JP2007148366A - Liquid crystal spacer and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for a liquid crystal spacer and a photosensitive element, and a liquid crystal spacer and a method for manufacturing the spacer so as to realize manufacturing of a liquid crystal display apparatus that can fully prevent display uneveness in a liquid crystal display screen and can display a high-quality image. <P>SOLUTION: The photosensitive resin composition that is used as a source material for a liquid crystal spacer to be included in a liquid crystal display apparatus, comprises (a) a (meth)acrylic polymer having a photopolymerizable unsaturated group; (b) a photopolymerizable unsaturated compound having at least one ethylenically unsaturated bond; (c) a photopolymerization initiator which generates radicals by actinic rays, where the component (c) contains (c1) a hexaarylbiimidazole compound and (c2) a hydrogen-donating compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition and a photosensitive element used as a raw material for a liquid crystal spacer, a liquid crystal spacer, and a method for producing the same.

  In recent years, liquid crystal color televisions, liquid crystal color display computers, and the like have been put into practical use. These liquid crystal display devices are provided between a transparent substrate member such as glass provided with a transparent electrode or the like and another substrate member. It has a gap of about 10 μm. An image is displayed by applying a voltage to the liquid crystal layer formed by enclosing the liquid crystal material in the gap through an electrode and aligning the liquid crystal material. In such a liquid crystal display device, when the gap of the liquid crystal layer changes, display irregularities and contrast abnormalities occur. Therefore, in order to keep the liquid crystal layer gap constant, spherical glass beads and resin beads having a uniform particle size distribution Have been used as liquid crystal spacers.

  However, such a liquid crystal spacer made of spherical glass beads or resin beads is generally only dispersed in a liquid crystal layer between opposing substrate members, and is not fixed to the substrate member. As a result, variations in the distribution of the liquid crystal spacers may cause display unevenness, the liquid crystal spacers may move due to vibrations of the liquid crystal display device, and the alignment abnormal area may increase, or the alignment film surface may be damaged. was there. Furthermore, since the liquid crystal spacers of such spherical glass beads or resin beads are also scattered on the display portion of the liquid crystal display device, there are problems such as lowering the contrast and lowering the display quality.

In order to solve these problems, Patent Documents 1 to 4 propose various methods. For example, Patent Document 1 describes a method of forming a liquid crystal spacer by applying an ultraviolet curable resin on a substrate member provided with a pixel electrode, drying, and then exposing and developing. Patent Document 2 describes a liquid crystal display device using a liquid crystal spacer formed of a photopolymer film, and Patent Document 3 describes a radiation-sensitive resin composition for a liquid crystal spacer.
JP-A-3-89320 Japanese Patent Laid-Open No. 10-168134 Japanese Patent Laid-Open No. 11-133600 JP-A-11-174461

  In these patent documents, a liquid crystal spacer is obtained through an exposure step and a development step after a layer made of a resin composition is formed on a substrate included in a base substrate. In addition, ultrasonic cleaning is performed as necessary after the development process. However, even when a conventional material and method including those described in the above-mentioned patent documents are employed to form a liquid crystal spacer on the substrate, the liquid crystal spacer can be easily formed on the substrate. It turned out to be in a state of moving from position or missing from the substrate.

  This is because the resin composition, which is a raw material for the liquid crystal spacer, is photocured (hereinafter referred to as “photocured body”) from the substrate-side surface serving as the base toward the surface opposite to the surface. This is because it has a tapered shape and the surface on the substrate side has an area smaller than desired. If the photocured body has such a shape, the adhesion to the substrate is reduced, so the photocured body may peel off from the substrate during the manufacturing process of the liquid crystal spacer, for example, during the development process or ultrasonic cleaning. Is expensive. Alternatively, even after the liquid crystal spacer is formed, it is difficult to sufficiently fix it in a predetermined position.

  As described above, when the photocured body and / or the liquid crystal spacer is peeled off from the substrate, the gap of the liquid crystal layer becomes non-uniform in the liquid crystal display screen, and the display unevenness becomes remarkable. There was a problem that the decrease was remarkable.

  Therefore, the present invention has been made in view of the above circumstances, and is a liquid crystal spacer photosensitive material that can sufficiently prevent display unevenness in a liquid crystal display screen and can manufacture a liquid crystal display device capable of displaying a high-quality image. It is an object to provide a photosensitive resin composition, a photosensitive element, a liquid crystal spacer, and a method for producing the same.

  The photosensitive resin composition of the present invention is a photosensitive resin composition used as a raw material of a liquid crystal spacer provided in a liquid crystal display device, and includes (a) a (meth) acrylic polymer having a photopolymerizable unsaturated group; (B) a photopolymerizable unsaturated compound having at least one ethylenically unsaturated bond, (c) a photopolymerization initiator that generates a free radical by actinic rays, and (c) a component comprising: (C1) a hexaarylbiimidazole compound and (c2) a hydrogen-donating compound.

  According to the photosensitive resin composition of the present invention, it is possible to obtain a liquid crystal spacer having sufficiently high adhesion to the substrate. Therefore, when the liquid crystal display device is manufactured, display unevenness on the liquid crystal display device screen due to peeling of the liquid crystal spacer from the substrate can be sufficiently prevented. As a result, a liquid crystal display device capable of displaying a high-quality image without display unevenness can be manufactured.

  The purpose of the present invention can be achieved by using the photosensitive resin composition of the present invention because the liquid crystal spacer obtained by the photosensitive resin composition of the present invention has a first surface in contact with the substrate and the opposite surface. And a second surface on the side, and is tapered from the first surface toward the second surface.

  The reason why the liquid crystal spacer has the above-mentioned shape by using the photosensitive resin composition of the present invention is not necessarily clear, but the present inventors consider as follows. As an exposure method for curing the photosensitive resin composition, a method of irradiating a known ultraviolet ray through a photomask to the photosensitive resin layer laminated on the substrate is generally used. At this time, when the conventional photosensitive resin composition is used, the irradiated ultraviolet rays cause diffraction and interference by the photomask, and thereby, the boundary between the exposed portion and the unexposed portion of the photosensitive resin layer is not good. It becomes clear. As a result, in the development process, the shape of the liquid crystal spacer often becomes a tapered shape from the surface on the substrate side toward the surface opposite to the surface. On the other hand, when the photosensitive resin composition of the present invention is used, a liquid crystal spacer having a tapered shape is obtained from the surface on the substrate side toward the surface opposite to the surface.

  Moreover, since the liquid crystal spacer made from the conventional photosensitive resin composition has the shape as described above, the liquid crystal aligning agent is sufficient in the vicinity of the liquid crystal spacer in the liquid crystal aligning agent coating step after the ultrasonic cleaning. There is a high possibility that it will not be applied. As described above, when the liquid crystal aligning agent is not sufficiently applied, liquid crystal alignment abnormality is caused, and display unevenness occurs on the liquid crystal display screen. On the other hand, since the liquid crystal spacer using the photosensitive resin composition of the present invention as a raw material has the shape as described above, it can sufficiently prevent liquid crystal alignment abnormality due to insufficient application of the liquid crystal aligning agent. Thus, a liquid crystal display device capable of displaying a high-quality image without display unevenness can be manufactured.

  In the photosensitive resin composition of the present invention, the component (c2) preferably contains an aryl glycine compound. By using such a photosensitive resin composition, a liquid crystal spacer having higher adhesion to the substrate can be obtained.

  In the photosensitive resin composition of the present invention, the amount of the component (c1) is 1 to 6 parts by mass with respect to 100 parts by mass of the total amount of the component (a) and the component (b). (C2) It is preferable that the compounding quantity of a component is 0.05-4 mass parts with respect to 100 mass parts of total amounts of (a) component and (b) component. Thereby, a liquid crystal spacer having higher adhesion to the substrate can be obtained.

  The liquid crystal spacer of the present invention has a first surface that is formed on a substrate and is in close contact with the substrate, and a second surface opposite to the first surface, from the first surface toward the second surface. It has a tapered shape.

  The liquid crystal spacer of the present invention has sufficiently high adhesion to the substrate. Therefore, display unevenness in the liquid crystal display screen due to peeling of the liquid crystal spacer from the substrate during the manufacture of the liquid crystal display device can be sufficiently prevented. As a result, a liquid crystal display device capable of displaying a high-quality image without display unevenness can be manufactured.

  The method for producing a liquid crystal spacer according to the present invention comprises a photosensitive layer forming step of forming a photosensitive layer comprising the above photosensitive resin composition on the surface of a substrate, and photocuring by irradiating a predetermined portion of the photosensitive layer with actinic rays. An actinic ray irradiating step for forming a portion, a removing step for selectively removing portions other than the photocured portion from the photosensitive layer, and a heating step for heating the photocured portion.

  According to the method for producing a liquid crystal spacer of the present invention, a liquid crystal spacer with sufficiently high adhesion to the substrate can be produced on the substrate. Therefore, display unevenness in the liquid crystal display screen due to the separation of the liquid crystal spacer from the substrate at the time of manufacturing the liquid crystal display device can be sufficiently prevented. As a result, a liquid crystal display device capable of displaying a high-quality image without display unevenness can be manufactured.

  Further, when the liquid crystal spacer formed on the substrate by the liquid crystal spacer manufacturing method of the present invention is used, the liquid crystal spacer is sufficiently prevented from peeling from the substrate in the manufacturing process of the liquid crystal display device, so that the liquid crystal can be efficiently A display device can be manufactured. That is, in manufacturing a liquid crystal display device, the yield and work efficiency can be improved, and the manufacturing cost can be reduced.

  Furthermore, the method for producing a liquid crystal spacer according to the present invention includes a photosensitive layer laminating step of laminating the photosensitive layer of the photosensitive element on the surface of the substrate, and a photocuring portion by irradiating a predetermined portion of the photosensitive layer with active light. An actinic ray irradiating step for forming a portion, a removing step for selectively removing portions other than the photocured portion from the photosensitive layer, and a heating step for heating the photocured portion.

  According to the method for producing a liquid crystal spacer of the present invention, a liquid crystal spacer having sufficiently high adhesion to the substrate can be formed. Therefore, display unevenness in the liquid crystal display screen due to peeling of the liquid crystal spacer from the substrate during the manufacture of the liquid crystal display device can be sufficiently prevented. As a result, a liquid crystal display device capable of displaying a high-quality image without display unevenness can be manufactured.

  Further, when the liquid crystal spacer formed on the substrate by the liquid crystal spacer manufacturing method of the present invention is used, the liquid crystal spacer is sufficiently prevented from peeling from the substrate in the manufacturing process of the liquid crystal display device, so that the liquid crystal can be efficiently A display device can be manufactured. That is, in manufacturing a liquid crystal display device, the yield and work efficiency can be improved, and the manufacturing cost can be reduced.

  Furthermore, in the method for producing a liquid crystal spacer according to the present invention, since a photosensitive element having a photosensitive layer formed on a support film is used, the photosensitive layer is formed on the substrate by a photosensitive layer laminating step. A photosensitive layer can be formed, and the trouble of applying a photosensitive resin to form the photosensitive layer can be saved.

  According to the present invention, there is provided a photosensitive resin composition for a liquid crystal spacer and a photosensitive element that can sufficiently prevent display unevenness in a liquid crystal display screen and can manufacture a liquid crystal display device capable of displaying a high-quality image. Provided. Moreover, according to the present invention, a liquid crystal spacer having sufficiently high adhesion to the substrate is provided. Furthermore, according to the present invention, a method of manufacturing a liquid crystal spacer having a sufficiently high yield and work efficiency is provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, (meth) acrylic acid means acrylic acid or methacrylic acid corresponding thereto, (meth) acrylate means acrylate or corresponding methacrylate, and (meth) acryloyl group means acryloyl group or A corresponding methacryloyl group is meant, and a (meth) acryloxy group means an acryloxy group or a methacryloxy group corresponding thereto.

  FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal display device on which the liquid crystal spacer of this embodiment is mounted. As shown in FIG. 1, the liquid crystal display device 1 has a pair of substrate members 6 a and 6 b disposed to face each other. The board | substrate member 6a consists of the electrode 2a, the board | substrate 3a, the buffer material layer 4a, and the polarizing plate 5a, and these are laminated | stacked in this order. Moreover, the board | substrate member 6b consists of the electrode 2b, the board | substrate 3b, the buffer material layer 4b, and the polarizing plate 5b, and these are laminated | stacked in this order. Further, alignment layers 17a and 17b are laminated on the side of the substrate members 6a and 6b where the electrodes 2a and 2b are formed. The liquid crystal layer 18 is sandwiched between the substrate members 6a and 6b via the alignment layers 17a and 17b. A sealing agent 13 is provided around the liquid crystal layer 18 between the substrate members 6a and 6b, thereby connecting the substrate members 6a and 6b.

  The liquid crystal spacer 10 is disposed at a predetermined position of the liquid crystal display device 1 in order to keep the thickness of the liquid crystal layer 18 constant. Here, since the absolute value of the thickness of the liquid crystal layer varies depending on the operating temperature, keeping the thickness of the liquid crystal layer constant means that the thickness of the liquid crystal layer designed at a certain temperature This means that it is kept uniform in the device screen.

  The liquid crystal spacer 10 is preferably patterned so as to be disposed at a position other than the display dot portion, which is a light transmitting portion, from the viewpoint of displaying a high-quality image. The liquid crystal spacer 10 has a tapered shape from the surface closely contacting the substrate member 6b toward the opposite surface, for example, a truncated conical shape.

  The liquid crystal spacers 10 are preferably arranged at equal intervals over the entire screen display area. The liquid crystal spacer 10 produced from the photosensitive resin composition is generally called a columnar spacer or a photosensitive spacer.

  The substrate members 6a and 6b in this embodiment are composed of electrodes 2a and 2b, substrates 3a and 3b, buffer material layers 4a and 4b, and polarizing plates 5a and 5b, respectively. 5a and b are not necessarily laminated. In addition, an insulating layer, a black matrix layer, a color filter layer, a TFT, and the like may be further provided on the surface of the substrate members 6a and 6b as necessary.

  As the electrodes 2a and 2b, a transparent electrode such as tin-doped indium oxide (ITO), a copper metal thin film or the like can be used for a printed circuit board or the like. Examples of the substrates 3a and 3b include ceramic plates, plastic plates, and glass plates. Moreover, a well-known buffer material layer and a polarizing plate can be used as the buffer material layers 4a and b and the polarizing plates 5a and b. The alignment layers 17a and 17b can be formed using a known liquid crystal aligning agent.

  The liquid crystal spacer 10 of the present embodiment can be made sufficiently high in adhesion to the substrate member 6b by being formed using a photosensitive resin composition to be described later.

  The photosensitive resin composition of the present invention is a photosensitive resin composition used as a raw material for a liquid crystal spacer provided in a liquid crystal display device, and includes (a) a (meth) acrylic polymer having a photopolymerizable unsaturated group ( (Hereinafter also referred to as “component (a)”), (b) a photopolymerizable unsaturated compound having at least one ethylenically unsaturated bond (hereinafter also referred to as “component (b)”), ( c) a photopolymerization initiator that generates free radicals by actinic rays (hereinafter also referred to as “component (c)”), and (c) component is (c1) a hexaarylbiimidazole compound (hereinafter referred to as “c1”). (Also referred to as “component (c1)”) and (c2) a hydrogen donating compound (hereinafter also referred to as “component (c2)”). Hereinafter, each component will be described.

<(A) component>
The (meth) acrylic polymer having a photopolymerizable unsaturated group (a) is not particularly limited in its composition and synthesis method. As this (meth) acrylic-type polymer, the (meth) acrylic-type polymer which has an ethylenically unsaturated group in a side chain is mentioned, for example. The (meth) acrylic polymer having an ethylenically unsaturated group in the side chain is, for example, a carboxyl group, a hydroxyl group, an amino group, an isocyanate group, an oxirane ring, or the following general formula (1);
-CO-O-OC- (1)
From the group consisting of at least one ethylenically unsaturated group, an oxirane ring, an isocyanate group, a hydroxyl group and a carboxyl group on the side chain of the (meth) acrylic prepolymer having a functional group such as a divalent group represented by It can be obtained by subjecting a compound having one selected functional group to an addition reaction in the presence of a catalyst such as dibutyltin dilaurate.

  Examples of the monomer used as the raw material for the (meth) acrylic prepolymer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, cinnamic acid, 2-hydroxyethyl acrylate, and methacrylic acid 2 -Hydroxyethyl, acrylamide, methacrylamide, ethyl isocyanate, glycidyl acrylate, glycidyl methacrylate, maleic anhydride and other carboxyl groups, hydroxyl groups, amino groups, oxirane rings, or divalent compounds represented by the above general formula (1) (Meth) acrylic monomers having a functional group such as These are used singly or in combination of two or more.

  For the production of such a (meth) acrylic polymer having an ethylenically unsaturated group in the side chain, a vinyl monomer other than the above (meth) acrylic prepolymer can be copolymerized as necessary. .

  Examples of the vinyl monomer include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, iso-propyl acrylate, iso-propyl methacrylate, N-butyl acrylate, n-butyl methacrylate, iso-butyl acrylate, iso-butyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, acrylic acid Pentyl, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, heptyl acrylate, heptyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, octyl acrylate, octyl methacrylate, acrylic Nonyl acid, nonyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tetradecyl acrylate, tetradecyl methacrylate, hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, eicosyl acrylate , Eicosyl methacrylate, docosyl acrylate, docosyl methacrylate, cyclopentyl acrylate, cyclopentyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, cycloheptyl acrylate, cycloheptyl methacrylate, benzyl acrylate, benzyl methacrylate, phenyl acrylate , Phenyl methacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, dimethyl methacrylate Aminoethyl, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, 2-chloroethyl acrylate, 2-chloroethyl methacrylate, 2-fluoroethyl acrylate, 2-fluoroethyl methacrylate, styrene, α-methylstyrene, cyclohexylmaleimide, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, vinyl toluene, vinyl chloride, vinyl acetate, N-vinyl pyrrolidone, butadiene, isoprene, chloroprene Is mentioned. These are used singly or in combination of two or more.

Moreover, it is preferable that the ethylenically unsaturated group density | concentration in the (meth) acrylic-type polymer which has an ethylenically unsaturated group in a side chain shall be 1.0 * 10 < ^-4 > -6.0 * 10 < ^-3 > mol / g. 2.0 × 10 ^{−4 to} 5.0 × 10 ⁻³ mol / g, more preferably 3 × 10 ^{−4 to} 4.0 × 10 ⁻³ mol / g. When the ethylenically unsaturated group concentration is less than 1.0 × 10 ⁻⁴ mol / g, when a liquid crystal spacer is formed, there is a tendency that the effect of improving the hardness for ensuring display quality is not sufficiently obtained. When it exceeds 0 × 10 ⁻³ mol / g, gelation tends to occur when a (meth) acrylic polymer having an ethylenically unsaturated group in the side chain is produced. The ethylenically unsaturated group concentration may be determined from the amount of raw materials charged.

  The weight average molecular weight of component (a) (measured by gel permeation chromatography and converted to standard polystyrene) is heat resistance, coating properties, and film properties (film-like properties) when used as a photosensitive element for liquid crystal spacers described later. From the viewpoints of properties that maintain the form), solubility in a solvent, solubility in a developing solution in the development step described below, and the like, the range is preferably 1000 to 300000, and more preferably 5000 to 150,000.

  The component (a) can have an acid value so that it can be developed with various known developing solutions in the (III) removal step described below.

  For example, when developing using an aqueous alkali solution of sodium carbonate, potassium carbonate, tetramethylammonium hydroxide, and triethanolamine, the acid value is preferably 50 to 260 mgKOH / g. When the acid value is less than 50 mgKOH / g, development tends to be difficult, and when it exceeds 260 mgKOH / g, developer resistance (property that the liquid crystal spacer pattern is not affected by the developer without being removed by development). Tends to decrease.

  Moreover, when developing using water or aqueous alkali solution and the aqueous alkali solution which consists of 1 or more types of surfactant, it is preferable that an acid value shall be 16-260 mgKOH / g. If the acid value is less than 16 mg KOH / g, development tends to be difficult, and if it exceeds 260 mg KOH / g, the developer resistance tends to be lowered.

  In addition, in this embodiment, although it is essential to contain the (meth) acrylic-type polymer which has the photopolymerizable unsaturated group of (a) component, it does not have a photopolymerizable unsaturated group as needed. A so-called binder polymer can be used in combination. There is no restriction | limiting in particular as the binder polymer, For example, the vinyl copolymer which does not have a photopolymerizable unsaturated group is mentioned, The above-mentioned thing is mentioned as a vinyl monomer used for a vinyl copolymer. These may be used alone or in combination of two or more.

<(B) component>
As the component (b), for example, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid, 2,2-bis [4- (di (meth) acryloxypolyethoxy) phenyl] Compound obtained by reacting propane, glycidyl group-containing compound with α, β-unsaturated carboxylic acid, urethane monomer, nonylphenyldioxylene (meth) acrylate, γ-chloro-β-hydroxypropyl-β ′-(meta ) Acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, (meth) Examples include alkyl acrylates.

  Examples of the α, β-unsaturated carboxylic acid include (meth) acrylic acid.

  Examples of the polyhydric alcohol include polyethylene glycol having 2 to 14 ethylene groups, polypropylene glycol having 2 to 14 propylene groups, trimethylolpropane, tetramethylolmethane, and erythritol.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 propylene groups. ~ 14 polypropylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, trimethylolpropane diethoxytri (meth) acrylate , Trimethylolpropane triethoxytri (meth) acrylate, trimethylolpropanetetraethoxytri (meth) acrylate, trimethylolpropane pentaethoxytri (meth) acrylate, tetramethylolmethane Examples include tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

  Examples of the 2,2-bis (4- (di (meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4- (di (meth) acryloxydiethoxy) phenyl) propane, 2 , 2-bis (4- (di (meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4- (di (meth) acryloxypentaethoxy) phenyl) propane, 2,2-bis (4 -(Di (meth) acryloxydecaethoxy) phenyl) propane.

  Examples of the compound obtained by reacting the glycidyl group-containing compound with an α, β-unsaturated carboxylic acid include trimethylolpropane triglycidyl ether tri (meth) acrylate and 2,2-bis (4- (meth)). Acryloxy-2-hydroxy-propyloxy) phenyl.

  Examples of the urethane monomer include an addition reaction product of a (meth) acrylic monomer having an OH group at the β-position and isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 1,6-hexamethylene diisocyanate , Tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, ethylene oxide modified urethane di (meth) acrylate, ethylene oxide, propylene oxide modified urethane di (meth) acrylate.

  Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, and (meth) acrylic acid 2-ethylhexyl ester.

  (B) A component can be used individually by 1 type or in combination of 2 or more types.

<(C) component>
The photopolymerization initiator that generates free radicals by active light, which is component (c), contains the following components (c1) and (c2) as main components.

  Examples of the hexaarylbiimidazole compound contained as the component (c1) include 2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2 , 4-di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer Body, 2-(p-methyl) -4,5-diphenyl imidazole dimer and the like. These are used singly or in combination of two or more.

  The hydrogen donating compound contained as the component (c2) is particularly limited as long as it is a compound that can donate hydrogen to a photoexcited photopolymerization initiator or a compound that can donate hydrogen to a radical generated from the photopolymerization initiator. For example, it may be disclosed as “photooxidant” in US Pat. No. 3,390,996. Specific examples of the component (c2) include N-arylglycine such as N-phenylglycine, N-phenylglycine ethyl ester, N-phenylglycine methyl ester, N-phenylglycine butyl ester, N-methylphenylglycine ethyl ester; Alkanolamines such as triethanolamine and methyldiethanolamine; aromatic amines such as 2-dimethylaminoethylbenzoic acid, ethyl 4-dimethylaminobenzoate, isobutyl 4-dimethylaminobenzoate, and 4,4-dimethylaminobenzophenone; Examples thereof include thiol compounds such as mercaptobenzothiazole, 2-mercaptobenzimidazole, and 2-mercaptobenzoxazole. Among these, N-arylglycines such as N-phenylglycine, N-phenylglycine ethyl ester, N-phenylglycine methyl ester, N-phenylglycine butyl ester and N-methylphenylglycine ethyl ester are more preferable, More preferred is phenylglycine.

  (C2) A component is used individually by 1 type or in combination of 2 or more types.

  The component (c) includes, for example, benzophenone, N, N′-tetramethyl-, as components other than the component (c1) and the component (c2) from the viewpoint of improving sensitivity when blended in the photosensitive resin composition. 4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4 -Morpholinophenyl) -butan-1-one (Irgacure-369, trade name of Ciba Specialty Chemicals Co., Ltd.), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one ( Irgacure-907, Ciba Specialty Chemicals Co., Ltd. trade name) aromatic ketone, 2-ethylant Quinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methyl Anthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, quinones of 2,3-dimethylanthraquinone, benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, etc. Benzoin ether compounds, benzoin compounds such as benzoin, methylbenzoin, ethylbenzoin, benzyl derivatives of benzyldimethyl ketal, 9-phenylacridine, 1,7-bis (9,9'-a Lysinyl) acridine derivative of heptane, a coumarin compound can be a suitable amount used. These are used singly or in combination of two or more.

<Ratio of each component>
The blending ratio of the component (a) is preferably 10 to 80 parts by mass, more preferably 20 to 75 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). It is especially preferable to set it as 25-73 mass parts, and it is very preferable to set it as 30-70 mass parts. If the blending ratio is less than 10 parts by mass, the coating property or the film property in the case of a photosensitive element for liquid crystal spacer described later tends to be lowered. If the blending ratio exceeds 80 parts by weight, the photocurability or heat resistance is lowered. Tend.

  The blending ratio of the component (b) is preferably 10 to 80 parts by mass, more preferably 20 to 75 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). It is especially preferable to set it as 25-73 mass parts, and it is very preferable to set it as 30-70 mass parts. If the blending ratio is less than 10 parts by mass, the photocurability or heat resistance tends to decrease, and if it exceeds 80 parts by mass, the coating properties or the film properties when used as a photosensitive element for a liquid crystal spacer described later decrease. Tend to.

  The mixing ratio of the component (c1) is preferably 1.0 to 6.0 parts by mass, and 1.3 to 5.7 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). More preferably 1.5 to 5.5 parts by mass, particularly preferably 1.7 to 5.2 parts by mass, and 2.0 to 5.0 parts by mass. It is very preferable to do this. If the blending ratio is less than 1.0 part by mass, the photocuring tends to be insufficient, and if it exceeds 6.0 parts by mass, in the (II) actinic ray irradiation step described later, the photosensitive resin composition layer Absorption of actinic rays at the surface increases and internal photocuring tends to be insufficient.

  The mixing ratio of the component (c2) is preferably 0.05 to 4.0 parts by mass, and 0.07 to 3.5 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). More preferably, it is 0.1-3 mass parts, More preferably, it is 0.13-2.5 mass parts, It is 0.15-2.0 mass parts Is very preferred. If the blending ratio is less than 0.05 parts by mass, the shape of the columnar spacer formed by the (III) removal step described later tends to be an inverted trapezoid, and if it exceeds 4.0 parts by mass, it will be described later (III) In the process, a residue of the photosensitive resin composition tends to be generated on the substrate member.

  In addition, the photosensitive resin composition of the present invention includes, as necessary, for example, a silyl group-containing adhesion improver represented by γ-methacryloxypropyltrimethoxysilane, a leveling agent, a plasticizer, a filler, an antifoaming agent. Containing about 0.01 to 20 parts by mass of an agent, a flame retardant, a stabilizer, an antioxidant, a fragrance, a thermal crosslinking agent, a polymerization inhibitor and the like with respect to 100 parts by mass of the total amount of the components (a) and (b). be able to. These are used alone or in combination of two or more.

  In addition, the photosensitive resin composition may be an aliphatic alcohol such as methanol, ethanol, n-propanol, i-propanol, n-butanol, n-pentanol or hexanol, or a hydrocarbon such as benzyl alcohol or cyclohexane, if necessary. , Diacetone alcohol, 3-methoxy-1-butanol, acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone, methyl pentyl ketone, methyl hexyl ketone, ethyl butyl ketone, dibutyl ketone, dibutyl ketone, cyclopentanone, Cyclohexanone, γ-butyrolactone, 3-hydroxy-2-butanone, 4-hydroxy-2-pentanone, 6-hydroxy-2-hexanone, ethylene glycol, diethylene glycol, triethyleneglycol , Tetraethylene glycol, propylene glycol, ethylene glycol monoacetate, ethylene glycol diacetate, propylene glycol monoacetate, propylene glycol diacetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene Ethylene glycol alkyl ether compounds such as glycol dibutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate or acetate thereof, diethylene glycol monoalkyl ether compound or acetate thereof, diethylene glycol dialkyl ether compound, triethylene glycol alkyl ether compound, propylene group Recall alkyl ether compound or its acetate, dipropylene glycol alkyl ether compound, toluene, ethyl formate, propyl formate, butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, butyric acid Carboxylic acid ester compounds such as methyl and ethyl butyrate, dimethylformamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, methyl lactate, ethyl lactate, methyl benzoate, ethyl benzoate, propylene carbonate, etc. And the viscosity can be adjusted as appropriate.

  Next, the photosensitive element for liquid crystal spacers according to a preferred embodiment of the present invention will be described. The photosensitive element for liquid crystal spacer of this embodiment is used for forming the liquid crystal spacer 10 in the liquid crystal display device 1.

  FIG. 2 is a partial cross-sectional view showing one embodiment of the photosensitive element of this embodiment. The photosensitive element 20 shown in FIG. 2 has a structure in which a photosensitive layer 22 and a protective film 25 are laminated in this order on a support film 24.

  As the support film 24, it is preferable to use polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, polyethersulfone, or the like. Moreover, there is no restriction | limiting in particular about the thickness of the support body film 24, However, It is preferable that it is about 5-100 micrometers.

  As the protective film 25 according to the present embodiment, it is preferable to use polyethylene, polypropylene, polyethylene terephthalate, polycarbonate or the like. Moreover, there is no restriction | limiting in particular about the thickness of the protective film 25, However, It is preferable that it is about 5-100 micrometers.

  The photosensitive layer 22 in the present embodiment is a layer made of the above-described photosensitive resin composition. The thickness is preferably 0.1 to 20 μm, more preferably 0.3 to 15 μm, taking into consideration the electrical characteristics and the alignment characteristics of the liquid crystal when the liquid crystal display device 1 is used. It is especially preferable to set it as 5-10 micrometers. When the thickness of the photosensitive layer 22 is smaller than 0.1 μm or larger than 20 μm, the function as a display device tends to be lowered.

  The viscosity of the photosensitive layer 22 in the present embodiment is preferably 15 to 100 MPa · s, more preferably 20 to 90 MPa · s, and particularly preferably 25 to 80 MPa · s at 30 ° C. When a roll-shaped photosensitive element wound around a core is produced using the photosensitive layer 22, the photosensitive resin composition can be prevented from oozing out from the end face of the photosensitive element 20 for one month or more. it can. In addition, when the photosensitive element 20 is cut, it is possible to prevent exposure failure or undeveloped development caused by fragments of the photosensitive resin composition adhering to the substrate.

In addition, the viscosity of the photosensitive layer was prepared using a disk-shaped photosensitive layer having a diameter of 7 mm and a thickness of 2 mm as a sample, and a load of 1.96 × 10 ⁻² N was applied at 30 ° C. and 80 ° C. in the thickness direction. The thickness change rate when added is measured, and from this change rate, the photosensitive layer is assumed to be a Newtonian fluid and converted to viscosity.

  In the photosensitive element 20 of this embodiment, a solution obtained by uniformly dissolving or dispersing a photosensitive resin composition in a solvent is applied on a support film 24 and dried to form a photosensitive layer 22, and It is obtained by forming the protective film 25 on top.

  As a method for forming the photosensitive layer 22 on the support film 24, a known coating method can be used. For example, a doctor blade coating method, a Meyer bar coating method, a roll coating method, a screen coating method, a spinner coating method, Examples include an inkjet coating method, a spray coating method, a dip coating method, a gravure coating method, a curtain coating method, and a die coating method.

  The photosensitive element 20 thus obtained can be stored in roll form or stored.

  Hereinafter, an example of the manufacturing method of the liquid crystal spacer in the liquid crystal display device 1 using the photosensitive element 20 of the present embodiment will be described. FIG. 3 is a process cross-sectional view schematically showing an embodiment of a manufacturing process of the liquid crystal spacer 10 shown in FIG.

  The manufacturing method of the liquid crystal spacer according to this embodiment includes (I) a photosensitive layer laminating step in which the protective film of the photosensitive element is peeled from the photosensitive layer, and the photosensitive layer is laminated on the substrate, and (II) lamination on the substrate. An actinic ray irradiating step of irradiating a predetermined portion of the photosensitive layer with actinic rays to form a photocured portion; and (III) a removing step of selectively removing portions other than the photocured portion from the photosensitive layer by development. And (IV) a heating step of heating the photocured portion to form a liquid crystal spacer.

(Photosensitive layer lamination process)
There is no restriction | limiting in particular in the board | substrate 3b used by this embodiment, For example, a ceramic plate, a plastic plate, a glass plate etc. are mentioned. An insulating layer, a black matrix layer, a color filter layer, a TFT, or the like may be provided on the substrate 3b instead of or in addition to the electrode 2b. An electrode such as ITO is used for the electrode 2b. Or the board | substrate member 46b may consist only of the board | substrate 3b.

  As shown in FIG. 3, the photosensitive layer 22 is laminated | stacked on the surface provided with the electrode 2b of the board | substrate member 46b, and the laminated body 7 is obtained.

  In this embodiment, as a method of laminating the photosensitive layer 22 in the photosensitive element 20 on the substrate member 46b in the laminating step, the protective layer 25 is removed from the photosensitive layer 20 and then the photosensitive layer 22 is formed on the substrate member 46b. There is a method of crimping with a crimping roll so as to make contact.

  The pressure roll may be provided with a heating means so that it can be heat-pressed. The heating temperature for thermocompression bonding is preferably 10 to 180 ° C, more preferably 20 to 160 ° C, and particularly preferably 30 to 150 ° C. If the heating temperature is less than 10 ° C., the adhesion between the photosensitive layer 22 and the substrate member 46b tends to decrease, and if it exceeds 180 ° C., the constituent components of the photosensitive layer 22 tend to be thermally cured or thermally decomposed. .

Moreover, it is preferable to set it as 50N / m-1 * 10 < ⁵ > N / m in linear pressure at the time of thermocompression bonding, and it is more preferable to set it as 2.5 * 10 < ² > -5 * 10 < ⁴ > N / m. 5 × 10 ² to 4 × 10 ⁴ N / m is particularly preferable. If this pressure is less than 50 N / m, the adhesion between the photosensitive layer 22 and the substrate member 46 b tends to be reduced, and if it exceeds 1 × 10 ⁵ N / m, the substrate member 46 b tends to be destroyed. .

  If the photosensitive element 20 is heated as described above, it is not necessary to pre-heat the substrate member 46b, but the substrate member 46b is preliminarily used in order to further improve the adhesion between the photosensitive layer 22 and the substrate member 46b. It is preferable to heat-treat. The preheating temperature at this time is preferably 30 to 180 ° C. In this manner, the photosensitive layer 22 of the photosensitive element 20 of the present embodiment can be laminated on the substrate member 46b.

(Actinic ray irradiation process)
In the present embodiment, as a method for exposing the photosensitive layer 22 by imagewise irradiation with the actinic light L, a known actinic light L is applied to the photosensitive layer 22 laminated on the substrate member 46b via the photomask 9. The method of irradiating is mentioned. At this time, after removing the support film 24 on the photosensitive layer 22, the actinic ray L can be irradiated imagewise, but when the support film 24 is present, the support film 24 is also interposed. Actinic rays can also be irradiated.

  In addition, as the actinic ray L in the present embodiment, a known actinic light source can be used, and examples thereof include a carbon arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, and a xenon lamp, and those that effectively emit ultraviolet rays. There is no particular limitation.

  Through the actinic ray irradiation process, the photosensitive layer 22 has an exposed portion (photocured portion) 22 a irradiated with the actinic ray L and a non-exposed portion 22 b shielded by the photomask 9.

(Removal process)
In the removing step, the non-exposed portion 22b of the structure 7 obtained in the actinic ray irradiation step is removed to obtain the structure 8 in which the spacer pattern 22a composed of the exposed portion 22a is developed.

  As a developing method in the present embodiment, using a known developer such as an alkaline aqueous solution, an aqueous developer, an organic solvent, etc., development is performed by a known method such as spraying, showering, rocking immersion, brushing, scraping, A method of removing the non-exposed part 22b which is an unnecessary part is mentioned. Among these, it is preferable to use an alkaline aqueous solution from the viewpoint of environment and safety. By performing development, a spacer pattern 22a to be a liquid crystal spacer later is obtained.

  Examples of the base of the alkaline aqueous solution include alkali hydroxide (lithium, sodium or potassium hydroxide, etc.), alkali carbonate (lithium, sodium or potassium carbonate or bicarbonate, etc.), alkali metal phosphate (potassium phosphate, etc.) , Sodium phosphate, etc.), alkali metal pyrophosphates (sodium pyrophosphate, potassium pyrophosphate, etc.), tetramethylammonium hydroxide, triethanolamine and the like. Of these, tetramethylammonium hydroxide is preferable.

  The development temperature and time can be adjusted according to the developability of the photosensitive layer 22 in this embodiment. Further, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like can be mixed in the alkaline aqueous solution. Further, the base of the alkaline aqueous solution remaining in the photosensitive layer after development and photocuring is converted into an acid by a known method such as spraying, rocking immersion, brushing or scraping using an organic acid, an inorganic acid or an aqueous acid solution thereof. It can be treated (neutralized). Furthermore, the water washing process can also be performed after an acid treatment (neutralization treatment).

(Heating process)
In the heating step, the spacer pattern 22a obtained through the actinic ray irradiation step and the removal step is heated to obtain the structure 11 in which the liquid crystal spacer 10 is formed on the substrate member 46b.

  In the present embodiment, the method for heating the spacer pattern 22a includes known methods such as hot air radiation and infrared irradiation heating, and is particularly limited as long as the spacer pattern 22a on the substrate member 46b is effectively heated. Not. The temperature during heating is preferably 140 to 300 ° C, more preferably 150 to 290 ° C, and particularly preferably 160 to 280 ° C. If the heating temperature is less than 140 ° C., the effect of thermosetting tends to be insufficient, and if it exceeds 300 ° C., the constituent components of the photosensitive layer tend to thermally decompose.

  In addition, the spacer pattern 22a of the present embodiment can be further irradiated with actinic rays after the development step described above for the purpose of improving the substrate adhesion and improving the chemical resistance.

Moreover, the actinic ray in this embodiment includes a known actinic light source that can be used in the above-described exposure step, and is not particularly limited as long as it effectively emits ultraviolet rays or the like. The irradiation amount of actinic rays at this time is usually 1 × 10 ² to 1 × 10 ⁵ J / m ² , and heating can be accompanied during irradiation. If the irradiation amount of actinic rays is less than 1 × 10 ² J / m ² , the effect of photocuring tends to be insufficient, and if it exceeds 1 × 10 ⁵ J / m ² , the photosensitive layer tends to discolor. is there.

  As described above, the liquid crystal spacer 10 can be formed in the liquid crystal display device 1.

  The photosensitive element of the present embodiment is not limited to the use of the liquid crystal display device, for example, a display comprising a layer of a substance having fluidity between opposing substrates such as an electrochromic display and electronic paper. It can also be suitably used for spacer applications such as devices.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, in the method for producing a liquid crystal spacer of the present invention, the photosensitive layer laminating step may be such that the photosensitive layer is laminated on the substrate by applying the photosensitive resin composition of the present invention directly on the substrate and drying it. Good. As a method of laminating the photosensitive layer on the substrate, each component constituting the photosensitive resin composition of the present invention is dissolved or mixed in a dispersible solvent to obtain a uniformly dispersed solution, which is applied onto the substrate. And a method of drying. As a coating method, a known coating method can be used, and all the methods of coating the photosensitive resin composition layer on the support film can be used when manufacturing the above-described photosensitive element. The drying temperature is preferably 60 to 130 ° C., and the drying time is preferably 1 minute to 1 hour. In this case, the thickness of the photosensitive layer is preferably 0.1 to 20 μm, more preferably 0.3 to 15 μm in consideration of the electrical characteristics of the liquid crystal display device and the alignment characteristics of the liquid crystal. It is especially preferable to set it as 0.5-10 micrometers.

  Moreover, the photosensitive element for liquid crystal spacers of the present invention may not include a protective film.

  Furthermore, the liquid crystal spacer of the present invention is not limited to the use of the liquid crystal display device, and is formed by, for example, a layer of a substance having fluidity between an electrochromic display, electronic paper, and opposing substrate members. It can also be suitably used for spacer applications in display devices.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to this.

(Production Example 1)
[Preparation of (meth) acrylic polymer solution (P-1) having a photopolymerizable unsaturated group]
Into a flask equipped with a stirrer, reflux condenser, inert gas inlet and thermometer, the materials shown in (1) of Table 1 were charged, and the temperature was raised to 80 ° C. in a nitrogen gas atmosphere, and the reaction temperature was 80 ° C. While maintaining the temperature at ± 2 ° C., the material shown in Table 1 (2) was uniformly dropped over 4 hours. After completion of the addition of the material shown in (2), stirring was continued at 80 ° C. ± 2 ° C. for 6 hours to obtain a prepolymer solution (solid content 35 mass%) (p-1) having a weight average molecular weight of about 25,000.

  Furthermore, in another flask equipped with a stirrer, a reflux condenser, an inert gas inlet and a thermometer, the above-mentioned prepolymer solution (p-1) and 0.1 part by weight of dibutyltin dilaurate were charged, The temperature was raised to 70 ° C. in a nitrogen gas atmosphere, and while maintaining the reaction temperature at 70 ° C. ± 2 ° C., a mixture of 20 parts by mass of ethyl isocyanate and 35 parts by weight of propylene glycol monomethyl ether acetate was uniformly added over 2 hours. It was dripped. After completion of dropping, stirring was continued for 2 hours at 70 ° C. ± 2 ° C., and a solution of a (meth) acrylic polymer having a photopolymerizable unsaturated group having a weight average molecular weight of about 26000 (solid content 35% by mass) (P-1 )

(Production Example 2)
[Preparation of binder polymer solution (B-1)]
Into a flask equipped with a stirrer, reflux condenser, inert gas inlet and thermometer, the materials shown in Table 2 (1) were charged, and the temperature was raised to 80 ° C. in a nitrogen gas atmosphere, and the reaction temperature was 80 ° C. While maintaining the temperature at ± 2 ° C., the material shown in (2) of Table 2 was uniformly dropped over 4 hours. After completion of dropping of the material shown in (2), stirring was continued at 80 ° C. ± 2 ° C. for 6 hours to obtain a binder polymer solution (solid content 35% by weight) (B-1) having a weight average molecular weight of about 30,000.

Example 1
[Preparation of photosensitive resin composition solution (V-1)]
The materials shown in Table 3 were mixed for 15 minutes using a stirrer to prepare a photosensitive resin composition solution (V-1).

[Manufacture of liquid crystal spacers in liquid crystal display devices]
A photosensitive resin composition solution (V-1) is applied onto a rectangular glass substrate having a thickness of 0.5 mm, a main surface of 100 mm in length and 100 mm in width, on which an ITO film is formed as a transparent electrode, and a spin coater is used. Then, spin coating was performed at 1000 rpm. Next, the solvent was removed by drying on a 90 ° C. hot plate for 5 minutes to form a photosensitive layer having a thickness of 4.5 μm.

Next, the obtained photosensitive layer was subjected to ultraviolet rays using a parallel light exposure machine (EXM1201 manufactured by Oak Manufacturing Co., Ltd.) using a photomask having an actinic ray transmitting portion having a circular pattern with a diameter of 15 μm at a pitch of 100 μm. Was imagewise irradiated. A gap of 100 μm was provided between the photomask and the photosensitive layer surface. In addition, irradiation with ultraviolet rays was performed at an exposure amount of 5 × 10 ² J / m ² (measured value at i-line (wavelength 365 nm)) from vertically above the photomask surface.

  Next, using a 0.5% by mass tetramethylammonium hydroxide aqueous solution containing 0.5% by mass of a surfactant, the photosensitive layer is selectively developed after shower development at 30 ° C. for 40 seconds with respect to the photosensitive layer. Removed to form a spacer pattern.

  When the obtained spacer pattern was observed from the side surface with a scanning electron microscope (SEM), the spacer pattern was tapered from the surface on the substrate member side toward the surface opposite to the surface (forward taper). I confirmed. The taper angle between the interface between the substrate member and the spacer pattern and the side surface of the spacer pattern was about 60 °.

  Next, the obtained spacer pattern was heated at 230 ° C. for 30 minutes in a box-type dryer to obtain a liquid crystal spacer. Thereafter, the liquid crystal spacer was ultrasonically cleaned in pure water using an ultrasonic cleaner (PUC-0851, high frequency output: 28 KHz, 3.6 kW) manufactured by Tokyo Ultrasonic Giken Co., Ltd. As a result of randomly observing 1000 liquid crystal spacers after ultrasonic cleaning using an optical microscope, it was confirmed that the liquid crystal spacers were not adhered to the substrate member but peeled off.

[Manufacture of liquid crystal display devices and evaluation of display quality]
Then, the liquid crystal aligning agent was apply | coated by the spin coat method on the board | substrate member after ultrasonic cleaning. And the laminated body with which the liquid crystal aligning agent was apply | coated was dried with the box-type dryer for 30 minutes at 180 degreeC, and the coating film with a dry film thickness of 0.05 micrometer was formed. Subsequently, the alignment film was rubbed using a rubbing machine having a roll around which a nylon cloth was wound.

  Next, an epoxy resin adhesive containing glass fiber was screen-printed and applied to the outer edge of the obtained substrate member. Thereafter, the epoxy resin adhesive was cured and the pair of substrate members were bonded in a state where the substrate member and the counter plate having the alignment film subjected to the rubbing process and having no liquid crystal spacer formed thereon were opposed to each other. The pair of substrate members were opposed so that the liquid crystal alignment film faces each other and the rubbing direction was orthogonal.

  Next, after filling a nematic liquid crystal between the pair of substrate members from the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy resin adhesive. Next, a polarizing plate was bonded to both outer surfaces of the substrate member so that the deflection direction coincided with the rubbing direction of the liquid crystal alignment film of each substrate member, and a liquid crystal display device was produced.

  When a voltage was applied to the obtained liquid crystal display device and the display quality was evaluated, display unevenness was not recognized on the screen and the display quality was good.

(Example 2)
[Production of photosensitive element (i) for liquid crystal spacer]
A polyethylene terephthalate film having a thickness of 100 μm was used as the support film, and the photosensitive resin composition solution (V-1) was uniformly applied on the support film using a comma coater. Next, the solvent was removed by drying with a hot air convection dryer at 100 ° C. for 1 minute to form a photosensitive layer. The thickness of the obtained photosensitive layer was 4.5 μm. Next, a polyethylene film having a thickness of 25 μm was further bonded as a cover film on the obtained photosensitive layer to prepare a photosensitive element (i) for a liquid crystal spacer.

[Manufacture of liquid crystal spacers in liquid crystal display devices]
While removing the cover film of the photosensitive element (i) for the liquid crystal spacer, a photosensitive layer was formed on a rectangular glass substrate having a thickness of 0.5 mm, a length of 100 mm and a width of 100 mm on which an ITO film was formed as a transparent electrode. Crimping was performed using a laminator (manufactured by Hitachi Chemical Co., Ltd., trade name: HLM-3000 type) so as to come into contact. The pressure bonding conditions were a roll temperature of 120 ° C., a substrate feed rate of 1 m / min, and a pressure bonding pressure (cylinder pressure) of 4 × 10 ⁵ Pa. Thus, the laminated body by which the photosensitive layer and the support body film were laminated | stacked on the glass substrate was produced.

Next, the support film laminated on the photosensitive layer was removed. Next, using a photomask having an actinic ray transmitting portion having a circular pattern with a diameter of 15 μm at a pitch of 100 μm as the photosensitive layer, an ultraviolet ray is imaged using a parallel light exposure machine (EXM1201 manufactured by Oak Manufacturing Co., Ltd.). Irradiated. A gap of 100 μm was provided between the photomask and the photosensitive layer surface. In addition, irradiation with ultraviolet rays was performed at an exposure amount of 5 × 10 ² J / m ² (measured value at i-line (wavelength 365 nm)) from vertically above the photomask surface.

  Next, using a 0.5% by mass tetramethylammonium hydroxide aqueous solution containing 0.5% by mass of a surfactant, the photosensitive layer is subjected to shower development for 40 seconds at 30 ° C. A portion other than was selectively removed to form a spacer pattern.

  When the obtained spacer pattern was observed from the side surface with a scanning electron microscope (SEM), the spacer pattern was tapered from the surface on the substrate member side toward the surface opposite to the surface (forward taper). I confirmed. The taper angle between the interface between the substrate member and the spacer pattern and the side surface of the spacer pattern was about 60 °.

  Next, the obtained spacer pattern was heated at 230 ° C. for 30 minutes in a box-type dryer to obtain a liquid crystal spacer. Thereafter, as in Example 1, the liquid crystal spacer was ultrasonically cleaned in pure water using an ultrasonic cleaner (PUC-0851, high frequency output: 28 KHz, 3.6 kW) manufactured by Tokyo Ultrasonic Giken Co., Ltd. did. As a result of randomly observing 1000 liquid crystal spacers after ultrasonic cleaning using an optical microscope, it was confirmed that the liquid crystal spacers were not adhered to the substrate member but peeled off.

[Manufacture of liquid crystal display devices and evaluation of display quality]
Subsequently, a liquid crystal display device was produced in the same manner as in Example 1 using a substrate member provided with a liquid crystal spacer after ultrasonic cleaning. When a voltage was applied to the obtained liquid crystal display device and the display quality was evaluated, display unevenness was not recognized on the screen and the display quality was good.

(Example 3)
[Preparation of photosensitive element (ii) for liquid crystal spacer]
The materials shown in Table 4 were mixed for 15 minutes using a stirrer to prepare a photosensitive resin composition solution (V-2).

  A polyethylene terephthalate film having a thickness of 100 μm was used as the support film, and the photosensitive resin composition solution (V-2) was uniformly applied on the support film using a comma coater. Next, the solvent was removed by drying with a hot air convection dryer at 100 ° C. for 1 minute to form a photosensitive layer. The resulting photosensitive layer had a thickness of 4.3 μm. Next, a polyethylene film having a thickness of 25 μm was further bonded as a cover film on the obtained photosensitive layer to prepare a photosensitive element (ii) for a liquid crystal spacer.

[Manufacture of liquid crystal spacers in liquid crystal display devices]
A spacer pattern was formed in the same manner as in Example 2 except that the photosensitive element for liquid crystal spacer (i) was replaced with the photosensitive element for liquid crystal spacer (ii).

  When the obtained spacer pattern was observed from the side surface with a scanning electron microscope (SEM), the spacer pattern was tapered from the surface on the substrate member side toward the surface opposite to the surface (forward taper). I confirmed. The taper angle between the interface between the substrate member and the spacer pattern and the side surface of the spacer pattern was about 50 °.

  Next, the obtained spacer pattern was heated at 230 ° C. for 30 minutes in a box-type dryer to obtain a liquid crystal spacer. Thereafter, as in Example 1, the liquid crystal spacer was ultrasonically cleaned in pure water using an ultrasonic cleaner (PUC-0851, high frequency output: 28 KHz, 3.6 kW) manufactured by Tokyo Ultrasonic Giken Co., Ltd. did. As a result of randomly observing 1000 liquid crystal spacers after ultrasonic cleaning using an optical microscope, it was confirmed that the liquid crystal spacers were not adhered to the substrate member but peeled off.

[Manufacture of liquid crystal display devices and evaluation of display quality]
Subsequently, a liquid crystal display device was produced in the same manner as in Example 1 using a substrate member provided with a liquid crystal spacer after ultrasonic cleaning. When a voltage was applied to the obtained liquid crystal display device and the display quality was evaluated, display unevenness was not recognized on the screen and the display quality was good.

Example 4
[Preparation of photosensitive element (iii) for liquid crystal spacer]
The materials shown in Table 5 were mixed for 15 minutes using a stirrer to prepare a photosensitive resin composition solution (V-3).

  A polyethylene terephthalate film having a thickness of 100 μm was used as the support film, and the photosensitive resin composition solution (V-3) was uniformly applied on the support film using a comma coater. Next, the solvent was removed by drying with a hot air convection dryer at 100 ° C. for 1 minute to form a photosensitive layer. The resulting photosensitive layer had a thickness of 4.4 μm. Next, a polyethylene film having a thickness of 25 μm was further bonded as a cover film on the obtained photosensitive layer to prepare a photosensitive element (iii) for a liquid crystal spacer.

[Manufacture of liquid crystal spacers in liquid crystal display devices]
A laminated body in which a photosensitive layer and a support film were laminated on a glass substrate in the same manner as in Example 2 except that the photosensitive element for liquid crystal spacer (i) was replaced with the photosensitive element for liquid crystal spacer (iii). Produced. Next, a spacer pattern was formed using the above laminate in the same manner as in Example 3 except that the exposure amount was changed to 4 × 10 ² J / m ² (measured value at i-line (wavelength 365 nm)).

  When the obtained spacer pattern was observed from the side surface with a scanning electron microscope (SEM), the spacer pattern was tapered from the surface on the substrate member side toward the surface opposite to the surface (forward taper). I confirmed. The taper angle between the interface between the substrate member and the spacer pattern and the side surface of the spacer pattern was about 60 °.

  Next, the obtained spacer pattern was heated at 230 ° C. for 30 minutes in a box-type dryer to obtain a liquid crystal spacer. Thereafter, as in Example 1, the liquid crystal spacer was ultrasonically cleaned in pure water using an ultrasonic cleaner (PUC-0851, high frequency output: 28 KHz, 3.6 kW) manufactured by Tokyo Ultrasonic Giken Co., Ltd. did. As a result of randomly observing 1000 liquid crystal spacers after ultrasonic cleaning using an optical microscope, it was confirmed that the liquid crystal spacers were not adhered to the substrate member but peeled off.

[Manufacture of liquid crystal display devices and evaluation of display quality]
Subsequently, a liquid crystal display device was produced in the same manner as in Example 1 using a substrate member provided with a liquid crystal spacer after ultrasonic cleaning. When a voltage was applied to the obtained liquid crystal display device and the display quality was evaluated, display unevenness was not recognized on the screen and the display quality was good.

(Comparative Example 1)
[Preparation of photosensitive resin composition solution (R-1)]
The materials shown in Table 6 were mixed for 15 minutes using a stirrer to prepare a photosensitive resin composition solution (R-1).

[Manufacture of liquid crystal spacers in liquid crystal display devices]
A photosensitive resin composition solution (R-1) is applied to a rectangular glass substrate with an ITO film formed as a transparent electrode and having a thickness of 0.5 mm and a main surface of 100 mm in length and 100 mm in width, and a spin coater is used. Then, spin coating was performed at 1000 rpm. Next, the solvent was removed by drying on a 90 ° C. hot plate for 5 minutes to form a photosensitive layer having a thickness of 4.5 μm.

Subsequently, a spacer pattern was formed in the same manner as in Example 1 except that the exposure amount of ultraviolet irradiation was changed to 7 × 10 ² J / m ² (measured value at i-line (wavelength 365 nm)). When the obtained spacer pattern was observed from the side with a scanning electron microscope (SEM), the spacer pattern became a shape (reverse taper) that tapers from the surface on the substrate member side toward the surface opposite to the surface. Confirmed that. The taper angle between the interface between the substrate member and the spacer pattern and the side surface of the spacer pattern was about 110 °.

  Next, the obtained spacer pattern was heated in a box type dryer at 230 ° C. for 30 minutes to obtain a liquid crystal spacer. Thereafter, as in Example 1, the liquid crystal spacer was ultrasonically cleaned in pure water using an ultrasonic cleaner (PUC-0851, high frequency output: 28 KHz, 3.6 kW) manufactured by Tokyo Ultrasonic Giken Co., Ltd. did. As a result of observing 1000 liquid crystal spacers after ultrasonic cleaning at random using an optical microscope, it was confirmed that 10% (100) liquid crystal spacers were peeled from the substrate member.

[Manufacture of liquid crystal display devices and evaluation of display quality]
Subsequently, a liquid crystal display device was produced in the same manner as in Example 1 using a substrate member provided with a liquid crystal spacer after ultrasonic cleaning. When a voltage was applied to the obtained liquid crystal display device and the display quality was evaluated, display unevenness was observed on the screen, and the display quality was inferior to that of the liquid crystal display device according to the example.

(Comparative Example 2)
[Preparation of photosensitive element (iv) for liquid crystal spacer]
A polyethylene terephthalate film having a thickness of 16 μm was used as the support film, and the photosensitive resin composition solution (R-1) was uniformly applied on the support film using a comma coater. Next, the solvent was removed by drying for 3 minutes with a hot air convection dryer at 100 ° C. to form a photosensitive layer. The resulting photosensitive layer had a thickness of 4.4 μm. Next, a polyethylene film having a thickness of 25 μm was further bonded as a cover film on the obtained photosensitive layer, to prepare a photosensitive element (iv) for a liquid crystal spacer.

[Manufacture of liquid crystal spacers in liquid crystal display devices]
A laminated body in which a photosensitive layer and a support film were laminated on a glass substrate in the same manner as in Example 2 except that the photosensitive element for liquid crystal spacer (i) was replaced with the photosensitive element for liquid crystal spacer (iv). Produced. Next, a spacer pattern was formed using the above laminate in the same manner as in Example 2 except that the exposure amount was changed to 7 × 10 ² J / m ² (measured value at i-line (wavelength 365 nm)).

  When the obtained spacer pattern was observed from the side surface with a scanning electron microscope (SEM), the spacer pattern became a shape (reverse taper) that tapers from the surface on the substrate member side toward the surface opposite to the surface. Confirmed that. The taper angle between the interface between the substrate member and the spacer pattern and the side surface of the spacer pattern was about 110 °.

  Next, the obtained spacer pattern was heated in a box type dryer at 230 ° C. for 30 minutes to obtain a liquid crystal spacer. Thereafter, as in Example 1, the liquid crystal spacer was ultrasonically cleaned in pure water using an ultrasonic cleaner (PUC-0851, high frequency output: 28 KHz, 3.6 kW) manufactured by Tokyo Ultrasonic Giken Co., Ltd. did. As a result of observing 1000 liquid crystal spacers after ultrasonic cleaning at random using an optical microscope, it was confirmed that 10% (100) liquid crystal spacers were peeled from the substrate member.

[Manufacture of liquid crystal display devices and evaluation of display quality]
Subsequently, a liquid crystal display device was produced in the same manner as in Example 1 using a substrate member provided with a liquid crystal spacer after ultrasonic cleaning. When a voltage was applied to the obtained liquid crystal display device and the display quality was evaluated, display unevenness was observed on the screen, and the display quality was inferior to that of the liquid crystal display device according to the example.

It is a schematic cross section of a liquid crystal display device. It is a typical fragmentary sectional view showing one embodiment of a photosensitive film concerning the present invention. It is process sectional drawing which shows one Embodiment of the manufacturing method of the liquid-crystal spacer based on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 2a, 2b ... Electrode, 3a, 3b ... Substrate, 4a, 4b ... Buffer material layer, 5a, 5b ... Polarizing plate, 6a, 6b, 46b ... Substrate member, 10 ... Liquid crystal spacer, 17a, 17b ... alignment layer, 18 ... liquid crystal layer, 20, ... photosensitive film, 22 ... photosensitive layer, 22a ... exposed part (spacer pattern), 22b ... non-exposed part, 24 ... support film, 25 ... cover film, L ... active Rays of light.

Claims (7)

A photosensitive resin composition used as a raw material for a liquid crystal spacer provided in a liquid crystal display device,
(A) a (meth) acrylic polymer having a photopolymerizable unsaturated group;
(B) a photopolymerizable unsaturated compound having at least one ethylenically unsaturated bond;
(C) a photopolymerization initiator that generates free radicals by actinic rays;
And the component (c) is
(C1) a hexaarylbiimidazole compound;
(C2) a hydrogen donating compound;
A photosensitive resin composition comprising:   The photosensitive resin composition according to claim 1, wherein the component (c2) contains an aryl glycine compound. The amount of the component (c1) is 1 to 6 parts by mass with respect to 100 parts by mass of the total amount of the component (a) and the component (b), and
The photosensitive resin composition of Claim 1 or 2 whose compounding quantity of the said (c2) component is 0.05-4 mass parts with respect to 100 mass parts of total amounts of the said (a) component and the said (b) component. object. A support film;
A photosensitive layer comprising the photosensitive resin composition according to any one of claims 1 to 3 formed on the support film;
A photosensitive element for a liquid crystal spacer. Formed on the substrate,
A first surface closely contacting the substrate, and a second surface opposite to the first surface;
A liquid crystal spacer tapered from the first surface toward the second surface. A photosensitive layer forming step of forming a photosensitive layer comprising the photosensitive resin composition according to any one of claims 1 to 3 on the surface of the substrate;
An actinic ray irradiation step of irradiating a predetermined portion of the photosensitive layer with actinic rays to form a photocured portion; and
A removal step of selectively removing portions other than the photocured portion from the photosensitive layer;
A heating step of heating the photocured portion;
A method for producing a liquid crystal spacer having A photosensitive layer laminating step of laminating the photosensitive layer of the photosensitive element according to claim 4 on the surface of the substrate,
An actinic ray irradiation step of irradiating a predetermined portion of the photosensitive layer with actinic rays to form a photocured portion; and
A removal step of selectively removing portions other than the photocured portion from the photosensitive layer;
A heating step of heating the photocured portion;
A method for producing a liquid crystal spacer having

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