JP6468786B2 - the film - Google Patents

Description

  The present invention relates to a film.

In recent years, with the expansion of the display market, there has been an increasing demand for clearer viewing of images, and there is a demand for optical materials that are given higher optical properties in addition to transparency, heat resistance, and strength.
As the optical material, acrylic resins have been attracting attention from the viewpoints of transparency, surface hardness, optical properties, and the like.

Conventionally, among acrylic resins, in particular, glutaric anhydride (for example, see Patent Document 1), maleic anhydride (for example, see Patent Document 2), and the like are copolymerized with a (meth) acrylic acid ester monomer. Thus, it has been proposed that an acrylic resin having improved heat resistance is excellent as an optical material.
However, the acrylic resin with improved heat resistance as described above (hereinafter sometimes referred to as heat-resistant acrylic resin) is a general-purpose acrylic resin, that is, a copolymer of methyl methacrylate and acrylic ester. Compared to this, there is a problem that when molding is performed under high temperature conditions, it tends to be thermally decomposed.
In addition, with the increase in size and thickness of molded products (such as film formation), molding is often performed under higher temperature conditions, and the residence time under higher temperature conditions becomes longer, so foaming occurs during molding processing. It has the problem that it may occur.

  Furthermore, since heat-resistant acrylic resins have relatively low strength and low toughness, there is a problem that productivity is inferior in terms of film moldability and handling properties.

In addition to the above, conventionally, as a technique for improving the strength of a heat-resistant acrylic resin, a technique for incorporating a cross-linked elastic body having a multilayer structure into an acrylic resin containing a glutaric anhydride unit has been disclosed. (For example, refer to Patent Document 3).
Moreover, the technique which adds an acrylic rubber to the acrylic resin containing a maleic anhydride unit is disclosed (for example, refer patent document 4).
Furthermore, a technique of adding a multilayer structure rubber and a heat stabilizer to an acrylic resin containing maleic anhydride units is disclosed (for example, see Patent Document 5).

JP 2006-241197 A Japanese Patent Laid-Open No. 03-023404 JP 2000-178399 A JP 05-119217 A JP 2010-126550 A

However, the acrylic resins disclosed in Patent Documents 1 and 2 have a problem that the heat resistance and heat stability are insufficient.
In addition, in the acrylic resin compositions disclosed in Patent Documents 3 and 4, there is a problem that heat resistance and thermal stability are reduced due to the addition of a rubbery component, and foaming and foreign matter are easily generated. Have.

  Furthermore, the acrylic resins or acrylic resin compositions disclosed in the cited documents 1 to 4 are particularly susceptible to thermal degradation, resin decomposition, and generation of foreign matters during film formation. There is a problem that the excellent optical properties possessed cannot be fully exhibited.

  Further, in the technique disclosed in Patent Document 5, by adding a heat stabilizer, it is possible to impart excellent mechanical strength and molding stability while imparting a certain degree of high heat resistance. Addition of a stabilizer causes a deterioration in color tone, and the heat stabilizer may bleed out during the molding process.

  Furthermore, in general, the heat-resistant acrylic resin has relatively poor fluidity, and when a thinner film is produced, it is necessary to increase the melting temperature, and thus higher molding stability is required. .

Furthermore, the acrylic resin film has a weak affinity with water compared to the TAC film conventionally used as a protective film for polarizing plates, so sufficient adhesion between the acrylic resin film and the PVA component polarizer. There is a problem that power cannot be secured.
In order to ensure sufficient adhesion between the acrylic resin film and the polarizer, the use of an acrylic UV curable adhesive has also been studied and its effectiveness has been sufficiently evaluated. However, it is necessary to separately carry out a UV curing process, and further, explosion-proof measures are essential in a solvent system, and there is a problem that the equipment cost is high.

  Therefore, there is a demand for an acrylic resin film that can secure a stable adhesive force with a polarizer using an existing adhesive.

  In view of the above-described problems of the prior art, an object of the present invention is to provide an acrylic resin film having excellent heat resistance and having a stable adhesive force as a polarizing plate protective film.

As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have completed the present invention.
That is, the present invention is as follows.

[1]
Methacrylic acid ester monomer unit (A): 50-96.4% by mass;
At least one structural unit (B) selected from the group consisting of a maleimide structural unit, a glutarimide structural unit, and a lactone ring structural unit, having a cyclic structure in the main chain: 3 to 30% by mass; Other vinyl monomer units (C) 0 that can be copolymerized into a monomer
. 6-20% by mass,
A methacrylic resin layer (I) containing a methacrylic resin (α) that satisfies the following conditions (i) and (ii):
A simple adhesive layer (II);
A, with a film,
The film wherein the simple adhesive layer (II) comprises an aqueous polyurethane (X) having a polycarbonate bond .
(I) The weight average molecular weight measured by gel permeation chromatography (GPC) is 650,000 to 300,000.
(Ii) When the total amount of the component (B) and the component (C) is 100% by mass, the content of the component (B) is 45% by mass or more and 98% by mass or less.
[2]
The film according to [1] , wherein the simple adhesive layer (II) includes a mixture containing the aqueous polyurethane (X) having the polycarbonate bond and an isocyanate compound.
[3]
The structural unit (B) having a ring structure in the main chain,
The film according to [1] or [2] , including at least one structural unit selected from the group consisting of a glutarimide structural unit and a maleimide structural unit.
[4]
The structural unit (B) having a ring structure in the main chain,
The film according to any one of [1] to [3] , comprising an N-cyclohexylmaleimide structural unit and / or an N-aryl group-substituted maleimide structural unit.
[5]
The amount of residual maleimide monomer in the methacrylic resin layer (I) is 0.01% by mass or more.
The film according to any one of [1] to [4] , which is 5% by mass or less.
[6]
For 100 parts by mass of the methacrylic resin layer (I),
The film according to any one of [1] to [5] , further including 0 to 5 parts by mass of an ultraviolet absorber.
[7]
Other vinyl monomer units (C) copolymerizable with the methacrylic acid ester monomer,
Any one of [1] to [6] , which is formed of at least one selected from the group consisting of an acrylate monomer, an aromatic vinyl monomer, and a vinyl cyanide monomer. Film.
[8]
Other vinyl monomer units (C) copolymerizable with the methacrylic acid ester monomer,
The film according to any one of [1] to [7] , wherein the film is formed of at least one selected from the group consisting of methyl acrylate, ethyl acrylate, styrene, and acrylonitrile.
[9]
The vinyl monomer unit (C) is an aromatic vinyl monomer unit (C-1),
The content of the aromatic vinyl monomer unit (C-1) is 23 parts by mass or less when the total amount of the component (A) and the component (B) is 100 parts by mass. 7].
[10]
The Vicat softening temperature of the molded body containing the methacrylic resin (α) is 110 ° C. or higher.
The film according to any one of [1] to [9] .
[11]
The film according to any one of [1] to [10] , wherein the thickness of the film is 0.002 to 1 mm.
[12]
In TGA (Thermogravimetric Analysis), the film according to any one of [1] to [11] , wherein a weight reduction rate after heating at a heating temperature of 270 ° C. for 0.5 hour is 5% or less.

  According to the present invention, a film excellent in heat resistance and exhibiting high adhesive force when used as a protective film for a polarizing plate can be obtained.

Hereinafter, although the form for implementing this invention (henceforth "this embodiment") is demonstrated in detail, this invention is not limited to the following description, In the range of the summary Various modifications can be made.
Hereinafter, the structural unit constituting the polymer is referred to as “˜monomer unit”.
Moreover, when describing as a constituent material of the methacrylic resin which comprises the film of this embodiment, a "unit" may be abbreviate | omitted and may only be described as "-monomer."

〔the film〕
The film of this embodiment is
Methacrylic acid ester monomer unit (A): 50-96.4% by mass;
At least one structural unit (B) selected from the group consisting of a maleimide structural unit, a glutarimide structural unit, and a lactone ring structural unit, having a cyclic structure in the main chain: 3 to 30% by mass; A methacrylic resin containing a methacrylic resin (α) containing 0.6 to 20% by mass of another vinyl monomer unit (C) copolymerizable to a monomer and satisfying the following conditions (i) and (ii) A resin layer (I);
A simple adhesive layer (II);
It is a film which has.
(I) The weight average molecular weight measured by gel permeation chromatography (GPC) is 650,000 to 300,000.
(Ii) When the total amount of the component (B) and the component (C) is 100% by mass, the content of the component (B) is 45% by mass or more and 98% by mass or less.

(Methacrylic resin layer (I))
The film of this embodiment has a methacrylic resin layer (I).
The methacrylic resin layer (I)
Methacrylic acid ester monomer unit (A): 50-96.4% by mass;
At least one selected from the group consisting of a maleimide structural unit, a glutarimide structural unit, and a lactone ring structural unit, a structural unit having a ring structure in the main chain (B): 3 to 30% by mass,
0.6-20% by mass of other vinyl monomer units (C) copolymerizable with the methacrylic acid ester monomer,
And a methacrylic resin (α) that satisfies the following conditions (i) and (ii).
(I): The weight average molecular weight measured by gel permeation chromatography (GPC) is 650,000 to 300,000.
(Ii): When the total amount of the component (B) and the component (C) is 100% by mass, the content of the component (B) is 45% by mass to 98% by mass.

The film of the present embodiment includes a methacrylic resin layer (I) containing a methacrylic resin (α). Thereby, high heat resistance is obtained.
The VICAT softening temperature of the molded body containing the methacrylic resin (α) is preferably 110 ° C. or higher, more preferably 112 ° C. or higher, still more preferably 113 ° C. or higher, even more preferably 110 ° C. or higher, and even more preferably. Is 117 ° C. or higher, particularly preferably 120 ° C. or higher, preferably 170 ° C. or lower, more preferably 150 ° C. or lower.
The VICAT softening temperature can be measured according to ISO 306 B50.

It describes in detail about each monomer component of methacrylic resin ((alpha)).
<Methacrylic acid ester monomer unit (A)>
The methacrylic acid ester monomer unit (A) constituting the methacrylic resin (α) forming the methacrylic resin layer (I) of the film of the present embodiment (hereinafter may be referred to as “component (A)”). Is preferably formed of a monomer represented by the following general formula (1).

In the general formula (1), R ₁ represents a methyl group.
R ₂ represents a group having 1 to 12 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, and may have a hydroxyl group on the carbon.

Examples of the methacrylic acid ester monomer represented by the general formula (1) include, but are not limited to, butyl methacrylate, ethyl methacrylate, methyl methacrylate, propyl methacrylate, isopropyl methacrylate, and methacrylic acid. Examples include cyclohexyl acid, phenyl methacrylate, methacrylic acid (2-ethylhexyl), methacrylic acid (t-butylcyclohexyl), benzyl methacrylate, methacrylic acid (2,2,2-trifluoroethyl), and the like. From the viewpoint of heat resistance, handleability and optical properties, methyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate and benzyl methacrylate are preferred. Methyl methacrylate is preferable from the viewpoint of availability.
The said methacrylic acid ester monomer may be used individually by 1 type, and may use 2 or more types together.

  The methacrylic ester monomer unit (A) of the methacrylic resin (α) has a heat resistance to the methacrylic resin (α) and the film of the present embodiment due to the structural unit (B) having a ring structure in the main chain described later. From the viewpoint of the effect of imparting properties, the methacrylic resin (α) is contained in an amount of 50 to 96.4% by mass, preferably 55 to 96.4% by mass, more preferably 55 to 95% by mass, and still more preferably 60. -93 mass%, More preferably, it is contained 60-90 mass%.

<Structural unit (B) having ring structure in main chain>
Structural unit (B) constituting the methacrylic resin (α) forming the methacrylic resin layer (I) of the film of the present embodiment and having a ring structure in the main chain (hereinafter sometimes referred to as component (B)). Is at least one selected from the group consisting of maleimide structural units, glutarimide structural units, and lactone ring structural units.
The structural unit (B) having a ring structure in the main chain may be used alone or in combination of two or more structural units, and two or more monomer units in a common structural unit may be combined. You may use together.

[Maleimide structural unit (B-1)]
As the monomer for forming the maleimide-based structural unit (B-1), it is preferable to use a monomer represented by the following general formula (2).

R ₃ in the general formula (2) is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms. Which may have a substituent on a carbon atom.

The monomer for forming the maleimide-based structural unit (B-1) is not limited to the following. For example, maleimide, N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide; N -Phenylmaleimide, N-methylphenylmaleimide, N-ethylphenylmaleimide, N-butylphenylmaleimide, N-dimethylphenylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N- (o-chlorophenyl) maleimide, N Examples include N-aryl group-substituted maleimides such as-(m-chlorophenyl) maleimide and N- (p-chlorophenyl) maleimide.
From the viewpoint of imparting heat resistance and heat and humidity resistance, N-cyclohexylmaleimide, N-phenylmaleimide, N-methylphenylmaleimide, N- (o-chlorophenyl) maleimide, N- (m-chlorophenyl) maleimide, N- ( p-chlorophenyl) maleimide, and from the viewpoint of easy availability and imparting heat resistance, more preferred are N-cyclohexylmaleimide and N-phenylmaleimide, and more preferred is N-phenylmaleimide.
The maleimide structural unit (B-1) described above may be used alone or in combination of two or more.

[Glutarimide structural unit (B-2)]
As the monomer for forming the glutarimide-based structural unit (B-2), it is preferable to use a monomer represented by the following general formula (3).

Here, in the general formula (3), R ₂₁ and R ₂₂ each independently represent a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.
The alkyl group may be substituted with, for example, a hydroxyl group.
R ₂₃ represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 18 carbon atoms.

The glutarimide-based structural unit (B-2) is obtained by copolymerizing the methacrylic acid ester monomer and / or methacrylic acid and then reacting with ammonia, amine, urea or unsubstituted urea at a high temperature, It can be obtained by a known method such as a method of reacting an acid anhydride with ammonia or an amine.
A preferable preparation method includes a method described in US Pat. No. 4,246,374 of RM Kopchik.

[Lactone ring structural unit (B-3)]
As a monomer for forming the lactone ring structural unit (B-3), it is preferable to use a monomer represented by the following general formula (4).

In the formula _{(4), R 31, R} 32, R 33 represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms independently. The organic residue may contain an oxygen atom.
A lactone ring structural unit (B-3) may be used individually by 1 type, and may be used in combination of 2 or more type.
The method for producing the lactone ring structural unit is not particularly limited. For example, after polymerizing a polymer having a hydroxyl group and an ester group in the molecular chain, the obtained polymer is subjected to the presence / absence of a predetermined catalyst. The method of introduce | transducing a lactone ring structure into a polymer by heat-processing below is mentioned.

The component (B) contained in the methacrylic resin (α) contains at least one structural unit selected from the group consisting of a glutarimide structural unit and a maleimide structural unit from the viewpoint of thermal stability and molding processability. It is more preferable that it contains a maleimide-based structural unit.
In view of availability, N-cyclohexylmaleimide-based structural units and / or N-aryl-substituted maleimide-based structural units are preferable, and N-aryl-substituted maleimide-based, considering the effect of imparting heat resistance with a small amount of addition. A structural unit is more preferable, and an N-phenylmaleimide-based structural unit is more preferable.

[(B) component ratio]
The structural unit (B) having a ring structure in the main chain is contained in an amount of 3 to 30% by mass in the methacrylic resin (α) from the viewpoints of heat resistance and thermal stability, strength and fluidity of the film of this embodiment. It is.
From the viewpoint of imparting heat resistance and thermal stability to the film of the present embodiment, it is preferably 5% by mass or more, more preferably 7% by mass or more, and further preferably 8% by mass or more.
In addition, from the viewpoint of maintaining a necessary balance of strength and fluidity required for the film, the structural unit (B) having a ring structure in the main chain is preferably 28% by mass or less in the methacrylic resin (α). Preferably it is 25 mass% or less, More preferably, it is 20 mass% or less, More preferably, it is 18 mass% or less, More preferably, it is less than 15 mass%.

[Relationship between structural unit (B) having a ring structure in the main chain and thermal stability]
By including the structural unit (B) having a ring structure in the main chain in the methacrylic resin (α), when the methacrylic resin (α) is placed in a high temperature environment, thermal decomposition is suppressed, Generation amount can be reduced. Thereby, the improvement effect of the thermal stability of the film of this embodiment is acquired.

<Other vinyl monomer units (C) copolymerizable with methacrylate monomers>
In the methacrylic resin (α) for a film of the present embodiment, the monomer constituting the component (A) (hereinafter simply referred to as the component (A) is simply described as long as the effects of the present invention are not impaired. To other vinyl-based monomer units (C) (hereinafter sometimes referred to as “component (C)”).
The content of the other vinyl monomer units (C) copolymerizable with the component (A) is 0 in the methacrylic resin (α) from the viewpoint of exerting the heat resistance imparting effect by the component (B). 0.6 to 20% by mass, preferably 0.6 to 18% by mass, and more preferably 0.6 to 15% by mass.
From the viewpoint of heat resistance and optical properties of the film of the present embodiment, when the total amount of the component (B) and the component (C) is 100% by mass, the content of the component (B) is 45% by mass or more and 98% by mass. %, And the content of component (C) is 2% by mass or more and 55% by mass or less. Preferably, the content of component (B) is 50% by mass or more and 98% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and further preferably 50% by mass or more and 80% by mass or less.

  The monomer for forming the component (C) is not limited to the following, but for example, an aromatic vinyl monomer represented by the following general formula (5), a general formula ( 6) Acrylic ester monomers represented by: vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) ) Ester, ethylene glycol such as acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate or the like, and both terminal hydroxyl groups of its oligomer esterified with acrylic acid or methacrylic acid; neopentyl glycol di (meth) Two alcohols such as acrylate and di (meth) acrylate Those hydroxyl group esterified with acrylic acid or methacrylic acid; trimethylolpropane, those polyhydric alcohol derivatives such as pentaerythritol was esterified with acrylic acid or methacrylic acid; polyfunctional monomers such as divinylbenzene, and the like.

In the general formula (5), R ₄₄ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and may have a hydroxyl group on the alkyl group.
n represents an integer of 0 to 5.
R ₄₅ is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 8 carbon atoms, and an aryloxy group having 6 to 8 carbon atoms. And any one of R ₄₅ may be the same group or different groups.
Further, R ₄₅ may form a ring structure.

In the general formula (6), R ₆ is a hydrogen atom, and R ₇ is an alkyl group having 1 to 18 carbon atoms.

  The component (C) can be appropriately selected depending on the properties required for the film of the present embodiment, but properties such as thermal stability, fluidity, mechanical properties, and chemical resistance are particularly necessary. In this case, at least one selected from the group consisting of an aromatic vinyl monomer unit, an acrylate monomer unit, and a vinyl cyanide monomer unit is preferable.

[Aromatic vinyl monomer units (C-1)]
The monomer for forming the aromatic vinyl monomer unit is not limited to the following, but examples thereof include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2 , 4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, p-ethylstyrene, m-ethylstyrene, о-ethylstyrene, p-tert-butylstyrene, 1 -Vinylnaphthalene, 2-vinylnaphthalene, 1,1-diphenylethylene, isopropenyl benzene (α-methylstyrene), isopropenyl toluene, isopropenyl ethyl benzene, isopropenyl propyl benzene, isopropenyl butyl benzene, isopropenyl pentyl benzene, iso Propenylhexylbenzene, isop And lopenyloctylbenzene.
These are appropriately selected according to required characteristics in the film of the present embodiment. Among these, styrene and isopropenylbenzene are preferable, and styrene is more preferable from the viewpoint of imparting fluidity and reducing unreacted monomers by improving the polymerization conversion rate.

  The content in the case of using the aromatic vinyl monomer unit (C-1) is the sum of the components (A) and (B) from the viewpoint of heat resistance, reduction of residual monomer species, and balance of fluidity. When the amount is 100 parts by mass, it is preferably 23 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 18 parts by mass or less, still more preferably 15 parts by mass or less, and still more preferably 10 parts by mass. It is below mass parts.

When the aromatic vinyl monomer unit (C-1) is used in combination with the above-described maleimide monomer unit (B-1), the content ratio (mass ratio) is a processing when the film is molded. From the viewpoints of fluidity and the effect of reducing silver streaks due to residual monomer reduction, it is preferable to satisfy the following formula.
0.3 ≦ (C-1) / (B-1) ≦ 5
From the viewpoint of maintaining good color tone and heat resistance, the upper limit value is preferably 5 or less, more preferably 3 or less, and even more preferably 1 or less.
Moreover, it is preferable that it is 0.3 or more from a viewpoint of residual monomer reduction, More preferably, it is 0.4 or more.
The aromatic vinyl monomer (C-1) described above may be used alone or in combination of two or more.

[Acrylic acid ester monomer unit (C-2)]
As the monomer for forming the acrylate monomer unit, as described above, in the general formula (6), a compound in which the substituent R ₇ is an alkyl group having 1 to 18 carbon atoms can be mentioned. Among them, in the methacrylic resin (α), methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, acrylic, from the viewpoint of improving weather resistance, heat resistance, fluidity, and thermal stability. Acid sec-butyl, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, etc. are preferred, more preferably methyl acrylate, ethyl acrylate, n-butyl acrylate, from the viewpoint of availability, More preferred is methyl acrylate.
The content in the case of using the acrylate monomer unit (C-2) is when the total amount of the component (A) and the component (B) is 100 parts by mass from the viewpoints of heat resistance and thermal stability. The amount is preferably 5 parts by mass or less, more preferably 3 parts by mass or less.
As the monomer for forming the acrylate monomer unit (C-2), only one type may be used alone, or two or more types may be used in combination.

[Vinyl cyanide monomer unit (C-3)]
The monomer for forming the vinyl cyanide monomer unit is not particularly limited, and examples thereof include acrylonitrile, methacrylonitrile, vinylidene cyanide and the like. From the viewpoint of imparting chemical properties, acrylonitrile is preferred.
In the case of using the vinyl cyanide monomer unit (C-3), the total amount of the component (A) and the component (B) is 100 parts by mass from the viewpoint of solvent resistance and heat resistance. When it is, it is preferable that it is 15 mass parts or less, More preferably, it is 12 mass parts or less, More preferably, it is 10 mass parts or less.

  Among the monomers constituting the component (C) described above, at least one monomer selected from the group consisting of methyl acrylate, ethyl acrylate, styrene, and acrylonitrile is preferable from the viewpoint of availability. .

<Molecular weight and molecular weight distribution of methacrylic resin (α)>
The methacrylic resin (α) for the methacrylic resin layer (I) of the film of this embodiment has a weight average molecular weight of 650,000 or more and 300,000 or less. By setting the weight average molecular weight of the methacrylic resin (α) within the above range, the film of this embodiment is excellent in mechanical strength, solvent resistance and fluidity. Preferably it is 650,000 or more and 250,000 or less, More preferably, it is 70,000 or more and 230,000 or less.
The molecular weight distribution (weight average molecular weight / number average molecular weight: Mw / Mn) of the methacrylic resin (α) is 1.5 or more and 5 or less in consideration of the balance between fluidity, mechanical strength, and solvent resistance. Is preferred. More preferably, it is 1.5 or more and 4.5 or less, More preferably, it is 1.6 or more and 4 or less, More preferably, it is 1.6 or more and 3 or less, More preferably, it is 1.5 or more and 2.5 or less.
The weight average molecular weight and number average molecular weight of the methacrylic resin (α) for the methacrylic resin layer (I) of the film of the present embodiment can be measured by gel permeation chromatography (GPC).
That is, using a standard methacrylic resin that is known in advance as a reagent and has a monodispersed weight average molecular weight, number average molecular weight, and peak molecular weight, and an analytical gel column that elutes a high molecular weight component first, elution time and weight average molecular weight Create a calibration curve. Next, from the obtained calibration curve, the weight average molecular weight and the number average molecular weight of the sample of the methacrylic resin to be measured can be obtained.

(Residual monomer amount)
In the methacrylic resin layer (I) of the film of this embodiment, the residual monomer is 0 in the methacrylic resin layer (I) in consideration of the balance of heat resistance, fluidity, moldability during molding, and scratch resistance. It is preferable that it is 1 mass%-1.5 mass%. More preferably 0.1% by mass to 1% by mass, further preferably 0.2% by mass to 1% by mass, even more preferably 0.2% by mass to 0.8% by mass, and still more preferably 0.3% by mass. % To 0.8% by mass.
The amount of residual monomer can be measured by gas chromatography.
The residual monomer here means the monomer remaining in the resin, that is, the components (A), (B), (C) contained in the methacrylic resin (α), and measured by gas chromatography. It refers to the component that can be made.

  In addition, when using a maleimide monomer as the component (B), from the viewpoint of color tone and fluidity, heat resistance, thermal stability and scratch resistance, the monomer content of the remaining maleimide monomer (hereinafter, The amount of maleimide-based residual monomer and the amount of MI-based residual monomer may be described as 0.01) to 0.5% by mass in the methacrylic resin layer (I). More preferably 0.02% by mass to 0.5% by mass, even more preferably 0.02% by mass to 0.4% by mass, even more preferably 0.02% by mass to 0.3% by mass, and still more preferably. It is 0.03 mass%-0.25 mass%.

(Method for producing methacrylic resin (α))
Hereinafter, although the manufacturing method of the methacrylic resin ((alpha)) for forming the methacrylic resin layer (I) of the film of this embodiment is demonstrated, it is not limited to the method shown below.
The methacrylic resin (α) is a methacrylic acid ester monomer unit (A), a structural unit (B) having a ring structure in the main chain, and other vinyl type copolymerizable with the above methacrylic acid ester monomer. Using each monomer for forming the monomer unit (C), it can be produced by a bulk polymerization method, a solution polymerization method, a suspension polymerization method, a precipitation polymerization method, or an emulsion polymerization method.
A bulk polymerization method, a solution polymerization method and a suspension polymerization method are preferably used, a solution polymerization method and a suspension polymerization method are more preferable, and a suspension polymerization method is more preferably used.

<Production method by solution polymerization method>
When the methacrylic resin (α) is produced by the solution polymerization method, an organic solvent that is a good solvent for the methacrylic resin is used in consideration of the removal efficiency in the step of removing the monomer remaining in the methacrylic resin (α) It is preferable.
Considering the solubility of the copolymer constituting the methacrylic resin (α), the solubility parameter δ of the organic solvent is preferably 7.0 to 12.0 (cal / cm ³ ) ^1/2 , more preferably ^{8.0~11.0 (cal / cm 3) 1/2} , still more preferably ^{8.2~10.5 (cal / cm 3) 1/2} .
The value of the solubility parameter δ and how to obtain the value are described in, for example, K. P. P-P118 in Non-Patent Document “Journal of Paint Technology Vol. 42, No. 541, February 1970”. L. Hoy “New Values of the Solubility Parameters From Vapor Pressure Data” For example, Brandrup et al., “Polymer Handbook Fourth Edition” P-VII / 675-P714 can be referred to.
1 (cal / cm ³ ) ^1/2 is about 0.489 (MPa) ^1/2 .

The addition amount of the organic solvent used in the polymerization step of the methacrylic resin (α) is preferably an amount that can be easily removed without polymerization or precipitation of the copolymer or the monomer used during production.
When the polymerization of the methacrylic resin (α) is performed by a solution polymerization method, the blending amount of the organic solvent is specifically 10 parts by mass or more and 200 parts by mass when the total amount of monomers to be blended is 100 parts by mass. Part or less. More preferably, they are 25 to 200 mass parts, More preferably, they are 50 to 200 mass parts, More preferably, they are 50 to 150 mass parts.

The polymerization temperature when the methacrylic resin (α) is produced by solution polymerization may be any temperature at which polymerization proceeds, but is preferably 50 ° C. or higher and 200 ° C. or lower, more preferably 80 from the viewpoint of productivity. It is at least 200 ° C. More preferably, it is 90 degreeC or more and 200 degrees C or less, More preferably, it is 100 degreeC or more and 180 degrees C or less, More preferably, it is 110 degrees C or more and 170 degrees C or less.
In addition, the polymerization time is not particularly limited as long as the required degree of polymerization can be obtained, but from the viewpoint of productivity and the like, it is preferably 0.5 hours or more and 10 hours or less, more preferably 1 hour. More than 8 hours.
The concentration of dissolved oxygen in the polymerization solution in the polymerization step of the methacrylic resin (α) is not particularly limited, but is preferably 10 ppm or less. The dissolved oxygen concentration can be measured using, for example, a dissolved oxygen meter DO meter B-505 (manufactured by Iijima Electronics Co., Ltd.).
As a method for lowering the dissolved oxygen concentration, a method of bubbling an inert gas in the polymerization solution, and an operation of releasing the pressure after pressurizing the container containing the polymerization solution with an inert gas to about 0.2 MPa before the polymerization are repeated. A method such as a method, a method of passing an inert gas through a container containing a polymerization solution, and a method of circulating the polymerization solution through a deoxidation tower while making countercurrent contact with the inert gas can be appropriately selected.

<Production method by suspension polymerization method>
When the methacrylic resin (α) is produced by a suspension polymerization method such as an organic suspension polymerization method or an inorganic suspension polymerization method, a polymerization step, a washing step, a dehydration step, and a drying step using a stirrer described later. Then, a particulate methacrylic resin (α) is produced.
Usually, an aqueous suspension polymerization method using water as a medium is preferably used.

<Polymerization process>
Using a stirrer to be described later, a monomer, a suspending agent, and a polymerization initiator and other additives as necessary are appropriately fed into the stirrer to perform polymerization, and a methacrylic resin slurry is prepared. obtain.
The stirrer used in the polymerization process to obtain methacrylic resin by suspension polymerization method includes inclined paddle blade, flat paddle blade, propeller blade, anchor blade, fiddler blade (retracted blade), turbine blade, bull margin Stirring devices with stirring blades such as blades, Max blend blades, full zone blades, ribbon blades, supermix blades, intermig blades, special blades and axial flow blades, stirring devices with shovel blades inside, chopper blades inside Examples of the stirring device include known stirring devices such as a stirring device having a rotating disk such as a disk type, a notch disk type, or a screw type.
The stirring speed at the time of polymerization depends on the type of stirring device used, the stirring efficiency of the stirring blade, the capacity of the polymerization tank, etc., but it is possible to obtain an appropriate particle size, and a component having a particle size of less than 0.15 mm Considering that the amount can be reduced, polymerization stability and the like, it is preferably about 1 to 500 revolutions / minute.

In the polymerization step of the methacrylic resin (α), the temperature at which the raw material is added may be within a range where the effects of the present invention can be exerted, and is preferably 0 ° C. or higher and lower than the boiling point of the raw material to be used.
If the temperature is high, the raw material tends to volatilize at the time of addition, so that a copolymer having a desired composition may not be obtained. In addition, depending on the raw material used, there is a possibility that the raw material may be partly hydrolyzed due to contact with water at a high temperature, which may cause a change in color tone under humid heat conditions. When the temperature is lower than 0 ° C., it takes time to increase the temperature after the addition of the raw material, and therefore it is preferable to add the raw material mixture at a certain temperature.
Specifically, it is preferably 0 ° C or higher and 85 ° C or lower, more preferably 10 ° C or higher and 85 ° C or lower, further preferably 10 ° C or higher and 80 ° C or lower, and even more preferably 15 ° C or higher and 70 ° C or lower, More preferably, it is 15 degreeC or more and 60 degrees C or less.

The temperature in the suspension polymerization step is preferably 40 ° C. or higher and 90 ° C. or lower in consideration of productivity and the amount of aggregates produced. More preferably, they are 50 degreeC or more and 85 degrees C or less, More preferably, they are 60 degreeC or more and 80 degrees C or less, More preferably, they are 65 degreeC or more and 80 degrees C or less.
In the case of producing by suspension polymerization, the polymerization time is preferably 20 minutes or more and 240 minutes or less from the viewpoint of effectively suppressing heat generation during polymerization and reducing the generation of aggregates and the residual monomer to be described later. is there. More preferably, they are 30 minutes or more and 210 minutes or less, More preferably, they are 45 minutes or more and 180 minutes or less, More preferably, they are 60 minutes or more and 180 minutes or less, More preferably, they are 90 minutes or more and 150 minutes or less.

Further, from the viewpoint of reducing the residual monomer, it is preferable to raise the temperature to a temperature higher than the polymerization temperature after the polymerization step and hold it for a certain time.
The temperature at the time of holding is preferably higher than the polymerization temperature from the viewpoint that the degree of polymerization can be increased, and is preferably raised by 5 ° C. or more from the polymerization temperature.
When raising temperature, it is preferable that it is below the glass transition temperature of the methacrylic resin ((alpha)) obtained from a viewpoint which prevents aggregation of the polymer obtained. Specifically, it is 120 ° C. or lower, preferably 80 ° C. or higher and 120 ° C. or lower, more preferably 90 ° C. or higher and 120 ° C. or lower, still more preferably 93 ° C. or higher and 120 ° C. or lower, and even more preferably 93 ° C. or higher and 110 ° C. or lower. It is.

By performing polymerization according to the polymerization temperature and holding time described above, polymer particles having a small angle of repose can be obtained after the drying step described below.
The time for maintaining the temperature after the temperature rise is preferably 15 minutes or more and 360 minutes or less, more preferably 30 minutes or more and 240 minutes or less, more preferably 30 minutes or more and 180 minutes, in view of the effect of reducing the residual monomer. Hereinafter, it is more preferably 30 minutes or longer and 150 minutes or shorter, and even more preferably 30 minutes or longer and 120 minutes or shorter.

<Washing process>
The slurry of the methacrylic resin (α) obtained through the above-described polymerization step is preferably subjected to a washing step such as acid washing, water washing, and alkali washing for removing the suspending agent.
In these washing steps, the number of times of washing operation may be selected from the work efficiency and the suspension removal efficiency, and may be repeated once or multiple times.
What is necessary is just to select the temperature at the time of performing washing | cleaning operation in consideration of the removal efficiency of a suspension agent, the coloring degree of the copolymer obtained, etc., and it is preferable that it is 20-100 degreeC. More preferably, it is 30-95 degreeC, More preferably, it is 40-95 degreeC.

  In addition, the cleaning time per cleaning operation is preferably 10 to 180 minutes, more preferably 20 to 150 minutes, from the viewpoints of cleaning efficiency, repose angle reduction effect, and process simplicity.

The pH of the cleaning solution used at the time of the cleaning may be within a range where the suspension can be removed, but is preferably pH 1-12.
The pH for acid washing is preferably pH 1-5, more preferably pH 1.2-4, from the viewpoint of the removal efficiency of the suspending agent and the color tone of the resulting copolymer. The acid used at that time is not particularly limited as long as the suspending agent can be removed, and conventionally known inorganic acids and organic acids can be used. As an example of the acid that is preferably used, the inorganic acid includes hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, boric acid and the like, and each may be used in a diluted solution diluted with water or the like. Examples of the organic acid include those having a carboxyl group, a sulfo group, a hydroxy group, a thiol group, or an enol. Considering the effect of removing the suspending agent and the color tone of the resulting resin, more preferred are nitric acid, sulfuric acid, and organic acids having a carboxyl group.
After the acid cleaning, it is preferable to further perform water washing or alkali washing from the viewpoint of reducing the color tone and angle of repose of the polymer obtained.
The alkaline solution used for the alkali cleaning is preferably pH 7.1 to 12, more preferably pH 7.5 to 11, and further preferably pH 7.5 to 10.5.
Although the alkaline component used for alkali washing is not limited to the following, for example, tetraalkylammonium hydroxide, alkali metal hydroxide, alkaline earth metal hydroxide and the like are preferably used. Alkali metal hydroxides and alkaline earth metal hydroxides are more preferable, and lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, hydroxide are more preferable. Calcium and barium hydroxide are more preferable, lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide and calcium hydroxide are more preferable, and sodium hydroxide and potassium hydroxide are still more preferable.
These alkaline components can be used by adjusting the pH by diluting with water or the like.

<Dehydration process>
As a method for separating the polymer particles from the polymer slurry of the obtained methacrylic resin, a conventionally known method can be applied.
For example, a dehydration method using a centrifuge that shakes off water using centrifugal force, a method of sucking and removing water on a perforated belt or a filtration membrane, and separating polymer particles can be mentioned.

<Drying process>
The water-containing methacrylic resin (α) obtained through the dehydration step described above can be recovered by performing a drying treatment by a known method.
For example, hot air drying for drying by sending hot air into the tank from a hot air blower or blow heater, etc., vacuum drying for drying by heating as necessary after reducing the pressure inside the system, and the obtained polymer For example, barrel drying for removing moisture by rotating the container in a container, spin drying for drying using centrifugal force, and the like.
These methods may be used alone or in combination of two or more.

  The water content of the obtained methacrylic resin (α) is preferably 0.01% by mass to 1% by mass, more preferably, considering the handleability, color tone, and the like of the obtained methacrylic resin (α). It is 0.05 mass%-1 mass%, More preferably, it is 0.1 mass%-1 mass%, More preferably, it is 0.27 mass%-1 mass%. The water content of the resulting methacrylic resin (α) can be measured using the Karl Fischer method.

When the methacrylic resin (α) is produced using the suspension polymerization method described above, the resulting methacrylic resin (α) is usually substantially spherical, but some aggregates may be formed.
The said aggregate refers to the residue which remains on a sieve, when the obtained polymer is passed through a 1.68 mm mesh sieve.
When the aggregate remains in the methacrylic resin (α), the color tone of the resulting methacrylic resin (α) tends to decrease.
The amount of aggregates in the methacrylic resin (α) is preferably 1.2% by mass or less, more preferably 1.0% by mass or less.
The agglomerate content was determined by measuring the mass after passing through a 1.68 mm mesh sieve and drying what was left on the sieve in a drying oven at 80 ° C. for 12 hours, and the obtained mass was the total amount of raw materials. It is obtained by dividing by the calculation of the aggregate production (mass%).

The average particle diameter of the methacrylic resin (α) obtained by using the suspension polymerization method described above is 0.1 mm in consideration of the molding processability of the film of the present embodiment and the workability during extrusion during pelletizing. In consideration of the color tone of the film of the present embodiment, it is more preferably 0.1 mm or more and 1 mm or less, further preferably 0.1 mm or more and 0.5 mm or less, and even more preferably 0.1 mm or more. 0.4 mm or less.
The average particle diameter of the methacrylic resin (α) can be measured based on, for example, JIS-Z8801, and sieves (Tokyo Screen JTS-200-45-44 (aperture 500 μm), 34 (aperture 425 μm)). , 35 (aperture 355 μm), 36 (aperture 300 μm), 37 (aperture 250 μm), 38 (aperture 150 μm), 61 (a saucer)), and vibration using a screening tester TSK B-1 It can be measured by measuring the mass of particles remaining on each sieve when sieving with force MAX for 10 minutes and determining the particle diameter when the mass is 50%.

In various polymerization methods for producing the methacrylic resin (α) contained in the film of the present embodiment, that is, in the polymerization step in the bulk polymerization method, the solution polymerization method, the suspension polymerization method, and the emulsion polymerization method, For the purpose of adjusting the degree of polymerization, a polymerization initiator may be used.
The polymerization initiator is not limited to the following when performing radical polymerization, but examples thereof include di-t-butyl peroxide, lauroyl peroxide, stearyl peroxide, benzoyl peroxide, and t-butyl peroxide. Oxyneodecanate, t-butylperoxypivalate, dilauroyl peroxide, dicumyl peroxide, t-butylperoxy-2-ethylhexanoate, 1,1-bis (t-butylperoxy) -3 , 3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, and the like, azobisisobutyronitrile, azobisisovaleronitrile, 1,1-azobis (1- Cyclohexanecarbonitrile), 2,2'-azobis-4-methoxy-2,4-azo Azo-based general radical polymerization initiators such as sisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2′-azobis-2-methylbutyronitrile and the like can be mentioned. .
These may be used alone or in combination of two or more.
A combination of these radical polymerization initiators and an appropriate reducing agent may be used as a redox initiator.
These polymerization initiators are generally used in the range of 0 to 1 part by mass with respect to 100 parts by mass of the total amount of all monomers used, taking into consideration the polymerization temperature and the half-life of the initiator. Can be selected as appropriate.

When a bulk polymerization method, a cast polymerization method, or a suspension polymerization method is selected as the polymerization method for the methacrylic resin (α), lauroyl par peroxide is a peroxide initiator from the viewpoint of preventing the methacrylic resin (α) from being colored. Oxide, decanoyl peroxide, t-butylperoxy-2-ethylhexanoate and the like can be particularly preferably used, and lauroyl peroxide is particularly preferably used.
In addition, in the case of performing solution polymerization or bulk polymerization at a high temperature of 90 ° C. or higher, a peroxide, azobis initiator, etc. having a 10-hour half-life temperature of 80 ° C. or higher and soluble in the organic solvent to be used preferable. Such a polymerization initiator is not limited to the following, and examples thereof include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, cyclohexane peroxide, and 2,5-dimethyl. Examples include -2,5-di (benzoylperoxy) hexane, 1,1-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) isobutyronitrile and the like.
These polymerization initiators are preferably used in the range of 0 to 1 part by mass with respect to 100 parts by mass of the total amount of all monomers used.

In the production process of the methacrylic resin (α) contained in the film of the present embodiment, the molecular weight of the polymer to be produced can be controlled within a range that does not impair the object of the present invention.
For example, the molecular weight can be controlled by using chain transfer agents such as alkyl mercaptans, dimethylacetamide, dimethylformamide, triethylamine; iniferters such as dithiocarbamates, triphenylmethylazobenzene, tetraphenylethane derivatives, etc. Can control the molecular weight by adjusting the addition amount of these chain transfer agents and iniferters.
When these chain transfer agents and iniferters are used, alkyl mercaptans are preferably used from the viewpoint of handleability and stability, and are not limited to the following. For example, n-butyl mercaptan, n-octyl mercaptan , N-dodecyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, 2-ethylhexyl thioglycolate, ethylene glycol dithioglycolate, trimethylolpropane tris (thioglycolate), pentaerythritol tetrakis (thioglycolate) ) And the like.
These can be appropriately added according to the required molecular weight, but generally used in the range of 0.001 to 3 parts by mass with respect to 100 parts by mass of the total amount of all monomers used. .
Other molecular weight control methods include a method of changing the polymerization method, a method of adjusting the amount of the polymerization initiator, and a method of changing the polymerization temperature.
These molecular weight control methods may be used alone or in combination of two or more.

(Additive)
A predetermined additive may be added to the methacrylic resin layer (I) constituting the film of the present embodiment in order to impart various characteristics such as rigidity and dimensional stability.

  Examples of additives include, but are not limited to, various stabilizers such as UV absorbers, heat stabilizers, and light stabilizers; plasticizers (paraffinic process oils, naphthenic process oils, aromatics) Process oil, paraffin, organic polysiloxane, mineral oil), flame retardants (eg, phosphorus compounds such as organic phosphorus compounds, red phosphorus, inorganic phosphates, halogens, silicas, silicones, etc.), flame retardant aids (For example, antimony oxides, metal oxides, metal hydroxides, etc.), curing agents (diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, diethylaminopropylamine, 3,9-bis (3-aminopropyl) ) -2,4,8,10-tetraoxaspiro [5,5] undecane, mensendiamine, isophoro Amines such as diamine, N-aminoethylpiperazine, m-xylenediamine, m-phenylenediamine, diaminophenylmethane, diaminodiphenylsulfone, dicyandiamide, adipic dihydrazide, and phenol resins such as phenol novolac resin and cresol novolac resin , Liquid polymercaptan, polymer sulfide such as polysulfide, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, pyromellitic anhydride, methylcyclohexene Tetracarboxylic anhydride, dodecyl succinic anhydride, trimellitic anhydride, chlorendic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bis Acid anhydrides such as (anhydrotrimate)), curing accelerators (2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2- Heptadecylimidazole, imidazoles such as 2-phenyl-4-methylimidazole, organic phosphines such as triphenylphosphine and tributylphosphine, benzyldimethylamine, 2-dimethylaminomethyl) phenol, 2,4,6-tris (diamino) Tertiary amines such as methyl) phenol and tetramethylhexanediamine, boron salts such as triphenylphosphine tetraphenylborate, tetraphenylphosphonium tetraphenylborate and triethylaminetetraphenylborate, 1,4-benzoyl , 1,4-naphthoquinone, 2,3-dimethyl-1,4-benzoquinone, 2,6-dimethylbenzoquinone, quinoid compounds such as 2,3-dimethoxy-1,4-benzoquinone), antistatic agents (for example, , Polyamide elastomer, quaternary ammonium salt system, pyridine derivative, aliphatic sulfonate, aromatic sulfonate, aromatic sulfonate copolymer, sulfate ester salt, polyhydric alcohol partial ester, alkyldiethanolamine, alkyldiethanolamide , Polyalkylene glycol derivatives, betaines, imidazoline derivatives, etc.), conductivity imparting agents, stress relieving agents, mold release agents (alcohols, esters of alcohols and fatty acids, alcohols and esters of dicarboxylic acids, silicone oils, etc.), Crystallization accelerators, hydrolysis inhibitors, lubricants (eg Higher fatty acids such as stearic acid, behenic acid, zinc stearate, calcium stearate, magnesium stearate, and metal salts thereof, higher fatty acid amides such as ethylene bisstearamide), impact imparting agents, slidability improvers ( Hydrocarbons such as low molecular weight polyethylene, higher alcohols, polyhydric alcohols, polyglycols, polyglycerols, higher fatty acids, higher fatty acid metal salts, fatty acid amides, esters of fatty acids and fatty alcohols, full of fatty acids and polyhydric alcohols Esters or partial esters, full esters or partial esters of fatty acids and polyglycols, silicones, fluororesins, etc.), compatibilizers, nucleating agents, fillers and other reinforcing agents, flow control agents, dyes (nitroso dyes, nitro dyes) , Azo dye, stilbene azo dye, ketoimine dye, trifer Nylmethane dye, xanthene dye, acridine dye, quinoline dye, methine / polymethine dye, thiazole dye, indamine / indophenol dye, azine dye, oxazine dye, thiazine dye, sulfur dye, aminoketone / oxyketone dye, anthraquinone dye, indigoid dye, phthalocyanine Dyes such as dyes), sensitizers, colorants (titanium oxide, carbon black, titanium yellow, iron oxide pigments, ultramarine, cobalt blue, chromium oxide, spinel green, lead chromate pigments, cadmium pigments, etc. Pigments, azo lake pigments, benzimidazolone pigments, diarylide pigments, azo pigments such as condensed azo pigments, phthalocyanine pigments such as phthalicyanine blue and phthalocyanine green, isoindolinone pigments, quinophthalone pigments, quinacrid Pigments, perylene pigments, anthraquinone pigments, perinone pigments, organic pigments such as condensed polycyclic pigments such as dioxazine violet, flake-like aluminum metallic pigments, spherical shapes used to improve weld appearance Aluminum pigments, mica powders for pearl-like metallic pigments, other metallic pigments such as glass coated inorganic polyhedral particles such as metal plating or sputtering), thickeners, anti-settling agents, anti-sagging agents, fillers (Fibrous reinforcing agents such as glass fiber and carbon fiber, as well as glass beads, calcium carbonate, talc, clay, etc.), antifoaming agents (silicone-based antifoaming agents, surfactants, polyethers, higher alcohols, etc.) Defoaming agents), coupling agents, light diffusing fine particles, rust preventives, antibacterial / antifungal agents, antifouling agents, conductive polymers, rubbery polymers It is below.

Examples of the light diffusing fine particles include, but are not limited to, inorganic fine particles such as alumina, titanium oxide, calcium carbonate, barium sulfate, silicon dioxide, and glass beads, styrene crosslinked beads, MS crosslinked beads, and siloxane. Organic fine particles such as system cross-linked beads.
Further, hollow cross-linked fine particles made of highly transparent resin materials such as acrylic resin, polycarbonate resin, MS resin, and cyclic olefin resin, hollow fine particles made of glass, and the like can be used as the light diffusing fine particles.
As the inorganic fine particles, alumina, titanium oxide, and the like are more preferable from the viewpoints of diffusibility and availability.
Further, the light diffusing fine particles may be used alone or in combination of two or more.
Here, the refractive index of the light diffusing fine particles is preferably 1.3 to 3.0, more preferably 1.3 to 2.5, and still more preferably 1.3 to 2.0.
When the refractive index is 1.3 or more, a practically sufficient scattering property is obtained, and when it is 3.0 or less, when the film of this embodiment is used for a member in the vicinity of the lamp, Scattering can be suppressed and the occurrence of uneven brightness and unevenness of the emitted light color tone can be effectively prevented.
The refractive index is a value at a temperature of 20 ° C. based on the D line (589 nm).
As a method for measuring the refractive index of the light diffusing fine particles, for example, immersing the light diffusing fine particles in a liquid whose refractive index can be changed little by little, and observing the interface of the light diffusing fine particles while changing the refractive index of the liquid. In addition, there is a method of measuring the refractive index of the liquid when the light diffusing fine particle interface becomes unclear. An Abbe refractometer or the like can be used to measure the refractive index of the liquid.

The average particle diameter of the light diffusing fine particles is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm, still more preferably 0.3 to 10 μm, and still more preferably 0.4 to 5 μm. .
An average particle diameter of 20 μm or less is preferable because light loss due to back reflection or the like is suppressed and incident light can be efficiently diffused to the light emitting surface side. In addition, it is preferable that the average particle diameter is 0.1 μm or more because emitted light can be diffused and desired surface emission luminance and diffusibility can be obtained.

  Further, the content of the light diffusing fine particles in the film of the present embodiment is 0.0001 to 0 with respect to 100 parts by mass of the methacrylic resin (α) from the viewpoint of the expression of the light diffusing effect and the uniformity of surface emission. 0.03 parts by mass is preferable, and 0.0001 to 0.01 parts by mass is more preferable.

  Examples of the heat stabilizer include, but are not limited to, hindered phenolic antioxidants and phosphorus antioxidants. From the viewpoint of imparting thermal stability to methacrylic resins, A hindered phenolic antioxidant is preferred.

  The content of the heat stabilizer is not limited as long as the effect of improving the heat stability is obtained. If the content is excessive, problems such as bleeding out during processing may occur. The amount is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, still more preferably 1 part by mass or less, still more preferably 0.8 parts by mass or less, and still more preferably 100 parts by mass or less based on the resin (α). Preferably they are 0.01 mass part or more and 0.8 mass part or less, Especially preferably, they are 0.01 mass part or more and less than 0.5 mass part.

Examples of the heat stabilizer include, but are not limited to, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], thiodiethylenebis [3- ( 3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 3,3 ′, 3 ″, 5 , 5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -O-cresol, 4,6-bis (dodecylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], hex Methylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3 , 5-Triazine-2,4,6 (1H, 3H, 5H) -trione, 1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylin) methyl] -1, 3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3,5-triazine 2-ylamine) phenol, acrylic acid 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl, acrylic acid 2-tert- Butyl-4-methyl-6- (2-hydroxy-3-tert-butyl) (Lu-5-methylbenzyl) phenyl and the like.
In particular, pentaerythritol terakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, Acrylic acid 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl is preferred.

The hindered phenolic antioxidant as the heat stabilizer may be a commercially available phenolic antioxidant, and such a commercially available phenolic antioxidant is limited to the following. However, for example, Irganox 1010 (Irganox 1010: pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], manufactured by Ciba Specialty Chemicals), Irganox 1076 (Irganox 1076: octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, manufactured by Ciba Specialty Chemicals), Irganox 1330 (Irganox 1330: 3, 3 ′, 3 ″ 5,5 ′, 5 ″ -hexa-t-butyl-a, a ′, a ″- (Mesitylene-2,4,6-triyl) tri-p-cresol, manufactured by Ciba Specialty Chemicals), Irganox 3114 (Irganox 3114: 1,3,5-tris (3,5-di-t-butyl) -4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, manufactured by Ciba Specialty Chemicals), Irganox 3125 (Irganox 3125, Ciba Specialty) Chemicals), Sumilizer BHT (Sumilizer BHT, manufactured by Sumitomo Chemical), Cyanox 1790 (Cyanox 1790, manufactured by Cytec), Sumilizer GA-80 (Sumilizer GA-80, manufactured by Sumitomo Chemical), Sumilizer GS (Sumilizer GS: Acrylic acid 2 -[1- (2 -Hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl, manufactured by Sumitomo Chemical Co., Ltd., Sumilizer GM (2-tert-butyl-4-methyl acrylate) -6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl, manufactured by Sumitomo Chemical Co., Ltd.), vitamin E (manufactured by Eisai) and the like.
Among these commercially available phenolic antioxidants, Irganox 1010, Irganox 1076, Sumilizer GS, and the like are preferable from the viewpoint of imparting thermal stability with the resin. These may be used alone or in combination of two or more.

The phosphorus-based antioxidant as the heat stabilizer is not limited to the following, and examples thereof include tris (2,4-di-t-butylphenyl) phosphite and bis (2,4- Bis (1,1-dimethylethyl) -6-methylphenyl) ethyl ester phosphorous acid, tetrakis (2,4-di-t-butylphenyl) (1,1-biphenyl) -4,4′-diylbisphos Phonite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4 -Dicumylphenyl) pentaerythritol-diphosphite, tetrakis (2,4-t-butylphenyl) (1,1-biphenyl) -4,4'-diylbisphosphonate , Di-t-butyl-m-cresyl-phosphonite, 4- [3-[(2,4,8,10-tetra-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphine Pin) -6-yloxy] propyl] -2-methyl-6-tert-butylphenol and the like.
Furthermore, a commercially available phosphorus antioxidant may be used as the phosphorus antioxidant. Examples of such commercially available phosphorus antioxidants are not limited to the following, but include Irgaphos 168 ( Irgafos 168: Tris (2,4-di-t-butylphenyl) phosphite, manufactured by Ciba Specialty Chemicals, Irgafos 12 (Irgafos 12: Tris [2-[[2,4,8,10-tetra- t-butyldibenzo [d, f] [1,3,2] dioxaphosphine-6-yl] oxy] ethyl] amine, manufactured by Ciba Specialty Chemicals, Irgafos 38 (Irgafos 38: Bis (2 , 4-Bis (1,1-dimethylethyl) -6-methylphenyl) ethyl ester phosphorous acid, manufactured by Ciba Specialty Chemicals) , ADK STAB 329K (ADK STAB-229K, manufactured by Asahi Denka), ADK STAB PEP36 (ADK STAB PEP36, manufactured by Asahi Denka), ADK STAB PEP-8 (ADK STAB PEP-8, manufactured by Asahi Denka), Sandstab P-EPQ (manufactured by Clariant) , Weston 618 (Weston 618, manufactured by GE), Weston 619G (Weston 619G, manufactured by GE), Ultranox 626 (Ultranox 626, manufactured by GE), Sumilyzer GP (Sumilizer GP: 4- [3-[(2, 4, 8 , 10-tetra-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphepine) -6-yloxy] propyl] -2-methyl-6-tert-butylphenol (manufactured by Sumitomo Chemical) Is mentioned.
These phosphorus antioxidants may be used alone or in combination of two or more.

Moreover, in the film of this embodiment, since the methacrylic resin (α) contains the structural unit (B) having a ring structure in the main chain without using the heat stabilizer described above, the film is good. Although thermal stability can be obtained, when trying to obtain better thermal stability, when the blending ratio of the thermal stabilizer to 100 parts by mass of the methacrylic resin (α) is (Y) parts by mass, The blending ratio (Y) of the methacrylic acid ester monomer unit, the structural unit (B) having a ring structure in the main chain, and the heat stabilizer preferably satisfies the following formula (i).
(Y) ≧ 0.053 × [content of methacrylic acid ester monomer unit / content of structural unit (B) having a ring structure in the main chain] −0.4 (i)

As described above, the methacrylic resin (α) used as the material of the methacrylic resin layer (I) constituting the film of the present embodiment includes the structural unit (B) having a ring structure in the main chain.
By containing the structural unit (B) having a ring structure in the main chain, the thermal decomposition of the methacrylic resin (α) is suppressed when the methacrylic resin (α) is exposed to high temperature conditions such as molding. Thus, the effect of reducing the amount of volatile components generated can be obtained.
That is, by increasing the content of the structural unit (B) having a ring structure in the main chain with respect to the methacrylic ester monomer unit (A) contained in the methacrylic resin (α), The amount of heat stabilizer added can be reduced.
On the other hand, when the proportion of the methacrylic acid ester monomer unit (A) is large with respect to the content of the structural unit (B) having a ring structure in the main chain, the thermal decomposition of the methacrylic resin (α) proceeds. Therefore, it is necessary to increase the amount of heat stabilizer added to compensate for this.
Specifically, using methyl methacrylate (MMA) and maleimide structural unit (MI) shown in the examples described later, MMA / MI: (methacrylic ester monomer unit (A) content / (B) As a result of studying the relationship between the amount of the thermal stabilizer necessary for obtaining practically excellent thermal stability, the above formula (i) is derived, and the above formula (i It has been found that by applying a methacrylic resin and a heat stabilizer amount satisfying the above conditions, particularly excellent thermal stability can be obtained in practical use.
At this time, “practically excellent thermal stability” means that the methacrylic resin decomposes when held at 270 ° C. for 30 minutes, as described in the examples described later, thereby reducing the mass. It means that the amount is 5% or less.
If a thermal stabilizer is contained so as to satisfy the above formula (i), a practically excellent thermal stability can be obtained, and excessive blending of the thermal stabilizer can be suppressed.

From the viewpoint of obtaining high thermal stability, (Y) ≧ 0.053 × [content of methacrylic acid ester monomer unit / content of structural unit (B) having a ring structure in the main chain] −0 .35, and more preferably (Y) ≧ 0.053 × [content of methacrylate ester monomer unit / content of structural unit (B) having a ring structure in the main chain] −0.3 Even more preferably, (Y) ≧ 0.053 × [content of methacrylic acid ester monomer unit / content of structural unit (B) having a ring structure in the main chain] −0.25.
If it is the said range, the high thermal stability suitable as a film can be hold | maintained.

  In addition, in said formula (i), "content of a methacrylic ester monomer unit" means methacrylic resin which comprises methacrylic resin layer (I) of the film of this embodiment is methacrylic resin ((alpha)). Is only equal to the content of the methacrylic acid ester monomer (A). On the other hand, when an acrylic resin is contained as the additive, the methacrylic acid ester monomer contained in the acrylic resin is also included in the “content of methacrylic acid ester monomer unit”.

Examples of the ultraviolet absorber include, but are not limited to, for example, benzotriazole compounds, benzotriazine compounds, benzoate compounds, benzophenone compounds, oxybenzophenone compounds, phenol compounds, oxazole compounds, Examples include malonic acid ester compounds, cyanoacrylate compounds, lactone compounds, salicylic acid ester compounds, and benzoxazinone compounds.
In particular, from the viewpoint of compatibility with the resin, benzotriazole compounds and benzotriazine compounds are preferable. These may be used alone or in combination of two or more.
The ultraviolet absorber preferably has a vapor pressure (P) at 20 ° C. of 1.0 × 10 ⁻⁴ Pa or less from the viewpoint of ensuring good moldability of the film of the present embodiment, and 1.0 × It is more preferably 10 ⁻⁶ Pa or less, and further preferably 1.0 × 10 ⁻⁸ Pa or less.
Here, good moldability means that, for example, when a film is formed, there is little adhesion of a low molecular compound to a roll. When it adheres to the roll, it re-adheres to the surface, which causes the appearance to deteriorate and the optical properties to deteriorate, so satisfy the above vapor pressure (P) value and obtain good moldability. Is preferred.

Further, the melting point (Tm) of the ultraviolet absorber is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, further preferably 130 ° C. or higher, and more preferably 160 ° C. or higher. More preferred.
The ultraviolet absorber preferably has a weight reduction rate of 50% or less, more preferably 30% or less, and more preferably 15% or less when the temperature is increased from 23 ° C. to 260 ° C. at a rate of 20 ° C./min. Is more preferably 10% or less, still more preferably 5% or less.
The blending amount of the ultraviolet absorber is not limited to heat resistance, moist heat resistance, thermal stability, and molding processability, as long as it is an amount that exhibits the effects of the present invention. Since problems such as bleeding out during processing may occur, it is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and still more preferably 100 parts by mass of the methacrylic resin (α). 1 part by mass or less, more preferably 0.8 part by mass or less, still more preferably 0.01 part by mass or more and 0.8 part by mass or less.

(Simple adhesive layer (II))
The film of this embodiment has a simple adhesive layer (II) in addition to the methacrylic resin layer (I) described above.

The simple adhesive layer (II) preferably contains an aqueous polyurethane (X), and can be formed by applying the aqueous polyurethane to the methacrylic resin layer (I) described above.
By using the aqueous polyurethane, it is possible to suppress the deterioration of the base material at the time of coating due to the solvent, which has occurred when a conventionally used solvent-based resin is used.

The aqueous polyurethane (X) can be produced by a known method.
For example, the following methods (1) to (3),
Method (1): After synthesizing a urethane compound obtained by reacting a compound having an acidic ion salt-forming group and two or more hydroxyl groups in the molecule with a polyol compound and a polyisocyanate compound, a basic neutralizing agent and water are added. A method of dissolving or dispersing, and chain extending as necessary,
Method (2): After synthesizing a urethane compound obtained by reacting a polyol compound and a polyisocyanate compound with a basic ionic salt-forming group and a compound having two or more hydroxyl groups in the molecule, an acidic neutralizer and water are added and dissolved. Or a method of dispersing and chain extending as necessary,
Method (3): A method of forcibly emulsifying an emulsifier and water after synthesizing a urethane compound obtained by reacting a polyol compound and a polyisocyanate compound,
Etc.
From the viewpoint of good stability in an aqueous solution, the method (1) is preferred.
In addition, as an aqueous polyurethane (X), the compound which has an ester bond and / or a carbonate bond is preferable including the specific compound shown below from a viewpoint that adhesiveness with a base material is excellent.

The compound having an acidic or basic ionic salt-forming group and two or more hydroxyl groups in the molecule is not limited to the following, but examples include glycolic acid, malic acid, glycine, alanine, and 2,2. Hydroxy acids such as' -bis (hydroxymethyl) alkanoic acid; aminocarboxylic acids, polyhydric hydroxy acids, aminosulfonic acids such as taurine, sulfamic acid, and 2-hydroxyethanesulfonic acid; acidic groups such as hydroxysulfonic acid and 2 Examples thereof include compounds having two or more hydroxyl groups, and compounds having a basic group such as a secondary amino group or a tertiary amino group and two or more hydroxyl groups.
Among these, 2,2′-bis (hydroxymethyl) alkanoic acid is preferable.

  Examples of 2,2′-bis (hydroxymethyl) alkanoic acid include, but are not limited to, for example, 2,2′-bis (hydroxymethyl) propionic acid (hereinafter referred to as DMPA), and 2,2 Examples include '-bis (hydroxymethyl) butanoic acid (hereinafter referred to as DMBA).

When 2,2′-bis (hydroxymethyl) alkanoic acid is used, the amount of carboxyl group incorporated in the urethane compound obtained by reacting 2,2′-bis (hydroxymethyl) alkanoic acid with a polyol compound and a polyisocyanate compound Is about 500 to 4000 in terms of the number average molecular weight of the urethane compound relative to one carboxyl group.
When the number average molecular weight of the urethane compound is 500 or more, the coating film properties of the obtained simple adhesive layer are further improved.
Moreover, the stability in the aqueous solution of water-based polyurethane improves more because the number average molecular weight of urethane compound becomes 4000 or less.

Examples of the polyisocyanate compound include, but are not limited to, 4,4′-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, p- or m. -Aromatic diisocyanates such as phenylene diisocyanate; cycloaliphatic diisocyanates such as isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexylene diisocyanate, hydrogenated tolylene diisocyanate; aliphatic such as hexamethylene diisocyanate Diisocyanate ;, xylylene diisocyanate, m-tetramethylxylylene diisocyanate and the like.
A polyisocyanate compound may be used individually by 1 type, and may use 2 or more types.
Moreover, you may use together the polyfunctional isocyanate compound etc. which are the reaction material with polyfunctional polyols, such as a multimer of the said polyisocyanate compound, or a trimethylol propane, as needed.

  Among the polyisocyanate compounds, aliphatic isocyanates and alicyclic isocyanates are preferable, and alicyclic isocyanates are more preferable from the viewpoint of excellent adhesion to the substrate.

The polyol compound is not particularly limited as long as it has two or more hydroxyl groups in one molecule. For example, polyether polyol, polyester polyol, polycarbonate polyol, polybutadiene polyol, hydrogenated polybutadiene polyol and the like are preferable. .
Examples of the polyether polyol include, but are not limited to, polyethylene glycol, polypropylene glycol, poly (ethylene / propylene) glycol, polytetramethylene ether glycol, and the like.
Among these, polyester polyol and polycarbonate polyol are preferable from the viewpoint of excellent adhesion to the substrate.
As the polyester polyol, a compound obtained by polycondensation of a low molecular weight diol and a dibasic acid, a compound obtained by a ring opening reaction of a dibasic acid using a low molecular weight diol as an initiator, and the like are preferable.
Examples of the low molecular weight diol include, but are not limited to, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1 , 6-hexanediol, neopentyl glycol and the like.
Examples of the dibasic acid that can be used for the polycondensation include, but are not limited to, adipic acid, azelaic acid, sebacic acid, isophthalic acid, and terephthalic acid.
Examples of the dibasic acid that can be used in the ring-opening reaction include, but are not limited to, poly ε-caprolactone and poly β-methyl-δ-valerolactone.
Examples of the polycarbonate polyol include, but are not limited to, 1,6-hexanediol polycarbonate polyol, 3-methyl-1,5-pentanediol polycarbonate polyol, and mixed diol polycarbonate having 4 to 6 carbon atoms. A polyol etc. are mentioned.
Examples of the polybutadiene polyol include, but are not limited to, polyols synthesized based on 1,4-polybutadiene and 1,2-polybutadiene.
Examples of the hydrogenated polybutadiene polyol include compounds having a paraffin skeleton obtained by hydrogenating polybutadiene polyol.
A polyol compound may be used individually by 1 type, and may use 2 or more types together.

The polyol compound is more preferably amorphous or liquid from the viewpoint of ease of handling.
Furthermore, short-chain diols such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, or trimethylol A short-chain triol such as propane or glycerin or a trifunctional polyol obtained by adding propylene oxide, ethylene oxide, ε-caprolactone or the like to these can be used in combination.

  The number average molecular weight of the polyol is preferably 500 to 10,000, and more preferably 500 to 4,000.

As the chain extender, a compound having two or more active hydrogen atoms can be used.
Examples of the chain extender include, but are not limited to, ethylenediamine, 1,2-propanediamine, tetramethylenediamine, hexamethylenediamine, 1,4-cyclohexylenediamine, isophoronediamine, 4,4 ′. -Dicyclohexylmethanediamine, m-xylylenediamine, diamines such as phenylenediamine; polyethylene polyamines such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; hydrazine, piperazine, hydrazine, and dihydrazide compounds.
Moreover, the short chain diol, the short chain triol, the trifunctional polyol etc. which were already illustrated can be used.
Further, a chain extender and a monoamine may be used in combination, and examples of the monoamine include monoethanolamine, diethanolamine, aminoethylaminoethanol and the like.
A chain extender may be used individually by 1 type, and may use 2 or more types together.

  When the synthesis of the aqueous polyurethane (X) is carried out by the method (1) or the method (2), it is preferable to carry out a urethane compound synthesis step, a neutralization step, a water dispersion step, and, if necessary, a chain extension step. However, the other steps can be performed in any order except that the step of synthesizing the urethane compound is performed first.

A process for synthesizing the urethane compound will be described.
For example, 2,2′-bis (hydroxymethyl) alkanoic acid, a polyisocyanate compound, a polyol compound, and, if necessary, a short-chain diol is reacted to produce a urethane compound having an isocyanato group at the terminal.

The said reaction temperature is about 20-120 degreeC normally, 40-100 degreeC is preferable and 50-95 degreeC is more preferable.
By reacting at 20 to 120 ° C., it becomes easy to prevent reaction rate and runaway of the reaction.
The reaction time is usually about 1 to 40 hours.

  In the synthesis of the urethane compound, the isocyanate group of the polyisocyanate compound and the hydroxyl group of the polyol compound have an equivalent ratio (isocyanato group: hydroxyl group) of 1.1: 1 to 30: 1, preferably 1.1: 1 to 15: 1. Is more preferable.

An organic solvent can be used in the synthesis of the urethane compound.
As the organic solvent, it is preferable to use a compound having a boiling point of 50 to 120 ° C. so that it can be easily removed after making the urethane compound aqueous. Although not limited to the following, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrafuran, 1,4-dioxane, ethyl acetate, toluene and the like can be mentioned.

  The synthesis of the urethane compound may be catalyst-free, but for the purpose of promoting the reaction, for example, organometallic catalysts such as dibutyltin dilaurate, dibutyltin dioctoate, stannous octoate, triethylenediamine, toluethylamine, tributylamine, etc. A tertiary amine catalyst may be used.

Next, a neutralization process, a water dispersion process, and a chain extension process will be described.
After producing the urethane compound, neutralize the ionic salt forming group in the urethane compound chain by adding a basic compound or acidic compound, and dissolve or disperse it in water. If necessary, extend the urethane compound with a chain extender. By doing so, an aqueous polyurethane (X) can be obtained.
In addition, after the urethane compound is produced, the chain is subsequently extended with a chain extender or a polyisocyanate compound, a basic or acidic compound is added to neutralize the ionic salt forming group in the urethane compound chain, and it is dissolved or dispersed in water. May be.

Examples of the basic compound include, but are not limited to, tertiary amines such as trimethylamine, triethylamine, methyldiethylamine, and tripropylamine; alkanols such as dimethylethanolamine, methyldiethanolamine, and triethanolamine Amines; alkali metal hydroxides such as ammonia, sodium, and potassium; and the alkali metal carbonates.
Of these, tertiary amines and alkanolamines are preferred.

  Examples of the acidic compound include inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid; organic acids such as acetic acid, formic acid, benzoic acid, paratoluenesulfonic acid, lactic acid, fatty acid, citric acid, oxalic acid, acrylic acid, and methacrylic acid. Is mentioned.

  A basic compound or an acidic compound can use 0.5-1.2 equivalent normally with respect to 1 equivalent of ion forming groups of a urethane compound.

A water dispersion process can be implemented using a well-known stirrer.
Examples of the stirrer include, but are not limited to, a stirrer having a stirring blade such as an anchor type, a paddle type, and a turbine type.
Moreover, when disperse | distributing a urethane compound more finely, a homodisper, a homogenizer, a line mixer, etc. can be used.

The aqueous polyurethane (X) may further have a functional group such as an ethylenically unsaturated double bond, triple bond, crosslinkable keto group, hydrazino group, polyalkoxysilano group, glycidyl group, and carbodiimide group. Good.
Examples of the method of introducing the functional group into the aqueous polyurethane (X) include a method of reacting an active hydrogen capable of reacting with an isocyanato group and a compound having the functional group with a urethane compound, a polyisocyanate compound having the functional group, Method using polyol compound having two or more hydroxyl groups in molecule, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and tris (2-hydroxyethyl) ) A method of reacting with an oxidative polymerizable compound such as isocyanuric (meth) acrylate.

The simple adhesive layer (II) may be formed of a mixture containing an aqueous polyurethane (X) and a crosslinking agent.
As a crosslinking agent, the compound which has multiple functional groups which can react with the functional group (for example, carboxyl group, amino group, hydroxyl group) which a polyurethane resin has can be used.
Examples of the functional group that reacts with a carboxyl group include a compound having an epoxy group, a carbodiimide group, an oxazoline group, an aziridine group, and the functional group that reacts with an amino group or a hydroxyl group. Examples thereof include compounds having an epoxy group, an isocyanate group, and the like.

Examples of the crosslinking agent include carbozimide crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, metal ions, isocyanate crosslinking agents, hydrazide crosslinking agents such as adipic acid dihydrazide, and the like.
Among these, from the viewpoint of curability and safety, an isocyanate crosslinking agent, an epoxy crosslinking agent, an oxazoline crosslinking agent, a carbodiimide crosslinking agent, and a hydrazide crosslinking agent are preferable, and an isocyanate crosslinking agent is more preferable.
A crosslinking agent may be used individually by 1 type, and may use 2 or more types together.

  The crosslinking agent is usually preferably from 0.01 to 3 equivalents, more preferably from 0.1 to 2 equivalents, based on the reactive functional group of the aqueous polyurethane (X). In addition, the stirrer already demonstrated can be used for mixing of a crosslinking agent.

The simple adhesive layer (II) may further contain a stabilizer.
Examples of the stabilizer include, but are not limited to, polymerization inhibitors such as benzoquinone, hydroquinone, hydroquinone monomethyl ether, and phenol, and chelating agents such as organic chelating agents and polymer chelating agents.

  The simple adhesive layer (II) is a plasticizer, pigment, dye, leveling agent, thickener, antifoaming agent, light stabilizer, flame retardant, yellowing inhibitor, film-forming aid, You may mix | blend well-known additives, such as an organic solvent.

[Method for producing film]
As described above, the film of the present embodiment has a methacrylic resin layer (I) and a simple adhesive layer (II).
The film of this embodiment can be manufactured by laminating the simple adhesive layer (II) on the methacrylic resin layer (I).
The methacrylic resin layer (I) contains a methacrylic resin (α) and various additives and other resins as required.

In order to produce the methacrylic resin layer (I), first, predetermined materials are mixed to produce a methacrylic resin composition, which is molded using the methacrylic resin composition.
Examples of the method for producing a methacrylic resin composition include a method of kneading using a kneader such as an extruder, a heating roll, a kneader, a roller mixer, and a Banbury mixer.
Among these, kneading with an extruder is preferable in terms of productivity.
The kneading temperature may be in accordance with the preferred processing temperature of the polymer constituting the methacrylic resin and other resins to be mixed, and is generally in the range of 140 to 300 ° C, preferably in the range of 180 to 280 ° C.

As a method for producing the methacrylic resin layer (I), a known method such as injection molding, sheet molding, blow molding, injection blow molding, inflation molding, T-die molding, press molding, extrusion molding, foam molding or the like is applied. Secondary processing molding methods such as compressed air molding and vacuum molding can also be used.
A method of kneading and producing a methacrylic resin composition using a kneader such as a heating roll, kneader, Banbury mixer, extruder, etc., cooling, pulverizing, and molding by transfer molding, injection molding, compression molding, etc. Can also be cited as an example.
After the above molding, the film to be the methacrylic resin layer (I) may be longitudinally uniaxially stretched in the mechanical flow direction and transversely uniaxially stretched in the direction orthogonal to the mechanical flow direction, or roll stretching and tenter stretching may be performed sequentially. A biaxially stretched film may be produced by stretching by a biaxial stretching method, a simultaneous biaxial stretching method by tenter stretching, a biaxial stretching method by tubular stretching, or the like. By stretching, the strength of the film can be improved. The final draw ratio can be determined from the heat shrinkage rate of the obtained molded body.
The draw ratio is preferably 0.1% or more and less than 300% in at least one direction, more preferably 0.2% or more and 300% or less, and 0.3% or more and 300% or less. Further preferred.
By designing in this range, a stretched molded article that is preferable in terms of birefringence, heat resistance, and strength can be obtained.
The film to be the methacrylic resin layer (I) can be stretched continuously by extrusion molding and cast molding.
In addition, when using the film of this embodiment as an optical film, in order to stabilize the optical isotropy and mechanical characteristic, it is preferable to perform heat processing (annealing) etc. after an extending | stretching process.
The conditions for the heat treatment may be appropriately selected similarly to the conditions for the heat treatment performed on a conventionally known stretched film, and are not particularly limited.

The material for forming the simple adhesive layer (II) so that the simple adhesive layer (II) constituting the film of the present embodiment has a predetermined thickness on the predetermined film corresponding to the methacrylic resin layer (I). It can form by apply | coating and performing a drying process.
As a coating method, a known coating method can be applied.
For example, it can be applied using a gravure roll method, a spray method, a roll coater method, etc., but the gravure roll method is suitable for adjusting the coating thickness.
Moreover, it is preferable to implement the drying process after application | coating on the conditions for 1 to 150 second at 50-150 degreeC.
In addition, the film corresponding to the methacrylic resin layer (I) before coating is subjected to physical treatment or chemical treatment such as corona treatment in advance in order to improve the adhesion with the simple adhesive layer (II). Also good.
The thickness of the simple adhesive layer (II) is preferably 0.1 to 20 μm, and more preferably 0.15 to 10 μm. When the thickness of the simple adhesive layer is 0.1 μm or more, the adhesion to the film is further improved. By setting the thickness to 20 μm or less, the coating film can be sufficiently dried and cannot be pulled out after winding. Generation | occurrence | production of a malfunction (blocking) can be suppressed.

[Characteristics of film]
(Film thickness)
The film thickness of the film of the present embodiment is preferably 0.002 mm or more and 1 mm or less, more preferably 0.01 mm or more and 1 mm or less, more preferably, in consideration of optical characteristics, strength, and handleability. It is 0.01 mm or more and 0.5 mm or less, still more preferably 0.01 mm or more and 0.3 mm or less, still more preferably 0.02 mm or more and 0.2 mm or less, and particularly preferably 0.02 mm or more and 0.1 mm or less.
When the film thickness is 0.002 mm or more, a practically sufficient strength is obtained, and when the film thickness is 1 mm or less, a practically sufficient thickness as a film can be secured, and good optical characteristics are obtained. .

(Physical properties)
The film of this embodiment may be exposed to high-temperature and high-humidity conditions in optical film applications, decorative film applications, and the like, and excellent moisture and heat resistance is required.
In addition, thinning is required due to the demand for weight reduction, and accordingly, higher thermal stability and moldability are required.

(Heat-resistant)
As a heat resistance index, VICAT softening temperature can be used.
The VICAT softening temperature of the molded body containing the methacrylic resin (α) forming the film of the present embodiment is preferably 110 ° C. or higher from the viewpoint of suppressing problems such as distortion during actual use. More preferably, it is 112 degreeC or more, More preferably, it is 113 degreeC or more, More preferably, it is 115 degreeC or more, More preferably, it is 117 degreeC or more, Most preferably, it is 120 degreeC or more.
The VICAT softening temperature can be measured according to ISO 306 B50.

(transparency)
The total light transmittance can be used as an index of transparency.
The total light transmittance in the film of the present embodiment may be appropriately optimized depending on the application, but when used in applications where transparency is required, the total light transmittance at a thickness of 200 μm is used from the viewpoint of visibility. Is preferably 70% or more. More preferably, it is 75% or more, More preferably, it is 80% or more.
Although it is preferable that the total light transmittance is high, practically sufficient visibility can be secured even at 94% or less.

(Moisture and heat resistance)
As an index of heat and moisture resistance, evaluation of the state of occurrence of defective shape under high temperature and high humidity conditions can be used.
When using the film of this embodiment, it may be put on hot and humid conditions.
When the film of this embodiment is left as it is for about 500 hours at a set temperature of 70 ° C. and a set humidity of 95% using a film having a thickness of about 0.2 mm as an evaluation of moisture and heat resistance, defects such as warping and distortion are found. Preferably it does not occur.

(Scratch resistance)
Pencil hardness can be used as an index of scratch resistance.
The film of this embodiment preferably has a pencil hardness of HB or higher as the surface hardness in order to prevent scratching of the surface during handling. More preferably, it is F or more, more preferably H or more.

(Molding processability)
As an index of moldability, fluidity and the presence or absence of bubbles can be used as indices.
The film of the present embodiment is required to be thin in order to reduce the weight, but in order to reduce the thickness, it is effective to increase the molding temperature and improve the fluidity. On the other hand, if the molding temperature is raised, bubbles may be generated in the film due to decomposition of the resin or the like.
Even in the case where the film of this embodiment is molded by raising the molding temperature in order to eliminate molding distortion or to obtain a thin film, it is preferable that defects such as silver do not occur.
Specifically, it is preferable that molding defects such as bubble generation are hardly observed when a film having a barrel temperature of 280 ° C. and a thickness of about 80 μm is molded.

(Thermal stability)
As a thermal stability index, a weight reduction ratio when held at a predetermined temperature for a predetermined time and a thermal decomposition start temperature can be used.
When manufacturing the film of this embodiment, resin may remain in a molten state in a molding machine. At that time, since the resin stays at a high temperature for a long time, the resin material is required to be hardly thermally decomposed.

  Specifically, in TGA (Thermogravimetric Analysis), the weight loss rate when held at about 270 ° C. for 30 minutes is preferably 5% or less, more preferably 3% or less, still more preferably 1% or less, More preferably, it is 0.5% or less.

When it is necessary to make the film of this embodiment thin, it is necessary to perform molding at a high temperature, and high thermal stability is required.
From this viewpoint, the thermal decomposition starting temperature of the methacrylic resin or methacrylic resin composition is preferably 300 ° C. or higher. More preferably, it is 310 degreeC or more, More preferably, it is 320 degreeC or more, More preferably, it is 325 degreeC or more, More preferably, it is 330 degreeC or more.

As described above, in order to prevent thermal decomposition and have practically excellent thermal stability in the molding process of the film of this embodiment, specifically, the methacrylic resin layer (I), In the methacrylic resin (α) contained in the film of the embodiment, the proportion of the structural unit (B) having a ring structure in the main chain is increased, and the methacrylic ester monomer unit (A) is relatively copolymerized. It is effective to reduce the amount to be generated.
However, if the ratio of the component (B) to the methacrylic acid ester monomer unit (A) is too high, characteristics such as molding fluidity and surface hardness required as a film may not be obtained. In consideration of the balance, it is necessary to determine the ratio of the component (A) and the component (B).
Increasing the copolymerization ratio of the structural unit (B) having a ring structure in the main chain is effective in terms of suppressing a decomposition reaction due to depolymerization when exposed to a high temperature. When the ratio with respect to the ester monomer unit (A) is increased, sufficient thermal stability can be imparted even if the amount of the thermal stabilizer is reduced.
On the other hand, if the proportion of the methacrylic ester monomer unit (A) is relatively large, the amount of thermal decomposition in a high temperature environment increases. A heat stabilizer may be added from the viewpoint of suppressing thermal decomposition, but adding too much may cause a decrease in heat resistance and may cause problems such as bleeding out during molding.

In order to obtain the characteristics required as a film, as described above, when the blending ratio of the thermal stabilizer to 100 parts by mass of the methacrylic resin is (Y: parts by mass), thermal decomposition is suppressed and molded at high temperatures. From the viewpoint of the balance between processability and heat resistance, it is preferable that the blending ratio of the methacrylic acid ester monomer unit, the structural unit (B) having a ring structure in the main chain, and the thermal stabilizer satisfies the following formula (i). .
(Y) ≧ 0.053 × [content of methacrylic acid ester monomer unit / content of structural unit (B) having a ring structure in the main chain] −0.4 (i)
More preferably, (Y) ≧ 0.053 × [content of methacrylate ester monomer unit / content of structural unit (B) having a ring structure in the main chain] −0.35, more preferably ( Y) ≧ 0.053 × [content of methacrylate ester monomer unit / content of structural unit (B) having a ring structure in the main chain] −0.3, and even more preferably (Y) ≧ 0.053 × [content of methacrylic acid ester monomer unit / content of structural unit (B) having a ring structure in the main chain] −0.27, more preferably (Y) ≧ 0.053 X [content of methacrylate ester monomer unit / content of structural unit (B) having a ring structure in the main chain] -0.25.

(Impact resistance)
As an index of impact resistance, Charpy impact strength can be used.
The film of this embodiment may be required to have high impact strength.
Specifically, the Charpy impact strength (without notch) measured in accordance with the IOS 179 / 1eU standard is preferably 15 kJ / m ² or more. More preferably 15 kJ / m ² or more 20 kJ / m less than ^2, more preferably 20 kJ / m ² or more 25 kJ / m less than ^2, particularly preferably 25 kJ / m ² or more.

[Use]
The film of this embodiment is, for example, a polarizing plate protective film, a quarter-wave plate, a half-wave plate, etc. used for a display such as a liquid crystal display, a plasma display, an organic EL display, a field emission display, and a rear projection television. It can be suitably used for liquid crystal optical compensation films such as retardation plates and viewing angle control films, display front plates, display substrates, transparent substrates such as touch panels, and decorative film applications.
The film of the present invention can be subjected to surface functionalization treatment such as antireflection treatment, transparent conductive treatment, electromagnetic wave shielding treatment, and gas barrier treatment.

Hereinafter, the present invention will be described in detail with specific examples and comparative examples, but the present invention is not limited to the following examples.
In addition, the raw material applied to the Example and the comparative example is as follows.

〔material〕
It shows below about the raw material used in the Example and comparative example which are mentioned later.
(A) component:
(A-1): Methyl methacrylate (MMA)
: Asahi Kasei Chemicals Co., Ltd. (2.5 ppm of 2,4-di-6-tert-butylphenol as a polymerization inhibitor, manufactured by Chugai Trading Co., Ltd.) Added)

(B) component:
(B-1): N-phenylmaleimide (NPMI)
: Nippon Catalyst Co., Ltd.

Component (C):
(C-1): Styrene (St)
: Asahi Kasei Chemicals Corporation

(Other ingredients):
n-octylmercaptan (n-OM)
: Arkema Co., Ltd., used as a chain transfer agent Lauroyl peroxide (LPO)
: Nippon Oil & Fats Co., Ltd., used as a polymerization initiator Tricalcium phosphate
: Nihon Kagaku Kogyo Co., Ltd., used as a suspending agent Calcium calbonate
: Shiraishi Kogyo Co., Ltd., used as a suspending agent Sodium lauryl sulfate
: Wako Pure Chemical Industries, Ltd., used as a suspension aid
2,2'-Methylenebis [6- (2H-benzotriazol-2-yl) -4-tert-octylphenol]
: Johoku Chemical Co., Ltd. JF832, used as UV absorber
Octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propanoate: BASF, Irganox 1076, used as an antioxidant

[Manufacture of acrylic film]
An acrylic film corresponding to the methacrylic resin layer (I) was produced as follows.
(Production Example 1)
2 kg of water, 65 g of tricalcium phosphate, 39 g of calcium carbonate, and 0.39 g of sodium lauryl sulfate were charged into a container having a stirrer equipped with four inclined paddle blades to obtain a mixed solution (a).
Next, water (26 kg) was charged into a 60 L reactor having a stirrer equipped with three retreating blades, the temperature was raised to 40 ° C., and the mixture (a) and (A-1) 17.6 kg (B- 1) 4.28 kg, (C-1) 1.9 kg, (LPO) 42 g, (n-OM) 48 g were dissolved in advance, and a raw material of methacrylic resin was added.
Next, the temperature was raised to 75 ° C. at a rate of about 1 ° C./min, suspension polymerization was carried out while maintaining about 75 ° C., and an exothermic peak was observed about 150 minutes after the starting material mixture was charged.
Thereafter, the temperature was raised to about 96 ° C. at a rate of about 1 ° C./min, and then aged for 120 minutes to substantially complete the polymerization reaction.
Next, in order to cool to 50 ° C. and dissolve the suspending agent, 20 mass% sulfuric acid was added.
Next, the polymerization reaction solution is passed through a 1.68 mm mesh sieve to remove aggregates, the water is filtered off, the resulting slurry is dehydrated to obtain a bead polymer, and the obtained bead polymer is After washing with water, it was dehydrated in the same manner as described above, and further washed with ion-exchanged water and repeated dehydration to obtain polymer particles.
The obtained polymer particles and 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4-tert-octylphenol] 1.8% by mass, 3- (3,5-di-tert- Butyl-4-hydroxyphenyl) octadecyl propanoate 1000 mass ppm was melt-kneaded in a twin screw extruder of φ30 mm set at 240 ° C., and the strands were cooled and cut to obtain methacrylic resin pellets. It was confirmed that the extrusion workability at that time was good.
The obtained pellet was applied to a biaxial stretching film forming machine to form a film having a film thickness of 50 μm, and it was confirmed that the film performance was good and suitable for an acrylic film material.

[Production of aqueous polyurethane]
An aqueous polyurethane as a material for the simple adhesive layer (II) was produced as follows.
(Synthesis Example 1)
In a four-necked flask, 3009 parts by mass of Newpol-BPE-20T (2 mol adduct of bisphenol A ethylene oxide, manufactured by Sanyo Chemical Industries), 369 parts by mass of isophthalic acid, 540 parts by mass of dimethyl terephthalate, 82 of phthalic anhydride Part by mass and 0.06 part by mass of tetrabutyl titanate were charged and reacted at 220 ° C. for 24 hours under a nitrogen stream.
After the reaction, the obtained polyetherester polyol was a light yellow solid at room temperature, and had an acid value of 0.05 and a hydroxyl value of 111.6.
Obtained polyether ester polyol: 1000 parts by mass was dehydrated under reduced pressure at 100 ° C., then cooled to 80 ° C., added with 900 parts by mass of methyl ethyl ketone, sufficiently stirred and dissolved, and 2,2′-dimethylolpropion. 80 parts by mass of acid and 5 parts by mass of neopentyl glycol were added, and then 276 parts by mass of hexamethylene diisocyanate was added and reacted at 75 ° C. for 8 hours to obtain a urethane compound having an ester bond.
Next, the mixture was cooled to 50 ° C. and neutralized by adding 61 parts by mass of the basic compound triethylamine, and then 7,000 parts by mass of water was added to make the urethane compound water-soluble.
After removing methyl ethyl ketone from the obtained transparent aqueous polyurethane under reduced pressure at 40 ° C. to 60 ° C., water was added to disperse in water, and the concentration of the nonvolatile content was adjusted to form an ester bond having a nonvolatile content of 20% by mass. An aqueous polyurethane (1) having was obtained.
In addition, an acid value is the value computed by titrating according to the potassium hydroxide method, and a hydroxyl value is a value measured by the method based on JISK1557-1 description.

(Synthesis Example 2)
In a four-necked flask, 272 parts by mass of ETERNACOLL UH-200 (registered trademark; polycarbonate diol manufactured by Ube Industries; number average molecular weight 2000; hydroxyl value 56.1 mgKOH / g), 2,2-dimethylolpropionic acid (DMPA) 18. 5 parts and 176 parts by mass of N-methylpyrrolidone (NMP) were charged under a nitrogen stream.
125 parts by mass of 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI) and 0.3 parts by mass of dibutyltin dilaurate (catalyst) were added and reacted at 90 ° C. for 5 hours to obtain a urethane compound having a carbonate bond.
Subsequently, 13.9 parts by mass of triethylamine as a basic compound was added and mixed, 564 parts by mass was extracted from the neutralized aqueous solution, added to 870 parts of water under strong stirring, and dispersed in water.
Next, 36.5 parts by mass of a 35% by mass 2-methyl-1,5-pentanediamine (MPMD) aqueous solution was added to carry out a chain extension reaction, water was further added to adjust the non-volatile content to 20%, and a carbonate bond was obtained. An aqueous polyurethane (2) was obtained.

  Next, a film was produced using the acrylic film obtained in Production Example 1 and the aqueous polyurethanes (1) and (2) obtained in Synthesis Examples 1 and 2.

[ Reference Example 1]
To the acrylic film obtained in (Production Example 1), the aqueous polyurethane obtained in (Synthesis Example 1) (1)
Was coated using a Mayer bar coater and dried at 80 ° C. for 2 minutes to obtain a film having a simple adhesive layer.
The thickness of the simple adhesive layer was 1 μm.

[Example 2]
Instead of the aqueous polyurethane (1), the aqueous polyurethane (2) obtained in (Synthesis Example 2)
) Was used. Other conditions produced a film having a simple adhesive layer in the same manner as in Reference Example 1.

Example 3
Instead of the aqueous polyurethane (1), the aqueous polyurethane (2) obtained in (Synthesis Example 2)
) Polyisocyanate in 100 parts by mass (Bernock DNW-6000, manufactured by Dainippon Ink)
1 part by mass was added. Other conditions obtained the film which has a simple contact bonding layer by the method similar to the reference example 1. FIG.

[ Reference Example 4]
Instead of the aqueous polyurethane (1), an aqueous polyurethane having an ether bond (Superflex 130 manufactured by Daiichi Kogyo Kagaku) was used. For other conditions, a film having a simple adhesive layer was obtained in the same manner as in Reference Example 1.

[ Reference Example 5]
In place of the aqueous polyurethane (1), polyvinyl alcohol (Kuraray Poval 10)
The 20% aqueous solution of 5) was used. Other conditions obtained the film which has a simple contact bonding layer by the method similar to the reference example 1. FIG.

Next, a polarizing plate was produced using the acrylic film produced in the above [Production Example 1] and the film produced in [ Reference Example 1] , [Examples 2-3] and [Reference Examples 4-5] , Peel strength and heat resistance were evaluated.

〔Evaluation method〕
<Peel strength>
Peel strength was measured according to JIS K6 854-4 Adhesive-Peel Adhesive Strength Test Method-Part 4: Floating Roller Method.
That is, the polarizing plate produced as described later was cut into a size of 25 mm × 150 mm using a cutter to obtain a measurement sample.
The sample for measurement was affixed on the metal plate using the double-sided adhesive tape.
The measurement polarizing plate was previously provided with a peeling peel between the acrylic film and the polarizer, and peeled off at an angle of 90 ° at a speed of 300 mm / min at 23 ° C. and a relative humidity of 50%. The peel strength was measured.
This peel strength was evaluated in four stages.
A: Unpeelable or polarizing plate breakage O: Peeling force is 2.0 (N / 25 mm) or more Δ: Peeling force is 1.0 (N / 25 mm) or more and less than 2.0 (N / 25 mm) ×: Peeling force Is less than 1.0 (N / 25mm) (no practicality)

<Heat resistance>
The polarizing plate was cut into a size of 50 mm × 40 mm and exposed for 1000 hours under the conditions of 80 ° C.-dry and 100 ° C.-dry.
After exposure, the presence or absence of peeling at the end of the polarizing plate was visually evaluated in the following four stages.
A: No peeling even at 100 ° C. dry condition ○: No peeling at 80 ° C.-dry condition Δ: Less than 1 mm peeling at 80 ° C.-dry condition X: 1 mm under 80 ° C.-dry condition Exfoliation above (no practicality)

[ Reference Example 6]
An adhesive was obtained by adding 2 parts by mass of methyl ethyl ketone to an aqueous solution composed of 5 parts by mass of PVA having an average polymerization degree of 1700 and a saponification degree of 99.8 mol% and 95 parts by mass of water.
After coating the acrylic film obtained in Production Example 1 so that the thickness of the adhesive after drying is 1 μm, the thickness is 40 μm, which is made of PVA having an average polymerization degree of 1700 and a saponification degree of 99.8 mol%.
Laminated on both sides of iodine-dyed PVA polarizing film uniaxially stretched to 0 times, and 10
Partially dried to produce a polarizing plate.
The peel strength and heat resistance results of the obtained polarizing plate are shown in Table 1 below.

Example 7
A polarizing plate was produced using the film produced in [Example 2], except that the other conditions were the same as in Reference Example 6.

Example 8
A polarizing plate was produced using the film produced in [Example 3], except that the other conditions were the same as in Reference Example 6.

[ Reference Example 9]
A polarizing plate was produced using the film produced in the above [ Reference Example 4] under the same conditions as in Reference Example 6 except for the above.

[ Reference Example 10]
A polarizing plate was produced using the film produced in the above [ Reference Example 5] and the other conditions were the same as in Reference Example 6.

As shown in Table 1, the polarizing plates of Reference Example 6, Examples 7-8, and Reference Examples 9-10 were all excellent in peel strength and heat resistance.
According to the present invention, a film having a simple adhesive layer excellent in adhesiveness and heat resistance was obtained.

  The film of the present invention is a polarizing plate protective film used for a display such as a liquid crystal display, a plasma display, an organic EL display, a field emission display, and a rear projection television, a retardation plate such as a quarter-wave plate and a half-wave plate. Further, it has industrial applicability as a liquid crystal optical compensation film such as a viewing angle control film, a display front plate, a display substrate, a transparent substrate such as a touch panel, and a decorative film.

Claims (12)

Methacrylic acid ester monomer unit (A): 50-96.4% by mass;
At least one structural unit (B) selected from the group consisting of a maleimide structural unit, a glutarimide structural unit, and a lactone ring structural unit, having a cyclic structure in the main chain: 3 to 30% by mass; Other vinyl monomer units (C) 0 that can be copolymerized into a monomer
. 6-20% by mass,
A methacrylic resin layer (I) containing a methacrylic resin (α) that satisfies the following conditions (i) and (ii):
A simple adhesive layer (II);
A, with a film,
The film wherein the simple adhesive layer (II) comprises an aqueous polyurethane (X) having a polycarbonate bond .
(I) The weight average molecular weight measured by gel permeation chromatography (GPC) is 650,000 to 300,000.
(Ii) When the total amount of the component (B) and the component (C) is 100% by mass, the content of the component (B) is 45% by mass or more and 98% by mass or less. The film according to claim 1 , wherein the simple adhesive layer (II) includes a mixture containing the aqueous polyurethane (X) having the polycarbonate bond and an isocyanate compound. The structural unit (B) having a ring structure in the main chain,
The film according to claim 1 or 2 , comprising at least one structural unit selected from the group consisting of a glutarimide structural unit and a maleimide structural unit. The structural unit (B) having a ring structure in the main chain,
The film according to any one of claims 1 to 3 , comprising an N-cyclohexylmaleimide-based structural unit and / or an N-aryl group-substituted maleimide-based structural unit. The amount of residual maleimide monomer in the methacrylic resin layer (I) is 0.01% by mass or more.
The film according to any one of claims 1 to 4 , which is 5% by mass or less. For 100 parts by mass of the methacrylic resin layer (I),
The film as described in any one of Claims 1 thru | or 5 which further contains 0 mass part-5 mass parts of ultraviolet absorbers. Other vinyl monomer units (C) copolymerizable with the methacrylic acid ester monomer,
The film according to any one of claims 1 to 6 , wherein the film is formed of at least one selected from the group consisting of an acrylate monomer, an aromatic vinyl monomer, and a vinyl cyanide monomer. . Other vinyl monomer units (C) copolymerizable with the methacrylic acid ester monomer,
The film according to any one of claims 1 to 7 , wherein the film is formed of at least one selected from the group consisting of methyl acrylate, ethyl acrylate, styrene, and acrylonitrile. The vinyl monomer unit (C) is an aromatic vinyl monomer unit (C-1),
The content of the aromatic vinyl monomer unit (C-1) is 23 parts by mass or less when the total amount of the component (A) and the component (B) is 100 parts by mass. 8. The film according to 7. The Vicat softening temperature of the molded body containing the methacrylic resin (α) is 110 ° C. or higher.
The film as described in any one of Claims 1 thru | or 9 . The film as described in any one of Claims 1 thru | or 10 whose thickness of a film is 0.002-1 mm. The film according to any one of claims 1 to 11 , wherein, in TGA (Thermogravimetric Analysis), the weight reduction rate after heating at a heating temperature of 270 ° C for 0.5 hours is 5% or less.