JP5532927B2 - Acrylic resin-containing film, polarizing plate and display device using the same - Google Patents

Description

  The present invention relates to an acrylic resin-containing film, a polarizing plate and a display device using the same, and more specifically, by blending acrylic resin and cellulose ester resin, and further using acrylic particles dispersed in a state incompatible with the resin. The present invention relates to an acrylic resin film that is transparent, highly heat resistant, and has markedly improved brittleness.

  Polymethyl methacrylate (hereinafter abbreviated as PMMA), which is a representative of conventional acrylic resins, has been suitably used for optical films from the viewpoint of its excellent transparency, dimensional stability, low hygroscopicity, and the like.

  However, the PMMA film has a problem that it has poor heat resistance and changes shape, and is inferior in brittleness and bending resistance when used under high temperatures or for long-term use.

  In particular, the surface hardness and flexibility at the time of film processing were not satisfactory performances, which was one of the causes of an increase in production yield.

  This problem is an important issue not only as a physical property of a single film but also in a polarizing plate and a display device using such a film.

  That is, in the liquid crystal display device, because the polarizing plate curls with the deformation of the film, the entire panel is warped, and the design phase difference changes even when used at the position on the viewing side surface. There was a problem that the viewing angle fluctuated and the color changed.

  In order to improve heat resistance, a method of adding polycarbonate (hereinafter abbreviated as PC) to an acrylic resin has been proposed, but there are limitations on the solvent that can be used, and the compatibility between resins is insufficient, It was easy to become cloudy and was difficult to use as an optical film (see, for example, Patent Document 1).

A method of introducing an alicyclic alkyl group as a copolymerization component of an acrylic resin, a method of forming a cyclic structure in a molecular main chain by carrying out an intramolecular cyclization reaction, and the like are disclosed. (For example, see Patent Documents 2, 3, and 4.)
However, in these methods, although the heat resistance is improved, the brittleness of the film is remarkably deteriorated, and the deterioration of the brittleness promotes the deformation of the liquid crystal panel and the polarizing plate itself, and eventually suppresses the change of the birefringence phase difference. It was not possible to solve the problems of fluctuation in viewing angle and change in color.

  This brittle deterioration has a problem of promoting the generation of dust even in the film cutting process.

Furthermore, with the recent increase in the size of displays, the reduction in the thickness of members, and the reduction in weight, these issues such as transparency, high heat resistance, and brittleness have become more prominent.
JP-A-5-306344 JP 2002-12728 A JP-A-2005-146084 JP 2007-191706 A

  Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide an acrylic resin-containing film that is transparent, has high heat resistance, and has markedly improved brittleness.

  It is another object of the present invention to provide a polarizing plate and a liquid crystal display device in which the acrylic resin-containing film has improved properties such as cutting properties, brittleness, bending resistance, surface hardness and the like, and optical properties.

    The above object of the present invention is achieved by the following configurations.

1. It has at least one curable resin layer , contains acrylic resin (A) and cellulose ester resin (B) in a mass ratio of 95: 5 to 30:70, and has a weight average molecular weight (Mw) of the acrylic resin (A). ) Is 80,000 to 1,000,000, the total substitution degree (T) of the acyl group of the cellulose ester resin (B) is 2.00 to 3.00, the acetyl group substitution degree (ac) is 0 to 1.89, and the acetyl group Other than the acyl group has 3 to 7 carbon atoms, a weight average molecular weight (Mw) of 75,000 to 280000, a haze value of less than 1%, a tension softening point of 105 to 145 ° C., and ductile fracture. An acrylic resin-containing film characterized by not causing it.

2. 2. The acrylic resin-containing film according to 1 above, wherein a total mass of the acrylic resin (A) and the cellulose ester resin (B) is 55 to 100% by mass with respect to the acrylic resin-containing film.

3. 3. The acrylic resin as described in 1 or 2 above, wherein the acrylic resin-containing film contains 0.5 to 45% by mass of acrylic particles (C) with respect to the total mass of the resin constituting the film. Containing film.

4). A polarizing plate, wherein the acrylic resin-containing film according to any one of 1 to 3 is used on at least one surface.

5. 4. A liquid crystal display device using the acrylic resin-containing film according to any one of 1 to 3 above.

6). It has at least one curable resin layer, contains acrylic resin (A) and cellulose ester resin (B) in a mass ratio of 95: 5 to 30:70, and has a weight average molecular weight (Mw) of the acrylic resin (A). ) Is 80,000 to 1,000,000, the total substitution degree (T) of the acyl group of the cellulose ester resin (B) is 2.00 to 3.00, the acetyl group substitution degree (ac) is 0 to 1.89, and the acetyl group An acrylic resin-containing film, wherein the number of carbon atoms of the acyl group other than is 3 to 7 and the weight average molecular weight (Mw) is 75000 to 280000.

7). 7. The acrylic resin-containing film as described in 6 above, wherein the total mass of the acrylic resin (A) and the cellulose ester resin (B) is 55 to 100% by mass with respect to the acrylic resin-containing film.

  According to the present invention, it is possible to provide an acrylic resin-containing film which is transparent, has high heat resistance, is brittle and has significantly improved surface hardness.

  Furthermore, it is possible to provide a polarizing plate and a liquid crystal display device using the acrylic resin-containing film with improved optical characteristics, cutting properties and the like.

It is the figure which showed typically the dope preparation process, casting process, and drying process of the solution casting film forming method used for this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Melting pot 3, 6, 12, 15 Filter 4, 13 Stock tank 5, 14 Liquid feed pump 8, 16 Conduit 10 Ultraviolet absorber charging pot 20 Merge pipe 21 Mixer 30 Die 31 Metal support 32 Web 33 Peeling position 34 Tenter device 35 Roll dryer 41 Particle charging vessel 42 Stock tank 43 Pump 44 Filter

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

  The present invention is a disadvantage of the conventional acrylic resin film, in that it has poor heat resistance, is used at high temperatures, is used for a long period of time, and the like, its shape is easily changed, is inferior in brittleness, and cannot be compatible with high surface hardness. It is an improvement.

  In other words, it has been found that the tension softening point is 105 to 145 ° C. and does not cause ductile fracture is heat resistance as an optical film used for liquid crystal display devices and the like, and as one means for achieving it. It has been found that by blending the acrylic resin (A) and the cellulose ester resin (B), an acrylic resin-containing film that is transparent, has high heat resistance, is brittle, and has significantly improved surface hardness can be obtained.

  The effect is further improved by having at least one curable resin layer.

  That is, the invention of claim 1 has at least one curable resin layer, has a haze value of less than 1%, has a tension softening point of 105 to 145 ° C., and does not cause ductile fracture. It has been found that an acrylic resin-containing film that is transparent, has high heat resistance, and has significantly improved brittleness can be obtained by the acrylic resin-containing film.

  In invention of Claim 2, acrylic resin (A) 30-95 mass parts, cellulose-ester resin (B) The said acrylic resin containing film is 95: 5-30: 70 of acrylic resin (A) and cellulose-ester resin. Contained in a mass ratio, the total substitution degree (T) of the acyl group of the cellulose ester resin (B) is 2.00 to 3.00, the acetyl group substitution degree (ac) is 0 to 1.89, and other than the acetyl group The acrylic resin-containing film according to claim 1, wherein the acyl group has 3 to 7 carbon atoms and a weight average molecular weight (Mw) of 75,000 to 280000, and is transparent and highly heat resistant. Thus, an acrylic resin-containing film for optically improved brittleness can be obtained.

  The invention according to claim 3 is the acrylic resin-containing film according to claim 2, wherein the acrylic resin (A) has a weight average molecular weight Mw of 80000 to 1000000.

  The invention according to claim 4 is characterized in that the acrylic resin-containing film contains 0.5 to 45% by mass of acrylic particles (C) with respect to the total mass of the resin constituting the film. It is an acrylic resin containing film in any one of 1-3, and when taking the effect of this invention, it is preferable to take the structure of Claims 2-3.

  The inventions of claim 5 and claim 6 use the polarizing plate characterized in that the acrylic resin-containing film is used on at least one surface, and the polarizing plate is used on at least one surface of a liquid crystal cell. This is a liquid crystal display device characterized in that the acrylic resin-containing film of the present invention, which is transparent, has high heat resistance, and remarkably improves brittleness, is applied to a polarizing plate and a liquid crystal display device as an optical film.

  Hereinafter, the present invention will be described in detail.

<Acrylic resin-containing film>
The acrylic resin-containing film of the present invention is characterized in that the haze value is less than 1%, the tension softening point is 105 to 145 ° C., and ductile fracture does not occur.

  The ductile fracture in the present invention is caused by a stress that is greater than the strength of a certain material, and is defined as a fracture accompanied by significant elongation or drawing of the material before the final fracture. The fracture surface is characterized by numerous indentations called dimples.

  Therefore, the “acrylic resin-containing film that does not cause ductile fracture” is characterized in that no fracture such as fracture is observed even when a large stress is applied to bend the film in two at 23 ° C. and 55% RH. .

  The demands for heat resistance and brittleness of optical films are increasingly high from the viewpoint of reworkability and productivity as optical films become larger and thinner with the recent increase in liquid crystal display devices. It is required that this does not happen.

  Forming an acrylic resin-containing film that does not cause ductile fracture is achieved by selecting the material configuration of the acrylic resin, cellulose ester, and other additives used as described below.

  The acrylic resin-containing film according to the present invention has a low haze, a high temperature device such as a projector, and a use in a high temperature environment such as an in-vehicle display device. It is preferable to set it as 105 to 145 degreeC, and it is more preferable to control to 110 to 130 degreeC.

  As a specific measuring method of the tension softening point temperature of the acrylic resin-containing film, for example, using a Tensilon tester (ORITC Corporation, RTC-1225A), the acrylic resin-containing film is 120 mm (length) × 10 mm (width). The temperature is increased at a rate of temperature increase of 30 ° C./min while pulling at a tension of 10 N, and the temperature at the time of 9 N is measured three times, and the average value can be obtained.

  The acrylic resin-containing film of the present invention preferably has a glass transition temperature (Tg) of 110 ° C. or higher. More preferably, it is 120 ° C. or higher. Especially preferably, it is 150 degreeC or more.

  The glass transition temperature referred to here is an intermediate value determined according to JIS K7121 (1987) using a differential scanning calorimeter (DSC-7 model manufactured by Perkin Elmer) at a temperature rising rate of 20 ° C./min. Point glass transition temperature (Tmg).

  In the acrylic resin-containing film of the present invention, the number of defects in the film plane of 5 μm or more is 1/10 cm square or less. More preferably, it is 0.5 piece / 10 cm square or less, more preferably 0.1 piece / 10 cm square or less.

  Here, the diameter of the defect indicates the diameter when the defect is circular, and when the defect is not circular, the range of the defect is determined by observing with a microscope by the following method, and the maximum diameter (diameter of circumscribed circle) is determined.

  The range of the defect is the size of the shadow when the defect is observed with the transmitted light of the differential interference microscope when the defect is a bubble or a foreign object. When the defect is a change in the surface shape, such as transfer of a roll flaw or an abrasion, the size is confirmed by observing the defect with the reflected light of a differential interference microscope.

  In addition, when observing with reflected light, if the size of the defect is unclear, aluminum or platinum is deposited on the surface for observation.

  In order to obtain a film having excellent quality expressed by such a defect frequency with high productivity, it is necessary to filter the polymer solution with high precision immediately before casting, to increase the cleanliness around the casting machine, It is effective to set drying conditions after rolling stepwise and to dry efficiently while suppressing foaming.

  If the number of defects is greater than 1/10 cm square, for example, when the film is tensioned during processing in a later step, the film may break with the defects as a starting point, and productivity may be significantly reduced. Moreover, when the diameter of a defect becomes 5 micrometers or more, it can confirm visually by polarizing plate observation etc., and when used as an optical member, a bright spot may arise.

  Moreover, even when it cannot be visually confirmed, when a hard coat layer or the like is formed on the film, the coating agent may not be formed uniformly, resulting in a defect (missing coating). Here, the defect is a void in the film (foaming defect) generated due to the rapid evaporation of the solvent in the drying process of the solution casting, a foreign matter in the film forming stock solution, or a foreign matter mixed in the film forming. This refers to the foreign matter (foreign matter defect) in the film.

  Moreover, the acrylic resin-containing film of the present invention preferably has a breaking elongation of at least one direction of 10% or more, more preferably 20% or more in the measurement based on JIS-K7127-1999.

  The upper limit of the elongation at break is not particularly limited, but is practically about 250%. In order to increase the elongation at break, it is effective to suppress defects in the film caused by foreign matter and foaming.

  The acrylic resin-containing film of the present invention preferably has a thickness of 20 μm or more. More preferably, it is 30 μm or more.

  The upper limit of the thickness is not particularly limited, but in the case of forming a film by a solution casting method, the upper limit is about 250 μm from the viewpoint of applicability, foaming, solvent drying, and the like. The thickness of the film can be appropriately selected depending on the application.

  The acrylic resin-containing film of the present invention preferably has a total light transmittance of 90% or more, more preferably 93% or more. Moreover, as a realistic upper limit, it is about 99%. In order to achieve excellent transparency expressed by such total light transmittance, it is necessary not to introduce additives and copolymerization components that absorb visible light, or to remove foreign substances in the polymer by high-precision filtration. It is effective to reduce the diffusion and absorption of light inside the film.

  Also, reduce the surface roughness of the film surface by reducing the surface roughness of the film contact part (cooling roll, calender roll, drum, belt, coating substrate in solution casting, transport roll, etc.) during film formation. It is also effective to reduce the diffusion and reflection of light on the film surface by reducing the refractive index of the acrylic resin.

  The acrylic resin-containing film of the present invention is characterized in that the haze value (turbidity), which is one of the indices indicating transparency, is 1.0% or less, but the luminance when incorporated in a liquid crystal display device, From the viewpoint of contrast, it is preferably 0.5% or less.

  In order to achieve such a haze value, it is effective to remove foreign substances in the polymer by high-precision filtration and reduce the diffusion of light inside the film.

  When acrylic particles are used, it is also effective to reduce the refractive index difference between the acrylic resin (A) and the acrylic particles (C).

  In addition, since the surface roughness also affects the haze value as surface haze, the particle diameter and addition amount of the acrylic particles (C) should be suppressed within the above range, or the surface roughness of the film contact portion during film formation should be reduced. Is also effective.

  In addition, the total light transmittance and haze value of the said acrylic resin containing film are the values measured according to JIS-K7361-1-1997 and JIS-K7136-2000.

  The acrylic resin-containing film of the present invention can be preferably used as an optical acrylic resin-containing film as long as it satisfies the physical properties as described above, but is excellent in workability and heat resistance by having the following composition. Film can be obtained.

  That is, from the viewpoint of achieving both workability and heat resistance, the acrylic resin-containing film contains the acrylic resin (A) and the cellulose ester resin in a mass ratio of 95: 5 to 30:70, and the cellulose ester resin (B ), The total substitution degree (T) of the acyl group is 2.00 to 3.00, the acetyl group substitution degree (ac) is 0 to 1.89, and the carbon number of the acyl group other than the acetyl group is 3 to 7, The excellent effect of the present invention can be obtained by an acrylic resin-containing film having a weight average molecular weight (Mw) of 75,000 to 280000.

  In the acrylic resin-containing film of the present invention, the acrylic resin (A) and the cellulose ester resin are contained in a mass ratio of 95: 5 to 30:70, preferably the acrylic resin (A) is 50% by mass or more. .

  The acrylic resin-containing film of the present invention may contain a resin other than the acrylic resin (A) and the cellulose ester resin (B).

  The total mass of the acrylic resin (A) and the cellulose ester resin (B) is 55 to 100 mass%, preferably 60 to 99 mass% of the acrylic resin-containing film.

<Acrylic resin (A)>
The acrylic resin used in the present invention includes a methacrylic resin. Although it does not restrict | limit especially as resin, What consists of 50-99 mass% of methyl methacrylate units and 1-50 mass% of other monomer units copolymerizable with this is preferable.

  Other monomers that can be copolymerized include alkyl methacrylates having 2 to 18 carbon atoms, alkyl acrylates having 1 to 18 carbon atoms, acrylic acid, methacrylic acid, and the like. Saturated acids, maleic acids, fumaric acids, unsaturated divalent carboxylic acids such as itaconic acid, aromatic vinyl compounds such as styrene, α-methylstyrene, and nucleus-substituted styrene, α, β- such as acrylonitrile, methacrylonitrile, etc. Examples thereof include unsaturated nitrile, maleic anhydride, maleimide, N-substituted maleimide, glutaric anhydride, and the like. These may be used alone or in combination of two or more.

  Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, 2-ethylhexyl acrylate, and the like are preferable from the viewpoint of thermal decomposition resistance and fluidity of the copolymer. n-Butyl acrylate is particularly preferably used.

  The acrylic resin (A) used in the acrylic resin-containing film of the present invention preferably has a weight average molecular weight (Mw) of 80000 to 1000000 from the viewpoint of mechanical strength as a film and fluidity when producing the film. .

  The weight average molecular weight of the acrylic resin of the present invention can be measured by gel permeation chromatography. The measurement conditions are as follows.

Solvent: Methylene chloride Column: Shodex K806, K805, K803G (Used by connecting three Showa Denko Co., Ltd.)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corp.) Mw = 2,800,000-500 calibration curves with 13 samples were used. The 13 samples are preferably used at approximately equal intervals.

  There is no restriction | limiting in particular as a manufacturing method of the acrylic resin (A) in this invention, You may use any well-known methods, such as suspension polymerization, emulsion polymerization, block polymerization, or solution polymerization. Here, as a polymerization initiator, a normal peroxide type and an azo type can be used, and a redox type can also be used. Regarding the polymerization temperature, suspension or emulsion polymerization may be performed at 30 to 100 ° C, and bulk or solution polymerization may be performed at 80 to 160 ° C. Furthermore, in order to control the reduced viscosity of the produced copolymer, polymerization can be carried out using alkyl mercaptan or the like as a chain transfer agent.

  With this molecular weight, both heat resistance and brittleness can be achieved.

  A commercially available thing can also be used as an acrylic resin of this invention. For example, Delpet 60N, 80N (Asahi Kasei Chemicals Co., Ltd.), Dialal BR52, BR80, BR83, BR85, BR88 (Mitsubishi Rayon Co., Ltd.), KT75 (Electric Chemical Co., Ltd.), etc. are mentioned. .

<Cellulose ester resin (B)>
The cellulose ester resin of the present invention may be substituted with either an aliphatic acyl group or an aromatic acyl group, but is preferably substituted with an acetyl group.

  When the cellulose ester resin of the present invention is an ester with an aliphatic acyl group, the aliphatic acyl group has 2 to 7 carbon atoms, and specifically includes acetyl, propionyl, butyryl, isobutyryl and the like.

  In the present invention, the aliphatic acyl group is meant to include those further having a substituent. When the aromatic ring is a benzene ring in the above-described aromatic acyl group, the substituent of the benzene ring Are exemplified.

  When the cellulose ester resin is an ester with an aromatic acyl group, the number of substituents X substituted on the aromatic ring is 0 or 1 to 5, preferably 1 to 3, particularly preferably One or two.

  Further, when the number of substituents substituted on the aromatic ring is 2 or more, they may be the same as or different from each other.

  As the structure used in the cellulose resin of the present invention, the cellulose ester resin has a structure having a structure selected from at least one of a substituted or unsubstituted aliphatic acyl group and a substituted or unsubstituted aromatic acyl group. Used, these may be single or mixed acid esters of cellulose.

  The substitution degree of the cellulose ester resin of the present invention is such that the total substitution degree (T) of the acyl group is 2.00 to 3.00 and the substitution degree (ac) of the acetyl group is 0 to 1.89. More preferably, the acyl group substitution degree (r) other than the acetyl group is 2.00 to 2.89.

  The acyl group other than the acetyl group preferably has 3 to 7 carbon atoms.

  In the cellulose ester resin of the present invention, those having an acyl group having 2 to 7 carbon atoms as a substituent, that is, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate It is preferably at least one selected from benzoate and cellulose benzoate.

  Among these, particularly preferable cellulose ester resins include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate.

  More preferably, the mixed fatty acid is a lower fatty acid ester of cellulose acetate propionate or cellulose acetate butyrate and having an acyl group having 2 to 4 carbon atoms as a substituent.

  The portion that is not substituted with an acyl group usually exists as a hydroxyl group. These can be synthesized by known methods.

In addition, the substitution degree of an acetyl group and the substitution degree of other acyl groups are obtained by a method prescribed in ASTM-D817-96.
If the weight average molecular weight (Mw) of the cellulose ester resin of the present invention is 75000 or more, the object of the present invention can be achieved even if it is about 1000000, but considering productivity, it is 75000 to 280000. The thing of 100000-2400 is still more preferable.

<Acrylic particles (C)>
In the present invention, the acrylic resin-containing film may contain acrylic particles.

  The acrylic particles (C) according to the present invention are characterized by being present in the state of particles in the acrylic resin (A) and the cellulose ester resin (B) and the acrylic resin-containing film (also referred to as an incompatible state). .

  The acrylic particles (C) are, for example, collected a predetermined amount of the prepared acrylic resin-containing film, dissolved in a solvent, stirred, and sufficiently dissolved / dispersed. It is preferable that the weight of the insoluble matter filtered and collected using a PTFE membrane filter having a pore size is 90% by mass or more of the acrylic particles (C) added to the acrylic resin-containing film.

  The acrylic particles (C) used in the present invention are not particularly limited, but are preferably acrylic particles (C) having a layer structure of two or more layers, particularly the following multilayer structure acrylic granular composite. It is preferable.

  The multilayer structure acrylic granular composite is formed by laminating an innermost hard layer polymer, a cross-linked soft layer polymer exhibiting rubber elasticity, and an outermost hard layer polymer from the center to the outer periphery. This refers to a particulate acrylic polymer having a structure.

  Preferred embodiments of the multilayer structure acrylic granular composite used in the acrylic resin composition of the present invention include the following. (A) Monomer composed of 80 to 98.9% by mass of methyl methacrylate, 1 to 20% by mass of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, and 0.01 to 0.3% by mass of polyfunctional grafting agent An innermost hard layer polymer obtained by polymerizing the body mixture, (b) in the presence of the innermost hard layer polymer, 75 to 98.5% by mass of an alkyl acrylate having an alkyl group with 4 to 8 carbon atoms, A crosslinked soft layer polymer obtained by polymerizing a monomer mixture comprising a multifunctional crosslinking agent of 0.01 to 5% by mass and a multifunctional grafting agent of 0.5 to 5% by mass; (c) the innermost hard In the presence of a polymer comprising a layer and a crosslinked soft layer, a monomer mixture comprising 80 to 99% by mass of methyl methacrylate and 1 to 20% by mass of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group is polymerized. Outermost hard layer weight And the obtained three-layer structure polymer is an innermost hard layer polymer (a) 5 to 40% by mass, a soft layer polymer (b) 30 to 60% by mass, and The outermost hard layer polymer (c) is composed of 20 to 50% by mass, has an insoluble part when fractionated with acetone, and an acrylic granular composite having a methyl ethyl ketone swelling degree of 1.5 to 4.0 at the insoluble part. .

  As disclosed in Japanese Patent Publication No. 60-17406 or Japanese Patent Publication No. 3-39095, not only the composition and particle size of each layer of the multilayer structure acrylic granular composite are defined, but also the multilayer structure acrylic granular composite. By setting the tensile modulus of the body and the degree of swelling of methyl ethyl ketone in the acetone-insoluble part within a specific range, it is possible to realize a further sufficient balance between impact resistance and stress whitening resistance.

  Here, the innermost hard layer polymer (a) constituting the multi-layer structure acrylic granular composite is 80 to 98.9% by mass of methyl methacrylate and 1 to 20% of alkyl acrylate having 1 to 8 carbon atoms in the alkyl group. % And a polyfunctional grafting agent obtained by polymerizing a monomer mixture consisting of 0.01 to 0.3% by mass.

  Here, examples of the alkyl acrylate having 1 to 8 carbon atoms in the alkyl group include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, 2-ethylhexyl acrylate, and the like. And n-butyl acrylate are preferably used.

  The proportion of the alkyl acrylate unit in the innermost hard layer polymer (a) is 1 to 20% by mass. When the unit is less than 1% by mass, the thermal decomposability of the polymer is increased, while the unit is 20% by mass. If it exceeds 50%, the glass transition temperature of the innermost hard layer polymer (c) is lowered, and the impact resistance imparting effect of the three-layer structure acrylic granular composite is lowered.

  Examples of the polyfunctional grafting agent include polyfunctional monomers having different polymerizable functional groups, such as allyl esters of acrylic acid, methacrylic acid, maleic acid, and fumaric acid, and allyl methacrylate is preferably used. . The polyfunctional grafting agent is used to chemically bond the innermost hard layer polymer and the soft layer polymer, and the ratio used during the innermost hard layer polymerization is 0.01 to 0.3% by mass. .

  The crosslinked soft layer polymer (b) constituting the acrylic granular composite is an alkyl acrylate 75-98.5 having 1 to 8 carbon atoms in the presence of the innermost hard layer polymer (a). What is obtained by polymerizing a monomer mixture consisting of mass%, polyfunctional crosslinking agent 0.01 to 5 mass% and polyfunctional grafting agent 0.5 to 5 mass% is preferable.

  Here, as the alkyl acrylate having 4 to 8 carbon atoms in the alkyl group, n-butyl acrylate or 2-ethylhexyl acrylate is preferably used.

  In addition to these polymerizable monomers, it is possible to copolymerize 25% by mass or less of other monofunctional monomers capable of copolymerization.

  Other monofunctional monomers that can be copolymerized include styrene and substituted styrene derivatives. As the ratio of the alkyl acrylate having 4 to 8 carbon atoms in the alkyl group and styrene increases, the glass transition temperature of the produced polymer (b) decreases as the former increases, that is, it can be softened.

  On the other hand, from the viewpoint of the transparency of the resin assembly, the refractive index of the soft layer polymer (b) at room temperature is set to the innermost hard layer polymer (a), the outermost hard layer polymer (c), and the hard heat. It is more advantageous to make it closer to the plastic acrylic resin, and the ratio between them is selected in consideration of these.

  For example, in applications where the coating layer thickness is small, it is not always necessary to copolymerize styrene.

  As the polyfunctional grafting agent, those mentioned in the item of the innermost layer hard polymer (a) can be used. The polyfunctional grafting agent used here is used to chemically bond the soft layer polymer (b) and the outermost hard layer polymer (c), and the proportion used during the innermost hard layer polymerization is impact resistance. 0.5-5 mass% is preferable from a viewpoint of the property provision effect.

  As the polyfunctional crosslinking agent, generally known crosslinking agents such as divinyl compounds, diallyl compounds, diacrylic compounds, and dimethacrylic compounds can be used, and polyethylene glycol diacrylate (molecular weight 200 to 600) is preferably used.

  The polyfunctional cross-linking agent used here is used to generate a cross-linked structure at the time of polymerization of the soft layer (b) and develop an effect of imparting impact resistance. However, if the above-mentioned polyfunctional grafting agent is used during the polymerization of the soft layer, the polyfunctional crosslinking agent is not an essential component because the crosslinked structure of the soft layer (b) is generated to some extent. Is preferably 0.01 to 5% by mass from the viewpoint of imparting impact resistance.

  In the presence of the innermost hard layer polymer (a) and the soft layer polymer (b), the outermost hard layer polymer (c) constituting the multilayer structure acrylic granular composite is 80 to 99 masses of methyl methacrylate. % And a monomer mixture obtained by polymerizing a monomer mixture consisting of 1 to 20% by mass of an alkyl acrylate having 1 to 8 carbon atoms in the alkyl group is preferable.

  Here, as the acrylic alkylate, those described above are used, and methyl acrylate and ethyl acrylate are preferably used. The ratio of the alkyl acrylate unit in the outermost hard layer (c) is preferably 1 to 20% by mass.

  Further, for the purpose of improving the compatibility with the acrylic resin (A) during the polymerization of the outermost hard layer (c), it is also possible to use an alkyl mercaptan or the like as a chain transfer agent in order to adjust the molecular weight.

  In particular, it is preferable to provide the outermost hard layer with a gradient such that the molecular weight gradually decreases from the inside toward the outside in order to improve the balance between elongation and impact resistance. As a specific method, the monomer mixture for forming the outermost hard layer is divided into two or more, and the molecular weight is increased from the inside by a method of sequentially increasing the amount of chain transfer agent added each time. It is possible to make it smaller toward the outside.

  The molecular weight formed at this time can also be examined by polymerizing the monomer mixture used each time under the same conditions and measuring the molecular weight of the obtained polymer.

  The particle diameter of the acrylic granular composite which is a multilayer structure polymer preferably used in the present invention is not particularly limited, but is preferably 10 nm or more and 1000 nm or less, and more preferably 20 nm or more and 500 nm or less. More preferably, it is most preferably 50 nm or more and 400 nm or less.

  In the acrylic granular composite that is a multilayer structure polymer preferably used in the present invention, the mass ratio of the core and the shell is not particularly limited, but when the entire multilayer structure polymer is 100 parts by mass, The core layer is preferably 50 parts by mass or more and 90 parts by mass or less, and more preferably 60 parts by mass or more and 80 parts by mass or less.

  Examples of such commercially available multilayered acrylic granular composites include, for example, “Metablene” manufactured by Mitsubishi Rayon Co., “Kane Ace” manufactured by Kaneka Chemical Co., Ltd., “Paralloid” manufactured by Kureha Chemical Co., Ltd., Rohm and Haas “Acryloid” manufactured by KK, “Staffyroid” manufactured by Ganz Kasei Kogyo Co., Ltd., “Parapet SA” manufactured by Kuraray Co., Ltd., and the like can be used alone or in combination.

  Further, specific examples of the acrylic particles (c-1) which are graft copolymers suitably used as the acrylic particles (C) preferably used in the present invention include unsaturated carboxylic acids in the presence of a rubbery polymer. A monomer mixture comprising an acid ester monomer, an unsaturated carboxylic acid monomer, an aromatic vinyl monomer, and, if necessary, other vinyl monomers copolymerizable therewith A polymerized graft copolymer may be mentioned.

  The rubbery polymer used for the acrylic particles (c-1) as the graft copolymer is not particularly limited, but diene rubber, acrylic rubber, ethylene rubber, and the like can be used. Specific examples include polybutadiene, styrene-butadiene copolymer, block copolymer of styrene-butadiene, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer, polyisoprene, butadiene-methyl methacrylate copolymer. , Butyl acrylate-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-isoprene copolymer, and ethylene-acrylic acid Examples thereof include a methyl copolymer. These rubbery polymers can be used alone or in a mixture of two or more.

  Moreover, since the transparency of the acrylic resin containing film of this invention can be obtained when each refractive index of an acrylic resin (A) and an acrylic particle (C) is approximate, it is preferable. Specifically, the refractive index difference between the acrylic particles (C) and the acrylic resin (A) is preferably 0.05 or less, more preferably 0.02 or less, and particularly preferably 0.01 or less.

  In order to satisfy such a refractive index condition, a method of adjusting the monomer unit composition ratio of the acrylic resin (A) and / or a rubbery polymer or monomer used for the acrylic particles (C) The difference in refractive index can be reduced by a method of adjusting the composition ratio, and an acrylic resin-containing film excellent in transparency can be obtained.

    The difference in refractive index referred to here is a solution in which the acrylic resin-containing film of the present invention is sufficiently dissolved in a solvent in which the acrylic resin (A) is soluble to obtain a cloudy solution, which is subjected to an operation such as centrifugation. By separating the solvent-soluble part and the insoluble part, and purifying the soluble part (acrylic resin (A)) and the insoluble part (acrylic particles (C)), respectively, the measured refractive index (23 ° C., measurement wavelength) : 550 nm).

  There is no restriction | limiting in particular in the method of mix | blending an acrylic particle (C) with an acrylic resin (A) in this invention, After blending an acrylic resin (A) and another arbitrary component previously, Usually at 200-350 degreeC, A method of uniformly melt-kneading with a single-screw or twin-screw extruder while adding acrylic particles (C) is preferably used.

  In addition, a solution in which acrylic particles (C) are dispersed in advance is added to and mixed with a solution (dope solution) in which acrylic resin (A) and cellulose ester resin (B) are dissolved, acrylic particles (C) and A method such as in-line addition of a solution obtained by dissolving or mixing other optional additives can be used.

  A commercially available thing can also be used as an acrylic particle of this invention. For example, metabrene W-341 (C2) (manufactured by Mitsubishi Rayon Co., Ltd.), Chemisnow MR-2G (C3), MS-300X (C4) (manufactured by Soken Chemical Co., Ltd.) and the like can be mentioned.

  The acrylic resin-containing film of the present invention preferably contains 0.5 to 45% by mass of acrylic particles (C) with respect to the total mass of the resin constituting the film.

<Other additives>
In the acrylic resin-containing film of the present invention, a plasticizer can be used in combination in order to improve the fluidity and flexibility of the composition. Examples of the plasticizer include phthalate ester, fatty acid ester, trimellitic ester, phosphate ester, polyester, and epoxy.

  Of these, polyester and phthalate plasticizers are preferably used. Polyester plasticizers are superior in non-migration and extraction resistance compared to phthalate ester plasticizers such as dioctyl phthalate, but are slightly inferior in plasticizing effect and compatibility.

  Therefore, it can be applied to a wide range of uses by selecting or using these plasticizers according to the use.

  The polyester plasticizer is a reaction product of a monovalent or tetravalent carboxylic acid and a monovalent or hexavalent alcohol, and is mainly obtained by reacting a divalent carboxylic acid with a glycol. . Representative divalent carboxylic acids include glutaric acid, itaconic acid, adipic acid, phthalic acid, azelaic acid, sebacic acid and the like.

  In particular, when adipic acid, phthalic acid or the like is used, those having excellent plasticizing properties can be obtained. Examples of the glycol include glycols such as ethylene, propylene, 1,3-butylene, 1,4-butylene, 1,6-hexamethylene, neopentylene, diethylene, triethylene, and dipropylene. These divalent carboxylic acids and glycols may be used alone or in combination.

  The ester plasticizer may be any of ester, oligoester and polyester types, and the molecular weight is preferably in the range of 100 to 10000, but preferably in the range of 600 to 3000, the plasticizing effect is large.

  The viscosity of the plasticizer has a correlation with the molecular structure and molecular weight. In the case of an adipic acid plasticizer, the viscosity is preferably in the range of 200 to 5000 mPa · s (25 ° C.) in view of compatibility and plasticization efficiency. Furthermore, some polyester plasticizers may be used in combination.

    The plasticizer is preferably added in an amount of 0.5 to 30 parts by mass with respect to 100 parts by mass of the composition containing the acrylic resin (A). If the added amount of the plasticizer exceeds 30 parts by mass, the surface becomes sticky, which is not preferable for practical use.

  The composition containing the acrylic resin (A) of the present invention preferably contains an ultraviolet absorber, and examples of the ultraviolet absorber used include benzotriazole, 2-hydroxybenzophenone, and salicylic acid phenyl ester. Can be mentioned. For example, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3 Triazoles such as 5-di-t-butyl-2-hydroxyphenyl) benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone And benzophenones.

  Here, among ultraviolet absorbers, ultraviolet absorbers having a molecular weight of 400 or more are less likely to volatilize at a high boiling point and are difficult to disperse even during high-temperature molding, so that the weather resistance is effectively improved with a relatively small amount of addition. be able to.

  In addition, since the UV absorber does not easily migrate from the inside of the film to the thin coating layer and is difficult to deposit on the surface, the amount of the UV absorber contained is maintained for a long time, and the durability of the weather resistance improvement effect is maintained. It is preferable from the point of being excellent.

  Examples of the ultraviolet absorber having a molecular weight of 400 or more include 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2-benzotriazole, 2,2-methylenebis [4- (1, 1,3,3-tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol], bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis ( Hindered amines such as 1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid Bis (1,2,2,6,6-pentamethyl-4-piperidyl), 1- [2- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl L] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine and the like, hindered phenol and hindered amine A hybrid system having both structures can be mentioned, and these can be used alone or in combination of two or more. Among these, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2-benzotriazole and 2,2-methylenebis [4- (1,1,3,3- Tetrabutyl) -6- (2H-benzotriazol-2-yl) phenol] is particularly preferred.

  Furthermore, various antioxidants can also be added to the acrylic resin (A) used in the acrylic resin-containing film of the present invention in order to improve the thermal decomposability and thermal colorability during molding. In addition, an antistatic agent can be added to impart antistatic performance to the acrylic resin-containing film.

  As the acrylic resin composition of the present invention, a flame retardant acrylic resin composition containing a phosphorus flame retardant may be used.

  Phosphorus flame retardants used here include red phosphorus, triaryl phosphate ester, diaryl phosphate ester, monoaryl phosphate ester, aryl phosphonate compound, aryl phosphine oxide compound, condensed aryl phosphate ester, halogenated alkyl phosphorus. Examples thereof include one or a mixture of two or more selected from acid esters, halogen-containing condensed phosphates, halogen-containing condensed phosphonates, halogen-containing phosphites, and the like.

  Specific examples include triphenyl phosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phenylphosphonic acid, tris (β-chloroethyl) phosphate, tris (dichloropropyl). Examples thereof include phosphate and tris (tribromoneopentyl) phosphate.

<At least one curable resin layer>
The acrylic resin-containing film of the present invention is characterized by having at least one curable resin layer. This curable resin layer exhibits an improvement effect not only on the surface hardness but also on brittleness, particularly flex resistance.

  The curable resin layer of the present invention may be a single layer, or may be two or more layers depending on the degree of use. From the point of productivity, it is preferable that it is 1 layer or more and 4 layers or less. Moreover, you may provide on both surfaces of an acrylic resin film.

  As a refractive index of the transparent resin which comprises the curable resin layer of this invention, it is preferable that it is 1.47 or more, More preferably, it is 1.47-1.70.

  In order to make the refractive index within this range, the type and amount ratio of the transparent resin may be appropriately selected. If the refractive index is less than 1.47, it is difficult to obtain a resin with high hardness. If the refractive index is greater than 1.70, unevenness of the film tends to be noticeable.

  The refractive index of the transparent resin can be quantitatively evaluated by, for example, directly measuring with an Abbe refractometer at 23 ° C. or measuring a spectral reflection spectrum or a spectral ellipsometry.

  The curable resin is preferably a binder polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a binder polymer having a saturated hydrocarbon chain as a main chain.

  As the curable resin, a resin curable by heat or actinic radiation can be used, and a resin curable by a crosslinking reaction or the like by actinic radiation such as ultraviolet rays or electron beams is particularly preferable.

  Specific examples of the curable resin include an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. The ultraviolet curable acrylate resin is preferably used.

  The UV curable urethane acrylate resin generally includes a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer, and further includes 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter, acrylate includes methacrylate). It can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate.

  For example, those described in JP 59-151110 A can be used. For example, a mixture of 100 parts Unidic 17-806 (Dainippon Ink Co., Ltd.) and 1 part Coronate L (Nihon Polyurethane Co., Ltd.) is preferably used.

  Examples of UV curable polyester acrylate resins include those which are easily formed when 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers are generally reacted with polyester polyols. JP-A-59-151112 Those described in the publication can be used.

  Specific examples of the ultraviolet curable epoxy acrylate resin include an epoxy acrylate as an oligomer, a reactive diluent and a photopolymerization initiator added thereto, and reacted to form an oligomer. Those described in Japanese Patent No. 105738 can be used.

  Specific examples of UV curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. Can be mentioned.

  Specific examples of photopolymerization initiators for these curable resins include benzoin and its derivatives, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. You may use with a photosensitizer.

  In addition, when using an epoxy acrylate photopolymerization initiator, a sensitizer such as n-butylamine, triethylamine, tri-n-butylphosphine can be used.

  The photopolymerization initiator or photosensitizer used in the curable resin composition is 0.1 to 25 parts by mass, preferably 1 to 15 parts by mass with respect to 100 parts by mass of the composition.

  As acrylate resins, methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyl dimethyl adiacrylate , Trimethylolpropane triacrylate, pentaerythritol tetraacrylic ester and the like.

  As these commercially available products, Adekaoptomer KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (manufactured by Asahi Denka Co., Ltd.); -101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS-101, FT-102Q8, MAG -1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Co., Ltd.); Seika Beam PHC2210 (S), PHC X-9 (K-3), PHC2213, DP-10, DP-20, DP -30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (manufactured by Dainichi Seika Kogyo Co., Ltd.); KRM7033, KRM703 , KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel UC Corporation); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120, RC-5122 RC-5152, RC-5171, RC-5180, RC-5181 (Dainippon Ink Chemical Co., Ltd.); 340 clear (manufactured by China Paint Co., Ltd.); Sunrad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (manufactured by Sanyo Chemical Industries); SP -1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.); RCC-15C (manufactured by Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), NK hard B-420, NK ester A-DOG, NK ester A-IBD-2E (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like can be appropriately selected and used.

  Other examples include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dioxane glycol acrylate, ethoxylated acrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. Can be mentioned.

<Anti-glare curable resin layer>
The curable resin layer of the present invention may contain particles in order to impart antiglare properties. That is, it may have a function as an antiglare hard coat layer.

  A transparent resin, for example, a binder layer mainly composed of an active energy ray curable resin can contain particles having an average particle size of 0.5 to 6 μm, but preferably has a structure containing fluorine-containing acrylic resin particles. . Moreover, you may further contain the particle | grains with an average particle diameter of 0.01-1.0 micrometer.

<Fluorine-containing acrylic resin particles having an average particle size of 0.5 to 6 [mu] m>
The fluorine-containing acrylic resin particles of the present invention are, for example, particles formed from a fluorine-containing acrylic ester or methacrylic ester polymer.

  Specific examples of the fluorine-containing acrylic ester or methacrylic ester include 1H, 1H, 3H-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, 1H, 1H, 7H- Dodecafluoroheptyl (meth) acrylate, 1H, 1H, 9H-hexadecafluorononyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (Meth) acrylate, 2- (perfluorobutyl) ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2-perfluorodecylethyl (Meth) acrylate, 3-par Fluorobutyl-2-hydroxypropyl (meth) acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth) acrylate, 3-perfluorooctyl-2-hydroxypropyl (meth) acrylate, 2- (perfluoro-3-methylbutyl) ) Ethyl (meth) acrylate, 2- (perfluoro-5-methylhexyl) ethyl (meth) acrylate, 2- (perfluoro-7-methyloctyl) ethyl (meth) acrylate, 3- (perfluoro-3-methylbutyl) ) -2-hydroxypropyl (meth) acrylate, 3- (perfluoro-5-methylhexyl) -2-hydroxypropyl (meth) acrylate, 3- (perfluoro-7-methyloctyl) -2-hydroxypropyl (meth) ) Acrylate, 1H-1 (Trifluoromethyl) trifluoroethyl (meth) acrylate, 1H, 1H, 3H-hexafluorobutyl (meth) acrylate, trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, perfluorooctylethyl acrylate, 2- (perfluorobutyl) Examples include ethyl-α-fluoroacrylate.

  Among the fluorine-containing acrylic resin particles, particles made of 2- (perfluorobutyl) ethyl-α-fluoroacrylate, fluorine-containing polymethyl methacrylate particles, and fluorine-containing methacrylic acid in the presence of a crosslinking agent are vinyl monomers. Particles copolymerized with are preferred, and fluorine-containing polymethyl methacrylate particles are more preferred.

  A vinyl monomer copolymerizable with a fluorine-containing (meth) acrylic acid ester may be copolymerized.

  These may be those having a vinyl group, specifically, methacrylic acid alkyl esters such as methyl methacrylate and butyl methacrylate, alkyl acrylates such as methyl acrylate and ethyl acrylate, styrene, α -Styrenes, such as methylstyrene, etc. are mentioned, These can be used individually or in mixture.

  The crosslinking agent used in the polymerization reaction is not particularly limited, but those having two or more unsaturated groups are preferably used. For example, bifunctional dimethacrylates such as ethylene glycol dimethacrylate and polyethylene glycol dimethacrylate are used. And trimethylolpropane trimethacrylate, divinylbenzene and the like.

  The polymerization reaction for producing the fluorine-containing polymethyl methacrylate particles may be either random copolymerization or block copolymerization. Specifically, for example, the method described in JP-A No. 2000-169658 can also be mentioned.

  As a commercial item, Nippon Paint Co., Ltd. product: F-191, Negami Kogyo Co., Ltd. product: MF-0043, etc. are mentioned. These fluorine-containing acrylic resin particles may be used alone or in combination of two or more.

  Moreover, the state of these fluorine-containing acrylic resin particles may be added in any state such as powder or emulsion.

  Moreover, you may use the fluorine-containing crosslinked particle as described in Paragraphs 0028-0055 of Unexamined-Japanese-Patent No. 2004-83707.

  The refractive index of the fluorine-containing acrylic resin particles of the present invention is preferably 1.38 to 1.46.

  As content of the fluorine-containing acrylic resin particle of this invention, 0.01-500 mass parts is preferable with respect to 100 mass parts of transparent resin which comprises an anti-glare hard-coat layer, More preferably, it is 0.1-100. Part by mass, particularly preferably 1 to 60 parts by mass.

  The average particle diameter of the fluorine-containing acrylic resin particles of the present invention is 0.5 to 6 μm, and preferably 0.55 to 4.0 μm.

  The average particle diameter is 100 particles obtained by taking a scanning electron micrograph of the particles (1000 particles or more), and using the image processing apparatus LUZEX-III (manufactured by Nireco) as the diameter of the particles in the photograph. The average value was measured and the average value was calculated.

<Particles with an average particle size of 0.01 to 1.0 μm>
Examples of the particles having an average particle diameter of 0.01 to 1 μm that are preferably contained in the present invention include acrylic particles and inorganic particles mainly composed of silica.

  Examples of the silica particles include product names such as Nippon Aerosil Co., Ltd., Aerosil 200, 200V, 300, Degussa, Aerosil OX50, TT600, Nippon Shokubai Co., Ltd., KEP-10, KEP-50, KEP-100 and the like.

  Colloidal silica may also be used. Colloidal silica is obtained by dispersing silicon dioxide in water or an organic solvent in a colloidal form, and is not particularly limited, and is spherical, acicular or beaded.

  Such colloidal silica is commercially available, and examples thereof include the Snowtex series of Nissan Chemical Industries, the Cataloid-S series of Catalytic Chemical Industries, and the Rebacil series of Bayer.

  Also, beaded colloidal silica in which primary particles of cation-modified with alumina sol or aluminum hydroxide are bonded in a bead shape by bonding the particles with divalent or higher metal ions.

  Examples of beaded colloidal silica include Snowtex-AK series, Snowtex-PS series, Snowtex-UP series, etc., manufactured by Nissan Chemical Industries, Ltd. Specifically, IPS-ST-L (isopropanol silica sol, particle size 40-50 nm). , Silica concentration 30%), MEK-ST-MS (methyl ethyl ketone silica sol, particle diameter 17-23 nm, silica concentration 35%), etc. MEK-ST (methyl ethyl ketone silica sol, particle diameter 10-15 nm, silica concentration 30%), MEK- ST-L (methyl ethyl ketone silica sol, particle diameter 40-50 nm, silica concentration 30%), MEK-ST-UP (methyl ethyl ketone silica sol, particle diameter 9-15 nm (chain structure), silica concentration 20%) and the like can be mentioned.

  Examples of the acrylic particles include fluorine-containing acrylic resin particles. For example, Nippon Paint: S-4000, FS-701, and acrylic-styrene particles include, for example, Nippon Paint: S-1200, MG-251. .

  Among these particles having an average particle diameter of 0.01 to 1 μm, fluorine-containing acrylic resin particles are preferable.

  Particles having an average particle diameter of 0.01 to 1 μm constitute the antiglare cured resin layer as the content from the stability of the coating liquid forming the antiglare cured resin layer and the dispersibility of the dispersion. 0.01-500 mass parts is preferable with respect to 100 mass parts of transparent resin, More preferably, it is 0.1-100 mass parts.

  The content ratio with respect to particles having an average particle diameter of 0.01 to 1 μm can be appropriately selected within a range of 0 to 500 mass% with respect to particles having an average particle diameter of 1.5 to 6 μm.

The particles may be added in any state such as powder or emulsion. Moreover, the density of the translucent particles is preferably 10 to 1000 mg / m ² , more preferably 100 to 700 mg / m ² .

<Other substances contained in the antiglare cured resin layer>
For the antiglare cured resin layer, other organic particles include silicone resin powder, polystyrene resin powder, polycarbonate resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, or poly An ultraviolet curable resin composition such as an ethylene fluoride resin powder can also be added.

  Moreover, you may further contain the particle | grains of Unexamined-Japanese-Patent No. 2000-241807 as needed.

  Further, the refractive index of the other particles is preferably 1.45 to 1.70, more preferably 1.45 to 1.65.

  Note that the refractive index of the particles is measured by measuring the turbidity by dispersing the same amount of particles in a solvent in which the refractive index is changed by changing the mixing ratio of two types of solvents having different refractive indexes. The refractive index of the solvent can be measured by measuring with an Abbe refractometer.

  Further, the antiglare cured resin layer preferably contains the following silicone surfactant, fluorine compound, polyoxyether compound or the like as the surfactant.

  These components increase productivity by imparting high-speed coating suitability while improving surface uniformity.

  Preferable examples of the fluorine-based compound include fluoroaliphatic group-containing copolymers, and specifically, the compounds and description methods described in paragraphs 0053 to 0082 of JP-A-2007-45142 can be used.

  In addition, the compounds and description methods described in paragraphs 0008 to 0031 of JP-A No. 2000-119354 can also be used.

  Since these components are added in the range of 0.01 to 5% by mass with respect to the solid content component in the coating solution, the effect of improving surface defects such as coating unevenness, drying unevenness, and point defects appears. preferable.

  In addition, as the fluorine-based compound, a copolymer polymer obtained by grafting siloxane (including polysiloxane) and / or organosiloxane (including organopolysiloxane) to a fluororesin can also be preferably used.

  Specific examples include ZX-022H, ZX-007C, ZX-049, and ZX-047-D manufactured by Fuji Chemical Industry Co., Ltd. These compounds may be used as a mixture.

  Commercially available products of polyoxyethylene alkyl ether include Emulgen 1108, Emulgen 1118S-70 (manufactured by Kao Corporation), and commercially available products of polyoxyethylene lauryl ether include Emulgen 103, Emulgen 104P, Emulgen 105, and Emulgen 106. , Emulgen 108P, Emulgen 109P, Emulgen 120P, Emulgen 123P, Emulgen 147, Emulgen 150, Emulgen 130K (above, manufactured by Kao Corporation), polyoxyethylene cetyl ether as commercially available products, Emulgen 210P, Emulgen 220 (above, Kao Corporation), polyoxyethylene stearyl ether commercially available products such as Emulgen 220, Emulgen 306P (above, Kao Corporation), polyoxyalkylene alkyl ether market As the products, Emulgen LS-106, Emulgen LS-110, Emulgen LS-114, Emulgen MS-110 (manufactured by Kao Corporation), polyoxyethylene higher alcohol ether, commercially available products such as Emulgen 705, Emulgen 707, Emulgen 709 and the like.

  The polyoxyether compounds may be used alone or in combination of two or more. Moreover, you may use together an acetylene glycol type compound, a nonionic surfactant, a radically polymerizable nonionic surfactant, etc.

  The antiglare cured resin layer may contain a color tone adjusting agent (dye or pigment) having a color tone adjusting function as a color correction filter for various display elements.

  Moreover, you may make it contain an electromagnetic wave shielding agent or an infrared absorber, etc. and to have each function.

  The antiglare cured resin layer may contain other functional thiol compounds as curing aids, such as 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate). 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione and the like.

  Moreover, as a commercial item, Showa Denko Co., Ltd. make, brand name Karenz MT series, etc. are mentioned. The other functional thiol compound is preferably added in the range of 0.01 to 50 parts by mass, more preferably 0.05 to 30 parts by mass with respect to 100 parts by mass of the active energy ray-curable resin.

  By adding in the above range, it suitably acts as a curing aid and also exists stably in the antiglare hard coat layer.

  In addition to the organic particles of the present invention, the antiglare cured resin layer is made of titanium, zirconium, aluminum, indium, zinc, tin, antimony in addition to the organic particles of the present invention in order to improve hardness, prevent static charge, and adjust the refractive index of the layer. The main component is an oxide of at least one metal selected from among them, and the average particle size is 10 μm or less, for example, 2 μm or less, preferably 0.2 μm or less, particularly preferably 0.1 μm or less, more preferably 0.06 μm or less. You may contain the inorganic particle which is.

  Of the oxides of at least one metal selected from titanium, zirconium, indium, zinc, tin, and antimony, titanium and zirconium are preferable.

  The surface of the inorganic particles used in the antiglare hard coat layer is preferably subjected to silane coupling treatment or titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.

  The surface treatment agent may be used by mixing in the coating composition without coupling treatment in advance.

  When these inorganic particles are used, the addition amount is preferably 10 to 90%, more preferably 20 to 80%, particularly preferably 30 to 75% of the total mass of the antiglare hard coat layer. It is.

  Such inorganic particles have a particle size that is sufficiently smaller than the wavelength of light, so that scattering does not occur, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.

<Formation of acrylic resin-containing film>
Although the example of the film forming method of an acrylic resin containing film is demonstrated, this invention is not limited to this.

  As a method for producing the acrylic resin-containing film of the present invention, production methods such as an inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, and a hot press method can be used. From the viewpoints of suppressing foreign matter defects and optical defects such as die lines, solution casting by casting is preferred.

(Organic solvent)
The organic solvent useful for forming the dope when the acrylic resin-containing film of the present invention is produced by the solution casting method dissolves the acrylic resin (A), the cellulose ester resin (B), and other additives at the same time. Anything can be used without limitation.

  For example, as the chlorinated organic solvent, methylene chloride, as the non-chlorinated organic solvent, methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro- Examples include 2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, and nitroethane. Methylene chloride, methyl acetate, ethyl acetate and acetone can be preferably used.

  In addition to the organic solvent, the dope preferably contains 1 to 40% by mass of a linear or branched aliphatic alcohol having 1 to 4 carbon atoms. When the ratio of alcohol in the dope increases, the web gels and peeling from the metal support becomes easy. When the ratio of alcohol is small, acrylic resin (A) and cellulose ester in non-chlorine organic solvent system. There is also a role of promoting dissolution of the resin (B).

  In particular, in a solvent containing methylene chloride and a linear or branched aliphatic alcohol having 1 to 4 carbon atoms, acrylic resin (A), cellulose ester resin (B), and acrylic particles (C) 3 A dope composition in which at least 15 to 45 mass% of the seed is dissolved is preferable.

  Examples of the linear or branched aliphatic alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Ethanol is preferred because of the stability of these dopes, the relatively low boiling point, and good drying properties.

  Hereinafter, the preferable film-forming method of the acrylic resin containing film of this invention is demonstrated.

1) Dissolution Step In an organic solvent mainly composed of a good solvent for the acrylic resin (A) and the cellulose ester resin (B), the acrylic resin (A), the cellulose ester resin (B), and optionally acrylic particles ( C), a step of dissolving other additives while stirring to form a dope, or the acrylic resin (A) and cellulose ester resin (B) solutions, optionally with acrylic particle (C) solutions and other additive solutions Are mixed to form a dope which is a main solution.

  For dissolving the acrylic resin (A) and the cellulose ester resin (B), a method performed at normal pressure, a method performed below the boiling point of the main solvent, a method performed under pressure above the boiling point of the main solvent, JP-A-9-95544 Various dissolution methods such as a method of performing a cooling dissolution method as described in JP-A-9-95557 or JP-A-9-95538, a method of performing at a high pressure as described in JP-A-11-21379, and the like. Although it can be used, a method in which pressure is applied at a temperature equal to or higher than the boiling point of the main solvent is particularly preferable.

  The total amount of the acrylic resin (A) and the cellulose ester resin (B) in the dope is preferably in the range of 15 to 45% by mass. An additive is added to the dope during or after dissolution to dissolve and disperse, then filtered through a filter medium, defoamed, and sent to the next step with a liquid feed pump.

  Filtration is preferably performed using a filter medium having a collected particle size of 0.5 to 5 μm and a drainage time of 10 to 25 sec / 100 ml.

  In this method, the aggregate remaining at the time of particle dispersion and the aggregate generated when the main dope is added are only aggregated by using a filter medium having a collected particle diameter of 0.5 to 5 μm and a drainage time of 10 to 25 sec / 100 ml. Can be removed. In the main dope, the concentration of particles is sufficiently thinner than that of the additive solution, so that aggregates do not stick together at the time of filtration and the filtration pressure does not increase suddenly.

  FIG. 1 is a diagram schematically showing a dope preparation step, a casting step, and a drying step of a solution casting film forming method preferable for the present invention.

  If necessary, large agglomerates are removed from the acrylic particle charging kettle 41 by the filter 44 and fed to the stock kettle 42. Thereafter, the acrylic particle additive solution is added from the stock kettle 42 to the main dope dissolving kettle 1.

  Thereafter, the main dope solution is filtered by the main filter 3, and an ultraviolet absorbent additive solution is added in-line from 16 to this.

  In many cases, the main dope may contain about 10 to 50% by mass of the recycled material. The return material may contain acrylic particles. In that case, it is preferable to control the addition amount of the acrylic particle addition liquid in accordance with the addition amount of the return material.

  The additive solution containing acrylic particles preferably contains 0.5 to 10% by mass of acrylic particles, more preferably 1 to 10% by mass, and 1 to 5% by mass. Most preferably.

  The above range is preferable because the smaller the acrylic particle content, the lower the viscosity and the easier the handling, and the higher the acrylic particle content, the smaller the addition amount and the easier the addition to the main dope.

  Recycled material is a finely pulverized acrylic resin-containing film that is generated when an acrylic resin-containing film is formed. The original fabric is used.

  In addition, an acrylic resin, a cellulose ester resin, and, in some cases, acrylic particles kneaded into pellets can be preferably used.

2) Casting process An endless metal belt 31, such as a stainless steel belt or a rotating metal drum, which feeds the dope through a liquid feed pump (for example, a pressurized metering gear pump) to the pressure die 30 and transfers it infinitely. This is a step of casting the dope from the pressure die slit to the casting position on the support.

  A pressure die that can adjust the slit shape of the die base and facilitates uniform film thickness is preferred. The pressure die includes a coat hanger die and a T die, and any of them is preferably used. The surface of the metal support is a mirror surface. In order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided and stacked. Or it is also preferable to obtain the film of a laminated structure by the co-casting method which casts several dope simultaneously.

3) Solvent evaporation step In this step, the web (the dope is cast on the casting support and the formed dope film is called a web) is heated on the casting support to evaporate the solvent.

  To evaporate the solvent, there are a method of blowing air from the web side and / or a method of transferring heat from the back side of the support by a liquid, a method of transferring heat from the front and back by radiant heat, and the like. High efficiency and preferable. A method of combining them is also preferably used. The web on the support after casting is preferably dried on the support in an atmosphere of 40 to 100 ° C. In order to maintain the atmosphere at 40 to 100 ° C., it is preferable to apply hot air at this temperature to the upper surface of the web or to heat by means such as infrared rays.

  From the viewpoint of surface quality, moisture permeability, and peelability, it is preferable to peel the web from the support within 30 to 120 seconds.

4) Peeling process It is the process of peeling the web which the solvent evaporated on the metal support body in a peeling position. The peeled web is sent to the next process.

  The temperature at the peeling position on the metal support is preferably 10 to 40 ° C, more preferably 11 to 30 ° C.

  The residual solvent amount at the time of peeling of the web on the metal support at the time of peeling is preferably peeled in the range of 50 to 120% by mass depending on the strength of drying conditions, the length of the metal support, and the like. When peeling off at a time when the amount of residual solvent is larger, if the web is too soft, the flatness at the time of peeling will be impaired, and slippage and vertical stripes are likely to occur due to peeling tension, so the balance between economic speed and quality The amount of residual solvent is determined.

  The residual solvent amount of the web is defined by the following formula.

Residual solvent amount (%) = (mass before web heat treatment−mass after web heat treatment) / (mass after web heat treatment) × 100
Note that the heat treatment for measuring the residual solvent amount represents performing heat treatment at 115 ° C. for 1 hour.

  The peeling tension at the time of peeling the metal support and the film is usually 196 to 245 N / m. However, when wrinkles easily occur at the time of peeling, it is preferable to peel with a tension of 190 N / m or less. It is preferable to peel at a minimum tension that can be peeled to 166.6 N / m, and then peel at a minimum tension to 137.2 N / m, and particularly preferably peel at a minimum tension to 100 N / m.

  In the present invention, the temperature at the peeling position on the metal support is preferably -50 to 40 ° C, more preferably 10 to 40 ° C, and most preferably 15 to 30 ° C.

5) Drying and stretching step After peeling, a drying device 35 that alternately conveys the web through a plurality of rolls arranged in the drying device and / or a tenter stretching device 34 that clips and conveys both ends of the web with a clip are used. And dry the web.

  Generally, the drying means blows hot air on both sides of the web, but there is also a means for heating by applying microwaves instead of the wind. Too rapid drying tends to impair the flatness of the finished film. Drying at a high temperature is preferably performed from about 8% by mass or less of the residual solvent. Throughout the drying is generally carried out at 40-250 ° C. It is particularly preferable to dry at 40 to 160 ° C.

  When a tenter stretching apparatus is used, it is preferable to use an apparatus that can independently control the film gripping length (distance from the start of gripping to the end of gripping) by the left and right gripping means of the tenter. In the tenter process, it is also preferable to intentionally create sections having different temperatures in order to improve planarity.

  It is also preferable to provide a neutral zone between different temperature zones so that the zones do not interfere with each other.

  The stretching operation may be performed in multiple stages, and it is also preferable to perform biaxial stretching in the casting direction and the width direction. When biaxial stretching is performed, simultaneous biaxial stretching may be performed or may be performed stepwise.

  In this case, stepwise means that, for example, stretching in different stretching directions can be sequentially performed, stretching in the same direction is divided into multiple stages, and stretching in different directions is added to any one of the stages. Is also possible. That is, for example, the following stretching steps are possible.

-Stretch in the casting direction-Stretch in the width direction-Stretch in the casting direction-Stretch in the casting direction-Stretch in the width direction-Stretch in the width direction-Stretch in the casting direction-Stretch in the casting direction Simultaneous biaxial stretching includes stretching in one direction and contracting the other while relaxing the tension. The preferable draw ratio of simultaneous biaxial stretching can be taken in the range of x1.01 to x1.5 times in both the width direction and the longitudinal direction.

  When the tenter is used, the residual solvent amount of the web is preferably 20 to 100% by mass at the start of the tenter, and it is preferable to perform drying while applying the tenter until the residual solvent amount of the web becomes 10% by mass or less. More preferably, it is 5% by mass or less.

  30-150 degreeC is preferable, as for the drying temperature in the case of performing a tenter, 50-120 degreeC is more preferable, and 70-100 degreeC is the most preferable.

  In the tenter process, it is preferable that the temperature distribution in the width direction of the atmosphere is small from the viewpoint of improving the uniformity of the film. The temperature distribution in the width direction in the tenter process is preferably within ± 5 ° C, and within ± 2 ° C. Is more preferable, and within ± 1 ° C is most preferable.

6) Winding step This is a step of winding up the acrylic resin-containing film by the winder 37 after the residual solvent amount in the web is 2% by mass or less, and by setting the residual solvent amount to 0.4% by mass or less. A film having good dimensional stability can be obtained.

  As a winding method, a generally used method may be used. There are a constant torque method, a constant tension method, a taper tension method, a program tension control method with a constant internal stress, and the like.

  The acrylic resin-containing film of the present invention is preferably a long film. Specifically, the acrylic resin-containing film is about 100 m to 5000 m, and is usually in the form of a roll. Moreover, it is preferable that the width | variety of a film is 1.3-4m, and it is more preferable that it is 1.4-2m.

Although there is no restriction | limiting in particular in the film thickness of the acrylic resin containing film of this invention, When using for the polarizing plate protective film mentioned later, it is preferable that it is 20-200 micrometers, it is more preferable that it is 25-100 micrometers, and 30-80 micrometers. It is particularly preferred that
<Method for producing cured resin layer>
The cured resin layer is coated by applying a coating composition for forming the cured resin layer on the acrylic-containing resin film using a known method such as a gravure coater, dip coater, reverse coater, wire bar coater, die coater, and inkjet method. Then, it is preferable to heat-dry and to perform UV curing treatment.

  The coating amount is suitably 0.1 to 40 μm, preferably 0.5 to 30 μm, as the wet film thickness.

  Moreover, as a dry film thickness, it is an average film thickness of 0.1-30 micrometers, Preferably it is 1-20 micrometers. Within this range, lack of hardness, deterioration of curling and brittleness, and deterioration of workability are prevented.

  As the light source for the UV curing treatment, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used.

Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 5 to 500 mJ / cm ² , preferably 5 to 150 mJ / cm ² .

  Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is preferably 30 to 300 N / m.

  The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. This makes it possible to obtain a film having further excellent flatness.

  The coating composition that forms the antiglare hard coat layer may contain a solvent. Examples of the organic solvent contained in the coating composition include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone). , Esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents may be appropriately selected or mixed for use.

As the organic solvent, propylene glycol monoalkyl ether (1 to 4 carbon atoms of the alkyl group) or propylene glycol monoalkyl ether acetate (1 to 4 carbon atoms of the alkyl group) is preferable. Moreover, as content of an organic solvent, 5-80 mass% is preferable in a coating composition.
<Polarizing plate>
The polarizing plate used in the present invention can be produced by a general method. It is preferable that an adhesive layer is provided on the side opposite to the curable resin layer of the acrylic resin-containing film of the present invention, and is bonded to at least one surface of a polarizer produced by immersion and stretching in an iodine solution.

  The film may be used on the other surface, or another polarizing plate protective film may be used. For example, commercially available cellulose ester films (for example, Konica Minoltack KC8UX, KC4UX, KC5UX, KC8UY, KC4UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR-5, KV8UY-HA, KV8UX-RHA, OP Etc.) are preferably used.

  A polarizer, which is a main component of a polarizing plate, is an element that transmits only light having a plane of polarization in a certain direction. A typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol. There are one in which iodine is dyed on a system film and one in which dichroic dye is dyed.

  For the polarizer, a polyvinyl alcohol aqueous solution is formed into a film and dyed by uniaxial stretching or dyed or uniaxially stretched and then preferably subjected to a durability treatment with a boron compound.

  As the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer, a pressure-sensitive adhesive having a storage elastic modulus at 25 ° C. in the range of 1.0 × 10 Pa to 1.0 × 10 Pa in at least a part of the pressure-sensitive adhesive layer is preferably used. A curable pressure-sensitive adhesive that forms a high molecular weight body or a crosslinked structure by various chemical reactions after applying and bonding the pressure-sensitive adhesive is suitably used.

  Specific examples include, for example, urethane adhesives, epoxy adhesives, aqueous polymer-isocyanate adhesives, curable adhesives such as thermosetting acrylic adhesives, moisture-curing urethane adhesives, polyether methacrylate types, Examples include anaerobic pressure-sensitive adhesives such as ester-based methacrylate type and oxidized polyether methacrylate, cyanoacrylate-based instantaneous pressure-sensitive adhesives, and acrylate-peroxide-based two-component instantaneous pressure-sensitive adhesives.

  The pressure-sensitive adhesive may be a one-component type or a type that is used by mixing two or more components before use.

The pressure-sensitive adhesive may be a solvent system using an organic solvent as a medium, or an aqueous system such as an emulsion type, a colloidal dispersion type, or an aqueous solution type that is a medium containing water as a main component. It may be a solvent type. The density | concentration of the said adhesive liquid should just be suitably determined with the film thickness after adhesion, the coating method, the coating conditions, etc., and is 0.1-50 mass% normally.
<Liquid crystal display device>
By incorporating the polarizing plate bonded with the acrylic resin-containing film of the present invention into a liquid crystal display device, various liquid crystal display devices with excellent visibility can be produced. The polarizing plate according to the present invention is bonded to a liquid crystal cell via the adhesive layer or the like.

  The polarizing plate according to the present invention is a reflective type, transmissive type, transflective type LCD or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type, etc. Preferably used. In particular, in a large-screen display device having a screen size of 30 or more, especially 30 to 54, there is no white spot at the periphery of the screen, and the effect is maintained for a long time.

  In addition, there was little color unevenness, glare and wavy unevenness, and the eyes were not tired even during long-time viewing.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
<Example 1>
The following acrylic resins A1-A5 were produced by a known method.
A1: Poly (MMA-MA) mass ratio 98: 2 Mw 70000
A2: Poly (MMA-MA) mass ratio 97: 3 Mw 800000
A3: Poly (MMA-MA) mass ratio 94: 6 Mw920000
A4: Poly (MMA-MA) mass ratio 95: 5 Mw1200000
MMA; methyl methacrylate MA; methyl acrylate (synthesis of A5)
First, a methyl methacrylate / acrylamide copolymer suspension was prepared as follows.
Methyl methacrylate 20 parts by weight Acrylamide 80 parts by weight Potassium persulfate 0.3 parts by weight Ion-exchanged water 1500 parts by weight The above was charged into the reactor and the reactor was replaced with nitrogen gas. The reaction was allowed to proceed at 70 ° C. until converted to coalescence. The obtained aqueous solution was used as a suspending agent. A solution in which 0.05 part by mass of the above suspending agent is dissolved in 165 parts by mass of ion-exchanged water is supplied to a stainless steel autoclave having a capacity of 5 liters and equipped with a baffle and a foudra-type stirring blade, and the system is filled with nitrogen gas. It stirred at 400 rpm, replacing.

Next, a mixed substance having the following charge composition was added while stirring the reaction system.
Methacrylic acid 27 parts by weight Methyl methacrylate 73 parts by weight t-dodecyl mercaptan 1.2 parts by weight 2,2′-azobisisobutyronitrile 0.4 parts by weight After the addition, the temperature was raised to 70 ° C. and the internal temperature was 70 The time when the temperature reached 0 ° C. was set as the polymerization start time, and the polymerization was allowed to proceed for 180 minutes.

  Thereafter, the reaction system was cooled, the polymer was separated, washed and dried in accordance with a normal method to obtain a bead-shaped copolymer. The polymerization rate of this copolymer was 97%, and the weight average molecular weight was 130,000.

  Add 0.2% by mass of additive (NaOCH) to this copolymer and use a twin screw extruder (TEX30 (manufactured by Nippon Steel), L / D = 44.5) to add 10 L of nitrogen from the hopper. While purging at an amount of / min, an intramolecular cyclization reaction is performed at a screw rotation speed of 100 rpm, a raw material supply rate of 5 kg / h, and a cylinder temperature of 290 ° C., and pellets are produced. A5 was obtained. The weight average molecular weight (Mw) of the acrylic resin A5 was 130,000, and Tg was 140 ° C.

<Preparation of acrylic resin-containing film 1>
(Dope solution composition)
Acrylic resin Dianal BR85 (Mitsubishi Rayon Co., Ltd.) 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, Mw = 200000 Eastman (Chemical Co., Ltd.)
30 parts by mass Methylene chloride 300 parts by mass Ethanol 40 parts by mass The above composition was sufficiently dissolved while heating to prepare a dope solution.

(Formation of acrylic resin film 1)
The produced dope solution was uniformly cast on a stainless steel band support at a temperature of 22 ° C. and a width of 2 m using a belt casting apparatus. With the stainless steel band support, the solvent was evaporated until the amount of residual solvent reached 100%, and peeling was performed from the stainless steel band support with a peeling tension of 162 N / m.

  The peeled acrylic resin web was evaporated at 35 ° C., slit to 1.6 m width, and then dried at a drying temperature of 135 ° C. while being stretched 1.1 times in the width direction by a tenter. At this time, the residual solvent amount when starting stretching with a tenter was 10%.

  After stretching with a tenter and relaxing at 130 ° C for 5 minutes, drying was completed while transporting the drying zone at 120 ° C and 130 ° C with a number of rolls, slitting to a width of 1.5 m, and 10 mm wide at both ends of the film. A knurling process having a thickness of 5 μm was performed, and the film was wound around a 6-inch inner diameter core with an initial tension of 220 N / m and a final tension of 110 N / m to obtain an acrylic resin-containing film 1.

  The draw ratio in the MD direction calculated from the rotational speed of the stainless steel band support and the operating speed of the tenter was 1.1 times.

  The residual solvent amount of the acrylic resin-containing film 1 described in Tables 1 and 2 was 0.1%, the film thickness was 60 μm, and the winding length was 4000 m.

  Hereinafter, other acrylic resin-containing films were prepared in the same manner as the acrylic resin-containing film 1 except that the types and composition ratios of the acrylic resin (A) and the cellulose ester resin (B) were changed as shown in Tables 1 and 2. Produced.

  The acrylic resin-containing films 6 and 11 are prepared by adding the following ultraviolet absorbers, and the acrylic resin-containing film 7 is a cellulose ester resin having a CAB 381-20 (acyl group total substitution degree 2.92, acetyl). A group substitution degree of 1.08, a propionyl group substitution degree of 1.84, Mw = 200000, manufactured by Eastman Chemical Co., Ltd.) were used.

6: Tinuvin 109 (Ciba Specialty Chemicals Co., Ltd.) 1.5 parts by mass Tinuvin 171 (Ciba Specialty Chemicals Co., Ltd.) 0.7 parts by mass 11: LA-31 (Adeka Co., Ltd.) 1.5 parts by mass Part Further, in the acyl group of the cellulose ester resin, p represents a propionyl group, b represents a butyryl group, bz represents a benzoyl group, and ph represents a phthalyl group.

  Moreover, the sample formed into a film by the melt casting method as the acrylic resin film 34 was produced by the normal method as follows.

Acrylic resin Dianal BR85 (manufactured by Mitsubishi Rayon Co., Ltd.) and CAP482-20 (manufactured by Eastman Chemical Co., Ltd.) are mixed at a ratio of 70:30, and 2 at 90 ° C. using a hot air dryer in which air is circulated. After drying for a long time and sufficiently removing moisture, a T-die film melt extrusion machine (T-die width 500 mm) having a resin melt kneader equipped with a 65 mmφ screw was used. An acrylic resin film 34 was formed by extrusion under molding conditions of a temperature of 240 ° C. The formed film had a thickness of 60 μm.
<Preparation of hard coat layer (curable resin layer)>
In the following manner, a hard coat layer, which is the following curable resin layer, was provided on the acrylic resin-containing film, and a back coat layer was provided on the back surface to prepare an example sample and a comparative example sample.

The acrylic resin film is die-coated with the hard coat layer coating composition 1 and dried at 80 ° C., and then irradiated with 0.30 J / cm ² of ultraviolet light with a high-pressure mercury lamp so that the film thickness after curing becomes 5 μm. A hard coat layer was applied. The refractive index of only the transparent resin was 1.49.

  On the surface opposite to the hard coat layer, the following coating solution 1 for back coat layer is die-coated so as to have a wet film thickness of 6 μm, a back coat layer is provided, a hard coat layer on the cellulose ester film, A hard coat film example sample provided with a back coat layer was prepared.

The contents changed by the sample are shown in Tables 1 and 2.
(Coating composition 1 for hard coat layer)
Acetone 35 parts by mass Ethyl acetate 35 parts by mass Cyclohexanone 15 parts by mass Toluene 15 parts by mass Pentaerythritol triacrylate 30 parts by mass Pentaerythritol tetraacrylate 45 parts by mass Urethane acrylate 25 parts by mass (trade name U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.)
1-hydroxycyclohexyl-phenyl-ketone 8 parts by mass (Irgacure 184 Ciba Specialty Chemicals Co., Ltd.)
2-methyl-1- [4- (methylthio) phenyl] -2-monophorinopropan-1-one (Irgacure 907, manufactured by Ciba Specialty Chemicals) 8 parts by mass The coating composition of Sample 36 The following particles were added to impart antiglare properties.

Particle 1: Particle A 5 parts by mass Particle 2: Particle B 20 parts by mass Other particles used in Examples and Comparative Examples are as follows.

Particle A: Fluorine-containing polymethyl methacrylate particles (F-191 average particle size 0.55 μm, refractive index 1.42 manufactured by Nippon Paint Co., Ltd.)
Particle B: Silica particle (Seahoster KE-P100, average particle diameter 1.10 μm, refractive index 1.43, manufactured by Nippon Shokubai Co., Ltd.)
In Sample 35 (Comparative Example), the hard coat layer and the following back coat layer were not applied to the acrylic resin film sample 1.
(Coating composition 1 for back coat layer)
Acetone 30 parts by weight Ethyl acetate 45 parts by weight Isopropyl alcohol 10 parts by weight Diacetylcellulose 0.6 part by weight Silica particles having an average particle diameter of 16 nm 2% acetone dispersion 0.2 part by weight As a comparative sample, JP 2007-191706 A was implemented. A thermoplastic copolymer described in Example 1 was prepared, a pellet composition according to Example 7 was prepared, and a comparative sample film 37 having a thickness of 60 μm was obtained in the same manner as in Example 34 of the present application.

"Evaluation method"
The following evaluation was implemented about the obtained acrylic resin containing film sample and a comparative sample.

(Haze)
About each produced said film sample, one film sample was measured using the haze meter (NDH2000 type | mold, Nippon Denshoku Industries Co., Ltd. product) according to JISK-7136.

(Tension softening point)
The following evaluation was performed using a Tensilon tester (ORITC Corporation, RTC-1225A).

  An acrylic resin-containing film conditioned for 24 hours in an air conditioning room at 23 ° C. and 55% RH is cut out at 120 mm (length) × 10 mm (width) and heated at a rate of temperature increase of 30 ° C./min while being pulled with a tension of 10 N. Then, the temperature at 9 N was measured three times, and the average was obtained.

(Ductile fracture)
An acrylic resin-containing film conditioned for 24 hours in an air-conditioned room at 23 ° C. and 55% RH is cut out at 100 mm (vertical) × 10 mm (width), and is fold-folded at the center in the vertical direction under the same air-conditioning conditions, with two folds. Each piece was folded once and this evaluation was measured three times and evaluated as follows. In addition, breaking of evaluation here represents having broken and isolate | separated into two or more pieces.

○ ・ ・ ・ Cannot be folded 3 times × ・ ・ ・ Can be folded at least 1 out of 3 times (Cutting property)
The sample was conditioned for 24 hours in an air-conditioned room at 23 ° C and 55% RH, and the film was torn using an Elmendorf tear tester (manufactured by Toyo Seiki Co., Ltd.) under the same air-conditioning conditions. The tear surface was evaluated as follows. did.

  ○: The tear surface is very smooth and is torn straight.

  Δ: There is a slight burr on the tear surface, but it is torn straight.

  X: There are considerable burrs on the tear surface, or it is not torn straight.

(Film deformation in response to humidity changes)
In the casting direction of the produced film, two marks (crosses) are attached and left to stand at 60 ° C. and 90% RH for 1000 hours, and the distance between the mark (cross) before and after treatment is measured with an optical microscope. The dimensional change rate was evaluated based on the following criteria.

Dimensional change rate (%) = [(a1-a2) / a1] × 100
a1: Distance before heat treatment a2: Distance after heat treatment ○ ・ ・ ・ less than 0.3% Δ ・ ・ ・ 0.3 to 0.5%
× ... 0.5% ~
The following evaluation was implemented about the acrylic resin containing film sample and comparative sample which provided the obtained hard-coat layer.

(Flexibility)
A bending resistance test was performed in accordance with JISK5600-5-1.

  The transparent film was examined under the conditions of 23 ° C. and 55% RH for the minimum bending diameter at which two or more of the three samples were not cracked when the cured resin layer was inside, and evaluated according to the following criteria.

In addition, although the sample 35 (comparative example) did not have a cured resin layer, the bending test was done and it evaluated on the same reference | standard.
◎: It does not crack even if a bending test with a diameter of 2 mm is performed ○: It does not crack even if a bending test with a diameter of 4 mm is performed, but it breaks at a diameter of 2 mm Δ: It does not crack even if a bending test with a diameter of 10 mm is performed, Crack,
However, practically usable range ×: cracked by a bending test with a diameter of 10 mm (hardness)
In accordance with JISK5600-5-4 under the conditions of 23 ° C. and 55% RH, a pencil with a known hardness is applied to the sample with a pencil hardness tester (HA-301, Clemens type scratch hardness tester, Tester Sangyo Co., Ltd.) was scratched with a load of 1 kg and visually evaluated for the presence or absence of scratches.

If the scratch has occurred 5 times after scratching, it will be accepted. (Example: When a scratch is entered twice or more with a 5H pencil, 4H is designated as 4H when a scratch is entered once or less with a 4H pencil.)
(Characteristic evaluation as a liquid crystal display device)
<Preparation of polarizing plate>
The polarizing plate which used the acrylic resin containing film of this invention and the comparative sample as a polarizing plate protective film was produced as follows.

  A 120 μm-thick long roll polyvinyl alcohol film was immersed in 100 parts by mass of an aqueous solution containing 1 part by mass of iodine and 4 parts by mass of boric acid, and stretched in the transport direction 5 times at 50 ° C. to form a polarizing film.

  Next, it bonded to the backcoat layer side of the acrylic resin containing film produced in Example 1 using the polyvinyl alcohol-type adhesive agent on the single side | surface of this polarizing film.

  Furthermore, KC8UCR-5 manufactured by Konica Minolta Opto Co., Ltd., which is a retardation film subjected to alkali saponification treatment, was bonded to the other surface of the polarizing film and dried to prepare a polarizing plate P.

  The polarizing plate using the acrylic resin-containing film of the present invention was excellent in film cutting properties and easy to process.

<Production of liquid crystal display device>
Display characteristics of the acrylic resin-containing film of the present invention were evaluated using the prepared polarizing plate.

  Remove the polarizing plates on both sides of the 32-inch TV AQ-32AD5 previously manufactured by Sharp Corporation so that the KC8UCR-5 is on the glass surface side of the liquid crystal cell. The liquid crystal display devices were each fabricated by pasting so that the absorption axis was directed in the same direction as the polarizing plate that had been pasted in advance.

(Viewing angle fluctuation)
The following evaluation was performed using the liquid crystal display device produced as described above.

  The viewing angle of the liquid crystal display device was measured using EZ-Contrast 160D manufactured by ELDIM in an environment of 23 ° C. and 55% RH. Subsequently, the polarizing plate treated at 60 ° C. and 90% RH for 1000 hours was measured in the same manner, and evaluated according to the following criteria in four stages.

◎: No viewing angle variation ○: Slight viewing angle variation is observed △: Viewing angle variation is observed ×: Viewing angle variation is very large (color shift)
The display was displayed in black, and the color change when observed from an oblique 45 ° angle was evaluated according to the following criteria.

A: No color change B: Color change is slightly observed Δ: Color change is observed X: Color change is very large Tables 3 and 4 show the results of the above evaluation.

  According to the acrylic resin film of the present invention, heat resistance as an optical film is improved, and not only film deformation and cutting properties but also bending resistance and hardness are improved.

  And the polarizing plate produced using the acrylic resin containing film of this invention and a liquid crystal display device show the characteristic excellent in visibility and a color shift.

Example 2
<Preparation of acrylic particles (C1)>
A reactor with a reflux condenser with an internal volume of 60 liters was charged with 38.2 liters of ion-exchanged water and 111.6 g of sodium dioctylsulfosuccinate, and the temperature was raised to 75 ° C. under a nitrogen atmosphere while stirring at a rotational speed of 250 rpm. The effect of oxygen was virtually eliminated. 0.36 g of APS was added, and after stirring for 5 minutes, a monomer mixture consisting of 1657 g of MMA, 21.6 g of BA, and 1.68 g of ALMA was added all at once. Completed.

  Next, 3.48 g of APS was added, and after stirring for 5 minutes, a monomer mixture consisting of BA 8105 g, PEGDA (200) 31.9 g, and ALMA 264.0 g was continuously added over 120 minutes. Hold for a minute to complete the soft layer polymerization.

  Next, 1.32 g of APS was added, and after stirring for 5 minutes, a monomer mixture consisting of 2106 g of MMA and 201.6 g of BA was continuously added over 20 minutes. The polymerization of was completed.

  Next, 1.32 g of APS was added, and after 5 minutes, a monomer mixture consisting of 3148 g of MMA, 201.6 g of BA, and 10.1 g of n-OM was continuously added over 20 minutes. Next, the temperature was raised to 95 ° C. and held for 60 minutes to complete the polymerization of the outermost hard layer 2.

  A small amount of the polymer latex thus obtained was collected, and the flat particle size was determined by the absorbance method, which was 0.10 μm. The remaining latex was put into a 3% by mass sodium sulfate warm aqueous solution, salted out and coagulated, and then dried after repeated dehydration and washing to obtain acrylic particles (C1) having a three-layer structure.

  The above abbreviations are the following materials.

MMA; methyl methacrylate MA; methyl acrylate BA; n-butyl acrylate ALMA; allyl methacrylate PEGDA; polyethylene glycol diacrylate (molecular weight 200)
n-OM; n-octyl mercaptan APS; ammonium persulfate <Preparation of acrylic resin-containing film 25-1>
(Dope solution composition)
Dianal BR80 (manufactured by Mitsubishi Rayon Co., Ltd.) 66.5 parts by mass Cellulose ester (cellulose acetate propionate acyl group total substitution degree 2.75, acetyl group substitution degree 0.19, propionyl group substitution degree 2.56, Mw = 100,000)
28.5 parts by mass The above prepared acrylic particles (C1) 5.0 parts by mass Methylene chloride 300 parts by mass Ethanol 40 parts by mass The above composition was sufficiently dissolved while heating to prepare a dope solution.

  Hereinafter, the production method of the acrylic resin-containing film 25 described in Example 1 except that the acrylic resin (A), the cellulose ester resin (B), the acrylic particles (C), and the composition ratio were changed as shown in Table 5. Similarly, acrylic resin-containing films 25-1 to 25-6 were produced.

  In addition, the acrylic resin containing film 25-5 added the following ultraviolet absorber and produced dope.

Tinuvin 109 (manufactured by Ciba Specialty Chemicals Co., Ltd.) 1.5 parts by mass Tinuvin 171 (manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.7 parts by mass The acrylic resin-containing film 25-4 is replaced with C2 instead of acrylic particles C1. METABLEN W-341 (manufactured by Mitsubishi Rayon Co., Ltd.), acrylic resin-containing film 25-5 is C-3 with MR-2G (manufactured by Soken Chemical Co., Ltd.) having a single layer structure, and acrylic resin-containing film 25-6 is MS-300X ( Soken Chemical Co., Ltd.) was used as C4.

"Evaluation method"
The following evaluation was implemented about the obtained acrylic resin containing films 25-1 to 25-6.

(Resin and particle state: compatible / incompatible)
Regarding the produced acrylic resin-containing film 25-1, 12g of a film sample was weighed, dissolved again in a methylo / ethanol solvent having the above composition, stirred, sufficiently dissolved and dispersed, and made of PTFE having a pore diameter of 0.1 μm. The membrane was filtered using a membrane filter T010A (manufactured by ADVANTEC), and the filtered insoluble matter was sufficiently dried and weighed to find 1.8 g.

  Moreover, when this unnecessary material was dispersed again in the solvent and the particle size distribution was measured using Malvern (Malvern), the distribution was found in the vicinity of 0.10 to 0.20 μm.

  From the above, it can be seen that 90% by mass or more of the added acrylic particles (C) remains as insoluble matter, and the acrylic particles (C) exist in an incompatible state in the acrylic resin-containing film. I found out.

  Similarly, when the same measurement was performed on the acrylic resin-containing films 25-2 to 25-6, only the acrylic resin-containing film 25-6 was free of insolubles, and the acrylic particles (C) were in a state compatible with the resin. I found that it existed.

  The hard coat layer described in Example 1 was applied to the acrylic resin film in the same manner as in Example 1.

  About these samples, evaluation similar to Example 1 was performed. The results are shown in Table 6.

  The polarizing plate and the liquid crystal display device produced using the acrylic resin-containing film containing the particles of the present invention showed further excellent characteristics in visibility and color shift.

Claims (7)

It has at least one curable resin layer , contains acrylic resin (A) and cellulose ester resin (B) in a mass ratio of 95: 5 to 30:70 , and has a weight average molecular weight (Mw) of the acrylic resin (A). ) Is 80,000 to 1,000,000, the total substitution degree (T) of the acyl group of the cellulose ester resin (B) is 2.00 to 3.00, the acetyl group substitution degree (ac) is 0 to 1.89, and the acetyl group Other than the acyl group has 3 to 7 carbon atoms, a weight average molecular weight (Mw) of 75,000 to 280000, a haze value of less than 1%, a tension softening point of 105 to 145 ° C., and ductile fracture. An acrylic resin-containing film characterized by not causing it. 2. The acrylic resin according to claim 1 , wherein the total mass of the acrylic resin (A) and the cellulose ester resin (B) is 55 to 100 mass% with respect to the acrylic resin-containing film. Containing film.   The said acrylic resin containing film contains 0.5-45 mass% acrylic particle (C) with respect to the total mass of resin which comprises this film, The Claim 1 or 2 characterized by the above-mentioned. The acrylic resin-containing film according to item.   A polarizing plate using the acrylic resin-containing film according to any one of claims 1 to 3 on at least one surface.   A liquid crystal display device using the acrylic resin-containing film according to any one of claims 1 to 3.   It has at least one curable resin layer, contains acrylic resin (A) and cellulose ester resin (B) in a mass ratio of 95: 5 to 30:70, and has a weight average molecular weight (Mw) of the acrylic resin (A). ) Is 80,000 to 1,000,000, the total substitution degree (T) of the acyl group of the cellulose ester resin (B) is 2.00 to 3.00, the acetyl group substitution degree (ac) is 0 to 1.89, and the acetyl group An acrylic resin-containing film, wherein the number of carbon atoms of the acyl group other than is 3 to 7 and the weight average molecular weight (Mw) is 75000 to 280000.   7. The acrylic resin according to claim 6, wherein the total mass of the acrylic resin (A) and the cellulose ester resin (B) is 55 to 100 mass% with respect to the acrylic resin-containing film. Containing film.