JP5846809B2 - Film made of acrylic resin composition - Google Patents

Description

  The present invention relates to a film formed by melt-extruding an acrylic resin composition. In more detail, this invention relates to the film excellent in transparency and a softness | flexibility formed by melt-extruding the acrylic resin composition excellent in film forming property.

  Conventionally, acrylic block copolymers having a structure in which a methacrylic ester polymer block is bonded to both ends of an acrylic ester polymer block are flexible and excellent in transparency and weather resistance. It is known to be useful. Such an acrylic block copolymer is formed into a sheet shape, for example, and is used in films and sheets in the optical field, outdoor building materials and the like.

  However, when a thin-walled film is formed by stretching thinly by melt extrusion for acrylic block copolymers, the neck-in and thickness at both ends of the melt curtain drawn from the die are called periodic. Therefore, it is difficult to produce a thin film having excellent thickness uniformity. On the other hand, although the composition containing 2 types of block polymers and acrylic resin is proposed (refer patent document 1), transparency may be impaired, and it is a block independent or the minimum compounding composition. Improvement of workability is desired. In addition, Patent Document 2 proposes a foam composition containing an acrylic block copolymer, a processing aid, and a foaming agent, but does not describe the film application.

International Application Publication WO2010 / 055798 JP 2010-106253 A Japanese Patent Publication No. 7-25859 JP-A-11-335432 JP-A-6-93060

Macromolecular Chemical Physics 201, 1108-1114 (2000)

  An object of the present invention is to provide a film having excellent transparency and flexibility, which is obtained by melt-extruding an acrylic resin composition having excellent film forming properties.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above-mentioned problems can be solved by blending a specific polymer processing aid in a specific ratio with respect to the acrylic block copolymer. The inventors have found that this can be solved, and have completed the present invention.

That is, the present invention provides at least one structure in the molecule in which the polymer block (a2) mainly composed of a methacrylic ester unit is bonded to both ends of the polymer block (a1) mainly composed of an acrylate unit. The acrylic block copolymer (A) having 100 parts by mass of methyl methacrylate units of 60% by mass or more and butyl acrylate units of 40% by mass or less, with an average degree of polymerization of 3,000 to 40,000. Molecular processing aid (B) 0.
A film formed by melt-extruding an acrylic resin composition containing 3 to 3 parts by mass is provided.

The present invention also provides at least one structure in the molecule in which a polymer block (a2) mainly composed of a methacrylic ester unit is bonded to both ends of the polymer block (a1) mainly composed of an acrylate unit. The acrylic block copolymer (A) has a methyl methacrylate unit of 80% by mass or more and a vinyl monomer unit of 20% by mass or less copolymerizable therewith, and the average degree of polymerization is 2,000 or less. Acrylic thermoplastic resin (C) is 3
It consists of 60% by weight or more of methyl methacrylate units and 40% by weight or less of butyl acrylate units with respect to 0 parts by weight / 70 parts by weight to 97 parts by weight / 3 parts by weight.
A film formed by melt-extruding an acrylic resin composition containing 0.3 to 3 parts by mass of a polymer processing aid (B) that is 40,000 is provided.

  One of the preferred embodiments of the present invention is the film described above, wherein the total light transmittance is 90% or more.

  One of the preferred embodiments of the present invention is the above film wherein the vinyl monomer unit copolymerizable with the methyl methacrylate unit in the polymer processing aid (B) is a butyl acrylate unit.

  Preferably, the acrylic resin composition constituting the film of the present invention is obtained by using a capillograph melt tension measuring device and a strand extruded at a piston speed of 10 mm / min from a 1 mmφ capillary at an extrusion temperature of 210 ° C. The variation value of the strand wire diameter (standard deviation / average value of wire diameter × 100) when taken at a draw ratio of 10 times is 3.1% or less.

  Preferably, the acrylic resin composition constituting the film of the present invention is obtained by using a capillograph melt tension measuring device and a strand extruded at a piston speed of 10 mm / min from a 1 mmφ capillary at an extrusion temperature of 210 ° C. When drawn, the draw ratio at which the strand breaks is 15 times or more.

  According to this invention, the film formed by melt-extruding the acrylic resin composition excellent in transparency and a softness | flexibility which consists of an acrylic resin composition excellent in film forming property by providing the said structure is provided. .

  Hereinafter, the present invention will be described in detail. In the acrylic resin composition of the present invention, the acrylic block copolymer (A) is a polymer mainly composed of methacrylate units at both ends of the polymer block (a1) mainly composed of acrylate units. Polymer processing aid (B) having an average degree of polymerization of 3,000 to 40,000 (B) of 0.3 to 40, which is an acrylic block copolymer having at least one structure in which the block (a2) is bonded in the molecule It is an acrylic melt extrusion film formed by blending 3 parts by mass.

  The acrylic block copolymer (A) which is the first component in the present invention is a polymer block mainly composed of methacrylate units at both ends of the polymer block (a1) mainly composed of acrylate units. Acrylic block copolymer having at least one structure in which (a2) is bonded, that is, a structure of (a2)-(a1)-(a2) (in the structure, “-” indicates a chemical bond). It is. In the acrylic block copolymer (A), the polymer block (a1) mainly composed of an acrylate unit is a polymer block mainly composed of an acrylate unit. Examples of the acrylic ester for forming the polymer block (a1) include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and sec sec acrylic acid. -Butyl, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, isobornyl acrylate, phenyl acrylate, acrylic Examples include benzyl acid, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-methoxyethyl acrylate, and the like. Among these, from the viewpoint of improving flexibility, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, phenoxyethyl acrylate, 2-methoxy acrylate Acrylic acid alkyl esters such as ethyl are preferable, and n-butyl acrylate and 2-ethylhexyl acrylate are more preferable. The polymer block (a1) may be composed of one kind of these acrylate esters or may be composed of two or more kinds.

  As long as the object and effect of the present invention are not hindered, the polymer block (a1) may be an acrylate unit having a reactive group, for example, other than glycidyl acrylate, allyl acrylate, or an acrylate unit. These polymerizable monomer units, for example, monomers such as the following methacrylic acid esters, methacrylic acid, acrylic acid, aromatic vinyl compounds, acrylonitrile, methacrylonitrile, and olefins may be included as a copolymerization component. The amount of these acrylate ester units or other polymerizable monomer units having a reactive group is preferably a small amount from the viewpoint of expressing the effects of the present invention, preferably 20% by mass or less, more preferably 10% by mass or less. is there.

  The polymer block (a2) mainly composed of methacrylic acid ester units in the acrylic block copolymer (A) is a polymer block mainly composed of methacrylic acid ester units. Examples of the methacrylic acid ester for forming the polymer block (a2) include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec sec methacrylate. -Butyl, tert-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, methacryl Examples include benzyl acid, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, and the like. Among these, from the viewpoint of improving transparency and heat resistance, methacrylic acid such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, and isobornyl methacrylate. Alkyl esters are preferred, and methyl methacrylate is more preferred. The polymer block (a2) may be composed of one of these methacrylic acid esters or may be composed of two or more.

  In addition, as long as the object and effect of the present invention are not hindered, the polymer block (a2) may be a methacrylic acid ester unit having a reactive group, for example, glycidyl methacrylate, allyl methacrylate, or other than methacrylic ester units. A small amount, preferably 20% by mass or less, of a polymerizable monomer unit, for example, a monomer such as acrylic acid ester, methacrylic acid, acrylic acid, aromatic vinyl compound, acrylonitrile, methacrylonitrile, olefin as a copolymerization component. Preferably it may contain 10 mass% or less.

  The acrylic block copolymer (A) comprises a polymer block (a1) mainly composed of one acrylate unit and a polymer block (a2) mainly composed of two methacrylate units (a2). )-(A1)-(a2) having at least one structure in the molecule. The molecular chain form of the acrylic block copolymer (A) is not particularly limited, and may be, for example, linear, branched, or radial. Among them, it is preferable to use a triblock body represented by (a2)-(a1)-(a2). Here, the molecular weight and composition of (a2) at both ends of (a1) may be the same or different from each other.

As long as the purpose and effect of the present invention are not hindered, the acrylic block copolymer (A) is a polymer block different from these polymer blocks (a1) and (a2). You may have a polymer block (d) derived from monomers other than a methacrylic acid ester monomer. The form of the bond between the polymer block (d) and the polymer block (a1) mainly composed of the acrylate unit and the polymer block (a2) mainly composed of the methacrylic ester unit is not particularly limited. ,
Structures such as (a2)-((a1)-(a2)) n- (d) and (d)-(a2)-((a1)-(a2)) n- (d) where n is 1 to An integer of 20).

  Examples of the monomer constituting the polymer block (d) include olefins such as ethylene, propylene, 1-butene, isobutylene and 1-octene, conjugated diene compounds such as 3-butadiene, isoprene and myrcene, styrene, α- Aromatic vinyl compounds such as methyl styrene, p-methyl styrene, m-methyl styrene, vinyl acetate, vinyl pyridine, acrylonitrile, methacrylonitrile, vinyl ketone, vinyl chloride, vinylidene chloride, vinylidene fluoride, acrylamide, methacrylamide, ε- Examples include caprolactone and valerolactone.

  The acrylic block copolymer (A) used in the present invention may have a functional group such as a hydroxyl group, a carboxyl group, an acid anhydride, or an amino group in the molecular chain or at the molecular chain end as necessary. .

  The weight average molecular weight of the acrylic block copolymer (A) is 10,000 to 150,000, and from the viewpoint of improving the flexibility and molding processability of a film made of the acrylic resin composition of the present invention, It is preferable that the weight average molecular weight of the acrylic block copolymer (A) is less than 10,000, and sufficient melt tension cannot be maintained in melt extrusion molding. It is difficult to obtain a film, and mechanical properties such as breaking strength of the obtained film are inferior. On the other hand, if it is larger than 150,000, the melted resin becomes highly viscous, and the surface of the film obtained by melt extrusion molding has fine grain-like irregularities and unevenness due to unmelted material (high molecular weight), It tends to be difficult to obtain a good film.

  In the acrylic block copolymer (A), the weight average molecular weight of the polymer block (a1) mainly composed of an acrylate unit is preferably 2,000 to 80,000, and is preferably 5,000 to 70,000. More preferably, it is 000. The weight average molecular weight of the polymer block (a2) mainly composed of methacrylic acid ester units is preferably 2,000 to 80,000, and more preferably 5,000 to 70,000.

  The ratio (Mw / Mn) of the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the acrylic block copolymer (A) is preferably in the range of 1.01 or more and less than 1.50. More preferably, it is in the range of 1.01 to 1.35. By taking such a range, content of the unmelted material which becomes a cause of the generation | occurrence | production of the flaw in the film which consists of an acrylic resin composition of this invention can be made very small.

  It does not specifically limit as a manufacturing method of an acryl-type block copolymer (A), The method according to a well-known method is employable. For example, as a method for obtaining the acrylic block copolymer (A), a method of living polymerization of monomers constituting each block is generally used. Examples of such living polymerization methods include anionic polymerization in the presence of a mineral acid salt such as an alkali metal or alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator (see Patent Document 3), organic A method of anionic polymerization using an alkali metal compound as a polymerization initiator in the presence of an organoaluminum compound (see Patent Document 4), a method of polymerizing using an organic rare earth metal complex as a polymerization initiator (see Patent Document 5), α-halogenated ester Examples include a method of radical polymerization using a compound as an initiator in the presence of a copper compound (see Non-Patent Document 1). Moreover, the method of polymerizing the monomer which comprises each block using a polyvalent radical polymerization initiator and a polyvalent radical chain transfer agent, and manufacturing as a mixture containing the acryl-type block copolymer (A) of this invention, etc. Also mentioned. Among these methods, an acrylic block copolymer is obtained with high purity, and the molecular weight and composition ratio can be easily controlled and economical. A method of anionic polymerization in the presence of an aluminum compound is recommended.

  In the present invention, the polymer processing aid (B) comprises 60% by mass or more of methyl methacrylate units and 40% by mass or less of vinyl monomer units copolymerizable therewith, and the average degree of polymerization is 3,000 to 40. 1,000 polymer compounds. Examples of vinyl monomers copolymerizable with methyl methacrylate include: methacrylates such as ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, ethyl acrylate, methyl acrylate, butyl acrylate, cyclohexyl acrylate Acrylic acid esters such as styrene, aromatic vinyl compounds such as styrene, p-methylstyrene, o-methylstyrene, maleimide compounds such as N-propylmaleimide, N-cyclohexylmaleimide, N-o-chlorophenylmaleimide, ethylene glycol dimethacrylate , Propylene glycol dimethacrylate, triethylene glycol dimethacrylate, hexanediol dimethacrylate, ethylene glycol diacrylate, propylene glycol diacrylate, triethylene Recall diacrylate, allyl methacrylate, can be mentioned polyfunctional monomers such as triallyl isocyanurate.

  Although there is no restriction | limiting in particular about the polymerization method for manufacturing a polymer processing aid (B), It is suitable by emulsion polymerization. Examples of the emulsifier that can be used in the emulsion polymerization include dialkyl sulfosuccinates such as sodium dioctyl sulfosuccinate and sodium dilauryl sulfosuccinate which are anionic emulsifiers, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, and sodium dodecyl sulfate. Polyoxyethylene nonyl phenyl ether sulfate such as polyoxyethylene alkyl ether, polyoxyethylene nonyl phenyl ether as nonionic emulsifier, polyoxyethylene nonyl phenyl ether sodium sulfate as nonionic anionic emulsifier, etc. , Polyoxyethylene alkyl ether sulfate such as sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene tridecyl ether acetate It may be used alkyl ether carboxylate such as um like.

  When the pH of the polymerization system is alkaline depending on the type of emulsifier used, an appropriate pH adjuster can be used to prevent hydrolysis of the methacrylic acid alkyl ester and acrylic acid alkyl ester. Examples of pH regulators used include boric acid-potassium chloride-potassium hydroxide, potassium dihydrogen phosphate-disodium hydrogen phosphate, boric acid-potassium chloride-potassium carbonate, citric acid-potassium hydrogen citrate, diphosphate Potassium hydrogen-boric acid, disodium hydrogen phosphate-citric acid and the like can be used.

  The polymerization initiator may be a water-soluble initiator or an oil-soluble initiator alone, or a redox-type initiator. Examples of water-soluble initiators include ordinary inorganic initiators such as persulfate alone. It can also be used as a redox initiator in combination with sulfites, bisulfites, thiosulfates and the like.

  Examples of oil-soluble initiators include organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, lauroyl peroxide, azo compounds, or sodium formaldehyde sulfoxylate. Although it can also be used as a redox-type initiator in combination with, etc., it is not limited only to this specific example.

  The average degree of polymerization of the polymer processing aid (B) can be arbitrarily adjusted by a chain transfer agent such as n-octyl mercaptan or t-dodecyl mercaptan, polymerization conditions, and the like.

  In the present invention, the average degree of polymerization of the polymer processing aid (B) is preferably in the range of 3,000 to 40,000. When the average degree of polymerization of the polymer processing aid (B) is less than 3,000, no sufficient effect of improving film formability is observed. On the other hand, when the average degree of polymerization of the polymer processing aid (B) exceeds 40,000, the transparency is lowered, or the melt tension becomes too high and both ends of the melt curtain are easily broken during film formation. Sometimes. The compounding quantity of a polymer processing aid (B) is 0.3-3 mass parts with respect to 100 mass parts of acrylic type block copolymers (A), Preferably it is 0.5-2 mass parts. When the blending amount of the polymer processing aid is less than 0.3 part by mass, the effect of sufficiently improving the film formability of the acrylic resin composition is not exhibited. On the other hand, when the blending amount of the polymer processing aid exceeds 3 parts by mass, the transparency may decrease, or the melt tension may become too high, and both ends of the melt curtain may be easily broken during film formation.

  In the present invention, the acrylic resin composition may further contain an acrylic thermoplastic resin (C) in addition to the acrylic block copolymer (A) and the polymer processing aid (B). The acrylic thermoplastic resin (C) that can be used is composed of 80% by mass or more of methyl methacrylate units and 20% by mass or less of vinyl monomer units copolymerizable therewith, and the average degree of polymerization is 2,000. It is as follows. Examples of vinyl monomers that can be copolymerized here include methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, acrylic Acrylic acid ester monomers such as benzyl acid, ethyl methacrylate, butyl methacrylate, propyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, methacrylic acid esters such as benzyl methacrylate, vinyl acetate, styrene, p -Aromatic vinyl compounds such as methyl styrene, o-methyl styrene, m-methyl styrene, α-methyl styrene, vinyl naphthalene, nitriles such as acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid, chloro Such as phosphate alpha, beta-unsaturated carboxylic acid, N- ethylmaleimide, and the like maleimide compounds such N- cyclohexyl maleimide. Two or more of these vinyl monomers can be used in combination.

  Here, the average degree of polymerization of the acrylic thermoplastic resin (C) to be blended is 2,000 or less. If it is higher than this, the viscosity of the acrylic resin composition after blending becomes very high, and melt extrusion becomes difficult.

  The blending ratio of the acrylic block copolymer (A) and the acrylic thermoplastic resin (C) is 30 parts by mass / 70 parts by mass to 97 parts by mass / 3 parts by mass. If the blending ratio of the acrylic thermoplastic resin (C) exceeds 70 parts by mass, the flexibility is impaired, which is not preferable.

  The acrylic thermoplastic resin (C) may be a commercially available methacrylic resin as long as the above-mentioned conditions are satisfied. Furthermore, ISO 8257-1: 1997 (E) “Plastic-poly (methyl methacrylate) (PMMA) It may be selected from the materials specified in “Forming and Extruding Materials” (“Plastics-Poly (Methyl Methylacrylate) (PMMA) molding and extension material-”). In the present invention, the polymerization method for producing the acrylic thermoplastic resin (C) is not particularly limited, and a known polymerization method such as emulsion polymerization, suspension polymerization, bulk polymerization, or solution polymerization can be employed. .

  The method for preparing the thermoplastic polymer composition of the present invention is not particularly limited, but in order to improve the dispersibility of each component constituting the thermoplastic polymer composition, a method of melt kneading and mixing is recommended. Examples of the preparation method include a method of melt-kneading the acrylic block copolymer (A), the polymer processing aid (B), and the acrylic resin (C). Additives may be mixed at the same time, or the acrylic block copolymer (A) may be mixed with the following additives and then mixed with the polymer processing aid (B) and the acrylic resin (C). Good. The mixing operation can be performed using a known mixing or kneading apparatus such as a kneader ruder, an extruder, a mixing roll, or a Banbury mixer. In particular, it is preferable to use a twin screw extruder from the viewpoint of improving kneadability and compatibility of the acrylic block copolymer (A), the polymer processing aid (B) and the acrylic resin (C).

  The temperature at the time of mixing and kneading is suitably adjusted according to the melting temperature of the acrylic block copolymer (A), acrylic resin (C), etc. to be used, and is usually within the range of 110 ° C to 300 ° C. Mix at temperature. When melt-kneading using a twin-screw extruder, it is preferable to use a vent and perform melt-kneading under reduced pressure and / or melt-kneading under a nitrogen stream from the viewpoint of suppressing coloration. Thus, the acrylic resin composition of the present invention can be obtained in any form such as pellets or powder. Acrylic resin compositions in the form of pellets, powders and the like are suitable for use as molding materials. Moreover, an acrylic resin composition containing an acrylic block copolymer is produced by dissolving the acrylic block copolymer (A) in a mixed solution of an acrylic monomer and a solvent such as toluene and polymerizing the acrylic monomer. You can also

  In the present invention, the film formed by melt-extruding the acrylic resin composition, in addition to the above-described components, as necessary, as long as the object of the present invention is not impaired, an ultraviolet absorber, an antioxidant, a light stabilizer, You may contain the 1 type (s) or 2 or more types of other components, such as anti-aging agent, a plasticizer, dye, a pigment, and a lubricant. The content of these components is generally 0.01 to 20% by mass with respect to 100% by mass of the acrylic resin composition.

  The acrylic melt-extruded film of the present invention has a thickness of 0.5 mm or less.

  As a method for producing the acrylic melt-extruded film of the present invention, melt extrusion molding by T-die method, inflation method, melt casting method or the like is preferable from the viewpoint of production processability, cost, etc., and excellent in productivity and thickness accuracy. From the viewpoint, the T-die method is more preferable.

  In the case of the production method by the T die method, the T die is not particularly limited, and examples thereof include known dies such as a coat hanger type and a straight type. Examples of the die material include, but are not limited to, SCM steel and stainless steel such as SUS.

  In the case of the production method by the T-die method, an extruder type melt extrusion apparatus equipped with a single screw or twin screw can be used. The melt extrusion temperature for producing the film of the present invention is preferably 100 to 300 ° C, more preferably 200 to 250 ° C. Further, when melt extrusion is performed using a melt extrusion apparatus, it is preferable to perform melt extrusion under reduced pressure or melt extrusion under a nitrogen stream from the viewpoint of suppressing coloring.

  In the case of the film formation method by the T-die method, from the viewpoint of the surface property of the film, a method of forming a film by bringing at least one surface of the film-like resin extruded by the T-die into contact with a roll or a belt is preferable. A method of forming a film by bringing both surfaces of a shaped resin into contact with two rolls or / and a belt is more preferable. There are no particular restrictions on the material, configuration and arrangement of the rolls and belts, and any known material can be used. However, in order to obtain a highly smooth film, a mirror-treated metal roll is used. It is preferable. Moreover, it is more preferable to use a roll (metal elastic roll) in which the metal outer cylinder has elastic deformability, because distortion during molding can be reduced. In addition, the surface of the roll or belt can be embossed or arbitrarily engraved, and the shape can be formed on the surface by transferring the shape to the film during melt film formation.

  If necessary, the film after film formation can be stretched. As a stretching method, a conventionally known stretching method can be used, and examples thereof include uniaxial stretching, and biaxial stretching methods such as sequential biaxial stretching and simultaneous biaxial stretching.

  The acrylic melt-extruded film of the present invention may be used as a single layer or as a laminate of two or more layers. When used as a laminate, only the film of the present invention may be laminated, or the film of the present invention and other materials may be laminated. When forming a laminated body, it is possible to manufacture each layer by a well-known method. That is, it is known to be cured by a co-extrusion method such as extrusion molding such as a T-die method or inflation method, a melt-extrusion laminating method, a heat fusion method, an ultrasonic fusion method, a high-frequency fusion method, an ultraviolet ray, heat or radiation And a method using an adhesive. Further, a known primer may be applied to the surface to be fused or bonded, and corona discharge treatment, plasma treatment, or the like may be performed. When forming a laminated body, the order of lamination | stacking, printing, provision of surface shape, and cutting to the target magnitude | size is not specifically limited. When forming the optical component in combination with other materials, such as when the film of the present invention is used as a laminated optical component, other materials can be appropriately selected according to the desired characteristics, and organic materials can be used. Any of compounds, polymers, inorganic substances, compositions containing these, and the like can be used. Specifically, for example, when an optical component is formed by laminating the film of the present invention and other materials, the other materials include organic compounds or compositions such as hard coat materials, antireflection materials, and liquid crystals. An organic polymer or composition such as a cyclic olefin ring-opening polymer or a hydrogenated product thereof, an addition polymerization type cyclic olefin polymer, an aliphatic olefin resin, an acrylic polymer, a polycarbonate resin, or a liquid crystal polymer, Commercially available or known materials such as inorganic substances or compositions such as soda glass and quartz glass can be used.

  The use of the film obtained by melt-extrusion of the acrylic resin composition of the present invention is not particularly limited, but it should be used in various applications such as the optical field, food field, medical field, consumer field, automobile field, and electric / electronic field. Can do. In particular, the sheet-like molded article of the present invention is excellent in surface smoothness and molding processability, excellent in flexibility, and excellent in optical characteristics such as light transmittance of short wavelength light. Optical devices represented by terminal boards, printed wiring boards, speakers, microscopes, binoculars, cameras, watches, etc., as well as cameras, VTRs, projection TVs, etc., filters as video / optical recording / optical communication / information equipment related parts , Prism, Fresnel lens, various optical discs (VD, CD, DVD, MD, LD, etc.), substrate protective film, optical switch, optical connector, liquid crystal display, light guide film / sheet for liquid crystal display, flat panel display, flat panel display Light guide film / sheet, plasma display, light guide film for plasma display Rum sheet, retardation film / sheet, polarizing film / sheet, polarizing plate protective film / sheet, wavelength plate, light diffusion film / sheet, prism film / sheet, reflective film / sheet, antireflection film / sheet, viewing angle expansion Known optics such as films and sheets, antiglare films and sheets, brightness enhancement films and sheets, display element substrates for liquid crystal and electroluminescence applications, touch panels, light guide films and sheets for touch panels, spacers between various front plates and various modules It can be suitably applied to applications. Specifically, for example, various liquid crystal display elements such as mobile phones, digital information terminals, pagers, navigation, in-vehicle liquid crystal displays, liquid crystal monitors, light control panels, displays for OA devices, displays for AV devices, and electroluminescence displays It can be used for an element or a touch panel. Moreover, from the point which is excellent in a weather resistance, a softness | flexibility, etc., for example, a building interior / exterior member, a curtain wall, a roof member, a roofing material, a window member, a gutter, an exterior, a wall material, a flooring material It can also be suitably applied to known building material applications such as construction materials, road construction members, retroreflective films and sheets, agricultural films and sheets, lighting covers, signboards, and translucent sound insulation walls.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Various physical properties in Examples and Comparative Examples were measured or evaluated by the following methods.

(1) Weight average molecular weight The weight average molecular weights of the acrylic block copolymers (A1), (A2) and the acrylic resin (B) are expressed in terms of polystyrene by gel permeation chromatography (hereinafter abbreviated as GPC). Asked.
Equipment: GPC equipment “HLC-8020” manufactured by Tosoh Corporation
Separation column: “TSKgeIGMHXL”, “G4000HxL” and “G5000HxL” manufactured by Tosoh Corporation are connected in series. Eluent: Tetrahydrofuran Eluent flow rate: 1. OmI / min. Column temperature: 400 ° C

(2) Average degree of polymerization The average degree of polymerization of the polymer processing aid (B) and the acrylic thermoplastic resin (C) is determined by using an automatic dilution type capillary viscometer (Ubbelohde type, capillary inner diameter = 0.5 mm) and chloroform. It measured at 20 degreeC as a solvent and calculated | required by the polymerization degree in PMMA.

(3) MMA composition The MMA composition of the polymer processing aid (B) was measured from 1H-NMR spectrum (JNM-GX270 manufactured by JEOL Ltd.) using deuterated chloroform as a solvent.

(4) Strand wire diameter fluctuation value The pellet of the acrylic resin composition obtained in the example or the comparative example was extruded at 210 ° C using a capillograph (Model 1D manufactured by Toyo Seiki Seisakusho Co., Ltd.), and the diameter was 1 mmφ long. A strand obtained by extruding from a 40 mm-capillary at a piston speed of 10 mm / min was drawn with an attached melt tension measuring device at a rate of 9.8 m / min (draw ratio 10 times), and a wire diameter of 8 mm from the capillary outlet Was measured with an attached laser die swell measuring device at a measurement interval of 0.125 seconds for 30 seconds, and the wire diameter fluctuation value was obtained from the equation (1).
Wire diameter fluctuation value = standard deviation value σ of wire diameter / average value of wire diameter × 100 (1)

(5) Fracture draw ratio The acrylic resin composition pellets obtained in the examples or comparative examples were extruded at 210 ° C. using a capillograph (Model 1D manufactured by Toyo Seiki Seisakusho Co., Ltd.), 1 mm in diameter and 40 mm in length. The strand obtained by extruding from the capillary at a piston speed of 10 mm / min is increased with the attached melt tension measuring device from the starting take-up speed of 2 m / min to the take-up speed at a time scale of 4 minutes, and the strand breaks. The draw ratio was determined.

(6) Evaluation of film forming property Using a 65 mmΦ vent type single screw extruder, extrusion was performed at a extrusion temperature of 210 ° C and a discharge rate of 12 kg / h from a die having a width of 400 mm, and nip was performed between 30 ° C and 50 ° C metal mirror rolls The film was drawn at 5 m / min to form a film having a thickness of 100 μm. At this time, the fluctuation and tear of the neck-in at both ends of the melt curtain pulled down from the die were evaluated.
○: Neck-in fluctuations and tears at both ends of the melt curtain are not observed.
X: Neck-in variation or tearing at both ends of the melt curtain.

(7) Transparency A test piece of 50 mm × 50 mm was cut out from a 100 μm-thick film obtained in the film-forming evaluation, and in accordance with JIS-K7105, using a haze meter HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd. , Haze and total light transmittance were measured.

(8) Light guiding properties Using a capilograph (Model 1D manufactured by Toyo Seiki Seisakusho Co., Ltd.), the length from the strand obtained by extruding at a piston speed of 10 mm / min from a capillary with a diameter of 1 mm and a length of 40 mm at an extrusion temperature of 210 ° C. A 127 mm test piece was cut out, LED light was incident from the end face of the test piece with the LED light source device, and the luminance of light emitted from the opposite end face was visually evaluated, and this was used as a light guide index.
○: Light loss due to absorption and diffusion is very small, and the luminance of the light exit surface is high. Δ: Light loss due to absorption and diffusion is slightly affected, and the luminance of the light exit surface is slightly low. Surface brightness is very low

  In the synthesis examples shown below, the compound was dried and purified by a conventional method and degassed with nitrogen. The compound was transferred and supplied in a nitrogen atmosphere.

Reference Example 1 [Organic Aluminum Compound: Preparation of Isobutylbis (2,6-di-t-butyl-4-methylphenoxy) Aluminum]
After drying with sodium, 25 ml of dry toluene obtained by distillation under an argon atmosphere and 11 g of 2,6-di-t-butyl-4-methylphenol were placed in a 200 ml flask whose internal atmosphere was replaced with argon. Added and dissolved with stirring at room temperature. By adding 6.8 ml of triisobutylaluminum to the resulting solution and stirring at 80 ° C. for about 18 hours, the corresponding organoaluminum compound [isobutylbis (2,6-di-t-butyl-4-methylphenoxy) was obtained. ) Aluminum]. A toluene solution containing a concentration of 6 mol / l was prepared.

Reference Example 2 [Synthesis of Acrylic Block Copolymer (A1)]
In the presence of isobutylbis (2,6-di-tert-butylphenoxy) aluminum, sec-butyllithium was used as a polymerization initiator, and monomers corresponding to each block in toluene, namely methyl methacrylate, butyl acrylate, Methyl methacrylate was sequentially added in this order and synthesized by a method of anion living polymerization. After removing the aluminum and lithium used, an acrylic triblock copolymer was obtained by a devolatilizing twin-screw extruder.
The obtained acrylic block copolymer had PMMA content = 50 mass%, weight average molecular weight = 62,000, and molecular weight distribution (weight average molecular weight / number average molecular weight) = 1.11.

<Reference Example 3> [Synthesis of acrylic block copolymer (A2)]
In the presence of isobutylbis (2,6-di-tert-butylphenoxy) aluminum, sec-butyllithium was used as a polymerization initiator, and monomers corresponding to each block in toluene, namely methyl methacrylate, butyl acrylate, Methyl methacrylate was sequentially added in this order and synthesized by a method of anion living polymerization. After removing the aluminum and lithium used, an acrylic triblock copolymer was obtained by a devolatilizing twin-screw extruder.
The obtained acrylic block copolymer had a PMMA content of 50 mass%, a weight average molecular weight of 105,000, and a molecular weight distribution (weight average molecular weight / number average molecular weight) = 1.09.

<Examples 1-6, Comparative Examples 1-3>
The acrylic block copolymer (A1, A2) obtained in the above reference example and a polymer processing aid [B1: Metablene P530A manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 24455, MMA 80 mass% / BA 20 mass) %), B2: Metablene P531A manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 37162, MMA 80 mass% / BA 20 mass%), B3: Metabrene P550A manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 7734, MMA 88 mass% / B12: Paraloid K125P (average polymerization degree: 19874, MMA 79% by mass / BA21% by mass) manufactured by Rohm & Haas Co., Ltd., B5: Metablene P570A manufactured by Mitsubishi Rayon Co., Ltd. (average polymerization degree: 2384, MMA53) Wt% / BA 47 wt%)] and acrylic resin [C : Kuraray Co., Ltd. Parapet H-1000B (average degree of polymerization: 820, MMA 90 mass% / MA 10 mass%)] was melt kneaded at 230 ° C. with a twin screw extruder at the blending ratio shown in Table 1 below. The pellets of the thermoplastic polymer composition were produced by extruding and cutting the strands. Using these pellets, the strand wire diameter fluctuation value, the fracture draw ratio, the film-forming property, the light guide property, and the transparency were evaluated by the above methods. The obtained results are shown in Table 1.

  From the results of Table 1, when the content of the polymer processing aid (B) is too small (Comparative Example 1), the average degree of polymerization of the polymer processing aid (B) is too small (Comparative Example 2) and high In the case where the content of the molecular processing aid (B) is too large (Comparative Example 3), the film forming property was poor, whereas in Examples 1 to 6 of the present invention, the film forming property was good. It can be seen that is obtained. Moreover, in Examples 1-6, the favorable result was obtained also about the other characteristic of film forming property, and the film excellent in a performance and manufacturing stability is obtained.

Claims (5)

Acrylic block copolymer having at least one structure in the molecule in which a polymer block (a2) mainly composed of methacrylic acid ester units is bonded to both ends of the polymer block (a1) mainly composed of acrylate units. For 100 parts by mass of combined (A),
A polymer processing aid (B) having an average polymerization degree of 3,000 to 40,000 consisting of 60% by mass or more of methyl methacrylate unit and 40% by mass or less of butyl acrylate unit is blended. A film formed by melt-extruding an acrylic resin composition. Acrylic block copolymer having at least one structure in the molecule in which a polymer block (a2) mainly composed of methacrylic acid ester units is bonded to both ends of the polymer block (a1) mainly composed of acrylate units. Acrylic thermoplastic resin (A) comprising 80% by mass or more of methyl methacrylate units and 20% by mass or less of vinyl monomer units copolymerizable therewith, and having an average degree of polymerization of 2,000 or less. C) comprises 30 parts by weight / 70 parts by weight to 97 parts by weight / 3 parts by weight of methyl methacrylate units of 60% by mass or more and butyl acrylate units of 40% by mass or less, and an average degree of polymerization of 3,000 to A film formed by melt-extruding an acrylic resin composition containing 0.3 to 3 parts by mass of a polymer processing aid (B) that is 40,000. The film according to claim 1 or 2 , wherein the total light transmittance is 90% or more. The acrylic resin composition was drawn with a draw ratio of 10 times from a 1 mmφ capillary at a piston speed of 10 mm / min at an extrusion temperature of 210 ° C. using a capillograph melt tension measuring device. The film according to any one of claims 1 to 3 , wherein the fluctuation value of the strand wire diameter (standard deviation / average value of wire diameter x 100) is 3.1% or less. The strand breaks when the acrylic resin composition takes a strand extruded at a piston speed of 10 mm / min from a 1 mmφ capillary at an extrusion temperature of 210 ° C. using a capillograph melt tension measuring device. The film according to any one of claims 1 to 4 , wherein the draw ratio is 15 times or more.