Photosensitive resin composition and cured product thereof

Abstract

Provided are: a photosensitive resin composition containing a paraffin wax, an inorganic filler, a photopolymerization initiator, a photosensitive resin, and a reactive diluent; and a cured product of the composition.

Description

Photosensitive resin composition and cured product thereof

[0001] This invention relates to a photosensitive resin composition and a cured product thereof.

[0002] Because electronic components such as displays and circuit boards are generally susceptible to moisture and humidity, attempts have been made to develop moisture-proofing agents and sealants to protect these components from external moisture and extend their lifespan.

[0003] For example, Patent Document 1 discloses an ink composition useful as a sealant for organic thin-film devices, comprising an inorganic filler, a (meth)acrylate monomer, and a polymerization initiator.

[0004] International Publication No. 2018 / 051732

[0005] However, the sealant obtained from the ink composition described in Patent Document 1 had room for improvement in terms of water vapor barrier properties.

[0006] The present invention aims to provide a photosensitive resin composition that exhibits good water vapor barrier properties in its cured product and good dispensing properties in a jet dispenser. Furthermore, the present invention aims to provide a cured product obtained from said composition.

[0007] In order to solve the above problems, the inventors conducted extensive research and found that a photosensitive resin composition containing paraffin wax, an inorganic filler, a photopolymerization initiator, a photosensitive resin, and a reactive diluent has good dispensing properties in a jet dispenser, and furthermore, the cured product has good water vapor barrier properties.

[0008] The present invention is completed based on these findings and includes the following broad embodiments: [Claim 1] A photosensitive resin composition comprising paraffin wax, an inorganic filler, a photopolymerization initiator, a photosensitive resin, and a reactive diluent. [Claim 2] The photosensitive resin composition according to Claim 1, wherein the paraffin wax content is 2 to 15% by mass of the total mass of the photosensitive resin composition. [Claim 3] The photosensitive resin composition according to Claim 1 or 2, wherein the inorganic filler content is 0.5 to 10 times the mass of the paraffin wax. [Claim 4] The photosensitive resin composition according to any one of Claims 1 to 3, wherein the inorganic filler is at least one selected from the group consisting of talc and mica. [Claim 5] The photosensitive resin composition according to any one of Claims 1 to 4, wherein the viscosity at 25°C is 100 to 50000 mPa·s or less. [Item 6] A photosensitive resin composition according to any one of items 1 to 5, wherein the thixoindex TI value is 1.2 to 4.0. [Item 7] A photosensitive resin composition according to any one of items 1 to 6 for jet dispenser application. [Item 8] A cured product of a photosensitive resin composition according to any one of items 1 to 7. [Item 9] A water vapor transmission rate (WVTR) of 110 g / m². ２ A cured product as described in item 8, which is less than or equal to / day.

[0009] According to the present invention, it is possible to provide a photosensitive resin composition that has good water vapor barrier properties in the cured product and good dispensing properties in a jet dispenser. Furthermore, according to the present invention, it is possible to provide a cured product obtained from said composition.

[0010] In this specification, singular nouns (a, an, the, etc.) include both singular and plural forms unless otherwise explicitly stated or the context clearly contradicts them. In this specification, "comprise" is a concept that also includes "consist essentially of" and "consist of." In this specification, (meth)acrylate means at least one selected from the group consisting of acrylates (acrylic acid esters) and methacrylates (methacrylic acid esters). Also, when numerical ranges are expressed using "~" such as "A~B", unless otherwise specified, this means "A or greater and B or less."

[0011] 1. Photosensitive Resin Composition The present invention provides a photosensitive resin composition. The photosensitive resin composition of the present invention comprises paraffin wax, an inorganic filler, a photopolymerization initiator, a photosensitive resin, and a reactive diluent.

[0012] <Paraffin Wax> The photosensitive resin composition of the present invention contains paraffin wax. Paraffin wax is a saturated aliphatic hydrocarbon having 20 or more carbon atoms and is solid at room temperature. Paraffin wax may be used alone or in combination of two or more types.

[0013] The melting point of paraffin wax is preferably 50 to 80°C, and more preferably 55 to 75°C. The melting point can be measured by a method in accordance with JIS K 0064.

[0014] Either synthetic or commercially available paraffin wax may be used. Commercially available paraffin products include: "Paraffin mp 50-52°C", "Paraffin mp 52-54°C", "Paraffin mp 54-56°C", "Paraffin mp 56-58°C", "Paraffin mp 58-60°C", "Paraffin mp 60-62°C", "Paraffin mp 62-64°C", "Paraffin mp 64-66°C", "Paraffin mp 66-68°C", "Paraffin mp 68°C-70°C" (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), "SP-0165", "SP-0160", "SP-0145", "SP-1039", "SP-3040", "SP-3035", "PARAFFIN WAX-120", "PARAFFIN WAX-125", "PARAFFIN WAX-130", "PARAFFIN Examples include "WAX-135", "PARAFFIN WAX-140", "PARAFFIN WAX-145", "PARAFFIN WAX-150", "PARAFFIN WAX-155", "HNP-3", "HNP-5", "HNP-9", "HNP-10", "HNP-11", "HNP-12", and "HNP-51" (all manufactured by Nippon Seiro Co., Ltd.).

[0015] In the photosensitive resin composition of the present invention, the paraffin wax content is preferably 2 to 15% by mass, more preferably 5 to 15% by mass, and particularly preferably 7 to 14% by mass, based on the total mass of the photosensitive resin composition, from the viewpoint of moisture resistance and dischargeability.

[0016] <Inorganic Filler> The photosensitive resin composition of the present invention contains an inorganic filler.

[0017] Examples of inorganic fillers include silica such as talc, mica, amorphous silica, crystalline silica, fused silica, and spherical silica, as well as kaolin, montmorilloid, montmorillonite, clay, Neuburg silica particles, boehmite, hydrotalcite, zeolite, silicon nitride, aluminum nitride, calcium zirconate, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, barium titanate, calcium carbonate, calcium silicate, lithium carbonate, gold, aluminum, copper, nickel, carbon black, carbon nanotubes, and graphite. Among these, talc and mica are preferred. These may be used individually or in combination of two or more. The inorganic fillers may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment.

[0018] The shape of the inorganic filler is not particularly limited and may include spherical, fibrous, plate-like, irregular, balloon-like, and so on.

[0019] From the viewpoint of dischargeability, the average particle size of the inorganic filler is preferably 0.01 to 15.0 μm, and more preferably 0.1 to 10.0 μm. The average particle size can be measured using a laser diffraction / scattering device.

[0020] Inorganic fillers are preferably subjected to hydrophobic treatment, surface treatment using a coupling agent, etc. The method of surface treatment of the inorganic filler is not particularly limited, and any known and conventional method may be used, but it is preferable to treat the surface of the inorganic filler with a surface treatment agent having a (meth)acrylic group, for example, a coupling agent having a (meth)acrylic group as an organic group.

[0021] The Mohs hardness of the inorganic filler is preferably 0.5 to 10, and more preferably 0.7 to 5. The Mohs hardness can be measured using a Mohs hardness tester.

[0022] In the photosensitive resin composition of the present invention, the inorganic filler content is preferably 0.5 to 10 times, and more preferably 1.5 to 5 times, relative to the mass of paraffin wax, from the viewpoint of extrusion properties.

[0023] Furthermore, from the viewpoint of dispensing properties, the inorganic filler content in the photosensitive resin composition of the present invention is preferably 3 to 35% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass, based on the total mass of the photosensitive resin composition.

[0024] <Photopolymerization Initiator> The photosensitive resin composition of the present invention contains a photopolymerization initiator. Known and commonly used photopolymerization initiators can be used in the photosensitive resin composition without particular limitations.

[0025] Examples of photopolymerization initiators include α-aminoacetophenone-based photopolymerization initiators such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone, 1-hydroxycyclohexylphenyl ketone, and 1-[4-(2-hydroxyethoxy)-phenyl] Hydroxyacetophenone-based photopolymerization initiators such as -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, and bis-(2,6-dichlorobenzoyl)-4-propylphenyl Phosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenyl Acylphosphine oxide-based photopolymerization initiators such as ylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinate methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinate isopropyl ester, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; benzoin-based photopolymerization initiators such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether;Benzoin alkyl ether photopolymerization initiators; Benzophenone-based photopolymerization initiators such as benzophenone, p-methylbenzophenone, Michla's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[ Acetophenone-based photopolymerization initiators such as 4-(methylthio)phenyl]-2-morpholino-1-propanone; thioxanthone-based photopolymerization initiators such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butyl Anthraquinone-based photopolymerization initiators such as anthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; ketal-based photopolymerization initiators such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid ester-based photopolymerization initiators such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, and p-dimethylbenzoate ethyl ester; 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-o Oxime ester-based photopolymerization initiators such as ctanedione and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyloxime); titanocene-based photopolymerization initiators such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium and bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr-1-yl)ethyl)phenyl]titanium;Examples include the following. Among these, α-aminoacetophenone-based photopolymerization initiators, anthraquinone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and oxime-based initiators are preferred. These may be used individually or in combination of two or more.

[0026] Commercially available α-aminoacetophenone-based photopolymerization initiators include Omnirad 907, 369, 369E, and 379 from IGM Resins. Commercially available acylphosphine oxide-based photopolymerization initiators include TPO from Kusumoto Chemicals, Inc. and Omnirad 819 from IGM Resins. Commercially available anthraquinone-based photopolymerization initiators include 2-ethyl AQ from Mitsui & Co. Chemicals Ltd. Commercially available oxime ester-based photopolymerization initiators include Irgacure OXE01 and OXE02 from BASF Japan Ltd., N-1919 from ADEKA Corporation, ADEKA Arclus NCI-831 and NCI-831E, and TR-PBG-304 from Changzhou Strong Electronic New Materials Co., Ltd.

[0027] From the viewpoint of photocurability and the physical properties of the cured coating film, the content of the photopolymerization initiator in the photosensitive resin composition is preferably 0.1 to 10% by mass, and more preferably 0.5 to 5% by mass, relative to the total amount of the photosensitive resin composition.

[0028] <Photosensitive Resin> The photosensitive resin composition of the present invention contains a photosensitive resin. The photosensitive resin is a polymer compound having one or more (preferably two or more) photopolymerizable groups in one molecule, and examples include photopolymerizable oligomers and photopolymerizable polymers. Examples of photopolymerizable groups include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, allyloxy groups, acryloyloxy groups, methacryloyloxy groups, oxyranyl groups, and oxetanyl groups. Among these, acryloyloxy groups, methacryloyloxy groups, and allyloxy groups are preferred.

[0029] The viscosity of the photosensitive resin at 45°C is preferably 1,500 mPa·s or higher, and more preferably 2,000 mPa·s or higher. It is also preferably 200,000 mPa·s or lower. The viscosity can be measured in accordance with JIS Z 8803:2011, item 10, "Method for measuring viscosity using a cone-plate rotational viscometer," at 45°C, 50 rpm, and 30 seconds, using a cone rotor of 3° × R9.7 and a cone-plate viscometer (Toki Sangyo Co., Ltd., TVE-33H).

[0030] The weight-average molecular weight of the photosensitive resin is preferably 500 to 100,000, and more preferably 1,000 to 30,000. The weight-average molecular weight can be measured using gel permeation chromatography (GPC) with standard polystyrene as the standard substance.

[0031] Examples of photosensitive resins include unsaturated polyester oligomers; epoxy (meth)acrylates such as phenol novolac epoxy (meth)acrylate, cresol novolac epoxy (meth)acrylate, and bisphenol-type epoxy (meth)acrylate; urethane (meth)acrylate, epoxy urethane (meth)acrylate, and polybutadiene urethane (meth)acrylate; polyether (meth)acrylates such as polyoxyethylene (meth)acrylate and polyoxypropylene (meth)acrylate; polyester (meth)acrylate; polybutadiene-modified (meth)acrylate; and polycarbonate methacrylate. The photosensitive resin may be used alone or in combination of two or more types.

[0032] From the viewpoint of dischargeability, the content of the photosensitive resin in the photosensitive resin composition is preferably 10 to 90% by mass, and more preferably 20 to 80% by mass, based on the total amount of the photosensitive resin composition.

[0033] <Reactive Diluent> The photosensitive resin composition of the present invention contains a reactive diluent. The reactive diluent is a compound having one or more photopolymerizable groups in one molecule and adjusting (reducing the viscosity of) the resin composition, and examples include photopolymerizable monomers. Examples of photopolymerizable groups include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, allyloxy group, acryloyloxy group, methacryloyloxy group, oxyranyl group, oxetanyl group, etc. Among these, acryloyloxy group, methacryloyloxy group, and allyloxy group are preferred.

[0034] The viscosity of the reactive diluent at 25°C is preferably 100 mPa·s or less, and more preferably 50 mPa·s or less. The lower limit of viscosity is not particularly limited, but is preferably, for example, 1 mPa·s or more. The viscosity can be measured in accordance with JIS Z 8803:2011, item 10, "Method for measuring viscosity using a cone-plate rotational viscometer," at 25°C, 50 rpm, and 30 seconds, using a cone rotor of 3° × R9.7 and a cone-plate viscometer (Toki Sangyo Co., Ltd., TVE-33H).

[0035] Examples of reactive diluents include alkyl(meth)acrylates such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, amyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth)acrylate, nonyl(meth)acrylate, dodecyl(meth)acrylate, hexadecyl(meth)acrylate, octadecyl(meth)acrylate; cycloalkyl(meth)acrylates such as cyclohexyl(meth)acrylate; aryl(meth)acrylates such as phenyl(meth)acrylate; benzyl(meth)acrylate, phenylbenzyl(meth)acrylate; isobornyl(meth)acrylate, dicyclopentanyl(meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate; methoxyethyl(meth)acrylate, butoxyethyl(meth)acrylate, phenyl Ether-containing (meth)acrylates such as phenoxyethyl (meth)acrylate, nonylphenoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate (e.g., methoxytriethylene glycol (meth)acrylate), butoxydiethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate; (poly)alkylene glycol-modified (meth)acrylates such as EO-modified (meth)acrylate of 2-ethylhexanol; glycidyl (meth)acrylate; amino-containing (meth)acrylates such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate; hydroxyl-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate;Difunctional (meth)acrylates such as ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, ethylene oxide modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, etc.; trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate Examples include trifunctional (meth)acrylates such as phosphate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, and tris(acryloxyethyl) isocyanurate; tetrafunctional or more (meth)acrylates such as ditrimethylolpropane tetra(meth)acrylate, propionic acid-modified dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; 2-(allyloxymethyl) acrylic acid esters such as 2-(allyloxymethyl)methyl acrylate, 2-(allyloxymethyl)ethyl acrylate, 2-(allyloxymethyl)propyl acrylate, and 2-(allyloxymethyl)butyl acrylate; and aromatic vinyl monomers such as styrene, p-methylstyrene, o-methylstyrene, and vinylnaphthalene. The reactive diluent may be used alone or in combination of two or more types.

[0036] From the viewpoint of dischargeability, the content of the reactive diluent in the photosensitive resin composition is preferably 5 to 50% by mass, and more preferably 15 to 40% by mass, based on the total amount of the photosensitive resin composition.

[0037] <Other Components> The photosensitive resin composition of the present invention may further contain components (additives) such as polymerization inhibitors, surfactants, co-sensitizers, ultraviolet absorbers, antioxidants, ion catchers, coupling agents, tackifiers, surface conditioners, leveling agents, defoaming agents, rheology control agents, pigments, etc., as long as the effects of the present invention can be exhibited.

[0038] The content of other components in the photosensitive resin composition of the present invention is preferably 0.01 to 10% by mass based on the total amount of the photosensitive resin composition.

[0039] The content of the organic solvent in the photosensitive resin composition of the present invention is preferably 1% by mass or less, more preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less based on the total amount of the photosensitive resin composition. By being 1% by mass or less, the drying process of the solvent can be omitted, and the process can be simplified. Also, it is preferable because it can prevent sagging in the drying process. In one embodiment, the photosensitive resin composition of the present invention does not contain an organic solvent (0% by mass).

[0040] <Preparation of Photosensitive Resin Composition> The photosensitive resin composition of the present invention is prepared as a uniform liquid composition by mixing paraffin wax, an inorganic filler, a photopolymerization initiator, a photosensitive resin, a reactive diluent, and optionally other components.

[0041] The viscosity of the photosensitive resin composition of the present invention at 25°C is preferably 100 to 50000 mPa·s, more preferably 500 to 20000 mPa·s, and particularly preferably 1000 to 10000 mPa·s from the viewpoint of dischargeability. By being within the above viscosity range, it becomes easy to apply using a jet dispenser. The viscosity is measured in accordance with 10 "Viscosity Measurement Method by Cone-Plate Type Rotational Viscometer" of JIS Z 8803:2011, at 25°C, 50 rpm, and the 30-second value, using a 3° × R9.7 as the cone and rotor, and can be measured using a cone-plate type viscometer (manufactured by Toki Sangyo Co., Ltd., TVE-33H).

[0042] The thixotropic index TI value of the photosensitive resin composition of the present invention is preferably 1.2 to 4.0, more preferably 1.5 to 3.8, and particularly preferably 2.0 to 3.6 from the viewpoint of sagging properties. When the TI value is within the above range, it is difficult for the photosensitive resin composition to spread when applied to a substrate, and the coating accuracy is improved, which is preferable. The TI value can be calculated based on the following formula. TI = viscosity (5 rpm) / viscosity (50 rpm) (Viscosity (5 rpm) and viscosity (50 rpm) comply with "Method for Measuring Viscosity by a Cone-and-Plate Rotational Viscometer" in JIS Z 8803:2011, and are values at 25°C, 5 rpm and 50 rpm for 30 seconds. As the cone-rotor, 3°×R9.7 is used, and it can be measured using a cone-plate viscometer (manufactured by Toki Sangyo Co., Ltd., TVE-33H).)

[0043] 2. Cured product of the photosensitive resin composition In one embodiment, a cured product of the photosensitive resin composition of the present invention is provided. In a preferred embodiment, the cured product can be formed by applying or filling the photosensitive resin composition to a substrate and then irradiating it with ultraviolet light.

[0044] The method of applying or filling the photosensitive resin composition to the substrate is not particularly limited. For example, an inkjet method, a dispenser method, a dip coating method, a flow coating method, a roll coating method, a bar coater method, a screen printing method, a curtain coating method, etc. can be mentioned. Among these, from the viewpoints of the degree of freedom of the cured product formation site and the physical properties of the cured product, the dispenser method, particularly the jet dispenser method, is preferable.

[0045] Examples of substrates include glass, ceramics, wafers, metals (copper, brass, phosphor bronze, beryllium copper, aluminum, gold, silver, nickel, tin, chromium, or stainless steel, etc.), resins (PET (polyethylene terephthalate) resin, PBT (polybutylene terephthalate) resin, PCT (polycyclohexylene dimethylene terephthalate) resin, PPS (polyphenylene sulfide) resin, PTFE (polytetrafluoroethylene) resin, polycarbonate resin, polyacetal resin, polyphenylene ether resin, polyamide resin, polyarylate resin, polysulfone resin, polyethersulfone resin, polyetherimide resin, polyamideimide resin, epoxy resin, acrylic resin, thermoplastic elastomer, liquid crystal polymer, etc.), and composite materials.

[0046] The peak wavelength of the irradiated ultraviolet light is preferably 200 to 450 nm, more preferably 250 to 420 nm, and particularly preferably 300 to 405 nm.

[0047] Examples of light sources for ultraviolet irradiation include UV-LEDs (light-emitting diodes), UV-LDs (laser diodes), mercury lamps, metal halide lamps, and ultraviolet fluorescent lamps. Of these, UV-LEDs and UV-LDs are preferred from the viewpoint of being small, having a long lifespan, and being highly efficient.

[0048] The cumulative amount of ultraviolet light (ultraviolet exposure) varies depending on the thickness of the coating film, but is generally between 10 and 10,000 mJ / cm². ２ The concentration is preferably 20 to 5000 mJ / cm². ２ More preferably 50 to 2000 mJ / cm² ２ That is the case.

[0049] The water vapor transmission rate (WVTR) of the cured material is 110 g / m². ２ Preferably, it should be less than / day, and 80 g / m² ２ It is more preferable that the amount is less than or equal to 70 g / m² / day. ２ It is particularly preferable that the amount be less than or equal to / day. Furthermore, the lower limit is not particularly limited, but for example, 10 g / m³ ２ / day or more. The WVTR conforms to JIS Z 0208 and can be measured under the conditions of a test piece thickness of 60 μm cured with a UV-LED (365 nm, 2000 mJ / cm ２ ), at 40 °C and 90% RH.

[0050] As described above, since the cured product of the photosensitive resin composition of the present invention is excellent in moisture resistance, it can be suitably used as a moisture-proof agent. Such applications include electronic components (LEDs, batteries, sensors, semiconductors, circuit boards, displays, home appliances, optical communication / optical circuits, optical recording, magnetic recording, etc.), pharmaceuticals / medical products, automotive parts, marine parts, building parts, acoustic parts, etc. Among these, it can be preferably used as a moisture-proof agent for electronic components.

[0051] Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto.

[0052] <Materials Used> - TE-2000: Manufactured by Nippon Soda Co., Ltd., polybutadiene urethane methacrylate, Mn: 2500, 150000 mPa·s @ 45 °C - EBECRYL 270: Manufactured by Daicel Ornex Co., Ltd., bifunctional urethane acrylate, Mw: *********************** ５０ ), = 0.6, methacrylic acid-treated product) - NS-8: Manufactured by Nippon Kogaku Kogyo Co., Ltd., synthetic mica (average particle diameter (D ５０ = 8 μm) - Aerosil R974: Manufactured by Evonik, fumed silica - Omnirad 379: Manufactured by IGM Resins, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone

[0053] <Example 1> TE-2000 (100 parts by mass), AOMA (40 parts by mass), and paraffin wax (5 parts by mass) were mixed, melted at 90°C, stirred, and then mixed with D-600C3-BM53 (10 parts by mass), Omnirad 379 (4 parts by mass), Ebecryl 270 (10 parts by mass), and Light Ester BZ (10 parts by mass). After pre-mixing using a stirrer, the mixture was kneaded using a three-roll mill to prepare a photosensitive resin composition. The prepared photosensitive resin compositions were evaluated as described below. The results are shown in Table 1.

[0054] <Viscosity> The prepared photosensitive resin composition was measured using a cone-plate viscometer (TVE-33H, manufactured by Toki Sangyo Co., Ltd.) with a cone rotor of 3° × R9.7, according to the viscosity measurement method using a 10-cone-plate rotational viscometer specified in JIS Z8803:2011, at 25°C, 50 rpm, and 30 seconds.

[0055] <TI Value> The viscosity measurement method described above was performed by changing the rotation speed to 5 rpm and measuring in the same manner as above. The TI value was calculated from the obtained viscosity value according to the following formula: TI = Viscosity (5 rpm) / Viscosity (50 rpm)

[0056] <WVTR> A photosensitive resin composition is applied to a PTFE sheet, and a UV-LED (365 nm, 2000 mJ / cm²) is used. ２ A 60 μm thick cured material was prepared by light curing using the ) method. The WVTR of this cured material was measured according to the cup method (JIS Z 0208, 40°C 90% RH) and evaluated as follows. A and B were judged as pass, and C as fail. A: WVTR is 80 or less. B: WVTR is greater than 80 but 110 or less. C: WVTR is greater than 110.

[0057] <Discharge Performance> The photosensitive resin composition was filled into a syringe, and the discharge performance was evaluated using a Musashi Engineering Co., Ltd. precision solid nozzle SHN-0.1N (nozzle diameter 0.1 mm) or SHN-0.15N (nozzle diameter 0.15 mm) as the nozzle, and a Musashi Engineering Co., Ltd. 350PCSmart SMΩX as the dispenser, at a discharge pressure of 30 MPa. The discharge performance was evaluated as follows. A and B were judged as pass, and C as fail. A: The photosensitive resin composition can be discharged with a 0.1 mm nozzle. B: The photosensitive resin composition cannot be discharged with a 0.1 mm nozzle, but can be discharged with a 0.15 mm nozzle. C: The photosensitive resin composition cannot be discharged even with a 0.15 mm nozzle.

[0058] <Examples 2-8, Comparative Examples 1-4> Photosensitive resin compositions were prepared in the same manner as in Example 1, except that the composition was changed as shown in Table 1. Subsequently, evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[0059]

[0060] The photosensitive resin compositions of Examples 1 to 8 showed good results in both moisture resistance and discharge properties. On the other hand, the photosensitive resin compositions of Comparative Examples 1 to 4 were outside the scope of the present invention and showed inferior results compared to the present invention in either low moisture resistance or poor discharge properties.

Claims

1. A photosensitive resin composition comprising paraffin wax, an inorganic filler, a photopolymerization initiator, a photosensitive resin, and a reactive diluent.

2. The photosensitive resin composition according to claim 1, wherein the paraffin wax content is 2 to 15% by mass relative to the total mass of the photosensitive resin composition.

3. The photosensitive resin composition according to claim 1, wherein the inorganic filler content is 0.5 to 10 times the mass of paraffin wax.

4. The photosensitive resin composition according to claim 1, wherein the inorganic filler is at least one selected from the group consisting of talc and mica.

5. The photosensitive resin composition according to claim 1, wherein the viscosity at 25°C is 100 to 50,000 mPa·s.

6. The photosensitive resin composition according to claim 1, wherein the thixoindex TI value is 1.2 to 4.

0.

7. The photosensitive resin composition according to claim 1, for use with a jet dispenser.

8. A cured product of the photosensitive resin composition according to any one of claims 1 to 7.

9. Water vapor transmission rate (WVTR) of 110 g / m² ２ The cured product according to claim 8, wherein the curing period is less than or equal to / day.

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