Photosensitive resin composition, liquid-repellent antifouling film, and inkjet recording head

Abstract

To provide a photosensitive resin composition having sufficient reactivity in curing and capable of achieving high liquid repellency and good resolution in patterning.SOLUTION: The composition contains an epoxy (A) represented by formula (1), an epoxy (B) which is different from the epoxy (A) and has an epoxy equivalence of 500g / eq. or less, and a cationic polymerization catalyst. (In the formula (1), R1, R2, R3, R4, and X1 are each independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an epoxy-containing group, X2 is an epoxy-containing group, m + n is an integer of 1 to 60, and the arrangement of the structure in parentheses with m and the structure in parentheses with n may be random or block.). ) SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a photosensitive resin composition, a liquid-repellent and stain-resistant film, and an inkjet recording head. [Background technology]

[0002] Fluorine-based water-repellent materials are generally known as materials for forming liquid-repellent and stain-resistant films. Compounds containing perfluoroalkyl or perfluoropolyether groups, in particular, have excellent liquid-repellent and durability properties and are widely used in a variety of applications. However, because fluorine-containing compounds are highly chemically stable and persistent, if they are continuously released into the environment, they may remain in the environment for long periods of time, potentially affecting human health and the habitat and growth of plants and animals through the environment and food chain. Therefore, in recent years, there has been a demand for a shift from fluorine-based water-repellent materials to non-fluorine-based water-repellent materials in order to realize a sustainable society, such as a recycling-oriented society.

[0003] Silicone compounds are fluorine-free water repellents that exhibit excellent liquid repellency and can be used as an alternative to fluorine-based water repellents. Silicone compounds can eliminate concerns about environmental impact and fluorine sources. For example, Patent Document 1 discloses a method using a silicone compound, particularly an epoxy resin composition, as a non-fluorine-based composition. The composition described in Patent Document 1 contains a photopolymerization initiator, and therefore can form a liquid-repellent and stain-resistant film in a short time and with high precision by photocuring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-20323 Summary of the Invention [Problem to be solved by the invention]

[0005] However, silicone compounds generally do not have a high reactivity with epoxy resins, resulting in insufficient crosslink density and insufficient liquid repellency. For example, when used to treat the surface of inkjet heads, the pigment components contained in the ink may adhere or the alkali components may cause structural degradation, making it difficult to maintain good print quality over long periods of use. One possible solution is to increase the crosslink density by increasing the exposure dose or the amount of photopolymerization initiator, but this affects the resolution during patterning and makes it difficult to achieve both improved liquid repellency and improved print quality.

[0006] The present disclosure provides a photosensitive resin composition that exhibits sufficient reactivity upon curing and that can achieve high liquid repellency and good resolution during patterning. The present disclosure also provides a liquid-repellent, stain-resistant film that can achieve high liquid repellency and good resolution during patterning. Furthermore, the present disclosure provides an inkjet recording head that can achieve high liquid repellency and good resolution during patterning. [Means for solving the problem]

[0007] The present disclosure provides: The present invention relates to a photosensitive resin composition comprising an epoxy resin (A) represented by formula (1), an epoxy resin (B) different from the epoxy resin (A) represented by formula (1) and having an epoxy equivalent of 500 g / eq. or less, and a cationic polymerization catalyst. [ka] (In formula (1), R1, R2, R3, R4, and X1 are each independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an epoxy-containing group; X2 is an epoxy-containing group; m+n is an integer of 1 to 60; and the arrangement of the parenthesized structure with m and the parenthesized structure with n may be random or block.)

[0008] The present disclosure also provides: The present disclosure relates to a liquid-repellent and stain-resistant film that is a cured product of the photosensitive resin composition of the present disclosure. Furthermore, the present disclosure provides An inkjet recording head, the ink jet recording head has a liquid-repellent and stain-resistant film on a surface where the ejection ports are provided, The present invention relates to an inkjet recording head, wherein the liquid-repellent and stain-resistant film is the liquid-repellent and stain-resistant film of the present disclosure. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a photosensitive resin composition that exhibits sufficient reactivity upon curing and that is capable of realizing high liquid repellency and good resolution during patterning. Furthermore, according to the present disclosure, it is possible to provide a liquid-repellent, antifouling film that is capable of realizing high liquid repellency and good resolution during patterning. Furthermore, according to the present disclosure, it is possible to provide an inkjet recording head that is capable of realizing high liquid repellency and good resolution during patterning. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B are schematic diagrams of an inkjet recording head using a liquid-repellent and stain-resistant film. [Figure 2] 2A to 2H are diagrams illustrating an example of a method for manufacturing an inkjet recording head using a liquid-repellent and stain-resistant film. [Figure 3] 3A to 3C are diagrams for explaining the procedure for forming a liquid-repellent and stain-resistant film. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined arbitrarily. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ. Note that when XX is a group, multiple XXs may be selected, and the same applies to YY and ZZ.

[0012] Components for obtaining the photosensitive resin composition according to the present disclosure will be described below. (Epoxy resin (A)) The photosensitive resin composition contains an epoxy resin (A) represented by formula (1). The epoxy resin (A) represented by formula (1) has an epoxy group in the molecule. The epoxy resin (A) represented by formula (1) functions as a water-repellent component. [ka] (In formula (1), R1, R2, R3, R4, and X1 are each independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an epoxy-containing group; X2 is an epoxy-containing group; and m+n is an integer of 1 to 60.)

[0013] The epoxy-containing group may be a group having a glycidyl ether group or a group having an alicyclic epoxy group, and is preferably a group having a glycidyl ether group or a group having an epoxycyclohexyl group. The epoxy-containing group is more preferably a glycidoxyalkyl group having an alkyl chain of 1 to 4 carbon atoms (preferably 2 to 4) or an epoxycyclohexylalkyl group having an alkyl chain of 1 to 8 carbon atoms (preferably 2 to 6).The epoxy-containing group is even more preferably a 3-glycidoxyalkyl group having an alkyl chain of 1 to 4 carbon atoms (preferably 2 to 4) or a 2-(3,4-epoxycyclohexyl)alkyl group having an alkyl chain of 1 to 8 carbon atoms (preferably 2 to 6).

[0014] More preferred examples of the epoxy-containing group include a 3-glycidoxypropyl group and a 2-(3,4-epoxycyclohexyl)ethyl group. In particular, an epoxycyclohexylalkyl group has excellent reactivity and can provide high liquid repellency.

[0015] It is also preferred that R1, R2, R3, and R4 are each independently an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms. In this case, the epoxy resin (A) has epoxy groups only at the terminals of its molecular structure. As a result, the orientation of the siloxane main chain is improved, resulting in high water repellency.

[0016] X1 is preferably an epoxy-containing group. When X1 is an epoxy-containing group, it forms an epoxy-containing group together with X2. In this case, the siloxane main chain is firmly fixed in the film while maintaining its orientation, resulting in excellent durability and the ability to maintain liquid repellency for a long period of time.

[0017] As the alkyl group having 1 to 12 carbon atoms in formula (1), an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, or a propyl group, is particularly preferred. From the viewpoint of compatibility with resins and film strength, a phenyl group or the like may be present as an aryl group having 6 to 12 carbon atoms.

[0018] In the formula (1), m+n is 1 to 60, preferably 10 to 60, from the viewpoint of compatibility with resins and solubility in solvents, and more preferably 30 to 60 from the viewpoint of liquid repellency. In formulas (1) and (2), m is preferably 0 or 1. The arrangement of the parenthesized structures with m and the parenthesized structures with n may be random or block. The arrangement of the parenthesized structures with m and the parenthesized structures with n is preferably random.

[0019] (Epoxy resin (B)) The photosensitive resin composition contains an epoxy resin (B) having an epoxy equivalent of 500 g / eq. or less. The epoxy resin (B) is an epoxy resin different from the epoxy resin (A) represented by formula (1). When the epoxy equivalent is greater than 500 g / eq., the difference between the reactivity of the epoxy resin (B) and the reactivity of the epoxy resin (A) becomes large. The resin (A) may aggregate, the reaction may proceed only in one resin, or the reaction may not proceed uniformly and sufficiently. As a result, the desired liquid repellency and resolution may not be achieved. Furthermore, an epoxy equivalent of 300 g / eq. or less is more preferable, especially from the viewpoint of resolution. The lower limit of the epoxy equivalent is not particularly limited, but may be, for example, 50 to 500 g / eq., 100 to 500 g / eq., or 100 to 300 g / eq. The epoxy equivalent is defined as (molecular weight of epoxy resin / number of epoxy groups in one molecule of epoxy resin).

[0020] The skeleton of the epoxy resin (B) can be selected from the viewpoint of the adhesion performance, mechanical strength, and swelling resistance of the cured product. The epoxy resin (B) is preferably at least one selected from the group consisting of epoxy resins having an alicyclic skeleton, epoxy resins having a bisphenol skeleton, epoxy resins having a phenol novolac skeleton, epoxy resins having a cresol novolac skeleton, epoxy resins having a norbornene skeleton, epoxy resins having a terpene skeleton, epoxy resins having a dicyclopentadiene skeleton, and epoxy resins having an oxycyclohexane skeleton.

[0021] More specifically, examples include cationically polymerizable epoxy resins such as epoxy resins having a bisphenol skeleton, such as bisphenol A-type and F-type epoxy resins, epoxy resins having a phenol novolac skeleton, such as phenol novolac-type epoxy resins, epoxy resins having a cresol novolac skeleton, such as cresol novolac-type epoxy resins, epoxy resins having a norbornene skeleton, epoxy resins having a terpene skeleton, epoxy resins having a dicyclopentadiene skeleton, and polyfunctional epoxy resins such as epoxy resins having an oxycyclohexane skeleton. One or a combination of two or more of these can be used.

[0022] The epoxy resin (B) is more preferably at least one selected from the group consisting of epoxy resins having an alicyclic skeleton, epoxy resins having a bisphenol skeleton, epoxy resins having a phenol novolac skeleton, epoxy resins having a cresol novolac skeleton, and epoxy resins having a dicyclopentadiene skeleton.

[0023] Examples of commercially available epoxy resins (B) include "jER157S70" and "jER1031S" (trade names) manufactured by Mitsubishi Chemical Corporation, "Epiclon N-695" and "Epiclon N-865" (trade names) manufactured by Dainippon Ink and Chemicals, Inc., "Celloxide 2021", "GT-300 series", "GT-400 series", and "EHPE3150" (trade names) manufactured by Daicel Corporation, "SU8" (trade name) manufactured by Nippon Kayaku Co., Ltd., "VG3101" (trade name) and "EPOX-MKR1710" (trade name) manufactured by Printec Co., Ltd., and "Denacol series" manufactured by Nagase ChemteX Corporation.

[0024] The mass ratio (A:B) of the epoxy resin (A) to the epoxy resin (B) is preferably 0.3:100 to 30:100. If the amount of epoxy resin (A) is less than 0.3, the liquid repellency may be insufficient depending on the application. On the other hand, if it is more than 30, the compatibility may decrease depending on the type of epoxy resin (B), making long-term storage difficult. A:B is more preferably 0.3:100 to 15:100, and even more preferably 0.3:100 to 5:100.

[0025] The total content of the epoxy resin (A) and the epoxy resin (B) in the photosensitive resin composition is not particularly limited, but is preferably 90 to 99 mass%, more preferably 93 to 99 mass%, and even more preferably 95 to 99 mass%.

[0026] (cationic polymerization catalyst) The photosensitive resin composition contains a cationic polymerization catalyst. When the photosensitive resin composition is applied to a substrate and cured, the cationic polymerization catalyst allows the photosensitive resin composition to be cured by light irradiation, thereby forming a water-repellent and stain-resistant film. In this case, the liquid repellency and mechanical strength are significantly improved compared to thermal curing, and microfabrication by patterning is also possible. The cationic polymerization catalyst contains a cation and an anion.

[0027] As the cationic polymerization catalyst, sulfonic acid compounds, diazomethane compounds, sulfonium salt compounds, iodonium salt compounds, disulfone compounds, etc. are preferred. Among them, it has high i-line (wavelength 365 nm) absorption and excellent cationic polymerization and crosslinking reaction performance. The cation of the cationic polymerization catalyst is preferably a sulfonium ion.

[0028] Specific examples of sulfonium-based cations include the following: Triphenylsulfonium, tri-p-tolylsulfonium, tri-o-tolylsulfonium, tris(4-methoxyphenyl)sulfonium, 1-naphthyldiphenylsulfonium, 2-naphthyldiphenylsulfonium, tris(4-fluorophenyl)sulfonium, tri-1-naphthylsulfonium, tri-2-naphthylsulfonium, tris(4-hydroxyphenyl)sulfonium, 4-(phenylthio)phenyldiphenylsulfonium, 4-(p-trilthio) (o)phenyldi-p-tolylsulfonium, 4-(4-methoxyphenylthio)phenylbis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(phenylthio)phenylbis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenyldi-p-tolylsulfonium, [4-(4-biphenylylthio)phenyl]-4-biphenylylphenylsulfonium, [4-(2-thioxanthonylthio)phenyl phenyl]diphenylsulfonium, bis[4-(diphenylsulfonio)phenyl]sulfide, bis[4-{bis[4-(2-hydroxyethoxy)phenyl]sulfonio}phenyl]sulfide, bis{4-[bis(4-fluorophenyl)sulfonio]phenyl}sulfide, bis{4-[bis(4-methylphenyl)sulfonio]phenyl}sulfide, bis{4-[bis(4-methoxyphenyl)sulfonio]phenyl}sulfide, 4-(4-benzoyl-2-chlorophenyl) thio)phenylbis(4-fluorophenyl)sulfonium, 4-(4-benzoyl-2-chlorophenylthio)phenyldiphenylsulfonium, 4-(4-benzoylphenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(4-benzoylphenylthio)phenyldiphenylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylsulfonium,10-Dihydroanthracen-2-yldiphenylsulfonium, 2-[(di-p-tolyl)sulfonio]thioxanthone, 2-[(diphenyl)sulfonio]thioxanthone, 4-(9-oxo-9H-thioxanthen-2-yl)thiophenyl-9-oxo-9H-thioxanthen-2-yl Phenylsulfonium, triarylsulfonium such as 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyldi-p-tolylsulfonium, 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyldiphenylsulfonium, 4-[4-(benzoylphenylthio)]phenyldi-p-tolylsulfonium, 4-[4-(benzoylphenylthio)]phenyldiphenylsulfonium, 5-(4-methoxyphenyl)thiaanthrenenium, 5-phenylthiaanthrenenium, 5-tolylthiaanthrenenium, 5-(4-ethoxyphenyl)thiaanthrenenium, and 5-(2,4,6-trimethylphenyl)thiaanthrenenium; Diphenylphenacylsulfonium, diphenyl 4-nitrophenacylsulfonium, diphenylbenzylsulfonium, diphenylmethylsulfonium, and other diaryls sulfonium; monoarylsulfoniums such as phenylmethylbenzylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 4-methoxyphenylmethylbenzylsulfonium, 4-acetocarbonyloxyphenylmethylbenzylsulfonium, 4-hydroxyphenyl-methyl-1-naphthylmethylsulfonium, 4-hydroxyphenyl(2-naphthylmethyl)methylsulfonium, 2-naphthylmethylbenzylsulfonium, 2-naphthylmethyl(1-ethoxycarbonyl)ethylsulfonium, phenylmethylphenacylsulfonium, 4-hydroxyphenylmethylphenacylsulfonium, 4-methoxyphenylmethylphenacylsulfonium, 4-acetocarbonyloxyphenylmethylphenacylsulfonium, 2-naphthylmethylphenacylsulfonium, 2-naphthyloctadecylphenacylsulfonium, and 9-anthracenylmethylphenacylsulfonium; trialkylsulfonium compounds such as dimethylphenacylsulfonium, phenacyltetrahydrothiophenium, dimethylbenzylsulfonium, benzyltetrahydrothiophenium, and octadecylmethylphenacylsulfonium;

[0029] The molar absorption coefficient of the cationic polymerization catalyst at a wavelength of 365 nm is 400 M -1 ·cm -1 It is preferable that the molar extinction coefficient is 400M or more. -1 ·cm -1 By satisfying the above conditions, the crosslinking density does not decrease during the curing reaction, and the liquid repellency and photopatterning properties can be further improved.

[0030] The molar absorption coefficient of a compound such as a cationic polymerization catalyst is measured as follows. The target compound is dissolved in a solvent that has no absorption at 365 nm, such as acetonitrile, to prepare a solution. The resulting solution is placed in a quartz cell, and the absorbance at 365 nm is measured using a UV-Vis-IR spectrophotometer (manufactured by JASCO). The molar extinction coefficient can be calculated from the absorbance using the following formula: Molar extinction coefficient = absorbance ÷ molar concentration of compound ÷ light path of cell

[0031] As the anion portion of the cationic polymerization catalyst, for example, borate-based, phosphorus-based, antimony-based, gallate-based, or the like, which have high acid strength, can be selected. Among them, tetrakis(pentafluorophenyl) is excellent in cationic polymerization and crosslinking reaction performance. trifluorotris(pentafluoroethyl)phosphate ion, Hexafluoroantimonate ion and tetrakis(pentafluorophenyl)gallate ion are more preferred, as the use of these ions can further improve the liquid repellency and the photopatterning properties.

[0032] The anion of the cationic polymerization catalyst is preferably at least one selected from the group consisting of a tetrakis(pentafluorophenyl)borate ion, a trifluorotris(pentafluoroethyl)phosphate ion, a hexafluoroantimonate ion, and a tetrakis(pentafluorophenyl)gallate ion.

[0033] Suitable cationic polymerization catalysts include commercially available products such as ADEKA Corporation's "ADEKA ARCLES SP-170," "ADEKA ARCLES SP-172," and "ADEKA ARCLES SP-150" (all trade names), and Midori Chemical Co., Ltd.'s "BBI-103" and "BBI-102" (all trade names). Other examples include Sanwa Chemical Co., Ltd.'s "IBPF," "IBCF," "TS-01," and "TS-91" (all trade names), and San-Apro Co., Ltd.'s "CPI-410S," "CR-C1," "CPI-410B," "CPI-310B," and "CPI-310FG" (all trade names). Furthermore, the composition may contain basic substances such as amines, photosensitizers such as anthracene derivatives, and silane coupling agents for the purpose of improving photolithography performance and adhesion performance. The content of the cationic polymerization catalyst is not particularly limited and can be appropriately changed depending on the resin used. The content of the cationic polymerization catalyst is preferably in the range of 0.5 to 5 parts by mass per 100 parts by mass of the total of the epoxy resin (A) and the epoxy resin (B) contained in the photosensitive resin composition.

[0034] (curing accelerator) The photosensitive resin composition may contain a phenolic compound or a polyol having at least two hydroxyl groups as a curing accelerator, which is effective in accelerating the cationic polymerization reaction of the epoxy resin.

[0035] Specific examples of phenolic compounds include cardanol, terpene diphenols, and their derivatives. Examples of cardanol compounds include cardanol and cardanol derivatives. Examples of cardanol derivatives include derivatives in which the -OH of cardanol is epoxy-modified. Commercially available products include Cardolite NX-2026, Cardolite NC-510, Cardolite LITE2020, and Cardolite Ultra LITE 513 manufactured by Cardolite.

[0036] If the polyol has one hydroxyl group, the effect of promoting the cationic polymerization reaction of the epoxy resin is small, so two or more hydroxyl groups are preferred. Furthermore, from the viewpoints of solubility in resins and solvents and reactivity, the polyol preferably has a number-average molecular weight of 3,000 or less. Furthermore, in order to avoid disappearance during the heating process, it is preferred that the polyol have a number-average molecular weight of 200 or more or a boiling point of 200°C or higher. The number-average molecular weight can be calculated in terms of polystyrene by a known method using gel permeation chromatography (e.g., manufactured by Shimadzu Corporation).

[0037] Specific examples of polyols include polyethylene glycols (200, 300, 400, 600, 1000, 2000) commercially available from various companies. In addition, examples of polyether polyols include the "ADEKA Polyether P Series," "BPX Series," "G Series," "SP Series," "SC Series," "CM Series," "AM Series," "EM Series," "BM Series," "PR Series," and "GR Series" (all trade names) manufactured by ADEKA.

[0038] The polyol may be a low-molecular-weight polyhydric alcohol. Examples of low-molecular-weight polyhydric alcohols include 1,2- or 1,6-hexanediol, glycerin, trimethylolpropane, 3-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,2,6-hexanetriol, 1,5-dihydroxypentan-3-one, 6-hydroxycaproic acid, and 2-hydroxymethyl-1,3-propanediol. At least one of these may be used.

[0039] The content of the curing accelerator is not particularly limited and can be appropriately changed depending on the resin used. The content of the curing accelerator is preferably in the range of 1 to 8 parts by mass per 100 parts by mass of the total of the epoxy resin (A) and the epoxy resin (B) contained in the photosensitive resin composition.

[0040] (Coating solvent) When the photosensitive resin composition is applied as a solution, it is preferable to use a polar organic solvent as the application solvent from the viewpoint of solubility. Specifically, polar solvents such as alcohols, ketones, esters such as ethyl acetate, butyl acetate, and PGMEA (propylene glycol monomethyl ether acetate), ethers such as diglyme, tetrahydrofuran, and PGME (propylene glycol monomethyl ether), and glycols such as diethylene glycol are used. Examples of alcohols include methanol, ethanol, propanol, isopropanol, and butanol, and examples of ketones include methyl ethyl ketone and methyl isobutyl ketone.

[0041] A method for producing a liquid-repellent and stain-resistant film according to the present disclosure will be described below. <Method of manufacturing liquid-repellent and stain-resistant film> The liquid-repellent and antifouling film is a cured product of a photosensitive resin composition. That is, the photosensitive resin composition can be used as a resin composition for forming the liquid-repellent and antifouling film. For example, a coating film of the photosensitive resin composition is formed on a substrate using a general-purpose coating device such as a spin coater, a die coater, a slit coater, a spray coater, etc. At this time, dip coating can also be applied by adjusting the concentration of the material.

[0042] The coating surface is cured by irradiation with light, and then heat-treated or washed as necessary to form a liquid-repellent, stain-resistant film. The exposure device can be a single-wavelength light source such as an i-line exposure stepper or a KrF stepper, or a projection exposure device with a broad-wavelength mercury lamp light source such as the Canon Mask Aligner MPA-600Super (trade name).

[0043] As an example of the application of the liquid-repellent and stain-resistant film, a method for manufacturing an inkjet recording head will be described below with reference to the drawings. However, the scope of application of the liquid-repellent and stain-resistant film according to the present disclosure is not limited to this.

[0044] <Method of manufacturing a recording head> Fig. 1A is a schematic diagram showing an example of an inkjet recording head, and Fig. 1B is a cross-sectional view of the recording head taken along a line AB in Fig. 1A and perpendicular to a substrate 1.

[0045] 1A and 1B has a substrate 1 on which energy generating elements 2 that generate energy used to eject liquid are arranged in two rows at a predetermined pitch. A liquid supply port 3 is opened in the substrate 1 between the two rows of the energy generating elements 2. On the substrate 1, ejection ports 5 are formed by an ejection port forming member 4 at positions facing each of the energy generating elements 2.

[0046] The shape of the discharge port 5 may be a so-called tapered shape in which the area of ​​the cross section parallel to the substrate 1 decreases from the substrate 1 side toward the discharge port 5. The discharge port forming member 4 is composed of a side wall 8 that forms individual flow paths 6 that communicate from the supply port 3 to each discharge port 5, and a top plate 9 on which the discharge ports 5 open. The discharge port forming member 4 may have the side wall 8 and the top plate 9 integrated together.

[0047] A liquid-repellent, anti-fouling film (liquid-repellent layer) 7 is provided on the ejection port forming member. For example, an inkjet recording head has the liquid-repellent, anti-fouling film 7 on the surface where the ejection ports are provided. The liquid-repellent, anti-fouling film 7 prevents ink ejected from the ejection ports 5 from adhering to the surface of the recording head. The shape, material, etc. of the substrate 1 are not particularly limited as long as it functions as part of the members that make up the flow path 6 and can also function as a support for the ejection port forming member 4. In this embodiment, a silicon substrate is used as the substrate 1 because it is easy to process.

[0048] This recording head is arranged so that the surface where the ejection ports 5 open faces the recording surface of the recording medium. Energy generated by the energy generating elements 2 is applied to ink filled in the flow paths 6 via the supply ports 3, causing ink droplets to be ejected from the ejection ports 5 and attached to the recording medium, thereby performing recording. The energy generating elements 2 can be elements that generate energy by heat, such as electrothermal conversion elements (so-called heaters), or elements that generate energy mechanically, such as piezoelectric elements.

[0049] The liquid-repellent, antifouling film 7 is a cured product of a photosensitive resin composition. Specifically, the liquid-repellent, antifouling film 7 can be formed as a cured product by applying a solution containing the photosensitive resin composition and curing the coating of the solution.

[0050] 2A to 2H, an example of a method for manufacturing an inkjet recording head will be described. In the inkjet recording head, known materials can be used except for the liquid-repellent and stain-proofing film 7.

[0051] 2A to 2H are schematic cross-sectional views showing an example of a method for manufacturing an inkjet recording head according to the steps, and the positions of the cross sections are the same as those in FIG. 1B.

[0052] First, as shown in Fig. 2A, a substrate 1 having energy generating elements 2 provided on its surface is prepared. Electrodes (not shown) for inputting control signals to operate the energy generating elements 2 are connected to the energy generating elements 2. Various functional layers may also be provided, such as a protective layer (not shown) for improving the durability of the energy generating elements 2 and an adhesion improving layer (not shown) for improving adhesion between the ejection port forming member 4 and the substrate 1.

[0053] 2B, an ink supply port 3 is formed penetrating the substrate 1. The supply port 3 can be formed by wet etching using an alkaline etching solution such as TMAH (tetramethylammonium hydroxide), or by dry etching such as reactive ion etching.

[0054] Next, as shown in FIG. 2C, a first photosensitive resin layer 10 containing a photosensitive resin and a photopolymerization initiator is formed on the substrate 1 including the energy generating elements 2. The first photosensitive resin layer 10 is a so-called negative photosensitive resin layer. The first photosensitive resin layer 10 is preferably formed by applying a photosensitive resin to a film substrate made of PET or polyimide and transferring it onto the substrate 1 using a lamination method. Epoxy resin is preferably used as the photosensitive resin contained in the first photosensitive resin layer 10 because it satisfies various performance requirements, such as high mechanical strength, adhesion to the substrate, ink resistance, and resolution for patterning the fine pattern of the ejection orifices 5.

[0055] The epoxy resin and photopolymerization initiator may be the same as those described above. The amount of the photopolymerization initiator added can be any amount that achieves the target sensitivity. The amount of the photopolymerization initiator added is preferably in the range of 0.5 to 5% by mass relative to the epoxy resin. If necessary, a wavelength sensitizer may be added, and an example of such a wavelength sensitizer is "SP-100" (trade name) manufactured by Adeka Corporation.

[0056] Furthermore, additives can be added to the photosensitive resin composition as needed, such as a flexibility-imparting agent to reduce the elastic modulus of the epoxy resin, or a silane coupling agent to improve adhesion to the substrate.

[0057] Next, as shown in FIG. 2D, pattern exposure is performed through a mask (not shown), followed by heat treatment to form side walls 8. The mask is a substrate made of a material such as glass or quartz that transmits light of the exposure wavelength, on which a light-shielding film such as a chromium film is formed in accordance with the pattern of the flow channel 6. As the exposure device, a single-wavelength light source such as an i-line exposure stepper or KrF stepper, or a projection exposure device having a broad-wavelength light source of a mercury lamp such as Canon's "Mask Aligner MPA-600Super" (product name) can be used.

[0058] On the substrate 1 on which the side walls 8 have been formed in this way, a second photosensitive resin is applied as shown in FIG. 2E. The second photosensitive resin layer 11 is a negative photosensitive resin layer similar to the first photosensitive resin layer 10. As the photosensitive resin contained in the second photosensitive resin layer 11, a bisphenol type epoxy resin or a novolac type epoxy resin is preferably used. The second photosensitive resin layer 11 can be formed by the same method as the first photosensitive resin layer 10.

[0059] 2F, a coating film 12 of a solution of a photosensitive resin composition for forming the liquid-repellent and stain-resistant film 7 is formed on the second photosensitive resin layer 11. The coating film 12 can be formed by applying the photosensitive resin composition by a method such as spin coating, roll coating, or slit coating.

[0060] Next, as shown in FIG. 2G, pattern exposure is performed through a mask (not shown) and the coating is cured to form a top plate 9 and a liquid-repellent, stain-resistant coating 7. The mask is a substrate made of a material such as glass or quartz that transmits light of the exposure wavelength, on which a light-shielding film such as a chrome film is formed in accordance with the pattern of the discharge ports 5. As the exposure device, a single-wavelength light source such as an i-line exposure stepper or KrF stepper, or a projection exposure device having a broad-wavelength mercury lamp as a light source such as Canon's "Mask Aligner MPA-600Super" (product name) can be used.

[0061] Next, as shown in FIG. 2H, the unexposed portions of the second photosensitive resin layer 11 and the coating film 12 are removed by a development process to form the discharge ports 5. By simultaneously exposing and developing the second photosensitive resin layer 11 and the coating film 12, the cationic polymerizable groups in the second photosensitive resin layer 11 and the coating film 12 react with each other, resulting in a highly durable, highly antistatic, liquid-repellent, and stain-resistant film 7. At this time, the unexposed portions of the first photosensitive resin layer 10 are also dissolved and removed at the same time, forming the flow paths 6.

[0062] Furthermore, if necessary, a heat treatment is carried out, and then bonding of members (not shown) for ink supply and electrical bonding (not shown) for driving the energy generating elements 2 are carried out to complete the inkjet recording head.

[0063] <Recording method> The recording method according to the embodiment of the present disclosure uses the inkjet recording head to record an image on a recording medium by ejecting a liquid, particularly an ink containing a pigment, an alkaline component, and the like, from the inkjet recording head. Inkjet recording heads may become unstable when some of the ink adheres to the vicinity of the nozzles during ejection, which may affect print quality. However, when the inkjet recording head of the present disclosure is used, the liquid-repellent and stain-resistant film 7 has high liquid repellency, so that adhesion of ink to the vicinity of the nozzles and the surface can be suppressed even after long-term use. [Example]

[0064] Examples of the present disclosure will be shown below to further explain the present disclosure in detail, but the present disclosure is not limited to the following examples.

[0065] <Epoxy resin (A)> As the epoxy resin (A), compounds represented by the following formulas (a) to (c) were prepared. [ka]

[0066] <Epoxy resin (B)> As the epoxy resin (B), the compounds shown in Table 1 were prepared. [Table 1]

[0067] <Cationic polymerization catalyst> The compounds shown in Table 2 were prepared as cationic polymerization catalysts. [Table 2]

[0068] <Curing accelerator> The compounds shown in Table 3 were prepared as curing accelerators. [Table 3]

[0069] <Formation of liquid-repellent and stain-resistant film> Example 1 A solution for forming a liquid-repellent and stain-resistant film was prepared as follows: 1.0 part by mass of epoxy resin (A), 1.5 parts by mass of CPI-410S (manufactured by San-Apro Co., Ltd.) as a cationic polymerization catalyst, and 250 parts by mass of PGMEA as a coating solvent were added to 100 parts by mass of epoxy resin (B), and the mixture was stirred at room temperature for 1 hour to obtain a coating solution. 3A to 3C show the procedure for forming a liquid-repellent and stain-resistant film. The solution obtained above was applied to a silicon substrate 13 to form a coating film 12, which was then heat-treated at 70°C for 3 minutes. The coating film was then exposed to light through a quartz mask (not shown) and heat-treated at 90°C for 5 minutes. An i-line exposure stepper (Canon, FPA-3000i5+) was used as the exposure device, and the exposure dose was 5000 Jm -2 The non-exposed portions of the coating film were dissolved and removed using PGMEA, and the coating was further heat-treated at 200° C. for 1 hour to form a liquid-repellent and stain-resistant film 7 and openings 14.

[0070] (Examples 2 to 16 and 20 to 22) The liquid-repellent and stain-resistant film 7 was formed in the same manner as in Example 1, except that the epoxy resin (A), epoxy resin (B) and cationic polymerization catalyst shown in Table 6 were used in the amounts of epoxy resin shown in Table 6.

[0071] (Examples 17 to 19) The liquid-repellent and stain-resistant film 7 was formed in the same manner as in Example 1, except that the epoxy resin (A), epoxy resin (B), and curing accelerator shown in Table 6 were used. The amount of curing accelerator added was 5 parts by mass per 100 parts by mass of epoxy resin (B).

[0072] (Comparative Examples 1 to 3) The liquid-repellent and stain-resistant film 7 was formed in the same manner as in Example 1, except that the epoxy resin (A) and the epoxy resin (B) shown in Table 6 were used.

[0073] Comparative Example 4 The liquid-repellent and stain-resistant film 7 was formed in the same manner as in Example 1, except that the epoxy resin (A), epoxy resin (B), and curing accelerator shown in Table 6 were used. The amount of curing accelerator added was 5 parts by mass per 100 parts by mass of epoxy resin (B).

[0074] <Fabrication of Inkjet Recording Head> Example 23 An ink jet recording head was fabricated by the steps shown in FIGS. 2A to 2H. First, as shown in FIG. 2A, a substrate 1 having an energy generating element 2 provided on its surface was prepared, and an ink supply port 3 penetrating the substrate 1 was formed by etching using TMAH as shown in FIG. 2B.

[0075] Next, as shown in FIG. 2C, a cationic polymerizable resin composition shown in Table 4 was transferred onto the substrate 1 including the energy generating elements 2 by lamination to form a first photosensitive resin layer 10. Furthermore, as shown in FIG. 2D, pattern exposure was performed through a quartz mask (not shown), and sidewalls 8 were formed by heat treatment at 90°C for 5 minutes. An i-line exposure stepper (Canon, FPA-3000i5+) was used as the exposure device, and the exposure dose was 10,000 Jm -2 It was decided.

[0076] On the substrate 1 on which the sidewalls 8 were thus formed, a second photosensitive resin layer 11 was formed as shown in Fig. 2E. The second photosensitive resin layer 11 was formed by transferring the cationic polymerizable resin composition shown in Table 5 by a lamination method. Next, as shown in FIG. 2F, the coating solution obtained in Example 4 was applied onto the second photosensitive resin layer 11 and heat-treated at 70°C for 3 minutes to form a liquid-repellent and stain-resistant film 7. Furthermore, the second photosensitive resin layer 11 and the coating film 12 were simultaneously subjected to pattern exposure through a mask (not shown) having a pattern of the discharge ports 5, and then heat-treated at 90°C for 5 minutes. An i-line exposure stepper (Canon, FPA-3000i5+) was used as the exposure device, and the exposure dose was 5000 Jm -2 (Figure 2G). Finally, the photosensitive resin layer and the non-exposed portions of the coating were dissolved and removed using PGMEA, and the resulting product was heat-treated at 200° C. for 1 hour to form the discharge port 5 and the flow path 6 (FIG. 2H). [Table 4] [Table 5]

[0077] (Comparative Example 5) An ink jet recording head was produced in the same manner as in Example 23, except that the coating solution used to form the liquid-repellent and stain-proofing film 7 was the coating solution obtained in Comparative Example 1.

[0078] <Evaluation of liquid-repellent and stain-resistant films> The liquid-repellent and stain-resistant films prepared by the methods of Examples 1 to 22 and Comparative Examples 1 to 4 were evaluated as follows.

[0079] (water repellent) The liquid-repellent antifouling film was immersed in an aqueous solution adjusted to pH 12 or higher at 60°C for one week, then washed with water and dried. The water repellency was then evaluated by measuring the contact angle of the liquid-repellent antifouling film surface. The contact angle was measured using a microcontact angle meter (Microjet Corporation, "DropMeasure" (trade name)) to measure the dynamic receding contact angle θr of the liquid-repellent antifouling film with pure water. When the water repellency was good at θr of 80° or more, the film was rated as A; when the water repellency was between 70° and less than 80°, the film was rated as B; and when the water repellency was less than 70° and the film was insufficient as a liquid repellent and stain-resistant film, the film was rated as C.

[0080] (resolution) Resolution was evaluated by measuring the area of ​​the opening. The area of ​​the opening was measured using a scanning white light interference microscope (Hitachi High-Tech Science, "Vertscan" (trade name)), and the resolution was evaluated by checking the reproducibility of the mask dimensions. That is, (((opening area) - (mask dimension)) / (mask dimension)) x 100 was calculated, and a deviation of less than ±3% was rated as resolution A, a deviation of ±3% to less than 5% was rated as resolution B, and a deviation of 5% or more was rated as resolution C.

[0081] The evaluation results are shown in Table 6 below. [Table 6] In the table, the amount added indicates the amount (parts by mass) of epoxy resin (A) added relative to 100 parts by mass of epoxy resin (B).

[0082] <Evaluation of liquid-repellent and stain-resistant films> As shown in Table 6, excellent water repellency was achieved in Examples 1 to 22. In particular, in Examples 1 to 10 and 12 to 16, the epoxy equivalent of the epoxy resin (B) was 300 or less, and therefore the reactivity with the epoxy resin (A) was excellent, and high resolution was exhibited. Furthermore, when attention was paid to the amount of epoxy resin (A) added, Examples 13 to 15 exhibited higher water repellency than Examples 12 and 16. These results indicated that a mass ratio (A:B) of the epoxy resin (A) to the epoxy resin (B) of 0.3:100 to 30:100 is more preferable.

[0083] Furthermore, in Examples 17 to 19 in which a curing accelerator was added, even when the epoxy equivalent of the epoxy resin (B) was relatively high at 450, the reaction with the epoxy resin (A) was promoted, and good water repellency was obtained. Furthermore, when focusing on the cationic polymerization catalyst, Examples 20 and 21 exhibited higher water repellency and resolution than Example 22. From these results, it can be seen that the molar absorption coefficient is 400M -1 ·cm -1 It was shown that the cationic polymerization catalyst of On the other hand, both water repellency and resolution were insufficient in Comparative Examples 1 to 3, in which the epoxy equivalent of the epoxy resin (B) was 500 or more. Similar results were obtained in Comparative Example 4, in which a curing accelerator was added.

[0084] <Evaluation of inkjet recording head> Using a Canon printer MB5330, a continuous printing test was conducted in an environment of 30°C and 80% RH, and the presence or absence of dot distortion was visually confirmed. The continuous printing test consisted of printing 100 sheets of A4 solid print in succession. If distortion occurred in even one place within the A4 print, the print quality was deemed NG. The results of these evaluations are as follows: Example 23 showed no distortion even in continuous printing, and high print quality was achieved, whereas Comparative Example 5 showed distortion after continuous printing.

[0085] As described above, fluorine-based water repellent materials exhibit good water repellency, but there are concerns about their impact on the environment. On the other hand, the photosensitive resin composition according to this embodiment exhibits good water repellency even without containing a fluorine-based water repellent material. Therefore, the technology described herein can contribute to the realization of a sustainable society, such as a decarbonized / recycling-based society.

[0086] The present disclosure includes the following configurations. (Configuration 1) A photosensitive resin composition comprising an epoxy resin (A) represented by formula (1), an epoxy resin (B) different from the epoxy resin (A) represented by formula (1) and having an epoxy equivalent of 500 g / eq. or less, and a cationic polymerization catalyst. TIFF2026028214000011.tif27153 (In formula (1), R1, R2, R3, R4, and X1 are each independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an epoxy-containing group; X2 is an epoxy-containing group; m+n is an integer of 1 to 60; and the arrangement of the parenthesized structure with m and the parenthesized structure with n may be random or block.) (Configuration 2) 2. The photosensitive resin composition according to claim 1, wherein the epoxy equivalent of the epoxy resin (B) is 300 g / eq. or less. (Configuration 3) 3. The photosensitive resin composition according to claim 1, wherein the epoxy resin (B) is at least one selected from the group consisting of epoxy resins having an alicyclic skeleton, epoxy resins having a bisphenol skeleton, epoxy resins having a phenol novolac skeleton, epoxy resins having a cresol novolac skeleton, epoxy resins having a norbornene skeleton, epoxy resins having a terpene skeleton, epoxy resins having a dicyclopentadiene skeleton, and epoxy resins having an oxycyclohexane skeleton. (Configuration 4) 4. The photosensitive resin composition according to any one of Aspects 1 to 3, wherein R1, R2, R3, and R4 are each independently an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms. (Configuration 5) 5. The photosensitive resin composition according to claim 4, wherein X1 is an epoxy-containing group. (Configuration 6) 6. The photosensitive resin composition according to any one of configurations 1 to 5, wherein the mass ratio (A:B) of the epoxy resin (A) to the epoxy resin (B) is 0.3:100 to 30:100. (Configuration 7) 7. The photosensitive resin composition according to any one of configurations 1 to 6, wherein the photosensitive resin composition contains a phenolic compound or a polyol having at least two hydroxyl groups as a curing accelerator. (Configuration 8) 8. The photosensitive resin composition according to any one of configurations 1 to 7, wherein the cation of the cationic polymerization catalyst is a sulfonium ion. (Configuration 9) The molar absorption coefficient of the cationic polymerization catalyst at a wavelength of 365 nm is 400 M -1 ·cm -1 The photosensitive resin composition according to any one of Configurations 1 to 8, wherein: (Configuration 10) 10. The photosensitive resin composition according to any one of Aspects 1 to 9, wherein the anion of the cationic polymerization catalyst is at least one selected from the group consisting of a tetrakis(pentafluorophenyl)borate ion, a trifluorotris(pentafluoroethyl)phosphate ion, a hexafluoroantimonate ion, and a tetrakis(pentafluorophenyl)gallate ion. (Configuration 11) 11. A liquid-repellent and stain-resistant film which is a cured product of the photosensitive resin composition according to any one of Aspects 1 to 10. (Configuration 12) An inkjet recording head, the ink jet recording head has a liquid-repellent and stain-resistant film on a surface where the ejection ports are provided, 12. An ink jet recording head, wherein the liquid-repellent and stain-resistant film is the liquid-repellent and stain-resistant film according to claim 11. [Explanation of symbols]

[0087] REFERENCE SIGNS LIST 1 substrate, 2 energy generating element, 3 ink supply port, 4 ejection port forming member, 5 ejection port, 6 flow path, 7 liquid-repellent and stain-resistant film, 8 side wall, 9 top plate, 10 first photosensitive resin layer, 11 second photosensitive resin layer, 12 coating film, 13 silicon substrate, 14 opening

Claims

1. A photosensitive resin composition comprising an epoxy resin (A) represented by formula (1), an epoxy resin (B) different from the epoxy resin (A) represented by formula (1) and having an epoxy equivalent of 500 g / eq. or less, and a cationic polymerization catalyst. (In formula (1), R １ , R ２ , R ３ , R ４ , and X １ are each independently an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an epoxy-containing group; ２ is an epoxy-containing group, m+n is an integer of 1 to 60, and the arrangement of the parenthesized structure with m and the parenthesized structure with n may be random or block.

2. 2. The photosensitive resin composition according to claim 1, wherein the epoxy equivalent of the epoxy resin (B) is 300 g / eq. or less.

3. 2. The photosensitive resin composition according to claim 1, wherein the epoxy resin (B) is at least one selected from the group consisting of epoxy resins having an alicyclic skeleton, epoxy resins having a bisphenol skeleton, epoxy resins having a phenol novolac skeleton, epoxy resins having a cresol novolac skeleton, epoxy resins having a norbornene skeleton, epoxy resins having a terpene skeleton, epoxy resins having a dicyclopentadiene skeleton, and epoxy resins having an oxycyclohexane skeleton.

4. The R １ , R ２ , R ３ , and R ４ and each independently represent an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms.

5. The X １ The photosensitive resin composition according to claim 4, wherein is an epoxy-containing group.

6. 2. The photosensitive resin composition according to claim 1, wherein the mass ratio (A:B) of the epoxy resin (A) to the epoxy resin (B) is 0.3:100 to 30:

100.

7. 2. The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition contains a phenolic compound or a polyol having at least two hydroxyl groups as a curing accelerator.

8. 2. The photosensitive resin composition according to claim 1, wherein the cation of the cationic polymerization catalyst is a sulfonium ion.

9. The molar absorption coefficient of the cationic polymerization catalyst at a wavelength of 365 nm is 400 M －１ ・cm －１ The photosensitive resin composition according to claim 1 .

10. 2. The photosensitive resin composition according to claim 1, wherein the anion of the cationic polymerization catalyst is at least one selected from the group consisting of a tetrakis(pentafluorophenyl)borate ion, a trifluorotris(pentafluoroethyl)phosphate ion, a hexafluoroantimonate ion, and a tetrakis(pentafluorophenyl)gallate ion.

11. A liquid-repellent and stain-resistant film which is a cured product of the photosensitive resin composition according to any one of claims 1 to 10.

12. An inkjet recording head, the ink jet recording head has a liquid-repellent and stain-resistant film on a surface where the ejection ports are provided, An ink jet recording head, wherein the liquid-repellent and stain-resistant film is the liquid-repellent and stain-resistant film according to claim 11.

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