JP2006185869A - Organic electroluminescent element and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element having reverse tapered partition walls excellent in water repellent, solvent repellent, heat resistance, and adhesiveness to substrate and having at least one layer formed by wet coating among laminated organic layers and a method of manufacturing the organic electroluminescent element. <P>SOLUTION: A plurality of first electrodes 12, the plurality of partition walls 16 crossing perpendicular to the first electrodes 12, the organic layers 18, and and second electrodes 20 are formed on the substrate 10. A high polymer compound having fluorine substitutional groups and ethylene double bonds is used as the material of the partition walls 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement of a passive drive type organic electroluminescent device.

  In manufacturing a passively driven organic electroluminescent device (hereinafter referred to as an organic EL device), a plurality of partition walls are formed in a direction orthogonal to a plurality of parallel striped first electrodes provided on a substrate. A plurality of organic layers such as a hole transport layer, a light emitting layer, and an electron transport layer are formed by vacuum deposition in a region where the first electrode between the partition walls is exposed, and then a metal film is deposited. Then, the second electrode is formed. In forming the second electrode, it has been proposed to form the partition wall in a reverse taper shape for the purpose of preventing conduction and short circuit between adjacent second electrodes.

  On the other hand, when a plurality of organic layers are formed by the vacuum deposition method, the minute foreign matters scattered on the first electrode, the scratches on the electrode surface, and the recesses cannot be covered, and the formed organic layer has a non-uniform state. appear. Therefore, when a voltage is applied between the first and second electrodes, there is a problem that an electric field concentrates on these non-uniform organic layer portions and induces a short circuit between the electrodes.

  In order to prevent such a short circuit between electrodes, a method of forming an organic material layer formed on the surface of the first electrode by a wet coating method has been proposed.

  Patent Document 1 listed below proposes a radiation-sensitive resin composition for forming a partition wall of an organic EL element having a vertical cross-sectional shape that is reversely tapered.

Patent Document 2 below proposes using an acid-curing resist material as a material for forming a reverse tapered resist pattern.
JP 2002-83688 (Claim 1, paragraphs 0057 to 0062) JP 2001-255666 (Claim 1, paragraph 0024)

  However, in the above-described conventional technology, when the organic layer material solution used in the wet coating method comes into contact with the partition wall having the reverse taper structure described above, a capillary phenomenon occurs at the reverse taper portion and the organic layer is not formed. There was a problem that the solution flowed out to the region. For example, the solution flows into a contact region where the second electrode and the mounting wiring are electrically connected, or a region where a sealing material for sealing and protecting the organic EL element from the outside air is applied. This may cause an increase in the adhesive strength of the seal.

  In order to overcome such a problem, the partition wall is required to have a property of repelling water or an organic solvent, so-called water repellency and solvent repellency. Therefore, if a fluorine-based or silicone-based surfactant exemplified in paragraphs 0057 to 0062 of Patent Document 1 described above is added to the partition material, water repellency and solvent repellency may be exhibited. However, since the exemplified surfactant does not have a reactive site that is covalently bonded to the constituent material of the partition wall forming composition, it is not stably fixed to the partition wall. For this reason, when placed in a high temperature environment, the surfactant volatilizes, and there is a problem that the water repellency and solvent repellency deteriorate with time.

  In addition, when the acid-curing resist material described in Patent Document 2 is used, if the exposure is performed using an ultra-high pressure mercury lamp that is widely used as an exposure machine, the absorption is in a wavelength region longer than 365 nm of I-line. The photoacid generator having a chlorine ion-containing compound. For this reason, when chlorine ions remain in the partition walls and a driving force such as heat is applied, there is a problem that migration to the light emitting layer occurs and the life of the light emitting layer is reduced.

  Furthermore, although the organic EL element is considered to be applied to various uses, it 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.

  The present invention has been made in view of the above-described conventional problems, and its purpose is to provide a reverse-tapered partition wall excellent in water repellency, solvent repellency, heat resistance and substrate adhesion, and an organic layer to be laminated. An object of the present invention is to provide an organic electroluminescent device in which at least one of them is formed by wet coating and a method for manufacturing the same.

  In order to achieve the above object, the present invention provides an organic electroluminescent element, which is formed so as to intersect a first electrode formed on a substrate and the first electrode, and the cross-sectional shape is reverse tapered. A plurality of barrier ribs, a plurality of barrier ribs separated by the plurality of barrier ribs, a plurality of layers formed on the first electrode, and at least one of them being a low molecular weight material, and the plurality of barrier ribs And a second electrode formed on the plurality of organic layers, and a polymer compound having a fluorine substituent and an ethylenic double bond is used as the material of the plurality of partition walls. It is characterized by that.

Further, as the material for the partition wall, a fluorine-containing polymer containing a fluorine-containing substituent represented by the following formula 1 and an ethylenic double bond is used.
-CFXRf Formula 1

  X represents a hydrogen atom or a fluorine atom, and Rf has a fluorine atom, an alkyl group having 15 or less carbon atoms in which at least one of the hydrogen atoms is substituted with a fluorine atom, or an etheric oxygen atom, An atomic group having 15 or less carbon atoms in which at least one of the bonded hydrogen atoms is substituted with a fluorine atom. The etheric oxygen atom may be present between the carbon-carbon bonds of the atomic group or may be present at the bond terminal.

  The present invention is also a method for manufacturing an organic electroluminescent device, wherein the substrate is cleaned with oxygen gas plasma before at least one of the organic layers is wet-coated.

  The cleaning with the oxygen gas plasma is characterized in that plasma irradiation is performed under a reduced pressure atmosphere or an atmospheric pressure atmosphere.

  The cleaning with oxygen gas plasma is characterized in that the partial pressure of oxygen gas in the processing pressure is 0.1% to 100%.

  The present invention also relates to a method for manufacturing an organic electroluminescent device, wherein before the wet coating of at least one of the organic layers, the substrate is cleaned by irradiating with an ultraviolet ray having a wavelength of 254 nm or an ultraviolet ray having a wavelength of 185 nm. Features.

  According to the present invention, a reverse-tapered partition wall excellent in water repellency, solvent repellency, heat resistance and substrate adhesion can be obtained. Moreover, in the organic electroluminescent element using these partition materials, the formation technique of the light emitting layer by wet application | coating can be used, there is no short circuit between electrodes, and high reliability can be acquired.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings.

  In addition, (meth) acrylate in the compound name of this specification means an acrylate and / or a 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%.

  FIG. 1 shows a cross-sectional view of the configuration of an organic EL element according to the present invention. In FIG. 1, a plurality of transparent first electrodes 12 such as indium tin oxide (ITO) are formed in parallel stripes on a substrate 10 such as glass, and are orthogonal to the first electrodes 12. A plurality of opening insulating films 14 and partition walls 16 are formed in the direction. A plurality of organic layers 18 such as a hole transport layer, a light emitting layer, and an electron transport layer are formed in a region where the first electrode 12 is exposed between the plurality of opening insulating films 14 and the partition walls 16. A second electrode 20 made of aluminum or the like is formed on the substrate.

  Of the organic layer 18, at least one layer that adheres to the first electrode 12 is formed by a wet coating method in which a liquid material dissolved in a solvent is applied to the surface of the first electrode 12. Thereby, minute foreign matters scattered on the first electrode 12, scratches on the electrode surface, and recesses can be covered, and a short circuit between the first electrodes 12 can be suppressed.

  In order to form the organic material layer 18 by a wet coating method, for example, the material of the organic material layer 18 is dissolved in a solvent such as an organic solvent, and the organic material layer 18 is formed only in a desired region by a mask spray method, an ink jet method, a printing method, or the like. To do.

  In addition, at least one layer of the organic material layer 18 is a low molecular substance. Here, the low molecular weight substance is a low molecular weight organic material generally used for a low molecular weight organic EL element. For example, the light emitting layer or the electron transporting layer includes an aluminum quinolinol complex (Alq). Further, as a material for dye dope, rubrene, coumarin derivative, quinacridone derivative, DCM1 or DCM2, perylene derivative, distyryl derivative, benzothioxanthene derivative, oxazole dye, cyanine dye, anthracene derivative, tetraphenylbutadiene, Examples include stilbene dyes, acridine dyes, rhodamine dyes, and rare earth complexes. Furthermore, as the light emitting layer / hole transporting layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (hereinafter referred to as α-NPD), N, N′-bis ( 3-methylphenyl) -4,4′-diaminobiphenyl, poly (N-vinylcarbazole) and the like.

  In addition, the partition wall 16 is formed in a reverse taper shape whose cross-sectional shape is a trapezoid whose bottom is shorter than the upper side in order to prevent conduction and short circuit between the adjacent second electrodes 20. Such a partition wall 16 of the present invention is formed of a negative photosensitive resin composition.

The negative photosensitive resin composition concerning this invention contains a fluorine-containing polymer (A). The fluorine-containing polymer (A) contains a group (p) represented by the following formula 1 and an ethylenic double bond (q).
-CFXRf Formula 1

  X represents a hydrogen atom or a fluorine atom, and Rf has a fluorine atom, an alkyl group having 15 or less carbon atoms in which at least one of the hydrogen atoms is substituted with a fluorine atom, or an etheric oxygen atom, An atomic group having 15 or less carbon atoms in which at least one of the bonded hydrogen atoms is substituted with a fluorine atom. The etheric oxygen atom may be present between the carbon-carbon bonds of the atomic group or may be present at the bond terminal.

  The group (p) represented by the formula 1 in the fluoropolymer (A) imparts water repellency and solvent repellency to the partition wall 16 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 water repellency and solvent repellency 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 10 is relatively reduced by the transition of the fluoropolymer (A) to the vicinity of the coating film surface during pre-baking, an opening insulating film with the partition wall 16 is formed. 14 can be prevented from being deteriorated. As a result, the adhesion of the substrate through the opening insulating film 14 of the partition wall 16 can be improved.

  The fluoropolymer (A) has an ethylenic double bond (q). Accordingly, 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 16 and the durability of water repellency and solvent repellency, that is, heat resistance is increased. .

Specific examples of Rf contained in the group (p) represented by the above formula 1 include
When Rf is an alkyl group having 15 or less carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom:
_{-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) 14 CF 3,
When Rf is an atomic group having 15 or less carbon atoms in which at least one hydrogen atom bonded to carbon is substituted with a fluorine atom having an etheric oxygen atom (the etheric oxygen atom is a carbon-carbon bond Present):
_{-CF 2 O (CF 2 CF 2} O) n CF 3 (n is 0-6),
_{-CF (CF 3) O (CF} 2 CF (CF 3) O) n (CF 2) 5 CF 3 (n is 0-2),
_{-CF (CF 3) O (CF} 2 CF (CF 3) O) n (CF 2) 2 CF 3 (n is 0-3)
When Rf is an atomic group having 15 or less carbon atoms in which at least one hydrogen atom bonded to carbon is substituted with a fluorine atom, having an etheric oxygen atom (the etheric oxygen atom is present at the bond terminal) :
_{-CF 2 O (CF 2 CF 2} O) n CF 2 OCF 3 (n is 0-6),
However, it is not limited to these.

  As shown in the above specific examples, the group (p) represented by the formula 1 is preferably a perfluoroalkyl group or a polyfluoroalkyl group containing one hydrogen atom, and a perfluoroalkyl group is particularly preferred. . Further, instead of the alkyl group, an atomic group containing an etheric oxygen atom may be used. As a result, the fluoropolymer (A) exhibits good water repellency and solvent repellency. 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. Further, when the fluorine-containing polymer (A) of the present invention is synthesized by copolymerization of a monomer having a group (p) represented by the formula 1 and a monomer which is another copolymerization component, both monomers are synthesized. The compatibility of the monomer is improved.

  Examples of the group having an ethylenic double bond (q) contained in the fluorine-containing polymer (A) include addition polymerizable unsaturated groups such as an acryl group, an allyl group, a vinyl group, and a vinyl ether group. It is done. 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.

  Moreover, it is preferable that a fluoropolymer (A) 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 fluorine-containing polymer (A) includes a monomer having the group (p) represented by the formula 1, a monomer having a reactive site (preferably a monomer having an acidic group (r), 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 (which may contain a monomer) is preferable.

As the monomer having the group (p) represented by the formula 1 described above,
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 are as follows:
_{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)
Etc. R ⁵ may be a single bond.

  Among the monomers having an acidic group (r) contained in the monomer having the reaction site, monomers having a carboxyl group include acrylic acid, methacrylic acid, vinyl acetic acid, crotonic acid, itaconic acid, Mention may be made of maleic acid, fumaric acid, cinnamic acid, or salts thereof.

  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 It is done.

  Furthermore, 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. Examples include compounds in which an atom is substituted with a halogen atom, a nitro group, a cyano group, or an amide group.

  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 compound having an isocyanate group and an ethylenic double bond (q) is reacted later. 3) A monomer having a hydroxyl group is previously copolymerized. A method of polymerizing and reacting an acyl chloride group and a compound having an ethylenic double bond (q) later, 4) an acid anhydride having an ethylenic double bond (q) is copolymerized in advance, and then a hydroxyl group and an ethylenic group Method of reacting a compound having a double bond (q) 5) Copolymerizing a monomer having a carboxyl group in advance, and later having an epoxy group and an ethylenic double bond (q) A method of reacting a compound, 6) is preliminarily copolymerizing a monomer having an epoxy group, a method of reacting a compound having a carboxyl group and an ethylenic double bond (q) after, and the like.

  The fluorine-containing polymer (A) is a monomer unit based on a monomer (other monomer) other than the monomer having the group (p) and the acidic group (r) represented by the formula 1. You may have.

  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 wall 16 to be formed, and can impart high water repellency and solvent repellency to the partition wall 16. Further, the coating film when the fluoropolymer (A) is applied to the substrate 10 does not become cloudy, the developability of the negative photosensitive resin composition is improved, and the substrate through the partition wall 16 and the opening insulating film 14 is improved. Adhesion with 10 is increased.

  Moreover, 10-200 (mgKOH / g) is preferable and, as for the acid value of a fluoropolymer (A), 20-80 (mgKOH / g) is more preferable. Within such a range, the alkali solubility of the fluoropolymer (A) and the developability of the negative photosensitive resin composition will be 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.

  Moreover, 1000 or more and less than 20000 are preferable, and, as for the weight average molecular weight of a fluoropolymer (A), 2000 or more and less than 10,000 are more preferable. Within this range, the contrast change due to exposure is large, and the sensitivity to light is high. Moreover, there exists an advantage that the solubility with respect to a developing solution is high and generation | occurrence | production of the melt | dissolution residue in a non-exposed part can be prevented.

  The proportion of the fluoropolymer (A) in the total solid content of the negative photosensitive resin composition is preferably from 0.01 to 20%, more preferably from 0.05 to 15%. Within this range, the developability of the negative photosensitive resin composition is good, the partition 16 formed has good water and solvent repellency, and the substrate adhesion of the partition 16 is good.

  Moreover, a negative photosensitive resin composition contains the alkali-soluble photosensitive resin (B). The alkali-soluble photosensitive resin (B) has an ethylenic double bond (q) and an acidic group (r). However, it 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 16 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).

  Examples of the alkali-soluble photosensitive resin (B) include an ethylenic group at 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 double bond (q), and a novolac resin (B2) into which an ethylenic double bond (q) is introduced.

  In addition, about the said acidic group (r) and ethylenic double bond (q), it is the same as that of what was demonstrated in the fluorine-containing polymer (A).

  Next, 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 an acidic group (r) and an ethylenic double bond (q) 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 will be 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, the contrast change due to exposure is large, and the sensitivity to light is high. Moreover, there exists an advantage that the solubility with respect to a developing solution is high and generation | occurrence | production of the melt | dissolution residue in a non-exposed part 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 will be 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 an acidic group (r). Moreover, it does not have the group (p) 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 of the crosslinking agent (C) include diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,9-nonane. Diol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. Is mentioned.

  The ratio 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 water repellency and solvent repellency, and the developability of the negative photosensitive resin composition becomes 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 ratio of the radical initiator (D) in the total solid content of the negative photosensitive resin composition is preferably 0.1 to 30%, and 1 to 20% with respect to the solid content in the negative photosensitive resin composition. More preferred. Within this range, the developability of the negative photosensitive resin composition will be good.

  Next, the partition 16 in the present invention will be described. When the cross-sectional shape of the partition wall 16 is a forward taper or a rectangle, that is, when the taper angle, which is the angle formed between the side and the bottom of the cross-section of the partition wall 16, is 90 degrees or less, the organic layer of the substrate 10 having the partition pattern When the cathode material as the second electrode 20 is vapor-deposited on 18, it is not preferable because the formed vapor-deposited film becomes continuous and easily short-circuits. Therefore, in order to make the deposited film non-continuous and ensure insulation, the cross-sectional shape of the partition wall 16 is preferably a reverse taper, that is, the taper angle is preferably greater than 90 degrees, more preferably 110 degrees or more.

  As a method for forming an inversely tapered shape, a negative photosensitive resin composition is applied on the substrate 10 and the irradiated light is absorbed by the coating surface. That is, the amount of light reaching from the coating film surface to the deep part is gradually decreased, and control is performed so that the curing does not progress as the deep part. By controlling in such a manner, the side wall is dissolved in the developer as the depth increases, so that the cross-sectional shape of the formed partition wall 16 becomes an inversely tapered shape.

  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 light transmittance of the coating film when added. However, the light absorber (E) does not contain 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 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.

  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.

Specific examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, and 2- (2-hydroxy-5-methylphenyl) benzo. Triazole, 2- (5-t-butyl-2-hydroxyphenyl) benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-butyl-2 -Hydroxy-5-methylphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t- Pentyl-2-hydroxyphenyl) benzotriazole, octyl 3- {3- (2H-benzotriazol-2-yl ) -5-t-butyl-4-hydroxyphenyl} propionate, phenyl salicylate, pt-butylphenyl salicylate, 2- {2-hydroxy-5- (2-acryloyloxyethyl) phenyl} benzotriazole, 2- And hydroxy-3-methacryloyloxypropyl-3- {3- (benzotriazol-2-yl) -4-hydroxy-5-t-butylphenyl} propionate.

  In the present invention, among the ultraviolet absorbers described above, 2- {2-hydroxy-5- (2-acryloyloxyethyl) phenyl} benzotriazole, 2-hydroxy-3-methacryloyloxypropyl-3- {3- ( Those having a photopolymerizable functional group in the molecule such as benzotriazol-2-yl) -4-hydroxy-5-t-butylphenyl} propionate are particularly preferred.

  The ratio of the light absorber in the total solid content of the negative photosensitive resin composition is preferably 0.5 to 40%. If the content of the light absorber is too small, light absorption at the upper part of the coating film of the negative photosensitive resin composition is small, so that light reaches the deep part of the coating film and is sufficiently cured. The shape of is difficult to be reverse tapered. On the other hand, if 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, so that the partition wall 16 may be peeled off during development.

  Moreover, in a negative photosensitive resin composition, a silane coupling agent (F) can be used as needed. If a silane coupling agent is used, the board | substrate adhesiveness of the partition 16 formed from a negative photosensitive resin composition will improve.

  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.

  Moreover, a diluent (G) can be used in a negative photosensitive resin composition. 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.

  Furthermore, in a negative photosensitive resin composition, a thickener, a plasticizer, an antifoamer, a leveling agent, a repellency inhibitor, etc. can be used as needed.

  Hereinafter, a photolithography process using the negative photosensitive resin composition will be described.

  First, a negative photosensitive resin composition is applied to the substrate 10. The material of the substrate 10 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, epoxy Examples thereof include thermosetting plastic sheets such as 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 a coating method, a commonly used 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 preferably a wide range of about 50 to 150 ° C. and about 10 to 2000 seconds can be adopted.

  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 specific examples thereof include laser light such as visible light, ultraviolet light, far ultraviolet light, KrF excimer laser, ArF excimer laser, and F2 excimer laser. . 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, for example, an ultra-high pressure mercury lamp widely used for exposure apparatus can be cited.

  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 16 is formed by heat treatment (hereinafter referred to as post-baking treatment) for 5 to 90 minutes, preferably at 120 to 250 ° C., using a heating device such as a hot plate or oven. The

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

  Next, a process of applying an organic material dissolved in a solvent or water to the substrate 10 on which the inversely tapered partition 16 is formed will be described. In the vicinity of the partition wall 16 developed with the alkaline component developer and the partition wall 16 baked by post-baking, the added solvent-soluble component is scattered, and electricity is supplied to the organic layer 18 of the organic EL element. In many cases, the first electrode 12 is attached as a thin film to the uppermost layer of the anode electrode. It is difficult to completely remove a thin film layer fixed by post-baking with pure water or a pure water to which a surfactant is added. Since the formed thin film is a mixed film of low molecular components having solvent properties, the solvent-soluble thin film is formed in a region where the organic material thin film is originally formed, and the organic layer 18 of the organic EL element is formed. It becomes difficult to form a uniform organic material thin film.

  Therefore, as a result of studying a cleaning method for removing a solvent-soluble thin film, a solvent-soluble substance on the anode electrode is effectively obtained by using dry cleaning utilizing plasma or the like rather than a wet cleaning method such as a solvent. Found that can be removed.

  For cleaning the substrate 10 with plasma, it is preferable to use oxygen gas plasma. Further, the plasma irradiation may be performed under a reduced pressure atmosphere or an atmospheric pressure atmosphere. Furthermore, the partial pressure of oxygen gas in the processing pressure when performing plasma irradiation is preferably 0.1% to 100%.

  Further, the substrate 10 may be cleaned by using ultraviolet light in addition to oxygen gas plasma. For example, it is preferable to clean the substrate by irradiating ultraviolet rays having a wavelength of 254 nm or ultraviolet rays having a wavelength of 185 nm.

  The surface of the partition wall 16 is cleaned simultaneously with the removal of the solvent thin film on the anode electrode. However, since the partition wall 16 is formed of a solvent-soluble material as described above, the cleaned surface layer includes發 Since the solvent-soluble component remains, the ability to repel the solution in which the organic material is dissolved can be sufficiently maintained.

  According to the negative photosensitive resin composition of the present invention described above, it can be used for forming the partition wall 16 that requires ink repelling properties. For example, it is suitably used for forming partition walls for color patterns for liquid crystal displays or organic EL displays, and partition walls for forming wiring patterns in semiconductor devices or electric circuits.

  Examples of the present invention will be described below, but the present invention is not limited to the examples. In this example, unless otherwise specified, parts and% are based on mass.

The abbreviations of the compounds used in the examples are shown below.
_{C6FMA: CH 2 = C (CH} 3) COOCH 2 CH 2 (CF 2) 6 F
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 KBM403: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KBM-403)
DEGDM: Diethylene glycol dimethyl ether

[Synthesis of fluoropolymer (A)]
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.

  Next, in a 300 mL glass flask equipped with a thermometer, a stirrer, and a heating device, polymer 1 (100 g), MOI (36.2 g), DBTDL (0.15 g), BHT (1.8 g) And acetone (100 g) were charged and the reaction was carried out at 30 ° C. for 18 hours with stirring to obtain a resin 1 solution. This resin 1 is obtained by introducing an ethylenic double bond (q) into the polymer 1. 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 A (135 g).

Synthesis example 2
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 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 resin 2 solution. Water was added to the obtained acetone solution of resin 2 for reprecipitation purification, and petroleum ether was added to the acetone solution again for reprecipitation purification, followed by vacuum drying to obtain resin B (240 g).

  Table 1 shows the blending amount, molecular weight, acid value, and fluorine atom content of the raw materials used for the synthesis of the resin A and the resin B described above.

  In Table 1, the weight average molecular weight is a value measured by gel permeation chromatography using polystyrene as a standard substance. Further, the acid value and fluorine atom content of each resin showed theoretical values calculated from the blending amounts of the raw materials shown in Table 1. The acid value is the mass (unit: mg) of potassium hydroxide required to neutralize 1 g of resin.

[Evaluation of negative photosensitive resin composition]
Using the above resins A and B, a negative photosensitive resin composition was obtained under the conditions of Examples a and b shown in Table 2 below to form a pattern, and developability, partition water repellency, solvent repellency The taper angle and heat resistance were evaluated.

Pattern formation Fluoropolymer (A), alkali-soluble photosensitive resin (B), crosslinking agent (C), radical initiator (D), light absorber (E), silane coupling in the proportions shown in Table 2 above The negative photosensitive composition of Examples ab was obtained by blending the agent (F) and the diluent (G).

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, developability, water repellency, solvent repellency, and heat resistance were evaluated by the following methods. The results are summarized in Table 2.

Developability Those that were developed (lines / space patterns could be formed) were marked with ◯. Both Example a and Example b were developed.

Water Repellency, Solvent Repellency Water repellency and solvent repellency can be estimated by contact angles 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 water repellency and solvent repellency of the coating film.

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

The glass substrate on which the heat resistant pattern was formed was placed in a thermostatic layer at 90 ° C. for 500 hours, and changes in water repellency, solvent repellency and shape of the partition over time were examined. Changes in water repellency and solvent repellency can be estimated by changes in the contact angles of water and xylene. The smaller the change in contact angle, the better the heat resistance. In Example a, the heat resistance was good, but in Example b, the change in the contact angle was large, indicating that thermal degradation occurred. This is because the resin 2 as the raw material of Example b did not undergo the modification reaction shown in Table 1 and no ethylenic double bond was introduced.

It is a cross-sectional schematic diagram of the organic EL element concerning this invention.

Explanation of symbols

  10 substrate, 12 1st electrode, 14 opening insulating film, 16 partition, 18 organic substance layer, 20 2nd electrode.

Claims (8)

A first electrode formed on a substrate;
A plurality of partition walls that are formed so as to intersect with the first electrode, and whose cross-sectional shape is an inversely tapered shape;
An organic layer separated by the plurality of partition walls and formed on the first electrode, wherein at least one of them is a low-molecular substance;
A second electrode separated by the plurality of partition walls and formed on the plurality of organic layers;
And an organic electroluminescent device using a polymer compound having a fluorine substituent and an ethylenic double bond as a material for the plurality of partition walls. The organic electroluminescent element according to claim 1, wherein a fluorine-containing polymer containing a fluorine-containing substituent represented by the following formula 1 and an ethylenic double bond is used as the material of the partition wall.
-CFXRf Formula 1
X represents a hydrogen atom or a fluorine atom, and Rf has a fluorine atom, an alkyl group having 15 or less carbon atoms in which at least one of the hydrogen atoms is substituted with a fluorine atom, or an etheric oxygen atom, An atomic group having 15 or less carbon atoms in which at least one of the bonded hydrogen atoms is substituted with a fluorine atom. The etheric oxygen atom may be present between the carbon-carbon bonds of the atomic group or may be present at the bond terminal.   2. The method of manufacturing an organic electroluminescent element according to claim 1, wherein the substrate is cleaned with oxygen gas plasma before at least one of the organic layers is wet-coated.   4. The method of manufacturing an organic electroluminescent element according to claim 3, wherein the cleaning with the oxygen gas plasma is performed by plasma irradiation under a reduced pressure atmosphere.   4. The method of manufacturing an organic electroluminescent element according to claim 3, wherein the cleaning with the oxygen gas plasma is performed by plasma irradiation under an atmospheric pressure atmosphere.   The organic electroluminescence device according to any one of claims 3 to 5, wherein the oxygen gas plasma cleaning has a partial pressure of oxygen gas in a processing pressure of 0.1% to 100%. Manufacturing method.   2. The method of manufacturing an organic electroluminescent element according to claim 1, wherein the substrate is cleaned by irradiating an ultraviolet ray having a wavelength of 254 nm before wet-coating at least one of the organic layers. 2. The method of manufacturing an organic electroluminescent element according to claim 1, wherein the substrate is cleaned by irradiating with an ultraviolet ray having a wavelength of 185 nm before wet-coating at least one of the organic layers.

Images