JP2005166645A - Forming method of barrier rib for image display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forming method for a barrier rib for an image display element with a sectional shape which is reverse tapered and superior in ink repellency, ink-dropping property, durability of these properties, heat resistance and adherence property of a substrate. <P>SOLUTION: In the forming method of the barrier rib for the image display element with the sectional shape which is reverse tapered, negative-type photoreceptive resin composite containing a fluorine polymer (A), alkali soluble photoreceptive resin (B), a crosslinking agent (C), a radical initiator (D) and an optical absorption agent (E) are coated on the substrate and are then exposure and development are carried out. This is provided such that the fluorine polymer (A) is provided with fluorine alkyl group (p) and an ethylene double bond (q), and the alkali soluble photoreceptive resin (B) is provided with ethylene double bond (q) and acidic group (r), and cross flow linking agent (C) is provided with two or more ethylene double bonds (q) and acidic group (r) is not provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for forming a partition wall of an image display device having a reverse taper in cross section using a negative photosensitive resin composition.

  In manufacturing a passively driven organic EL element, a plurality of partition walls are provided at predetermined intervals in a direction perpendicular to the plurality of parallel stripe-shaped first electrodes provided on the substrate. By forming a plurality of films such as a hole transport layer, a light emitting layer, and an electron transport layer by vacuum deposition on the region where the first electrode is exposed from above, and then depositing a metal film to form the second electrode An organic EL element is formed. Since it is necessary to prevent conduction and short-circuit between adjacent second electrodes when forming the second electrode, it has been proposed that the partition walls have an inverse taper shape. Although technology using this method is being put into practical use, if an attempt is made to manufacture a pixel in which red (R), blue (B), and green (G) light emitting layers are separately applied, light is emitted through a metal mask. The layer has to be deposited three times, causing problems such as low material utilization efficiency and poor yield.

  In order to overcome the above problem, it has been proposed to form an organic EL element by depositing a metal film on the entire surface after spray-coating a hole transport layer or a light emitting layer into a minute pixel by an inkjet method. In this case, in order to prevent ink color mixing between adjacent pixel regions, the partition wall is required to have a property of repelling an ink solvent such as water or an organic solvent, so-called ink repellency. Further, in order for ink ejected slightly shifted onto the pixel partition wall to be within the target pixel, ink fall-off property is required.

  As a kind of ink, water-based ink containing polyethylenedioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS) for forming a hole transport layer, and pigment materials such as perylene and coumarin 6 for forming a light emitting layer Since xylene-based ink containing water is often used, it is particularly required to have water repellency and xylene repellency.

  In addition, the organic EL display is considered to be applied to various uses, but is often used for in-vehicle uses such as an instrument panel portion of an automobile and a car navigation that require particularly high durability. Of the durability required for such in-vehicle applications, heat resistance is a particularly severe test item, and is required to be less deteriorated when exposed to high temperature conditions.

  Patent Document 1 proposes a radiation-sensitive resin composition that forms a partition wall of an EL display element whose vertical cross-sectional shape is a reverse taper. However, since the partition wall to be formed does not have ink repellency, there is a problem that color mixing of the light emitting layer between pixels is likely to occur, and the film thickness of the formed layer is large because ink remains in the partition wall. There is a problem that it is not uniform. On the other hand, when a fluorine-based or silicone-based surfactant exemplified in paragraphs 0057 to 0062 is added, ink repellency may be exhibited. However, the exemplified surfactants volatilize when placed in a high-temperature environment, resulting in a problem that ink repellency decreases with time and a life of a light emitting layer.

  Patent Document 2 proposes using an acid-curing resist material as a material for forming a reverse tapered resist pattern. However, when exposure is performed with an ultra-high pressure mercury lamp that is widely used as an exposure machine, the photoacid generator having absorption in a wavelength region longer than 365 nm of I-line is a compound containing chlorine ions. When chlorine ions remain in the partition walls, if a driving force such as heat is applied, migration to the light emitting layer occurs, and there is a problem that the life of the light emitting layer is reduced.

JP 2002-83688 A (Claim 1, paragraphs 0057 to 0062) JP 2001-255666 A (Claim 1, paragraph 0024)

  It is an object of the present invention to provide a method of forming a partition wall of an inversely tapered image display element that is excellent in ink repellency, ink falling property, sustainability, heat resistance, and substrate adhesion.

The present invention relates to a negative type comprising a fluoropolymer (A), an alkali-soluble photosensitive resin (B), a crosslinking agent (C), a radical initiator (D), and a light absorber (E). Provided is a method for forming a partition wall of an image display element having a reverse taper in cross-sectional shape, wherein a photosensitive resin composition is applied to a substrate, exposed, and developed. However, the fluoropolymer (A) has a group (p) represented by the following formula 1 and an ethylenic double bond (q), and the alkali-soluble photosensitive resin (B) is ethylenic. It has a double bond (q) and an acidic group (r), does not have the group (p) represented by Formula 1, and the crosslinking agent (C) has 2 ethylenic double bonds (q). The group (p) and the acidic group (r) represented by Formula 1 are not included.
-CFXR ^f Formula 1
In the formula, X represents a hydrogen atom or a fluorine atom, R ^f represents an alkyl group having 20 or less carbon atoms in which at least one of the fluorine atom or the hydrogen atom is substituted with a fluorine atom (provided that the alkyl group is an etheric oxygen atom) Is included).

  The group (p) represented by the formula 1 in the fluoropolymer (A) imparts ink repellency and ink tumbling property to the partition wall to be formed. Since group (p) represented by Formula 1 has surface migration, the fluoropolymer (A) migrates to the vicinity of the coating film surface during pre-baking (drying of the coating film). Therefore, even when a small amount of the fluorine-containing polymer (A) is added, sufficient ink repellency and ink falling property can be imparted to the coating film surface during pre-baking.

  Further, since the concentration of the fluoropolymer (A) in the vicinity of the substrate is relatively reduced due to the transition of the fluoropolymer (A) to the vicinity of the coating surface during pre-baking, the substrate adhesion of the partition walls is reduced. Can be prevented.

  The fluoropolymer (A) has an ethylenic double bond (q). Therefore, the fluorine-containing polymer (A) is covalently bonded to the other constituent components of the negative photosensitive resin composition by light irradiation, so that it is fixed to the partition wall, and the durability of the ink repellency and ink falling property, that is, the heat resistance is increased. .

  According to the forming method of the present invention, a reverse-tapered partition wall having excellent ink repellency, ink falling property, their durability, heat resistance, and substrate adhesion can be obtained.

  In the compound name of this specification, (meth) acrylate means acrylate and / or methacrylate. Similarly, (meth) acrylic acid means acrylic acid and / or methacrylic acid, and (meth) acrylamide means acrylamide and / or methacrylamide.

  In the present specification, unless otherwise specified,% represents mass%.

The negative photosensitive resin composition used for forming the partition wall of the present invention contains a fluorine-containing polymer (A). The fluorine-containing polymer (A) has a group (p) represented by the following formula 1 and an ethylenic double bond (q).
-CFXR ^f Formula 1
X represents a hydrogen atom or a fluorine atom, and R ^f represents an alkyl group having 20 or less carbon atoms in which at least one of the fluorine atom or the hydrogen atom is substituted with a fluorine atom (provided that the alkyl group represents an etheric oxygen atom). Including those possessed). The etheric oxygen atom may be present between the carbon-carbon bonds of the alkyl group or may be present at the bond terminal.

Specific examples of the group (p) represented by Formula 1 include
_{-CF 3, -CF 2 CF 3,} -CF 2 CHF 2,
_{- (CF 2) 2 CF 3} , - (CF 2) 3 CF 3, - (CF 2) 4 CF 3, - (CF 2) 5 CF 3,
_{- (CF 2) 6 CF 3} , - (CF 2) 7 CF 3, - (CF 2) 8 CF 3, - (CF 2) 9 CF 3,
_{- (CF 2) 11 CF 3} , - (CF 2) 15 CF 3,
_{-CF 2 O (CF 2 CF 2} O) n CF 3 (n is 0-8),
_{-CF (CF 3) O (CF} 2 CF (CF 3) O) n (CF 2) 5 CF 3 (n is 0-4),
_{-CF (CF 3) O (CF} 2 CF (CF 3) O) n (CF 2) 2 CF 3 (n is 0-5)
Is mentioned.

  The group (p) represented by the formula 1 is preferably a perfluoroalkyl group or a polyfluoroalkyl group containing one hydrogen atom, and particularly preferably a perfluoroalkyl group (provided that the alkyl group is an ether Including those having a reactive oxygen atom). As a result, the fluoropolymer (A) exhibits good ink repellency and ink falling properties. Moreover, it is preferable that the total carbon number of group (p) represented by Formula 1 is 15 or less. As a result, the fluoropolymer (A) exhibits good ink repellency, particularly organic repellency. When the fluorine-containing polymer (A) of the present invention is synthesized by copolymerization of a monomer having a group (p) represented by formula 1 and a monomer which is another copolymerization component, both monomers The compatibility of is improved.

  Examples of the group having an ethylenic double bond (q) include addition polymerizable unsaturated groups such as an acryl group, an allyl group, a vinyl group, and a vinyl ether group. Some or all of the hydrogen atoms in these groups may be substituted with hydrocarbon groups. As the hydrocarbon group, a methyl group is preferable.

  The fluorinated polymer (A) preferably has an acidic group (r). Thereby, since developability becomes favorable, a finer pattern can be formed.

  Examples of the acidic group (r) include at least one acidic group selected from the group consisting of a carboxyl group, a sulfonic acid group, and a phenolic hydroxyl group, or a salt thereof.

The fluorinated polymer (A) preferably has a group (s) represented by the following formula 2. The group (s) represented by Formula 2 has a role of imparting excellent ink tumbling property to the partition walls with respect to highly polar ink.
_{^{- (SiR 1 R 2 -O)}} n -SiR 1 R 2 R 3 ··· Equation 2
In the group represented by Formula 2, R ¹ and R ² independently represent hydrogen, an alkyl group, a cycloalkyl group, or an aryl group, R ³ represents hydrogen or an organic group having 1 to 10 carbon atoms, and n is An integer of 1 to 200 is shown. R ¹ and R ² may be the same or different for each siloxane unit. Since the fluorine-containing polymer (A) exhibits excellent ink falling properties, R ¹ and R ² are preferably hydrogen, a methyl group or a phenyl group, and moreover, R ¹ and R ² of all siloxane units are methyl. The group is preferred. R ³ may contain a nitrogen atom, an oxygen atom, or the like.

  The fluorine-containing polymer (A) is a monomer having a group (p) represented by formula 1, a monomer having a reactive site, (preferably a monomer having an acidic group (r) and / or a formula 2), a monomer having a group (s) represented by 2 and other monomers may be copolymerized), and an ethylenic double bond ( A polymer obtained by reacting a compound having q) is preferred.

As a monomer having a group (p) represented by Formula 1,
CH ₂ = CR ⁴ COOR ⁵ [p],
CH ₂ = CR ⁴ COOR ⁶ NR ⁴ SO ₂ [p],
CH ₂ = CR ⁴ COOR ⁶ NR ⁴ CO [p],
^{_{CH 2 = CR 4 COOCH 2 CH}} (OH) R 5 [p],
CH ₂ = CR ⁴ CR ⁴ = CF [p]
Etc. However, the ^{R 4} is a hydrogen atom or a methyl group, ^{R 5} is a divalent organic group single bond or a 1 to 6 carbon atoms, ^{R 6} is a divalent organic group having 1 to 6 carbon atoms, [p] is the formula The group (p) represented by 1 is shown respectively.

Specific examples of R ⁵ and R ⁶ include CH ₂ , CH ₂ CH ₂ , CH (CH ₃ ), CH ₂ CH ₂ CH ₂ , C (CH ₃ ) ₂ , CH (CH ₂ CH ₃ ), CH ₂ CH ₂ CH ₂ CH ₂ , CH (CH ₂ CH ₂ CH ₃ ), CH ₂ (CH ₂ ) ₃ CH ₂ , CH (CH ₂ CH (CH ₃ ) ₂ ) and the like. R ⁵ may be a single bond.

  Among the monomers having an acidic group (r), the monomers having a carboxyl group include acrylic acid, methacrylic acid, vinyl acetic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, cinnamic acid, or those Of the salt.

  Examples of the monomer having a sulfonic acid group include vinyl sulfonic acid, styrene sulfonic acid, (meth) allyl sulfonic acid, 2-hydroxy-3- (meth) allyloxypropane sulfonic acid, and (meth) acrylic acid-2-sulfoethyl. , (Meth) acrylic acid-2-sulfopropyl, 2-hydroxy-3- (meth) acryloxypropanesulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, or salts thereof.

  Examples of the monomer having a phenolic hydroxyl group include o-hydroxystyrene, m-hydroxystyrene, and p-hydroxystyrene. In addition, one or more hydrogen atoms of these benzene rings are one or more hydrogen atoms of an alkyl group such as methyl, ethyl or n-butyl, an alkoxy group such as methoxy, ethoxy or n-butoxy, a halogen atom or an alkyl group. Haloalkyl group substituted with a halogen atom, a nitro group, a cyano group, a compound substituted with an amide group, and the like.

The monomer having a group (s) of the formula _{2, CH 2 = CHCOO [s} ], CH 2 = C (CH 3) COO [s] , and the like. However, [s] represents group (s) represented by Formula 2.

  As a method for introducing the ethylenic double bond (q) into the fluoropolymer (A), 1) an acid anhydride having an ethylenic double bond (q) after copolymerizing a monomer having a hydroxyl group in advance. 2) A method in which a monomer having a hydroxyl group is copolymerized in advance and a monomer having an isocyanate group is reacted later. 3) A monomer having a hydroxyl group is copolymerized in advance, followed by an acyl chloride group. 4) A method in which an acid anhydride having an ethylenic double bond is copolymerized in advance and a monomer having a hydroxyl group is reacted later. 5) A monomer having a carboxyl group is reacted. A method of copolymerizing in advance and then reacting with a monomer having an epoxy group; 6) a monomer having an epoxy group previously copolymerized and then having a carboxyl group A method of reacting, and the like.

  The fluorine-containing polymer (A) is a monomer other than the monomer having the group (p), the acidic group (r) or the group (s) represented by the formula 2 (other monomer) May have a monomer unit based on the (body).

  Other monomers include hydrocarbon olefins, vinyl ethers, isopropenyl ethers, allyl ethers, vinyl esters, allyl esters, (meth) acrylic esters, (meth) acrylamides, aromatic Examples thereof include vinyl compounds, chloroolefins, and conjugated dienes. These compounds may contain a functional group, and examples thereof include a hydroxyl group, a carbonyl group, and an alkoxy group. In particular, (meth) acrylic acid esters and (meth) acrylamides are preferable because they are excellent in heat resistance of a coating film formed from a negative photosensitive resin composition. In addition, a monomer having a bulky group such as isobornyl (meth) acrylate or cyclohexyl (meth) acrylate is preferable because it can prevent association due to a hydrogen bond caused by a carboxyl group during the polymerization of the fluoropolymer (A). .

  The fluorine atom content in the fluoropolymer (A) is preferably from 5 to 25%, more preferably from 12 to 20%. Within such a range, the fluoropolymer (A) is excellent in the effect of lowering the surface tension of the partition walls to be formed, and imparts high ink repellency and ink tumbling properties to the partition walls. Moreover, the developability of the negative photosensitive resin composition is good without causing the coating film to become cloudy, and the adhesion between the coating film and the substrate is increased.

  The silicon atom content in the fluoropolymer (A) is preferably from 0.01 to 5%, more preferably from 0.03 to 3%. Within such a range, the fluorine-containing polymer (A) exhibits better ink tumbling properties and can maintain good adhesion between the coating film and the substrate.

  The acid value of the fluoropolymer (A) is preferably from 10 to 200 (mgKOH / g), more preferably from 20 to 80 (mgKOH / g). Within this range, the alkali solubility of the fluoropolymer (A) and the developability of the negative photosensitive resin composition are good.

  In the fluoropolymer (A), the proportion of monomer units formed from other monomers is preferably 90% or less, more preferably 70% or less. Within this range, the developability of the negative photosensitive resin composition becomes good.

  The weight average molecular weight of the fluoropolymer (A) is preferably 1000 or more and less than 20000, and more preferably 2000 or more and less than 10,000. Within this range, there is an advantage that the change in contrast due to exposure is large and the sensitivity to light is high, while the solubility in the developer is high, and the generation of dissolved residues in the non-exposed area can be prevented.

  The proportion of the fluoropolymer (A) in the total solid content of the negative photosensitive resin composition is preferably 0.01 to 20%, more preferably 0.05 to 15%. Within this range, the developability of the negative photosensitive resin composition is good, the formed partition exhibits good ink repellency and ink tumbling properties, and the partition has good substrate adhesion.

  The negative photosensitive resin composition contains an alkali-soluble photosensitive resin (B). The alkali-soluble photosensitive resin (B) has an ethylenic double bond (q) and an acidic group (r), and does not have the group (p) represented by the formula 1. The alkali-soluble photosensitive resin (B) improves the developability of the negative photosensitive resin composition and the substrate adhesion of the partition formed from the negative photosensitive resin composition. The ethylenic double bond (q) and the acidic group (r) are the same as those described in the fluoropolymer (A).

  As an example of the alkali-soluble photosensitive resin (B), an ethylenic disulfide is added to the reaction site of a polymer obtained by copolymerizing a monomer having an acidic group (r) and a monomer having a reaction site. Examples thereof include a polymer (B1) obtained by reacting a compound having a heavy bond (q), and a novolac resin (B2) into which an ethylenic double bond (q) is introduced.

  A polymer obtained by reacting a compound having an ethylenic double bond (q) with the reaction site of a polymer obtained by copolymerizing a monomer having an acidic group (r) and a monomer having a reaction site. The union (B1) is the same as described in the fluorine-containing polymer (A).

  The novolak resin (B2) introduced with the ethylenic double bond (q) will be described. The novolak resin is obtained by polycondensation of phenols with aldehydes, and examples thereof include phenol / formaldehyde resins, cresol / formaldehyde resins, phenol / cresol / formaldehyde cocondensation resins, and the like.

  Examples of a method for introducing an ethylenic double bond (q) into the novolac resin include 1) a method in which a part of a phenolic hydroxyl group is reacted with a monomer having an epoxy group, and 2) one phenolic hydroxyl group. A method of reacting a monomer having an epoxy group and a carboxyl group after reacting part or all with epichlorohydrin and introducing an epoxy group into a novolak resin can be mentioned. In addition, the hydroxyl group produced | generated by this reaction and an acid anhydride can be made to react, and a carboxyl group can also be introduce | transduced in a molecule | numerator.

  Commercially available novolak resins having acidic groups and ethylenic double bonds include KAYARAD PCR-1069, K-48C, CCR-1105, CCR-1115, TCR-1025, TCR-1064, TCR-1286, ZFR-1122. , ZFR-1124, ZFR-1185 (manufactured by Nippon Kayaku Co., Ltd.) and the like.

  The acid value of the alkali-soluble photosensitive resin (B) is preferably 10 to 300 mgKOH / g, more preferably 30 to 200 mgKOH / g. Within this range, the developability of the negative photosensitive resin composition becomes good.

  The weight average molecular weight of the alkali-soluble photosensitive resin (B) is preferably 500 or more and less than 20000, and more preferably 2000 or more and less than 15000. Within this range, there is an advantage that the change in contrast due to exposure is large and the sensitivity to light is high, while the solubility in the developer is high, and the generation of dissolved residues in the non-exposed area can be prevented.

  The proportion of the alkali-soluble photosensitive resin (B) in the total solid content of the negative photosensitive resin composition is preferably 30 to 90%, more preferably 50 to 85%. Within this range, the developability of the negative photosensitive resin composition is good.

  A negative photosensitive resin composition contains a crosslinking agent (C). The crosslinking agent (C) has two or more ethylenic double bonds (q) and does not have the group (p) and the acidic group (r) represented by the formula 1. A crosslinking agent (C) improves the photocurability of a negative photosensitive resin composition. The ethylenic double bond (q) and the acidic group (r) are the same as those described for the fluoropolymer (A).

  Specific examples include diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,9-nonanediol di (meth) acrylate. , Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like.

  The proportion of the crosslinking agent (C) in the total solid content of the negative photosensitive resin composition is preferably 20 to 70%, more preferably 30 to 60%. Within such a range, the fluoropolymer (A) exhibits good ink repellency and ink tumbling properties, and the developability of the negative photosensitive resin composition is good.

  The negative photosensitive resin composition contains a radical initiator (D). The radical initiator (D) is a compound that generates radicals by light.

  Examples of the radical initiator (D) include α-diketones such as benzyl and diacetyl, acyloins such as benzoin, acyloin ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether, acetophenone, 2- ( 4-toluenesulfonyloxy) -2-phenylacetophenone, p-dimethylaminoacetophenone, 2,2′-dimethoxy-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl [4- (methylthio) phenyl] -2-morpholino Acetophenones such as -1-propanone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, quinones such as anthraquinone and 1,4-naphthoquinone, 2-dimethylamino benzoic acid Aminobenzoic acids such as til, ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, phenacyl chloride, Examples thereof include halogen compounds such as trihalomethylphenylsulfone, peroxides such as acylphosphine oxides, and di-t-butyl peroxide.

  The proportion of the radical initiator (D) in the total solid content of the negative photosensitive resin composition is preferably from 0.1 to 30%, more preferably from 1 to 20%, based on the solid content in the negative photosensitive resin composition. More preferred. Within this range, the developability of the negative photosensitive resin composition is good.

  The partition in this invention is demonstrated. When the cross-sectional shape of the barrier rib is a forward taper or a rectangle, that is, when the taper angle that is an angle formed between the side and the base of the barrier rib cross-section is 90 degrees or less, when the cathode material is deposited on the substrate having the barrier rib pattern, Since the formed vapor deposition film becomes continuous and energizes, it is not preferable. Therefore, in order to make the deposited film discontinuous and to ensure insulation, the cross-sectional shape of the partition wall is preferably reverse tapered, that is, the taper angle is larger than 90 degrees, more preferably 110 degrees or more.

  It is considered that the technique for creating the inverse tapered shape is achieved by absorbing the irradiated light on the surface of the coating film. That is, the amount of light reaching from the coating film surface to the deep part is reduced, and control is performed so that the hardening does not progress as the deep part. By controlling in such a manner, since the side wall is more easily dissolved in the developer as the depth increases, the cross-sectional shape of the formed partition wall is inversely tapered.

  A negative photosensitive resin composition contains a light absorber (E). The light absorber (E) is a compound that absorbs light emitted from the exposure machine, and substantially reduces the transmittance of the coating layer when added. However, in this specification, the light absorber (E) does not include the radical initiator (D).

  The wavelength of light emitted from the exposure machine varies depending on the type of exposure machine, but is in the range of 100 to 600 nm. Examples of the material that absorbs such a wide range of wavelengths include black pigments. Further, examples of the material that absorbs the I-line (365 nm) and G-line (436 nm), which are the emission wavelengths of exposure apparatuses that are widely used at present, include sensitizers and ultraviolet absorbers.

  As the black pigment, carbon black, titanium black, black metal oxide pigment, and organic pigment are preferable.

Examples of carbon black include lamp black, acetylene black, thermal black, channel black, and furnace black. Titanium black is obtained by oxidation of titanium or reduction of titanium dioxide, and is at least one kind represented by Ti _u O _2u-1 (u is a number of 1 or more).

  Examples of black metal oxide pigments include copper, iron, chromium, manganese, and cobalt oxides. A composite metal oxide of at least two or more selected from the metal oxides is also preferable. Examples thereof include copper-chromium oxide, copper-chromium-manganese oxide, copper-iron-manganese oxide, and cobalt-iron-manganese oxide. Examples of organic pigments include perylene and aniline black.

  The black pigment may be dispersed by a dispersing machine such as a sand mill or a roll mill together with a dispersant (for example, a polycaprolactone compound, a long-chain alkylpolyaminoamide compound, etc.), and then added to the photosensitive resin composition. The particle size is preferably 1 μm or less. Within this range, the developability of the negative photosensitive resin composition becomes good.

  Further, such a black pigment is more preferable because it imparts light-shielding properties to the coating film and can also impart performance as a black matrix in a color filter.

  Examples of sensitizers include flavones, dibenzylacetones, dibenzylcyclohexanes, chalcones, xanthones, thioxanthones, porphyrins, phthalocyanines, acridines, anthracenes, benzophenones, and coumarins. Can do.

  Specifically, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4-dimethylaminobenzophenone, 4-diethylaminobenzophenone, 4-dimethylaminopropiophenone, ethyl-4 -Dimethylaminobenzoate, 2-ethylhexyl-1,4-dimethylaminobenzoate, 2,5-bis (4-diethylaminobenzal) cyclohexanone, 7-diethylamino-3- (4-diethylaminobenzoyl) coumarin, 4- (diethylamino) Examples thereof include chalcone and diethylthioxanthone. Of these, benzophenone-based compounds and coumarins having particularly high absorbance and low quantum efficiency are preferred.

  As the ultraviolet absorber, a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, a salicylic acid-based ultraviolet absorber, a phenyltriazine-based ultraviolet absorber and the like that are usually used as an ultraviolet absorber for synthetic resins are preferable.

  Specifically, the compounds described in paragraph No. 0093 of JP-A-11-240103 can be mentioned. In the present invention, 2- {2-hydroxy-5- (2-acryloyloxyethyl) phenyl} benzotriazole, 2-hydroxy-3-methacryloyloxypropyl-3- {3- (benzotriazol-2-yl)- Those having a photopolymerizable functional group in the molecule such as 4-hydroxy-5-t-butylphenyl} propionate are particularly preferred.

  It is preferable that the ratio in the total solid of the negative photosensitive resin composition of a light absorber is 0.5 to 40%. If the light absorber content is too low, light absorption at the top of the coated film is small, so that the light reaches the deep part of the coating and cures sufficiently. Hateful. On the other hand, when the content of the light absorber is too large, the absorption of light at the upper part of the coating film is too large, and curing of the deep part of the coating film does not occur.

  The partition wall of the present invention can also be used as a black matrix in a color filter. In that case, in addition to containing the black pigment, two types selected from red, blue, green, purple, yellow, cyan, magenta, and the like. It is also preferable to mix the above organic pigments to blacken them.

  Red pigments include quinacridone pigments, pyrrolo-pyrrole pigments, anthraquinone pigments, blue pigments include phthalocyanine pigments, green pigments include halogenated phthalocyanine pigments, and purple pigments. , Dioxazine violet, fast violet B, methyl violet equine, indanthrene brilliant violet, yellow pigment, tetrachloroisoindolinone pigment, Hansairo pigment, benzidine yellow pigment, azo pigment, cyan pigment Examples of the metal-free phthalocyanine, merocyanine, and magenta pigments include dimethylquinacridone and thioindigo.

  In a negative photosensitive resin composition, a silane coupling agent (F) can be used as needed. When the silane coupling agent is used, the substrate adhesion of the partition formed from the negative photosensitive resin composition is improved.

  Specific examples of the silane coupling agent (F) include tetraethoxysilane, 3-glycidoxypropyltrimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-chloropropyl. Examples include trimethoxysilane, 3-mercaptopropyltrimethoxysilane, heptadecafluorooctylethyltrimethoxysilane, polyoxyalkylene chain-containing triethoxysilane, and the like.

  In the negative photosensitive resin composition, a diluent (G) can be used. Specific examples of the diluent (G) include, for example, alcohols, ketones, cellosolves, carbitols, esters, chain hydrocarbons, cyclic saturated hydrocarbons, aromatic hydrocarbons, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl. Examples include ether.

  In the negative photosensitive resin composition, a thickener, a plasticizer, an antifoaming agent, a leveling agent, a repellency inhibitor, and the like can be used as necessary.

Hereinafter, a photolithography process using the negative photosensitive resin composition will be described.
First, a negative photosensitive resin composition is coated on a substrate. The material of the substrate is not particularly limited. For example, various glass plates, polyester such as polyethylene terephthalate, polypropylene, polyolefin such as polyethylene, polycarbonate, polymethyl methacrylate, polyimide, polysulfone thermoplastic sheet And thermosetting plastic sheets such as epoxy resins and polyester resins. In particular, a heat-resistant plastic such as a glass plate or polyimide is preferably used from the viewpoint of heat resistance. As the coating method, a commonly used coating method can be employed without any particular limitation, and examples thereof include a spray method, a roll coating method, a spin coating method, and a bar coating method.

  The coating is then heated (referred to as pre-baking). By pre-baking, the solvent is volatilized and a non-fluid coating film is obtained. The heating conditions vary depending on the type of each component, the blending ratio, etc., but it can be preferably used in a wide range of about 50 to 150 ° C. and about 10 to 2000 seconds.

Next, the heated coating film is exposed through a mask having a predetermined pattern. The light used is preferably an electromagnetic wave having a distribution in the range of 100 to 600 nm, and specifically includes laser light such as visible light, ultraviolet light, far ultraviolet light, KrF excimer laser, ArF excimer laser, and F ₂ excimer laser. It is done. However, when irradiating light with a short wavelength, since the energy is strong, the composition material of the exposed part may decompose | disassemble depending on irradiation time. Accordingly, light having an ultraviolet wavelength or more is preferable, and as such a light source, an ultra-high pressure mercury lamp widely used widely for exposure apparatus applications can be mentioned.

  Then, it develops with a developing solution and an unexposed part is removed. As the developing solution, for example, an alkaline aqueous solution composed of alkalis such as inorganic alkalis, amines, alcohol amines, and quaternary ammonium salts can be used.

  The development time is preferably 30 to 180 seconds. Further, the developing method may be either a liquid piling method or a dipping method. After development, the substrate is washed with running water and air-dried with compressed air or compressed nitrogen to remove moisture on the substrate. Subsequently, a reverse-tapered partition wall is formed by performing a heat treatment (hereinafter referred to as a post-bake treatment) for 5 to 90 minutes, preferably at 120 to 250 ° C., with a heating device such as a hot plate or an oven. .

  The ink repellency can be estimated by the contact angle of water and xylene, and the contact angle of water is preferably 80 degrees or more, more preferably 90 degrees or more. The contact angle of xylene is preferably 25 degrees or more, and more preferably 40 degrees or more.

  The ink falling property can be estimated by the falling angle of water and xylene, and the falling angle of water is preferably 35 degrees or less, and more preferably 25 degrees or less. The falling angle of xylene is preferably 30 degrees or less, and more preferably 20 degrees or less.

  Although it demonstrates based on the synthesis examples 1-4, an Example (Examples 1-3), and a comparative example (Example 4) below, this invention is not limited to these. In the following, unless otherwise specified, parts and% are based on mass. The weight average molecular weight is a value measured by gel permeation chromatography using polystyrene as a standard substance.

Abbreviations of the compounds used in the following examples are shown.
_{C6FMA: CH 2 = C (CH} 3) COOCH 2 CH 2 (CF 2) 6 F
_{C8FA: CH 2 = CHCOOCH 2 CH} 2 (CF 2) 8 F
X-174DX: Dimethyl silicone chain-containing methacrylate (manufactured by Shin-Etsu Chemical Co., Ltd., trade name X-22-174DX)
MAA: methacrylic acid HEMA: 2-hydroxyethyl methacrylate IBMA: isobornyl methacrylate DSH: n-dodecyl mercaptan V-70: 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (Wako Pure Chemical) Product name V-70)
MOI: 2-methacryloyloxyethyl isocyanate DBTDL: dibutyltin dilaurate BHT: 2,6-di-t-butyl-p-cresol cyclomer P: photosensitive resin (Daicel Chemical Industries, Cyclomer P (ACA) 250)
D310: Dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name KAYARAD D-310)
IR907: Photopolymerization initiator (Ciba-Geigy, trade name IRGACURE-907)
DEAB: 4,4′-bis (diethylamino) benzophenone tinuvin 400: UV absorber (manufactured by Ciba Geigy, trade name Tinuvin 400)
KBM403: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-403)
DEGDM: Diethylene glycol dimethyl ether carbon black dispersion: manufactured by Mikuni Dye Co., Ltd., trade name EX-3295

[Synthesis of photosensitive resin]
[Synthesis Example 1]
To an autoclave with an internal volume of 1 L equipped with a stirrer, acetone (555.0 g), C6FMA (96.0 g), MAA (72.0 g), HEMA (72.0 g), chain transfer agent DSH (9.7 g) and Polymerization initiator V-70 (5.0 g) was charged, and a polymerization reaction was performed at 40 ° C. for 18 hours while stirring in a nitrogen atmosphere to obtain a solution of polymer 1. Water was added to the obtained acetone solution of the polymer for reprecipitation purification, and petroleum ether was again added to the acetone solution for reprecipitation purification, followed by vacuum drying to obtain 240 g of polymer 1.

  Into a 300 mL glass flask equipped with a thermometer, stirrer, and heating device, polymer 1 (100 g), MOI (36.2 g), DBTDL (0.15 g), BHT (1.8 g) and acetone ( 100 g) was added, and the reaction was carried out at 30 ° C. for 18 hours with stirring to obtain a resin 1 solution. Water was added to the obtained acetone solution of resin 1 for reprecipitation purification, and petroleum ether was again added to the acetone solution for reprecipitation purification, followed by vacuum drying to obtain resin 1 (135 g).

[Synthesis Examples 2 and 3]
Resins 2 and 3 were obtained in the same manner as in the synthesis of Resin 1 except that the blending amount of the raw materials was changed as shown in Table 1.

[Synthesis Example 4]
To an autoclave with an internal volume of 1 L equipped with a stirrer, acetone (555.0 g), C6FMA (72.0 g), MAA (48.0 g), IBMA (120.0 g), chain transfer agent DSH (24.2 g) and A polymerization initiator V-70 (5.0 g) was charged and a polymerization reaction was performed at 40 ° C. for 18 hours while stirring in a nitrogen atmosphere to obtain a polymer 4 solution. Water was added to the obtained acetone solution of the polymer for reprecipitation purification, and petroleum ether was added to the acetone solution again for reprecipitation purification, followed by vacuum drying to obtain Resin 4 (240 g).

[Evaluation of negative photosensitive resin composition]
Using the above resins 1 to 4, a negative photosensitive resin composition is obtained under the conditions of Examples 1 to 4 below to form a pattern, and developability, partition wall ink repellency, ink falling property, taper angle, and heat resistance. Sex was evaluated.

[Developability]
Those that could be developed were marked with ◯, and those that could not form a line / space pattern were marked with x.

[Ink repellency]
The ink repellency can be estimated by the contact angle of water and xylene. The contact angle (degree) of water and xylene on the surface of the coating film portion of the pattern formed on the glass substrate was measured. The contact angle is an angle formed by a solid surface and a tangent to the liquid surface at a point where the solid and the liquid come into contact, and is defined as an angle including the liquid. The larger the angle, the better the ink repellency of the coating film.

[Ink fallability]
The ink falling property can be estimated by the falling angle of water and xylene. 10 μL of water or xylene is dropped onto the surface of the coating film portion of the pattern on the glass substrate held horizontally, and the substrate surface and the horizontal plane when the droplet starts to fall gradually by lifting one side and tilting it gradually. And read the angle. It means that the smaller the angle, the better the ink falling property of the coating film.

[Taper angle]
The partition formed on the glass substrate was cut vertically, and the cross-sectional shape was observed by SEM. The angle between the side and the bottom of the partition wall cross section was read.

[Heat-resistant]
The glass substrate on which the pattern was formed was placed in a constant temperature layer at 90 ° C. for 500 hours, and the change in ink repellency, ink falling property and shape of the partition over time were examined. The smaller the change, the better the heat resistance.

[Examples 1-4]
Fluoropolymer (A), alkali-soluble photosensitive resin (B), crosslinking agent (C), radical initiator (D), light absorber (E), silane coupling agent (F) in the proportions shown in Table 2 ), Diluent (G) was blended to obtain negative photosensitive compositions of Examples 1 to 4.

The obtained composition was applied to a glass substrate by a spin coating method (wet thickness 10 μm) and dried in an oven at 100 ° C. for 2 minutes. Thereafter, the gap between the coating film and the mask (line / space = 20 μm / 20 μm) was fixed to 20 μm in an air atmosphere, and irradiation with 150 mJ / cm ² was performed with an ultrahigh pressure mercury lamp. Next, the unexposed portion was immersed in a 1% tetramethylammonium hydroxide aqueous solution for 1 minute, developed, rinsed with pure water, and dried. Subsequently, the glass substrate in which the pattern was formed was obtained by heating on a hotplate at 220 degreeC for 1 hour.
About the glass substrate in which the pattern was formed, ink repellency, ink fall-off property, and heat resistance were evaluated by the said method. The results are summarized in Table 2.

  The present invention can be applied to a method of forming a partition that requires ink repelling properties. For example, it is suitably used as a method for forming partition walls for color patterns for liquid crystal displays, organic EL displays, and the like, and partition walls for forming wiring patterns in semiconductor devices or electrical circuits. In particular, it is useful in a passively driven organic EL element that requires a reverse-tapered partition.

The cross-sectional schematic diagram of the partition by this invention.

Explanation of symbols

1: Partition 2: Substrate θ: Taper angle

Claims (5)

Negative photosensitive resin composition comprising a fluoropolymer (A), an alkali-soluble photosensitive resin (B), a crosslinking agent (C), a radical initiator (D), and a light absorber (E) A method for forming a partition wall of an image display element having a reverse taper in cross-sectional shape, wherein an object is applied to a substrate, exposed, and developed.
However, the fluoropolymer (A) has a group (p) represented by the following formula 1 and an ethylenic double bond (q).
The alkali-soluble photosensitive resin (B) has an ethylenic double bond (q) and an acidic group (r), does not have the group (p) represented by Formula 1,
The crosslinking agent (C) has two or more ethylenic double bonds (q) and does not have the group (p) and the acidic group (r) represented by the formula 1.
-CFXR ^f Formula 1
In the formula, X represents a hydrogen atom or a fluorine atom, R ^f represents an alkyl group having 20 or less carbon atoms in which at least one of the fluorine atom or the hydrogen atom is substituted with a fluorine atom (provided that the alkyl group is an etheric oxygen atom) Is included).   The fluorine atom content in the fluoropolymer (A) is 5 to 25%, and the proportion of the fluoropolymer (A) in the total solid content of the negative photosensitive composition is 0.01 to 20%. Item 2. The forming method according to Item 1.   The forming method according to claim 1 or 2, wherein the fluoropolymer (A) further has an acidic group (r). The forming method according to any one of claims 1 to 3, wherein the fluoropolymer (A) further has a group (s) represented by the following formula 2.
_{^{- (SiR 1 R 2 -O)}} n -SiR 1 R 2 R 3 ··· Equation 2
In the formula, R ¹ and R ² independently represent hydrogen, an alkyl group, a cycloalkyl group, or an aryl group, R ³ represents hydrogen or an organic group having 1 to 10 carbon atoms, and n represents an integer of 1 to 200. . The formation method according to claim 1, wherein the light absorber (E) is a black pigment.

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