WO2019194210A1

WO2019194210A1 - (meth)acrylic resin composition, film, and method for production thereof

Info

Publication number: WO2019194210A1
Application number: PCT/JP2019/014729
Authority: WO
Inventors: 香織前田; 東田　昇
Original assignee: 株式会社クラレ
Priority date: 2018-04-03
Filing date: 2019-04-03
Publication date: 2019-10-10
Also published as: JP7322002B2; JPWO2019194210A1

Abstract

A (meth)acrylic resin composition comprising total 100 mass parts of a (meth)acrylic resin (A) and a core/shell graft copolymer (B), and 0.03 to 0.3 mass parts of an aliphatic alcohol (C).

Description

(Meth) acrylic resin composition, film and method for producing the same

The present invention relates to a (meth) acrylic resin composition capable of stably and simply forming a film having excellent optical properties, surface hardness, flex resistance and impact resistance by long-term continuous operation, a film using the same, and production thereof Regarding the method.

The (meth) acrylic resin composition has characteristics such as high transparency, high surface hardness, excellent weather resistance, and easy molding, so it can be used for display materials such as signboards and flat panel displays, and decorative films. It is used in various applications such as interior and exterior materials for vehicles, interior materials and exterior materials for building materials, interior members, and the like. In particular, it is used as a skin material for various members because of its excellent surface properties such as high pencil hardness. Further, since it has excellent transparency and low birefringence, it is used as various optical members such as a polarizer protective film, a retardation film, and an anti-scattering film. However, the present invention is not limited to acrylic resins, and when a thermoplastic resin is formed by a melt extrusion method, there is a problem that a gel-like deteriorated product is generated by a staying portion, which becomes a fish eye defect, and there is little fish eye. There are still problems to be solved in the long-term continuous operation for stable production of films for a long time.

As a method for long-term continuous operation, there is a method of forming a film at a low temperature, but there arises a problem that a film having good surface smoothness cannot be obtained. Although the method of reducing a stay location is generally used, the stay location remains at present (patent document 1). An aliphatic alcohol is known as a lubricant for (meth) acrylic resin. For example, an acrylic sheet obtained by adding 0.01 to 5 parts by mass of aliphatic alcohol to 100 parts by mass of (meth) acrylic resin It is known that even if it is cut, fusion to the tool can be suppressed, and addition of a lubricant is unnecessary, so that productivity is improved (Patent Document 2).

JP 2017-170620 A International Publication No. 2014/156032

However, the method described in Patent Document 2 has room for further improvement in order to enable stable production of the film itself by long-term continuous operation.
Further, as described above, further improvement is required for long-term continuous operation, and in the case of a (meth) acrylic resin film excellent in impact resistance to which a rubber component is added, fish eyes are likely to occur. Long-term continuous operation was more difficult. That is, a film excellent in impact resistance to which a rubber component is added, having a low haze, good optical properties, high surface hardness, and excellent flex resistance in a stable and simple manner by long-term continuous operation. However, there was still room for examination from the viewpoint of cost reduction.

The present invention has been made in view of the above background, and a film having low haze, good optical properties, high surface hardness, excellent bending resistance, and excellent impact resistance can be stably and simply by long-term continuous operation. It aims at providing the (meth) acrylic resin composition which can be formed into a film, the film using the same, and its manufacturing method.

As a result of intensive studies to achieve the above object, the present inventors have used (meth) acrylic resin (A) and core-shell type graft copolymer (B) in combination, and further identified aliphatic alcohol (C). According to the (meth) acrylic resin composition obtained by blending in an amount, a film having low haze, good optical properties, high surface hardness, excellent bending resistance, and excellent impact resistance can be provided. The (meth) acrylic resin composition is excellent in long-term stability at the time of melting, and when the film is formed, the formation of the film is stable and simple by long-term continuous operation with little generation of fish eyes. The present invention has been completed through further investigation based on the findings.

That is, the present invention relates to the following.
[1] (Meth) acrylic containing (meth) acrylic resin (A) and core-shell type graft copolymer (B) in total of 100 parts by mass and aliphatic alcohol (C) in an amount of 0.03 to 0.3 parts by mass Resin composition.
[2] The (meth) acrylic resin composition according to [1], wherein the melt viscosity at 270 ° C. shear rate of 12.2 / sec is 2,000 Pa · s or less.
[3] The (meth) acrylic resin composition according to [1] or [2], wherein the (meth) acrylic resin (A) includes at least two types of (meth) acrylic resins having different weight average molecular weights.
[4] Any of [1] to [3], wherein the mass ratio of the (meth) acrylic resin (A) and the core-shell type graft copolymer (B) is the former / the latter = 70/30 to 90/10 The (meth) acrylic resin composition as described in any one.
[5] The (meth) acrylic resin composition according to any one of [1] to [4], wherein the aliphatic alcohol (C) is stearyl alcohol.
[6] The (meth) acrylic resin composition according to any one of [1] to [5], further comprising 0.1 to 3% by mass of the polymer processing aid (D).
[7] A film comprising the (meth) acrylic resin composition according to any one of [1] to [6].
[8] The film according to [7], wherein the pencil hardness is HB or higher.
[9] The film according to [7] or [8], wherein the folding endurance is 30 or more.
[10] A decorative film comprising the film according to any one of [7] to [9].
[11] An optical film comprising the film according to any one of [7] to [9].
[12] A polarizer protective film comprising the film according to any one of [7] to [9].
[13] A polarizing plate comprising the polarizer protective film according to [12].
[14] A method for producing a film as described in any one of [7] to [9], wherein an extrusion apparatus including a vent, a gear pump, a polymer filter, and a T die in this order is used, from the vent to the T die. The method for producing a film, wherein the temperature is controlled at 230 to 290 ° C.

According to the present invention, a film having low haze, good optical properties, high surface hardness, excellent flex resistance, and excellent impact resistance can be stably and easily formed by a long-term continuous operation (meta). An acrylic resin composition, a film using the same, and a method for producing the same are provided.

The (meth) acrylic resin composition of the present invention has a total of 100 parts by mass of the (meth) acrylic resin (A) and the core-shell type graft copolymer (B), and 0.03-0. Including 3 parts by mass.

<(Meth) acrylic resin (A)>
As the (meth) acrylic resin (A) used in the present invention, for example, a resin mainly composed of a structural unit derived from methyl methacrylate can be used. From the viewpoint of heat resistance, the content of the structural unit derived from methyl methacrylate (methyl methacrylate unit) in the (meth) acrylic resin (A) is preferably 50% by mass or less, and 80% by mass or less. More preferably, it is more preferably 90% by mass or more, particularly preferably 95% by mass or more, and all the structural units may be methyl methacrylate units.

(Meth) acrylic resin (A) may contain a structural unit derived from another monomer other than methyl methacrylate. Such other monomers are not particularly limited as long as they can be copolymerized with methyl methacrylate. For example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate , Isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, acrylic acid Acrylic acid such as phenyl, benzyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-ethoxyethyl acrylate, glycidyl acrylate, allyl acrylate, cyclohexyl acrylate, norbornyl acrylate, isobornyl acrylate Steal; ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, n-methacrylate Hexyl, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-ethoxyethyl methacrylate, glycidyl methacrylate, Methacrylic acid esters other than methyl methacrylate, such as allyl methacrylate, cyclohexyl methacrylate, norbornyl methacrylate, isobornyl methacrylate; acrylic acid, meta Unsaturated carboxylic acids such as lauric acid, maleic anhydride, maleic acid and itaconic acid or their anhydrides; olefins such as ethylene, propylene, 1-butene, isobutylene and 1-octene; conjugated dienes such as butadiene, isoprene and myrcene Aromatic vinyl compounds such as styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene; acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl pyridine, vinyl ketone, vinyl chloride, vinylidene chloride, fluorine And vinylidene chloride.

The stereoregularity of the (meth) acrylic resin (A) is not particularly limited, and for example, a (meth) acrylic resin (A) having stereoregularity such as isotactic, heterotactic, syndiotactic and the like can be used.

The (meth) acrylic resin composition of the present invention may contain only one kind of (meth) acrylic resin as the (meth) acrylic resin (A), but the effect of the present invention is more remarkably exhibited. From the above, it is preferable that at least two (meth) acrylic resins are included, and at least two (meth) acrylic resins (A-1 and A-2) having different weight average molecular weights are particularly preferable.

The (meth) acrylic resin (A-1) is preferably a resin having a high methyl methacrylate unit content and a high weight average molecular weight (Mw) in order to enhance heat resistance. The content of the preferred methyl methacrylate unit in the (meth) acrylic resin (A-1) is 95% by mass or more, more preferably 97% by mass or more, and further preferably 99% by mass or more. The (meth) acrylic resin (A-1) preferably has a weight average molecular weight of 80,000 to 150,000, more preferably 85,000 to 120,000, still more preferably 90,000 to 100,000. 000. When the weight average molecular weight of the (meth) acrylic resin (A-1) is 80,000 or more, the mechanical properties are good, and the weight average molecular weight of the (meth) acrylic resin (A-1) is 150,000 or less. It can suppress that melt viscosity becomes high too much, and workability becomes favorable.

The (meth) acrylic resin (A-2) is mainly used as a compatibilizer for enhancing the dispersibility of the core-shell type graft copolymer (B) in the (meth) acrylic resin composition of the present invention. For example, in the case of the above purpose, the content of the methyl methacrylate unit in the (meth) acrylic resin (A-2) is the same as the above (meth) acrylic. The content of the methyl methacrylate unit in the resin (A-1) and the content of the methyl methacrylate unit in the thermoplastic polymer (II) constituting the outermost layer of the core-shell type graft copolymer (B) described later It is preferable that it is between (including the same case). The weight average molecular weight of the (meth) acrylic resin (A-2) is preferably lower than the weight average molecular weight of the (meth) acrylic resin (A-1). The weight average molecular weight of the (meth) acrylic resin (A-2) is preferably 30,000 to 80,000, more preferably 40,000 to 75,000, still more preferably 50,000 to 70,000. When the weight molecular weight of the (meth) acrylic resin (A-2) is 30,000 or more, the mechanical properties are good, and when the weight average molecular weight of the (meth) acrylic resin (A-2) is 80,000 or less. A role like a container can be fully demonstrated.

The molecular weight distribution of the (meth) acrylic resin (A) is represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) as measured by GPC, and is 1.05 to 3. It is preferably 1.3 to 2.5. When the molecular weight distribution is 1.05 or more, molding is facilitated, and when the molecular weight distribution is 3 or less, physical properties such as creep properties are improved.
In addition, a weight average molecular weight (Mw) can be measured by the method mentioned later in the column of an Example, and a number average molecular weight (Mn) can also be measured similarly to this.

The method for producing the (meth) acrylic resin (A) is not particularly limited, and can be obtained, for example, by polymerizing a monomer mainly composed of methyl methacrylate. In addition, the polymerization degree of (meth) acrylic resin (A) can be adjusted with the quantity of a polymerization initiator and a chain transfer agent.

Further, as the (meth) acrylic resin (A), a commercially available product may be used. Examples of the methacrylic resin include “Parapet H1000B” (MFR: 22 g / 10 min (230 ° C., 37.3 N)), “Parapet GF” (MFR: 15 g / 10 min (230 ° C., 37.3 N)), “ “Parapet EH” (MFR: 1.3 g / 10 min (230 ° C., 37.3 N)), “Parapet HRL” (MFR: 2.0 g / 10 min (230 ° C., 37.3 N)), “Parapet HRS” ( MFR: 2.4 g / 10 min (230 ° C., 37.3 N)) and “Parapet G” (MFR: 8.0 g / 10 min (230 ° C., 37.3 N)) [all trade names, manufactured by Kuraray Co., Ltd. ] Etc. are mentioned.

The glass transition temperature (Tg) of the (meth) acrylic resin (A) is preferably 80 to 140 ° C., more preferably 95 to 130 ° C., and still more preferably 110 to 120 ° C. The glass transition temperature can be adjusted by changing the stereoregularity depending on the kind and amount of the monomer copolymerized with methyl methacrylate and the polymerization temperature. The glass transition temperature is a value measured in accordance with JIS K7121: 2012. That is, the differential scanning calorific value is obtained under the condition that the (meth) acrylic resin (A) is once heated to 200 ° C., then cooled to room temperature (25 ° C.), and then heated from room temperature to 200 ° C. at 10 ° C./min. The DSC curve is measured by a measurement method, and the midpoint glass transition temperature obtained from the DSC curve measured at the second temperature rise can be set as the glass transition temperature of the (meth) acrylic resin (A).

<Core-shell type graft copolymer (B)>
As the core-shell type graft copolymer (B) used in the (meth) acrylic resin composition of the present invention, crosslinked rubber particles having an outermost layer and an inner layer can be used. The type of the crosslinked rubber particles is not particularly limited as long as it has an outermost layer and an inner layer. For example, the core (inner layer) is a crosslinked rubber polymer (I) -the outer shell (outermost layer) is a thermoplastic polymer. (II) two-layer polymer particles; core (inner layer) is polymer (III)-inner shell (inner layer) is crosslinked rubber polymer (I)-outer shell (outermost layer) is thermoplastic polymer (II) Three-layer polymer particles; core (inner layer) is crosslinked rubber polymer (I) -first inner shell (inner layer) is polymer (III) -second inner shell (inner layer) is crosslinked rubber polymer (I) -outer Various laminated structures such as four-layer polymer particles whose shell (outermost layer) is thermoplastic polymer (II) are possible, but three-layer polymer particles are preferred.

The crosslinked rubber polymer (I) has 70 to 98 structural units derived from an alkyl acrylate ester monomer having 1 to 8 carbon atoms in the alkyl group with respect to the mass of the crosslinked rubber polymer (I). It is preferably contained by mass%, more preferably by 75 to 90 mass%, further preferably by 80 to 85 mass%. When the content is the above, it becomes a flexible rubber material and can impart impact resistance. The crosslinked rubber polymer (I) preferably contains 2 to 30% by mass of structural units derived from the aromatic vinyl monomer with respect to the mass of the crosslinked rubber polymer (I). More preferably, it is more preferably 15 to 20% by mass. By having the above content, the refractive index of the crosslinked rubber polymer (I) can be adjusted to match that of the (meth) acrylic resin (A), and a (meth) acrylic resin composition having high transparency can be obtained. it can.
The crosslinked rubber polymer (I) preferably contains 1 to 5% by mass of a structural unit derived from a crosslinkable monomer with respect to the mass of the crosslinked rubber polymer (I). More preferably. By having the above content, an appropriate crosslinking density is obtained, and the behavior as a rubber material is improved.

The thermoplastic polymer (II) preferably contains 80 to 100% by mass of methyl methacrylate units, more preferably 85 to 97% by mass, more preferably 90 to 90% by mass relative to the mass of the thermoplastic polymer (II). More preferably, the content is 96% by mass. By being said content, compatibility with a (meth) acrylic resin (A) improves.
The thermoplastic polymer (II) has 0 structural units derived from an acrylic acid alkyl ester monomer having 1 to 8 carbon atoms in the alkyl group with respect to the mass of the thermoplastic polymer (II). It is preferably contained in an amount of ˜20% by mass, more preferably 3-15% by mass, and still more preferably 4-10% by mass. By being said content, compatibility with a (meth) acrylic resin (A) improves.

The polymer (III) preferably contains 80 to 99.95% by mass of methyl methacrylate units, more preferably 85 to 98% by mass, and more preferably 90 to 96% by mass with respect to the mass of the polymer (III). % Is more preferable. The above content is preferable because the hardness is good.
The polymer (III) contains 0 to 19.95% by mass of a structural unit derived from an acrylic acid alkyl ester monomer having an alkyl group having 1 to 8 carbon atoms based on the mass of the polymer (III). , And 0.05 to 2% by mass of a crosslinkable monomer, and 2 to 15% by mass of a structural unit derived from an acrylic acid alkyl ester monomer having an alkyl group having 1 to 8 carbon atoms. More preferably, it contains 0.05 to 1.5% by mass of a structural unit derived from a crosslinkable monomer, and is derived from an acrylic acid alkyl ester monomer having an alkyl group having 1 to 8 carbon atoms. More preferably, the structural unit contains 4 to 10% by mass of the structural unit and 0.1 to 1% by mass of the structural unit derived from the crosslinkable monomer. The above content is preferable because the hardness is good.

The content of each monomer is calculated for each layer. For example, in a four-layer polymer particle, when both the core (inner layer) and the second inner shell (inner layer) are composed of the crosslinked rubber polymer (I), the content of the structural unit derived from each monomer is The core (inner layer) and the second inner shell (inner layer) are calculated separately.

From the viewpoint of transparency of the core-shell type graft copolymer (B), the difference in refractive index between adjacent layers is preferably less than 0.005, more preferably less than 0.004, and even more preferably less than 0.003. It is preferable to select a polymer contained in each layer so that

The mass ratio of the inner layer to the outermost layer in the core-shell type graft copolymer (B) is preferably the former / the latter = 30/70 to 95/5, more preferably 70/30 to 90/10. In the present specification, the outermost layer of the core-shell type graft copolymer (B) refers to the outermost layer of the particles, and the inner layer refers to all the layers inside the outermost layer. In the inner layer, the proportion of the layer containing the crosslinked rubber polymer (I) is preferably 20 to 70% by mass, more preferably 30 to 50% by mass.

The average particle size of the core-shell type graft copolymer (B) in the present invention is preferably 0.05 to 1 μm, more preferably 0.07 to 0.5 μm, still more preferably 0.1 to 0.00. It is 4 μm, particularly preferably 0.15 to 0.3 μm. When the core-shell type graft copolymer (B) having an average particle diameter in such a range is used, toughness can be expressed with a small amount of blending, and the possibility of impairing rigidity and surface hardness can be suppressed. . In addition, the average particle diameter in this specification is an arithmetic average value in the volume-based particle size distribution measured by the light scattering method, and can be specifically obtained by the method described in the examples.

The production method of the core-shell type graft copolymer (B) is not particularly limited and can be performed by a known method, but an emulsion polymerization method is preferable. Specifically, emulsion polymerization of monomers constituting the core (inner layer) is performed to obtain seed particles, and in the presence of the seed particles, the monomers constituting each layer are sequentially added to the outermost layer sequentially. It can be obtained by carrying out polymerization.

Examples of the emulsifier used in the emulsion polymerization method include dialkyl sulfosuccinates such as sodium dioctyl sulfosuccinate and sodium dilauryl sulfosuccinate which are anionic emulsifiers, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, sodium dodecyl sulfate and the like. Nonionic emulsifier polyoxyethylene alkyl ether, polyoxyethylene nonyl phenyl ether, etc .; Nonionic anionic emulsifier polyoxyethylene nonyl phenyl ether sodium sulfate polyoxyethylene nonyl phenyl ether sulfate, Polyoxyethylene alkyl ether sulfate such as sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene tridecyl ether acetate Alkyl ether carboxylates, such as beam; and the like. These may be used alone or in combination of two or more. In addition, the average number of repeating units of ethylene oxide units in the exemplified compounds of the nonionic emulsifier and the nonionic anionic emulsifier is preferably 30 or less, more preferably in order to prevent the foaming property of the emulsifier from becoming extremely large. It is 20 or less, more preferably 10 or less.

The polymerization initiator used in the emulsion polymerization is not particularly limited, and examples thereof include persulfate-based initiators such as potassium persulfate and ammonium persulfate; redox such as persulfoxylate / organic peroxide, persulfate / sulfite. A system initiator or the like can be used.

Separation and acquisition of the core-shell type graft copolymer from the polymer latex obtained by emulsion polymerization can be performed by a known method such as a salting out coagulation method, a freeze coagulation method, or a spray drying method. Among these, the salting out coagulation method and the freeze coagulation method are preferable, and the freeze coagulation method is more preferable from the viewpoint that impurities contained in the crosslinked rubber particle component can be easily removed by washing with water. Since the freeze coagulation method does not use a flocculant, it is easy to obtain a film excellent in water resistance. In order to remove foreign matters mixed in the polymer latex before the coagulation step, it is preferable to filter the polymer latex with a wire mesh having an opening of 50 μm or less. From the viewpoint of being easily dispersed uniformly in the melt-kneading with the (meth) acrylic resin (A), the core-shell type graft copolymer (B) is preferably taken out as aggregated particles of 1,000 μm or less, and the aggregated particles of 500 μm or less It is more preferable to take out as The form of the aggregated particles is not particularly limited. For example, the aggregated particles may be in the form of pellets fused to each other at the outermost layer portion, or may be powder or granulated powder.

The content of the core-shell type graft copolymer (B) in the (meth) acrylic resin composition of the present invention is not particularly limited, but the mass ratio of the (meth) acrylic resin (A) and the core-shell type graft copolymer (B) However, the former / the latter is preferably 70/30 to 90/10, more preferably 75/25 to 85/15, and still more preferably 77/23 to 83/17. When the mass ratio is in this range, a (meth) acrylic resin composition having an excellent balance between hardness and impact resistance can be obtained.

<Fatty alcohol (C)>
In the (meth) acrylic resin composition of the present invention, 0.03 of the aliphatic alcohol (C) is added to 100 parts by mass of the total amount of the (meth) acrylic resin (A) and the core-shell type graft copolymer (B). Including 0.3 parts by mass. The content of the aliphatic alcohol (C) is preferably 0.03 to 0.2 parts by mass with respect to 100 parts by mass of the total amount of the (meth) acrylic resin (A) and the core-shell type graft copolymer (B). More preferably, it is 0.04 to 0.09 parts by mass. When the content of the aliphatic alcohol (C) is less than 0.03 parts by mass, the long-term stability at the time of melting becomes insufficient, and when the content of the aliphatic alcohol (C) exceeds 0.3 parts by mass, Long-term stability deteriorates.

The type of the aliphatic alcohol (C) is not particularly limited, but an aliphatic alcohol having 12 to 18 carbon atoms such as lauryl alcohol, palmityl alcohol, stearyl alcohol, and oleyl alcohol is preferable. Lauryl alcohol, palmityl alcohol, stearyl alcohol More preferred are saturated aliphatic alcohols having 12 to 18 carbon atoms, such as saturated aliphatic alcohols having 16 to 18 carbon atoms such as palmityl alcohol and stearyl alcohol, and particularly preferred is stearyl alcohol. An aliphatic alcohol (C) may be used individually by 1 type, or may use 2 or more types together.

<Other additives>
In the (meth) acrylic resin composition of the present invention, various additives such as a polymer processing aid (D), an ultraviolet absorber (E), and the like, as long as the effects of the present invention are not impaired. Antioxidants, heat stabilizers, lubricants, antistatic agents, colorants, impact resistance aids, etc. (meth) acrylic resin (A), core-shell type graft copolymer (B) and aliphatic alcohol (C) You may add other additives other than. In addition, it is preferable not to add a foaming agent, a filler, a matting agent, a light diffusing agent, a softening agent, and a plasticizer in a large amount from the viewpoint of mechanical properties and surface hardness of the film of the present invention.

<Polymer processing aid (D)>
The (meth) acrylic resin composition of the present invention preferably further contains a polymer processing aid (D) as the other additive described above. The polymer processing aid (D) is a compound that exhibits an effect in thickness accuracy, film formation stability, fisheye reduction, and the like when the resin composition of the present invention is molded. As the polymer processing aid (D), an ultra high molecular weight (weight average molecular weight of 500,000 or more) mainly comprising methyl methacrylate units (including 50% by mass or more), which can be usually produced by an emulsion polymerization method. Methacrylic resin can be used, and polymer particles having a particle diameter of 0.05 to 0.5 μm are preferable.

Commercially available products can be used for the polymer processing aid (D). Specifically, “Kane Ace” PA series (manufactured by Kaneka), “Metablene” P series (manufactured by Mitsubishi Rayon), “Paralloid” K Series (made by Dow) is listed. Among these, “paraloid” K125P is preferable from the viewpoint of compatibility with the resin.

The content of the polymer processing aid (D) in the (meth) acrylic resin composition of the present invention is preferably 0.1 to 3% by mass. The content of the polymer processing aid (D) varies depending on the use, but from the viewpoint of further reducing fish eyes, it is more preferably 1.0% by mass or more, and 1.3% by mass or more. More preferably. Moreover, from a viewpoint of suppressing cost and suppressing melt viscosity, it is more preferably 2.5% by mass or less, and further preferably 2.0% by mass or less.

<Ultraviolet absorber (E)>
The (meth) acrylic resin composition of the present invention preferably further contains an ultraviolet absorber (E) as the other additive described above. The ultraviolet absorber (E) is a compound having an ability to absorb ultraviolet rays, and mainly has a function of converting light energy into heat energy.

Examples of the ultraviolet absorber (E) include benzophenones, benzotriazoles, triazines, benzoates, salicylates, cyanoacrylates, oxalic anilides, malonic esters, formamidines, and the like. These may be used alone or in combination of two or more. Among these, benzotriazoles and triazines are preferable because they have a high ability to suppress resin deterioration when irradiated with ultraviolet rays and have high compatibility with the resin.

Benzotriazole ultraviolet absorbers have a high effect of suppressing deterioration of optical properties such as coloring due to ultraviolet irradiation. As UV absorbers for benzotriazoles, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol (“TINUVIN” 329 manufactured by BASF), 2 -(2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol (“TINUVIN” 234 manufactured by BASF) and 2,2′-methylenebis [6- ( 2H-benzotriazol-2-yl) -4-tert-octylphenol] (“ADEKA STAB” LA-31 manufactured by ADEKA) and the like. From the viewpoint of compatibility with the (meth) acrylic resin composition of the present invention, 2 , 2′-methylenebis [6- (2H-benzotriazol-2-yl) -4-tert-octylphenol] (“ADEKA STAB” manufactured by ADEKA) LA-31) are preferred.

Examples of UV absorbers for triazines include UV absorbers for hydroxyphenyl triazines. More specifically, 2,4-bis (2-hydroxy-4-butyroxyphenyl) -6- ( 2,4-Butyloxyphenyl) -1,3,5-triazine (“TINUVIN” 460 manufactured by BASF), 2- (4- (2-hydroxy-3- (2-ethylhexyloxy) propyloxy) -2- Hydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine (“TINUVIN” 405 manufactured by BASF), 2- (2-hydroxy-4- [1-octyloxycarbonyl) Ethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine (“TINUVIN” 479 manufactured by BASF), Bottle "1477, 400, 477, 1600; 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5- (2- (2-ethylhexanoyloxy) ethoxy) phenol (ADEKA) “ADK STAB” LA-46), 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenoxy) -1,3,5-triazine (“ADEKA STAB” LA-F70 manufactured by ADEKA) 2- [4-[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1, , Such as 5-triazine, and the like.

The content of the ultraviolet absorber (E) in the (meth) acrylic resin composition of the present invention is preferably 0.1 to 3% by mass. Although content of the said ultraviolet absorber (E) changes with kinds and use of an ultraviolet absorber (E), it is more preferable that it is 0.2 mass% or more, and it is 0.4 mass% or more. Is more preferable. Moreover, from a viewpoint of suppressing cost, it is more preferably 2.8% by mass or less, and further preferably 2.5% by mass or less.

<Other polymers>
The (meth) acrylic resin composition of the present invention is a polymer processing aid that can be a (meth) acrylic resin (A), a core-shell type graft copolymer (B), and a polymer as long as the effects of the present invention are not impaired. A polymer other than the agent (D) can further be contained. Such other polymers include polyolefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, polynorbornene, etc .; ethylene ionomers; polystyrene, styrene-maleic anhydride copolymer, high impact polystyrene , AS resins, ABS resins, AES resins, AAS resins, ACS resins, MBS resins and other styrene resins; methyl methacrylate-styrene copolymers; polyethylene resins such as polyethylene terephthalate and polybutylene terephthalates; nylon 6, nylon 66, polyamide Polyamides such as elastomers: polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacetal, polyvinylidene fluoride, polyurea Emissions, modified polyphenylene ether, polyphenylene sulfide, silicone-modified resins; acrylic rubber, silicone rubber; SEPS, SEBS, styrene-based thermoplastic elastomer SIS like; IR, EPR, and olefin-based rubber EPDM and the like.

<(Meth) acrylic resin composition>
The (meth) acrylic resin composition of the present invention preferably has a melt viscosity of 2,000 Pa · s or less at a 270 ° C. shear rate of 12.2 / sec. From the viewpoint of easy film formation at a low temperature, the melt viscosity at 270 ° C. shear rate 12.2 / sec is more preferably 1,800 Pa · s or less, still more preferably 1,500 Pa · s or less, particularly Preferably, it is 1,200 Pa · s or less. When the melt viscosity is 2,000 Pa · s or less, the film forming temperature does not become too high, and a stable long-term continuous operation becomes possible. The lower limit of the melt viscosity is preferably 300 Pa · s, more preferably 500 Pa · s from the viewpoint of mechanical properties. The melt viscosity depends on the weight average molecular weight of the (meth) acrylic resin (A), the mass ratio of the (meth) acrylic resin (A) and the core-shell type graft copolymer (B), the content of other additives, and the like. Can be adjusted. The said melt viscosity can be measured by the method as described in an Example.

The method for preparing the (meth) acrylic resin composition of the present invention is not particularly limited, but a method of melt kneading and mixing is preferable. Specifically, the (meth) acrylic resin (A), the core-shell type graft copolymer (B) and the aliphatic alcohol (C), and if necessary, a polymer processing aid (D), an ultraviolet absorber ( A method of dry blending and melt-kneading other additives such as E) and other polymers in advance is generally used. 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 viewpoints of kneadability and productivity. The shear rate at the time of melt kneading is preferably 10 to 1,000 / second. The temperature during mixing and kneading is usually from 150 to 320 ° C., preferably from 200 to 300 ° C. When melt kneading using a twin screw extruder, it is preferable to use a vent and perform melt kneading under reduced pressure or melt kneading under a nitrogen stream from the viewpoint of suppressing coloration. Thus, the (meth) acrylic resin composition of the present invention can be obtained, for example, in the form of pellets.

The lower limit of the total content of the (meth) acrylic resin (A) and the core-shell type graft copolymer (B) in the (meth) acrylic resin composition of the present invention is usually 50% by mass, preferably 70% by mass. %, More preferably 80% by mass, still more preferably 85% by mass. The upper limit is preferably 99.97% by mass, more preferably 99.96% by mass, and still more preferably 99.95% by mass.

<Film>
The (meth) acrylic resin composition of the present invention can be molded into a film. The film can be produced using a known method such as a T-die method, an inflation method, a melt casting method, or a calendar method. From the viewpoint of obtaining a film having good surface smoothness and low haze, the (meth) acrylic resin composition of the present invention is melt-kneaded and extruded in a molten state from a T die, and both surfaces thereof are applied to a mirror roll surface or a mirror belt surface. It is preferable to include the process of making it contact and shape | mold. The roll or belt used at this time is preferably made of metal. In the case of forming a film by bringing both sides of the melt-kneaded product thus extruded into contact with a mirror surface, it is preferable to press and sandwich the melt-kneaded product (which may be a film) with a mirror roll or a mirror belt. The pinching pressure by the mirror roll or the mirror belt is preferably high, and the linear pressure is preferably 10 N / mm or more, and more preferably 20 N / mm or more. Further, the surface temperature of the mirror roll or mirror belt to be sandwiched is preferably 60 ° C. or higher, more preferably 70 ° C. or higher. Moreover, it is preferable that it is 130 degrees C or less, and it is more preferable that it is 100 degrees C or less. When the surface temperature of the mirror roll or mirror belt sandwiching the melt-kneaded product is 60 ° C. or higher, the resulting film has good surface smoothness and haze, and when the surface temperature is 130 ° C. or lower, the film and mirror roll or mirror surface When the film is peeled off from the mirror roll or the mirror belt, surface roughness and recumbency are hardly generated, and the appearance of the film can be improved.

In the case of the production method by the T-die method, an extruder type melt extrusion apparatus with a single screw or a twin screw extrusion screw can be used. The melt extrusion temperature for producing the film of the present invention is preferably 230 ° C or higher, more preferably 240 ° C or higher. The melt extrusion temperature is preferably 290 ° C. or lower, and more preferably 280 ° C. or lower. In addition, when using a melt extrusion device, from the viewpoint of suppressing coloration, a melt pump is used under reduced pressure using a vent to attach a gear pump from the viewpoint of producing a film with a uniform film thickness, in order to further reduce fish eye defects. It is preferable to melt-extrusion with a polymer filter. Furthermore, it is preferable to perform melt extrusion under a nitrogen stream from the viewpoint of suppressing oxidative degradation.

When the film comprising the (meth) acrylic resin composition of the present invention is produced by an extrusion apparatus equipped with a vent, a gear pump, a polymer filter and a T die in this order, from the vent to the T die including the gear pump and the polymer filter. It is preferable to control the temperature in the range of 230 to 290 ° C. By producing in such a temperature range, a film having little deterioration, little fish eye, and excellent mechanical properties and optical characteristics can be obtained.

The haze of the film comprising the (meth) acrylic resin composition of the present invention is preferably 1.5% or less, more preferably 1.2% or less, and 1.0% or less at a thickness of 75 μm. More preferably it is. By being in the above-mentioned range, when used for applications requiring design properties, the surface gloss and the sharpness of the picture layer printed on the film of the present invention become more excellent. Moreover, in optical uses, such as a polarizer protective film and a light guide film, the utilization efficiency of the light source is increased, which is preferable. Furthermore, it is preferable because it is excellent in shaping accuracy when performing surface shaping. The haze can be obtained by the method described in Examples.

The pencil hardness of the film made of the (meth) acrylic resin composition of the present invention is preferably HB or higher, more preferably F or higher, still more preferably H or higher. High pencil hardness makes it difficult to damage the surface of the film, so it is preferable as a decorative and surface protective film on the surface of molded products that require design properties. It is preferable because the generation of scratches generated therein can be suppressed. The pencil hardness can be determined by the method described in the examples.

It is preferable that the folding endurance of the film made of the (meth) acrylic resin composition of the present invention is 30 times or more, more preferably 40 times or more, and still more preferably 50 times or more. When measuring the folding endurance in both the MD direction and the TD direction of the film, it is preferable that the lower one of these is in the above range. Thereby, also when using as a decorative film, a polarizer protective film, etc., it can suppress a crack at the time of receiving an impact, a process, and handling of a final product, and is preferable. The folding endurance number can be measured as the number of reciprocal bending until the test piece breaks in accordance with JIS P8115: 2001, and can be specifically measured by the method described later in Examples.

The film made of the (meth) acrylic resin composition of the present invention may be subjected to a stretching treatment. By the stretching treatment, a film that has high mechanical strength and is difficult to crack can be obtained. The stretching method is not particularly limited, and examples thereof include a simultaneous biaxial stretching method, a sequential biaxial stretching method, a tuber stretching method, and a rolling method. The temperature during stretching can be uniformly stretched, and from the viewpoint of obtaining a high-strength film, the lower limit is preferably 5 ° C. higher than the glass transition temperature of the (meth) acrylic resin (A), and the upper limit is ( The temperature is preferably 40 ° C. higher than the glass transition temperature of the (meth) acrylic resin (A). When the stretching temperature is not less than the above lower limit value, the film is hardly broken during stretching, and when the stretching temperature is not more than the above upper limit value, the effect of the stretching treatment is sufficiently exerted and the strength of the film can be increased. Stretching is usually performed at a stretching rate of 100 to 5,000% / min. When the stretching speed is 100% / min or more, the strength of the film can be increased and the productivity is also improved. When the stretching speed is 5,000% / min or less, the film can be stretched uniformly. Further, it is more preferable to perform heat setting after stretching. A film with little heat shrinkage can be obtained by heat setting.

The thickness of the film made of the (meth) acrylic resin composition of the present invention is preferably less than 500 μm in an unstretched state (before stretching treatment). When it is less than 500 μm, secondary processability such as laminating property, handling property, cutting property, punching property and the like can be improved, and the unit price per unit area can be suppressed, which is excellent in economic efficiency. The non-stretched (before stretching treatment) thickness of the film made of the (meth) acrylic resin composition of the present invention is preferably 30 μm or more, and more preferably 50 μm or more. Moreover, it is more preferable that it is 300 micrometers or less, It is still more preferable that it is 200 micrometers or less, It is especially preferable that it is 100 micrometers or less.
The thickness of the film made of the (meth) acrylic resin composition of the present invention after stretching is preferably 10 to 200 μm, more preferably 30 to 60 μm.

The film made of the (meth) acrylic resin composition of the present invention may be colored. As a coloring method, a method of coloring a (meth) acrylic resin composition itself before film formation by containing a pigment or a dye; a film made of a (meth) acrylic resin composition is immersed in a liquid in which a dye is dispersed. However, it is not particularly limited thereto.

The film made of the (meth) acrylic resin composition of the present invention may be printed on at least one surface. Patterns and colors such as pictures, characters and figures can be given by printing. The pattern may be chromatic or achromatic.

The film made of the (meth) acrylic resin composition of the present invention has, on at least one surface, (i) a layer made of a metal and / or a metal oxide, (ii) a thermoplastic resin layer, and (iii) a base material layer. A laminated film in which at least one layer is laminated as another layer may be used. The method for laminating other layers is not particularly limited, and the layers can be joined directly or via an adhesive layer. As the base material layer, for example, a wooden base material, a non-wood fiber such as kenaf or the like may be used. Other layers may be laminated, or a plurality of layers may be laminated.

As thermoplastic resins suitable for lamination, polycarbonate resin, polyethylene terephthalate resin, polyamide resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, (meth) acrylic resin other than (meth) acrylic resin (A), Examples thereof include ABS resin, ethylene-vinyl alcohol resin, polyvinyl butyral resin, polyvinyl acetal resin, styrene-based thermoplastic elastomer, olefin-based thermoplastic elastomer, and acrylic-based thermoplastic elastomer.

The thickness of the above laminated film may vary depending on the use and is not particularly limited, but is preferably 500 μm or less from the viewpoint of secondary workability.

The film made of the (meth) acrylic resin composition of the present invention may be used alone, as an inner layer or a part of the laminate, or as an outermost layer of the laminate. The other resin used for the lamination is preferably a transparent resin such as a methacrylic resin from the viewpoint of the design of the film. From the viewpoint that the film is not easily scratched and the design properties last for a long time, the film forming the outermost layer preferably has a high surface hardness and weather resistance, and is a film made of the (meth) acrylic resin composition of the present invention. It is preferable.

The film made of the (meth) acrylic resin composition of the present invention has low haze, good optical properties, high surface hardness, excellent bending resistance and impact resistance, and less fish eye defects. Taking advantage of these excellent features, the (meth) acrylic resin film of the present invention is suitably used as a decorative film or an optical film. Specific examples of the optical film include a polarizer protective film. The polarizer protective film can be used for a polarizing plate including the polarizing plate, a liquid crystal display device including at least one polarizing plate, an organic EL display device, an image display device such as a PDP, and the like. The film made of the (meth) acrylic resin composition of the present invention includes a light guide film, a moth-eye film, a Fresnel lens, a lenticular lens, a front film for various displays, a diffusion film, a glass scattering prevention film, a liquid crystal ASF film, and a transparent conductive film. It can be suitably used as an optical substrate film such as a heat shielding film and various barrier films.

As a more specific example, a film made of the (meth) acrylic resin composition of the present invention has low haze, good optical properties, high surface hardness, excellent bending resistance and impact resistance, and fish eyes. Taking advantage of characteristics such as few defects, molded products that require design and molded products that require advanced optical properties, that is, billboard parts such as advertising towers, stand signs, sleeve signs, bamber signs, and roof signs ; Display parts such as showcases, partition plates, store displays; fluorescent lamp covers, mood lighting covers, lamp shades, lighting ceilings, light walls, chandeliers, etc .; interior parts such as furniture, pendants, mirrors; doors, domes Building parts such as safety window glass, partitions, staircases, balcony stools, roofs of leisure buildings; aircraft windshields, pilot visors, o Toby, motorboat windshield, bus shading plate, automotive side visor, rear visor, head wing, headlight cover, automotive interior parts, automotive exterior parts such as bumpers, etc .; sound image nameplate, stereo cover, TV Electronic equipment parts such as protective masks, vending machines, mobile phones and personal computers; medical equipment parts such as incubators and X-ray parts; equipment-related parts such as machine covers, instrument covers, experimental devices, rulers, dials, observation windows; Traffic-related parts such as road signs, guide boards, curved mirrors, noise barriers, etc .; greenhouses, large tanks, box tanks, bathroom components, clock panels, bathtubs, sanitary, desk mats, game parts, toys, face protection during welding It can be suitably used for decorative and protective films on the surface of masks, etc., wallpaper, marking films, etc. That.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, this invention is not restrict | limited by a following example. Moreover, this invention includes all the aspects formed by arbitrarily combining matters representing the technical characteristics such as the characteristic values, forms, manufacturing methods, and uses. In addition, the measurement of the physical-property value in an Example and a comparative example was implemented with the following method.

[Weight average molecular weight (Mw)]
The chromatogram was measured under the following conditions by gel permeation chromatography (GPC), and the value converted into the molecular weight of standard polystyrene was calculated. The baseline is that the slope of the peak on the high molecular weight side of the GPC chart changes from zero to positive when viewed from the earlier retention time, and the slope of the peak on the low molecular weight side is from negative to zero when viewed from the earlier retention time. A line connecting points that change to.
GPC device: manufactured by Tosoh Corporation, HLC-8320
Detector: Differential refractive index detector Column: TSKgel SuperMultipore HZMM manufactured by Tosoh Corporation and Super HZ4000 connected in series were used.
Eluent: Tetrahydrofuran Eluent flow rate: 0.35 mL / min Column temperature: 40 ° C
Calibration curve: Created using 10 standard polystyrene data

[Average particle size]
The measurement was performed using a laser diffraction / scattering particle size distribution measuring apparatus LA-910 manufactured by Horiba.

[Glass transition temperature (Tg)]
The glass transition temperature of the (meth) acrylic resin (A) was measured according to JIS K7121: 2012. That is, the DSC curve was measured by differential scanning calorimetry under the condition that the sample was heated once to 200 ° C., then cooled to 30 ° C. or lower, and then heated from 30 ° C. to 200 ° C. at 10 ° C./min. The intermediate glass transition temperature obtained from the DSC curve measured at the time of the second temperature rise was defined as the glass transition temperature in the present invention.

[Melt viscosity]
Using a capillograph (Model 1D manufactured by Toyo Seiki Seisakusho Co., Ltd., capillary diameter 1 mmφ, length 40 mm), the measurement was performed under the predetermined temperature and shear rate conditions shown in Table 1.

[Long-term stability during melting]
5 g of the (meth) acrylic resin composition obtained in each Example or Comparative Example was added to a metal screw tube containing a polytetrafluoroethylene sheet, and left in a hot air dryer at 270 ° C. for 24 hours. One piece was collected from the central part of the sample before and after the heating, a section was cut out with a microtome, placed on a grid, stained with osmium acid, and observed with a transmission electron microscope. From the particle aggregation state of the core-shell type graft copolymer at that time, the long-term stability during melting was evaluated according to the following criteria.
A: There are few agglomerated parts and no change is observed. B: Aggregation is progressing as a whole. C: Aggregation is intensely occurring.

〔thickness〕
The film manufactured in each Example or Comparative Example was measured with a micrometer at a total of three points with a thickness of 100 mm from the center and both ends, and the average value was taken as the thickness of the film.

[Fisheye defects]
Each example or comparative online defect inspection device a film of 300m wound prepared in Example (Nagase & manufactured, Scantec8000C1 System3) to through, to measure the number of fish eyes drawback of 0.03 mm ² or more in size, per 1 m ² The number of fish eye defects was calculated.

[Haze]
The film manufactured in each Example or Comparative Example was cut into 50 mm × 50 mm to obtain a test piece, and haze was measured at 23 ° C. in accordance with JIS K7136: 2000.

〔Pencil hardness〕
The film produced in each example or comparative example was cut into 10 cm × 10 cm to obtain a test piece, and the pencil hardness was measured in accordance with JIS K5600-5-4: 1999.

[Flexibility]
The film manufactured in each Example or Comparative Example was cut out to 15 mm × 110 mm to obtain a test piece, and the number of folding times was measured according to JIS P8115: 2001.

[Reference Example 1]
Production of (meth) acrylic resin (A-1-1) 99 parts by weight of methyl methacrylate and 1 part by weight of methyl acrylate were subjected to polymerization initiator (2,2′-azobis (2-methylpropionitrile), hydrogen abstraction ability 1%, 1 hour half-life temperature: 83 ° C.) 0.1 part by mass and chain transfer agent (n-octyl mercaptan) 0.24 part by mass were added and dissolved to obtain a raw material liquid.
100 parts by mass of ion-exchanged water, 0.03 parts by mass of sodium sulfate and 0.45 parts by mass of the suspension / dispersant were mixed to obtain a mixed solution. In a pressure-resistant polymerization tank, 420 parts by mass of the mixed solution and 210 parts by mass of the raw material liquid were charged, and the polymerization reaction was started at a temperature of 70 ° C. while stirring in a nitrogen atmosphere. After 3 hours from the start of the polymerization reaction, the temperature was raised to 90 ° C. and stirring was continued for 1 hour to obtain a liquid in which the bead copolymer was dispersed. Although some polymer adhered to the wall of the polymerization tank or the stirring blade, there was no foaming and the polymerization reaction proceeded smoothly.
The obtained copolymer dispersion is washed with an appropriate amount of ion-exchanged water, the bead-like copolymer is taken out with a bucket-type centrifuge, and dried with a hot air dryer at 80 ° C. for 12 hours. Acrylic resin (A-1-1) was obtained.
The obtained (meth) acrylic resin (A-1-1) had a methyl methacrylate unit content of 99% by mass, a methyl acrylate unit content of 1% by mass, and a weight average molecular weight (Mw ) Was 95,000 and the glass transition temperature was 120 ° C.

[Reference Example 2]
Production of (meth) acrylic resin (A-1-2) Reference Example, except that the monomer used was changed to 100 parts by weight of methyl methacrylate and the amount of chain transfer agent was changed to 0.21 parts by weight (Meth) acrylic resin (A-1-2) was obtained in the same manner as in Example 1.
The obtained (meth) acrylic resin (A-1-2) had a methyl methacrylate unit content of 100 mass%, a weight average molecular weight (Mw) of 113,000, and a glass transition temperature of 121 ° C. It was.

[Reference Example 3]
Production of (meth) acrylic resin (A-2-1) The monomer used was changed to 90 parts by weight of methyl methacrylate and 10 parts by weight of methyl acrylate, and the amount of chain transfer agent was changed to 0.39 parts by weight. Except for the above, a (meth) acrylic resin (A-2-1) was obtained in the same manner as in Reference Example 1.
The obtained (meth) acrylic resin (A-2-1) has a methyl methacrylate unit content of 90% by mass, a methyl acrylate unit content of 10% by mass, and a weight average molecular weight of 60%. The glass transition temperature was 111 ° C.

[Reference Example 4]
Production of core-shell type graft copolymer (B-1) (1) 1050 parts by mass of ion-exchanged water in a reactor equipped with a stirrer, thermometer, nitrogen gas introduction tube, monomer introduction tube and reflux condenser Then, 0.3 parts by mass of sodium polyoxyethylene tridecyl ether acetate and 0.7 parts by mass of sodium carbonate were charged, and the inside of the reactor was sufficiently replaced with nitrogen gas. The internal temperature was then 80 ° C. Thereto, 0.25 part by mass of potassium persulfate was added and stirred for 5 minutes. To this, 245 parts by mass of a monomer mixture consisting of 95.4% by mass of methyl methacrylate, 4.4% by mass of methyl acrylate and 0.2% by mass of allyl methacrylate was continuously added dropwise over 60 minutes. After completion of the dropping, a polymerization reaction was further performed for 30 minutes so that the polymerization conversion rate was 98% or more.
(2) Next, 0.32 parts by mass of potassium persulfate was charged into the reactor and stirred for 5 minutes. Thereafter, 315 parts by mass of a monomer mixture consisting of 80.5% by mass of butyl acrylate, 17.5% by mass of styrene and 2% by mass of allyl methacrylate was continuously added dropwise over 60 minutes. After completion of the dropping, a polymerization reaction was further performed for 30 minutes so that the polymerization conversion rate was 98% or more.
(3) Next, 0.14 parts by mass of potassium persulfate was added to the reactor and stirred for 5 minutes. Thereafter, 140 parts by mass of a monomer mixture consisting of 95.2% by mass of methyl methacrylate, 4.4% by mass of methyl acrylate and 0.4% by mass of n-octyl mercaptan was continuously added dropwise over 30 minutes. After completion of the dropping, the polymerization reaction was further performed for 60 minutes so that the polymerization conversion rate was 98% or more.
Through the above operation, a latex containing the core-shell type graft copolymer (B-1) was obtained. The latex containing the core-shell type graft copolymer (B-1) was frozen and coagulated. Subsequently, it was washed with water and dried to obtain a particulate core-shell type graft copolymer (B-1). The average particle diameter of the particles was 0.23 μm.

The following were used as other materials.
<Fatty alcohol (C)>
“CALCOAL 8098” manufactured by Kao, stearyl alcohol <polymer processing aid (D)>
Dow Chemical's “Paraloid” K125P
<UV protection agent (E)>
"ADEKA STAB" LA31RG made by ADEKA

[Example 1]
70 parts by weight of (meth) acrylic resin (A-1-1), 10 parts by weight of (meth) acrylic resin (A-2-1), 20 parts by weight of core-shell type graft copolymer (B-1), aliphatic alcohol (C) A 41 mmφ twin-screw kneading extruder (Toshiba Machine TEM41-SS, with a polymer filter with a filtration accuracy of 10 μm) while controlling 0.05 parts by mass and 2.0 parts by mass of an ultraviolet-ray inhibitor (E) with a weight feeder The temperature under the hopper is set to 150 ° C., the barrel temperature, and the polymer filter temperature are set to 230 ° C., and the (meth) acrylic resin composition is extruded into a strand shape and cut with a pelletizer ( A pellet of a (meth) acrylic resin composition was produced.
The obtained pellets were melt-extruded using an extruder equipped with a gear pump and a polymer filter with a filtration accuracy of 10 μm in this order in a 65 mmφ single screw extruder with a vent, and a T-die with a width of 900 mm at the tip. (Film forming temperature including temperature from vent to T-die) Extruded at 270 ° C., discharge rate 40 kg / h, and formed by sandwiching between 80 ° C. metal mirror elastic roll and 80 ° C. metal mirror rigid roll, The film was taken up at 10 m / min to form a film having a thickness of 75 μm. The evaluation results of the obtained film are shown in Table 1. Fisheye defects were inspected online during film formation.

[Examples 2 to 5]
A film was obtained in the same manner as in Example 1 except that the formulation shown in Table 1 was used. The evaluation results are shown in Table 1.

[Example 6]
A film was obtained in the same manner as in Example 5 except that the melt extrusion temperature shown in Table 1 (film forming temperature including the temperature from the vent to the T die) was used. The evaluation results are shown in Table 1.

[Comparative Examples 1 and 2]
A film was obtained in the same manner as in Example 1 except that the addition amount of the aliphatic alcohol (C) shown in Table 1 was used. The evaluation results are shown in Table 1. Both when the aliphatic alcohol (C) was not added and when it was added as much as 0.5 parts by mass, the long-term stability at the time of melting was insufficient, suggesting that long-term continuous operation becomes difficult.

[Comparative Example 3]
A film was obtained in the same manner as in Example 1 except that an aliphatic ester (“Excel” T95 manufactured by Kao, stearyl monoglyceride) was used instead of the aliphatic alcohol (C). The evaluation results are shown in Table 1. When aliphatic ester was used, it was suggested that long-term stability at the time of melting is insufficient, and long-term continuous operation becomes difficult.

[Comparative Examples 4 to 6]
A film was obtained in the same manner as in Example 1 except that the formulation shown in Table 1 was used. The evaluation results are shown in Table 1. When the core-shell type graft copolymer (B) was not added, the fisheye defect was small, but the folding resistance was low and the bending resistance was poor.

Claims

A total of 100 parts by weight of the (meth) acrylic resin (A) and the core-shell type graft copolymer (B),
Containing 0.03-0.3 parts by mass of an aliphatic alcohol (C),
(Meth) acrylic resin composition.
The (meth) acrylic resin composition according to claim 1, wherein the melt viscosity at 270 ° C and a shear rate of 12.2 / sec is 2,000 Pa · s or less.
The (meth) acrylic resin composition according to claim 1 or 2, wherein the (meth) acrylic resin (A) includes at least two types of (meth) acrylic resins having different weight average molecular weights.
The mass ratio of the (meth) acrylic resin (A) to the core-shell type graft copolymer (B) is the former / the latter = 70/30 to 90/10, according to any one of claims 1 to 3. The (meth) acrylic resin composition as described.
The (meth) acrylic resin composition according to any one of claims 1 to 4, wherein the aliphatic alcohol (C) is stearyl alcohol.
The (meth) acrylic resin composition according to any one of claims 1 to 5, further comprising 0.1 to 3% by mass of a polymer processing aid (D).
A film comprising the (meth) acrylic resin composition according to any one of claims 1 to 6.
The film according to claim 7, wherein the pencil hardness is HB or higher.
The film according to claim 7 or 8, wherein the folding endurance number is 30 times or more.
A decorative film comprising the film according to any one of claims 7 to 9.
An optical film comprising the film according to any one of claims 7 to 9.
A polarizer protective film comprising the film according to any one of claims 7 to 9.
A polarizing plate comprising the polarizer protective film according to claim 12.
The method for producing a film according to any one of claims 7 to 9, wherein an extrusion apparatus including a vent, a gear pump, a polymer filter, and a T die in this order is used, and a temperature from the vent to the T die is set to 230 to A method for producing a film, which is controlled at 290 ° C.