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

Abstract

The invention relates to a photosensitive resin composition, a liquid-repellent antifouling film, and an inkjet recording head. The photosensitive resin composition includes: an epoxy resin (A) represented by formula (1); an epoxy resin (B) having an epoxy equivalent weight of 500 g / eq or less and different from the epoxy resin (A) represented by formula (1); and a cationic polymerization catalyst, 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 group-containing group; x2 is a group containing an epoxy group; m + n is an integer from 1 to 60; and the sequence of the bracket structure labeled with m and the sequence of the bracket structure labeled with n may be random or block.

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

[0002] As a material for forming a liquid-repellent and stain-resistant film, fluorine-based water-repellent materials, particularly compounds having a perfluoroalkyl group or a perfluoropolyether group, which exhibit excellent liquid repellency and excellent durability, are generally known and are widely used for various applications. However, since fluorine-containing compounds exhibit high chemical stability and are difficult to degrade, if they are continuously discharged into the environment, they can remain in the environment for a long period of time and can affect human health as well as the habitat and growth of animals and plants by moving in the environment and food chain. Therefore, in order to realize a sustainable society, such as a recycling society, a shift from fluorine-based water-repellent materials to non-fluorine-based water-repellent materials has been desired in recent years.

[0003] Silicone compounds are non-fluorine-containing water-repellent materials, but they still exhibit excellent liquid repellency and thus can be used as a substitute for fluorine-based water-repellent materials. Silicone compounds can particularly eliminate concerns about environmental impact and concerns about fluorine sources.

[0004] For example, Japanese Patent Publication No. 2003-20323 discloses a technique of using a silicone compound, particularly a resin composition containing an epoxy group, as a non-fluorine-based composition. The composition described in Japanese Patent Publication No. 2003-20323 contains a photopolymerization initiator and thus enables rapid and very precise formation of a liquid-repellent and stain-resistant film through photocuring.

[0005] However, silicone compounds generally do not exhibit extremely high reactivity with epoxy resins, and thus the crosslinking density can be insufficient and an acceptable liquid repellency can not be obtained. For example, when used for surface treatment of an inkjet head, pigment components contained in ink can stick or can cause structural degradation due to alkaline components, and a good print quality can not be maintained during long-term use. In response to this, a method of improving the crosslinking density by increasing a light exposure dose or increasing a photopolymerization initiator has been considered, but this affects the resolution during patterning, and thus it is difficult to achieve both and improved liquid repellency. SUMMARY

[0006] The present disclosure provides a photosensitive resin composition that exhibits satisfactory reactivity during curing and enables high liquid repellency and good resolution during patterning. The present disclosure also provides a liquid-repellent and stain-resistant film that enables high liquid repellency and good resolution during patterning. The present disclosure additionally provides an inkjet recording head that enables high liquid repellency and good resolution during patterning.

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

[0008] Further, the present disclosure relates to a liquid repellent stain-proof film which is a cured product of the photosensitive resin composition of the present disclosure. Furthermore, the present disclosure relates to an inkjet recording head having a liquid repellent stain-proof film on a surface provided with a discharge port, wherein the liquid repellent stain-proof film is a cured product of the photosensitive resin composition of the present disclosure.

[0009] The present disclosure provides a photosensitive resin composition which exhibits satisfactory reactivity during curing and which enables high liquid repellency and good resolution during patterning. The present disclosure also provides a liquid repellent stain-proof film which enables high liquid repellency and good resolution during patterning. The present disclosure can further provide an inkjet recording head which enables high liquid repellency and good resolution during patterning. The features of the present disclosure will become apparent from the following description of the embodiments with reference to the attached drawings. The following description of the embodiments is presented by way of example. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1A and 1B is a schematic view of an inkjet recording head employing a liquid repellent stain-proof film; Figures 2A to 2H is a diagram for describing an example of a manufacturing method of an inkjet recording head using a liquid repellent stain-proof film; and Figures 3A to 3C is a diagram for describing a process of forming a liquid repellent stain-proof film. DETAILED DESCRIPTION

[0011] In the present disclosure, the expression "from XX to YY" or "XX to YY" indicating a numerical range means a numerical range including the lower limit and the upper limit as the end points, unless otherwise specified. Furthermore, when a numerical range is described in a stepwise manner, the upper limit and the lower limit of each numerical range can be arbitrarily combined. In addition, in the present disclosure, for example, a description such as "at least one selected from XX, YY, and ZZ" means any of the following: XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, and a combination of XX, YY, and ZZ.

[0012] The following describes components for obtaining the photosensitive resin composition according to the present disclosure. 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. In Formula (1), R1, R2, R3, R4, and X1 are each independently an alkyl group having a carbon number of 1 to 12, an aryl group having a carbon number of 6 to 12, or an epoxy group-containing group; X2 is an epoxy group-containing group; and m + n is an integer of 1 to 60.

[0013] The epoxy group-containing group can be, for example, a glycidyl ether group-having group and an alicyclic epoxy group-having group. The epoxy group-containing group is preferably a glycidyl ether group-having group or an epoxy cyclohexyl group-having group. The epoxy group-containing group is more preferably a glycidoxyalkyl group in which the alkyl chain has 1 to 4 (preferably 2 to 4) carbons or an epoxy cyclohexylalkyl group in which the alkyl chain has 1 to 8 (preferably 2 to 6) carbons. The epoxy group-containing group is more preferably a 3-glycidoxyalkyl group in which the alkyl chain has 1 to 4 (preferably 2 to 4) carbons or a 2-(3,4-epoxycyclohexyl)alkyl group in which the alkyl chain has 1 to 8 (preferably 2 to 6) carbons.

[0014] More preferable examples of the epoxy group-containing group are a 3-glycidoxypropyl group and a 2-(3,4-epoxycyclohexyl)ethyl group. The epoxy cyclohexylalkyl group is particularly capable of producing excellent reactivity and high water repellency.

[0015] In addition, R1, R2, R3, and R4 are each independently preferably an alkyl group having a carbon number of 1 to 12 or an aryl group having a carbon number of 6 to 12. In this case, the epoxy resin (A) has an epoxy group only at the terminal position in the molecular structure. As a result, the orientation of the siloxane main chain is improved, and high water repellency is obtained.

[0016] X1is preferably an epoxy group-containing group. When X1is an epoxy group-containing group, it is then an epoxy group-containing group together with X2. In this case, excellent durability can be achieved and liquid repellency is maintained for a long period of time due to firm anchoring in the film while maintaining the orientation of the siloxane main chain.

[0017] The alkyl group of carbon number 1 to 12 in formula (1) is particularly preferably an alkyl group of carbon number 1 to 4, such as a methyl group, an ethyl group, a propyl group, and the like. From the viewpoint of compatibility with the resin and film strength, for example, a phenyl group can be present as the aryl group of carbon number 6 to 12.

[0018] From the viewpoint of compatibility with the resin and solubility in a solvent, m + n in formula (1) is an integer of 1 to 60, and is preferably an integer of 10 to 60. From the viewpoint of liquid repellency, it is more preferable to be an integer of 30 to 60. m in formula (1) is preferably 0 or 1. Furthermore, the sequence of the bracket structure labeled with m and the sequence of the bracket structure labeled with n can be random or blocky. Preferably, the sequence of the bracket structure labeled with m and the sequence of the bracket structure labeled with n are random.

[0019] Epoxy resin (B) The photosensitive resin composition has an epoxy resin (B) having an epoxy equivalent of 500 g / eq. or less. This 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., there is a large difference between the reactivity of the epoxy resin (B) and the reactivity of the epoxy resin (A). Then, the epoxy resin (A) can aggregate and / or the reaction can proceed only in one resin, and thus the reaction can not proceed uniformly and sufficiently. Therefore, it can not be possible to obtain the desired liquid repellency or resolution. Particularly from the viewpoint of resolution, an epoxy equivalent of 300 g / eq. or less is more advantageous. The lower limit of the epoxy equivalent is not particularly limited, and the epoxy equivalent can be, for example, 50 to 500 g / eq., or 100 to 500 g / eq., or 100 to 300 g / eq. The epoxy equivalent is defined as (molecular weight of the epoxy resin / number of epoxy groups in one molecule of the epoxy resin).

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

[0021] More specifically, examples are cationically polymerizable epoxy resins, such as multifunctional epoxy resins, such as epoxy resins having a bisphenol skeleton, such as bisphenol A epoxy resins and bisphenol F epoxy resins, epoxy resins having a phenol novolac skeleton, such as phenol novolac epoxy resins, epoxy resins having a cresol novolac skeleton, such as cresol novolac epoxy resins, 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. A single one of these can be used, or a combination of two or more can be used.

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

[0023] 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 DIC Corporation; "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 Corporation; and "Denacol series" manufactured by Nagase Chemtex Corporation.

[0024] The mass ratio (A:B) between the epoxy resin (A) and the epoxy resin (B) is preferably 0.3:100 to 30:100. When the amount of the epoxy resin (A) is less than 0.3, the liquid repellency can be insufficient in some cases depending on the application. On the other hand, when it is greater than 30, depending on the kind of the epoxy resin (B), the compatibility can be reduced so that long-term storage can be problematic. A:B is more preferably 0.3:100 to 15:100, and A:B is 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 coated onto a substrate and cured, due to the presence of the cationic polymerization catalyst, a water-repellent stain-proof film can be formed by producing a cured product by exposure to light. In this case, the liquid repellency and mechanical strength are significantly improved compared to thermal curing, and also can be microfabricated by patterning. The cationic polymerization catalyst contains a cation and an anion.

[0027] For the cationic polymerization catalyst, a sulfonic acid compound, a diazomethane compound, a sulfonium salt compound, an iodonium salt compound, a disulfone compound, or the like is preferred. Among these, sulfonium is more preferred, which has high i-line (wavelength of 365 nm) absorbance and exhibits excellent cationic polymerization properties and excellent crosslinking reactivity. The cation in the cationic polymerization catalyst is preferably a sulfonium ion.

[0028] The following are specific examples of sulfonium-type cationic ions: triarylsulfoniums such as triphenylsulfonium, tritolylsulfonium, tri-o-tolylsulfonium, tris(4-methoxyphenyl)sulfonium, 1-naphthyl diphenylsulfonium, 2-naphthyl diphenylsulfonium, tris(4-fluorophenyl)sulfonium, tri-1-naphthylsulfonium, tri-2-naphthylsulfonium, tris(4-hydroxyphenyl)sulfonium, 4-(phenylthio)phenyldiphenylsulfonium, 4-(p-tolylthio)phenylditolylsulfonium, 4-(4-methoxyphenylthio)phenyl bis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenyl bis(4-fluorophenyl)sulfonium, 4-(phenylthio)phenyl bis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenyl ditolylsulfonium, [4-(4-biphenylylthio)phenyl]-4-biphenylylsulfonium, [4-(2-thioxanthonylthio)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-chlorophenylthio)phenyl bis(4-fluorophenyl)sulfonium, 4-(4-benzoyl-2-chlorophenylthio)phenyldiphenylsulfonium, 4-(4-benzoylphenylthio)phenyl bis(4-fluorophenyl)sulfonium, 4-(4-benzoylphenylthio)phenyldiphenylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yl ditolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yl diphenylsulfonium, 2-[(ditolyl)sulfonio]thioxanthone, 2-[(diphenyl)sulfonio]thioxanthone, 4-(9-oxo-9H-thioxanthen-2-yl)phenylthio-9-oxo-9H-thioxanthen-2-ylphenylsulfonium, 4-[4-(4-tert-butylbenzoyl)phenylthio]phenylditolylsulfonium, 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyldiphenylsulfonium, 4-[4-(benzoylphenylthio)]phenylditolylsulfonium, 4-[4-(benzoylphenylthio)]phenyldiphenylsulfonium, 5-(4-methoxyphenyl)thianthrenium, 5-phenylthianthrenium, 5-tolylthianthrenium, 5-(4-ethoxyphenyl)thianthrenium, and 5-(2,4,6-trimethylphenyl)thianthrenium; diarylsulfoniums such as diphenyl phenacylsulfonium, diphenyl-4-nitrobenzoyl methylsulfonium, diphenyl benzylsulfonium, and diphenyl methylsulfonium; Monoarylsulfonates, such as phenylmethylbenzylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 4-methoxyphenylmethylbenzylsulfonium, 4-acetylcarbonyloxyphenylmethylbenzylsulfonium, 4-hydroxyphenylmethyl-1-naphthylmethylsulfonium, 4-hydroxyphenyl(2-naphthylmethyl)methylsulfonium, 2-naphthylmethylbenzylsulfonium, 2-naphthylmethyl(1-ethoxycarbonyl)ethylsulfonium, phenylmethylbenzoylmethylsulfonium, 4-hydroxyphenylmethylbenzoylmethylsulfonium, 4-methoxyphenylmethylbenzoylmethylsulfonium, 4-acetylcarbonyloxyphenylmethylbenzoylmethylsulfonium, 2-naphthylmethylbenzoylmethylsulfonium, 2-naphthyloctadecylbenzoylmethylsulfonium, and 9-anthraylmethylbenzoylmethylsulfonium; and Trialkylsulfonium, such as dimethylbenzoylmethylsulfonium, benzoylmethyltetrahydrothiophenonium, dimethylbenzylsulfonium, benzyltetrahydrothiophenonium and octadecylmethylbenzoylmethylsulfonium.

[0029] At a wavelength of 365 nm, the molar extinction coefficient of the cationic polymerization catalyst is preferably 400 M. -1 ·cm -1 The above. By setting the molar extinction coefficient to 400M. -1 ·cm -1 The above methods can improve photopatterning capabilities while achieving additional improvements in liquid repellency without reducing crosslinking density during the curing reaction.

[0030] The molar extinction coefficient of compounds, such as cationic polymerization catalysts, is measured as follows. A solution is prepared by dissolving the target compound in a solvent, such as acetonitrile, which does not absorb at 365 nm. The resulting solution is introduced into a quartz cell, and the absorbance at 365 nm is measured using a UV-Vis-IR spectrophotometer (JASCO Corporation). The molar extinction coefficient can be calculated from the obtained absorbance using the following formula. Molar extinction coefficient = absorbance ÷ molar concentration ÷ optical path length of the cell

[0031] For example, borate, phosphorus, antimony, or gallium phosphate types with high acid strength can be selected for the anionic portion of cationic polymerization catalysts. Among these, tetra(pentafluorophenyl)borate, trifluorotri(pentafluoroethyl)phosphate, hexafluoroantimonate, and tetra(pentafluorophenyl)gallate ions, which exhibit excellent cationic polymerization properties and crosslinking reactivity, are preferred. Using these ions improves photopatterning capabilities while achieving additional improvements in liquid repellency.

[0032] The anion in the cationic polymerization catalyst is preferably selected from at least one of tetra(pentafluorophenyl)borate ion, trifluorotri(pentafluoroethyl) phosphate ion, hexafluoroantimonate ion and tetra(pentafluorophenyl)gallate ion.

[0033] The following are examples of cationic polymerization catalysts that can be advantageously used: commercially available products such as "ADEKA ARKLS SP-170", "ADEKA ARKLS SP-172", and "ADEKA ARKLS SP-150" (all trade names) manufactured by ADEKA Corporation, "BBI-103" and "BBI-102" (both trade names) manufactured by Midori Kagaku Co., Ltd. Other examples are "IBPF", "IBCF", "TS-01", and "TS-91" (all trade names) manufactured by Sanwa Chemical Co., Ltd., and "CPI-410S", "CR-C1", "CPI-410B", "CPI-310B", and "CPI-310FG" (all trade names) manufactured by San-Apro Ltd. In addition, the composition of the present application can contain, for example, basic substances such as amines, photosensitizers such as anthracene derivatives, and silane coupling agents, in order to particularly improve the lithographic performance and adhesion performance. The content of the cationic polymerization catalyst can be appropriately varied depending on the resin used, and is not particularly limited. The content of the cationic polymerization catalyst is preferably in the range of 0.5 to 5 parts by mass, relative to 100 parts by mass of the total amount of the epoxy resin (A) and the epoxy resin (B) contained in the photosensitive resin composition.

[0034] Curing accelerator The photosensitive resin composition can contain a phenolic compound or a polyol having at least 2 hydroxyl groups as a curing accelerator. The addition of these results in acceleration of the cationic polymerization reaction of the epoxy resin.

[0035] Specific examples of the phenolic compound include cardanol, terpene diol, and derivatives thereof. Examples are cardanol compounds such as cardanol and cardanol derivatives. Examples of cardanol derivatives can be derivatives in which the -OH of cardanol has been modified with an epoxy group. Commercially available products include "Cardolite NX-2026", "Cardolite NC-510", "Cardolite LITE 2020", and "Cardolite Ultra LITE 513" manufactured by Cardolite Corporation.

[0036] When the polyol has one hydroxyl group, there is little effect on promoting the cationic polymerization reaction of the epoxy resin, and thus the polyol preferably has two or more hydroxyl groups. In addition, from the viewpoints of solubility in the resin and solvent and reactivity, the polyol preferably has a number average molecular weight of 3000 or less. In addition, in order not to disappear during the heating step, the polyol preferably has 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 as polystyrene by a known method, such as gel permeation chromatography (for example, Shimadzu Corporation).

[0037] Specific examples of the polyol can be polyethylene glycol (200, 300, 400, 600, 1000, 2000), which is commercially available from various companies. In addition, examples of the polyether polyol can be "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 are trade names) manufactured by ADEKA Corporation.

[0038] The polyol can be a low molecular weight polyol. Examples of the low molecular weight polyol can be 1,2- or 1,6-hexanediol, glycerol, trimethylolpropane, 3-methyl-1,5-pentanediol, 1,2,6-hexanetriol, 1,5-dihydroxypentan-3-one, 6-hydroxyhexanoic acid, and 2-hydroxymethyl-1,3-propanediol. One or more of these can be used.

[0039] The content of the curing accelerator can be appropriately changed depending on the resin used, and is not particularly limited. The content of the curing accelerator is preferably 1 to 8 parts by mass, relative to 100 parts by mass of the total amount 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 coating layer in the form of a solution, a polar organic solvent is preferably used as the coating solvent from the viewpoint of solubility. Specific examples here are polar solvents such as alcohols; ketones; esters such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate (PGMEA); ethers such as diethylene glycol dimethyl ether, tetrahydrofuran, and propylene glycol monomethyl ether (PGME); and glycols such as diethylene glycol. Examples of the alcohols can be methanol, ethanol, propanol, isopropanol, and butanol, and examples of the ketones can be methyl ethyl ketone and methyl isobutyl ketone.

[0041] The method for producing the liquid-repellent antifouling film of the present disclosure will be described below. Method for producing liquid-repellent antifouling film The liquid-repellent and antifouling film is a cured product of the 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 of a photosensitive resin composition can be made on a substrate using general-purpose coating equipment, such as a spin coater, die coater, slot coater, or spray coater. Dip coating can also be used by adjusting the material concentration.

[0042] A liquid-repellent and antifouling film can be formed by curing the coating surface with light and, if necessary, by heat treatment and cleaning. The following can be used as exposure devices: projection exposure devices with a single wavelength light source, such as i-line exposure steppers or KrF steppers, or exposure devices with a wide wavelength light source of mercury lamps, such as Canon's "Mask Aligner MPA-600Super" (trade name).

[0043] As an example of the application of the liquid-repellent and anti-fouling membrane, a method for manufacturing an inkjet recording head is described below with reference to the accompanying drawings. The application scope of the liquid-repellent and anti-fouling membrane disclosed herein is not limited to this.

[0044] Method for manufacturing recording heads Figure 1A This is a schematic diagram showing an example of an inkjet recording head. Figure 1B It is along Figure 1A The AB section shows a cross-sectional view of the recording head in a section perpendicular to substrate 1.

[0045] Figure 1A and 1B The depicted recording head has a substrate 1 in which energy generating elements 2 are arranged side-by-side in two rows at a predetermined interval, the energy generating elements generating energy for discharging liquid. A liquid supply port 3 is formed in the substrate 1 between the two rows of energy generating elements 2. A discharge port forming member 4 forms a discharge port 5 on the substrate 1, and this discharge port is positioned facing each energy generating element 2.

[0046] The outlet 5 can be so-called conical in shape, whereby the cross-sectional area parallel to the substrate 1 decreases from the substrate 1 side toward the outlet 5. The outlet forming component 4 consists of: a sidewall 8 forming an individual flow path 6 from the supply port 3 to each outlet 5; and a top plate 9 in which the outlet 5 opens. The sidewall 8 and the top plate 9 in the outlet forming component 4 can also be integrally formed.

[0047] A liquid repellent soil resistant film (liquid repellent layer) 7 is provided on the discharge port forming member. For example, an inkjet recording head can have the liquid repellent soil resistant film 7 on the surface in which the discharge port is provided. The liquid repellent soil resistant film 7 inhibits the ink discharged from the discharge port 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 the substrate 1 can function as a part of the member constituting the flow path 6 and can function as a support of the discharge port forming member 4. In the present embodiment, a silicon substrate is used for the substrate 1 based on the easiness of processing.

[0048] The recording head is disposed so that the recording surface of the recording medium faces the surface of the recording head in which the discharge port 5 is opened. Recording is performed as follows: the energy generated by the energy generating element 2 is transmitted to the ink filled in the flow path 6 via the supply port 3, causing the ink droplets to be discharged from the discharge port 5 and adhere to the recording medium. For example, the following can be used for the energy generating element 2: for example, a thermoelectric conversion element (so-called heater) as an element that generates energy by heating; or for example, a piezoelectric element as an element that generates energy mechanically.

[0049] The liquid repellent soil resistant film 7 is a cured product of a photosensitive resin composition. Specifically, the liquid repellent soil resistant film 7 can be formed by the following manner: a solution containing a photosensitive resin composition is applied by coating, and the coating film of the solution is cured to form the liquid repellent soil resistant film as a cured product.

[0050] Examples of the manufacturing method of the inkjet recording head will be described below with reference to Figures 2A to 2H Known components other than the liquid repellent soil resistant film 7 can be used in the inkjet recording head.

[0051] Figures 2A to 2H are schematic cross-sectional views, which show examples of the manufacturing method of the inkjet recording head according to the steps involved, and the positions of the cross sections are the same as in Figure 1B

[0052] First, as shown in Figure 2A , a substrate 1 provided with an energy generating element 2 in the surface thereof is prepared. An electrode (not shown) for inputting a control signal for operating the energy generating element 2 is connected to the element. Various functional layers, for example, a protective layer (not shown) for improving the durability of the energy generating element 2 and an adhesion improving layer (not shown) for improving the adhesion between the discharge port forming member 4 and the substrate 1, can also be provided.

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

[0054] As shown in Figure 2C ​As shown, a first photosensitive resin layer 10 comprising a photosensitive resin and a photopolymerization initiator is then formed on a substrate 1 containing the energy generating element 2. The first photosensitive resin layer 10 is a so-called negative photosensitive resin layer. Preferably, the first photosensitive resin layer 10 is formed by coating the photosensitive resin onto a film substrate made of PET or polyimide and transferring it onto the substrate 1 using a lamination method. Epoxy resin can be advantageously used for the photosensitive resin present in the first photosensitive resin layer 10 because it meets various performance requirements, such as high mechanical strength, adhesion to the substrate layer, ink resistance, and resolution for patterning the fine patterns of the discharge port 5.

[0055] Here, the same epoxy resin and photopolymerization initiator as described above can be used for the epoxy resin and photopolymerization initiator. The amount of photopolymerization initiator added can be any amount to achieve the target sensitivity. The amount of 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 can be added. An example of such a wavelength sensitizer is "SP-100" (trade name) manufactured by ADEKA Corporation.

[0056] When necessary and appropriate, additives may be added to the photosensitive resin composition described above. For example, to reduce the elastic modulus of the epoxy resin, a flexible agent may be added, or to obtain greater adhesion strength to the substrate layer, a silane coupling agent may be added.

[0057] like Figure 2D As shown, the sidewalls 8 are then formed by patterned exposure through a mask (not shown) followed by heat treatment. The mask comprises a light-shielding film, such as a chromium film, formed on a substrate made of a material (e.g., glass or quartz) that transmits light of the exposure wavelength, consistent with the pattern of the flow path 6. The following can be used as exposure devices: projection exposure devices with a single wavelength light source, such as i-line exposure steppers or KrF steppers, or exposure devices with a wide-wavelength mercury lamp light source, such as Canon's "Mask Aligner MPA-600Super" (trade name).

[0058] like Figure 2E As shown, a second photosensitive resin layer 11 is formed on the substrate 1, on which the sidewalls 8 have been formed. The second photosensitive resin layer 11 is a negative photosensitive resin layer similar to the first photosensitive resin layer 10. Bisphenol-type epoxy resin or phenolic epoxy resin is preferably used as the photosensitive resin contained in the second photosensitive resin layer 11. The second photosensitive resin layer 11 can be formed by a method similar to that used for the first photosensitive resin layer 10.

[0059] like Figure 2FThe second photosensitive resin layer 11 is then formed on the first photosensitive resin layer 10, and a coating film 12 of a photosensitive resin composition solution for forming the liquid-repellent antifouling film 7 described above is formed on the second photosensitive resin layer 11. The coating film 12 can be formed by applying the photosensitive resin composition using a method such as spin coating, roll coating, slit coating, or the like.

[0060] As shown in FIG. 1, a first photosensitive resin layer 10 is formed on the substrate 1. The first photosensitive resin layer 10 is formed by applying a photosensitive resin composition solution for forming the liquid-repellent antifouling film 7 described above. The photosensitive resin composition solution can be applied using a method such as spin coating, roll coating, slit coating, or the like. Figure 2G As shown in FIG. 2, the first photosensitive resin layer 10 is then exposed in a pattern by a mask (not shown), and then cured, forming the top plate 9 and the liquid-repellent antifouling film 7. The mask contains a light-shielding film, such as a chromium film, formed in accordance with the pattern of the discharge port 5 on a substrate composed of a material that transmits light of the exposure wavelength, such as glass or quartz. The following can be used as an exposure device: a projection exposure device having a single-wavelength light source, such as an i-line exposure stepper or a KrF stepper, or an exposure device having a mercury lamp wide-wavelength light source, such as "Mask Aligner MPA-600 Super" (trade name) by Canon Inc.

[0061] As shown in FIG. 3, the unexposed portions of the first photosensitive resin layer 10 and the coating film 12 are then removed by a development treatment, forming the discharge port 5. By simultaneously exposing and developing both the first photosensitive resin layer 10 and the coating film 12, the cationically polymerizable groups in the first photosensitive resin layer 10 and the coating film 12 can react with each other, resulting in a highly durable liquid-repellent antifouling film 7 having strong antistatic properties. The unexposed portions of the first photosensitive resin layer 10 are also simultaneously dissolved and removed, forming the flow path 6. Figure 2H As shown in FIG. 4, the second photosensitive resin layer 11 is then formed on the first photosensitive resin layer 10, and a coating film 12 of a photosensitive resin composition solution for forming the liquid-repellent antifouling film 7 described above is formed on the second photosensitive resin layer 11. The coating film 12 can be formed by applying the photosensitive resin composition using a method such as spin coating, roll coating, slit coating, or the like.

[0062] If necessary, heat treatment is also performed, and components for supplying ink (not shown) are connected, and electrical connections (not shown) for driving the energy-generating element 2 are performed, thereby completing the inkjet recording head.

[0063] Recording method The recording method according to the embodiments of the present disclosure records an image on a recording medium by discharging a liquid, particularly ink containing, for example, a pigment and / or a basic component, from the inkjet recording head using the inkjet recording head described above. When some of the ink adheres near the nozzle during discharge by the inkjet recording head, the discharge can become unstable and the print quality can be affected. When the inkjet recording head of the present disclosure is used, ink adhesion near or at the surface of the nozzle can be inhibited even during long-term use, because the liquid-repellent antifouling film 7 has high liquid repellency. Example

[0064] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to the following examples.

[0065] Epoxy resin (A) The compounds given by the following formulae (a) to (c) were prepared as the epoxy resin (A).

[0066] Epoxy resin (B) The compounds given in Table 1 were prepared as the epoxy resin (B). [Table 1]

[0067] The compounds given in Table 2 were prepared as the cationic polymerization catalyst. [Table 2]

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

[0069] Formation of liquid-repellent antifouling film Example 1 A solution for forming a liquid-repellent antifouling film was prepared using the following procedure. A coating solution was obtained by adding 1.0 parts by mass of the epoxy resin (A), 1.5 parts by mass of CPI-410S (San-Apro Ltd.) as the cationic polymerization catalyst, and 250 parts by mass of PGMEA as the coating solvent to 100 parts by mass of the epoxy resin (B) and stirring at room temperature for 1 hour. The procedure for forming a liquid-repellent antifouling film is shown in Figures 3A to 3C A coating film 12 was formed by coating the obtained solution on a silicon substrate 13, and heat treatment was performed at 70°C for 3 minutes. The coating film was then exposed by a mask (not shown) composed of quartz, and heat treatment was performed at 90°C for 5 minutes. An i-line exposure stepper (FPA-3000i5+, Canon Inc.) was used as the exposure device, and an exposure dose of 5000 J m -2 was used. PGMEA was used to dissolve and remove unexposed regions of the coating film, and heat treatment was also performed at 200°C for 1 hour to form a liquid-repellent antifouling film 7 and an opening 14.

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

[0071] Examples 17 to 19 A liquid-repellent and antifouling 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 weight relative to 100 parts by weight of epoxy resin (B).

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

[0073] Comparative Example 4 A liquid-repellent and antifouling 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 weight relative to 100 parts by weight of epoxy resin (B).

[0074] Inkjet recorder head manufacturing Example 23 according to Figures 2A to 2H The process shown is used to fabricate the inkjet recording head. like Figure 2A As shown, a substrate 1 with energy generating elements 2 provided on its surface is first prepared, and as shown in the figure... Figure 2B As shown, an ink supply port 3 is formed through the substrate 1 by etching with TMAH.

[0075] like Figure 2C As shown, the cationic polymeric resin composition shown in Table 4 is then transferred onto the substrate 1 containing the energy generating element 2 by lamination, thereby forming the first photosensitive resin layer 10. Figure 2D As shown, the sidewall 8 is formed by patterning exposure using a quartz mask (not shown) and heat treatment at 90°C for 5 minutes. For the exposure apparatus, an i-line exposure stepper (FPA-3000i5+, Canon) was used, and a 10000J / m² exposure was applied. -2 Exposure dose.

[0076] like Figure 2E As shown, a second photosensitive resin layer 11 is formed on a substrate 1 on which the sidewalls 8 have been formed. The second photosensitive resin layer 11 is transferred by lamination using the cationic polymerizable resin composition shown in Table 5. like Figure 2FAs shown, a liquid-repellent and anti-fouling film 7 was formed by coating the second photosensitive resin layer 11 with the coating solution obtained in Example 4 and heat-treating it at 70°C for 3 minutes. Both the second photosensitive resin layer 11 and the coating film 12 were simultaneously exposed in a patterned manner using a mask (not shown) with a patterned outlet 5, and heat-treated at 90°C for 5 minutes. For the exposure apparatus, an i-line exposure stepper (FPA-3000i5+, Canon) was used, and a 5000J / m² exposure was applied. -2 Exposure dose ( Figure 2G ). Finally, PGMEA is used to dissolve and remove the unexposed areas of the photosensitive resin layer and coating, followed by heat treatment at 200°C for 1 hour to form the outlet 5 and flow path 6. Figure 2H ). [Table 4] [Table 5] Epoxy resin Trade name: EP-157S70, manufactured by Mitsubishi Chemical Corp. 100 parts by mass Photopolymerization initiator Trade name: CPI-410S, manufactured by San-Apro Ltd. 0.01 parts by mass Solvent Trade name: PGMEA, manufactured by Kishida Chemical Co., Ltd. 20 parts by mass

[0077] Comparative Example 5 The inkjet recording head was fabricated in the same manner as in Example 23, except that the coating solution obtained in Comparative Example 1 was used to form the liquid-repellent and anti-fouling film 7.

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

[0079] Water repellency The antifouling membrane was immersed in an aqueous solution adjusted to a pH of 12 or higher at 60°C for one week, then rinsed with water and dried. The water repellency was then evaluated by measuring the contact angle of the membrane surface. For the contact angle, the dynamic receding contact angle θr of the antifouling membrane relative to water was measured using a micro contact angle meter (“DropMeasure”, manufactured by Microjet Corporation). When θr is above 80°, the water repellency is excellent, and it is rated A; when θr is above 70° but less than 80°, it is rated B, and it can be used as a liquid-repellent and antifouling membrane; when θr is less than 70°, it is rated C, where the water repellency is insufficient for a liquid-repellent and antifouling membrane.

[0080] resolution The resolution was evaluated by measuring the area of the opening. The area of the opening was measured using a scanning white light interference microscope ("Vertscan" (trade name), manufactured by Hitachi High-Tech Corporation), and the resolution was evaluated by checking the reproducibility of the mask size. Thus, (((opening area - mask size)) / (mask size)) x 100 was determined, and resolution of A was assigned for less than ±3%, resolution of B was assigned for ±3% or more and less than ±5%, and resolution of C was assigned for ±5% or more.

[0081] The results of these evaluations are given in Table 6 below. In this table, the addition amount indicates the epoxy resin (A) addition amount (mass parts) with respect to 100 mass parts of the epoxy resin (B).

[0082] Evaluation of liquid-repellent and stain-resistant film As shown in Table 6, excellent water repellency can be exhibited in Examples 1 to 22. In particular, in Examples 1 to 10 and 12 to 16, since the epoxy equivalent of the epoxy resin (B) is 300 or less, the reactivity with the epoxy resin (A) is excellent and high resolution is exhibited. Further, focusing on the addition amount of the epoxy resin (A), higher water repellency than in Examples 12 and 16 was obtained in Examples 13 to 15. Based on this result, it was demonstrated that the mass ratio (A:B) between the epoxy resin (A) and the epoxy resin (B) is more favorably 0.3:100 to 30:100.

[0083] Further, in Examples 17 to 19 in which a curing accelerator was added, the reactivity with the epoxy resin (A) can be promoted, and excellent water repellency can be obtained even at a relatively high epoxy equivalent of the epoxy resin (B) of 450. Focusing on the cationic polymerization catalyst, Examples 20 and 21 exhibited higher water repellency and resolution than Example 22. Based on these results, it was demonstrated that the molar extinction coefficient is more favorably 400 M -1 ·cm -1 The above cationic polymerization catalyst is more favorable. On the other hand, in Comparative Examples 1 to 3 in which the epoxy equivalent of the epoxy resin (B) was 500 or more, both the water repellency and the resolution were not satisfactory. The same results were obtained in Comparative Example 4 in which a curing accelerator was added.

[0084] Evaluation of inkjet recording head A continuous printing test was performed using an MB5330 printer from Canon Inc. in a 30°C / 80%RH environment, and visual inspection was performed for the presence or absence of dot distortion. In the continuous printing test, 100 A4 solid texts were continuously printed. As for printing distortion, if distortion occurred at even one location in A4 printing, the printing quality was evaluated as NG. The results of these evaluations were as follows. In Example 23, no distortion occurred even during continuous printing, and high printing quality was observed. On the other hand, in Comparative Example 5, distortion was observed after continuous printing was performed.

[0085] As described above, fluorine-based water repellent materials, while exhibiting good water repellency, are a cause for concern regarding their impact on the environment. On the other hand, even without the addition of fluorine-based water repellent materials, the photosensitive resin composition of the present embodiment exhibits good water repellency. Thus, the technology described in the present specification can contribute to the realization of a sustainable society, such as a decarbonization / recycling society.

[0086] While the present disclosure has been described with reference to embodiments, it is to be understood that the present disclosure is not limited to the disclosed embodiments. The scope of the following claims is to be given the broadest interpretation to encompass all such modifications and equivalent structures and functions.

Claims

1. A photosensitive resin composition, said photosensitive resin composition comprising: Epoxy resin (A) represented by formula (1); Epoxy resin (B), having an epoxy equivalent of less than 500 g / eq and different from the epoxy resin (A) represented by formula (1); and cationic polymerization catalyst, in, 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 group; X2 is an epoxy group; m+n is an integer from 1 to 60; and the sequence of bracketed structures labeled with m and the sequence of bracketed structures labeled with n can be random or block.

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

3. The photosensitive resin composition according to claim 1 or 2, wherein, The epoxy resin (B) is selected from at least one of the following: epoxy resin having an alicyclic backbone, epoxy resin having a bisphenol backbone, epoxy resin having a phenolic backbone, epoxy resin having a cresol backbone, epoxy resin having a norbornene backbone, epoxy resin having a terpene backbone, epoxy resin having a dicyclopentadiene backbone, and epoxy resin having an oxycyclohexane backbone.

4. The photosensitive resin composition according to claim 1 or 2, 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.

5. The photosensitive resin composition according to claim 4, wherein, X1 is an epoxy group.

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

100.

7. The photosensitive resin composition according to claim 1 or 2, wherein, The photosensitive resin composition contains phenolic compounds or polyols having at least two hydroxyl groups as curing accelerators.

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

9. The photosensitive resin composition according to claim 1 or 2, wherein, The cationic polymerization catalyst has a molar extinction coefficient of 400 M at a wavelength of 365 nm. -1 ·cm -1 Or higher.

10. The photosensitive resin composition according to claim 1 or 2, wherein, The anion in the cationic polymerization catalyst is selected from at least one of tetra(pentafluorophenyl)borate ion, trifluorotri(pentafluoroethyl) phosphate ion, hexafluoroantimonate ion and tetra(pentafluorophenyl)gallate ion.

11. A liquid-repellent and antifouling film, wherein the liquid-repellent and antifouling film is a cured product of a photosensitive resin composition, wherein: The photosensitive resin composition comprises: Epoxy resin (A) represented by formula (1); Epoxy resin (B), having an epoxy equivalent of less than 500 g / eq and different from the epoxy resin (A) represented by formula (1); and cationic polymerization catalyst, 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 group; X2 is an epoxy group; m+n is an integer from 1 to 60; and the sequence of the bracket structure marked with m and the sequence of the bracket structure marked with n can be random or block.

12. An inkjet recording head, wherein the inkjet recording head has a liquid-repellent and anti-fouling film on a surface having an outlet, wherein, The liquid-repellent and antifouling film is a cured product of a photosensitive resin composition, and The photosensitive resin composition comprises: Epoxy resin (A) represented by formula (1); Epoxy resin (B), having an epoxy equivalent of less than 500 g / eq and different from the epoxy resin (A) represented by formula (1); and cationic polymerization catalyst, 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 group; X2 is an epoxy group; m+n is an integer from 1 to 60; and the sequence of the bracket structure marked with m and the sequence of the bracket structure marked with n can be random or block.

Images