JP2006028286A - Acrylic resin composition for molding use, and molded product obtained by using the resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible-type acrylic resin composition for molding use slight in environmental burden, excellent in molding processability, tensile strength and tear strength, low in shrinkage after undergoing hot molding in particular, and moldable by various molding processes including injection molding alternatively to conventional flexible vinyl chloride resin compositions, and to provide a molded product obtained by molding the resin composition. <P>SOLUTION: The acrylic resin composition for molding use solid at room temperature comprises 50-90 wt.% of an acrylic resin with a weight-average molecular weight of 100,000-3,000,000, 5-45 wt.% of a specific acrylic-styrene-butadiene-based copolymer and 5-45 wt.% of a polyester plasticizer of linear structure with a number-average molecular weight of 500-3,000. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a soft acrylic resin composition for molding applicable to molding methods such as a calendar molding method, an extrusion molding method, and an injection molding method, and a molded product obtained by molding the resin composition.

  Conventionally, a soft vinyl chloride resin composition obtained by blending a plasticizer or the like with a vinyl chloride resin is further injection-molded, for example, into a film or a sheet by a calendar molding method, or into a hose or a tube by an extrusion molding method. According to the law, it has been processed by various molding methods into toys, packings, etc. and has been used for various purposes.

  However, vinyl chloride resin is inferior in weather resistance and has a large change in color tone, and a large amount of hydrogen chloride gas is generated when the resin is extinguished, so there are concerns about adverse effects on the natural environment. There has been a strong demand for conversion from halogen-based resins to non-halogen-based resins.

  In order to meet these market demands, a plasticizer is blended into an acrylic resin, and if necessary, a soft acrylic resin composition for molding that contains a filler and other additives is calendered and extruded. A molding method is performed by a molding method, an injection molding method, or the like.

  However, in the case of a soft type acrylic resin composition for molding containing a plasticizer, the presence of the plasticizer reduces the melt viscosity of the resin and improves the flowability, but the movement of the resin during the cooling process after molding is also improved. Since it became large, there was a tendency for shrinkage to become large.

For the purpose of improving such poor flowability of acrylic resin, a soft type acrylic resin composition for molding to which an acrylic-styrene copolymer resin is added (for example, Patent Document 1) has been proposed.
However, when the composition is molded by an injection molding method that requires precise dimensional accuracy, the shrinkage is still large and still has practical problems.

On the other hand, the shape of the acrylic resin used in the production of a soft type acrylic resin composition for molding used in molding methods such as calendar molding, extrusion molding, injection molding, etc. Pellets have a relatively large shape, and when these are used, the plasticizer is inferior in its absorbability, that is, it is inferior in dry-up properties. There is a problem that the phenomenon easily occurs and the workability in the subsequent process is seriously hindered.
The “dry-up property” as used in the present invention refers to the property that after the mixing, the plasticizer is absorbed into the resin to become a more free state.

Japanese Patent Laying-Open No. 2003-003033 (Claims-7th Mitsugu left column paragraph 0061)

  The present invention has a small impact on the environment, is excellent in moldability, tensile strength, tear strength, and particularly has a small shrinkage ratio after heat molding, and is a calender molding method instead of the conventional soft vinyl chloride resin composition. An object of the present invention is to provide a soft acrylic resin composition for molding that can be molded by a molding method such as an extrusion molding method or an injection molding method, and a molded product obtained by molding the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that an acrylic acid alkyl ester in the presence of an acrylic resin having a weight average molecular weight in the range of 100,000 to 3 million and a styrene-butadiene copolymer. An acrylic-styrene-butadiene copolymer obtained by graft copolymerization of styrene monomer and a polyester plasticizer having a linear structure having a number average molecular weight of 500 to 3,000, and at room temperature The acrylic resin composition obtained by stirring until it is solid is excellent in processability at the time of molding, and the molded product obtained by molding the composition has a small shrinkage ratio, tensile properties and tear properties. It was found to be excellent.

  In particular, the acrylic resin which has an average particle diameter of 0.1 to 100 μm and a weight average molecular weight of 100,000 to 3 million and is a granular solid has a linear shape having a number average molecular weight of 500 to 3,000. It is excellent in the absorbability of the polyester plasticizer of the structure, the acrylic resin that is the granular solid, the acrylic-styrene-butadiene copolymer, and the linear having the number average molecular weight of 500 to 3,000. The present invention has been completed by finding that a polyester plasticizer mixture having a structure is excellent in dry-up property and that an acrylic resin composition can be obtained efficiently.

  That is, the present invention provides an acrylic acid alkyl ester (C) in the presence of 50 to 90% by weight of an acrylic resin (A) having a weight average molecular weight of 100,000 to 3 million and a styrene-butadiene copolymer (B). 5 to 45% by weight of an acrylic-styrene-butadiene copolymer (E) obtained by graft copolymerization of styrene monomer (D) and a number average molecular weight of 500 to 3,000 The present invention provides an acrylic resin composition for molding which comprises 5 to 45% by weight of the polyester plasticizer (F) having a structure and is solid at room temperature.

  The present invention also provides an acrylic resin (a) having an average particle diameter of 0.1 to 100 μm and a weight average molecular weight of 100,000 to 3 million and being a powdered solid, the acrylic-styrene-butadiene copolymer The present invention provides a method for producing an acrylic resin composition for molding, which comprises melt-kneading a mixture of union (E) and polyester plasticizer (F) and then pulverizing the mixture.

  Furthermore, the present invention provides a molded article obtained by molding the acrylic resin composition for molding by any one of a calendar molding method, an extrusion molding method and an injection molding method.

  According to the present invention, the load on the environment is small, the moldability, the tensile strength, the tear strength, and the low shrinkage after heat molding are excellent, and the calender molding method and extrusion molding are used instead of the conventional soft vinyl chloride resin composition. It is possible to provide a soft type acrylic resin composition that can be molded by a molding method such as an injection molding method or an injection molding method.

The molded article using the acrylic resin composition for molding is, for example, a sheet, film, hose, tube, packing, leather, tape, canvas (tent), wallpaper, flooring, doll, toy, automobile interior. Can be used in a wide range of materials.
Furthermore, since the acrylic resin composition for molding of the present invention and the molded product using the resin composition do not use a halogen-based resin such as a vinyl chloride resin, the environment does not generate hydrogen chloride gas when the resin is extinguished. It is extremely effective as a pollution countermeasure.

  The acrylic resin composition for molding of the present invention is an acrylic acid alkyl ester (C) in the presence of an acrylic resin (A) having a weight average molecular weight of 100,000 to 3 million and a styrene-butadiene copolymer (B). ) And a styrene monomer (D), and an acrylic-styrene-butadiene copolymer (E) obtained by graft copolymerization, and a polyester-based plastic having a linear structure having a number average molecular weight of 500 to 3,000. It comprises the agent (F) and is solid at room temperature.

  The acrylic resin composition for molding of the present invention comprises the acrylic resin (A), the acrylic-styrene-butadiene copolymer (E) and the polyester plasticizer (F), for example, a high-speed mixer, a Henschel mixer, a tumbler. By adopting a sufficiently blendable means such as a mold blender, the liquid polyester plasticizer (F) is absorbed by the acrylic resin (A) and the acrylic-styrene-butadiene copolymer (E), and the surface It can be obtained by mixing and stirring until the sticky feeling disappears and the whole is in a solid state.

  At that time, when an acrylic resin (a) having an average particle diameter of 0.1 to 100 μm and a weight average molecular weight of 100,000 to 3 million and being a granular solid is used as the acrylic resin (A), an acrylic resin ( a) The acrylic-styrene-butadiene copolymer (E) and the polyester plasticizer (F) mixture have good dry-up properties and efficiently produce the molding acrylic resin composition of the present invention. Can do.

  Moreover, as a form of the acrylic resin composition for molding of the present invention, the liquid polyester plasticizer (F) is absorbed by the acrylic resin (A) and the acrylic-styrene-butadiene copolymer (E). In addition, a composition obtained by mixing and stirring until the surface does not feel sticky and is in a solid state as a whole is preferably pelletized using a calender roll or an extruder.

  The acrylic resin (a) having an average particle diameter of 0.1 to 100 μm and a weight average molecular weight of 100,000 to 3 million will be described. The acrylic resin (a) is a single polymer and / or copolymer of an acrylic monomer, and has an average particle diameter of 0.1 to 100 μm and a weight average molecular weight of 100,000 to 3 million.

  The acrylic resin (a) can be produced by using a monomer exemplified below and applying a polymerization method such as an emulsion polymerization method, a suspension polymerization method, a bulk polymerization, or a solution polymerization. Among them, the emulsion polymerization method is preferable, and it is easy to obtain a powder having a fine particle diameter by using this method.

  Monomers that can be used in producing the acrylic resin (a) include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, and i-butyl acrylate. I-butyl methacrylate, t-butyl acrylate, t-butyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, octyl acrylate, octyl methacrylate, cyclohexyl acrylate Cyclohexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and the like.

  In addition, if necessary, the following various monomers can also be copolymerized, such as styrene and its derivatives, vinyl acetate, urethane-modified alkyl acrylate and alkyl methacrylate, epoxy-modified alkyl acrylate and alkyl methacrylate, and the like. And silicone-modified alkyl acrylates and alkyl methacrylates, and one or more of these can be used.

  The acrylic resin (a) has a weight average molecular weight (Mw) of 100,000 to 3,000,000 as a value based on measurement by gel permeation chromatograph (GPC) in terms of polystyrene using THF as an eluent. Yes, more preferably in the range of 500,000 to 1,000,000. If the weight average molecular weight of the acrylic resin is within such a range, the obtained molded article can have excellent tensile properties.

  The acrylic resin (a) used in the present invention is in the form of a solid powder at normal temperature, preferably the average particle size is in the range of 0.1 μm to 100 μm, more preferably in the range of 0.3 μm to 50 μm. Acrylic resin. Here, the average particle size is a scattering formula of laser diffraction using a suspension in which polymer powder is dispersed in water and subjected to an ultrasonic shaker with an oscillation frequency of 50 KHz for 1 minute and then left for 3 minutes. The cumulative particle size distribution is obtained by a particle size distribution measuring device, and is expressed by a particle size (referred to as “median diameter”) that has a cumulative value of 50% by weight.

  The shape of the acrylic resin (a) used in the present invention is fine particles such as a granular solid having an average particle diameter in the range of 0.1 μm to 100 μm, so that the absorbability of the polyester plasticizer (F) is obtained. The acrylic resin composition for molding of the present invention can be produced efficiently and efficiently.

Next, acrylic-styrene-butadiene obtained by graft copolymerization of alkyl acrylate (C) and styrene monomer (D) in the presence of the styrene-butadiene copolymer (B) used in the present invention. The system copolymer (E) will be described.
The styrene-butadiene copolymer (B) is preferably a block copolymer of polystyrene and polybutadiene, and the ratio of styrene to butadiene is a styrene / butadiene weight ratio of 5/95 to 40/60. Those are preferred.

  Examples of the alkyl acrylate ester (C) include methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, cyclohexyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate. And acrylic acid such as allyl methacrylate, polymer acrylic acid using methacrylic acid and alkyl esters thereof, and the like, and methyl methacrylate is particularly preferable.

  Examples of the styrenic monomer (D) include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ethylstyrene, isobutylstyrene, tertiary butylstyrene, o-bromostyrene, Examples include m-bromostyrene, p-bromostyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, and the like, and styrene is particularly preferable.

  The polymerization method of the acrylic-styrene-butadiene copolymer (E) used in the present invention may be suspension polymerization method, solution polymerization, bulk polymerization, or any conventionally known method. Bulk polymerization is preferred in that it can be controlled.

  The weight average molecular weight (Mw) of the acrylic-styrene-butadiene copolymer (E) is a value based on measurement by gel permeation chromatography (GPC) in terms of polystyrene using THF as an eluent. Yes, preferably 50,000 to 300,000, more preferably 100,000 to 200,000. When the weight average molecular weight of the acryl-styrene-butadiene copolymer (E) is within such a range, the melt fluidity during processing is excellent.

  The following copolymerizable monomer is added to the acrylic resin composition for molding of the present invention when the acrylic-styrene-butadiene copolymer (E) is produced within a range not impairing the object of the present invention. May be polymerized.

  Examples of the monomer copolymerizable with the acrylic-styrene-butadiene copolymer (E) include, for example, vinyl / cyan compounds such as acrylonitrile; polymerizable properties such as itaconic acid, maleic acid, fumaric acid, crotonic acid, and cinnamic acid. Unsaturated fatty acids; N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-octylmaleimide, N-isopropylmaleimide, N-phenylmaleimide, Np-bromophenylmaleimide, N-o-chlorophenylmaleimide, Maleimides such as N-cyclohexylmaleimide; unsaturated carboxylic acid anhydrides typified by maleic anhydride, itaconic anhydride, citraconic anhydride, etc .; containing amino groups such as allylamine, aminoethyl acrylate, and aminopropyl acrylate Unsaturated compounds; acrylamide, N Methyl acrylamide acrylamide compounds; 2-hydroxyethyl - acrylate, 3-hydroxypropyl acrylate, 4-hydroxy-2-butene hydroxyl group-containing unsaturated compounds such like.

  The acrylic-styrene-butadiene copolymer (E) has a styrene-butadiene copolymer (B) structural unit of 5 to 20% by weight and a structural unit derived from an acrylic acid alkyl ester (C) of 35 to 35%. 50% by weight and preferably 30 to 45% by weight of structural units derived from the styrenic monomer (D). If the composition ratio of the copolymer (E) is in such a range, the acrylic resin (A) and the polyester plasticizer used in the present invention are excellent in low shrinkage after heat molding, tensile strength and tear strength. Compatibility with (F) is also improved.

  Next, the linear plastic polyester (F) having a number average molecular weight of 500 to 3,000 used in the present invention will be described. The polyester plasticizer (F) can be produced by an ordinary esterification reaction of glycol, dicarboxylic acid, monocarboxylic acid and / or monohydric alcohol using an esterification catalyst.

  In order to obtain the polyester plasticizer (F), lower alkyl esters such as aliphatic dicarboxylic acid methyl ester and / or aromatic dicarboxylic acid methyl ester, or aliphatic dicarboxylic acid anhydride and / or aromatic dicarboxylic acid. It is also possible to use ester-forming compounds such as anhydrides.

It is preferable to use a polyester plasticizer (F) having a linear structure having a number average molecular weight of 500 to 3,000, more preferably a number average molecular weight of 600 to 1,500. . If the number average molecular weight of the polyester plasticizer (F) is within the range, the dry-up property and workability before molding, the heat aging property during molding, and the tensile strength and tear strength in the molded product are good. Become. The number average molecular weight can be measured by gel permeation chromatography (GPC) in terms of polystyrene using THF as an eluent.

  The glycol that can be used in the production of the polyester plasticizer (F) used in the present invention may have a linear structure or a branched structure. For example, ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl Propanediol, 1,4-butanediol, 3-methylpentanediol, 1,5-pentanediol, pentyl glycol, neopentyl glycol, hexanediol, 1,8-octanediol, decanediol, 1,4-cyclohexanedimethanol 1,3-cyclohexanediol, 1,3-cyclopentanediol, 1,4-cyclopentanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3- Hexanediol, 2,2,4-trimethyl-1, - pentanediol, 2,4-diethyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, and 2-butyl-2-ethyl-1,3-propanediol. These may be used alone or in combination of two or more.

  Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, dimethyl 1,4-cyclohexanedicarboxylate, Examples include cyclohex-4-ene-1,2-dicarboxylic acid, orthophthalic acid, isophthalic acid, terephthalic acid, and phthalic anhydride. These may be used alone or in combination of two or more.

  Examples of the monocarboxylic acid include isobutyric acid, pentanoic acid, hexanoic acid, heptanoic acid, octylic acid, 2-ethylhexanoic acid, nonanoic acid, decanoic acid, undecylic acid, lauric acid, tridecylic acid, versatic acid, and cyclohexanecarboxylic acid. Acid, benzoic acid, toluic acid, t-butylbenzoic acid, dimethyl aromatic monocarboxylic acid, ethyl aromatic monocarboxylic acid, cumic acid, tetramethyl aromatic monocarboxylic acid, naphthoic acid, biphenylcarboxylic acid, furic acid, etc. Can be mentioned. These monocarboxylic acids may be used alone or in combination of two or more.

  Examples of the monohydric alcohol include propanol, 1-butanol, 2-butanol, hexanol, octanol, 2-octanol, 2-ethylhexanol, 1-nonanol, isononyl alcohol, decanol, tridecanol, 2-methyl- Examples include 2-propanol, 2-butoxyethanol, cyclohexanol, 2-cyclohexylethanol, benzyl alcohol, and phenol. These monohydric alcohols may be used alone or in combination of two or more.

The acrylic resin composition for molding of the present invention comprises 50 to 90% by weight of acrylic resin (A),
The acrylic-styrene-butadiene copolymer (E) is included in an amount of 5 to 45% by weight, and the polyester plasticizer (F) is included in an amount of 5 to 45% by weight.
If the weight composition of each constituent component is within such a range, the desired good plasticizing effect is exhibited, the molding processability is excellent, and a molding acrylic resin composition having a particularly low shrinkage ratio after heat molding is obtained. Furthermore, a molded product having excellent tensile strength and tear strength can be obtained.

In the acrylic resin composition for molding of the present invention, a plasticizer other than the polyester plasticizer (F) may be used in combination as long as the object of the present invention is not impaired.
Examples of plasticizers that can be used in combination other than the polyester plasticizer (F) include phthalate ester plasticizers, phosphate ester plasticizers, adipate ester plasticizers, sebacate ester plasticizers, and trimellitic acid. Examples include various plasticizers such as ester plasticizers, pyromellitic acid ester plasticizers, epoxidized ester plasticizers, sulfonic acid plasticizers, benzoic acid plasticizers, and alkylene ether glycol diester plasticizers.

The acrylic resin composition for molding of the present invention can be used by adding a thermoplastic resin as exemplified below within a range not impairing the effects of the present invention. Specific examples of the thermoplastic resin include olefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; ethylene ionomer; polystyrene, styrene-maleic anhydride copolymer, high Styrenic resins such as impact polystyrene, ABS, AES, ACS, MBS; acrylic resins other than those specified in the present invention such as methyl methacrylate-styrene copolymer and other acrylic multilayer structure polymer particles; polyethylene terephthalate, polybutylene Polyester resins such as terephthalate; Polyamides such as nylon 6, nylon 66, polyamide elastomer; Polycarbonate; Polyvinyl chloride; Polyvinylidene chloride; Ethylene-vinyl acetate copolymer; Polyvinyl alcohol; Alcohol copolymers; polyacetals; polyvinylidene fluoride; polyurethane; modified polyphenylene ether; polyphenylene sulfide; silicone rubber-modified resins.

  If necessary, for example, known and commonly used additives such as antioxidants, ultraviolet absorbers, fillers, antistatic agents, lubricants, processing aids, pigments and the like can be blended.

Examples of the antioxidant include phenolic antioxidants such as 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4). -Hydroxyphenyl) propionate] and other hindered phenol antioxidants, dilauryl thiodipropionate and other thioether antioxidants, and tris (2,4-t-butylphenyl) phosphite and other phosphate antioxidants Agents and the like.
The amount of the antioxidant is preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the acrylic resin (A).

Examples of the ultraviolet absorber include salicylate ultraviolet absorbers such as phenyl salicylate, benzophenone ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone, and 2- (2′-hydroxy-5′-t-butylphenyl). ) Benzotriazole UV absorbers such as benzotriazole, cyanoacrylate UV absorbers such as 2-ethylhexyl-2-cyano-3,3′-diphenylacrylate, bis (2,2,6,6-tetramethyl-4) -Hindered amine ultraviolet absorbers such as piperidyl) sebacate.
The blending amount of the ultraviolet absorber is preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the acrylic resin (A).

Examples of the filler include calcium carbonate, clay, talc, silica, aluminum hydroxide, magnesium oxide, magnesium carbonate, magnesium silicate, and calcium silicate.
The blending amount of the filler is preferably in the range of 1 to 150 parts by weight with respect to 100 parts by weight of the acrylic resin (A).

Examples of the antistatic agent include nonionic surfactants such as glycerin monostearate and behenyl alcohol, anionic surfactants such as alkylbenzene sulfonate soda, and cationic surfactants including quaternary ammonium salts. Is mentioned.
The blending amount of the antistatic agent is preferably in the range of 0.01 to 3 parts by weight with respect to 100 parts by weight of the acrylic resin (A).

Examples of the lubricant include fatty acid metal salts such as calcium, magnesium, zinc, and barium of stearic acid or behenic acid, polyethylene wax, polymer lubricants, ester lubricants, and the like.
The blending amount of the lubricant is preferably in the range of 0.01 to 3 parts by weight with respect to 100 parts by weight of the acrylic resin (A).

  As the processing aid and the pigment, known and commonly used ones can be used, and the blending amount thereof is not particularly limited as long as it does not impair the object of the present invention.

  The acrylic resin composition for molding according to the present invention comprises a polyester structure having a linear structure having a number average molecular weight of 500 to 3,000, the acrylic resin (a), the acrylic-styrene-butadiene copolymer (E). A mixture of the three components of the plasticizer (F), preferably pelletized, and can be formed by a technique such as injection molding or extrusion molding.

  By adopting a molding method such as a calendar molding method, an extrusion molding method, an injection molding method, etc., using the acrylic resin composition for molding of the present invention, a sheet, a film, an outdoor signboard, a hose, a tube, a packing, a leather , Tapes, canvas (tents), wallpaper, flooring, packaging materials, dolls, toys, automobile interior materials, and the like can be obtained.

[Example 1]
In a 3 L polymerization vessel equipped with a reflux condenser, 420 parts of deionized water, 6.9 parts by weight of polyoxyethylene nonylphenyl ether, 150 parts by weight of methyl methacrylate and 150 parts by weight of butyl acrylate were charged. The temperature was raised to 70 ° C. with stirring at 150 rpm in the atmosphere. Then, the catalyst liquid which consists of 0.6 weight part of ammonium persulfate and 90 weight part of ion-exchange water was dripped over 4 hours in nitrogen atmosphere, and reaction was performed. Further, the temperature was raised to 80 ° C. and held for 1 hour, and then the reaction was completed. Subsequently, the reaction solution obtained was dried with an atomizer spray dryer to obtain a granular acrylic resin (a). The obtained acrylic resin (a) had a weight average molecular weight of 800,000, and the average particle size measured by a laser type particle size distribution analyzer was 10 μm.

  Next, 5 parts by weight of a styrene-butadiene copolymer (styrene / butadiene = 25/75), 32 parts by weight of styrene, 62 parts by weight of methyl methacrylate, and 10 parts of ethylbenzene are placed in a 3 L capacity polymerization vessel equipped with a reflux condenser. A mixed solution consisting of parts by weight was prepared, and further 0.1 parts by weight of n-dodecyl mercaptan and 100 parts by weight of the monomer mixture as an organic peroxide with respect to 100 parts by weight of the monomer mixture as a chain transfer agent. On the other hand, 0.02 part by weight of t-butyl peroxybenzoate was added, and bulk polymerization was performed at 120 ° C. The mixed solution obtained by polymerization was heated to 225 ° C. with a heat exchanger, and volatile components were removed under a reduced pressure of 50 mmHg to obtain an acrylic-styrene-butadiene copolymer (b). The weight average molecular weight of the obtained acrylic-styrene-butadiene copolymer (b) was 120,000.

  Next, 6.8 mol of propylene glycol and 10.0 mol of adipic acid were charged into a 5 liter four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a decanter. Heat with stirring, raise the temperature of the reaction solution to 220 ° C, react for 1 hour, then cool to 200 ° C, charge 8.5 mol of isononyl alcohol, and total reaction with tetraisopropyl titanate as an esterification catalyst After adding 0.05% by weight with respect to the component amount and reacting by raising the temperature to 230 ° C. again, the excess monohydric alcohol was distilled off under reduced pressure, and the polyester plasticizer (c) of the present invention (melt viscosity 160 mPa S, acid value 0.3 mgKOH / g) was obtained. The number average molecular weight of the obtained polyester plasticizer (c) was 800.

  Antioxidant to acrylic resin composition comprising 50% by weight of acrylic resin (a), 20% by weight of acrylic-styrene-butadiene copolymer (b) and 30% by weight of polyester plasticizer (c). Add 0.6 parts by weight and 0.3 parts by weight of lubricant (magnesium behenate), mix and stir with a Henschel mixer and dry up, then knead with two rolls at 170 ° C. for 7 minutes for roll processing It was. At that time, the dry-up state and the roll processing state were evaluated according to the following criteria. Further, the roll sheet obtained subsequently was pressed at 170 ° C. for 5 minutes to produce a 1 mm thick press sheet, and the tensile test, tear test, and compatibility evaluation were evaluated by the following methods. Moreover, the obtained roll sheet was pulverized and pelletized, injection molded by an injection molding machine, and shrinkage was evaluated by the following method.

[Dry-up property]
A sample in which the inside of the Henschel mixer after stirring was not sticky with a plasticizer was marked with ◯.

[Roll processability]
The adhesion to the roll surface and the peelability were evaluated visually and evaluated according to the following criteria.
○: Adhered moderately to the roll surface.
Δ: Slightly too close to the roll surface, or slightly peeled.
X: Excessively adhered to the roll surface, or conversely exfoliated excessively.

[Tensile test]
From the sheet | seat produced with the said heat press, it cut out to the shape of dumbbell No. 2 (Japanese Industrial Standards JIS K7113), the tensile test and the elongation were measured at room temperature according to JISK7113.

[Tear test]
A tensile test was performed at room temperature according to JIS K7128-3 using the sheet produced by the above hot press, and the tear strength was measured.

[Compatibility test]
A test piece cut into a strip of 30 mm × 40 mm from the sheet produced by the above heat press is left in a constant temperature and humidity of 95% relative humidity at 50 ° C., and the degree of bleeding on the sheet surface is visually observed after 14 days. According to the following evaluation.

○: There was no bleeding.
Δ: Slightly bleed.
X: Remarkably bleed.

[Test method for shrinkage after injection molding]
Using a compound, a test flat plate having a length of 100 mm, a width of 50 mm and a thickness of 3 mm was molded at a constant temperature of 200 ° C. with an injection molding machine (manufactured by Yamashiro Seiki Seisakusho) with a clamping pressure of 75 tons. Using the test flat plate, the shrinkage in the length direction was calculated by the following formula and used for evaluation.

Shrinkage rate (%) = (L ₀ −L ₁ ) / L ₀ × 100
L ₀ : Mold dimension in the length direction of the test flat plate (100 mm)
L ₁ : Actual dimension in the length direction of the molded product

[Example 2]
In the acrylic resin composition of Example 1, the weight average molecular weight was 1,500,000, and the average particle diameter was changed to an acrylic resin made of methyl methacrylate and butyl acrylate having a diameter of 20 μm. went.

[Example 3]
In the acrylic resin composition of Example 1, an acrylic-styrene-butadiene copolymer obtained by polymerizing 20 parts by weight of a styrene-butadiene copolymer, 50 parts by weight of methyl methacrylate, and 30 parts by weight of styrene was obtained. The procedure was the same as in Example 1 except for the change.

[Example 4]
Example 1 is the same as Example 1 except that the acrylic resin composition of Example 1 was changed to a polyester-based plasticizer having a linear structure with a number average molecular weight of 1000 synthesized using propylene glycol, phthalic acid and isononyl alcohol. The same was done.

[Comparative Example 1]
The acrylic resin composition of Example 1 was the same as Example 1 except that the acrylic resin composition was changed to an acrylic resin composed of methyl methacrylate and butyl acrylate having a weight average molecular weight of 50,000 and an average particle diameter of 30 μm. went.

[Comparative Example 2]
In the acrylic resin composition of Example 1, the weight average molecular weight is 800,000, and the average particle diameter is 200 μm, except that the acrylic resin composed of methyl methacrylate and butyl acrylate is used. went.

[Comparative Example 3]
In the acrylic resin composition of Example 1, it carried out like Example 1 except having used the methyl methacrylate-butyl acrylate-styrene copolymer instead of the acrylic-styrene-butadiene type copolymer. .

[Comparative Example 4]
The same procedure as in Example 1 was performed except that the acrylic resin composition of Example 1 was not added with an acrylic-styrene-butadiene copolymer.

[Comparative Example 5]
Example 1 is the same as Example 1 except that the acrylic resin composition of Example 1 is changed to a polyester-based plasticizer having a linear structure with a number average molecular weight of 4000 synthesized using ethylene glycol, adipic acid and isononyl alcohol. The same was done.

[Comparative Example 6]
The same procedure as in Example 1 was performed except that, in the acrylic resin composition of Example 1, a commercially available dioctyl phthalate (DOP) was used instead of the polyester plasticizer having a linear structure.

  The results evaluated for the examples and comparative examples are shown in Table 1 and Table 2, respectively.

Claims (4)

An acrylic acid alkyl ester (C) and a styrene monomer (D) in the presence of 50 to 90% by weight of the acrylic resin (A) having a weight average molecular weight of 100,000 to 3 million and the styrene-butadiene copolymer (B). Polyester-based plastics having a linear structure having a number average molecular weight of 5 to 45% by weight and 500 to 3,000 of the acrylic-styrene-butadiene copolymer (E) obtained by graft copolymerization) An acrylic resin composition for molding, comprising 5 to 45% by weight of the agent (F) and being solid at room temperature. The acrylic-styrene-butadiene-based copolymer (E) contains 5 to 20 wt% of structural units derived from the styrene-butadiene copolymer (B), and 35 to 35 structural units derived from the acrylic acid alkyl ester (C). 2. The acrylic resin composition for molding according to claim 1, comprising 50 to 50% by weight and 30 to 45% by weight of a structural unit derived from the styrene monomer (D). Acrylic resin (a), acrylic-styrene-butadiene copolymer (E), which has an average particle diameter of 0.1 to 100 μm, a weight average molecular weight of 100,000 to 3 million, and is a granular solid, and 500 2. The acrylic resin composition for molding according to claim 1, wherein a mixture of a polyester plasticizer (F) having a linear structure having a number average molecular weight of ˜3,000 is melt kneaded and then pulverized. Manufacturing method. A molded product obtained by molding the acrylic resin composition for molding according to claim 1 or 2 by any one of a calendar molding method, an extrusion molding method and an injection molding method.