Two-component curable resin composition, products, dry films, cured products, and printed circuit boards

Abstract

To provide a two-pack curable resin composition which prevents generation of an exposed-copper phenomenon and is excellent in a packaging form (storage property) in conveyance while excellent in dispersibility and printability after mixing of an A agent and a B agent.SOLUTION: A two-pack curable resin composition contains an agent A containing a carboxyl group-containing resin, and an agent B containing a thermosetting component, wherein viscosity of a 5 rpm value at 25°C of the agent A is within a range of 50 dPa s or more and 200 dPa s or less, viscosity of 5 rpm value at 25°C of the agent B is within a range of 100 dPa s or more and 300 dPa s or less, a degree of dispersion in a grind gauge after mixing of the agent A and the agent B is 20 μm or less, and with respect to the total content of the agent A and the agent B, a mixing ratio of the agent A is 75 mass% or more and less than 100 mass%, and a mixing ratio of the agent B is more than 0 mass% and 25 mass% or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a two-component curable resin composition. The present invention also relates to a product filled with the two-component curable resin composition in a container. Furthermore, the present invention relates to a dry film, a cured product, and a printed wiring board using the two-component curable resin composition.

Background Art

[0002] Currently, for most solder resists of printed wiring boards, from the viewpoints of high precision and high density, a liquid alkali-developable solder resist (curable resin composition) that forms an image by developing after exposure and forms a coating film by heat curing is used. As such a curable resin composition, from the viewpoint of storage stability, the attention of two-component types is increasing compared to one-component types. For example, in a photocurable / thermocurable resin composition containing a carboxyl group-containing resin, a reactive diluent, and an epoxy compound, the epoxy resin is blended in a composition different from at least the composition blended with the above carboxyl group-containing resin and reactive diluent, and it has been proposed to be composed of at least a two-component system (see Patent Document 1).

[0003] In the two-component curable resin composition as described above, it is used by mixing the two components before use. Adjustment of the viscosity after mixing is to be performed by the ink supplier before shipment. In recent years, from the viewpoint of improving the yield during component mounting, the film thickness of the coating film has been thinned (for example, Patent Document 2). In recent years, more strict film thickness control has been required for thinner films.

[0004] However, in the two-component curable resin composition, since a plurality of components are mixed to satisfy various required characteristics, when the mixing state of each component is insufficient, a concentration imbalance may occur in the two-component curable resin composition. Therefore, the film thickness of the coating film before drying applied to a substrate or the like using the two-component curable resin composition varies, and particularly in the case of a thin film, for example, an appearance defect due to "copper visible" where the metal (copper) wiring of the underlying substrate becomes uneven and is visible through the film may become a problem. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2004 / 048434 [Patent Document 2] Japanese Patent Publication No. 2004-264560 [Overview of the project] [Problems that the invention aims to solve]

[0006] In two-component curable resin compositions, two components are often used: component A containing a carboxyl group-containing resin and component B containing a thermosetting component. When curing such a two-component curable resin composition, the crosslinking reaction between the carboxyl group-containing resin and the thermosetting component improves the crosslinking density, thereby improving the uniformity and density of the cured coating film, providing a solder resist effect, and suppressing the copper appearance phenomenon. However, if the dispersibility of at least one of component A or B is poor, the dispersibility of component A and B after mixing may also be poor. As a result, the copper appearance phenomenon may occur. Therefore, one example of a method to improve the dispersibility of both component A and B is bead mill dispersion. Bead mill dispersion requires low viscosity. However, if both component A and B are made low viscosity, the viscosity after mixing tends to become too low, making it unsuitable for screen printing. Also, if component B contains a filler and has high viscosity, the viscosity after mixing can be made suitable for screen printing, but there is still room for improvement in the dispersibility after mixing due to the poor dispersibility of component B. On the other hand, in two-component curable resin compositions, the main component and the curing agent are filled into separate containers for transport, resulting in larger packaging and increased transportation costs, which presents room for improvement.

[0007] Therefore, an object of the present invention is to provide a two-component curable resin composition that exhibits excellent dispersibility and printability after mixing of agent A and agent B, does not cause copper-like appearance, and has excellent packaging form (storability) during transport. Another object of the present invention is to provide a dry film having a resin layer made of a dried coating film of the resin composition, a cured product of the resin composition or the resin layer of the dry film, and a printed circuit board having the cured product. [Means for solving the problem]

[0008] As a result of diligent research, the inventors have discovered that by adjusting the viscosity range of components A and B, as well as the mixing ratio of components A and B, it is possible to obtain a two-component curable resin composition that exhibits excellent dispersibility and printability after mixing of components A and B, does not cause copper-like appearance, allows for smaller packaging, and reduces transportation costs. This has led to the completion of the present invention. In this specification, "after mixing" refers to the period after mixing and stirring.

[0009] In other words, the two-component curable resin composition according to the present invention is a two-component curable resin composition comprising agent A containing a carboxyl group-containing resin and agent B containing a thermosetting component, The viscosity of agent A at 25°C at 5 rpm is within the range of 50 dPa·s to 200 dPa·s. The viscosity of agent B at 25°C at 5 rpm is within the range of 100 dPa·s to 300 dPa·s. The dispersion of agent A and agent B in a grind gauge after mixing is 20 μm or less, the mixing ratio of agent A is 75% by mass or more and less than 100% by mass with respect to the total amount of agent A and agent B, and the mixing ratio of agent B is greater than 0% by mass and 25% by mass or less.

[0010] In an embodiment of the present invention, it is preferable that the viscosity at 5 rpm at 25°C after mixing agent A and agent B is within the range of 30 dPa·s to 200 dPa·s.

[0011] In an embodiment of the present invention, it is preferable that the viscosity of agent B is higher than that of agent A, and that the difference between the viscosity of agent A at 25°C at 5 rpm and the viscosity of agent B at 25°C at 5 rpm is in the range of greater than 0 dPa·s and less than or equal to 250 dPa·s.

[0012] In an embodiment of the present invention, it is preferable that the thermosetting component includes a polyfunctional epoxy compound.

[0013] A product according to another aspect of the present invention is characterized in that the two-component curable resin composition, component A and component B, are filled in separate containers, and at least one of component A and component B is filled in a bag.

[0014] A dry film according to another aspect of the present invention is characterized by comprising a first film and a resin layer consisting of a dried coating film of the two-component curable resin composition formed on the first film.

[0015] A cured product according to another aspect of the present invention is characterized by being obtained by curing the resin layer of the two-component curable resin composition or the dry film.

[0016] Another embodiment of the present invention is a printed circuit board characterized by comprising the cured material. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a two-component curable resin composition that exhibits excellent dispersibility and printability after mixing of agent A and agent B, does not cause copper-like appearance, and has excellent packaging form (storability) during transport. Furthermore, according to the present invention, it is possible to provide a dry film having a resin layer made of a dried coating film of the resin composition, a cured product of the resin composition or the resin layer of the dry film, and a printed wiring board having the cured product. [Modes for carrying out the invention]

[0018] [Two-component curable resin composition] The two-component curable resin composition according to the present invention consists of Agent A and Agent B. Agent A contains at least a carboxyl group-containing resin and may further contain a photopolymerizable monomer, a photoinitiator, a sensitizer, a thermosetting catalyst, an extender pigment, a colorant, etc., as long as it satisfies the following viscosity. Agent B contains at least a thermosetting component and may further contain an organic solvent, a photopolymerizable monomer, a photoinitiator, a thermosetting catalyst, an extender pigment, etc., as long as it satisfies the following viscosity.

[0019] The viscosity of Agent A at 5 rpm at 25°C is within the range of 50 dPa·s or more and 200 dPa·s or less, preferably within the range of 70 dPa·s or more and 150 dPa·s or less, and more preferably within the range of 100 dPa·s or more and 120 dPa·s or less. If the viscosity of Agent A at 5 rpm at 25°C is within the above numerical range, the dispersibility can be improved, and as a result, a coating film without the copper visible phenomenon can be formed. The viscosity of Agent B at 5 rpm at 25°C is within the range of 100 dPa·s or more and 300 dPa·s or less, preferably within the range of 150 dPa·s or more and 300 dPa·s or less, and more preferably within the range of 200 dPa·s or more and 300 dPa·s or less. If the viscosity of Agent B at 5 rpm at 25°C is within the above numerical range, the dispersibility can be improved, and as a result, a coating film without the copper visible phenomenon can be formed. In the present invention, the viscosity was measured according to JIS-Z8803:2011, specifically, the 30-second value measured under the conditions of 25°C and a rotor rotation speed of 5.0 rpm using a cone-plate type rotational viscometer (manufactured by Toki Sangyo Co., Ltd., TVE-33H, rotor 3°×R9.7) in accordance with 10 "Viscosity measurement method using a cone-plate rotational viscometer" of JIS-Z8803:2011 was taken as the viscosity.

[0020] With respect to the total amount of Agent A and Agent B, the mixing ratio of Agent A is 75% by mass or more and less than 100% by mass, preferably 77% by mass or more and 97% by mass or less, more preferably 80% by mass or more and 95% by mass or less, and the mixing ratio of Agent B is more than 0% by mass and 25% by mass or less, preferably 3% by mass or more and 23% by mass or less, more preferably 5% by mass or more and 20% by mass or less.

[0021] The viscosity at 5 rpm at 25°C after mixing Agent A and Agent B is preferably in the range of 30 dPa·s or more and 200 dPa·s or less, more preferably in the range of 60 dPa·s or more and 160 dPa·s or less, and even more preferably in the range of 90 dPa·s or more and 130 dPa·s or less.

[0022] If the mixing ratio of Agent A and Agent B is within the above range, the volume ratio of Agent B decreases, and as a result, the packaging property is improved.

[0023] The degree of dispersion in the grind gauge after mixing Agent A and Agent B is 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less. If the degree of dispersion is within the above numerical range, a coating film without a copper visibility phenomenon can be formed particularly by screen printing. The degree of dispersion in the grind gauge in the present invention is measured by the granular method using a grind gauge with a width of 90 mm, a length of 240 mm, and a maximum depth of 50 μm in accordance with JIS K 5600-2-5:1999. The granular method is specifically as follows. That is, observe the point at which significant spots start to appear on the product (the sample to be measured). In particular, observe the point where 5 to 10 particles are included in a 3 mm-wide band along the groove. Ignore the sparse spots that appear before the point where significant spots start to appear.

[0024] In the two-component curable resin composition of the present invention, the viscosity of component B at 25°C at 5 rpm is preferably higher than that of component A, and the difference in viscosity between component A and component B at 25°C at 5 rpm is preferably in the range of greater than 0 dPa·s and less than or equal to 250 dPa·s. The higher viscosity of component B reduces dripping during filling, resulting in excellent workability and productivity. It is more preferably in the range of greater than 0 dPa·s and less than or equal to 200 dPa·s, and even more preferably in the range of greater than 0 dPa·s and less than or equal to 150 dPa·s.

[0025] [product] The two-component curable resin composition of the present invention is provided as a product in which agent A and agent B are filled in separate containers. Both agent A and agent B are preferably filled into containers such as bags, aluminum foil containers, packaging wrap film containers, or syringes from the viewpoint of environmental protection and packaging form (storability) during transport, and among these, agent B, which has high viscosity, is more preferably filled into a bag. A pouch is preferred as the bag. Examples of materials include a film made by laminating (processing) a synthetic resin such as polypropylene on the filling side and polyester (PET) on the outside or aluminum foil. Furthermore, when a bag is used as the container for agent A or agent B, it is preferable to increase the proportion of agent A or agent B to the bag, as this provides a two-component curable resin composition with even better packaging properties, and it is more preferable that the bag be small. The proportion of agent A or agent B is preferably 50 to 100% by volume.

[0026] The following describes the components that make up agent A and agent B of the two-component curable resin composition according to the present invention.

[0027] [Components of Agent A] [Carboxyl group-containing resin] As the carboxyl group-containing resin, various conventionally known resins having carboxyl groups in their molecules can be used. By including a carboxyl group-containing resin in a two-component curable resin composition, alkali developability can be imparted to the two-component curable resin composition. In particular, carboxyl group-containing photosensitive resins having an ethylenically unsaturated double bond in their molecules are preferred in terms of photocurability and developability. The ethylenically unsaturated double bond is preferably derived from acrylic acid, methacrylic acid, or their derivatives. When using only carboxyl group-containing resins that do not have an ethylenically unsaturated double bond, it is necessary to use a compound having multiple ethylenically unsaturated groups in its molecule, i.e., a photopolymerizable monomer, as described later, in order to make the composition photocurable. Specific examples of carboxyl group-containing resins include the following compounds (which may be either oligomers or polymers).

[0028] (1) A carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid such as (meth)acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth)acrylate, or isobutylene.

[0029] (2) A carboxyl group-containing urethane resin obtained by polyaddition reaction of diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates with carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and diol compounds such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

[0030] (3) A carboxyl group-containing photosensitive urethane resin obtained by polyaddition reactions of diisocyanate with (meth)acrylates or partially acid anhydride-modified products thereof of difunctional epoxy resins such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, and biphenol type epoxy resin, carboxyl group-containing dialcohol compounds, and diol compounds.

[0031] (4) A carboxyl group-containing photosensitive urethane resin obtained by adding a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule, such as hydroxyalkyl (meth)acrylate, during the synthesis of the resin of (2) or (3) above, and then (meth)acrylicating the terminal (meth)acrylic.

[0032] (5) A carboxyl group-containing photosensitive urethane resin in which a compound having one isocyanate group and one or more (meth)acryloyl groups in the molecule is added to the resin of (2) or (3) above during synthesis and then (meth)acrylicated at the terminal.

[0033] (6) A carboxyl group-containing photosensitive resin obtained by reacting a bifunctional or polyfunctional (solid) epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride to the hydroxyl groups present in the side chain.

[0034] (7) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy resin, in which the hydroxyl groups of a bifunctional (solid) epoxy resin are further epoxidized with epichlorohydrin, with (meth)acrylic acid, and then adding a dibasic acid anhydride to the resulting hydroxyl groups.

[0035] (8) A carboxyl group-containing polyester resin obtained by reacting a bifunctional oxetane resin with dicarboxylic acids such as adipic acid, phthalic acid, and hexahydrophthalic acid, and adding dibasic acid anhydrides such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride to the resulting primary hydroxyl groups.

[0036] (9) A carboxyl group-containing photosensitive resin obtained by reacting an epoxy compound having multiple epoxy groups in one molecule with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol, and an unsaturated group-containing monocarboxylic acid such as (meth)acrylic acid, and then reacting the alcoholic hydroxyl group of the resulting reaction product with a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic acid.

[0037] (10) A carboxyl group-containing photosensitive resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, reacting the reaction product with an unsaturated group-containing monocarboxylic acid, and then reacting the resulting reaction product with a polybasic acid anhydride.

[0038] (11) A carboxyl group-containing photosensitive resin obtained by reacting a reaction product obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate with an unsaturated group-containing monocarboxylic acid, and then reacting the resulting reaction product with a polybasic acid anhydride.

[0039] (12) A carboxyl group-containing photosensitive resin obtained by adding a compound having one epoxy group and one or more (meth)acryloyl groups in one molecule to the resins of (1) to (11) above.

[0040] In this specification, (meth)acrylate is a general term referring to acrylates, methacrylates, and mixtures thereof, and the same applies to other similar expressions.

[0041] The carboxyl group-containing resins that can be used in the present invention are not limited to those listed above. Furthermore, the carboxyl group-containing resins listed above may be used individually or in combination of multiple types.

[0042] In the present invention, considering the developability and resist pattern drawing properties when using a weakly alkaline developer such as an aqueous sodium carbonate solution, the acid value of the carboxyl group-containing resin is preferably in the range of 30 to 150 mg KOH / g, and more preferably in the range of 50 to 120 mg KOH / g. Although the developability improves as the acid value of the carboxyl group-containing resin increases, the dissolution of the exposed areas by the developer progresses, and in some cases, the exposed and unexposed areas may be dissolved and peeled off by the developer without distinction.

[0043] The weight-average molecular weight of carboxyl group-containing resins varies depending on the resin skeleton, but is generally in the range of 2,000 to 150,000, with those in the range of 3,000 to 100,000 being preferred. Using carboxyl group-containing resins with a weight-average molecular weight of 2,000 or more can improve resolution and tack-free performance. Furthermore, using carboxyl group-containing resins with a weight-average molecular weight of 150,000 or less can improve developability and storage stability. The weight-average molecular weight can be measured by gel permeation chromatography (GPC).

[0044] The content of carboxyl group-containing resin in agent A can be appropriately set according to the desired viscosity of agent A. The content of carboxyl group-containing resin in agent A is preferably 20 to 80% by mass, and more preferably 25 to 75% by mass, in terms of solid content of the total amount of agent A.

[0045] [Components of Agent B] [Thermosetting component] Any known thermosetting component can be used. The inclusion of a thermosetting component in a two-component curable resin composition can improve the heat resistance of the cured film. Examples of known thermosetting components include melamine resin, benzoguanamine resin, melamine derivatives, amino resins such as benzoguanamine derivatives, isocyanate compounds, blocked isocyanate compounds, cyclocarbonate compounds, epoxy compounds, oxetane compounds, episulfide resins, bismaleimide, and carbodiimide resins. Particularly preferred are thermosetting components having multiple cyclic ether groups or cyclic thioether groups (hereinafter abbreviated as cyclic (thio) ether groups) in their molecules. The thermosetting component can be used alone or in combination of two or more.

[0046] The thermosetting components having multiple cyclic (thio) ether groups in the molecule described above are compounds having multiple 3, 4, or 5-membered cyclic (thio) ether groups in the molecule. Examples include compounds having multiple epoxy groups in the molecule, i.e., polyfunctional epoxy compounds; compounds having multiple oxetanyl groups in the molecule, i.e., polyfunctional oxetane compounds; and compounds having multiple thio ether groups in the molecule, i.e., episulfide resins. Polyfunctional epoxy compounds are particularly preferred.

[0047] Examples of such polyfunctional epoxy compounds include bisphenol A type epoxy resins, bisphenol F type epoxy resins, hydrogenated bisphenol A type epoxy resins, brominated bisphenol A type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, biphenyl type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, and triphenylmethane type epoxy resins.

[0048] Examples of commercially available epoxy resins include jER 828, 806, 807, YX8000, YX8034, 834 from Mitsubishi Chemical Corporation; YD-128, YDF-170, ZX-1059, ST-3000 from Nippon Steel Chemical & Material Corporation; EPICLON 830, 835, 840, 850, N-730A, N-695 from DIC Corporation; and RE-306 from Nippon Kayaku Co., Ltd.

[0049] Examples of polyfunctional oxetane compounds include bis[(3-methyl-3-oxetanylmethoxy)methyl] ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl] ether, 1,4-bis[(3-methyl-3-oxetanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, (3-methyl-3-oxetanyl)methyl acrylate, and (3-ethyl-3-oxetanyl)methyl acrylate. Examples include polyfunctional oxetanes such as relates, (3-methyl-3-oxetanyl)methyl methacrylate, (3-ethyl-3-oxetanyl)methyl methacrylate, and their oligomers or copolymers, as well as ethers of oxetane alcohols with resins having hydroxyl groups such as novolac resins, poly(p-hydroxystyrene), cardo-type bisphenols, calixarenes, calixresorcinarenes, or silsesquioxane. Other examples include copolymers of unsaturated monomers having an oxetane ring with alkyl (meth)acrylates.

[0050] Examples of compounds having multiple cyclic thioether groups in their molecules include bisphenol A-type episulfide resins. Furthermore, episulfide resins obtained by replacing the oxygen atoms in the epoxy groups of novolac-type epoxy resins with sulfur atoms using a similar synthesis method can also be used.

[0051] Examples of amino resins such as melamine derivatives and benzoguanamine derivatives include methylolmelamine compounds, methylolbenzoguanamine compounds, methylol glycol uryl compounds, and methylol urea compounds.

[0052] Polyisocyanate compounds can be incorporated as isocyanate compounds. Examples of polyisocyanate compounds include aromatic polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, and 2,4-tolylene dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate), and isophorone diisocyanate; alicyclic polyisocyanates such as bicycloheptane triisocyanate; and adducts, biuret compounds, and isocyanurates of the isocyanate compounds mentioned above.

[0053] As the blocking isocyanate compound, the addition reaction product of an isocyanate compound and an isocyanate blocking agent can be used. Examples of isocyanate compounds that can react with an isocyanate blocking agent include the polyisocyanate compounds mentioned above. Examples of isocyanate blocking agents include phenol-based blocking agents, lactam-based blocking agents, active methylene-based blocking agents, alcohol-based blocking agents, oxime-based blocking agents, mercaptan-based blocking agents, acid amide-based blocking agents, imide-based blocking agents, amine-based blocking agents, imidazole-based blocking agents, and imine-based blocking agents.

[0054] The content of the thermosetting component in agent B can be appropriately set according to the desired viscosity of agent B. The content of the thermosetting component in agent B is preferably 20 to 100% by mass, and more preferably 25 to 100% by mass, of the total amount of agent B in terms of solid content.

[0055] [An ingredient that may be contained in at least one of Agent A and Agent B] [Photopolymerization initiator] Photopolymerization initiators are used to react carboxyl group-containing resins or photopolymerizable monomers upon exposure to light. Any known photopolymerization initiator can be used. A single photopolymerization initiator may be used, or two or more may be used in combination.

[0056] Examples of photopolymerization initiators include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylphenylphosphate. Bisacylphosphine oxides such as tylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinate methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloyl Monoacyl phosphine oxides such as isopropyl phenylphosphinate and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate, 1-hydroxycyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methyl-propan-1-one Hydroxyacetophenones such as 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, Michlar's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone;Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl)-1-[4-(4-morpholinyl)phenyl]-1-bu Acetophenones such as tanone and N,N-dimethylaminoacetophenone; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone Anthraquinones such as 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, and p-dimethylbenzoate ethyl ester; 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], etanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetylo Examples include oxime esters such as xime; titanosenes 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; phenyl disulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, and tetramethylthiuram disulfide.

[0057] 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 Omnirad TPO H and 819 from IGM Resins. 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.

[0058] Other examples include carbazole oxime ester compounds described in Japanese Patent Publication No. 2004-359639, Japanese Patent Publication No. 2005-097141, Japanese Patent Publication No. 2005-220097, Japanese Patent Publication No. 2006-160634, Japanese Patent Publication No. 2008-094770, Japanese Patent Publication No. 2008-509967, Japanese Patent Publication No. 2009-040762, and Japanese Patent Publication No. 2011-80036.

[0059] The content of the photopolymerization initiator in agent A can be appropriately set according to the desired viscosity of agent A. When agent A contains a photopolymerization initiator, its content is preferably more than 0% by mass and 20% by mass or less, and more preferably 0.5 to 10% by mass, based on solid content. Furthermore, if the B component contains a photopolymerization initiator, its content can be appropriately set according to the desired viscosity of the B component. The content of the photopolymerization initiator in the B component is preferably more than 0% by mass and 20% by mass or less, and more preferably 0.5 to 10% by mass, based on solid content. Furthermore, when a photopolymerization initiator is included in the two-component curable resin composition, its content is preferably more than 0% by mass and 20% by mass or less, and more preferably 0.5 to 10% by mass, based on solid content. When the photopolymerization initiator content in the two-component curable resin composition is greater than 0% by mass, the photocurability of the two-component curable resin composition is good, and the film properties such as chemical resistance are also good. On the other hand, when it is 20% by mass or less, light absorption at the surface of the resist film (cured film) is good, and the deep curing properties are less likely to decrease.

[0060] In combination with the above-mentioned photopolymerization initiator, a photoinitiator or sensitizer may be used. Examples of photoinitiators or sensitizers include benzoin compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthone compounds. In particular, it is preferable to use thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone. The inclusion of a thioxanthone compound can improve deep curing properties. These compounds can sometimes be used as photopolymerization initiators, but it is preferable to use them in combination with a photopolymerization initiator. Furthermore, one type of photoinitiator or sensitizer may be used alone, or two or more types may be used in combination.

[0061] These photopolymerization initiators, photoinitiators, and sensitizers absorb specific wavelengths, which can sometimes lead to reduced sensitivity and cause them to function as UV absorbers. However, they are not used solely for the purpose of improving the sensitivity of resin compositions. By absorbing light of specific wavelengths as needed, they can enhance the photoreactivity of the surface, change the line shape and aperture of the resist pattern to vertical, tapered, or reverse tapered shapes, and improve the accuracy of line width and aperture diameter.

[0062] [Photopolymerizable monomers] The two-component curable resin composition of the present invention may contain photopolymerizable monomers. Photopolymerizable monomers are monomers having an ethylenically unsaturated double bond. Examples of such photopolymerizable monomers include: alkyl (meth)acrylates such as 2-ethylhexyl (meth)acrylate and cyclohexyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; mono- or di(meth)acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, and dipentaerythritol. Examples include polyhydric alcohols such as trishydroxyethyl isocyanurate or polyhydric (meth)acrylates of ethylene oxide or propylene oxide adducts thereof; (meth)acrylates of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth)acrylate and polyethoxydigestyl (meth)acrylate of bisphenol A; (meth)acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and melamine (meth)acrylate. Photopolymerizable monomers may be used individually or in combination of two or more.

[0063] The content of photopolymerizable monomers in agent A can be appropriately set according to the desired viscosity of agent A. When agent A contains photopolymerizable monomers, the content is preferably 0 to 30% by mass, and more preferably 5 to 20% by mass, of the total amount of agent A in terms of solid content. Furthermore, if the B component contains a photopolymerizable monomer, its content can be appropriately set according to the desired viscosity of the B component. When the B component contains a photopolymerizable monomer, its content is preferably more than 0% by mass and 30% by mass or less, and more preferably 5 to 20% by mass, in terms of solid content of the total composition. Furthermore, the content of photopolymerizable monomers in the two-component curable resin composition is preferably more than 0% by mass and 30% by mass or less, and more preferably 5 to 20% by mass, based on solid content. When the content of photopolymerizable monomers in the two-component curable resin composition is greater than 0% by mass, the photocurability is good and pattern formation is easy during alkaline development after irradiation with active energy rays. On the other hand, when the content is 30% by mass or less, halation is less likely to occur and good resolution can be obtained.

[0064] [Thermosetting catalyst] The two-component curable resin composition of the present invention may be formulated with a thermosetting catalyst. Examples of thermosetting catalysts include imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, and 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacate dihydrazide; and phosphorus compounds such as triphenylphosphine. Furthermore, commercially available examples include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, and 2P4MHZ (all trade names for imidazole compounds) manufactured by Shikoku Chemicals, Inc., and U-CAT 3513N (trade name for a dimethylamine compound), DBU, DBN, and U-CAT SA 102 (all bicyclic amidine compounds and their salts) manufactured by Sunapro Co., Ltd. In particular, it is not limited to these, and any thermosetting catalyst for epoxy resins or oxetane compounds, or any catalyst that promotes the reaction between at least one of an epoxy group and an oxetanyl group and a carboxyl group, may be used, either alone or in combination of two or more.

[0065] Furthermore, S-triazine derivatives such as guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine isocyanuric acid adduct can also be used, and preferably these compounds that also function as adhesion imparters are used in combination with the thermosetting catalyst. The thermosetting catalyst may be used alone or in combination of two or more types.

[0066] The content of the thermosetting catalyst in agent A can be appropriately set according to the desired viscosity of agent A. When agent A contains a thermosetting catalyst, its content is preferably more than 0% by mass and 20% by mass or less, and more preferably 1 to 10% by mass, based on solid content of the total amount of agent A. Furthermore, the content of the thermosetting catalyst in agent B can be appropriately set according to the desired viscosity of agent B. When agent B contains a thermosetting catalyst, its content is preferably more than 0% by mass and 20% by mass or less, and more preferably 1 to 10% by mass, based on solid content. Furthermore, when a thermosetting catalyst is included in the two-component curable resin composition, its content is preferably more than 0% by mass and 20% by mass or less, and more preferably 1 to 10% by mass, based on solid content. When the thermosetting catalyst content in the two-component curable resin composition is greater than 0% by mass, it exhibits excellent heat resistance. On the other hand, when it is 20% by mass or less, it leads to improved stability over time.

[0067] [Coloring agent] The two-component curable resin composition of the present invention may contain a coloring agent. The coloring agent is not particularly limited, and known coloring agents such as red, blue, green, and yellow can be used. It may be a pigment, dye, or colorant, but from the viewpoint of reducing environmental impact and minimizing effects on the human body, a halogen-free coloring agent is preferred.

[0068] Red colorants include monoazo, disazo, azolake, benzimidazolon, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone, and specifically those that are assigned a color index (CI; issued by The Society of Dyers and Colorists) number, as follows:

[0069] Examples of monoazo-based red colorants include Pigment Red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151, 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, and 269. Examples of disazo-based red colorants include Pigment Red 37, 38, and 41. Examples of monoazolake-based red colorants include Pigment Red 48:1, 48:2, 48:3, 48:4, 49:1, 49:2, 50:1, 52:1, 52:2, 53:1, 53:2, 57:1, 58:4, 63:1, 63:2, 64:1, and 68. Examples of benzimidazolone-based red colorants include Pigment Red 171, 175, 176, 185, and 208. Examples of perylene-based red colorants include Solvent Red 135, 179, Pigment Red 123, 149, 166, 178, 179, 190, 194, and 224. Examples of diketopyrrolopyrrole-based red colorants include Pigment Red 254, 255, 264, 270, and 272. Examples of condensed azo-based red colorants include Pigment Red 220, 144, 166, 214, 220, 221, and 242. Examples of anthraquinone-based red colorants include Pigment Red 168, 177, and 216, and Solvent Red 149, 150, 52, and 207. Examples of quinacridone-based red colorants include Pigment Red 122, 202, 206, 207, and 209.

[0070] Blue colorants include phthalocyanine-based and anthraquinone-based compounds, while pigment-based compounds include those classified as pigments, such as Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, and 60. Dye-based compounds such as Solvent Blue 35, 63, 68, 70, 83, 87, 94, 97, 122, 136, 67, and 70 can be used. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

[0071] Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolon, isoindolinone, and anthraquinone. For example, anthraquinone yellow colorants include Solvent Yellow 163, Pigment Yellow 24, 108, 193, 147, 199, and 202. Isoindolinone yellow colorants include Pigment Yellow 110, 109, 139, 179, and 185. A condensed azo yellow colorant is Pigment Yellow Examples include 93, 94, 95, 128, 155, 166, and 180. Examples of benzimidazolone-based yellow colorants include Pigment Yellow 120, 151, 154, 156, 175, and 181. Examples of monoazo-based yellow colorants include Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62:1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, and 183. Examples of disazo-based yellow colorants include Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, and 198.

[0072] Other colorants such as purple, orange, brown, and black may be added. Specifically, examples include Pigment Black 1, 6, 7, 8, 9, 10, 11, 12, 13, 18, 20, 25, 26, 28, 29, 30, 31, 32; Pigment Violet 19, 23, 29, 32, 36, 38, 42; Solvent Violet 13, 36; CIPigment Orange 1, 5, 13, 14, 16, 17, 24, 34, 36, 38, 40, 43, 46, 49, 51, 61, 63, 64, 71, 73; Pigment Brown 23, 25; and Carbon Black.

[0073] The content of the coloring agent in agent A can be appropriately set according to the desired viscosity of agent A. When agent A contains a coloring agent, its content is preferably more than 0% by mass and 10% by mass or less, and more preferably 0.2 to 5% by mass, based on solid content. The content of the coloring agent in component B can be appropriately set according to the desired viscosity of component B. When component B contains a coloring agent, its content is preferably more than 0% by mass and 10% by mass or less of the total amount of component B in terms of solid content. Furthermore, if a colorant is included in the two-component curable resin composition, its content is preferably more than 0% by mass and 10% by mass or less, and more preferably 0.2 to 5% by mass, based on solid content.

[0074] [Body pigments] The two-component curable resin composition of the present invention may contain extender pigments. Examples of extender pigments include silica such as barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, and spherical silica, as well as talc, clay, Neuburg silica particles, boehmite, magnesium carbonate, calcium carbonate, titanium dioxide, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, and calcium zirconate. Extender pigments may be used individually or in combination of two or more. The inclusion of extender pigments can improve heat resistance and reduce variations during application.

[0075] The content of the extender pigment in Agent A can be appropriately set according to the desired viscosity of Agent A. When Agent A contains an extender pigment, its content is preferably 10 to 60% by mass, and more preferably 20 to 50% by mass, of the total amount of Agent A in terms of solid content. The content of the extender pigment in component B can be appropriately set according to the desired viscosity of component B. When component B contains an extender pigment, its content is preferably 0% by mass or more and 70% by mass or less of the total amount of component B in terms of solid content. Furthermore, if the two-component curable resin composition contains an extender pigment, its content is preferably 5 to 70% by mass, and more preferably 10 to 50% by mass, of the total composition in terms of solid content.

[0076] [Organic solvents] The two-component curable resin composition of the present invention may contain an organic solvent for purposes such as preparing the composition or adjusting its viscosity when applying it to a substrate or film. As organic solvents, known and commonly used organic solvents can be used, such as ketones like methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons like toluene, xylene, and tetramethylbenzene; glycol ethers like cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; esters like ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons like octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha. These organic solvents may be used individually or in combination of two or more.

[0077] The content of the organic solvent in Agent A can be appropriately set according to the desired viscosity of Agent A. When Agent A contains an organic solvent, its content is preferably 10 to 50% by mass, and more preferably 20 to 40% by mass, of the total amount of Agent A. The content of the organic solvent in Agent B can be appropriately set according to the desired viscosity of Agent B. When Agent B contains an organic solvent, its content is preferably 1 to 60% by mass, and more preferably 5 to 50% by mass, of the total amount of Agent B. Furthermore, if the two-component curable resin composition contains an organic solvent, its content is preferably 10 to 50% by mass, and more preferably 20 to 40% by mass, of the total amount of the composition.

[0078] [Other additives] The two-component curable resin composition of the present invention may optionally contain further components such as photoinitiators, cyanate compounds, elastomers, mercapto compounds, urethane catalysts, thixonating agents, adhesion promoters, block copolymers, chain transfer agents, polymerization inhibitors, copper damage inhibitors, antioxidants, rust inhibitors, thickeners such as fine silica, organic bentonite, and montmorillonite, defoaming agents and / or leveling agents such as silicone-based, fluorine-based, and polymer-based agents, silane coupling agents such as imidazole-based, thiazole-based, and triazole-based agents, and flame retardants such as phosphinates, phosphate ester derivatives, and phosphorus compounds such as phosphazene compounds. These components may be those known in the field of electronic materials.

[0079] [Preparation method] To prepare the above-mentioned Agent A and Agent B, each component is weighed and mixed, then pre-mixed in a stirrer. Subsequently, the components are dispersed in a kneader and kneaded to prepare the mixture.

[0080] Examples of the mixing machines mentioned above include bead mills, ball mills, sand mills, three-roll mills, and two-roll mills. Among these, bead mills are preferable in terms of improving dispersibility. For example, by using a bead mill to prepare agent A and a three-roll mill to prepare agent B, it becomes easier to adjust the viscosity of agent A and agent B, and the difference between their viscosities, within a desired range. The dispersion conditions of a bead mill, such as the type of beads and rotation speed, can be appropriately set according to the desired viscosity. Similarly, the dispersion conditions of a three-roll mill, such as the rotation ratio of each roll, can be appropriately set according to the desired viscosity.

[0081] [Application] The two-component curable resin composition according to the present invention is useful for forming pattern layers as permanent coatings for printed circuit boards, such as solder resists, coverlays, and interlayer insulating layers, and is particularly useful for forming solder resists. Furthermore, since the two-component curable resin composition of the present invention can form cured products with excellent film strength even when thin, it can be suitably used for forming pattern layers in printed circuit boards where thinness is required, such as package substrates (printed circuit boards used in semiconductor packages). Moreover, cured products obtained from the two-component curable resin composition of the present invention can also be suitably used in flexible printed circuit boards.

[0082] Furthermore, the two-component curable resin composition of the present invention can be used not only for forming a patterned layer in a cured film, but also for applications that do not require the formation of a patterned layer, such as molding applications (sealing applications).

[0083] [Dry film] The two-component curable resin composition of the present invention can also be in the form of a dry film comprising a first film and a resin layer formed on the first film, which consists of a dried coating of the two-component curable resin composition. For dry film formation, the A and B components of the two-component curable resin composition of the present invention are mixed and stirred in a predetermined ratio, then diluted with the above organic solvent as needed to adjust to an appropriate viscosity, and applied to the first film to a uniform thickness using a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, spray coater, etc., and dried at a temperature of 50 to 130°C for 1 to 30 minutes to obtain a film. There are no particular restrictions on the coating film thickness, but generally, the film thickness after drying is appropriately selected within the range of 1 to 150 μm, preferably 10 to 60 μm.

[0084] The first film can be any known film without particular limitations, and for example, films made of thermoplastic resins such as polyester films (polyethylene terephthalate, polyethylene naphthalate, etc.), polyimide films, polyamide-imide films, polypropylene films, and polystyrene films can be suitably used. Among these, polyester films are preferred from the viewpoint of heat resistance, mechanical strength, and ease of handling. Laminates of these films can also be used as the first film.

[0085] Furthermore, from the viewpoint of improving mechanical strength, the thermoplastic resin film described above is preferably a film stretched in one or two axes.

[0086] The thickness of the first film is not particularly limited, but can be, for example, 10 μm to 150 μm.

[0087] After forming a resin layer consisting of a dried coating film of the two-component curable resin composition of the present invention on the first film, it is preferable to further laminate a peelable second film onto the surface of the resin layer (the side opposite to the first film) for purposes such as preventing dust from adhering to the surface of the resin layer. As the peelable second film, for example, polyethylene film, polytetrafluoroethylene film, polypropylene film, surface-treated paper, etc., it is sufficient that the adhesive force between the resin layer and the second film is less than the adhesive force between the resin layer and the first film when the second film is peeled off.

[0088] The thickness of the second film is not particularly limited, but can be, for example, 10 μm to 150 μm.

[0089] To create a cured coating on a printed circuit board using a dry film, a second film is peeled off from the dry film, the exposed resin layer of the dry film is placed on the circuit-formed substrate, and the two are bonded together using a laminator or the like to form a resin layer on the circuit-formed substrate. Then, the formed resin layer is exposed to light, developed, and heat-cured to form a cured coating. The first film can be peeled off either before or after exposure.

[0090] [Cured product] The cured product of the present invention is obtained by curing the resin layer of the two-component curable resin composition of the present invention or the dry film of the present invention. The cured product of the present invention can be suitably used in printed circuit boards, electronic components, and the like. Because the cured product of the present invention has excellent flexibility, it can be particularly suitably used in flexible printed circuit boards. Furthermore, the cured product of the present invention also has excellent infrared shielding properties and long-term stability.

[0091] [Printed wiring board] The printed circuit board of the present invention has a cured product obtained from the resin layer of the two-component curable resin composition of the present invention or a dry film. As a method for manufacturing the printed circuit board of the present invention, for example, the two-component curable resin composition of the present invention is adjusted to a viscosity suitable for the coating method using the above-mentioned organic solvent, and applied to a substrate by methods such as dip coating, flow coating, roll coating, bar coating, screen printing, or curtain coating. Then, the organic solvent contained in the composition is evaporated and dried (pre-dried) at a temperature of 60 to 100°C to form a tack-free resin layer. In the case of a dry film, the resin layer is bonded to the substrate using a laminator or the like so that the resin layer is in contact with the substrate, and then the first film is peeled off to form a resin layer on the substrate.

[0092] The above-mentioned substrates include printed circuit boards and flexible printed circuit boards with circuits pre-formed using copper, etc., as well as materials such as copper-clad laminates for high-frequency circuits using paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / nonwoven epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, fluororesin / polyethylene / polyphenylene ether, polyphenylene oxide / cyanate, etc., and can be described as copper-clad laminates of all grades (FR-4, etc.), as well as metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafers, etc.

[0093] The dry film is preferably laminated onto the substrate under pressure and heat using a vacuum laminator or the like. By using such a vacuum laminator, even if the circuit-formed substrate has irregularities on its surface, the dry film adheres closely to the circuit board, preventing the inclusion of air bubbles and improving the ability to fill in depressions on the substrate surface. The pressure is preferably around 0.1 to 2.0 MPa, and the heating is preferably around 40 to 120°C.

[0094] The volatilization drying performed after applying the two-component curable resin composition of the present invention can be carried out using a hot air circulation drying oven, an IR oven, a hot plate, a convection oven, etc. (a method in which hot air inside the dryer is brought into countercurrent contact with a heat source that uses steam to heat the air, and a method in which hot air is blown onto the support from a nozzle).

[0095] After forming a resin layer on a substrate, it is selectively exposed to active energy rays through a photomask with a predetermined pattern, and the unexposed areas are developed with a dilute alkaline aqueous solution (for example, a 0.3-3% by mass sodium carbonate aqueous solution) to form the pattern of the cured product. In the case of a dry film, after exposure, the first film is peeled off from the dry film and developed to form a patterned cured product on the substrate. However, within the limits that do not impair the properties, the first film may be peeled off from the dry film before exposure, and the exposed resin layer may be exposed and developed.

[0096] Furthermore, by irradiating the cured material with active energy rays followed by heat curing (for example, 100-220°C), or irradiating it with active energy rays after heat curing, or by performing final finishing curing (main curing) by heat curing alone, a cured film with excellent properties such as adhesion and hardness can be formed.

[0097] The exposure machine used for the above-mentioned active energy ray irradiation can be any device equipped with a high-pressure mercury lamp, ultra-high-pressure mercury lamp, metal halide lamp, mercury short-arc lamp, etc., that irradiates ultraviolet light in the range of 350 to 450 nm. Furthermore, a direct writing device (for example, a laser direct imaging device that directly draws images with a laser using CAD data from a computer) can also be used. The lamp light source or laser light source of the direct writing device can have a maximum wavelength in the range of 350 to 450 nm. The exposure amount for image formation varies depending on the film thickness, etc., but is generally 10 to 1000 mJ / cm². 2 Preferably 20-800 mJ / cm² 2 It can be within the range of

[0098] The above-mentioned development method can be the dipping method, shower method, spray method, brush method, etc., and alkaline aqueous solutions such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, and amines can be used as the developing solution. [Examples]

[0099] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the following, "parts" and "%" all refer to mass unless otherwise specified.

[0100] (Synthesis of carboxyl group-containing resin varnish 1) 220 parts of cresol novolac epoxy resin (DIC Corporation, EPICLON N-695, epoxy equivalent: 220) were placed in a four-necked flask equipped with a stirrer and reflux condenser, and 214 parts of carbitol acetate were added and heated until dissolved. Next, 0.1 parts of hydroquinone as a polymerization inhibitor and 2.0 parts of dimethylbenzylamine as a reaction catalyst were added. This mixture was heated to 95-105°C, and 72 parts of acrylic acid were gradually added dropwise, and the mixture was reacted for 16 hours. The reaction product was cooled to 80-90°C, 106 parts of tetrahydrophthalic anhydride were added, and the mixture was reacted for 8 hours. After cooling, the product was removed. Thus, a carboxyl group-containing resin varnish 1 was obtained with a solid acid value of 100 mg KOH / g, a solid content of 65%, and a weight-average molecular weight Mw of approximately 3,500.

[0101] (Preparation of Agent A and Agent B) For each composition of Agent A, the components were mixed according to the formulations shown in Table 1 below and stirred with a stirrer. Subsequently, the composition of Formulation Example 1 was dispersed and kneaded using a bead mill to prepare it. The compositions of Formulation Examples 2, 3, and 6 were dispersed and kneaded using a three-roll mill to prepare them. Furthermore, for each composition of Agent B, the components were mixed according to the formulations shown in Table 2 below, stirred with a stirrer, and then the compositions of Formulation Examples 4, 5, and 7 were stirred for 10 minutes using a drilling machine with a stirring blade (rotation speed: 500 rpm). The composition of Formulation Example 6 was dispersed and kneaded using a three-roll mill. The dispersion using the bead mill described above was performed under the following conditions: Each composition was dispersed using 1.0 mm zirconia beads in a horizontal wet mill (manufactured by Bühler AG) with a bead filling rate of 85% at an agitator rotation speed of 1,000 rpm. Furthermore, for the dispersion using the roll mill described above, each composition was dispersed using a three-roll mill manufactured by Inoue Seisakusho Co., Ltd., with the three rolls rotating at a rotation ratio of 1:3:9 and a roll rotation speed of 360 rpm.

[0102] [Table 1]

[0103] The amounts in Table 1 are shown in parts by mass. The details of each component in Table 1 are as follows: *1: The carboxyl group-containing resin varnish 1 synthesized above, the amount added is calculated on a solid content basis. *2: Dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) *3: 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane (manufactured by IGM Resins, Inc., Omnirad 907) *4:2,4-Diethylthioxanthone (manufactured by Nippon Kayaku Co., Ltd., KAYACURE DETX-S) *5: Dicyandiamide *6: Barium sulfate (manufactured by Sakai Chemical Industry Co., Ltd., B-30) *7: Red coloring agent (Paliogen Red K3580, manufactured by BASF Japan Ltd.) *8: Diethylene glycol monoethyl ether acetate *9: Dipropylene glycol methyl ether

[0104] [Table 2]

[0105] The amounts in Table 2 represent parts by mass. The details of each component in Table 2 are as follows: *10: Cresol novolac type epoxy resin (EOCN-1020, manufactured by Nippon Kayaku Co., Ltd.) *11: Bisphenol A type epoxy resin (manufactured by DIC Corporation, EPICLON 850-S) *12: Barium sulfate (manufactured by Sakai Chemical Industry Co., Ltd., B-30) *13: Diethylene glycol monoethyl ether acetate

[0106] (Examples 1-2, Comparative Examples 1-4) (Preparation of two-component curable resin composition) The above-mentioned A and B components were diluted with an organic solvent (carbitol acetate) as needed to achieve the viscosity values ​​shown in Table 3. Subsequently, the viscosity-adjusted A and B components were mixed and stirred at the mixing ratio (mass) shown in Table 3 to obtain the two-component curable resin compositions of Examples 1-2 and Comparative Examples 1-4. The obtained two-component curable resin compositions were evaluated according to the following. The results are shown in Table 3 below. The stirring method for A and B components was manual stirring (5 minutes).

[0107] (viscosity) 0.2 ml of each of the two-component curable resin compositions prepared above (A, B, and each example and comparative example) was taken, and measured using a cone-plate viscometer (TV-33H, manufactured by Toki Sangyo Co., Ltd.) at 25°C and a rotation speed of 5 rpm (shear rate 10 -1 The viscosity at 30 seconds was measured. The measurement results are shown in Table 3. Except for the above, the measurements were performed in accordance with JIS-Z8803:2011, section 10, "Method for measuring viscosity using a cone-plate rotational viscometer."

[0108] (dispersibility) The dispersion of the two-component curable resin compositions of Examples 1-2 and Comparative Examples 1-4 (after mixing with the prepared A and B agents) obtained above was measured using the granular method in accordance with JIS K 5600-2-5:1999, with a grind gauge measuring 90 mm in width, 240 mm in length, and a maximum depth of 50 μm. Specifically, the point at which significant spots began to appear in each mixture was observed. In particular, points containing 5-10 particles in a 3 mm wide band along the groove were observed. Sparse spots appearing before the point at which significant spots began to appear were ignored. The measurement results are shown in Table 3.

[0109] (Printability) The two-component curable resin compositions of Examples 1-2 and Comparative Examples 1-4 obtained above (after mixing with the prepared A and B agents) were screen printed using a 180-mesh polyester plate (with bias) on a 300mm x 150mm copper foil substrate with a 35μm thickness and a buffed surface, so that the cured film thickness would be 12μm. The print quality was evaluated according to the following criteria. The evaluation results are shown in Table 3. ○: Both the release of the printing plate from the substrate and the sagging of the printed ink on the substrate are excellent. ×: Either the printing plate release from the circuit board after printing is poor, or the ink applied to the circuit board is poor.

[0110] (Confirmation of the copper-like appearance phenomenon) For the two-component curable resin compositions of Examples 1-2 and Comparative Examples 1-4 (after mixing with the prepared A and B agents), solid prints were made using screen printing with a 180-mesh polyester plate (with bias) on a 300mm x 150mm copper foil substrate with a 35μm thickness whose surface had been buffed. The printed prints were then cured at 150°C for 60 minutes using a hot air circulation drying oven (DF610, manufactured by Yamato Scientific Co., Ltd.), and allowed to cool at room temperature for 30 minutes under a yellow lamp to prepare evaluation substrates. In all of the prepared evaluation substrates, a cloth soaked in isopropyl alcohol (IPA) was placed on the surface of the cured coating film in an environment of 25°C and 50%RH. A 500g weight was then placed on top of the cloth and left for 1 minute. After that, the cloth was removed, and it was confirmed that all or part of the resin layer was not adhering to the surface of the cloth that had been in contact with the cured coating film. Subsequently, areas within a 70mm x 70mm area where the underlying copper was visible were examined using an optical microscope (50x magnification). The evaluation results are shown in Table 3. ○: No areas where copper was visible were found. ×: Areas where copper is visible were identified.

[0111] (Packaging) This evaluation was conducted to assess the packaging (storability) during transportation. The amounts of Agent A and Agent B in each example and comparative example were confirmed so that the total amount of Agent A and Agent B was 1,000g. The optimal container capable of holding these amounts was selected, and 10 sets were packed into a 280mm x 360mm x 300mm cardboard box. The storage capacity was evaluated as packaging efficiency. The evaluation was conducted according to the following criteria. The evaluation results are shown in Table 3. ○: It was possible to store it with plenty of room to spare. ×: There was insufficient storage space, or it was not possible to store at least one of Agent A and Agent B. The containers listed in Table 3 refer to the following types of containers. Packaging: Pouch (Material: Aluminum (body / exterior), Contents: Approx. 300mL) Plastic containers: Black polyethylene containers, Part A container BHS-1200 black (manufactured by Kinki Container Co., Ltd., material: HDPE (body), capacity: approx. 1,200 mL) and Part B container BHS-300 black (manufactured by Kinki Container Co., Ltd., material: HDPE (body), capacity: approx. 310 mL)

[0112] [Table 3]

[0113] As is clear from Table 3, the two-component curable resin composition of the example exhibits excellent dispersibility and printability after mixing of component A and component B, while also not exhibiting the copper-like appearance phenomenon and having excellent packaging (storability) during transport.

Claims

1. A two-component curable resin composition comprising agent A containing a carboxyl group-containing resin and agent B containing a thermosetting component, The viscosity of agent A at 25°C at 5 rpm is in the range of 50 dPa·s or more and 150 dPa·s or less. The viscosity of agent B at 25°C at 5 rpm is within the range of 100 dPa·s to 300 dPa·s. The degree of dispersion in the grind gauge after mixing agent A and agent B is 20 μm or less. A two-component curable resin composition characterized in that, with respect to the total amount of agent A and agent B, the mixing ratio of agent A is 75% by mass or more and less than 100% by mass, and the mixing ratio of agent B is greater than 0% by mass and 25% by mass or less.

2. The two-component curable resin composition according to claim 1, wherein the viscosity at 5 rpm at 25°C after mixing agent A and agent B is in the range of 30 dPa·s to 200 dPa·s.

3. The two-component curable resin composition according to claim 1 or 2, wherein the viscosity of agent B is higher than that of agent A, and the difference between the viscosity of agent A at 5 rpm at 25°C and the viscosity of agent B at 5 rpm at 25°C is in the range of greater than 0 dPa·s and less than or equal to 250 dPa·s.

4. The two-component curable resin composition according to claim 1 or 2, wherein the viscosity of agent A at 25°C at 5 rpm is in the range of 50 dPa·s to 120 dPa·s.

5. The two-component curable resin composition according to claim 1 or 2, wherein the thermosetting component comprises a polyfunctional epoxy compound.

6. A product in which component A and component B of the two-component curable resin composition according to claim 1 or 2 are filled in separate containers, A product in which at least one of agent A and agent B is filled into a bag.

7. A dry film comprising a first film and a resin layer formed on the first film, the resin layer being a dried coating film of the two-component curable resin composition according to claim 1 or 2.

8. A cured product characterized by being obtained by curing the two-component curable resin composition described in claim 1 or 2.

9. A printed circuit board characterized by comprising the cured material described in claim 8.

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