JP2006208763A - Coating material, substrate having protrusion for controlling liquid crystal alignment formed by using coating material and its manufacturing method, and liquid crystal display using substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display having excellent reliability without causing display burning or the like while maintaining high positional accuracy and dimensional accuracy at low costs and in a short step, in the liquid crystal display of an MVA system. <P>SOLUTION: It has been found that a substrate having protrusions for controlling alignment having a high definition pattern can be manufactured at low costs and in a short step as compared with the case by photolithography, when the protrusions for controlling alignment of the liquid crystal display is formed by a printing method using a coating liquid having a specified composition by which burning is prevented and printability is heightened. Addition of a monomer of a curing component causing occurrence of burning is not needed. Thus, the substrate having the protrusions for controlling alignment can be manufactured at low costs and in a short step without causing burning. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color filter for a liquid crystal display device, and more particularly to a color filter having alignment control projections used for an alignment division vertical alignment type (MVA type) liquid crystal display device and the same. It relates to coating materials.

  Liquid crystal display devices are widely used from small-area devices such as mobile phones and digital cameras to large-area devices such as personal computers and workstation display devices and television image display devices. The use of is expanding rapidly.

  Among them, the alignment-divided vertical alignment type (MVA type) liquid crystal display device has a high contrast ratio and a very wide viewing angle compared to a general twisted nematic type (TN type) liquid crystal display device. Since it has a characteristic that it can be taken, it is an optimal liquid crystal display device used for a television image display device, and the amount of use is expected to be greatly increased. FIG. 1 shows a schematic diagram of an alignment-divided vertical alignment type liquid crystal display device.

  In this alignment-divided vertical alignment type liquid crystal display device, minute protrusions 4 for dividing the alignment of the liquid crystal are provided on the color filter 2 corresponding to the counter substrate of the electrode. The protrusions 4 are provided to divide the orientation of the liquid crystal in the pixel and widen the viewing angle, and require high positional accuracy and dimensional accuracy, and do not impair the opening of the liquid crystal display device. Therefore, it is necessary to form a pattern with minute dimensions. Typical pattern formation techniques include photolithography, etching, printing, and ink-jet methods. In particular, the printing method is a simple and inexpensive method, but this type of micropattern orientation control projection is formed. For this reason, a sufficient coating technique has not been established. For this reason, conventionally, a projection for dividing the liquid crystal alignment is formed by a photolithography technique using a positive or negative photosensitive material. It was common.

  However, when a positive photosensitive material that dissolves the photosensitive area is used, the photomask has almost the entire area as an opening, and a large number of identical defective patterns are formed due to minute scratches and foreign matter on the photomask. The ease is a big problem. On the other hand, in the negative photosensitive material in which the photosensitive portion is cured, there is a case where a problem of display burn-in described in detail below occurs. Negative photosensitive materials basically contain a monomer component as a curing component in addition to the binder resin, and it is particularly known that this monomer component adversely affects electrical characteristics that cause display burn-in. Yes.

  Display burn-in is an alignment-divided vertical alignment type liquid crystal display device. When a pattern of a certain shape is displayed for a long time, the previous pattern remains and is visible even if a uniform display is subsequently displayed. Therefore, the elimination of this problem is a major issue in ensuring reliability. This display burn-in phenomenon is caused by the fact that the response characteristic of the transmittance with respect to the applied voltage, that is, the VT characteristic deviates from the original characteristic only in the part where the signal has been continuously input. The shift is due to a phenomenon called residual DC in which an electric field remains in a portion where a signal is input.

  In order to solve this problem, Japanese Patent Application Laid-Open No. 2001-83521 (Patent Document 1), Japanese Patent Application Laid-Open No. 2003-35905 (Patent Document 3), etc., alleviate charges that cause residual DC in a short time. For this purpose, it has been proposed to add a certain amount of conductivity by mixing a small amount of carbon black or metal fine particles with the projection forming material.

  However, it is difficult to control the conductivity, and there is a problem that if the conductivity is excessively imparted to the projection material, the properties are deteriorated. Furthermore, imparting conductivity is effective in mitigating the generated residual DC in a short time, but does not prevent the generation of the residual DC itself and cannot be said to be a fundamental solution.

In Japanese Patent Laid-Open No. 2001-324715 (Patent Document 2), when the time constant of the liquid crystal material is τ _LC (30 Hz) and the time constant of the projection material is τ _RIB (30 Hz), 0.1 × τ _LC <τ It has been proposed that _RIB <10 × τ _LC . Setting the time constant to a value close to that of the liquid crystal material and the protrusion material is effective for preventing the occurrence of residual DC. However, since the liquid crystal display device includes an alignment film material in addition to the liquid crystal material, In addition to the characteristics, it is necessary to consider the characteristics of the alignment film material. In addition, it is possible to point out problems that do not describe specific materials and means for realizing these characteristics.

  Furthermore, since the formation of the alignment control protrusions by the method described in the literature as described above uses photolithography, there have been problems such as a long process and a high material cost.

JP 2001-83521 A (2 pages, claims 3 and 4) JP 2001-324715 A (2 pages, claims 7 and 3 to 4) JP 2003-35905 A (page 2, claim 1, pages 3 to 4, and page 6 Table 1)

  The present invention has been made in order to solve the above-mentioned problems, and the object of the present invention is to maintain high positional accuracy and dimensional accuracy in an alignment-divided vertical alignment (MVA) liquid crystal display device. An object of the present invention is to provide a liquid crystal display device with excellent reliability that does not cause display burn-in and the like at low cost and in a short process.

  By the way, according to the study of the present inventor, when the alignment control protrusions of the liquid crystal display device are formed by a printing method using a coating liquid having a specific composition, the process is lower in cost and shorter than that by photolithography. Thus, it has been found that a substrate having a fine pattern orientation control protrusion can be manufactured. Using the printing method eliminates the need for expensive materials such as photopolymerization initiators that have been added in the past, and eliminates the need for adding a monomer of a curing component that has caused burn-in. For this reason, a substrate having alignment control projections could be produced at low cost and in a short process without causing image sticking.

The present invention has been made based on such knowledge, and the invention according to claim 1 of the present application is at least a coating material for forming alignment control protrusions of a liquid crystal display device by a printing method.
A coating material comprising (a) a resin component (b) a filler component (c) a solvent component.

  The invention according to claim 2 of the present application is characterized in that, in the coating material, the dielectric loss tangent of the dried cured product is 0.010 or less in a frequency range of 25 ° C. and 10 to 50 Hz. Coating material.

  The invention according to claim 3 of the present application is the coating material according to claim 1 or 2, wherein (a) the resin component contains a resin having an aromatic ring.

  The invention according to claim 4 of the present application is the coating material according to claim 3, wherein (a) the resin component contains a resin having an aromatic ring structure in the main chain.

  The invention according to claim 5 is characterized in that (b) the particle size of the filler component is 10 to 30 nm, and the proportion of the filler component in the solid content of the coating material is 5 to 50%. The coating material according to any one of claims 1 to 4.

  Invention of Claim 6 of this application contains (d) a crosslinking component, and the ratio of (d) crosslinking component in solid content of a coating material is 1 to 50%, It is characterized by the above-mentioned. Coating material in any one of 1-5.

  The invention described in claim 7 is a liquid crystal display device substrate having alignment control protrusions, wherein the alignment control protrusions are formed using the coating material according to any one of claims 1 to 6. Display device substrate.

  The invention described in claim 8 is a liquid crystal display device using the substrate according to claim 7 as at least one of the opposing substrates.

The invention described in claim 9 is a method for manufacturing a substrate of a liquid crystal display device having alignment control protrusions, wherein at least (a) a step of forming a color filter on a glass substrate (b) a transparent electrode on the color filter. (C) A method of manufacturing a substrate of a liquid crystal display device, comprising a step of forming an alignment control protrusion on a color filter by a printing method.

  According to the present invention, it is possible to form alignment control protrusions of a liquid crystal display device by a printing method. As a result, the alignment control protrusions of the liquid crystal display device can be manufactured at low cost and in a short process. At the same time, it was possible to obtain a liquid crystal display device having alignment control protrusions having high definition and high reliability that does not cause the problem of image sticking due to electrical characteristics and the like.

  The coating material of the present invention is characterized in that the dielectric loss tangent of the dried and cured product is 0.010 or less in a frequency range of 10 to 50 Hz in order to prevent seizure.

  The reason why the coating material having such physical properties is preferable for preventing the burn-in of the liquid crystal display device is shown below.

  First, the influence of the dielectric loss tangent of the projection material on the display burn-in of the alignment-divided vertical alignment type liquid crystal display device will be described in detail below. In the display burn-in phenomenon of the liquid crystal display device, if a signal is continuously input only to a certain portion of the display device, even if a uniform signal is input to the entire screen after that, it is not displayed uniformly on the entire screen. This is a phenomenon in which the shape of the portion remains and is visible (see FIG. 2). This phenomenon is caused by the fact that the response characteristic of the transmittance with respect to the applied voltage, that is, the VT characteristic has deviated from the original characteristic only in the part where the signal has been input as described above. This shift in the VT characteristic is due to the occurrence of a phenomenon called residual DC in which an electric field remains in a portion where a signal is input.

A liquid crystal cell in a liquid crystal display device can be regarded as a capacitor in which several kinds of dielectrics are laminated. Therefore, a behavior when a capacitor having a plurality of types of dielectrics laminated with a signal having an amplitude V ₀ and a period 2T as shown in FIG. 3 for a long time as a model for driving a liquid crystal display device is short-circuited at both ends will be considered. First, for the sake of simplicity, consider a capacitor in which two types of dielectrics are stacked as shown in FIG. Assuming a parallel equivalent circuit as shown in FIG. 5 for each dielectric, and setting R _p , C _p of each dielectric as R ₁ , C ₁ , R ₂ , C ₂ , a signal as shown in FIG. 3 is obtained. Charges q ₁ and q ₂ accumulated in each dielectric when applied for a long time are due to R ₁ , C ₁ , R ₂ , C _2, etc.
It can be expressed as

That is, when a signal as shown in FIG. 3 is given to this capacitor for a sufficiently long time, a charge amount proportional to the product of R _p and C _p is accumulated in each dielectric. The product of R _p and C _p is a physical quantity called a time constant for dielectric relaxation, and is the time taken for the charge quantity accumulated in the dielectric to decay to 1 / e (about 0.367). Next, when the electrodes at both ends are short-circuited, if the amounts of charges accumulated in the dielectrics are equal, that is, if the dielectric relaxation time constants (= R _p × C _p ) are equal for each dielectric, the charges are mutually All of them cancel out and disappear, leaving no charge in the capacitor. However, when the accumulated charge amounts are different from each other, that is, when R _p × C _p is different from each other, the charge corresponding to the difference from the charge amount of the adjacent dielectric is included in one of the dielectric bodies. Will remain, and the capacitor will not be fully discharged. In other words, when short-circuiting, if the charge amount in each dielectric is q ₁ (short) and q ₂ (short),
It is expressed. That is, a charge proportional to the difference between the time constants of each dielectric relaxation remains in any one of the dielectric bodies.

The above holds true for a capacitor in which n types of dielectrics are stacked as shown in FIG. That is, if R _p and C _p of the dielectric i in FIG. 6 are R _i and C _i, and the accumulated charge amount when a signal is input for a long time is q _i ,
So expressed as, again in each of the dielectric so that the charge amount which is proportional to the product of each of R _p and C _p are accumulated. For example, when n = 4, the amount of charge accumulated in the dielectric i is
It becomes.
Accordingly, considering the case where both ends are short-circuited in the same manner, when the amount of charge accumulated for all dielectrics is equal, that is, when the dielectric relaxation time constants R _p × C _p are equal for all dielectrics, the charge is They cancel each other and disappear, leaving no charge in the capacitor.

However, when there are dielectrics with different accumulated charge amounts, that is, when there are dielectrics with different R _p × C _p , depending on the difference between the charge amount of the surrounding dielectrics in any one of the dielectrics As a result, the electric charge remains, and the capacitor is not completely discharged. If these dielectrics are made to correspond to a liquid crystal material, a liquid crystal alignment control projection material, and an alignment film material, this phenomenon corresponds to a so-called residual DC in a liquid crystal display device. That is, it is a necessary condition for preventing the residual DC of the liquid crystal display device that R _p × C _p of the liquid crystal material, the liquid crystal alignment control protrusion material, and the alignment film material coincide with each other.

The time constant R _p × C _p of dielectric relaxation is obtained by using a general dielectric tangent tan δ and a signal period (in this case, 2T) as material characteristics of the dielectric material.
Therefore, when discussing the characteristics of the material, it is easier to understand if the dielectric loss tangent tan δ is used as an index. The relationship between the dielectric loss tangent and the time constant of dielectric relaxation depends on the signal period, as can be seen from Equation (5). Accordingly, it is necessary to determine at what frequency the dielectric loss tangent is appropriately measured as the material characteristic. However, the signal of the liquid crystal display device is about 60 Hz per pulse, that is, T = Since it is 1/60 (seconds), it is appropriate to measure the dielectric loss tangent at a period of 2T = 1/30 (seconds), that is, in the vicinity of 30 Hz in frequency and generally in a frequency of 10 to 50 Hz.

  In general, polyimide is used as the alignment film material, and the dielectric loss tangent of polyimide is very small and is about 0.003 to 0.004 or less at a frequency of 10 to 50 Hz. These materials are about 002 to 0.004, and the dielectric loss tangents of these materials are relatively small and close to each other. Therefore, the dielectric loss tangent of the projection material has a great influence on the generation of residual DC, that is, the occurrence of display burn-in of the liquid crystal display device, and the residual DC is not generated even in combination with these alignment film materials and liquid crystal materials. It is desirable that the projection material for controlling the liquid crystal alignment also has a dielectric loss tangent of the same level. Specifically, it is necessary to be 0.010 or less, more preferably 0.006 or less in a frequency range of at least 10 to 50 Hz.

  Therefore, the resin component of the present invention preferably contains an aromatic ring in a weight ratio of 25% or more, or those aromatic ring structures contained in the main chain of the resin. Examples of such a resin include polyester, polystyrene, phenol resin, xylene resin, epoxy resin, polycarbonate, aromatic nylon resin, or a copolymer containing styrene, aromatic acid, phenol, and the like. In particular, when a resin containing an aromatic ring or a resin containing an aromatic ring structure in the main chain is used as the resin component, the dielectric loss tangent in the frequency range of 10 to 50 Hz of the dried cured product of the coating material is 0.010 or less, Furthermore, it is preferable to make it 0.006 or less.

Other examples include aromatic ring-containing epoxy resins and novolac resins represented by the following chemical structural formulas (1) to (4).
However, m is an integer greater than or equal to 0, n is an integer greater than or equal to 1, and R1-R8 each independently represents H, CH ₃ or a halogen atom. R9 and R10 are H or CH3. Further, E means a linking group represented by the following (Chemical Formula 5).
In addition, cardo compounds, bisphenol A compounds and the like represented by the following structural formulas (6), (7), (8) and the like can also be used as the resin component of the present invention.
However, n represents an integer of 1 or more, and R11 or R12 represents H or CH3. R13 or R14 independently represents H, CH3 or a halogen atom.

  The filler component in the coating material of the present invention is formed by pressing the removal plate against the coating material uniformly coated on the silicon blanket to remove the non-image area and forming a pattern of liquid crystal distribution control projections. It is contained to improve the cutting of the pattern at the time of formation, and the particle size of the filler component is 10 to 30 nm, and the proportion of the filler component in the solid content of the coating material is 5 to 50%. Therefore, it is possible to form a fine pattern of the liquid crystal distribution control protrusion while keeping the dielectric loss tangent of the liquid crystal distribution control protrusion low, and without adversely affecting the color characteristics of the pixel of the color filter. . When the particle size of the filler component is smaller than 10 nm, it is difficult to uniformly disperse in the coating material, and when the particle size is larger than 30 nm, the shape of the liquid crystal distribution control projection is deteriorated, which is not preferable. Further, if the proportion of the filler component in the solid content of the coating material is less than 5%, the effect of addition is hardly exhibited, and if it exceeds 50%, the above-described electrical characteristics are deteriorated and the resistance is lowered, which is not preferable. As the filler component used in the present invention, colloidal silica having a particle size of 10 to 30 nm is particularly preferable.

  The solvent component in the coating material of the present invention uniformly dissolves or disperses various components, and controls the viscosity, wettability, and drying property of the coating material together with the role of maintaining the coating material stably. In order to give uniform coating properties to the silicon blanket, and to develop and control the transferability of the coating film by volatilization of the solvent component on the silicon blanket and penetration of the solvent into the silicon blanket. It plays an important role. Specifically, as a solvent component of the present invention, in order to improve solubility and volatility, low boiling ester solvents such as ethyl acetate, isopropyl acetate and butyl acetate, and ketone solvents such as acetone, 2-butanone and cyclohexanone In order to improve the dispersibility and coatability of solvents, high boiling point ester solvents such as ethyl lactate and propylene glycol monomethyl acetate (PGMAC), and aromatic solvents such as toluene and xylene have leveling properties. In order to improve, an ether solvent such as propylene glycol monomethyl ether is preferably used. Moreover, as a solvent component of the coating material of this invention, what mixed the said solvent with sufficient balance is especially preferable. The viscosity of the coating material of the present invention is preferably adjusted to 1 to 10 mPa · s in view of uniform coating properties and drying properties.

  Moreover, the tolerance with respect to the solvent and heat | fever of the protrusion for liquid crystal orientation control can be improved by making a crosslinking component contain 1-50% with respect to solid content in coating material. As the crosslinking component used in the present invention, amino resins such as alkylated methylol melamine, epoxy resins having a glycidyl group, divinyl ether having a vinyl group, carbodiimide, isocyanate and the like are preferably used, and two or more types are mixed. It may be used. By adding a cross-linking component, it is possible to improve the pattern transferability during printing and to improve the resistance of the projection for controlling liquid crystal alignment to acids, alkalis, organic solvents, and heat. At this time, it is preferable that the dielectric loss tangent in the frequency range of 10 to 50 Hz of the dried cured material of the coating material containing the crosslinking component is 0.010 or less.

  Furthermore, the coating material of the present invention can be adjusted by adding additives such as a leveling agent, a dispersant, a viscosity modifier, an antifoaming agent, and an antioxidant within the scope of the present invention as necessary. it can.

  As a pattern forming method by the printing method of the alignment control protrusions in the present invention, a publicly known method disclosed in JP-A-11-58921 or JP-A-2000-289320 can be used. Specifically, the coating material is uniformly coated on a silicon blanket, and a relief or intaglio is pressed to remove a non-image area, and then transferred to a glass substrate to form a pattern. By containing an appropriate solvent component, it is possible to form a coating film that has a uniform coating property on the silicon blanket and is easy to form a pattern by volatilization of the solvent component on the blanket. Furthermore, by containing a filler component having a particle size of 10 to 30 nm in the solid content of 5 to 50%, a fine pattern can be formed by a printing method while suppressing the influence on electrical characteristics such as dielectric loss tangent, resistance, and transparency. Is possible. This is an example of a printing method for forming the alignment control protrusion of the present invention, and the present invention is not limited to these methods.

  In the present invention, by using a printing method, a monomer component and an initiator that adversely affect electrical characteristics are not necessary, and a liquid crystal display device that reduces burn-in can be manufactured. In addition, since the printing method does not require a resin component, a photosensitive material, or an alkali-soluble material, which is conventionally required in photolithography, the range of material selection can be expanded.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

(Example 1) [Preparation of coloring material]
The following were used as the coloring agents for coloring the coloring material used for producing the color filter.

Red pigment: C.I. I. Pigment Red 254 (“Ilgar Forred B-CF” manufactured by Ciba Specialty Chemicals) and C.I. I. Pigment Red 177 (“Chromophthal Red A2B” manufactured by Ciba Specialty Chemicals)
Green pigment: C.I. I. Pigment Green 36 (“Lionol Green 6YK” manufactured by Toyo Ink) and C.I. I. Pigment Yellow 150 (Bayer's “Funcheon First Yellow Y-5688”)
Blue pigment: C.I. I. Pigment Blue 15 (“Rionol Blue ES” manufactured by Toyo Ink) C.I. I. Pigment Violet 23 (manufactured by BASF “Paliogen Violet 5890”)

Red, green, and blue coloring materials were prepared using the respective pigments.
-Red coloring material After stirring and mixing the mixture of the following composition uniformly, it disperse | distributed with the sand mill for 5 hours using the glass bead of diameter 1mm, Then, it filtered with a 5 micrometer filter, and produced the dispersion of the red pigment.
Red pigment: C.I. I. Pigment Red 254 18 parts by weight Red pigment: C.I. I. Pigment Red 177 2 parts by weight Acrylic varnish (solid content 20%) 108 parts by weight

Thereafter, a mixture having the following composition was stirred and mixed to be uniform, and then filtered through a 5 μm filter to obtain a red colored material.
150 parts by weight of the above dispersion 13 parts by weight of trimethylolpropane triacrylate (“NK ester ATMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.)
3 parts by weight of photoinitiator (“Irgacure 907” manufactured by Ciba Specialty Chemicals)
Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 1 part by weight Cyclohexanone 253 parts by weight

-Green coloring material It produced with the method similar to a red coloring material so that a composition might become the following composition, respectively.
Green pigment: C.I. I. Pigment Green 36 16 parts by weight Yellow pigment: C.I. I. Pigment Yellow 150 8 parts by weight Acrylic varnish (solid content 20%) 102 parts by weight Trimethylolpropane triacrylate 14 parts by weight (“NK ESTER ATMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.)
4 parts by weight of photoinitiator (Ciba Specialty Chemicals)
"Irgacure 907")
Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 257 parts by weight

-Blue coloring material The blue coloring material was prepared in the same manner as the red coloring material so that the composition was as follows.
Blue pigment: C.I. I. Pigment Blue 15 50 parts by weight Purple pigment: C.I. I. Pigment Violet 23 2 parts by weight Dispersant (“Sols Birds 20000” manufactured by Zeneca) 6 parts by weight Acrylic varnish (solid content 20%) 200 parts by weight Trimethylolpropane triacrylate 19 parts by weight (“NK Ester ATMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.) )
Photoinitiator 4 parts by weight (“Irgacure907” manufactured by Ciba Specialty Chemicals)
Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 214 parts by weight

[Colored layer formation and transparent conductive film formation]
A colored layer was formed using the obtained coloring material.
A red coloring material was applied to a glass substrate by spin coating so as to have a film thickness of 2 μm. After drying at 90 ° C. for 5 minutes, light from a high pressure mercury lamp was irradiated through a striped photomask for forming a colored layer at 300 mJ / cm 2 and developed with an alkaline developer for 90 seconds to obtain a striped red colored layer. . The alkaline developer has the following composition.
Sodium carbonate 1.5% by weight
Sodium bicarbonate 0.5% by weight
Anionic surfactant (Kao Perillex NBL) 8.0% by weight
90% by weight of water

  Next, the green coloring material is similarly applied by spin coating so that the film thickness becomes 2 μm. After drying, the green colored layer adjacent to the above-mentioned red colored layer was obtained by exposing and developing at a place shifted from the above-mentioned red colored layer.

  Further, in the same manner as red and green, a blue colored layer adjacent to the red and green colored layers with a film thickness of 2 μm was obtained for the blue colored material. Thus, a color filter having a striped colored layer of three colors of red, green and blue on the transparent substrate was obtained. Indium tin oxide (ITO) was formed on this color filter by 1500 Å by a general sputtering method.

[Preparation of projection forming coating material]
The coating material used for forming the protrusions was prepared with the following composition.
Cresol novolac resin (Mw = 11000) 12% (55% based on solid content)
3% methylated methylol melamine (14% based on solids)
Colloidal silica (particle size 12nm) 6% (27% based on solid content)
Silicone leveling agent 1%
PGMAC 60%
Ethyl acetate 18%
The dielectric loss tangent at 30 Hz of the dried cured product of this coating material is shown in Table 1 described later.

[Formation of protrusions]
Using the coating material, a projection for controlling liquid crystal alignment was formed on the color filter with ITO by the printing method shown below.
The above-mentioned coating material was applied to a blanket cylinder on which a silicon blanket was wound using a slit die, and a uniform film having a thickness of 2 μm was formed on the silicon blanket. Thereafter, the blanket cylinder is pressed onto the glass relief plate corresponding to the non-image portion of the liquid crystal alignment control protrusion pattern to remove the non-image portion, and subsequently the liquid crystal alignment control protrusion formed on the silicon blanket. The pattern was transferred onto a color filter with ITO and heated and cured at 230 ° C. for 30 minutes to form protrusions for controlling liquid crystal alignment.

(Example 2)
A color filter having protrusions for controlling liquid crystal alignment was obtained by the same method as in Example 1 except that the coating material used for forming the protrusions had the following composition.
Phenol novolac resin (Mw = 5000) 9% (45% based on solid content)
Bisphenol A type epoxy resin 4% (20% based on solid content)
Methylated methylol melamine 2% (10% based on solid content)
Colloidal silica (particle size 25 nm) 4% (20% based on solid content)
Silicone leveling agent 1%
PGMAC 42%
Isopropyl acetate 38%
The dielectric loss tangent at 30 Hz of the dried cured product of this coating material is shown in Table 1 described later.

(Example 3)
A color filter having protrusions for controlling liquid crystal alignment was obtained by the same method as in Example 1 except that the coating material used for forming the protrusions had the following composition.
Cresol novolak resin (Mw = 13000) 9% (39% based on solid content)
Bisphenol A type epoxy resin 4% (17% based on solid content)
Colloidal silica (particle size 12 nm) 9% (39% of solid content)
Fluorine leveling agent 1%
PGMAC 39%
Isopropyl acetate 38%
The dielectric loss tangent at 30 Hz of the dried cured product of this coating material is shown in Table 1 described later.

(Comparative Example 1)
A color filter having protrusions for controlling liquid crystal alignment was obtained by the same method as in Example 1 except that the coating material used for forming the protrusions had the following composition.
1,4-butanediol glycidyl ether 7% (30% based on solid content)
Butylated methylol melamine 8% (35% of solids)
Colloidal silica (particle size 12 nm) 7% (30% of solid content)
Fluorine leveling agent 1%
PGMAC 39%
Isopropyl acetate 38%
The dielectric loss tangent at 30 Hz of the dried cured product of this coating material is shown in Table 1 described later.

(Comparative Example 2)
A color filter having protrusions for controlling liquid crystal alignment was obtained by the same method as in Example 1 except that the coating material used for forming the protrusions had the following composition.
Cresol novolac resin (Mw = 13000) 6% (27% based on solid content)
Butylated methylolmelamine 3% (14% based on solids)
Colloidal silica (particle size 12nm) 12% (55% based on solid content)
Fluorine leveling agent 1%
PGMAC 40%
Isopropyl acetate 38%
The dielectric loss tangent at 30 Hz of the dried cured product of this coating material is shown in Table 1 described later.

(Comparative Example 3)
Using a coating material having the following composition, an attempt was made to form a liquid crystal alignment control protrusion by a printing method in the same manner as in Example 1, but the pattern of the non-image area could not be transferred by the removed plate, and the protrusion was Could not be formed.
Cresol novolac resin (Mw = 13000) 14% (67% based on solid content)
Butylated methylol melamine 6% (29% based on solid content)
Fluorine leveling agent 1%
PGMAC 41%
Isopropyl acetate 38%

(Comparative Example 4)
The process is exactly the same as in Example 1 until a color filter with ITO is obtained, and a protrusion-forming photosensitive material having the following composition is spin-coated on the color filter with ITO so that the coating film thickness is 2 μm, and is 90 ° C. For 5 minutes. The light from a high-pressure mercury lamp was irradiated through a photomask for forming protrusions at 100 mJ / cm ² . Then, it developed using the developing solution similar to preparation of a color filter. After washing with water, post-baking was performed at 230 ° C. for 30 minutes to form a liquid crystal alignment control protrusion on the color filter.
n-butyl methacrylate, methacrylic acid, methyl methacrylate,
Acrylic resin made of 2-hydroxyethyl methacrylate 12%
Polyfunctional polymerizable monomer (Aronix M402 manufactured by Toagosei Co., Ltd.) 12%
Photopolymerization initiator (Irgacure 907 manufactured by Ciba Specialty Chemicals)
1%
PGMAC 75%
The dielectric loss tangent at 30 Hz of the cured product of the photosensitive material is shown in Table 1 described later.

(Evaluation results of Examples and Comparative Examples)
The results of evaluating the color filters produced in Examples 1 to 3 and Comparative Examples 1, 2, and 4 using a liquid crystal display device are shown below. As shown in FIG. 7, the evaluation was performed based on the luminance ratio of the A part and the B part in the figure when the rectangular pattern was displayed for 48 hours and then the entire surface was displayed in 51/255 gray levels. It can be said that the closer the luminance ratio between the A part and the B part is to 1, the better the result is that there is no display burn-in.

As shown in the table above, display burn-in does not occur at all in the liquid crystal display device using the color filter produced in the example, whereas display burn-in occurs in all liquid crystal display devices using the color filter produced in the comparative example. It was. The liquid crystal alignment control protrusion of the present invention can be said to be a color filter having excellent reliability.

It is a schematic explanatory drawing of the cross section of an alignment division | segmentation vertical alignment system color liquid crystal display device. It is explanatory drawing which represented typically the display image sticking phenomenon in the alignment division | segmentation vertical alignment system color liquid crystal display device. It is a figure which shows the model of the signal of a liquid crystal display device drive. It is explanatory drawing which shows the capacitor | condenser which laminated | stacked two types of dielectric materials. It is the figure which showed the RC parallel equivalent circuit of the dielectric material. It is explanatory drawing which shows the capacitor | condenser which laminated | stacked n types of dielectrics. It is explanatory drawing which showed the conditions for evaluating the image | video image sticking generation | occurrence | production of the alignment division | segmentation vertical alignment system color liquid crystal display device using the color filter produced in the Example and the comparative example.

Explanation of symbols

1 Substrate 2 Color filter 3 Transparent electrode (common electrode)
4 Projection 5 Liquid Crystal Layer 6 Pixel Electrode 7 Polarizing Plate

Claims (9)

In the coating material for forming the alignment control protrusion of the liquid crystal display device by a printing method, at least,
(A) Resin component (b) Filler component (c) Solvent component A coating material for alignment control protrusions of a liquid crystal display device. 2. The coating material according to claim 1, wherein the dielectric loss tangent of the dried and cured product is 0.010 or less in a frequency range of 25 ° C. and 10 to 50 Hz. The coating material according to claim 1 or 2, wherein the resin component (a) includes a resin having an aromatic ring.   The coating material according to claim 3, wherein the resin component (a) includes a resin having an aromatic ring structure in the main chain.   The particle size of the filler component (b) is 10 to 30 nm, and the proportion of the filler component in the solid content of the coating material is 5 to 50%. Coating material according to crab.   6. The composition according to any one of claims 1 to 5, wherein (d) a crosslinking component is contained, and the proportion of the (d) crosslinking component in the solid content of the coating material is 1 to 50%. Coating material.   A substrate for a liquid crystal display device having an alignment control protrusion, wherein the alignment control protrusion is formed using the coating material according to claim 1.   A liquid crystal display device using the substrate according to claim 7 as at least one of the opposing substrates. In a method of manufacturing a substrate of a liquid crystal display device having alignment control protrusions, at least (a) a step of forming a color filter on a glass substrate (b) a step of forming a transparent electrode on the color filter (c) on the color filter A method for manufacturing a substrate of a liquid crystal display device, comprising a step of forming alignment control protrusions by a printing method.