JP2022080252A - Curable resin composition and dry film - Google Patents

Abstract

To provide a curable resin composition having excellent cleaning and removing performance in the case where the composition is attached and dried on a blending tub or a tool used in a production process of solder-resist ink.SOLUTION: A curable resin composition of the present invention contains (A) curable resin, (B) filler and (C) organic solvent, wherein dissolving start time of a completely dried coating film having the length 20 mm×width 20 mm×thickness 7 μm which is formed by using the curable resin composition with respect to propyleneglycol monomethylether acetate being cleaning solvent is within 20 seconds from the start of immersion into the cleaning solvent.SELECTED DRAWING: None

Description

The present invention relates to a curable resin composition. More specifically, the present invention relates to a curable resin composition having excellent wash-removability. The present invention also relates to a dry film using the curable resin composition.

Generally, solder resist ink is an insulating ink for the purpose of preventing solder adhesion to unnecessary parts and protecting circuits when soldering parts to printed wiring boards of electronic devices, and is a liquid type or dry film type. Used in. The curable resin composition used as a solder resist ink is composed of a curable resin as a main raw material, an organic solvent, a filler, and the like (see, for example, Patent Document 1).

By the way, in the manufacturing process of solder resist ink, the mixture is mixed in a cauldron tub, pre-dispersed by a mixing stirrer such as a dissolver, a planetary mixer, and a butterfly mixer, and used as a kneader such as a three-roll mill, a bead mill, and a blender. Is evenly dispersed. Since it is an important issue to uniformly disperse the powder in a highly viscous liquid using these mixing stirrers and kneaders, various instruments have been developed and used (see, for example, Patent Document 2). ).

Here, since the solder resist ink forms a pattern by a chemical reaction, it is important to clean the equipment used in order to prevent the mixing of compounds that cause changes in characteristics (see, for example, Patent Document 3). However, it is considered that the cleaning and removal of the solder resist ink, which has undergone a curing reaction, is more difficult than that of a general paint ink.

Japanese Unexamined Patent Publication No. 1-141904 Japanese Unexamined Patent Publication No. 2014-147883 Special Table 2012-52068 Gazette

For repeated use of the compounding tubs and instruments used in the manufacturing process of the solder resist ink, it is desirable that the solder resist ink that has adhered and dried can be easily washed and removed. This is because if it takes a long time to wash and remove, the cost of manufacturing the solder resist ink becomes high. Therefore, an object of the present invention is to provide a curable resin composition having excellent cleaning and removing properties even when it adheres to a compounding tub or an instrument used in the manufacturing process of solder resist ink and dries. Another object of the present invention is to provide a dry film using the curable resin composition.

As a result of diligent research, the present inventors have adjusted the dissolution start time of a completely dry coating film having a length of 20 mm, a width of 20 mm, and a film thickness of 7 μm formed by using a curable resin composition in a specific cleaning solvent. The present invention has been completed by finding that a curable resin composition having excellent wash-removability can be obtained even when it adheres to a compounding tub or an instrument used in the manufacturing process of a solvent resist ink and dries.

That is, the curable resin composition according to the present invention is a curable resin composition containing (A) a curable resin, (B) a filler, and (C) an organic solvent.
The dissolution start time of the completely dry coating film having a length of 20 mm, a width of 20 mm, and a film thickness of 7 μm formed by using the curable resin composition in propylene glycol monomethyl ether acetate as a cleaning solvent is from the start of immersion in the cleaning solvent. It is characterized by being within 20 seconds.

In the aspect of the present invention, it is preferable that the dissolution completion time of the completely dry coating film is within 40 seconds from the start of immersion in the cleaning solvent.

In the aspect of the present invention, the content of propylene glycol monomethyl ether acetate is preferably 20% by mass or more in the curable resin composition.

In the aspect of the present invention, the content of the filler (B) is preferably 45% by mass or less in the curable resin composition.

In the aspect of the present invention, it is preferable that the curable resin (A) contains a carboxyl group-containing resin.

In the embodiment of the present invention, the weight average molecular weight of the carboxyl group-containing resin is preferably 6000 or less.

In the aspect of the present invention, it is preferable that the curable resin contains two or more kinds of carboxyl group-containing resins.

In the aspect of the present invention, it is preferably used for forming a solder resist layer.

In the aspect of the present invention, it is preferably used for forming an interlayer insulating layer.

A dry film according to another aspect of the present invention comprises a first film and a resin layer composed of a dry coating film of a curable resin composition formed on the first film.
The curable resin composition contains (A) a curable resin, (B) a filler, and (C) an organic solvent.
The dissolution start time of the completely dry coating film of 20 mm in length × 20 mm in width × 7 μm in thickness obtained from the dry film in propylene glycol monomethyl ether acetate as a cleaning solvent is within 20 seconds from the start of immersion in the cleaning solvent. It is characterized by being.

According to the present invention, it is possible to provide a curable resin composition having excellent wash-removability even when it adheres to a compounding tub or an instrument used in the manufacturing process of solder resist ink and dries. Further, according to the present invention, it is possible to provide a dry film using the curable resin composition.

It is a schematic diagram of the apparatus used for the measurement of the dissolution start time and the dissolution completion time of a completely dry coating film in an Example.

[Curable resin composition]
The curable resin composition according to the present invention contains (A) a curable resin, (B) a filler, and (C) an organic solvent. The curable resin composition according to the present invention may further contain a photopolymerization initiator, a colorant, an antifoaming agent, a leveling agent, other components, etc., as long as they satisfy the following physical properties. Further, the curable resin may contain any one of a thermosetting resin, a carboxyl group-containing resin and a photopolymerizable monomer, or may be a combination of a plurality of types. By satisfying the following physical properties, the curable resin composition according to the present invention has excellent wash-removability even when it adheres to a compounding tub or an instrument used in the manufacturing process of solder resist ink and dries. It is presumed that this is because the wash-removability (solubility in the wash solvent) of the dried composition (completely dry coating film) is mainly reflected in the dissolution start time in the wash solvent.

[Physical characteristics]
In the curable resin composition of the present invention, the dissolution start time of a completely dry coating film having a length of 20 mm × width of 20 mm × thickness of 7 μm in propylene glycol monomethyl ether acetate as a cleaning solvent is 20 seconds from the start of immersion in the cleaning solvent. It is within, preferably within 15 seconds, more preferably within 10 seconds, further preferably within 9 seconds, and particularly preferably within 8 seconds.
Further, the dissolution completion time of the completely dried coating film is preferably 40 seconds or less, more preferably 30 seconds or less, further preferably 28 seconds or less, and 26 seconds or less from the start of immersion in the cleaning solvent. It is particularly preferably within 25 seconds, and most preferably within 25 seconds.

洗浄溶剤に対する完全乾燥塗膜の溶解過程は、平滑的であった表面が凹凸状になり、完全に塗膜が溶解すると基材表面が現れる。本発明においては、最も乾燥して洗浄しにくい塗膜表面の溶解が目的であるため、溶解の基準は塗膜表面の状態で判断する。 For the formation of the completely dry coating film in the present invention, it is important that the solvent contained in the completely dry coating film is sufficiently volatilized. In the present specification, the criteria for determining that the coating film is completely dry is a dry composition prepared by heating a coating film having a film thickness of 7 μm immediately after being formed by printing or the like at 80 ° C. for 3 hours. It is assumed that the difference in volatility from the composition left at room temperature (25 ° C.) is within 10%. As a method of obtaining the difference in volatilization rate, the weight was measured using an electronic balance and calculated by the following mathematical formula (1). That is, it is judged that a completely dry coating film is formed if the above conditions are satisfied.

In the process of dissolving the completely dry coating film in the cleaning solvent, the smooth surface becomes uneven, and when the coating film is completely dissolved, the surface of the substrate appears. Since the purpose of the present invention is to dissolve the surface of the coating film, which is the most dry and difficult to clean, the criterion for dissolution is determined based on the state of the surface of the coating film.

Hereinafter, each component constituting the curable resin composition according to the present invention will be described.

[(A) Curable resin]
The curable resin includes a thermosetting resin that contributes to a thermosetting reaction by heating, a photocurable resin that contributes to a photocuring reaction by light irradiation, and a photocurable thermosetting resin that contributes to any of the reactions. Can be mentioned. The curable resin composition may contain only one of a thermosetting resin and a photocurable resin, or may contain both.

The content of the curable resin in the curable resin composition is preferably 20 to 80% by mass, more preferably 25 to 75% by mass, and further preferably 50 to 70% by mass in terms of solid content. Is. When the content of the curable resin is within the above range, a more excellent cured product can be obtained. Hereinafter, each curable resin will be described.

[Thermosetting resin]
Any known thermosetting resin can be used. When the curable resin composition contains a thermosetting resin, the heat resistance of the cured coating film can be improved. Examples of the thermosetting resin include known and commonly used resins such as epoxy resins, isocyanate compounds, blocked isocyanate compounds, amino resins, polyfunctional oxetane compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, and episulfide resins. Among these, the preferred thermosetting resin is an epoxy resin. As the thermosetting resin, one type may be used alone or two or more types may be used in combination.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, and cresol novolak type. Examples thereof include epoxy resin, bisphenol A novolak type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin and the like.

Examples of commercially available epoxy resins include jER 828, 806, 807, YX8000, YX8034, 834 manufactured by Mitsubishi Chemical Corporation, YD-128, YDF-170, ZX-1059 manufactured by Nittetsu Chemical & Materials Co., Ltd. Examples thereof include ST-3000, EPICLON 830, 835, 840, 850, N-730A, N-695 manufactured by DIC Corporation, and RE-306 manufactured by Nippon Kayaku Co., Ltd.

As the isocyanate compound, a polyisocyanate compound can be blended. Examples of the polyisocyanate compound include 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate and Aromatic polyisocyanates such as 2,4-tolylene dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate; bicyclo Alicyclic polyisocyanates such as heptanetriisocyanate; and adducts, burettes, and isocyanurates of the isocyanate compounds mentioned above can be mentioned.

As the blocked isocyanate compound, an addition reaction product of the isocyanate compound and the isocyanate blocking agent can be used. Examples of the isocyanate compound that can react with the isocyanate blocking agent include the above-mentioned polyisocyanate compound and the like. Examples of the isocyanate blocking agent 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; imine-based blocking agents and the like can be mentioned.

Examples of the amino resin include a methylol melamine compound, a methylol benzoguanamine compound, a methylol glycol uryl compound, a methylol urea compound and the like.

Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, and 1,4-bis [(3-3-oxythanylmethoxy) methyl] ether. Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-3) Polyfunctional oxetane such as oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and their oligomers or copolymers, as well as oxetane alcohols and novolak resins. , Poly (p-hydroxystyrene), cardo-type bisphenols, calix allenes, calix resorcin allenes, etherified compounds with a resin having a hydroxyl group such as silsesquioxane and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate can also be mentioned.

Regarding the content of the thermosetting resin, when the composition contains a carboxyl group-containing resin described later, the number of functional groups of the thermosetting component that reacts with respect to 1 mol of the carboxyl group contained in the carboxyl group-containing resin is 0.5. It is preferably about 2.5 mol, more preferably 0.8 to 2.0 mol.

The thermosetting component preferably contains an alkali-soluble resin having an alkali-soluble group in that it can impart alkali developability to the composition. Examples of the alkali-soluble resin include a carboxyl group-containing resin, a compound having two or more phenolic hydroxyl groups, a compound having a phenolic hydroxyl group and a carboxyl group, and a compound having two or more thiol groups. Of these, a carboxyl group-containing resin or a phenol resin is preferable because the adhesion to the substrate is improved, and a carboxyl group-containing resin is more preferable because the developability is particularly excellent. Hereinafter, the carboxyl group-containing resin will be described.

As the carboxyl group-containing resin, various conventionally known resins having a carboxyl group in the molecule can be used. The carboxyl group-containing resin may or may not have an ethylenically unsaturated double bond in the molecule, but in particular, it contains a carboxyl group having an ethylenically unsaturated double bond in the molecule. A photosensitive resin is preferable from the viewpoint of photocurability and development resistance. In such a case, it corresponds to a photocurable thermosetting resin. When the curable composition of the present invention contains a carboxyl group-containing resin, it may be used not only for alkaline development but also for non-alkali development. The ethylenically unsaturated double bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof. When only a carboxyl group-containing resin having no ethylenically unsaturated double bond is used, in order to make the composition photocurable, a compound having a plurality of ethylenically unsaturated groups in the molecule described later, that is, light It is necessary to use a polymerizable monomer together. Specific examples of the carboxyl group-containing resin include the following compounds (either oligomer or polymer).

(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, and isobutylene. Examples of the lower alkyl (meth) acrylate include methyl (meth) acrylate).

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates, carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, polycarbonate-based polyols and polyether-based compounds. A carboxyl group-containing urethane resin obtained by a double addition reaction of a diol compound such as a polyol, a polyester-based polyol, a polyolefin-based polyol, an acrylic polyol, a bisphenol A-based alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(3) Diisocyanate and bifunctional epoxy resin 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, biphenol type epoxy resin ( Meta) A carboxyl group-containing photosensitive urethane resin produced by a double addition reaction of an acrylate or a modified partial acid anhydride thereof, a carboxyl group-containing dialcohol compound and a diol compound.

(4) During the synthesis of the resin according to (2) or (3), a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule such as hydroxyalkyl (meth) acrylate is added to the terminal (4). Meta) Acryloylated carboxyl group-containing photosensitive urethane resin.

(5) During the synthesis of the resin according to (2) or (3), one isocyanate group and one or more (meth) acryloyl groups are formed in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. Carboxyl group-containing photosensitive urethane resin that has been acrylicized at the end (meth) by adding the compound.

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

(7) Carboxyl in which (meth) acrylic acid is reacted with a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin, and a dibasic acid anhydride is added to the generated hydroxyl group. Group-containing photosensitive resin.

(8) A dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid is reacted with a bifunctional oxetane resin, and two bases such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride are added to the generated primary hydroxyl group. Carboxyl group-containing polyester resin to which acid anhydride is added.

(9) An epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol, and (meth). It is reacted with an unsaturated group-containing monocarboxylic acid such as acrylic acid, and the alcoholic hydroxyl group of the obtained reaction product is subjected to maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and adipine. A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride such as an acid.

(10) Reaction obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide with an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting a product with a polybasic acid anhydride.

(11) Obtained by reacting an unsaturated group-containing monocarboxylic acid with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate. A carboxyl group-containing photosensitive resin obtained by reacting a reaction product with a polybasic acid anhydride.

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

As the carboxyl group-containing resin, a carboxyl group-containing copolymer resin may be used. Examples of the carboxyl group-containing copolymer resin include the resin of (1) and the copolymer resin of (12). Examples of the resin (12) include glycidyl methacrylate or 3,4-epoxycyclohexylmethyl (meth) acrylate in addition to the carboxyl group-containing resin obtained by the copolymerization of (meth) acrylic acid and methyl (meth) acrylate. Examples thereof include a carboxyl group-containing photosensitive resin obtained by adding a (meth) acrylate having an alicyclic epoxy group.

In addition, in this specification, (meth) acrylate is a generic term for acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

The carboxyl group-containing resin that can be used in the present invention is not limited to those listed above. In addition, one type of the carboxyl group-containing resin listed above may be used alone, or a plurality of types may be mixed and used.

In the present invention, the acid value of the carboxyl group-containing resin is preferably in the range of 30 to 150 mgKOH / g in consideration of the developability when using a weak alkaline developer such as an aqueous sodium carbonate solution and the drawability of the resist pattern. More preferably, it is in the range of 50 to 120 mgKOH / g. Although the higher the acid value of the carboxyl group-containing resin, the higher the developability, the more the exposed portion is dissolved by the developing solution, so that the exposed portion and the unexposed portion may be dissolved and peeled off by the developing solution.

The weight average molecular weight of the carboxyl group-containing resin is preferably 6,000 or less, and preferably 2,000 or more. By using a carboxyl group-containing resin having a weight average molecular weight of 6,000 or less, the solubility of the completely dry coating film in a dissolving solvent can be improved, and the wash-removability can be improved. Further, by using a carboxyl group-containing resin having a weight average molecular weight of 2,000 or more, resolution and tack-free performance can be improved. The weight average molecular weight can be measured by gel permeation chromatography (GPC).

The content of the carboxyl group-containing resin in the curable resin composition is preferably 20 to 80% by mass, more preferably 20 to 75% by mass, and further preferably 20 to 50% by mass in terms of solid content. %. By setting the content to 20% by mass or more, the strength of the cured coating film can be improved. Further, when the content is 80% by mass or less, the viscosity of the curable resin composition becomes appropriate and the workability is improved.

[Photocurable resin]
The photocurable resin is a compound having an ethylenically unsaturated group, and examples thereof include polymers, oligomers, and monomers, and may be a mixture thereof. By including the photocurable resin, the strength of the cured film can be improved. As the photocurable resin, one type may be used alone or two or more types may be used in combination.

As the compound having an ethylenically unsaturated group, known and commonly used photopolymerizable oligomers, photopolymerizable monomers and the like can be used. Among these, it is preferable to use a photopolymerizable monomer in terms of further imparting crosslinkability and curability of the cured coating film.

The photopolymerizable oligomer is an oligomer having an ethylenically unsaturated double bond. Examples of the photopolymerizable oligomer include unsaturated polyester-based oligomers and (meth) acrylate-based oligomers. Examples of the (meth) acrylate-based oligomer include epoxy (meth) acrylates such as phenol novolac epoxy (meth) acrylate, cresol novolak epoxy (meth) acrylate, and bisphenol type epoxy (meth) acrylate, urethane (meth) acrylate, and epoxy urethane (meth). ) Acrylic, polyester (meth) acrylate, polyether (meth) acrylate, polybutadiene-modified (meth) acrylate and the like.

The photopolymerizable monomer is a monomer 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; 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth). Hydroxyalkyl (meth) acrylates such as acrylates; mono or di (meth) acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane , Polyvalent alcohols such as dipentaerythritol, trishydroxyethyl isocyanurate, or polyvalent (meth) acrylates of these ethylene oxides or propylene oxide adducts; phenoxyethyl (meth) acrylates, polyethoxydi (meth) acrylates of bisphenol A, etc. Phenol ethylene oxide or propylene oxide adduct (meth) acrylates; (meth) acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate; and melamine (meth). Acrylate can be mentioned. As the photopolymerizable monomer, one type may be used alone, or two or more types may be used in combination.

The content of the photocurable resin is preferably 3 to 20% by mass, more preferably 5 to 15% by mass in terms of solid content in the curable resin composition. When the content of the photopolymerizable monomer is 3% by mass or more, the photocurability is good, and pattern formation is easy in alkaline development after irradiation with active energy rays. On the other hand, when it is 20% by mass or less, halation is less likely to occur and good resolution is easily obtained.

[(B) Filler]
Any known filler can be used. Examples of the filler include silica such as amorphous silica, crystalline silica, molten silica, and spherical silica, talc, boehmite, hydrotalcite, slaked lime, calcium hydroxide, calcium carbonate, calcium sulfate, potassium carbonate, and magnesium carbonate. Examples thereof include clay, mica powder, aluminum oxide, aluminum hydroxide, barium sulfate, copper sulfide, alumina, zinc oxide, iron, zinc sulfide, zirconium oxide, chromium oxide, cadmium oxide, cadmium sulfide and copper oxide. Among these, silica and barium sulfate are preferable from the viewpoint of dispersibility. One type of filler may be used alone, or two or more types may be used in combination. By containing a filler, heat resistance can be improved and variation during application can be reduced. Further, from the viewpoint of lowering the gloss, aluminum silicate or the like containing SiO ₂ and Al ₂ O ₃ as main components may be used.

The presence or absence of surface treatment of the filler is not particularly limited, but surface treatment for enhancing dispersibility may be performed. Aggregation can be suppressed by using a filler that has been surface-treated. The surface treatment method of the filler is not particularly limited, and a known and commonly used method may be used. However, it is an inorganic filler such as a surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group. It is preferable to treat the surface of.

An average particle size of the filler of 10 μm or less can be preferably used, but from the viewpoint of dispersibility, it is more preferably 0.1 to 5.0 μm, and further preferably 0.2 to 3.0 μm. .. The average particle size of the filler is an average particle size (D ₅₀ ) including not only the particle size of the primary particles but also the particle size of the secondary particles (aggregates), and the average particle size of the filler is D ₅₀ measured by the laser diffraction method. The value. Examples of the measuring device by the laser diffraction method include Microtrac MT3300EXII manufactured by Microtrac Bell Co., Ltd. Further, the value of each particle size of the filler described above is a value measured as described above for the filler before adjusting (preliminary stirring, kneading) the curable resin composition.

Depending on the mode of use, the filler may be mixed with other components in a powder or solid state, or may be mixed with a solvent or a dispersant to form a slurry, and then mixed with other components. The content of the filler, which will be described later, refers to the value in the powder or solid state.

The content of the filler in the curable resin composition is preferably 45% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less, and preferably 5% by mass. The above is more preferably 10% by mass or more, still more preferably 20% by mass or more. When the content of the filler is within the above range, it is possible to improve the cleaning and removing property of the completely dried coating film while increasing the strength of the cured product.

[(C) Organic solvent]
The curable resin composition of the present invention may contain an organic solvent for the purpose of preparing the composition, adjusting the viscosity when applied to a substrate or a film, and the like. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol and propylene glycol monomethyl ether. , Dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether and other glycol ethers; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, Esters such as butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, and solvent naphtha. , Known and commonly used organic solvents can be used. Among these, when the curable resin composition in the present invention is porous such as amorphous silica, the surface of the silica is easily oil-absorbed during curing and drying, and as a result, the cured coating film is glossy. Esters are preferred and propylene glycol monomethyl ether acetates are more preferred in that the degree is lower. These organic solvents may be used alone or in combination of two or more.

The content of the organic solvent is not particularly limited, and can be appropriately set according to the desired viscosity so that the curable resin composition can be easily prepared.

In the present invention, the content of propylene glycol monomethyl ether acetate is preferably 20% by mass or more, more preferably 25% by mass or more, still more preferably 30% by mass or more in the curable resin composition. It is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 40% by mass or less. In the present invention, the content of propylene glycol monomethyl ether acetate in the curable resin composition is not only the amount of (C) propylene glycol monomethyl ether acetate blended as an organic solvent, but also other components (the above (A)). It is a value including the amount of propylene glycol monomethyl ether acetate in the liquid component used for the preparation of the curable resin and (B) filler and the like). When the content of propylene glycol monomethyl ether acetate is within the above range, the cleaning and removing property of the completely dried coating film can be improved.

The curable resin composition of the present invention may further contain the following optional components.

[Photopolymerization initiator]
The photopolymerization initiator is for reacting a carboxyl group-containing resin or a photopolymerizable monomer by exposure. Any known photopolymerization initiator can be used. As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination.

Specific examples of the photopolymerization initiator include bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphinoxide, and bis. -(2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphin oxide , Bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, Bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphinoxide, Bis- (2, 4,6-trimethylbenzoyl) -bisacylphosphinoxides such as phenylphosphinoxide; 2,6-dimethoxybenzoyldiphenylphosphinoxide, 2,6-dichlorobenzoyldiphenylphosphinoxide, 2,4,6-trimethyl Monoacylphosphinoxides such as benzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; phenyl ( 2,4,6-trimethylbenzoyl) ethyl phosphinate, 1-hydroxy-cyclohexylphenylketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1- On, 2-hydroxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1-one, 2-hydroxy-2-methyl-1 -Hydroxyacetophenones such as phenylpropane-1-one; benzoins such as benzoin, benzyl, benzoinmethyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; benzophenone , P-Methylbenzophenone, Michler's ketone, Methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone and other benzophenones; acetphenone, 2,2-dimethoxy-2-phenyla Setophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1- On, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl) -1- [4- ( 4-Molholinyl) Phenyl] -1-butanone, N, N-dimethylaminoacetophenone and other acetophenones; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, Anthraquinones such as 2-amylanthraquinone and 2-aminoanthraquinone; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethylbenzoate, p-dimethylbenzoic acid ethyl ester And other benzoic acid esters; 1,2-octanedione, 1- [4- (phenylthio) phenyl]-, 2- (O-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-) Methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime) and other oxime esters; bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-- Difluoro-3- (1H-pyrrole-1-yl) phenyl) Titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (1-pyll-1-yl) ethyl) phenyl ] Titanosens such as Titanium; Phenyldisulfide 2-nitrofluorene, butyloin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthium disulfide and the like can be mentioned.

Examples of commercially available alkylphenone-based photopolymerization initiators include Omnirad 907, 369, 369E, 379 manufactured by IGM Resins. Examples of commercially available acylphosphine oxide-based photopolymerization initiators include Omnirad 819 manufactured by IGM Resins. Commercially available oxime ester-based photopolymerization initiators include Irgacure OXE01 and OXE02 manufactured by BASF Japan Ltd., N-1919 manufactured by ADEKA Corporation, NCI-831 and NCI-831E manufactured by ADEKA Arkuru's Co., Ltd. TR-PBG-304 and the like can be mentioned.

In addition, JP-A-2004-359639, JP-A-2005-097141, JP-A-2005-22007, JP-A-2006-160634, JP-A-2008-09470, JP-A-2008-50967, Examples thereof include carbazole oxime ester compounds described in JP-A-2009-040762 and JP-A-2011-80036.

The content of the photopolymerization initiator in the curable resin composition is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass in terms of solid content. When the content of the photopolymerization initiator is 0.1% by mass or more, the photocurability of the curable resin composition is good, and the coating properties such as chemical resistance are also good. On the other hand, when it is 10% by mass or less, the light absorption on the surface of the resist film (cured coating film) becomes good, and the deep curability does not easily decrease.

A photoinitiator aid or a sensitizer may be used in combination with the above-mentioned photopolymerization initiator. Examples of the photoinitiator aid or sensitizer 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. By containing the thioxanthone compound, deep curability can be improved. Although these compounds may be used as a photopolymerization initiator, they are preferably used in combination with a photopolymerization initiator. In addition, one type of photoinitiator aid or sensitizer may be used alone, or two or more types may be used in combination.

Since these photopolymerization initiators, photoinitiator aids, and sensitizers absorb specific wavelengths, their sensitivities may be lowered in some cases, and they may function as ultraviolet absorbers. However, these are not used only for the purpose of improving the sensitivity of the resin composition. It absorbs light of a specific wavelength as needed to increase the photoreactivity of the surface, change the line shape and aperture of the resist pattern to vertical, tapered, or reverse tapered, and the accuracy of the line width and aperture diameter. Can be improved.

[Colorant]
A colorant can be added to the curable resin composition of the present invention. The colorant is not particularly limited, and known colorants such as red, blue, green, and yellow can be used, and any of pigments, dyes, and pigments may be used, but the environmental load is reduced and the effect on the human body is affected. It is preferable that the colorant does not contain halogen from the viewpoint of less.

Examples of the red colorant include monoazo, disazo, azolake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, quinacridone, etc. -Indexed (CI; issued by The Society of Dyersand Colorists).

Pigment Red 1,2,3,4,5,6,8,9,12,14,15,16,17,21,22,23,31,32,112,114, as monoazo red colorants 146,147,151,170,184,187,188,193,210,245,253,258,266,267,268,269 and the like can be mentioned. Examples of the disazo-based red colorant include Pigment Red 37, 38, 41 and the like. Further, as the monoazolake-based red colorant, 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: 1,68 and the like can be mentioned. Examples of the benzimidazolone-based red colorant include Pigment Red 171 and 175, 176, 185 and 208. Examples of the perylene-based red colorant include Solvent Red 135, 179, Pigment Red 123, 149, 166, 178, 179, 190, 194, 224 and the like. Examples of the diketopyrrolopyrrole-based red colorant include Pigment Red 254, 255, 264, 270, and 272. Examples of the condensed azo-based red colorant include Pigment Red 220, 144, 166, 214, 220, 211, 242 and the like. Examples of the anthraquinone-based red colorant include Pigment Red 168, 177, 216 and Solvent Red 149, 150, 52, 207. Examples of the quinacridone-based red colorant include Pigment Red 122, 202, 206, 207, 209 and the like.

Examples of the blue colorant include phthalocyanine-based and anthraquinone-based compounds, and pigment-based compounds include compounds classified as Pigment. For example, Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15 :. 4,15: 6,16,60. As the dye system, Solvent Blue 35, 63, 68, 70, 83, 87, 94, 97, 122, 136, 67, 70 and the like can be used. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Examples of the yellow colorant include monoazo, disazo, condensed azo, benzimidazolone, isoindolenone, anthraquinone and the like. For example, the anthraquinone yellow colorant includes Solvent Yellow 163, Pigment Yellow 24, 108, 193, 147, 199, 202 and the like can be mentioned. Examples of the isoindolinone-based yellow colorant include Pigment Yellow 110, 109, 139, 179, 185 and the like. Examples of the condensed azo-based yellow colorant include Pigment Yellow 93, 94, 95, 128, 155, 166, 180 and the like. Examples of the benzimidazolone-based yellow colorant include Pigment Yellow 120, 151, 154, 156, 175, 181 and the like. As a monoazo yellow colorant, 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, 183 and the like can be mentioned. Examples of the disazo-based yellow colorant include Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198 and the like. Can be mentioned.

In addition, colorants such as purple, orange, brown, black, and white may be added. Specifically, 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, C.I. I. Pigment Orange 1,5,13,14,16,17,24,34,36,38,40,43,46,49,51,61,63,64,71,73, PigmentBrown 23,25, Carbon Black, Examples include titanium oxide.

The content of the colorant is preferably 0.1 to 2.0% by mass, more preferably 0.3 to 1.5% by mass in terms of solid content in the curable resin composition.

[Other additive components]
The curable resin composition of the present invention further contains, if necessary, a photoinitiator aid, a thermosetting catalyst, a cyanate compound, an elastomer, a mercapto compound, a urethanization catalyst, a thixotropic agent, an adhesion accelerator, and a block copolymer. , Chain transfer agent, polymerization inhibitor, copper damage inhibitor, antioxidant, rust preventive, fine powder silica, organic bentonite, thickener such as montmorillonite, silicone-based, fluorine-based, polymer-based defoaming agent and At least one of the leveling agents, silane coupling agents such as imidazole, thiazole, and triazole, and flame-retardant agents such as phosphinates, phosphoric acid ester derivatives, and phosphorus compounds such as phosphazenic compounds may be blended. can. As these, those known in the field of electronic materials can be used.

[Preparation method]
To prepare the curable resin composition of the present invention, each component is weighed and mixed, and then pre-stirred with a stirrer. Subsequently, if necessary, each component is dispersed in a kneader and kneaded to prepare the mixture.

Examples of the kneading machine include a bead mill, a ball mill, a sand mill, a 3-roll mill, a 2-roll mill and the like. Dispersion conditions such as the type of beads and the particle size of the bead mill can be appropriately set according to the target viscosity, and examples of the types of beads include zirconia beads and alumina beads. Examples of the particle size of the beads include a range of φ0.015 to 2.0 mm. Of these, the range of φ0.3 to 1.5 mm is more preferable. The bead filling factor is preferably 50 to 95%, and the rotor rotation speed is preferably 800 to 1300 rpm. Further, as the target viscosity, it is preferable that the composition viscosity at the time of charging the bead mill is 200 dPa · s or less in terms of improving the dispersibility and lowering the gloss of the cured coating film. On the other hand, the lower limit is preferably 50 dPa · s or more. The viscosity in the present invention is 50 ° C., 100 rpm, 30 seconds according to the viscosity measurement method using a 10-cone-plate type rotary viscometer of JIS Z 8803: 2011, and a cone using 3 ° × R9.7 as a cone rotor. It is a value measured by a plate type viscometer (TVE-33H, manufactured by Toki Sangyo Co., Ltd.).

On the other hand, dispersion conditions such as the rotation ratio of each roll of the three-roll mill can be appropriately set according to the target viscosity.

Further, in order to further improve the dispersibility, the raw materials may be first weighed and blended in a slurry using a kneader such as a bead mill or a three-roll mill, and then pre-stirred with a stirrer. When the raw material is slurried, it is preferable to weigh and mix a wet dispersant such as a silane coupling agent and then knead with a bead mill or the like. Subsequently, each component including the one slurried by the above-exemplified kneader may be dispersed and kneaded by a bead mill or the like.

[Use]
The curable resin composition according to the present invention is useful for forming a pattern layer as a permanent coating of a printed wiring board such as a solder resist layer, a coverlay, and an interlayer insulating layer, and is particularly useful for forming a solder resist layer. be. Further, since the curable resin composition of the present invention can form a cured product having excellent film strength even with a thin film, it is used in a printed wiring board that requires thinning, for example, a package substrate (printed wiring board used for a semiconductor package). It can also be suitably used for forming a pattern layer. Further, the cured product obtained from the curable resin composition of the present invention is excellent in flexibility and can be suitably used for a flexible printed wiring board.

Further, the curable resin composition of the present invention can be used not only for forming a pattern layer of a cured coating film but also for an application not forming a pattern layer, for example, a molding application (sealing application).

[Dry film]
The curable resin composition of the present invention is in the form of a dry film including a first film and a resin layer composed of a dry coating film of the curable resin composition formed on the first film. You can also do it. The completely dry coating film of 20 mm in length × 20 mm in width × 7 μm in film thickness obtained from the dry film of the present invention satisfies the same physical properties as those described in [Physical characteristics] of the above [Curable resin composition]. It is a feature.

The first film in the present invention is at least when laminated by heating or the like so that the resin layer side of the curable resin layer formed on the dry film is in contact with the substrate such as a substrate and integrally molded. It means that it is adhered to the resin layer. When forming a dry film, the curable resin composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate level, and a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, and a photoresist coater are formed. , A gravure coater, a spray coater or the like is applied onto the first film to a uniform thickness, and the film is usually dried at a temperature of 50 to 130 ° C. for 1 to 30 minutes to obtain a film. The coating film thickness is not particularly limited, but is generally selected as appropriate in the range of 1 to 150 μm, preferably 5 to 60 μm after drying.

As the first film, any known film can be used without particular limitation. For example, heat of a polyester film such as polyethylene terephthalate or polyethylene naphthalate, a polyimide film, a polyamide imide film, a polypropylene film, a polystyrene film or the like can be used. A film made of a plastic resin can be preferably used. Among these, a polyester film is preferable from the viewpoint of heat resistance, mechanical strength, handleability and the like. Further, the laminate of these films can also be used as the first film.

Further, the thermoplastic resin film as described above is preferably a film stretched in the uniaxial direction or the biaxial direction from the viewpoint of improving the mechanical strength.

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

After forming the resin layer of the curable resin composition of the present invention on the first film, the resin layer can be peeled off from the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. It is preferable to laminate the second film. The second film in the present invention is used for laminating by heating or the like so that the resin layer side of the curable resin layer formed on the dry film is in contact with the substrate such as a substrate, and before laminating. A substance that peels off from the curable resin layer. As the peelable second film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper or the like can be used, and when the second film is peeled off, the resin layer and the first It suffices if the adhesive force between the resin layer and the second film is smaller than the adhesive force with the film.

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

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. In the following, "part" and "%" are all based on mass unless otherwise specified.

(Synthesis of curable resin solution A-1 (containing carboxyl group))
An autoclave equipped with a thermometer, a nitrogen introduction device / alkylene oxide introduction device and a stirring device, and a novolak type cresol resin (manufactured by Aika Kogyo Co., Ltd., trade name "Shonol CRG951", OH equivalent: 119.4), 119.4 g, 1.19 g of potassium hydroxide and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 g of propylene oxide was gradually added dropwise, and the mixture was reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm2 for 16 hours. Then, it was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to and mixed with this reaction solution to neutralize potassium hydroxide, the non-volatile content was 62.1%, and the hydroxyl value was 182.2 g / eq. A propylene oxide reaction solution of the novolak type cresol resin was obtained. This had an average of 1.08 mol of alkylene oxide added per equivalent amount of phenolic hydroxyl group.
Next, 293.0 g of an alkylene oxide reaction solution of the obtained novolak type cresol resin, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methylhydroquinone and 252.9 g of toluene were added to a stirrer, a thermometer and air. The mixture was charged into a reactor equipped with a blow tube, air was blown at a rate of 10 ml / min, and the reaction was carried out at 110 ° C. for 12 hours with stirring. As the water produced by the reaction, 12.6 g of water was distilled off as an azeotropic mixture with toluene. Then, the mixture was cooled to room temperature, the obtained reaction solution was neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution, and then washed with water. Then, toluene was distilled off while being replaced with 118.1 g of propylene glycol monomethyl ether acetate (hereinafter referred to as “PMA”) by an evaporator to obtain a novolak type acrylate resin solution. Next, 332.5 g of the obtained novolak-type acrylate resin solution and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown at a rate of 10 ml / min. With stirring, 60.8 g of tetrahydrophthalic acid anhydride was gradually added and reacted at 95 to 101 ° C. for 6 hours to obtain a curable resin solution A-1. The solid content of the obtained curable resin solution A-1 was 65%, the acid value of the solid was 88 mgKOH / g, and the weight average molecular weight was about 2,500 (in terms of polystyrene).

(Synthesis of curable resin solution A-2)
A flask equipped with a cooling tube and a stirrer was charged with 456 parts of bisphenol A, 228 parts of water, and 649 parts of 37% formalin, kept at a temperature of 40 ° C. or lower, and 228 parts of a 25% sodium hydroxide aqueous solution was added. After that, the reaction was carried out at 50 ° C. for 10 hours. After completion of the reaction, the mixture was cooled to 40 ° C. and neutralized to pH 4 with a 37.5% aqueous phosphoric acid solution while maintaining 40 ° C. or lower. After that, it was allowed to stand and the aqueous layer was separated. After separation, 300 parts of methyl isobutyl ketone was added and uniformly dissolved, followed by washing with 500 parts of distilled water three times, and the water, solvent and the like were removed under reduced pressure at a temperature of 50 ° C. or lower. The obtained trimethylol compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the trimethylol compound. When a part of the obtained methanol solution of the polymethylol compound was dried in a vacuum dryer at room temperature, the solid content was 55.2%.
500 parts of a methanol solution of the obtained trimethylol compound and 440 parts of 2,6-xylenol were charged and uniformly dissolved at 50 ° C. After uniform dissolution, methanol was removed under reduced pressure at a temperature of 50 ° C. or lower. Then, 8 parts of oxalic acid was added, and the reaction was carried out at 100 ° C. for 10 hours. After completion of the reaction, the distillate was removed at 180 ° C. under a reduced pressure of 50 mmHg to obtain 550 parts of novolak resin A. Further, in an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device, 130 parts of the above novolak resin A, 2.6 parts of a 50% sodium hydroxide aqueous solution, and toluene / methyl isobutyl ketone (mass ratio). = 2/1) 100 parts were charged, the inside of the system was replaced with nitrogen while stirring, then the temperature was raised by heating, and 45 parts of ethylene oxide was gradually introduced at 150 ° C. and 8 kg / cm2 for reaction. The reaction was continued for about 4 hours until the gauge pressure reached 0.0 kg / cm 2, and then cooled to room temperature. 3.3 parts of a 36% aqueous hydrochloric acid solution was added to and mixed with this reaction solution to neutralize sodium hydroxide. The neutralization reaction product was diluted with toluene, washed with water three times, and desolvated with an evaporator to give a hydroxyl value of 175 g / eq. An ethylene oxide adduct of novolak resin A was obtained. This had an average of 1 mol of ethylene oxide added per equivalent amount of phenolic hydroxyl group. 175 parts of the ethylene oxide adduct of the novolak resin A thus obtained, 75 parts of methacrylic acid, 3.0 parts of p-toluenesulfonic acid, 0.1 part of hydroquinone monomethyl ether, and 130 parts of toluene were mixed with a stirrer, a thermometer, and the like. It was charged into a reactor equipped with an air blowing tube, stirred while blowing air, heated to 115 ° C., and the water produced by the reaction was distilled off as an azeotropic mixture with toluene and reacted for another 4 hours. , Cooled to room temperature. The obtained reaction solution was washed with water using a 5% NaCl aqueous solution, toluene was removed by distillation under reduced pressure, and then PMA was added to obtain a curable resin solution A-2. The solid content of the obtained curable resin solution A-2 was 70%, and the weight average molecular weight was about 5,500 (in terms of polystyrene).

(Synthesis of curable resin solution A-3 (containing carboxyl group))
In a four-necked flask equipped with a stirrer and a reflux condenser, 220 g of a cresol novolac type epoxy resin (EPICLON N-695, epoxy equivalent: 220) manufactured by DIC Corporation is placed, and diethylene glycol monoethyl ether acetate (carbitol acetate) is placed. 214 g was added and the mixture was heated and dissolved. Next, 0.1 g of hydroquinone as a polymerization inhibitor and 2.0 g of dimethylbenzylamine as a reaction catalyst were added. The mixture was heated to 95-105 ° C., 72 g of acrylic acid was gradually added dropwise, and the mixture was reacted for 16 hours. The reaction product was cooled to 80-90 ° C., 106 g of tetrahydrophthalic anhydride was added, the mixture was reacted for 8 hours, cooled, and then removed. A resin solution of the curable resin solution A-3 thus obtained was obtained. The solid content of the obtained curable resin solution A-3 was 65%, the acid value of the solid content was 100 mgKOH / g, and the weight average molecular weight was about 8,000 (in terms of polystyrene).

(Synthesis of curable resin solution A-4 (containing carboxyl group))
In a flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux cooler, 325.0 parts by mass of dipropylene glycol monomethyl ether as a solvent was heated to 110 ° C., and 174.0 parts by mass of methacrylic acid was modified with ε-caprolactone. 174.0 parts by mass of methacrylic acid (average molecular weight 314), 77.0 parts by mass of methyl methacrylate, 222.0 parts by mass of dipropylene glycol monomethyl ether (DPM), and t-butylperoxy2-ethyl as a polymerization catalyst. A mixture of 12.0 parts by mass of hexanoate (manufactured by Nichiyu Co., Ltd., Perbutyl O) was added dropwise over 3 hours, and the mixture was further stirred at 110 ° C. for 3 hours to deactivate the polymerization catalyst to obtain a resin solution. rice field. After cooling this resin solution, 289.0 parts by mass of 3,4-epoxycyclohexylmethylmethacrylate (Cyclomer M100 manufactured by Daicel Co., Ltd.), 3.0 parts by mass of triphenylphosphine and 1.3 parts by mass of hydroquinone monomethyl ether. Was added, the temperature was raised to 100 ° C., and the mixture was stirred to carry out a ring-opening addition reaction of an epoxy group to obtain a curable resin solution A-4. The solid content of the obtained curable resin solution A-4 was 46% by mass, the acid value of the solid content was 79.8 mgKOH / g, and the weight average molecular weight was about 18,000 (in terms of polystyrene).

(Preparation of silica slurry without surface treatment)
Dispersion treatment was performed using 700 g of spherical silica (manufactured by Admatech Co., Ltd.), 300 g of PMA as a solvent, and 0.7 μm zirconia beads in a bead mill. This was repeated 3 times and filtered through a 3 μm filter to prepare a silica slurry having an average particle size of 0.7 μm. The solid content of the obtained silica slurry was 70% by mass.

(Preparation of silica slurry with surface treatment)
Using the silica slurry having an average particle size of 0.7 μm (solid content 70% by mass in PMA) obtained above, 4% by mass of methacrylicsilane (Shinetsu Chemical Industry Co., Ltd., KBM-503) with respect to silica. Was added and treated with a bead mill for 10 minutes to obtain a silica slurry surface-treated with methacrylic silane. The solid content of the obtained silica slurry was 70% by mass.

(Preparation of barium sulfate slurry)
700 g of barium sulfate (B-30 manufactured by Sakai Chemical Industry Co., Ltd.) having an average particle size of 0.3 μm, 295 g of diethylene glycol monoethyl ether acetate (carbitol acetate) as a solvent, and 5 g of a wet dispersant are mixed and stirred, and 0 in a bead mill. Dispersion treatment was performed using 0.7 μm zirconia beads. This was repeated 3 times and filtered through a 3 μm filter to prepare a barium sulfate slurry having an average particle size of 0.3 μm. The solid content of the obtained barium sulfate slurry was 70% by mass.

[Examples 1 to 6, Comparative Examples 1 to 3]
(Preparation of curable resin composition)
According to the formulation shown in Table 1 below, each component was blended and dispersed with a stirrer to prepare a curable resin composition. The blending amount in the table indicates a part by mass. The evaluation was performed as follows using the adjusted curable resin composition.

The blending amount in Table 1 indicates a part by mass.
The details of each component in Table 1 are as follows.
* 1: Curable resin solution A-1 (containing carboxyl group) synthesized above
* 2: Curable resin solution A-2 synthesized above
* 3: Curable resin solution A-3 (containing carboxyl group) synthesized above
* 4: Curable resin solution A-4 (containing carboxyl group) synthesized above
* 5: Epoxy resin (manufactured by DIC Corporation, HP-7200L) carbitol acetate cut product * 6: Silica slurry without surface treatment synthesized above * 7: Silica slurry with surface treatment synthesized above * 8: Barium sulfate slurry synthesized above
* 9: PMA
* 10: 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (manufactured by IGM Resins, Omnirad 907)
* 11: Black colorant (manufactured by Mitsubishi Chemical Corporation, MA-100)
* 12: White colorant (manufactured by Ishihara Sangyo Co., Ltd., Thai Bake CR-58)
* 13: Acrylate-based leveling agent (BIC Chemie Japan, BYK-350)
* 14: Acrylate leveling agent (BIC Chemy Japan, BYK-361N)
* 15: Polymerization inhibitor (manufactured by Kawasaki Kasei Kogyo Co., Ltd., QS-30)
The "content of PMA in the curable resin composition" of * 16 is not only the amount of PMA blended as the above (C) organic solvent, but also the above (A) curable resin and (B) filler. It is a value including the amount of PMA in the liquid component used for the preparation of (slurry).

<Preparation of Completely Dry Coating Film (Examples 1 to 6 and Comparative Examples 1 to 3)>
The curable resin compositions of Examples 1 to 6 and Comparative Examples 1 to 3 were applied by screen printing on a copper plate as a base material, left at room temperature (25 ° C.) for 4 months to dry, and 20 mm in length × A coating film having a width of 20 mm and a film thickness of 7 μm was prepared. Since the difference in volatility calculated by the above formula (1) was within 10% in the obtained coating film, it was judged that a completely dry coating film was formed. The film thickness of the completely dried coating film was measured using a laser microscope (VR-3200, manufactured by KEYENCE CORPORATION).

<Preparation of a completely dry coating film (Example 7)>
The curable resin composition of Example 6 was applied onto a polyethylene terephthalate film, which is the first film, using an applicator, dried at 80 ° C. for 10 minutes, and a resin layer composed of a dry coating film of the curable resin composition. A dry film with and was obtained. After that, laminating is performed on a copper plate as a base material using a vacuum laminator, the first film is peeled off, and then left at room temperature (25 ° C.) for 4 months to dry, and the length is 20 mm × width 20 mm × film thickness 7 μm. The coating film of was prepared. Since the difference in volatility calculated by the above formula (1) was within 10% in the obtained coating film, it was judged that a completely dry coating film was formed. The film thickness of the completely dried coating film was measured using a laser microscope (VR-3200, manufactured by KEYENCE CORPORATION).

(Dissolution start time and dissolution completion time)
The apparatus shown in FIG. 1 was used for measuring the dissolution start time and the dissolution completion time of the completely dried coating film. Specifically, 70 ml of PMA, which is a cleaning solvent 5, and a stirrer 6 were placed in a 100 ml beaker 2 and placed in a water bath set at 25 ° C. The temperature of the cleaning solvent was stabilized by stirring the cleaning solvent using a stirrer 7 (manufactured by AS ONE Corporation, M-3, 500 rpm). Subsequently, the copper plate 1 coated with the completely dry coating film 3 produced above was arranged so that the immersion depth was 20 mm from the water surface of the cleaning solvent, and was immersed perpendicularly to the water surface of the cleaning solvent. .. Using a laser marking device (ZEROS-KJC, manufactured by TJM Design Co., Ltd.), a laser (visible light semiconductor laser, wavelength 635 nm, line width 2 mm, optical output 2.5 mW) was applied to the completely dried coating film on the immersed copper plate. The line of (below) was incident horizontally, and a part of the completely dried coating film was irradiated in the flow direction of the cleaning solvent. The dissolution start time was defined as the time when the emission line on the underlying copper plate generated by the dissolution of the completely dried coating film was confirmed in the region of 2 mm × 1 mm in the entire irradiated portion (2 mm × 20 mm) of the laser beam 4. On the other hand, the time when the emission line on the underlying copper plate generated by the dissolution of the completely dried coating film was confirmed in the region of 2 mm × 19 mm in the entire irradiated portion (2 mm × 20 mm) of the laser beam was defined as the dissolution completion time. .. The emission line may be confirmed at any point of the entire irradiation portion of the laser beam. The limit for measuring the dissolution time was 120 seconds. Therefore, if the dissolution is not started or completed even after 120 seconds have passed, it is indicated by x in Table 1.

(Confirmation of wash removal property)
The surface of the completely dry coating film of the copper plate coated with the completely dry coating film prepared above was wiped with a clean waste cloth impregnated with PMA as a cleaning solvent, and visually evaluated according to the following criteria.
◯: Completely dry coating film could be completely removed from the copper plate.
Δ: A part of the completely dried coating film could be removed from the copper plate.
X: The completely dry coating film could not be removed from the copper plate.

As is clear from Table 2, it can be seen that the curable resin compositions of Examples 1 to 6 and the dry film of Example 7 are excellent in cleaning and removing properties of the completely dry coating film. On the other hand, it can be seen that the completely dry coating films of Comparative Examples 1 to 3 are inferior in cleaning and removability because the dissolution is not started or completed even after 120 seconds have passed from the start of immersion in PMA, which is a cleaning solvent.

1: Copper plate 2: 100 ml beaker 3: Completely dry coating film 4: Laser light 5: Cleaning solvent 6: Stirrer 7: Stirrer

Claims (9)

A curable resin composition containing (A) a curable resin, (B) a filler, and (C) an organic solvent.
The dissolution start time of the completely dry coating film having a length of 20 mm, a width of 20 mm, and a film thickness of 7 μm formed by using the curable resin composition in propylene glycol monomethyl ether acetate as a cleaning solvent is from the start of immersion in the cleaning solvent. A curable resin composition, characterized in that it is within 20 seconds. The curable resin composition according to claim 1, wherein the dissolution completion time of the completely dry coating film is within 40 seconds from the start of immersion in the cleaning solvent. The curable resin composition according to claim 1 or 2, wherein the content of propylene glycol monomethyl ether acetate is 20% by mass or more in the curable resin composition. The curable resin composition according to any one of claims 1 to 3, wherein the content of the filler (B) is 45% by mass or less in the curable resin composition. The curable resin composition according to any one of claims 1 to 4, wherein the curable resin (A) contains a carboxyl group-containing resin. The curable resin composition according to any one of claims 1 to 5, wherein the carboxyl group-containing resin has a weight average molecular weight of 6000 or less. The curable resin composition according to any one of claims 1 to 6, which is used for forming a solder resist layer. The curable resin composition according to any one of claims 1 to 6, which is used for forming an interlayer insulating layer. A dry film comprising a first film and a resin layer composed of a dry coating film of a curable resin composition formed on the first film.
The curable resin composition contains (A) a curable resin, (B) a filler, and (C) an organic solvent.
The dissolution start time of the completely dry coating film of 20 mm in length × 20 mm in width × 7 μm in thickness obtained from the dry film in propylene glycol monomethyl ether acetate as a cleaning solvent is within 20 seconds from the start of immersion in the cleaning solvent. A dry film characterized by being present.

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