TW201427823A - Flexographic printing plate and manufacturing method thereof and manufacturing method of substrate for liquid crystal panel - Google Patents

Abstract

A flexographic printing plate and a manufacturing method thereof are provided, wherein the flexographic printing plate can reduce frictional wear by distributing a contact pressure between the flexographic printing plate and an anilox roller so that the flexographic printing plate can be used for a long period. A flexographic printing plate 1 roughens a printing surface 2 by letting an average length of roughness curve element RSm to be 0.1 times or more and 0.5 times or less of a formation pitch P<SB>A</SB> in a plane direction of an uneven pattern of a combined anilox roller 4. In the manufacturing method of the flexographic printing plate, a layer of a photosensitive resin composition is formed on a shaping surface which is an underlying of a printing surface, and the layer of a photosensitive resin composition is irradiated by actinic rays to conduct a curing reaction.

Description

Flexible printed board, method of manufacturing the same, and method of manufacturing substrate for liquid crystal panel

The present invention relates to a flexible printed board which can be preferably used for forming a liquid crystal alignment film such as a liquid crystal panel substrate by flexographic printing, a method for producing the same, and a method for producing a liquid crystal panel substrate using the flexible printed board .

In order to form a liquid crystal alignment film on the electrode formation surface of the liquid crystal panel substrate, it has been studied to use a printing method, in particular, a flexible printing method.

The liquid crystal alignment film needs to be as uniform as possible in thickness and free from pinholes and the like, and is thin.

Therefore, the printing surface of the flexible printing plate for flexible printing (the surface on which the ink is held at the time of printing) must have high retention of the ink which is the basis of the liquid crystal alignment mold. That is, it is required to have good retention on the printing surface, and even a small amount of ink corresponding to the thickness of the liquid crystal alignment film does not cause perforations or weak spots, and can be kept as uniform as possible over the entire surface of the printing surface.

In order to improve the ink retaining property of the printing, the printing surface may have a concave-convex shape and the specific surface area may be increased to improve the wettability of the printing surface with respect to the ink.

For example, Patent Document 1 and Patent Document 2 describe the case where the printing surface is on the printing surface. A plurality of minute protrusions having a geometrical planar shape such as a circle are provided, whereby the printing surface is formed into a concave-convex shape by using a plurality of minute protrusions and a groove portion therebetween, thereby improving the wetting of the printing surface with respect to the ink. Sex.

Further, in Patent Document 1 and Patent Document 2, it is described that the wettability can be arbitrarily controlled for each region in the printing surface by making the size, distribution, arrangement, and the like of the surface direction of the microprotrusions different. .

The minute protrusions are formed by, for example, a photo lithography method. In other words, a layer of a photosensitive resin composition which is a basis of a flexible printed board is prepared, and is exposed in a state in which a mask is superposed on a layer of the photosensitive resin composition, and the mask is formed with a small The negative film or the positive film of the fine pattern (such as a dot pattern) corresponding to the planar shape of the protrusion is selectively cured after the photosensitive resin composition is selectively patterned corresponding to the mask, and then developed to obtain an uncured photosensitive property. The resin composition is removed, whereby a plurality of minute protrusions are formed.

Further, Patent Document 3 describes that the printing surface is roughened by an arbitrary roughening method such as etching or sandblasting, and the printing surface is finished to have a shape or a small size. When the uneven surface such as a satin surface such as a random irregular protrusion is formed, and the center line average roughness Ra is expressed, the surface roughness of the printing surface is set to be 1 μm to 5 μm.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-293049

[Patent Document 2] Japanese Patent No. 2933790

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2009-34913

In the flexible printing, for example, the ink is supplied to the printing surface of the flexible printed board wound on the board main body via a textured [ANILOX (registered trademark) roll having a concave-convex pattern on the outer peripheral surface, and the printed surface of the flexible printed board is made The predetermined printing contact is applied to the printing surface such as the electrode forming surface of the liquid crystal panel substrate, whereby an ink pattern corresponding to the printing pattern formed on the printing surface is printed on the surface to be printed.

An anilox roller is generally formed of a metal, and a concave-convex pattern on the outer peripheral surface thereof is generally formed into a shape in which a tip end is sharpened, such as a pyramid shape, so that printing of a flexible printed board in contact with an anilox roll is performed by reverse printing. The face is getting worn out.

In order to reduce the wear and prolong the life of the flexible printed board, it is preferable to make the unevenness of the printed surface of the flexible printed board as small as possible to increase the contact amount between the convex portion of the anilox roller and the convex portion of the printing surface, thereby making the two The contact pressure between them is as dispersed as possible.

However, the unevenness of the printing surface formed by the photolithography method is such that the pitch in the surface direction in which the unevenness is not formed due to the limit of the resolution of the mask is 35 μm or less, and there is a problem that the effect of dispersing the contact pressure cannot be sufficiently obtained.

An object of the present invention is to provide a flexible printed board, a method of manufacturing the same, and a method of manufacturing a substrate for a liquid crystal panel using the flexible printed board, which can disperse the contact pressure with the anilox roll to reduce abrasion. It can be used for a long time.

The present invention is a flexible printed board used for flexible printing in which ink is supplied to a flexible printing plate via an anilox roll having a concave-convex pattern on the outer peripheral surface, wherein the flexible printed board is formed as a single side. Printed surface In the flat shape, the printing surface is roughened, and the average length RSm of the roughness curve elements of the printing surface is 0.1 times or more and 0.5 times or less of the forming pitch of the surface of the relief pattern of the anilox roll.

In order to solve the problem, the inventors have studied the pitch of the unevenness in the plane direction of the printing surface described in Patent Document 3, which is not limited by the method of the photolithography method. When the pitch of the surface of the relief roll pattern in the surface direction is small, the contact pressure between the printing surface and the anilox roller is dispersed to reduce the abrasion.

As a result, it was found that the average pitch in the plane direction of the unevenness of the printing surface was determined by Japanese Industrial Standard JIS (Japanese Industrial Standard) B0601:2001 "Geometrical Product Specifications (GPS) - Surface Properties: Outline The average length RSm of the roughness curve elements of the printing surface specified in the curve method - term, definition, and surface property parameter is defined as 0.5 times or less of the formation pitch of the concave-convex pattern of the combined anilox roller, and the texture can be increased. The contact amount of the convex portion of the roller with the convex portion of the printing surface is such that the contact pressure between the two is dispersed as much as possible to reduce the abrasion, thereby prolonging the life of the flexible printed board.

In other words, when the average length RSm of the roughness curve element exceeds 0.5 times the formation pitch of the relief pattern of the anilox roll, the number of contact between the convex portion of the printing surface of the flexible printed board and the convex portion of the anilox roll becomes small. However, the effect of dispersing the contact pressure between the two cannot be obtained. Therefore, as the printing surface is repeatedly printed, the life of the flexible printed board is shortened.

Moreover, since the uneven shape of the printing surface becomes too large, it is made in the ink When the printing surface is transferred to the surface to be printed, the uneven transfer of the ink becomes large. Therefore, there is also a problem in that the ink after transfer cannot be sufficiently smoothed by so-called self-leveling, so that the smoothness of the surface of the liquid crystal alignment film containing the ink is lowered, or the thickness is uneven, and pinholes are generated. Wait.

On the other hand, when the average length RSm of the roughness curve element is less than 0.1 times the formation pitch of the relief pattern of the anilox roll, the uneven shape of the printing surface is too small, and it is not possible to obtain the printing surface relative to the ink by providing the unevenness. The wettability and the effect on the amount of ink retained. Therefore, a liquid crystal alignment film or the like having a uniform thickness and having no pinhole or the like and having a predetermined thickness cannot be formed.

On the other hand, the average length RSm of the roughness curve elements of the average pitch in the plane direction of the unevenness of the printing surface is set to 0.1 times or more and 0.5 of the formation pitch of the surface of the combined anilox roll. Within the range of the following, it is possible to provide a flexible printed board which can form a liquid crystal alignment film or the like having a uniform thickness and no pinholes and the like, and which has a small abrasion and can be used for a long period of time.

The present invention provides a method of manufacturing a flexible printed board, comprising: a step of preparing a profile, the profile comprising a material that is transparent to active light, and a single face formed to correspond to a shape of a printed surface of the flexible printed board a step of forming a layer of a photosensitive resin composition in a shaped area of a profile in such a manner that the photosensitive resin composition is in contact with the shaping surface of the profile; and irradiating the active light through the profile to form a photosensitive resin composition a step of hardening the layer by a hardening reaction; a step of peeling the layer of the cured photosensitive resin composition from the shaping surface of the profile; and forming a layer of the peeled photosensitive resin composition into a flexible printed board step.

According to the present invention, a flexible printed board in which a printing surface is specified to a specific surface state can be produced with high productivity and at low cost.

Preferably, the step of forming the flexible printed board comprises the step of: forming a surface of the photosensitive resin composition from the surface on which the shaping surface of the profile is peeled off (the surface in contact with the shaping surface) as a roughened printing surface And the rough surface of the printing surface other than the area corresponding to the printed pattern is removed by mechanical or heat.

The step of preparing the profile may further include the steps of: preparing a support substrate comprising a hard material and having permeability to the active light; and contacting the surface of the profile opposite to the shaping surface and fixing the surface of the support substrate.

As the photosensitive resin composition to be the basis of the flexible printed board, a prepolymer, a monomer having at least one type of ethylenically unsaturated group, and a photopolymerization initiator can be used.

The present invention relates to a method for producing a substrate for a liquid crystal panel, comprising the steps of forming a liquid crystal alignment film for a liquid crystal panel by flexographic printing using the flexible printed board of the present invention.

According to the present invention, it is possible to manufacture a liquid crystal panel substrate having a liquid crystal alignment film which is uniform in thickness and excellent in reproducibility in thickness and has no pinholes, based on the surface shape of the printing surface described above.

According to the present invention, it is possible to provide a flexible printed board, a method of manufacturing the same, and a method of manufacturing a substrate for a liquid crystal panel using the flexible printed board, which can disperse between the flexible printed board and the anilox roll, compared with the prior art. Reduced by contact pressure Wear and thus can be used for a long time.

1‧‧‧Flexible printing plate

2‧‧‧Printed surface

3, 5‧‧‧ convex

4‧‧‧ anilox roller

6‧‧‧Support substrate

7‧‧‧ surface

8‧‧‧Shaping

9‧‧‧Rough surfaced sheet

10‧‧‧ opposite side

11‧‧‧Photosensitive resin composition

12‧‧‧ reinforcing film

13 ‧ ‧ layer

14‧‧‧ Alignment substrate

15‧‧‧ opposite

16‧‧‧Layer

17‧‧‧Working table

18‧‧‧Ray head

19‧‧‧carbonated gas laser

C‧‧‧Chuck fixture

P _A ‧ ‧ forming spacing

Xs (Xs1, Xs2, Xs3, Xs4...Xsi) ‧‧‧The length of the contour curve element

L ₁ ‧‧‧ length

L ₂ ‧‧‧ size

LB‧‧‧active light

(a) and (b) of FIG. 1 are the positional relationship between the convex portion of the roughened printing surface of the flexible printed board of the present invention and the convex portion of the anilox roll, and the roughness curve element of the printing surface. A schematic diagram illustrating the difference in average length RSm.

(a) and (b) of FIG. 2 are plan views showing a predetermined method of forming a pitch in the surface direction of the uneven pattern in each shape of the anilox roll.

(a) to (c) of Fig. 3 are cross-sectional views for explaining a manufacturing procedure of the flexible printed board.

(a) to (c) of Fig. 4 are cross-sectional views for explaining the subsequent steps of the manufacturing method of Fig. 3.

(a) and (b) of FIG. 5 are cross-sectional views illustrating an example of a method of detachably fixing the roughened sheet to the surface of the flat support substrate.

(a) of FIG. 1 and (b) of FIG. 1 are the positional relationship between the convex portion of the roughened printing surface of the flexible printed board of the present invention and the convex portion of the anilox roll, and the roughness of the printing surface. A schematic diagram illustrating the difference of the curve elements at each average length RSm.

The present invention is a flexible printed board formed into a flat shape and having a single side as a printing surface. Further, the printing surface is roughened, and the average length RSm of the roughness curve elements of the printing surface is 0.1 of the forming pitch of the surface direction of the concave-convex pattern of the combined anilox roll. More than twice and less than 0.5 times.

In the present invention, the roughness curve measured by, for example, a scanning confocal laser microscope is used as the reference length as described in Section 4.3.1 of "JIS B0601:2001""Average length of contour curve elements". The average value of the length Xs of the lower contour curve element is obtained, and the average length RSm of the roughness curve element is obtained by the following formula (1):

According to the present invention, it is possible to provide a flexible printed board which can form a liquid crystal alignment film having a uniform thickness, a pinhole-free surface, and the like, and having a predetermined thickness, by defining the uneven shape of the roughened printing surface as described above. And wear is small and can be used for a long time.

That is, referring to (b) of FIG. 1, the lengths Xs (Xs1, Xs2, ..., Xsi) of the respective convex portions 3 of the printing surface 2 constituting the flexible printed board 1 according to the contour elements are obtained by the above formula (1). When the average length RSm of the roughness curve elements obtained is more than 0.5 times the formation pitch P _A of the surface direction of the concave-convex pattern of the combined anilox roll 4, the convex portion of the printing surface 2 of the flexible printed board 1 3 The number of contact with the convex portion 5 of the anilox roller 4 is small, and the effect of dispersing the contact pressure between the two is not obtained. Therefore, the convex portion 3 constituting the printing surface 2 is worn out by the reverse printing to make the flexible printed board The life of 1 is shortened.

Further, since the size of the uneven surface of the printing surface 2 in the height direction is too large, the transfer unevenness of the ink becomes large when the ink is transferred from the printing surface 2 to the printing surface. Therefore, it is not possible to sufficiently smooth the ink after transfer by so-called self-leveling, and there is a concern that the smoothness of the surface of the liquid crystal alignment film including the ink is lowered, or the thickness is not uniform, and pinholes are generated. .

On the other hand, referring to (a) of FIG. 1, the lengths Xs (Xs1, Xs2, ..., Xsi) of the respective convex portions 3 of the printing surface 2 constituting the flexible printed board 1 according to the contour elements are The average length RSm of the roughness curve elements obtained by the formula (1) is set to be 0.5 or less times the formation pitch P _A of the surface direction of the combined anilox roll 4, and the printed surface of the flexible printed board 1 is printed. When the number of contact between the convex portion 3 of the second portion 2 and the convex portion 5 of the anilox roller 4 is increased, the contact pressure between the convex portions 3 of the anilox roller 4 can be dispersedly received by the plurality of convex portions 3, so that the wear can be reduced and the life of the flexible printed board 1 can be prolonged.

However, if the average length RSm of the roughness curve elements is less than 0.1 times the formation pitch P _A of the surface direction of the concave-convex pattern of the combined anilox roll 4, the size of the uneven shape of the printed surface 2 in the height direction is too small to be obtained. By providing the unevenness, the effect of the wettability of the printing surface 2 with respect to the ink and the amount of ink retained can be improved. Therefore, there has been a problem that a liquid crystal alignment film or the like having a uniform thickness and having no pinhole or the like and having a predetermined thickness cannot be formed.

Therefore, the average length RSm of the roughness curve elements is limited to 0.1 times or more of the formation pitch P _A of the surface direction of the concave-convex pattern of the combined anilox roll 4 . Thereby, a liquid crystal alignment film or the like having a uniform thickness and having no pinholes and the like and having a predetermined thickness can be formed.

Further, in order to further improve the effects, the average length RSm of the roughness curve elements is preferably 0.3 times or more and 0.4 times or less the pitch P _A .

The specific size of the average length RSm is not particularly limited. The size may be set so as to be the predetermined magnification of the formation pitch P _A of the combined anilox roll 4 .

The general formation pitch P _A of the anilox roll 4 is about 21 μm to 141 μm.

Therefore, for example, the average length RSm of the roughness curve elements of the printing surface 2 of the flexible printed board 1 combined with the anilox roll 4 having the pitch P _A of 63.5 μm is set to be in the range of 6.35 μm or more and 31.75 μm or less.

(a) of FIG. 2 and (b) of FIG. 2 are plan views which show the predetermined method of the formation pitch of the surface of the uneven pattern in each shape of the anilox roll 4. FIG.

With reference to (a) of FIG. 2, for example, when the anilox roll 4 is a diamond pattern, the distance between the apexes of the adjacent convex portions 5 in the width direction orthogonal to the circumferential direction is set as described above. The pitch P _A , the diamond pattern of the anilox roll 4 is such that each convex portion 5 constituting the concave-convex pattern is formed into a quadrangular pyramid shape (pyramid shape) having a square bottom surface, and a diagonal line of the bottom surface is oriented toward the anilox roller 4 The circumferential direction (indicated by solid arrows in the drawing) is parallel, and the other diagonal line is arranged at equal intervals in the width direction orthogonal to the circumferential direction.

Further, referring to (b) of FIG. 2, when the anilox roller 4 is a so-called honeycomb pattern, the distance between the apexes of the adjacent convex portions 5 in the direction of 30° in the circumferential direction is set as described above. The pitch P _A , the honeycomb pattern of the anilox roll 4 is formed by forming each convex portion 5 into a hexagonal pyramid having a regular hexagonal surface, and a diagonal line of the bottom surface is oriented to the circumferential direction of the anilox roller 4 (in the figure) The width direction of the orthogonal direction is indicated by the solid arrows, and the other two diagonal lines are arranged at equal intervals in a direction of 30° with respect to the circumferential direction.

Further, although not shown, when the anilox roll 4 is a honeycomb pattern, the distance between the apexes of the adjacent convex portions 5 in the width direction orthogonal to the circumferential direction is defined as the above-described formation pitch P _A . The honeycomb pattern of the anilox roll 4 is such that a diagonal line of the bottom surface of the hexagonal-concave convex portion 5 faces a direction parallel to the circumferential direction of the anilox roll 4, and the other two diagonal lines are respectively oriented toward the circumferential direction. Arranged at equal intervals in a direction of 60°.

In order to make the printing surface 2 of the flexible printed board 1 a concave-convex shape satisfying the range of the average length RSm of the roughness curve element, in the method of manufacturing the flexible printed board of the present invention described below, the profile corresponding to the printing surface 2 is used. The shaped surface may be formed into a concave-convex shape satisfying the above range.

In addition, in order to form the shaped surface into a concavo-convex shape that satisfies the above-described range, the forming surface is formed by roughening the press sheet formed by using an emboss roll as follows, for example. In the case, the outer peripheral surface of the embossing roll may be formed into an uneven shape satisfying the above range.

Specifically, for example, when the embossing roll is a metal roll, the outer peripheral surface thereof is formed into a concavo-convex shape by etching, shot blasting, laser engraving, or the like, and in the case of a rubber roll. The outer peripheral surface is formed into an uneven shape by an impression, polishing, finely mixed material, or the like, and in the case of a resin roll, it is molded, polished, etched, finely mixed, or the like. The outer peripheral surface is formed as Concave shape.

In the case where the outer peripheral surface of the metal roll is formed into a concavo-convex shape by a bead blast, for example, the average length RSm of the roughness curve element is within the above range, and the particle size of the spray powder to be used is controlled. (F600 or more) and the time of the attack.

The flexible printed board of the present invention can be produced by the manufacturing method of the present invention. Thereby, a flexible printed board in which the printing surface is specified to a specific surface state can be manufactured with high productivity and at low cost.

(a) to (c) of FIG. 3, (a) of FIG. 4, and (c) of FIG. 4 are cross-sectional views for explaining the manufacturing steps of the flexible printed board, respectively.

Referring to (a) of FIG. 3, in the manufacturing method of this example, first, a support substrate 6 containing a hard material such as glass or a hard resin such as an acrylic resin, a polycarbonate resin or a polyester resin is prepared. Active light rays such as ultraviolet rays which cause a curing reaction of the photosensitive resin composition are permeable.

Then, a roughened sheet 9 having a roughened surface 8 having a concave-convex shape corresponding to the shape of the printing surface of the flexible printed board is formed as a single surface, and is detachably fixed to the support substrate 6 in the following manner. The surface 7 on the upper side of the figure is such that the forming surface 8 faces upward and the opposite side surface (opposite surface) 10 faces downward, and the opposite surface 10 contacts the surface 7, as shown, for example, in (a) of FIG. The one-dotted line arrow is sequentially overlapped from one end to the other end.

In addition, in the figure, it is easy to understand, and the unevenness of the concave-convex surface 8 is drawn to be large, but the actual unevenness does not affect the shape of the liquid crystal alignment film to be printed, etc., and satisfies the requirements of the present invention. Roughness curve element average length RSm The range of the size is smaller than the size of the roughened sheet 9 shown in the figure.

The roughened sheet 9 is preferably formed by roughening the surface of a sheet having permeability to active light by, for example, press sheet forming using an embossing roll, and the sheet includes For example, polyethylene (PE), polypropylene (PP), thermoplastic polyurethane elastomer (TPU), polyethylene terephthalate (PET), four A thermoplastic resin such as fluorinated ethylene propylene (FEP).

By forming the pressed sheet material, it is possible to easily and continuously produce a large amount of roughened sheet 9 corresponding to, for example, a large-screen liquid crystal display element.

Further, a relatively soft thermoplastic resin such as polyethylene, polypropylene, or a thermoplastic polyurethane elastomer, and a relatively thin (for example, about 150 μm or less) roughened sheet 9 itself have weak adhesion, and sometimes It is difficult to uniformly adhere to the surface 7 of the flat support substrate 6 without wrinkles.

In this case, a reinforcing sheet containing, for example, polyethylene terephthalate or the like and having permeability to active light may be bonded to the opposite surface 10 of the roughened sheet 9.

The roughening sheet 9 prevents the shearing force when the liquid photosensitive resin composition is applied to the roughened sheet 9 or the shrinkage force when the photosensitive resin composition is cured. And the like, resulting in the roughened sheet 9 relative to the support substrate 6 The roughened sheet 9 is easily displaced, and the roughened sheet 9 is preferably detachably fixed by any of the following methods (i) to (iii). On the surface 7 of the support substrate 6.

(i) The surface 7 of the support substrate 6 is detachably adhered and fixed via a weak adhesive layer containing a material transparent to active light.

(ii) A suction groove is formed on the surface of the support substrate, and is detachably attached to the surface by vacuum suction through the suction groove.

(iii) detachably and detachably attached to the surface of the support substrate in a state in which the chuck jig is spaced apart from each other at a position spaced apart from the surface of the support substrate 6.

As the weak adhesive layer used for the adhesive fixing of (i), any adhesive containing a weak adhesiveness to the forming material of the support substrate 6 and the roughened sheet 9 and having permeability to active light can be used. A layer. The weak adhesive layer is formed by applying an adhesive to at least one of the surface 7 of the support substrate 6 and the opposite surface 10 of the roughened sheet 9 by various coating methods such as spraying.

After the weak adhesion layer is formed on the surface 7 of the support substrate 6 and/or the opposite surface 10 of the roughened sheet 9, as shown by the arrow of the one-dot chain line in (a) of FIG. 3, The roughened sheet 9 is self-supporting from one end to the other end of the surface 7 of the support substrate 6 so as not to allow air to enter between the opposite surface 10 and the surface 7 by the weak adhesion layer. The roughened sheet 9 can be fixed to the surface 7 by force.

Also, in order to remove the fixed roughened sheet 9 from the surface 7, as long as Contrary to, for example, the arrow of (a) in FIG. 3, the roughened sheet 9 may be peeled off from the other end of the support substrate 6 toward the one end and the adhesive force against the weak adhesive layer.

When the adsorption fixation of (ii) is performed, the surface 7 of the support substrate 6 is finished to be smooth, and a suction groove is formed on substantially the entire surface of the surface 7. The suction tank is connected to a vacuum system including a vacuum pump or the like.

Then, in a state in which the roughened sheet 9 is superposed on the surface 7 of the support substrate 6 with the opposite surface 10 facing downward, the vacuum system is operated, or the vacuum system that operates first is connected to the suction tank, and the like. The suction groove is vacuum suctioned, whereby the roughened sheet 9 can be fixed to the surface 7.

In order to remove the fixed roughened sheet 9 from the surface 7, it is only necessary to stop the vacuum system or disconnect the vacuum system from the suction tank.

(a) of FIG. 5 and (b) of FIG. 5 are cross-sectional views explaining the method of crimp bonding of (iii).

Referring to (a) of FIG. 5 and (b) of FIG. 5, in the pressure bonding method, for example, a pair of chuck jigs C are prepared, which will correspond to the screen of the liquid crystal display element. The two parallel sides of the roughened sheet 9 formed into a rectangular shape are held over the entire length thereof.

As a roughened sheet 9, to prepare a length L ₁ between the two sides of the same form as compared between the two long-side dimension L ₂ corresponding to a sheet 6 of a rectangular support substrate, the two sides over its entire length by The chuck fixture C is kept. Although not shown, the roughened sheet 9 holds the shaping surface 8 in a state of being oriented toward the upper side of the drawing.

Further, by arranging the chuck jig C at a distance larger than the size L _{2 of the} support substrate 6, it is possible to form a state in which the roughened sheet 9 is unslipped between the two chucks C ( (a)) in Fig. 5.

Then, in this state, when the chuck jig C is moved downward in the drawing, the roughened sheet 9 developed between the chuck jigs C is as shown by the hollow arrow in (a) of FIG. 5 . When the direction of the surface 7 of the support substrate 6 is lowered and pressed against the surface 7 of the support substrate as shown in FIG. 5(b), the roughened sheet 9 can be fixed to the surface 7.

Further, in order to remove the fixed roughened sheet 9 from the surface 7, as long as the roughened sheet 9 is caused by the pair of chuck jigs C, the surface is opposite to the arrow of (a) in Fig. 5 7 Move up.

Referring to (b) of FIG. 3, in the manufacturing method of this example, a predetermined amount is supplied to the shaping surface 8 of the roughened sheet 9 fixed to the surface 7 of the support substrate 6 by any of the above methods. Liquid photosensitive resin composition 11.

Then, the photosensitive resin composition 11 is sandwiched between the roughened sheet 9 and the reinforcing film 12 serving as the reinforcing layer, as shown by the arrow of the one-dot chain line in (b) of FIG. One end of the surface 7 of the support substrate 6 is applied to the other end so as to prevent air from entering between the surface 7 and the roughened sheet 9, and the coating of the roughened sheet 9 is sequentially applied. A layer 13 of a photosensitive resin composition is formed on the surface 8, and a reinforcing film 12 is laminated on the layer 13 of the photosensitive resin composition.

Next, referring to (c) of FIG. 3, the opposite surface 15 of the opposite substrate 14 is made. Contact with the reinforcing film 12.

Then, the opposing surface 15 of the counter substrate 14 is maintained in parallel at a fixed interval between the opposing surface 15 and the surface 7, and is directed to the support substrate 6 as indicated by a solid arrow in FIG. 3(c). The direction is pressed against the counter substrate 14, whereby the layer 13 is pressed against the shaping surface 8 of the roughened sheet 9.

Then, in this state, as shown by the solid arrow in (c) of FIG. 3, the layer 13 is exposed by the active light ray LB through the support substrate 6 and the roughened sheet 9, thereby forming the layer 13 The photosensitive resin composition 11 produces a hardening reaction.

At this time, the interval between the surface 7 of the support substrate 6 and the opposing surface 15 of the counter substrate 14 is maintained at the thickness of the manufactured flexible printed board plus the thickness of the roughened sheet 9.

Further, the counter substrate 14 may be formed of any material such as metal, glass, or hard resin.

In particular, the counter substrate 14 may be formed of the same material that is transparent to the active light as the support substrate 6, and the reinforcing film 12 may be formed of the same material that is transparent to the active light as the roughened sheet 9. Therefore, the layer 13 of the photosensitive resin composition can be exposed from the side of the counter substrate 14 by active light to cause a crosslinking reaction.

Next, referring to (a) of FIG. 4 and (b) of FIG. 4, the reinforcing film 12, the crosslinked layer 13, and the laminated body 16 of the roughened sheet 9 are self-supporting the substrate 6 and the opposite substrate. The 14 is taken out and turned upside down, and the reinforcing film 12 is placed downward on the work table 17.

Then, as shown by the arrow of the one-dot chain line in (b) of FIG. 4, the roughened sheet 9 is sequentially peeled from one end of the laminated body 16 to the other end, and the upper layer of the layer 13 is as shown. On the surface side, a printing surface 13 which is roughened by the uneven shape of the shaping surface 8 of the roughened sheet 9 is transferred.

Then, as shown in FIG. 4(c), a region other than the region corresponding to the printed pattern of the printing surface 2 is irradiated with a carbon dioxide gas 19 or the like while scanning from the laser head 18, thereby utilizing heat. The unevenness of the surface is removed, whereby the printed surface 2 is patterned into a predetermined printed pattern, thereby completing the flexible printed board 1.

As the photosensitive resin composition, various resin compositions can be used, which can be cured by active light such as ultraviolet rays, and can be formed to have a moderate degree suitable for, for example, flexible printing after hardening. The rubber is elastic and is a cured product excellent in solvent resistance to a solvent contained in an ink used for printing or a solvent used for cleaning a printing plate.

The photosensitive resin composition is not limited thereto, and examples thereof include a prepolymer having a 1,2-butadiene structure and having an ethylenic double bond at the terminal, an ethylenically unsaturated monomer, and photopolymerization. Starter, etc.

The photopolymerization initiator is preferably a benzoin alkyl ether, and it is preferable that the content ratio of the benzoin is 500 ppm or less in the total amount of the photosensitive resin composition, and the benzoin is visible light from a fluorescent lamp or the like. The reaction causes the yellowing of the original resin plate for printing. Thereby, a printing resin original plate excellent in light resistance which is not yellowed in a short period of time can be obtained.

As the reinforcing film 12, the following film can be used similarly to the roughened sheet 9. The sheet comprises, for example, polyethylene (PE), polypropylene (PP), thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), tetrafluoroethylene-hexafluoropropylene A thermoplastic resin such as a copolymer (FEP) and having permeability to active light.

The present invention relates to a method for producing a substrate for a liquid crystal panel, comprising the steps of forming a liquid crystal alignment film for a liquid crystal panel by flexographic printing using a flexible printing plate.

According to the present invention, it is possible to manufacture a substrate for a liquid crystal panel having a liquid crystal alignment film which is uniform in thickness and excellent in reproducibility and has no pinhole. Moreover, the wear of the flexible printed board can be reduced based on the surface shape of the printing surface explained above, so that one piece of the flexible printed board can be continuously used over a long period of time compared with the present.

The other steps of the above manufacturing method can be carried out in the same manner as before.

In other words, a transparent electrode layer corresponding to a predetermined matrix pattern or the like is formed on one surface of a transparent substrate such as a soda lime glass substrate, and a liquid crystal alignment film is formed by flexible printing using the flexible printed board of the present invention, and further, as needed The surface of the liquid crystal alignment film is subjected to alignment treatment by rubbing or the like to thereby produce a substrate for a liquid crystal panel.

In addition, two liquid crystal panel substrates are prepared, and the liquid crystal material is sandwiched between the two liquid crystal panel substrates while being aligned with each other, and is further fixed to each other as needed. A polarizing plate is disposed on both outer sides, thereby manufacturing a liquid crystal panel.

The present invention is not limited to the illustrated examples. For example, the reinforcing film 12 may be omitted. Further, instead of applying a layer of the photosensitive resin composition in the direction of the support substrate by the counter substrate, the coating may be spread by a roll of a roughened sheet or the like. The thickness is fixed.

Further, various modifications can be made without departing from the spirit and scope of the invention.

[Examples] <Example 1>

(rough surfaced sheet)

As a roughened sheet, a sheet of a thermoplastic polyurethane elastomer is formed by using a press sheet using an embossing roll [SILKLON (registered trademark) SNESS 80-150 μm manufactured by Ogura Kogyo Co., Ltd.] The surface of the thermoplastic polyurethane elastomer exposed on the opposite side of the surface to which the reinforcing sheet is bonded is roughened to form a shaped surface, and the thermoplastic polyurethane elastomer sheet is formed. A polyethylene terephthalate sheet having a thickness of 100 μm was attached as a reinforcing sheet on one side. The roughened sheet is permeable to ultraviolet rays as active light.

A roughness curve measured by using a scanning confocal laser microscope [LEXT (registered trademark) OLS (registered trademark) 3100 manufactured by Olympus (share), as 4.3 of JIS B0601:2001 The average value of the length Xs of the contour curve element in the reference length is described in the "average length of the contour curve element", and the average length of the roughness curve element of the shaping surface is obtained by the above formula (1). In the case of RSm, the average length RSm of the roughness curve element is 9.0 μm. Further, the reference length was set to 270 μm.

(Manufacture of flexible printed board)

Referring to (a) of FIG. 3 to (c) of FIG. 3, the above roughened sheet 9 is used. The support substrate of the manufacturing apparatus for the printing resin original plate is detachably attached to the printing resin original plate by spraying the adhesive layer so that the shaping surface 8 faces upward and the opposite surface 10 faces downward to bring the opposite surface 10 into contact with the surface 7. On the surface 7 of the film 6, the original resin plate for printing has a transparent transparent glass plate and a counter substrate 14 having ultraviolet ray permeability as the support substrate 6.

Next, a liquid photosensitive resin composition of a predetermined amount of ultraviolet curable liquid is applied to the shaping surface 8 [NK resin manufactured by Sumitomo Rubber Industries Co., Ltd.] 11 and is reinforced on the roughened sheet 9 The layer of the reinforcing film (polyethylene terephthalate film, BF/CF manufactured by Sumitomo Rubber Industries Co., Ltd.) 12 is shown by the arrow of the one-dot chain line in (b) of Fig. 3 Generally, one end of the surface 7 of the self-supporting substrate 6 is paid to the other end in such a manner that air does not enter between the roughened sheet 9 and the surface 7, and the coating is spread on the shaping surface 8 of the roughened sheet 9. On the other hand, the layer 13 of the photosensitive resin composition is formed, and the reinforcing film 12 is laminated on the layer 13 of the photosensitive resin composition.

Next, the opposing surface 15 of the counter substrate 14 is brought into contact with the reinforcing film 12.

Then, while the opposing surface 15 is maintained in parallel at a fixed interval between the opposing surface 15 and the surface 7, the opposing substrate 14 is directed to the supporting substrate as indicated by the solid arrow in FIG. 3(c). The direction of 6 is pressed, whereby the layer 13 is pressed against the shaping surface 8 of the roughened sheet 9.

Then, in this state, as shown by the solid arrow in (c) of FIG. 3, the layer 13 is exposed by ultraviolet rays through the support substrate 6 and the roughened sheet 9, and the layer 13 is formed. The photosensitive resin composition 11 produces a hardening reaction. As a light source An ultraviolet (UV) light source manufactured by Philips is used.

Next, referring to (a) of FIG. 4 and (b) of FIG. 4, the laminated body 16 of the reinforcing film 12, the crosslinked layer 13 and the roughened sheet 9 is self-supporting the substrate 6 and the opposite substrate 14. The take-up is reversed and turned upside down, and the reinforcing film 12 is placed downward on the work table 17.

Then, as shown by the arrow of the one-dot chain line in (b) of FIG. 4, the roughened sheet 9 is sequentially peeled from one end of the laminated body 16 to the other end, and the upper side of the layer 13 is formed. The surface side is a printed surface 2 which is roughened by transferring the uneven shape of the shaping surface 8 of the roughened sheet 9.

Next, as shown in FIG. 4(c), the laser head laser 19 is irradiated while scanning the laser head 18, and the area other than the area corresponding to the printed pattern of the printing surface 2 is removed by heat. The printed surface 2 is patterned into a predetermined printed pattern to produce the flexible printed board 1.

The patterning conditions were set as follows: output of carbon dioxide gas laser: 400 W x 2 beam, beam diameter: 20 μm, feed pitch: 60 μm, feed speed: 40 cm/sec.

After the patterning, the contamination caused by the ablation droplet resin was washed using the trade name KS-HG thinner manufactured by Sun Chemical Co., Ltd., and then sufficiently dried.

According to the roughness curve measured by the scanning confocal laser microscope described above, the average value of the length Xs of the contour curve element at the same reference length is obtained, and the flexible printed board 1 is obtained by the above formula (1). When the average length RSm of the roughness curve elements of the printed surface 2 is RSm, the average length of the roughness curve elements is RSm It is 9.0 μm.

As a result of the above, it was confirmed that the uneven shape of the printing surface 2 of the flexible printed board 1 is a concave-convex shape in which the shaped surface 8 of the roughened sheet 9 is faithfully transferred.

The above-mentioned flexible printed board 1 was produced by an anilox roll 4 (Asahi Kasei E-materials) having a diamond pattern as shown in (a) of FIG. 2 and having a pitch P _A of 63.5 μm. #400]Combined use. The average length RSm of the roughness curve elements is 0.14 times the formation pitch P _A .

<Example 2, Example 3, Comparative Example 1, Comparative Example 2>

The following roughened sheet 9 is prepared, and the roughened sheet 9 is an embossing roll which is modified to roughen the surface of the thermoplastic polyurethane elastomer by press sheet forming. On the other hand, the average length RSm of the roughness curve elements of the shaping surface 8 was a value shown in the following Table 1, which was the same sheet of the thermoplastic polyurethane elastomer as the user of Example 1. It is exposed on the opposite side of the face to which the reinforcing sheet is attached.

Then, the flexible printed board 1 was produced in the same manner as in Example 1 except that each of the roughened sheets 9 was used.

When the average length RSm of the roughness curve elements of the printing surface 2 of the flexible printed board 1 is obtained in the same manner as described above, as shown in the following Table 1, it is confirmed that the uneven shape of the printing surface 2 of the flexible printed board 1 is faithfully The uneven shape of the shaping surface 8 of the roughened sheet 9 is transferred.

<real machine test>

(flexible printing)

The flexible printed board produced in each of the examples and the comparative examples was incorporated in the above-described anilox roll #400 (forming pitch P _A : 63.5 μm) into a flexible printing machine for liquid crystal alignment film [Nakan Techno ( The shares are manufactured in model A45].

Then, a varnish for liquid crystal alignment film [OPTOMA (registered trademark) AL60702 manufactured by JSR Co., Ltd., contact angle of 30° with respect to a soda lime glass substrate] was flexibly printed on a soda lime glass substrate having a thickness of 0.7 mm. After the above, the varnish was pre-dried by heating at 120 ° C for 30 minutes to form a liquid crystal alignment film.

The condition of the flexible printing is set to a thickness of 1000 of the liquid crystal alignment film after pre-drying .

(initial thickness evaluation)

The thickness of the pre-dried liquid crystal alignment film was measured, and the initial thickness was evaluated on the basis of the following criteria.

○○: The thickness is just 1000 .

○: thickness is 1000 Outside and 1000±100 Within.

×: thickness is 1000±100 other than.

(wear evaluation)

In the first to third examples and the second comparative example in which the initial thickness was evaluated as ○○ or ○, 50,000 sheets were continuously printed under the same conditions as described above, and the liquid crystal alignment film was obtained by abrasion of the flexible printed board. Thickness less than 900 The number of printed sheets that could be previously printed, and the wear reduction effect of the flexible printed board was evaluated on the basis of the following criteria. Further, Comparative Example 1 in which the initial thickness was evaluated as × was not subjected to wear evaluation.

○○○: The thickness of the liquid crystal alignment film up to 50,000 pieces is still not lower than 900 . The wear reduction effect is excellent.

○○: The thickness of the liquid crystal alignment film is less than 900 in the range of 40,000 or more and less than 50,000 . The wear reduction effect is good.

○: The thickness of the liquid crystal alignment film is less than 900 in the range of 30,000 or more and less than 40,000 . The wear reduction effect is the usual level.

×: The thickness of the liquid crystal alignment film is less than 900 in the range of less than 30,000 sheets. . The wear reduction effect is not good.

(Comprehensive judgment)

From the results of the initial thickness evaluation and the wear evaluation, the quality of the flexible printed board was comprehensively determined based on the following criteria.

○○○: The initial thickness was evaluated as ○○, and the abrasion resistance was ○○○ or ○○.

○○: The initial thickness was evaluated as ○○, and the abrasion resistance was ○, or the initial thickness was evaluated as ○ and the abrasion resistance was ○○○ or ○○.

○: The initial thickness was evaluated as ○ and the abrasion resistance was ○.

×: Any one or both of them are ×.

The above results are shown in Table 2.

From the result of the comparative example 1 of Table 2, it is judged that if the average length RSm of the roughness curve element of the printing surface of the flexible printing plate is less than 0.1 times the formation pitch P _A of the surface direction of the uneven pattern of the combined anilox roll, When the uneven shape is too small, the effect of providing the unevenness on the printing surface with respect to the ink and the amount of the ink to be held can not be obtained, and a liquid crystal alignment film having a predetermined initial thickness or the like cannot be formed.

Moreover, from the result of the comparative example 2, when the average length RSm of the roughness curve element exceeds 0.5 times of the formation pitch P _A , the contact of the convex part of the printing surface of the flexible printed board with the convex part of the anilox roll was judged. Since the amount is small, the effect of dispersing the contact pressure between the two cannot be obtained, so that the printed surface is easily worn, and the life of the flexible printed board is shortened.

On the other hand, from the results of the first to third embodiments, it is determined that a flexibility is obtained by setting the average length RSm of the roughness curve elements to be within the range of 0.1 times or more and 0.5 times or less the pitch P _A . A printing plate which can form a liquid crystal alignment film having a uniform thickness, a pinhole-free shape, or the like and having a predetermined thickness, and has a small abrasion and can be used for a long period of time.

Moreover, from the results of Examples 1 to 3, it is determined that the effect of the improvement is that the average length RSm of the roughness curve elements is preferably 0.3 times or more and 0.4 times or less the formation pitch P _A .

1‧‧‧Flexible printing plate

2‧‧‧Printed surface

3, 5‧‧‧ convex

4‧‧‧ anilox roller

P _A ‧ ‧ forming spacing

Length of Xs1, Xs2, Xs3, Xs4‧‧‧ contour curve elements

Claims (6)

A flexible printing plate for use in flexible printing in which ink is supplied to a flexible printing plate via an anilox roll having a concave-convex pattern on the outer peripheral surface, wherein the flexible printed plate is formed into one side for printing In the flat shape of the surface, the printing surface is roughened, and the average length RSm of the roughness curve elements of the printing surface is 0.1 times or more and 0.5 times or less of the formation pitch of the surface direction of the relief pattern of the anilox roll. A method of manufacturing a flexible printed board according to the first aspect of the invention, characterized by comprising the step of preparing a profile, the profile comprising a material transparent to active light and The one surface is formed as a shaping surface corresponding to the shape of the printing surface of the flexible printing plate; the photosensitive resin composition is in contact with the shaping surface of the profile, and the layer of the photosensitive resin composition is formed in the shaped area of the profile. a step of irradiating the active light with a profile to cure the layer of the photosensitive resin composition by a curing reaction; a step of peeling the layer of the cured photosensitive resin composition from the shaping surface of the profile; and peeling off The layer of the photosensitive resin composition is formed into a flexible printing plate. The method for producing a flexible printed board according to claim 2, wherein the step of forming the flexible printed board comprises: peeling the surface of the layer of the photosensitive resin composition from the shaped surface of the profile (with the shaped surface) The surface to be contacted is set to be roughened The step of brushing the surface and removing the rough surface of the printing surface other than the area corresponding to the printed pattern by mechanical or heat. The method of manufacturing a flexible printed board according to claim 2, wherein the step of preparing the profile comprises: preparing a support substrate comprising a hard material and having permeability to active light; and making the profiled surface of the profile The surface of the opposite side is in contact with and fixed to the surface of the support substrate. The method for producing a flexible printed board according to any one of claims 2 to 4, wherein, as the photosensitive resin composition, a single prepolymer comprising at least one ethylenically unsaturated group is used. The composition of the body and the photopolymerization initiator. A method for producing a substrate for a liquid crystal panel, comprising the step of forming a liquid crystal alignment film for a liquid crystal panel by flexographic printing using the flexible printed board according to claim 1 of the patent application.