Alkali-developable photocurable thermosetting resin composition

Abstract

[Question] To provide an alkali-developable curable resin composition that suppresses performance degradation even under relatively harsh storage conditions. [Solution] An alkali-developable curable resin composition characterized by comprising at least (A) an alkali-soluble resin, (B) a photopolymerization initiator having an oxime bond, (C) a reactive diluent, and (D) a thermosetting resin, wherein the composition is at least a two-component system in which the (B) photopolymerization initiator having an oxime bond and the (A) alkali-soluble resin are blended into separate compositions, and at least one (E) orthoester compound is blended with the (B) photopolymerization initiator having an oxime bond.

Description

Technical Field

[0001] The present invention relates to an alkali-developable photocurable thermosetting resin composition, a cured product obtained by curing the composition, and an electronic component having the cured product. Background Art

[0002] Conventionally, solder resists have been used as protective materials for circuit boards in printed circuit boards. An example of such material compositions is an alkali-developable photocurable thermosetting resin composition (hereinafter also referred to as a curable resin composition).

[0003] In order to form a more precise pattern, a photopolymerization initiator with a higher sensitivity may be used in the curable resin composition to increase the sensitivity during exposure and enable photocuring to proceed deep into the coating film.

[0004] As such a photopolymerization initiator, for example, a technique of using a photopolymerization initiator having an oxime bond has been proposed (Patent Document 1).

[0005] On the other hand, however, photopolymerization initiators containing oxime bonds have the property of easily degrading their performance upon contact with resins containing carboxyl groups, and there is a concern that they may thicken upon contact with reactive diluents, thereby potentially deteriorating the quality of compositions containing them.

[0006] Therefore, the technology of Patent Document 1 is characterized by forming a curable resin composition having a two-component system, wherein a photopolymerization initiator having an oxime bond and a resin having a carboxyl group or a reactive diluent are mixed as separate components. This two-component system provides a curable resin composition having excellent storage stability.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2004 / 048434 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] Therefore, for compositions containing highly photosensitivity compounds, such as the aforementioned photopolymerization initiators containing oxime bonds, it is desirable to achieve higher quality stability during storage in order to maintain stable performance. This allows for the provision of curable resin compositions that maintain stable quality even under harsh storage conditions, such as those encountered during transportation on ships, where temperatures are often elevated and transportation times are prolonged. Under these storage conditions, it is believed that the performance of the curable resin composition must be maintained to the greatest extent possible even after being stored at 50°C for at least five days.

[0012] In this regard, the technology described in Patent Document 1 forms a two-component system as described above, thereby suppressing degradation of the performance of the photopolymerization initiator having an oxime bond and maintaining the performance of the curable resin composition containing the photopolymerization initiator.

[0013] However, this technology does not even envision leaving the curable resin composition at least at 50° C. for more than 5 days.

[0014] Therefore, an object of the present invention is to provide a curable resin composition that suppresses degradation of performance even under such relatively severe storage conditions.

[0015] Solutions for solving problems

[0016] First, a two-component curable resin composition containing a photopolymerization initiator having an oxime bond was subjected to a 5-day aging test at 50° C. However, pattern formation by exposure / development was not possible due to a decrease in sensitivity.

[0017] Therefore, a new investigation into the mechanism of degradation of photopolymerization initiators containing oxime bonds in curable resin compositions has yielded the following insight: trace amounts of water contained in the composition adversely affect the oxime bonds within the chemical structure of the photopolymerization initiator containing oxime bonds. This water decomposes the oxime bonds, resulting in inactivation of the photopolymerization initiator containing oxime bonds, which in turn negatively impacts the formation of a cured film. Furthermore, as described above, even when the photopolymerization initiator containing oxime bonds is blended with a resin containing a carboxyl group and a reactive diluent as separate components to form a two-component system, the adverse effects of the presence of water cannot be fully avoided.

[0018] In light of this perspective, attempts have been made to simultaneously add dehydrating agents such as zeolite and silica gel when adding a photopolymerization initiator having an oxime bond to a two-component curable resin composition. However, these agents pose a separate problem of difficulty dispersing them within the composition, and therefore cannot be directly used to inhibit the deactivation of the photopolymerization initiator having an oxime bond.

[0019] Therefore, further in-depth research resulted in the discovery that by forming a photopolymerization initiator having an oxime bond and an alkali-soluble resin into separate compositions and compounding a specific orthoester compound together with the photopolymerization initiator having an oxime bond into a curable resin composition, the deactivation of the photopolymerization initiator having an oxime bond can be effectively suppressed even when stored at 50°C for 5 days, thereby improving the storage stability of the composition. This led to the completion of the present invention.

[0020] That is, it has been found that the object of the present invention can be achieved by an alkali-developable curable resin composition, characterized in that the alkali-developable curable resin composition comprises at least (A) an alkali-soluble resin, (B) a photopolymerization initiator having an oxime bond, (C) a reactive diluent, and (D) a thermosetting resin, and is composed of at least a two-component system in which the (B) photopolymerization initiator having an oxime bond and the (A) alkali-soluble resin are mixed in different compositions.

[0021] Among these, at least one (E) orthoester compound is blended together with the (B) photopolymerization initiator having an oxime bond.

[0022] Furthermore, in the alkali-developable curable resin composition of the present invention, the (E) orthoester compound is preferably at least one selected from the group consisting of trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, tributyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, tripropyl orthoacetate, tributyl orthoacetate, trimethyl orthopropionate, triethyl orthopropionate, propyl orthopropionate, and butyl orthopropionate; more preferably, at least one selected from the group consisting of trimethyl orthoformate, triethyl orthoformate, and triethyl orthoacetate; and most preferably, triethyl orthoformate.

[0023] Furthermore, the present invention also provides a cured product obtained by curing the alkali-developable curable resin composition, and an electronic component having the cured product.

[0024] Effects of the Invention

[0025] According to the present invention, a two-component curable resin composition can be provided in which a decrease in performance, for example, sensitivity, is effectively suppressed after at least 5 days at 50°C.

[0026] Therefore, the composition is suitable for storage under relatively severe conditions such as transportation on ships. DETAILED DESCRIPTION

[0027] The curable resin composition of the present invention is composed of at least a two-component system in which (B) the photopolymerization initiator having an oxime bond and (A) the alkali-soluble resin are blended in separate compositions.

[0028] For example, the main agent composition and the curing agent composition can be prepared separately and mixed before use. Of course, these compositions can also be further separated as needed to form a three-component system or more.

[0029] Examples of the components of the base composition include an alkali-soluble resin, a reactive diluent, a solvent, a pigment, and a photopolymerization initiator, while examples of the components of the curing agent composition include a thermosetting resin, a solvent, and a photopolymerization initiator having an oxime bond.

[0030] Furthermore, according to the present invention, not only are (B) the photopolymerization initiator having an oxime bond and (A) the alkali-soluble resin blended into separate compositions, but (E) the orthoester compound is also blended together with (B) the photopolymerization initiator having an oxime bond. This is presumably because the decomposition of the oxime bond by moisture in the composition is effectively suppressed, thereby maintaining sensitivity.

[0031] The curable resin composition of the present invention blended in this manner can effectively suppress degradation of its performance even after a lapse of at least 5 days at 50°C.

[0032] Hereinafter, each component will be described.

[0033] [(A) Alkali-soluble resin]

[0034] The alkali-soluble resin (A) is a resin containing one or more functional groups selected from the group consisting of a phenolic hydroxyl group, a mercapto group, and a carboxyl group, and being soluble in an alkaline solution. Preferred examples include compounds having two or more phenolic hydroxyl groups, carboxyl-containing resins, compounds having a phenolic hydroxyl group and a carboxyl group, and compounds having two or more mercapto groups. Examples of the alkali-soluble resin (A) include carboxyl-containing resins and phenolic hydroxyl-containing resins, with carboxyl-containing resins being preferred.

[0035] For carboxyl resin, from the viewpoint of light curing property, resistance to developing, except carboxyl, preferably also have ethylenically unsaturated bond in molecule, also can use the carboxyl resin that does not have ethylenically unsaturated double bond.As ethylenically unsaturated bond, preferably be derived from acrylic acid or methacrylic acid or their derivatives.In carboxyl resin, preferably have the carboxyl resin of copolymerization structure, have the carboxyl resin of urethane structure, take epoxy resin as starting raw material, take phenolic compound as starting raw material carboxyl resin.As the specific example of carboxyl resin, can enumerate the compound (oligomer or polymer) of enumerating below.

[0036] (1) A carboxyl group-containing photosensitive resin obtained by reacting a bifunctional or higher polyfunctional epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the hydroxyl groups present in the side chains. The bifunctional or higher polyfunctional epoxy resin is preferably a solid.

[0037] (2) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy resin obtained by epoxidizing the hydroxyl groups of a bifunctional epoxy resin with epichlorohydrin with (meth)acrylic acid and adding a dibasic acid anhydride to the generated hydroxyl groups. The bifunctional epoxy resin is preferably solid.

[0038] (3) A carboxyl group-containing photosensitive resin obtained by reacting an epoxy compound having two or more epoxy groups in one molecule with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule and a monocarboxylic acid containing an unsaturated group such as (meth)acrylic acid, so that the alcoholic hydroxyl group of the obtained reaction product reacts with a polyacid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic anhydride.

[0039] (4) A compound having two or more phenolic hydroxyl groups in one molecule, such as bisphenol A, bisphenol F, bisphenol S, novolac-type phenolic resin, poly(p-hydroxystyrene), condensates of naphthol and aldehydes, condensates of dihydroxynaphthalene and aldehydes, is reacted with an alkylene oxide such as ethylene oxide and propylene oxide to obtain a reaction product, and the obtained reaction product is reacted with a monocarboxylic acid containing an unsaturated group such as (meth) acrylic acid, and the obtained reaction product is reacted with a polyacid anhydride to obtain a carboxyl-containing photosensitive resin.

[0040] (5) A carboxyl group-containing photosensitive resin obtained by reacting a compound having two or more phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate to obtain a reaction product, reacting the obtained reaction product with a monocarboxylic acid containing an unsaturated group, and reacting the obtained reaction product with a polyacid anhydride.

[0041] (6) A polyurethane resin containing terminal carboxyl groups, obtained by reacting the ends of a polyurethane resin obtained by polyaddition reaction of a diisocyanate compound such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, an aromatic diisocyanate, and a diol compound such as a polycarbonate polyol, a polyether polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a bisphenol A-based alkylene oxide adduct diol, or a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group with an acid anhydride.

[0042] (7) In the synthesis of a carboxyl group-containing polyurethane resin obtained by a polyaddition reaction of a diisocyanate, a carboxyl group-containing diol compound such as dimethylolpropionic acid and dimethylolbutanoic acid, and a diol compound, a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule such as (meth)propionic acid hydroxyalkyl ester is added to obtain a carboxyl group-containing polyurethane resin with terminal (meth)acryloylation.

[0043] (8) In the synthesis of a carboxyl group-containing polyurethane resin obtained by a polyaddition reaction of a diisocyanate, a carboxyl group-containing diol compound, and a diol compound, a compound having one isocyanate group and one or more (meth)acryloyl groups in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol tripropionate, is added to obtain a carboxyl group-containing polyurethane resin with terminal (meth)acryloylation.

[0044] (9) Carboxyl group-containing photosensitive resins obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, a lower alkyl (meth)propionate, or isobutylene.

[0045] (10) A polyfunctional oxetane resin described later is reacted with a dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid, and a dibasic acid anhydride is added to the generated primary hydroxyl group to obtain a carboxyl-containing polyester resin, and a compound having one epoxy group and one or more (meth)acryloyl groups in one molecule, such as (meth)propionic acid glycidyl ester or (meth)propionic acid α-methyl glycidyl ester, is further added to the obtained carboxyl-containing polyester resin to obtain a carboxyl-containing photosensitive resin.

[0046] (11) A carboxyl group-containing photosensitive resin obtained by adding a compound having a cyclic ether group and a (meth)acryloyl group in one molecule to any of the carboxyl group-containing resins described in (1) to (10).

[0047] It should be noted that (meth)propionic acid ester herein is a term that collectively refers to propionic acid ester, methacrylic acid ester, and a mixture thereof, and the same applies to other similar expressions below.

[0048] The acid value of the carboxyl group-containing resin is preferably 40 to 150 mgKOH / g. When the acid value of the carboxyl group-containing resin is 40 mgKOH / g or higher, alkaline development is improved. Furthermore, when the acid value is 150 mgKOH / g or lower, a normal resist pattern can be easily drawn. More preferably, the acid value is 50 to 130 mgKOH / g.

[0049] The mass average molecular weight of the alkali-soluble resin (A) depends on the resin backbone, but is preferably in the range of 1,500 to 150,000, more preferably 1,500 to 100,000. A mass average molecular weight of 1,500 or greater provides excellent tack-free properties, good moisture resistance of the exposed coating film, and suppressed film loss during development, thereby suppressing a decrease in resolution. On the other hand, a mass average molecular weight of 150,000 or less provides good developability and excellent storage stability.

[0050] In the present invention, the content of the alkali-soluble resin (A) is preferably 10 to 60% by mass, more preferably 20 to 50% by mass, relative to the total composition. When the content is 10 to 60% by mass, the coating film strength is good, the viscosity of the composition is moderate, and the coating properties can be improved.

[0051] These (A) alkali-soluble resins can be used alone or in combination of two or more.

[0052] [(B) Photopolymerization Initiator Having Oxime Bond]

[0053] As the (B) photopolymerization initiator having an oxime bond, for example, known ones such as o-acyl oxime ester compounds, oxime sulfonate compounds, and keto oxime ether compounds can be used.

[0054] Examples of commercially available products include CGI-325, TOE-04-A3 (Nippon Chemical Industry Co., Ltd.), Irgacure OXE01 and Irgacure OXE02 (both BASF Japan Co., Ltd.), and N-1919 and NCI-831 (both ADEKA CORPORATION), but are not limited thereto.

[0055] The content of the photopolymerization initiator (B) having an oxime bond is preferably 0.01 to 30% by mass, more preferably 0.1 to 10% by mass, relative to the alkali-soluble resin (A). When the content of the photopolymerization initiator (B) having an oxime bond is 0.01% by mass or greater, the photocurability on copper is improved, the coating film is less likely to peel, and the coating film properties such as chemical resistance are improved. On the other hand, when the content of the photopolymerization initiator (B) having an oxime bond is 30% by mass or less, the light absorption of the photopolymerization initiator (B) having an oxime bond is improved, and deep curing properties are improved.

[0056] [(C) Reactive diluent]

[0057] The reactive diluent (C) used in the present invention is used to adjust the viscosity of the composition to improve workability, increase the crosslinking density, and obtain a coating film with adhesion. Examples of such reactive diluents (C) include: compounds having one or more unsaturated double bonds in one molecule, for example, alkyl (meth)propionic acid esters such as 2-ethylhexyl (meth)propionate and cyclohexyl (meth)propionate; hydroxyalkyl (meth)propionic acid esters such as 2-hydroxyethyl (meth)propionate and 2-hydroxypropyl (meth)propionate; mono- or di-(meth)propionic acid esters of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; hexanediol, trimethylolpropane, pentaerythritol, dimethicone ... Polyvalent (meth)propionic acid esters of polyols such as (trimethylol)propane, dipentaerythritol, and trihydroxyethyl isocyanurate, or their ethylene oxide or propylene oxide adducts; (meth)propionic acid esters of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth)propionate and polyethoxydi(meth)propionic acid ester of bisphenol A; (meth)propionic acid esters of glycidyl ethers such as glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and melamine (meth)propionic acid esters. Among these, liquid ones are preferred from the perspectives of reactivity and dilutability.

[0058] Furthermore, as the (C) reactive diluent, a compound having an unsaturated double bond in one molecule and further having a carboxyl group can also be used. As such a compound, a reaction product of a saturated or unsaturated dibasic acid anhydride and a (meth)propionic acid ester having one hydroxyl group per molecule can be used. For example, half esters obtained by reacting a saturated or unsaturated dibasic acid anhydride such as succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, itaconic anhydride, or methylendomethylenetetrahydrophthalic anhydride with a (meth)propionic acid ester having one hydroxyl group per molecule such as hydroxyethyl (meth)propionate, hydroxypropyl (meth)propionate, hydroxybutyl (meth)propionate, polyethylene glycol mono(meth)propionate, glycerol di(meth)propionate, trimethylolpropane di(meth)propionate, pentaerythritol tri(meth)propionate, dipentaerythritol penta(meth)propionate, or (meth)propionic acid ester of phenyl glycidyl ether in an equimolar ratio can be used. These (C) reactive diluents can be used alone or in combination of two or more.

[0059] From the viewpoint of the properties and sensitivity of the formed coating film, the content of the reactive diluent (C) is preferably approximately 2 to 60% by mass, more preferably 10 to 40% by mass, relative to the alkali-soluble resin (A).

[0060] [(D) Thermosetting resin]

[0061] Examples of the thermosetting resin (D) include: polyfunctional epoxy compounds, polyfunctional oxetane compounds, episulfide resins having two or more cyclic ether groups and / or cyclic thioether groups in the molecule; polyisocyanate compounds, blocked isocyanate compounds, etc. having two or more isocyanate groups in one molecule, or compounds having blocked isocyanate groups; melamine resins, benzoguanamine resins, and other amine resins and derivatives thereof; bismaleimides, oxazines, cyclic carbonate compounds, carbodiimide resins, and other well-known thermosetting resins.

[0062] As the epoxy resin, a well-known and commonly used multifunctional epoxy resin having at least two epoxy groups in one molecule can be used. The epoxy resin may be liquid, solid or semisolid. Examples of the multifunctional epoxy resin include: bisphenol A type epoxy resin; brominated epoxy resin; novolac type epoxy resin; bisphenol F type epoxy resin; hydrogenated bisphenol A type epoxy resin; glycidylamine type epoxy resin; hydantoin type epoxy resin; alicyclic epoxy resin; trihydroxyphenylmethane type epoxy resin; bixylenol type or biphenol type epoxy resin or a mixture thereof; bisphenol S type epoxy resin; bisphenol A novolac type epoxy resin; tetrahydroxyphenylmethane type epoxy resin; Examples include, but are not limited to, phenylethane epoxy resins; heterocyclic epoxy resins; diglycidyl phthalate resins; tetraglycidyl ditoluoylethane resins; naphthyl-containing epoxy resins; epoxy resins having a dicyclopentadiene skeleton; glycidyl methacrylate copolymer epoxy resins; cyclohexylmaleimide and glycidyl methacrylate copolymer epoxy resins; epoxy-modified polybutadiene rubber derivatives; and CTBN-modified epoxy resins. Preferred epoxy resins include bisphenol A-type or bisphenol F-type novolac epoxy resins, bixylenol-type epoxy resins, biphenol-type epoxy resins, biphenol novolac (biphenyl aralkyl-type) epoxy resins, naphthalene-type epoxy resins, and mixtures thereof.

[0063] Among them, epoxy resins having a hydrogenated cyclic skeleton are preferred from the viewpoint of improving resolution and light resistance.

[0064] Examples of the epoxy resin having a hydrogenated cyclic skeleton include YX-8000, YX-8034, and YX-8040 manufactured by Mitsubishi Chemical, ST-3000 and ST-4000D manufactured by Nippon Steel Chemical, and EP-4080 manufactured by ADEKA.

[0065] The content of the thermosetting resin (D) described above is preferably in the range of approximately 30 to 90% by mass, more preferably in the range of 40 to 70% by mass, based on the alkali-soluble resin (A).

[0066] [(E) Orthoester compound]

[0067] The orthoester compound (E) discovered in the present invention does not react with the substrate or ink components, and volatilizes during the initial drying process after applying the solder resist composition containing it to the substrate, without remaining in the composition. Therefore, it offers the advantage of suppressing the deactivation of the oxime-bearing photopolymerization initiator (B) while also eliminating the risk of undesirable effects on developability or cured film properties.

[0068] As described above, in the present invention, the (E) orthoester compound is blended together with the (B) photopolymerization initiator having an oxime bond in the same system.

[0069] Preferred examples of the orthoester compound (E) used in the present invention include trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, tributyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, tripropyl orthoacetate, tributyl orthoacetate, trimethyl orthopropionate, triethyl orthopropionate, propyl orthopropionate, and butyl orthopropionate.

[0070] Among them, trimethyl orthoformate, triethyl orthoformate and triethyl orthoacetate are more preferred, and triethyl orthoformate is most preferred.

[0071] The (E) orthoester compound is preferably contained in an amount of 1 to 10% by mass, more preferably 3 to 6% by mass, relative to the total amount of the curing agent composition in the two-component composition in order to effectively exhibit its performance.

[0072] [Colorant]

[0073] As the colorant, a known colorant can be used. In addition, the colorant may be used alone or in combination of two or more.

[0074] As the colorant, commonly used and well-known colorants such as red, blue, green, yellow, white, and black can be used, and any of them can be pigments, dyes, and pigments. More specifically, as the colorant, a colorant with a color index (CI; issued by The Society of Dyers and Colourists) number can be mentioned.

[0075] As red colorants, there are: monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, quinacridone, etc. As blue colorants, there are: phthalocyanine, anthraquinone, etc., and pigments can use compounds classified as pigments. In addition, metal-substituted or unsubstituted phthalocyanine compounds can also be used. As green colorants, there are: phthalocyanine, anthraquinone, perylene. In addition, metal-substituted or unsubstituted phthalocyanine compounds can also be used. As yellow colorants, there are: monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, anthraquinone, etc. As white colorants, rutile or anatase titanium oxide can be mentioned. Examples of black colorants include carbon black, graphite, iron oxide, titanium black, iron oxide, anthraquinone, cobalt oxide, copper oxide, manganese oxide, antimony oxide, nickel oxide, perylene, aniline, molybdenum sulfide, and bismuth sulfide. Furthermore, purple, orange, and brown colorants may be added to adjust the color tone.

[0076] When the curable resin composition of the present invention is used as a solder resist composition, the content of the colorant is 0.03 to 7% by mass, more preferably 0.05 to 5% by mass, based on the total amount of the curable resin composition of the present invention in terms of solid content.

[0077] Here, the curable resin composition of the present invention can be suitably used for a black shielding agent or the like using a highly sensitive photopolymerization initiator so as to suppress the deactivation of the (B) photopolymerization initiator having an oxime bond.

[0078] When the curable resin composition of the present invention is used as a black masking agent, etc., the content of the colorant is preferably 5 to 50% by mass, calculated as solid content, relative to the total amount of the curable resin composition of the present invention, from the viewpoint of improving the hiding power of the cured product. This allows for achieving both hiding power and resolution, and is more preferably 10 to 30% by mass.

[0079] When the curable resin composition of the present invention is used as a black masking agent, etc., it is preferable to include carbon black as a colorant, and preferably to use carbon black in combination with a mixed black colorant. In particular, when using carbon black and a mixed black colorant in combination, the carbon black is preferably present in an amount of 4 to 10% by mass and the mixed black colorant is present in an amount of 8 to 20% by mass, based on the total amount of the curable resin composition, calculated as solids.

[0080] It should be noted that a mixed black colorant refers to a colorant obtained by mixing colorants such as red, blue, green, yellow, violet, and orange to produce a black or near-black color. The mixed black colorant is preferably added to the resin composition after premixing the colorants. However, the colorants that constitute the mixed black colorant can be added separately to the resin composition.

[0081] [Other ingredients]

[0082] The curable resin composition of the present invention may, of course, contain further additives as other components as necessary within the scope of the object of the present invention.

[0083] Examples of such components include: (B) photopolymerization initiators other than photopolymerization initiators having an oxime bond, solvents, thermal inhibitors, ultraviolet absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, antioxidants, antibacterial / antifungal agents, leveling agents, thickeners, adhesion-imparting agents, thixotropy-imparting agents, photoinitiator aids, sensitizers, photobase generators, thermoplastic resins, elastomers, organic fillers such as urethane beads, inorganic fillers, release agents, surface treatment agents, dispersants, dispersing aids, surface modifiers, stabilizers, phosphors, and cellulose resins.

[0084] [cured material]

[0085] When forming a cured product using the curable composition of the present invention, the composition is applied to a substrate, and after the solvent is evaporated and dried, the obtained resin layer is exposed (light irradiated) so that the exposed portion (light-irradiated portion) is cured. Specifically, a contact or non-contact method is used, and active energy rays are selectively used for exposure by forming a patterned photomask, or a laser direct exposure machine is used to directly perform pattern exposure, and the unexposed portion is developed using an alkaline aqueous solution (e.g., a 0.3-3% by mass sodium carbonate aqueous solution) to form a resist pattern. Further heating to a temperature of about 100-180°C and heat curing (post-curing) can form a cured film (cured product) having excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties.

[0086] [Electronic components]

[0087] In addition, the present invention provides an electronic component comprising the cured product.

[0088] By using the curable resin composition of the present invention, it is possible to provide an electronic component having high quality, durability, and reliability.

[0089] It should be noted that the electronic components in the present invention refer to components used in electronic circuits, including active components such as printed circuit boards, transistors, light-emitting diodes, laser diodes, etc., as well as passive components such as resistors, capacitors, inductors, connectors, etc.

[0090] [Methods for producing and using the curable resin composition of the present invention]

[0091] The curable resin composition of the present invention can be prepared by mixing and dispersing the components of the main agent composition and the curing agent composition in predetermined amounts using, for example, a three-roll mill. These two compositions can be prepared in advance and then mixed at the time of use.

[0092] The coating film formed using the curable resin composition of the present invention is obtained as follows.

[0093] First, a curable resin composition is applied to a substrate, and after the solvent is evaporated and dried, the obtained resin layer is exposed (light irradiated) so that the exposed portion (light-irradiated portion) is cured. Specifically, a contact or non-contact method is used to selectively expose the film using active energy rays by forming a patterned photomask, or a laser direct exposure machine is used to directly expose the pattern. Thereafter, the unexposed portion is developed using an alkaline aqueous solution (e.g., a 0.3-3% by mass sodium carbonate aqueous solution) to form a resist pattern. Further heating to a temperature of about 100-180°C and heat curing (post-curing) can form a cured film having excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties.

[0094] Here, the curable resin composition of the present invention can be adjusted to a viscosity suitable for the coating method using an organic solvent, and then applied to a substrate by a method such as dip coating, flow coating, roll coating, bar coating, screen printing, or curtain coating, and then the organic solvent contained in the composition is evaporated and dried (temporary drying) at a temperature of about 60 to 100° C. to form a non-sticky resin layer.

[0095] As substrates, in addition to printed circuit boards and flexible printed circuit boards with circuits pre-formed from copper or the like, there can also be mentioned: copper-clad laminates of all grades (FR-4, etc.), as well as metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates, etc. The copper-clad laminates use materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, and copper-clad laminates for high-frequency circuits using fluororesin / polyethylene / polyphenylene ether (polyphenylene oxide) / cyanate ester, etc.

[0096] Volatilization drying or thermal curing can be carried out, for example, using a hot air circulation drying furnace, IR furnace, hot plate, convection oven, etc. (using a device with a heat source that uses steam to heat the air, a method of making the hot air in the dryer contact by convection, and a method of blowing it onto the support using a nozzle).

[0097] As an exposure machine used in active energy ray irradiation, any device that irradiates ultraviolet rays in the range of 350 to 450 nm using a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc. can be used. Furthermore, a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser using CAD data from a computer) can also be used. The maximum wavelength of the lamp light source or laser light source of the direct drawing machine can be in the range of 350 to 410 nm. The exposure amount used for image formation varies depending on the film thickness, etc., and generally can be set to 20 to 2000 mJ / cm 2 , preferably 20 to 1500 mJ / cm 2 within the range.

[0098] As the developing method, immersion, showering, spraying, brushing, etc. can be used, and as the developing solution, an alkaline aqueous solution of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc. can be used.

[0099] Example

[0100] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is of course not limited to the following Examples.

[0101] It should be noted that, unless otherwise specified, "parts" and "%" are expressed on a mass basis.

[0102] As described below, a two-component curable resin composition consisting of a base composition and a curing agent composition was prepared.

[0103] Example 1

[0104] 100 parts of alkali-soluble resin, 7.2 parts of photopolymerization initiator, 3.8 parts of additives, 28.6 parts of reactive diluent, 553.3 parts of solvent A, 10.0 parts of carbon black, 10.0 parts of perylene red and 10.0 parts of phthalocyanine blue were mixed and dispersed using a triple-roll mill to obtain the main agent composition of Example 1.

[0105] On the other hand, 56.7 parts of thermosetting resin, 4.0 parts of photopolymerization initiator A having an oxime bond, 20.0 parts of solvent B, and 4.0 parts of trimethyl orthoformate were mixed and dispersed using a triple roll mill to obtain a curing agent composition of Example 1.

[0106] Example 2

[0107] By the same method as in Example 1, the main agent composition of Example 2 was obtained.

[0108] On the other hand, a curing agent composition of Example 2 was obtained by the same method as in Example 1 except that trimethyl orthoformate was replaced with triethyl orthoformate.

[0109] Example 3

[0110] By the same method as in Example 1, the main agent composition of Example 3 was obtained.

[0111] On the other hand, a curing agent composition of Example 3 was obtained by the same method as in Example 1 except that trimethyl orthoformate was replaced with triethyl orthoacetate.

[0112] Example 4

[0113] By the same method as in Example 1, the main agent composition of Example 4 was obtained.

[0114] On the other hand, except that the photopolymerization initiator A having an oxime bond was replaced with the photopolymerization initiator B having an oxime bond, the same method as in Example 1 was carried out to obtain a curing agent composition of Example 4.

[0115] Example 5

[0116] By the same method as in Example 1, the main agent composition of Example 5 was obtained.

[0117] On the other hand, except that the photopolymerization initiator A having an oxime bond was replaced with the photopolymerization initiator B having an oxime bond, the same method as in Example 2 was carried out to obtain a curing agent composition of Example 5.

[0118] Example 6

[0119] By the same method as in Example 1, the main agent composition of Example 6 was obtained.

[0120] On the other hand, except that the photopolymerization initiator A having an oxime bond was replaced with the photopolymerization initiator B having an oxime bond, the same method as in Example 3 was carried out to obtain a curing agent composition of Example 6.

[0121] Example 7

[0122] By the same method as in Example 1, the main agent composition of Example 6 was obtained.

[0123] On the other hand, a curing agent composition of Example 7 was obtained by the same method as in Example 2 except that triethyl orthoformate was replaced with 0.8 parts.

[0124] Example 8

[0125] By the same method as in Example 1, the main agent composition of Example 6 was obtained.

[0126] On the other hand, a curing agent composition of Example 7 was obtained by the same method as in Example 2 except that triethyl orthoformate was replaced with 9.0 parts.

[0127] Comparative Example 1

[0128] 100 parts of alkali-soluble resin, 7.2 parts of photopolymerization initiator, 3.8 parts of additives, 28.6 parts of reactive diluent, 553.3 parts of solvent A, 10.0 parts of carbon black, 10.0 parts of perylene red and 10.0 parts of phthalocyanine blue were mixed and dispersed using a triple roll mill to obtain the main agent composition of Comparative Example 1.

[0129] On the other hand, 56.7 parts of a thermosetting resin, 4.0 parts of a photopolymerization initiator A having an oxime bond, and 20.0 parts of a solvent B were mixed and dispersed using a triple roll mill to obtain a curing agent composition of Comparative Example 1.

[0130] Comparative Example 2

[0131] By the same method as in Comparative Example 1, the main agent composition of Comparative Example 2 was obtained.

[0132] On the other hand, a curing agent composition of Comparative Example 2 was obtained by the same method as in Comparative Example 1 except that the compounding amount of the photopolymerization initiator A having an oxime bond was changed to 8.0 parts.

[0133] Comparative Example 3

[0134] By the same method as in Comparative Example 1, a main agent composition of Comparative Example 3 was obtained.

[0135] On the other hand, a curing agent composition of Comparative Example 3 was obtained by the same method as in Comparative Example 1 except that the compounding amount of the photopolymerization initiator A having an oxime bond was changed to 12.0 parts.

[0136] Comparative Example 4

[0137] By the same method as in Comparative Example 1, a main agent composition of Comparative Example 4 was obtained.

[0138] On the other hand, except that the photopolymerization initiator A having an oxime bond was replaced with the photopolymerization initiator B having an oxime bond, the same method as in Comparative Example 1 was carried out to obtain a curing agent composition of Comparative Example 4.

[0139] The compositions of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 1 below.

[0140] [Table 1]

[0141] Table 1: Composition of curable resin composition

[0142]

[0143] Alkali-soluble resin: Cyclomer P(ACA)Z250 (Daicel Co., Ltd.) (carboxyl group-containing acrylic copolymer with an alicyclic skeleton)

[0144] Photopolymerization initiator: Omnirad TPO (IGM Resins)

[0145] Additive: BYK-361N (nonionic surfactant; BYK Corporation)

[0146] Reactive diluent: LR8863 (EO-modified trimethylolpropane tripropionate; BASF Japan Co., Ltd.)

[0147] Solvent A: DOWANOL PM (propylene glycol monomethyl ether; Dow Chemical Japan Co., Ltd.)

[0148] Carbon black: MA-100 (carbon black, Mitsubishi Chemical Corporation)

[0149] Perylene Red (Perylene Red Colorant) (CI Pigment Red 149)

[0150] Phthalocyanine Blue (Phthalocyanine Blue Colorant) (CI Pigment Blue 15:3)

[0151] Thermosetting resin: YX-8034 (hydrogenated bisphenol A epoxy resin; Mitsubishi Chemical Corporation)

[0152] Photopolymerization initiator A with oxime bond: TOE-04-A3 (Nippon Chemical Industry Co., Ltd.)

[0153] Photopolymerization initiator B having an oxime bond: Irgacure OXE02 (BASF Japan Co., Ltd.)

[0154] Solvent B: Propylene carbonate (propylene carbonate; Kanto Chemical Co., Ltd.)

[0155] Test example

[0156] The curable resin compositions of Examples 1 to 8 and Comparative Examples 1 to 4 were tested for sensitivity of coating films prepared from these samples after being left at 50°C for 7 days to determine the extent to which deactivation of the photopolymerization initiator having an oxime bond could be suppressed.

[0157] Test methods

[0158] <Coating Film Production>

[0159] After the main agent compositions of Examples 1 to 8 and Comparative Examples 1 to 4 were well mixed with the curing agent compositions, they were applied on a glass substrate with an applicator so that the film thickness after drying became 10 μm. Thereafter, they were dried in a hot air circulation drying oven at 80° C. for 30 minutes to produce each coating film (initial).

[0160] Separately, base compositions and curing agent compositions were prepared, and each was placed in a thermostatic chamber at 50°C for 7 days. They were then mixed and dried in the same manner as above to produce a coating film (after 7 days at 50°C).

[0161] Sensitivity

[0162] A STEP Tablet (Kodak No. 2) was placed on each of the dried coating films and an exposure device using a metal halide lamp was used at 1000 mJ / cm 2 The film was exposed to an exposure dose of 100 nm and developed at 30° C. for 1 minute using a 1% by mass sodium carbonate aqueous solution at a spray pressure of 0.2 MPa. The sensitivity was evaluated based on the residual level and gloss level obtained using a STEP Tablet.

[0163] The results are shown in Table 2 below.

[0164] [Table 2]

[0165] Table 2: Sensitivity of coating films

[0166]

[0167] [OD value]

[0168] The glass substrate (initial, after 7 days at 50°C) prepared in the above coating preparation was placed with its coating side facing the measuring instrument and attached to a transmission densitometer (manufactured by Sakata Inx Corporation, model: X-Rite 361T, light source wavelength: 400-800 nm) to evaluate the OD value. The evaluation criteria are as follows.

[0169] ○···OD value exceeds 4

[0170] △···OD value is 3 or more and 4 or less

[0171] ×···OD value is lower than 3

[0172] Results

[0173] In Examples 1 to 8, it was found that the decrease in sensitivity, both in the initial residual level and the gloss level, after 7 days at 50°C was effectively suppressed. This is believed to be because the addition of the (E) orthoester compound effectively suppressed the deactivation of the photopolymerization initiator having an oxime bond over time. This confirmed that the curable resin composition of the present invention exhibits excellent storage stability under relatively harsh conditions.

[0174] Although the results of OD value evaluation are omitted in Table 2, Examples 1 to 8 showed that both the initial OD value and the OD value after 7 days at 50° C. were greater than 4 (evaluation standard: 0).

[0175] The evaluation results of the OD values of Comparative Examples 1 to 4 are omitted in Table 2. However, the initial OD values exceeded 4 (evaluation standard: 0). However, no coating film was formed after 7 days at 50°C, and evaluation was not possible.

[0176] Thus, the curable resin composition of the present invention effectively suppresses deactivation of the photopolymerization initiator having an oxime bond over time, and therefore does not experience a change in the initial OD value and the OD value after 7 days at 50° C., making it suitable for use as a black masking agent.

Claims

1. An alkali-developable curable resin composition comprising at least: (A) an alkali-soluble resin, (B) a photopolymerization initiator having an oxime bond, (C) a reactive diluent, and (D) a thermosetting resin, wherein the composition is an alkali-developable curable resin composition of at least a two-component system comprising a main agent composition and a curing agent composition, wherein: The alkali-soluble resin (A) contains one or more functional groups selected from the group consisting of phenolic hydroxyl, mercapto, and carboxyl groups, and is mixed with the main agent composition. The (B) photopolymerization initiator having an oxime bond is blended into a curing agent composition that is different from the main agent composition containing the (A) alkali-soluble resin, and is blended together with at least one (E) orthoester compound.

2. The alkali-developable curable resin composition according to claim 1, wherein The (E) orthoester compound is at least one selected from the group consisting of trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, tributyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, tripropyl orthoacetate, tributyl orthoacetate, trimethyl orthopropionate, triethyl orthopropionate, propyl orthopropionate, and butyl orthopropionate.

3. The alkali-developable curable resin composition according to claim 1 or 2, wherein The (E) orthoester compound is at least one selected from the group consisting of trimethyl orthoformate, triethyl orthoformate, and triethyl orthoacetate.

4. The alkali-developable curable resin composition according to claim 1 or 2, wherein The (E) orthoester compound is triethyl orthoformate.

5. A solidified product, characterized in that: This is obtained by curing the alkali-developable curable resin composition according to any one of claims 1 to 4. An electronic component comprising the cured product according to claim 5 .

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