JP2008083511A - Liquid crystal composition, color filter and liquid crystal display apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal composition which can form a retardation layer producing no sinking deformation when external force load is applied, such as strong pushing force by a finger is given on a touch panel when used as a liquid crystal display apparatus or strong load is given during manufacturing process or transportation, further to provide a color filter and a liquid crystal display apparatus equipped with the retardation layer. <P>SOLUTION: In the liquid crystal composition containing a cross-linking liquid crystal molecule, hydrophobic or hydrophilic inorganic fine particles are included to adjust the liquid crystal composition. Further a retardation layer 4 is formed in a color filter 1 by using the liquid crystal composition and further the color filter 1 equipped with the retardation layer 4 is used for the liquid crystal display apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal composition, a color filter having a retardation layer made of the liquid crystal composition, and a liquid crystal display device using the color filter.

  Since the liquid crystal display device has the great advantages of being thin and light and low power consumption, it is actively used in display devices such as personal computers, mobile phones, and electronic notebooks. These liquid crystal display devices perform light switching by utilizing the birefringence of liquid crystal (driving liquid crystal) molecules contained in the driving liquid crystal layer.

  When performing color display with a liquid crystal display device, for example, a color filter having three color patterns of R (red), G (green), and B (blue) is arranged to face the liquid crystal cell, and the transmitted visible light is spectrally separated. It is common to do this. The color filter is configured by arranging a color pattern on a transparent substrate such as glass. This transparent substrate can also be used as a display side substrate of a liquid crystal cell. As a result, the entire liquid crystal display device is reduced in thickness and the number of parts is reduced.

  As described above, the liquid crystal display device using the birefringence of the liquid crystal (driving liquid crystal) molecules contained in the driving liquid crystal layer has a problem of viewing angle dependency due to the birefringence of the driving liquid crystal. In order to solve the problem by using a retardation layer that compensates for the retardation of light, for example, a retardation layer-forming film has been developed as a member in which various retardation layers are formed. This retardation layer forming film is usually produced by stretching a film of polyacrylate, polycarbonate, triacetyl cellulose or the like. The retardation forming film is usually installed at an outer position of a liquid crystal cell having a structure in which a liquid crystal is sealed between a facing display side substrate and a driving liquid crystal side substrate. That is, the retardation forming film is installed as a retardation layer disposed at an outer position of the liquid crystal cell.

  However, the retardation layer is not limited to the case where it is installed outside the liquid crystal cell as described above. Recently, a method of installing the retardation layer inside the liquid crystal cell using a crosslinkable liquid crystal or a polymer liquid crystal has been proposed. (Patent Document 1), a high mechanical strength and heat resistance can be obtained by providing a retardation layer inside the liquid crystal cell.

  As for the retardation layer installed inside the liquid crystal cell, a method of laminating a protective layer on the surface of the retardation layer has been proposed in order to further improve the mechanical strength (Patent Document 2). Furthermore, a method for forming a retardation layer having a high hardness by aligning and curing a polymerizable monomer having a special skeleton on an alignment film has also been proposed (Patent Document 3).

JP 2000-221506 A JP 2004-126534 A JP 2005-309255 A

  In recent years, since a so-called touch panel type liquid crystal display device has been widely used, a user often applies a strong pressing force to the display panel with a finger. At this time, the thickness of the liquid crystal cell is locally reduced, the amount of phase difference given to the light transmitted through the region is lowered, and there is a problem that the light leakage and the color tone fluctuate. Such a problem of subsidence deformation can also occur during the process of combining the color filter with the driving liquid crystal side substrate, or during the test or transport of the assembled liquid crystal display device.

  The above problem is that the retardation layer formed by polymerizing and curing polymerizable liquid crystal molecules is a viscoelastic body, and has a lower compression elastic modulus than other components such as a colored layer and a transparent substrate, and stress is applied. This is due to the fact that it is easily deformed by the above, and that when a stress exceeding a predetermined value is applied, permanent deformation occurs, so that the original shape does not recover even after the applied stress is removed.

  The method proposed in Patent Document 2 is based on the technical idea that the retardation layer is protected by another layer. However, even if this method is used, an external force that presses the liquid crystal cell is loaded. In this case, since the load is transmitted to the retardation layer through the protective film, the retardation layer is also sunk and deformed around the columnar body. Further, in this method, since a protective film for protecting the retardation layer is formed, the number of manufacturing steps is inevitably increased, resulting in a decrease in yield and an increase in manufacturing cost.

  Further, according to the method proposed in Patent Document 3, although the rigidity of the retardation layer itself can be increased, subsidence deformation during external force loading can be suppressed to some extent, but there is a limit to the range of improvement in rigidity. Further, since this method requires the use of a polymerizable monomer having a special molecular skeleton structure as a material, the synthesis of the material is complicated, and an increase in manufacturing cost is also a problem.

  The present invention has been made in view of the above problems, that is, the thickness of the liquid crystal cell can be suitably maintained even when a pressing load is applied to the display panel, and is easy and inexpensive. Provided are a liquid crystal composition capable of forming a retardation layer that can be produced, a color filter including a retardation layer formed using the liquid crystal composition portion, and a liquid crystal display device using the same. Objective.

  In the present invention, when a liquid crystal composition containing a crosslinkable liquid crystal molecule is added with hydrophobic or hydrophilic inorganic fine particles, a retardation layer is formed on a substrate using the liquid crystal composition. This is based on the knowledge that the hardness of the retardation layer can be improved.

That is, the present invention
(1) A liquid crystal composition comprising a crosslinkable liquid crystal molecule and at least one kind of hydrophobic inorganic fine particles,
(2) A liquid crystal composition comprising a crosslinkable liquid crystal molecule and at least one kind of hydrophilic inorganic fine particles,
(3) The liquid crystal composition according to the above (1) or (2), wherein the crosslinkable liquid crystal molecule has at least one (meth) acryloyl group in at least one molecule.
(4) The liquid crystal composition according to any one of (1) to (3), wherein an average particle size of the inorganic fine particles is 500 nm or less.
(5) The liquid crystal composition according to any one of (1) to (4), wherein the inorganic fine particles are contained in an amount of 0.1% by weight or more and 20% by weight or less in terms of a formulation.
(6) The liquid crystal composition according to any one of (1) to (5) above, which contains a silane coupling agent,
(7) A colored layer and a retardation layer are laminated on a light-transmitting substrate, and the retardation layer is formed by curing the liquid crystal composition according to any one of (1) to (6). A color filter characterized by
(8) The retardation layer directly coats the liquid crystal composition according to any one of the above (1) to (6) on the substrate surface to form a liquid crystal coating film, and the surface of the liquid crystal coating film is irradiated with light. The color filter according to the above (7), which is formed by polymerizing crosslinkable liquid crystal molecules present in the liquid crystal coating film by irradiation treatment or heat treatment, thereby curing the liquid crystal coating film,
(9) The color filter according to any one of (7) and (8), wherein the crosslinkable liquid crystal molecules contained in the retardation layer are homeotropically aligned.
(10) The color filter according to any one of (7) to (9) above, wherein the retardation layer has a universal hardness of 300 mN / mm ² or more,
(11) A liquid crystal display device in which a liquid crystal material is sealed between an opposing display side substrate and a driving liquid crystal side substrate to form a driving liquid crystal layer, wherein the display side substrate is the above (7) to (10). A liquid crystal display device characterized by being a color filter according to any one of
Is a summary.

In addition, some terms used in this specification are defined as follows.
“Liquid crystal composition” means a composition which is a mixture containing at least a crosslinkable liquid crystal molecule and inorganic fine particles and further mixed with other substances used for forming a retardation layer, and the above mixture as a solvent. It means both the composition in the solution state prepared by dissolving or suspending in the solution. In the present specification, the liquid crystal composition of the present invention which is the above-described “composition in a solution state” is also referred to as a “liquid crystal composition solution” for convenience.

  The “(meth) acryloyl group” is used as a general term for two functional groups, “acryloyl group” and “methacryloyl group”. Examples of acryloyl groups include acrylate groups (acryloyloxy groups), and methacryloyl groups include methacrylate groups.

  “Comparison value of compound” means that when the liquid crystal composition of the present invention is the above mixture, each compound when the total weight of each compound formulated as a substance constituting the mixture is 100 In the case where the liquid crystal composition of the present invention is a solution obtained by dissolving or mixing the above-mentioned composition with a solvent, the weight obtained by subtracting the weight of the solvent from the weight of the solution (that is, dissolved or suspended in the solvent). It means the weight ratio of each compound when the total weight of each compound before turbidity is taken as 100.

  The “retardation layer” means a layer having a retardation control function capable of optically compensating for a change in retardation of light.

  “Homeotropic alignment” refers to an alignment state in which the optical axes of liquid crystal molecules constituting the retardation layer rise perpendicularly or substantially perpendicularly to the substrate surface. Further, “the retardation layer is homeotropically aligned” means that liquid crystal molecules constituting the retardation layer are homeotropically aligned. In the present invention, the ideal homeotropic alignment of the liquid crystal molecules means that the xyz orthogonal coordinate is assumed in the x-axis direction when the xyz orthogonal coordinate is assumed with the thickness direction of the retardation layer as the z-axis. The case where the refractive index ny is substantially the same and the phase difference value when the measurement angle is 0 ° is 4 nm or less, preferably 3.5 nm or less, more preferably 3 nm or less. .

  “Hydrophobic inorganic fine particles” are non-polar atomic groups having a very small affinity for water on the surface of inorganic fine particles, and the surface properties are hydrophobic, or the surface properties of the fine particles are hydrophobic. It means the fine particles that have been surface-treated.

  “Hydrophilic inorganic fine particles” are polar particles having a strong interaction with water on the surface of inorganic fine particles, and the surface properties are hydrophilic, or the surface properties of the fine particles are hydrophilic. Means surface-treated fine particles.

  The liquid crystal composition of the present invention contains crosslinkable liquid crystal molecules and hydrophobic or hydrophilic inorganic fine particles. According to this configuration, the liquid crystal composition of the present invention is applied onto the substrate surface to form a film (liquid crystal coating film), and a predetermined orientation is imparted to the crosslinkable liquid crystal molecules contained in the liquid crystal coating film. In the case where the crosslinkable liquid crystal molecules in the liquid crystal coating film are polymerized to cure the composition to form a retardation layer, the retardation layer is formed by inorganic fine particles while maintaining the excellent viewing angle improvement function of the retardation layer. Can increase the hardness. In addition, the retardation layer obtained from the liquid crystal composition can be easily and inexpensively manufactured and has excellent mechanical strength over a long period of time. For this reason, a color filter in which a retardation layer is formed from the liquid crystal composition of the present invention and a liquid crystal display device using this color filter as a display-side substrate exhibit an excellent viewing angle improvement effect over a long period of time.

  The liquid crystal composition of the present invention is a composition containing a crosslinkable liquid crystal molecule having a crosslinkable molecular structure, hydrophobic or hydrophilic inorganic fine particles, and a silane coupling agent.

(About crosslinkable liquid crystal molecules)
Examples of the crosslinkable liquid crystal molecules used in the liquid crystal composition of the present invention include nematic liquid crystal molecules having crosslinkability (crosslinkable nematic liquid crystal molecules). Examples of the crosslinkable nematic liquid crystal molecules include monomers, oligomers, and polymers having at least one polymerizable group such as a (meth) acryloyl group, an epoxy group, an octacene group, and an isocyanate group in one molecule. More specifically, as such a crosslinkable liquid crystal molecule, one compound (compound (I)) of the compounds represented by the general formula (1) shown in the following chemical formula 1 is used. One of the compounds represented by the general formula (2) shown (compound (II)) or a mixture of two or more, or the compounds shown in chemical formulas 3 and 4 (compound (III)) These compounds, a mixture of two or more kinds, or a mixture of these can be used.

In the general formula (1) shown in Chemical formula 1, each of R ¹ and R ² represents hydrogen or a methyl group, but at least R ¹ is required to broaden the temperature range in which the crosslinkable liquid crystal molecules exhibit a liquid crystal phase. And R ² is preferably hydrogen, more preferably hydrogen. X in the general formula (1) and Y in the general formula (2) may be any of hydrogen, chlorine, bromine, iodine, an alkyl group having 1 to 4 carbon atoms, a methoxy group, a cyano group, or a nitro group. Is preferably a chlorine or methyl group. Moreover, a and b which show the chain length of the alkylene group between the (meth) acryloyloxy group and aromatic ring of the both ends of the molecular chain of General formula (1), and d and e in General formula (2) are respectively 2 Although an arbitrary integer can be taken in the range of -12, it is preferable that it is the range of 4-10, and it is further more preferable that it is the range of 6-9. The compound (I) of the general formula (1) in which a = b = 0 or the compound (II) of the general formula (2) in which d = e = 0 has poor stability and is easily hydrolyzed, and the compound (I) or (II) itself has high crystallinity. Further, the compound (I) of the general formula (1) or the compound (II) of the general formula (2) in which a and b or d and e are each 13 or more has a low isotropic phase transition temperature (TI). For these reasons, both of these compounds have a narrow temperature range (temperature range in which the liquid crystal phase is maintained) that stably exhibits liquid crystallinity, and are not preferable for use in the liquid crystal composition of the present invention.

  As the crosslinkable liquid crystal molecules blended in the liquid crystal composition, the above-described chemical formula 1, chemical formula 2, chemical formula 3, and chemical formula 4 exemplify liquid crystal (polymerizable liquid crystal) monomers having polymerizable properties. Polymers or the like of polymerizable liquid crystals may be used. Also for these, known ones such as the above-described oligomers and polymers such as Chemical Formula 1, Chemical Formula 2, Chemical Formula 3, and Chemical Formula 4 can be appropriately selected and used.

  The retardation amount and the orientation characteristic indicating the characteristics of the retardation layer are determined by the birefringence Δn of the crosslinkable liquid crystal molecules and the film thickness of the retardation layer. For example, the retardation is obtained by homeotropically aligning the crosslinkable liquid crystal molecules. When forming an optical element having a layer, that is, a so-called positive C plate, Δn of the crosslinkable liquid crystal molecules is preferably about 0.03 to 0.20, and more preferably about 0.05 to 0.15.

  In the case of forming a retardation layer using the liquid crystal composition of the present invention, compound components other than the crosslinkable liquid crystal molecules in the liquid crystal composition are added so as to be 30% by weight or less in terms of the compound equivalent. It is desirable. If compound components other than the crosslinkable liquid crystal molecules are added in an amount of 30% by weight or more in terms of the compound, the orientation of the crosslinkable liquid crystal molecules may be deteriorated. However, this means that, in the case where a so-called negative C plate is prepared using a liquid crystal composition constituted by adding a chiral agent to be described later, a compound component other than the crosslinkable liquid crystal molecule is used as a counter compound. It does not exclude that 30% by weight or more in terms of conversion value is added and the addition amount of the crosslinkable liquid crystal molecules is less than 70% by weight.

(Inorganic fine particles in the present invention)
The liquid crystal composition of the present invention contains inorganic fine particles. As the inorganic fine particles, those having a hydrophobic surface or a hydrophilic surface can be used. When blended in the liquid crystal composition, one or more hydrophobic inorganic fine particles or one or more hydrophilic inorganic fine particles are used. That is, specific examples of the inorganic fine particles are listed below, but they may be used alone or in a plurality of arbitrarily selected types. However, it is not desirable to mix and mix the hydrophilic inorganic particles and the hydrophobic inorganic fine particles because of the problem of affinity with the solvent used when dissolving the liquid crystal composition to obtain the liquid crystal composition solution.

  Examples of the fine particles made of an inorganic material used in the present invention include silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. By using conductive inorganic fine particles such as ITO and ATO, antistatic properties can also be achieved.

  As more specific examples of silica fine particles, the fine particles whose surface properties are hydrophobic include, for example, commercially available silica particles AEROSIL50, AEROSIL200, OX50, RM50, RY200, R-805, R-976 manufactured by Nippon Aerosil Co., Ltd. , R-974, R-972, R-812, R-809, Hoechst's HDKH-2000, HVK21, HVK-2150, H-2000 / 4, H-2050EP, H-200, commercially available from Cabot Products TS-720, TS-530, TS-610, H-5, MS-5, MEK-ST manufactured by Nissan Chemical Co., Snowtech OL and the like. Examples of the fine particles having hydrophilic surface properties include commercially available silica particles 90G, 200V, and 300CF manufactured by Nippon Aerosil Co., Ltd.

  Further, as examples of more specific titanium fine particles, as the fine particles whose surface properties are hydrophobic, for example, commercially available product T-805 manufactured by Nippon Aerosil Co., Ltd., commercially available products MT-100S and MT-100T manufactured by Teika Co., Ltd. Examples include ST-455 manufactured by Titanium Industry Co., Ltd., commercial products TTO-51C and TTO-55C manufactured by Ishihara Sangyo Co., Ltd., and commercial products MEK-ST and MIBK-ST manufactured by Nissan Chemical Co., Ltd. Examples of the fine particles having hydrophilic surface properties include, for example, commercially available product P25 manufactured by Nippon Aerosil Co., Ltd., commercially available products MT-100SA, MT-500H, MT-500SAS, MT-600SA manufactured by Teika, and ST manufactured by Titanium Industry Co., Ltd. -495M, commercial products manufactured by Ishihara Sangyo Co., Ltd. TTO-51A, TTO-55A, commercial products manufactured by Nissan Chemical Co., Ltd. MA-ST-M, IPA-ST, and the like.

  As a more specific example of alumina fine particles, for example, a commercial product Alu C (hydrophilic) manufactured by Nippon Aerosil Co., Ltd. may be mentioned.

In addition, as long as the method of surface-treating inorganic fine particles and making the surface property hydrophobic is a conventionally well-known method, it can employ | adopt suitably. For example, the surface of the fine particles can be chemically covered with a CH ₃ group using a coupling agent or the like. Similarly, a conventionally known method may be appropriately employed as a method for surface-treating fine particles to make the surface property hydrophilic.

  A particularly preferred combination exists in the relationship between the inorganic fine particles and the solvent used in preparing the liquid crystal composition solution by dissolving the liquid crystal composition of the present invention. That is, when an organic solvent is used as a solvent, it is particularly desirable to use a liquid crystal composition in which hydrophobic inorganic fine particles are blended. On the other hand, when a solvent having a high affinity with a hydrophilic group such as an alcohol is used. In particular, it is desirable to use a liquid crystal composition containing hydrophilic inorganic fine particles.

Since the liquid crystal composition of the present invention is mainly used to form a retardation layer that exhibits a retardation control function, the inorganic fine particles added to the liquid crystal composition have excellent light transmittance or light scattering. It is desirable not to cause it. From this viewpoint, silica fine particles having excellent permeability are preferable. In the present invention, “silica” includes silicon dioxide (SiO ₂ ) as a pure chemical species, and further, regardless of the presence of silicon, the total silicon content contained in the sample, for example, silicate, silica This is a general term for acids, silicon dioxide, and the like.

The fine particles used in the present invention preferably have an average particle size of 500 nm or less, more preferably 100 nm or less, still more preferably 50 nm or less, and particularly preferably 20 nm or less.
When the average particle diameter of the fine particles is increased, the orientation of the crosslinkable liquid crystal molecules contained in the liquid crystal composition may be disturbed. However, in such a case, this problem can be solved by the following method. That is, as a means for satisfactorily bringing the planned alignment of the crosslinkable liquid crystal molecules, an alignment film can be provided, or an auxiliary agent or the like can be added. More specifically, for example, when the crosslinkable liquid crystal molecules are homeotropically aligned, it is effective to further add a vertical alignment aid, a silane coupling agent, and the like described later to the liquid crystal composition.
The problem of disorder of the orientation of the crosslinkable liquid crystal molecules often occurs particularly when the average particle diameter of the fine particles exceeds 500 nm. However, when the fine particles having an average particle diameter of 500 nm or less are used in the liquid crystal composition of the present invention. Even in such a case, in order to obtain a retardation layer exhibiting better orientation, means for assisting orientation such as addition of the above-described orientation aid may be used.

The compounding amount of the inorganic fine particles in the liquid crystal molecules of the present invention is preferably 1% by weight or more and 20% by weight or less in terms of the compound equivalent.
In particular, the upper limit of the blending amount is preferably 20% by weight or less, more preferably 15% by weight or less, still more preferably 10% by weight or less, and particularly preferably 6% by weight or less in terms of the amount of the compound. In addition, when the compounding quantity of inorganic fine particle increases, aggregation of fine particles will occur, and there exists a possibility that the hardness improvement effect of a phase difference layer may not be obtained as intended. Such a phenomenon of aggregation tends to be frequently observed particularly when the fine particles are blended in the liquid crystal composition in an amount exceeding 15% by weight. The aggregation can be prevented by further adding a known dispersant to the liquid crystal composition. From the viewpoint that there is no problem of agglomeration and the addition of a dispersant is not necessary from this point of view, the blending amount of the fine particles is preferably 15% by weight or less, particularly 6% by weight or less.

  On the other hand, the lower limit of the amount of fine particles in the present invention is preferably 1% by weight or more, more preferably 1.5% by weight or more, still more preferably 2% by weight or more, and particularly preferably 3% by weight in terms of the amount of the compound. That's it. Even if the blending amount is about 1% by weight, the effect of improving the hardness of the retardation layer formed using the same can be obtained, but depending on the fine particles used, the expected alignment of the crosslinkable liquid crystal molecules may be disturbed. In some cases, the optical characteristics are deteriorated. Therefore, from the viewpoint of obtaining the effect of improving the hardness of the retardation layer and maintaining good optical properties, the blending amount of the fine particles is preferably 1.5% by weight or more, and more preferably 3% by weight or more. preferable.

(About silane coupling agents)
A silane coupling agent can be blended in the liquid crystal composition of the present invention. As the silane coupling agent, mainly, a silane coupling agent containing a sulfide group, a silane coupling agent containing a mercapto group, a silane coupling agent containing an amino group, or a silane coupling agent having a (meth) acryloyl group. 1 type (s) or 2 or more types can be used.

By the way, the crosslinkable liquid crystal molecules contained in the liquid crystal composition are subjected to a polymerization reaction by light irradiation or heat treatment after the liquid crystal composition is directly applied on the upper surface of the substrate or the alignment film, thereby cross-linking each other. And exhibit the desired orientation. Here, as a result of the presence of contaminants of a certain size in the liquid crystal composition or a coating film formed by coating the liquid crystal composition on a substrate, the contaminants form a cross-linking that constitutes the retardation layer. The orientation of the liquid crystalline molecules may be disturbed.
Therefore, in the liquid crystal composition of the present invention, when there is a possibility that the alignment of the crosslinkable liquid crystal molecules contained in the liquid crystal composition is disturbed due to the presence of the inorganic fine particles, the particle diameter of the inorganic fine particles, surface treatment, etc. It is desirable to determine the fine particles in consideration of various factors. Alternatively, as another means, it is possible to broaden the selection range of the inorganic fine particles used by adding the silane coupling agent.

That is, when the silane coupling agent is added to a liquid crystal composition containing a crosslinkable liquid crystal molecule, the inventors configure the retardation layer when forming the retardation layer using the liquid crystal composition. It has been found that crosslinkable liquid crystal molecules can be aligned very well (for example, Japanese Patent Application No. 2006-164105). Based on this knowledge, the present inventors conducted further diligent research. As a result, even if the above-mentioned contaminants are present, the above-described alignment can be used as long as the liquid crystal composition has the silane coupling agent added in advance. It was found that the disturbance of the can be suppressed.
Therefore, the addition of the silane coupling agent to the liquid crystal composition of the present invention improves the hardness of the phase difference layer in the phase difference layer formed using the liquid crystal composition of the present invention containing inorganic fine particles, In addition, since the orientation of the crosslinkable liquid crystal molecules is well shown, an advantageous result of widening the selection range of the inorganic fine particles to be used is brought about.

Specific examples of the silane coupling agent used in the present invention include, for example, 3-mercaptopropylmethyldimethoxysilane (KBM-802 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-mercaptopropyltrimethoxy as mercapto-based silane coupling agents. Silane (KBS-803 manufactured by Shin-Etsu Chemical Co., Ltd., TSL8380 manufactured by Toshiba Silicone), 3-mercaptopropyltriethoxysilane (SIM6475.0 manufactured by Gelest), 11-mercaptoundecyltrimethoxysilane (SIM6480.0 manufactured by Gelest), Examples thereof include mercaptomethylmethyldiethoxysilane (SIM 6473.0 manufactured by Gelest), S- (octanoyl) mercaptopropyltriethoxysilane (SIM 6704.0 manufactured by Gelest), and the like.
Examples of the sulfide-based silane coupling agent include bis [3- (triethoxysilyl) propyl] tetrasulfide (KBE-846 manufactured by Shin-Etsu Chemical Co., Ltd.), bis [3- (triethoxysilyl) propyl] disulfide (Gelest). SIB1824.6), bis [m- (2-triethoxysilylethyl) tolyl] polysulfide (SIB1820.5 manufactured by Gelest), and the like.
Examples of the amino silane coupling agent include N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane (KBM-602 manufactured by Shin-Etsu Chemical Co., Ltd., TSL8345 manufactured by Toshiba Silicone Co., Ltd.), N-2 (aminoethyl) 3 -Aminopropyltrimethoxysilane (KBE-603 manufactured by Shin-Etsu Chemical Co., Ltd., TSL8340 manufactured by Toshiba Silicone), 3-aminopropyltriethoxysilane (KBE-603 manufactured by Shin-Etsu Chemical Co., Ltd., TSL8331 manufactured by Toshiba Silicone Co., Ltd.), 3-aminopropyltri Methoxysilane (Shin-Etsu Chemical KBM-903), 3-aminopropyltriethoxysilane (Shin-Etsu Chemical KBE-903), 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine (Shin-Etsu) Chemicals KBE-9103), N-phenyl-3- Mino trimethoxysilane (Shin-Etsu Chemical Co., Ltd. KBM-573), and the like.
Examples of the (meth) acryloyl-based silane coupling agent include 3-methacryloxypropylmethyldimethoxysilane (KBM-502 manufactured by Shin-Etsu Chemical Co., Ltd., TSL8375 manufactured by Toshiba Silicone Co., Ltd.), 3-methacryloxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.). KBM-503 manufactured by Toshiba Silicone Co., Ltd. TSL8370), 3-methacryloxypropylmethyldiethoxysilane (KBE-502 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyltriethoxysilane (KBE-503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-acryloxypropyltrimethoxysilane (KBE-5103 manufactured by Shin-Etsu Chemical Co., Ltd.), (3-acryloxypropyl) trimethoxysilane (SIA0200.0 manufactured by Gelest), methacryloxymethyltriethoxysilane (64 manufactured by Gelest) 2.0), it can be exemplified methacryloxy methyl trimethoxy silane (Gelest Inc. 6483.0) or the like.
Two or more different silane coupling agents or a combination of two or more different silane coupling agents can be used. As the silane coupling agent used in the present invention, the vertical alignment of crosslinkable liquid crystal molecules, particularly in the retardation layer. From the standpoint of realizing the above well, it is preferable to use a silane coupling agent having an amino group.

When one or more of a silane coupling agent containing a sulfide group, a silane coupling agent having a (meth) acryloyl group, and a silane coupling agent containing a mercapto group are used in combination, the formulation in the composition The amount may be added so as to be 1 to 20% by weight in terms of the compound, but it is added so as to be 1 to 10% by weight, more preferably 1 to 5% by weight.
In addition, in the following description of this specification, when it describes as "weight%" without a notice, it shall mean the conversion value with respect to a compound in the composition of this invention. By adding 1% by weight or more of the silane coupling agent, it is possible to impart sufficient alignment stability to the retardation layer, and when the addition amount is 20% by weight or less, the silane coupling agent Thus, it is possible to suppress the alignment failure of the liquid crystal molecules in the retardation layer or the decrease in the electrical reliability of the retardation layer to a negligible level.
The compounding ratio of the crosslinkable liquid crystal molecules and the silane coupling agent used in the liquid crystal composition of the present invention is preferably 2.0 parts by weight to 9.5 parts of the silane coupling agent with respect to 100 parts by weight of the crosslinkable liquid crystal molecules. Parts by weight.

The amount of the amino silane coupling agent is generally 0.01 to 20% by weight, preferably 0.01 to 5% by weight, and more preferably 0.01 to 2% by weight in terms of the compound. %, Particularly preferably 0.1 to 2% by weight. By adding 0.01% by weight or more of the silane coupling agent, it is possible to impart sufficient alignment stability to the retardation layer, and by adding 20% by weight or less, By adding the ring agent, it is possible to suppress a poor alignment of liquid crystal molecules in the retardation layer or a decrease in electrical reliability of the retardation layer to a negligible level.
The compounding ratio of the crosslinkable liquid crystal molecules and the silane coupling agent used in the liquid crystal composition of the present invention is preferably 0.5 parts by weight to 5.5 parts by weight of the silane coupling agent with respect to 100 parts by weight of the crosslinkable liquid crystal molecules. Parts by weight.

(About polymerization initiator)
In the liquid crystal composition, a polymerization initiator such as a photopolymerization initiator is usually blended. As the photopolymerization initiator, a radical polymerizable initiator can be used. Radical polymerizable initiators are compounds that generate free radicals by the energy of ultraviolet rays, for example, benzophenone derivatives such as benzoin and benzophenone or derivatives thereof; xanthone and thioxanthone derivatives; chlorosulfonyl, chloromethyl polynuclear aromatic compounds Halogen-containing compounds such as chloromethyl heterocyclic compounds and chloromethylbenzophenones; triazines; fluorenones; haloalkanes; redox couples of a photoreductive dye and a reducing agent; organic sulfur compounds; It is done. As photopolymerization initiators, Irgacure 184, Irgacure 369, Irgacure 651, Irgacure 907 (all manufactured by Ciba Specialty Chemicals), Darocur (Merck), Adeka 1717 (Asahi Denka Kogyo Co., Ltd.) Company-made), 2,2′-bis (o-chlorophenyl) -4,5,4′-tetraphenyl-1,2′-biimidazole (manufactured by Kurokin Kasei Co., Ltd.), etc. Etc. are preferred. These polymerization initiators can be used alone or in combination of two or more. When using 2 or more types together, it is preferable to combine polymerization initiators having different absorption wavelengths so as not to inhibit the absorption spectral characteristics.

  The photopolymerization initiator needs to be added within a range that does not impair the alignment performance of the crosslinkable liquid crystal molecules in the liquid crystal composition, and is generally 0.01 to 15% by weight in terms of the formulation, Preferably, it is added in an amount of 0.1 to 12% by weight, more preferably 0.5 to 10% by weight.

  In addition, although a polymerization inhibitor may be added to the liquid crystal composition, the storage stability of the liquid crystal composition can be further improved. In addition to the photopolymerization initiator, a sensitizer, a surfactant and the like can be appropriately added to the liquid crystal composition as long as the object of the present invention is not impaired.

(About retardation layer)
The liquid crystal composition of the present invention is applied directly on a substrate, and a cross-linkable liquid crystal molecule contained in the liquid crystal composition is crosslinked to form a retardation layer having a birefringence control function. Can do. The coated surface side of the base material may be a light-transmitting substrate surface, or may be another constituent layer such as a colored layer surface or an alignment film surface. Then, the color filter of the present invention is formed by forming the colored layer and the retardation layer in this order or in the reverse order on the substrate having optical transparency. The color filter can be used as an optical element that enables colorization in a liquid crystal display device and exhibits a birefringence control function. The color filter of the present invention does not exclude that layers other than the substrate, the retardation layer, and the colored layer are further laminated.

By using the liquid crystal composition of the present invention and fixing the crosslinkable liquid crystal molecules contained in the liquid crystal composition by vertical alignment (homeotropic alignment), the optical axis of the liquid crystal molecules is normal to the retardation layer. It is possible to form a so-called positive C plate that faces the direction and has an extraordinary ray refractive index larger than the ordinary ray refractive index in the normal direction of the retardation layer. In such a case, the crosslinkable liquid crystal molecules in the composition can be vertically aligned by using a known vertical alignment film. In order to make the vertical alignment state of the crosslinkable liquid crystal molecules more stable and reliable, a vertical alignment assistant may be further added to the liquid crystal composition in combination with the above vertical alignment film or alone.
The vertical alignment aid has an effect of making the alignment state of the crosslinkable liquid crystal molecules more stable and reliable when the crosslinkable liquid crystal molecules are homeotropically aligned. The vertical alignment aids include surface coupling agents having vertically aligned alkyl or fluorocarbon chains, such as lecithin or quaternary ammonium surfactants such as HTAB (hexadecyl-trimethylammonium bromide), DMOAP (N, N Specific examples include (dimethyl-N-octadecyl-3-aminopropyltrimethoxysilyl chloride) or N-perfluorooctylsulfonyl-3-aminopropyltrimethylammonium iodide, silane polymer, and long-chain alkyl alcohol.

  The vertical alignment aid is blended so as to be 0.1 to 10% by weight, preferably 0.5 to 5% by weight, in terms of the compound. The blending amount of the vertical alignment aid is particularly preferably 0.8 to 2% by weight in terms of blending value. When the content of the vertical alignment aid relative to the total weight of the composition component is less than 0.1% by weight, it may not sufficiently contribute to imparting homeotropic alignment to the crosslinkable liquid crystal molecules contained in the liquid crystal composition. Yes, when the content exceeds 10% by weight, the alignment performance of the crosslinkable liquid crystal molecules in the liquid crystal composition is disturbed, and when the liquid crystal composition is cured by crosslinking polymerization of the crosslinkable liquid crystal molecules, the curing rate decreases. There is a risk of causing problems such as lowering the crosslink density.

  Further, when the positive C plate is prepared, the effect of improving the alignment by the above-described blending of the silane coupling agent in the liquid crystal composition of the present invention is particularly good, and the silane coupling agent and the vertical alignment aid are further improved. Both agents may be blended. According to the liquid crystal composition in which the vertical alignment aid and / or the silane coupling agent is blended, when the retardation layer is formed using the liquid crystal composition, a very stable and good homeotropic alignment is obtained. Therefore, the formation of an alignment film for promoting the alignment of the retardation layer can be omitted, which is advantageous in terms of reducing the number of steps and reducing the layer thickness.

  Further, the retardation layer formed by using the liquid crystal composition of the present invention has an extraordinary ray refractive index larger than the ordinary ray refractive index while the optical axis of the crosslinkable liquid crystal molecules is parallel to the retardation layer. It can be formed as a so-called positive A plate having an inward direction. In such a case, a leveling agent is applied to the phase difference layer to suppress the surface free energy of the crosslinkable liquid crystal molecules with respect to the air interface by applying the alignment regulating force by the horizontal alignment film subjected to the rubbing treatment to the crosslinkable liquid crystal molecules. By adding to the liquid crystal composition, the molecules can be horizontally aligned.

  Furthermore, by using the liquid crystal composition of the present invention, the optical axis of the crosslinkable liquid crystal molecules is parallel to the retardation layer and has an extraordinary ray refractive index smaller than the ordinary ray refractive index in the normal direction of the retardation layer. A negative C-plate can be created. The negative C plate means a retardation layer in which a chiral nematic liquid crystal structure is realized by imparting cholesteric regularity to crosslinkable liquid crystal molecules contained in the liquid crystal composition. Specifically, a known chiral agent may be added after horizontally aligning the crosslinkable liquid crystal molecules in the same manner as the positive A plate. The chiral agent used in the present invention does not necessarily have a crosslinking property, but in consideration of the thermal stability of the obtained retardation layer, the crosslinking contained in the liquid crystal composition for the retardation layer. It is preferable to use a chiral agent having a crosslinking ability that can be immobilized with a state in which the cholesteric regularity is imparted to the crosslinkable liquid crystal molecules by polymerizing with the crosslinkable liquid crystal molecules. As such a chiral agent, those having a crosslinkable functional group at both ends of the molecular structure are more preferable for improving the heat resistance of the retardation layer.

  The chiral agent is preferably a low molecular weight compound having an optically active site in the molecule and having a molecular weight of 1500 or less. Also, the compound of the compound (I) shown in Chemical formula 1, the compound (II) shown in Chemical formula 2, and the compound (III) shown in Chemical formula 3 and Chemical formula 4 are compatible with each other in a solution state or a molten state, and are crosslinkable nematic liquid crystal molecules. Those capable of inducing a helical pitch without impairing the liquid crystallinity of these are preferred.

  Examples of the chiral agent that can be used in the present invention include a compound having one or more asymmetric carbons, a compound having an asymmetric point on a heteroatom such as a chiral amine, a chiral sulfoxide, or the like. And compounds having axial asymmetry such as binaphthol. Depending on the nature of the selected chiral agent, it may cause nematic regularity breakage and orientation degradation, and in the case of non-polymerizable chiral agent, it will not only cause the curing performance to deteriorate due to polymerization of crosslinkable liquid crystal molecules. In addition, there is a risk of reducing the electrical reliability of the retardation layer formed using the liquid crystal composition, and the use of a large amount of a chiral agent having an optically active site increases the cost. Accordingly, as the chiral agent used in the present invention, it is preferable to select a chiral agent having a large effect of inducing a helical pitch in the orientation of the crosslinkable liquid crystal molecules even in a small amount, and in particular, the use of a low molecular compound having axial asymmetry in the molecule. Is preferred. More specifically, as the chiral agent, for example, a commercially available product such as S-811 manufactured by Merck can be used.

  The optimum range of the amount of the chiral agent is appropriately determined in consideration of the ability to induce helical pitch and the degree of cholesteric regularity of the crosslinkable liquid crystal molecules contained in the finally obtained retardation layer. It varies greatly depending on the type of liquid crystal molecules. Specifically, the chiral agent is generally 0.01 to 30% by weight, preferably 0.1 to 20% by weight, and more preferably 0.5 to 15% by weight in terms of the compound. Is blended into A particularly preferable amount of the chiral agent is 1 to 15% by weight in terms of the compound. When the content of the chiral agent in the composition component is less than 0.01% by weight, the cholesteric regularity may not be sufficiently imparted to the crosslinkable liquid crystal molecules contained in the liquid crystal composition. In the case of exceeding, the alignment performance of the crosslinkable liquid crystal molecules in the liquid crystal composition is hindered, and when the liquid crystal composition is cured by crosslinking polymerization of the crosslinkable liquid crystal molecules, the curing rate is lowered or the crosslinking density is lowered. May cause problems.

(About solvent)
The liquid crystal composition of the present invention may be formed by mixing components such as the crosslinkable liquid crystal molecules constituting the liquid crystal composition, or may be formed in a state of being suspended or dissolved in a solvent as appropriate. . When the liquid crystal composition is in a state of a liquid crystal composition solution dissolved in a solvent, the coating property of the liquid crystal composition on the substrate surface can be improved. The solvent is not particularly limited as long as it can dissolve compound components such as the above-described crosslinkable liquid crystal and silane coupling agent and does not impair the performance of the counterpart material to be applied. .

  Specific examples of the solvent include hydrocarbons such as benzene, toluene, xylene, n-butylbenzene, diethylbenzene, and tetralin, ethers such as methoxybenzene, 1,2-dimethoxybenzene, and diethylene glycol dimethyl ether, acetone, and methyl ethyl ketone. , Ketones such as methyl isobutyl ketone, cyclohexanone, 2,4-pentanedione, esters such as ethyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, γ-butyrolactone, 2- Amido solvents such as pyrrolidone, N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, chloroform, dichloromethane, carbon tetrachloride Halogen solvents such as dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, orthodichlorobenzene, t-butyl alcohol, diacetone alcohol, glycerin, monoacetin, ethylene glycol, triethylene glycol, hexylene glycol, ethylene glycol monomethyl ether, ethyl One type or two or more types of alcohols such as cellsolve and butylcellsolve and phenols such as phenol and parachlorophenol can be used. If only one type of solvent is used and the solubility of the compound components such as the crosslinkable liquid crystal monomer is insufficient, or if there is a risk that the material of the other side to be coated may be affected, two or more types of solvents may be used. These disadvantages can be avoided by mixing the solvents. Among the above-mentioned solvents, hydrocarbon solvents and glycol monoether acetate solvents are preferable as the sole solvent, and preferable solvents are ethers or ketones and glycols mixed. It is a mixed solvent. The concentration of the compound component of the birefringence functional layer composition liquid varies depending on the solubility of the compound component used in the birefringence functional layer composition liquid in the solvent and the layer thickness desired for the birefringence functional layer. Is in the range of 1 to 60% by weight, preferably 3 to 40% by weight.

  According to the liquid crystal composition of the present invention, it can be applied to a substrate to form a retardation layer to form an optical element. This optical element can be used as an element that can be incorporated in a liquid crystal display device and can exhibit a phase difference compensation function for adjusting a viewing angle.

  Further, according to the liquid crystal composition of the present invention, a retardation layer can be directly formed on a member constituting the liquid crystal display device. For example, the retardation layer is provided on a color filter constituting the liquid crystal display device. it can. Even in this case, the retardation layer can exhibit a retardation compensation function for adjusting the viewing angle in the liquid crystal display device.

  Next, a color filter provided with a retardation layer will be described with reference to the drawings.

FIG. 1 shows one embodiment of a color filter in the present invention.
The color filter 1 is provided with a black matrix 5 (BM), a red (R) sub-pixel 6, a green (G) sub-pixel 7, and a blue (B) sub-pixel 8 on the surface of the substrate 2 to provide a colored layer. 3 is formed, and the retardation layer 4 is further laminated on the surface of the colored layer 3. Furthermore, a plurality of spacers 9 arranged at arbitrary intervals are formed on the surface of the retardation layer 4.

  The substrate 2 is preferably transparent and optically isotropic with light transmission, but if necessary, a region having optical anisotropy or a region having light shielding properties is locally applied. It can also be provided. The light transmittance can be appropriately selected according to the use of the color filter.

  Specifically, the substrate 2 may be a base material (organic base material) based on an organic material in addition to a base material based on an inorganic material such as glass, silicon, or quartz. Examples of organic base materials include acrylic resins such as polymethyl methacrylate, polyamide, polyacetal, polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, or syndiotactic polystyrene, polyphenylene sulfide, polyether ketone, poly Ether ether ketone, fluororesin, or polyether nitrile, polycarbonate, modified polyphenylene ether, polycyclohexene, polynorbornene resin, or the like, or polysulfone, polyethersulfone, polypropylene, polyarylate, polyamideimide, polyetherimide, Examples thereof include polyether ketones or thermoplastic polyimides. It can be used those composed of specific plastics. Also about the thickness of the board | substrate 2, the thing of about 5 micrometers-3 mm is used according to a use, for example.

  A black matrix 5 (BM) is provided on the substrate 2 in a predetermined position and pattern, and further, a red (R) subpixel 6, a green (G) subpixel 7, and a blue (B) subpixel. Sub-pixels 8 are sequentially provided, and the colored layer 3 is formed by a black matrix 5 (BM), a red (R) sub-pixel 6, a green (G) sub-pixel 7, and a blue (B) sub-pixel 8. It is formed.

  The black matrix 5 is an area corresponding to the position where the sub-pixels (colored sub-pixels) 6, 7, 8 of each color are arranged on the surface of the substrate 2, for each colored sub-pixel 6, 7, 8 in plan view. It is formed so as to be partitioned.

  The black matrix 5 can be formed by patterning a light-shielding or light-absorbing metal thin film such as a metal chromium thin film or a tungsten thin film on the surface of the substrate 2 in a predetermined shape. The black matrix 5 can also be formed by printing an organic material such as a black resin in a predetermined shape.

  The red (R) sub-pixel 6, the green (G) sub-pixel 7, and the blue (B) sub-pixel 8 constituting the coloring layer 3 are each made by dispersing coloring materials for red, green, and blue in a solvent, respectively. In addition to being formed by patterning the coating film of the colored material dispersion liquid into a predetermined shape by, for example, photolithography, a solution (coloring material dispersion liquid) in which the coloring material corresponding to each color of the colored sub-pixel is dispersed is formed. Patterning can also be performed by applying in a predetermined shape. As a patterning pattern for applying the coloring material dispersion, various patterns such as a stripe type, a mosaic type, and a triangle type can be appropriately selected.

  However, in the present invention, the black matrix 5 may not be necessary depending on the use of the color filter 1 and optical specifications, and when it is used, in addition to a rectangular lattice shape, a stripe shape or a triangular lattice shape may be used. There is also.

  The color pattern constituting the colored layer 3 can also be a CMY system that is a complementary color system in addition to the RGB system of three colors, and further, in the case of a single color or two colors, or more than four colors. Cases can also be taken.

  The retardation layer 4 is formed by forming a film as follows using the liquid crystal composition of the present invention.

  On the surface of the colored layer 3, the liquid crystal composition of the present invention is applied to form a liquid crystal coating film. For the application of the liquid crystal composition, for example, gravure printing, offset printing, relief printing, screen printing, transfer printing, electrostatic printing, plateless printing, gravure coating, roll coating, etc. Coating methods such as coating method, knife coating method, air knife coating method, bar coating method, dip coating method, kiss coating method, spray coating method, die coating method, comma coating method, ink jet method, spin coating method, slit coating method, etc. A combination of these methods can be used as appropriate.

  In forming the liquid crystal coating film, when the surface of the colored layer 3 is preliminarily subjected to a process of irradiating UV (ultraviolet light) (UV cleaning process) or a process of applying corona discharge (corona process), The wettability of the colored layer 3 is improved, and the contact between the colored layer 3 and the liquid crystal coating film can be made closer, which is preferable.

  When the liquid crystal coating film is formed on the colored layer 3, the crosslinkable liquid crystal molecules are crosslinked and polymerized by imparting a predetermined orientation to the crosslinkable liquid crystal molecules contained in the liquid crystal coating film.

  For example, when the liquid crystal coating film is used as the retardation layer 4 having a function as a positive C plate, the crosslinkable liquid crystal molecules are polymerized by homeotropic alignment of the crosslinkable liquid crystal molecules in the liquid crystal coating film. Giving homeotropic alignment to the crosslinkable liquid crystal molecules means that the liquid crystal coating film is heated by means of heating with infrared rays, etc., and the temperature of the liquid crystal coating film is changed so that the crosslinkable liquid crystal contained therein has a liquid crystal phase. The temperature (liquid crystal phase temperature) is equal to or higher than the temperature at which the crosslinkable liquid crystal becomes the isotropic phase (liquid phase).

  In addition, the polymerization (crosslinking polymerization) between the crosslinkable liquid crystal molecules imparted with alignment in the liquid crystal coating film is performed by using light having a photosensitive wavelength such as a cross-linked liquid crystal molecule or a photopolymerization initiator contained in the liquid crystal composition. It can be advanced by irradiating the surface. At this time, the wavelength of light applied to the liquid crystal coating film is appropriately selected according to the absorption wavelength of the liquid crystal composition, but is generally about 200 to 500 nm. The light applied to the liquid crystal coating film is not limited to monochromatic light, and may be light having a certain wavelength range including the photosensitive wavelength of the photopolymerization initiator. In addition, in making the liquid crystal coating film into the retardation layer 4, the liquid crystal coating film is irradiated with light to advance the crosslinking polymerization reaction of the crosslinkable liquid crystal molecules, and the liquid crystal coating film is further baked using an oven or the like. It may be done. By performing such firing, the polymerization reaction of the crosslinkable liquid crystal molecules contained in the retardation layer 4 can be promoted.

  Thus, the crosslinkable liquid crystal molecules contained in the liquid crystal coating film are polymerized to form the retardation layer 4 fixed in a state where the crosslinkable liquid crystal molecules are aligned in a desired direction.

The spacer 9 formed on the surface of the retardation layer 4 is made of, for example, a photo-curable photosensitive paint made of a material such as an acrylic-based and amide-based or ester-based polymer containing a polyfunctional acrylate. It is applied and dried, exposed through a mask having a pattern corresponding to the position where the spacer 9 is to be formed, and then developed to remove the photosensitive paint other than the position where the spacer is to be formed, thereby forming the spacer. It can be formed by baking the photosensitive paint left at the predetermined position.
The spacer 9 is made of a photo-curable photosensitive paint made of a material such as an acrylic, amide or ester polymer containing a polyfunctional acrylate, on the other of the retardation layer 4, the colored layer 3 or the protective layer. It is formed by applying to the substrate and drying it, further exposing and curing the paint through a mask pattern corresponding to the position where the spacer 9 is to be formed, etching away the uncured portion, and firing the whole. The

  In the color filter of the present invention, the spacer 9 is not an indispensable structure, and another embodiment of the color filter that saves the spacer 9 can be implemented. Further, as shown in FIG. 1, the spacer 9 is not only formed on the upper surface of the retardation layer 4, but in the color filter laminated in the order of the substrate, the retardation layer, and the colored layer, the upper surface of the colored layer, Or it can form on the upper surface of the layer (for example, protective layer etc.) further laminated | stacked on the upper surface of the phase difference layer 4. FIG.

  The protective layer is made of a transparent resin material made of a material such as an acrylic, amide or ester polymer containing a polyfunctional acrylate, or a material such as an acrylic, amide or ester polymer containing a polyfunctional epoxy. The transparent resin paint to be formed can be applied to the surface of the base material and further dried and cured to form the transparent resin paint. For the curing of the protective layer, for example, a method of irradiating with UV light can be employed according to the properties of the transparent resin material.

  In the color filter 1 shown in FIG. 1, although this invention was demonstrated using the aspect in which the phase difference layer 4 was formed in the colored layer 3 upper surface, this aspect does not restrict | limit the color filter of this invention, for example, A retardation layer may be first formed on the upper surface of the substrate, and a colored layer may be further formed on the upper surface of the retardation layer.

The color filter 1 of the present invention, the universal hardness of the phase difference layer 4 (UH _C) is preferably at 300 mN / mm ² or more, more preferably 350mN / mm ² or more, more preferably 400 mN / mm ² or more Hardness is desirable. If the hardness of the phase difference layer 4 shows the said preferable range, when using the color filter of this invention provided with this phase difference layer as a member for liquid crystal display devices of a touch panel system, for example, a user has a strong pressing force Even when the screen is touched, local deformation of the retardation layer can be prevented, and the problem of light leakage and color tone variation can be prevented by reducing the amount of retardation. Similarly, even when a pressure is applied to the display screen from the outside during a work process using the color filter or during transportation of a liquid crystal display device including the color filter, the local deformation of the retardation layer is similarly performed. Can be prevented. Accordingly, the hardness of the retardation layer in the present invention is preferably as long as it is hard from the above viewpoint.

In addition, the layer hardness of the retardation layer described in the present invention means so-called universal hardness, and the measuring method thereof is a Fisherscope H-manufactured by Fisher Instruments Co., Ltd. equipped with a Vickers indenter (square pyramid shape). Using 100, a load was applied to the retardation layer surface at a rate of 0.3 mN / sec in the thickness direction up to 3 mN at room temperature, held for 5 seconds, and then loaded at a rate of 0.3 mN / sec in the thickness direction. The deformation (μm) after removing and holding for 5 seconds in a state where the load is 0 mN can be measured to measure the universal hardness of the retardation layer.
In consideration of the non-uniform thickness of the retardation layer of the test piece, measurement is performed under the same conditions at a plurality of locations for each test, and the average of the obtained results is defined as the universal hardness of the test piece.

  In a color filter in which a colored layer or other layer is formed on the upper surface of the retardation layer, when measuring the universal hardness, other layers such as a colored layer laminated on the side of the retardation layer that is not on the transparent substrate side Is removed, and the surface of the retardation layer is exposed on the side opposite to the transparent substrate side, whereby the universal hardness can be measured.

  As shown in FIG. 2, the color filter 1 of the present invention has a liquid crystal material (driving liquid crystal material) between two opposing substrates (a display side substrate 12 and a driving circuit side substrate 13 as a driving liquid crystal side substrate). 14) In the liquid crystal display device 11 formed by appropriately arranging the linear deflection plates 23, 32, etc. in the liquid crystal cell 15 formed by enclosing the drive liquid crystal layer and enclosing the liquid crystal display device 11, the observer side of the liquid crystal display device 11 It can be used as the display-side substrate 12 installed (corresponding to the upper part in the figure). In the case of the example of FIG. 2, the retardation layer 4 of the color filter 1 is fixed in a state where, for example, the crosslinkable liquid crystal molecules are homeotropically aligned with respect to the transparent substrate 2 (sometimes referred to as a transparent substrate). The positive C plate is formed.

  The driving circuit side substrate 13 includes a driving circuit 33 on the in-cell side of the transparent substrate 31 (side on which the driving liquid crystal material 14 is sealed), and a driving electrode 34 that controls the voltage load. Is provided.

  When the liquid crystal display device 11 is in the IPS mode, the linearly polarizing plate 23 of the display side substrate 12 and the linearly polarizing plate 32 of the driving circuit side substrate 13 are arranged so that their transmission axes are orthogonal to each other. ing.

  Further, in the liquid crystal display device 11, if necessary, a transparent conductive film 21 is interposed so as to be sandwiched between the display side substrate 12 and the linear deflection plate 23, and a retardation film such as a positive A plate 22 is interposed. 20 may be interposed, and a negative C plate may be further interposed.

  According to the color filter 1 of the present invention, the retardation layer 4 is disposed inside the liquid crystal cell so as to be sandwiched between the transparent substrate 2 of the color filter 1 and the transparent substrate 31 constituting the driving circuit side substrate 13. It is possible to form a liquid crystal display device that is disposed and includes a so-called in-cell type retardation layer 4.

Example 1
A mixture of compounds (a) to (d) shown in the following chemical formula 8 is used as a crosslinkable liquid crystal molecule, BHT (2,6-di-tert-butyl-4-hydroxytoluene) as a polymerization inhibitor, and Irgacure 907 as a polymerization initiator. In addition, dodecanol was used as an additive, and these were mixed to prepare a composition (Composition A) having the following composition. Composition A was produced according to the description in JP-T-2004-524385.

Component A of composition A (a) 32.67% by weight
Compound (b) 18.67% by weight
Compound (c) 21.00% by weight
Compound (d) 21.00% by weight
Dodecanol 1.02% by weight
BHT 0.04% by weight
Irgacure 907 5.60% by weight

  To the composition A, silica powder (T-RM50 manufactured by Nippon Aerosil Co., Ltd., particle size 40 nm, hydrophobic) is added as fine particles in an amount of 5% by weight with respect to the formulation, and as a solvent. It melt | dissolved with propylene glycol monomethyl ether acetate (PGMEA), and obtained the liquid crystal composition solution whose compounding component density | concentration is 20 weight%. Here, the compounding component concentration indicates the weight ratio of the entire compounding component excluding the solvent with respect to the total weight of the liquid crystal composition solution.

A glass substrate (manufactured by Corning, 1737 glass) (dimensions: length 100 mm × width 100 mm × thickness 0.7 mm) was set on a spin coater (manufactured by Mikasa, 1H-360S), and obtained on the glass substrate as described above. The liquid crystal composition was spin-coated to form a liquid crystal coating film, which was dried under reduced pressure. Next, the glass substrate on which the liquid crystal coating film was formed was irradiated with ultraviolet rays (365 nm) at 20 mW / cm ² for 10 seconds by an ultraviolet irradiation device having an ultrahigh pressure mercury lamp (“TOSCURE 751” manufactured by Harrison Toshiba Lighting Co., Ltd.). The crosslinkable liquid crystal molecules contained in the liquid crystal coating film are cross-linked and polymerized, and then baked at 230 ° C. for 30 minutes using an oven to form the liquid crystal coating film as a retardation layer (film thickness: 1.5 μm). An optical element having a layer formed thereon was obtained as Example 1.

  For the retardation layer formed in the obtained optical element, the alignment state and hardness of the crosslinkable liquid crystal molecules were measured.

(Evaluation 1) Alignment state of crosslinkable liquid crystal molecules (alignment)
The alignment state of the crosslinkable liquid crystal molecules contained in the retardation layer formed in the optical element was evaluated by measuring the retardation produced when light having a wavelength of 589 nm passed through the retardation layer as follows. The retardation layer was measured using RETS-1250AV manufactured by Otsuka Electronics.

  As shown in FIG. 3, an x-axis and a y-axis orthogonal to each other are assumed on the surface S of the retardation layer of the optical element, and a z-axis perpendicular to the x-axis and the y-axis is assumed. And the phase difference of the optical element was measured about the z-axis direction and the direction inclined in the x-axis direction and the y-axis direction with respect to the z-axis. In addition, when measured in the direction tilted in the x-axis direction, when measured in the direction tilted in the y-axis direction, it is measured whether or not the phase difference generated in the optical element exhibits symmetry with respect to the z-axis. did. Based on these measurement results, the quality of the orientation as to whether or not the crosslinkable liquid crystal molecules are homeotropically oriented was evaluated as follows. The results are shown in Table 1. In addition, taking Example 1 as an example, a graph showing that the phase difference is symmetrical in both the x-axis direction and the y-axis direction and the value of the phase difference in the z-axis direction is 4 nm or less is shown in FIG.

The phase difference exhibits symmetry in both the x-axis direction and the y-axis direction, and the phase difference value in the z-axis direction is 4 nm or less.
The phase difference is symmetric in both the x-axis direction and the y-axis direction, or the phase difference value in the z-axis direction satisfies 4 nm or less.
The phase difference is disturbed in symmetry in both the x-axis direction and the y-axis direction, and the value of the phase difference in the z-axis direction is larger than 4 nm.

  In addition, regarding the reference of the above-mentioned retardation of 4 nm, when a phase difference is generated between two polarizing plates arranged in crossed Nicols and light is transmitted through the two polarizing plates, it is visually checked. In addition, the reference value of the phase difference that falls within such a range that light transmission cannot be confirmed is 4 nm.

(Evaluation 2) Presence or absence of aggregation of fine particles Depending on the mixing ratio of the fine particles, an aggregate of fine particles may be generated in the retardation layer. The presence or absence of fine particle aggregates generated in the retardation layer was visually confirmed using an optical microscope.

(Evaluation 3) Retardation layer hardness (layer hardness)
For the retardation film obtained in Example 1, a Fischer Instruments H-100 manufactured by Fisher Instruments Co., Ltd. equipped with a Vickers indenter (quadrangular pyramid shape) was used, and the thickness was 0.3 mN / sec in the thickness direction at room temperature. After applying a load up to 3 mN and holding it for 5 seconds, remove the load at a rate of 0.3 mN / sec in the thickness direction, and measure the deformation (μm) after holding for another 5 seconds with the load applied at 0 mN. The universal hardness of the retardation layer was measured. The results are shown in Table 1.

Example 2
A liquid crystal composition solution was prepared in the same manner as in Example 1 except that titanium powder (T-805 manufactured by Nippon Aerosil Co., Ltd., particle size 21 nm, hydrophobic) was used as the fine particles, and this was used to form a retardation layer. The formed optical element was produced as Example 2. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation, presence / absence of aggregation of fine particles, and layer hardness were measured. evaluated. The results are shown in Table 1.

Example 3
A liquid crystal composition solution was prepared in the same manner as in Example 1 except that silica powder (R-972 manufactured by Nippon Aerosil Co., Ltd., particle size of 16 nm, hydrophobic) was used as the fine particles, and this was used to form a retardation layer. And an optical element was manufactured as Example 3. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation, presence / absence of aggregation of fine particles, and layer hardness were measured. evaluated. The results are shown in Table 1.

Comparative Example 1
A liquid crystal composition solution was prepared in the same manner as in Example 1 except that fine particles were not used, and an optical element in which a retardation layer was formed using this was prepared as Comparative Example 1. For the retardation layer of the obtained optical element, the orientation state of the crosslinked liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation, presence / absence of fine particle aggregation, and layer hardness were evaluated. did. The results are shown in Table 1.

  According to the liquid crystal composition of the present invention according to Examples 1 to 3 and Comparative Example 1, the alignment of the cross-linked liquid crystal molecules contained in the retardation layer with respect to the retardation layer formed using the liquid crystal composition. It can be seen that the hardness of the retardation layer can be improved while maintaining the properties.

Example 4 to Example 7
As fine particles, the amount of silica powder (Nippon Aerosil Co., Ltd., R-972, particle size 16 nm, hydrophobic) was changed to 1% by weight, 3% by weight, 15% by weight, and 20% by weight, respectively, in terms of the compound equivalent. Except for the above, a liquid crystal composition solution was prepared in the same manner as in Example 1, and an optical element in which a retardation layer was formed using the liquid crystal composition solution was prepared, and in order, Example 4, Example 5, Example 6, and Example 7 was adopted. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation, presence / absence of aggregation of fine particles, and layer hardness were measured. evaluated. The amount of the composition A was adjusted as shown in Table 2 along with the change in the amount of silica powder. The results are shown in Table 2.

  Examples 4 to 7 show that the hardness enhancement effect of the retardation layer can be obtained even by adding a very small amount of fine particles. However, in Example 4 in which 1% by weight of fine particles were added to the liquid crystal composition, it was found that the alignment of the retardation layer tends to be somewhat disturbed. In Example 7 where the amount of fine particles added was as high as 20% by weight, aggregation of the fine particles was confirmed.

Next, liquid crystal compositions were prepared using fine particles having different particle diameters, and optical elements were obtained as follows. These were designated as Examples 8 to 11.

Example 8
A retardation layer was formed in the same manner as in Example 3 except that 3-mercaptopropylmethyldimethoxysilane (KBM-802 manufactured by Shin-Etsu Chemical Co., Ltd.) was further used in Example 3 as a mercapto-based silane coupling agent. An optical element was produced as Example 8. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 3.

  In addition, the compounding quantity of the composition A was adjusted as shown in Table 3 by addition of the silane coupling agent. The same applies to Examples 9 to 11 below.

Example 9
Silica powder (R-974 manufactured by Nippon Aerosil Co., Ltd., particle size 12 nm, hydrophobic) is used as the fine particles, and 2-mercaptopropylmethyldimethoxysilane (KBM-802 manufactured by Shin-Etsu Chemical Co., Ltd.) is used as the mercapto-based silane coupling agent. An optical element having a retardation layer was produced in the same manner as in Example 3 except that wt% was used, and Example 9 was obtained. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 3.

Example 10
Silica powder (MEK-ST manufactured by Nissan Chemical Industries, particle size 20 nm, hydrophobic) is used as fine particles, and 3-ethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine is used as an amino-based silane coupling agent. An optical element having a retardation layer was produced in the same manner as in Example 3 except that 1 wt% (KBE-9103 manufactured by Shin-Etsu Chemical Co., Ltd.) was used. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 3.

Example 11
Silica powder (Snowtech OL manufactured by Nissan Chemical Industries, particle size 50 nm, hydrophobic) is used as fine particles, and 3-ethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine is used as an amino-based silane coupling agent. An optical element having a retardation layer formed in the same manner as in Example 1 except that 3% by weight (KBE-9103 manufactured by Shin-Etsu Chemical Co., Ltd.) was used was prepared as Example 11. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 3.

Example 12
An optical element in which a retardation layer was formed in the same manner as in Example 11 except that no amino-based silane coupling agent was used as fine particles was prepared as Example 12. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 3.

  According to Examples 8 to 12, it was shown that even when the particle diameters of the added fine particles are different, the effect of improving the hardness can be obtained satisfactorily.

  Further, according to Example 10 and Example 11, even when the orientation of the retardation layer is disturbed due to the addition of fine particles, the disorder of the orientation is improved by the addition of the silane coupling agent. It has been shown.

  Next, the effect | action of these microparticles | fine-particles was compared using the Example and reference example from which the surface property of the microparticles | fine-particles to be used differs.

Example 13
A liquid crystal composition solution was prepared in the same manner as in Example 3 except that silica powder (R-202 manufactured by Nippon Aerosil Co., Ltd., particle size: 14 nm, hydrophobic) was used as the fine particles. And an optical element was manufactured as Example 13. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. Table 4 shows the results.

Example 14
A liquid crystal composition solution was prepared in the same manner as in Example 3 except that silica powder (R-812 manufactured by Nippon Aerosil Co., Ltd., particle size: 7 nm, hydrophobic) was used as the fine particles. And an optical element was manufactured as Example 14. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 4.

Reference example 1
A liquid crystal composition solution was prepared in the same manner as in Example 3 except that silica powder (90G manufactured by Nippon Aerosil Co., Ltd., particle size 20 nm, hydrophilic property) was used as the fine particles, and a retardation layer was formed using this. Then, an optical element was fabricated and used as Reference Example 1. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 4.

Reference example 2
A liquid crystal composition solution was prepared in the same manner as in Example 3 except that silica powder (200 V, particle size 12 nm, hydrophilic property, manufactured by Nippon Aerosil Co., Ltd.) was used as the fine particles, and a retardation layer was formed using this. Then, an optical element was fabricated and used as Reference Example 2. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 4.

Reference example 3
A liquid crystal composition solution was prepared in the same manner as in Example 3 except that silica powder (300CF manufactured by Nippon Aerosil Co., Ltd., particle size: 7 nm, hydrophilic) was used as the fine particles, and this was used to form a retardation layer. Then, an optical element was fabricated and used as Reference Example 3. For the retardation layer of the obtained optical element, the orientation state of the crosslinkable liquid crystal molecules and the hardness of the retardation layer were measured in the same manner as in Example 1, and the orientation and layer hardness were evaluated. The results are shown in Table 4.

  From Examples 3, 13, and 14 and Reference Examples 1 to 3, it was suggested that the effect of adding fine particles in the liquid crystal composition differs depending on the combination with the solvent used to dissolve the liquid crystal composition.

  That is, even in the case where the addition amount is the same and the particle size is almost the same, in Reference Examples 1 to 3 in which the surface property of the fine particles is hydrophilic and an organic solvent (PGMEA) is used, The orientation of the retardation layer was disturbed, the aggregation of fine particles was confirmed, and the effects of improving the hardness of the target retardation layer were not as good as those of Examples 1, 13, and 14.

It is a schematic longitudinal cross-sectional view for demonstrating one Example of the color filter using the liquid-crystal composition in this invention. It is a schematic longitudinal cross-sectional view for demonstrating one Example of the liquid crystal display device using the color filter in this invention. It is explanatory drawing for demonstrating the direction which measures the phase difference measurement direction of a phase difference layer. 4 is a graph showing the relationship between the measurement angle of the homeotropically aligned retardation layer and the retardation of Example 1;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color filter 2 Board | substrate 3 Colored layer 4 Phase difference layer 5 Black matrix 6, 7, 8 Sub pixel

Claims (11)

  A liquid crystal composition comprising a crosslinkable liquid crystal molecule and at least one or more types of hydrophobic inorganic fine particles. A liquid crystal composition comprising a crosslinkable liquid crystal molecule and at least one hydrophilic inorganic fine particle.   The liquid crystal composition according to claim 1, wherein the crosslinkable liquid crystal molecule has at least one (meth) acryloyl group in at least one molecule.   The liquid crystal composition according to claim 1, wherein the average particle size of the inorganic fine particles is 500 nm or less.   The liquid crystal composition according to claim 1, wherein the inorganic fine particles are contained in an amount of 0.1% by weight or more and 20% by weight or less in terms of a compound.   The liquid crystal composition according to claim 1, further comprising a silane coupling agent.   A colored layer and a retardation layer are laminated on a substrate having optical transparency, and the retardation layer is formed by curing the liquid crystal composition according to claim 1. A color filter characterized by   A retardation layer is formed by directly applying the liquid crystal composition according to claim 1 on a substrate surface to form a liquid crystal coating film, and subjecting the surface of the liquid crystal coating film to light irradiation treatment or heat treatment. The color filter according to claim 7, wherein the color filter is formed by polymerizing crosslinkable liquid crystal molecules present in the liquid crystal coating film and thereby curing the liquid crystal coating film.   The color filter according to claim 7 or 8, wherein the crosslinkable liquid crystal molecules contained in the retardation layer are homeotropically aligned. The color filter according to claim 7, wherein the retardation layer has a universal hardness of 300 mN / mm ² or more.   A liquid crystal display device in which a liquid crystal material is sealed between an opposing display side substrate and a driving liquid crystal side substrate to form a driving liquid crystal layer, wherein the display side substrate is according to any one of claims 7 to 10. A liquid crystal display device which is a color filter.

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