JP2000193808A - Surface side substrate and manufacture of the same, and reflection display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface side substrate usable in a reflection liquid crystal display element and industrially manufacturable with a good productivity, and excellent in light diffusing uniformity. SOLUTION: In a surface side substrate, a transparent layer having an uneven surface (an uneven film 2) is arranged on a transparent substrate 1, and a transparent flattening layer having a different refractive index from that of the transparent layer 2 (an flattening film 3) is arranged on the transparent layer 2. Accordingly, the surface side substrate is constructed so as to diffusedly transmit an incident light. A color filter substrate is obtained by arranging a color filter (a color resist 4) and a transparent electrode 5. The transparent layers comprise a fluororesin having a fluoride-containing aliphatic ring structure in the main chain and a partially hydrolyzed condensate of alkoxysilanes having the formula R1mR2nSi(OR3)4-(m+n), wherein R1 and R2 are each 1-14C organic groups and both of them may be same or not; R3 is a 1-8C alkyl group; (m) and (n) are integer of 0 to 3 wherein (m+n)<=3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front substrate used in combination with a liquid crystal display device and the like, a method of manufacturing the same, and a reflective display device using the same.

When used as a front substrate of a reflection type liquid crystal display device manufactured in combination with a substrate having a reflection electrode, the incident light is diffused and transmitted very effectively on the front substrate, and then the incident light is diffused and reflected effectively on the reflection electrode. Since it enables bright white display, it is suitable for use on the front substrate of this display element. In particular, when the light diffusion layer is disposed on the inner surface of the liquid crystal element, a high-definition display can be performed.

[0003]

2. Description of the Related Art Liquid crystal display devices have been widely used in portable electronic devices such as notebook personal computers and portable information terminals. In these applications, since the battery is driven by a battery, a reflective liquid crystal display element having lower power consumption than that of a conventional transmissive liquid crystal display element is required, and its development is being promoted. In a reflection type liquid crystal display element, a layer for scattering incident light is required somewhere in the element in order to widen the viewing angle that looks bright and to realize “white” display without metallic luster. 2. Description of the Related Art Conventionally, a reflection type liquid crystal display element has been manufactured by a method of providing a diffuse reflection plate outside a cell of a liquid crystal display element (conventional example 1).

However, in recent years, a high-definition display element has been required. In Conventional Example 1, since there is a parallax due to the thickness of the glass used for the transparent substrate, reflected light is mixed between pixels, causing a decrease in contrast and the like, and a sufficient image quality cannot be obtained.

On the other hand, a method has been proposed in which a reflective electrode is formed on the inner surface of the cell and a film or the like is provided outside the front substrate to scatter light. However, this method is not sufficient for a demand for higher definition (conventional examples). 2).

Recently, there has been proposed a reflection type liquid crystal display device in which a concave / convex pattern is formed on an electrode by photolithography using a photomask as a reflection electrode on the inner surface of the cell, and a diffusion reflection electrode is provided. For example, monthly LCD I
ntelligence, January 1998, p. 36 (conventional example 3). According to Conventional Example 3, a high-definition reflective liquid crystal display device can be realized.

[0007]

However, if the concavo-convex pattern of the conventional example 3 is simply repeated in the plane direction, the reflective electrode will act as a diffraction grating, and when the display is visually recognized, it will develop a rainbow color. In addition, display defects such as so-called moiré fringes may be generated due to a slight shift in the positional relationship with other repeated patterns such as wiring and a black matrix. Therefore, in designing a photomask used for forming a concavo-convex pattern, it is not possible to use simple repetition as in the case of forming a normal pixel pattern, and it is necessary to perform a very complicated and difficult design. However, it is inevitable that the pattern will be repeated.

Further, even in photolithography, a slight displacement of the positional relationship with other repetitive patterns, and a slight displacement of a joint at the time of divided exposure using a stepper, are visually recognized after completion as a display element. May be done. For this reason, strict accuracy control is required even in manufacturing. As described above, it is not easy to form a reflective electrode having an appropriate diffusion ability by ordinary photolithography. Therefore, it is an issue to provide a light diffusion layer having some light diffusion function on the inner surface of the cell while maintaining high productivity.

As a method of forming a diffusion function on the inner surface of the front substrate, a method in which a light scattering layer mainly composed of a transparent resin and fine particles dispersed in the transparent resin and having a different refractive index from the transparent resin is provided. Although proposed (see Japanese Patent Application Laid-Open No. 7-98446), there are manufacturing difficulties such as ensuring uniformity in dispersion and arrangement of fine particles and surface flatness.

As a method for forming a diffusion function on the inner surface of the front substrate, a method has been proposed in which a glass substrate used as a transparent substrate itself is polished on the inner surface side of a display element to form a ground glass, thereby forming a ground glass shape ( JP-A-8-33899
No. 3). However, it is difficult to control the light diffusion intensity by controlling the degree of surface roughening of the glass substrate. Further, there is a problem in terms of cost to uniformly roughen a large-area substrate used for manufacturing a display element.

An object of the present invention is to provide a front side substrate which ensures uniformity of light diffusing ability, can be easily manufactured industrially, has excellent surface flatness, etc., and is particularly suitable for use in a reflection type liquid crystal display device. An object of the present invention is to provide a manufacturing method and a reflective display element using the same.

[0012]

According to the present invention, a transparent layer having an uneven surface can be provided on a transparent substrate such as glass using various coating methods. Is preferably formed. In order to dispose the transparent flattening layer, a transparent flattening layer may be provided on the transparent layer so as to be in contact with the uneven surface. In that case, it is preferable to use a composition to form a resin coating film.

Examples of the composition include compositions containing at least two components (a) and (b) and a solvent as essential components. As the components (a) and (b), polymers or oligomers having different basic skeletons which are soluble in the same solvent are preferable.

According to this resin coating film forming method, by applying and curing the composition, the solvent volatilization and (b)
With the curing of the components, phase separation between the cured product of the component (a) and the component (b) occurs, and as a result, a light-diffusing layer of the front substrate can form a coating film having irregularities with excellent characteristics. It is particularly preferable because it is possible.

The combination of the components (a) and (b) can be exemplified as follows. (A) a fluororesin having a fluorinated aliphatic ring structure in the main chain; and (b) a formula R ¹ _m R ² _n Si (OR ³ ) _{4- (m + n) wherein} R ¹ and R ² are An organic group having 1 to 14 carbon atoms,
R ³ may be the same or different, R ³ is an alkyl group having 1 to 8 carbon atoms, and m and n are integers of 0 to 3 satisfying m + n ≦ 3. A) a partially hydrolyzed condensate of an alkoxysilane represented by the formula:

The fluororesin having an aliphatic ring structure in the main chain of the component (a) used in the present invention is obtained by cyclopolymerization of a fluorine-containing monomer having two or more polymerizable double bonds. A fluororesin having a fluorinated alicyclic structure in the main chain, a fluororesin having a fluorinated alicyclic structure in the main chain obtained by polymerizing a monomer having a fluorinated alicyclic structure, and these two types of monomers are used in common. Examples thereof include a fluororesin obtained by polymerization, a fluororesin obtained by copolymerizing at least one of these two types of monomers, and a monomer other than these.

Having a fluorinated aliphatic ring structure in the main chain means that at least one of the carbon atoms constituting the aliphatic ring is a carbon atom in the carbon chain constituting the main chain and the aliphatic ring is constituted. It has a structure in which a fluorine atom or a fluorine-containing group is bonded to at least a part of carbon atoms.

Examples of the fluorine-containing monomer having two or more polymerizable double bonds include those represented by the following formulas (e), (f), (g) or (h). However, T ^{1 to} T ¹² , Y ^{1 to} Y ¹⁰ , Z in the formulas (e) to (h)
^{1 to} Z ⁸ and W ^{1 to} W ⁸ are each independently F or CF
₃

A monomer having a fluorinated aliphatic ring structure;
Is expressed by the following equation (i), equation (j) or equation (k).
Are exemplified. However, in equations (i) to (k)
X ¹~ X⁶Are independently F or CF_ThreeAnd R^Four
~ R⁹Are independently F and C_nF_{2n + 1}Or C_nF
_{2n + 1-p}H_pO_qWhere n is an integer of 1 to 5 and p is 0
An integer of 0 to 5, q is an integer of 0 to 2, or R^Four~
R⁹Each independently represents an alkylene group or a fluoroalkyl group.
A alkylene group and R^FourAnd R^Five, R⁶And R⁷, R ⁸When
R⁹May be connected to each other to form a ring.

(E) CT ¹ T ² = CT ³ CT ⁴ T ⁵ CT ⁶ T ^{7
CT 8 T 9 CT 10 = CT} 11 T 12; (f) CY 1 Y 2 = CY 3 OCY 4 Y 5 CY 6 Y 7 CY 8 = CY
^{9 Y 10; (g) CZ} 1 Z 2 = CZ 3 OCZ 4 Z 5 CZ 6 = CZ 7 Z 8; (h) CW 1 W 2 = CW 3 OCW 4 W 5 OCW 6 = CW 7 W 8;

Fluorine resins having an aliphatic ring structure in the main chain obtained by cyclopolymerization of a fluorine-containing monomer having two or more polymerizable double bonds are described in JP-A-63-238111.
JP-A-63-238115, JP-A-7-316235
It is publicly known in Japanese Patent Publication No. For example, perfluoro (allyl vinyl ether), perfluoro (butenyl vinyl ether), perfluoro (bis (vinyloxy)
A fluororesin obtained by homopolymerizing a monomer such as methane) or copolymerizing these monomers with a radical polymerizable monomer can be used.

The radical polymerizable monomer is preferably selected from olefins such as ethylene, perfluoroolefins such as tetrafluoroethylene and hexafluoropropylene, and perfluoro (alkyl vinyl ether) such as perfluoro (butyl vinyl ether). One or more types can be selected.

A fluororesin having an aliphatic ring structure in the main chain obtained by polymerizing a monomer having a fluorinated aliphatic ring structure is disclosed in JP-B-63-18964, JP-A-7-1986.
It is known in, for example, Japanese Patent Application Publication No. 70107. For example, monomers having a fluorinated ring structure such as perfluoro (2,2-dimethyl-1,3-dioxol) and 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole are homopolymerized, Alternatively, a fluororesin obtained by copolymerizing these monomers and the above-mentioned radical polymerizable monomer can be used.

In addition, perfluoro (2,2-dimethyl-
1,3-dioxole), 2,2,4-trifluoro-
Polymerization of a monomer having a fluorinated aliphatic ring structure such as 5-trifluoromethoxy-1,3-dioxole and two or more monomers such as perfluoro (allyl vinyl ether), perfluoro (butenyl vinyl ether) and perfluoro (bisvinyloxymethane) It is also possible to use a fluororesin obtained by copolymerizing a fluorine-containing monomer having an acidic double bond.

As the fluororesin having a fluorinated alicyclic structure in the main chain, those having a fluorinated alicyclic structure in a repeating unit of the fluororesin in an amount of from 20 to 100 mol% are transparent,
It is preferable from the viewpoint of mechanical properties and the like, and the weight average molecular weight is not particularly limited, but may be 3,000 to 1,000,0.
About 00 is preferable, and about 5,000 to 500,000 is particularly preferable.

As the component (b) used in the present invention, a partially hydrolyzed condensate of an alkoxysilane represented by the formula R ¹ _m R ² _n Si (OR ³ ) _{4- (m + n)} is used as described above. can do.

In the above formula, R ¹ and R ² have 1 to 1 carbon atoms.
And R ³ is an alkyl group having 1 to 8 carbon atoms, m and n
Is an integer of 0 to 3 satisfying m + n ≦ 3. R ¹ and R ² each independently represent a methyl group, an ethyl group,
Propyl group, aliphatic alkyl group such as butyl group, phenyl group, aryl group such as tolyl group, trifluoromethyl group,
Trifluoropropyl group, pentafluorobutyl group, nonafluorohexyl group, tridecafluorooctyl group,
Preferred are fluorine-containing alkyl groups such as a heptadecafluorodecyl group and a heptadecafluoroundecyl group.

R ³ in the above formula is preferably an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group.

Preferred examples of such alkoxysilanes include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane and tetrapropoxysilane; monoalkyltrialkoxysilanes such as methyltrimethoxysilane and methyltriethoxysilane; Monoaryl trialkoxysilanes such as phenyltrimethoxysilane, trifluoromethyltrimethoxysilane,
Trifluoropropyltrimethoxysilane, pentafluorobutyltrimethoxysilane, nonafluorohexyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecylmethyldimethoxysilane, heptadecafluoroundecyl Examples thereof include fluoroalkylalkoxysilanes such as trimethoxysilane.

These alkoxysilanes may be used alone or in combination of two or more. When two or more kinds are used in combination, it is preferable to use a fluoroalkylalkoxysilane and an alkoxysilane containing no fluorine (particularly, tetraalkoxysilane is preferable). Also,
Fluoroalkylalkoxysilanes are preferably used because of their high solubility in a fluorine solvent described below.

The condensation reaction of these alkoxysilanes is as follows:
It can be performed by a well-known method. For example, there is a method in which water is added to an alkoxysilane in the presence of a solvent and a catalyst to cause a hydrolytic condensation reaction. In this case, heating may be performed if necessary. As the catalyst, inorganic acids such as hydrochloric acid, nitric acid and sulfuric acid, and organic acids such as formic acid, oxalic acid and acetic acid can be used. Usually, it is preferable to set the molecular weight of the product in the range of about 500 to 10000 in terms of weight average molecular weight in terms of polystyrene, from the viewpoint of solubility in a solvent described below. Next, if necessary, water present in the system may be removed by distillation or the like, and the catalyst may be removed with an ion exchange resin or the like.

In the present invention, in preparing a mixed solution of the components (a) and (b), it is important to select a solvent which can simultaneously dissolve these components.

For example, a mixture of an aprotic fluorinated solvent and a protic fluorinated solvent as described in JP-A-7-112126 is exemplified. Here, the characteristic feature is that the fluororesin (a) having a fluorinated aliphatic ring structure in the main chain is soluble in an aprotic fluorinated solvent, but is not dissolved in a protic fluorinated solvent, but is partially hydrolyzed. The decomposition condensate (b) is soluble in a protic fluorinated solvent but may not be dissolved in an aprotic fluorinated solvent. Therefore, the point is that both are dissolved simultaneously by using a mixed solvent. .

The aprotic fluorinated solvent is a fluorinated solvent which does not dissociate under normal reaction conditions and does not generate a proton, and any known or well-known solvent can be used. For example, perfluorodecalin, perfluorocyclohexane, perfluorohexane, perfluorooctane, 1H, 1
H, 1H, 2H, 2H-perfluorooctane, 1H,
Fluorinated aliphatic hydrocarbons such as 1H, 1H, 2H, 2H-perfluorodecane, fluorinated alkylamines such as perfluorotripentylamine, perfluorotributylamine and perfluorotripropylamine, perfluoro (2-butyltetrahydrofuran) and the like A preferred example is a fluorinated cyclic ether. These may be used in combination of two or more.

The protic fluorinated solvent is a fluorinated solvent which is easily dissociated to generate protons, and any known or well-known one can be used. CF ₃ CH ₂ OH, CF ₃ CF ₂ CH ₂
OH, CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ OH, CF ₃ (C
F ₂ ) ₅ CH ₂ CH ₂ OH, CF ₃ CF ₂ CH ₂ CH ₂ CH ₂ O
H and fluorinated alcohols such as CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ CH ₂ OH are preferred. These may be used in combination of two or more.

In determining the total solvent composition, it is needless to say that the total solvent composition must be set within a range that does not impair the solubility of both the fluororesin having an aliphatic ring structure in the main chain and the partially hydrolyzed condensate of alkoxysilane. . From this perspective,
Usually, aprotic fluorinated solvent: protic fluorinated solvent = 99: 1 to 60:40 (weight ratio), and more preferably 9
It is preferable to set in the range of 8: 2 to 70:30 (weight ratio).

When the partially hydrolyzed condensate of alkoxysilane contains fluoroalkylalkoxysilanes, it may be dissolved in an aprotic fluorinated solvent depending on its composition. In this case, it is necessary to add a protic fluorinated solvent. In some cases, a homogeneous mixed solution can be prepared by adding a very small amount of 1% by weight or less.

The ratio of (a) to (b) in the composition used in the present invention can be set to an arbitrary ratio according to the required unevenness of the coating film.
It is advisable to mix (b) with 100 parts by weight or more, preferably 150 to 400 parts by weight, per 100 parts by weight of (a).

The solid content concentration in the solution obtained by mixing (a) and (b) is within a range in which the solid content is dissolved, from the viewpoint of a desired solution viscosity or a film thickness of a coating film obtained by coating. What is necessary is just to select suitably. For example, when a coating film having a thickness of 0.1 to 5 μm is to be obtained by a spin coating method, the solid content concentration is generally set to 1 to 15% by weight.

The composition used in the present invention comprises (a)
As components other than (b), an adhesion enhancer according to the purpose,
An additive such as a surfactant can be blended.

As a method for forming the transparent layer on a substrate using this composition, a method in which the above-mentioned composition containing a solvent is applied to the substrate and then heated and dried to volatilize the solvent is preferably adopted. You. At this time, the surface of the base may be treated with a coupling agent such as a silane coupling agent in order to ensure sufficient adhesion to the base.

Examples of the method of applying the composition include a spin coating method, a dipping method, a potting method, a die coating method, a spray coating method and the like, which can be appropriately selected from the shape of the substrate to be coated, the required film thickness and the like. I just need. The spin coating method and the die coating method are preferred from the viewpoint of uniformity of the in-plane distribution of the film thickness.

In order to form a coating film, a baking step after coating is required to evaporate the solvent and form irregularities due to phase separation between the components (a) and (b). The bake condition is
It may be appropriately selected depending on the thickness of the coating film and the like.
A final bake of about 50 ° C. is required. Baking is necessary also from the viewpoint of sufficiently curing the partially hydrolyzed condensate (b) of the alkoxysilane, and is preferably at 200 ° C. to prevent the unreacted alkoxysilyl group or silanol group from remaining. Preferably, a final bake at 250 ° C. or higher is required. The unreacted alkoxysilyl group or silanol group itself causes deterioration of the insulating properties of the coating film, and furthermore, it can serve as a water-absorbing site. It is desirable that it does not remain.

For the purpose of controlling the phase separation structure of the coating film or improving the flattening property of the coating film, 50 to 150
It is also possible to add a pre-baking step at about ° C. or to divide the baking step into several stages.

In the front substrate of the present invention, a transparent layer having irregularities is formed by disposing a first transparent material on a transparent substrate and changing the state of the first transparent material. Laminate the transparent material, flatten the surface of the transparent material, form a transparent flat layer, form irregularities between the transparent layer and the transparent flat layer, the refractive index of the transparent layer and the refractive index of the transparent flat layer Can be manufactured by providing differently, and this method is also included in the present invention.

When the composition is applied as a first transparent material, the state of the material of the coating film can be changed to form a transparent layer having the irregularities. When a film constituting a transparent flattening layer is stacked thereover, desired unevenness can be formed between the transparent layer and the transparent flattening layer. On this occasion,
Naturally, it is necessary to provide the refractive index of the transparent layer different from the refractive index of the transparent flattening layer.

[0048]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described based on preferred specific examples with reference to the drawings, but the present invention is not limited to these.

In the front substrate of the present invention, for example, a transparent coating film having irregularities on the surface is formed on the substrate by applying a resin such as the above-described composition, and a transparent flattening layer is formed on the transparent coating film. Is to form a light diffusion layer having a random pattern with no repetition in a planar direction by forming flattening films having different refractive indices. When the front substrate is visually recognized at a distance of several tens of cm, it is only necessary to exhibit uniform scattering in the plane.

FIG. 1 is a sectional view of an example in which a color filter substrate including a light diffusion layer obtained in the present invention is formed.
After forming a transparent coating film having unevenness on the surface (irregularity film 2) by applying a resin such as a composition on the transparent substrate 1, a flat surface having a refractive index different from that of the uneven transparent coating film is used as a transparent flattening layer. An oxide film 3 is formed. When a color filter is formed thereon (color resist 4) and a transparent electrode 5 is formed by a normal process, a color filter substrate is obtained. Although not shown, a black matrix and an overcoat film may be formed.

FIG. 2 shows another example in which a color filter substrate including a light diffusion layer obtained by the present invention is formed. In this manner, the uneven film 2 and the flattening film 3 may be formed on the color filter. . In this case, in the above method, instead of forming the color resist 4 by the pigment dispersion method on the flattening film 3, the color resist 4 is formed on a glass substrate, and the uneven film 2, the flattening film 3, By laminating the transparent electrodes 5 respectively, the front substrate of the present invention can be manufactured. Further, the present invention may be applied to a monochrome display element without forming a color filter.

The material of another transparent layer disposed on the transparent layer having the irregularities is selected so that the difference in refractive index from the transparent layer is as large as possible. If a material having a low refractive index such as CYTOP (registered trademark, manufactured by Asahi Glass Co., Ltd.) is used for the transparent layer, a material having a high refractive index is used for the flattening layer. Conversely, a combination of the transparent layer having a high refractive index and the flattening layer having a low refractive index is also possible.

The characteristics required for the flattening layer should be excellent in flattening performance. Be transparent in visible light. It is preferable that the adhesiveness to the lower transparent layer (concavo-convex layer) is good. Further, it is preferable that heat resistance, solvent resistance, and plasma resistance are good. For example, epoxy resin, acrylic resin, phenoxy resin, polyimide resin, urethane resin, silicone resin, polyetherimide resin, polyester resin, bismaleimide triazine resin (B
T resin), a phenol resin and the like.

In the present invention, it is preferable to use the above-described composition as the uneven film used for the transparent layer having the uneven surface. Further, other materials may exhibit the same effect. It is a material in which phase separation is induced by the treatment after coating, and an uneven structure is generated.

On the uneven surface of the transparent layer according to the present invention, the pitch p 'of the unevenness in one direction in the plane is 0.5 to 10.0 μm in order to secure the uniformity of the light diffusing ability.
It is preferable that the average height h ′ of the unevenness is 1.0 to 5.0 μm. As described above, according to the coating method using the composition used in the present invention, the uneven surface can be easily formed. Regarding the measurement of the pitch of the unevenness, for example, the surface, the cross section may be observed with a scanning electron microscope,
In a simple manner, the state of the unevenness can be known even with a stylus-type profilometer, or the measurement may be performed by another appropriate method.

Although the uneven film 2 and the flattening film are in contact with each other on the uneven surface, in order to obtain a sufficient diffusion performance, the difference in the refractive index between the uneven film 2 and the flattening film 3 must be 0.1 or more. Is preferable, and it is more preferable that it is 0.2 or more. When the refractive index of the uneven film is different from that of the substrate, it is also effective to form the unevenness on the surface of the substrate by etching, blasting or the like, and then form the unevenness film.

In order to increase the diffusion strength, a plurality of layers of the uneven film and the flattening film may be repeatedly formed, or a plurality of uneven layers having different refractive indexes may be repeatedly formed, and finally, the flattening layer may be formed. Is also good. The range of the refractive index of the material of the transparent film is 1.3 to
It is preferably about 1.7, and the maximum difference in refractive index is preferably about 0.5 or less.

In the front substrate according to the present invention, if the unevenness is formed by forming a coating film of a resin or the like, a random pattern light diffusion layer can be obtained, so that a reflective display element having a uniform display within a screen can be easily formed. it can. The front substrate of the present invention can be used as a display device, particularly as a front substrate of a reflective liquid crystal display device.

FIG. 3 is a sectional view of an example of an active matrix liquid crystal display device manufactured using a color filter including a light diffusion layer obtained by the present invention, and FIG. The cross-sectional views of examples of a simple matrix liquid crystal display element manufactured using a filter are respectively shown.

On the color filter substrate 8 including the light diffusion layer obtained by the present invention, the alignment films 6 and 6 are formed by a conventionally known manufacturing method.
When the liquid crystal layer 7 is provided and the active matrix substrate 9 is further provided, an active matrix liquid crystal display element can be manufactured (see FIG. 3).

On the other hand, when the alignment film 6 and the liquid crystal layer 7 are provided on the substrate 8 and the simple matrix substrate 10 is disposed thereon, a simple matrix liquid crystal display device can be manufactured (see FIG. 4).

[0062] In any of the above cases,
After forming the alignment film 6 on each substrate, cells are formed via a spacer and a sealing member, and then liquid crystal is preferably injected between the two substrates.

The display element using the front substrate of the present invention is not particularly limited as long as it is a reflection type, and can be used for a light-receiving display element such as an electrochromic display element in addition to a liquid crystal display element.

Further, portable information terminals and portable communication terminals using the reflective display element having the front substrate of the present invention are excellent in visibility.

[0065]

The present invention will be described below in detail with reference to examples.

Example 1 Synthesis of Component (a) (a) Synthesis of Fluororesin Having Fluorine-Containing Alicyclic Structure in Main Chain 35 g of perfluoro (butenyl vinyl ether), 150 g of ion-exchanged water, 20 g of methanol and polymerization initiation 90 mg of ((CH ₃ ) ₂ CHOCOO) ₂ as an agent was placed in a pressure-resistant glass autoclave having an internal volume of 200 cc,
After the inside of the system was replaced with nitrogen three times, suspension polymerization was performed at 40 ° C. for 22 hours to obtain 28 g of polymer A. The intrinsic viscosity [η] of the polymer A was 0.2 dl / g at 30 ° C. in perfluoro (2-butyltetrahydrofuran).

Example 2: Synthesis of component (b) (b) Synthesis of partially hydrolyzed condensate of alkoxysilane In a reaction vessel, tetramethoxysilane and CF ₃ (C
F ₂ ) ₅ CH ₂ CH ₂ Si (OCH ₃ ) ₃ in a molar ratio of 1: 0.5
Was dissolved in methanol at a ratio of 2. Then, nitric acid and water were added, and the mixture was reacted at room temperature for 72 hours to synthesize a partially hydrolyzed condensate. The weight average molecular weight of this partially hydrolyzed condensate was 1,050 (standard polystyrene equivalent value determined by GPC). Next, nitric acid is removed by passing the reaction solution through an ion exchange resin tower, solvent replacement is performed, and a partially hydrolyzed condensate (hereinafter, referred to as “condensate B”) perfluorotributylamine and CF are removed. ₃ CF ₂ CH ₂ OH mixed solvent (weight ratio 95: 5)
A solution was obtained. The solid concentration of the condensate B in the solution was 9% by weight.

[Example 3: Preparation and application] (a), (b) Preparation of mixed solution The composition ratio of A to B is different from that of polymer A obtained in Example 1 and condensate B obtained in Example 2. A solution was prepared. At this time, the solid content concentration and the solvent composition of the solution were as follows.

The total solid content of A and B is 9% by weight. Perfluorotributylamine: CF ₃ CF ₂ CH ₂ OH
= 90:10 (weight ratio).

The mixed solution was spin-coated at 60 rpm.
It is applied on a glass substrate at 0 RPM, and then on a hot plate at 80 ° C. for 90 seconds, and further in an electric furnace at 350 ° C. for 1 second.
Heating was carried out for a period of time to completely cure. The thickness of the cured resin film became random irregularities of about 2 to 4 μm.

To observe the difference in surface irregularities due to the composition ratio of A and B, an Al film having a thickness of 120 nm was formed on the cured resin film by a sputtering method, and the regular reflectance was measured. For example, when A: B is 80:20, the condensing angle is 8
° and 31% at a converging angle of 2 °. A vs. B is 4
In the case of 0:60, it was 23% at a converging angle of 8 ° and 0.4% at a converging angle of 2 °. It was found that by increasing the ratio of the condensate B to the polymer A, the shape of the film surface could be controlled in the direction in which larger irregularities were formed.

Example 4 Production of Color Filter Substrate A front substrate (color filter substrate) having a configuration as shown in FIG. 1 was produced. On a transparent glass substrate (transparent substrate 1; AN635, manufactured by Asahi Glass Co., Ltd .; refractive index: 1.56), a solution of 30:70 A: B prepared as in Example 3 was spin-coated at 600 RPM. Was applied over the entire surface. After that, it was heated on a hot plate at 80 ° C. for 90 seconds, and further heated in an electric furnace at 350
C. for 1 hour to completely cure. The thickness of the cured resin film (refractive index: 1.35) 2 was random irregularities of about 2 to 4 μm (irregularities 2). Next, after a nitrogen plasma treatment for 30 seconds, an epoxy-based flattening film 3 (V259EH manufactured by Nippon Steel Chemical Co., Ltd .: refractive index: about 1.6) was applied and cured by heating. A pigment-dispersed color resist 4 was formed thereon in three colors of red, green and blue, and finally a transparent electrode 5 was formed. A color filter substrate having good light diffusion performance was obtained.

In the above method, instead of forming the pigment-dispersed color resist 4 on the flattening film 3, a front substrate disposed on a glass substrate was manufactured (see FIG. 2). It is to be noted that a method of further improving the light diffusion effect by using a glass substrate having a ground glass surface as the glass substrate is also possible.

[0074]

In the front substrate of the present invention, light is effectively diffused particularly by the uneven pattern formed on the surface by the resin coating film, so that a reflective display element having a uniform display within a screen can be easily formed. be able to. Further, the light-diffusing transparent film obtained by applying the composition according to the present invention can control the size of the unevenness by adjusting the composition ratio,
In addition, since a micro-random and macro-uniform uneven surface can be simultaneously formed in the substrate surface in a single coating, the problem of agglomeration during coating such as a method of dispersing fine particles in a film is also reduced. In addition, element design and manufacturing are easy, and manufacturing can be performed with high productivity.

In the front substrate of the present invention, the surface of the light diffusion layer is flattened by the transparent flattening layer.
Even if the light diffusion layer is formed on the inner surface of the cell, it does not adversely affect the orientation of the liquid crystal, and when used for the substrate of the liquid crystal display device, various liquid crystal modes can be adopted for the liquid crystal display device.

Further, according to this method, since the light diffusion surface is on the inner surface of the cell, it is not affected by the parallax due to the thickness of the substrate. A reflective liquid crystal display device can be realized.

The substrate of the present invention can be widely applied as long as it is a reflection type display element. For example, it can be applied to an active matrix type liquid crystal display element and a simple matrix type liquid crystal display element.

Further, since the refractive index of the coating film formed from the composition used in the present invention is extremely low at 1.35, it is easy to obtain a large difference in the refractive index in combination with the transparent flattening layer. Sufficient diffusion strength can be obtained with irregularities in an easy range.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example in which a color filter substrate including a light diffusion layer obtained by the present invention is formed.

FIG. 2 is a cross-sectional view of another example in which a color filter substrate including a light diffusion layer obtained by the present invention is formed.

FIG. 3 is a cross-sectional view of an example of an active matrix liquid crystal display device manufactured using a color filter substrate including a light diffusion layer obtained by the present invention.

FIG. 4 is a cross-sectional view of an example of a simple matrix liquid crystal display device manufactured using a color filter substrate including a light diffusion layer obtained by the present invention.

[Explanation of symbols]

1: transparent substrate 2: uneven film 3: flattening film 4: color resist 5: transparent electrode 6: alignment film 7: liquid crystal layer 8: color filter substrate including a light diffusion layer obtained by the present invention 9: active matrix substrate 10 : Simple matrix substrate.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiaki Yokozuka 1150 Hazawa-cho, Kanagawa-ku, Yokohama-shi, Kanagawa F-term within Asahi Glass Co., Ltd. 2H042 BA01 BA04 BA15 BA20 2H090 HA04 HA08 HB15X HC05 HD03 HD06 LA04 LA15 LA20 2H091 FA02Y FA16Y FA31Y FB02 FD06 GA07 KA01 KA10 LA12 LA16 4J038 CM011 DL022 DL032 GA12 PA07 PB09

Claims (6)

[Claims] 1. A front-side substrate for a reflective display element, wherein a transparent layer having an uneven surface is disposed on a transparent substrate, and a transparent flattening layer having a different refractive index from the transparent layer is provided on the transparent layer. Wherein the incident light is diffused and transmitted. 2. The method according to claim 1, wherein the transparent layer comprises the following (a) and (b):
2. The front substrate according to claim 1, which is formed of a composition containing: (a) a fluororesin having a fluorinated aliphatic ring structure in a main chain; and (b) a formula R ¹ _m R ² _n Si (OR ³ _{4- (m + n)} (wherein, R ¹ and R ² are an organic group having 1 to 14 carbon atoms;
R ³ may be the same or different, R ³ is an alkyl group having 1 to 8 carbon atoms, and m and n are m + n ≦ 3
Is an integer of 0 to 3 that satisfies A) a partially hydrolyzed condensate of an alkoxysilane represented by the formula: 3. The composition according to claim 1, wherein the ratio of (a) to (b) is (a) 1.
3. The front substrate according to claim 2, wherein (b) is at least 100 parts by weight based on 00 parts by weight. 4. A pitch p 'of irregularities in one direction in a plane on the surface of the transparent layer is 0.5 to 10.0 μm.
4. The front substrate according to claim 1, wherein the average height h ′ of the unevenness is 1.0 to 5.0 μm. 5. 5. A transparent layer having irregularities is formed by applying a first transparent material on a transparent substrate and changing the state of the first transparent material, and a second transparent material is laminated thereon. , Flatten the surface of the transparent material, form a transparent flat layer, form irregularities between the transparent layer and the transparent flattening layer, so that the refractive index of the transparent layer and the refractive index of the transparent flattening layer are different The method of manufacturing the front substrate to be provided. 6. A reflective display element using the front substrate according to claim 1, 2, 3, or 4.