JP7803041B2 - Composition for forming a protective film - Google Patents

Description

The present invention relates to a protective film-forming composition suitable for coating and forming a film on an organic semiconductor film.

In recent years, there has been active development of technology for the production of organic electronic devices using all-printing methods, which are low-cost and highly productive. One example of an electronic device that is being developed is organic transistors. These organic transistors are manufactured through a number of processes, including a process in which a protective film made of resin protects the organic transistor and forms a pattern for the EL light-emitting portion. This pattern is formed so as to cover, for example, the source electrode, drain electrode, and organic semiconductor layer or polymer layer, and is not present on the electrodes that form the EL light-emitting portion.

Typically, EL light-emitting sections are formed using photolithography, a technique in which a substrate surface coated with a photosensitive material (resist) is exposed to a pattern through a photomask or reticle to form a pattern consisting of exposed and unexposed areas, and the EL light-emitting section is then opened using dry etching or wet etching.

There is a need for a material that can be patterned using photolithography, which can be used to form openings in the EL light-emitting areas. After the material is dissolved in ink and applied, it is dried and then becomes insoluble in solvents through photocrosslinking at room temperature and short-term exposure.

Patent Document 1 lists such materials as a negative photosensitive resin composition and photocured patterns produced from it that are highly photoreactive, allowing for patterning, and capable of forming coatings with excellent dielectric properties. However, this resin is an alkali-soluble polymer, and requires the use of water during development. Furthermore, the composition must be solvented with an organic solvent such as xylene or PGMEA (1-methoxy-2-propanol acetate). Organic solvents and water can degrade the performance of electronic devices, so solubility in a fluorine-containing solvent is necessary.

To prevent the performance of electronic devices from being reduced by water or organic solvents, there is a method of forming patterns using fluorine-based resins that are soluble in fluorine solvents, as described in Patent Document 2 and Non-Patent Document 1. However, fluorine-based resins have the problem of not being photocrosslinkable.

Examples of fluororesins that dissolve in fluorosolvents and undergo photocrosslinking include fluororesins that use anthracene crosslinking groups, such as those described in Non-Patent Document 2. However, because they are soluble in fluorosolvents, they have a high proportion of fluorine residues, which results in poor crosslinkability.

One way to increase solubility in fluorine solvents is to use compounds with eight or more perfluoroalkyl groups, but their use is being reconsidered due to their potential for accumulation in the environment and the human body, as well as their harmful effects. Therefore, efforts are being made to replace them with compounds with perfluoroalkyl groups with six or fewer carbon atoms (see, for example, Patent Document 3 or Patent Document 4).

In light of the above, there has been a demand for a composition that is a compound containing a perfluoroalkyl group with six or fewer carbon atoms, yet is highly soluble in fluorine solvents, and can be made insoluble in solvents by photocrosslinking with exposure to light, allowing for the formation of patterns while preventing a decrease in the performance of electronic devices.

JP 2017-167513 A Patent No. 6281427 Japanese Patent Application Laid-Open No. 2006-185869 JP 2014-006273 A

Appl. Phys. Express 7, 101602 (2014) J Polym Sci A Polym Chem 53, 1252 (2015)

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a composition for forming a protective film that prevents performance degradation without damaging the organic semiconductor.

As a result of extensive research into resolving the above-mentioned problems, the inventors discovered that the above-mentioned problems could be resolved by using the protective film-forming composition described below, leading to the completion of the present invention.

That is, the present invention provides a composition for forming a protective film, comprising a fluorine-based resin and a fluorine-based solvent, characterized in that it contains 30 mol % or more of at least one member selected from the group consisting of a residue unit represented by formula (1), a residue unit represented by formula (2), or a residue unit represented by formula (3).

(In formulas (1) to (3), R ₁ represents one of the group consisting of a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. Rf ₁ represents one of the group consisting of a linear perfluoroalkyl group having 1 to ₆ carbon atoms and having a terminal CF ₃ , a branched perfluoroalkyl group having 3 to 6 carbon atoms and having a terminal CF ₃ , or a cyclic perfluoroalkyl group having 3 to 6 carbon atoms and having a terminal CF 3. Rf ₂ represents one of the group consisting of a linear perfluoroalkylene group having 1 to 6 carbon atoms, a branched perfluoroalkylene group having 3 to 6 carbon atoms, or a cyclic perfluoroalkylene group having 3 to 6 carbon atoms. Rf ₃ represents a linear perfluoroalkyl group having 1 to 5 carbon atoms and having a terminal CF ₃ , a branched perfluoroalkyl group having 3 to 5 carbon atoms and having a terminal CF ₃ , or a cyclic perfluoroalkyl group having 3 to 5 carbon atoms and having a terminal CF _3. Rf ₄ represents a linear perfluoroalkylene group having 1 to 5 carbon atoms, a branched perfluoroalkylene group having 3 to 5 carbon atoms, or a cyclic perfluoroalkylene group having 3 to 5 carbon atoms. _{R 2} to R ₅ each independently represent a hydrogen atom or a fluorine atom. n represents an integer of 1 to 5. X represents one member of the group consisting of a single bond, CH ₂ , an oxygen atom, or a sulfur atom. L represents a linking group.

The present invention provides a protective film-forming composition that is soluble in a fluorine-containing solvent and becomes insoluble in the solvent when photocrosslinked at room temperature with a low exposure dose, enabling the formation of a pattern while preventing a decrease in the performance of electronic devices, as well as an electronic device using the same.

1 is a diagram showing the cross-sectional shape of an organic transistor.

The present invention is described in detail below.

The protective film-forming composition of the present invention contains a fluorine-based resin containing 30 mol % or more of at least one member selected from the group consisting of residue units represented by formula (1), residue units represented by formula (2), and residue units represented by formula (3), and a fluorine-based solvent.

The protective film-forming composition of the present invention contains a fluorine-based resin containing 30 mol % or more of at least one member selected from the group consisting of residue units represented by formula (1), residue units represented by formula (2), and residue units represented by formula (3). This allows the resin to dissolve in a fluorine-based solvent.

The resin composition for forming a protective film of the present invention contains a fluorine-based solvent. This allows patterns to be formed on the organic semiconductor without damaging it.

In formulas (1) to (3), _R1 represents a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. _Rf1 represents a C1 to C6 linear perfluoroalkyl group having a terminal _CF3 , a C3 to C6 branched perfluoroalkyl group having a terminal _CF3 , or a C3 to C6 cyclic perfluoroalkyl group having a terminal _CF3 . _Rf2 represents a C1 to C6 linear perfluoroalkylene group, a C3 to C6 branched perfluoroalkylene group, or a C3 to C6 cyclic perfluoroalkylene group. _Rf3 represents a C1 to C5 linear perfluoroalkyl group having a terminal _CF3 , a C3 to C5 branched perfluoroalkyl group having a terminal _CF3 , or a C3 to C5 cyclic perfluoroalkylene group having a terminal _CF3 . _Rf4 represents a linear perfluoroalkylene group having 1 to 5 carbon atoms, a branched perfluoroalkylene group having 3 to 5 carbon atoms, or a cyclic perfluoroalkylene group having 3 to 5 carbon atoms. _R2 to _R5 each independently represent a hydrogen atom or a fluorine atom. n represents an integer of 1 to 5. X represents one member of the group consisting of a single bond, _CH2 , an oxygen atom, or a sulfur atom. L represents a linking group.

The residue units represented by formulas (1) to (3) contain fluorine atoms, which gives the fluororesin a high affinity with fluorine-based solvents. Furthermore, because formulas (1), (2), and (3) have ester bonds, which are polar groups, adjacent to the main chain, the fluororesin film formed by coating is highly flexible, and a flat, crack-free fluororesin film can be obtained. Furthermore, because the side chains contain fluorinated hydrocarbon groups, the fluororesin has excellent solubility in fluorine-based solvents.

Specific structures of the Rf1-(CR3=CR2-X-Rf2)n- portion in formula (1) and formula (2) include, for example, C2F5-CH=CH-C4F8-, C2F5-CH=CF-C4F8-, C2F5-CF=CH-C4F8-, C2F5-CF=CF-C4F8-, C2F5-CF=CF-C4F8-, C2F5-(CH=CH-C4F8)2 -, C2F5-(CH=CH-C4F8)3-, C2F5-CH=CH-C6F12-, C4F9-CH=CH-C4F8-, C4F9-CH=CH-C6F 12, C6F13-CH=CH-C4F8-, C6F13-CH=CH-C6F12-, C2F5-CH=CH-C4F8-, CF3-CF=CHCH2C4 F8-, CF3-CF=CHCH2C6F12-, C3F7-CF=CHCH2C4F8-, C3F7-CF=CHCH2C6F12-, C5F11-CF= CHCH2C4F8-, C5F11-CF=CHCH2C6F12-, C2F5-CH2CH=CF-C3F6-, C2F5-CH2CH=CF-C5F10 -, C4F9-CH2CH=CF-C3F6-, C4F9-CH2CH=CF-C5F10-, C6F13-CH2CH=CF-C3F6-, C6F13-CH2CH=CF-C5F10-, C6F13-(CH2CH=CF-C3F6)2-, C6F13-(CH2CH=CF-C3F6)3-, etc.

In the present invention, the linking group L is preferably represented by the following general formula (4), as it can be easily synthesized.

In formula (4), the sum of l and m is an integer from 2 to 6, and when l and/or m is 2 or greater, the compound may contain a -CH=CH- structure instead of -CH2CH2-.

Q is a single bond, -OCONH-, -CONH-, -O-, -NH-, -CO-O-, -O-CO-, -NHCONH-, or -C6H4-. When Q is -C6H4-, examples include the ortho-, meta-, and para-isomers, with the para-isomer being preferred.

In the fluororesin, the _Rf3 group in the residue unit represented by formula (3) is preferably a linear perfluoroalkyl group having 1 to 5 carbon atoms and a _CF3 terminal. This facilitates the formation of a self-associated structure. The _Rf4 group is preferably a linear perfluoroalkylene group having 1 to 5 carbon atoms.

Specific structures of the Rf3-(CF=CR5-CR4=CF-Rf4)n- portion in formula (3) include, for example, CF3-CF=CH-CH=CF-C3F6-, CF3-CF=CH-CH=CF-C5F10-, C3F7-CF=CH-CH=CF-C3F6-, C3F7-CF=CH-CH=CF-C5F10-, C5F11-CF=CF-CH=CF-C5F10-, C5F11-CF= CH-CF=CF-C5F10-, C5F11-CF=CF-CF=CF-C5F10-, C5F11-CF=CH-CH=CF-C3F6-, C5F11-CF=CH-CH=CF-C5F10- , CF3-(CF=CH-CH=CF-C5F10)2-, C3F7-(CF=CH-CH=CF-C5F10)2-, C5F11-(CF=CH-CH=CF-C5F10)2-, and the like.

In formula (3), R4 and/or R5 are preferably hydrogen atoms.

Specific examples of residue units represented by formula (1) include the following structures:

Specific examples of residue units represented by formula (2) include the following structures:

Specific examples of residue units represented by formula (3) include the following structures:

The fluorine-based resin contained in the protective film-forming composition of the present invention contains one or more repeating units represented by formulas (1) to (3). In addition, it may contain repeating units with structures other than those represented by formulas (1) to (3).

The fluorine-based resin contained in the protective film-forming composition of the present invention contains 30 mol % or more, and more preferably 40 mol % or more, of repeating units represented by formulas (1) to (3) in order to have sufficient solubility in fluorine-based solvents.

The fluorine-based solvent contained in the protective film-forming composition of the present invention may be any solvent that dissolves the above-mentioned fluorine-based resin.

There are no particular restrictions on the fluorine content of the fluorine-based solvent, but to ensure rapid dissolution, it should be 50% by mass or more and 90% by mass or less, more preferably 60% by mass or more and 80% by mass or less, and more preferably 65% by mass or more and 80% by mass or less, based on the total mass of the fluorine-based solvent. If it exceeds 90% by mass, the fluorine-based resin will not dissolve sufficiently. If it is less than 50% by mass, the surface of the organic semiconductor film may dissolve or swell when applied or printed on the organic semiconductor film. The fluorine-containing hydrocarbons, fluorine-containing ethers, or fluorine-containing alcohols shown below can preferably be used as the fluorine-based solvent contained in the protective film-forming composition of the invention.

Fluorinated hydrocarbons have a low ozone depletion potential and are preferred as fluorine-based solvents contained in the protective film-forming composition of the present invention. In particular, linear, branched, or cyclic hydrocarbons with 4 to 8 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom are preferred because they are easy to apply.

Specific examples of such fluorine-containing hydrocarbons include butane, pentane, hexane, heptane, octane, cyclopentane, and cyclohexane in which at least one hydrogen atom has been substituted with a fluorine atom. Specific examples include fluorine-containing hydrocarbons such as 1,1,1,3,3-pentafluorobutane, 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane, 2H,3H-decafluoropentane, 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorooctane, hexafluorocyclopentane, and 1,1,2,2,3,3,4-heptafluorocyclopentane.

The boiling point of the fluorine-containing hydrocarbon must be higher than the substrate temperature when the protective film-forming composition is applied, preferably by 20°C or more, more preferably by 50°C or more than the substrate temperature. If the boiling point of the fluorine-containing hydrocarbon is lower than the substrate temperature when the protective film-forming composition is applied, the fluorine-containing hydrocarbon will rapidly volatilize during the application process, making it difficult to achieve sufficient flatness in the fluororesin film that is formed. Furthermore, the fluorine-containing hydrocarbon used preferably has a boiling point of 60°C or more and 200°C or less, more preferably 80°C or more and 180°C or less. If the boiling point of the fluorine-containing hydrocarbon is 60°C or more and 200°C or less, the fluorine-containing hydrocarbon can be easily evaporated and removed by heating from the fluororesin film formed by applying the protective film-forming composition.

Among the above fluorinated hydrocarbons, the following are examples having particularly preferred boiling points:

Examples include 2H,3H-decafluoropentane, 1,1,2,2,3,3,4-heptafluorocyclopentane, 1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorooctane, and 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane.

Furthermore, due to their low ozone depletion potential, fluorinated ethers can be used as fluorinated solvents. In particular, the boiling point of the fluorinated ether must be higher than the substrate temperature when the protective film-forming composition is applied, preferably at least 20°C higher than the substrate temperature, and more preferably at least 50°C higher. If the boiling point of the fluorinated ether is lower than the substrate temperature when the protective film-forming composition is applied, the fluorinated aliphatic ether will rapidly volatilize during the application process, making it difficult to achieve sufficient flatness in the fluorinated resin film that is formed. Furthermore, the boiling point of the fluorinated ether used is preferably 200°C or lower, more preferably 180°C or lower. If the boiling point of the fluorinated ether is 200°C or lower, the fluorinated ether can be easily evaporated and removed by heating from the fluorinated resin film formed by applying the protective film-forming composition.

Preferred examples of fluorine-containing ethers include 1,1,2,3,3,3-hexafluoro-1-(2,2,2-trifluoroethoxy)propane, 1,1,2,3,3,3-hexafluoro-1-(2,2,3,3,3-pentafluoropropoxy)propane, 1,1,2,3,3,3-hexafluoro-1-(2,2,3,3-tetrafluoropropoxy)propane, or 2,2,3,3,3-pentafluoro-1-(1,1,2,2-tetrafluoroethoxy)propane, 1,1,1,2,2,3,3-heptafluoro Examples include 3-methoxypropane, methyl perfluorobutyl ether, ethyl nonafluorobutyl ether, 1,1,1,2,3,4,4,5,5,5-decafluoro-3-methoxy-2-(trifluoromethyl)pentane, 2-(trifluoromethyl)-3-ethoxydodecafluorohexane, (1,1,1,2,3,3-hexahexafluoropropoxy)pentane, 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether, and methoxyperfluoroheptene.

Examples of fluorinated ethers having preferred boiling points include ethyl nonafluorobutyl ether, methyl perfluorobutyl ether, ethyl nonafluorobutyl ether, 1,1,1,2,3,4,4,5,5,5-decafluoro-3-methoxy-2-(trifluoromethyl)pentane, 2-(trifluoromethyl)-3-ethoxydodecafluorohexane, (1,1,1,2,3,3-hexahexafluoropropoxy)pentane, 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether, and methoxyperfluoroheptene.

Furthermore, since it can be applied evenly by application methods such as spin coating, fluorine-containing alcohols can be used as fluorine-based solvents. In particular, the boiling point of the fluorine-containing alcohol must be higher than the substrate temperature when the protective film-forming composition is applied, preferably at least 20°C higher than the substrate temperature, and more preferably at least 50°C higher. If the boiling point of the fluorine-containing alcohol is lower than the substrate temperature when the protective film-forming composition is applied, the fluorine-containing aliphatic alcohol will rapidly volatilize during the application process, making it difficult to achieve sufficient flatness in the fluorine-based resin film that is formed. Furthermore, the boiling point of the fluorine-containing alcohol used is preferably 200°C or lower, and more preferably 180°C or lower. If the boiling point of the fluorine-containing alcohol is 200°C or lower, the fluorine-containing alcohol can be easily evaporated and removed by heating from the fluorine-based resin film formed by applying the protective film-forming composition.

Preferred examples of fluorine-containing alcohols include 1H,1H-trifluoroethanol, 1H1H-pentafluoropropanol, 1H,1H-heptafluorobutanol, 2-(perfluorobutyl)ethanol, 3-(perfluorobutyl)propanol, 2-(perfluorohexyl)ethanol, 3-(perfluorohexyl)propanol, 1H,1H,3H-tetrafluoropropanol, 1H,1H,5H-octafluoropentanol, 1H,1H,7H-dodecafluoroheptanol, 2H-hexafluoro-2-propanol, and 1H,1H,3H-hexafluorobutanol.

The above fluorine-based solvents are used in order to achieve solubility and to apply them to semiconductors without damaging them, and are generally selected from the following: 1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorooctane, 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane, 1,1,2,2,3,3,4-heptafluorocyclopentane, ethyl nonafluorobutyl ether, 1,1,1,2,3,4,4,5,5,5-decafluoro-3-methoxy-2-(trifluoromethyl)pentane, 2-(trifluoromethyl)-3-ethoxydodecafluorohexane, methoxyperfluoroheptene, 1H1H-pentafluoropropanol, 1H,1H-heptafluorobutanol, 2-(perfluoro (perfluorobutyl)ethanol, 1H,1H,3H-tetrafluoropropanol, 1H,1H,5H-octafluoropentanol and 1H,1H,7H-dodecafluoroheptanol are preferred, and 1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorooctane, 1,1,2,2,3,3,4-heptafluorocyclopentane, 1,1,1,2,3,4,4,5,5,5-decafluoro-3-methoxy-2-(trifluoromethyl)pentane, methoxyperfluoroheptene, 1H,1H,3H-tetrafluoropropanol, 1H,1H,5H-octafluoropentanol and 1H,1H,7H-dodecafluoroheptanol are more preferred.

Furthermore, two or more types of fluorine solvents may be contained to flatten the applied film, and a mixed solvent of the fluorine-containing hydrocarbon and the fluorine-containing alcohol, or the fluorine-containing ether and the fluorine-containing alcohol, is preferred.

The protective film-forming composition of the present invention, which is made of a fluorine-based resin and a fluorine-based solvent, preferably contains 1 wt% to 50 wt% of the fluorine-based resin and 50 wt% to 99 wt% of the fluorine-based solvent, and more preferably contains 1 wt% to 30 wt% of the fluorine-based resin and 70 wt% to 99 wt% of the fluorine-based solvent.

In the ethylenically unsaturated monomer residue units having a photocrosslinkable group in the side chain of the fluororesin contained in the protective film-forming composition of the present invention, the photocrosslinkable group refers to a functional group that can form a crosslinked structure between functional groups when exposed to light such as ultraviolet light or visible light. By including the above-mentioned photocrosslinkable group in the side chain of the resin, the fluororesin of the present invention selectively insolubilizes only the site exposed to light. Examples of photocrosslinkable groups include photodimerization-reactive groups; radical-reactive groups such as methacryloyl groups, acryloyl groups, aromatic vinyl groups, and vinyl ether groups; and cation-reactive groups such as epoxy groups and oxetane groups. Photodimerization-reactive groups are preferred because they do not require the use of a photoradical generator or photocation generator and provide excellent long-term stability when formed into a film.

Examples of photodimerization reactive groups include cinnamic acid groups, chalcone groups, stilbenyl groups, stilbazolyl groups, coumarinyl groups, anthracenyl groups, naphthoquinonyl groups, acenaphthyl groups, maleimidyl groups, phenylcyclohexenonyl groups, tetracenyl groups, benzazepinyl groups, and naphthalenonyl groups. Among these, at least one photodimerization reactive group selected from the group consisting of general formulas (5), (6), (7), and (8) below is preferred because of its high photocrosslinkability, economical efficiency, and ease of introduction as a functional group.

(In formula (5), A ₁ represents hydrogen, a hydroxyl group, an amino group, a C ₁ to C ₆ alkyl group, a C ₁ to C ₆ primary or secondary alkylamino group, a C ₁ to C ₆ alkoxy group, or a single bond; A ₂ may be the same or different and represent hydrogen, halogen, cyano group, nitro group, carboxyalkyl group, alkyl ether group, aryl ether group, C ₁ to C ₁₈ alkyl group, fluoroalkyl group, cycloalkyl group, or a single bond; B ₁ may be the same or different and represent hydrogen, a C ₁ to C ₆ alkyl group, halogen, cyano group, or aryl group, provided that only one of one A ₁ and five A ₂ is bonded to another substituent via a single bond.)

(In formula (6), _A3s are the same or different and represent hydrogen, halogen, cyano group, nitro group, carboxyalkyl group, alkyl ether group, aryl ether group, _C1 to _C18 alkyl group, fluoroalkyl group, cycloalkyl group, or a single bond. _B2s are the same or different and represent hydrogen, _C1 to _C6 alkyl group, halogen, cyano group, or aryl group. L is absent or represents a carbonyl group, provided that only one of the ten _A3s is bonded to another substituent via a single bond.)

(In formula (7), A ₄ 's may be the same or different and represent hydrogen, halogen, cyano group, nitro group, carboxyalkyl group, alkyl ether group, aryl ether group, C ₁ to C ₁₈ alkyl group, fluoroalkyl group, cycloalkyl group, or a single bond. _{B 3} 's may be the same or different and represent hydrogen, C ₁ to C ₆ alkyl group, halogen, cyano group, or aryl group, provided that only one of the four A _4's is bonded to another substituent via a single bond.)

(In formula (8), _A5 may be the same or different and represent hydrogen, halogen, cyano group, nitro group, carboxyalkyl group, alkyl ether group, aryl ether group, _C1 to _C18 alkyl group, fluoroalkyl group, cycloalkyl group, or a single bond, provided that only one of the ten _A5 is bonded to another substituent via a single bond.)

Specific examples of groups represented by formula (5) include the following. In the formula, * represents the moiety that bonds to the side chain.

Specific examples of groups represented by formula (6) include the following:

Specific examples of groups represented by formula (7) include the following:

Specific examples of photodimerization reactive groups represented by formula (8) include the following:

The acrylic resin residue unit in the fluorine-based resin contained in the protective film-forming composition of the present invention preferably has a group represented by formula (5) in its side chain. Furthermore, since this makes it easier to synthesize the monomer that serves as the raw material for the residue unit, the residue unit represented by formula (5) is preferably a residue unit represented by the following formula (9).

(In formula (9), _R1 represents a hydrogen atom or a methyl group; _B4 may be the same or different and represent a hydrogen atom, a _C1 - _C6 alkyl group, a halogen atom, a cyano group, or an aryl group; D may be the same or different and represent a hydrogen atom, a halogen atom, a cyano group, a nitro group, a carboxyalkyl group, an alkyl ether group, an aryl ether group, a _C1 - _C18 alkyl group, a fluoroalkyl group, or a cycloalkyl group; and M represents a halogen atom or an aryl ether group.)

In formula (9), R ₁ represents either a hydrogen atom or a methyl group, and is preferably a methyl group.

In formula (9), _B4 may be the same or different and represents one member of the group consisting of a hydrogen atom, _{a C1} - _C6 alkyl group, a halogen atom, a cyano group, or an aryl group, and is preferably either a hydrogen atom or a _C1 - _C6 alkyl group, and more preferably a hydrogen atom.

In formula (9), D's may be the same or different and represent one of the group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, a carboxyalkyl group, an alkyl ether group, an aryl ether group, a _C1 - _C18 alkyl group, a fluoroalkyl group, or a cycloalkyl group, and are preferably either a hydrogen atom or a _C1 - _C18 alkyl group, and more preferably a hydrogen atom.

In formula (9), M represents either a halogen atom or an aryl ether group, preferably a halogen atom.

The protective film-forming composition of the present invention may contain a photosensitizer. Any photosensitizer may be used as long as it promotes the crosslinking reaction of the photocrosslinkable groups. When a photosensitizer is contained, the protective film-forming composition may be a composition containing the fluororesin of the present invention and the photosensitizer, or the solution of the present invention described above may further contain a photosensitizer.

Examples of photosensitizers include acyloins such as benzoin, benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; carbonyls such as anthraquinone, 2-methylanthraquinone, 1,2-benzanthraquinone, 1-chloroanthraquinone, and cyclohexanone; diketones such as diacetyl and benzil; organic sulfides such as diphenyl monosulfide, diphenyl disulfide, and tetramethylthiuram disulfide; phenones such as acetophenone, benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, o-methoxybenzophenone, and 2,4,6-trimethoxybenzophenone; p-toluenesulfonyl chloride, 1-naphthalene Examples of suitable photosensitizers include sulfonyl halides such as sulfonyl chloride, 1,3-benzenesulfonyl chloride, 2,4-dinitrobenzenesulfonyl bromide, and p-acetamidobenzenesulfonyl chloride; aromatic nitro compounds such as 5-nitrofluorene, 5-nitroacenaphthene, N-acetyl-4-nitro-1-naphthylamine, and biclamide; coumarins such as 7-diethylamino-3-thenoylcoumarin and 3,3'-carbonylbis(7-diethylaminocoumarin); halogenated hydrocarbons such as carbon tetrachloride, hexabromoethane, and 1,1,2,2-tetrabromoethane; nitrogen derivatives such as diazomethane, bisisobutyronitrile, hydrazine, and trimethylbenzylammonium chloride; and dyes such as ethionine, thionine, and methylene blue. The addition of a photosensitizer enables crosslinking (insolubilization) of the fluororesin of the present invention at lower exposure doses. Two or more types of such sensitizers can be used in combination as needed.

When the protective film-forming composition of the present invention further contains a photosensitizer, it preferably contains 1 wt% to 50 wt% of a fluorine-based resin, 50 wt% to 99 wt% of a fluorine-based solvent, and 0.001 wt% to 5 wt% of a sensitizer, and more preferably contains 1 wt% to 30 wt% of a fluorine-based resin, 70 wt% to 99 wt% of a fluorine-based solvent, and 0.01 wt% to 3 wt% of a sensitizer.

The following describes a pattern made of fluorine-based resin, which is one aspect of the present invention.

The fluorine-based resin contained in the protective film-forming composition of the present invention can form a pattern.

First, we will explain the pattern formation method using the protective film-forming composition of the present invention.

First, a coating film of a fluorine-based resin is formed on the surface of a substrate by a known coating film forming method.
Examples of the substrate include various glass plates; polyesters such as polyethylene terephthalate; polyolefins such as polypropylene and polyethylene; thermoplastic plastic sheets such as polycarbonate, polymethyl methacrylate, polysulfone, and polyimide; epoxy resins; polyester resins; and thermosetting plastic sheets such as poly(meth)acrylic resins.

Methods for forming the coating film include, for example, spin coating, drop casting, dip coating, doctor blade coating, pad printing, squeegee coating, roll coating, rod bar coating, air knife coating, wire bar coating, flow coating, gravure printing, flexographic printing, superflexographic printing, screen printing, inkjet printing, letterpress reverse printing, reverse offset printing, and adhesion contrast printing.

Next, the coating is dried. This process evaporates the solvent, resulting in a non-sticky coating. Drying conditions vary depending on the boiling point and blend ratio of the solvent used, but a wide range of temperatures, preferably 50 to 150°C and 10 to 2000 seconds, can be used.

When forming a coating film using a printing method to create a desired pattern, exposure to light causes the pattern to undergo photocrosslinking and become fixed, forming the pattern.

On the other hand, if no pattern is formed when the coating film is formed, a desired pattern can be formed in the coating film using photolithography technology. When using photolithography technology, the dried coating film is first exposed to light through a mask with the desired pattern, causing photocrosslinking.

When the fluorine-based resin contained in the protective film-forming composition of the present invention is cured by photocrosslinking, radiation such as ultraviolet light or visible light is used, for example, ultraviolet light with a wavelength of 245 to 435 nm. The irradiation dose varies depending on the resin composition, but may be, for example, 10 to 5000 mJ/ ^cm². To prevent a decrease in the degree of crosslinking and improve economic efficiency by shortening the process time, the irradiation dose is preferably 100 to 4000 mJ/ ^cm² . Specific examples of light irradiation devices or light sources include germicidal lamps, ultraviolet fluorescent lamps, carbon arcs, xenon lamps, high-pressure mercury lamps for copying, medium- or high-pressure mercury lamps, ultra-high-pressure mercury lamps, electrodeless lamps, and metal halide lamps.

Ultraviolet irradiation is usually carried out in the atmosphere, but can also be carried out in an inert gas atmosphere or in a stream of a certain amount of inert gas if necessary. If necessary, the photo-crosslinking reaction can be accelerated by adding the aforementioned photosensitizer. The unexposed areas are then removed by development using a developer. Any solvent that dissolves uncured fluororesin can be used as the developer, including, for example, aromatic solvents such as benzene, toluene, and xylene; ether-based solvents such as dioxane, diethyl ether, tetrahydrofuran, and diethylene glycol dimethyl ether; ketone-based solvents such as acetone and methyl ethyl ketone; and ester-based solvents such as ethyl acetate, butyl acetate, isopropyl acetate, and propylene glycol monomethyl ether acetate.

The development time is preferably 30 to 300 seconds. The development method may be either the puddle method or the dipping method. After development, the substrate is washed with a solvent and air-dried with compressed air or compressed nitrogen to remove the solvent from the substrate. The substrate is then heated using a heating device such as a hot plate or oven, preferably at 40 to 150°C for 5 to 90 minutes, to form a pattern.

After forming a pixel pattern through the above photolithography process, dirt on the substrate surface within the pixels may be removed. For example, the substrate surface may be cleaned by irradiating it with short-wavelength ultraviolet light such as a low-pressure mercury lamp or excimer UV, or by photo-ashing. Photo-ashing is a process in which short-wavelength ultraviolet light is irradiated in the presence of ozone gas. The short-wavelength ultraviolet light is light with a main peak at wavelengths between 100 and 300 nm.

As such, the fluorine-based resin contained in the protective film-forming composition of the present invention is itself soluble in fluorine-based solvents or organic solvents, and upon irradiation with light, the photocrosslinkable groups in the side chains crosslink and harden, rendering the composition insoluble in fluorine-based solvents or organic solvents. By utilizing this property, the fluorine-based resin contained in the protective film-forming composition of the present invention can be used as a negative resist in which, when crosslinked by light irradiation, the non-irradiated portions are removed by the fluorine-based solvent or organic solvent.

After patterning the fluororesin contained in the protective film-forming composition of the present invention, the contact angle of the remaining crosslinked fluororesin (outside the pattern) with respect to the organic solvent is preferably 50° or greater to prevent the organic solvent from wetting and spreading.

The fluororesin contained in the protective film-forming composition of the present invention has excellent liquid-repellent properties and can be used as a pattern material when manufacturing organic transistor elements, color filters, and organic EL elements. The fluororesin of the present invention can also be used in electronic devices including the aforementioned organic transistor elements, color filters, and organic EL elements.

The electronic device, which is one aspect of the present invention, is described in detail below.

The protective film-forming composition of the present invention can be used in electronic devices. Examples of electronic devices include organic transistors, as they cause less damage to organic semiconductors.

When the protective film-forming composition of the present invention is used in an organic transistor, the organic transistor has a gate insulating layer on a substrate, and is obtained by further depositing an organic semiconductor layer on this gate insulating layer, followed by the addition of a source electrode, a drain electrode, and a gate electrode.

The organic transistor of the present invention may have any of the following device structures shown in Figure 1: bottom gate-top contact type (A), bottom gate-bottom contact type (B), top gate-top contact type (C), or top gate-bottom contact type (D). Here, 1 represents the organic semiconductor layer, 2 represents the substrate, 3 represents the gate electrode, 4 represents the gate insulating layer, 5 represents the source electrode, and 6 represents the drain electrode.

The substrate that can be used in this organic transistor is not particularly limited as long as it can ensure sufficient flatness for fabricating the device. Examples include inorganic material substrates such as glass, quartz, aluminum oxide, highly doped silicon, silicon oxide, tantalum dioxide, tantalum pentoxide, and indium tin oxide; plastics; metals such as gold, copper, chromium, titanium, and aluminum; ceramics; coated paper; and surface-coated nonwoven fabric. Composite materials made from these materials or multilayered materials made from these materials are also acceptable. Furthermore, the surfaces of these materials can be coated to adjust the surface tension.

Examples of plastics that can be used as the substrate include polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, polycarbonate, polymethyl acrylate, polymethyl methacrylate, polyvinyl chloride, polyethylene, ethylene-vinyl acetate copolymer, polymethylpentene-1, polypropylene, cyclic polyolefins, fluorinated cyclic polyolefins, polystyrene, polyimide, polyvinylphenol, polyvinyl alcohol, poly(diisopropyl fumarate), poly(diethyl fumarate), poly(diisopropyl maleate), polyethersulfone, polyphenylene sulfide, polyphenylene ether, polyester elastomers, polyurethane elastomers, polyolefin elastomers, polyamide elastomers, and styrene block copolymers. Furthermore, two or more of the above plastics can be laminated together and used as the substrate.

When the protective film-forming composition of the present invention is applied to an organic semiconductor, it does not dissolve or swell the organic semiconductor film, so a coating film can be formed by wet deposition on top of the organic semiconductor film. Furthermore, this fluororesin film can be patterned using photolithography, printing, or imprinting, and then when wet etching the organic semiconductor film, the organic semiconductor film can be patterned without being immersed in an etchant such as a hydrocarbon solvent or aromatic solvent.

The protective film-forming composition of the present invention can be applied to organic semiconductor or organic light-emitting materials that are sensitive to water and organic solvents, and can therefore be used as a protective layer to protect these materials from water and organic solvents.

There are no limitations on the organic semiconductors that can be used in the present invention; both N-type and P-type organic semiconductors can be used, and bipolar transistors that combine N-type and P-type can also be used. In addition, both low-molecular-weight and high-molecular-weight organic semiconductors can be used, and they can also be mixed and used. Specific examples of compounds include those represented by formulas (F-1) to (F-11).

In the present invention, examples of methods for forming an organic semiconductor layer include vacuum deposition of an organic semiconductor, or dissolving an organic semiconductor in an organic solvent and coating or printing it, but there are no limitations on the method as long as it can form a thin film of an organic semiconductor layer. When coating or printing using a solution in which the organic semiconductor layer is dissolved in an organic solvent, the solution concentration varies depending on the structure of the organic semiconductor and the solvent used, but from the perspective of forming a more uniform semiconductor layer and reducing the layer thickness, it is preferably 0.5% to 5% by weight. The organic solvent used in this case is not limited as long as it dissolves the organic semiconductor at a certain concentration that allows film formation, and examples thereof include hexane, heptane, octane, decane, dodecane, tetradecane, hexadecane, decalin, indane, 1-methylnaphthalene, 2-ethylnaphthalene, 1,4-dimethylnaphthalene, a mixture of dimethylnaphthalene isomers, toluene, xylene, ethylbenzene, 1,2,4-trimethylbenzene, mesitylene, isopropylbenzene, pentylbenzene, hexylbenzene, tetralin, octylbenzene, cyclohexylbenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, trichlorobenzene, 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, γ-butylbenzene, 1,2-butylbenzene, 1,4 ... Tyrolactone, 1,3-butylene glycol, ethylene glycol, benzyl alcohol, glycerin, cyclohexanol acetate, 3-methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, anisole, cyclohexanone, mesitylene, 3-methoxybutyl acetate, cyclohexanol acetate, dipropylene glycol diacetate, dipropylene glycol methyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 1,6-hexanediol diacetate, 1,3-butylene Glycol diacetate, 1,4-butanediol diacetate, ethyl acetate, phenyl acetate, dipropylene glycol dimethyl ether, dipropylene glycol methyl-N-propyl ether, tetradecahydrophenanthrene, 1,2,3,4,5,6,7,8-octahydrophenanthrene, decahydro-2-naphthol, 1,2,3,4-tetrahydro-1-naphthol, α-terpineol, isophorone triacetin decahydro-2-naphthol, dipropylene glycol dimethyl ether, 2,6-dimethylanisole, 1,2-dimethylanisole, 2,3-dimethylanisole, 3,4-dimethylanisole, 1-benzothiophene, 3-methylbenzothiophene, 1,2-dic Examples of suitable solvents include chloroethane, 1,1,2,2-tetrachloroethane, chloroform, dichloromethane, tetrahydrofuran, 1,2-dimethoxyethane, dioxane, cyclohexanone, acetone, methyl ethyl ketone, diethyl ketone, diisopropyl ketone, acetophenone, N,N-dimethylformamide, N-methyl-2-pyrrolidone, and limonene. However, to obtain a crystal film with desirable properties, a solvent with a high dissolving power for organic semiconductors and a boiling point of 100°C or higher is suitable, and xylene, isopropylbenzene, anisole, cyclohexanone, mesitylene, 1,2-dichlorobenzene, 3,4-dimethylanisole, pentylbenzene, tetralin, cyclohexylbenzene, and decahydro-2-naphthol are preferred. Mixed solvents containing two or more of the above solvents in appropriate ratios can also be used.

If necessary, various organic and inorganic polymers or oligomers, or organic and inorganic nanoparticles can be added to the organic semiconductor layer as a solid or as a dispersion of nanoparticles in water or an organic solvent, and a protective film can be formed by applying the polymer solution to the insulating layer. Furthermore, various moisture-proof coatings, light-resistant coatings, etc. can be applied to this protective film as needed.

Examples of gate electrodes, source electrodes, or drain electrodes that can be used in the present invention include conductive materials such as inorganic electrodes made of aluminum, gold, silver, copper, highly doped silicon, polysilicon, silicide, tin oxide, indium oxide, indium tin oxide, chromium, platinum, titanium, tantalum, graphene, and carbon nanotubes, as well as organic electrodes made of doped conductive polymers (e.g., PEDOT-PSS). Multiple layers of these conductive materials can also be stacked. Furthermore, to increase carrier injection efficiency, these electrodes can be surface-treated using a surface treatment agent. Examples of such surface treatment agents include benzenethiol and pentafluorobenzenethiol.

In addition, there are no particular limitations on the method for forming an electrode on the substrate, insulating layer, or organic semiconductor layer, and examples include vapor deposition, high-frequency sputtering, and electron beam sputtering. It is also possible to use ink in which nanoparticles of the conductive material are dissolved in water or an organic solvent, and methods such as solution spin coating, drop casting, dip coating, doctor blade coating, die coating, pad printing, roll coating, gravure printing, flexographic printing, superflexographic printing, screen printing, inkjet printing, and letterpress reverse printing can also be used.

From the viewpoint of practicality of the organic transistor element, the organic transistor of the present invention preferably has a mobility of 0.20 cm ² /Vs or more.

In view of the practicality of the organic transistor element, the organic transistor of the present invention preferably has an on-current/off-current ratio of 10 ⁵ or more.

From the viewpoint of practicality of the organic transistor element, it is preferable that the organic transistor of the present invention has no hysteresis in the source-drain current.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, the resin composition, spin coating, film thickness measurement, UV irradiation, evaluation method of photocrosslinking (curing) property, and pattern formation were carried out under the conditions and with the apparatus shown below.

<Fluorine-based resin composition>
The values were determined by proton nuclear magnetic resonance spectroscopy ( ¹ H-NMR) spectrum analysis using a nuclear magnetic resonance analyzer (manufactured by JEOL Ltd., trade name JNM-ECZ400S).
<Solubility in fluorinated solvents>
The fluororesin and the resin for the comparative example were added to each fluorosolvent so as to be 10 wt %, and mixed while heating to 100°C. The temperature was then lowered to room temperature, and the presence of insoluble or precipitated matter was visually confirmed. This is hereinafter referred to as "solubility evaluation."
<Spin coating>
MS-A100 manufactured by Mikasa Co., Ltd. was used.
<Flatness>
The fluorine-based resin described below was adjusted to 10 wt % in each fluorine solvent, and spin-coated onto a cleaned and dried 30 x 30 ^mm2 glass substrate (Eagle XG manufactured by Corning Incorporated) at 500 rpm for 5 seconds, then 1000 rpm for 20 seconds. After drying at 90°C for 1 minute, the surface of the spin-coated film was confirmed using a laser microscope, OPTELICS (registered trademark) HYBRID manufactured by Lasertec Corporation. Hereinafter, this will be referred to as "flatness evaluation."
<Film thickness measurement>
Measurements were made using a DektakXT stylus profiler manufactured by Bruker.
<UV irradiation>
A UV mask aligner UPE-1605MA manufactured by Ushio Lighting Inc. was used, and the UV irradiation time was adjusted by changing the conveying speed under the condition of a UV intensity of 13.0 mW/cm ² .
<Method for evaluating photocrosslinking (curing) properties>
A solution of a fluororesin or a protective film-forming composition was spin-coated onto a cleaned and dried 30 x 30 ^mm² glass substrate (Corning EagleXG) using a spin coater to form a film with a dry thickness of 2000 nm or more, and the resulting film was thoroughly dried. The fluororesin was irradiated with 500 mJ/ ^cm² of ultraviolet light to photocrosslink a protective film-forming composition film. The thickness of this film was measured using a Bruker DektakXT stylus profiler and designated _T0 . Next, the glass plate coated with this photocrosslinked protective film-forming composition film was immersed in AE-3000 (AGC), a good solvent for the protective film-forming composition, for 1 minute, then removed and dried at 100°C using a hot plate. The film thickness was then measured and designated _T1 . Using these film thickness measurements, the remaining film ratio (R) was calculated using the following formula:
R=T ₁ /T ₀ ×100 (%)
The photocrosslinking (curing) property was evaluated using a residual film rate of 95% or more as the criterion for crosslinking. (Hereinafter referred to as "photocrosslinking property evaluation"). The lower the ultraviolet irradiation required to reach a residual film rate of 95% or more, the higher (faster) the photocrosslinking property.

In the examples, the synthesis of fluororesin, evaluation of solubility in fluorosolvents, and evaluation of solvent resistance and pattern formation were carried out under the following conditions, and the results were obtained.

Example 1
A 75 mL glass ampoule was charged with 25.3 g of the compound represented by general formula (10), 4.7 g of glycidyl methacrylate, 1.3 g of Perhexyl ND (NOF Corp.) as a polymerization initiator, and 70 g of 1,1,2,2,3,3,4-heptafluorocyclopentane (ZEON Corp.). The ampoule was repeatedly purged with nitrogen and depressurized, and then sealed under reduced pressure. The ampoule was placed in a thermostatic chamber at 45°C and maintained for 24 hours to allow radical polymerization. After completion of the polymerization reaction, the polymer solution was removed from the ampoule, and the polymer solution was precipitated by dropwise addition to 300 mL of methanol. The precipitate was then washed twice with 200 mL of methanol. The resulting mixture was then vacuum dried at 30°C for 8 hours, yielding 27 g of fluororesin precursor 1 (yield: 90%). Furthermore, ¹ H-NMR measurement confirmed that the copolymer composition was such that the residue unit represented by the general formula (11)/glycidyl methacrylate residue unit=48/52 (mol %).

After heating and drying a 200 mL Schlenk flask, 8 g of fluororesin precursor 1, 4.73 g of cinnamic acid chloride, 1.25 g of tetraethylammonium chloride as a catalyst, and 72 g of 1,1,2,2,3,3,4-heptafluorocyclopentane were added under a nitrogen atmosphere and sealed with a stopcock. The mixture was stirred at room temperature until fluororesin precursor 1 was dissolved, and then stirred in an oil bath at 80°C for 8 hours. The resulting resin solution was added dropwise to 500 mL of hexane to precipitate, followed by washing twice with 300 mL of methanol. This was followed by vacuum drying at 40°C for 6 hours to obtain 9.75 g of fluororesin 1. Furthermore, ^1H -NMR analysis confirmed that the glycidyl methacrylate residue units of the raw material had decreased and were converted to the residue units represented by formula (12). As a result, ^1H -NMR measurement confirmed that the copolymerization composition of Fluorine-based Resin 1 was formula (13), in which the residue unit (fluorine-based unit) represented by general formula (11)/residue unit (photocurable group unit) represented by formula (12)=52/48 (mol %).

The synthesized fluorine-based resin 1 was subjected to a solubility evaluation using the following fluorine-based solvents.
Solvent 1: Methoxyperfluoroheptene Solvent 2: 1,1,1,2,3,4,4,5,5,5-decafluoro-3-methoxy-2-(trifluoromethyl)pentane Solvent 3: 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane

Fluorine-based resin 1 was soluble in fluorine-based solvents 1 to 3, demonstrating excellent solubility. The results are shown in Table 1.

<Flatness evaluation>
The synthesized fluorine-based resin 1 was subjected to a flatness evaluation using the following fluorine-based solvents.
Solvent 1: Methoxyperfluoroheptene Solvent 4: 1H,1H,5H-octafluoropentanol Solvent 5: Methoxyperfluoroheptene and 1H,1H,5H-octafluoropentanol mixed in a volume ratio of 7:3 Solvent 6: Methoxyperfluoroheptene and 1H,1H,5H-octafluoropentanol mixed in a volume ratio of 5:5

When using Fluorine-based Resin 1 and Fluorine-based Solvent 1, the surface of the fluororesin film was wavy and not flat. When solutions of Fluorine-based Solvents 4 to 6 were used, the surface of the resulting fluororesin film was confirmed to be flat and free of wavy edges.

<Photocuring evaluation>
The synthesized fluororesin 1 was mixed with 4,4'-bis(diethylamino)benzophenone as a sensitizer and dissolved in 1H,1H,5H-octafluoropentanol solvent to prepare a solution. The photocuring properties of the prepared solution (fluororesin 1: 15 wt%, sensitizer: 0.2 wt%) were evaluated, and the residual film rate was 95% or more, confirming photocuring.

<Pattern formation>
For pattern formation, 4,4'-bis(diethylamino)benzophenone was added as a sensitizer to fluororesin 1, and the mixture was dissolved in methoxyperfluoroheptene solvent to prepare a solution (fluororesin 2: 3 wt%, sensitizer: 0.1 wt%).

A 10cm x 10cm glass substrate was used, on which a chrome-patterned mask (patterning mask) was used, in which 10 squares, each 50 microns on a side, were arranged vertically and horizontally. The solution was spin-coated onto the substrate, the mask was placed on the film, and the film was irradiated with ultraviolet light. The uncrosslinked portions were then washed away with Asahiklin AE-3000 (manufactured by AGC), forming a pattern on the film with 100 holes, each 50 x 50 ^μm2 in size.

<Damage evaluation of organic semiconductors>
Aluminum was vacuum-deposited onto a cleaned and dried 100 x 100 ^mm² glass substrate (Corning Eagle XG) to form a 50 nm thick gate electrode, followed by chemical vapor deposition of Parylene C as an insulating film. Silver was then sputter-deposited to form a 50 nm thick source and drain electrode with a channel length of 10 μm and an electrode width of 500 μm. The substrate was then immersed in a 2-propanol solution containing 30 mmol/L of pentafluorobenzenethiol for 5 minutes, removed, rinsed with 2-propanol, and blow-dried.

A 0.8 wt% tetralin solution of an organic semiconductor (di-n-hexyldithienobenzodithiophene) was inkjet printed onto the channel portion, the solvent was evaporated, and the device was dried at 90°C for 20 minutes. The device characteristics were then evaluated, revealing a mobility of 0.30 cm ² /V·s. Next, 4,4'-bis(diethylamino)benzophenone was added as a sensitizer to fluororesin 1, which was dissolved in methoxyperfluoroheptene solvent. The solution (fluororesin 1: 3 wt%, sensitizer: 0.1 wt%) was spin-coated onto the organic transistor at 500 rpm for 5 seconds and 1000 rpm for 20 seconds, and then dried at 50°C. The device characteristics were then evaluated, revealing a mobility of 0.30 cm ² /V·s, confirming no degradation in mobility.

Comparative Example 1
A 75 mL glass ampoule was charged with 5.71 g of the compound represented by general formula (10), 4.28 g of glycidyl methacrylate, 0.29 g of Perhexyl ND (NOF Corp.) as a polymerization initiator, and 23.3 g of dehydrated butyl acetate. The ampoule was repeatedly purged with nitrogen and depressurized, and then sealed under reduced pressure. The ampoule was placed in a thermostatic chamber at 45°C and maintained for 24 hours to allow radical polymerization. After completion of the polymerization reaction, the polymer solution was removed from the ampoule, and the polymer solution was precipitated by dripping into 300 mL of methanol. The precipitate was then washed twice with 200 mL of methanol. The resulting mixture was vacuum-dried at 30°C for 8 hours to obtain 9.4 g of fluororesin precursor 3 (yield: 94%). Furthermore, ¹ H-NMR analysis confirmed that the copolymer composition was a ratio of residue units represented by general formula (11)/glycidyl methacrylate residue units = 20/80 (mol %).

After heating and drying a 200 mL Schlenk flask, 8 g of fluororesin precursor 3, 6.02 g of cinnamic acid chloride, 1.60 g of tetraethylammonium chloride as a catalyst, and 72 g of butyl acetate were added under a nitrogen atmosphere and sealed with a stopcock. The mixture was stirred at room temperature until fluororesin precursor 1 was dissolved, and then stirred in an oil bath at 100 °C for 8 hours. The resulting resin solution was dropped into 500 mL of hexane to precipitate, and then washed twice with 300 mL of methanol. This was followed by vacuum drying at 40 °C for 6 hours to obtain 9.5 g of fluororesin 3. Furthermore, ¹ H-NMR analysis confirmed that the glycidyl methacrylate residue units of the raw material had decreased and were converted to the residue units represented by formula (12). As a result, ^1H -NMR measurement confirmed that the copolymer composition of Fluorine-based Resin 2 was formula (15), where the residue unit (fluorine-based unit) represented by general formula (11)/residue unit represented by formula (12)=21/79 (mol %).

The solubility of the synthesized Fluorine-Based Resin 2 was evaluated in the same manner as in Example 1. Fluorine-Based Resin 1 was insoluble in all fluorine-based solvents. The results are shown in Table 1.

Claims (4)

A residue unit represented by formula (1):
A composition for forming a protective film, comprising a fluorine-based resin containing at least one kind of a group consisting of residue units represented by formula (2) or residue units represented by formula (3) in an amount of 30 mol % or more of all residue units of the fluorine-based resin, and residue units of an ethylenically unsaturated monomer having a photocrosslinkable group in a side chain represented by the following formula (4), and a fluorine-based solvent:
(In formulas (1) to (3), R ₁ represents one of the group consisting of a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. Rf ₁ represents one of the group consisting of a linear perfluoroalkyl group having 1 to ₆ carbon atoms and having a terminal CF ₃ , a branched perfluoroalkyl group having 3 to 6 carbon atoms and having a terminal CF ₃ , or a cyclic perfluoroalkyl group having 3 to 6 carbon atoms and having a terminal CF 3. Rf ₂ represents one of the group consisting of a linear perfluoroalkylene group having 1 to 6 carbon atoms, a branched perfluoroalkylene group having 3 to 6 carbon atoms, or a cyclic perfluoroalkylene group having 3 to 6 carbon atoms. Rf ₃ represents a linear perfluoroalkyl group having 1 to 5 carbon atoms and having a terminal CF ₃ , a branched perfluoroalkyl group having 3 to 5 carbon atoms and having a terminal CF ₃ , or a cyclic perfluoroalkyl group having 3 to 5 carbon atoms and having a terminal CF _3. Rf ₄ represents a linear perfluoroalkylene group having 1 to 5 carbon atoms, a branched perfluoroalkylene group having 3 to 5 carbon atoms, or a cyclic perfluoroalkylene group having 3 to 5 carbon atoms. _{R 2} to R ₅ each independently represent a hydrogen atom or a fluorine atom. n represents an integer of 1 to 5. X represents one member of the group consisting of a single bond, CH ₂ , an oxygen atom, or a sulfur atom. L is represented by the following general formula (a):
(Here, _R2 represents either a hydrogen atom or a methyl group. _B4 may be the same or different and represent one of the group consisting of a hydrogen atom, a _C1 to _C6 alkyl group, a halogen atom, a cyano group, or an aryl group. D may be the same or different and represent one of the group consisting of a hydrogen atom, a halogen atom, a cyano group, a nitro group, a carboxyalkyl group, an alkyl ether group, an aryl ether group, a _C1 to _C18 alkyl group, a fluoroalkyl group, or a cycloalkyl group. M represents either a halogen atom or an aryl ether group.)
(Here, in formula (a), the sum of l and m is an integer of 2 to 6, and when l and/or m is 2 or more, a —CH═CH— structure may be included instead of —CHCH—. Q is a single bond, —OCONH—, —CONH—, —O—, —NH—, —CO—O—, —O—CO—, —NHCONH—, or —CH—.) The composition for forming a protective film according to claim 1, wherein the fluorine-containing solvent is at least one member selected from the group consisting of fluorine-containing hydrocarbons, fluorine-containing ethers, and fluorine-containing alcohols. The protective film-forming composition according to any one of claims 1 to 2, which contains a photosensitizer. A method for manufacturing an organic semiconductor device, in which a fluororesin film is formed on an organic semiconductor film using the protective film-forming composition described in any one of claims 1 to 3.