JP6457862B2 - Acrylic resin composition, film formed from the resin composition, polarizing plate provided with the film, and image display device provided with the polarizing plate - Google Patents

Description

  The present invention relates to an acrylic resin composition containing an acrylic resin and a metal component, a film formed of the resin composition, a polarizing plate provided with the film, and an image display device provided with the polarizing plate.

In recent years, transparent resins have been widely used in optical materials such as optical lenses, prisms, mirrors, optical disks, optical fibers, liquid crystal display sheets and films, and light guide plates.
Conventionally, polymethyl methacrylate (hereinafter also referred to as PMMA) has been mainly used as the resin for optical materials.

  PMMA has a problem that heat resistance is not sufficient. However, as PMMA having high heat resistance, Patent Document 1 discloses from a specific copolymer having an unsaturated carboxylic acid alkyl ester unit and a glutaric anhydride unit. Is described as having excellent transparency, heat resistance, and scratch resistance. In Patent Document 2, when a thermoplastic resin material containing a lactone ring-containing polymer as a main component is formed into a film or a sheet under specific conditions, an optical film suitable for an optical protective film, an optical film, and an optical sheet, respectively. It describes that it is possible to provide an optical planar thermoplastic resin molded article having both properties and mechanical properties, and having both transparency and heat resistance.

  Patent Document 3 discloses an acrylic containing a thermoplastic acrylic resin containing a specific proportion of methyl methacrylate and (meth) acrylic acid, a copolymer of ethylene and (meth) acrylic acid, and a metal salt. The thermoplastic resin composition is excellent in solvent resistance while maintaining the optical properties, mechanical strength, heat resistance, and other properties as it is, and is exposed to the solvent in a state in which internal stress remains or is externally stressed. However, it is described that cracks, breakage, deformation, discoloration and the like do not occur.

  Conventionally, a mixture of an acrylic resin and a cellulose ester resin has been used as a resin for optical applications used for a polarizer protective film. For example, Patent Document 4 describes that a resin film containing a specific molecular weight acrylic resin and a cellulose ester resin in a specific ratio is used as a polarizer protective film.

JP 2004-051928 A JP 2006-96960 A Japanese Patent Application Laid-Open No. 2004-224813 JP 2009-271284 A

The objective of this invention is providing the film formed with the acrylic resin composition excellent in film formability, and this acrylic resin composition.
Another object of the present invention is to provide an acrylic resin composition useful for obtaining a film having excellent flexibility and a film formed from the acrylic resin composition.
Still another object of the present invention is to provide an acrylic resin composition excellent in compatibility with a cellulose resin and a film formed from the acrylic resin composition.
Another object of the present invention is to provide a polarizer protective film formed of the resin composition, a polarizing plate provided with the polarizer protective film, and an image display device provided with the polarizing plate.

  As a result of intensive studies to solve the above problems, the present inventors have introduced an ionic group (such as an acid group) into the methacrylic resin, and a methacrylic resin in which such an ionic group has been introduced [ For example, by combining a metal component with a monomer having methyl methacrylate as a main component and a monomer having an acid group (for example, (meth) acrylic acid) as a copolymer component and a metal component, the film-forming property of the methacrylic resin can be improved. It has been found that a resin composition containing a combination of such components can be improved or improved, and is excellent in compatibility with a cellulose resin and useful for forming a film excellent in flexibility and the like. It was.

  In addition to the above, the present inventors have obtained various new findings as will be described below, and have made further studies and completed the present invention.

That is, the present invention relates to the following resin compositions and the like.
[1] An acrylic resin composition containing an acrylic resin (A) having a methacrylic acid ester unit as a polymerization unit and having an ionic group, and a metal component (B).
[2] In the acrylic resin (A), the proportion of methacrylic acid ester units is 50 mol% or more of the whole polymerization units, and the proportion of ionic groups is 1 × 10 ⁻⁵ to 1 × 10 ⁻² mol / g. The acrylic resin composition according to the above [1].
[3] The resin composition according to [1] or [2], wherein the acrylic resin (A) has a weight average molecular weight of 100,000 or more.
[4] The resin composition according to any one of [1] to [3], wherein the acrylic resin (A) has a weight average molecular weight of more than 300,000.
[5] The acrylic resin composition according to any one of [1] to [4], wherein the ionic group is an acid group in the acrylic resin (A).
[6] The ratio of the metal component (B) is any one of the above [1] to [5], which is 0.01 to 10 parts by weight in terms of metal atoms with respect to 100 parts by weight of the acrylic resin (A). Acrylic resin composition.
[7] The acrylic resin composition according to any one of [1] to [6], wherein the ratio of the metal component (B) is 0.05 to 1.2 equivalents per 1 mol of the ionic group.
[8] A monomer unit in which the acrylic resin (A) has at least one acid group selected from a methacrylic acid ester unit (A1) containing 70 mol% or more of a methyl methacrylate unit, and a carboxyl group and a sulfonic acid group ( A2) in a molar ratio of (A1) / (A2) of 99/1 to 80/20 and an ionic group in a ratio of 1 × 10 ^{−4 to} 5 × 10 ⁻³ mol / g. A resin having a weight average molecular weight of 200,000 or more,
The metal component (B) includes a periodic table group 1-13 metal,
The ratio of the metal component (B) is 0.1 to 1.1 equivalents per 1 mol of the ionic group,
And acrylic resin composition in any one of said [1]-[7] which is 0.1-5 weight part in conversion of a metal atom with respect to 100 weight part of acrylic resins (A).
[9] The resin composition according to any one of [1] to [8], which is a dope.
[10] The resin composition according to any one of [1] to [9], which is an additive for cellulose resin.
[11] The resin composition according to any one of [1] to [10], which is for optical use.
[12] The resin composition according to any one of [1] to [11], wherein an elastic modulus at 120 ° C. is 2 × 10 ⁷ Pa or more.
[13] A film formed of the resin composition according to any one of [1] to [12].
[14] The film according to [13], which is a polarizer protective film.
[15] A polarizing plate comprising the film according to [13] or [14].
[16] An image display device comprising the polarizing plate according to [15].

The resin composition of the present invention is excellent in film formability.
Moreover, the film formed with the resin composition of this invention is excellent in flexibility.
Moreover, the resin composition of this invention is excellent in compatibility with a cellulose resin.
Further, the resin composition of the present invention has a high elastic modulus in a molten state.
Furthermore, since the solvent is easily volatilized in the film formed from the resin composition of the present invention, the workability is good in the film manufacturing process.

Hereinafter, the present invention will be described in detail.
The acrylic resin composition of this invention contains the acrylic resin (A) which has an ionic group, and a metal component (B).

[Acrylic resin (A)]
The acrylic resin (A) used in the present invention usually has a ionic group with a methacrylic acid ester as a polymerization component (monomer). In other words, the acrylic resin (A) used in the present invention is a unit derived from a methacrylic acid ester (or a polymerization unit, sometimes simply referred to as “methacrylic acid ester unit”. The same applies in the same expression hereinafter). Is a resin having an ionic group as a polymerization unit.

The ionic group may be a group that can be ionized (or easily ionized), regardless of whether it is actually ionized.
As an ionic group, a base (for example, ammonium base etc.), an acid group, etc. are mentioned, for example. In particular, the ionic group may be at least an acid group.
Examples of the acid group include a carboxyl group and a sulfonic acid group (sulfo group).

The acrylic resin (A) may have one kind or two or more kinds of ionic groups. When it has 2 or more types of ionic groups, it may have a base and an acid group, and may have 2 or more types of bases or acid groups.
The method for introducing the ionic group is not particularly limited, and (1) a method in which a polymerization component (ionic monomer) derived from the ionic group is copolymerized with a methacrylic acid ester, and (2) an ionic property in the acrylic resin. A method of graft polymerization of a monomer, (3) a method of introducing an initiator having an ionic group or a chain transfer agent at the time of polymerization of an acrylic resin, and (4) a method of modifying an acrylic resin (for example, a resin skeleton Examples include a method of introducing a carboxyl group by hydrolysis of an ester group) and (5) a method of introducing them in combination.
A preferred introduction method is method (1). In the method (1), it is easy to prepare an acrylic resin (A) containing an ionic group at a desired content ratio.

In the acrylic resin (A), the ratio of the ionic group is usually 1 × 10 ⁻⁵ to 1 × 10 ⁻² mol / g, preferably 5 × 10 ^{−5 to} 5 × 10 ⁻³ mol / g. Yes, more preferably 1 × 10 ⁻⁴ to 2 × 10 ⁻³ mol / g. If it is such a range, since the resin composition of this invention is excellent in film forming property, and the film formed with this resin composition is excellent in flexibility, it is preferable. Moreover, if it is such a range, since the resin composition of this invention becomes solution viscosity suitable for solution film forming, it is preferable.

Examples of the methacrylic acid ester (or the methacrylic acid ester constituting the methacrylic acid ester unit) include, for example, aliphatic methacrylate [for example, methacrylic acid alkyl ester (for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacrylic acid). C _1-20 alkyl methacrylate, preferably C _1-12 alkyl methacrylate, more preferably C _1-8 methacrylate, such as n-butyl, t-butyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, etc. Alkyl), etc.], alicyclic methacrylates [eg, methacrylic acid cycloalkyl esters (eg, methacrylic acid C _5-10 cycloalkyl, such as cyclohexyl methacrylate)], cross-linked cyclic methacrylates (eg, methacrylate). Dicyclopentanyl acrylate)], aromatic methacrylate [eg, aryl methacrylates (eg, C _6-12 aryl methacrylate such as phenyl methacrylate), aralkyl methacrylates [eg, methacrylic acid such as benzyl methacrylate] Acid C _6-10 aryl C _1-4 alkyl) and the like.

In addition, the methacrylic acid ester may have a substituent such as a halogen group (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a hydroxyl group.
The methacrylic acid ester having such a substituent may be a methacrylic acid ester in which the substituent is substituted on the methacrylic acid ester exemplified above. For example, a methacrylic acid ester having a halogen group [for example, methacrylic acid haloalkyl ester ( For example, methacrylic acid halo C _1-12 alkyl such as chloromethyl methacrylate), methacrylic acid ester having a hydroxyl group [for example, hydroxyalkyl ester of methacrylic acid (for example, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate) like methacrylic acid hydroxyalkyl _{C 2-12} alkyl), etc.] and the like.

  The methacrylic acid ester (or methacrylic acid ester unit) is preferably methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, benzyl methacrylate or the like, more preferably methyl methacrylate. , Cyclohexyl methacrylate, dicyclopentanyl methacrylate, benzyl methacrylate and the like are preferable, and at least methyl methacrylate is particularly preferable.

Typically, a methacrylic acid ester (or methacrylic acid ester unit) contains a methyl methacrylate unit as a main unit (for example, 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more). May be.
Methacrylic acid esters (or methacrylic acid ester units) may be used alone or in combination of two or more.

The polymerization component of the acrylic resin (A) may contain a polymerization component (other polymerization component) other than the methacrylic acid ester. In other words, the acrylic resin (A) may have units derived from other polymerization components (or polymerization units, sometimes simply referred to as “other units”).
Other polymerization components (also “other units”) may be used alone or in combination of two or more.

The other unit is not particularly limited as long as it can form a copolymer with a methacrylic ester, but is largely divided into an ionic monomer (ionic monomer) unit and a nonionic monomer (nonionic monomer) unit. Can be separated.
In particular, the ionic monomer unit is suitable because it easily introduces an ionic group into the acrylic resin. Therefore, the other unit (or acrylic resin (A)) may have at least an ionic monomer unit.
The “ionic group” may be any group that can be ionized (or easily ionized), regardless of whether it is actually ionized.

The ionic monomer (ionic monomer corresponding to the ionic monomer unit) is not particularly limited as long as it has an ionic group, and may be a monomer having a base (for example, a monomer having an ammonium base). Usually, it may be a monomer having an acid group.
Examples of the acid group include a carboxyl group and a sulfonic acid group (sulfo group). The monomer which has an acid group may have 1 or 2 or more acid groups, and when it has 2 or more acid groups, it may have the same or different acid groups.

Specific examples of the monomer having an acid group (a monomer corresponding to a monomer unit having an acid group) include a monomer having a carboxyl group (for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride). Acid, vinyl benzoic acid [for example, 4-vinyl benzoic acid (4-ethenyl benzoic acid, etc.)}, monomers having a sulfonic acid group {for example, acrylamide having a sulfonic acid group (for example, 2-acrylamido-2-methylpropane) Sulfonic acid), (meth) acrylate having a sulfonic acid group [for example, (meth) acryloyloxyalkanesulfonic acid (for example, (meth) acryloyloxy C _2-6 alkanesulfonic acid such as sulfoethylacrylic acid and sulfoethylmethacrylic acid) ), Styrene sulfonic acid, etc.]} It is.

Of these ionic monomer units, (meth) acrylic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, and styrenesulfonic acid are particularly preferable from the viewpoint of copolymerization with a methacrylic acid ester.
The acrylic resin (A) may have ionic monomer units alone or in combination of two or more.

  In addition, although an ionic monomer unit can be generally introduced by using an ionic monomer as a polymerization component, depending on the kind of the ionic monomer unit, it can also be obtained by modification of a nonionic monomer unit. For example, methacrylic acid units can be obtained by hydrolysis of methacrylic acid ester units.

The nonionic monomer unit is not particularly limited as long as it is a unit derived from a monomer that does not belong to the category of methacrylic acid ester unit and ionic monomer unit.
Nonionic monomers (monomers corresponding to nonionic monomer units) include, for example, acrylic acid esters, vinyl compounds (eg, styrene compounds such as styrene and α-methylstyrene; vinyl toluene, vinyl acetate, methyl vinyl ketone) , N-vinylpyrrolidone, N-vinylcarbazole, etc.), α, β-unsaturated nitriles (eg, acrylonitrile, methacrylonitrile, etc.), maleimides, N-substituted maleimides [eg, N-alkylmaleimides (eg, N-methyl) maleimide, N- _{N-C 1-10} alkyl maleimides such as ethyl maleimide), N- aryl maleimides (e.g., N- _{phenyl-N-C 6-10} aryl maleimides such as maleimide), etc.], (meth) acrylamides [such as , (Meth) acrylic aliphatic amides (eg , N- methyl (meth) acrylamide, N- methoxymethyl (meth) acrylamide), (meth) acrylic aryl amides (e.g., N- phenyl (meth) acrylamide, etc.) and the like.

Examples of the acrylic ester include acrylic esters corresponding to the methacrylic esters. Specific acrylic esters include, for example, aliphatic acrylates [e.g., alkyl acrylate esters (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, t-butyl acrylate, C _1-20 alkyl acrylate such as n-hexyl acrylate and 2-ethylhexyl acrylate, preferably C _1-12 alkyl acrylate, and more preferably C _1-8 alkyl acrylate)], alicyclic acrylate [ For example, acrylic acid cycloalkyl ester (for example, C _5-10 cycloalkyl acrylate such as cyclohexyl acrylate), cross-linked cyclic acrylate (for example, dicyclopentanyl acrylate)], aromatic acrylate [for example, acrylic acid Aryl esters (eg, Acrylic acid C _6-12 aryl such as phenyl _crylate ), acrylic acid aralkyl ester [for example, acrylic acid C _6-10 aryl C _1-4 alkyl) such as benzyl acrylate], acrylic acid ester having a halogen atom [ For example, acrylic acid haloalkyl ester (for example, halo C _1-12 alkyl acrylate such as chloromethyl acrylate), acrylic acid ester having hydroxyl group [for example, hydroxyalkyl ester of acrylic acid (for example, 2-hydroxyethyl acrylate) , Hydroxy C _2-12 alkyl acrylates such as 3-hydroxypropyl acrylate) and the like.

  Nonionic monomer units also include units obtained by modification or modification, such as glutaric anhydride units.

Among these nonionic monomer units, acrylic acid esters, styrene compounds, and N-substituted maleimides are particularly preferable from the viewpoint of copolymerization with methacrylic acid esters and the like.
The acrylic resin (A) may have a nonionic monomer unit alone or in combination of two or more.

  In the acrylic resin (A), the ratio of the methacrylic acid ester unit (or methacrylic acid ester) is not particularly limited, but is preferably 50 mol% or more of the entire polymerization unit (or polymerization component) of the acrylic resin (A), and is 60 mol. % Or more (for example, 50 to 100 mol%) is more preferable, and 70 mol% or more (for example, 70 to 98 mol%) is more preferable.

  Further, when the acrylic resin (A) has an ionic monomer unit, the content ratio of the ionic monomer unit (for example, a monomer unit having an acid group) in the acrylic resin (A) is methacrylic acid ester unit (A1). / Molar ratio of ionic monomer unit (A2) is, for example, 99.9 / 0.1 to 50/50, preferably 99.5 / 0.5 to 60/40, more preferably 99/1 to 70 /. 30, more preferably about 99/1 to 80/20, and usually about 99/1 to 85/15.

Further, when the acrylic resin (A) has a nonionic monomer unit, the content ratio of the nonionic monomer unit in the acrylic resin (A) is methacrylic acid ester unit (or methacrylic acid ester) (A1) / non- The molar ratio of the ionic monomer unit (A3) is, for example, about 99.9 / 0.1 to 30/70, preferably about 99/1 to 50/50, and more preferably about 98/2 to 70/30. Also good.
In addition, when the acrylic resin (A) has an ionic monomer unit and a nonionic monomer unit, the total amount of the methacrylic acid ester unit (A1) and the nonionic monomer unit (A3) / the ionic monomer unit (A2) The molar ratio is, for example, 99.9 / 0.1 to 50/50, preferably 99.5 / 0.5 to 60/40, more preferably 99/1 to 70/30, still more preferably 99/1 to It is about 80/20, and may generally be about 99/1 to 85/15.

  The weight average molecular weight of the acrylic resin (A) can be selected from the range of, for example, 50,000 or more (for example, 8 to 1,500,000), 100,000 or more (for example, 15 to 1,200,000), and preferably 100,000 to 1,000,000. Preferably, it may be 200,000 to 800,000, more preferably 300,000 to 600,000, particularly more than 300,000 (for example, 310,000 or more). If it is such a range, since the resin composition of this invention is excellent in film forming property, and the effect that the film formed with this resin composition is excellent in flexibility is easy to be acquired, it is preferable. Moreover, if it is such a range, since the solution viscosity and melt viscosity of the resin composition of this invention will become the thing excellent in dope preparation and film forming, it is preferable.

  The molecular weight distribution (Mw / Mn) of the acrylic resin (A) is preferably 4 or less. If it is such a range, since there are few low molecular weight components and it becomes difficult to produce the appearance defect by bleed-out, etc., it is preferable.

  Although the glass transition temperature (Tg) of an acrylic resin (A) is not specifically limited, Preferably it is 80-180 degreeC, More preferably, it is 90-160 degreeC. If it is these ranges, since the heat resistance of the resin composition of this invention becomes high enough, and a moldability is favorable, it is preferable. Tg is a value evaluated by the method described in Examples described later.

[Method for producing acrylic resin (A)]
The manufacturing method of the acrylic resin (A) used for this invention is not specifically limited, You may follow the manufacturing method of a conventionally well-known acrylic resin.

  As a manufacturing method of the acrylic resin (A) used for this invention, the method of radical-polymerizing the monomer composition containing polymeric components, such as a methacrylic ester, for example is preferable. The radical polymerization method is not particularly limited, and conventionally known methods such as solution polymerization, emulsion polymerization and suspension polymerization can be used, and solution polymerization is preferable.

  The polymerization solvent used in the solution polymerization is not particularly limited, but an organic solvent is preferable. The organic solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene, xylene, and ethylbenzene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ether solvents such as tetrahydrofuran; methanol, ethanol, butanol, and the like Examples include alcohol solvents. These solvents may be used alone or in combination of two or more.

Moreover, since the residual volatile matter of the acrylic resin (A) finally obtained will increase when the boiling point of the polymerization solvent is too high, the polymerization solvent is preferably a solvent having a boiling point of 40 to 200 ° C. Considering that solution casting is carried out using the resin composition of the present invention containing A), a solvent having a boiling point of 40 to 100 ° C. is more preferable.
When the boiling point of the polymerization solvent exceeds 100 ° C., a method of lowering the boiling point of the organic solvent by reducing the pressure in the polymerization tank, or cooling the jacket part or cooling with a coil introduced into the polymerization tank is performed. The temperature may be controlled by the method.

  The amount of the polymerization solvent used is not particularly limited, but may be appropriately selected from the range of usually 10 to 200 parts by mass with respect to 100 parts by mass of the total amount of the monomer composition in the polymerization system, preferably 15 It is -150 mass parts, More preferably, it is 15-100 mass parts.

  The polymerization temperature can be appropriately selected according to the reaction scale and the like, but is usually within the range of the internal temperature of the reaction solution of 30 to 200 ° C, preferably 50 to 180 ° C, more preferably 70. ~ 160 ° C. In this case, coloring of the acrylic resin (A) can be suppressed, and a molded product excellent in appearance can be obtained.

  The polymerization time is not constant depending on the reaction scale, reaction temperature, and the like, but is usually selected appropriately in the range of several minutes to 20 hours, preferably 0.5 to 20 hours, more preferably 1 to 10 hours. It is. Several minutes means about 1 to 10 minutes.

In the polymerization of the acrylic resin (A), a polymerization initiator may be used during the polymerization. A polymerization initiator is not specifically limited, A well-known compound can be used.
Examples of the polymerization initiator include cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butyl peroxyisopropyl carbonate, and t-amyl peroxyisononanoate. , Organic peroxides such as t-amylperoxy-2-ethylhexanoate and 1,1-di (t-butylperoxy) cyclohexane; 2,2′-azobis (methyl isobutyrate), 2,2 ′ -Azobis (isobutyronitrile), 1,1'-azobis (cyclohexanecarbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, etc. An azo compound etc. are mentioned. These polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator used is not particularly limited as long as it is appropriately set according to the combination of monomers and reaction conditions.

In the polymerization of the acrylic resin, a chain transfer agent may be used during the polymerization. A chain transfer agent is not specifically limited, A well-known compound can be used.
Chain transfer agents include, for example, thiol compounds such as dodecyl mercaptan, 2-mercaptoethanol, 3-mercaptopropionic acid, halogen compounds such as chloroform and carbon tetrachloride, polycyclic aromatic quinone compounds, α-methylstyrene dimer, etc. Is mentioned. These chain transfer agents may be used alone or in combination of two or more. The amount of chain transfer agent used is not particularly limited as long as it is appropriately set according to the combination of the monomers, reaction conditions, and the like.

  In the polymerization of the acrylic resin, an ionic group can be introduced at the end of the main chain of the acrylic resin by using a polymerization initiator or a chain transfer agent.

Further, an organic solvent may be added during the polymerization in order to control the viscosity of the polymerization solution and the polymerization temperature. Although it does not specifically limit as a form to add, For example, a polymerization solvent may be continuously added to a polymerization solution, and a polymerization solvent may be added intermittently.
In addition, the polymerization solvent to be added may be, for example, the same type of polymerization solvent as that used at the initial stage of the polymerization reaction or a different type of polymerization solvent. It is preferred to use the same type of solvent that is sometimes used.
Further, the polymerization solvent to be added may be only one kind of single solvent or two or more kinds of mixed solvents. By adding a polymerization solvent during the polymerization of the resin, the viscosity of the polymerization solution in the polymerization tank can be controlled within a certain range, and sufficient stirring can be performed. Branching and cross-linking of the generated polymer chain can be suppressed. In addition, since a polymerization solvent having a temperature lower than the polymerization temperature is added, the polymerization temperature in the polymerization system that generates heat during the polymerization can be easily controlled.

  The polymerization solution after completion of the polymerization may be subjected to a devolatilization step described in JP-A No. 2000-230016, JP-A No. 2007-262396, JP-A No. 2007-262399, and the like.

  The polymer solution containing the acrylic resin obtained as described above can reduce foreign matters contained in the acrylic resin by filtering with a filter having a filtration accuracy of 0.01 to 15 μm. The filtration method is not particularly limited, and may be a conventional method.

[Metal component (B)]
The metal component (B) contained in the acrylic resin composition of the present invention is not particularly limited as long as it contains a metal, and may be an atom or an ion (ion bonding) form. Also good. In addition, when it is a form of ion, a cation may be sufficient normally.

The metal is preferably a Group 1-13 metal of the periodic table, among which alkali metals (lithium, sodium, rubidium, cesium, etc.), alkaline earth metals (magnesium, calcium, strontium, etc.), boron group elements (aluminum, etc.) ), Transition metals (such as zinc, copper, manganese, nickel, cobalt, iron, chromium) and the like are preferable.
A metal may be individual or may combine 2 or more types.

  The metal is preferably sodium, zinc, lithium, calcium, magnesium, potassium or the like, and more preferably sodium, zinc or the like.

  In the case of an ion form, the valence of the metal is not particularly limited, but is, for example, 1 to 6 valence, preferably 1 to 4 valence, and more preferably 1 to 3 valence.

When the metal component (B) contains a metal in the form of ions, the metal component (B) is usually a metal compound (or an ion derived from a metal compound).
Examples of the metal compound include oxides, hydroxides, halides (fluoride, chloride, bromide, iodide, etc.), alkoxides (C _1-10 alkoxides such as methoxide, ethoxide, propoxide, butoxide; phenoxide, etc.) Aryl oxides, etc.), organic acid salts [e.g. fatty acid salts (e.g. formate, acetate, propionate, butanoate, octylate, etc., preferably _C1-12 alkanoates) Etc.], inorganic acid salts (for example, carbonates, hydrogencarbonates, sulfates, nitrates, hydrochlorides, etc.). The metal compound may be either a single salt or a double salt, or a complex (complex salt). A metal compound may be individual or may combine 2 or more types.

Specific metal compounds include, for example, metal alkoxides [for example, alkali metal alkoxides (for example, alkali metal C _1-10 alkoxides such as sodium methoxide and sodium ethoxide), alkaline earth metal alkoxides], metal halides [ For example, metal fluorides such as alkali metal fluoride (such as sodium fluoride), alkaline earth metal fluoride (such as magnesium fluoride and calcium fluoride); alkali metal chloride (such as sodium chloride and cesium chloride), alkaline earth chloride Metal chlorides such as group metals (magnesium chloride, calcium chloride, etc.), periodic table Group 3-12 metal chlorides (zinc chloride, aluminum chloride, etc.); metal bromides such as alkali metal bromides (sodium bromide, etc.); Alkali metal iodide (sodium iodide), cycle Table 3-13 metal iodides such as metal iodides (zinc iodide, aluminum iodide, etc.), metal organic acid salts [eg, alkali metal salts of carboxylic acids (sodium alkanoates such as sodium formate, sodium acetate, etc.) Alkali metal salts, etc.), alkaline earth metal salts of carboxylic acids (alkali metal salts of alkanoic acids, such as alkaline earth metal acetates), Group 3-12 metal salts of carboxylic acids (for example, zinc acetate, acetic acid) Periodic group 3-12 metal salts of alkanoic acids such as nickel and zinc octylate)], metal inorganic acid salts [for example, metal carbonates or metal hydrogen carbonates (sodium carbonate, cesium carbonate, sodium hydrogen carbonate, etc.) Alkali metal carbonates or bicarbonates; alkaline earth metal carbonates or bicarbonates such as magnesium carbonate and calcium carbonate), metal sulfates (eg And alkaline metal sulfates such as sodium sulfate; alkaline earth metal sulfates such as magnesium sulfate and calcium sulfate; periodic group 3-13 metal sulfates such as copper sulfate and nickel sulfate)], etc. Are metal alkoxides, metal organic acid salts and the like.

  In the acrylic resin composition, the content of the metal component (B) is not particularly limited, and may be included as a free metal component. The ionic group (for example, acid group) of the acrylic resin (A) may be included in the form of ions. ) And a salt (or ionic bond) may be included.

  Although the ratio of the metal component (B) in the acrylic resin composition of the present invention is not particularly limited, it is preferably 0.01 to 10 parts by weight in terms of metal atoms with respect to 100 parts by weight of the acrylic resin (A). More preferably, it is 0.1 to 5 parts by weight. In this case, coloring of molded articles, such as a film obtained by shape | molding the resin composition of this invention and this resin composition, can be suppressed.

  When the metal which comprises a metal component (B) is a form of an ion (cation), the ratio of the metal component (B) in the acrylic resin composition of this invention is 1 mol of ionic groups of an acrylic resin (A). On the other hand, 0.05-1.2 equivalent is preferable and 0.1-1.1 equivalent is more preferable. In this case, coloring of molded articles, such as a film obtained by shape | molding the resin composition of this invention and this resin composition, can be suppressed. The number of moles of ionic groups in the acrylic resin (A) is a value calculated by the method described in the examples described later.

[Other resin components]
The acrylic resin composition of the present invention may contain other resin components in addition to the acrylic resin (A). In particular, the acrylic resin composition of the present invention is excellent in compatibility with the cellulose resin, and by combining with the cellulose resin, it is possible to efficiently obtain a novel resin having both excellent properties of the acrylic resin and the cellulose resin. it can. Therefore, the acrylic resin composition of the present invention is also suitable as an additive (modifier) for cellulose resin.

  Although it does not specifically limit as a cellulose resin, Preferably, it is a cellulose ester etc.

  Although it does not specifically limit as a cellulose ester, For example, aromatic carboxylic acid ester, the fatty acid ester of a cellulose, etc. are mentioned, Especially the lower fatty acid ester (for example, C1-C5 fatty acid ester) of a cellulose is preferable.

Examples of the fatty acid ester of cellulose include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose pivalate, cellulose acetate acylate, cellulose mixed acid ester [for example, cellulose acetate such as cellulose acetate propionate, cellulose acetate butyrate, etc. Acylate (such as cellulose acetate C _3-5 acylate)] and the like.
Among these, cellulose acetate C _3-5 acylate may be preferably used.
These can use 1 type (s) or 2 or more types.

  The number average molecular weight (Mn) of the cellulose resin (for example, cellulose ester) is preferably from 50,000 to 150,000, more preferably from 55,000 to 120,000, and even more preferably from 60000 to 100,000. The weight average molecular weight (Mw) / number average molecular weight (Mn) ratio of the cellulose resin (for example, cellulose ester) is preferably 1.3 to 5.5, more preferably 1.5 to 5.0. 0.7 to 4.0 is more preferable, and 2.0 to 3.5 is most preferable. Mw and Mn are values calculated in terms of polystyrene by gel permeation chromatography (GPC) using the method described in the examples below. If it is in these ranges, since compatibility with an acrylic resin is favorable and it is excellent also in flexibility, it is preferable.

Although the substitution degree of a cellulose resin (for example, cellulose ester) is not specifically limited, For example, about 2-3 may be sufficient.
In the cellulose acetate acylate, the degree of acetyl substitution is, for example, 0.1 to 2.0, and preferably 0.1 to 1.0. Further, the acyl substitution degree _{(e.g., C 3-5} acyl group substitution degree) is, for example, from 1.0 to 2.9, preferably from 2.0 to 2.9. In this case, the compatibility with the acrylic resin (A) is good.

  The blending ratio (mass ratio) of acrylic resin (A) / cellulose resin is preferably 95/5 to 30/70, more preferably 80/20 to 20/80, and even more preferably 70/30 to 30. / 70.

  Examples of the resin other than the cellulose resin include thermoplastic resins, for example, olefin polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, poly (4-methyl-1-pentene); halogens such as vinyl chloride and chlorinated vinyl resins. Containing polymer; polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene polymer such as acrylonitrile-butadiene-styrene block copolymer; polyester such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; nylon 6, polyamides such as nylon 66 and nylon 610; polyacetal: polycarbonate; polyphenylene oxide; polyphenylene sulfide: polyether ether ketone; Nitrile; polysulfone; polyether sulfone; polyoxyethylene Penji alkylene; polyamideimide; and the like. These may contain 1 type, or 2 or more types.

  The blending ratio (mass ratio) of the acrylic resin (A) / thermoplastic resin is, for example, 50/50 to 99/1, and preferably 70/30 to 98/2.

[Additives and solvents]
The acrylic resin composition of the present invention may contain an additive as long as the effects of the present invention are exhibited. These may be added during the polymerization of the acrylic resin (A) or after the polymerization, or may be added during or after the addition of the metal atom or metal compound from which the metal component (B) is derived.
Although it does not specifically limit as an additive, For example, a ultraviolet absorber, antioxidant, a plasticizer, elastic fine particles, another additive etc. are mentioned. These can use 1 type (s) or 2 or more types.

The ultraviolet absorber (UVA) is not particularly limited as long as it is a substance that has ultraviolet absorbing ability and is compatible with the resin composition of the present invention. From the viewpoint of compatibility with the resin composition, UVA preferably does not contain a repeating unit derived from a monomer (that is, it is not a polymer).
As the UVA, for example, at least one selected from benzophenone compounds, salicinate compounds, benzoate compounds, triazole compounds, and triazine compounds can be used. Among these, UVA which is a triazole compound or a triazine compound is preferable because of its high ultraviolet absorption ability.

  Although the molecular weight of UVA is not specifically limited, For example, it is 600 or more, Preferably it is 600-10000, More preferably, it is 600-8000, More preferably, it is 600-5000.

  When the resin composition of this invention contains UVA, the compounding quantity of UVA in the said composition is 0.1-5 mass parts with respect to 100 mass parts of the said resin compositions, for example, and 0.5-5 mass Part is preferable, and 0.7 to 3 parts by mass, 1 to 3 parts by mass, and 1 to 2 parts by mass are more preferable.

As antioxidant, a phenolic antioxidant etc. are mentioned, for example.
Although the compounding quantity of antioxidant is not specifically limited, It is 0.01-2 mass parts normally with respect to 100 mass parts of resin compositions of this invention, Preferably it is 0.02-1 mass parts, More preferably, it is 0. 0.02 to 0.5 parts by mass.

The phenol-based antioxidant is preferably used in combination with a thioether-based antioxidant or a phosphate-based antioxidant.
The amount of the antioxidant added when these are combined is not particularly limited, but the phenolic antioxidant and the thioether antioxidant are each 0.01 parts by mass with respect to 100 parts by mass of the resin composition of the present invention. It is preferable that each of the phenolic antioxidant and the phosphoric acid antioxidant is 0.025 parts by mass or more.

Examples of the plasticizer include phthalate ester plasticizer, fatty acid ester plasticizer, fatty acid amide plasticizer, trimellitic ester plasticizer, phosphate ester plasticizer, polyester plasticizer, and epoxy plasticizer. Etc. By using a plasticizer, the fluidity and flexibility of the resin composition of the present invention can be improved.
Although the compounding quantity of a plasticizer is not specifically limited, It is 0.1-20 mass parts normally with respect to 100 mass parts of resin compositions of this invention, Preferably it is 0.1-10 mass parts.

Examples of the elastic fine particles include acrylic elastic fine particles and butadiene elastic fine particles. Moreover, the flexibility, dispersibility, and whitening resistance of the resin composition of the present invention can be improved by making the fine particles have a multilayer structure. As commercially available elastic fine particles, for example, metablene manufactured by Mitsubishi Rayon Co., Ltd. can be used. By using elastic fine particles, the flexibility of the resin composition of the present invention can be improved.
The compounding amount of the elastic fine particles is not particularly limited, but is usually 1 to 40 parts by mass, preferably 2 to 30 parts by mass with respect to 100 parts by mass of the resin composition of the present invention.

  Examples of other additives contained in the acrylic resin composition of the present invention include stabilizers such as light-resistant stabilizers, weather-resistant stabilizers, and heat stabilizers; reinforcing materials such as glass fibers and carbon fibers; near-infrared absorbers Flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate and antimony oxide; antistatic agents represented by anionic, cationic and nonionic surfactants; colorants such as inorganic pigments, organic pigments and dyes Organic fillers, inorganic fillers, resin modifiers, anti-blocking agents, matting agents, acid scavengers, metal deactivators, lubricants, flame retardants, and rubber masses such as ASA and ABS.

  Although the compounding quantity of the said other additive contained in the acrylic resin composition of this invention is not specifically limited, It is 0.1-0.1 normally except UVA with respect to 100 mass parts of resin compositions of this invention. 5 parts by mass, preferably 0.1-2 parts by mass, more preferably 0.1-1 parts by mass.

Moreover, the composition (dope) containing a solvent may be sufficient as the acrylic resin composition of this invention.
As the solvent, an organic solvent is preferable. The organic solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene, xylene, and ethylbenzene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and acetone; ether solvents such as tetrahydrofuran; methanol, ethanol, and butanol And alcohol solvents such as methyl acetate and fatty acid ester solvents such as ethyl acetate, and chlorine solvents such as methylene chloride. These solvents may be used alone or in combination of two or more.

The viscosity of the dope is, for example, 1 to 500 Pa · s, and preferably 2 to 100 Pa · s.
The content of the acrylic resin composition of the present invention in the dope is, for example, 1 to 50% by weight, preferably 2 to 40% by weight, more preferably 5 to 35% by weight, based on the total amount of the dope. It is.

[Acrylic resin composition]

The acrylic resin composition of the present invention has an elastic modulus at 120 ° C. of preferably 2 × 10 ⁷ Pa or more, more preferably 2 × 10 ⁷ to 1 × 10 ⁹ Pa, and further preferably 2 × 10 ^7. It is -50 * 10 < ⁸ > Pa, Most preferably, it is 2 * 10 < ⁷ > -1 * 10 < ⁸ > Pa.
The elastic modulus at 120 ° C. can be measured by the method described in the examples described later.

  Although the glass transition temperature (Tg) of the acrylic resin composition of this invention is not specifically limited, Usually, it is 80 degreeC or more, Preferably it is 80-180 degreeC, More preferably, it is 90-160 degreeC. Within these ranges, the acrylic resin composition of the present invention is preferable because the heat resistance is sufficiently high and the moldability is good.

The method for producing the acrylic resin composition of the present invention is not particularly limited as long as the acrylic resin (A) and the metal component (B) (and other components as necessary) are mixed.
As a mixing method of the acrylic resin (A) and the metal component (B), for example, a metal atom and / or a metal compound and the acrylic resin (A) may be mixed by melt kneading or the acrylic resin (A). During polymerization, a polymerization component in which a salt is formed from the metal component (B) may be used. In addition, a metal atom and / or a metal compound may be mixed during the resin solution before the solvent removal after the acrylic resin (A) polymerization or during the solvent removal step, or at the time of preparing the dope for solution film formation after the solvent removal. Good.
The acrylic resin composition of the present invention can be used for optical applications.

[the film]
The present invention also includes a film formed from the acrylic resin composition of the present invention.

  Although the thickness of the film of this invention is not specifically limited, Usually, they are 10 micrometers-500 micrometers, Preferably they are 15 micrometers-300 micrometers, More preferably, they are 20 micrometers-100 micrometers.

  The haze of the film of the present invention is not particularly limited, but is preferably 5% or less (for example, 0.3 to 5)%, more preferably 3% or less (for example, 0.3 to 3)%, More preferably, it is 2% or less (for example, 0.3-2)%. Incidentally, the haze is a value calculated by the method described in Examples described later.

[Film Production Method]
The production method of the film of the present invention is not particularly limited, and examples thereof include a solution casting method (solution casting method), a melt extrusion method, a calendering method, and a compression molding method, and preferably a solution casting method (solution flow method). A casting method), and a melt extrusion method, more preferably a solution casting method (solution casting method). Conventionally known methods can be used for these.

  When the film of the present invention is produced by a solution casting method, a method having (1) a dissolution step, then (2) a casting step, and then (3) a drying step is preferable.

(1) Dissolution process:
A dissolution process is a process of manufacturing the composition (dope) used for manufacture of the film of this invention, specifically, an acrylic resin (A) and a metal component (B), and ultraviolet absorption as needed. It is a step of preparing a dope containing an acrylic resin composition of the present invention containing an agent, an antioxidant, other additives, other resin components, and the like, and optionally a solvent.

  Although the ratio of the acrylic resin (A) contained in the dope used for the production of the film of the present invention is not particularly limited, it is usually 1 to 50% by weight, preferably 2 with respect to the total amount of the dope. -40% by weight, more preferably 5-35% by weight.

  The viscosity of the dope is, for example, 1 to 500 Pa · s, and preferably 2 to 100 Pa · s. It is preferable for the dope to have a low viscosity because (2) when the composition is applied in the casting step, the film thickness is uniformed by the leveling effect.

(2) Casting process:
This is a step of casting a dope used for producing the film of the present invention on a support to obtain a uniform film.

  The coating method for casting the dope on a support is not particularly limited, and a conventionally known coating method can be used. For example, a die coater, a doctor blade coater, a roll coater, a comma coater, a lip A method using a coater or the like is preferable. These may use conventional methods.

  The support for casting the dope is not particularly limited, and a conventionally known support used for solution casting can be used. For example, a metal such as a stainless steel endless belt or a rotating metal drum can be used. Examples thereof include a support, a film such as a polyimide film, a biaxially stretched polyethylene terephthalate film, and the like.

(3) Drying process:
It is a step of heating the dope film in which the dope used for production of the film of the present invention is cast on a support and evaporating the solvent to obtain a dry film (heating and drying the dope film).

In heating and drying, in the state where the dope is cast or the liquid film immediately after coating is not dried, if there is a sudden flow of air or heating, thickness unevenness is likely to occur. It is preferable to do. For example, it is preferable not to give wind directly to the film, or to use a means of heating by applying a microwave instead of the wind.
It is also preferable to prevent rapid heating and cooling. Furthermore, since the dope film is foamed by the humidity in the atmosphere, the humidity is preferably controlled. After these are dried to be in a semi-solid state, it is preferably dried by blowing hot air or the like so as to reduce the residual solvent.

Heat drying can be performed with the dope film still supported on the support, but if necessary, the pre-dried film is peeled off from the support until it has self-supporting property, and further, It can also be dried.
The heat drying method is not particularly limited, and a conventionally known method can be used. For example, a float method, a tenter method, a roll conveying method, or the like can be used.

  In addition to the steps (1) to (3) described above, the film production process of the present invention is a process such as saponification treatment, corona treatment, plasma treatment, and coating of an easy-adhesion layer, etc., in order to improve adhesion. You may have. It is also possible to have a process of providing a functional coating layer and a stretching process. The method of these processes, application | coating, coating, and extending | stretching is not specifically limited, A conventionally well-known method can be used.

  Examples of the functional coating layer include an antistatic layer, an adhesive layer, an adhesive layer, an easy-adhesion layer, an antiglare layer (non-glare) layer, an antifouling layer such as a photocatalyst layer, an antireflection layer, a hard coat layer, and an ultraviolet ray. Examples thereof include a shielding layer, a heat ray shielding layer, an electromagnetic wave shielding layer, and a gas barrier layer. The method for forming these functional coating layers is not particularly limited, and may be according to a conventional method.

  The stretching method may be uniaxial stretching or biaxial stretching. When biaxial stretching, simultaneous biaxial stretching or sequential biaxial stretching may be used. When stretched, the mechanical strength of the film is improved and the film performance is improved.

  Although it does not specifically limit as temperature of the said extending | stretching, For example, it is preferable to carry out in the glass transition temperature vicinity of a film. Specifically, it is preferably performed at (glass transition temperature −30) ° C. to (glass transition temperature +100) ° C., more preferably (glass transition temperature −20) ° C. to (glass transition temperature +80) ° C. preferable. In this case, a sufficient stretch ratio is obtained, which is preferable.

  The stretching ratio is not particularly limited, but the court stretching ratio defined by the area ratio is preferably in the range of 1.1 to 25 times, more preferably in the range of 1.3 to 10 times. In this case, since it leads to the improvement of toughness accompanying drawing, it is preferable.

  Although it does not specifically limit as the speed | rate (one direction) of the said extending | stretching, Preferably it is the range of 10-20000% / min, More preferably, it is the range of 100-10000% / min.

In order to stabilize the optical isotropy and mechanical properties of the film, heat treatment (annealing) or the like may be performed after the solution film formation or after the stretching process.

Although the use of the film of the present invention obtained as described above is not particularly limited, it can be suitably used as an optical member.
Although it does not specifically limit as an optical member, For example, an optical protective film etc. are mentioned, Specifically, the protective film of various optical disk (VD, CD, DVD, MD, LD, etc.) board | substrates, a liquid crystal display device ( Examples thereof include a polarizer protective film used for a polarizing plate provided in an image display device such as an LCD).
In addition, the film of the present invention can be used as a retardation film, a viewing angle compensation film, a light diffusion film, a reflection film, an antireflection film, an antiglare film, a brightness enhancement film, a conductive film for touch panels, and the like. The film of the present invention is particularly suitably used as a polarizer protective film or a retardation film.

[Polarizer protective film]
The film of the present invention can be used as a polarizer protective film used for a polarizing plate provided in an image display device such as a liquid crystal display device (LCD), and can usually be used as a polarizer protective film as it is.

[Polarizer]
The present invention also includes a polarizing plate provided with the film of the present invention.
That is, the film of the present invention can be used as a polarizer protective film for a polarizing plate.
In this invention, the manufacturing method of a polarizing plate is not specifically limited, You may follow a conventionally well-known method. For example, a polarizing plate can be obtained by bonding the film of the present invention to at least one surface of a polarizer using a conventional method. In the bonding, the side of the film of the present invention bonded to the polarizer is subjected to alkali saponification treatment, and after applying a completely saponified polyvinyl alcohol aqueous solution to at least one surface of the polarizer, the film of the present invention and the polarizer are bonded together. Therefore, it can be suitably implemented.

  The polarizer is an element that passes only polarized waves in a certain direction. The polarizer used in the present invention is not particularly limited, and conventionally known polarizers can be used, and examples thereof include a polyvinyl alcohol film. As a polyvinyl alcohol-type film, what dye | stained the iodine and what dye | stained the dichroic dye can be used.

The polyvinyl alcohol film is formed, for example, by forming a polyvinyl alcohol aqueous solution and uniaxially stretching it to dye or dyeing it and then uniaxially stretching it, and then preferably performing a durability treatment using a boron compound. Etc. can be used suitably.
Moreover, 5-30 micrometers is preferable and, as for the film thickness of a polarizer, 10-20 micrometers is more preferable.

[Image display device]
The present invention also includes an image display device provided with the polarizing plate of the present invention described above.
In the present invention, the manufacturing method of the image display device is not particularly limited, and may be a conventionally known method. As the image display device, a liquid crystal display device (LCD) or the like is preferable.

  The liquid crystal display device is usually composed of a liquid crystal cell and polarizing plates disposed on both sides thereof, and it is preferable to dispose the film of the present invention in contact with the liquid crystal cell. Moreover, it is preferable to further laminate | stack a prism sheet and a diffusion film in a liquid crystal display device using a conventional method.

The present invention will be specifically described with reference to the following examples and comparative examples, but the present invention is not limited thereto.
Initially, the evaluation method of the resin composition produced in the present Example is shown.

[Weight average molecular weight and number average molecular weight]
The weight average molecular weight (Mw) and number average molecular weight (Mn) of the acrylic resin were determined by gel permeation chromatography (GPC) in terms of polystyrene. The apparatus and measurement conditions used for the measurement are as follows. When the sample was difficult to dissolve, a small amount of methanol was added to chloroform.
System: Tosoh GPC system HLC-8220
Measurement column configuration:
Guard column (manufactured by Tosoh, TSK guard column Super HZ-L)
・ Two separation columns (manufactured by Tosoh, TSKgel SuperHZM-M) in series connection Reference side column configuration:
・ Reference column (manufactured by Tosoh Corporation, TSKgel SuperH-RC)
Developing solvent: Chloroform (Wako Pure Chemical Industries, special grade)
Flow rate of developing solvent: 0.6 mL / min Standard sample: TSK standard polystyrene (manufactured by Tosoh, PS-oligomer kit)
Column temperature: 40 ° C

[Haze]
The haze of the produced optical film was determined in accordance with JIS K7136 using a turbidimeter (Nippon Denshoku Industries, NDH-5000).

[Film thickness]
The thickness of the film (optical film) was determined with a Digimatic micrometer (Mitutoyo).

[Film formability]
The dope liquid used in each Example and Comparative Example was cast using an applicator so that the film thickness was uniformly 40 to 50 μm on a glass plate at 25 ° C. After leaving still on the glass plate for 30 seconds, the dope was peeled off from the glass plate only slightly by using a cutter blade, and the whole was peeled off from the glass plate by pinching the portion with a finger. The ease of peeling at that time was compared as follows.
○: Easily peels off and a film without deformation is obtained.
X: It is difficult to peel off and the film stretches and deforms.

[Flexibility = Ductile fracture]
The flexibility was evaluated by the following ductile fracture test.
An optical film conditioned for 24 hours in an air-conditioned room at 23 ° C. and 55% RH is cut out at 100 mm (length) × 10 mm (width) under the conditions of 5 ° C. and 22% RH. The film was folded so that the film was exactly overlapped at 0 mm and the bending angle was 180 °. This evaluation was measured three times and evaluated as follows. In addition, "break" by evaluation here represents that it broke and separated into two or more pieces.
○ ・ ・ ・ Cannot be folded once out of 3 times △ ・ ・ ・ Can be folded only once out of 3 times × ・ ・ ・ Folded twice or more out of 3 times

[Measurement of elastic modulus]
The elastic modulus at 120 ° C. was measured by the following method.
Test piece: Thickness 40-100 μm, width 10 mm, length 40 mm, and sufficiently dried in advance.
Measuring device: Dynamic viscoelasticity measuring device manufactured by TA Co., Ltd. RSA-III, Tensile method Measuring conditions: While raising the temperature from room temperature to 130 ° C at 3 ° C / min, the storage elastic modulus is measured at a measurement frequency of 1 Hz, and at 120 ° C. The value of was read.

[Glass transition temperature (Tg)]
The glass transition temperature (Tg) was determined in accordance with JIS K7121 regulations. Specifically, using a differential scanning calorimeter (Rigaku, Thermo plus EVO DSC-8230), a sample of about 10 mg was heated from room temperature to 200 ° C. (heating rate 20 ° C./min) in a nitrogen gas atmosphere. From the DSC curve obtained in this way, the starting point method was used for evaluation. Α-alumina was used as a reference.

[Method for Measuring Content of Metal Component (B)]
A sample (acrylic resin composition) was dissolved in N-methylpyrrolidone at about 2.5 wt%, and the content (concentration) of metal atoms was determined using an ICP emission spectroscopic analyzer (CIROS-120, manufactured by Rigaku Corporation). It was measured. From the obtained concentration, the number of moles of metal atoms contained in the acrylic resin composition was determined.

[Quantification of acid components]
The content of the acid component in the acrylic resin was measured by the following back titration method.
About 0.15 g of the sample was dissolved in a mixed solution of about 25 g of methylene chloride and 15 g of methanol. Next, 2 drops of 1% phenolphthalein solution was added as an indicator. While stirring, add 0.1N sodium hydroxide aqueous solution until the solution turns pink to purple to make the amount of sodium hydroxide excessive from the amount of acid component, and record the required amount (V1). Subsequently, a 0.1N aqueous hydrochloric acid solution is slowly added while stirring, and the amount (V2) required for neutralizing the excess sodium hydroxide is recorded. Similarly, a blank test without adding a resin sample was performed to obtain v1 and v2. From [(V1-V2)-(v1-v2)] and the sample weight, the number of moles of the acid component per unit weight of the acrylic resin was calculated.
The number of moles of the acid component per unit weight indicates the content of ionic groups per unit weight of the acrylic resin.

[acrylic resin]
(Production Example 1)
In a glass container with a capacity of 100 ml, 19 parts by weight (0.1898 mol) of methyl methacrylate (MMA), 1 part by weight (0.0139 mol) of acrylic acid (AA), 10 parts by weight (0.1368 mol) of dimethylformamide, methyl ethyl ketone (MEK) ) 10 parts by mass (0.1387 mol), 2,2′-azobis (isobutyric acid) dimethyl (V-601 Wako Pure Chemical Industries) 0.05 parts by mass (2.171 × 10 ⁴ mol) were charged, and nitrogen was added thereto. Gas was introduced and sealed, and the mixture was reacted at 60 ° C. for 3 hours and at 50 ° C. for 48 hours. Subsequently, the obtained polymerization solution was diluted with MEK, and acrylic resin (A-1, number average molecular weight Mn 222,000, weight average molecular weight Mw 447,000) was obtained by reprecipitation, filtration and drying using hexane. It was. After collecting the acrylic resin (A-1) by repeating the same polymerization operation, 30 parts by mass of the acrylic resin (A-1) was melt-kneaded at 200 ° C. and 50 rpm with a laboratory plastic mill manufactured by Toyo Seiki. Then, a toluene solution of zinc octylate (1.46 parts by mass of zinc octylate, 1.83 parts by mass of toluene) was dropped little by little, and after completion of the dropwise addition, kneading was continued for 10 minutes, and the metal-containing acrylic resin (B-1) Got.
In addition, in the acrylic resin (A-1), the actual measurement value of the acid component monomer content was 0.7 × 10 ³ mol per 1 g of the acrylic resin, and reflected the acid component monomer charge content.
In the metal-containing acrylic resin (B-1), the measured metal amount relative to the acrylic resin was 0.85% by mass, reflecting the amount of charged metal.
Moreover, in the metal-containing acrylic resin (B-1), the actual measurement ratio of the metal content with respect to the acid component was 0.4 mol equivalent, reflecting the amount of charged metal.

(Production Example 2)
In a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, a nitrogen introduction tube, and a dropping funnel, 135 parts by mass of methyl methacrylate (MMA) (1.3484 mol), 7.5 parts by weight of methacrylic acid (MAA) (0 0.0871 mol), methyl acrylate (MA) 7.5 parts by mass (0.0872 mol), antioxidant (ADK STAB 2112, made by ADEKA) 0.05 part by mass (7.728 × 10 ⁵ mol), and toluene 100 parts by mass Part (1.085 mol) was charged, and the content was heated to 105 ° C. while introducing nitrogen gas. When refluxing with increasing temperature started, 0.15 parts by mass of t-amylperoxyisononanoate (manufactured by Arkema Yoshitomi, Luperox 570) (6.137 × 10 ⁴ mol as 100% purity) was used as a polymerization initiator. A solution of 0.225 parts by mass of t-amyl peroxyisononanoate (9.206 × 10 ⁴ mol with a purity of 100%) dissolved in 20 parts by mass of toluene (0.2171 mol) over 2 hours The solution polymerization was allowed to proceed while dropping, and when the dropping was completed, 30 parts by mass (0.3256 mol) of toluene was added for dilution, and after completion of the dropping, aging was further performed for 2 hours. Subsequently, the obtained polymerization solution was dried at 200 ° C. under a reduced pressure of 0.01 MPa for 1 hour to obtain an acrylic resin (A-2, number average molecular weight Mn 92,000, weight average molecular weight Mw 269000). It was. Subsequently, 30 parts of acrylic resin (A-2) was melt-kneaded at 200 ° C. and 50 rpm in a lab plast mill manufactured by Toyo Seiki. A methanol solution of zinc octylate (0.61 parts by mass of zinc octylate, Methanol (3.76 parts by mass) was added dropwise little by little, and kneading was continued for 10 minutes after the completion of the dropwise addition to obtain a metal-containing acrylic resin (B-2).
In addition, in the acrylic resin (A-2), the actual measurement value of the acid component monomer content was 0.7 × 10 ³ mol per 1 g of the acrylic resin, and reflected the acid component monomer charge content.
Moreover, in the metal-containing acrylic resin (B-2), the measured metal amount with respect to the acrylic resin was 0.39% by mass, reflecting the amount of charged metal.
Moreover, in the metal-containing acrylic resin (B-2), the actual measurement ratio of the metal content with respect to the acid component was 0.2 mol equivalent, reflecting the amount of charged metal.

(Production Example 3)
Except having changed to 18 parts by mass (MMA) of methyl methacrylate (MMA) and 2 parts by mass (0.0232 mol) of methacrylic acid (MAA), the same operation as in Production Example 1 was performed, and an acrylic resin (A-3, Number average molecular weight Mn 262,000, weight average molecular weight Mw 519000).
In addition, in the acrylic resin (A-3), the actual measurement value of the acid component monomer content was 1.1 × 10 ³ mol per 1 g of the acrylic resin, and reflected the acid component monomer charge content.

(Production Example 4)
Methyl methacrylate (MMA) 139.5 parts by mass (1.393 mol), methacrylic acid (MAA) 3 parts by mass (0.0348 mol), methyl acrylate (MA) 7.5 parts by mass (0.0872 mol) were used. Otherwise, an acrylic resin (A-4, number average molecular weight Mn 147,000, weight average molecular weight Mw 36.0 million) was obtained in the same manner as in Production Example 2.

(Production Example 5)
In a reaction vessel equipped with a stirrer, a temperature sensor, a cooling pipe, a nitrogen introduction pipe, and a dropping funnel, 84 parts by mass (0.8390 mol) of methyl methacrylate (MMA) and 10 parts by mass of N-phenylmaleimide (PMI) (0 .0577 mol), 2 parts by mass (0.0232 mol) of methacrylic acid (MAA), 4 parts by mass (0.0465 mol) of methyl acrylate (MA), 0.1 part by mass of n-dodecyl mercaptan (4.941 × 10 ⁴ mol) ), An antioxidant (ADK STAB 2112, manufactured by ADEKA) 0.05 parts by mass (7.728 × 10 ⁵ mol), and 100 parts by mass of toluene (1.085 mol), while introducing nitrogen gas to the contents, The product was heated to 105 ° C. When refluxing with increasing temperature started, 0.15 parts by mass of t-amylperoxyisononanoate (manufactured by Arkema Yoshitomi, Luperox 570) (6.137 × 10 ⁴ mol as 100% purity) was used as a polymerization initiator. While adding, 0.1 parts by mass of t-amyl peroxyisononanoate (Lupelox 570 manufactured by Arkema Yoshitomi) in 20 parts by mass (0.2171 mol) of toluene (4.092 × 10 ⁴ mol as 100% purity) was dissolved. Solution polymerization was allowed to proceed while dropping the solution over 2 hours, and after completion of the dropwise addition, aging was further performed for 2 hours. Subsequently, the obtained polymerization solution was dried at 240 ° C. under reduced pressure of 0.01 MPa for 1 hour to obtain an acrylic resin (A-5, number average molecular weight Mn 54,000, weight average molecular weight Mw 124,000). It was.

(Production Example 6)
In a glass container, methyl methacrylate (MMA) 19 parts by mass (0.1898 mol), methyl acrylate (MA) 1 part by mass (0.0116 mol), methyl isobutyl ketone (MIBK) 20 parts by mass (0.1997 mol), 2 , 2'-azobis (isobutyric acid) dimethyl (V-601 Wako Pure Chemical Industries, Ltd.) 0.06 parts by mass (2.606 × 10 ⁴ mol) was charged, nitrogen gas was introduced into this and sealed, at 60 ° C. The reaction was carried out for 4 hours at 50 ° C. for 48 hours. Subsequently, the obtained polymerization solution was diluted with MIBK, and acrylic resin (A-6, number average molecular weight Mn 235,000, weight average molecular weight Mw 537,000) was obtained by reprecipitation, filtration and drying using hexane. It was.

[Optical film]
Example 1
(Optical film 1)
Dope solution composition Acrylic resin B-1: 100 parts by mass Methylene chloride: 855 parts by mass Ethanol: 45 parts by mass The above composition was sufficiently dissolved to prepare a dope solution.
This dope solution was uniformly cast on a glass plate using an applicator. After being dried on the glass plate for 30 minutes at room temperature and further dried in an oven at 80 ° C. for 10 minutes, it was peeled off from the glass plate to obtain an optical film 1 having a thickness of 45 μm.

(Optical film 2)
(Example 2)
Dope liquid composition Acrylic resin B-2: 70 parts by mass CAP482-20 (acyl group total substitution degree 2.75, acetyl group substitution degree 0.19, propionyl group substitution degree 2.56 Cellulose acetate propio manufactured by Eastman Chemical Nate): 30 parts by mass Methylene chloride: 855 parts by mass Ethanol: 45 parts by mass The above composition was sufficiently dissolved to prepare a dope solution.
This dope solution was uniformly cast on a glass plate using an applicator. The glass plate was dried for 30 minutes at room temperature and further dried in an oven at 80 ° C. for 10 minutes, and then peeled from the glass plate to obtain an optical film 2 having a thickness of 43 μm.

(Example 3)
(Optical film 3)
Dope solution composition Acrylic resin A-3: 100 parts by mass Methylene chloride: 855 parts by mass Ethanol: 45 parts by mass Sodium methoxide: 1.88 parts by mass The above composition was sufficiently dissolved to prepare a dope solution. . It was prepared in the same manner as the optical film 1 except that this dope solution was used.
Moreover, in this dope solution, the measured metal amount with respect to the acrylic resin was 0.81% by mass, reflecting the charged metal amount.
Moreover, in this dope liquid, the actual measurement ratio of the metal content with respect to the acid component was 0.3 mol equivalent, reflecting the amount of charged metal.

(Example 4)
(Optical film 4)
Dope solution composition Acrylic resin A-4: 70 parts by mass CAP482-20: 30 parts by mass Methylene chloride: 855 parts by mass Ethanol: 45 parts by mass Sodium methoxide: 0.88 parts by mass It melt | dissolved and the dope liquid was created. It was produced in the same manner as the optical film 2 except that this dope solution was used.

(Example 5)
(Optical film 5)
It was created in the same manner as the optical film 4 except that A-5 was used as the acrylic resin.

(Comparative Example 1)
(Optical film 6)
It was created in the same manner as the optical film 1 except that A-6 was used as the acrylic resin.

(Comparative Example 2)
(Optical film 7)
It was created in the same manner as the optical film 2 except that A-6 was used as the acrylic resin.

Table 1 shows the physical properties of the optical films obtained in Examples 1 to 5 and Comparative Examples 1 and 2.
In Table 1, the charged content of the acid component monomer indicates the content of the acid component monomer per 1 g of the monomer composition used for the polymerization of the acrylic resin.

  As described above, the films of Examples 1 to 5 formed of the acrylic resin composition of the present invention including an acrylic resin having an ionic group and a metal component include an acrylic resin having no ionic group, and a metal Unlike the films of Comparative Examples 1 and 2 formed of an acrylic resin composition containing no components, there were no problems in all of flexibility, film formability, and elastic modulus at 120 ° C.

  Moreover, since the film containing the acrylic resin composition of this invention and a cellulose resin has small haze so that it may become clear from the result of Example 2, 4, and 5, the acrylic resin composition of this invention is cellulose resin. It is understood that it is excellent in compatibility and can be used as an additive for cellulose resin.

  According to the present invention, since an optical film excellent in flexibility and film formability can be obtained, an excellent polarizer protective film, polarizing plate, and image display device are produced using the optical film. Can do.

Claims (18)

An acrylic resin composition containing an acrylic resin (A) having a methacrylic acid ester unit as a polymerization unit and having an ionic group, and a metal component (B) ,
The acrylic resin (A) contains 50 mol% or more of the entire polymerized units of the acrylic resin (A) with methacrylic acid ester units,
The weight average molecular weight of the acrylic resin (A) is 200,000 to 1,200,000,
In the acrylic resin (A), the ionic group is an acid group,
The metal component (B) includes at least one metal selected from sodium, zinc, lithium, calcium, magnesium, and potassium;
The ratio of the metal component (B) is 0.01 to 10 parts by weight in terms of metal atom with respect to 100 parts by weight of the acrylic resin (A),
The ratio of the metal component (B) is 0.05 to 1.2 equivalents relative to 1 mol of the ionic group,
A resin composition which is a dope . An acrylic resin composition containing an acrylic resin (A) having a methacrylic acid ester unit as a polymerization unit and having an ionic group, and a metal component (B),
In the acrylic resin (A), the ionic group is an acid group,
The metal component (B) includes at least one metal selected from sodium, zinc, lithium, calcium, magnesium, and potassium;
The ratio of the metal component (B) is 0.01 to 10 parts by weight in terms of metal atom with respect to 100 parts by weight of the acrylic resin (A),
The ratio of the metal component (B) is 0.05 to 1.2 equivalents relative to 1 mol of the ionic group,
Furthermore, the resin composition containing a cellulose resin . In the acrylic resin (A), the proportion of methacrylic ester units is 50 mol% or more of the whole polymerized units, and the proportion of ionic groups is 1 × 10 ⁻⁵ to 1 × 10 ⁻² mol / g. Or the acrylic resin composition of 2. The resin composition according to claim 2 or 3, wherein the acrylic resin (A) has a weight average molecular weight of 100,000 or more. The resin composition according to any one of claims 1 to 4 , wherein the acrylic resin (A) has a weight average molecular weight of more than 300,000. The acrylic resin composition according to any one of claims 1 to 5, wherein in the acrylic resin (A), the ionic group has at least one selected from a carboxyl group and a sulfonic acid group . The acrylic resin (A) contains at least one ionic monomer unit selected from (meth) acrylic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, and styrenesulfonic acid. 7. The resin composition according to any one of 6. Ratio of the metal component (B), relative to the acrylic resin (A) 100 parts by weight of an acrylic resin composition according to any one of claims 1 to 7, which is 0.1 to 5 parts by weight in terms of metal atom. The ratio of a metal component (B) is 0.1-1.1 equivalent with respect to 1 mol of ionic groups, The acrylic resin composition in any one of Claims 1-8 . Acrylic resin (A) is a methacrylic acid ester unit (A1) containing 70 mol% or more of a methyl methacrylate unit, and a monomer unit (A2) having at least one acid group selected from a carboxyl group and a sulfonic acid group. and comprises (A1) / molar ratio of (A2) comprises at a rate of 99 / 1-80 / 20, and an ionic group at a ratio of 1 × ¹⁰ -4 ~5 × ^{10 -3} mol / g, tree Fat ,
The proportion of metallic component (B) is 0.1 to 1.1 equivalents to the ionic group 1 mol,
And from 0.1 to 5 parts by weight in terms of metal atom of the acrylic resin (A) 100 parts by weight of an acrylic resin composition according to any one of claims 1-9. The resin composition according to any one of claims 2 to 10 , which is a dope. The resin composition according to any one of claims 1, 3 to 11 is an additive for the cellulose resin. The resin composition according to any one of claims 1 to 12, which is for optics. The resin composition according to any one of claims 1 to 13 , which has an elastic modulus at 120 ° C of 2 × 10 ⁷ Pa or more. Film formed by the resin composition according to any one of claims 1-14. The film according to claim 15, which is a polarizer protective film. Polarizer having a film according to claim 15 or 16, wherein. An image display device comprising the polarizing plate according to claim 17 .