KR20190100169A - Manufacturing Method of Optical Film, Polarizing Plate, and Display Device - Google Patents

Abstract

It includes the peeling process of providing a multilayer film to a peeling process, The said multilayer film contains the film (A) which consists of thermoplastic resin A, and the film (B) provided in one or both surfaces of the said film (A). It is a long multilayer film, The said peeling process includes peeling the said film (B) so that a force may be applied to the thickness direction of the said film (A) from the said film (A) in temperature Tov (degreeC). The temperature Tov and the glass transition temperature TgA (° C.) of the film A satisfy a relationship of Tov ≧ TgA, and the film B has a shrinkage ratio Xb of 0% or more and less than 4%, Said shrinkage rate Xb is a manufacturing method of an optical film which is a shrinkage rate of the width direction of the said film (B) when the said film (B) is processed on condition of temperature Tov and 60 second; And a polarizing plate and a display device using the optical film.

Description

Manufacturing Method of Optical Film, Polarizing Plate, and Display Device

This invention relates to the manufacturing method of an optical film, a polarizing plate, and a display apparatus.

In display devices, such as a liquid crystal display device, in order to provide optical compensation etc., providing the optical film made from resin which has a phase difference is widely performed. As a method of providing a phase difference to the resin film, extending | stretching such a film is widely performed.

As such an optical film, a film in which the NZ coefficient Nz satisfies 0 <Nz <1, preferably a film of 0.4 <Nz <1, more preferably a film of Nz = 0.5, may be required. However, when the film is stretched by the usual method, the value of the NZ coefficient is smaller than 0 or larger than 1, so that it is difficult to obtain a film with 0 <Nz <1.

As a method of obtaining the film of 0 <Nz <1, it is possible to employ | adopt the multilayer film which combined several films. However, it is required to realize a film of 0 <Nz <1 with a simpler single layer structure.

The method of patent document 1 is known as a method of realizing the film of 0 <Nz <1 by the film of a single | mono layer. In patent document 1, a shrink film is bonded to the resin film of a process target, a shrink film is shrunk after that, and a resin film is shrunk by this, and as a result, 0 <Nz <1 is achieved.

Japanese Patent Application Laid-Open No. 08-207119 (corresponding foreign publication: European Patent Application Publication No. 0707938)

However, with the method of patent document 1, it is difficult to control the shrinkage force of a shrink film, and the process of shrinking a shrink film is complicated, and it is difficult to manufacture a film of 0 <Nz <1 simply.

Therefore, the objective of this invention is providing the manufacturing method of the optical film which can manufacture the optical film of 0 <Nz <1 easily. Another object of the present invention is to provide a polarizing plate which can be easily manufactured and has a high optical compensation function, and a display device which can be easily manufactured and has high optical compensation.

This inventor examined in order to solve said subject. As a result, this inventor discovered that such a subject can be solved by extending | stretching a film to thickness direction using the peeling force of a film as a manufacturing method of the optical film which has never existed. Moreover, it was discovered that favorable thickness direction extending | stretching operation can be performed by making the temperature of extending | stretching in such a thickness direction, and the characteristic of the film peeled as specific. This invention is made | formed based on this knowledge.

That is, this invention is as follows.

[1] including a peeling step of providing the multilayer film to the peeling treatment,

The said multilayer film is a long multilayer film containing the film (A) which consists of thermoplastic resin A, and the film (B) provided in the one or both surfaces of the said film (A),

The peeling treatment includes peeling the film (B) from the film (A) at a temperature Tov (° C.) so that a force is applied in the thickness direction of the film (A),

The temperature Tov and the glass transition temperature TgA (° C.) of the film A satisfy a relationship of Tov ≧ TgA,

The said film (B) has the shrinkage rate Xb of 0% or more and less than 4%, The said shrinkage rate Xb is the width | variety of the said film (B) when the said film (B) is processed on condition of temperature Tov and 60 second. Shrinkage in the direction,

Method for producing an optical film.

[2] The method for producing an optical film according to [1], wherein the thermoplastic resin A contains an alicyclic structure-containing polymer.

[3] The method for producing an optical film according to [1] or [2], further comprising an stretching step of stretching the multilayer film in the in-plane direction.

[4] A polarizing plate comprising an optical film and a polarizer produced by the production method according to any one of [1] to [3].

[5] A display device comprising the optical film produced by the production method according to any one of [1] to [3].

According to this invention, the manufacturing method of the optical film which can manufacture the optical film of 0 <Nz <1 easily; A polarizing plate which can be easily manufactured and has a high optical compensation function; In addition, a display device that can be easily manufactured and has high optical compensation is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows typically an example of the peeling apparatus which performs the peeling process in the manufacturing method of this invention, and the peeling process operation using the said apparatus.
It is a side view which shows typically a peeling apparatus which performs the peeling process in the manufacturing method of this invention, and another example of the peeling process operation using the said apparatus.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment and an illustration are shown and this invention is demonstrated in detail. However, this invention is not limited to embodiment and illustration shown below, It can implement by changing arbitrarily in the range which does not deviate from the Claim of this invention, and its equal range.

In the following description, unless otherwise indicated, in-plane retardation Re of a film is a value represented by Re = (nx-ny) xd, and unless otherwise mentioned, retardation Rth of the thickness direction of a film is mentioned. , Rth = {(nx + ny) / 2-nz} × d. In addition, the NZ coefficient Nz of a film is a value represented by Nz = (nx-nz) / (nx-ny), and can also be represented by Nz = (Rth / Re) +0.5. Here, nx represents the refractive index of the direction which gives a maximum refractive index as an in-plane direction of a film, ie, the direction orthogonal to the thickness direction. ny represents the refractive index of the direction orthogonal to the direction of nx as said in-plane direction. nz represents the refractive index of the thickness direction. d represents the thickness of a film. The measurement wavelength is 590 nm unless otherwise noted.

In the following description, unless otherwise indicated, a "polarizing plate" includes not only a rigid member but also a member which has flexibility like a film made of resin, for example.

In the following description, the film "long" refers to a film having a length of five times or more with respect to the width, and preferably has a length of 10 times or more, and specifically, a degree of being wound and stored or transported in a roll shape. Refers to a film having a length of. There is no restriction | limiting in particular in the upper limit of the length of a long film, For example, it can be 100,000 times or less with respect to width.

In the art, "stretching" of a film usually means an operation of deforming the film so as to expand the shape of the film in one or more directions of the in-plane direction of the film. However, in the present application, the "stretching" of the film is not limited thereto, and the film is deformed so as to expand the shape of the film in directions other than the in-plane direction (direction parallel to the film direction of the film, for example, thickness direction). It also includes the operation to make it. In the following description, when it is clear from the context, the operation of deforming the film so as to expand the shape of the film in one or more directions of the in-plane direction of the film is generally referred to simply as "stretching". On the other hand, the process of deforming the film so as to extend the shape of the film in a direction other than the in-plane direction is referred to as "thickness direction stretching" to distinguish it from such normal "stretching", and the film which passed such processing is "thickness direction stretching". Film ”.

[One. Manufacturing Method of Optical Film]

The manufacturing method of the optical film of this invention includes the peeling process of providing a specific multilayer film to a specific peeling process.

1.1. Multilayer film]

The multilayer film provided in a peeling process is a long multilayer film containing the film (A) which consists of thermoplastic resin A, and the film (B) provided in the one or both surfaces of the film (A).

1.1.1. Film (A)]

The thermoplastic resin A constituting the film (A) is not particularly limited, and a resin containing various polymers capable of imparting desired physical properties as an optical film can be appropriately selected and adopted.

As a preferable example of the polymer contained in the thermoplastic resin A, an alicyclic structure containing polymer is mentioned.

The alicyclic structure-containing polymer is a polymer having an alicyclic structure in the repeating unit, and any polymer containing an alicyclic structure in the main chain and a polymer containing an alicyclic structure in the side chain can be used. An alicyclic structure containing polymer can contain crystalline resin and an amorphous polymer. From the viewpoint of obtaining the desired effect of the present invention and the production cost, an amorphous alicyclic structure-containing polymer is preferable.

As an alicyclic structure which an amorphous alicyclic structure containing polymer has, a cycloalkane structure, a cycloalkene structure, etc. are mentioned, for example, A cycloalkane structure is preferable from a viewpoint of thermal stability.

Although there is no restriction | limiting in particular in carbon number which comprises the repeating unit of one alicyclic structure, Usually, 4-30, Preferably it is 5-20, More preferably, it is 6-15.

The proportion of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer is appropriately selected depending on the intended use, but is usually 50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more. By increasing the number of repeating units which have an alicyclic structure in this way, the heat resistance of a base film can be improved.

Specific examples of the alicyclic structure-containing polymer include (1) norbornene polymers, (2) monocyclic cyclic olefin polymers, (3) cyclic conjugated diene polymers, (4) vinyl alicyclic hydrocarbon polymers, and hydrides thereof. Can be mentioned. Among these, norbornene polymers and their hydrides are more preferable from the viewpoint of transparency and moldability.

As a norbornene polymer, For example, the ring-opening polymer of a norbornene monomer, the ring-opening copolymer of the norbornene monomer and the other monomer which can be ring-opened-copolymerized, and those hydrides; The addition polymer of a norbornene monomer, the addition copolymer with the other monomer copolymerizable with a norbornene monomer, etc. are mentioned. Among these, the ring-opening polymer hydride of a norbornene monomer is especially preferable from a transparency viewpoint.

As an example of the said alicyclic structure containing polymer, the polymer disclosed by Unexamined-Japanese-Patent No. 2002-321302 is mentioned, for example.

Moreover, the polymer disclosed by Unexamined-Japanese-Patent No. 2016-26909 is mentioned as an example of a crystalline alicyclic structure containing polymer.

As another example of the polymer contained in the thermoplastic resin A, general purpose polymers, such as a triacetyl cellulose and a polystyrene polymer, are mentioned. In particular, among the polystyrene-based polymers, in particular, a polystyrene-based polymer having a syndiotactic structure can be preferably employed. As an example of the polystyrene polymer which has a syndiotactic structure, the polymer disclosed by Unexamined-Japanese-Patent No. 2014-186273 is mentioned.

Although the weight average molecular weight of the polymer contained in the thermoplastic resin A is not specifically limited, Preferably it is 10000 or more, More preferably, it is 20000 or more, On the other hand, Preferably it is 300000 or less, More preferably, it is 250000 or less. When the weight average molecular weight is within this range, the thermoplastic resin A excellent in mechanical strength and molding processability can be easily obtained.

Although thermoplastic resin A may consist only of polymers which are main components, such as those mentioned above, as long as the effect of this invention is not impaired remarkably, you may include arbitrary compounding agents. The ratio of the polymer which is a main component in resin becomes like this. Preferably it is 70 weight% or more, More preferably, it is 80 weight% or more.

As the thermoplastic resin A, those having desired characteristics can be appropriately selected from various commercial products. As an example of such a commercial item, the product name of a brand name "Zenooa" (made by Nippon Xeon Corporation), a brand name "topas" (made by Polyplastics Co., Ltd.), and a brand name "Aton" (made by JSR Corporation) is mentioned.

Glass transition temperature TgA of thermoplastic resin A becomes like this. Preferably it is 100 degreeC or more, More preferably, it is 110 degreeC or more, On the other hand, Preferably it is 180 degrees C or less, More preferably, it is 170 degrees C or less. When TgA is such a range, the process of thickness direction extending | stretching etc. can be performed smoothly, and the optical film which has a desired optical body characteristic can be obtained easily.

The thickness of the film (A) is preferably 10 μm or more, more preferably 20 μm or more, while preferably 200 μm or less, and more preferably 190 μm or less. When the thickness of the film A is such a range, the process of thickness direction extending | stretching etc. can be performed smoothly, and the optical film which has a desired optical body characteristic can be obtained easily.

The method of manufacturing a film (A) is not specifically limited, Any manufacturing method can be employ | adopted. For example, the film A can be manufactured by shape | molding thermoplastic resin A to a desired shape. Preferable examples of the molding method for molding the resin A include extrusion molding. By performing extrusion molding, the film (A) having a desired dimension can be efficiently produced.

1.1.2. Film (B)]

It does not specifically limit as a material which comprises a film (B), Resin containing various polymers suitable for implementation of this invention can be selected suitably, and can be employ | adopted. Below, this resin is simply called "resin B."

As the resin B, a thermoplastic resin can be used. Examples of the polymer contained in the resin B and a preferable range of the molecular weight thereof include the same examples as those described above as examples of the alicyclic structure-containing polymer and other polymers contained in the thermoplastic resin A.

Examples of the further layer of the alicyclic structure-containing polymer contained in the resin B include at least two polymer blocks having a cyclic hydrocarbon group-containing compound hydride unit [I], a chain hydrocarbon compound hydride unit [II], or a unit [I] ] And hydrogenated block copolymers comprising at least one polymer block having a combination of units [II]. Specific examples of such hydrogenated block copolymers include polymers disclosed in WO 2016/152871.

As an example of the further layer of the polymer contained in resin B, general-purpose polymers, such as a polypropylene, a (meth) acrylate polymer, and a polyimide, are mentioned. As resin B, what has a desired characteristic can be suitably selected from the various commercial items, and it can employ | adopt. As an example of such a commercial item, the self-adhesive stretched polypropylene film (For example, Fitamura Chemical Co., Ltd. make, brand name "FSA 010M # 30") is mentioned.

As for the film (B) in a multilayer film, the shrinkage rate Xb is a value within a specific range. Shrinkage rate Xb is a shrinkage rate of the width direction of the film B when the film B is processed on condition of temperature Tov and 60 second. Here, temperature Tov is the temperature of the film in the peeling process of the manufacturing method of this invention.

Shrinkage rate Xb is 0% or more, preferably 0.3% or more, more preferably 0.5% or more, even more preferably 1.4% or more, while less than 4%, preferably 3.9% or less, more preferably 3.8 % Or less When shrinkage rate Xb is such a range, generation | occurrence | production of the wrinkle in the process to a peeling process is suppressed, and also peeling of the unintentional film (B) in the step before a peeling process is suppressed, and the desired thickness direction extending | stretching of A force can be applied to the film A. Shrinkage rate Xb can be calculated | required by heat-processing the sample of the film B for 60 second at temperature Tov, measuring the dimension before and behind heat processing, and calculating those ratios.

The thickness of the film (B) is preferably 10 μm or more, more preferably 15 μm or more, while preferably 100 μm or less, and still more preferably 90 μm or less. When the thickness of the film (B) is such a range, the process of thickness direction extending | stretching etc. can be performed smoothly, and the optical film which has a desired optical body characteristic can be obtained easily.

The method of manufacturing the film (B) is not particularly limited, and any manufacturing method can be adopted. For example, the film B can be manufactured by shape | molding resin B to a desired shape. Preferable examples of the molding method for molding the resin B include extrusion molding. By performing extrusion molding, the film (B) having a desired dimension can be efficiently produced.

[1.1.3. Other layers]

The multilayer film may include any layer in addition to the films (A) and (B). For example, the adhesive layer may be included. As an adhesive which comprises an adhesive layer, various adhesives commercially available can be used. Specifically, the adhesive containing an acrylic polymer can be used as a polymer which is a main component. For example, the adhesive layer is transferred to a film (A) or a film (B) from a film (for example, Fujimori Industrial Co., Ltd. "Mastack series") which has a commercially available adhesive layer, and this is an adhesive layer in a multilayer film. It can be used as.

When a multilayer film has an adhesive layer between films (A) and (B), it is preferable that the adhesive force with respect to the film (B) of such an adhesive layer is higher than the adhesive force with respect to the film (A). By having such a difference of adhesive force, the remainder of the paste with respect to an optical film can be reduced and a high quality optical film can be obtained easily. Such a difference in adhesive force can be obtained by appropriately selecting the material of the pressure-sensitive adhesive layer and by performing appropriate surface treatment on the surfaces of the films (A) and (B) as necessary.

[1.1.4. Preparation method of multilayer film]

The method of preparing the multilayer film provided for the manufacturing method of this invention is not specifically limited, Arbitrary methods can be employ | adopted. Such preparation can be performed, for example by bonding together the film (A) and the film (B). Prior to bonding, if necessary, surface treatment such as corona treatment can be performed on the film (A) and / or the film (B). In addition, prior to bonding, an adhesive layer can be formed in the surface of the film (A) and / or the film (B) as needed, and bonding can be performed through this adhesive layer. Bonding can be performed by bonding a long film (A) and a long film (B) with a roll to roll with the longitudinal direction.

1.2. Peeling process]

In the peeling process in the manufacturing method of this invention, a multilayer film is provided to a peeling process. The peeling process includes peeling the film (B) from the film (A). By performing such a peeling process, the force which pulls the film A in the thickness direction can be applied, and as a result, the thickness direction extending | stretching of the film A can be achieved. When a multilayer film has two or more layers of film (B), the film (B) of multiple layers peels normally simultaneously.

1: is a side view which shows typically an example of the peeling apparatus which performs the peeling process in the manufacturing method of this invention, and the operation of the peeling process using the said apparatus. In FIG. 1, the long multilayer film 100 is conveyed in the arrow A11 direction, and is provided to a peeling process in the peeling area | region P after that.

The multilayer film 100 has the film (A) 131, the film (B) 111 provided in one surface of the film (A) 131, and the other surface of the film (A) 131. It includes a film (B) 112 installed in. The multilayer film 100 also includes the pressure-sensitive adhesive layers 121 and 122 interposed between the films (A) and (B). The thickness of the film (A) 131 in a multilayer film is shown by the arrow A14.

The process of peeling in a peeling process can be performed by pulling the film B in the direction different from the in-plane direction of the film A conveyed. In the example of FIG. 1, in peeling area | region P, the film (B) 111 is pulled in the arrow A12 direction along the longitudinal direction, and also the film (B) 112 is extended in the longitudinal direction. Along the direction of the arrow A13. Thereby, peeling advances from the downstream of the conveyance direction of a multilayer film to an upstream, and it can peel so that a force may be applied to the film (B) 111 and 112 in the thickness direction of the film (A) 131. The force in the thickness direction of the film here is a force in a direction parallel to the in-plane direction of the film, and is preferably a direction close to the direction perpendicular to the surface of the film. As a result of this peeling process, the optical film 132 extended | stretched in the thickness direction is obtained. In addition, by balancing the traction force in the direction of the arrow A12 and the traction force in the direction of the arrow A13, these tractions are not imparted to the multilayer film 100 and the optical film 132 in an undesired in-plane direction. It can be done without.

In the example of FIG. 1, the thickness of the optical film 132 is shown by the arrow A15. The optical film 132 has thickness thicker than the film (A) 131 in the multilayer film 100 as a result of the thickness direction extending | stretching. However, the production method of the present invention is not limited thereto. For example, when a peeling process also involves extending | stretching to an in-plane direction, the thickness of an optical film does not necessarily become thicker than the thickness of the film A, but even in such a case, the optical film of 0 <Nz <1 This may be obtained.

The optical film 132 obtained as a result of the peeling process in the peeling region P is further conveyed in the arrow A11 direction. The multilayer film 100 and the optical film 132 are conveyed in the state held by the nip rolls 151 and 152 upstream of a peeling area | region, and the nip rolls 161 and 162 downstream of a peeling area | region. The conveyance speed can be adjusted by adjusting the peripheral speed of these nip rolls suitably.

In addition, if necessary, the circumferential speed of the downstream nip roll can be adjusted at a speed faster than the circumferential speed of the upstream nip roll. By performing such adjustment, a desired tension can be given to the multilayer film 100 and the optical film 132. If necessary, by adjusting such tension, the stretching step in the film length direction according to the peeling step can be performed. Furthermore, you may extend | stretch to arbitrary directions in a film plane with a peeling process or upstream or downstream of the peeling area | region P as needed.

In the manufacturing method of the optical film of this invention, extending | stretching magnification at the time of extending | stretching of in-plane direction in addition to thickness direction extending | stretching can be suitably adjusted according to the desired optical performance requested | required to give to an optical film. The specific draw ratio is preferably 1 or more times, more preferably 1.01 times or more, while preferably 2 times or less, and more preferably 1.8 times or less. When the draw ratio of in-plane direction is such a range, desired optical performance can be obtained easily.

In the peeling apparatus WHEREIN: When performing a peeling process continuously with respect to a long multilayer film, peeling area | region P can be set to the position with a peeling device by making the conveyance speed of a multilayer film and the speed | rate of peeling balanced. In that case, the conveyance speed of a multilayer film becomes a peeling speed. The peeling speed can be appropriately adjusted in accordance with desired optical performance required to be imparted to the optical film. The specific peeling speed is preferably 1 m / min or more, more preferably 2 m / min or more, while preferably 50 m / min or less, and more preferably 40 m / min or less. When the peeling rate is in this range, desired optical performance can be easily obtained.

In the manufacturing method of the optical film of this invention, a peeling process is performed at temperature Tov (degreeC). The temperature Tov and the glass transition temperature TgA (° C.) of the film A satisfy a relationship of Tov ≧ TgA. Tov becomes like this. Preferably it is (TgA + 3) degreeC or more, More preferably, it is (TgA + 5) degreeC or more. By adjusting Tov in such a range, optical characteristics, such as desired NZ coefficient, can be easily given to an optical film. Although the upper limit of Tov is not specifically limited, For example, it can be set to (TgA + 40) degrees C or less. Temperature Tov in a peeling process can be adjusted by heating the temperature in oven (not shown) which surrounds the area | region containing a peeling area in a peeling apparatus with a suitable heating apparatus.

FIG. 2: is a side view which shows typically the peeling apparatus which performs the peeling process in the manufacturing method of this invention, and another example of the peeling process operation using the said apparatus. In FIG. 2, the long multilayer film 200 is conveyed in the direction of an arrow A21, and is then provided to a peeling process in the peeling region P. In FIG. The multilayer film 200 includes a film (A) 231 and a film (B) 211 provided on one surface of the film (A) 231, but the other one of the film (A) 231. The film (B) is not provided in the surface. The multilayer film 200 also includes the pressure-sensitive adhesive layer 221 interposed between the films (A) and (B). The thickness of the film (A) 231 in a multilayer film is shown by the arrow A24.

In this example, since the multilayer film 200 has the film (B) 211 only on one surface, the peeling process in a peeling process conveys such a film (B) 211. It carries out by pulling in the direction of arrow A22 which is a direction different from the in-plane direction of film A. FIG. Therefore, tension is applied to the multilayer film 200 and the optical film 232 after the peeling process by the nip rolls 151 and 152 upstream of the peeling region and the nip rolls 161 and 162 downstream of the peeling region. Such tension is opposed to the pulling of the film (B) 211. As a result of this peeling process, the film (A) 231 is extended in the thickness direction, and the optical film 232 is obtained. The optical film 232 has the thickness shown by the arrow A25 thicker than the film (A) 231.

[2. Optical film]

According to the manufacturing method of this invention, the optical film whose NZ coefficient Nz is 0 <Nz <1 can be manufactured easily. Nz is more preferably 0.4 <Nz <1, and ideally Nz = 0.5. While it is difficult to manufacture the optical film which has such an NZ coefficient by extending | stretching a film to a normal in-plane direction, it can be usefully used for the purpose of optical compensation of a display apparatus. Accordingly, the production method of the present invention exhibits a high effect from the viewpoint of being difficult to manufacture and easily producing useful products.

In-plane retardation Re of an optical film becomes like this. Preferably it is 100 nm or more, More preferably, it is 120 nm or more, On the other hand, Preferably it is 350 nm or less, More preferably, it is 300 nm or less. When Re is such a range, the optical film which can be usefully used for uses, such as optical compensation, can be comprised. Retardation Rth of the thickness direction of an optical film becomes like this. Preferably it is -80 nm or more, More preferably, it is -70 nm or more, On the other hand, Preferably it is 80 nm or less, More preferably, it is 70 nm or less. When Re is such a range, the optical film which has characteristics, such as desired Nz coefficient, can be usefully used for uses, such as optical compensation, can be comprised.

[3. Use of optical film: polarizer and display device]

The optical film obtained by the manufacturing method of this invention can be used as a component of optical apparatuses, such as a display apparatus. For example, optical components, such as a polarizing plate, can be comprised combining an optical film and another member.

The polarizing plate of this invention is equipped with the optical film and polarizer manufactured by the manufacturing method of the said invention. The polarizing plate of this invention can be manufactured by bonding an optical film and a polarizer.

Prior to bonding with a polarizing plate, arbitrary layers can be formed in the surface of an optical film. As an example of arbitrary layers, the hard-coat layer which raises the surface hardness of a film, the mat layer which improves the slidability of a film, and an antireflection layer are mentioned.

The polarizing plate of this invention may further be equipped with the adhesive bond layer for bonding these between the film cut out from the optical film and polarizer.

The polarizer is not particularly limited, and any polarizer can be used. As an example of a polarizer, what carried out extending | stretching, after making material, such as iodine and a dichroic dye, adsorb | suck to a polyvinyl alcohol film. As an adhesive agent which comprises an adhesive bond layer, what made various polymers the base polymer is mentioned. Examples of such base polymers include, for example, acrylic polymers, silicone polymers, polyesters, polyurethanes, polyethers, and synthetic rubbers.

A polarizing plate can be equipped with a protective film. Although the number of polarizers and protective films with which a polarizing plate is equipped is arbitrary, the polarizing plate of this invention can be normally equipped with one layer of polarizer and two layers of protective films provided in the both surfaces. Among these two layers, the film cut out from the optical film of this invention may be sufficient as both, and the film cut out from the optical film of this invention may be sufficient as either one.

The display apparatus of this invention is equipped with the optical film manufactured by the manufacturing method of the said invention. The display device of the present invention may preferably include the polarizing plate of the present invention. The display device of the present invention can be appropriately configured by combining the optical film of the present invention with other components of the display device.

The display device of the present invention is preferably a liquid crystal display device. As the liquid crystal display device, for example, in-plane switching (IPS) mode, vertical alignment (VA) mode, multi-domain vertical alignment (MVA) mode, continuous pinwheel alignment (CPA) mode, hybrid alignment nematic (HAN) The liquid crystal display which has the liquid crystal cell of the drive system, such as a mode, a twisted nematic (TN) mode, a super twisted nematic (STN) mode, and an optically compounded bend (OCB) mode, is mentioned.

In the case where the display device of the present invention is a liquid crystal display device, the polarizing plate can be provided as a layer for transmitting only desired specific polarization among light incident on the liquid crystal cell and light emitted from the liquid crystal cell. The polarizing plate may also be provided as part of a component for preventing reflection of external light.

The display device of the present invention may also be an organic electroluminescent display device. In this case, for example, the polarizing plate of the present invention is provided as part of a component for preventing reflection of external light.

Example

Hereinafter, an Example is shown and this invention is demonstrated concretely. However, this invention is not limited to the Example shown below, It can implement by changing arbitrarily in the range which does not deviate from the Claim of this invention, and its equal range.

In the following description, "%" and "part" indicating the amount are by weight unless otherwise indicated. In addition, the operation demonstrated below was performed on the conditions of normal temperature and normal pressure unless there is particular notice.

[Assessment Methods]

(Measurement Method of Glass Transition Temperature of Resin)

Pellets of the measurement target resin were prepared, and the glass transition temperature of the resin pellets was measured using a differential scanning calorimeter ("DSC6220" manufactured by Seiko Instruments Inc.). The conditions were 10 mg of sample weight and 20 degree-C / min of temperature increase rate.

(Measurement of phase difference and NZ coefficient)

Re and Rth were measured using the phase difference measuring apparatus (product name "Axoscan" by Axometric company) at the wavelength of 590 nm, and NZ coefficient was calculated | required based on them.

(Measuring method of shrinkage rate Xb)

The elongate film of the measurement object was cut out and the slice of length direction x width direction = 120 mm x 120 mm was obtained. The four corners of the rectangle 10 mm inside of the section were marked with an oil pen. That is, the square had a dimension of 100 mm x 100 mm, located at the center of the section, and each side of the square was parallel to the side of the section.

Then, the distance between four displays was measured using the universal projector ("V-12BDC" by Nikon Corporation). Thereafter, the sample was placed in an oven and placed at a predetermined temperature for 60 seconds for heat treatment. After the heat treatment, the distance between the four marks was again measured. Shrinkage rate Xb was calculated | required from ratio of the distance of the width direction before heat processing and after heat processing. Shrinkage rate Xb (%) = ((distance before treatment-distance after treatment) / distance before treatment) × 100

Production Example 1. Preparation of Film (A) -1

The pellet of resin containing the alicyclic structure containing polymer (resin of the norbornene polymer of glass transition temperature of 126 degreeC, brand name "Xeonoa", the Nippon Xeon company make) was dried at 100 degreeC for 5 hours. Then, the pellet of dry resin was supplied to the single screw extruder. After the resin was melted in an extruder, it was extruded in a sheet form onto a casting drum from a T die, via a polymer pipe and a polymer filter, and cooled. This obtained long film (A) -1 of thickness 80micrometer, and width 1000mm. Manufactured film (A) -1 was wound up and collect | recovered in roll shape.

Production Example 2. Preparation of Film (A) -2]

The same operation as in Production Example 1 was performed except that the area of the opening of the T die was changed. Thereby, the elongate film A-2 of 185 micrometers in thickness and 1000 mm in width was obtained, and it wound up and collect | recovered in roll shape.

Production Example 3. Production of Film (A) -3]

The same operation as in Production Example 1 was performed except that the area of the opening of the T die was changed. Thereby, the elongate film (A) -3 of thickness 133 micrometers and width 1000mm was obtained, it wound up in roll shape, and it collect | recovered.

Production Example 4. Production of Raw Material Film of Film (B)

The pellet of the polyester resin ("PET-G 6763" by the Eastman company) was dried at 120 degreeC for 5 hours. The dried pellets were fed to the extruder, melted in the extruder, extruded in a sheet form onto the casting drum from the T die, through a polymer pipe and a polymer filter under conditions of a resin temperature of 260 ° C., and cooled. This obtained the raw material film of thickness 60micrometer and the width 1400mm.

Production Example 5. Production of Film (B) -1]

The raw material film obtained by the manufacture example 4 was continuously supplied to the roll type longitudinal stretch apparatus. Using this longitudinal drawing machine, the raw material film was extended in the longitudinal direction on the conditions of extending | stretching temperature 80 degreeC, and draw ratio twice. Both ends of the stretched film width direction were trimmed, and the corona treatment was given to the surface on one side. This obtained the elongate film (B) -1 of 900 mm in width and 42 micrometers in thickness. As a result of measuring the shrinkage rate in 135 degreeC x 60 second conditions in air of this film (B) -1, the shrinkage rate Xb of the film width direction was 2%. This film (B) was wound up and collect | recovered in the shape of a roll with the corona treatment surface as the winding inside.

Production Example 6. Preparation of Film (B) -2]

The raw material film obtained by the manufacture example 4 was continuously supplied to the tenter type lateral stretch apparatus. Using this horizontal drawing machine, it extended | stretched in the film width direction on the conditions of extending | stretching temperature 80 degreeC, and draw ratio twice. Thereafter, both ends of the film width direction were trimmed, and corona treatment was further performed on one side to obtain a long film (B) -2 having a width of 1000 mm and a thickness of 30 µm. Shrinkage rate Xb of the film width direction was 20% when the shrinkage rate in 135 degreeC x 60 second conditions in the air of this film (B) -2 was measured. This film (B) -2 was wound up and collect | recovered in the roll shape, making the corona treatment surface into the winding inner side.

Production Example 7. Preparation of Multilayer Film (C) -1

The film (B) -1 obtained in the manufacture example 5 was unwound from the roll, and the adhesive layer (pressure-sensitive adhesive layer of Fujimori Industrial Co., Ltd. "Mastack series") was transferred to the corona-treated surface of the film (B) -1. In addition, the film (B) -1 was bonded together by the usual method through the adhesive layer on both surfaces of the film (A) -1 obtained by the manufacture example 1. Thereby, the elongate multilayer film (C) which has a laminated constitution of (film (B) -1) / (adhesive layer) / (film (A) -1) / (adhesive layer) / (film (B) -1) )-1 was obtained. This multilayer film (C) -1 was wound up and collect | recovered in roll shape. The thickness of each layer was 42 μm / 25 μm / 80 μm / 25 μm / 42 μm.

Production Example 8. Production of Multilayer Film (C) -2

The film (B) -2 obtained in the manufacture example 6 was unwound from the roll, and the adhesive layer (pressure-sensitive adhesive layer of Fujimori Industrial Co., Ltd. "Mastack series") was transferred to the corona-treated surface of the film (B) -2. Moreover, the film (B) -2 was bonded together by the usual method through the adhesive layer on both surfaces of the film (A) -1 obtained by the manufacture example 1. Thereby, the elongate multilayer film (C) which has a laminated constitution of (film (B) -2) / (adhesive layer) / (film (A) -1) / (adhesive layer) / (film (B) -2) )-2 was obtained. This multilayer film (C) -2 was wound up and collect | recovered in roll shape. The thickness of each layer was 30 μm / 25 μm / 80 μm / 25 μm / 30 μm.

Production Example 9. Fabrication of Multilayer Film (C) -3]

As film (B) -3, the self-adhesive stretched polypropylene film ("FSA 010M # 30" by Futura Chemical Co., Ltd.) was prepared. Shrinkage rate Xb of the film width direction under the conditions of 120 degreeC * 60 second, 126 degreeC * 60 second, 130 degreeC * 60 second, 135 degreeC * 60 second, 140 degreeC * 60 second in air of this film (B) -3 is , 0.9%, 1.4%, 1.6%, 2.5%, and 3.5%. Film (B) -3 was bonded together on both surfaces of film (A) -1 obtained in manufacture example 1 by a conventional method. This obtained the long multilayer film (C) -3 which has a laminated constitution of (film (B) -3) / (film (A) -1) / (film (B) -3). This multilayer film (C) -3 was wound up and collect | recovered in roll shape. The thickness of each layer was 30 micrometers / 80 micrometers / 30 micrometers.

Production Example 10 Preparation of Multilayer Film (C) -4]

Except for using the film (A) -2 obtained in the preparation example 2 instead of the film (A) -1, by the same operation as the manufacture example 9, it is (film (B) -3) / (film (A) -2) The long multilayer film (C) -4 which has a laminated constitution of / (film (B) -3) was obtained. This multilayer film (C) -4 was wound up and collect | recovered in roll shape. The thickness of each layer was 30 μm / 185 μm / 30 μm.

Production Example 11. Preparation of Multilayer Film (C) -5]

Except for using the film (A) -3 obtained in the manufacturing example 3 instead of the film (A) -1, by the same operation as the manufacturing example 9, it is (film (B) -3) / (film (A) -3) / The long multilayer film (C) -5 which has a laminated constitution of / (film (B) -3) was obtained. This multilayer film (C) -5 was wound up and collect | recovered in roll shape. The thickness of each layer was 30 micrometers / 133 micrometers / 30 micrometers.

Example 1

Floating longitudinal drawing machine was prepared. This stretching machine is a stretching machine which can stretch the elongate film conveyed in the longitudinal direction in the oven by which temperature was adjusted. The multilayer film (C) -1 obtained in the manufacture example 7 was unwound from a roll, it was conveyed in the film longitudinal direction, and was supplied to said longitudinal drawing machine. The multilayer film (C) -1 was conveyed in the oven of a longitudinal drawing machine. At the time of conveyance, the oven temperature Tov was 135 degreeC and it extended | stretched by the draw ratio 1.07 times.

Moreover, the peeling process was performed in the vicinity of the exit in oven. The peeling process was performed by pulling the film (B) -1 of both sides of multilayer film (C) -1, and peeling film (B) -1 continuously from film (A) -1. The direction of pulling two films (B) -1 was the direction perpendicular | vertical to the surface of the film (A) -1 to be conveyed, and also made it the direction opposite to each other. Thereby, peeling to which force was applied in the thickness direction of the film (A) -1 was performed, and the film (A) -1 was extended | stretched in the thickness direction. Peeling rate was 5 m / min. As a result, the film (A) -1 stretched in the thickness direction was obtained as an optical film.

In-plane retardation Re, thickness, and NZ coefficient of the obtained optical film were measured. The results are shown in Table 1. As can be seen from the results in Table 1, the obtained optical film had a NZ coefficient between 0 and 1.

Example 2

The multilayer film (C) -3 obtained in the manufacture example 9 was unwound from a roll, it was conveyed in the film longitudinal direction, and was supplied to the same longitudinal stretcher as used in Example 1. The multilayer film (C) -3 was conveyed in the oven of a longitudinal drawing machine. At the time of conveyance, oven-temperature Tov was 126 degreeC. In addition, the draw ratio was 1.00 times, that is, conveyance which does not involve drawing was performed.

Moreover, the peeling process was performed in the vicinity of the exit in oven. The peeling process was performed by pulling the film (B) -3 of both sides of multilayer film (C) -3, and peeling film (B) -3 continuously from film (A) -1. The direction of pulling two films (B) -3 was the direction perpendicular | vertical to the surface of the film (A) -1 to be conveyed, and also made it the direction opposite to each other. Thereby, peeling to which force was applied in the thickness direction of the film (A) -1 was performed, and the film (A) -1 was extended | stretched in the thickness direction. Peeling rate was 1 m / min. As a result, the film (A) -1 stretched in the thickness direction was obtained as an optical film.

In-plane retardation Re, thickness, and NZ coefficient of the obtained optical film were measured. The results are shown in Table 1. As can be seen from the results in Table 1, the obtained optical film had a NZ coefficient between 0 and 1.

Example 3

The optical film was obtained and evaluated by operation similar to Example 2 except having changed the temperature Tov in oven from 126 degreeC to 130 degreeC, and extending | stretching and changing draw ratio from 1.00 time to 1.02 time. The peeling speed in the peeling process was 1 m / min. The results are shown in Table 1. As can be seen from the results in Table 1, the obtained optical film had a NZ coefficient between 0 and 1.

Example 4

The multilayer film (C) -4 obtained in the manufacture example 10 was unwound from a roll, it was conveyed in the film longitudinal direction, and was supplied to the same longitudinal stretcher as used in Example 1. The multilayer film (C) -4 was conveyed in the oven of a longitudinal drawing machine. At the time of conveyance, the oven temperature Tov was 135 degreeC and it extended | stretched by the draw ratio 1.07 times.

Moreover, the peeling process was performed in the vicinity of the exit in oven. The peeling process was performed by pulling the film (B) -3 of both sides of multilayer film (C) -4, and peeling film (B) -3 continuously from film (A) -2. The direction which pulls out two films (B) -3 was the direction perpendicular | vertical to the surface of the film (A) -2 conveyed, and was made into the direction opposite to each other. Thereby, peeling to which force was applied in the thickness direction of the film (A) -2 was performed, and the film (A) -2 was extended in the thickness direction. Peeling rate was 1 m / min. As a result, film (A) -2 stretched in the thickness direction was obtained as an optical film.

In-plane retardation Re, thickness, and NZ coefficient of the obtained optical film were measured. The results are shown in Table 1. As can be seen from the results in Table 1, the obtained optical film had a NZ coefficient between 0 and 1.

Example 5

The optical film was obtained and evaluated by operation similar to Example 2 except having changed the temperature Tov in oven from 126 degreeC to 135 degreeC, and extending | stretching and changing draw ratio from 1.00 time to 1.07 time. The peeling speed in the peeling process was 5 m / min. The results are shown in Table 1. As can be seen from the results in Table 1, the obtained optical film had a NZ coefficient between 0 and 1.

Example 6

The multilayer film (C) -5 obtained in the manufacture example 11 was unwound from a roll, it was conveyed in the film longitudinal direction, and was supplied to the same longitudinal stretcher as used in Example 1. The multilayer film (C) -5 was conveyed in the oven of a longitudinal drawing machine. At the time of conveyance, the oven temperature Tov was 140 degreeC and it extended | stretched by the draw ratio 1.07 times.

Moreover, the peeling process was performed in the vicinity of the exit in oven. The peeling process was performed by pulling the film (B) -3 of both sides of multilayer film (C) -5, and peeling film (B) -3 continuously from film (A) -3. The direction of pulling two films (B) -3 was the direction perpendicular | vertical to the surface of the film (A) -3 to be conveyed, and also made it the direction opposite to each other. Thereby, peeling to which force was applied in the thickness direction of the film (A) -3 was performed, and the film (A) -3 was extended in the thickness direction. Peeling rate was 1 m / min. As a result, film (A) -3 stretched in the thickness direction was obtained as an optical film.

In-plane retardation Re, thickness, and NZ coefficient of the obtained optical film were measured. The results are shown in Table 1. As can be seen from the results in Table 1, the obtained optical film had a NZ coefficient between 0 and 1.

Comparative Example 1

The multilayer film (C) -2 obtained in the manufacture example 8 was unwound from a roll, it conveyed in the film longitudinal direction, and was supplied to the same longitudinal stretcher as used in Example 1. The multilayer film (C) -2 was conveyed in the oven of a longitudinal drawing machine. At the time of conveyance, the oven temperature Tov was 135 degreeC and it extended | stretched by the draw ratio 1.07 times.

Moreover, although the peeling process was attempted in the vicinity of the exit in oven, peeling of the film (B) -2 occurs in the multilayer film (C) -2 which reached the exit in the oven, and film (A) -1 Wrinkles generate | occur | produced in the whole surface of and the peeling process was not able to be performed.

Comparative Example 2

Except having changed the temperature Tov in oven from 126 degreeC to 120 degreeC, the optical film was obtained and evaluated by the operation similar to Example 2. The peeling speed in the peeling process was 5 m / min. The results are shown in Table 1. As can be seen from the results in Table 1, the obtained optical film had a value of NZ coefficient of 1.6 and higher than 1.

The result of an Example and a comparative example is put together in Table 1, and is shown.

The meaning of the abbreviation in a table | surface is as follows.

COP: Resin containing an alicyclic structure containing polymer (resin of the norbornene polymer of glass transition temperature of 126 degreeC, brand name "Zenooa", the Nippon Xeon Corporation make).

PET: Polyester resin ("PET-G 6763" by Eastman).

OPP: Self-adhesive stretched polypropylene film ("FSA 010M # 30" by Futamura Chemical Corporation).

As is clear from the results in Table 1, in the Examples of the present application in which the relationship between Tov and TgA and the value of Xb satisfies the requirements of the present application, the optical film of 0 <Nz <1 can be easily produced. .

100: multilayer film
111: film (B)
112: film (B)
121: adhesive layer
122: pressure-sensitive adhesive layer
131: film (A)
132: optical film
151: Nip roll upstream of peeling area
152: nip roll upstream of the peeling area
161: Nip roll downstream of peeling area
162: Nip roll downstream of peeling area
200: multilayer film
231 film (A)
211: film (B)
221: pressure-sensitive adhesive layer
232: optical film
P: peeling area

Claims (5)

Including peeling process which provides multilayer film to peeling process,
The said multilayer film is a long multilayer film containing the film (A) which consists of thermoplastic resin A, and the film (B) provided in one or both surfaces of the said film (A),
The peeling treatment includes peeling the film (B) from the film (A) at a temperature Tov (° C.) so that a force is applied in the thickness direction of the film (A),
The temperature Tov and the glass transition temperature TgA (° C.) of the film A satisfy a relationship of Tov ≧ TgA,
The said film (B) has the shrinkage rate Xb of 0% or more and less than 4%, The said shrinkage rate Xb is the width | variety of the said film (B) when the said film (B) is processed on condition of temperature Tov and 60 second. Shrinkage in the direction,
Method for producing an optical film. The method of claim 1,
The said thermoplastic resin A is a manufacturing method of the optical film containing an alicyclic structure containing polymer. The method according to claim 1 or 2,
The manufacturing method of the optical film further including the extending process of extending | stretching the said multilayer film to the in-plane direction. The polarizing plate provided with the optical film and polarizer manufactured by the manufacturing method in any one of Claims 1-3. The display apparatus provided with the optical film manufactured by the manufacturing method in any one of Claims 1-3.

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