JPWO2006134973A1 - Resin composition for coating and laminated molded article using the same - Google Patents

Abstract

A coating resin composition comprising a methacrylic resin composition laminated to form a surface layer on a resin substrate, comprising 80 to 20% by mass of a methyl methacrylate polymer (I) and an inner layer polymer ( A) and a multistage polymerization graft copolymer (II) having an outer layer polymer (B) (20) to 80% by mass, and the inner layer polymer (A) contains an acrylic acid alkyl ester, an aromatic vinyl compound and a polyfunctional compound. A first-stage polymer obtained by polymerizing a monomer component containing a monomer and having a mass average particle diameter of 200 to 300 nm, and the outer layer polymer (B) is the inner layer polymer (A). A resin composition for coating, which is a second-stage polymer obtained by polymerizing a monomer component containing an alkyl methacrylate in the presence and having a glass transition temperature of 20 to 80 ° C.

Description

  The present invention relates to a laminated molded article excellent in weather resistance and impact resistance and a coating resin composition used for the surface layer thereof, and particularly relates to a laminated molded article excellent in impact resistance at a low temperature of room temperature or lower.

  Conventionally, vinyl chloride resins have been widely used for building materials such as window frames, wall materials, and decorative panels from the viewpoint of freedom of shape and workability. However, when the molded article of vinyl chloride resin is used outdoors, the weather resistance of the vinyl chloride resin is low, which causes problems such as surface whitening, gloss reduction, and yellowing. As a method for improving this problem, a resin layer mainly composed of a methacrylic resin having excellent weather resistance is formed on the surface of a molded article of vinyl chloride resin by coextrusion molding or the like (for example, patents). Literature 1: JP-A-5-93122, Patent Literature 2: JP-A-9-59473).

  However, a laminated molded product having a resin layer mainly composed of a methacrylic resin as a surface layer has a low impact resistance of the methacrylic resin, and thus tends to be damaged when an impact is applied from the surface layer side of the laminated molded product. . Since the methacrylic resin is particularly inferior in impact resistance at a low temperature of room temperature or lower, the use in which the laminated molded product can be used has been limited.

  For the purpose of improving the impact resistance of this laminated molded product, a technique for incorporating a butadiene rubber into a methacrylic resin has been disclosed (for example, Patent Document 3: JP-A-5-339459, Patent Document 4: Special Patent). (Kaihei 6-285934).

  However, the laminated molded article obtained by this technique has improved impact resistance at a low temperature of room temperature or lower, but contains polybutadiene rubber having poor weather resistance, so that it turns yellow when exposed to sunlight. It was easy, and it did not have sufficient weather resistance for outdoor applications such as window frames and outer wall materials.

  The present invention has been made in consideration of the above-mentioned problems of the prior art, and provides a laminated molded article excellent in weather resistance and impact resistance, and a coating resin composition used for the surface layer thereof. With the goal.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a methacrylic resin containing a multistage polymerization graft copolymer having a specific structure to provide a laminate having excellent weather resistance and impact resistance. The inventors found that a molded product can be obtained and completed the present invention.

  That is, the present invention is a coating resin composition comprising a methacrylic resin composition laminated to form a surface layer on a resin substrate, wherein the methacrylic resin composition mainly comprises methyl methacrylate units. 80 to 20% by mass of methyl methacrylate polymer (I) as a component, and 20 to 80% by mass of a multistage polymerization graft copolymer (II) having an inner layer polymer (A) and an outer layer polymer (B). The inner layer polymer (A) contains 70 to 90% by mass of an acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, 10 to 30% by mass of an aromatic vinyl compound, and other copolymerizable monomers. It is obtained by polymerizing a monomer component consisting of 100 parts by mass of a monomer mixture consisting of 0 to 20% by mass and 0.1 to 2 parts by mass of a polyfunctional monomer, and has a mass average particle size of 200 to It is the first stage polymer that is 300 nm. In the presence of the inner layer polymer (A), the outer layer polymer (B) is an alkyl group having 50 to 100% by mass of a methacrylic acid alkyl ester having 1 to 4 carbon atoms and an alkyl group having 1 to 8 carbon atoms. It is obtained by polymerizing a monomer component consisting of 0 to 50% by mass of acrylic acid alkyl ester and 0 to 20% by mass of other copolymerizable monomers, and has a glass transition temperature (Tg) of 20 to 80 ° C. It is a certain second-stage polymer, and is a coating resin composition in which the content of the outer layer polymer (B) is 30 to 100 parts by mass when the inner layer polymer (A) is 100 parts by mass.

  In the present invention, the acrylic polymer lubricant (C) is added in an amount of 0.1 to 10 masses per 100 mass parts in total of the methyl methacrylate polymer (I) and the multistage polymerization graft copolymer (II). It is the said resin composition for a coating | cover containing a part.

  Further, the present invention provides a methacrylic polymer (D) containing 70% by mass or more of a methyl methacrylate unit and having a reduced viscosity in the range of 0.3 to 1.5 L / g. It is the said resin composition for a coating | cover containing 0.1-10 mass parts with respect to a total of 100 mass parts of (I) and a multistage polymerization graft copolymer (II).

  Moreover, this invention is a laminated molded article which has a resin base material and the surface layer which consists of said resin composition for a coating | stacking laminated | stacked on this resin base material.

  Moreover, this invention is the said laminated molded product in which the said resin base material consists of a vinyl chloride resin.

  According to the present invention, there are provided a laminated molded article having high weather resistance and excellent impact resistance, particularly impact resistance under a low temperature of room temperature or lower, and a coating resin composition used for the surface layer. be able to.

  Hereinafter, the present invention will be described in detail.

  The coating resin composition of the present invention can provide a laminated molded article excellent in weather resistance and impact resistance by being laminated on a resin substrate to form a surface layer.

  As this resin base material, a vinyl chloride resin can be suitably used from the viewpoint of the degree of freedom of shape and workability. Other examples of the resin base material in the present invention include thermoplastic resins such as ABS (Acrylonitrile Butadiene Styrene) resin and ASA (Acrylate Styrene Acrylonitrile) resin, which are generally used for various molding materials such as building materials. be able to.

  The vinyl chloride resin used in the present invention is a vinyl chloride homopolymer or a copolymer having vinyl chloride units as a main component. As the copolymer, a copolymer of 80% by mass or more of vinyl chloride and another copolymerizable monomer is preferable. These homopolymers or copolymers can be used singly or as a mixture of plural kinds of polymers. Examples of other monomers copolymerizable with vinyl chloride include vinyl acetate, methacrylic acid ester, acrylic acid ester, acrylonitrile, α-olefin, and olefin chloride. The average degree of polymerization of the vinyl chloride resin is preferably about 600 to 1100. The vinyl chloride resin used in the present invention can be produced by a known polymerization method. In addition, the vinyl chloride resin in the present invention is filled with various compounding agents such as impact modifiers such as polybutadiene, acrylic resin processing aids, UV absorbers, stabilizers such as antioxidants, and titanium oxide. What mix | blended an agent, a coloring agent, a foaming agent, etc. can be used.

  The methacrylic resin composition (coating resin composition) used in the present invention comprises 80 to 20% by mass of a methyl methacrylate polymer (I) having a methyl methacrylate unit as a main component, and a multistage polymerization graft copolymer ( II) A resin composition containing 20 to 80% by mass. Here, the total of the polymer (I) and the polymer (II) is 100% by mass. The multistage polymerization graft copolymer is preferably 20% by mass or more because good impact resistance can be obtained. Moreover, it is preferable that the multistage polymerized graft copolymer is 80% by mass or less because good fluidity can be obtained during molding such as extrusion. This resin composition may contain other components within a range in which desired properties such as impact resistance and fluidity are not impaired, but the other components are 10% by mass with respect to the total amount of the resin composition. The following is preferable, and it is more preferable that it is 5 mass% or less.

  The methyl methacrylate polymer (I) is a homopolymer of methyl methacrylate or a copolymer having a methyl methacrylate unit as a main component. As the copolymer, a copolymer of 50% by mass or more, preferably 70% by mass or more of methyl methacrylate and another copolymerizable monomer is preferable.

  Monomers that can be copolymerized with methyl methacrylate include ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, methyl methacrylate other than methyl methacrylate such as phenyl methacrylate, methyl acrylate, ethyl acrylate, acrylic Examples thereof include acrylic acid esters such as butyl acid, cyclohexyl acrylate, and phenyl acrylate, methacrylic acid, acrylic acid, styrene, α-methylstyrene, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide, and cyclohexylmaleimide. Two or more of these may be used as necessary.

  There is no restriction | limiting in particular in the manufacturing method of methyl methacrylate type | system | group polymer (I), Methods, such as solution polymerization, suspension polymerization, emulsion polymerization, block polymerization, etc. which are well-known polymerization methods are employable. At that time, a known azo compound, a peroxide, a known mercaptan compound or the like as a polymerization initiator can be used as appropriate.

  The multistage polymerized graft copolymer (II) has at least two layers of an inner layer polymer (A) and an outer layer polymer (B) obtained by stepwise polymerization, and each layer in the multistage polymerized graft copolymer Is constituted by a monomer component having the composition shown below.

  The inner layer polymer (A) is composed of 70 to 90% by mass (preferably 75 to 85% by mass) of an alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, and 10 to 30% by mass (preferably 15 to 15% by mass) of the aromatic vinyl compound. ˜25% by mass), and other copolymerizable monomers 0 to 20% by mass (preferably 0 to 10% by mass), 100 parts by mass of a monomer mixture, and 0.1 to 0.1% of polyfunctional monomer It is obtained by polymerizing a monomer component consisting of 2 parts by mass (preferably 0.1 to 1 part by mass) (first stage polymerization).

  By setting the composition of the monomer component within the above ranges, a resin composition having excellent impact resistance and transparency can be obtained. In particular, if the amount of alkyl alkyl ester having 1 to 8 carbon atoms of the alkyl group in the monomer mixture is too small, a resin composition having sufficient impact resistance cannot be obtained. It is necessary to use it. Moreover, the transparency which was excellent by using the usage-amount of an aromatic vinyl compound in the said range is obtained, and the outstanding impact resistance is obtained by making the usage-amount of a polyfunctional monomer into the said range.

  Examples of the alkyl acrylate ester having 1 to 8 carbon atoms in the inner layer polymer (A) include methyl acrylate, ethyl acrylate, acrylic acid-i-propyl, acrylic acid-n-butyl, and acrylic acid-2. -Ethylhexyl etc. are mentioned, These can be used individually or in combination of 2 or more types. From the viewpoint of cost and reactivity, it is preferable to use n-butyl acrylate.

  Examples of the aromatic vinyl compound in the inner layer polymer (A) include styrene, α-methylstyrene, vinyltoluene and the like, and these can be used alone or in combination of two or more. From the viewpoint of cost and reactivity, styrene is preferably used.

  The other copolymerizable monomer in the inner layer polymer (A) is not particularly limited as long as it is copolymerizable with the above alkyl acrylate ester and aromatic vinyl compound. For example, phenyl methacrylate, cyclohexyl methacrylate , Benzyl methacrylate, methacrylic acid, acrylic acid, hydroxyethyl methacrylate, acrylamide, glycidyl methacrylate and the like, and these can be used alone or in combination of two or more.

  The polyfunctional monomer in the inner layer polymer (A) includes ethylene glycol diacrylate, 1,3-butanediol diacrylate, allyl acrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate. Allyl methacrylate, triallyl cyanurate, diallyl maleate, divinylbenzene, diallyl phthalate, diallyl fumarate, triallyl trimelliate, and the like can be used alone or in combination of two or more. From the viewpoint of cost and reactivity, a bifunctional acrylate monomer is preferable, and allyl methacrylate is particularly preferable.

  The inner layer polymer (A) has a mass average particle diameter of 200 to 300 nm, preferably 230 to 260 nm. If the mass average particle diameter of the inner layer polymer (A) is too small, it becomes difficult to obtain sufficient impact resistance of the resin composition. If the mass average particle diameter is too large, the transparency of the resin composition tends to be lowered.

  The outer layer polymer (B) is 50 to 100% by mass (preferably 60 to 85% by mass) of an alkyl methacrylate having 1 to 4 carbon atoms in the presence of the inner layer polymer (A). 0 to 50% by mass (preferably 15 to 40% by mass) of acrylic acid alkyl ester having 1 to 8 carbon atoms in the alkyl group, and 0 to 20% by mass of other copolymerizable monomers (preferably 0 to 10%). Mass%) is obtained by polymerizing the monomer component (second stage polymerization). Further, the glass transition temperature (hereinafter referred to as “Tg”) when this monomer component is polymerized needs to be 20 to 80 ° C. This Tg is preferably 20 to 70 ° C. If the Tg is too low, it is easy to block when collected as a powder, and the handleability is reduced. On the other hand, if Tg is too high, a resin composition having sufficient impact resistance cannot be obtained. By making the usage-amount of the said monomer component into said composition range, the resin composition excellent in productivity, workability, and impact resistance can be obtained. Use of an alkyl acrylate alkyl ester having an alkyl group having 1 to 8 carbon atoms makes it easy to obtain a desired Tg, and as a result, a resin composition that is superior in productivity, workability, and impact resistance can be obtained. .

  Examples of the alkyl methacrylate having 1 to 4 carbon atoms of the alkyl group in the outer layer polymer (B) include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and n-butyl methacrylate, and these are independent. Alternatively, two or more kinds can be used in combination. From the viewpoint of cost and reactivity, it is preferable to use methyl methacrylate.

  As an alkyl acrylate ester having 1 to 8 carbon atoms in the outer layer polymer (B), an alkyl acrylate ester having 1 to 8 carbon atoms can be used in the inner layer polymer (A) described above. The same ones listed as examples can be used. From the viewpoints of Tg control, cost, and reactivity, it is preferable to use n-butyl acrylate.

  Examples of other copolymerizable monomers in the outer layer polymer (B) include those exemplified as the aromatic vinyl compound and other copolymerizable monomers that can be used in the inner layer polymer (A) described above. Can be used.

In addition, Tg of the polymer said by this invention is the formula of FOX generally known:
1 / Tg = a1 / Tg1 + a2 / Tg2 + a3 / Tg3 +
According to the calculation. Tg1, Tg2 and Tg3 in the formula represent Tg of each homopolymer obtained when each monomer contained in the monomer component used for forming the polymer is polymerized alone. The values described in "Handbook 3rd edition" (POLYMER HANDBOOK, THIRD EDITION), John Wiley & Sons, Inc. (1989) are cited. Further, a1, a2 and a3 in the formula of FOX represent the mass fraction of each monomer contained in the monomer component used to form the polymer.

  When the inner layer polymer (A) of the multistage polymerization graft copolymer is 100 parts by mass, the content of the outer layer polymer (B) is 30 to 100 parts by mass, and preferably 50 to 80 parts by mass. When it is less than 30 parts by mass, it is difficult to obtain sufficient impact resistance of the resin composition, and when it exceeds 100 parts by mass, it is difficult to obtain an effect corresponding to the content.

  The multistage polymerization graft copolymer (II) in the present invention may form a new polymer by performing polymerization in three or more stages within a range where desired properties are not impaired. That is, a hard or soft polymer layer may be provided inside the particles made of the inner layer polymer (A), and an intermediate layer between the inner layer polymer (A) and the outer layer polymer (B) formed on the outer periphery thereof. A polymer layer may be provided, and a polymer layer may be further provided outside the multilayer polymer (B).

  In addition, the mass of the polymer of each layer constituting the multistage polymerization graft copolymer (II) is calculated as the sum of the masses of the monomer components constituting each layer.

  The multistage polymerization graft copolymer (II) in the present invention is produced by emulsion polymerization of the above monomer components to produce a latex of the multistage polymerization graft copolymer and recover the multistage polymerization graft copolymer therefrom. Can be obtained. Emulsion polymerization may be performed according to a known method.

  As an emulsifier used for emulsion polymerization, any of an anionic emulsifier, a cationic emulsifier, and a nonionic emulsifier can be used, and an anionic emulsifier is particularly preferable. As an anionic emulsifier, carboxylic acid salts such as potassium oleate, sodium stearate, sodium myristate, sodium N-lauroyl sarcosinate, dipotassium alkenyl succinate, sulfate salts such as sodium lauryl sulfate, sodium dioctyl sulfosuccinate, Examples thereof include sulfonates such as sodium dodecylbenzenesulfonate and sodium alkyldiphenyl ether disulfonate, and phosphate esters such as sodium polyoxyethylene alkyl ether phosphate.

  The amount of the emulsifier may be appropriately determined depending on the type and blending ratio of the emulsifier and the monomer component to be used, and the polymerization conditions, but is usually 0.1 parts by mass or more, particularly 0. It is preferably 5 parts by mass or more. Moreover, in order to suppress the residual amount to a polymer, it is preferable that it is 10 mass parts or less with respect to 100 mass parts of monomer components, especially 5 mass parts or less.

  Although the polymerization initiator used for the polymerization reaction for forming each layer of the multistage polymerization graft copolymer (II) is not particularly limited, examples of the radical polymerization initiator include benzoyl peroxide, cumene hydroperoxide, and t-butyl. Hydroperoxide, peroxides such as hydrogen peroxide; azo compounds such as azobisisobutyronitrile; persulfate compounds such as potassium persulfate and ammonium persulfate; perchloric acid compounds; perborate compounds; Examples thereof include a redox initiator composed of a combination with a reducing sulfoxy compound. The amount of these radical polymerization initiators to be added varies depending on the type and mixing ratio of the radical polymerization initiator and the monomer component to be used, but is usually about 0.01 to 10 parts by mass with respect to 100 parts by mass of the monomer component. It is.

  In the production of the multistage polymerization graft copolymer (II), the monomer component and the polymerization initiator are added by various methods such as a batch addition method, a division addition method, a continuous addition method, a monomer addition method, and an emulsion addition method. can do. In order to make the reaction proceed smoothly, the reaction system may be replaced with nitrogen, or in order to remove the residual monomer, a selected catalyst may be added as necessary after the reaction is completed. Moreover, when performing the polymerization for forming each layer, additives such as a pH adjuster, an antioxidant, and an ultraviolet absorber can be present together.

  In the polymerization of the monomer component of each layer, a chain transfer agent such as an alkyl mercaptan can be used. Examples of the alkyl mercaptan include n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan and the like. As for the usage-amount of a chain transfer agent, 0.1-2 mass parts is preferable with respect to 100 mass parts of monomer components.

  The solid content in the latex of the multistage polymerization graft copolymer (II) thus obtained is preferably 10% by mass or more, and preferably 30% by mass or more from the viewpoint of increasing the productivity of the polymer. From the viewpoint of not impairing the stability of the latex, it is preferably 60% by mass or less, and more preferably 50% by mass or less.

  As a method for recovering the multistage polymerization graft copolymer (II) from the latex, various methods such as an acid coagulation method, a salt coagulation method, a freeze coagulation method, and a spray drying method can be used.

  Examples of the recovery agent used in the salt coagulation method include inorganic salts such as aluminum chloride, aluminum sulfate, sodium sulfate, magnesium sulfate, sodium nitrate, and calcium acetate. Calcium acetate is particularly preferable in order to suppress coloring of the molded product of the resin composition using the multistage polymerization graft copolymer. These recovery agents are usually used as an aqueous solution. The concentration of the recovery agent aqueous solution is preferably 0.1 to 20% by mass, and more preferably 1 to 15% by mass. If the concentration is too low, the multistage polymerization graft copolymer may not be recovered stably. If the concentration is too high, a large amount of recovery agent remains in the recovered multilayered graft copolymer, resulting in increased coloration. This may reduce the performance of the molded product, which is undesirable.

  When the latex of the multistage polymerization graft copolymer (II) is brought into contact with the recovery agent, a latex of a hard polymer having a small particle size may coexist. Thereby, it becomes difficult to block the collect | recovered multilayered structure graft polymer, and handleability improves.

  The temperature at which the latex of the multistage polymerization graft copolymer (II) is brought into contact with the recovery agent is preferably 30 ° C to 100 ° C.

  The precipitated multistage polymerization graft copolymer (II) is washed, dehydrated and dried by various known methods. A lubricant such as silica gel fine particles may be added to the dried multistage polymerization graft copolymer. Thereby, it becomes difficult to block a multistage polymerization graft polymer, and handleability improves.

  As a method for mixing the methyl methacrylate polymer (I) and the multistage polymerization graft copolymer (II) for obtaining the coating resin composition (methacrylic resin composition) of the present invention, a known method is applied. it can. For example, the methyl methacrylate polymer (I) and the multistage polymerization graft copolymer (II) are blended at a predetermined ratio, and if necessary, various additives are added and blended with a Henschel mixer or the like. Examples thereof include a method of melt-kneading and pelletizing using a single-screw or twin-screw extruder or various kneaders.

  Further, the coating resin composition (methacrylic resin composition) of the present invention comprises an acrylic polymer lubricant (C) comprising the methyl methacrylate polymer (I) and the multistage polymerization graft copolymer (II). It is preferable to contain 0.1-10 mass parts with respect to a total of 100 mass parts. By blending the acrylic polymer lubricant (C), an effect of improving the melt tension at the time of extrusion molding can be obtained. When the acrylic polymer lubricant (C) is 0.1 part by mass or more, the melt tension at the time of extrusion molding is sufficient, and a laminated molded product having a uniform thickness is obtained. When the acrylic polymer lubricant (C) is 10 parts by mass or less, desired properties such as impact resistance of the laminated molded product tend to be sufficiently obtained. The content is more preferably in the range of 0.1 to 5 parts by mass, and still more preferably in the range of 0.1 to 1 part by mass.

  The acrylic polymer lubricant (C) used in the present invention preferably has a reduced viscosity of 0.01 to 0.5 L / g. The reduced viscosity is more preferably in the range of 0.05 to 0.15 L / g. When the reduced viscosity is 0.01 L / g or more, various physical properties such as impact resistance tend to be improved. Further, when the reduced viscosity is 0.5 L / g or less, an improvement effect of molding processability, particularly a die line at the time of extrusion molding can be seen.

  The content of methyl methacrylate units in the acrylic polymer lubricant (C) is preferably 30 to 70% by mass. That is, it is preferably 30% by mass or more from the viewpoint of compatibility with the methyl methacrylate polymer, and preferably 70% by mass or less from the viewpoint of the appearance of the molded product.

  The structural unit other than the methyl methacrylate unit in the acrylic polymer lubricant (C) includes an alkyl group having 2 to 18 carbon atoms in the alkyl group, and acrylic acid having 1 to 18 carbon atoms in the alkyl group. The unit of an alkyl unit or the other vinyl-type monomer copolymerizable with the monomer which forms the structural unit of an acrylic polymer lubricant (C) is preferable. The acrylic polymer lubricant (C) is preferably obtained by emulsion polymerization of a monomer or monomer mixture as a raw material.

  The coating resin composition (methacrylic resin composition) of the present invention contains methyl methacrylate units in an amount of 70% by mass or more in order to adjust the melt viscosity during molding or to improve the appearance of a molded product obtained by molding. The methacrylic polymer (D) having a reduced viscosity in the range of 0.3 to 1.5 L / g is the sum of the methyl methacrylate polymer (I) and the multistage polymerization graft copolymer (II). It is preferable to mix | blend within the range of 0.1-10 mass parts with respect to 100 mass parts. This content is more preferably in the range of 0.1 to 5 parts by mass, and still more preferably in the range of 0.1 to 1 part by mass.

  The reduced viscosity (ηsp / c) in the present invention is measured at 25 ° C. by dissolving 0.1 g of a sample in 100 mL of chloroform.

  The coating resin composition (methacrylic resin composition) of the present invention may contain an antioxidant, an ultraviolet absorber, a light stabilizer, a release agent, a pigment, a dye, and the like.

  Although there is no restriction | limiting in particular as a method of shape | molding integrally the resin base material and a methacrylic-type resin composition for obtaining the laminated molded product of this invention, The method of laminating | stacking by coextrusion molding can be mentioned. For example, there is a method in which each resin is melted by a plurality of extruders, and these molten resins are passed through a laminating device such as a die to obtain a laminated molded product. In addition, a method in which a methacrylic resin composition is preliminarily formed into a film by extrusion molding or the like, and this film is overlaid on a vinyl chloride resin molded product separately manufactured by extrusion molding or the like, and this is press molded and laminated. Is mentioned.

  The laminated molded article according to the present invention is usually composed of two layers of a resin base material and a layer made of a methacrylic resin composition provided on the base material. A laminate of three or more layers in which both are laminated may be used. In the laminate of three or more layers, at least one layer composed of the methacrylic resin composition is configured to be positioned on the surface layer (outermost layer). The thickness of each layer of the laminated molded product is appropriately set depending on the use of the product, but the thickness of the layer made of the methacrylic resin composition located on the surface layer of the molded product is preferably set to 0.05 to 1 mm.

  Hereinafter, although an example and a comparative example explain the present invention still in detail, the present invention is not limited to these. The test piece preparation methods and evaluation methods in Examples and Comparative Examples are shown below.

(1) Production of Laminated Molded Product Pellets of methacrylic resin composition were rolled into a cylinder at a temperature of 240 ° C. in a φ25 mm single screw extruder equipped with a T die (width 100 mm) and a polishing roll (three, vertical type). Extrusion was performed at a temperature of 90 ° C. to produce a film having a thickness of 0.4 mm. This methacrylic resin film is layered on a commercially available vinyl chloride resin sheet (Takiron plate ET1980, thickness 2 mm, manufactured by Takiron Co., Ltd.), and pressure-bonded at 140 ° C. with a press molding machine to obtain a laminated molded product. It was.

(2) Impact Resistance Evaluation of Laminated Molded Product The laminated molded product obtained above is cut into a length of 80 mm and a width of 10 mm, and a notch having a depth of 2 mm in the width direction is opposed to the central portion in the length direction. I put it in. Using this test piece, a double notch Charpy impact test (flatwise) based on JIS K7111 Annex A was performed to evaluate the impact resistance of the laminated molded product. Measurement temperature is 23 degreeC and -10 degreeC. The hammer was struck from the vinyl chloride resin side, and the fracture occurred from the methacrylic resin side.

(3) Surface Impact Resistance Evaluation of Laminated Molded Product The laminated molded product obtained above is cut out to 100 mm × 100 mm, and a surface impact resistance test is performed using a high-speed instrumented surface impact device (Hydroshot) manufactured by Shimadzu Corporation. Went. The conditions are a falling weight speed of 1.0 m / sec, a punch tip diameter of 1/2 inch, a sample receiving part diameter of 3 inch, the number of samples n = 20, and a test temperature of −10 ° C. The fracture forms after the test were classified as follows and the ratio was calculated. The case where the plate was broken and broken was brittle, and the hole where the punch was removed was opened and the impact surface was absorbed and the fracture surface became white. The ratio which became ductile by the said test was shown as a ductile fracture rate (%). The higher the ductile fracture rate, the higher the impact resistance.

(4) Weather resistance evaluation of laminated molded product The laminated molded product obtained above was cut into a size of 50 mm x 50 mm, and a metal weather tester (KU-R4CI-A, manufactured by Daipura Wintes Co., Ltd.). The methacrylic resin was exposed for 200 hours at an irradiation intensity of 80 mW / cm ² , 63 ° C. and 50% RH. The appearance after exposure was visually evaluated. ○ indicates that the appearance change (yellowing color, whitening, gloss reduction, rough skin, etc.) is small, and x is large.

(5) Workability When producing a film with the φ25 mm single screw extruder, the occurrence of die lines was visually observed. The results were classified as follows.
○: Die line does not occur, good workability,
Δ: Slight die line occurred,
X: A large amount of die lines were generated.

(6) Measurement of mass average particle diameter The obtained latex was diluted with distilled water, 0.1 ml of diluted latex having a concentration of about 3% was used as a sample, and a flow rate of 1 was measured using a CHDF2000 type particle size distribution analyzer manufactured by Matec Applied Sciences. It was measured under conditions of 0.4 ml / min, a pressure of about 2.76 MPa (about 4000 psi), and a temperature of 35 ° C. In the measurement, a capillary cartridge for particle separation and a carrier liquid were used, and the liquidity was made almost neutral. Before the measurement, a standard curve was prepared by measuring a total of 12 particle diameters from 0.02 μm to 0.8 μm using monodispersed polystyrene with a known particle diameter manufactured by DUKE Co., USA as the standard particle size substance. .

(Production Example 1) Production of multistage polymerization graft copolymer (1) The following component 1 was placed in a 5-neck flask equipped with a stirrer, reflux condenser, nitrogen blowing port, monomer addition port, and thermometer. .
(Component 1)
250 parts by weight of deionized water,
0.5 parts by mass of sodium formaldehyde sulfoxylate (hereinafter referred to as “SFS”),
Ferrous sulfate 1.3 × 10 ⁻⁴ parts by mass,
Ethylenediaminetetraacetic acid disodium 3.9 × 10 ⁻⁴ parts by mass,
Sodium carbonate 0.035 parts by mass.

  Next, after the components in the flask were heated to 80 ° C. while mixing and stirring with nitrogen, the mixture (a-1) having the following composition was charged over 4 hours and kept at 80 ° C. for 2 hours. This was held to complete the polymerization of the inner layer polymer (A). The degree of polymerization of the obtained latex (A-1) (calculated by measuring unreacted monomer by gas chromatography, the same applies hereinafter) is 99% by mass or more, and the mass average particle of the inner layer polymer (A) The diameter was 240 nm.

(Mixture (a-1))
18.5 parts by mass of styrene,
Acrylic acid-n-butyl 81.5 parts by mass,
0.9 parts by weight of allyl methacrylate,
0.3 parts by mass of t-butyl hydroperoxide,
Emulsifier A 3.2 parts by mass (emulsifier A: polyoxyethylene alkyl ether phosphate ester salt (phosphanol RS-610NA, manufactured by Toho Chemical Co., Ltd.)).

  Subsequently, a solution obtained by dissolving 0.14 parts by mass of SFS in 5.0 parts by mass of deionized water was added to the latex (A-1) and held for 15 minutes, and then a mixture (b-1) having the following composition was added. The solution was added dropwise over 1 hour 30 minutes and held for 1 hour to complete the polymerization of the outer layer polymer (B). The polymerization rate of the obtained final latex (B-1) was 99% by mass or more. The Tg of the outer layer polymer (B) is shown in Table 1.

(Mixture (b-1))
57.4 parts by weight of methyl methacrylate,
Acrylic acid-n-butyl 10.5 parts by mass,
2.1 parts by mass of styrene,
0.11 parts by mass of t-butyl hydroperoxide,
0.29 parts by mass of n-octyl mercaptan,
Emulsifier A 0.47 parts by mass.

  Subsequently, 300 parts by mass of a 2.0% by mass aqueous calcium acetate solution as a recovery agent aqueous solution is charged in a stainless steel container, and the temperature is raised to 60 ° C. with mixing and stirring, and 300 parts by mass of the latex (B-1) is added for 10 minutes. Added continuously. Thereafter, the temperature was raised to 90 ° C. and held for 5 minutes. Cool to room temperature, wash with deionized water and filter by centrifugal dehydration (1300 G, 3 minutes) to obtain a wet resin, and dry at 75 ° C. for 48 hours to obtain a white powdered multistage polymerization graft copolymer (1 )

(Production Examples 2, 4, 5, 6)
Production of multistage polymerized graft copolymer (2), (4), (5), (6) Except that the monomer composition of the mixture (b-1) was changed as shown in Table 1, it is shown in Production Example 1. The multistage polymerized graft copolymers (2), (4), (5), and (6) were obtained in the same manner as the method for producing the multilayered graft copolymer (1). Table 1 shows the mass average particle diameter of the inner layer polymer (A) and the Tg of the outer layer polymer (B).

(Production Example 3)
Production of multistage polymerized graft copolymer (3) Ingredient 1 shows 0.5 parts by weight of emulsifier A, and emulsifier A in the mixture (a-1) is changed to 1.6 parts by weight. The multistage polymerization graft copolymer (3) was obtained in the same manner as in the method for producing the multistage polymerization graft copolymer (1).

  In Table 1, MMA represents methyl methacrylate, BA represents acrylate-n-butyl, St represents styrene, and MA represents methyl acrylate.

(Production Example 7)
Production of acrylic polymer lubricant (C) First, the following mixture 1, mixture 2, and mixture 3 were prepared.
Mixture 1: 30 parts by weight of methyl methacrylate and 0.03 parts by weight of n-octyl mercaptan,
Mixture 2: 20 parts by mass of n-butyl methacrylate, 30 parts by mass of n-butyl acrylate and 0.25 parts by mass of n-octyl mercaptan,
Mixture 3: 20 parts by mass of methyl methacrylate and 0.05 parts by mass of n-octyl mercaptan.

  Next, 280 parts by mass of distilled water, 1.5 parts by mass of a mixture of potassium vinyl succinate and potassium allyl succinate, 2 parts by mass of ammonium persulfate, and the mixture 1 are charged into a separable flask equipped with a stirrer, and after nitrogen replacement The temperature was raised to 65 ° C. and stirred for 2 hours.

  Subsequently, the mixture 2 was dropped over 1 hour and stirred for 2 hours.

  Thereafter, the mixture 3 was added over 30 minutes and stirred for 2 hours to obtain a copolymer latex. The obtained copolymer latex was dropped into 200 parts by mass of 0.5% sulfuric acid aqueous solution at 50 ° C., coagulated and separated, washed, dried at 75 ° C. for 16 hours, and powdered acrylic polymer lubricant ( C-1) was obtained.

  The reduced viscosity (ηsp / c) of the acrylic polymer lubricant (C-1) was 0.10 L / g.

Example 1
50 parts by mass of a methyl methacrylate polymer (Acrypet SV, manufactured by Mitsubishi Rayon Co., Ltd.) and 50 parts by mass of the multistage polymerization graft copolymer (1) produced in Production Example 1 were mixed, and a φ30 mm twin screw extruder A pellet-like methacrylic resin composition was obtained at a cylinder temperature of 240 ° C. using (PCM30, manufactured by Ikegai Co., Ltd.). Using this pellet-like methacrylic resin composition, a film having a thickness of 0.4 mm was prepared and laminated on a vinyl chloride resin sheet (Takiron plate ET1980, thickness 2 mm, manufactured by Takiron Co., Ltd.) with a press molding machine. Using this laminated molded product, impact resistance and weather resistance were evaluated. The results are shown in Table 2.

(Example 2)
50 parts by mass of a methyl methacrylate polymer (Acrypet SV, manufactured by Mitsubishi Rayon Co., Ltd.) and 50 parts by mass of the multistage polymerization graft copolymer (2) produced in Production Example 2 are mixed to form a pellet-like methacrylic resin composition A laminated molded product was produced and evaluated in the same manner as in Example 1 except that the product was produced. The results are shown in Table 2.

(Comparative Example 1)
Test pieces were prepared using only a vinyl chloride resin sheet and evaluated for impact resistance and weather resistance. The results are shown in Table 2.

(Comparative Example 2)
A laminated molded product was prepared and evaluated in the same manner as in Example 1 except that only a methyl methacrylate polymer (Acrypet SV, manufactured by Mitsubishi Rayon Co., Ltd.) was used and a multilayer structure graft copolymer was not used. did. The results are shown in Table 2.

(Comparative Examples 3-5)
50 parts by mass of methyl methacrylate polymer (Acrypet SV, manufactured by Mitsubishi Rayon Co., Ltd.) and 50 parts by mass of the multistage polymerization graft copolymers (3) to (5) produced in Production Examples 3 to 5 were mixed. A laminated molded article was produced and evaluated in the same manner as in Example 1 except that a pellet-like methacrylic resin composition was produced. The results are shown in Table 2.

（実施例３〜６、比較例６〜７）
表３に示す配合で多段グラフト共重合体、メタクリル酸メチル系樹脂（アクリペットＳＶ、三菱レイヨン（株）製）、アクリル系高分子滑剤（Ｃ）およびメタクリル系重合物（Ｄ）（メタブレンＰ５３０Ａ、三菱レイヨン（株）製、還元粘度０．９０Ｌ／ｇ）をハンドブレンドし、それぞれをφ３０ｍｍ二軸押出機（ＰＣＭ３０、（株）池貝製）を用いてシリンダー温度２４０℃でペレット化した。このペレットを用いて厚み０．４ｍｍのフィルムを作製し、プレス成形機で塩化ビニル系樹脂シートに積層した。この積層成形品を用いて、耐面衝撃性、耐候性、加工性の評価を行った。結果を表３に示す。なお、比較例７においてはＡＳＡ樹脂（ＣＲ７０２０、ＧＥ社製）からなる厚み０．４ｍｍのフィルムを作製し、塩化ビニル系樹脂シートに積層した。

(Examples 3-6, Comparative Examples 6-7)
In the formulation shown in Table 3, multistage graft copolymer, methyl methacrylate resin (Acrypet SV, manufactured by Mitsubishi Rayon Co., Ltd.), acrylic polymer lubricant (C), and methacrylic polymer (D) (methabrene P530A, Mitsubishi Rayon Co., Ltd., reduced viscosity 0.90 L / g) was hand blended, and each was pelletized at a cylinder temperature of 240 ° C. using a φ30 mm twin screw extruder (PCM30, manufactured by Ikekai Co., Ltd.). A film having a thickness of 0.4 mm was produced using the pellets and laminated on a vinyl chloride resin sheet with a press molding machine. Using this laminated molded product, surface impact resistance, weather resistance, and workability were evaluated. The results are shown in Table 3. In Comparative Example 7, a 0.4 mm thick film made of ASA resin (CR7020, manufactured by GE) was prepared and laminated on a vinyl chloride resin sheet.

表中の「ＳＶ」はメタクリル酸メチル系樹脂（アクリペットＳＶ）を示す。

“SV” in the table indicates a methyl methacrylate resin (Acrypet SV).

  As shown in Tables 2 and 3, a molded product obtained by laminating a methacrylic resin containing a multistage polymerization graft copolymer according to the present invention on a vinyl chloride resin significantly reduces the impact resistance of the vinyl chloride resin. And weather resistance can be imparted. Particularly in a low temperature environment, weather resistance can be imparted while sufficiently ensuring impact resistance. Such an effect is greatly improved as compared with a molded product using a commercially available acrylic impact modifier.

Since the laminated molded article of the present invention is excellent in weather resistance and impact resistance, it can be suitably used as a building material for outdoor use such as a window frame and an outer wall material.

Claims (7)

A coating resin composition comprising a methacrylic resin composition laminated to form a surface layer on a resin substrate,
The methacrylic resin composition has 80 to 20% by mass of a methyl methacrylate polymer (I) having a methyl methacrylate unit as a main component, an inner layer polymer (A) and an outer layer polymer (B). Containing 20 to 80% by mass of the graft copolymer (II),
The inner layer polymer (A) is composed of 70 to 90% by mass of an alkyl acrylate ester having an alkyl group having 1 to 8 carbon atoms, 10 to 30% by mass of an aromatic vinyl compound, and other copolymerizable monomers 0 to 90% by mass. It is obtained by polymerizing a monomer component consisting of 100 parts by mass of a monomer mixture comprising 20% by mass and 0.1-2 parts by mass of a polyfunctional monomer, and has a mass average particle diameter of 200-300 nm. The first stage polymer,
In the presence of the inner layer polymer (A), the outer layer polymer (B) is an acrylic acid having 50 to 100% by mass of an alkyl group having 1 to 4 carbon atoms and an alkyl group having 1 to 8 carbon atoms. It is obtained by polymerizing a monomer component consisting of 0 to 50% by mass of an acid alkyl ester and 0 to 20% by mass of another copolymerizable monomer, and has a glass transition temperature (Tg) of 20 to 80 ° C. A second stage polymer,
The resin composition for coating | covering whose content of an outer layer polymer (B) when an inner layer polymer (A) is 100 mass parts is 30-100 mass parts.   In the presence of the inner layer polymer (A), the outer layer polymer (B) is an acrylic acid alkyl ester having 60 to 85% by mass of an alkyl group having 1 to 4 carbon atoms and an alkyl group having 1 to 8 carbon atoms. It is obtained by polymerizing a monomer component consisting of 15 to 40% by mass of an acid alkyl ester and 0 to 10% by mass of other copolymerizable monomers, and has a glass transition temperature (Tg) of 20 to 80 ° C. The coating resin composition according to claim 1, which is a polymer.   The acrylic polymer lubricant (C) is contained in an amount of 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of the methyl methacrylate polymer (I) and the multistage polymerization graft copolymer (II). Or the coating resin composition according to 2.   The acrylic polymer lubricant (C) contains 30 to 70% by mass of methyl methacrylate units, and the reduced viscosity of the acrylic polymer lubricant (C) is in the range of 0.01 to 0.5 L / g. Item 4. The coating resin composition according to Item 3.   A methacrylic polymer (D) containing 70% by mass or more of methyl methacrylate units and having a reduced viscosity in the range of 0.3 to 1.5 L / g is multistaged with the methyl methacrylate polymer (I). The coating resin composition according to any one of claims 1 to 4, comprising 0.1 to 10 parts by mass with respect to 100 parts by mass in total with the polymerized graft copolymer (II).   A laminated molded article having a resin base material and a surface layer made of the coating resin composition according to any one of claims 1 to 5 laminated on the resin base material. The laminated molded product according to claim 6, wherein the resin base material is made of a vinyl chloride resin.