KR20130110085A - Rubbing treatment method and optical film manufacturing method - Google Patents

Abstract

PURPOSE: A rubbing treatment method and a method for manufacturing an optical film are provided to reduce the difference of optical properties by using a packaging material that comprises a pulp cloth and a pile yarn. CONSTITUTION: A packaging material comprises a pulp cloth and a pile yarn (4). A pulp cloth consists of warp and weft. The pulp cloth is woven from pile yarn. A sea part (100) is made of EVA. An island part (110) is made of a resin.

Description

Rubbing treatment method and manufacturing method of optical film {RUBBING TREATMENT METHOD AND OPTICAL FILM MANUFACTURING METHOD}

TECHNICAL FIELD This invention relates to the rubbing process method and the manufacturing method of an optical film. Specifically, It is related with the rubbing process method and the manufacturing method of an optical film which are used when manufacturing the optical compensation film of a liquid crystal display device, etc.

In recent years, the development of a liquid crystal display device advances, and the liquid crystal display device is spreading worldwide. Various optical films are used for a liquid crystal display device. Among them, a film to which orientation is imparted by a rubbing treatment such as an orientation film or an optical compensation film is performed, and these play an important role.

The viewing angle improvement film which is one of the films provided with these orientation is generally apply | coated and dried an alignment film formation material on the surface of the strip-shaped flexible support body (henceforth "a web") made of transparent resin, and forms the resin layer for orientation film formation. After that, the surface is subjected to a rubbing treatment to form an alignment film. And it is manufactured by apply | coating and drying a liquid crystalline coating liquid on an oriented film, forming a liquid crystal layer, and hardening after that.

A rubbing process is typical of the orientation processing method of a liquid crystal molecule, The rubbing roller which formed (film forming) the film of the orientation film formation material on the web surface, and wound the surface of this alignment film formation material around the rubbing cloth By rubbing by rotating.

As such a rubbing treatment method, Patent Document 1 includes a paper fabric composed of warp and weft yarns and pile yarns woven into the paper fabric, and the pile yarns cover a resin coating material on the surface of the filament. The rubbing processing method using the rubbing cloth formed by this is disclosed.

Thereby, even if a film is lengthened, it is said that the optical compensation film which has little deviation of an optical characteristic and has a low frequency of bright spots can be manufactured.

Japanese Unexamined Patent Publication No. 2010-204173

However, the rubbing treatment method described in Patent Literature 1 has a problem that the oscillation is still small.

In view of such a situation, the present invention is to provide a rubbing treatment method capable of having good orientation and a reduction in oscillation and a method of manufacturing an optical film.

The subject of this invention can be solved by each following invention.

That is, the rubbing treatment method of the present invention is a rubbing treatment method for imparting orientation to an alignment film forming material, and includes a step of rubbing the surface of the alignment film forming material with a wrapping material, and the wrapping material is a paper cloth structure composed of a warp and a weft yarn. And a pile yarn incorporated in the zippo tissue, and the pile yarn has a main island structure.

As a result, since the pile yarn has a sea island structure, a rubbing treatment with good orientation and reduced oscillation is possible.

In addition, the rubbing treatment method of the present invention is characterized in that the pile yarn is formed of EVA and the seam is formed of a resin selected from PET, PBT and nylon.

Thereby, the rubbing process by which orientation was favorable and reduced oscillation is attained.

Moreover, in the rubbing processing method of this invention, in the cross section perpendicular | vertical to the longitudinal direction of a pile yarn, it is the main thing that the ratio which the area of a sea part occupies is 50%-67%, and the ratio which the area of a drawing part occupies is 50%-33%. It features.

Thereby, the rubbing process by which orientation was favorable and reduced oscillation is attained.

Moreover, the rubbing process method of this invention has the principal feature that the islands structure of a pile yarn is a structure which has three or more island parts.

Thereby, the rubbing process by which orientation was favorable and reduced oscillation is attained.

The rubbing treatment method of the present invention is characterized in that the tensile modulus of the pile yarn is 0.1 × 10 ¹¹ to 2.0 × 10 ¹¹ Pa.

Thereby, the rubbing process by which orientation was favorable and reduced oscillation is attained.

Moreover, the manufacturing method of the optical film of this invention performs the process of forming the film | membrane of the orientation film formation material in a support body, and the rubbing process of the surface of the said film of the said orientation film formation material formed in the said support body by any one of the above-mentioned rubbing treatment methods. It is a main feature of what is equipped with the process to make.

Thereby, orientation is favorable and an oscillation can be reduced and an optical film can be manufactured.

Oscillation can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the manufacturing line of an optical film.
2 is a partially enlarged perspective view of the rubbing cloth 1.
3 is an explanatory diagram for explaining an internal structure of a pile yarn.
It is explanatory drawing which shows the installation place of a particle counter.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail, referring an accompanying drawing. Here, the part shown with the same symbol in the figure is the same element which has the same function. In addition, when showing a numerical range using "-" in this specification, the numerical value of the upper limit and lower limit shown by "-" shall also be included in a numerical range.

<Production method of optical film>

EMBODIMENT OF THE INVENTION One Embodiment of the manufacturing method of the optical film which concerns on this invention is described with reference to drawings. 1: is explanatory drawing which shows the manufacturing line of an optical film.

The optical film manufacturing method which concerns on this invention mainly comprises the process of forming (film forming) the film | membrane of the orientation film formation material in the web which is a support body, and the process of carrying out the rubbing process method of the surface of the film of the orientation film formation material formed in the web.

In detail with reference to FIG. 1, the web 16 which is a transparent support body is sent out from the feeder 66. FIG. The web 16 is guided by the guide roller 68, and removes dust adhering to the surface of the web 16 by passing through the vibration damper 15A. As the vibration damper 15A, various known types can be adopted. For example, the structure which removes the dust adhering to the surface of the web 16 by spraying the compressed air (nitrogen gas) electrostatically damped to the surface of the web 16 can be employ | adopted.

A bar coating device 11A is formed downstream of the web traveling direction (hereinafter simply referred to as a downstream) of the vibration damper 15A, and a coating liquid containing an alignment film forming material is applied to the web 16. In addition, the coating apparatus is not limited to the bar coating apparatus, and various coating apparatuses such as gravure coater, roll coater (transfer roll coater), reverse roll coater, etc.), die coater, extrusion coater, fountain coater, curtain coater, A dip coater, spray coater or slide hopper can be employed.

Downstream of the bar coating device 11A, a drying zone 76A and a heating zone 78A are sequentially formed, and an alignment film forming material layer is formed on the web 16.

After application and drying of the coating liquid, the web 16 is guided by the guide roller 68 and sent to the rubbing processing apparatus 70. The rubbing rollers 72A (72B) are formed to perform a rubbing treatment on the alignment film forming material layer. A vibration damper 71A 71B is formed upstream of the rubbing roller 72A 72B to remove dust adhering to the surface of the web 16.

The rubbing processing apparatus 70A (70B) is a device for performing a rubbing treatment on the polymer layer, and has a two-stage roller configuration by the rubbing rollers 72A, 72B in this example. In addition, as the rubbing processing apparatus 70, a single-stage roller configuration can also be adopted.

The rubbing processing apparatus 70A (70B) is a device for rotating and driving a rubbing roller 72A (72B) in which a rubbing cloth is wound on the outer circumferential surface, and the rotational speed thereof is, for example, about 1000 rpm. Can be controlled. The shape of the rubbing rollers 72A (72B) is, for example, an outer diameter of 150 mm, and can be made into a roller shape that is slightly longer than the width of the web 16 even in a state in which the length has given a rubbing angle. Moreover, the rubbing processing apparatus 70A (70B) is able to rotate freely in a horizontal plane with respect to the running direction of the web 16 so that it may adjust to arbitrary rubbing angles.

The roller stage 84A (84B) is formed above the rubbing roller 72A (72B), and the backup roller 86A (86B), (a spring is provided in the lower surface of this roller stage 84A (84B) through a spring. 88A (88B) is mounted so that it can rotate freely. The backup rollers 86A (86B) and 88A (88B) are equipped with a mechanism for detecting the tension of the web 16, and can manage the tension during rubbing.

In addition, the back up rollers 86A (86B) and 88A (88B) can be adjusted up and down, and can move the roller up and down to adjust the lap angle with respect to the rubbing roller 72A (72B) of the web 16. .

With the above configuration, the web 16 is pressed by the rubbing roller 72A (72B) pressed from the lower side while the web 16 is pressed from the top by the backup rollers 86A (86B) and 88A (88B). The surface of the orientation film formation material layer of the surface (lower surface) is rubbed, and the orientation film provided with the orientation is formed.

The vibration damper 15B is formed downstream of the rubbing processing apparatus 70 to remove dust adhering to the surface of the web 16.

Downstream of the vibration damper 15B, a bar coating device 11B is formed, and a coating liquid containing a discomatic liquid crystal is applied to the web 16. As the coating device 11B, various coating devices can be used similarly to the case where the coating liquid containing the alignment film forming material is applied to the web 16.

Downstream of the bar coating apparatus 11B, the drying zone 76B and the heating zone 78B are formed in order, and the liquid crystal layer is formed on the web 16. FIG. In addition, an ultraviolet lamp 80 is formed downstream of this, and the liquid crystal is crosslinked by ultraviolet irradiation to form a desired polymer. Then, a web (on which a polymer is formed by a winding machine 82 formed by the winding machine 82, which is inspected by the inspection device 84, and the protective film 88A fed out from the laminate group 88, is laminated on the web 16. 16) is wound up.

In this embodiment, the manufacturing line 10 whole of an optical film, especially bar coating apparatus 11A, 11B may be installed in clean atmosphere, such as a clean room. In that case, class 1000 or less is preferable, class 100 or less is more preferable, and class 10 or less is more preferable.

<Rubbing cloth>

Next, the rubbing cloth 1 which is a characteristic part of this invention is demonstrated. 2 is a partially enlarged perspective view of the rubbing cloth 1.

(1) Outline of rubbing cloth

The rubbing cloth 1 is formed by incorporating the pile yarn 4 into a bubble 5 in which the warp yarn 2 of the paper cloth structure and the weft yarn 3 of the paper cloth structure are woven into a lattice shape. . Among these, like the rubbing cloth 1 shown in FIG. 2 (A), the pile yarn 4 woven into the three weft yarns 3 is called a W structure, and the rubbing cloth shown in FIG. 2 (B). As in (1), the pile yarn 4 incorporated into one weft yarn 3 is called a V structure. W structure and V structure differ only in the method of weaving of pile yarn 4, and the material used can use the same material.

Examples of the bubbles 5 include polyamides such as nylon 6 and 6 (registered trademark), polyesters such as polyethylene terephthalate, polyolefins such as polyethylene, polyvinyl alcohol, polyvinylidene chloride and poly Synthetic fibers such as acryl-based, polyvinylidene-based, polyfluoroethylene-based and polyurethane-based, such as vinyl chloride, polyacrylonitrile, acrylamide and methacrylamide, silk, cotton, wool, cellulose and cellulose ester The fiber which combined 1 type (s) or 2 or more types chosen from natural fiber, such as natural fiber and recycled fiber (rayon, acetate, etc.) is mentioned.

In these fiber materials, Preferably, polyamide type, such as nylon 6 and nylon 6 * 6 (trademark), acrylic type, such as polyacrylonitrile, acrylamide, and methacrylamide, polyester type, such as polyethylene terephthalate, And cellulose-based, cellulose-ester-based rayon and acetate as regenerated fibers.

It is preferable that the warp yarn 2 and the weft yarn 3 of the bubble 5 are used in a state where, for example, 1.4 denier fibers are combined from 70 pieces and become about 100 denier filaments (long continuous fibers). . As such a warp yarn 2 and a weft yarn 3, for example, cupra rayon manufactured by Asahi Chemical Co., Ltd. (registered trademark of Asahi Chemical Co., Ltd. of this product is Schönberg) can preferably be used.

(2) About file companies

Next, a pile yarn which is the most characteristic part of this invention is demonstrated with reference to drawings. 3 is an explanatory diagram for explaining an internal structure of a pile yarn.

As shown in Fig. 3, the pile yarn 4 of the rubbing cloth has a fiber cross-sectional structure and has PET (polyethylene terephthalate) and PBT (polyethylene) in the anatomy 100 formed of EVA (ethylene vinyl acetate). A dove 110 formed of butylene terephthalate), nylon, or the like exists. The conductive portion 110 is continuously present in the longitudinal direction of the pile yarn 4.

Although the sea island structure here means that there is at least 2 or more islands, it is preferable that there are 3 or more islands, it is more preferable that it is 7 or more, and it is most preferable that it is 15 or more. The reason is as follows. In other words, the shrinkage of pile yarns is easy to occur due to the difference in thermal expansion coefficient of the island and the anatomy, but by arranging the trenches evenly in three cross-sections, tension due to the difference of the coefficient of thermal expansion occurs in part of the pile yarn, This is because it can prevent the cause.

In the case where there is only one groove, the tensile stress caused by the difference in thermal expansion rate can be released by arranging the groove at the center of the cross section, but it is difficult to completely arrange the center at the center of the pile yarn throughout the longitudinal direction. A slight shift from the pile yarn causes shrinkage of the pile yarn.

However, in the case of three or more islands, even if the position of the islands fluctuates slightly randomly in the longitudinal direction, random swings between different islands release tensile stresses due to differences in thermal expansion coefficients, thereby preventing pile yarns from shrinking. can do.

This effect is more remarkable as there are more parts, and according to the research of the present inventors, it is preferable that there are 3 or more parts, it is more preferable that it is 7 or more, and it is most preferable that it is 15 or more.

By rubbing using the rubbing cloth provided with the pile yarn 4 which has such an island-in-water structure, the rubbing process with little dust generation and which can provide favorable orientation can be performed.

<Evaluation>

Next, the rubbing process was performed using various kinds of rubbing materials, and the orientation, oscillation property, and printing of the alignment film were evaluated. The rubbing cloth used for evaluation differs only in a pile company, and a paper fabric organization is common.

Below, it shows about the pile yarn used for evaluation.

Comparative Example 1: A core portion having a core portion of PET in the center and an EVA portion around the periphery thereof, and having an area ratio in the fiber cross section (cross section perpendicular to the length direction) is EVA: PET = 50.

Comparative Example 2: The core portion was provided with a core portion of PET at the center and an EVA portion around the periphery thereof, and the area ratio in the fiber cross section (cross section perpendicular to the length direction) was EVA: PET = 67: 33. that.

Comparative Example 3: One consisting of PET alone.

Comparative Example 4: One composed of EVA alone.

Comparative Example 5: Rayon alone.

Example 1: A seam structure having an anatomical part of EVA and a seam part of PET is provided, and the area ratio in the fiber cross section (cross section perpendicular to the length direction) is EVA: PET = 50: 50.

Example 2 A seam structure having an anatomical portion of EVA and a seam portion of PET is provided, and the area ratio in the fiber cross section (cross section perpendicular to the length direction) is EVA: PET = 67: 33.

Example 3: A seam structure having an anatomical part of EVA and a drawing part of PBT is provided, and the area ratio in the fiber cross section (cross section perpendicular to the length direction) is EVA: PBT = 50: 50.

Example 4 A sea-island structure having an anatomical portion of EVA and a seam portion of nylon, wherein the area ratio in the fiber cross section (cross section perpendicular to the length direction) is EVA: nylon = 50: 50.

<< evaluation method of irregularities of the pile yarn surface >>

The electron microscope manufactured by Nippon Electronics Co., Ltd. was used for evaluation of the unevenness | corrugation of the pile yarn surface. In this apparatus, the magnification was 2000 times, and the unevenness was evaluated by focusing on the surface of one pile yarn.

<< evaluation method of shrinkage of pile company >>

The electron microscope manufactured by Nippon Electronics Co., Ltd. was used for evaluation of the unevenness | corrugation of the pile yarn surface. In this apparatus, the magnification was made 100 times, and the shrinkage was evaluated by focusing on the whole pile yarn.

<< Evaluation method of orientation by extinction degree >>

Otsuka Electronics Co., Ltd. quenching degree measuring apparatus was used for evaluation of the orientation by quenching degree. In this apparatus, the measurement wavelength was 550 nm, and the transmittance of the paranichol polarizing plate was 100%. And the orientation of the two discotic liquid crystals arrange | positioned by the cross nicol was evaluated. In addition, paranicol means that the angle which the transmission axis of a polarizer and an analyzer makes is 0 degree, and cross nicol means that the angle which the transmission axis of a polarizer and an analyzer makes is 90 degree.

About oscillation property, as shown in FIG. 4, rubbing process is performed by rubbing the side in which the orientation film formation material of the web 16 was formed, rotating the rubbing material 1 wound by the roller 120 in the arrow direction, The particle counter HANDHELD3016 by Lighthouse was provided in the measuring point (A) upstream and the measuring point (B) on the upstream side of the web 16 at that time, and suspended particles having a particle diameter of 0.3 µm or more. The number of was measured and represented by the relative ratio when the number in the comparative example 1 was made into 100. 4 is an explanatory diagram showing a place where a particle counter is installed.

In addition, the factor is the value which evaluated the number of the bright spot defects of the transparent film after a rubbing process by the bright spot occurrence frequency of the planar inspection apparatus using a CCD camera, and it showed by the relative ratio when making Comparative Example 1 into 1.

Below, the table which put together evaluation conditions and evaluation results is shown.

Here, the criteria of each evaluation result are as follows.

Unevenness on the surface of pile yarn: excellent (without unevenness), not possible (with unevenness)

Pile yarn shrinkage: Excellent (no shrinkage), impossible (with shrinkage)

Orientation: Excellent (the orientation of the alignment film at the end compared to the start of the rubbing treatment is almost the same and passed), possible (the passability of the alignment film at the time of finishing as compared with the start of the rubbing treatment is slightly worse, the pass line), impossible (rubbing treatment) The alignment property of the alignment film at the time of completion compared with the start time worsens, and orientation uniformity in a rubbing process cannot be maintained for a long time, and it fails)

Oscillation: Excellent (0 to 50), Possible (51 to 250), Impossible (251 or more)

Factors: excellent (0 to 0.50), possible (0.51 to 2.50), impossible (2.51 to)

Comprehensive evaluation: Excellent (all evaluations are excellent), possible (no one is possible, no possible is included), no (not even one is included)

As the evaluation result shows, all the Examples 1-4 which have an island-in-water structure became excellent comprehensive evaluation. From this, it was found that the pile yarn had a sea island structure, so that the orientation of the alignment film was good, the oscillation was small, and the printing could be performed with good rubbing.

Moreover, it turned out that it is preferable that a seam part is formed from EVA and that a seam part is formed from resin chosen from PET, PBT, and nylon as a sea island structure. Moreover, in the cross section perpendicular | vertical to the longitudinal direction of a pile yarn, it turned out that the ratio which the area of an anatomical part occupies is 50%-67%, and the ratio which the area of a drawing part occupies is 50%-33%.

In addition, the present inventors know that in the pile yarn having the island-in-sea structure as described above, the tensile modulus of 0.1 × 10 ¹¹ to 2.0 × 10 ¹¹ GPa is preferable in view of the orientation, oscillation, printing, etc. of the alignment film. Came out.

In this invention, when the pile yarn of a rubbing cloth material has a sea island structure, the mechanism which can provide favorable orientation property to an orientation film formation material is guessed for the following reasons. That is, the pile yarn according to the present invention has less unevenness on the surface of the pile yarn as compared with natural fibers such as rayon and cotton, and crimps (shrinkage) of the pile yarn as a whole compared to the yarn of the EVA coating structure (EVA-based vinegar structure). It is thought that this is because rubbing debris generated at the time of rubbing treatment does not accumulate well in the pile yarn, and the surface state suitable for rubbing treatment can be maintained for a long time.

1: Rubbing Cloth
2: slope
3: weft
4: File company
5: bubble
10: manufacturing line
11A: Bar applicator
11B: Bar Applicator
15A: Vibrator
15B: Vibrator
16: web
66: discharge machine
68: guide roller
70: rubbing processing device
70A: Rubbing Processing Unit
71A: Damper
72A: Rubbing Roller
76A: Dry Zone
76B: Drying Zone
78A: heating zone
78B: heating zone
80: UV lamp
82: winder
84: inspection device
84A: Roller Stage
86A: Backup Roller
88: laminate
88A: Protective Film
100: anatomy
110: Tobu
120: roller
A: measuring point
B: measuring point

Claims (6)

As a rubbing treatment method for imparting orientation to an alignment film forming material,
And rubbing the surface of the alignment film forming material with a wrapping material,
The said cladding material consists of the paper fabric which consists of warp and weft, and the pile yarn which was woven into the paper fabric,
A rubbing treatment method, wherein said pile yarn is a fiber having an island-in-sea structure. The method of claim 1,
The pile yarn is a rubbing treatment method, the anatomical portion is formed of EVA, the conductive portion is formed of a resin selected from PET, PBT, nylon. 3. The method according to claim 1 or 2,
The cross section perpendicular | vertical to the longitudinal direction of the said pile yarn WHEREIN: The rubbing process method whose ratio which the area of an anatomical part occupies is 50%-67%, and the ratio which the area of a drawing part occupies is 50%-33%. 3. The method according to claim 1 or 2,
The rubbing process method of the said pile yarn is a structure which has three or more to-do parts. 3. The method according to claim 1 or 2,
The rubbing treatment method whose tensile elasticity modulus of the said pile yarn is 0.1 * 10 <^11> -2.0 * 10 <^11> Pa. Forming a film of an alignment film forming material on a support;
The manufacturing method of the optical film provided with the process of performing the rubbing process on the surface of the said film | membrane of the oriented film formation material formed in the said support body by the rubbing process method in any one of Claims 1-5.

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