JP2007034265A - Photosensitive resin composition and photosensitive element for liquid crystal spacer, and method for producing liquid crystal spacer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition and a photosensitive element which suppress thickness reduction of a pattern and allow production of a liquid crystal display capable of displaying a high-quality image free of display unevenness, and a method for producing liquid crystal spacers. <P>SOLUTION: The photosensitive resin composition is used in the method for producing liquid crystal spacers including: (I) a step of forming a layer comprising the photosensitive resin composition on a transparent electrode disposed on a substrate; (II) a step of curing exposed portions by imagewise irradiating the layer comprising the photosensitive resin composition with active rays; (III) a step of forming a pattern by selectively removing the layer comprising the photosensitive resin composition except the exposed portions by development; and (IV) a step of heating the pattern, wherein the photosensitive resin composition has such physical properties that the thickness of the pattern formed at the step (III) becomes 85-100% of the thickness of the layer comprising the photosensitive resin composition formed at the step (I). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition for a liquid crystal spacer and a photosensitive element used for a liquid crystal spacer disposed in order to keep the thickness of a liquid crystal layer in a liquid crystal display device constant, and a method for producing the liquid crystal spacer.

  In recent years, liquid crystal display devices such as liquid crystal color televisions and computers equipped with liquid crystal color displays have been increasingly used. These liquid crystal display devices have a gap (gap) of about 1 to 10 μm between a transparent substrate such as glass provided with a transparent electrode or the like and another substrate. An image is displayed by applying an electric field to the liquid crystal layer formed by enclosing the liquid crystal material in the gap through the electrodes and aligning the liquid crystal material. In such a liquid crystal display device, when the gap of the liquid crystal layer changes, image quality deterioration such as display unevenness and contrast abnormality occurs. As a means of preventing image quality degradation due to gap non-uniformity, a method is used in which spherical glass beads or resin beads having a uniform particle size distribution are arranged on the liquid crystal layer and the gap of the liquid crystal layer is kept constant. I came.

  However, the spacers of such spherical glass beads and resin beads are generally only scattered on the liquid crystal layer between the opposing substrates, and are not fixed to the substrates. For this reason, spherical glass beads and resin beads show a distribution that varies in the liquid crystal layer, causing display unevenness, spacers moving due to vibration of the liquid crystal display device, and an abnormal alignment region becoming larger, or alignment film surface There was a problem such as damaging. In addition, since such spherical glass beads and resin beads are also dispersed in the display portion which is a light transmitting portion of the liquid crystal display device, there are problems such as a decrease in contrast of displayed images and a decrease in display quality. there were.

  In order to solve these problems, Patent Documents 1 to 4 propose various means. For example, Patent Documents 1 to 3 disclose a method of forming a spacer by applying an ultraviolet curable resin on a substrate, drying, and performing exposure and development (see Patent Documents 1 to 3).

Patent Document 4 discloses a method of using a film formed by applying a photocurable resin coating liquid in advance, transferring the film, and then patterning it by exposure and development to form a spacer. Yes. The spacers formed by these methods are called columnar spacers or photosensitive spacers, and solve problems such as display unevenness, alignment abnormalities, and contrast reduction that occur when spherical glass beads or resin beads are used. It has been proposed as a possible means (see Patent Document 4).
Japanese Patent Laid-Open No. 03-089320 Japanese Patent Laid-Open No. 10-168134 Japanese Patent Laid-Open No. 11-133600 JP-A-11-174461

  However, since columnar spacers or photosensitive spacers formed by conventional materials and methods including those described in Patent Documents 1 to 4 described above use radical polymerization type ultraviolet curable resins, There is a drawback that it is easily affected by oxygen inhibition and the surface curability is lowered. Such a decrease in surface curability causes film loss in the development process.

  Further, the film reduction causes variations in the height of the columnar spacers in the substrate surface due to unevenness of illuminance of the exposure machine in the exposure process and uneven contact of the developer in the development process.

  Further, the variation in the height of the columnar spacers causes a problem that the gap of the liquid crystal layer becomes non-uniform when a panel is formed, and the display unevenness becomes remarkable and the display quality is deteriorated.

  The present invention relates to a photosensitive resin composition, a photosensitive element, and a method for manufacturing a liquid crystal spacer capable of manufacturing a liquid crystal display device capable of displaying a high-quality image without display unevenness by suppressing film loss of a pattern. The purpose is to provide.

  As a result of intensive studies on the above problems, the present inventors have found that the photosensitive resin composition according to the present invention has a thickness of a pattern formed from the resin layer with respect to the thickness of the resin layer laminated on the substrate. A photosensitive resin composition having a physical property of 85 to 100% was found. Further, by using such a photosensitive resin composition, it is possible to manufacture a liquid crystal display device having good display quality without display unevenness by sufficiently suppressing the film thickness reduction of the pattern, thereby completing the present invention. It was.

  The photosensitive resin composition according to the present invention is a liquid crystal disposed in order to keep the thickness of a liquid crystal layer of a liquid crystal display device having a liquid crystal layer in which a liquid crystal is sealed between substrates disposed opposite to each other. In the spacer, (I) a step of forming a layer made of a photosensitive resin composition (hereinafter also referred to as “photosensitive layer” or “photosensitive resin composition layer”) on a transparent electrode provided on the substrate. And (II) a step of imagewise irradiating the layer made of the photosensitive resin composition with an actinic ray to cure the exposed portion, and (III) other than the exposed portion of the layer made of the photosensitive resin composition by development. A photosensitive resin composition for use in a method for producing a liquid crystal spacer, comprising: a step of selectively removing a portion of the substrate to form a pattern; and a step of (IV) heating the pattern, the step (I) Of the layer made of the photosensitive resin composition formed in With respect to the physical properties such that a 85 to 100% the thickness of the pattern formed by the (III) step is.

  The photosensitive resin composition according to the present invention generates free radicals from (a) a binder polymer, (b) a photopolymerizable unsaturated compound having at least one ethylenically unsaturated group, and (c) an actinic ray. And a photopolymerization initiator.

  Moreover, as for the photosensitive resin composition which concerns on this invention, the content rate of the said (c) component should be 0.5-30 mass parts with respect to 100 mass parts of total amounts of (a) component and (b) component. preferable.

  In the photosensitive resin composition of the present invention, when the content of the component (c) with respect to 100 parts by mass of the total amount of the components (a) and (b) is within such a numerical range, sufficient photocuring is possible. In the step (II), when actinic rays are imagewise irradiated onto the photosensitive layer, the increase in absorption of actinic rays on the actinic ray-irradiated surface of the photosensitive layer is suppressed, and photocuring inside the photosensitive layer becomes insufficient. Can be prevented.

  Furthermore, the binder polymer as component (a) is preferably an acrylic polymer having an ethylenically unsaturated group in the side chain.

  The photosensitive resin composition of the present invention can achieve the object of the present invention more effectively and surely by using an acrylic polymer having an ethylenically unsaturated group in the side chain as the component (a). .

  From the same viewpoint, the photosensitive resin composition according to the present invention contains 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one as the component (c). Is preferred.

  The photosensitive element which concerns on this invention equips a support body film with the layer which consists of the above-mentioned photosensitive resin composition.

  By using this photosensitive element, it is possible to sufficiently reduce the film thickness of the pattern and to manufacture a liquid crystal display device having a good display quality without display unevenness with a high yield. The photosensitive element of the present invention is excellent in workability and can contribute to cost reduction.

  The method for manufacturing a liquid crystal spacer according to the present invention includes a liquid crystal disposed in order to keep the thickness of a liquid crystal layer of a liquid crystal display device having a liquid crystal layer in which liquid crystal is sealed between substrates disposed opposite to each other. A method for producing a spacer, comprising: (I) a step of forming a layer made of a photosensitive resin composition on a transparent electrode provided on a substrate; and (II) an actinic ray imaged on the layer made of the photosensitive resin composition. Irradiating the exposed portion to cure the exposed portion, and (III) developing to selectively remove portions other than the exposed portion of the layer made of the photosensitive resin composition to form a pattern, IV) heating the pattern.

  In addition, the method for manufacturing a liquid crystal spacer according to the present invention is provided in order to keep the thickness of the liquid crystal layer of a liquid crystal display device including a liquid crystal layer in which liquid crystal is sealed between substrates disposed opposite to each other. A method for producing a liquid crystal spacer, comprising: (I) forming a layer comprising the photosensitive element according to claim 5 on a transparent electrode provided on a substrate; and (II) comprising a photosensitive resin composition. The step of imagewise irradiating the layer with actinic rays to cure the exposed portion, and (III) development selectively removing portions other than the exposed portion of the layer made of the photosensitive resin composition to form a pattern. And (IV) a step of heating the pattern.

  Since the liquid crystal spacer manufacturing method of the present invention can suppress the film loss of the pattern by using the photosensitive resin composition or the photosensitive element of the present invention, it has good display quality without display unevenness. It becomes possible to manufacture the liquid crystal spacer having high yield.

  ADVANTAGE OF THE INVENTION According to this invention, the photosensitive resin composition and photosensitive element which can manufacture the liquid crystal display device which can suppress the film loss of a pattern and can display a high quality image without display unevenness, and liquid crystal spacer A manufacturing method can be 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 positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, “(meth) acrylic acid” means “acrylic acid” and its corresponding “methacrylic acid”, “(meth) acrylate”, “acrylate” and its corresponding “methacrylate”. “(Meth) acryloxy group” means “acryloxy group” and the corresponding “methacryloxy group”, and “(meth) acryloyl group” means “acryloyl group” and the corresponding “methacryloyl group”. To do.

  First, prior to the description of the photosensitive resin composition of the present embodiment, the configuration of the liquid crystal display device will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal display device equipped with a liquid crystal spacer (hereinafter, also simply referred to as “spacer”) manufactured from the photosensitive resin composition of the present embodiment. 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, a sealing agent 13 is provided between the board members 6a and 6b, and thereby the board members 6a and 6b are coupled.

  In such a liquid crystal display device, as shown in FIG. 1, the 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. From the viewpoint of displaying a high-quality image, the spacer 10 is preferably disposed at a position other than the display dot portion that is a light transmitting portion.

  The substrate members 6a and 6b shown in FIG. 1 are composed of the electrodes 2a and 2b, the substrates 3a and 3b, the buffer material layers 4a and 4b, and the polarizing plates 5a and 5b. Absent.

  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. Further, an insulating layer, a black matrix layer, a color filter layer, and the like may be provided on the substrate members 6a and 6b. A transparent electrode such as ITO can be used as the electrode 2b.

  A photosensitive resin composition used in the production of the liquid crystal spacer of the present embodiment (hereinafter referred to as “for liquid crystal spacer”) is a liquid crystal display device in which liquid crystal is sealed between substrates disposed to face each other. I) a photosensitive layer forming step of forming a photosensitive resin composition layer on the transparent electrode formed on the substrate, (II) an actinic ray irradiation step of imagewise irradiating the photosensitive resin composition layer with actinic rays, (III A pattern development step of selectively removing the photosensitive resin composition layer by development to form a pattern, and (IV) a liquid crystal layer formed by a heating step of heating the photosensitive resin composition layer on which the pattern is formed. A photosensitive resin composition used for a spacer disposed in order to keep the thickness of the substrate constant, and (I) with respect to the thickness of the photosensitive resin composition layer formed in the photosensitive layer forming step, (III) Pattern development The thickness of the pattern formed by the extent are those having physical properties as shown the residual film ratio to be 85 to 100%.

  The liquid crystal spacer is a liquid crystal display device in which liquid crystal is sealed between substrates disposed to face each other, and is disposed in order to keep the thickness of the liquid crystal layer 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 depends on the liquid crystal display device. Indicates that it is kept uniform in the screen.

  As described above, the liquid crystal spacer in this embodiment is formed by (I) a photosensitive layer forming step, (II) an actinic ray irradiation step, (III) a pattern developing step, and (IV) a heating step.

  Hereinafter, an example of the manufacturing method of the liquid crystal spacer in a liquid crystal display device using the photosensitive resin composition for liquid crystal spacers of this embodiment or the photosensitive element for liquid crystal spacers is demonstrated.

  A photosensitive element may be used in the method for manufacturing the liquid crystal spacer. Therefore, prior to the description of the manufacturing method of the liquid crystal spacer, the photosensitive element for the liquid crystal spacer will be described. FIG. 2 is a partial cross-sectional view showing one embodiment of the photosensitive element for liquid crystal spacer of the present embodiment. As shown in FIG. 2, the photosensitive element 20 for liquid crystal spacer of the present embodiment is a layer of a photosensitive resin composition for liquid crystal spacer (hereinafter also referred to as “photosensitive resin composition layer”) on a support film 24. .) 22.

  In the photosensitive element 20 for liquid crystal spacer of the present embodiment, a solution in which each component constituting the photosensitive resin composition layer 22 is uniformly dissolved or dispersed in a solvent is applied on a support film 24 and dried. It is obtained by forming the conductive resin composition layer 22.

  Examples of the support film 24 in the present embodiment include a film having a thickness of about 5 to 100 μm made of polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, polyethersulfone, or the like.

  As a method for forming the photosensitive resin composition layer on the support film 24 in the present embodiment, 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, spinner coating method, inkjet coating method, spray coating method, dip coating method, gravure coating method, curtain coating method, die coating method and the like.

  The thickness of the photosensitive resin composition layer 22 in the present embodiment is preferably set to 0.1 to 20 μm in consideration of electrical characteristics or liquid crystal alignment characteristics when the liquid crystal display device 1 is formed. It is more preferable to set it as 3-15 micrometers, and it is especially preferable to set it as 0.5-10 micrometers.

  Moreover, the viscosity of the photosensitive resin composition layer 22 in the present embodiment is preferably 15 to 100 MPa · s, more preferably 20 to 90 MPa · s at 30 ° C., and 25 to 80 MPa · s. It is particularly preferred. This is to prevent the photosensitive resin composition from oozing out from the end face of the photosensitive element for one month or more when a roll-shaped photosensitive element for liquid crystal spacer described later is prepared. Further, when cutting the photosensitive element, the photosensitive resin composition fragments are prevented from adhering to the substrate to prevent exposure failure, development residue, and the like.

The viscosity is 7 mm in diameter and 2 mm in thickness in the thickness direction of the disc-shaped photosensitive resin composition sample by applying a load of 1.96 × 10 ⁻² N at 30 ° C. and 80 ° C. This is a value obtained by measuring the rate of change and converting it to viscosity from this rate of change assuming a Newtonian fluid.

  Moreover, the cover film may be further laminated | stacked so that the surface F20 of the photosensitive resin composition layer 22 of the photosensitive element 20 for liquid crystal spacers may be opposed. FIG. 3 is a schematic partial sectional view showing another embodiment of the photosensitive element for liquid crystal spacer on which the cover film 25 is laminated.

  Examples of the cover film 25 include a film made of polyethylene, polypropylene, polyethylene terephthalate, polycarbonate or the like and having a thickness of about 5 to 100 μm.

  The photosensitive element 30 for a liquid crystal spacer thus obtained can be stored in a roll or stored.

  Since the photosensitive element according to the present embodiment includes a layer made of a photosensitive resin composition to be described later, it is preferable to suppress the film loss of the pattern, and it is excellent in workability and contributes to cost reduction. The liquid crystal spacer and the liquid crystal display device to be obtained can be manufactured.

  FIG. 4 is a process sectional view schematically showing a manufacturing process of the spacer 10 shown in FIG. When using the photosensitive resin composition as a raw material for the spacer as it is, a step of applying a photosensitive layer can be employed as the photosensitive layer forming step.

[(I) Photosensitive layer forming step]
In this step, the photosensitive resin composition layer 12 is formed on the substrate member 46b. As shown in FIG. 4, the substrate member 46b includes an electrode 2b on one surface of the substrate 3b. The photosensitive resin composition layer 12 is formed on the surface of the substrate member 46b provided with the electrode 2b, and the laminate 7 is obtained.

  In this embodiment, as a method of forming the photosensitive resin composition layer 12 for liquid crystal spacers on the transparent electrode formed on the substrate 3b, each component constituting the photosensitive resin composition for liquid crystal spacers of this embodiment is used. For example, there is a method in which a uniformly dispersed solution is obtained by dissolving or mixing in a solvent that can be dissolved or dispersed, and the solution is applied and dried on the substrate member 46b.

  As a coating method in this embodiment, a known coating method can be used, and all the methods of coating the photosensitive resin composition layer on the support film when manufacturing the above-described photosensitive element for liquid crystal spacer are used. Can do.

  The drying temperature when the solvent in the solution is volatilized and dried is preferably 60 to 130 ° C., and the drying time is preferably 1 minute to 1 hour.

  The thickness of the photosensitive resin composition layer 12 in the present embodiment is preferably 0.1 to 20 μm in consideration of the electrical characteristics of the liquid crystal display device 1 and the alignment characteristics of the liquid crystal, and is preferably 0.3 to 15 μm. More preferably, the thickness is more preferably 0.5 to 10 μm.

  Thus, the photosensitive resin composition layer 12 for liquid crystal spacers of this embodiment can be laminated | stacked on the board | substrate member 46b.

  In the present embodiment, as another method for forming the photosensitive resin composition layer for the liquid crystal spacer on the substrate member 46b, the photosensitive resin composition layer 22 is in contact with the substrate member 46b. The process etc. which laminate | stack the photosensitive element 20 or 30 for liquid crystal spacers are mentioned.

  In this embodiment, as a method of laminating the photosensitive element 20 or 30 for the liquid crystal spacer so that the photosensitive resin composition layer is in contact with the substrate member 46b, the cover film 25 is in contact with the photosensitive resin composition layer 22. If the cover film 25 is removed, it can be performed by, for example, pressing with a pressing roll so that the photosensitive resin composition layer 22 is in contact with the substrate member 46b.

  The crimping roll may be provided with a heating means so that it can be thermocompression bonded. The heating temperature in the case of thermocompression bonding is preferably 10 to 180 ° C, more preferably 20 to 160 ° C. 30-150 ° C. is particularly preferable. If the heating temperature is less than 10 ° C., the adhesion between the photosensitive resin composition layer 22 and the substrate member 46b tends to decrease, and if it exceeds 180 ° C., the constituent components of the photosensitive resin composition layer 22 are heated. There is a tendency to cure or thermally decompose.

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 shall be 2.5 * 10 < ² > N / m-5 * 10 < ⁴ > N / m. it is more preferable, and particularly preferably ^{5 × 10 2 N / m~4 ×} 10 4 N / m. If this pressure is less than 50 N / m, the adhesion between the photosensitive resin composition layer 22 and the substrate member 46 b tends to decrease, and if it exceeds 1 × 10 ⁵ N / m, the substrate member 46 b is destroyed. There is a tendency to.

  If the photosensitive element 20 or 30 for the liquid crystal spacer is heated as described above, it is not necessary to pre-heat the substrate member 46b, but the adhesion between the photosensitive resin composition layer 22 and the substrate member is further improved. In view of this, it is preferable to pre-heat the substrate member 46b. The preheating temperature at this time is preferably 30 to 180 ° C.

  In this manner, the photosensitive resin composition layer 22 of the liquid crystal spacer photosensitive element 20 or 30 of the present embodiment can be laminated on the substrate member 46b.

[(II) Actinic ray irradiation step]
In this step, the photosensitive resin composition layer 12 is irradiated with an actinic ray L imagewise. In the present embodiment, the method of irradiating actinic light L imagewise is a method of irradiating the photosensitive resin composition layer 12 laminated on the substrate member 46b with a known actinic light via the photomask 9. Is mentioned. At this time, when the photosensitive resin composition layer 12 is formed on the substrate member 46b using the photosensitive element 20 or 30 for the liquid crystal spacer, dust / foreign matter adhering to the support film 24 and the support From the viewpoint that it is possible to eliminate the influence of local shortage of active light irradiation due to scratches on the film 24, the support film 24 on the photosensitive resin composition layer 12 is removed, and then the active light L is imagewise irradiated. Is preferred.

  Further, 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 ultra-high pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, etc. There is no particular limitation.

[(III) Pattern development step]
In this step, the unexposed portion 12b of the photosensitive resin composition layer 12 is selectively removed by development to obtain a pattern composed of the exposed portion 12a. 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, The method of removing an unnecessary part is mentioned, Especially, it is mentioned as a preferable thing to use alkaline aqueous solution from a viewpoint of environment and safety.

  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, etc. Among them, tetramethylammonium hydroxide, etc. are preferred. It is done.

  The development temperature and time can be adjusted according to the developability of the photosensitive resin composition layer 12 of the present 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 resin composition layer 12 after development and photocuring is sprayed, rocking dipping, brushing, scraping, etc. using an organic acid, an inorganic acid or an aqueous acid thereof. The acid treatment (neutralization treatment) can be performed by a known method. Furthermore, the water washing process can also be performed after an acid treatment (neutralization treatment).

[(IV) Heating step]
In this step, the exposed portion 12a on which the pattern has been formed is heated. In the present embodiment, as a method for heating the exposed portion 12a, known methods such as hot air radiation, infrared irradiation heating, and the like can be cited, and the exposed portion 12a of the photosensitive resin composition layer in which a pattern is formed on the substrate member 46b. There is no particular limitation as long as it is an effective heating method.

  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 thermosetting effect tends to be insufficient, and if it exceeds 300 ° C, the constituent components of the photosensitive resin composition layer tend to thermally decompose.

  The photosensitive resin composition for a liquid crystal spacer of the present embodiment can form a liquid crystal spacer suitable for a liquid crystal display device by the manufacturing method described above, and is formed in the (I) photosensitive layer forming step. With respect to the thickness of the photosensitive resin composition layer, (III) the pattern formed in the pattern development step has a remaining film ratio of 85 to 100%.

  Hereinafter, a method for measuring the remaining film ratio of a pattern serving as a spacer disposed in a certain region on the substrate will be described in detail.

  In the present embodiment, the photosensitive resin composition layer formed in the above-mentioned (I) photosensitive layer forming step is used to measure the remaining film ratio of a pattern serving as a spacer disposed in a certain region on the substrate. It is necessary to measure the thickness of the pattern and the thickness of the pattern formed in the above-described (III) pattern development step.

  As a method for measuring the thickness of the photosensitive resin composition layer formed in the above-mentioned (I) photosensitive layer forming step, for example, a part of the photosensitive resin composition layer formed on the substrate is mechanically cut. There is a method of exposing a part of the substrate surface by removing and measuring a step from the substrate surface to the surface of the photosensitive resin composition layer. As a more specific method for measuring the level difference, for example, a method using an atomic force microscope can be used, and the surface of the photosensitive resin composition layer is scanned from the substrate surface by scanning the probe of the atomic force microscope. Can be measured, that is, the thickness of the photosensitive resin composition layer.

  Similarly, a method of measuring the thickness of the pattern formed in the above-described (III) pattern development step using an atomic force microscope is preferable. By scanning the probe of an atomic force microscope, the shape of a pattern serving as a spacer can be analyzed and the thickness can be measured.

  The remaining film ratio of the pattern serving as a spacer is expressed as a percentage of the thickness of the pattern formed in (III) pattern development step to the thickness of the photosensitive resin composition layer formed in (I) photosensitive layer formation step. It is. For example, when the thickness of the photosensitive resin composition layer formed in the (I) photosensitive layer forming step is 4 μm and the thickness of the pattern formed in the (III) pattern developing step is 3.6 μm, the spacer The remaining film ratio of the pattern becomes 3.6 / 4 × 100 = 90 (%).

  In this embodiment, the thickness of the pattern formed in the (III) pattern development step is 85 to 100% with respect to the thickness of the photosensitive resin composition layer formed in the (I) photosensitive layer forming step. In order to achieve the remaining film ratio, the photosensitive resin composition for a liquid crystal spacer comprises (a) a binder polymer, (b) a photopolymerizable unsaturated compound having at least one ethylenically unsaturated group, and (c ) It contains a photopolymerization initiator that generates free radicals by actinic rays, and the content of component (c) is 0.5-30 with respect to 100 parts by mass of the total amount of components (a) and (b). It is preferable that it is a mass part.

  There is no restriction | limiting in particular as (a) binder polymer in this embodiment, For example, a vinyl copolymer is mentioned. The vinyl copolymer can be synthesized by a conventional method, and a commercially available product may be obtained. Examples of the vinyl monomer used in the vinyl copolymer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, and acrylic acid n. -Propyl, n-propyl methacrylate, iso-propyl acrylate, iso-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, iso-butyl acrylate, iso-butyl methacrylate, sec-acrylic acid Butyl, sec-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, heptyl acrylate, heptyl methacrylate, 2-ethylhexyl acrylate 2-ethylhexyl methacrylate, octyl acrylate, octyl methacrylate, nonyl acrylate, 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, methacrylate Phenyl acid, methoxyethyl acrylate, methoxyethyl methacrylate, methoxydiethylene glycol acrylate, methoxydiethylene glycol methacrylate, methoxydipropylene glycol acrylate, methoxydipropylene glycol methacrylate, methoxytriethylene glycol acrylate, methoxytriethylene glycol methacrylate , 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, acrylic 2-chloroethyl acid, 2-chloroethyl methacrylate, 2-fluoroacrylic acid Roethyl, 2-fluoroethyl methacrylate, 2-cyanoethyl acrylate, 2-cyanoethyl methacrylate, styrene, α-methylstyrene, cyclohexylmaleimide, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, vinyl toluene, vinyl chloride , Vinyl acetate, N-vinylpyrrolidone, butadiene, isoprene, chloroprene, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile and the like. These may be used alone or in combination of two or more.

From the viewpoint of further improving the (a) binder polymer residual film ratio in the present embodiment, a radical polymerizable copolymer having an ethylenically unsaturated group in the side chain can also be used. The copolymer is, for example, a carboxyl group, a hydroxyl group, an amino group, an isocyanate group, an oxirane ring, or the following formula (1);
-CO-O-OC- (1)
The vinyl copolymer having a functional group such as a divalent group represented by the formula has at least one ethylenically unsaturated group and one functional group such as an oxirane ring, an isocyanate group, a hydroxyl group, and a carboxyl group. It can be obtained by subjecting a compound to an addition reaction using a catalyst such as dibutyltin dilaurate.

  Examples of the essential vinyl monomer used in the production of a vinyl copolymer having a functional group such as a carboxyl group, a hydroxyl group, an amino group, an oxirane ring, or a divalent group represented by the above formula (1) include: , Acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, cinnamic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, ethyl isocyanate, glycidyl acrylate, glycidyl methacrylate, Examples thereof include vinyl monomers having a functional group such as a carboxyl group, a hydroxyl group, an amino group, an oxirane ring, and an acid anhydride such as maleic anhydride. These are used alone or in combination of two or more.

  In the production of such a radical polymerizable copolymer having an ethylenically unsaturated group in the side chain, a carboxyl group, a hydroxyl group, an amino group, an oxirane ring, or the above formula (1) is optionally represented. A vinyl monomer other than a vinyl monomer having a functional group such as a divalent group can be copolymerized. These can be used alone or in combination of two or more.

The concentration of the ethylenically unsaturated group in the radically polymerizable copolymer having an ethylenically unsaturated group in the side chain is preferably 1.0 × 10 ^{−4 to} 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 the pattern is formed in the step (III), there is a tendency that the effect of improving the remaining film ratio cannot be sufficiently obtained. When it exceeds 0.0 × 10 ⁻³ mol / g, gelation tends to occur when a radical polymerizable copolymer having an ethylenically unsaturated group in the side chain is produced.

  In the present embodiment, (a) the weight average molecular weight of the binder polymer (measured by gel permeation chromatography and converted into standard polystyrene, that is, converted into polystyrene as a standard sample) is heat resistance, coatability, and liquid crystal described later. From the viewpoints of film properties (characteristics for maintaining a film-like form) when forming a photosensitive element for spacer, solubility in a solvent, solubility in a developing solution in a development step described later, and the like, the range is set to 1000 to 300,000. It is preferable that it is 5000-150,000.

  The acid value of the binder polymer (a) in this embodiment can be regulated so that it can be developed with various known developing solutions in the step (III).

  For example, when the development is performed using an alkaline aqueous solution such as sodium carbonate, potassium carbonate, tetramethylammonium hydroxide, or triethanolamine, the acid value is preferably 50 to 260 mgKOH / g. If the acid value is less than 50 mgKOH / g, development tends to be difficult, and if it exceeds 260 mgKOH / g, the developer resistance (the portion that becomes a pattern without being removed by development is not affected by the developer). ) Tends to decrease.

  Moreover, when developing using the aqueous alkali solution which consists of water or aqueous alkali solution and 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.

  Examples of the photopolymerizable unsaturated compound (b) having at least one ethylenically unsaturated group in this embodiment include compounds obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid, 2 , 2-bis (4- (di (meth) acryloxypolyethoxy) phenyl) propane, a compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid, a urethane monomer, nonylphenyldioxylene ( (Meth) acrylate, y-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxypropyl -Β '-(meth) acryloyloxyethyl-o-phthalate, (meth) acrylic acid alkyl ester, etc. And the like.

  Examples of the compound obtained by reacting a 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, tetramethylolmethanetri (meth) ) Acrylate (also known as: pentaerythritol tri (meth) acrylate), tetramethylolmethane tetra (meth) acrylate, polypropylene glycol di (meth) acrylate having 2 to 14 propylene groups, dipentaerythritol penta (meth) acrylate And dipentaerythritol hexa (meth) acrylate.

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

  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 and the like.

  Examples of the glycidyl group-containing compound include trimethylolpropane triglycidyl ether tri (meth) acrylate, 2,2-bis (4- (meth) acryloxy-2-hydroxy-propyloxy) phenyl, and the like.

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

  Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2-ethylhexyl ester, and the like. It is done. These can be used alone or in combination of two or more.

  The component (b) described above may be synthesized by a conventional method, or a commercially available product may be obtained.

  Examples of the photopolymerization initiator (c) that generates free radicals by actinic rays in the present embodiment include aromatic ketones, quinones, benzoin ether compounds, benzoin compounds, benzyl derivatives, 2,4,5-triarylimidazole. Examples thereof include dimers, acridine derivatives, N-phenylglycine, N-phenylglycine derivatives, and coumarin compounds. Examples of aromatic ketones include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (also known as Michler ketone), N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy- 4′-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino -Propan-1-one and quinones include, for example, 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenyl Anthraquinone, 2,3-diphenylanthraquinone, 1 Examples of chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone and 2,3-dimethylanthraquinone, and benzoin ether compounds include, for example, benzoin methyl Examples of ethers, benzoin ethyl ether and benzoin phenyl ether, and benzoin compounds include benzoin, methyl benzoin and ethyl benzoin, benzyl derivatives such as benzyl dimethyl ketal, and 2,4,5-triarylimidazole dimers. 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl)- 4 , 5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer and 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, acridine derivatives Examples thereof include 9-phenylacridine and 1,7-bis (9,9′-acridinyl) heptane.

  Examples of commercially available products include Irgacure-369 (trade name, manufactured by Ciba Specialty Chemicals) as 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-methyl Examples of -1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one include Irgacure-907 (trade name, manufactured by Ciba Specialty Chemicals).

  In the 2,4,5-triarylimidazole dimer, the substituents substituted with two 2,4,5-triarylimidazoles may be the same or different.

  Moreover, you may combine a thiosantone type compound and a tertiary amine compound like the combination of diethylthioxanthone and dimethylaminobenzoic acid.

  Among these, 2,4,5-triarylimidazole dimer is preferable from the viewpoint of adhesion and sensitivity in the photolithography process, and 2-methyl-1- [ 4- (Methylthio) phenyl] -2-morpholino-propan-1-one is more preferred. These can be used alone or in combination of two or more.

  The component (c) described above may be synthesized by a conventional method, or a commercially available product may be obtained.

  The amount of the (a) binder polymer used in the present embodiment is preferably 10 to 80 parts by mass and preferably 20 to 75 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). Is more preferably 25 to 73 parts by mass, particularly preferably 30 to 70 parts by mass. When the amount used is less than 10 parts by mass, the coating property or the film property when the photosensitive element for liquid crystal spacer is formed tends to be lowered, and when it exceeds 80 parts by mass, the photocurability or heat resistance tends to be lowered. There is.

  In this embodiment, (b) the photopolymerizable unsaturated compound having at least one ethylenically unsaturated group is used in an amount of 10 to 80 masses per 100 mass parts of the total amount of components (a) and (b). Part, preferably 20 to 75 parts by weight, more preferably 25 to 73 parts by weight, and particularly preferably 30 to 70 parts by weight. If the amount used is less than 10 parts by mass, the photocurability or heat resistance tends to decrease, and if it exceeds 80 parts by mass, the film property when a coating element or a photosensitive element for liquid crystal spacer is formed decreases. Tend.

  The amount of the (c) photopolymerization initiator used in this embodiment is preferably 0.5 to 30 parts by mass, and 1 to 25 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). Part is more preferable, 1.5 to 20 parts by mass is particularly preferable, and 2 to 17 parts by mass is extremely preferable. If the amount used is less than 0.5 parts by mass, the photocuring is insufficient, and there is a tendency that the effect of improving the remaining film ratio cannot be ensured, and if it exceeds 30 parts by mass, Absorption of actinic rays at the actinic ray-irradiated surface of the photosensitive resin composition layer increases and internal photocuring tends to be insufficient.

In addition, the photosensitive resin composition of the present embodiment contains a silyl group having at least one hydrolyzable group-containing silyl group in one molecule from the viewpoint of improving the substrate adhesion when a liquid crystal spacer is formed. Organic compounds can be used. For example, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane / hydrochloride, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyltriethoxysilane, vinyltris (Β-methoxyethoxy) silane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, N -Β- (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane Etc. . Among these, γ-methacryloxypropyltrimethoxysilane is preferable from the viewpoint of storage stability of the photosensitive resin composition. These can be used in an amount of about 0.01 to 20 parts by mass per 100 parts by mass of the total amount of components (a) and (b), and can be used alone or in combination of two or more.
In addition, when synthesize | combining each above-mentioned component, solvents, such as a propylene glycol monomethyl ether acetate, 2, 2'- azobis (isobutyronitrile), etc. can be used suitably.

  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.

  In the photosensitive resin composition of the present embodiment, a leveling agent, a plasticizer, a filler, an antifoaming agent, a flame retardant, a stabilizer, an antioxidant, a fragrance, a thermal cross-linking agent, a polymerization inhibitor, and the like as necessary. Can be contained in an amount of about 0.01 to 20 parts by mass per 100 parts by mass of the total amount of components (a) and (b). These are used alone or in combination of two or more.

  The photosensitive resin composition for a liquid crystal spacer and the photosensitive element 20 or 30 for a liquid crystal spacer in the present embodiment are not limited to the use of a liquid crystal display device. For example, an opposing substrate such as an electrochromic display or electronic paper It can also be suitably used for spacer applications such as a display device comprising a layer of a substance having fluidity therebetween.

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

  Hereinafter, although an example explains this embodiment in detail, this embodiment is not limited to this.

(Production Example 1)
[Preparation of Binder Polymer Solution (p-1)]
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., each material shown in (1) of Table 1 was uniformly dropped over 4 hours.
After dripping the material shown in (2), stirring was continued at 80 ° C. ± 2 ° C. for 6 hours to obtain a binder polymer solution (p-1; solid content of 35% by mass) having a weight average molecular weight of about 30,000.

(Production Example 2)
[Preparation of Binder Polymer Solution (p-2)]
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 dropping the material shown in (2), stirring was continued at 80 ° C. ± 2 ° C. for 6 hours to obtain a prepolymer solution (solid content 35% by mass) having a weight average molecular weight of about 25,000.

  Furthermore, the prepolymer solution obtained here was charged into a flask equipped with a stirrer, a reflux condenser, an inert gas inlet, and a thermometer, and the temperature was raised to 70 ° C. in a nitrogen gas atmosphere to increase the reaction temperature. While maintaining at 70 ° C. ± 2 ° C., a mixture of 20 parts by mass of ethyl isocyanate, 35 parts by mass of propylene glycol monomethyl ether acetate and 0.1 parts by mass of dibutyltin dilaurate was uniformly added dropwise over 2 hours.

  After dropping, stirring was continued at 70 ° C. ± 2 ° C. for 2 hours to obtain a binder polymer solution (p-2; solid content 35% by mass) having a photopolymerizable unsaturated group having a weight average molecular weight of about 26000.

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

[Manufacture of liquid crystal spacers in liquid crystal display devices]
The photosensitive resin composition solution (V-1) was applied on a glass substrate on which an ITO film having a thickness of 1 mm was formed, and spin-coated at 1500 rpm using a spin coater, and then on a hot plate. It dried at 90 degreeC for 5 minute (s), the solvent was removed, and the board | substrate with which the photosensitive resin composition layer was formed was obtained. A portion of the obtained photosensitive resin composition layer was cut off until the substrate surface was exposed, and the substrate surface was scanned using a scanning probe microscope (atomic force microscope) SPI3800N / SPA500 manufactured by Seiko Instruments Inc. The thickness of the photosensitive resin composition layer was 4.5 μm when the level difference between the surface of the photosensitive resin composition layer and the surface of the photosensitive resin composition layer was measured.

Next, a substrate on which a photosensitive resin composition layer was formed was prepared in the same manner as described above, and a parallel light exposure machine (EXM1201 manufactured by Oak Seisakusho Co., Ltd.) was passed through the photosensitive resin composition layer through a photomask. ) Was used to image-irradiate ultraviolet rays. The photomask has a circular shape with a light-transmitting portion having a diameter of 10 microns, and is patterned at a pitch of 100 μm in the vertical and horizontal directions in a 50 mm × 50 mm rectangular region of the photosensitive resin composition layer. A gap of 150 μm was provided between the photomask and the photosensitive resin composition layer surface. 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, the photosensitive resin composition layer is selectively removed by spray development at 30 ° C. for 40 seconds using a 0.5 mass% tetramethylammonium hydroxide aqueous solution containing 0.5 mass% of a surfactant. As a result, a cylindrical pattern was formed.

  The shape of the obtained cylindrical pattern was analyzed using a scanning probe microscope (atomic force microscope) as described above, and the thickness was measured to be 4.2 μm. Since the thickness of the photosensitive resin composition layer was 4.5 μm, it was confirmed that the remaining film ratio of the columnar pattern serving as the spacer was 93.3%.

  Next, the photosensitive resin composition layer on which the pattern was formed was heated with a box-type dryer at 230 ° C. for 30 minutes to obtain a liquid crystal spacer pattern.

  When the pattern of the liquid crystal spacer was observed with a scanning electron microscope, a cylindrical pattern was formed in a good shape.

(Example 2)
[Production of photosensitive element (i) for liquid crystal spacer]
As the support film, a polyethylene terephthalate film was used, and the photosensitive resin composition solution (V-1) for liquid crystal spacer obtained in Example 1 was uniformly coated on the support film using a comma coater. The solvent was removed by drying with a hot air convection dryer at 0 ° C. for 1 minute to obtain a photosensitive resin composition layer.

  Next, a polyethylene film having a thickness of 25 μm was further laminated as a cover film on the obtained photosensitive resin composition layer to produce a photosensitive element (i) for liquid crystal spacers.

[Manufacture of liquid crystal spacers in liquid crystal display devices]
As a transparent electrode, a laminator (manufactured by Hitachi Chemical Co., Ltd., trade name: HLM-3000 type) is used so that the photosensitive resin composition layer is in contact with the photosensitive element (i) for the liquid crystal spacer while peeling off the polyethylene film. Lamination was performed on a glass substrate on which an ITO film having a thickness of 1 mm was formed. The laminating conditions were a roll temperature of 120 ° C., a substrate feed rate of 1 m / min, a pressure bonding pressure (cylinder pressure) of 4 × 10 ⁵ Pa (thickness of 1 mm, length of 10 cm × width of 10 cm, and the linear pressure at this time was 9.8 × 10 ³ N / m). Thus, the laminated body by which the photosensitive resin composition layer and the support body film were laminated | stacked on the glass substrate was produced.

  The support film on the photosensitive resin composition layer of the laminate was peeled off, and a part of the photosensitive resin composition layer was removed by cutting until the substrate surface was exposed. When the level | step difference with the resin composition layer surface was measured, the thickness of the photosensitive resin composition layer was 4.1 micrometers.

  Next, a laminate was produced by the same operation as described above, and after peeling off the support film, the photosensitive resin composition layer was subjected to ultraviolet imagewise irradiation and development in the same manner as in Example 1, A cylindrical pattern was obtained. It was 3.75 micrometers when the thickness of the obtained cylindrical pattern was measured by the method similar to Example 1. FIG.

  Since the thickness of the photosensitive resin composition layer was 4.1 μm, it was confirmed that the remaining film ratio of the columnar pattern serving as the spacer was 91.5%.

  Next, the photosensitive resin composition layer on which the pattern was formed was heated with a box-type dryer at 230 ° C. for 30 minutes to obtain a liquid crystal spacer pattern.

  When the pattern of the liquid crystal spacer was observed with a scanning electron microscope, a cylindrical pattern was formed in a good shape.

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

[Preparation of photosensitive element (ii) for liquid crystal spacer]
A polyethylene terephthalate film is used as the support film, and the photosensitive resin composition solution (V-2) for liquid crystal spacers is uniformly coated on the support film using a comma coater, and a hot air convection dryer at 100 ° C. And dried for 3 minutes to remove the solvent to obtain a photosensitive resin composition layer.

  Next, a polyethylene film having a thickness of 25 μm was further laminated as a cover film on the obtained photosensitive resin composition layer, to produce a photosensitive element (ii) for a liquid crystal spacer.

[Manufacture of liquid crystal spacers in liquid crystal display devices]
A liquid crystal spacer pattern was formed in the same manner as in Example 2, except that the liquid crystal spacer photosensitive element (i) in Example 2 was replaced with the liquid crystal spacer photosensitive element (ii). When the thickness of the photosensitive resin composition layer and the cylindrical pattern was measured, the thickness of the photosensitive resin composition layer was 4.3 μm, and the thickness of the cylindrical pattern serving as a spacer was 4.2 μm. . Therefore, it was confirmed that the remaining film ratio of the cylindrical pattern serving as the spacer was 97.7%.

  Next, the photosensitive resin composition layer on which the pattern was formed was heated with a box-type dryer at 230 ° C. for 30 minutes to obtain a liquid crystal spacer pattern.

  When the pattern of the liquid crystal spacer was observed with a scanning electron microscope, a cylindrical pattern was formed in a good shape.

(Comparative Example 1)
[Preparation of Comparative Photosensitive Resin Composition Solution (C-1)]
The materials shown in Table 5 were mixed for 15 minutes using a stirrer to prepare a comparative photosensitive resin composition solution (C-1).

[Manufacture of liquid crystal spacers in liquid crystal display devices]
A liquid crystal spacer pattern was formed in the same manner as in Example 1 except that the photosensitive resin composition solution (V-1) in Example 1 was replaced with the comparative photosensitive resin composition solution (C-1). When the thickness of the photosensitive resin composition layer and the cylindrical pattern was measured, the thickness of the photosensitive resin composition layer was 4.2 μm, and the thickness of the cylindrical pattern serving as a spacer was 3.3 μm. . Therefore, the remaining film ratio of the cylindrical pattern serving as a spacer was 78.6%.

Next, the photosensitive resin composition layer on which the pattern was formed was heated with a box-type dryer at 230 ° C. for 30 minutes to obtain a liquid crystal spacer pattern.
When the pattern of the liquid crystal spacer was observed with a scanning electron microscope, the columnar pattern showed severe film loss.

It is a schematic cross section of a liquid crystal display device. It is a typical fragmentary sectional view which shows one Embodiment of the photosensitive element for liquid crystal spacers concerning this invention. It is a typical fragmentary sectional view which shows other embodiment of the photosensitive element for liquid crystal spacers concerning this invention. It is process sectional drawing of the manufacturing method of the spacer which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 2 ... Electrode, 3 ... Substrate member, 4 ... Buffer material layer, 5 ... Polarizing plate, 6a, 6b, 46b ... Substrate, 10 ... Liquid crystal spacer, 12, 22 ... Photosensitive resin composition layer, DESCRIPTION OF SYMBOLS 12a ... Exposed part, 12b ... Non-exposed part, 18 ... Liquid crystal layer, 20, 30 ... Photosensitive element, 24 ... Support film, 25 ... Cover film, L ... Actinic ray.

Claims (8)

In a liquid crystal display device including a liquid crystal layer in which liquid crystal is sealed between substrates disposed to face each other, in a method of manufacturing a liquid crystal spacer disposed to keep the thickness of the liquid crystal layer constant,
(I) forming a layer made of a photosensitive resin composition on the transparent electrode provided on the substrate;
(II) a step of imagewise irradiating actinic rays to the layer comprising the photosensitive resin composition to cure the exposed portion;
(III) a step of selectively removing portions other than the exposed portion of the layer made of the photosensitive resin composition by development to form a pattern;
(IV) heating the pattern;
The photosensitive resin composition used in the method for producing the liquid crystal spacer comprising:
Physical properties such that the thickness of the pattern formed in the step (III) is 85 to 100% with respect to the thickness of the layer made of the photosensitive resin composition formed in the step (I). A photosensitive resin composition. (A) a binder polymer;
(B) a photopolymerizable unsaturated compound having at least one ethylenically unsaturated group;
(C) a photopolymerization initiator that generates free radicals by actinic rays;
The photosensitive resin composition of Claim 1 containing this.   The photosensitive resin of Claim 1 or 2 whose content rate of the said (c) component is 0.5-30 mass parts with respect to 100 mass parts of total amounts of the said (a) component and the said (b) component. Composition.   The photosensitive resin composition as described in any one of Claims 1-3 which contains the acrylic polymer which has an ethylenically unsaturated group in a side chain as said (a) component.   The photosensitivity according to any one of claims 1 to 4, comprising 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one as the component (c). Resin composition.   A photosensitive element provided with the layer which consists of a photosensitive resin composition as described in any one of Claims 1-5 on a support body film. In a liquid crystal display device comprising a liquid crystal layer in which liquid crystal is sealed between substrates disposed to face each other, a method for producing a liquid crystal spacer disposed to keep the thickness of the liquid crystal layer constant,
(I) a step of forming a layer made of the photosensitive resin composition according to any one of claims 1 to 5 on a transparent electrode provided on the substrate;
(II) a step of imagewise irradiating actinic rays to the layer comprising the photosensitive resin composition to cure the exposed portion;
(III) a step of selectively removing portions other than the exposed portion of the layer made of the photosensitive resin composition by development to form a pattern;
(IV) heating the pattern;
A method for producing a liquid crystal spacer. In a liquid crystal display device comprising a liquid crystal layer in which liquid crystal is sealed between substrates disposed to face each other, a method for producing a liquid crystal spacer disposed to keep the thickness of the liquid crystal layer constant,
(I) a step of laminating a layer made of the photosensitive resin composition in the photosensitive element according to claim 6 on the transparent electrode provided on the substrate;
(II) a step of imagewise irradiating actinic rays to the layer comprising the photosensitive resin composition to cure the exposed portion;
(III) a step of selectively removing portions other than the exposed portion of the layer made of the photosensitive resin composition by development to form a pattern;
(IV) heating the pattern;
A method for producing a liquid crystal spacer.

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