JP2014182274A - Polarizing plate, liquid crystal display device, and method for manufacturing liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate that is a polarizing plate with a protective film on one surface thereof, in which moisture resistance is improved without polishing a cut surface.SOLUTION: The polarizing plate with a protective film on one surface thereof comprises a single polarizing plate protective film and a polarizer; and the polarizing plate includes less than 9.0 points where an absolute value B(n) represented by (formula 2):B(n)=A(n)-A(n-1) (where n≥1) is 0.5 or more. In (formula 2), A(n) is defined by (formula 1):A(n)=T(n)-T(n-1) (where n≥1); n represents a distance (μm) along a thickness direction on a cross section of the polarizing plate, from one surface of the polarizing plate along a line which is drawn from a specified position on the outermost surface of the polarizing plate in a direction that is orthogonal to the surface and along the thickness of the polarizing plate; and T(n) represents a distance (μm) from the point on the line which is drawn from the specified position on the outermost surface of the polarizing plate in the direction that is orthogonal to the surface and along the thickness of the polarizing plate, the point where the distance in the thickness direction is n (μm), to one cut surface of the polarizing plate, measured along a direction parallel to the outermost surface of the polarizing plate.

Description

  The present invention relates to a polarizing plate, a liquid crystal display device, and a method for manufacturing a liquid crystal display device.

In recent years, thinning of liquid crystal display devices, particularly liquid crystal display devices for small and medium-sized applications, has been rapidly progressing. For example, the thickness of the entire polarizing plate including a hard coat layer is required to be thinned, and members used ( There is an urgent need to reduce the thickness of films and polarizing plates.
In addition, liquid crystal display devices, particularly liquid crystal display devices for small and medium-sized applications, are required to have higher definition, and there is a method for manufacturing a liquid crystal display device that improves the axis system by bonding and has good optical characteristics after bonding. It has been demanded.
For example, Patent Document 1 describes a polarizing plate with a single-sided protective film in which a protective film provided on both sides of a conventional polarizer is only one side, and describes a thinned polarizing plate.
Further, in Patent Document 1, a thin film was formed using a polarizer having a thickness of 10 μm or less obtained by stretching a polyvinyl alcohol-based resin coated and formed on a base of an ester-based thermoplastic resin together with the thermoplastic resin base. A polarizing plate is described.
Further, Patent Document 2 describes a method for manufacturing a liquid crystal display device with good axial accuracy and optical characteristics by bonding with a roll-to-panel.
In the production of a general polarizing plate having a polarizing plate protective film on both sides of the polarizer, the polarizing plate is subjected to end face polishing after cutting, and the chipping of the polarizer at the time of cutting or the peeled portion between the polarizer and the polarizing plate protective film Is being removed. This is because if the chipped part of the polarizer or the peeled part between the polarizer and the polarizing plate protective film is allowed to stand, water will easily enter the chipped part of the polarizer or the peeled part between the polarizer and the polarizing plate protective film. This is because it is assumed that the water resistance of the plate is deteriorated.
However, in the polarizing plate with a single-sided protective film described in Patent Document 1, no polarizing plate protective film is disposed on both sides of the polarizer. Peeling easily occurs between the two, and the water resistance of the polarizing plate has been a problem even after polishing. In addition, when a polarizer having a thickness of 10 μm or less is used, the mechanical strength of the polarizer is further reduced, so that it is a problem that the polarizer is not easily chipped or peeling between the polarizer and the polarizing plate protective film is likely to occur. It was.
Moreover, in the manufacturing method of the liquid crystal display device by a roll to panel, since a polarizing plate roll will be cut | judged during conveyance, it is difficult to provide a cut surface grinding | polishing process in a process, and it originates in the moisture resistance of a polarizing plate. However, it is difficult to improve the yield of the liquid crystal display device with good moisture resistance.

Japanese Patent No. 4804588 JP 2011-48381 A

  The problem to be solved by the present invention is to improve the moisture resistance of a polarizing plate with a single-sided protective film without a cross-section polishing, and a liquid crystal display device manufactured by a roll-to-panel manufacturing method using the polarizing plate with a single-sided protective film Is to improve both moisture resistance and yield.

As a result of intensive studies by the present inventors, a polarizing plate with a single-sided polarizing plate protective film in a polarizing plate with a single-sided polarizing plate protective film, in which the bonded interface between the polarizing plate protective film and the polarizer and the film are liable to break during the cut surface polishing, By adjusting the cut surface to satisfy the specific formula, it was found that it had excellent moisture resistance even without polishing of the cut surface, and the present invention was completed.
This is because the chipping of the polarizer and peeling between the polarizer and the polarizing plate protective film are reduced, and by adjusting the cut surface to satisfy the specific formula, water can be prevented from entering from the peeling portion. I guess there is.
Moreover, in the manufacturing method of a liquid crystal display device using a roll-to-panel, the yield of manufacturing a liquid crystal display device with good moisture resistance can be improved by adjusting the cut surface of the polarizing plate with a single-sided polarizing plate protective film to satisfy the specific formula. I understood.
This is because a liquid crystal display device with good moisture resistance can be prepared easily because polishing is not required and chipping of the polarizer and peeling between the polarizer and the polarizing plate protective film can be reduced.

Specifically, the above-described problem has been solved by the following means <1>, more preferably <2> to <9>.
<1> A polarizing plate with a single-sided protective film composed of one polarizing plate protective film and a polarizer, and the point that the absolute value of B (n) represented by the following formula 2 is 0.5 or more is 9.0. There are less than one polarizing plate with a single-sided protective film.
(Formula 1) A (n) = T (n) −T (n−1) (n ≧ 1)
(Formula 2) B (n) = A (n) −A (n−1) (n ≧ 1)
Here, n represents a distance (μm) in the thickness direction from one surface on a line drawn perpendicularly to the thickness direction of the polarizing plate from a specific position on the outermost surface of the polarizing plate in the cross section of the polarizing plate.
T (n) is the outermost surface of the polarizing plate in terms of the thickness direction distance n (μm) on the line perpendicular to the thickness direction of the polarizing plate from the specific position on the outermost surface of the polarizing plate in the cross section of the polarizing plate. And the distance (μm) to one cut surface in the horizontal direction.
<2> The polarizing plate protective film is a (meth) acrylic resin, a polycarbonate resin, a polystyrene resin, a cyclic polyolefin resin, a polyester resin, a polypropylene resin, a cellulose resin, and a plurality of types selected from these <1> polarizing plate, which is a film made of a mixed resin of the above resins.
<3> The above-mentioned polarizing plate protective film is provided with at least one of a hard coat layer, an antiglare layer, an antireflection layer, an easy adhesion layer, an antistatic layer, and an optically anisotropic layer on the surface <1> or <2 > Polarizing plate.
<4> The polarizing plate according to any one of <1> to <3>, wherein the polarizing plate protective film has a moisture permeability of 200 g / m ² · day or less.
<5> The polarizing plate according to any one of <1> to <4>, wherein the polarizer has a thickness of 1 to 10 μm.
<6> The polarizing plate according to any one of <1> to <5>, wherein the polarizing plate is cut into a desired size by a laser and end face polishing is not performed.
<7> The polarizing plate according to any one of <1> to <6>, wherein the polarizing plate is bonded to a liquid crystal panel by a roll-to-panel manufacturing method.
<8> A liquid crystal display device comprising at least one polarizing plate of any one of <1> to <7>.
<9> In the manufacturing method of the liquid crystal display device which bonds the polarizing plate in any one of <1>-<7> to a liquid crystal panel,
The manufacturing method of the liquid crystal display device is a roll-to-panel manufacturing method,
A method of manufacturing a liquid crystal display device, wherein the polarizing plate is cut into a desired size by a laser.

  ADVANTAGE OF THE INVENTION According to this invention, the polarizing plate which improved the moisture resistance of the polarizing plate with a single-sided protective film can be provided even without grinding | polishing of a cut surface. In addition, the roll-to-panel manufacturing method can provide a method for manufacturing a liquid crystal display device with good moisture resistance, which includes a polarizing plate with a single-side protective film that improves yield.

(Polarizing plate with single-sided polarizing plate protective film)
(Polarizing plate cross section)
The cut surface of the polarizing plate with a single-sided protective film of the present invention satisfies the following formula.
(Formula 1) A (n) = T (n) −T (n−1) (n ≧ 1)
(Formula 2) B (n) = A (n) −A (n−1) (n ≧ 1)
Here, n represents the distance (μm) in the thickness direction from one surface on a line drawn perpendicularly to the polarizing plate thickness direction from a specific position on the outermost surface of the polarizing plate in the cross section of the polarizing plate.
T (n) is the outermost surface of the polarizing plate from the point of the thickness direction distance n (μm) on the line perpendicular to the thickness direction of the polarizing plate from the specific position on the outermost surface of the polarizing plate in the cross section of the polarizing plate. And the distance (μm) to one cut surface in the horizontal direction.
Here, n is the distance in the thickness direction from one outermost surface to the other outermost surface of the cross section of the polarizing plate, and for calculating A (n) and B (n), n is set at 1 μm intervals. What is necessary is just to measure T (n).
The number of points at which the absolute value of B (n) is 0.5 or more is less than 9.0, more preferably less than 5.0, and still more preferably less than 2.0.
By satisfying the above formula, excellent moisture resistance can be obtained without polishing the cut surface. When the absolute value of B (n) is small, the cut surface unevenness is small, and when the absolute value of B (n) is 0.5 or less, it is less than 9.0 points. Represents a small number. That is, due to less chipping of the polarizer on the cross section of the polarizing plate and less peeling between the polarizer and the polarizing plate protective film, the unevenness of the cut surface is small, and the absolute value of B (n) is 0.5 or more. The number is also reduced, and it is assumed that water is prevented from entering from the peeled portion.
In the measurement, when the polarizing plate protective film has a surface layer and the surface layer has irregularities, the value is measured with the polarizer side as the outermost surface of the polarizing plate, or the interface between the film and the surface layer is measured. The value may be measured as a change of the outermost surface of the polarizing plate.

The polarizing plate of the present invention is a polarizing plate in which a protective film is bonded to one side of a polarizer.
The polarizing plate protective film is preferably subjected to surface treatment (also described in JP-A-6-94915 and JP-A-6-118232) to make it hydrophilic, for example, glow discharge treatment, corona discharge treatment, or It is preferable to perform alkali saponification treatment or the like. In the case of a cellulose acylate film, alkali saponification is most preferably used as the surface treatment.

As the polarizer, for example, a film obtained by immersing and stretching a polyvinyl alcohol film in an iodine solution can be used. When using a polarizer obtained by immersing and stretching a polyvinyl alcohol film in an iodine solution, the surface-treated surface of the polarizing plate protective film of the present invention can be directly bonded to one side of the polarizer using an adhesive.
A water-based adhesive can be used as the adhesive. As the water-based adhesive, an aqueous solution of polyvinyl alcohol or polyvinyl acetal (for example, polyvinyl butyral) or a latex of a vinyl-based polymer (for example, polybutyl acrylate) can be used. A particularly preferred aqueous adhesive is an aqueous solution of fully saponified polyvinyl alcohol.

  A photocurable adhesive can also be used for the adhesive in the polarizing plate of the present invention. Examples of the photocurable adhesive include those obtained by adding a radical polymerization initiator and / or a cationic polymerization initiator to an epoxy resin, an acrylic resin, an okitacene resin, a urethane resin, a polyvinyl alcohol resin, or the like. Especially, what added the cationic polymerization type initiator to the mixture of the alicyclic epoxy resin and the epoxy resin which does not have an alicyclic structure is preferable. In this case, the photocurable adhesive is cured by irradiating with active energy rays. The light source of the active energy ray is not particularly limited, but an active energy ray having a light emission distribution at a wavelength of 400 nm or less is preferable. A microwave excitation mercury lamp, a metal halide lamp and the like are preferable.

(Polarizer)
The film thickness of the polarizer is preferably 30 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.

(Thin polarizer)
As the thin polarizer, representatively, JP-A-51-069644, JP-A-2000-338329, WO2010 / 100917 pamphlet, PCT / JP2010 / 001460 specification, or Japanese Patent Application 2010- The thin polarizing film described in 269002 specification and Japanese Patent Application No. 2010-263692 specification can be mentioned. These thin polarizing films can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as PVA-based resin) layer and a stretching resin base material in a laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.

  As the thin polarizing film, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, WO2010 / 100917 pamphlet, PCT / PCT / PCT / JP 2010/001460 specification, or Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 as described in the manufacturing method including a step of stretching in a boric acid aqueous solution is preferable. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary | assistant before extending | stretching in the boric acid aqueous solution as described in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 is preferable.

  The thin high-performance polarizing film described in the specification of PCT / JP2010 / 001460 is a thin film having a thickness of 7 μm or less made of a PVA-based resin oriented with a dichroic material, which is integrally formed on a resin substrate. It is a high-functional polarizing film, and has optical properties such as a single transmittance of 42.0% or more and a polarization degree of 99.95% or more.

  The thin high-performance polarizing film generates a PVA-based resin layer by applying and drying a PVA-based resin on a resin substrate having a thickness of at least 20 μm, and the generated PVA-based resin layer is used as a dichroic dyeing solution. So that the dichroic substance is adsorbed on the PVA resin layer, and the PVA resin layer on which the dichroic substance is adsorbed is integrated with the resin base material in the boric acid aqueous solution so that the total draw ratio is the original length. It can manufacture by extending | stretching so that it may become 5 times or more.

  Moreover, it is a method for producing a laminate film including a thin high-performance polarizing film in which a dichroic substance is oriented, and includes a resin base material having a thickness of at least 20 μm and a PVA resin on one side of the resin base material. The said laminated body containing the process of producing | generating the laminated body film containing the PVA-type resin layer formed by apply | coating and drying aqueous solution, and the PVA-type resin layer formed in the single side | surface of the resin base material A step of adsorbing the dichroic substance to the PVA resin layer contained in the laminate film by immersing the film in a dye solution containing the dichroic substance, and a PVA resin adsorbing the dichroic substance A step of stretching the laminate film including a layer in a boric acid aqueous solution so that the total stretching ratio is 5 times or more of the original length, and a PVA resin layer on which a dichroic substance is adsorbed Stretched together with As a result, a thickness of 7 μm or less, a single transmittance of 42.0% or more, and a degree of polarization of 99.95% or more consisting of a PVA-based resin layer in which a dichroic material is oriented on one side of a resin base material The thin high-performance polarizing film can be manufactured by including a step of manufacturing a laminate film on which a thin high-performance polarizing film having the above optical characteristics is formed.

  In the present invention, as described above, the polarizing film with the pressure-sensitive adhesive layer is a continuous web polarizing film made of a PVA resin in which a dichroic substance is oriented as a polarizer having a thickness of 10 μm or less, What was obtained by extending | stretching the laminated body containing the polyvinyl-alcohol-type resin layer formed into a film on the plastic resin base material by the 2 step | paragraph extending | stretching process which consists of air auxiliary | assistant extending | stretching and boric-acid-water extending | stretching can be used. The thermoplastic resin substrate is preferably an amorphous ester thermoplastic resin substrate or a crystalline ester thermoplastic resin substrate.

  The thin polarizing film in the above-mentioned Japanese Patent Application Nos. 2010-269002 and 2010-263692 is a continuous web polarizing film made of a PVA resin in which a dichroic material is oriented, and is amorphous. The laminate including the PVA-based resin layer formed on the ester-based thermoplastic resin base material was stretched in a two-stage stretching process consisting of air-assisted stretching and boric acid-water stretching, so that the thickness was 10 μm or less. Is. Such a thin polarizing film has P> − (100.929T-42.4-1) × 100 (where T <42.3) and P ≧ 99, where T is the single transmittance and P is the polarization degree. .9 (where T ≧ 42.3) is preferable.

  Specifically, the thin polarizing film is a stretch intermediate formed of an oriented PVA resin layer by high-temperature stretching in the air with respect to the PVA resin layer formed on the amorphous ester thermoplastic resin substrate of the continuous web. A colored intermediate product comprising a PVA-based resin layer in which a dichroic material (preferably iodine or a mixture of iodine and an organic dye) is oriented by adsorption of the dichroic material to the stretched intermediate product and a step of generating the product. A thin polarizing film comprising: a step of producing a product; and a step of producing a polarizing film having a thickness of 10 μm or less comprising a PVA resin layer in which a dichroic substance is oriented by stretching in a boric acid solution with respect to a colored intermediate product It can manufacture with the manufacturing method of.

In this production method, the total draw ratio of the PVA resin layer formed on the amorphous ester thermoplastic resin base material by high-temperature drawing in air and drawing in boric acid solution should be 5 times or more. desirable. The liquid temperature of the boric acid aqueous solution for boric-acid water extending | stretching can be 60 degreeC or more. Before stretching the colored intermediate product in the aqueous boric acid solution, it is desirable to insolubilize the colored intermediate product. In this case, the colored intermediate product is added to the aqueous boric acid solution whose liquid temperature does not exceed 40 ° C. It is desirable to do so by dipping. The amorphous ester-based thermoplastic resin base material is amorphous polyethylene containing copolymerized polyethylene terephthalate copolymerized with isophthalic acid, copolymerized polyethylene terephthalate copolymerized with cyclohexanedimethanol, or other copolymerized polyethylene terephthalate. It can be terephthalate and is preferably made of a transparent resin, and the thickness thereof can be 7 times or more the thickness of the PVA resin layer to be formed. Moreover, the draw ratio of the high temperature stretching in the air is preferably 3.5 times or less, and the stretching temperature of the high temperature stretching in the air is preferably not less than the glass transition temperature of the PVA resin, specifically in the range of 95 ° C to 150 ° C. When performing high temperature stretching in the air by free end uniaxial stretching, the total stretching ratio of the PVA resin layer formed on the amorphous ester thermoplastic resin base material is preferably 5 to 7.5 times . In addition, when performing high-temperature stretching in the air by uniaxial stretching at the fixed end, the total stretching ratio of the PVA-based resin layer formed on the amorphous ester-based thermoplastic resin base material is 5 times or more and 8.5 times or less. Is preferred.
More specifically, a thin polarizing film can be produced by the following method.

  A base material of a continuous web of isophthalic acid copolymerized polyethylene terephthalate (amorphous PET) in which 6 mol% of isophthalic acid is copolymerized is prepared. The glass transition temperature of amorphous PET is 75 ° C. A laminate comprising a continuous web of amorphous PET substrate and a polyvinyl alcohol (PVA) layer is prepared as follows. Incidentally, the glass transition temperature of PVA is 80 ° C.

  A 200 μm-thick amorphous PET base material and a 4-5% concentration PVA aqueous solution in which PVA powder having a polymerization degree of 1000 or more and a saponification degree of 99% or more are dissolved in water are prepared. Next, a PVA aqueous solution is applied to a 200 μm thick amorphous PET substrate and dried at a temperature of 50 to 60 ° C. to obtain a laminate in which a 7 μm thick PVA layer is formed on the amorphous PET substrate. .

  A laminated body including a PVA layer having a thickness of 7 μm is subjected to the following steps including a two-step stretching process of air-assisted stretching and boric acid water stretching to produce a thin high-functional polarizing film having a thickness of 3 μm. In the first-stage aerial auxiliary stretching step, the laminate including the 7 μm-thick PVA layer is integrally stretched with the amorphous PET substrate to produce a stretched laminate including the 5 μm-thick PVA layer. Specifically, in this stretched laminate, a laminate including a 7 μm-thick PVA layer is subjected to a stretching apparatus disposed in an oven set to a stretching temperature environment of 130 ° C. so that the stretching ratio is 1.8 times. Are stretched uniaxially at the free end. By this stretching treatment, the PVA layer contained in the stretched laminate is changed to a 5 μm thick PVA layer in which PVA molecules are oriented.

  Next, a colored laminate in which iodine is adsorbed on a PVA layer having a thickness of 5 μm in which PVA molecules are oriented is generated by a dyeing process. Specifically, this colored laminate has a single layer transmittance of the PVA layer constituting the high-functional polarizing film that is finally produced by using the stretched laminate in a staining solution containing iodine and potassium iodide at a liquid temperature of 30 ° C. Iodine is adsorbed to the PVA layer contained in the stretched laminate by dipping for an arbitrary period of time so as to be 40 to 44%. In this step, the staining solution uses water as a solvent and an iodine concentration in the range of 0.12 to 0.30% by weight and a potassium iodide concentration in the range of 0.7 to 2.1% by weight. The concentration ratio of iodine and potassium iodide is 1 to 7. Incidentally, potassium iodide is required to dissolve iodine in water. More specifically, by immersing the stretched laminate in a dyeing solution having an iodine concentration of 0.30% by weight and a potassium iodide concentration of 2.1% by weight for 60 seconds, iodine is applied to a 5 μm-thick PVA layer in which PVA molecules are oriented. A colored laminate is adsorbed on the substrate.

  Further, the colored laminated body is further stretched integrally with the amorphous PET base material by the second stage boric acid underwater stretching step to produce an optical film laminate including a PVA layer constituting a highly functional polarizing film having a thickness of 3 μm. To do. Specifically, this optical film laminate is stretched by applying a colored laminate to a stretching apparatus provided in a treatment apparatus set to a boric acid aqueous solution having a liquid temperature range of 60 to 85 ° C. containing boric acid and potassium iodide. It is stretched uniaxially at the free end so that the magnification is 3.3 times. More specifically, the liquid temperature of the boric acid aqueous solution is 65 ° C. It also has a boric acid content of 4 parts by weight with respect to 100 parts by weight of water and a potassium iodide content of 5 parts by weight with respect to 100 parts by weight of water. In this step, the colored laminate with adjusted iodine adsorption amount is first immersed in a boric acid aqueous solution for 5 to 10 seconds. After that, the colored laminate is passed as it is between a plurality of sets of rolls having different peripheral speeds, which is a stretching apparatus provided in the processing apparatus, and the stretching ratio is freely increased to 3.3 times over 30 to 90 seconds. Stretch uniaxially. By this stretching treatment, the PVA layer contained in the colored laminate is changed into a PVA layer having a thickness of 3 μm in which the adsorbed iodine is oriented higher in one direction as a polyiodine ion complex. This PVA layer constitutes a highly functional polarizing film of the optical film laminate.

  Although not an indispensable step for the production of an optical film laminate, the optical film laminate was removed from the boric acid aqueous solution and adhered to the surface of the 3 μm-thick PVA layer formed on the amorphous PET substrate by the washing step. It is preferable to wash boric acid with an aqueous potassium iodide solution. Thereafter, the washed optical film laminate is dried by a drying process using hot air at 60 ° C. The cleaning process is a process for eliminating appearance defects such as boric acid precipitation.

  Similarly, it is not an indispensable process for producing an optical film laminate, but an adhesive is applied to the surface of a 3 μm-thick PVA layer formed on an amorphous PET substrate by a bonding and / or transfer process. However, after bonding the 80 μm thick triacetyl cellulose film, the amorphous PET substrate can be peeled off, and the 3 μm thick PVA layer can be transferred to the 80 μm thick triacetyl cellulose film.

(Polarizing plate protective film)
<Thermoplastic resin>
The thermoplastic resin that can be preferably used as a main component in the polarizing plate protective film of the present invention will be described.
In addition, the main component of the said polarizing plate protective film film means the component exceeding 50 mass% of this polarizing plate protective film.

  As a material constituting the polarizing plate protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, cyclic Examples thereof include polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof.

In the polarizing plate protective film, the optimum thermoplastic resin includes (meth) acrylic resin, olefin resin, cellulose resin, polycarbonate resin, polystyrene resin, and polyester resin. These resins and these It can be selected from a mixed resin of plural kinds of resins.
Among them, (meth) acrylic resin, cyclic polyolefin resin, cellulose acylate and cellulose acylate and (meth) acrylic resin mixed resin are preferable, (meth) acrylic resin, cellulose acylate and cellulose acylate A mixed resin of (meth) acrylic resin is more preferable, and (meth) acrylic resin is particularly preferable.

The (meth) acrylic resin is a concept including both a methacrylic resin and an acrylic resin, and includes an acrylate / methacrylate derivative, particularly an acrylate ester / methacrylate ester (co) polymer.
Furthermore, the (meth) acrylic resin includes a methacrylic resin, an acrylic resin, a (meth) acrylic polymer having a ring structure in the main chain, a polymer having a lactone ring, and a succinic anhydride ring. A maleic anhydride-based polymer having, a polymer having a glutaric anhydride ring, and a glutarimide ring-containing polymer.

((Meth) acrylic polymer)
The repeating structural unit of the (meth) acrylic polymer is not particularly limited. The (meth) acrylic polymer preferably has a repeating structural unit derived from a (meth) acrylic acid ester monomer as a repeating structural unit.

The (meth) acrylic acid ester is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, and benzyl acrylate. Acrylic acid esters; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, methacrylic acid esters such as benzyl methacrylate; These may be used alone or in combination of two or more. Among these, methyl methacrylate is particularly preferable from the viewpoint of excellent heat resistance and transparency.
When using the (meth) acrylic acid ester as a main component, the content ratio in the monomer component to be subjected to the polymerization step is preferably 50 to 100% by mass in order to sufficiently exhibit the effects of the present invention. Preferably it is 70-100 mass%, More preferably, it is 80-100 mass%, Most preferably, it is 90-100 mass%.
The glass transition temperature Tg of the resin mainly composed of the (meth) acrylic acid ester is preferably in the range of 80 to 120 ° C.
The weight average molecular weight of the resin mainly composed of the (meth) acrylic acid ester is preferably in the range of 50,000 to 500,000.

  In order to improve flexibility and handleability, it is preferable to mix rubber elastic particles in the (meth) acrylic resin. The rubber elastic particle is a particle containing a rubber elastic body, and may be a particle made of only a rubber elastic body, or may be a multi-layered particle having a rubber elastic body layer, and may be a film surface. From the viewpoint of hardness, light resistance and transparency, an acrylic elastic polymer is preferably used.

  Rubber elastic particles containing an acrylic elastic polymer can be obtained with reference to JP2012-180422A, JP2012-032773A, and JP2012-180423A.

  The number average particle diameter of the rubber elastic particles is preferably in the range of 10 to 300 nm, more preferably in the range of 50 to 250 nm.

  The (meth) acrylic resin composition forming the (meth) acrylic resin film may contain 25 to 45% by mass of rubber elastic body particles having a number average particle diameter of 10 to 300 nm in a transparent acrylic resin. preferable.

-(Meth) acrylic polymer having a ring structure in the main chain-
Among (meth) acrylic polymers, those having a ring structure in the main chain are preferred. By introducing a ring structure into the main chain, the rigidity of the main chain can be improved and the heat resistance can be improved.
In the present invention, among (meth) acrylic polymers having a ring structure in the main chain, a polymer having a lactone ring structure in the main chain, a maleic anhydride polymer having a succinic anhydride ring in the main chain, It is preferably either a polymer having a glutaric anhydride ring structure or a polymer having a glutarimide ring structure in the main chain. Among them, a polymer having a lactone ring structure in the main chain and a polymer having a glutarimide ring structure in the main chain are more preferable.
The following polymers having a ring structure in these main chains will be described in order.

(1) A (meth) acrylic polymer having a lactone ring structure in the main chain A (meth) acrylic polymer having a lactone ring structure in the main chain (hereinafter also referred to as a lactone ring-containing polymer) has a lactone ring in the main chain. Although it will not specifically limit if it is a (meth) acrylic-type polymer which has this, Preferably it has a lactone ring structure shown by the following general formula (100).

Formula (100):

In the general formula (100), R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms, and the organic residue may contain an oxygen atom. .
Here, the organic residue having 1 to 20 carbon atoms is preferably a methyl group, an ethyl group, an isopropyl group, an n-butyl group, a t-butyl group, or the like.

  The content ratio of the lactone ring structure represented by the general formula (100) in the structure of the lactone ring-containing polymer is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, and still more preferably 10 to 60% by mass. %, Particularly preferably 10 to 50% by mass. By setting the content ratio of the lactone ring structure to 5% by mass or more, the heat resistance and surface hardness of the obtained polymer tend to be improved, and by setting the content ratio of the lactone ring structure to 90% by mass or less. The moldability of the obtained polymer tends to be improved.

The content ratio of the lactone ring structure can be calculated from the following formula.
Lactone ring content (% by mass) = B × A × M _R / M _m
(Wherein, B is the mass proportion in the monomer composition used in the copolymerization raw monomer having a structure (hydroxyl group) responsible for the lactonization, M _R lactone ring structure to generate The unit formula weight, M _m is the molecular weight of the raw material monomer having a structure (hydroxyl group) involved in lactone cyclization, and A is the lactone cyclization rate)
In addition, when the cyclization reaction involves a dealcoholization reaction, for example, the lactone cyclization rate can be determined by removing the theoretical weight loss from 150 ° C. before the weight reduction starts to 300 ° C. before the polymer decomposition starts. It can be calculated from the weight loss heating weight loss rate due to the alcohol reaction.

The method for producing the (meth) acrylic resin having a lactone ring structure is not particularly limited. Preferably, the (meth) acrylic resin having a lactone ring structure is obtained by polymerizing the following predetermined monomer to obtain a polymer (p) having a hydroxyl group and an ester group in the molecular chain. The obtained polymer (p) is heat-treated in a temperature range of 75 ° C. to 120 ° C. to obtain lactone cyclization condensation for introducing a lactone ring structure into the polymer.
In the polymerization step, a polymer having a hydroxyl group and an ester group in the molecular chain is obtained by performing a polymerization reaction of a monomer component containing a monomer represented by the following general formula (101).
Formula (101):

(In the formula, R ¹ and R ² each independently represents a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)

  Examples of the monomer represented by the general formula (101) include methyl 2- (hydroxymethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, isopropyl 2- (hydroxymethyl) acrylate, 2- ( Hydroxymethyl) normal butyl acrylate, 2- (hydroxymethyl) acrylate t-butyl and the like. Among these, methyl 2- (hydroxymethyl) acrylate and 2- (hydroxymethyl) ethyl acrylate are preferable, and methyl 2- (hydroxymethyl) acrylate is particularly preferable in that the effect of improving heat resistance is high. As for the monomer represented by the general formula (101), only one type may be used, or two or more types may be used in combination.

  The content ratio of the monomer represented by the general formula (101) in the monomer component used in the polymerization step has a lower limit value in a preferable range in terms of heat resistance, solvent resistance, and surface hardness, and was obtained. There is an upper limit of a preferable range from the viewpoint of molding processability of the polymer, and based on these viewpoints, it is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, still more preferably 10 to 60% by mass, and particularly preferably. Is 10-50 mass%.

  The monomer component used in the polymerization step may contain a monomer other than the monomer represented by the general formula (101). Such a monomer is not particularly limited. For example, (meth) acrylic acid ester, a hydroxyl group-containing monomer, an unsaturated carboxylic acid, and a monomer represented by the following general formula (102) are preferable. It is done. Only one type of monomer other than the monomer represented by formula (101) may be used, or two or more types may be used in combination.

  The weight average molecular weight of the lactone ring-containing polymer is preferably 10,000 to 2,000,000, more preferably 20,000 to 1,000,000, and particularly preferably 50,000 to 500,000.

  The lactone ring-containing polymer has a mass reduction rate within a range of 150 to 300 ° C. in dynamic TG measurement, preferably 1% or less, more preferably 0.5% or less, and still more preferably 0.3% or less. It is good. As a method for measuring dynamic TG, the method described in JP-A-2002-138106 can be used.

  Since the lactone ring-containing polymer has a high cyclization condensation reaction rate, there is little dealcoholization reaction in the production process of the molded product, and bubbles and silver stripes (silver streaks) are formed in the molded product after molding due to the alcohol. The disadvantage of entering can be avoided. Furthermore, since the lactone ring structure is sufficiently introduced into the polymer due to a high cyclization condensation reaction rate, the obtained lactone ring-containing polymer has high heat resistance.

  The lactone ring-containing polymer has a coloring degree (YI) of preferably 6 or less, more preferably 3 or less, still more preferably 2 or less, and particularly preferably 1 or less when a chloroform solution having a concentration of 15% by mass is used. . If the degree of coloring (YI) is 6 or less, problems such as loss of transparency due to coloring are unlikely to occur, and therefore, it can be preferably used in the present invention.

  The lactone ring-containing polymer has a 5% mass reduction temperature in thermal mass spectrometry (TG) of preferably 330 ° C. or higher, more preferably 350 ° C. or higher, and still more preferably 360 ° C. or higher. The 5% mass reduction temperature in thermal mass spectrometry (TG) is an indicator of thermal stability, and by setting it to 330 ° C. or higher, sufficient thermal stability tends to be exhibited. The thermal mass spectrometry can use the apparatus for measuring the dynamic TG.

  The glass transition temperature (Tg) of the lactone ring-containing polymer is preferably 115 ° C to 180 ° C, more preferably 120 ° C to 170 ° C, and still more preferably 125 ° C to 160 ° C.

(2) Maleic anhydride-based polymer having a succinic anhydride ring in the main chain A succinic anhydride structure is formed in the main chain in the molecular chain of the polymer (in the main skeleton of the polymer). The acrylic resin is preferably given high heat resistance and has a high glass transition temperature (Tg).
The glass transition temperature (Tg) of the maleic anhydride polymer having a succinic anhydride ring in the main chain is preferably 110 ° C. to 160 ° C., more preferably 115 ° C. to 160 ° C., further preferably 120 ° C. to 160 ° C. is there.
The weight average molecular weight of the maleic anhydride polymer having a succinic anhydride ring in the main chain is preferably in the range of 50,000 to 500,000.

The maleic anhydride unit used for copolymerization with the acrylic resin is not particularly limited, but JP-A-2008-216586, JP-A-2009-052021, JP-A-2009-196151, JP-T-2012-504783. Mention may be made of maleic acid-modified resins described in the respective publications.
In addition, these do not limit this invention.
As a commercially available maleic acid-modified resin, Delpet 980N manufactured by Asahi Kasei Chemicals Corporation, which is a maleic acid-modified MAS resin (methyl methacrylate-acrylonitrile-styrene copolymer), can be preferably used.
In addition, a method for producing an acrylic resin containing a maleic anhydride unit is not particularly limited, and a known method can be used.

  The maleic acid-modified resin is not limited as long as the resulting polymer contains maleic anhydride units, and examples thereof include (anhydrous) maleic acid-modified MS resin, (anhydrous) maleic acid-modified MAS resin (methacrylic acid). Methyl-acrylonitrile-styrene copolymer), (anhydrous) maleic acid modified MBS resin, (anhydrous) maleic acid modified AS resin, (anhydrous) maleic acid modified AA resin, (anhydrous) maleic acid modified ABS resin, ethylene-maleic anhydride Examples include acid copolymers, ethylene- (meth) acrylic acid-maleic anhydride copolymers, maleic anhydride grafted polypropylene, and the like.

The maleic anhydride unit has a structure represented by the following general formula (200).
General formula (200):

In the general formula (200), R ²¹ and R ²² each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.
The organic residue is not particularly limited as long as it has 1 to 20 carbon atoms, and examples thereof include a linear or branched alkyl group, a linear or branched alkylene group, an aryl group, and an -OAc group. , -CN group and the like. The organic residue may contain an oxygen atom. Ac represents an acetyl group.
R ²¹ and R ²² preferably have 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.

In the case where each of R ²¹ and R ²² represents a hydrogen atom, it is preferable to further contain other copolymer components from the viewpoint of adjusting the intrinsic birefringence. As such a ternary or higher heat-resistant acrylic resin, for example, methyl methacrylate-maleic anhydride-styrene copolymer can be preferably used.

(3) Polymer having glutaric anhydride ring structure in the main chain The polymer having glutaric anhydride ring structure in the main chain is a polymer having a glutaric anhydride unit.

  The polymer having a glutaric anhydride unit preferably has a glutaric anhydride unit represented by the following general formula (300) (hereinafter referred to as a glutaric anhydride unit).

General formula (300):

In the general formula ^{(300), R 31, R} 32 each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom. R ³¹ and R ³² particularly preferably represent the same or different hydrogen atoms or alkyl groups having 1 to 5 carbon atoms.

The polymer having a glutaric anhydride unit is preferably a (meth) acrylic polymer containing a glutaric anhydride unit. The (meth) acrylic polymer preferably has a glass transition temperature (Tg) of 120 ° C. or higher from the viewpoint of heat resistance.
The glass transition temperature (Tg) of the polymer having a glutaric anhydride ring structure in the main chain is preferably 110 ° C to 160 ° C, more preferably 115 ° C to 160 ° C, and further preferably 120 ° C to 160 ° C.
The weight average molecular weight of the polymer having a glutaric anhydride ring structure in the main chain is preferably in the range of 50,000 to 500,000.

  As content of the glutaric anhydride unit with respect to a (meth) acrylic-type polymer, 5-50 mass% is preferable, More preferably, it is 10-45 mass%. When the content is 5% by mass or more, more preferably 10% by mass or more, an effect of improving heat resistance can be obtained, and further an effect of improving weather resistance can be obtained.

(4) (Meth) acrylic polymer having a glutarimide ring structure in the main chain (meth) acrylic polymer having a glutarimide ring structure in the main chain (hereinafter also referred to as glutarimide resin) By having an imide ring structure, a desirable balance of properties can be expressed in terms of optical properties and heat resistance. The (meth) acrylic polymer having a glutarimide ring structure in the main chain is at least the following general formula (400):

Formula (400):

Wherein R ³⁰¹ , R ³⁰² and R ³⁰³ are independently hydrogen or an unsubstituted or substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group or an aryl group. It is preferable to contain a glutarimide resin having 20% by mass or more.

As preferred glutarimide units constituting the glutarimide resin used in the present invention, R ³⁰¹ and R ³⁰² are hydrogen or a methyl group, and R ³⁰³ is a methyl group or a cyclohexyl group. The glutarimide unit may be a single type, or may include a plurality of types in which R ³⁰¹ , R ³⁰² , and R ³⁰³ are different.

  A preferred second structural unit constituting the glutarimide resin used in the present invention is a unit composed of an acrylate ester or a methacrylate ester. Preferable acrylic acid ester or methacrylic acid ester structural unit includes methyl acrylate, ethyl acrylate, methyl methacrylate, methyl methacrylate and the like. Another preferred imidizable unit includes N-alkyl methacrylamide such as N-methyl methacrylamide and N-ethyl methacrylamide. These second structural units may be of a single type or may include a plurality of types.

  The content of the glutarimide unit represented by the general formula (400) in the glutarimide resin is 20% by mass or more based on the total repeating unit of the glutarimide resin. The preferable content of the glutarimide unit is 20% by mass to 95% by mass, more preferably 50 to 90% by mass, and still more preferably 60 to 80% by mass. When a glutarimide unit is smaller than this range, the heat resistance of the film obtained may be insufficient or transparency may be impaired. On the other hand, if it exceeds this range, the heat resistance is unnecessarily increased and it becomes difficult to form a film, the mechanical strength of the resulting film becomes extremely brittle, and the transparency may be impaired.

  The glutarimide resin may be further copolymerized with a third structural unit, if necessary. Preferred examples of the third structural unit include styrene monomers such as styrene, substituted styrene and α-methylstyrene, acrylic monomers such as butyl acrylate, and nitrile monomers such as acrylonitrile and methacrylonitrile. , A structural unit obtained by copolymerizing maleimide monomers such as maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide can be used. These may be directly copolymerized with the glutarimide unit and the imidizable unit in the glutarimide resin, and graft copolymerized with the resin having the glutarimide unit and the imidizable unit. It may be polymerized. When the third component is added, the content in the glutarimide resin is preferably 5 mol% or more and 30 mol% or less based on the total repeating units in the glutarimide resin.

  The glutarimide resin is described in US Pat. No. 3,284,425, US Pat. No. 4,246,374, JP-A-2-153904, and the like, and is obtained by using methyl methacrylate as a main raw material as a resin having an imidizable unit. It can be obtained by using a resin and imidizing the resin having an imidizable unit with ammonia or a substituted amine. When obtaining a glutarimide resin, a unit composed of acrylic acid, methacrylic acid, or an anhydride thereof may be introduced into the glutarimide resin as a reaction by-product. The presence of such a structural unit, particularly an acid anhydride, is not preferable because it reduces the total light transmittance and haze of the obtained film of the present invention. The acrylic acid or methacrylic acid content is 0.5 milliequivalent or less per gram of resin, preferably 0.3 milliequivalent or less, more preferably 0.1 milliequivalent or less. In addition, as seen in JP-A No. 02-153904, it is also possible to obtain a glutarimide resin by imidization using a resin mainly composed of N-methylacrylamide and methacrylic acid methyl ester.

The glass transition temperature (Tg) of the glutaric resin is preferably 110 ° C to 160 ° C, more preferably 115 ° C to 160 ° C, and still more preferably 120 ° C to 160 ° C.
The weight average molecular weight of the glutar resin is preferably in the range of 50,000 to 500,000.

-Manufacturing method of polarizing plate protective film mainly composed of (meth) acrylic polymer-
Hereinafter, a manufacturing method for forming a thermoplastic resin film mainly composed of a (meth) acrylic polymer will be described in detail.
In order to form a polarizing plate protective film using a (meth) acrylic polymer as a main component, for example, after pre-blending the film raw material with a conventionally known mixer such as an omni mixer, the resulting mixture is extruded. Knead. In this case, the mixer used for extrusion kneading is not particularly limited. For example, a conventionally known mixer such as an extruder such as a single screw extruder or a twin screw extruder or a pressure kneader can be used. .

  Examples of the film forming method include conventionally known film forming methods such as a solution casting method (solution casting method), a melt extrusion method, a calendar method, and a compression molding method. Of these film forming methods, the melt extrusion method is particularly suitable.

  Examples of the melt extrusion method include a T-die method and an inflation method, and the molding temperature at that time may be appropriately adjusted according to the glass transition temperature of the film raw material, and is not particularly limited. For example, it is preferably 150 ° C to 350 ° C, more preferably 200 ° C to 300 ° C.

  When forming a film by the T-die method, a roll-shaped film can be obtained by attaching a T-die to the tip of a known single-screw extruder or twin-screw extruder and winding the film extruded into a film. it can. At this time, it is possible to perform uniaxial stretching by appropriately adjusting the temperature of the take-up roll and adding stretching in the extrusion direction. Further, simultaneous biaxial stretching, sequential biaxial stretching, and the like can be performed by stretching the film in a direction perpendicular to the extrusion direction.

The polarizing plate protective film containing a (meth) acrylic polymer as a main component may be either an unstretched film or a stretched film. In the case of a stretched film, either a uniaxially stretched film or a biaxially stretched film may be used. In the case of a biaxially stretched film, either a simultaneous biaxially stretched film or a sequential biaxially stretched film may be used. In the case of biaxial stretching, the mechanical strength is improved and the film performance is improved. When the (meth) acrylic polymer is a (meth) acrylic polymer having a cyclic structure in the main chain, mixing with other thermoplastic resins increases the retardation even when stretched. It is possible to obtain a film that can be suppressed and retains optical isotropy.
The thickness of the polarizing plate protective film obtained using a (meth) acrylic polymer as a main component is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm. When the thickness is less than 5 μm, not only the strength of the film is lowered, but also when the durability test is performed by sticking to other parts, the crimp may be increased. On the other hand, when the thickness exceeds 80 μm, not only the transparency of the film is lowered, but also the moisture permeability is reduced, and when a water-based adhesive is used when sticking to other parts, water that is the solvent is used. The drying speed may be slow.

(Cyclic polyolefin resin)
As the thermoplastic resin that can be used in the present invention, a cyclic polyolefin resin can be used. Here, the cyclic polyolefin resin represents a polymer resin having a cyclic olefin structure.
The cyclic polyolefin resins preferably used in the present invention are listed below.
As a polymer having a cyclic olefin structure preferable for the present invention, a cyclic polyolefin resin which is an addition (co) polymer containing at least one repeating unit represented by the following general formula (II) and, if necessary, a general A cyclic polyolefin resin which is an addition (co) polymer further comprising at least one repeating unit represented by formula (I). Further, a ring-opening (co) polymer containing at least one cyclic repeating unit represented by the general formula (III) can also be suitably used.

In formulas (I) to (III), m represents an integer of 0 to 4. R ^{1 to} R ⁶ are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, X ^{1 to} X ³ and Y ^{1 to} Y ³ are a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, and a halogen atom. substituted hydrocarbon group having 1 to 10 carbon _{atoms, - (CH 2) n COOR} 11, - (CH 2) n OCOR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - ( _{CH 2) n CN, - (} CH 2) n CONR 13 R 14, - (CH 2) n NR 13 R 14, - (CH 2) n OZ, - (CH 2) n W, or X ¹ and Y ¹ Alternatively, (—CO) ₂ O and (—CO) ₂ NR ¹⁵ composed of X ² and Y ² or X ³ and Y ³ are shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with a halogen, and W is SiR ¹⁶ _p. D _3-p (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom, —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), n is an integer of 0 to 10 Show.

Norbornene polymer hydrides can also be preferably used. JP-A-1-240517, JP-A-7-196636, JP-A-60-26024, JP-A-62-19801, JP-A-2003-1159767. As disclosed in Japanese Patent Application Laid-Open No. 2004-309979 or the like, the polycyclic unsaturated compound is hydrogenated after addition polymerization or metathesis ring-opening polymerization. In the norbornene-based polymer used in the present invention, R ^{5 to} R ⁶ are preferably a hydrogen atom or —CH ₃ , X ³ and Y ³ are preferably a hydrogen atom, Cl, —COOCH ₃ , and other groups are appropriately selected. The This norbornene-based resin is sold under the trade name Arton G or Arton F by JSR Corporation, and from Zeon Corporation, Zeonor ZF14, ZF16, Zeonex 250 or Zeonex. They are commercially available under the trade name 280 and can be used.

  Furthermore, norbornene-based addition (co) polymers can also be preferably used, and are disclosed in JP-A No. 10-7732, JP 2002-504184 A, US Published Patent No. 20020042157A1 or WO 2004 / 070463A1. It can be obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. If necessary, norbornene-based polycyclic unsaturated compounds and ethylene, propylene, butene; conjugated dienes such as butadiene and isoprene; nonconjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride It is also possible to carry out addition polymerization with linear diene compounds such as acid, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate and vinyl chloride. This norbornene-based addition (co) polymer is marketed by Mitsui Chemicals, Inc. under the name of Apel, and has different glass transition temperatures (Tg) such as APL8008T (Tg70 ° C), APL6013T (Tg125 ° C) or APL6015T ( Grades such as Tg145 ° C). Pellets such as TOPAS 8007, 6013, and 6015 are sold by Polyplastics Co., Ltd. Further, Appear 3000 is sold by Ferrania.

In this invention, the glass transition temperature (Tg) of cyclic polyolefin resin becomes like this. Preferably it is 110 to 200 degreeC, More preferably, it is 115 to 190 degreeC, More preferably, it is 120 to 180 degreeC.
The weight average molecular weight of the cyclic polyolefin resin is preferably in the range of 50,000 to 500,000.

-Manufacturing method of polarizing plate protective film mainly composed of cyclic olefin resin-
About the polarizing plate protective film which has cyclic olefin resin as a main component, it can manufacture with the manufacturing method similar to the manufacturing method of the polarizing plate protective film which has a (meth) acrylic-type polymer as a main component, for example, solution Conventionally known film forming methods such as a casting method (solution casting method), a melt extrusion method, a calender method, and a compression molding method can be mentioned, and among these, the melt extrusion method is particularly suitable.

Examples of the melt extrusion method include a T-die method and an inflation method, and the molding temperature at that time may be appropriately adjusted according to the glass transition temperature of the film raw material.
When forming a film by the T-die method, a roll-shaped film can be obtained by attaching a T-die to the tip of a known single-screw extruder or twin-screw extruder and winding the film extruded into a film. it can. At this time, it is possible to perform uniaxial stretching by appropriately adjusting the temperature of the take-up roll and adding stretching in the extrusion direction. Further, simultaneous biaxial stretching, sequential biaxial stretching, and the like can be performed by stretching the film in a direction perpendicular to the extrusion direction.

(Cellulosic resin)
In the present invention, a cellulose resin can be used as the thermoplastic resin. Cellulosic resin represents a resin containing a cellulose ester and an acrylic resin.
The cellulose used as a raw material for the cellulose ester used in the present invention includes cotton linter and wood pulp (hardwood pulp, softwood pulp), etc., and any cellulose ester obtained from any raw material cellulose can be used. May be. As for these raw material celluloses, for example, plastic material course (17) Fibrous resin (Maruzawa, Uda, Nikkan Kogyo Shimbun, published in 1970) and Invention Association Open Technical Report 2001-1745 (pages 7-8). Although the cellulose described in 1 can be used, the cellulose ester used in the present invention is not particularly limited to that described.

The cellulose ester used in the present invention is preferably an ester of cellulose and a fatty acid (including an aromatic fatty acid). A cellulose acylate acylated by substituting an acyl group of the fatty acid for a certain hydroxyl group is preferred.
For example, cellulose alkyl carbonyl ester, alkenyl carbonyl ester, aromatic carbonyl ester, aromatic alkyl carbonyl ester, etc., and cellulose ester in which acyl groups of two or more fatty acids are substituted are also preferable. These cellulose esters may further have a substituted group.
As the acyl group that substitutes for the hydroxyl group, an acetyl group having 2 carbon atoms and an acyl group having 3 to 22 carbon atoms can be preferably used.
In the case of using a mixture with an acrylic resin, an acetyl group having 2 carbon atoms and an acyl group having 3 to 7 carbon atoms are preferable from the viewpoint of compatibility between the two.
The total substitution degree of acyl groups in the cellulose ester used in the present invention (the ratio of substitution of acyl groups with hydroxyl groups in the β-glucose unit of cellulose) Although it is 3 is not particularly limited, the higher the total substitution degree of the acyl group is preferable. For this reason, the total substitution degree of the acyl group is preferably 2.00 to 3.00, more preferably 2.50 to 3.00, and still more preferably 2.50 to 2.90.
In the cellulose ester used in the present invention, examples of the method for measuring the degree of substitution of the acyl group substituted on the hydroxyl group of cellulose include a method according to ASTM D-817-91 and an NMR method.

  The acyl group that substitutes for the hydroxyl group of the β-glucose unit of cellulose may be either an aliphatic group or an aromatic group, and is not particularly limited. Moreover, the acyl group substituted on the hydroxyl group may be a single acyl group or two or more kinds. Examples of the cellulose ester substituted with the acyl group include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate petitate, cellulose acetate propionate butyrate, and cellulose benzoate.

  The degree of polymerization of the cellulose ester used in the cellulosic resin is preferably 180 to 700 in terms of viscosity average polymerization degree. In particular, in cellulose acetate propionate substituted with an acetyl group and a propionyl group, 180 to 550 is more preferable. Preferably, 180 to 400 is more preferable, and 180 to 350 is particularly preferable. If the degree of polymerization is within this range, the viscosity of the dope solution containing the cellulose ester can be made suitable for film production by casting, and the compatibility with the acrylic resin is high, and the transparency and mechanical strength are high. It is preferable because a high film can be obtained. The viscosity average degree of polymerization can be measured by Uda et al.'S limiting viscosity method (Kazuo Uda, Hideo Saito, Journal of Textile Science, Vol. 18, No. 1, pages 105-120, 1962). This is described in detail in JP-A-9-95538.

A mixed resin of a cellulose acylate resin and the acrylic resin is also preferable. The mass ratio of the cellulose acylate resin and the acrylic resin is preferably 70:30 to 15:85, more preferably 70:30 to 30:70, and still more preferably 49:51 to 30:70. It is.
The acrylic resin used in combination with the cellulose-based resin may be a homopolymer of one kind of (meth) acrylic acid derivative or a copolymer of two or more (meth) acrylic acid derivatives. It may be a copolymer with other monomer copolymerizable with.
Examples of copolymerizable components that can be copolymerized with (meth) acrylic acid derivatives include α, β-unsaturated acids such as acrylic acid and methacrylic acid, and unsaturated group-containing divalent carboxylic acids such as maleic acid, fumaric acid, and itaconic acid. Unsaturated acids such as acids, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-ethylstyrene, p-tert-butylstyrene, α-methylstyrene, α- Aromatic vinyl compounds such as methyl-p-methylstyrene, α, β-unsaturated nitriles such as acrylonitrile and methacrylonitrile, lactone ring units, glutaric anhydride units, glutarimide units, maleic anhydride, etc. And maleimides such as saturated carboxylic acid anhydrides, maleimides and N-substituted maleimides.
Examples of acrylic resins and (meth) acrylic acid derivatives used in combination with cellulosic resins and other copolymerizable monomers are JP2009-122664A, JP2009-139661A, and JP2009-139754A. In addition, those described in JP-A 2009-294262, International Publication No. 2009/054376, and the like can also be used. In addition, these do not limit this invention, These can be used individually or in combination of 2 or more types.

  The acrylic resin used in combination with the cellulose resin preferably has a weight average molecular weight Mw of 80000 or more. When the weight average molecular weight Mw of the acrylic resin is 80000 or more, the mechanical strength is high and the handling suitability during film production is excellent. From this viewpoint, the acrylic resin preferably has a weight average molecular weight Mw of 100,000 or more. Moreover, from a viewpoint of a compatibility improvement with a cellulose ester, it is preferable that the weight average molecular weight Mw of an acrylic resin is 3000000 or less, and it is more preferable that it is 2000000 or less.

  A commercially available thing can also be used as an acrylic resin used together with a cellulose resin. For example, Delpet 60N, 80N (Asahi Kasei Chemicals Co., Ltd.), Dianal BR80, BR85, BR88, BR102 (Mitsubishi Rayon Co., Ltd.), KT75 (Electrochemical Industry Co., Ltd.), etc. are mentioned. More than one species can be used in combination.

(Polycarbonate resin)
A polycarbonate resin can be used as the thermoplastic resin that can be used in the present invention.
(Polystyrene resin)
As the thermoplastic resin that can be used in the present invention, a polystyrene resin can be used.
(Polyester resin)
A polyester resin can be used as the thermoplastic resin that can be used in the present invention.
As the polyester resin, polyethylene terephthalate and polyethylene naphthalate are preferable.

(Other thermoplastic resins)
The thermoplastic resin that can be used in the present invention may contain other thermoplastic resins other than the thermoplastic resin that can be preferably used as the main component of the polarizing plate protective film.
The other thermoplastic resin is not particularly limited as long as it does not contradict the gist of the present invention, but heat that is thermodynamically compatible with the thermoplastic resin that can be preferably used as the main component of the polarizing plate protective film. A plastic resin is preferred in terms of improving mechanical strength and desired physical properties.
In particular, when a (meth) acrylic resin is used as a main component of the polarizing plate protective film, the other thermoplastic resin is preferably contained in the polarizing plate protective film in an amount of 0 to 30% by mass. It is more preferably 20% by mass, and particularly preferably 5 to 15% by mass.

  Examples of the other thermoplastic resins include polyethylene, polypropylene, ethylene-propylene copolymers, olefin thermoplastic resins such as poly (4-methyl-1-pentene), polystyrene, and styrene-methyl methacrylate copolymers. And styrene-based thermoplastic resins such as acrylonitrile-butadiene-styrene block copolymer, polybutadiene rubber, and rubbery polymers such as ABS resin blended with acrylic rubber.

When a (meth) acrylic resin is used as the main component of the polarizing plate protective film, the other thermoplastic resin includes a vinyl cyanide monomer unit and an aromatic vinyl monomer unit. It is preferable to include a copolymer.
When a copolymer containing the vinyl cyanide monomer unit and the aromatic vinyl monomer unit, specifically, an acrylonitrile-styrene copolymer is used, the glass transition temperature is 120 ° C. or more, the surface direction A film having a phase difference per 100 μm of 20 nm or less and a total light transmittance of 85% or more is obtained.
One or more kinds of arbitrary appropriate additives may be contained in the polarizing plate protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an anti-coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent.

<Ultraviolet absorber>
The ultraviolet absorber preferably used for the polarizing plate protective film will be described. The optical film of the present invention including the polarizing plate protective film is used for a polarizing plate, a liquid crystal display member or the like, and an ultraviolet absorber is preferably used from the viewpoint of preventing deterioration of the polarizing plate or the liquid crystal. As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Only one type of ultraviolet absorber may be used, or two or more types may be used in combination. For example, the ultraviolet absorber as described in Unexamined-Japanese-Patent No. 2001-72782 and Special Table 2002-543265 is mentioned. Specific examples of the ultraviolet absorber include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like.
Among them, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′- Hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2 '-Hydroxy-3'-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3 -Tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2'-hydroxy-3'-tert-butyl-5'-methyl) Enyl) -5-chlorobenzotriazole, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis (2-methoxy-4-hydroxy) -5-benzoylphenylmethane), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, 2 (2 '-Hydroxy-3', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) -5-chlorobenzo Triazole, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-ter -Butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- ( 3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1, 3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl -4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy -Hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl- 4-hydroxybenzyl) -isocyanurate and the like. In particular, (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, 2 (2′-hydroxy-3 ′, 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) -5-chlorobenzotriazole, 2,6-di -Tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl -5-methyl-4-hydroxyphenyl) propionate] is preferred.
In addition, triazine-based ultraviolet absorbers represented by the general formula described in the republished patent WO2005 / 109052 are also useful, and specific examples of compounds Nos. 1 to 36 can be preferably used.

<Other additives>
(Matting agent fine particles)
Fine particles can be added as a matting agent to the polarizing plate protective film. Fine particles used as a matting agent include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and Mention may be made of calcium phosphate. Fine particles containing silicon are preferred in that the haze of the film is reduced, and silicon dioxide is particularly preferred.
The silicon dioxide fine particles preferably have a primary average particle size of 20 nm or less and an apparent specific gravity of 70 g / liter or more. Those having an average primary particle size as small as 5 to 16 nm are more preferred because they can reduce the haze of the film. The apparent specific gravity is preferably 90 to 200 g / liter or more, and more preferably 100 to 200 g / liter or more. A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  These fine particles usually form secondary particles having an average particle diameter of 0.1 to 3.0 μm, and these fine particles are present as aggregates of primary particles in the film, and 0.1 to 0.1 μm on the film surface. An unevenness of 3.0 μm is formed. The average particle diameter of the secondary particles is preferably from 0.2 μm to 1.5 μm, more preferably from 0.4 μm to 1.2 μm, and most preferably from 0.6 μm to 1.1 μm. The particle diameter of the primary particles and the secondary particles was determined by observing the particles in the film with a scanning electron microscope and determining the diameter of a circle circumscribing the particles as the particle diameter. In addition, 200 particles were observed at different locations, and the average value was taken as the average particle size.

  As fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Among these, Aerosil 200V and Aerosil R972V are fine particles of silicon dioxide having an average primary particle diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more, while keeping the turbidity of the optical film low. This is particularly preferable because the effect of reducing the friction coefficient is great.

(Other additives)
In addition to the matte particles, the polarizing plate protective film has other various additives (for example, retardation developing agent, plasticizer, ultraviolet absorber, deterioration inhibitor, release agent, infrared absorber, wavelength dispersion adjustment). Agents), which can be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of ultraviolet absorbing material at 20 ° C. or lower and 20 ° C. or higher, and similarly mixing of a plasticizer is described in, for example, JP-A-2001-151901. Furthermore, infrared absorbing dyes are described in, for example, JP-A No. 2001-194522. Moreover, the addition time may be added at any time in the dope preparation step, but may be added by adding an additive to the final preparation step of the dope preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when an optical film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ. For example, it is described in Japanese Patent Application Laid-Open No. 2001-151902, and these are conventionally known techniques. For these details, materials described in detail on pages 16 to 22 in the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical No. 2001-1745, published on March 15, 2001, Japan Institute of Invention) are preferably used.

Plasticizers with good compatibility with thermoplastic resins (especially cellulose esters and acrylic resins) are difficult to bleed out, have low haze, and are films that realize liquid crystal display devices with excellent light leakage, front contrast, and brightness. It is effective for production.
You may use a plasticizer for the said polarizing plate protective film. Although it does not specifically limit as a plasticizer, A phosphate ester plasticizer, a phthalate ester plasticizer, a polyhydric alcohol ester plasticizer, a polycarboxylic acid ester plasticizer, a glycolate plasticizer, a citrate ester Examples thereof include plasticizers, fatty acid ester plasticizers, carboxylic acid ester plasticizers, polyester oligomer plasticizers, sugar ester plasticizers, and ethylenically unsaturated monomer copolymer plasticizers.
Preferred are phosphate ester plasticizers, glycolate plasticizers, polyhydric alcohol ester plasticizers, polyester oligomer plasticizers, sugar ester plasticizers, ethylenically unsaturated monomer copolymer plasticizers, and more preferred. Is a polyester oligomer plasticizer, sugar ester plasticizer, ethylenically unsaturated monomer copolymer plasticizer, more preferably an ethylenically unsaturated monomer copolymer plasticizer, sugar ester plasticizer, particularly preferably Is an ethylenically unsaturated monomer copolymer plasticizer.

From the viewpoint of polarizing plate moisture resistance, the moisture permeability of the polarizing plate protective film is preferably 200 g / m ² · day or less, more preferably 50 g / m ² · day or less, and 20 g / m ² · day or less. More preferably.
The thickness of the polarizing plate protective film of the present invention is preferably 80 μm or less, more preferably 60 μm or less, and further preferably 40 μm or less.
The thickness of the polarizing plate with a single-sided protective film of the present invention is preferably 100 μm or less, more preferably 80 μm or less, further preferably 60 μm or less, and particularly preferably 50 μm or less.

(Polarizing plate cutting method)
The cutting method of the polarizing plate is preferably laser cutting or a double-edged cutter. Moreover, you may use together. Laser cutting is more preferable.

(Laser cutting)
The sheet-like laminate is cut by irradiating the resin film side with a laser. The reason why the above-mentioned protrusions and protrusions can be prevented by such a method is probably that the laser film is not irradiated on the polarizing plate side which is easily affected by heat, but from the resin film side with high heat resistance. This is presumably because the deterioration of the polarizing plate can be suppressed by laser irradiation. In particular, there is a phenomenon that protrusions are likely to occur along the absorption axis direction of the polarizing plate. This is presumed to be because the draw ratio in the absorption axis direction is higher than that in the vertical direction.

  Examples of the laser include a CO2 laser, a YAG laser, and a UV laser. Among these, a CO2 laser is preferable because it has high applicability in the thickness range and does not cause cracking or notching. In the laser irradiation, the output and the speed are not limited, and the laser irradiation may be performed by a single irradiation or a plurality of irradiations. The output of the laser irradiation is, for example, 10 W to 800 W, preferably 100 W to 350 W when cutting with one irradiation, and preferably 50 W to 200 W when cutting with two irradiations.

  The shape of the laminated polarizing plate cut out from the laminate is not particularly limited, but is generally quadrangular, and it may be cut out in the absorption axis direction and the vertical axis direction (polarization axis and perpendicular direction) in the polarizing plate in the laminate. .

  In addition, if the laminate is bonded onto a surface protective sheet via an adhesive and laser irradiation is performed, finally, a plurality of cut laminated polarizing plates are deposited on one surface protective sheet. Sheets can be provided. In such a form, a plurality of laminated polarizing plates can be carried and stored with a single sheet, which is useful in the distribution process.

  Thus, the following method is mentioned as a method of sticking a plurality of laminated polarizing plates on one sheet. First, after sticking the laminate to the surface protective sheet via an adhesive, only either the absorption axis or the vertical axis of the polarizing plate in the laminate, that is, either the horizontal direction or the vertical direction. Then, cutting is performed by laser irradiation from the resin film side. And after peeling off the said surface protection sheet, a new surface protection sheet is again laminated | stacked on the said laminated body through an adhesive, and the laser irradiation is performed to the other axial direction which is not cut | disconnected next. As a result, the laminate is in a state where both the absorption axis and the vertical axis are cut, but the newly re-applied surface protection sheet is cut because only one axial direction is cut. The laminated polarizing plate is stuck on the surface protective sheet without being separated. In addition, a surface protection sheet may be affixed on any one surface of the said laminated body, and may be affixed on both surfaces.

(Double-edged cutter cutting)

  As a method for cutting a laminated film having the optical film of the present invention, a film having a cutting edge using a double-edged blade and having a cutting angle of the blade with respect to the surface of the film to be cut is less than 10 °, and the blade is moved in a fixed state. Tear off.

  According to this structure, only the laminated film is cut from the laminated film with a separator obtained by laminating the separator on the laminated film, and the separator is not cut. Since the cutting angle of the blade with respect to is less than 10 ° and the blade is moved without moving the blade while moving the both blades to draw the film, there is no delamination on the cut surface of the cut film layer. . Moreover, the crack in the cut | disconnected film member does not arise. Here, “cut” means a state in which individual film members are completely divided, and does not include a cut in a state where the film members are not completely divided. Therefore, “not cutting the separator” includes a state in which the separator is cut by the blade. Examples of the “blade” include a flat blade, a round blade, a polygonal blade, and the like. What is important in the present invention is that the cutting angle of the blade with respect to the film surface is less than 10 °.

  Similarly, when the laminated film is divided in the thickness direction including the separator (this kind of cutting is referred to as full cut), the cutting edge of the blade with respect to the surface of the film to be cut is similarly used using a double-edged blade. Is less than 10 °, and the blade is moved in a fixed state to cut the film, so that delamination on the cut surface of the cut film layer does not occur. Moreover, the crack in the cut | disconnected film member does not arise.

  Moreover, as one Embodiment of this invention, the said blade is comprised with a round blade.

  According to this structure, delamination generation | occurrence | production can be favorably suppressed by fixing a round blade and drawing a film.

  Moreover, as one Embodiment of this invention, there exists a structure which rotates the said fixed round blade at predetermined timings other than the time of a cutting | disconnection, and changes the blade-tip position for a cutting | disconnection.

  According to this configuration, when the cutting edge of the round blade is damaged, worn, etc., the round blade can be rotated by a predetermined angle, fixed, and set to a new cutting edge, so that the cutting accuracy can be maintained, There is no work to remove like a flat blade, the blade tip can be easily replaced, and the working time can be shortened effectively. To replace the blade edge, the image of the blade edge imaged by the imaging means is processed, and it is determined whether or not the blade edge is damaged or worn. If it is determined that the edge is damaged or worn, the round blade is released. And the structure which is rotated a predetermined angle and fixed again is illustrated. In addition, the timing can be notified by display, sound, etc., and the operator can manually replace the blade edge. As another timing, the number of times of cutting may be counted and the count may reach a predetermined value (for example, 5000 times, 10000 times, etc.).

(Roll to panel manufacturing method)
A roll-to-panel manufacturing method is preferred.

  In a manufacturing method of a liquid crystal display device, after a long roll-shaped polarizing plate is continuously bonded to a liquid crystal panel, the liquid crystal panel is cut into a desired size while being cut by a laser, or is bonded to a panel after cutting. A manufacturing method is adopted, which is preferable for improving productivity and yield.

The above manufacturing method is called “roll-to-panel manufacturing method”. However, this manufacturing method directly feeds the polarizing plate from the roll to the liquid crystal panel without cutting the roll-shaped long polarizing plate into the liquid crystal panel size in advance. It is a manufacturing method that cuts into liquid crystal panel size with a laser cutter etc. after bonding or before bonding.
The roll-to-panel manufacturing method is described in JP2011-48381, JP2009-175653, JP4628488, JP4729647, WO2012 / 014602, WO2012 / 014571, etc. It is not limited to.

(Surface layer)
The antireflection layer in the optical film of the present invention has at least an antiglare layer.
The antireflection layer has an oxygen permeability of 450 cc / [m ² · day · atom] or more of the entire support (anti-reflection layer) (laminate) for the reason that the light resistance of the optical film is further improved. it is preferred, more preferably those a ^{500cc / [m 2 · day ·} atom] or more, and particularly preferably made with ^{600cc / [m 2 · day ·} atom] or more.

Although the example of the specific layer structure of the optical film of this invention which has an antireflection layer is shown below, as a layer structure of the optical film of this invention, it is not limited to the following example.
In the following examples, the antireflection layer in the present invention includes a low refractive index layer, a medium refractive index layer, and a high refractive index layer in addition to the antiglare layer, but the present invention is not limited thereto.
Support / Support / Anti-Glare Layer Support / Support / Anti-Glare Layer / Low Refractive Index Layer Support / Support / Anti-Glare Layer / Medium Refractive Index Layer / High Refractive Index Layer / Low Refractive Index Layer Support / Support / hard coat layer / antiglare layer Support / support / hard coat layer / antiglare layer / low refractive index layer Support / support / hard coat layer / antiglare layer / medium refractive index layer / high refractive index Layer / low refractive index layer support / antiglare layer support / antiglare layer / low refractive index layer support / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer support / hard coat layer / Anti-glare layer Support / Hard coat layer / Anti-glare layer / Low refractive index layer Support / Hard coat layer / Anti-glare layer / Medium refractive index layer / High refractive index layer / Low refractive index layer

In each of the above configurations, an embodiment in which the optically anisotropic layer and the antireflection layer are formed on separate supports and then the supports are laminated is also preferable, but the optically anisotropic layer and the antireflection layer are formed on both sides of the support. The embodiment of forming is more preferable. In addition, each layer may be arrange | positioned through an adhesive or an adhesive agent, and another layer may be directly formed on each layer.
A preferable support in the case where the optically anisotropic layer and the antireflection layer are formed on separate supports is the same as the preferable support in the present invention.

  In the present invention, when a large number of layers are arranged in the above-described layer configuration, the oxygen permeability of the antireflection layer decreases, and therefore, an embodiment having only an antiglare layer as the antireflection layer is preferable.

[Anti-glare layer]
The antiglare layer in the antireflection layer is formed for the purpose of imparting to the film an antiglare property due to surface scattering and preferably a hard coat property for improving the hardness and scratch resistance of the film.
Further, the antiglare layer is optically anisotropic when an optically anisotropic layer containing a liquid crystalline compound is disposed further outside the polarizer on the viewing side as in the image display device of the present invention described later. This is useful from the viewpoint of suppressing reflection at the air interface of the surface film on which the conductive layer is formed.

The antiglare layer that can be used in the present invention contains a binder and translucent particles for imparting antiglare properties, and has a surface formed by projections of the translucent particles themselves or projections formed by an aggregate of a plurality of particles. It is preferable that the unevenness is formed.
Further, it is preferable to use an antiglare layer having hard coat properties because it is not necessary to separately form a hard coat layer and the oxygen permeability of the antireflection layer can be lowered.

Specific examples of the translucent particles include particles of inorganic compounds such as silica particles and TiO ₂ particles; resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles; Are preferred. Of these, crosslinked styrene particles, crosslinked acrylic particles, and silica particles are preferred.
The shape of the light-transmitting particles can be either spherical or irregular.

  From the viewpoint of adjusting internal haze and surface haze, the refractive index of the binder is preferably adjusted in accordance with the refractive index of each light-transmitting particle selected from the above-mentioned particles. As a binder according to the translucent particles, for example, a binder (having a refractive index after curing of 1.55 to 1.70) mainly composed of a trifunctional or higher functional (meth) acrylate monomer, and a styrene content of 50 to 50 Examples thereof include a combination of one or both of translucent particles and benzoguanamine particles composed of a crosslinked poly (meth) acrylate polymer that is 100% by mass, and among these, the binder and styrene content of 50 to 100% by mass The combination with the translucent particle | grains (refractive index of 1.54-1.59) which consists of a crosslinked poly (styrene-acrylate) copolymer which is is suitably illustrated.

Moreover, from the viewpoint mentioned above, the absolute value of the difference between the refractive index of the binder and the refractive index of the translucent particles is preferably 0.04 or less. The absolute value of the difference between the refractive index of the binder and the refractive index of the translucent particles is preferably 0.001 to 0.030, more preferably 0.001 to 0.020, and still more preferably 0.001 to 0.00. 015.
Here, the refractive index of the binder can be quantitatively evaluated by directly measuring it with an Abbe refractometer or by measuring a spectral reflection spectrum or a spectral ellipsometry. The refractive index of the translucent particles is determined by measuring the turbidity by dispersing the same amount of the translucent particles in the solvent in which the refractive index is changed by changing the mixing ratio of two kinds of solvents having different refractive indexes. It is measured by measuring the refractive index of the solvent when the degree becomes minimum with an Abbe refractometer.

  The content of the translucent particles is preferably 3 to 30% by mass, and 5 to 20% by mass with respect to the total solid content in the formed antiglare layer, from the viewpoint of antiglare properties and the like. Is more preferable.

  Moreover, you may use together and use 2 or more types of translucent particle | grains from which a particle diameter differs. It is possible to impart an antiglare property with a light-transmitting particle having a larger particle size and to impart another optical characteristic with a light-transmitting particle having a smaller particle size.

  In the present invention, in order to control the cohesiveness of the light-transmitting particles, an embodiment using a smectite-type clay organic composite obtained by intercalating a quaternary ammonium salt to the smectite-type clay is also preferable. Illustrated. The content of the smectite-type clay organic complex is preferably 0.2 to 8.0% by mass, more preferably 0.3 to 4.0% by mass, based on the total solid content of the formed antiglare layer. 0.4-3.0 mass% is further more preferable, and 0.5-2.0 mass% is especially preferable.

As the quaternary ammonium salt, a quaternary ammonium salt represented by the following general formula (1) is preferable.
[(R ¹ ) ₃ (R ² ) N] + · X ⁻ (1)
(In the formula, R ¹ and R ² are not the same, R ¹ represents an alkyl group, an alkenyl group or an alkynyl group having 4 to 24 carbon atoms, and R ² represents an alkyl group or an alkenyl group having 1 to 10 carbon atoms. Or an alkynyl group, and X ⁻ represents an anion.)

  Examples of the ammonium ion of the general formula (1) include trioctyl methyl ammonium ion, tristearyl ethyl ammonium ion, trioctyl ethyl ammonium ion, tristearyl methyl ammonium ion, tridecyl hexyl ammonium ion, Examples thereof include tritetradecyl propyl ammonium ion, among which trioctyl methyl ammonium ion and tristearyl ethyl ammonium ion are preferably exemplified.

In the general formula (1), X ⁻ represents an anion. Examples of such anions include C
l ⁻ , Br ⁻ , OH ⁻ , NO ₃ ^{− and the} like can be mentioned, and among these, Cl ⁻ is preferably exemplified.

  Examples of commercially available smectite-type clay organic composites include Lucentite SAN, Lucentite STN, Lucentite SEN, and Lucentite SPN (manufactured by Coop Chemical Co., Ltd.). These can be used alone or in combination of two or more. it can.

  The film thickness of the antiglare layer in the present invention is preferably 0.5 μm to 50 μm, more preferably 1 to 35 μm, still more preferably 1 μm to 25 μm.

The center line average roughness (Ra ₇₅ ) of the antiglare layer in the present invention is preferably in the range of 0.10 to 0.40 μm.
The strength of the antiglare layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test.

  Examples of the method for forming the antiglare layer include a method of laminating and forming a mat-shaped shaping film having fine irregularities on the surface as described in claim 22 of JP-A-6-16851, A method of forming by curing shrinkage of an ionizing radiation curable resin due to a difference in ionizing radiation dose as described in claim 10 of Kai 2000-206317, and claim 6 of JP 2000-338310 A A method of forming irregularities on the surface of a coating film by solidifying the light-transmitting fine particles and the light-transmitting resin by gelation by reducing the weight ratio of the good solvent to the light-transmitting resin upon drying, As described in claim 8 of -275404, a method of imparting surface irregularities by external pressure is known, and these known methods can be used.

  Moreover, the aspect which made the support body contain translucent particle | grains and provided the anti-glare function to the support body can also be used preferably. As such an embodiment, a film having an antiglare function described in claim 1 of JP-A-2009-258720 and claim 1 of JP-A-2005-105926 is preferably exemplified.

[High refractive index layer, medium refractive index layer, and low refractive index layer]
The refractive index of the high refractive index layer is preferably 1.70 to 1.74, more preferably 1.71 to 1.73. The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the medium refractive index layer is preferably 1.60 to 1.64, and more preferably 1.61 to 1.63. The low refractive index layer preferably has a refractive index of 1.30 to 1.47. In the case of a multilayer thin film interference type antireflection film (medium refractive index layer / high refractive index layer / low refractive index layer), the refractive index of the low refractive index layer is preferably 1.33-1.38. More preferably, it is 35-1.37.
The high refractive index layer, medium refractive index layer, and low refractive index layer are formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method, particularly a vacuum vapor deposition method or a sputtering method, which is a kind of physical vapor deposition method, and an inorganic substance. Although a transparent oxide thin film can be used, a method using all wet coating is preferred.
As the high refractive index layer, the medium refractive index layer, and the low refractive index layer, those described in paragraphs [0197] to [0211] of JP-A-2009-98658 can be used.

These layers can be formed on the antiglare layer. However, as the number of layers increases, the oxygen permeability tends to decrease. Therefore, the oxygen of the entire layer existing on the antireflection layer side rather than the optically anisotropic layer. It is preferable to appropriately adjust the material and thickness so as to satisfy the condition that the transmittance is 100 cc / [m ² · day · atom] or more.

Other layers:
[Hard coat layer]
In the optical film of the present invention, a hard coat layer may be provided in order to impart physical strength of the film. Although it is not necessary to provide a hard coat layer, it is preferable to provide a hard coat layer because the scratch-resistant surface such as a pencil scratch test becomes stronger.
As the hard coat layer, those described in paragraphs [0190] to [0196] of JP-A-2009-98658 can be used.

UV absorber:
Since the optical film in the present application is disposed on the viewing side, in consideration of the influence of external light (particularly, ultraviolet rays), at least one of the layers present on the antireflection layer side of the optically anisotropic layer is exposed to ultraviolet rays (UV). ) It is preferable that an absorber is included, and it is more preferable that the support (particularly, the polymer film) includes an ultraviolet absorber.

(Optically anisotropic layer)
An optically anisotropic layer can also be provided on the optical film of the present invention. The optically anisotropic layer may be an optically anisotropic layer in which a film having a constant retardation is uniformly formed in the plane, and the direction of the slow axis and the magnitude of the retardation are different from each other. It may be an optically anisotropic layer having a pattern in which retardation regions are regularly arranged in a plane.
As described above, the optical film of the present invention is preferably a surface film on which a hard coat layer of a liquid crystal display device is laminated. When the optical film of the present invention has both a hard coat layer and an optically anisotropic layer, the optically anisotropic layer is preferably formed on a surface on which the hard coat layer is not laminated via a base film. .

(Liquid crystal display device)
The liquid crystal cell used in the image display device of the present invention is preferably VA mode, OCB mode, IPS mode, or TN mode, but is not limited thereto.
In a TN mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and are twisted and aligned at 60 to 120 °. The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.
In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied. The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625) (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Proceed) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle. ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVIVAL mode liquid crystal cells (announced at LCD International 98). Also, PVA (Patterned Vertical Alignment) type, optical alignment type (Optical Alignment), and PSA (Polym).
er-Stained Alignment). Details of these modes are described in JP-A-2006-215326 and JP-T-2008-538819.
In an IPS mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially parallel to the substrate, and the liquid crystal molecules respond in a planar manner when an electric field parallel to the substrate surface is applied. The IPS mode displays black when no electric field is applied, and the absorption axes of the pair of upper and lower polarizing plates are orthogonal. JP-A-10-54982, JP-A-11-202323, and JP-A-9-292522 are methods for reducing leakage light at the time of black display in an oblique direction and improving a viewing angle using an optical compensation sheet. No. 11-133408, No. 11-305217, No. 10-307291, and the like.
The polarizing plate with a single-side protective film of the present invention is particularly preferably used for an IPS or VA liquid crystal display device, and more preferably used for an IPS liquid crystal display device.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.

[Production Example 1]
<Preparation of polarizing plate protective film roll 1>
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution (dope 1) having a solid content concentration of 22% by mass.
[Composition of cellulose acetate solution (Dope 1)]
Cellulose acetate with an acetyl substitution degree of 2.86 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by weight Ultraviolet absorber (manufactured by Tinuvin 328 Ciba Japan) 0.9 Part by weight Ultraviolet absorber (manufactured by Tinuvin 326 Ciba Japan) 0.2 part by weight Methylene chloride (first solvent) 336 parts by weight Methanol (second solvent) 29 parts by weight 1-butanol (third solvent) 11 parts by weight

The prepared dope was uniformly cast from a casting die onto a stainless steel endless band (casting support) having a width of 2000 mm using a band casting apparatus as shown in FIG. When the amount of residual solvent in the dope reaches 40% by mass, it is peeled off as a polymer film from the casting support, transported without being actively stretched by a tenter, and dried at 130 ° C. in a drying zone. went.
The thickness of the obtained polarizing plate protective film roll 1 was 40 μm.

[Production Example 2]
<Preparation of polarizing plate protective film roll 2>
JP2009-052021A

~

The transparent pellet A which consists of an acrylic resin which has a lactone ring structure in a principal chain was obtained by the method of description. The resin constituting the pellet A has a lactone cyclization rate of 96.9%, a lactone ring structure content of 28.2% by mass, a weight average molecular weight of 148,000, a melt flow rate (according to JIS K7120, the test temperature is 240 ° C. and a load of 10 kg.) Was 11.0 g / 10 min, and the glass transition temperature was 130 ° C.

  Next, transparent pellet A and AS resin (made by Toyo Styrene, Acrylonitrile-styrene copolymer, trade name: Toyo AS AS20) made of an acrylic resin having a lactone ring structure in the main chain was obtained as pellet A / AS. By kneading using a single screw extruder (φ = 30 mm) at a mass ratio of resin = 90/10, transparent pellets 2 having a glass transition temperature of 127 ° C. were obtained.

  The pellet 2 of the resin composition produced above was melt-extruded from a coat hanger type T die using a twin screw extruder to produce a resin film having a thickness of about 160 μm.

  Next, the obtained unstretched resin film is biaxially stretched 2.0 times in the longitudinal direction and 2.0 times in the transverse direction (stretching ratio is 4 times in area ratio), thereby producing a transparent plastic film base. A material was prepared. Thus, the thickness of the polarizing plate protective film roll 2 which is a biaxially stretchable film was 40 micrometers.

[Production Example 3]
<Preparation of polarizing plate protective film roll 3>
The imidized resin (III) was obtained by the method of paragraphs 0173 to 0176 of JP2011-138119A. The imidized resin (III) is an acrylic resin having a glutarimide structure in the main chain and not having an aromatic vinyl structure.

  About imidized resin (III), the imidation ratio, the glass transition temperature, and the acid value were measured in accordance with the following method. As a result, the imidation ratio was 4 mol%, the glass transition temperature was 128 ° C., and the acid value was 0.40 mmol / g.

100 parts by weight of the imidized resin (III) obtained and 0.10 parts by mass of compound No. 18 described in WO2005 / 109052, which is a triazine compound as an ultraviolet absorber, were pelleted using a single screw extruder, and pellet 3 Got.
Using the pellet 3, a transparent plastic film substrate was produced in the same manner as in Production Example 2. The thickness of the polarizing plate protective film roll thus obtained was 40 μm.

[Calculation of imidation ratio] 1H-NMR 1H-NMR measurement of the resin was performed using BRUKER Avance III (400 MHz). From the area A of the peak derived from the O-CH3 proton of methyl methacrylate in the vicinity of 3.5 to 3.8 ppm and the area B of the peak derived from the N-CH3 proton of glutarimide in the vicinity of 3.0 to 3.3 ppm, Obtained by the formula.

Im% (imidation ratio:%) = B / (A + B) × 100
Here, the “imidization rate” refers to the ratio of the imide carbonyl group in the total carbonyl group.

[Production Example 4]
<Preparation of polarizing plate protective film roll 4>
PMMA (polymethyl methacrylate) resin (Delpet 80N manufactured by Asahi Kasei Chemicals Corporation) is dried with a 90 ° C. vacuum dryer to a moisture content of 0.03% or less, and then PMMA (polymethyl methacrylate) resin. 100 parts by mass, 1.0 part by mass of UV absorber (ADEKA STAB LA-31 manufactured by ADEKA Corporation), 0.3 part by weight of stabilizer (Irganox 1010 (manufactured by Ciba Geigi Co., Ltd.)), biaxial kneading The PMMA resin pellet 4 was produced by mixing at 230 ° C. using a machine.

  The PMMA resin pellet 4 produced above was melt-extruded from a coat hanger type T die using a twin screw extruder to produce a polarizing plate protective film roll 4 having a thickness of 40 μm.

[Production Example 5]
<Preparation of polarizing plate protective film roll 5>
Instead of PMMA (polymethyl methacrylate) resin in Production Example 5, Production Example 4 except that (meth) acrylic resin having a maleic anhydride ring structure in the main chain (Delpet 980N manufactured by Asahi Kasei Chemicals Corporation) was used. Similarly, pellet preparation and film formation were performed to prepare a polarizing plate protective film roll 5 having a thickness of 40 μm.

[Production Example 6]
<Preparation of polarizing plate protective film roll 6>
First, the cellulose ester, acrylic resin, and ultraviolet absorber used in the polarizing plate protective film 6 will be described.

(Cellulose ester)
A cellulose ester having a total acyl group substitution degree of 2.75, an acetyl substitution degree of 0.19, a propionyl substitution degree of 2.56 and a molecular weight of 200,000 was used.
This cellulose ester was synthesized as follows.
Sulfuric acid (7.8 parts by mass with respect to 100 parts by mass of cellulose) was added to cellulose as a catalyst, and carboxylic acid serving as a raw material for the acyl substituent was added to carry out an acylation reaction at 40 ° C. At this time, the substitution degree of the acetyl group and the propionyl group was adjusted by adjusting the amount of the carboxylic acid. In addition, aging was performed at 40 ° C. after acylation. Furthermore, the low molecular weight component of this cellulose ester was removed by washing with acetone (hereinafter referred to as cellulose ester CE-1).

(acrylic resin)
The acrylic resin described below was used. This acrylic resin is commercially available.
・ Dianar BR88 (trade name), manufactured by Mitsubishi Rayon Co., Ltd.

(UV absorber)
The ultraviolet absorber described below was used.
-Tinuvin 328 (Ciba Specialty Chemicals Co., Ltd.)

(Preparation of dope 6)
The composition described below was put into a mixing tank and stirred while heating to dissolve each component to prepare a dope.
(Composition of dope 6)
Cellulose ester CE-1 30 parts by mass Dianal BR85 (manufactured by Mitsubishi Rayon Co., Ltd.) 70 parts by mass (cellulose ester and acrylic resin total 100 parts by mass)
Tinuvin 328 (Ciba Specialty Chemicals Co., Ltd.) 2 parts by mass Dichloromethane 319 parts by mass Ethanol 43 parts by mass

  The solid content concentration of the dope (total concentration of cellulose ester, acrylic resin, and UV absorber) was 22% by mass.

Using the band casting apparatus, the prepared dope was uniformly cast from a casting die to a stainless steel endless band (casting support) having a width of 2000 mm. When the amount of residual solvent in the dope reaches 40% by mass, it is peeled off as a polymer film from the casting support, transported without being actively stretched by a tenter, and dried at 130 ° C. in a drying zone. went.
The thickness of the obtained polarizing plate protective film roll 6 was 40 μm.

[Production Example 7]
<Thermoplastic resin film roll 7>
A commercially available norbornene-based polymer film “ZEONOR ZF14-060” (manufactured by Optes Co., Ltd.) was prepared and used as a thermoplastic resin film roll 7 having a film thickness of 60 μm.

[Production Example 8]
<Preparation of polarizing plate protective film roll 8>
<Synthesis of raw material polyester>
(Raw material polyester 1)
As shown below, terephthalic acid and ethylene glycol are directly reacted to distill off water, esterify, and then use a direct esterification method in which polycondensation is performed under reduced pressure, and a polyester (Sb catalyst) by a continuous polymerization apparatus. System PET) was obtained.

(1) Esterification reaction In a first esterification reactor, 4.7 tons of high-purity terephthalic acid and 1.8 tons of ethylene glycol are mixed over 90 minutes to form a slurry, and continuously at a flow rate of 3800 kg / h. It supplied to the 1st esterification reaction tank. Further, an ethylene glycol solution of antimony trioxide was continuously supplied, and the reaction was carried out at a reaction vessel temperature of 250 ° C. with stirring and an average residence time of about 4.3 hours. At this time, antimony trioxide was continuously added so that the amount of Sb added was 150 ppm in terms of element.

  This reaction product was transferred to a second esterification reaction vessel, and reacted with stirring at a temperature in the reaction vessel of 250 ° C. and an average residence time of 1.2 hours. To the second esterification reaction tank, an ethylene glycol solution of magnesium acetate and an ethylene glycol solution of trimethyl phosphate are continuously supplied so that the added amount of Mg and the added amount of P are 65 ppm and 35 ppm in terms of element, respectively. did.

(2) the polycondensation reaction above-obtained esterification reaction product supplied to the first polycondensation reaction vessel continuously stirring, the reaction temperature 270 ° C., the reaction vessel pressure 20 torr (2.67 × 10 ^{- 3} MPa) and polycondensation with an average residence time of about 1.8 hours.

Further, the mixture was transferred to the second double condensation reaction tank, and while stirring in this reaction tank, the reaction tank temperature was 276 ° C., the reaction tank pressure was 5 torr (6.67 × 10 ⁻⁴ MPa), and the residence time was about 1.2 hours. The reaction (polycondensation) was performed under the conditions.

Subsequently, it was further transferred to the third triple condensation reaction tank. In this reaction tank, the reaction tank temperature was 278 ° C., the reaction tank pressure was 1.5 torr (2.0 × 10 ⁻⁴ MPa), and the residence time was 1.5 hours. The reaction product (polyethylene terephthalate (PET)) was obtained by reaction (polycondensation) under the following conditions.

  Next, the obtained reaction product was discharged into cold water in a strand form and immediately cut to prepare polyester pellets (cross section: major axis: about 4 mm, minor axis: about 2 mm, length: about 3 mm).

  The obtained polymer had IV = 0.63 (hereinafter abbreviated as PET1).

(Raw material polyester 2)
10 parts by weight of a dried UV absorber (2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazinon-4-one), 90 parts by weight of PET1 (IV = 0.63) And a raw material polyester 2 containing an ultraviolet absorber was obtained using a kneading extruder (hereinafter abbreviated as PET2).

-Film forming process-
90 parts by weight of the raw material polyester 1 (PET1) and 10 parts by weight of the raw material polyester 2 (PET2) containing an ultraviolet absorber are dried to a water content of 20 ppm or less, and then the hopper 1 of the uniaxial kneading extruder 1 having a diameter of 50 mm. And melted at 300 ° C. with the extruder 1. Extrusion was performed from a die through a gear pump and a filter (pore diameter: 20 μm) under the following extrusion conditions.
The molten resin was extruded from the die under the conditions that the pressure fluctuation was 1% and the temperature distribution of the molten resin was 2%. Specifically, the back pressure was increased by 1% with respect to the average pressure in the barrel of the extruder, and the piping temperature of the extruder was heated at a temperature 2% higher than the average temperature in the barrel of the extruder.
The molten resin extruded from the die was extruded onto a cooling cast drum set at a temperature of 25 ° C., and was brought into close contact with the cooling cast drum using an electrostatic application method. It peeled using the peeling roll arrange | positioned facing the cooling cast drum, and obtained the unstretched polyester film.

-Transverse stretching process-
The unstretched polyester film was guided to a tenter (lateral stretching machine), and was stretched laterally by the following method and conditions while holding the end of the film with a clip.

(Preheating part)
The preheating temperature was 90 ° C., and the mixture was heated to a temperature at which stretching was possible.

(Extension part)
The preheated unstretched polyester film was horizontally stretched in the width direction under the following conditions.
<Condition>
-Transverse stretching temperature: 90 ° C
・ Horizontal stretch ratio: 4.3 times

(Heat fixing part)
Next, a heat setting treatment was performed while controlling the film surface temperature of the polyester film within the following range.
<Condition>
・ Heat setting temperature: 180 ℃
・ Heat setting time: 15 seconds

(Heat relaxation part)
The polyester film after heat setting was heated to the following temperature to relax the film.
-Thermal relaxation temperature: 170 ° C
-Thermal relaxation rate: TD direction (film width direction) 2%

(Cooling section)
Next, the polyester film after heat relaxation was cooled at a cooling temperature of 50 ° C.

(Recovery of film)
After cooling, both ends of the polyester film 1 were trimmed by 20 cm. Then, after extruding (knurling) at a width of 10 mm at both ends, it was wound up with a tension of 18 kg / m.
As described above, a uniaxially stretched polyester film having a thickness of 65 μm was produced. This film was designated as a polarizing plate protective film roll 8.

[Production Example 9]
<Preparation of Polarizing Film Roll 9>
(Preparation of coating solution for antiglare layer)
Each component was mixed with a mixed solvent (89 to 11 (mass ratio)) of MIBK (methyl isobutyl ketone) and MEK (methyl ethyl ketone) so as to have the following composition. It filtered with the polypropylene filter with the hole diameter of 30 micrometers, and prepared the coating liquid 1 for glare-proof layers. The solid concentration of each coating solution is 40% by mass. In preparing the coating solution, the resin particles and smectite were added in the state of a dispersion described later.
――――――――――――――――――――――――――――――――――――
Antiglare layer coating solution 1
――――――――――――――――――――――――――――――――――――
Smectite (Lucentite STN, manufactured by Co-op Chemical) 1.00% by mass
Resin particles (Techpolymer SSX, manufactured by Sekisui Plastics Co., Ltd.) 8.00% by mass
Acrylate monomer (NK ester A9550, manufactured by Shin-Nakamura Chemical Co., Ltd.)
87.79% by mass
Polymerization initiator (Irgacure 907, manufactured by BASF) 3.00% by mass
Leveling agent (P-4) 0.15% by mass
Dispersant (DISPERBYK-2164, manufactured by Big Chemie Japan)
0.06 mass%
――――――――――――――――――――――――――――――――――――

(Preparation of resin particle dispersion)
The dispersion of translucent resin particles is gradually added to the stirred MIBK solution until translucent resin particles (Techpolymer SSX, manufactured by Sekisui Kasei Co., Ltd.) reach a solid content concentration of 30% by mass. For 30 minutes.

(Preparation of smectite dispersion)
As the smectite dispersion, all MEKs used in the coating solution for the antiglare layer are finally added. While stirring, the smectite (Lucentite STN, manufactured by Corp Chemical Co.) is gradually added and stirred for 30 minutes. Prepared.

(Coating of antiglare layer)
The produced polarizing plate protective film roll 1 was unwound in roll form, and the antiglare layer coating solution 1 was used to coat the antiglare layer so as to have a film thickness of 4 μm.
Specifically, in the die coating method using the slot die described in JP-A-2006-122889, Example 1, each coating solution was applied under the condition of a conveyance speed of 30 m / min, and after drying at 80 ° C. for 150 seconds, Furthermore, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with an oxygen concentration of about 0.1% under nitrogen purge, an illuminance of 400 mW / cm ² and an irradiation amount of 180 mJ /
After irradiating cm ² ultraviolet rays to cure the coating layer to form an antiglare layer, it was wound up to prepare a polarizing plate protective film roll 9.

<Preparation of polarizing plate roll 1>

1) Saponification of film The polarizing plate protective film roll 1 was immersed in a 1.5 mol / L NaOH aqueous solution (saponification solution) kept at 55 ° C. for 2 minutes, then washed with water, and then 0.05 mol at 25 ° C. After being immersed in a / L sulfuric acid aqueous solution for 30 seconds, a water washing bath was further passed under running water for 30 seconds to make the film neutral. Then, draining with an air knife was repeated 3 times, and after dropping water, the film was retained in a drying zone at 70 ° C. for 15 seconds and dried to produce a saponified film roll.

2) Production of Polarizer According to Example 1 of Japanese Patent No. 4691205, a laminate roll having a 3 μm thick PVA layer formed on an amorphous PET substrate was obtained.

3) Preparation of polarizing plate A polarizing plate film roll 1 after the saponification treatment and a laminate roll having a PVA layer having a thickness of 3 μm formed on the amorphous PET base material are combined with a polyvinyl alcohol adhesive. The polarizing film roll 1 after the saponification treatment was attached to the PVA layer of the laminate roll, dried at 70 ° C. for 10 minutes or more, and bonded.
Thereby, the polarizing plate roll 1 whose film length is 500 m and whose absorption axis is the longitudinal direction was obtained.

<Preparation of polarizing plate rolls 2-8>

[Adhesive for polarizing plate]
A polarizing plate adhesive was prepared by blending 100 parts by weight of 2-hydroxyethyl acrylate, 10 parts by weight of tolylene diisocyanate, and 3 parts by weight of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals).

[Preparation of polarizing plate]
The surfaces of the polarizing plate protective film rolls 2 to 8 were subjected to corona treatment. Next, on the polarizing plate protective film rolls 2 to 8, the polarizing plate adhesive is made to have a thickness of 5 μm using a micro gravure coater (gravure roll: # 300, rotation speed 140% / line speed). Coated on one side. Next, a laminate roll having a PVA layer having a thickness of 3 μm formed on the amorphous PET substrate used in the polarizing plate protective film rolls 2 to 8 and the polarizing plate 1 is used as the polarizing plate film roll. It laminated | stacked so that the adhesive application side of 2-8 might contact | connect the PVA side of a laminated body roll, and it bonded together by the roll to roll with the roll machine.
Thereafter, ultraviolet rays were irradiated from both sides to obtain polarizing plate rolls 2 to 8. The line speed was 20 m / min, and the cumulative amount of ultraviolet light was 300 mJ / cm 2.
Thus, polarizing plate rolls 2 to 8 having a film length of 500 m and an absorption axis in the longitudinal direction were obtained.

<Preparation of polarizing plate roll 9>
In the production of the polarizing plate protective film roll 1, instead of the polarizing plate protective film roll 1, one side of the polarizing plate protective film roll 8 is formed on one surface of the polarizing plate protective film roll 1.

A polarizing plate roll 9 was produced in the same manner as the production of the polarizing plate roll 1 except that the easy-adhesion layer described in 1 was applied by 0.3 μm.

<Preparation of polarizing plate roll 10>
In making the polarizing plate protective film roll 1, instead of the polarizing plate protective film roll 1, the polarizing plate protective film roll 9 after saponification treatment is used, and the side opposite to the functional layer of the polarizing plate protective film roll 9 is used. A polarizing plate roll 10 was produced in the same manner except that the surface was attached to the PVA layer of the laminate roll using a polyvinyl alcohol-based adhesive.

<Preparation of polarizing plate roll 11>
2) Production of Polarizer According to Example 1 of Japanese Patent Application Laid-Open No. 2001-141926, iodine was adsorbed to a stretched polyvinyl alcohol film to produce a polarizer having a thickness of 20 μm.

In the production of the polarizing plate roll 2, the polarizing plate roll was similarly prepared except that the 20 μm polarizer roll was used instead of the laminate roll having a 3 μm-thick PVA layer formed on the amorphous PET substrate. A roll 11 was produced.
A known peelable PET film roll was laminated and bonded to the polarizer side surfaces of these polarizing plate rolls.

<Preparation of polarizing plate roll A>
1) Saponification of film A commercially available cellulose triacetate film roll (Fujitac TD60, manufactured by Fuji Film Co., Ltd.) was immersed in a 1.5 mol / L NaOH aqueous solution (saponification solution) maintained at 55 ° C for 2 minutes. The film was washed with water and then immersed in a 0.05 mol / L sulfuric acid aqueous solution at 25 ° C. for 30 seconds, and then a water washing bath was passed under running water for 30 seconds to make the film neutral. Then, draining with an air knife was repeated 3 times, and after dropping water, the film was retained in a drying zone at 70 ° C. for 15 seconds and dried to produce a saponified film roll.

2) Production of Polarizer According to Example 1 of Japanese Patent Application Laid-Open No. 2001-141926, iodine was adsorbed to a stretched polyvinyl alcohol film to produce a polarizer having a thickness of 20 μm.

3) Production of polarizing plate The polarizing film roll A after the saponification treatment is dried on both surfaces of the 20 μm polarizer at 70 ° C. for 10 minutes or more using a polyvinyl alcohol-based adhesive, and then rolled with a roll machine. Bonded with two rolls.
Thereby, a polarizing plate roll A having a film length of 500 m and an absorption axis in the longitudinal direction was obtained. The absorption axis of this film and the slow axis of the film were parallel.

(Evaluation of film)
(1) Moisture permeability (moisture permeability at 40 ° C and 90% relative humidity)
70 mmφ film sample was conditioned at 40 ° C. and 90% relative humidity for 24 hours, respectively, and using a moisture permeable cup according to JIS Z-0208, moisture permeability = mass after humidity adjustment-mass before humidity adjustment per unit area The amount of water (g / m ² ) was calculated.

(Evaluation of polarizing plate)
The polarizing plate was cut by any of the following methods.

<Laser cutting>
In order to cut into small pieces of 16 × 9 cm from the polarizing plate roll, using a CO2 laser cutting device, with a wavelength of 10.6 μm, an output of 80 W, an irradiation diameter of 200 μmφ (output density of 400 W / mm2), a conveyance speed of 30 m / min, Laser was irradiated from the protective film side under the condition of gas pressure of 0.2 MPa supplied with assist gas (dry air), cut along the absorption axis direction, and then cut in the vertical direction.

<Double-edged cutter cutting>
In order to cut into small pieces of 16 × 9 cm from the polarizing plate roll, a cutting edge with an outer diameter of the blade of 80 mm was cut along the absorption axis direction using a double-edged round blade, and then cut in the vertical direction.

<Punching cut>
The polarizing plate was cut using a push-cut type cutting device in order to cut into small pieces of 16 × 9 cm from the polarizing plate roll.

(Cutting failure)
The frequency of peeling and cracking of the polarizing plate was confirmed at the time of cutting. Defects and cracks in the polarizing plate were counted as failures that were confirmed visually. D is an evaluation that is not allowed at a practical level.

A: Peeling and cracking of the polarizing plate were not confirmed in 10 polarizing plate cut products.
B: Peeling and cracking of the polarizing plate were confirmed in one sample out of 10 polarizing plate cut products.
C: Peeling and cracking of the polarizing plate were confirmed in 2 samples among 10 polarizing plate cut products.
D: Peeling and cracking of the polarizing plate were confirmed in 3 or more samples out of 10 polarizing plate cut products.

(Evaluation of polarizing plate cross section)
The cross-sectional direction of the polarizing plate was observed with a 20-fold objective lens with an optical microscope to obtain a photographic image. This image is an enlarged image of 860 times on the screen, and using this, an arbitrary point on the polarizing plate side or the polarizer side was determined as a specific position.
Here, n represents the distance (μm) in the thickness direction from one surface on a line drawn perpendicularly to the polarizing plate thickness direction from a specific position on the outermost surface of the polarizing plate in the cross section of the polarizing plate.
T (n) is the outermost surface of the polarizing plate from the point of the thickness direction distance n (μm) on the line perpendicular to the thickness direction of the polarizing plate from the specific position on the outermost surface of the polarizing plate in the cross section of the polarizing plate. And the distance (μm) to one cut surface in the horizontal direction.

(Formula 1) A (n) = T (n) −T (n−1) n ≧ 1
(Formula 2) B (n) = A (n) −A (n−1) n ≧ 1

A: Less than 2.0 points where the absolute value of B (n) is 0.5 or more B: 2.0 or more and less than 5.0 points where the absolute value of B (n) is 0.5 or more C: Absolute value of B (n) 5.0 or more and less than 9.0 points where A is 0.5 or more D: 9.0 or more points where the absolute value of B (n) is 0.5 or more

Here, n is the distance in the thickness direction from one outermost surface to the other outermost surface in the cross section of the polarizing plate, and n is set at 1 μm intervals for the calculation of A (n) and B (n). T (n) was measured.
Here, A (n) of the following formula 1 was obtained and B (n) was obtained from the following formula 2. Each of the results was observed and calculated at 10 points, and the cross-sectional shape of the polarizing plate was evaluated from the average value of B (n). D is an evaluation that is not allowed at a practical level.

(Production of liquid crystal display device by roll-to-panel manufacturing method)
A liquid crystal display device was produced by a roll-to-panel manufacturing method. The polarizing plate rolls 1 to 11 were bonded to one side of the liquid crystal cell, and the polarizing plate roll A was bonded to the other side so as to be crossed Nicol.
The polarizing plate rolls 1-10 peeled the amorphous PET base material used at the time of polarizer preparation before bonding to a liquid crystal cell. The polarizing plate roll 11 peeled the peelable PET film before bonding to the liquid crystal cell. The polarizing plate was cut by any one of the methods described above, and the polarizer side of the polarizing plate roll and the liquid crystal cell substrate were bonded with an adhesive.

(Black display unevenness after high temperature and high humidity environment)
After the liquid crystal display device was allowed to pass for 24 hours at 60 ° C. and 90% RH, it was lit after being conditioned for 24 hours in an environment of 25 ° C. and 60% RH, and the degree of color unevenness during black display was visually observed The evaluation was made in four stages according to the following criteria. D is an evaluation that is not allowed at a practical level.

A: Color unevenness was not observed.
B: Weak color unevenness was observed in an area less than half of the display surface.
C: Weak color unevenness was observed in an area of more than half of the display surface, or strong color unevenness was observed in an area of less than half.
D: Strong color unevenness was observed in an area of more than half of the display surface.

レーザー裁断と両刃カッターではレーザー裁断の方がより故障が少なく、耐湿性に優れるとの結果であった。これはレーザー裁断時に偏光板保護フィルムが溶融して偏光子端面の外気に触れる面積を減少させるからか、または偏光板に直接外力が印加しないので、偏光子の欠けや偏光子と偏光板保護フィルムの間の剥離がより生じにくいからであると推測している。

Laser cutting and double-edged cutters showed that laser cutting had fewer failures and better moisture resistance. This is because the polarizing plate protective film melts at the time of laser cutting and reduces the area that touches the outside air of the polarizer, or because no external force is applied directly to the polarizing plate, the polarizer is missing or the polarizer and the polarizing plate protective film It is presumed that this is because peeling between the layers is less likely to occur.

In the production of the liquid crystal display device by the roll-to-panel manufacturing method, the results were also obtained in the roll-to-panel manufacturing method in which the polarizing plate roll was cut into a panel size after the polarizer side of the polarizing plate roll and the liquid crystal cell substrate were bonded with an adhesive. Was the same.
In addition, a similar experiment was conducted using a polarizing plate with two sides cut with a laser and two sides cut with a double-edged cutter. It was.

Claims (9)

A polarizing plate with a single-sided protective film comprising a polarizing plate protective film and a polarizer, and there are less than 9.0 points where the absolute value of B (n) represented by the following formula 2 is 0.5 or more. A polarizing plate with a single-sided protective film.
(Formula 1) A (n) = T (n) −T (n−1) (n ≧ 1)
(Formula 2) B (n) = A (n) −A (n−1) (n ≧ 1)
Here, n represents a distance (μm) in the thickness direction from one surface on a line drawn perpendicularly to the thickness direction of the polarizing plate from a specific position on the outermost surface of the polarizing plate in the cross section of the polarizing plate.
T (n) is the outermost surface of the polarizing plate in terms of the thickness direction distance n (μm) on the line perpendicular to the thickness direction of the polarizing plate from the specific position on the outermost surface of the polarizing plate in the cross section of the polarizing plate. And the distance (μm) to one cut surface in the horizontal direction. The polarizing plate protective film is made of (meth) acrylic resin, polycarbonate resin, polystyrene resin, cyclic polyolefin resin, polyester resin, polypropylene resin, cellulose resin, and a plurality of resins selected from these. The polarizing plate according to claim 1, which is a film made of a mixed resin. The polarizing plate according to claim 1 or 2, wherein the polarizing plate protective film is provided with at least one of a hard coat layer, an antiglare layer, an antireflection layer, an easy adhesion layer, an antistatic layer, and an optically anisotropic layer on the surface. Board. The polarizing plate of any one of Claims 1-3 whose moisture permeability of the said polarizing plate protective film is 200 g / m < ² > * day or less. The polarizing plate according to claim 1, wherein the polarizer has a thickness of 1 to 10 μm. The polarizing plate according to any one of claims 1 to 5, wherein the polarizing plate is cut into a desired size by a laser and is not subjected to end face polishing. The polarizing plate according to any one of claims 1 to 6, wherein the polarizing plate is bonded to a liquid crystal panel by a roll-to-panel manufacturing method. A liquid crystal display device comprising at least one polarizing plate according to claim 1. In the manufacturing method of the liquid crystal display device which bonds the polarizing plate of any one of Claims 1-7 to a liquid crystal panel,
The manufacturing method of the liquid crystal display device is a roll-to-panel manufacturing method,
A method of manufacturing a liquid crystal display device, wherein the polarizing plate is cut into a desired size by a laser.