resin film is printed on one side thereof, and the printed surface is laminated on a substrate.
Interior wall material described.