KR102024448B1 - Method for producing a diagonal stretched film - Google Patents

Abstract

The manufacturing method of a diagonal stretched film has a diagonal stretch process and a heat fixation process. In the oblique stretching step, the film is inclined with respect to the width direction by holding the two grippers relatively in advance and relatively slowing the other gripper while conveying the film with the pair of gripping ends. To extend. A heat fixing process is a process for fixing the optical axis of a diagonal stretched film after completion | finish of a diagonal stretch process. In this heat fixing process, width expansion is performed with respect to the said diagonal stretched film after completion | finish of a diagonal stretch process. The width of the inclined stretched film after the completion of the oblique stretching and before the enlargement of the width is referred to as L1, and in the heat fixing step, the width of the portion which is widened to the front side and the retardation side before the portion corresponding to the width L1 of the inclined stretched film before the widening. When L2 and L3 are respectively, L3> L2? 0 mm is satisfied.

Description

Method for producing a diagonal stretched film

This invention relates to the manufacturing method of the diagonal stretched film which extends a film in the diagonal direction with respect to the width direction.

Background Art Conventionally, a self-luminous display device such as an organic electroluminescence (EL) display device, also called an OLED (organic light-emitting diode), has attracted attention. In OLED, in order to improve the light extraction efficiency, a reflector such as an aluminum plate is provided on the back side of the display, so that external light incident on the display is reflected by the reflector, thereby reducing the contrast of the image.

Then, in order to improve the contrast contrast by external light reflection prevention, it is known to bond a stretched film and a polarizer, and to comprise a circular polarizing plate, and to arrange this circular polarizing plate on the surface side of a display. At this time, the circular polarizing plate is formed by bonding the polarizer and the stretched film so that the in-plane slow axis of the stretched film is inclined at a desired angle with respect to the transmission axis of the polarizer.

By the way, a general polarizer (polarizing film) is obtained by extending | stretching high magnification in the longitudinal direction, and the transmission axis is coincident with the width direction. In addition, the conventional retardation film is manufactured by longitudinal stretch or lateral stretch, and the slow axis in surface becomes a direction of 0 degrees or 90 degrees with respect to the longitudinal direction of a film in principle. For this reason, in order to incline the transmission axis of a polarizer and the slow axis of a stretched film to a desired angle as mentioned above, the batch type which cuts an elongate polarizing film and / or a stretched film at a specific angle and bonds film pieces one by one is not employ | adopted. It was impossible, and productivity was worsening.

On the other hand, the elongate oblique stretching of the film is performed in the direction of the desired angle with respect to the longitudinal direction (in the oblique direction), and the direction of the slow axis can be freely controlled in the direction of 0 ° or 90 ° with respect to the longitudinal direction of the film. Various manufacturing methods of a film are proposed. For example, in the manufacturing method of patent document 1, a resin film is extracted from the direction different from the winding direction of the film after extending | stretching, and both ends of the said resin film are gripped and conveyed by a pair of holding | gripping tool. And the resin film is extended to a diagonal direction by changing the conveyance direction of a resin film on the way. Thereby, a long diagonal stretched film having a slow axis at a desired angle of greater than 0 ° and less than 90 ° with respect to the longitudinal direction is produced.

By using such a long diagonal stretched film, it becomes possible to join a long polarizing film and a long diagonal stretched film by the roll-to-roll system, and to manufacture a circularly polarizing plate, and the productivity of a circularly polarizing plate improves dramatically.

However, when the circularly polarizing plate produced as described above was applied to the OLED, and the display image was observed with the OLED in a different temperature and humidity environment, the fact that the display unevenness of the inclined stripes was shown as shown in FIG. I learned. In addition, it was confirmed that intentionally imparting environmental fluctuations (temperature change, humidity change) causes the display unevenness to become large (significant).

As a result of analyzing the causes of the display unevenness of the inclined stripes, it was found that the λ / 4 film used for the circularly polarizing plate had a cause. More specifically, in manufacture of the diagonal stretched film which functions as a (lambda) / 4 film, as shown in FIG. 8, the width direction both ends of a film are gripped with a pair of holding | gripping tool Ci * Co, and one holding | gripping tool Ci is shown. Is relatively preceded, and the other gripper Co is relatively delayed to thereby convey the film, whereby oblique stretching is performed. At the time of holding | maintenance of the film after diagonal stretch, shrinkage force acts on a film according to the reaction of diagonal stretch and temperature fall, and this remains as residual stress T of the rib shape (clamp shape, corrugation shape) of an invisible diagonal direction. For this reason, as shown in FIG. 9, when the film 51 after diagonal drawing and the polarizer 52 are bonded together and the circular polarizing plate 50 is comprised, since residual stress T remains in the film 51, temperature-humidity fluctuations When there existed, it is thought that the characteristic of the film 51 changes with residual stress T, and the display nonuniformity shown in FIG. 7 arises.

FIG. 10: has shown the mode which the rib-shaped residual stress T generate | occur | produces in manufacture of a diagonal stretched film. In manufacture of a normal diagonal stretched film, after passing a film through the preheating zone Z1 of a stretching machine, diagonal stretch is performed in extending zone Z2, and the optical axis (ground axis) is fixed in the thermal fixation zone Z3 after that. do. The film stretched obliquely in the stretching zone Z2 is a gripper side (preceding) that travels relatively earlier than a gripper side (delay side) that runs relatively slowly among a pair of grippers that hold both ends in the width direction of the film. Side) first enters the heat setting zone Z3, so that the shrinkage of the film starts from the preceding side. For this reason, as shown in the same figure, the residual stress T of rib shape arises in order of a leading side, the width direction center part, and a delay side.

The generation of such a rib-shaped residual stress T, as in Patent Literature 2, expands the width of the rail through which a pair of grip holes are advanced in the stretching zone (during inclined stretching), thereby widening the film. It happens in the same way. 11 schematically shows how rib-shaped residual stress T is generated when the film is expanded in the stretching zone Z2. Since the film extends in the width direction by widening the film in the stretching zone Z2, the film does not shrink in the stretching zone Z2, and therefore, no rib-shaped residual stress occurs during the diagonal stretching. However, after the end of the oblique stretching (in the heat-setting zone Z3), since the film shrinks from the preceding side, the rib-shaped remains in the order of the preceding side, the width direction center portion, and the delaying side in the same manner as in FIG. Stress T occurs.

Thus, in the diagonal stretched film manufactured by the conventional manufacturing method, as shown in FIG. 10 and FIG. 11, it is a diagonal direction with respect to the conveyance direction of the film (direction from the stretching zone Z2 toward the heat fixation zone Z3), and the width direction. As a result, the rib-shaped residual stress T is generated, so that the display irregularity of the stripe shape occurs in the oblique direction in the OLED as shown in FIG. 7. Therefore, in order to suppress such display nonuniformity, it is desired to manufacture the diagonal stretched film so that the rib-shaped residual stress T may not remain in the film after diagonal stretch.

International Publication No. 2007/111313 Pamphlet (see claim 1, FIG. 1, etc.) Japanese Patent Application Laid-Open No. 2007-203556 (see claims 1, paragraph [0046], [0060], [0061], FIGS. 1 to 4, etc.).

The objective of this invention is providing the manufacturing method of the diagonal stretched film which can suppress that a rib-shaped residual stress generate | occur | produces after diagonal stretch in view of the said situation.

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

In the method for producing an inclined stretched film according to an aspect of the present invention, while holding both ends of the film in the width direction with a pair of grippers, one gripper is relatively preceded, and the other gripper is relatively delayed to provide the film. It is a manufacturing method of the diagonal stretched film which has a diagonal stretch process which extends the said film in a diagonal direction with respect to the width direction by conveying,

It further has a heat fixing process for fixing the optical axis of the said diagonal stretched film after completion | finish of the said diagonal stretch process,

In the said heat fixing process, width enlargement is performed with respect to the said diagonal stretched film after completion | finish of the said diagonal stretch process,

The width | variety of the said diagonal stretched film after completion | finish of diagonal stretch and before width expansion is called L1, and in the said heat fixing process, it expanded width to the front side and the delay side rather than the part corresponded to the width L1 of the said diagonal stretched film before width expansion. When the widths of the portions are referred to as L2 and L3, the following conditional expression (1) is satisfied. In other words,

 L3 > L2 > (One)

to be.

In the heat fixing process after completion | finish of diagonal stretch, a diagonal stretched film is expanded and the film is stretched in the width direction, and it can suppress that a rib-shaped residual stress arises in a film after diagonal stretch. Thereby, a circularly polarizing plate is comprised using the produced diagonal stretched film, this circularly polarizing plate is applied to OLED, and even if OLED is placed in a temperature-humidity environment different from usual, it will be inclined stripe shape resulting from the residual stress of the said rib shape. It can suppress that display nonuniformity appears. In addition, by satisfying Conditional Expression (1), it is possible to suppress the occurrence of the rib-shaped residual stress without substantially changing the direction of the optical axis (ground axis) oriented in the predetermined direction by oblique stretching. Therefore, even if the film is enlarged in the heat fixing step after the oblique stretching, the oblique stretched film having the desired orientation characteristic can be obtained by fixing the optical axis in a predetermined direction.

1: is a top view which shows typically the structure of the outline of the manufacturing apparatus of the diagonal stretched film which concerns on embodiment of this invention.
2: is a top view which shows typically an example of the rail pattern of the extending | stretching part of the said manufacturing apparatus.
It is explanatory drawing which shows typically the shape of the film which passes the said extending | stretching part.
FIG. 4: is explanatory drawing which shows typically the mode in which the residual stress of a rib shape is loosened when the diagonal stretched film is expanded in the heat setting zone of the said extending part.
5 is a cross-sectional view showing a schematic configuration of an organic EL image display device to which the inclined stretched film is applied.
It is sectional drawing which shows the outline structure of the liquid crystal display device to which the said diagonal stretched film is applied.
7 is an explanatory diagram showing display unevenness on a display screen of a conventional organic EL image display device.
It is explanatory drawing which shows typically the method of the conventional general diagonal stretch.
9 is an exploded perspective view of a circularly polarizing plate manufactured using a film diagonally stretched by a conventional method.
FIG. 10: is explanatory drawing which shows typically the state in which the rib-shaped residual stress generate | occur | produces in manufacture of the conventional diagonal stretched film.
FIG. 11: is explanatory drawing which shows typically how the rib-shaped residual stress generate | occur | produces when expanding a film in a drawing zone.

EMBODIMENT OF THE INVENTION When one Embodiment of this invention is described based on drawing, it is as follows. In addition, in this specification, when numerical range is described as A-B, the value of the minimum A and the upper limit B shall be contained in the numerical range.

In the manufacturing method of the elongate diagonal stretched film which concerns on this embodiment, the elongate diagonal stretched film which extends the elongate raw film containing a thermoplastic resin in diagonal direction with respect to the width direction and the longitudinal direction, and manufactures a long diagonal stretched film. It is a manufacturing method.

The orientation direction of a long diagonal stretched film, ie, the direction of a slow axis, is a direction which makes an angle of more than 0 degree and less than 90 degree with respect to the width direction of a film in film surface (in surface perpendicular | vertical to a thickness direction). (It becomes the direction which makes the angle more than 0 degree and less than 90 degree also automatically with respect to the longitudinal direction of a film). Since the slow axis is usually expressed in the stretching direction or in a direction perpendicular to the stretching direction, the elongated diagonal stretched film having such a slow axis can be produced by stretching in a direction exceeding 0 ° and less than 90 ° with respect to the width direction of the film. Can be. The angle which the width direction of a long diagonal stretched film and a slow axis make, ie, an orientation angle, can be arbitrarily set to a desired angle in the range exceeding 0 degree and less than 90 degree.

In this embodiment, long means having length of about 5 times or more with respect to the width | variety of a film, Preferably it has a length of 10 times or more, specifically, it is wound in roll shape and stored or It is conceivable to have a length that is enough to be transported (film roll).

After forming a long unoriented film in a long diagonal stretched film, this may be wound up to a winding core once to make a winding body (fabric film), and a raw film may be supplied to this diagonal stretch process and manufactured from this winding body, It can also manufacture by supplying continuously to the diagonal stretch process from a film forming process, without winding up the elongate film after film forming. It is preferable to perform a film forming process and a diagonal stretch process continuously because a desired long diagonal stretched film can be obtained by feeding back the result of the film thickness and optical value of the film after extending | stretching, and obtaining a desired long diagonal stretched film. In addition, by continuously producing the elongated oblique stretched film, the elongated oblique stretched film of the desired length can be obtained.

As the thermoplastic resin contained in the raw film, an alicyclic olefin polymer resin (COP), polycarbonate resin (PC), cellulose ester resin, or the like can be used. Among them, the cellulose ester-based resin easily absorbs moisture and tends to change the orientation angle θ due to humidity fluctuations associated with long-term use, and therefore, suppresses the variation of the orientation angle θ in the width direction of the diagonally stretched film. The effect of embodiment becomes larger.

Moreover, the diagonal stretched film obtained by diagonally stretching the said raw film can be applied also to the liquid crystal display device which can attach and visualize polarized sunglasses. That is, the inclined stretched film is further bonded to the visual recognition side with respect to the polarizer of the polarizing plate of the visual recognition side rather than a liquid crystal layer, and a circular polarizing plate is comprised. At this time, both are bonded so that the slow axis of a diagonal stretched film and the transmission axis of a polarizer may be 45 degrees. In this configuration, the linearly polarized light emitted from the liquid crystal layer and transmitted through the polarizer on the viewing side is converted into circularly polarized light in the diagonally stretched film (functioning as QWP). Therefore, when the observer attaches polarized sunglasses and observes the display image of the liquid crystal display device, even if the transmission axis of the polarizer and the transmission axis of the polarized sunglasses form an angle, the component of light parallel to the transmission axis of the polarized sunglasses is The display image can be observed by inducing the observer's eye. Therefore, it becomes possible to suppress that the display image becomes difficult to be seen depending on the angle to be observed (in the direction of the transmission axis of the polarized sunglasses). In particular, since the nonuniformity of the orientation angle | corner (theta) of a film width direction can be suppressed by constructing a diagonal stretched film using the raw film of this embodiment, even if it uses a liquid crystal display device for a long time, the uniform image which does not have a nonuniformity across the screen Can be observed through polarized sunglasses.

Thus, when apply | coating a diagonal stretched film to the circularly-polarizing plate of a liquid crystal display device corresponding to polarized sunglasses, it is preferable to provide the hard-coat layer for protecting a surface in the visual recognition side of a diagonal stretched film.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described concretely with reference to drawings.

<Cellulose ester resin>

As a cellulose-ester type resin film used for the raw film of this embodiment, what contains the cellulose acylate which satisfy | fills following formula (1) and (2), and also contains the compound represented by the following general formula (A). Can be mentioned.

 Equation (1) 2.0≤Z1 <3.0

 Equation (2) 0≤X <3.0

(In formulas (1) and (2), Z1 represents the total acyl substitution degree of cellulose acylate, and X represents the sum of propionyl substitution degree and butyryl substitution degree of cellulose acylate.)

Hereinafter, general formula (A) is demonstrated in detail. In General Formula (A), L ₁ and L ₂ each independently represent a single bond or a divalent linking group. Examples of L ₁ and L ₂ include the following structures (the following R represents a hydrogen atom or a substituent).

As L ₁ and L ₂ , they are preferably -O-, -COO-, -OCO-.

R ₁ , R ₂ and R ₃ each independently represent a substituent. As a specific example of the substituent represented by R <_1> , R <_2> and R <_3> , a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc.), an alkyl group (methyl group, an ethyl group, n-propyl group, isopropyl group, tert- Butyl group, n-octyl group, 2-ethylhexyl group, etc.), cycloalkyl group (cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group, etc.), alkenyl group (vinyl group, allyl group, etc.), Cycloalkenyl group (2-cyclopenten-1-yl, 2-cyclohexen-1-yl group, etc.), alkynyl group (ethynyl group, propargyl group, etc.), aryl group (phenyl group, p-tolyl group, naphthyl group, etc.) , Heterocyclic group (2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group, etc.), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group (methoxy group, ethoxy group, Isopropoxy group, tert-butoxy group, n-octyloxy group, 2-methoxyethoxy group, etc.), aryloxy group (phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitro Phenoxy, 2-te Radecanoylaminophenoxy group), acyloxy group (formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group, etc.), amino group (amino group , Methylamino group, dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group, etc.), acylamino group (formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group, etc.), Alkyl and arylsulfonylamino groups (methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group, etc.), mercapto group, alkylthio group (Methylthio group, ethylthio group, n-hexadecylthio group, etc.), arylthio group (phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group, etc.), sulfamoyl group (N-ethyl Sulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N- Methyl sulfamoyl group, N-acetyl sulfamoyl group, N-benzoyl sulfamoyl group, N- (N'phenylcarbamoyl) sulfamoyl group, etc.), sulfo group, acyl group (acetyl group, pivaloylbenzoyl group, etc.) ), Carbamoyl group (carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N-di-n-octylcarbamoyl group, N- (methylsulfonyl) carbamoyl group, etc.) ).

As R <_1> and R <_2> , Preferably they are a substituted or unsubstituted phenyl group, a substituted or unsubstituted cyclohexyl group, More preferably, they are a phenyl group which has a substituent, and a cyclohexyl group which has a substituent, More preferably, It is a phenyl group which has a substituent in 4 position, and a cyclohexyl group which has a substituent in 4 position.

R ₃ is preferably a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, a hydroxyl group, a carboxyl group, an alkoxy group, an aryloxy group, an acyloxy group, a cyano group or an amino group, and more preferably Is a hydrogen atom, a halogen atom, an alkyl group, a cyano group, or an alkoxy group.

Wa and Wb represent a hydrogen atom or a substituent,

(I) Wa and Wb may combine with each other and form a ring,

(II) at least one of Wa and Wb may have a ring structure, or

At least one of (III) Wa and Wb may be an alkenyl group or an alkynyl group.

As a specific example of the substituent represented by Wa and Wb, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc.), an alkyl group (methyl group, an ethyl group, n-propyl group, isopropyl group, tert-butyl group, n- Octyl group, 2-ethylhexyl group, etc.), cycloalkyl group (cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl group, etc.), alkenyl group (vinyl group, allyl group, etc.), cycloalkenyl group (2 -Cyclopenten-l-yl, 2-cyclohexen-l-yl group, etc.), alkynyl group (ethynyl group, propargyl group, etc.), aryl group (phenyl group, p-tolyl group, naphthyl group, etc.), heterocyclic group (2 -Furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group, etc.), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group (methoxy group, ethoxy group, isopropoxy group, tert-butoxy group, n-octyloxy group, 2-methoxyethoxy group, etc.), aryloxy group (phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2- Tetradeca Monoaminophenoxy group), acyloxy group (formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group, etc.), amino group (amino group, methyl Amino group, dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group, etc.), acylamino group (formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group, etc.), alkyl and Arylsulfonylamino group (methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group, etc.), mercapto group, alkylthio group (methyl Thiothio, ethylthio group, n-hexadecylthio group, etc.), arylthio group (phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group, etc.), sulfamoyl group (N-ethylsulfamo Diary, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfate Moyl group, N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N'phenylcarbamoyl) sulfamoyl group, etc.), sulfo group, acyl group (acetyl group, pivaloylbenzoyl group, etc.), Carbamoyl groups (carbamoyl groups, N-methylcarbamoyl groups, N, N-dimethylcarbamoyl groups, N, N-di-n-octylcarbamoyl groups, N- (methylsulfonyl) carbamoyl groups, etc.) Can be mentioned.

The said substituent may be substituted by the said group further.

(I) When Wa and Wb combine with each other to form a ring, the ring is preferably a nitrogen-containing 5-membered ring or a sulfur-containing 5-membered ring. Moreover, it is especially preferable that general formula (A) is a compound represented by the following general formula (1) or general formula (2).

In General formula (1), A <_1> and A <_2> respectively independently represent -O-, -S-, -NRx- (Rx represents a hydrogen atom or a substituent), or -CO-. Examples of the substituent represented by Rx have the same meanings as specific examples of the substituent represented by Wa and Wb. As Rx, Preferably they are a hydrogen atom, an alkyl group, an aryl group, and a heterocyclic group.

In General formula (1), X represents the nonmetallic atom of group 14-16. As X, = O, = S, = NRc, and = C (Rd) Re are preferable. Rc, Rd, and Re represent a substituent here and are synonymous with the specific example of the substituent represented by said Wa and Wb as an example. _{L 1, L 2, R 1} , R 2, R 3, n , is _{L 1, L 2, R 1} , R 2, R 3, n and copper in the formula (A).

In formula (2), Q ₁ represents -O-, -S-, -NRy- (Ry represents a hydrogen atom or a substituent), -CRaRb- (Ra and Rb represents a hydrogen atom or a substituent) or- CO-. Here, Ry, Ra, Rb represents a substituent, and is synonymous with the specific example of the substituent represented by said Wa and Wb as an example.

Y represents a substituent. As an example of a substituent represented by Y, it is synonymous with the specific example of the substituent represented by said Wa and Wb. As Y, Preferably they are an aryl group, a heterocyclic group, an alkenyl group, and an alkynyl group.

As an aryl group represented by Y, a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a biphenyl group, etc. are mentioned, A phenyl group and a naphthyl group are preferable, and a phenyl group is more preferable.

Examples of the heterocyclic group include a heterocyclic group containing at least one hetero atom such as nitrogen atom, oxygen atom, sulfur atom, such as furyl group, pyrrolyl group, thienyl group, pyridinyl group, thiazolyl group, benzothiazolyl group, and the like. , Furyl group, pyrrolyl group, thienyl group, pyridinyl group and thiazolyl group are preferable.

These aryl groups or heterocyclic groups may have at least one substituent. As this substituent, a halogen atom, a C1-C6 alkyl group, a cyano group, a nitro group, a C1-C6 alkylsulfinyl group, a C1-C6 alkylsulfonyl group, a carboxyl group, a C1-C6 fluoroalkyl group, carbon number An alkoxy group having 1 to 6, an alkylthio group having 1 to 6 carbon atoms, an N-alkylamino group having 1 to 6 carbon atoms, an N, N-dialkylamino group having 2 to 12 carbon atoms, and an N-alkylsulfamoyl group having 1 to 6 carbon atoms And a C 2-12 N, N-dialkylsulfamoyl group.

_{L 1, L 2, R 1} , R 2, R 3, n , is _{L 1, L 2, R 1} , R 2, R 3, n and copper in the formula (A).

(II) In general formula (A), As a specific example in the case where at least one of Wa and Wb has a ring structure, Preferably it is following General formula (3).

In General formula (3), Q <_3> represents = N- or = CRz- (Rz is a hydrogen atom or a substituent), and Q <_4> represents the nonmetallic atom of group 14-16. Z represents the nonmetallic atom group which forms a ring with Q <_3> and Q <_4> .

The ring formed of Q ₃ , Q ₄ and Z may be further condensed into another ring. The ring formed of Q ₃ , Q ₄ and Z is preferably a nitrogen-containing 5- or 6-membered ring condensed with a benzene ring.

_{L 1, L 2, R 1} , R 2, R 3, n , is _{L 1, L 2, R 1} , R 2, R 3, n and copper in the formula (A).

(III) When at least one of Wa and Wb is an alkenyl group or alkynyl group, they are preferably a vinyl group or an ethynyl group having a substituent.

Among the compounds represented by the general formula (1), the general formula (2) and the general formula (3), the compound represented by the general formula (3) is particularly preferable.

The compound represented by the general formula (3) is superior in heat resistance and light resistance to the compound represented by the general formula (1), and has a solubility in an organic solvent and a polymer compared with the compound represented by the general formula (2). Compatibility is good.

Although the compound represented by general formula (A) can adjust and contain a suitable amount in order to provide a desired wavelength dispersibility and the spreading prevention property, It is preferable to contain 1-15 mass% with respect to a cellulose derivative as addition amount, Especially, it is preferable to contain 2-10 mass%. If it is in this range, sufficient wavelength dispersion property and bleeding prevention property can be provided to the said cellulose derivative.

In addition, the compound represented by General formula (A), General formula (1), General formula (2), and General formula (3) can be obtained with reference to a known method. Specifically, Journal of Chemical Crystallography (1997); 27 (9); 512-526), Japanese Patent Application Laid-Open No. 2010-31223, Japanese Patent Application Laid-Open No. 2008-107767, and the like.

(About cellulose acylate)

The cellulose acylate film which concerns on this embodiment contains a cellulose acylate as a main component. For example, the cellulose acylate film which concerns on this embodiment contains cellulose acylate in the range of 60-100 mass% with respect to the total mass (100 mass%) of a film preferably. Moreover, the total acyl group substitution degree of a cellulose acylate is 2.0 or more and less than 3.0, and it is more preferable that it is 2.2-2.7.

As cellulose acylate, ester of a cellulose and a C2-C22 aliphatic carboxylic acid and / or an aromatic carboxylic acid is mentioned, Especially, it is preferable that it is an ester of a cellulose and lower fatty acid of 6 or less carbon atoms.

The acyl group which couple | bonds with the hydroxyl group of a cellulose may be linear or branched, and may form a ring. In addition, another substituent may be substituted. In the case of the same degree of substitution, since the birefringence decreases when the number of carbon atoms described above is large, the carbon number is preferably selected from acyl groups having 2 to 6 carbon atoms, and the sum of propionyl substitution degree and butyryl substitution degree is 0 or more and less than 3.0. to be. It is preferable that carbon number as said cellulose acylate is 2-4, and it is more preferable that carbon number is 2-3.

Specifically, as the cellulose acylate, in addition to acetyl groups such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionate butyrate or cellulose acetate phthalate, a mixture of celluloses in which a propionate group, butyrate group or phthalyl group is bonded Fatty acid esters can be used. In addition, the butyryl group which forms butyrate may be linear or branched.

In this embodiment, cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate is used especially preferably as cellulose acylate.

Moreover, it is preferable that the said cellulose acylate satisfy | fills following formula (i) and formula (ii) simultaneously.

Equation (i) 2.0≤X + Y <3.0

Formula (ii) 0≤X <3.0

In the formula, Y represents the degree of substitution of the acetyl group, X represents the degree of substitution of the propionyl group or the butyryl group or a mixture thereof.

Moreover, in order to acquire the optical characteristic suitable for the objective, you may mix and use resin from which substitution degree differs. As a mixing ratio in that case, 1: 99-99: 1 (mass ratio) are preferable.

Among the above-mentioned, especially cellulose acetate propionate is used preferably as a cellulose acylate. In cellulose acetate propionate, it is preferable that it is 0≤Y≤2.5, and 0.5≤X≤3.0 (but 2.0≤X + Y <3.0), 0.5≤Y≤2.0, and 1.0≤X≤2.0 ( However, it is more preferable that it is 2.0 <= X + Y <3.0). In addition, substitution degree of an acyl group can be measured according to ASTM-D817-96 which is one of the standards which the American Society for Testing and Materials (ASTM) devises and publishes.

The number average molecular weight of cellulose acylate is preferable in the range of 60000-300000, since the mechanical strength of the film obtained becomes strong. More preferably, cellulose acylate having a number average molecular weight of 70000 to 200000 is used.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of a cellulose acylate are measured using gel permeation chromatography (GPC). Measurement conditions are as follows. In addition, this measuring method can be used also as a measuring method of the other polymer in this embodiment.

Solvent: methylene chloride;

Column: Shodex K806, K805, K803G (produced by Showa Denko Co., Ltd.) are used in connection with three;

Column temperature: 25 ° C .;

Sample concentration: 0.1 mass%;

Detector: RI Model 504 (manufactured by GL Science);

Pump: L6000 (manufactured by Hitachi Seisakusho Co., Ltd.);

Flow rate: 1.0 ml / min

Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corporation) Mw = 1000000 to 500 using a calibration curve by 13 samples. 13 samples are used at substantially equal intervals.

It is preferable that residual sulfuric acid content in a cellulose acylate is 0.1-45 mass ppm in conversion of sulfur element. It is believed that they are contained in the form of salts. When residual sulfuric acid content exceeds 45 mass ppm, it exists in the tendency to become easy to fracture | rupture at the time of thermal stretching or the slitting after thermal stretching. Moreover, the range of 1-30 mass ppm of residual sulfuric acid content is more preferable. Residual sulfuric acid content can be measured by the method of the prescription | regulation to ASTM-D 817-96.

Moreover, it is preferable that the free acid content in a cellulose acylate is 1-500 mass ppm. If it is the said range, since it is hard to break similarly to the above, it is preferable. In addition, it is preferable that it is the range of 1-100 mass ppm of free acid content, and it becomes hard to fracture | rupture further. In particular, the range of 1-70 mass ppm is preferable. The free acid content can be measured by the method specified in ASTM-D817-96.

The washing of the synthesized cellulose acylate is more sufficiently performed than in the case of using the solution casting method, whereby the residual alkaline earth metal content, the residual sulfuric acid content and the residual acid content can be in the above range, which is preferable.

Although there is no limitation in particular as a cellulose which is a raw material of a cellulose acylate, Cotton linter, wood pulp, kenaf, etc. are mentioned. In addition, the cellulose acylate obtained from them can be mixed and used in arbitrary ratios, respectively.

A cellulose acylate can be manufactured by a well-known method. Specifically, it can synthesize | combine with reference to the method of Unexamined-Japanese-Patent No. 10-45804, for example.

In addition, cellulose acylate is also affected by the trace metal component in cellulose acylate. It is thought that these trace metal components are related to water used in a manufacturing process, but it is preferable that few components can become insoluble nuclei. In particular, metal ions, such as iron, calcium, and magnesium, may form an insoluble matter by salt-forming a polymer decomposition product etc. which may contain the organic acidic group, and a small thing is preferable. In addition, the calcium (Ca) component easily forms acidic components such as carboxylic acid and sulfonic acid, and many ligands and coordination compounds (that is, complexes), and scum (insoluble precipitation and haze) derived from many insoluble calcium. Since there is a possibility of forming a), few are preferable.

Specifically, it is preferable that content in a cellulose acylate is 1 mass ppm or less about an iron (Fe) component. Moreover, about a calcium (Ca) component, content in a cellulose acylate becomes like this. Preferably it is 60 mass ppm or less, More preferably, it is 0-30 mass ppm. Moreover, about too much magnesium (Mg) component, since an insoluble content will generate | occur | produce, it is preferable that content in cellulose acylate is 0-70 mass ppm, and it is especially preferable that it is 0-20 mass ppm.

In addition, content of metal components, such as content of an iron (Fe) component, content of a calcium (Ca) component, and content of a magnesium (Mg) component, the sulfur of the dried cellulose acylate in a micro digest wet decomposition apparatus. After decomposition with nitric acid and pretreatment with alkali melting, it can be analyzed using ICP-AES (Inductively Coupled Plasma Emission Spectroscopy).

<Alicyclic olefin polymer type resin>

As an alicyclic olefin polymer resin used for the raw film of this embodiment, the cyclic olefin random polyone copolymer described in Unexamined-Japanese-Patent No. 05-310845, and Unexamined-Japanese-Patent No. 05-97978 are described. A hydrogenated polymer, the thermoplastic dicyclopentadiene ring-opening polymer described in Unexamined-Japanese-Patent No. 11-124429, its hydrogenated substance, etc. can be employ | adopted.

The alicyclic olefin polymer-based resin is a polymer having an alicyclic structure such as a saturated alicyclic hydrocarbon (cycloalkane) structure or an unsaturated alicyclic hydrocarbon (cycloalkene) structure. The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually in the range of 4 to 30, preferably 5 to 20, more preferably 5 to 15, in terms of mechanical strength, heat resistance and long film. Formability is highly balanced and suitable.

Although the ratio of the repeating unit which consists of an alicyclic structure in an alicyclic olefin polymer should just select suitably, Preferably it is 55 weight% or more, More preferably, it is 70 weight% or more, Especially preferably, it is 90 weight% or more. When the ratio of the repeating unit which has alicyclic structure in alicyclic polyolefin resin exists in this range, since transparency and heat resistance of optical materials, such as retardation film obtained from the elongate diagonal stretched film of this embodiment, improve, it is preferable.

Examples of the olefin polymer-based resin having an alicyclic structure include norbornene-based resins, monocyclic cyclic olefin resins, cyclic conjugated diene resins, vinyl alicyclic hydrocarbon resins, and hydrides thereof. Of these, norbornene-based resins can be suitably used because of their good transparency and moldability.

As norbornene-based resin, for example, a ring-opening polymer of a monomer having a norbornene structure or a ring-opening copolymer of a monomer having a norbornene structure and another monomer or an addition polymer of a monomer having a hydride or norbornene structure thereof Or an addition copolymer of monomers having a norbornene structure with other monomers or hydrides thereof. Among these, the ring-opening (co) polymer hydride of the monomer which has a norbornene structure can be used especially suitably from a viewpoint of transparency, moldability, heat resistance, low hygroscopicity, dimensional stability, and lightweight.

As a method of shape | molding the long film (fabric film) using said norbornene-type resin, the manufacturing method of the solution film forming method or the melt-extrusion method is preferable. Examples of the melt extrusion method include an inflation method using a die, but a method using a T die is preferable because of excellent productivity and thickness precision.

As an extrusion molding method using a T die, a retardation or orientation is carried out by a method of keeping the molten thermoplastic resin in a stable state when being brought into close contact with a cooling drum, as described in JP-A-2004-233604. Long films with small variations in optical properties such as angles can be produced.

Specifically, 1) when manufacturing a long film by the melt extrusion method, the sheet-like thermoplastic resin extruded from the die is brought into close contact with a cooling drum under a pressure of 50 kPa or less and taken off; 2) When manufacturing a long film by the melt-extrusion method, cover from the die opening part to the cooling drum which adhering initially, with a surrounding member, and make the distance from the enclosure member to the die opening or the cooling drum which adhering initially to 100 mm or less. Way; 3) When manufacturing a long film by melt extrusion method, the method of heating the temperature of the atmosphere within 10 mm from a sheet-like thermoplastic resin extruded from the die opening part to a specific temperature; 4) a method in which a sheet-shaped thermoplastic resin extruded from a die is brought into close contact with a cooling drum under a pressure of 50 kPa or less to satisfy a relationship; 5) When manufacturing a long film by the melt extrusion method, the method of injecting the wind whose speed difference with the take-up speed | rate of the cooling drum which adheres initially to the sheet-like thermoplastic resin extruded from the die opening part is 0.2 m / s or less is mentioned. Can be.

This long film may be a single layer or a laminated film of two or more layers. Laminated | multilayer film can be obtained by well-known methods, such as a co-extrusion shaping | molding method, a co-compression molding method, a film lamination method, a coating method. Of these, the coextrusion molding method and the co-lead molding method are preferable.

<Polycarbonate Resin>

As polycarbonate resin used for the raw film of this embodiment, various things can be used without a restriction | limiting in particular, In terms of chemical property and a physical property, aromatic polycarbonate resin is preferable, and bisphenol-A polycarbonate is especially preferable. Nate resins are preferred. Especially, it is more preferable to use the bisphenol A derivative which introduce | transduced the benzene ring, the cyclohexane ring, an aliphatic hydrocarbon group, etc. into bisphenol A. Also particularly preferred are polycarbonate resins having a structure in which the anisotropy in the unit molecule is reduced, obtained by using a derivative in which the functional group is introduced asymmetrically with respect to the central carbon of bisphenol A. As such a polycarbonate resin, the thing which substituted two methyl groups of the central carbon of bisphenol A with the benzene ring, for example, and one hydrogen of each benzene ring of bisphenol A was asymmetrically with respect to the center carbon by methyl group, a phenyl group, etc. Polycarbonate resin obtained using the substituted thing is especially preferable.

Specifically, it is obtained by phosgene method or transesterification method from 4,4'- dihydroxy diphenyl alkane or a halogen substituent thereof, For example, 4,4'- dihydroxy diphenylmethane, 4,4 ' -Dihydroxy diphenyl ethane, 4,4'- dihydroxy diphenyl butane, etc. are mentioned. In addition, for example, Japanese Patent Laid-Open No. 2006-215465, Japanese Patent Laid-Open No. 2006-91836, Japanese Patent Laid-Open No. 2005-121813, Japanese Patent Laid-Open No. 2003-167121, and Japanese Patent The polycarbonate resin described in Unexamined-Japanese-Patent No. 2009-126128, Unexamined-Japanese-Patent No. 2012-31369, Unexamined-Japanese-Patent No. 2012-67300, International Publication No. 00/26705, etc. are mentioned.

You may use polycarbonate resin in mixture with transparency resins, such as a polystyrene resin, methyl methacrylate resin, and a cellulose acetate resin. Moreover, you may laminate | stack the resin layer containing polycarbonate resin on at least one surface of the resin film formed using cellulose acetate type resin.

The glass transition point (Tg) of polycarbonate resin is 110 degreeC or more, and it is preferable that a water absorption (value measured on condition of 24 hours in 23 degreeC water) is 0.3% or less. Moreover, it is more preferable that Tg is 120 degreeC or more and water absorption is 0.2% or less.

The polycarbonate resin film which can be used by this embodiment can be formed into a film by a well-known method, and the solution casting method and the melt casting method are especially preferable.

<Additive>

The raw film of this embodiment may contain the additive. As an additive, a plasticizer, a ultraviolet absorber, a retardation regulator, antioxidant, antidegradation agent, peeling adjuvant, surfactant, dye, microparticles | fine-particles, etc. are mentioned. In this embodiment, about additives other than microparticles | fine-particles, you may add at the time of preparation of a dope liquid, and may add at the time of preparation of a microparticle dispersion.

(Plasticizer)

Phthalic acid ester type, fatty acid ester type, trimellitic acid ester type, phosphate ester type, polyester type, sugar ester type, acrylic polymer etc. are mentioned as a plasticizer added to a raw film. In this, the plasticizer of polyester type and sugar ester type polymer is used preferably from a moisture permeability viewpoint.

The polyester plasticizer is excellent in non-migration and extraction resistance compared to phthalic ester plasticizers such as dioctyl phthalate. By selecting or using these plasticizers according to a use, it can apply to a wide range of uses. As an acryl-type polymer, the homopolymer or copolymer of acrylic acid or methacrylic acid alkylester is preferable. As a monomer of an acrylate ester, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-), nonyl acrylate (n-, i-), myristyl acrylate (n- , i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid ( 4-hydroxybutyl), acrylic acid (2-hydroxybutyl), acrylic acid (2-methoxyethyl), acrylic acid (2-ethoxyethyl), or the like, or those obtained by replacing the acrylic acid ester with methacrylic acid ester. . Although an acryl-type polymer is a homopolymer or copolymer of the said monomer, it is preferable that the acrylic acid methyl ester monomeric unit has 30 mass% or more, and it is preferable that the methacrylic acid methyl ester monomeric unit has 40 mass% or more. In particular, homopolymers of methyl acrylate or methyl methacrylate are preferred.

The polyester plasticizer is a reactant of a monovalent to tetravalent carboxylic acid with a monovalent to hexavalent alcohol, but a compound obtained mainly by reacting a divalent carboxylic acid with glycol is used. Representative divalent carboxylic acids include glutaric acid, itaconic acid, adipic acid, phthalic acid, azelaic acid, sebacic acid and the like. The polyester plasticizer is preferably an aromatic terminal ester plasticizer. As an aromatic terminal ester plasticizer, the ester compound which has a structure which made phthalic acid, adipic acid, at least 1 sort (s) of benzene monocarboxylic acid, and at least 1 sort (s) of C2-C12 alkylene glycol react is preferable. What is necessary is just to have adipic acid residue and a phthalic acid residue as a structure of a final compound, and when manufacturing an ester compound, you may react as acid anhydride or esterified substance of dicarboxylic acid.

Examples of the benzene monocarboxylic acid component include benzoic acid, paratert-butylbenzoic acid, orthotoluic acid, metatoluic acid, paratoluic acid, dimethylbenzoic acid, ethylbenzoic acid, normalpropylbenzoic acid, aminobenzoic acid, acetoxybenzoic acid, and the like. And benzoic acid are most preferred. In addition, these can be used individually by 1 type or in mixture of 2 or more types.

Examples of the alkylene glycol component having 2 to 12 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,2-propanediol, and 2-methyl -1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentylglycol), 2,2-diethyl-1,3- Propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl-1,5-pentanediol, 1 , 6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc. are mentioned. Among these, 1,2-propylene glycol is especially preferable. You may use these glycol as 1 type, or 2 or more types of mixtures.

The aromatic terminal ester plasticizer may be either an oligoester or a polyester type, and the molecular weight is preferably in the range of 100 to 10000, but preferably in the range of 350 to 3000. The acid value is 1.5 mg KOH / g or less, the hydroxy (hydroxyl group) value is 25 mg KOH / g or less, more preferably the acid value is 0.5 mg KOH / g or less, and the hydroxy (hydroxyl group) value is 15 mg KOH / g or less.

Although the compound etc. which are specifically shown below are mentioned, It is not limited to these.

As a sugar ester type compound, it is ester other than a cellulose ester, It is a compound which esterified all or one part of OH groups of sugars, such as the following monosaccharide, disaccharide, trisaccharide, or oligosaccharide, and as a more specific example, it is represented by General formula (4). The compound shown etc. are mentioned.

Wherein, R ₁ to R ₈ represents a hydrogen atom, a substituted or unsubstituted alkylcarbonyl group having 2 to 22, or an aryl group a substituted or unsubstituted C2 to 22 ring. R ₁ to R ₈ may be the same or different.

Although the compound represented by General formula (4) below is shown more concretely (compound 1-1 to compound 1-23), it is not limited to these. In addition, when the average degree of substitution is less than 8.0 according to the table below, any of R ₁ to R ₈ is a hydrogen atom.

It is preferable that these plasticizers add 0.5-30 mass parts with respect to 100 mass parts of cellulose ester films.

(Retardation adjustment agent)

As a compound added in order to adjust retardation, the aromatic compound which has two or more aromatic rings as described in European patent 911,656A2 specification can be used.

Moreover, you may use together 2 or more types of aromatic compounds. It is especially preferable that the aromatic ring of this aromatic compound contains an aromatic hetero ring in addition to an aromatic hydrocarbon ring. Aromatic heterocycles are generally unsaturated heterocycles. Especially, the 1,3,5-triazine ring is especially preferable.

(Polymer or oligomer)

The raw film of this embodiment has a cellulose ester, a substituent selected from a carboxyl group, a hydroxyl group, an amino group, an amide group, and a sulfonic acid group, and the polymer or oligomer of the vinyl compound which has a weight average molecular weight in the range of 500-200,000. It is preferable to contain. It is preferable that the mass ratio of content of the said cellulose ester and the said polymer or oligomer exists in the range of 95: 5-50: 50.

(Mat made)

In this embodiment, microparticles | fine-particles can be contained in a raw film as a mat agent, and conveyance and winding of a raw film and the elongate diagonal stretched film manufactured using it can be made easy by this.

It is preferable that the particle diameter of a mat agent is a primary particle or secondary particle of 10 nm-0.1 micrometer. The substantially spherical matting agent whose needle shape ratio of a primary particle is 1.1 or less is used preferably.

As microparticles | fine-particles, it is preferable that silicon is included and especially silicon dioxide is preferable. As microparticles | fine-particles of silicon dioxide which are preferable to this embodiment, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above Nippon aerosil, Ltd. make), for example. The commercially available thing is mentioned by the brand name of (the manufacture), Aerosol 200V, R972, R972V, R974, R202, R812 can be used preferably. Examples of the fine particles of the polymer include silicone resins, fluororesins, and acrylic resins. Silicone resin is preferable and it is especially preferable to have a three-dimensional network structure. As such resin, tospearl 103, copper 105, copper 108, copper 120, copper 145, copper 3120, and copper 240 (Toshiba Silicone Co., Ltd. product) is mentioned, for example.

The fine particles of silicon dioxide preferably have a primary average particle diameter of 20 nm or less and an apparent specific gravity of 70 g / L or more. The average diameter of the primary particles is more preferably 5 to 16 nm, more preferably 5 to 12 nm. The smaller the average diameter of the primary particles is, the lower the haze is preferable. 90-200 g / L or more is preferable and, as for an apparent specific gravity, 100-200 g / L or more is more preferable. The larger the apparent specific gravity, the higher the concentration of the fine particle dispersion can be made, and no haze or aggregates are generated, which is preferable.

0.01-1.0g per 1m <2> of raw film is preferable, as for the addition amount of the mat agent in this embodiment, 0.03-0.3g is more preferable, 0.08-0.16g are still more preferable.

(Other additives)

In addition, heat stabilizers such as inorganic fine particles such as kaolin, talc, diatomaceous earth, quartz, calcium carbonate, barium sulfate, titanium oxide and alumina, and alkaline earth metal salts such as calcium and magnesium may be added. Moreover, you may add surfactant, a peeling accelerator, an antistatic agent, a flame retardant, a lubricating agent, an oil agent, etc.

(Tension softening point)

The raw film of this embodiment is required to be able to endure use in a higher temperature environment. For this reason, since the tension softening point of a raw film shows sufficient heat resistance as it is 105 degreeC-145 degreeC, it is preferable that it is 110 degreeC-130 degreeC especially.

As a specific measuring method of the tension softening point, a sample film is cut out to 120 mm (length) x 10 mm (width) using the Tensilon tester (The product made by Orientec, RTC-1225A), The temperature is continuously increased at a temperature increase rate of 30 ° C./min while tensioning at a tension of 10 N, and the temperature at the time of 9 N can be measured three times, and the average value can be obtained.

(Dimension change rate)

When the film after diagonally stretching the raw film of the present embodiment is used in an organic EL image display device, problems such as a thickness unevenness or a change in phase difference value, a decrease in contrast, or a color unevenness occur due to dimensional change due to moisture absorption. In order not to make it, the dimensional change rate (%) of the diagonal stretched film is preferably less than 0.5%, and more preferably less than 0.3%.

(fault)

It is preferable that the raw film of this embodiment has few defects in a film. Here, a fault is a foreign substance in a film (foreign defect) resulting from the cavity (foam defect) in the film which arises from the rapid evaporation of a solvent in the drying process of solution film forming, the foreign material in a film forming undiluted | stock solution, or the foreign material mixed in film forming. Means.

Specifically, it is preferable that the fault of 5 micrometers or more in diameter inside a film plane is 1/10 cm square or less. More preferably, it is 0.5 piece / 10 cm square or less, More preferably, it is 0.1 piece / 10 cm square or less.

The diameter of the said defect shows the diameter when a fault is circular, and when it is not circular, the range of a fault is observed and determined with a microscope by the following method, and it is set as the largest diameter (diameter of an circumscribed circle).

The range of a fault is the magnitude | size of the shadow when a fault is observed with the transmitted light of a differential interference microscope, when a fault is a bubble or a foreign material. When a fault is a change of surface shape, such as transfer of a scratch or a scratch, a fault is observed with the reflected light of a differential interference microscope, and a magnitude | size is confirmed.

In addition, when observing with reflected light, if the magnitude | size of a fault is unclear, it will observe by depositing aluminum or platinum on a surface. In order to obtain a product with excellent quality expressed by such a defect frequency with high productivity, high precision filtration of the polymer solution immediately before casting, increasing the cleanliness around the casting machine, and setting the drying conditions after casting, step by step, It is effective to suppress foaming and to dry.

If the number of defects is larger than 1/10 cm square, for example, when tension is applied to the film during processing in a subsequent step, the film may break from the defect and the productivity may decrease. Moreover, when the diameter of a fault becomes 5 micrometers or more, it can visually confirm by observing a polarizing plate etc., and a bright spot may generate | occur | produce when used as an optical member.

(Total light transmittance)

It is preferable that the total light transmittance of the raw film of this embodiment is 90% or more, More preferably, it is 93% or more. The upper limit of the total light transmittance is about 99%. In order to achieve excellent transparency expressed by such a total light transmittance, it is necessary not to introduce an additive or a copolymerizing component which absorbs visible light, or to remove foreign substances in the polymer by high precision filtration, thereby reducing light diffusion and absorption inside the film. It is valid to let. In addition, the surface roughness of the film contact portion (cooling roll, calender roll, drum, belt, coating base material, conveyance roll, etc. in solution film formation) at the time of film forming is made small, and the surface roughness of the film surface is made small, so that light diffusion of the film surface or It is effective to reduce reflection.

<Film forming method of fabric film>

The raw film of this embodiment containing the above-mentioned resin can be formed into either of the solution casting film forming method and the melt casting film forming method described below. In addition, although the case where a raw film contains a cellulose ester-type resin here is demonstrated, it is the same also when it contains another resin.

When manufacturing a raw film by the solution casting film forming method, the dope which is a raw material solution of the raw film of a cellulose-ester type resin is flexible on the support body containing a rotating metal endless belt by a casting die. When the dope film | membrane, ie, a web formed on a support body by the casting | flow_spread is carried out about the support body about one round, it peels by a peeling roll. The peeled web (film) is then introduce | transduced into the stretching apparatus containing a tenter.

When the original film is produced by the melt casting film forming method, in the extrusion method using a T die, the polymer is melted at a meltable temperature, extruded from the T die into a film shape (sheet shape) on the cooling drum, and solidified by cooling to form a cooling drum. The film is peeled off. The peeled film is then introduce | transduced into the extending | stretching apparatus containing a tenter.

Hereinafter, the detail of each film forming method is demonstrated.

[Solution flexible film forming method]

In the manufacturing method of the raw film by the solution casting film forming method, solid content concentration of the dope which is a cellulose-ester solution is about 10-40 mass% normally, and the dope viscosity at the time of casting | flow_spread in a casting | flow_spread process is a range of 1-200 poise. Are prepared from.

Here, first, the dissolution of the cellulose ester is usually a means such as a stirring dissolving method, a heating dissolving method, an ultrasonic dissolving method or the like in a melting kiln, and under pressure, a range not higher than the boiling point at the normal pressure of the solvent and the solvent does not boil. The method of heating at a temperature of and stirring to dissolve while stirring is more preferable because it prevents the generation of bulky debris called gels or lumps. Moreover, you may use the cooling dissolution method of Unexamined-Japanese-Patent No. 9-95538, the method of melt | dissolving under the high pressure of Unexamined-Japanese-Patent No. 11-21379, etc. can be used.

After mixing a cellulose ester with a poor solvent and making it wet or swell, the method of mixing with a good solvent and melt | dissolving is also used preferably. Under the present circumstances, you may divide into the apparatus which mixes a cellulose ester with a poor solvent, and wets or swells, and the apparatus which mixes and melts with a good solvent separately.

The kind of pressurized container used for dissolving a cellulose ester is not specifically taken, It can endure predetermined pressure, What is necessary is just to be able to heat and stir under pressure. In the pressurized container, instruments such as a pressure gauge and a thermometer are appropriately disposed. Pressurization may be performed by press-injecting an inert gas such as nitrogen gas or by increasing the vapor pressure of the solvent by heating. It is preferable to perform heating from the outside, for example, a jacket type thing is preferable because temperature control is easy.

The heating temperature at the time of adding a solvent is more than the boiling point of the solvent to be used, and in the case of two or more types of mixed solvents, the temperature of the range which heated to the temperature more than the boiling point of the solvent of the lower boiling point, and the said solvent does not boil. Is preferred. If heating temperature is too high, required pressure will become large and productivity will worsen. The range of preferable heating temperature is 20-120 degreeC, 30-100 degreeC is more preferable, and the range of 40-80 degreeC is still more preferable. In addition, pressure is adjusted so that a solvent may not boil at a preset temperature.

In addition to a cellulose ester and a solvent, additives, such as a required plasticizer and a ultraviolet absorber, may be previously mixed with a solvent, melt | dissolve, or disperse, and may be thrown into the solvent before cellulose ester melt | dissolution, or may be thrown into the dope after cellulose ester melt | dissolution.

After dissolving the cellulose ester, it is taken out from the container while cooling, or is taken out of the container by a pump or the like, cooled by a heat exchanger or the like, and provided to the film forming of the dope of the obtained cellulose ester, but cooling at this time may be performed at room temperature.

When melt | dissolving the mixture of a cellulose-ester raw material and a solvent in the melting apparatus which has a stirrer, the circumferential speed of a stirring blade is at least 0.5 m / sec or more, It is preferable to melt | dissolve by stirring for 30 minutes or more.

The foreign matter (particularly the foreign matter misrecognized as an image in a liquid crystal display device) contained in cellulose ester dope must be removed by filtering this. The quality as an optical film may be determined by this filtration.

As for the filter medium used for filtration, it is preferable that absolute filtration accuracy is small, but when absolute filtration precision is too small, clogging of a filter material will occur easily, there exists a problem that the filter medium must be changed frequently, and productivity falls. For this reason, as for the filter medium used for cellulose-ester dope, the thing of absolute filtration accuracy 0.008 mm or less is preferable, The range of 0.001-0.008 mm is more preferable, The filter medium of the range of 0.003-0.006 mm is more preferable.

There is no restriction | limiting in particular in the material of a filter medium, Although a normal filter medium can be used, The filter medium made from plastics, such as polypropylene and Teflon (trademark), and the filter medium made from metals, such as a stainless steel fiber, are preferable because a fiber does not fall off. .

Filtration of cellulose ester dope can be performed by a normal method, but the method of filtering, heating under pressurization at the temperature of the range which is above the boiling point in the normal pressure of a solvent and a solvent does not boil, and the differential pressure before and behind a filter medium (hereinafter, filtration pressure) Rise)) is small, which is preferable.

The range of preferable filtration temperature is 45-120 degreeC, 45-70 degreeC is more preferable, It is more preferable that it is the range of 45-55 degreeC.

It is preferable that a filtration pressure is 3500 kPa or less, 3000 kPa or less is more preferable, It is still more preferable that it is 2500 kPa or less. In addition, the filtration pressure can be controlled by appropriately selecting the filtration flow rate and the filtration area.

In order to manufacture the raw film of cellulose ester-type resin, a cellulose ester is first melt | dissolved in the mixed solvent of a good solvent and a poor solvent, the said plasticizer and an ultraviolet absorber are added to this, and a cellulose ester solution (dope) is prepared.

The dope may be flexible on the support in the range of the temperature of the support is generally 0 ℃ to less than the boiling point of the solvent, and further may be flexible on the support in the temperature range of 5 ℃ to solvent boiling point-5 ℃, It is more preferred to be flexible on the support in the temperature range. At this time, it is necessary to control the ambient atmospheric humidity above the dew point.

Moreover, the dope adjusted so that a dope viscosity might be 1-200 poise is cast so that it may become a substantially uniform film thickness from a casting die on a support body, and when the amount of residual solvent in a casting film is large solid content weight 200% or more, a casting film temperature The casting film (web) is dried by dry air so that the casting film temperature may be in the range of the solvent boiling point +20 degrees C or less until the soluble solvent boiling point is further 200% or less and peeling.

Here, the residual solvent amount can be represented by the following formula.

Residual solvent amount (mass%) = {(M-N) / N} × 100

However, in formula, M is a weight at the arbitrary time of a web, and N is a weight at the time of drying what is weight M at 110 degreeC for 3 hours.

On the support, in order to dry-solidify until a web becomes the film strength which can peel from a support, it is preferable to dry the amount of residual solvent in a web to 150 mass% or less, and 50-120% is more preferable.

As for the web temperature at the time of peeling a web from a support body, 0-30 degreeC is preferable. In addition, since the temperature of the web is rapidly lowered immediately by the evaporation of the solvent from the support surface, immediately after peeling from the support, volatile components such as water vapor and solvent vapor in the atmosphere tend to condense. 30 degreeC is more preferable.

In the drying process of a web (or film), the method of drying while conveying a web by a roll suspension system, a pin tenter system, or a clip tenter system is employ | adopted generally.

The web after peeling is introduce | transduced into a primary drying apparatus, for example. In the primary drying apparatus, the web is meandered and conveyed by a plurality of conveying rolls arranged in a zigzag view from the side, during which the web is blown from the ceiling of the drying apparatus and discharged from the bottom part of the drying apparatus. By drying.

Subsequently, the obtained film (sheet) is stretched in the uniaxial direction. The molecules are oriented by stretching. Although the method of extending | stretching does not have a restriction | limiting in particular, A well-known pin tenter, a clip-type tenter, etc. can be used preferably. Although the extending | stretching direction may be arbitrary directions (tilting direction), even if it is a longitudinal direction, or a width direction, it is easy to adjust the breaking elongation of a raw film by making an extending | stretching direction into a width direction, and it is preferable.

In particular, in the drying process after peeling from a support body, a web will shrink | contract in the width direction by evaporation of a solvent. Drying at high temperature increases shrinkage. Drying while suppressing this shrinkage as much as possible is preferable in making the planarity of the finished film favorable. In this respect, for example, a method (tenter method) of drying the entire drying process or a part of the processes disclosed in Japanese Patent Application Laid-Open No. 62-46625 while maintaining both ends of the width of the web with a clip in the width direction is preferable. .

As stretching conditions of a raw film, temperature and a magnification can be selected so that a desired breaking elongation characteristic may be obtained. Usually, a draw ratio is 1.1-2.0 times, Preferably it is 1.2-1.5 times, and extending | stretching temperature is the glass transition temperature (Tg) -40 degreeC-Tg + 50 degreeC of resin which comprises a sheet normally, Preferably it is Tg It is set in the temperature range of -40 degreeC to Tg + 40 degreeC. If the draw ratio is too small, the desired breaking elongation characteristics may not be obtained. On the contrary, if the drawing ratio is too large, the breaking ratio may be broken. When extending | stretching temperature is too low, it breaks and when too high, desired breaking elongation characteristic may not be acquired.

When modifying the breaking elongation characteristic of the thermoplastic resin film produced by the said method to the desired characteristic according to the objective, you may extend | stretch or shrink | contract a film in the longitudinal direction or the width direction. In order to shrink | contract in the longitudinal direction, there exists a method of shrinking a film, for example, by clipping out width extension temporarily and relaxing in the longitudinal direction, or narrowing the space | interval of the adjacent clip of a transverse stretching apparatus gradually. The latter method can be performed by using a general simultaneous biaxial stretching apparatus to smoothly narrow the interval between adjacent clips in the longitudinal direction, for example, by driving the clip portion by a pantograph method or a linear drive method.

Although gripping and extending | stretching in a tenter can be performed anywhere in the range where the residual solvent amount of the film | membrane immediately after peeling is 50 mass%, and the substantial residual solvent quantity just before winding-up is 0 mass%, in the range of 5 to 10% of residual solvent amount It is preferable to carry out.

It is also common to divide the tenter into several temperature zones in the running direction of the base. The temperature at the time of extending | stretching selects the temperature from which desired physical property and planar property are acquired, but the temperature of the drying zone before and behind a tenter may also select the temperature different from the temperature at the time of extending | stretching for various reasons. For example, when the atmospheric temperature of the drying zone before the tenter is different from the temperature in the tenter, it is generally set to set the temperature of the zone near the tenter to an intermediate temperature between the temperature of the drying zone before the tenter and the temperature of the tenter center. It is done. Similarly, in the case where the temperature in the tenter after the tenter is different, the temperature in the zone close to the tenter outlet is similarly set to the temperature intermediate between the temperature after the tenter and the temperature in the tenter. The temperature of the drying zone before and after the tenter is generally 30 to 120 ° C, preferably 50 to 100 ° C, and the temperature of the stretching portion in the tenter is 50 to 180 ° C, preferably 80 to 170 ° C, and the tenter inlet or outlet The negative temperatures are appropriately selected at their intermediate temperatures.

The stretching pattern, i.e., the trajectory of the gripping clip, is selected from the optical properties and the planarity of the film as well as the temperature, and varies, but the pattern is stretched for some time after the start of the gripping, and is stretched after the end of the stretching, and is maintained at the constant width again after the completion of the stretching. This is often used. In the vicinity of the grip of the clip near the tenter exit, width reduction is generally performed to suppress the base vibration by opening the grip.

The pattern of stretching is also related to the stretching speed, but the stretching speed is generally 10 to 1000 (% / min), preferably 100 to 500 (% / min). This stretching speed is not constant when the trajectory of the clip is curved, and gradually changes in the traveling direction of the base.

In addition, the web (film) after drying by the said tenter system is continuously introduce | transduced into a secondary drying apparatus. In the secondary drying apparatus, the web is meandered and conveyed by a plurality of conveying rolls zigzag arranged in the side view, during which the web is blown from the ceiling of the secondary drying apparatus, and the bottom portion of the secondary drying apparatus is further reduced. It is dried by the warm air discharged | emitted from and wound up by a winding machine as a raw film of cellulose ester-type resin.

The means for drying the web is not particularly limited, and hot air, infrared rays, heating rolls, microwaves and the like are generally used. In view of simplicity, drying with hot air is preferable. 40-150 degreeC is preferable and since drying temperature improves planarity and dimensional stability, it is more preferable.

In this manner, in the drying step of the web, the web peeled off from the support is further dried, and finally the amount of residual solvent is 3 mass% or less, preferably 1 mass% or less, and more preferably 0.5 mass% or less. In order to obtain the film with favorable dimensional stability, it is preferable.

These processes from casting to post drying may be performed in an air atmosphere or may be performed in an inert gas atmosphere such as nitrogen gas. In this case, it goes without saying that the drying atmosphere is carried out in consideration of the explosion limit concentration of the solvent.

Furthermore, in the front end which introduce | transduces into a winding process about the raw film of cellulose-ester type resin which completed the conveyance drying process, embossing is formed in the both edges of the raw film of cellulose-ester type resin film by an embossing apparatus. It is preferable to perform a process. As an embossing apparatus, the apparatus described in Unexamined-Japanese-Patent No. 63-74850 can be used, for example.

The winding machine which concerns on manufacture of the raw film of a cellulose-ester type resin should just be used normally, and it can wind up by winding methods, such as the static tension method, the static torque method, the taper tension method, and the program tension control method with constant internal stress. .

Although the film thickness of the raw film after winding differs according to a use purpose, the film thickness range is 20-200 micrometers, and in the recent thin tendency, the range of 30-120 micrometers is preferable, Especially the range of 40-100 micrometers desirable.

When the raw film of this embodiment is manufactured by the melt casting film forming method, as an ultraviolet absorber which can be used, the thing similar to what is used in the manufacturing method of the raw film by the above-mentioned solution casting film forming method can be used.

As for the compounding quantity of these ultraviolet absorbers, the range of 0.01-10 mass% is preferable with respect to a thermoplastic resin, and also 0.1-5 mass% is preferable. If the amount is too small, the ultraviolet absorbing effect may be insufficient. On the contrary, if the amount is too large, the transparency of the film may deteriorate. It is preferable that a ultraviolet absorber has high thermal stability.

In order to provide slipperiness | lubricacy of a film, it is preferable to add microparticles | fine-particles to a raw film. As microparticles | fine-particles to be used, any of an inorganic compound or an organic compound may be sufficient as heat resistance at the time of melting, For example, as an inorganic compound, the compound containing silicon, silicon dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay Calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate, and the like, and more preferably, an inorganic compound containing zirconium oxide or zirconium oxide. Especially, silicon dioxide is especially used at the point which can suppress a haze small. Even when manufacturing a raw film by a melt casting film forming method, as a mat agent to be used, the thing similar to what is used in the manufacturing method of the raw film by the said solution casting film forming method can be used.

As the melt casting film forming method, there are a melt extrusion method such as a method using a T die or an inflation method, a calender method, a hot press method, an injection molding method and the like. Especially, the method of using the T die which is small in thickness nonuniformity and is easy to process to thickness of about 50-500 micrometers, and can make film nonuniformity and retardation nonuniformity small is preferable. An extrusion method using a T die is a method of melting a polymer at a meltable temperature, extruding it from a T die into a film shape (sheet shape) on a cooling drum, cooling and solidifying and peeling from the cooling drum. It is excellent and can be used preferably.

Melt extrusion can be performed on the conditions similar to the conditions used for thermoplastic resins, such as another polyester. For example, the cellulose ester dried under hot air, vacuum, or reduced pressure is melted at an extrusion temperature of about 200 to 300 ° C. using a single screw or twin screw extruder, filtered through a leaf disc filter, and the like to remove foreign substances. It is flexible in a film form (sheet shape) from a T die, and solidifies on a cooling drum. When introducing into an extruder from a feed hopper, it is preferable to prevent oxidative decomposition and the like under reduced pressure or inert gas atmosphere.

The extrusion flow rate is preferably performed stably by introducing a gear pump. Moreover, as a filter used for removal of a foreign material, a stainless fiber sintering filter is used preferably. The stainless steel fiber sintered filter is made by integrating stainless fiber bodies into a complicated entanglement, and then compressed and sintered to form a contact point. The filtration precision can be adjusted by varying the density according to the thickness and compression amount of the fiber. . It is preferable to set it as the multilayer body which repeated filtration precision several times continuously by the rough and the mill. Moreover, it is preferable because the filter life of a filter can be extended and the replenishment precision of a foreign material, a gel, etc. can be improved by taking the structure which raises filtration precision sequentially, or the method of repeating the crumbness and mill of filtration precision.

If scratches or foreign matter adhere to the die, striped defects may occur. Although such defects are called die lines, in order to reduce defects on the surface of die lines and the like, it is preferable that the piping from the extruder to the die has a structure in which the retention portion of the resin is as small as possible. Moreover, it is preferable to use the thing which does not have scratches etc. in the inside of a die | dye or a lip as much as possible. Since a volatile component may precipitate from a resin around die | dye and may cause a die line, it is preferable to aspirate the atmosphere containing a volatile component. Moreover, since it may precipitate also in apparatuses, such as an electrostatic application, it is preferable to apply alternating current or to prevent precipitation by other heating means.

Additives, such as a plasticizer, may be previously mixed with resin, and may be put in the middle of an extruder. In order to add uniformly, it is preferable to use mixing apparatuses, such as a static mixer.

It is preferable that the temperature of a cooling drum is below the glass transition temperature of a thermoplastic resin. In order to bring the resin into close contact with the cooling drum, it is preferable to use a method of contacting by electrostatic application, a method of contacting by wind pressure, a method of nip contacting the entire width or end portion, a method of contacting at reduced pressure, and the like.

The raw film of the thermoplastic resin molded by such a melt casting film method has a characteristic that the thickness direction retardation (Rt) is small unlike the raw film formed by the solution casting film forming method, and it is different from the solution casting film forming method. This may be necessary. In order to acquire desired optical physical property, in some cases, both extending | stretching of the advancing direction of a film, and extending | stretching of a film width direction may be performed simultaneously or sequentially. Moreover, depending on a case, it may be only extending | stretching of the film width direction. The molecule | numerator is oriented by this extending | stretching operation, and a film is adjusted to the required retardation value.

<Specifications of Fabric Film>

The thickness of the raw film in this embodiment is 1-400 micrometers, Preferably it is 20-200 micrometers, More preferably, it is 30-120 micrometers, It is especially preferable that it is the range of 40-100 micrometers. In addition, in this embodiment, thickness nonuniformity (sigma) m of the flow direction (conveying direction) of the raw film supplied to the extending | stretching zone mentioned later maintains the take-up tension of the film in the diagonal stretch tenter entrance mentioned later, an orientation angle, or a rita. From the standpoint of stabilizing optical properties such as dating, it is necessary to be less than 0.30 µm, preferably less than 0.25 µm, more preferably less than 0.20 µm. When thickness nonuniformity (sigma) m of the flow direction of a raw film becomes 0.30 micrometer or more, the fluctuation | variation of optical characteristics, such as retardation and orientation angle of a long diagonal stretched film, will remarkably worsen.

In addition, in this embodiment, in order to suppress that an orientation angle nonuniformity arises in the width direction by thickness nonuniformity of the width direction by diagonal stretch, the thickness nonuniformity of the width direction of a raw film is preferable. For example, in the width direction of a raw film, the thickness difference in the edge part of a thick side and the edge part of a thin side is less than 2.0% of thickness, Preferably it is less than 1.0%, More preferably, less than 0.5% It is preferable to make it into the range of a degree.

Although the width | variety of a raw film is not specifically limited, 500-4000 mm, Preferably it can be 1000-2000 mm.

Preferable elastic modulus at the extending | stretching temperature at the time of diagonal stretch of a raw film is represented by a Young's modulus, and is 0.01 MPa or more and 5000 MPa or less, More preferably, it is 0.1 MPa or more and 500 MPa or less. When the elastic modulus is too low, the shrinkage ratio at the time of stretching and after stretching is low, and wrinkles are hard to disappear. Moreover, when elastic modulus is too high, the tension | tensile_strength at the time of extending | stretching will become large, the need of raising the intensity | strength of the part holding the both edges of a film will arise, and the load on the tenter of a subsequent process will become large.

As a raw film, an unoriented thing may be used and the film which has orientation in advance may be supplied. Moreover, if necessary, the width direction distribution of the orientation of a raw film may be arched, what is called boeing. In other words, the orientation state of the raw film can be adjusted so that the orientation of the film at the position where the stretching of the subsequent step is completed can be made desired.

<The manufacturing method and manufacturing apparatus of an inclined stretched film>

Next, the manufacturing method and manufacturing apparatus of the diagonal stretched film which extend | stretch the above-mentioned elongate film in the diagonal direction with respect to the width direction to manufacture an elongate diagonal stretched film are demonstrated.

(Overview of the device)

1: is a top view which shows typically schematic structure of the manufacturing apparatus 1 of the diagonal stretched film. The manufacturing apparatus 1 has the film feeding part 2, the conveying direction change part 3, the guide roll 4, the extending | stretching part 5, and the guide roll from the conveyance direction upstream of the long film in order. (6), the conveyance direction change part 7 and the film winding-up part 8 are provided. Moreover, you may provide a film cutting device between the conveyance direction change part 7 and the film winding-up part 8, cut the film after diagonal stretch to desired length, and may make it wind up by the film winding-up part 8. In addition, the detail of the extending | stretching part 5 is mentioned later.

The film feeding part 2 unwinds the above-mentioned long film and supplies it to the extending | stretching part 5. This film feeding part 2 may be comprised separately from the film forming apparatus of a long film, and may be comprised integrally. In the former case, a long film is taken out from the film feeding part 2 by loading in a film feeding part 2 the thing which became a winding object (long film original fabric) by winding up a long film to a winding core after film forming once. On the other hand, in the latter case, the film feeding part 2 feeds out the extending | stretching part 5, without winding up the long film after film forming of a long film.

The conveyance direction change part 3 changes the conveyance direction of the elongate film drawn out from the film feeding part 2 to the direction toward the inlet of the extending | stretching part 5 as a diagonal stretch tenter. Such conveying direction changing part 3 is comprised including the turn bar which changes conveyance direction by folding, for example, conveying a film, and the turntable which rotates the turn bar in the plane parallel to a film.

By changing the conveyance direction of a long film in the conveyance direction change part 3 as mentioned above, it becomes possible to narrow the width | variety of the manufacturing apparatus 1 whole, and to control the feeding position and angle of a film finely. It becomes possible, and it becomes possible to obtain the diagonal stretched film with small fluctuation | variation of a film thickness and an optical value. In addition, when the film feeding part 2 and the conveyance direction change part 3 are movable (slidable and orbitable), the left-right clip which grips the both ends of the width direction of the elongate film in the extending | stretching part 5 (gripping tool) The bite defect with respect to the film of can be effectively prevented.

In addition, the said film feeding part 2 may be able to slide and turn so that a long film may be sent out at a predetermined angle with respect to the entrance part of the extending | stretching part 5. In this case, it is also possible to set it as the structure which omitted the installation of the conveyance direction change part 3.

At least one guide roll 4 is provided in the upstream of the extending | stretching part 5, in order to stabilize the track | orbit at the time of the run of a long film. In addition, the guide roll 4 may be comprised by a pair of upper and lower roll pairs which pinch | interpose a film, and may be comprised by several roll pair. The guide roll 4 which is closest to the inlet of the extending | stretching part 5 is a driven roll which guides the running of a film, and is axially rotatably supported by the bearing part which is not shown, respectively. As a material of the guide roll 4, a well-known thing can be used. In order to prevent the occurrence of scratches on the film, it is preferable to reduce the weight of the guide roll 4 by applying a ceramic coating to the surface of the guide roll 4 or by chromium plating a light metal such as aluminum.

Moreover, it is preferable that one of the rolls upstream than the guide roll 4 closest to the inlet of the extending | stretching part 5 presses a rubber roll and nips. By setting it as such a nip roll, it becomes possible to suppress the fluctuation | variation of the feeding tension in the flow direction of a film.

In the pair of bearing portions at both ends (left and right) of the guide roll 4 closest to the inlet of the stretching section 5, the first tension detection device is used as a film tension detection device for detecting tension generated in the film in the roll. A device and a second tension detection device are respectively provided. As a film tension detection apparatus, a load cell can be used, for example. As a load cell, the well-known thing of tension or compression type can be used. A load cell is an apparatus which converts and loads the load acting on a landing point into an electrical signal by the strain gauge provided in the distortion body.

The load cell is provided in the left and right bearing portions of the guide roll 4 closest to the inlet of the stretched portion 5, so that the force exerted on the roll by the film while traveling, that is, in the film advancing direction generated in the vicinity of both edge portions of the film. The tension is detected independently left and right. In addition, a strain gauge may be directly installed on a support constituting the bearing portion of the roll to detect a load, that is, a film tension, based on the deformation occurring in the support. The relationship between the deformation | transformation and film tension which generate | occur | produce is previously measured and shall be known.

When the position and conveyance direction of the film supplied to the extending | stretching part 5 from the film feed part 2 or the conveyance direction change part 3 are shifted from the position and conveyance direction toward the inlet of the extending | stretching part 5, According to the amount of shift | deviation, a difference arises in the tension of the edge part vicinity of the film in the guide roll 4 closest to the entrance of the extending | stretching part 5. Therefore, by providing the above-mentioned film tension detection apparatus and detecting the said tension difference, the grade of the said deviation can be discriminated. That is, if the conveyance position and conveyance direction of a film are appropriate (as long as it is a position and direction toward the entrance of the extending | stretching part 5), although the load acting on the said guide roll 4 will become substantially equal at both ends of an axial direction, Otherwise, a difference occurs in the film tension from left to right.

Therefore, for example, the above-mentioned conveyance direction changing part 3 positions the film and the conveying direction (stretching part (1) so that the left and right film tension differences of the guide roll 4 closest to the inlet of the stretching part 5 become equal. When the angle with respect to the inlet of 5) is adjusted appropriately, the film holding by the holding | gripping tool of the inlet part of the extending | stretching part 5 is stabilized, and generation | occurrence | production of obstacles, such as a gripper deviation, can be reduced. Moreover, the physical property in the width direction of the film after diagonal stretch by the extending | stretching part 5 can be stabilized.

At least one guide roll 6 is provided in the downstream of the extending | stretching part 5, in order to stabilize the track | orbit at the time of the run of the film diagonally stretched by the extending | stretching part 5.

The conveyance direction change part 7 changes the conveyance direction of the film after extending | stretching conveyed from the extending | stretching part 5 to the direction toward the film winding part 8.

Here, in order to cope with the fine adjustment of an orientation angle (direction of the in-plane slow axis of a film), and product variation, the film advancing direction in the inlet of the extending | stretching part 5, and the film advancing direction in the exit of the extending | stretching part 5 are It is necessary to adjust the angle to be achieved. For this angle adjustment, the advancing direction of the film formed into a film is changed by the conveying direction changing part 3 to guide and / or guide the film to the inlet of the drawing section 5, or the film emerges from the exit of the drawing section 5. It is necessary to change the advancing direction by the conveyance direction changing part 7 and to return a film to the direction of the film winding-up part 8.

Moreover, it is preferable to perform film forming and diagonal stretch continuously in terms of productivity or a yield. When performing a film forming process, a diagonal stretch process, and a winding process continuously, the advancing direction of a film is changed by the conveyance direction change part 3 and / or conveyance direction change part 7, and the film | membrane process and the winding process of a film are carried out. 1, that is, as shown in FIG. 1, the advancing direction (feeding direction) of the film conveyed from the film feeding part 2, and the film advancing direction immediately before being wound up by the film winding part 8 ( By matching the winding direction), the width | variety of the whole apparatus with respect to a film advancing direction can be made small.

 In addition, although the advancing direction of a film does not necessarily need to match in a film forming process and a winding process, the conveyance direction change part 3 and / or so that it may become a layout which does not interfere with the film feeding part 2 and the film winding part 8. Or it is preferable to change the advancing direction of a film by the conveyance direction change part 7.

As the above-mentioned conveyance direction changing part 3 * 7, it can implement | achieve by a well-known method, such as using an air flow roll or an air turn bar.

The film winding-up part 8 winds the film conveyed through the conveyance direction change part 7 from the extending | stretching part 5, and is comprised with a winder apparatus, a mounting apparatus, a drive apparatus, etc., for example. It is preferable that the film winding-up part 8 is a structure which can slide to a horizontal direction in order to adjust the winding position of a film.

The film winding-up part 8 is able to finely control the take-up position and angle of a film so that a film may be taken in with respect to the exit of the extending | stretching part 5 at a predetermined angle. Thereby, it becomes possible to obtain the elongate diagonal stretched film with small fluctuation | variation of a film thickness and an optical value. Moreover, while the wrinkle generation of a film can be prevented effectively, since the winding property of a film improves, it becomes possible to wind a film long.

This film winding-up part 8 comprises the take-up part which takes out the film extended | stretched and conveyed by the extending | stretching part 5 by a fixed tension | tensile_strength. Moreover, you may provide the take-up roll for pulling a film by fixed tension between the extending | stretching part 5 and the film winding-up part 8. Moreover, you may give the above-mentioned guide roll 6 the function as the said take-up roll.

In this embodiment, the film take-out tension T (N / m) after extending | stretching is adjusted to 100N / m <T <300N / m, Preferably it is between 150N / m <T <250N / m. When the said pulling tension is 100 N / m or less, relaxation of a film and wrinkles are easy to generate | occur | produce, and the profile of the film width direction of retardation and an orientation angle also worsens. On the contrary, when take-out tension becomes 300 N / m or more, the fluctuation | variation in the film width direction of an orientation angle will worsen, and the width yield (drawal efficiency of width direction) will worsen.

In addition, in this embodiment, it is preferable to control the fluctuation | variation of the said pull tension T with the precision of less than +/- 5%, Preferably it is less than +/- 3%. If the variation in the pulling tension T is ± 5% or more, the variation in the optical characteristics in the width direction and the flow direction (the conveying direction) is increased. As a method of controlling the fluctuation | variation of the said pulling tension T in the said range, the load applied to the first roll (guide roll 6) of the exit side of the extending | stretching part 5, ie, the tension of a film, is measured, and the value is The method of controlling the rotational speed of the take-up roll or the take-up roll of the film take-up part 8 by a general PID control system is mentioned so that it may become constant. As a method of measuring the said load, the load cell is attached to the bearing part of the guide roll 6, and the method of measuring the load applied to the guide roll 6, ie, the tension of a film, is mentioned. As a load cell, a well-known thing of a tension | pulling type | mold or a compression type can be used.

After the film is stretched, the grip by the gripper of the stretcher 5 is opened, discharged from the outlet of the stretcher 5, and both ends (both sides) of the film held by the gripper are trimmed. It is wound up by (winding roll), and it becomes the winding body of a long diagonal stretched film. In addition, the trimming may be performed as necessary.

In addition, before winding up a long diagonal stretched film, you may wind up a masking film on a long diagonal stretched film at the same time for the purpose of preventing the blocking of films, or at least one of the long diagonal stretched films overlapped by winding (preferably You may wind up, joining a tape etc. at both ends. The masking film is not particularly limited as long as it can protect the long diagonal stretched film, and examples thereof include polyethylene terephthalate film, polyethylene film, and polypropylene film.

Moreover, before winding up the elongate diagonal stretched film, the part made thicker than the film surface called a knurling part or an embossing part in the width direction both ends of the at least one surface (preferably both surfaces) of this film (convex) You may make it prevent the blocking of films when winding up a film. In addition, the height and shape of a knurling part may differ in both ends of a width direction (it may be asymmetrical).

(The details of the drawing part)

Next, the detail of the extending | stretching part 5 mentioned above is demonstrated. FIG. 2: is a top view which shows an example of the rail pattern of the extending | stretching part 5 typically. However, this is an example and the structure of the extending | stretching part 5 is not limited to this.

Manufacture of the elongate diagonal stretched film in this embodiment is performed as the extending | stretching part 5 using the tenter (inclined stretching machine) which can be diagonally stretched. This tenter is an apparatus which heats a long film to arbitrary temperatures which can be extended | stretched, and diagonally stretches. This tenter shows only one set of holding | gripping tools Ci and Co (in FIG. 2, many holding | gripping tools which drive along a heating zone Z, a pair of rail RiRo and right and left, and a rail RiRo). ). In addition, the detail of heating zone Z is mentioned later. The rails Ri · Ro are each configured by connecting a plurality of rail parts by connecting portions (the white circles in FIG. 2 are examples of the connecting portions). Holding | gripping tool Ci * Co is comprised by the clip which grips the both ends of the width direction of a film.

In FIG. 2, the feeding direction D1 of the elongated film is different from the winding direction D2 of the elongated obliquely stretched film after stretching, and forms the feeding angle θi between the winding directions D2. The feeding angle θi can be arbitrarily set to a desired angle in a range exceeding 0 ° and below 90 °.

Thus, since the feeding direction D1 and the winding direction D2 are different, the rail pattern of a tenter becomes asymmetrical shape left and right, and the conveyance path of a film is bent in the middle. And a rail pattern can be adjusted manually or automatically according to the orientation angle | corner (theta), a draw ratio, etc. which are given to the elongate diagonal stretched film which should be manufactured. In the diagonal drawing machine used by the manufacturing method of this embodiment, it is preferable that the position of each rail part and rail connection part which comprise rail RiRo can be set freely, and a rail pattern can be changed arbitrarily.

In this embodiment, the holding | gripping tool Ci * Co of a tenter keeps a fixed space | interval with the holding | gripping tool Ci / Co of the front and back, and it runs at a fixed speed. Although the running speed of the holding | gripping tool Ci * Co can be selected suitably, it is 1-150 m / min normally. In the present embodiment, as described later, the film is reliably heated in the width direction to impart a temperature change, and the productivity of the film is considered, and preferably 20 to 100 m / min. The difference between the traveling speeds of the pair of left and right grippers Ci · Co is usually 1% or less, preferably 0.5% or less, and more preferably 0.1% or less of the travel speed. This is because when there is a difference in the moving speed at the right and left sides of the film at the stretching step exit, wrinkles and rolling occur at the stretching step exit, and therefore, the speed difference between the left and right grippers Ci · Co is required to be substantially the same speed. . In a general tenter device or the like, there is a speed nonuniformity generated in an order of seconds or less depending on the period of the sprocket of the sprocket driving the chain, the frequency of the drive motor, and the like, and often generates a nonuniformity of several percent, but in the embodiment of the present invention, It does not correspond to the speed difference described.

In the inclined drawing machine used by the manufacturing method of this embodiment, the rail which regulates the trajectory of a holding | gripping tool is requested | required especially large bending rate especially in the place where the conveyance of a film becomes oblique. For the purpose of avoiding interference between the grippers due to sudden bending or localized stress concentration, it is preferable that the trajectory of the grippers bend at the bent portion.

Thus, the diagonal stretch tenter used in order to give an elongate orientation to a long film can set the orientation angle of a film freely by varying a rail pattern, and also the orientation axis (ground axis) of a film It is preferable that it is a tenter which can orientate highly precisely to right and left over the film width direction, and can control film thickness and retardation with high precision.

Next, the extending | stretching operation | movement in the extending | stretching part 5 is demonstrated. Both ends of a long film are gripped by the holding | gripping tool Ci * Co of right and left, and it is conveyed in the heating zone Z as the holding | gripping tool Ci * Co runs. The grippers Ci · Co on the left and right face each other in a direction substantially perpendicular to the advancing direction (feeding direction D1) of the film at the inlet portion (the position of A in the drawing) of the stretched portion 5, and are asymmetrical left and right. The film is held on the rails Ri and Ro, respectively, and the film held by the exit portion (the position B in the drawing) at the end of stretching is opened. The film opened from the holding | gripping tool Ci * Co is wound up by the winding core by the film winding part 8 mentioned above. The pair of rails Ri · Ro each have an endless continuous trajectory, and the gripper Ci · Co which opens the gripping of the film at the outlet of the tenter is returned to the inlet part by traveling the outer rail.

At this time, since the rails Ri and Ro are asymmetrical, in the example of FIG. 2, the left and right grippers Ci and Co, which are opposed to each other at the position A in the drawing, move along the rails Ri and Ro, The holding | gripping tool Ci which travels in an in-course side) becomes a positional position precedent compared with the holding | gripping tool Co which travels a rail Ro side (out-course side).

That is, when one holding | gripping tool Ci reached | attained the position B at the time of extending | stretching of a film among the holding | gripping tools Ci and Co which were facing in the direction substantially perpendicular to the feeding direction D1 of a film in the position of A in the figure, The straight line which connected holding | gripping tool Ci * Co is inclined by the angle (theta) L with respect to the direction substantially perpendicular to the winding-up direction D2 of a film. By the above behavior, elongate film is diagonally stretched by the angle of (theta) L with respect to the width direction. Here, substantially vertical means that it exists in the range of 90 +/- 1 degree.

Next, the detail of the said heating zone Z is demonstrated. The heating zone Z of the extending | stretching part 5 is comprised from the preheating zone Z1, the extending zone Z2, and the heat fixing zone Z3. In the extending | stretching part 5, the film hold | maintained by holding | gripping tool Ci * Co passes through preheating zone Z1, extending zone Z2, and heat fixing zone Z3 in order. In this embodiment, the preheating zone Z1 and the drawing zone Z2 are partitioned by partition walls, and the drawing zone Z2 and the row fixing zone Z3 are partitioned by partition walls. In addition, in each zone of the preheating zone Z1, the drawing zone Z2, and the heat fixing zone Z3, partition walls may be appropriately provided (the inside of each zone may be further divided into partition walls).

The preheating zone Z1 refers to a section in which the holding tool Ci · Co gripping both ends of the film runs while maintaining a constant distance from side to side (in the film width direction) at the inlet of the heating zone Z.

The stretching zone Z2 refers to a section until the interval between the holding regions Ci and Co holding the both ends of the film begins to increase and reaches a predetermined interval. At this time, oblique stretching is performed as described above, but may be stretched in the longitudinal direction or the transverse direction before and after the oblique stretching as necessary. That is, in the stretching zone Z2, the film is conveyed by holding one of the grippers Ci and Co relatively relatively, and the other of the grippers Co relatively delayed, while holding both ends of the film in the width direction with a pair of grippers Ci · Co. In addition, the diagonal stretch process of extending | stretching a film in the diagonal direction with respect to the width direction is performed by bending the conveyance path | route of a film along the way.

The thermal fixation zone Z3 refers to the section for fixing the optical axis (ground axis) of the diagonal stretched film after completion of the diagonal stretch process in the stretched zone Z2. That is, in the heat fixation zone Z3, the heat fixation process for fixing the optical axis of a diagonal stretched film is performed. In the row fixing zone Z3, the holding | gripping tool Ci * Co of both ends travels in parallel with each other. Thereby, the optical axis of the diagonal stretched film is fixed.

In addition, after extending | stretching the film, after passing through the heat setting zone Z3, you may pass the section (cooling zone) in which the temperature in a zone is set to the glass transition temperature Tg (degreeC) or less of the thermoplastic resin which comprises a film.

Regarding the glass transition temperature Tg of the thermoplastic resin, the temperature of the preheating zone Z1 is Tg to Tg + 60 ° C, the temperature of the stretching zone Z2 is Tg to Tg + 50 ° C, the temperature of the heat fixation zone Z3 and the cooling zone is Tg-40 to It is preferable to set it to Tg + 30 degreeC.

In addition, the lengths of the preheating zone Z1, the drawing zone Z2 and the heat fixing zone Z3 can be appropriately selected, and the length of the preheating zone Z1 is usually 50 to 200% and the length of the heat fixing zone Z3 is usually relative to the length of the drawing zone Z2. 50 to 150%.

Moreover, when the width | variety of the film before extending | stretching is Wo (mm), and the film width after extending | stretching is W (mm), the draw ratio R (W / Wo) in an extending process becomes like this. Preferably it is 1.1-3.0, More preferably Preferably 1.15 to 2.0. When a draw ratio exists in this range, since the thickness nonuniformity of the width direction of a film becomes small, it is preferable.

In addition, the method of diagonal stretch in the extending | stretching part 5 is not limited to the method mentioned above, For example, as disclosed in Unexamined-Japanese-Patent No. 2008-23775, by simultaneous biaxial stretching, You may diagonally stretch. In addition, simultaneous biaxial stretching is holding the width direction both ends of the long film supplied with each holding | gripping tool, conveying a long film, moving each holding | gripping tool, and making the conveyance direction of a long film constant, It is a method of extending | stretching a long film in the diagonal direction with respect to the width direction by making the movement speed of one holding | gripping tool different from the moving speed of the other holding | gripping tool. In addition, you may diagonally stretch by the method as disclosed by Unexamined-Japanese-Patent No. 2011-11434.

(Expanding the width of the film in the heat fixing step)

FIG. 3: has shown typically the shape of the film which passes the extending | stretching part 5 of FIG. As shown to the same figure, the width | variety of the diagonal stretched film after completion | finish of diagonal stretch in extending zone Z2, and before width expansion is called L1, and the diagonal stretched film before width expansion in heat fixing zone Z3 (heat fixing process). The widths of the portions that are wider on the preceding side and the delaying side than the portions corresponding to the width L1 are referred to as L2 and L3 respectively. In addition, the said preceding side refers to the holding | gripping tool Ci side which runs relatively early among a pair of holding | gripping tool Ci * Co holding both ends of a film, and the delaying side is the holding | gripping tool Co side which runs relatively delayed. Point to. In addition, all the units of L1, L2, and L3 shall be mm.

In this embodiment, in the heat fixing process after completion | finish of a diagonal stretch process, width expansion is performed with respect to a diagonal stretched film so that the following conditional formula (1) may be satisfied. In other words,

L3 > L2 &gt; (One)

to be.

FIG. 4: has shown typically the mode in which the rib-shaped residual stress is relaxed when the diagonal stretched film is expanded in heat fixing zone Z3. The film obliquely stretched in the stretching zone Z2 enters the thermal fixation zone Z3, but at this time, since the front side enters the thermal fixation zone Z3 before the retardation side, the shrinkage of the film starts from the preceding side and is in the vicinity of the width direction center part. Until the residual stress T of the rib shape occurs. However, since the film is extended in the width direction by widening the film in the thermal fixing zone Z3, the residual stress in the rib shape generated in the thermal fixing zone Z3 is relaxed and does not remain in the film.

Thus, in the heat fixing process after completion | finish of a diagonal stretch process, width expansion is performed with respect to a diagonal stretched film, and it can suppress that a rib-shaped residual stress arises in a film after diagonal stretch. Thereby, the circularly-polarizing plate mentioned later is comprised using the produced diagonal stretched film, and this circularly-polarizing plate is applied to OLED (organic EL image display apparatus), and even if it puts OLED in a temperature and humidity environment different from normal, It can suppress that display nonuniformity appears.

In addition, the predetermined direction of the optical axis (ground axis) oriented in a predetermined direction by oblique stretching by satisfying the conditional expression (1), that is, increasing the width width of the film on the delay side from the preceding side. It is possible to hardly generate a deviation from the edge, and to suppress the occurrence of the rib-shaped residual stress.

That is, in widening a diagonal stretched film, when the preceding side is enlarged too much, the film is stretched in the direction in which the preceding side is widened (the direction toward the lower right in FIG. 4), whereby the direction of the optical axis of the film is shifted. There is a case. For example, when the orientation angle of the film orientated in the direction of 45 degrees with respect to the width direction expands the preceding side too much, it will become small at 44 degrees.

On the other hand, the retardation side of the film tends to be smaller in the original orientation angle (due to the bowing phenomenon), and the direction of widening the retardation side (the direction toward the upper left in FIG. 4) represents the orientation angle of the retardation side (for example, Since it is the direction which enlarges from 44 degrees to 45 degrees, even if the delay side is expanded larger than the preceding side, it does not interfere, but it is preferable because an orientation direction becomes close to a predetermined direction.

Thus, by satisfy | filling the conditional formula (1), it can suppress that an optical axis shift | deviates from a predetermined direction (for example, the direction of 45 degrees with respect to the width direction) in the leading side and the retardation side of a film. Thereby, even if it expands width | variety in a film at a heat fixing process, the optical axis can be fixed to a predetermined direction and the diagonal stretched film which has a desired orientation characteristic can be obtained.

In this embodiment, it is preferable to satisfy | fill the following conditional formula (2) further. In other words,

5%> B> A ≧ 0%. (2)

only,

A = (L2 / L1) × 100

B = (L3 / L1) × 100

to be.

When the ratio B becomes 5% or more, the width-expanded width of the delay side becomes too large, and the optical characteristic value adjusted in the stretching zone changes in accordance with the thermal fixation zone stretching, resulting in deterioration of uniformity. For this reason, by satisfy | filling 5%> B, the residual stress of a rib shape and uniformity can be made compatible. Moreover, by satisfying B> A≥0%, at least the retardation side of a film can be expanded more than the preceding side, and it can suppress that a rib-shaped residual stress arises in a film after diagonal stretch.

Moreover, by cooling a diagonal stretched film in a heat fixing process, the optical axis provided by diagonal stretch in a diagonal stretch process can be fixed reliably. For this reason, in a heat fixing process, it is preferable to expand a diagonal stretched film width | variety at the temperature 10 degreeC-60 degreeC lower than the extending | stretching temperature in a diagonal stretch process, More preferably, the temperature lower than 20 degreeC-50 degreeC is good.

Moreover, when the said ratio B is less than 1%, the width | variety expansion width of a delay side becomes small, and the effect by the width expansion of a film, ie, the effect of suppressing generation | occurrence | production of the residual stress of a rib shape, becomes small. Moreover, when the ratio B is larger than 4%, the effect of extending | stretching in a heat setting zone will become strong, and the level of uniformity will fall. Therefore, it is preferable that it is 4% ≥B≥1% from a viewpoint of avoiding the fall of the level of uniformity, ensuring the effect by the width expansion of a film reliably.

In addition, when the preceding side of the film is enlarged in width, the film is stretched to the preceding side, so that the orientation angle of the film given in the oblique stretching step may be changed (smaller). For this reason, L2 = 0mm may be sufficient as the width L2 of the width expansion part of the film of a preceding side.

Moreover, when a diagonal stretched film contains the cellulose-ester type resin with high moisture permeability and hygroscopicity, an orientation angle tends to fluctuate by water absorption. For this reason, as mentioned above, the method of this embodiment which expands the retardation side of a film larger than a preceding side in a heat fixing process, and suppresses generation | occurrence | production of the residual stress of a rib shape by suppressing the fluctuation | variation of an orientation angle by this, It becomes very effective when a diagonal stretched film contains cellulose ester-type resin.

<Quality of Long Slant Stretched Film>

In the elongate diagonal stretched film obtained by the manufacturing method of this embodiment, the orientation angle | corner (theta) is inclined in the range which is larger than 0 degree and less than 90 degree with respect to a winding direction, for example, in the width direction in the width of at least 1300 mm. It is preferable that the variation of the in-plane retardation Ro is 2 nm or less, and the variation of the orientation angle θ is less than 0.6 °. Moreover, it is preferable that the in-plane retardation value Ro (550) of the said elongate diagonal stretched film measured in wavelength 550nm exists in the range of 80 nm or more and 160 nm or less, and it is further in the range of 90 nm or more and 150 nm or less. desirable.

That is, in the elongate diagonal stretched film obtained by the manufacturing method of this embodiment, the variation of in-plane retardation Ro is 2 nm or less in at least 1300 mm of the width direction, and it is preferable that it is 1 nm or less. By making the fluctuation of in-plane retardation Ro into the said range, when a long diagonal stretched film is bonded to a polarizer and made into a circularly polarizing plate, when this is applied to an organic EL image display device, the color nonuniformity by the leakage of the external light reflection light at the time of black display Can be suppressed. Moreover, when using a long diagonal stretched film as a retardation film for liquid crystal display devices, it becomes possible to make display quality favorable.

Moreover, in the elongate diagonal stretched film obtained by the manufacturing method of this embodiment, the fluctuation | variation of orientation angle | corner (theta) is less than 0.6 degrees, it is preferable that it is less than 0.4 degrees or less, and is less than 0.2 degrees in at least 1300 mm of the width direction. Is most preferred. When the long inclined stretched film whose variation in the orientation angle θ exceeds 0.6 ° is bonded to the polarizer to form a circularly polarizing plate, and this is installed in an image display device such as an organic EL display device, light leakage occurs and the contrast of light and dark is reduced. It may be made.

The in-plane retardation Ro of the elongate diagonal stretched film obtained by the manufacturing method of this embodiment selects an optimal value according to the design of the display apparatus used. The Ro is a value obtained by multiplying the difference between the refractive index nx in the in-plane slow axis direction and the refractive index ny in the direction orthogonal to the slow axis in the plane by the average thickness d of the film (Ro = (nx-ny) × d) to be.

The average thickness of the elongate diagonal stretched film obtained by the manufacturing method of this embodiment is 1-400 micrometers, Preferably it is 10-200 micrometers, More preferably, it is 10-60 micrometers, Especially preferably, from a viewpoint of mechanical strength etc. Is 15 to 45 µm. Moreover, since the thickness nonuniformity of the width direction of the said elongate diagonal stretch film affects the provision of winding, it is preferable that it is 2 micrometers or less, and it is more preferable that it is 1 micrometer or less.

The elongate diagonal stretched film obtained by the manufacturing method of this embodiment may have a functional layer on the surface. Examples of the functional layer include an antireflection layer, a low refractive index layer, a hard coat layer, a light scattering layer, a light diffusion layer, an antistatic layer, a conductive layer, an electrode layer, a birefringence layer, a surface energy adjusting layer, a UV absorbing layer, a colorant layer, a water resistant layer, and a specific gas barrier. A layer, a heat resistant layer, a magnetic layer, an antioxidant layer, an overcoat layer, etc. can be considered.

Circular Polarizer

In the circular polarizing plate of the present embodiment, a polarizing plate protective film, a polarizer, and a λ / 4 film are laminated in this order, and the angle formed between the slow axis of the λ / 4 film and the absorption axis (or transmission axis) of the polarizer is 45 °. . When the circularly polarizing plate of this embodiment is used for an organic EL display device, the polarizing plate protective film, the polarizer, and the λ / 4 film are the protective film 313, the polarizer 311, and the λ / 4 film 316 of FIG. 5. Corresponds to each. In this embodiment, it is preferable that a long polarizing plate protective film, a long polarizer, and a long (lambda) / 4 film (long diagonal stretched film) are laminated | stacked and formed in this order.

In addition, when the circularly-polarizing plate of this embodiment is used for a liquid crystal display device, the said polarizing plate protective film, a polarizer, and (lambda) / 4 film are the protective film 506 of FIG. 6, the polarizer 501, and the (lambda) / 4 film (503). Respectively). The protective film 506 and the polarizer 501 are arrange | positioned on the outer side (viewing side) of the display cell 401, and (lambda) / 4 film 503 further outside (on the viewing side) of the polarizer 501 Since it is arrange | positioned, the linearly polarized light radiate | emitted from the display cell 401 and transmitted through the polarizer 501 is converted into circularly polarized light or elliptical polarized light in (lambda) / 4 film 503. Therefore, when the observer attaches polarized sunglasses and observes the display image of the display device 400, even when observing at any angle (the transmission axis of the polarizer 501 (perpendicular to the absorption axis) and the transmission of the polarized sunglasses No matter how the axis is shifted), the component of light parallel to the transmission axis of the polarized sunglasses can be guided to the observer's eye to observe the display image, and the display image can be suppressed from being difficult to see depending on the angle of observation.

The circularly polarizing plate of this embodiment can be manufactured by bonding together the structure of (lambda) / 4 film / polarizer using what extended | stretched polyvinyl alcohol doped with iodine or a dichroic dye as a polarizer. The film thickness of a polarizer is 5-40 micrometers, Preferably it is 5-30 micrometers, Especially preferably, it is 5-20 micrometers.

A polarizing plate can be produced by a general method. It is preferable that the (lambda) / 4 film processed by alkali saponification is bonded to one surface of the polarizer which immersed and stretched the polyvinyl alcohol-type film in the iodine solution using the fully saponified polyvinyl alcohol aqueous solution.

The polarizing plate can be further comprised by bonding a release film to the opposite surface of the polarizing plate protective film of the said polarizing plate. A protective film and a peeling film are used for the purpose of protecting a polarizing plate at the time of a polarizing plate shipment, a product inspection, etc.

<Organic EL display device>

5 is a cross-sectional view showing a schematic configuration of an organic EL display device 100 as an OLED of the present embodiment. In addition, the structure of the organic electroluminescence display 100 is not limited to this.

The organic EL display device 100 is configured by forming the circular polarizing plate 301 on the organic EL element 101 via the adhesive layer 201. The organic EL element 101 has the metal electrode 112, the light emitting layer 113, the transparent electrode (ITO etc.) 114, and the sealing layer 115 in order on the board | substrate 111 using glass, polyimide, etc. Consists of. In addition, the metal electrode 112 may be comprised from the reflection electrode and the transparent electrode.

The circular polarizing plate 301 is a λ / 4 film 316, an adhesive layer 315, a polarizer 311, an adhesive layer 312, a protective film 313, and a cured layer 314 in this order from the organic EL element 101 side. ) Is laminated, and the polarizer 311 is sandwiched by the λ / 4 film 316 and the protective film 313. The circularly polarizing plate is bonded to each other so that the angle formed between the transmission axis of the polarizer 311 and the slow axis of the λ / 4 film 316 including the elongated diagonal stretched film of the present embodiment is about 45 ° (or 135 °). 301 is configured.

It is preferable that the hardening layer 314 is laminated | stacked on the said protective film 313. The cured layer 314 not only prevents surface scratches of the organic EL display device 100, but also has an effect of preventing warping by the circular polarizing plate 301. In addition, an antireflection layer may be formed on the cured layer 314. The thickness of the organic EL element 101 itself is about 1 μm.

In the above configuration, when a voltage is applied to the metal electrode 112 and the transparent electrode 114, electrons are injected into the light emitting layer 113 from the electrode serving as the cathode among the metal electrode 112 and the transparent electrode 114. Holes are injected from the electrode serving as the anode, and both are recombined in the light emitting layer 113, whereby light emission of visible light corresponding to the light emission characteristics of the light emitting layer 113 occurs. The light generated in the light emitting layer 113 is directly or reflected by the metal electrode 112, and then is extracted to the outside through the transparent electrode 114 and the circular polarizing plate 301.

In general, in an organic EL display device, an element (organic EL element) that is a light emitting body is formed by stacking a metal electrode, a light emitting layer, and a transparent electrode in order on a transparent substrate. Here, a light emitting layer is a laminated body of various organic thin films, For example, the laminated body of the hole injection layer containing a triphenylamine derivative etc., and the light emitting layer containing fluorescent organic solids, such as anthracene, and such a light emitting layer and perylene The structure which has various combinations, such as the laminated body with the electron injection layer containing a derivative | guide_body, etc., these laminated bodies of a hole injection layer, a light emitting layer, and an electron injection layer, is known.

In an organic EL display device, holes and electrons are injected into a light emitting layer by applying a voltage to a transparent electrode and a metal electrode, and energy generated by recombination of these holes and electrons excites a fluorescent material, and the excited fluorescent material is based on It emits light on the principle of emitting light when returning to the state. The mechanism of intermediate recombination is the same as that of a general diode, and as can be expected from this, the current and the emission intensity exhibit strong nonlinearity accompanied by rectification with respect to the applied voltage.

In the organic EL display device, at least one electrode must be transparent in order to extract light from the light emitting layer, and a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is usually used as an anode. On the other hand, in order to easily inject electrons and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and metal electrodes such as Mg-Ag and Al-Li are usually used.

In the organic EL display device having such a configuration, the light emitting layer is formed of an extremely thin film having a thickness of about 10 nm. For this reason, the light emitting layer also transmits light almost completely like the transparent electrode. As a result, light incident on the surface of the transparent substrate during non-emission, and reflected by the metal electrode through the transparent electrode and the light emitting layer again comes out to the surface side of the transparent substrate. The display surface looks like a mirror.

The circularly polarizing plate of the present embodiment is suitable for an organic EL display device in which such external light reflection is particularly problematic.

That is, at the time of non-emission of the organic EL element 101, the external light incident from the outside of the organic EL element 101 by indoor lighting or the like is half absorbed by the polarizer 311 of the circular polarizing plate 301, and the rest is absorbed. Half is transmitted as linearly polarized light, and is incident on the λ / 4 film 316. Since the transmission axis of the polarizer 311 and the slow axis of the λ / 4 film 316 intersect at 45 ° (or 135 °), the light incident on the λ / 4 film 316 is λ / 4. The light is converted into circularly polarized light by passing through the film 316.

The circularly polarized light emitted from the λ / 4 film 316 is inverted in phase by 180 degrees when specularly reflected by the metal electrode 112 of the organic EL element 101, and is reflected as circularly polarized light of reverse rotation. The reflected light is converted into linearly polarized light perpendicular to the transmission axis of the polarizer 311 (parallel to the absorption axis) by being incident on the λ / 4 film 316, so that all of the reflected light is absorbed by the polarizer 311 and emitted to the outside. Will not be. That is, the circularly polarizing plate 301 can reduce external light reflection in the organic EL element 101.

<Liquid crystal display device>

6 is a cross-sectional view showing a schematic configuration of a display device 400 as a liquid crystal display device of the present embodiment. The display device 400 is configured by arranging the polarizing plate 402 on one surface side of the display cell 401.

The display cell 401 can consider the liquid crystal cell which pinched the liquid crystal layer between a pair of board | substrates. In addition, although the polarizing plate 402 and the other polarizing plate arrange | positioned in the cross nicol state and the backlight which illuminates a liquid crystal cell are provided in the opposite side to the polarizing plate 402 with respect to the liquid crystal cell, in FIG. 6, those illustration was abbreviate | omitted. .

In addition, the display device 400 may have the front window 403 on the side opposite to the display cell 401 with respect to the polarizing plate 402. The front window 403 serves as an exterior cover of the display device 400, and is formed of, for example, cover glass. Between the front window 403 and the polarizing plate 402, the filler 404 which consists of ultraviolet curable resin, for example is filled. In the absence of the filler 404, since an air layer is formed between the front window 403 and the polarizing plate 402, the display is reflected by the reflection of light at the interface between the front window 403 and the polarizing plate 402 and the air layer. The visibility of an image may fall. However, since the air layer is not formed between the front window 403 and the polarizing plate 402 by the filler 404, a decrease in the visibility of the display image due to the reflection of light at the interface can be avoided.

The polarizing plate 402 has a polarizer 501 which transmits predetermined linearly polarized light. On one surface side (opposite side of the display cell 401) of the polarizer 501, the λ / 4 film 503 and the cured layer 504 containing an ultraviolet curable resin are disposed in this order via the adhesive layer 502. Are laminated. In addition, the protective film 506 is bonded to the other surface side (display cell 401 side) of the polarizer 501 via the adhesive layer 505.

The polarizer 501 is obtained by, for example, dyeing a polyvinyl alcohol film with a dichroic dye and stretching the film at high magnification. After the polarizer 501 is alkali treated (also referred to as saponification), the λ / 4 film 503 is bonded to one surface side via the adhesive layer 502, and the protective film 506 is bonded to the other surface side. Bonded via 505.

If the thickness of the polarizer 501 is B 占 퐉, the thickness of the polarizing plate 402 is reduced.

1 μm <B ≦ 20 μm

Is preferably,

1 μm <B ≦ 15 μm

More preferably.

Although the adhesive layer 502 * 505 is a layer containing polyvinyl alcohol adhesive (PVA adhesive, water glue), for example, the layer containing an ultraviolet curable adhesive (UV adhesive) may be sufficient. These adhesives are liquid in the state apply | coated to an adhesive surface, and they adhere | attach both by hardening by drying or ultraviolet irradiation after application | coating. That is, the adhesive layer 502 * 505 adhere | attaches the polarizer 501, (lambda) / 4 film 503, the polarizer 501, and the protective film 506, respectively, by the state change from a liquid phase. Thus, since the adhesion layers 502 * 505 adhere | attach both by the state change from a liquid phase, the adhesive layer (sheet-shaped adhesion layer which has an adhesive on a base material) adheres together without causing such a change of state, and Is different.

(lambda) / 4 film (503) is a layer which gives the in-plane phase difference of about 1/4 of a wavelength with respect to transmitted light, and contains cellulose-type resin (cellulose-type polymer), for example in this embodiment. In addition, (lambda) / 4 film (503) may contain polycarbonate resin (polycarbonate polymer) instead of a cellulose polymer, and may contain cycloolefin resin (cycloolefin polymer). . However, from the viewpoint of chemical resistance, it is preferable that the λ / 4 film 503 contains a cellulose polymer or a polycarbonate polymer.

(lambda) / 4 film (503) is a thin film (lambda) / 4 film whose thickness is 10 micrometers-70 micrometers. In addition, the angle (intersection angle) which the slow axis of the (lambda) / 4 film 503 and the absorption axis of the polarizer 501 make is 30 degrees-60 degrees, whereby linearly-polarized light from the polarizer 501 is (lambda) It is converted into circularly polarized or elliptical polarized light by the / 4 film 503.

The hardened layer 504 (also called a hard coat layer) is comprised from active energy ray hardening-type resin (for example, ultraviolet curable resin).

The protective film 506 is comprised with the optical film containing a cellulose resin (cellulosic polymer), an acrylic resin, cyclic polyolefin (COP), polycarbonate (PC), for example. The protective film 506 is merely provided as a film for protecting the back side of the polarizer 501, but may be provided as an optical film that also serves as a retardation film having a desired optical compensation function.

Moreover, in the case of a liquid crystal display device, the other polarizing plate arrange | positioned on the opposite side to the polarizing plate 402 with respect to the display cell 401 (liquid crystal cell) is comprised by sandwiching the surface of a polarizer with two optical films, The said polarizer And as an optical film, the thing similar to the polarizer 501 and the protective film 506 of the polarizing plate 402 can be used.

Here, the above-mentioned polarizer 501 and the λ / 4 film 503 may each have an elongated shape. In this case, it is preferable that the slow axis of the (lambda) / 4 film (503) inclines 30 degrees-60 degrees with respect to the longitudinal direction of the (lambda) / 4 film (503). In this case, an elongate λ / 4 film 503 is produced by oblique stretching to form a roll-shaped film, which is bonded to the roll-shaped polarizer 501 by a so-called roll-to-roll method to form an elongated shape. Polarizing plate 402 can be produced. Therefore, compared with the case where the polarizing plate 402 is produced by the batch type which bonds a piece of film one by one, productivity is remarkably improved and a yield can also be improved significantly.

Moreover, the easily bonding layer for improving the adhesiveness of the (lambda) / 4 film (503) may be provided in the contact bonding layer 502 side of (lambda) / 4 film (503). The easily bonding layer is formed by performing an adhesion facilitating treatment on the adhesive layer 502 side of the λ / 4 film 503. Examples of the adhesion facilitating treatment include corona treatment (discharge) treatment, plasma treatment, flame treatment, estro treatment, glow treatment, ozone treatment, primer coating treatment, and the like, but at least one of these may be performed. Of these adhesion facilitation treatments, from the viewpoint of productivity, corona treatment and plasma treatment are preferred as the adhesion facilitation treatments.

<Example>

Hereinafter, the Example which is a specific example regarding manufacture of the diagonal stretched film in this embodiment is demonstrated, also giving a comparative example. In addition, this invention is not limited to a following example. In addition, although the notation of "part" or "%" is used below, unless otherwise indicated, these shall represent a "mass part" or "mass%."

[Production of fabric film]

By the following method, the long films 1-2 as a raw film were produced.

(Long film 1)

The long film 1 is a cellulose ester-type resin film, and it produced by the following manufacturing methods.

`` Particle dispersion ''

11 parts by mass of fine particles (Aerosil R972V Nippon Aerosil Co., Ltd. product)

Ethanol 89 parts by mass

After stirring and mixing the above for 50 minutes with a dissolver, it disperse | distributed with manton Gaulin and prepared the microparticle dispersion liquid 1.

≪Particulate additives≫

Based on the following composition, the said fine particle dispersion was added slowly, stirring sufficiently to the dissolution tank containing methylene chloride. In addition, the particle size of the secondary particles was dispersed with an attritor so as to have a predetermined size. This was filtered by FineMet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle addition liquid 1.

 Methylene chloride 99 parts by mass

 5 parts by mass of fine particle dispersion

≪Main dope liquid≫

The main dope liquid of the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. It injected | threw-in stirring the cellulose acetate to the pressure dissolution tank containing a solvent. It melt | dissolves completely, heating this, stirring, and this is Azumi filter paper No. of Azumi Roshi Corporation. Filtration was carried out using 244 to prepare a main dope liquid. In addition, the compound synthesize | combined by the following synthesis examples was used for the sugar ester compound and the ester compound.

<< composition of main dope liquid >>

 Methylene chloride 340 parts by mass

Ethanol 64 parts by mass

100 mass parts of cellulose acetate propionate (acetyl group substitution degree 1.50, propionyl group substitution degree 0.90, total substitution degree 2.40)

5.0 parts by mass of a sugar ester compound

5.0 parts by mass of ester compound

1.5 mass parts of ultraviolet absorbers

1 part by mass of fine particle addition liquid

<< synthesis of sugar ester compound >>

The sugar ester compound was synthesize | combined by the following processes.

To the four heads of the cobenbene equipped with a stirring device, a reflux condenser, a thermometer and a nitrogen gas introduction tube, 34.2 g (0.1 mol) of sucrose, 180.8 g (0.6 mol) of benzoic anhydride and 379.7 g (4.8 mol) of pyridine were added thereto under stirring. The temperature was raised while bubbling nitrogen gas through a nitrogen gas introduction tube, and esterification reaction was performed at 70 ° C for 5 hours.

Next, the inside of the corbene was decompressed to 4 × 10 ² Pa or less, and excess pyridine was distilled off at 60 ° C., and then the inside of the benbene was reduced to 1.3 × 10 Pa or less, and the temperature was raised to 120 ° C., benzoic anhydride and the resulting benzoic acid. Most of was distilled off.

Finally, water was added to 100g at a separated toluene layer and washed with water at room temperature for 30 minutes, to obtain a toluene layer, and distilling off toluene under reduced pressure (4 × 10 ² or less Pa), 60 ℃, compound A- A mixture (sugar ester compound) of 1, A-2, A-3, A-4 and A-5 was obtained.

The resulting mixture was analyzed by HPLC and LC-MASS, whereby 1.3% by mass of A-1, 13.4% by mass of A-2, 13.1% by mass of A-3, 31.7% by mass of A-4 and 40.5% of A-5. %. Average substitution degree was 5.5.

<< measurement conditions of HPLC-MS >>

1) LC part

Equipment: Nippon Bunco Co., Ltd. column oven (JASCO CO-965), detector (JASCO UV-970-240nm), pump (JASCO PU-980), degasser (JASCO DG-980-50)

Column: Inertsil ODS-3 particle diameter of 5 μm 4.6 × 250 mm (manufactured by GE Science Co., Ltd.)

Column temperature: 40 ℃

Flow rate: 1ml / min

Mobile phase: THF (1% acetic acid): H ₂ O (50:50)

Injection volume: 3 μl

2) MS part

Device: LCQ DECA (manufactured by Thermo Quest Co., Ltd.)

Ionization Method: Electrospray Ionization (ESI) Method

Spray Voltage: 5㎸

Capillary temperature: 180 ° C

Vaporizer Temperature: 450 ℃

`` Synthesis of ester compound ''

The ester compound was synthesize | combined with the following process.

251 g of 1,2-propylene glycol, 278 g of phthalic anhydride, 91 g of adipic acid, 610 g of benzoic acid, and 0.191 g of tetraisopropyl titanate as an esterification catalyst were placed in a 2 L four-necked flask equipped with a thermometer, agitator, and a completion cooling tube. The temperature is gradually increased while stirring until it reaches 230 ° C in the nitrogen stream. The ester compound was obtained by dehydrating condensation reaction for 15 hours, and depressurizingly distilling unreacted 1, 2- propylene glycol at 200 degreeC after completion | finish of reaction. The ester compound has ester of benzoic acid at the terminal of the polyester chain formed by condensation of 1,2-propylene glycol, phthalic anhydride and adipic acid. The acid value of the ester compound was 0.10 and the number average molecular weight was 450.

Then, using an endless belt casting apparatus, it was cast uniformly on the stainless steel belt support body.

In the endless belt casting apparatus, the main dope liquid was uniformly cast on the stainless steel belt support. On the stainless steel belt support, the solvent is evaporated until the amount of the residual solvent in the cast (long cast) film is 75%, peeled off from the stainless steel belt support, and the drying is terminated while being conveyed by a large number of rolls to obtain a width of 1500 mm. Long film 1 was obtained.

(Long film 2)

Long film 2 is a cycloolefin resin film (COP), and was produced by the following production method.

In a nitrogen atmosphere, 1.2 parts by mass of 1-hexene, 0.15 parts by mass of dibutyl ether, and 0.30 parts by mass of triisobutylaluminum were mixed in a reactor at room temperature, mixed with 500 parts by mass of dehydrated cyclohexane, and then maintained at 45 ° C. 20 parts by mass of cyclo [4.3.0.12,5] deca-3,7-diene (dicyclopentadiene, hereinafter abbreviated as DCP), 1,4-methano-1,4,4a, 9a-tetrahydrofluorene ( Hereinafter, a norbornene-based monomer mixture comprising 140 parts by mass of MTF, and 40 parts by mass of 8-methyl-tetracyclo [4.4.0.12,5.17,10] -dodeca-3-ene (hereinafter, abbreviated as MTD); , 40 parts by mass of tungsten hexachloride (0.7% toluene solution) was continuously added over 2 hours to polymerize. 1.06 mass parts of butylglycidyl ethers and 0.52 mass part of isopropyl alcohols were added to the polymerization solution, the polymerization catalyst was inactivated, and the polymerization reaction was stopped.

Subsequently, 270 parts by mass of cyclohexane is added to 100 parts by mass of the reaction solution containing the obtained ring-opened polymer, and 5 parts by mass of a nickel-alumina catalyst (manufactured by Nikki Shokubai Kasei Co., Ltd.) is added as a hydrogenation catalyst. It heated to the temperature of 200 degreeC, stirring at 5 Mpa, stirring, and made it react for 4 hours, and obtained the reaction solution containing 20% of DCP / MTF / MTD ring-opening polymer hydrogenated polymer.

After removing the hydrogenation catalyst by filtration, a soft polymer (manufactured by Kuraray Co .; Septon 2002) and an antioxidant (manufactured by Ciba Specialty Chemical Co .; Irganox 1010) were added and dissolved in the obtained solution, respectively ( 0.1 mass part per 100 mass parts of polymers of all). Subsequently, cyclohexane and other volatile components, which are solvents, were removed from the solution by using a cylindrical concentrated dryer (manufactured by Hitachi Seisakusho Co., Ltd.), the hydrogenated polymer was extruded from the extruder into a strand shape in a molten state, and cooled. It was then pelletized and recovered. The copolymerization ratio of each norbornene-based monomer in the polymer was calculated by the residual norbornene composition (by gas chromatography) in the solution after polymerization, which was almost equivalent to the charged composition at DCP / MTF / MTD = 10/70/20. It was. The weight average molecular weight (Mw) of this ring-opening polymer hydrogenated product was 31,000, molecular weight distribution (Mw / Mn) was 2.5, the hydrogenation rate was 99.9%, and Tg was 134 degreeC.

The pellet of the obtained ring-opened polymer hydrogenated substance was dried at 70 degreeC for 2 hours using the hot air dryer which distribute | circulated air, and water was removed. Subsequently, the pellet was subjected to a single screw extruder having a T-die of a coat hanger type (manufactured by Mitsubishi Chigogyo Co., Ltd .: screw diameter 90 mm, T die lip material is tungsten carbide and peel strength with molten resin 44 N). Melt extrusion molding produced a cycloolefin polymer film. Extrusion molding obtained the long film 2 of width 1500mm in the shaping | molding conditions of melt resin temperature 240 degreeC and T die temperature 240 degreeC in the clean room of class 10,000 or less.

[Production of inclined stretched film]

The elongate film 1 containing the cellulose resin manufactured above was obliquely stretched by the extending | stretching part 5, and the elongate diagonal stretched film was obtained (refer Examples 1-4 of Table 1, and Comparative Examples 1-2). At this time, the moving speed of the film was 15 m / min, the temperature of the preheating zone Z1 was 196 ° C, the temperature of the stretching zone Z2 was 196 ° C, the temperature of the heat fixing zone Z3 was 188 ° C, the stretching ratio was 1.16 times, and the thickness was increased. 40 micrometers and the final film width after trimming were made to be 1300 mm.

In addition, in manufacture of the diagonal stretched film of Examples 1-4, the width expansion of the diagonal stretched film was performed in heat setting zone Z3. That is, the width | variety of the long diagonal stretched film after completion | finish of diagonal stretch and before width expansion in heat fixing zone Z3 is called L1 (mm), and corresponds to the width L1 of the diagonal stretched film before width expansion in a heat fixing process. The width | variety of the part extended width to the front side and the retardation side rather than the part is L2 (mm) and L3 (mm), When the width | variety inclination stretched film is made so that width L1, width L2, and width L3 become the values shown in Table 1, respectively. Enlarged. In addition, Table 1 also describes the ratio A and the ratio B which are represented by the following formula | equation. In particular, in manufacture of the diagonal stretched film of Example 2, the temperature in heat setting zone Z3 was adjusted to temperature 30 degreeC lower than the temperature in extending zone Z2.

A = (L2 / L1) × 100

B = (L3 / L1) × 100

In addition, in manufacture of the diagonal stretched film of the comparative example 1, the width expansion in the heat setting zone Z3 was not performed. On the other hand, in manufacture of the diagonal stretched film of the comparative example 2, the width | variety expansion of the diagonal stretched film was performed in extending zone Z2 instead of heat setting zone Z3. At this time, in the stretched zone Z2, the width of the elongated diagonal stretched film before the width expansion is called L1 (mm), and the width of the portion which is wider on the front side and the delay side than the portion corresponding to the width L1 of the diagonal stretched film before the width expansion. Were denoted L2 (mm) and L3 (mm), respectively.

In addition, the original film (long film 2) containing COP was also diagonally stretched in the same manner to the above. That is, first, both ends of the unstretched film A sent from the film feeding part 2 in the vicinity of the front of the heating zone Z, the first clip as the gripper Ci on the front side and the second clip as the gripper Co on the delay side It was gripped with. In addition, when holding the unstretched film A, the unstretched film A is gripped by moving the clip levers of a 1st, 2nd clip by a clip closure. In the case of holding the clip, the both ends of the unstretched film A are simultaneously gripped by the first and second clips, and the grip line is connected so that the lines connecting the grip positions at both ends are parallel to the axis parallel to the width direction of the film. do.

Subsequently, the unstretched film A (long film 2) was diagonally stretched by the extending | stretching part 5 mentioned above, and the elongate diagonal stretched film was obtained (refer Example 5 of Table 1, the comparative example 3). That is, while conveying while holding the unstretched film A held by the 1st, 2nd clip, it heats by passing the preheating zone Z1, the drawing zone Z2, and the heat fixing zone Z3 in the heating zone Z, and about the width direction The stretched film A 'extended | stretched in the diagonal direction was obtained.

At this time, in manufacture of the diagonal stretched film of Example 5, the diagonal stretched film was widened so that width L1, width L2, and width L3 might be the values shown in Table 1 in heat setting zone Z3. On the other hand, in manufacture of the diagonal stretched film of the comparative example 3, width magnification was performed in extending zone Z2 instead of heat setting zone Z3. In addition, the definition of the width L1, the width L2, and the width L3 in the comparative example 3 is the same as the definition in the comparative example 2 which expanded similarly in extending zone Z2.

In addition, the film moving speed in the case of heating and extending | stretching was 15 m / min. Moreover, the temperature of the preheating zone Z1 was 147 degreeC, the temperature of the extending zone Z2 was 147 degreeC, and the temperature of the heat fixing zone Z3 was 140 degreeC. In addition, the draw ratio of the film before and after extending | stretching was 1.16 times, and it was made so that the film thickness after extending | stretching might be 50 micrometers.

[Production of Circular Polarizing Plates 1 to 8]

Circularly polarizing plates 1-8 were produced as follows using the elongate diagonal stretched film diagonally stretched on the conditions similar to the above.

That is, a polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature 110 ° C., draw ratio 5 times), immersed for 60 seconds in an aqueous solution containing 0.075 g of iodine, 5 g of potassium iodide, and 100 g of water, followed by iodization. It was immersed in the aqueous solution of 68 degreeC containing 6 g of potassium, 7.5 g of boric acid, and 100 g of water. The film after immersion was washed with water and dried, and the polarizer was obtained.

Subsequently, the long diagonal stretched films of Examples 1 to 5 and Comparative Examples 1 to 3 produced were bonded to one side of the polarizer using 5% aqueous polyvinyl alcohol as an adhesive. At that time, it bonded together so that the transmission axis of a polarizer and the slow axis of a diagonal stretched film might be 45 degrees. And Konica Minolta tag film KC4UAH (made by Konica Minolta Co., Ltd.) which gave alkali saponification process to the other surface of the polarizer was bonded similarly, and circular polarizing plates 1-8 were produced.

[Production of Circular Polarizing Plates 11 to 18]

Circularly polarizing plates 11-18 were produced as follows using the elongate diagonal stretched film diagonally stretched on the conditions similar to the above.

That is, a polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature 110 ° C., draw ratio 5 times), immersed for 60 seconds in an aqueous solution containing 0.075 g of iodine, 5 g of potassium iodide, and 100 g of water, followed by iodization. It was immersed in the aqueous solution of 68 degreeC containing 6 g of potassium, 7.5 g of boric acid, and 100 g of water. The film after immersion was washed with water and dried, and the polarizer was obtained.

Subsequently, the long diagonal stretched films of Examples 1 to 5 and Comparative Examples 1 to 3 produced were bonded to one side of the polarizer using 5% aqueous polyvinyl alcohol as an adhesive. At that time, it bonded together so that the transmission axis of a polarizer and the slow axis of a diagonal stretched film might become 45 degrees. And on the other side of the polarizer, the Konica Minolta tag film KC2CT1 (made by Konica Minolta Co., Ltd.) which carried out the alkali saponification process was bonded similarly, and circular polarizing plates 11-18 were produced.

[Production of Organic EL Display Devices 1 to 8]

The reflective electrode containing chromium of thickness 80nm was formed into a film by the sputtering method on the glass substrate. Next, ITO (indium tin oxide) was formed into a film by thickness of 40 nm on the reflective electrode by sputtering. Subsequently, poly (3,4-ethylenedioxythiophene) -polystyrenesulfonate (PEDOT: PSS) was formed into a film at a thickness of 80 nm by sputtering on the anode as a hole transporting layer. Then, each light emitting layer of RGB was formed in the film thickness of 100 nm using the shadow mask on the hole transport layer.

In addition, calcium was formed into a film with a thickness of 4 nm as a first cathode having a low work function by which electrons can be efficiently injected onto the light emitting layer by a vacuum deposition method. Thereafter, aluminum was formed into a film with a thickness of 2 nm on the first negative electrode as the second negative electrode. Here, aluminum used as a 2nd negative electrode has a role which prevents chemical deterioration of calcium which is a 1st negative electrode when forming the transparent electrode formed on it by sputtering. The organic light emitting layer was obtained as mentioned above.

Next, the transparent conductive film was formed into a film by thickness of 80 nm by the sputtering method on the cathode. ITO was used here as a transparent conductive film. In addition, silicon nitride was formed into a film by a CVD method (chemical vapor deposition method) on a transparent conductive film, and it was set as the insulating film. This produced the organic electroluminescent element. The size of the produced organic EL device was 1296 mm x 784 mm.

On the insulating film of the organic electroluminescent element produced above, circularly polarizing plates 1-8 produced as mentioned above are fix | immobilized with an adhesive so that the surface of a diagonal stretched film may face the surface of the insulating film of organic electroluminescent element. As a result, organic EL display devices 1 to 8 were produced.

[Production of Liquid Crystal Display Devices 1 to 8]

<< production of liquid crystal display device >>

The polarizing plate of the visual recognition side which was previously bonded of the commercially available 10-inch liquid crystal display device was peeled off, and the above-mentioned circularly polarizing plates 11-18 were bonded together with an adhesive so that the surface of Konica Minolta tack film KC2CT1 may face the surface of a liquid crystal cell. Thus, liquid crystal display devices 1 to 8 were produced. In addition, bonding of circularly polarizing plates 11-18 was performed so that the polarizer absorption axis of circularly polarizing plates 11-18 may face the same direction as the polarizer absorption axis of the polarizing plate previously bonded.

[Quantitative evaluation]

In order to investigate the fluctuation | variation of the orientation angle of the manufactured film in the width direction, the orientation angle of the width direction was made into the following with respect to the diagonal stretched film produced by the method similar to Examples 1-5 and Comparative Examples 1-3 of Table 1. It measured by the method and calculated | required the left-right difference of an orientation angle. That is, after leaving the diagonal stretched film in the room of 23 degreeC 55% RH for 24 hours, 10 pieces of film pieces were cut out in the conveyance direction from 30 mm inside from the tip of the diagonal stretched film. And about each film piece, the orientation angle is measured in each position of the width direction using a phase difference measuring apparatus (Oji Keisoku Co., Ltd. product, KOBRA-WXK), and the average of ten pieces of the difference of the left-right orientation angle is calculated | required, , The obtained average value was made into the difference of left-right orientation angle. And the orientation angle nonuniformity of the width direction was quantitatively evaluated based on the following evaluation criteria.

"Evaluation standard"

A: The difference in left-right orientation angle is less than 0.3 degrees.

B: The difference between the left and right orientation angles is 0.3 ° or more and less than 0.6 °.

C: The difference in left-right orientation angle is 0.6 degree or more and less than 0.8 degree.

D: The difference in left-right orientation angle is 0.8 degrees or more.

[Sensory evaluation]

The produced organic EL display devices 1 to 8 and the liquid crystal display devices 1 to 8 were placed in an environment of 60 ° C. 90% RH for 500 hours, and then allowed to stand for 24 hours in an environment of 23 ° C. 55% RH. A black screen was displayed on the screen, and the color display state was visually observed and evaluated based on the following criteria. In addition, about the liquid crystal display devices 1-8, it observed with the eyes in the state which attached polarized sunglasses, and evaluated based on the following criteria.

<Evaluation Criteria>

A: The screen was uniformly displayed in black, and color unevenness due to uneven amount of reflected light was not observed.

B: A little stripe irregularity was observed at the end of the screen, but this is a practically problem-free level.

C: Light streaks of unevenness were observed throughout the screen.

D: Stripe irregularities were observed throughout the screen.

Table 1 has shown the result of evaluation about the diagonal stretched film of Examples 1-5 and Comparative Examples 1-3.

From Table 1, in Comparative Example 1 in which the film was not expanded, both the quantitative evaluation and the sensory evaluation were not good (the evaluation was all D), and the comparison was also performed in Comparative Examples 2 and 3 in which the film was expanded in the diagonal stretching step. Although quantitative evaluation is higher than Example 1, since the evaluation is C or D, it cannot be said that it is favorable. In contrast, in Examples 1 to 5 in which the film is expanded in the heat fixing step after the diagonal stretching, both the quantitative evaluation and the sensory evaluation are good (the evaluation is A or B). This can suppress generation | occurrence | production of the rib-shaped residual stress in the film after diagonal stretch, by widening a width | variety with respect to the diagonal stretched film in the heat fixing process after diagonal stretch, and especially the delay side at the time of diagonal stretch It is considered that by widening the width larger than the preceding side, it is possible to suppress the occurrence of the rib-shaped residual stress in the film with little variation in the optical axis oriented in the predetermined direction by oblique stretching.

Particularly, as in Examples 3 to 5, when the ratio B is smaller than 4%, since the quantitative evaluation is the best with A, such width enlargement (setting of the width L1 and the width L3) is preferable. have. In addition, as in Examples 4 to 5, when the width L2 of the width extension of the preceding side is 0 mm, both the quantitative evaluation and the sensory evaluation are the best in A, so that the width expansion is performed at L2 = 0 mm. It can be said that it is more preferable.

The manufacturing method of the diagonal stretched film of this embodiment demonstrated above can be expressed as follows.

1. The film is conveyed in an inclined direction with respect to the width direction by holding the two grippers relatively in advance and holding the other grippers with relative delay, while holding both ends in the width direction of the film with a pair of grippers. It is a manufacturing method of the diagonal stretched film which has the diagonal stretch process to extend,

It further has a heat fixing process for fixing the optical axis of the said diagonal stretched film after completion | finish of the said diagonal stretch process,

In the said heat fixing process, width enlargement is performed with respect to the said diagonal stretched film after completion | finish of the said diagonal stretch process,

The width | variety of the said diagonal stretched film after completion | finish of diagonal stretch and before width expansion is called L1, and in the said heat fixing process, it expanded width to the front side and the delay side rather than the part corresponded to the width L1 of the said diagonal stretched film before width expansion. When the width | variety of a part is said to L2 and L3, the manufacturing method of the diagonal stretched film characterized by the following conditional formula (1);

L3 > L2 &gt; (One)

to be.

2. It satisfies the following conditional formula (2) further, The manufacturing method of the diagonal stretched film of 1 characterized by the above-mentioned;

5%> B> A ≧ 0%. (2)

only,

A = (L2 / L1) × 100

B = (L3 / L1) × 100

to be.

3. In the heat fixing step, the inclined stretched film is widened at a temperature 10 ° C to 60 ° C lower than the stretching temperature in the inclined stretching step, wherein the inclined stretched film according to 1 or 2 described above. .

4. 4% ≥B≥1%

It is a manufacturing method of the diagonal stretched film of 2 characterized by the above-mentioned.

5.L2 = 0mm

The manufacturing method of the diagonal stretched film in any one of said 1-4 characterized by the above-mentioned.

6. Film diagonally stretched by the said diagonal stretch process contains cellulose-ester type resin, The manufacturing method of the optical film in any one of said 1-5 characterized by the above-mentioned.

The present invention can be used, for example, in the manufacture of circularly polarizing plates for preventing external light reflection of organic EL image display devices.

1: Manufacturing apparatus of diagonal stretched film
5: drawing
Ci: grip
Co: grip

Claims (6)

The film is stretched in an inclined direction with respect to the width direction by holding the two grippers relatively in advance and relatively slowing the other gripper to convey the film while holding both ends of the film in the width direction. It is a manufacturing method of the diagonal stretched film which has a diagonal stretch process,
It further has a heat fixing process for fixing the optical axis of the said diagonal stretched film after completion | finish of the said diagonal stretch process,
In the said heat fixing process, width expansion is performed with respect to the said diagonal stretched film after completion | finish of the said diagonal stretch process at the temperature 10 degreeC-60 degreeC lower than the extending | stretching temperature in the said diagonal stretch process,
The width | variety of the said diagonal stretched film after completion | finish of diagonal stretch and before width expansion is called L1, and in the said heat fixing process, it expanded width to the front side and the delay side rather than the part corresponded to the width L1 of the said diagonal stretched film before width expansion. When the width | variety of a part is L2 and L3, respectively, the following conditional formula (1) is satisfied, The manufacturing method of the diagonal stretched film characterized by the above-mentioned.
L3 > L2 &gt; (One) The method for producing an inclined stretched film according to claim 1, further satisfying the following conditional formula (2);
5%>B> A ≧ 0%. (2)
only,
A = (L2 / L1) × 100
B = (L3 / L1) × 100
to be. delete The method of claim 2, wherein 4% ≥B≥1%
The manufacturing method of the diagonal stretched film characterized by the above-mentioned. The method according to claim 1 or 2, wherein L2 = 0 mm
The manufacturing method of the diagonal stretched film characterized by the above-mentioned. The manufacturing method of the diagonal stretched film of Claim 1 or 2 in which the film diagonally stretched in the said diagonal stretch process contains cellulose-ester type resin.

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