Melamine-free photosensitive thermosetting developable two-component resin composition, dry film and cured product thereof, and printed circuit board

Abstract

Provided are: a melamine-free photosensitive thermosetting developable two-component resin composition which has a cured product that has excellent acid resistance, metal plating resistance, high-temperature storage properties, and discoloration resistance, reduces the volatilization of harmful substances during a soldering stage, and has excellent drying management amplitude; a dry film thereof; a cured product thereof; and a printed circuit board formed using the same. The present invention relates to a melamine-free photosensitive thermosetting developable two-component resin composition comprising (A) a carboxyl group-containing vinyl ester resin, (B) a photopolymerization initiator, (C) a melamine phthalate, and (D) an epoxy resin, the (A) carboxyl group-containing vinyl ester resin and the (B) photopolymerization initiator being contained in a first component, the (A) carboxyl group-containing vinyl ester resin being contained in a second component, the (B) photopolymerization initiator being contained in a third component, and the (D) epoxy resin being contained in a fourth component. The epoxy resin (D) is contained in a second component different from the first component, and the amount of the melamine phthalate (C) is 1.2-11.8 parts by weight per 100 parts by weight of the carboxyl group-containing vinyl ester resin (A) in terms of solid content.

Description

Technical Field

[0001] The present invention relates to a melamine-free photosensitive thermosetting developable two-component resin composition, a dry film thereof, and a cured product thereof. In particular, the present invention relates to a melamine-free photosensitive thermosetting developable two-component resin composition, a dry film thereof, and a cured product thereof, which are applicable to the formation of solder resist for long-term reliable printed circuit boards. Background Art

[0002] Heretofore, on printed circuit boards, a solder resist (also referred to as solder resist ink) has been used as a protective material for circuit boards. At present, in the solder resist of a part of consumer printed circuit boards and almost all industrial printed circuit boards, an alkali-developable solder resist that forms an image by developing after ultraviolet exposure and is completely cured (main curing) by heat and / or light irradiation is used. In addition, in semiconductor devices for vehicles such as automobiles, trains, ships, and airplanes, there is a tendency to use a solder resist for high-reliability electronic materials as a solder resist for long-term reliable printed circuit boards.

[0003] Currently commercially available solder resist inks generally contain melamine, which is used as a thermosetting agent and an antioxidant, and at the same time improves characteristics such as acid and alkali resistance, metal plating resistance, and adhesion of the ink. However, there are also many problems with melamine in the ink. It will volatilize during the soldering process (usually 260°C), and based on the EU REACH Regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals), melamine belongs to the category of SVHC (Substances of Very High Concern) environmental control substances.

[0004] For example, melamine is used in the solder resist coating with high adhesion disclosed in Patent Document 1, the two-component solder resist photoresist disclosed in Patent Document 2, and the high-resolution solder resist ink disclosed in Patent Document 3. Patent Document 4 discloses a photosensitive solder resist ink, which has better durability and corrosion resistance of the coating film by adding a melamine copolymer resin to the curing agent. Patent Document 5 discloses grafting modified melamine onto an epoxy resin to provide a thermosetting ink that is resistant to yellowing and does not dry on the screen. The modified melamine is dimethoxymelamine, trimethoxymelamine, tetramethylolmelamine, methylene melamine, or methyl etherified melamine.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: CN116239938A

[0008] Patent Document 2: CN116560187A

[0009] Patent Document 3: CN111100499A

[0010] Patent Document 4: CN114605867A

[0011] Patent Document 5: CN114656833A Summary of the Invention

[0012] Technical problems to be solved by the present invention

[0013] In the past, solder resist inks generally contained melamine as a thermal curing agent and an antioxidant. With the increasingly strict environmental requirements, it is thus desired to reduce or avoid the use of melamine. However, the inventors found through research that when reducing the amount of melamine in existing solder resist inks (such as Patent Documents 1 - 3), the properties such as acid resistance and metal plating resistance of the solder resist ink after post - baking (i.e., post - curing) become poor. In addition, in the prior art, although there have been attempts to use resins derived from melamine as curing agents or curing components, the requirements for drying management range, acid resistance, metal plating resistance, high - temperature storage stability, and discoloration resistance cannot be satisfied simultaneously. For example, in Patent Document 4, a melamine copolymer resin is used. Due to its large molecular weight, sufficient thermal curability and antioxidant properties cannot be imparted to the solder resist ink. In Patent Document 5, trimethoxymelamine is used. Since it has methoxy groups, it has strong reactivity in thermally curable inks, but if used in developable inks, the developability is low, resulting in impracticality.

[0014] Therefore, there is an urgent need to produce a developable resin composition with excellent drying management range without using melamine, and further, its cured product has excellent acid resistance, metal plating resistance (immersion gold resistance), high - temperature storage stability, and discoloration resistance (i.e., is not prone to oxidation discoloration).

[0015] Therefore, the object of the present invention is to provide: a non - melamine photosensitive thermosetting developable two - component resin composition whose cured product has excellent acid resistance, metal plating resistance, high - temperature storage stability, and discoloration resistance, and reduces the volatilization of harmful substances during the soldering stage, and has an excellent drying management range.

[0016] Furthermore, the object of the present invention is to provide: a dry film and a cured product having excellent properties as described above obtained by using such a non - melamine photosensitive thermosetting developable two - component resin composition, and a printed circuit board formed by forming a cured coating film such as a solder resist using such a non - melamine photosensitive thermosetting developable two - component resin composition, its dry film, or its cured product.

[0017] Solutions for solving problems

[0018] The inventors of the present invention conducted repeated and in-depth studies to solve the above problems, and as a result, it was found that in a photosensitive thermosetting developable two-component resin composition, when melamine phthalate is used in a specific amount to replace melamine as a curing agent and an antioxidant, melamine phthalate does not volatilize during the welding process due to its unique structure, and moreover, its antioxidant performance is the same as that of melamine. Thus, the obtained melamine-free photosensitive thermosetting developable two-component resin composition has substantially the same other properties when used in solder resist inks.

[0019] On this basis, the inventors of the present invention found that the above problems can be solved by the following melamine-free photosensitive thermosetting developable two-component resin composition, and thus completed the present invention. The melamine-free photosensitive thermosetting developable two-component resin composition is characterized by containing (A) a carboxyl group-containing vinyl ester resin, (B) a photoinitiator, (C) melamine phthalate, and (D) an epoxy resin. The (A) carboxyl group-containing vinyl ester resin and the (B) photoinitiator are contained in a first component, and the (D) epoxy resin is contained in a second component different from the first component. Relative to 100 parts by weight of the (A) carboxyl group-containing vinyl ester resin based on solid content, the (C) melamine phthalate is 1.2 to 11.8 parts by weight.

[0020] As a preferred embodiment of the present invention, in the above melamine-free photosensitive thermosetting developable two-component resin composition, relative to 100 parts by weight of the (D) epoxy resin based on solid content, the (C) melamine phthalate is 1.8 to 18.2 parts by weight.

[0021] As a preferred embodiment of the present invention, the above (C) melamine phthalate is contained in the first component.

[0022] As a preferred embodiment of the present invention, in the above melamine-free photosensitive thermosetting developable two-component resin composition, it further contains (E) an inorganic filler.

[0023] As a more preferred embodiment of the present invention, in the above melamine-free photosensitive thermosetting developable two-component resin composition, the (E) inorganic filler is contained in the first component.

[0024] As a preferred embodiment of the present invention, in the above melamine-free photosensitive thermosetting developable two-component resin composition, it further contains (F) a photosensitive monomer.

[0025] As a more preferred embodiment of the present invention, in the above-mentioned melamine-free photosensitive thermosetting developable two-component resin composition, the (F) photosensitive monomer is contained in the second component.

[0026] As a preferred embodiment of the present invention, in the above-mentioned melamine-free photosensitive thermosetting developable two-component resin composition, the first component and / or the second component further contains (G) an organic solvent.

[0027] In addition, another embodiment of the present invention further relates to a dry film, which is characterized by comprising a carrier film and a resin layer obtained by coating the above-mentioned melamine-free photosensitive thermosetting developable two-component resin composition on the carrier film and drying.

[0028] Yet another embodiment of the present invention further relates to the above-mentioned melamine-free photosensitive thermosetting developable two-component resin composition, which is characterized in that it is used as a solder resist.

[0029] Yet another embodiment of the present invention further relates to a cured product, which is characterized in that it is obtained by curing the above-mentioned melamine-free photosensitive thermosetting developable two-component resin composition.

[0030] Yet another embodiment of the present invention further relates to a cured product, which is characterized in that it is obtained by curing the resin layer of the above-mentioned dry film.

[0031] Yet another embodiment of the present invention further relates to a printed circuit board, which is characterized by having the above-mentioned cured product.

[0032] Effects of the invention

[0033] As described above, by using the present invention, it is possible to provide a melamine-free photosensitive thermosetting developable two-component resin composition, its dry film, its cured product, and a printed circuit board, the cured product of which has excellent acid resistance, metal plating resistance, high-temperature storage stability, color change resistance, and reduces the volatilization of harmful substances during the soldering stage, and has excellent drying management range. Detailed Embodiments

[0034] Hereinafter, the melamine-free photosensitive thermosetting developable two-component resin composition of the present invention will be described.

[0035] The melamine-free photosensitive thermosetting developable two-component resin composition of the present invention (hereinafter sometimes simply referred to as "photosensitive thermosetting developable two-component resin composition", "two-component resin composition" or "composition") comprises (A) a carboxyl group-containing vinyl ester resin, (B) a photopolymerization initiator, (C) melamine phthalate, and (D) an epoxy resin. The (A) carboxyl group-containing vinyl ester resin and the (B) photopolymerization initiator are contained in the first component, and the (D) epoxy resin is contained in a second component different from the first component. With respect to 100 parts by weight of the (A) carboxyl group-containing vinyl ester resin based on solid content, the (C) melamine phthalate is 1.2 to 11.8 parts by weight.

[0036] The melamine-free photosensitive thermosetting developable two-component resin composition of the present invention comprises a first component and a second component different from the first component. Herein, "two-component type" means that it is composed of at least a two-component system. Therefore, the two-component resin composition of the present invention may further comprise other components such as a third component in addition to the first component and the second component.

[0037] As a two-component system, for example, there can be cited a two-component system in which one resin composition is used as a main agent composition and another resin composition is used as a curing agent composition. For a two-component resin composition, different components, such as the main agent composition and the curing agent composition, are mixed just before use. During the preparation, storage, and transportation processes, in order to avoid reactions due to the mixing of components, the different components exist independently of each other and do not come into contact with each other.

[0038] In the present invention, the first component containing the (A) carboxyl group-containing vinyl ester resin and the (B) photopolymerization initiator can be regarded as the main agent composition, and the second component containing the (D) epoxy resin can be regarded as the curing agent composition. Therefore, in the two-component resin composition of the present invention, in order to avoid reactions between the main agent and the curing agent during storage and damage to the properties as a solder resist ink, preferably, the first component does not contain the (D) epoxy resin, and the second component does not contain the (A) carboxyl group-containing vinyl ester resin and the (B) photopolymerization initiator.

[0039] Hereinafter, each component contained in the melamine-free photosensitive thermosetting developable two-component resin composition of the present invention will be described.

[0040] (A) Carboxy vinyl ester resin

[0041] The first component in the two-component resin composition of the present invention contains (A) a carboxyl group-containing vinyl ester resin. As the (A) carboxyl group-containing vinyl ester resin used in the present invention, from the aspects of being able to be used to impart alkali developability, photocurability, and developability resistance, a carboxyl group-containing vinyl ester resin having an ethylenically unsaturated double bond in the molecule is particularly preferred. For example, a resin starting from an epoxy resin, a polyurethane resin having a urethane skeleton, a copolymer resin having a copolymer structure of an unsaturated carboxylic acid, and a resin starting from a phenolic compound. Specific examples of the carboxyl group-containing vinyl ester resin are shown below.

[0042] (1) A carboxyl group-containing vinyl ester resin obtained by reacting a polyfunctional epoxy compound and an unsaturated monocarboxylic acid with a compound having at least 1 alcoholic hydroxyl group and 1 reactive group other than the alcoholic hydroxyl group that reacts with an epoxy group in 1 molecule, and then reacting with a saturated or unsaturated polybasic acid anhydride;

[0043] (2) For a carboxyl group-containing resin obtained by reacting an unsaturated monocarboxylic acid with a polyfunctional epoxy resin and then reacting with a polybasic acid anhydride, a carboxyl group-containing vinyl ester resin is further obtained by reacting a compound having 1 oxirane ring and 1 or more ethylenically unsaturated groups in the molecule therewith;

[0044] (3) A carboxyl group-containing vinyl ester resin obtained by reacting a polyfunctional epoxy resin such as a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, a bisphenol A cresol novolac type epoxy resin, or a dicyclopentadiene cresol novolac type epoxy resin with (meth)acrylic acid, and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the hydroxyl groups present in the side chain;

[0045] (4) A carboxyl group-containing vinyl ester resin obtained by reacting a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl groups of the polyfunctional epoxy resin in the above (3) with epichlorohydrin with (meth)acrylic acid, and adding a polybasic acid anhydride to the generated hydroxyl groups;

[0046] (5) A carboxyl group-containing vinyl ester resin obtained by adding a cyclic ether such as ethylene oxide or a cyclic carbonate such as propylene carbonate to a polyfunctional phenolic compound such as a novolac resin, partially esterifying the resulting hydroxyl groups with (meth)acrylic acid, and reacting the remaining hydroxyl groups with a polybasic acid anhydride;

[0047] (6) A carboxyl group-containing vinyl ester resin obtained by further adding a compound having 1 epoxy group and 1 or more (meth)acryloyl groups in the molecule, such as glycidyl (meth)acrylate or α-methylglycidyl (meth)acrylate, to any one of the resins in the above (3) to (5), etc.

[0048] As particularly preferred substances in these examples, carboxyl group-containing vinyl ester resins of cresol novolak type and phenol novolak type, namely, the carboxyl group-containing vinyl ester resins of (3), (4), (5), and (6) above.

[0049] It should be noted that in this specification, (meth)acrylate is a term collectively referring to acrylate, methacrylate, and their mixtures, and the same applies to other similar expressions.

[0050] The above-mentioned (A) carboxyl group-containing vinyl ester resin has multiple free carboxyl groups on the side chain of the main chain polymer, and thus can be developed using a dilute aqueous alkali solution.

[0051] In addition, the acid value of the above-mentioned (A) carboxyl group-containing vinyl ester resin is preferably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. When the acid value is less than 40 mgKOH / g, alkali development is difficult. On the other hand, when it exceeds 200 mgKOH / g, the developer will promote the dissolution of the exposed part, so the line becomes thinner than required, and sometimes the exposed part and the unexposed part are dissolved and peeled off by the developer without distinction, making it difficult to draw a normal resist pattern, so it is not preferred.

[0052] Furthermore, the weight average molecular weight of the above-mentioned (A) carboxyl group-containing vinyl ester resin varies depending on the resin skeleton, and is generally preferably in the range of 2000 to 150000, more preferably in the range of 5000 to 100000. When the weight average molecular weight is less than 2000, sometimes the non-stick property (finger-touch dryness) after coating and drying on the substrate deteriorates. In addition, sometimes the moisture resistance of the coated film after exposure deteriorates, film reduction occurs during development, and the resolution significantly deteriorates. On the other hand, when the weight average molecular weight exceeds 150000, sometimes the developability will deteriorate significantly and the storage stability will become poor.

[0053] The blending amount of the (A) carboxyl group-containing vinyl ester resin is preferably in the range of 20 to 60% by mass of the total composition based on solid content, more preferably 25 to 50% by mass. When the blending amount of the (A) carboxyl group-containing vinyl ester resin is less than the above range, the film strength decreases, so it is not preferred. On the other hand, when it is more than the above range, the viscosity of the composition becomes high or the coatability etc. decreases, so it is not preferred.

[0054] (B) Photoinitiator

[0055] The first component in the photosensitive thermosetting developable two-component resin composition of the present invention contains (B) a photoinitiator. As the (B) photoinitiator, any photoinitiator commonly used in photosensitive thermosetting developable resin compositions can be used without particular limitation.

[0056] As the (B) photoinitiator, known substances can be used. For example, 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, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and other bisacylphosphine oxides; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, methyl 2,4,6-trimethylbenzoylphenylphosphonate, 2-methylbenzoyldiphenylphosphine oxide, isopropyl neopentanoyl phenylphosphonate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and other monoacylphosphine oxides; 1-hydroxycyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one and other hydroxyacetophenones; benzoin, benzil, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether and other benzoins; benzoin alkyl ethers; benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone and other benzophenones; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholin-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone and other acetophenones; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone and other thioxanthones; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-pentylanthraquinone, 2-aminoanthraquinone and other anthraquinones; acetophenone dimethyl ketal, benzil dimethyl ketal and other ketals; ethyl 4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, ethyl p-dimethylbenzoate and other benzoates;1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethanone 1-(O-acetyl oxime) and other oxime esters; bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyrrol-1-yl)ethyl)phenyl]titanium and other titanocene compounds; phenyl disulfide 2-nitrofluorene, benzoin, benzoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, etc. (B) The photoinitiator can be used alone or in combination of two or more kinds.

[0057] As commercially available products of the (B) photoinitiator, examples include oxime esters such as Irgacure OXE01, Irgacure OXE02 manufactured by BASF Japan Co., Ltd., N-1919, NCI-831 manufactured by ADEKA CORPORATION; α-hydroxyalkyl phenyl ketones such as Omnirad 184, Omnirad 1173, Omnirad 2959, Omnirad 127 manufactured by IGM Resins B.V.; acetophenones such as Omnirad 907, Omnirad 369, Omnirad 379 manufactured by IGM Resins B.V.; acylphosphine oxides such as Omnirad TPO manufactured by IGM Resins Co., Omnirad 819, Omnipol TP manufactured by IGM Resins B.V.; titanocene compounds such as Omnirad 784 manufactured by IGM Resins B.V.

[0058] Regarding the compounding ratio of these (B) photoinitiators, 0.01 to 30 parts by weight, preferably 5 to 25 parts by weight, more preferably 10 to 20 parts by weight, based on 100 parts by weight of the (A) carboxyl group-containing vinyl ester resin in terms of solid content, is appropriate. When the amount of the (B) photoinitiator used is less than the above range, the photocurability of the composition deteriorates. On the other hand, when it is excessive, the characteristics of the two-component resin composition of the present invention as a solder resist decrease, so it is not preferred.

[0059] (C) Melamine phthalate

[0060] The photosensitive thermosetting and developable two-component resin composition of the present invention contains (C) melamine phthalate. The (C) melamine phthalate can be contained in either the first component or the second component, but is preferably contained in the first component, that is, preferably contained in the main agent composition.

[0061] The inventors of the present invention compared the weight loss (i.e., the weight of volatile matter) after thermal curing of a photosensitive thermosetting developable two-component resin composition containing melamine and melamine phthalate, respectively, and found that the volatile matter of the composition containing melamine phthalate was significantly less than that of the composition containing melamine. At the same time, the composition containing melamine phthalate can achieve a drying management range, high-temperature storage properties, discoloration resistance, acid resistance, metal plating resistance, etc. of the cured product at a level substantially equivalent to that of the composition containing melamine. Although the principle has not been fully elucidated, the inventors of the present invention speculate as follows. On the one hand, the structure of melamine phthalate contains the structure of melamine, so it plays the role of a curing agent and an antioxidant in the same way as melamine. In other words, melamine phthalate can improve the adhesion between the substrate with a copper circuit and the cured product by preventing the oxidation of the copper circuit. Therefore, acid resistance, metal plating resistance, and high-temperature storage performance are improved. Moreover, melamine phthalate inhibits the discoloration of the copper circuit serving as the base of the cured product, thus improving the discoloration resistance of the cured product. On the other hand, due to its unique structure, melamine phthalate exists relatively stably in the composition during the soldering process usually carried out at 260 °C, and is not easily volatilized in large amounts like melamine. Therefore, when melamine phthalate is used instead of melamine, the volatilization of harmful substances during the soldering process can be reduced without affecting the various properties of the composition.

[0062] Regarding the blending ratio of (C) melamine phthalate, it is 1.2 to 11.8 parts by weight, preferably 1.8 to 10.2 parts by weight, based on 100 parts by weight of the (A) carboxyl group-containing vinyl ester resin in terms of solid content. If the amount of (C) melamine phthalate used is less than 1.2 parts by weight, it is difficult to effectively play the role of a curing agent and an antioxidant, and a cured product with good discoloration resistance cannot be obtained, and acid resistance, high-temperature storage properties, and metal plating resistance also tend to become insufficient. If the amount of (C) melamine phthalate used exceeds 11.8 parts by weight, the drying management range of the composition is poor, and the volatile matter increases significantly during the soldering process.

[0063] (D) Epoxy resin

[0064] The second component in the photosensitive thermosetting developable two-component resin composition of the present invention contains (D) an epoxy resin. This (D) epoxy resin functions as a thermosetting component in the photosensitive thermosetting developable two-component resin composition of the present invention to form a cured product.

[0065] As such an epoxy resin, a known and commonly used polyfunctional epoxy resin having at least two epoxy groups in one molecule can be used.

[0066] The (D) epoxy resin used in the present invention can be liquid at room temperature, or can be solid or semi-solid.

[0067] As the polyfunctional epoxy resin, preferably, bisphenol A type epoxy resin; brominated epoxy resin; novolak type epoxy resin; bisphenol F type epoxy resin; hydrogenated bisphenol A type epoxy resin; glycidylamine type epoxy resin; hydantoin type epoxy resin; alicyclic epoxy resin; trihydroxyphenylmethane type epoxy resin; xylenol type or biphenol type epoxy resin or a mixture thereof; bisphenol S type epoxy resin; bisphenol A novolak type epoxy resin; tetrahydroxyphenylethane type epoxy resin; heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl xylylenediamine resin; naphthalene group-containing epoxy resin; epoxy resin having a dicyclopentadiene skeleton; glycidyl methacrylate copolymer type epoxy resin; copolymer epoxy resin of cyclohexyl maleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivative; CTBN-modified epoxy resin, epoxy resin having an isocyanurate ring, etc. can be mentioned, but of course it is not limited to these. These epoxy resins can be used alone or in combination of two or more.

[0068] "Epoxy resins that are solid or semi-solid at room temperature" can also be those that are publicly known and commonly used. For example, as the epoxy resin that is solid at room temperature, bisphenol A type epoxy resin (jER1001 manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resin (jER4004P manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin (HP-4700 manufactured by DIC Corporation), polyfunctional solid epoxy resin containing a naphthalene skeleton (NC-7000 manufactured by Nippon Kayaku Co., Ltd.), triphenol epoxy resin (EPPN-502H manufactured by Nippon Kayaku Co., Ltd.), polyfunctional solid epoxy resin containing a dicyclopentadiene skeleton (Epiclon HP-7200 manufactured by DIC Corporation), phosphorus-containing epoxy resin (TX0712 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), tris(2,3-epoxypropyl) isocyanurate (TEPIC manufactured by Nissan Chemical Industries, Ltd.), and as the epoxy resin that is semi-solid at room temperature, bisphenol A type epoxy resin (jER834 manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin (HP-4032 manufactured by DIC Corporation), etc. can be mentioned.

[0069] Here, being solid or semi-solid at room temperature in the present invention means being solid or semi-solid at 15°C. The determination of solid or semi-solid can be carried out according to the "Confirmation Method of Liquid State" in Appendix 2 of the ordinance regarding tests and properties of dangerous substances (Autonomous Province Ordinance No. 1 of 1989).

[0070] As the biphenyl type epoxy resin, known and commonly used polyfunctional epoxy resins having a biphenyl skeleton can be used. For example, polyfunctional solid epoxy resins containing a biphenyl skeleton (NC-3000H, NC-3000 manufactured by Nippon Kayaku Co., Ltd.), biphenyl type epoxy resins (YX-4000, YL-6121HA manufactured by Mitsubishi Chemical Corporation), etc. can be cited.

[0071] As the novolak type epoxy resin, cresol novolak type epoxy resin (Epiclon N-690 manufactured by DIC Corporation), phenol novolak type epoxy resin (Epiclon N-770 manufactured by DIC Corporation, jER152 manufactured by Mitsubishi Chemical Corporation), etc. can be cited.

[0072] The content of the epoxy resin (D) described above is preferably in the range of approximately 30 to 100 parts by weight, more preferably in the range of 40 to 90 parts by weight, and still more preferably in the range of 50 to 85 parts by weight, based on 100 parts by weight of the carboxyl group-containing vinyl ester resin (A) in terms of solid content.

[0073] From the perspective of further exerting the effects of the present invention such as improving discoloration resistance and reducing the volatilization of harmful substances during the soldering stage, with respect to 100 parts by weight of the epoxy resin (D) in terms of solid content, the aforementioned melamine phthalate (C) is preferably 1.8 to 18.2 parts by weight, more preferably 2.3 to 16.9 parts by weight, and still more preferably 3.0 to 16.0 parts by weight.

[0074] (E) Inorganic filler

[0075] In the melamine-free photosensitive thermosetting developable two-component resin composition of the present invention, an inorganic filler (E) may be included. The inorganic filler (E) may be used alone or in combination of two or more.

[0076] Examples of the inorganic filler (E) include titanium oxide, silica, barium sulfate, barium titanate, Neuburg silica, talc, clay, magnesium carbonate, calcium carbonate, alumina, aluminum hydroxide, silicon nitride, aluminum nitride, etc. Among them, it is preferable to contain at least any one of talc, silica, and barium sulfate, which can inhibit the curing shrinkage of the cured product of the photosensitive thermosetting developable two-component resin composition and improve characteristics such as adhesion, hardness, and gloss.

[0077] From the perspective of improving the mechanical properties, high-temperature storage stability, processability, and chemical resistance of the cured product, the inorganic filler (E) is preferably contained in the main agent, that is, preferably contained in the first component of the two-component resin composition of the present invention. At this time, as the inorganic filler (E), at least any one of silica and barium sulfate is preferable.

[0078] (E) The inorganic filler may be a surface-treated one, and it is more preferable to perform a surface treatment on them that can introduce a curable reactive group.

[0079] Here, the curable reactive group refers to a group that undergoes a curing reaction with (A) the carboxyl group-containing vinyl ester resin, (E) the epoxy resin, etc., and it can be a photo-curable reactive group or a thermo-curable reactive group. As the photo-curable reactive group, examples include a methacryloyl group, an acryloyl group, a vinyl group, a styryl group, etc., and as the thermo-curable reactive group, examples include an epoxy group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, an imino group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, an oxazolinyl group, etc.

[0080] The method for introducing a curable reactive group onto the surface of the inorganic filler is not particularly limited, and a known and commonly used method can be used for the introduction. The surface of the inorganic filler can be treated with a surface treatment agent having a curable reactive group, such as a coupling agent having a curable reactive group as an organic group. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent, etc. can be used. It should be noted that as the inorganic filler subjected to a surface treatment without a curable reactive group, examples include silica-alumina surface treatment, titanate-based coupling agent treatment, aluminate-based coupling agent treatment, organically treated inorganic filler, etc.

[0081] (E) The shape of the inorganic filler can be spherical, needle-like, flaky, scaly, hollow, irregular, hexagonal, cubic, sheet-like, etc. From the viewpoint of high filling of the inorganic filler, a spherical shape is preferred.

[0082] As the average particle diameter (D50) of the (E) inorganic filler, it is 2000 nm or less, more preferably 1200 nm or less. In addition, its lower limit value is preferably 0.1 nm or more in terms of the average particle diameter (D50).

[0083] The smaller the average particle diameter of the (E) inorganic filler, the more the diffuse reflection during light irradiation is suppressed, and the fine processing of the cured product pattern becomes easier. The average particle diameter (D50) can be determined using a laser diffraction particle size distribution measuring device and a measuring device based on the dynamic light scattering method. As the measuring device based on the laser diffraction method, MicrotracMT3300EXII manufactured by MicrotracBEL Inc. can be cited, and as the measuring device based on the dynamic light scattering method, Nanotrac Wave II UT151 manufactured by MicrotracBEL Inc. can be cited.

[0084] (E) The compounding amount of the inorganic filler is preferably in the range of 20 to 240 parts by weight, more preferably in the range of 50 to 200 parts by weight, and still more preferably in the range of 80 to 160 parts by weight, relative to 100 parts by weight of the (A) carboxyl group-containing vinyl ester resin based on solid content. When the compounding amount of the inorganic filler is 20 parts by weight or more, there is a tendency to obtain a cured film with more excellent acid resistance, metal plating resistance, and discoloration resistance. When the compounding amount of the inorganic filler is 240 parts by weight or less, there is a tendency to obtain a photosensitive thermosetting and developing two-component resin composition with more excellent defoaming property, resolution, and deep part curability.

[0085] (F) Photosensitive monomer

[0086] The photosensitive thermosetting and developing two-component resin composition of the present invention without melamine may contain (F) a photosensitive monomer. The (F) photosensitive monomer may be used alone or in combination of two or more.

[0087] The (F) photosensitive monomer in the present invention is not particularly limited, and known and commonly used photosensitive monomers can be used. The (F) photosensitive monomer may be, for example, a compound having one or more ethylenically unsaturated groups in the molecule. Such a photosensitive monomer contributes to the photocuring of the (A) carboxyl group-containing vinyl ester resin based on the irradiation of active energy rays, and cures the photosensitive thermosetting and developing two-component resin composition.

[0088] From the perspective of avoiding reactions during storage and impairing the performance as a solder resist ink, the (F) photosensitive monomer is preferably contained in the curing agent, that is, preferably contained in the second component of the two-component resin composition of the present invention.

[0089] Examples of the (F) photosensitive monomer preferably used in the present invention include methyl α-(allyloxymethyl) acrylate, or diacrylates of diols such as 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, diacrylates of diols obtained by adding at least one of ethylene oxide and propylene oxide to neopentyl glycol, diacrylates of diols such as ε-caprolactone-modified hydroxypivalic acid neopentyl glycol diacrylate, EO adduct diacrylate of bisphenol A, PO adduct diacrylate of bisphenol A, tricyclodecane dimethanol diacrylate, hydrogenated dicyclopentadienyl diacrylate, cyclohexyl diacrylate and other diacrylates having a cyclic structure, or bifunctional (meth)acrylate monomers corresponding to them, such as pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolmethane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, tetramethylolmethane tetraacrylate, ethylene oxide-modified tris(acryloyloxyethyl) phosphate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxy pentaacrylate, or polyfunctional acrylates represented by their silsesquioxane-modified products, or corresponding methacrylate monomers, trifunctional methacrylate, ε-caprolactone-modified tris(acryloyloxyethyl) isocyanurate and other polyfunctional (meth)acrylates, or combinations of two or more of them, etc.

[0090] The content of such (F) photosensitive monomer is preferably in the range of 5 to 90 parts by weight, more preferably in the range of 20 to 60 parts by weight, and still more preferably in the range of 30 to 50 parts by weight, based on 100 parts by weight of the solid content of the (A) carboxyl group-containing vinyl ester resin.

[0091] If the content of the (F) photosensitive monomer is within this range, the photosensitive thermosetting and developing two-component resin composition without melamine has sufficient photocurability, the patterning becomes better during development, and the touch dryness also becomes good.

[0092] (G) Organic solvent

[0093] In the melamine-free photosensitive thermosetting developable two-component resin composition of the present invention, in order to synthesize the aforementioned (A) carboxyl group-containing vinyl ester resin, prepare each component in the composition, or adjust the viscosity of the overall composition obtained by mixing each component for coating on a substrate or a carrier film, (G) an organic solvent can be used in at least one component.

[0094] Examples of such organic solvents include: ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, etc. More specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and pseudocumene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha. The above organic solvents can be used alone or in the form of a mixture of two or more.

[0095] The content of such (G) organic solvent is preferably in the range of 30 to 200 parts by weight, more preferably in the range of 40 to 150 parts by weight, and still more preferably in the range of 50 to 120 parts by weight, based on 100 parts by weight of the solid content of the aforementioned (A) carboxyl group-containing vinyl ester resin.

[0096] Other components

[0097] In the melamine-free photosensitive thermosetting developable two-component resin composition of the present invention, within the scope not departing from the object of the present invention, further additives can of course be blended as other components according to need.

[0098] Examples of such other components include colorants such as pigments and dyes, thermal polymerization inhibitors, ultraviolet absorbers, plasticizers, flame retardants, antistatic agents, anti-aging agents, antibacterial / mildew-proof agents, defoamers, leveling agents, anti-sagging agents, thickeners, adhesion-imparting agents, thixotropy-imparting agents, photoinitiator aids, sensitizers, photo-base generators, thermoplastic resins, elastomers, organic fillers, mold release agents, surface treatment agents, dispersants, dispersion aids, surface modifiers, stabilizers, phosphors, cellulose resins, etc.

[0099] It should be noted that the photosensitive thermosetting developable two-component resin composition of the present invention does not contain melamine. Therefore, the aforementioned other components do not include melamine.

[0100] The compounding ratio of the aforementioned other components is preferably 0.01% by weight or more and 20% by weight or less based on the total amount of the photosensitive thermosetting developable two-component resin composition. When it is less than 0.01% by weight, the corresponding effects cannot be fully obtained, and when it exceeds 20% by weight, the printability and hardness of the photosensitive thermosetting developable two-component resin composition deteriorate, so it is not preferred.

[0101] The first component and the second component of the photosensitive thermosetting developable two-component resin composition of the present invention can be respectively prepared by mixing and dispersing each component to be contained in a prescribed amount, for example, using a three-roll mill or the like.

[0102] Dry film

[0103] A dry film can be made from the photosensitive thermosetting developable two-component resin composition of the present invention.

[0104] The dry film of the present invention has a resin layer, which is obtained by coating the photosensitive thermosetting developable two-component resin composition of the present invention on a carrier film and drying. When forming the dry film, first, the first component and the second component (i.e., the main agent composition and the curing agent composition) of the photosensitive thermosetting developable two-component resin composition of the present invention are fully mixed with each other, and then the mixed composition is directly or, if necessary, diluted with a solvent to adjust the viscosity to an appropriate value, and then coated on the carrier film to a uniform thickness by using a comma coater, a knife coater, a lip coater, a bar coater, an extrusion coater, an inverse coater, a transfer roll coater, an intaglio coater, a spray coater, etc. After that, the coated composition is usually dried at a temperature of 50 to 130 °C for 1 to 30 minutes, thereby forming a resin layer. There is no particular limitation on the coating film thickness, and it is usually preferably selected within the range of 10 to 150 μm, more preferably 20 to 60 μm, in terms of the dried film thickness.

[0105] As the carrier film, a plastic film is used. For example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, etc. can be used. There is no particular limitation on the thickness of the carrier film, and it is usually preferably selected within the range of 10 to 150 μm.

[0106] After forming a resin layer formed of the composition of the present invention on the carrier film, in order to prevent dust and the like from adhering to the surface of the resin layer, it is preferable to further laminate a peelable cover film on the surface of the resin layer. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, etc. can be used. As the cover film, as long as it is less adhesive than the resin layer and the carrier film when peeling off the cover film.

[0107] It should be noted that in the present invention, the composition of the present invention can also be coated on the above-mentioned cover film and dried to form a resin layer, and a carrier film is laminated on its surface. That is, in the present invention, when manufacturing a dry film, either a carrier film or a cover film can be used as the film for coating the composition of the present invention.

[0108] Here, the photosensitive thermosetting developable two-component resin composition of the present invention is adjusted to a viscosity suitable for the coating method using a high-boiling solvent, and after being coated on a substrate by methods such as dip coating, flow coating, roll coating, bar coating, screen printing, curtain coating, etc., the high-boiling solvent contained in the composition is volatilized and dried (preliminary drying) at a temperature of about 60 to 100 °C, thereby forming a non-tacky resin layer. In addition, in the case of a dry film formed by coating the above composition on a carrier film or a cover film and drying it and winding it into a film form, after laminating it on a substrate in a manner that the layer of the composition of the present invention is in contact with the substrate using a laminator or the like, the carrier film is peeled off, thereby forming a resin layer.

[0109] As the above-mentioned substrate, in addition to printed circuit boards and flexible printed circuit boards pre-formed with circuits made of copper or the like, the following can also be cited: copper-clad laminates of all grades (such as FR-4, etc.), metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer boards, etc. The copper-clad laminates use materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven fabric epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, and copper-clad laminates for high-frequency circuits using fluorine, polyethylene, polyphenylene oxide (polyphenylene oxide), cyanate ester, etc.

[0110] Cured product

[0111] When forming a cured product using the photosensitive thermosetting developable two-component resin composition of the present invention, the composition is coated on a substrate, and after the solvent is volatilized and dried, a resin layer is obtained. The obtained resin layer is exposed (irradiated with light), so that the exposed part (the part irradiated with light) is cured. Specifically, by a contact or non-contact method, selective exposure is performed using active energy rays through a patterned photomask, or direct pattern exposure is directly performed using a laser direct exposure machine, and the unexposed part is developed using an alkaline aqueous solution (for example, 0.3 to 3 mass% sodium carbonate aqueous solution), thereby forming an etching pattern. Further heating to a temperature of about 100 to 180 °C for thermal curing (post-curing), a cured film (cured product) with excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties can be formed.

[0112] When forming the above-mentioned cured product, volatile drying or thermal curing can be carried out, for example, by using a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven, etc. (a method of making hot air in the dryer convectively contact by using a device equipped with a heat source using an air heating method using steam and a method of blowing through a nozzle onto a support).

[0113] In addition, as the exposure machine used in the above-mentioned active energy ray irradiation, any device that irradiates ultraviolet rays in the range of 350 to 450 nm by mounting a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc. can be used. Furthermore, a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser using CAD data from a computer) can also be used. As the light source or laser source of the direct drawing machine, the maximum wavelength can be in the range of 350 to 410 nm. The exposure amount for image formation varies depending on the film thickness, etc., and can usually be set to 20 to 1000 mJ / cm 2 and preferably can be set to 20 to 800 mJ / cm 2 within the range.

[0114] Next, as the developing step, the dried coating film after the exposure step is treated with a developer. Thereby, the unexposed portion in the coating film is removed, and a pattern film of the curable composition of the present invention can be formed.

[0115] Here, as the method used in this developing step, an immersion method, a pouring method, a spraying method, a brushing method, etc. can be used. As the developer, an aqueous sodium carbonate solution with a mass concentration of 0.5 to 5% can usually be used, and other alkaline aqueous solutions can also be used, such as: alkaline aqueous solutions of potassium hydroxide, sodium hydroxide, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc.

[0116] In this developing step, it is carried out at a developer temperature of 20 to 40 °C and a developing time within 180 seconds.

[0117] It should be noted that in this developing step, if necessary, the obtained pattern film is washed with a rinsing solution. As the rinsing solution, distilled water, methanol, ethanol, isopropyl alcohol, etc. can be used alone or in combination.

[0118] Printed circuit board

[0119] In addition, the present invention can also provide a printed circuit board having the above-mentioned cured product. The photosensitive thermosetting developable two-component resin composition, dry film or cured product of the present invention can be used as a solder resist for printed circuit boards.

[0120] The present invention will be described in more detail based on the examples and comparative examples, but the scope of protection and the implementation manners of the present invention are not limited to these. In the examples and comparative examples, "parts" or "%" are based on weight unless otherwise specified. The property value tests of the compositions of this example were carried out by the methods described below.

[0121] Example

[0122] [Synthesis Example: Synthesis of Carboxyl-Containing Vinyl Ester Resin]

[0123] 214 parts of cresol novolak type epoxy resin EPICLON N-695 (manufactured by DIC Corporation, epoxy equivalent = 214) were put into a four-necked flask equipped with a stirrer and a reflux condenser, 103 parts of carbitol acetate and 103 parts of petroleum-based hydrocarbon solvent (trade name: Cactus Fines SF-01, manufactured by Japan Energy Corporation) were added and heated for dissolution. Then, 0.1 part of hydroquinone as a polymerization inhibitor and 2.0 parts of triphenylphosphine as a reaction catalyst were added. The mixture was heated to 95 - 105 °C, and 72 parts of acrylic acid was slowly added dropwise and reacted for 16 hours. The resulting reaction product was cooled to 80 - 90 °C, 91.2 parts of tetrahydrophthalic anhydride was added and reacted for 8 hours, and then taken out after cooling. The non-volatile content of the carboxyl-containing vinyl ester resin obtained by such operation was 65%, and the acid value of the solid content was 87.5 mgKOH / g.

[0124] Using the carboxyl-containing vinyl ester resin solution (varnish) of the above synthesis example, various components and ratios (parts by weight) shown in Table 1 were compounded, pre-mixed with a stirrer, and then kneaded with a three-roll mill to prepare a photosensitive heat-curable developable two-component resin composition. And the drying control range, acid resistance, metal plating resistance, high-temperature storage stability, volatile matter and color change resistance were evaluated according to the following methods.

[0125] Table 1

[0126]

[0127] "ND" indicates that the result was not detected because it was below the detection limit.

[0128] Each component described in Table 1 is as follows.

[0129] *1: Carboxyl-containing vinyl ester resin obtained by the synthesis example, solid content 65%, solvent 35%

[0130] *2: Pigment: 6Y-501, manufactured by TOYOCOLOR CO., LTD.

[0131] *3: Additive: KS-66, manufactured by Shin-Etsu Chemical Co., Ltd., BYK-1790, manufactured by BYK Additives (Shanghai) Co., Ltd.

[0132] *4: Initiator: ITX, isopropylthioxanthone (manufactured by DKSH JAPAN Co., Ltd.), #907: α-aminophenylacetone-based photoinitiator (Omnirad 907 manufactured by IGM Resins B.V.)

[0133] *5: Filler: B-30, manufactured by Sakai Chemical Industry Co., Ltd., A-8, manufactured by Sibelco

[0134] *6: Solvent: DPM: dipropylene glycol monomethyl ether, manufactured by Formosa Plastics Corporation, Taiwan

[0135] *7: Melamine: MELAMINE-JC, manufactured by Jiangsu Kingenta Serei Chemical Technology Co., Ltd.

[0136] *8: Melamine phthalate: THPAMELAMINESALT, manufactured by Shikoku Chemicals Corporation

[0137] *9: Epoxy resin: N-770, manufactured by DIC Corporation, novolak type polyfunctional epoxy resin, solid content 100%

[0138] *10: Photosensitive monomer: DPHA, dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.

[0139] For the photosensitive thermosetting and developable two-component resin compositions of the above Examples and Comparative Examples, the following tests were carried out after mixing the first component and the second component.

[0140] <Drying management range (time from drying to exposure and development)>

[0141] Each composition described in Table 1 was screen-printed over the entire surface on a patterned copper foil substrate and dried in a hot air circulation drying oven at 80°C. After the start of drying, the substrate was taken out every 10 minutes from 20 minutes to 70 minutes and slowly cooled to room temperature. Using a 1 wt% sodium carbonate aqueous solution at 30°C, the substrate was developed for 60 seconds at a spraying pressure of 0.2 MPa, and the maximum allowable drying time without residue was taken as the drying management range.

[0142] ○: The maximum allowable drying time without residue is 50 minutes or more

[0143] ×: The maximum allowable drying time without residue is less than 50 minutes

[0144] <Acid resistance>

[0145] Each composition described in Table 1 was screen-printed to coat the entire surface of a substrate having a 2-mm copper wire pattern so that the thickness became 40 μm, and dried in a hot air circulation drying oven at 80 °C for 30 minutes. After cooling to room temperature, pattern exposure was performed using an exposure apparatus equipped with a high-pressure mercury lamp at 400 mJ / cm 2 Then, after developing for 60 seconds in a 1 wt% aqueous sodium carbonate solution at a pressure of 0.2 MPa and a liquid temperature of 30 °C, curing was performed in a hot air circulation drying oven at 150 °C for 60 minutes. An evaluation substrate was produced by irradiating ultraviolet rays in a UV conveyor oven under the condition of an accumulated exposure amount of 2000 mJ / cm 2

[0146] The evaluation substrate was immersed in a 10 vol% aqueous H2SO4 solution at room temperature for 20 minutes, and this was repeated a total of 5 times. The infiltration and dissolution of the coating film were visually confirmed, and furthermore, the peeling caused by tape peeling was confirmed.

[0147] ○: No change was observed

[0148] △: Only a slight change

[0149] ×: The coating film has bulges or swelling and peeling

[0150] <Metal plating resistance>

[0151] An evaluation substrate was separately produced by the same production method as the evaluation substrate described in <Acid resistance> above. Using this evaluation substrate, plating was performed under the conditions of nickel 0.5 μm and gold 0.03 μm using a commercially available electroless nickel plating bath and electroless gold plating bath, and the infiltration of the plating was evaluated. Then, the peeling of the anti-corrosion layer was evaluated by tape peeling. The judgment criteria are as follows.

[0152] ○: No infiltration or peeling is seen

[0153] △: Slight infiltration can be seen after plating, and peeling can still be seen after tape peeling

[0154] ×: Peeling occurs after plating

[0155] <High-temperature storage stability (TS test)>

[0156] An evaluation substrate was separately produced by the same production method as the evaluation substrate described in <Acid resistance> above. The evaluation substrate was placed in an oven at 160 °C and set to be placed for several different times, and the cross-cut test was performed as follows. Record the maximum number of hours without peeling in the cross-cut test.

[0157] Cross-cut test: After post-baking, use a brand-new blade to draw on the ink surface with a force of 30° to the plate surface to draw grids, and perform a peeling test with 3M tape. The judgment criteria are as follows.​

[0158] ○: The high-temperature storage time with no peeling in the cross-cut test reaches over 1000 hours.

[0159] ×: The high-temperature storage time with no peeling in the cross-cut test is less than 1000 hours.

[0160] <Volatile matter evaluation>

[0161] An evaluation substrate was separately fabricated by the same fabrication method as the evaluation substrate described in <Acid resistance> above. For this evaluation substrate, the post-cured ink was pretreated in accordance with US EPA 3550C:2007, and the volatile matter content was analyzed using HPLC, GC-MC, and LC-MS-MS.

[0162] The smaller the amount of volatile matter measured by LC-MS / MS, the less the volatilization of harmful substances during the soldering process. In the present invention, a volatile matter of less than 1000 ppm is evaluated as qualified.

[0163] <Color fastness>

[0164] An evaluation substrate was separately fabricated by the same fabrication method as the evaluation substrate described in <Acid resistance> above. For this evaluation substrate, the L of the cured coating film was measured using a spectrophotometer CM-2600d manufactured by Konica Minolta, Inc. * a * b * . Then, a heat treatment (i.e., accelerated deterioration) was performed at 150 °C for 2 hours, and the L * a * b * was measured in the same manner. The ΔEab was calculated from the measured values using the following formula.

[0165] ΔEab = ((L * 2 - L * 1) 2 + (a * 2 - a * 1) 2 + (b * 2 - b * 1) 2 ) 0.5

[0166] (In the formula, L * 1, a * 1, b * 1 respectively represent the values of L * , a * , b * before the heat treatment, and L * 2, a * 2, b *2 respectively represent L after heat treatment * 、a * 、b * values.)

[0167] Here, ΔEab calculates the difference between the initial value and the value after accelerated deterioration in the L * a * b * chromaticity system. The larger the value, the easier it is to oxidize and discolor, indicating low color fastness.

[0168] From the above, it can be seen that in Examples 1 to 4, by containing melamine phthalate in an appropriate amount, a melamine-free photosensitive thermosetting and developable two-component resin composition with excellent evaluations in terms of drying management range, acid resistance, metal plating resistance, high-temperature storage stability, volatile matter, and color fastness can be obtained. In contrast, in Comparative Example 1, neither melamine phthalate nor melamine was contained, and the acid resistance, metal plating resistance, and color fastness of the cured product obtained from the composition were poor. In Comparative Example 2 containing a small amount of melamine and Comparative Example 7 containing an insufficient amount of melamine phthalate, the acid resistance and metal plating resistance were slightly improved compared to Comparative Example 1, but were still insufficient, and the color fastness was still poor. In Comparative Examples 2 - 6, the acid resistance, metal plating resistance, and color fastness were improved by using a certain amount of melamine, but the volatile matter increased significantly. In addition, in Comparative Example 6 containing a large amount of melamine and Comparative Example 8 containing an excessive amount of melamine phthalate, the drying management range was poor and the amount of volatile matter was slightly high.

[0169] From these results, it can be determined that the melamine-free photosensitive thermosetting and developable two-component resin composition of the present invention has an excellent drying management range, can reduce the volatilization of harmful substances during the soldering stage, and can obtain a cured product with excellent acid resistance, metal plating resistance, high-temperature storage stability, and color fastness. The melamine-free photosensitive thermosetting and developable two-component resin composition of the present invention, the dry film using the same, and their cured products are suitable for use as solder resistants for printed circuit boards.

Claims

1. A melamine-free photosensitive thermosetting developable two-component resin composition, characterized in that, Comprising (A) a carboxyl group-containing vinyl ester resin, (B) a photopolymerization initiator, (C) melamine phthalate, and (D) an epoxy resin, wherein the (A) carboxyl group-containing vinyl ester resin and the (B) photopolymerization initiator are contained in a first component, the (D) epoxy resin is contained in a second component different from the first component, and with respect to 100 parts by weight of the (A) carboxyl group-containing vinyl ester resin based on solid content, the (C) melamine phthalate is 1.2 to 11.8 parts by weight.

2. The melamine-free photosensitive thermosetting developable two-component resin composition according to claim 1, characterized in that, With respect to 100 parts by weight of the (D) epoxy resin based on solid content, the (C) melamine phthalate is 1.8 to 18.2 parts by weight.

3. The melamine-free photosensitive thermosetting developable two-component resin composition according to claim 1 or 2, characterized in that, The (C) melamine phthalate is contained in the first component.

4. The melamine-free photosensitive thermosetting developable two-component resin composition according to claim 1 or 2, characterized in that, Also containing (E) an inorganic filler.

5. The melamine-free photosensitive thermosetting developable two-component resin composition according to claim 4, characterized in that, The (E) inorganic filler is contained in the first component.

6. The melamine-free photosensitive thermosetting developable two-component resin composition according to claim 1 or 2, characterized in that, Also containing (F) a photosensitive monomer.

7. The melamine-free photosensitive thermosetting developable two-component resin composition according to claim 6, characterized in that, The (F) photosensitive monomer is contained in the second component.

8. The melamine-free photosensitive thermosetting developable two-component resin composition according to claim 1 or 2, characterized in that, The first component and / or the second component further contains (G) an organic solvent.

9. The melamine-free photosensitive thermosetting developable two-component resin composition according to claim 1 or 2, characterized in that, For solder resist.

10. A dry film, characterized in that, It comprises: a carrier film, and a resin layer obtained by coating the carrier film with the melamine-free photosensitive thermosetting developable two-component resin composition according to any one of claims 1 to 9 and drying.

11. A cured product, characterized in that, It is obtained by curing the melamine-free photosensitive thermosetting developable two-component resin composition according to any one of claims 1 to 9.

12. A cured product, characterized in that, It is obtained by curing the resin layer of the dry film according to claim 10.

13. A printed circuit board, characterized in that, Having the cured product according to claim 11 or 12.

Images