JP7112170B2 - Curable composition for inkjet printing, cured product thereof, and electronic component having cured product thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a curable composition, and more particularly to a curable composition applicable to printing by an inkjet method. The present invention also relates to a cured product of the curable composition and an electronic component having the cured product.

Conventionally known curable compositions used for heat-curable, ultraviolet-curable, and alkali-developable solder resists contain high-molecular-weight polymers in order to meet requirements such as heat resistance. . However, when the viscosity of the curable composition is reduced for application to inkjet printing, these high-molecular-weight polymers cannot be used due to their high viscosity.

Therefore, in recent years, the composition of curable compositions used in solder resists for inkjet printing has been designed around low-viscosity monomers. For example, Patent Literature 1 discloses a curable composition that can be used for printing by an inkjet method.

Since the curable composition of Patent Document 1 has a monomer-based composition, it has a low viscosity, can be applied as an ink for an inkjet printer, and can print a pattern directly on a substrate for a printed wiring board. It is possible to save the trouble of forming a resist pattern by exposure and development as in the photodeveloping method, and to reduce the amount of materials used for forming the resist pattern, such as the photosensitive resin material, developer, and cleaning solvent. can.

Similarly, unlike the formation of a resist pattern by screen printing, there is no need to make a plate, thus saving time and effort, and reducing the amount of materials used such as emulsion.

Like Patent Document 1, Patent Document 2 discloses a photocurable inkjet ink comprising a radically polymerizable urethane (meth)acrylate oligomer, at least one radically polymerizable monomer, a photoradical polymerization initiator, and glycol ethers. Disclosed is a photocurable inkjet ink comprising a non-reactive diluent that is

Patent Document 3 discloses an active energy ray-curable composition for optical parts that can be used for forming a solder resist for flexible printed wiring, although it is not a resin composition for inkjet. Specifically, this active energy ray-curable composition for optical parts comprises a urethane polyfunctional (meth)acrylate oligomer (A), a bifunctional polyoxyalkylene polyol (meth)acrylate (B) containing no aromatic ring, Tri- to hexa-functional (meth)acrylate (C) containing no urethane group, monofunctional (meth)acrylate (D), and light It contains a polymerization initiator (E).

International Publication No. 2013/146706 JP 2016-124907 A JP 2017-083668 A

However, since the curable composition used in the conventional inkjet printing method, such as the curable composition of Patent Document 1, has a monomer-based configuration, it has a low viscosity and a low molecular weight, compared with a composition mainly using a polymer. Therefore, it is presumed that the cured product after curing has a low molecular weight.

Therefore, when used for making solder resists for inkjet printing, it is difficult to obtain the same heat resistance as when using polymers, and problems such as cracks may occur in the coating film due to heat history such as reflow. It was found by the investigation of et al.

Specifically, when components are mounted on a double-sided board with wiring printed on both sides of the board or a multi-layer board made by stacking the boards, repeated heating causes the conductors to become solder resist on the lands where the components are mounted. It has been found that problems such as peeling of the film and cracking of the solder resist itself may occur.

According to the photocurable inkjet ink of Patent Document 2, although the storage stability of the photocurable inkjet ink is improved by the non-reactive diluent that is a glycol ether, the heat resistance of the film formed from the ink is not improved. No mention is made of measures for this.

Since the active energy ray-curable composition for optical components of Patent Document 3 is a composition mainly composed of acrylate monomers as in Patent Document 1, the obtained cured product is also considered to be weak against repeated heating. describes a solder resist for flexible printed wiring with a relatively small thermal history. In addition, the active energy ray-curable composition for optical parts of Patent Document 3 is not a composition for inkjet printing.

The present invention has been made in view of the above problems, and an object of the present invention is to use a curable composition for inkjet printing in which the heat resistance of the obtained film is improved than before, the cured product thereof, and the cured product. It is to provide electronic parts.

In order to increase the heat resistance of the film after curing of the curable composition mainly composed of acrylate monomers used in the inkjet printing method, we investigated the acrylate monomers to be blended. Cracks tend to occur in the film after repeated heating, but other mechanical properties (adhesion to conductors, film hardness, chemical resistance, hereinafter also referred to as solder heat resistance) are excellent, and cracks after heating It has become clear from the studies of the inventors that there is a material that suppresses the occurrence of soldering but is inferior in soldering heat resistance.

The invention of the present application has been made based on the results of the above study, with the object of improving the heat resistance of the coating, that is, improving the heat resistance of the coating, including suppressing the occurrence of cracks after heating. That is, the above object of the present invention is a curable composition for inkjet printing,
(A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less;
(B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures;
(B2) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having a monoalkylene glycol structure;
(C) a photoinitiator.

In the curable composition for inkjet printing of the present invention, the amount of (A) a cyclic skeleton per 100 parts by mass of the curable composition and an alkylene oxide modification number of 1 or more and 6 or less (meth) acrylate monomer. is preferably 5 parts by mass or more and 40 parts by mass or less.

Furthermore, (B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures and (B2) a bifunctional (meth)acrylate having no cyclic skeleton and having a monoalkylene glycol structure The mass ratio ((A)/(B1)+(B2)) of (A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less to the total amount of rate monomers is 0. It is preferably 10 or more and 0.70 or less.

In addition, (B2) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having a monoalkylene glycol structure (B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures The mass ratio ((B1)/(B2)) of the acrylate monomers is preferably 1.0 or more and 3.0 or less.

The above objects of the present invention are also achieved by a cured product of the curable composition of the present invention and an electronic component having the cured product.

According to the present invention, the film (cured product) formed from the curable composition for inkjet printing does not generate cracks even after repeated heating assuming reflow soldering, and after soldering or plating. It maintains sufficient adhesion to the substrate (solder heat resistance, plating resistance) and film hardness even in , and has good mechanical properties expected as a solder resist.

FIG. 1 is a graph showing the conditions of reflow treatment of a cured product (test substrate) of a curable composition according to an example of the present invention.

<Curable composition for inkjet printing>
The curable composition for inkjet printing of the present invention (hereinafter sometimes abbreviated as "curable composition") is
(A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less;
(B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures;
(B2) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having a monoalkylene glycol structure;
(C) a photopolymerization initiator.

[(A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less]
(A) A (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less has a relatively high viscosity, but the film obtained by adding it cracks after repeated reflow. A monomer that improves durability and solder heat resistance.

The cyclic skeleton includes a cyclic carbon skeleton in which the ring structure is composed only of carbon, and a heterocyclic skeleton containing atoms other than carbon atoms such as oxygen, nitrogen and sulfur atoms in the ring structure. Furthermore, the ring structure may be an aromatic ring or a saturated or unsaturated ring structure.

Examples of (meth)acrylate monomers having an aromatic ring and an alkylene oxide modification number of 1 or more and 6 or less include EO adducts and PO adducts of acrylates of polyhydric phenols.

Examples of polyhydric phenols include bisphenols such as bisphenol A, bisphenol AP, bisphenol B, bisphenol BP, bisphenol E, bisphenol F, bisphenol M, bisphenol P, bisphenol PH and bisphenol Z, and biphenols.

In addition, as the (meth)acrylate monomer having a saturated or unsaturated ring structure and an alkylene oxide modification number of 1 to 6, hydrogenated acrylates of the above polyhydric phenols and dicyclodecanedimethanol Examples include alkylene oxide adducts of diacrylates of diols having a carbon ring such as acrylates and cyclohexyl diacrylates.

Examples of the alkylene oxide include ethylene oxide, propylene oxide and butylene oxide, preferably modified with at least one of ethylene oxide and propylene oxide, and most preferably modified with ethylene oxide.

When the modification number of the alkylene oxide is 1 or more and 6 or less, the crack resistance and solder heat resistance of the obtained film become good. The number of modifications of alkylene oxide is the number of modifications of alkylene oxide in one molecule of a monomer, specifically, in one molecule of a monomer, the total number of -R-O- (R is an alkylene group) n. .

The modification number of the alkylene oxide is preferably 1 or more and 4 or less.

(A) A (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less is a polyfunctional (meth)acryloyl group-containing monomer (polyfunctional (meth)acrylate), It may be a functional (meth)acryloyl group-containing monomer (monofunctional (meth)acrylate), but from the viewpoint of maintaining a low viscosity as a composition and the heat resistance of the cured film, a bifunctional (meth) ) is preferably an acryloyl group-containing monomer (bifunctional (meth)acrylate). In addition, a (meth)acryloyl group is a general term for an acryloyl group and a methacryloyl group.

(A) A (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less is blended in an amount of 5 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the curable composition. preferable. This concentration range facilitates making the viscosity of the curable composition within a range usable for the inkjet method, and promotes improvement in reflow crack resistance and solder heat resistance of the obtained coating. In addition, it is preferably added in an amount of 5 parts by mass or more and 30 parts by mass or less, more preferably 10 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the curable composition.

Commercially available products include ABE-300 (manufactured by Shin-Nakamura Chemical Co., Ltd.), BPE-80N (manufactured by Shin-Nakamura Chemical Co., Ltd.), BPE-100 (manufactured by Shin-Nakamura Chemical Co., Ltd.), BPE-4 (Daiichi Kogyo Seiyaku Co., Ltd.), BPE-200 (Shin-Nakamura Chemical Co., Ltd.), HBPE-4 (Daiichi Kogyo Seiyaku Co., Ltd.), and Aronix M-208 (Toagosei Co., Ltd.).

[(B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and two or more alkylene glycol structures]
(B1) A bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures is added among the diluents added to reduce the viscosity of the curable composition. It improves the crack resistance during reflow of the film obtained by. That is, the bifunctional (meth)acrylate monomer includes (A) a cyclic skeleton and a (meth)acrylate monomer having an alkylene oxide modification number of 1 or more and 6 or less, and (B2) having no cyclic skeleton, which will be described later. , By combining with a bifunctional (meth)acrylate monomer having a monoalkylene glycol structure, the obtained film improves the crack resistance and solder heat resistance during reflow while maintaining the liquid properties that can be used in the inkjet method.

In the present invention, the (B1) bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures is, for example, an ester of di- or trialkylene glycol and (meth)acrylic acid. It is a bifunctional (meth)acryloyl group-containing monomer (bifunctional (meth)acrylate).

Dialkylene glycol includes diethylene glycol, dipropylene glycol and dibutylene glycol, and trialkylene glycol includes triethylene glycol, tripropylene glycol and tributylene glycol.

From the viewpoint of suppressing the viscosity to a viscosity suitable for the inkjet method, an ester of dialkylene glycol and (meth)acrylic acid is preferable.

Specifically, (B1) the bifunctional (meth)acrylate monomer having a di- or trialkylene glycol structure without having both an aromatic ring and a saturated or unsaturated carbocyclic ring includes diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, dibutylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tributylene glycol di(meth)acrylate.

Commercially available products include 2G (manufactured by Shin-Nakamura Chemical Co., Ltd.), 3G (manufactured by Shin-Nakamura Chemical Co., Ltd.), DPGDA (manufactured by Toyo Chemicals Co., Ltd.), T0948 (manufactured by Tokyo Chemical Industry Co., Ltd.), T2389 (Tokyo Kasei Kogyo Co., Ltd.), Viscoat #310HP (manufactured by Osaka Organic Chemical Industry Co., Ltd.), and the like.

(B1) A bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures is blended in an amount of 20 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the curable composition. is preferred.

[(B2) a bifunctional (meth)acrylate monomer having a monoalkylene glycol structure and having no cyclic skeleton]
(B2) A bifunctional (meth)acrylate monomer having no cyclic skeleton and a monoalkylene glycol structure is obtained by adding a diluent added to reduce the viscosity of the curable composition. It improves the solder heat resistance of the coated film. That is, the bifunctional (meth)acrylate monomer includes (A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less, and (B1) the above (B1) having no cyclic skeleton, By combining with a bifunctional (meth)acrylate monomer having two or more alkylene glycol structures, the reflow crack resistance and solder heat resistance of the obtained film are improved while maintaining the liquid properties that can be used in the inkjet method.

In the present invention, (B2) the bifunctional (meth)acrylate monomer having a monoalkylene glycol structure without a cyclic skeleton is, for example, a bifunctional (meth)acrylate ester of monoalkylene glycol and (meth)acrylic acid. meth)acrylate monomer.

The monoalkylene glycol structure moiety is preferably a linear or branched alkylene chain having 3 to 16 carbon atoms in one molecule, and is particularly a linear alkylene chain having 6 to 9 carbon atoms. Preferably.

Specifically, (B2) the bifunctional (meth)acrylate monomer having a monoalkylene glycol structure without having both an aromatic ring and a saturated or unsaturated carbocyclic ring includes 1,3-butylene glycol di(meth) ) acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol acrylate, 1,10-decanediol diacrylate, 1,16-hexadecanediol and diacrylate.

Commercially available products include HDDA (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), A-NOD-N (manufactured by Shin-Nakamura Chemical Co., Ltd.), B1065 (manufactured by Tokyo Chemical Industry Co., Ltd.), Viscoat #195 (Osaka Organic Chemical Kogyo Co., Ltd.), A-DOD-N (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), and the like.

(B2) The bifunctional (meth)acrylate monomer having no cyclic skeleton and having a monoalkylene glycol structure is preferably blended in an amount of 10 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the curable composition. .

Further, (B2) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having a monoalkylene glycol structure (B1) a bifunctional (meth)acrylate having no cyclic skeleton and having two or more alkylene glycol structures It is preferable that the mass ratio of the monomers is 1.0 or more and 3.0 or less.

When the mass ratio of the two is within the above range, (A) in combination with a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less, the reflow crack resistance of the resulting film is improved. And the improvement of solder heat resistance can be realized at a higher level.

Furthermore, (B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures and (B2) a bifunctional (meth)acrylate having no cyclic skeleton and having a monoalkylene glycol structure The mass ratio of (A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less to the total amount of the monomers is preferably 0.10 or more and 0.70 or less.

By setting the mass ratio of the three components within the above range, it is possible to achieve a higher level of reflow crack resistance and solder heat resistance of the obtained film.

Furthermore, (A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less, (B1) a bifunctional (meth) acrylate monomer having no cyclic skeleton and having an alkylene glycol structure of 2 or more ) acrylate monomers and (B2) bifunctional (meth)acrylate monomers having no cyclic skeleton and having a monoalkylene glycol structure may or may not contain hydroxyl groups in their molecules.

Moreover, the curable composition used in the present invention further contains the following photopolymerization initiator.

[(C) Photoinitiator]
The photopolymerization initiator is not particularly limited as long as it can polymerize (meth)acrylate by irradiation with energy rays, and a radical polymerization initiator can be used.

As the radical photopolymerization initiator, any compound can be used as long as it generates radicals by light, laser, electron beam or the like and initiates a radical polymerization reaction. Examples of the photoradical polymerization initiator include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether; Acetophenones such as diethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino -Aminoacetophenones such as 1-(4-morpholinophenyl)-butan-1-one and N,N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone Anthraquinones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone and the like; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; ,5-triarylimidazole dimer; riboflavin tetrabutyrate; thiol compounds such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole; 2,4,6-tris-s-triazine, 2 , 2,2-tribromoethanol, tribromomethylphenylsulfone and other organic halogen compounds; benzophenone, 4,4′-bisdiethylaminobenzophenone and other benzophenones or xanthones; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc. is mentioned.

The radical photopolymerization initiators may be used alone or in combination. Furthermore, in addition to these, tertiary amines such as N,N-dimethylaminobenzoic acid ethyl ester, N,N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine, etc. Co-photoinitiators can be used. In addition, a titanocene compound such as CGI-784 (manufactured by BASF Japan Ltd.) having absorption in the visible light region can also be added to the radical photopolymerization initiator in order to promote the photoreaction. The components to be added to the photoradical polymerization initiator are not limited to these, as long as they absorb light in the ultraviolet or visible light region and radically polymerize unsaturated groups such as (meth)acryloyl groups. , a photopolymerization initiator, and a photoinitiation aid, they can be used singly or in combination.

The amount of the photopolymerization initiator compounded is 0.5 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the curable composition.

Examples of product names of commercially available photopolymerization initiators include Omnirad 907, Omnirad 127, Omnirad 379 (all manufactured by IGM Resins), 2-isopropylthioxanthone (manufactured by Nippon Kayaku Co., Ltd.), and the like.

Moreover, the curable composition of the present invention preferably contains a thermosetting component. By including a thermosetting component, it can be expected that the heat resistance of the obtained film, such as adhesion after soldering or plating (solder heat resistance and plating resistance) and crack suppression after heating, will be improved.

As thermosetting components, known amino resins such as melamine resins, benzoguanamine resins, melamine derivatives and benzoguanamine derivatives, blocked isocyanate compounds, cyclocarbonate compounds, thermosetting components having a cyclic (thio)ether group, bismaleimide, carbodiimide resins, etc. thermosetting resin. Among them, it is preferable to use a blocked isocyanate compound because of its excellent storage stability.

A thermosetting component having a plurality of cyclic (thio)ether groups in the molecule is a compound having a plurality of 3-, 4-, or 5-membered cyclic (thio)ether groups or two groups in the molecule. , for example, compounds having multiple epoxy groups in the molecule, i.e. polyfunctional epoxy compounds, compounds having multiple oxetanyl groups in the molecule, i.e. polyfunctional oxetane compounds, compounds having multiple thioether groups in the molecule, i.e. episulfide Resin etc. are mentioned.

Examples of polyfunctional epoxy compounds include epoxidized vegetable oils such as Adekasizer O-130P and Adekasizer O-180A manufactured by ADEKA; jER828 manufactured by Mitsubishi Chemical Corporation; EHPE3150 manufactured by Daicel Chemical Industries, Ltd.; Epotato YD-011 manufactured by Tohto Kasei Co., Ltd., D.O. manufactured by Dow Chemical Co., Ltd.; E. R. 317, Sumie-Epoxy ESA-011 manufactured by Sumitomo Chemical Co., Ltd., A.M. E. R. Bisphenol A type epoxy resin such as 330 (both trade names); hydroquinone type epoxy resin; bisphenol F type epoxy resin such as YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; type epoxy resin; jERYL903 manufactured by Mitsubishi Chemical Corporation, Epiclon 152 manufactured by DIC Corporation, Epotato YDB-400 manufactured by Tohto Kasei Co., Ltd., D.I. E. R. 542, Sumie-Epoxy ESB-400 manufactured by Sumitomo Chemical Co., Ltd., A.M.D. manufactured by Asahi Chemical Industry Co., Ltd. E. R. Brominated epoxy resins such as 711 (both trade names); jER152 manufactured by Mitsubishi Chemical Corporation; E. N. Epiclon N-730 manufactured by 431DIC, Epotote YDCN-701 manufactured by Tohto Kasei Co., Ltd., EPPN-201 manufactured by Nippon Kayaku Co., Ltd., Sumie-Epoxy ESCN-195X manufactured by Sumitomo Chemical Co., Ltd., A.P. manufactured by Asahi Chemical Industry Co., Ltd. E. R. ECN-235 and the like (both trade names) novolac epoxy resins; Nippon Kayaku NC-3000 and other biphenol novolak epoxy resins; DIC Epiclon 830, Mitsubishi Chemical jER807, Toto Kasei Co. Bisphenol F type epoxy resins such as Epotoot YDF-170, YDF-175, YDF-2004 (all trade names); Hydrogenated bisphenol A epoxy resins such as Epotoot ST-2004 (trade name) manufactured by Toto Kasei Co., Ltd.; Mitsubishi Glycidylamine type epoxy resins such as jER604 manufactured by Kagaku Co., Ltd., Epotote YH-434 manufactured by Toto Kasei Co., Ltd., and Sumi-Epoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd. (all trade names); Hydantoin type epoxy resin; Daicel Chemical Industries Alicyclic epoxy resins such as Celoxide 2021 (both trade names) manufactured by Nippon Kayaku Co., Ltd.; trihydroxyphenylmethane type epoxy resins such as EPPN-501 (both trade names) manufactured by Nippon Kayaku; -6056, YX-4000, YL-6121 (all trade names) bixylenol type or biphenol type epoxy resins or mixtures thereof; EBPS-200 manufactured by Nippon Kayaku, EPX-30 manufactured by ADEKA, manufactured by DIC bisphenol S type epoxy resin such as EXA-1514 (trade name); bisphenol A novolac type epoxy resin such as jER157S (trade name) manufactured by Mitsubishi Chemical; Heterocyclic epoxy resins such as TEPIC (both trade names) manufactured by Nissan Chemical Industries, Ltd.; Diglycidyl phthalate resins such as BLEMMER DGT manufactured by NOF Corporation; ZX-1063 manufactured by Tohto Kasei Co., Ltd. Tetraglycidyl xylenoyl ethane resin such as; ESN-190 manufactured by Nippon Steel Chemical Co., Ltd., epoxy resin containing naphthalene group such as HP-4032 manufactured by DIC; Epoxy resin having a dicyclopentadiene skeleton such as HP-7200 manufactured by DIC ; glycidyl methacrylate copolymer epoxy resins such as CP-50S and CP-50M manufactured by NOF Corporation; further copolymer epoxy resins of cyclohexylmaleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivatives (for example, Daicel Chemical Industries PB- 3600, etc.), CTBN-modified epoxy resins (eg, YR-102, YR-450, etc. manufactured by Tohto Kasei Co., Ltd.), etc., but are not limited to these. These epoxy resins can be used alone or in combination of two or more. Among these, novolak-type epoxy resins, bixylenol-type epoxy resins, biphenol-type epoxy resins, biphenol-novolac-type epoxy resins, naphthalene-type epoxy resins, and mixtures thereof are particularly preferable.

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

Incidentally, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate, etc. , A monomer that has both a radical polymerization site (methacrylic group) and a cationic polymerization site (oxetanyl site) in the molecule is both a photocurable component and a thermosetting component, so when performing two-step curing of photocuring and thermosetting is preferably included in the composition.

Examples of such components include, in addition to polyfunctional oxetane compounds, (meth)acryloyl group-containing bisphenol A type epoxy resin (product name: EA-1010LC, manufactured by Shin-Nakamura Chemical Co., Ltd.), 4-hydroxybutyl acrylate glycidyl ether. (product name, 4HBAGE, manufactured by Nippon Kasei Co., Ltd.), 3,4-epoxycyclohexylmethyl methacrylate (product name, CYCLOMER M100, manufactured by Daicel Corporation), and the like.

Examples of compounds having a plurality of cyclic thioether groups in the molecule include bisphenol A episulfide resin YL7000 manufactured by Mitsubishi Chemical Corporation. Also, an episulfide resin obtained by replacing the oxygen atom of the epoxy group of the novolac type epoxy resin with a sulfur atom by using a similar synthesis method can be used.

Amino resins such as melamine derivatives and benzoguanamine derivatives include, for example, methylolmelamine compounds, methylolbenzoguanamine compounds, methylolglycoluril compounds and methylolurea compounds. In addition, the alkoxymethylated melamine compounds, alkoxymethylated benzoguanamine compounds, alkoxymethylated glycoluril compounds and alkoxymethylated urea compounds can replace the methylol groups of the respective methylol melamine compounds, methylol benzoguanamine compounds, methylol glycol uril compounds and methylol urea compounds. It is obtained by converting to an alkoxymethyl group. The type of this alkoxymethyl group is not particularly limited, and may be, for example, a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, a butoxymethyl group, or the like. In particular, melamine derivatives having a formalin concentration of 0.2% or less, which are friendly to the human body and the environment, are preferred.

Examples of these commercially available products include Cymel 300, Cymel 301, Cymel 303, Cymel 370, Cymel 325, Cymel 327, Cymel 701, and Cymel 266 (all manufactured by Mitsui Cyanamid), Nikalac Mx-750, and Cymel Mx-032. , Mx-270, Mx-280, Mx-290, and Mx-706 (all manufactured by Sanwa Chemical Co., Ltd.). Such thermosetting components may be used singly or in combination of two or more.

Isocyanate compounds and blocked isocyanate compounds are compounds having a plurality of isocyanate groups or blocked isocyanate groups in one molecule. Examples of such compounds having a plurality of isocyanate groups or blocked isocyanate groups in one molecule include polyisocyanate compounds and blocked isocyanate compounds. The blocked isocyanate group is a group in which the isocyanate group is protected by a reaction with a blocking agent and is temporarily inactivated. is generated. By adding the polyisocyanate compound or blocked isocyanate compound, the curability and the toughness of the resulting cured product can be improved.

Examples of such polyisocyanate compounds include aromatic polyisocyanates, aliphatic polyisocyanates and alicyclic polyisocyanates.

Specific examples of aromatic polyisocyanates include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, Examples include m-xylylene diisocyanate and 2,4-tolylene dimer.

Specific examples of aliphatic polyisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate) and isophorone diisocyanate.

A specific example of the alicyclic polyisocyanate is bicycloheptane triisocyanate. and adducts, biurets and isocyanurates of the above-mentioned isocyanate compounds.

As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent is used. Examples of the isocyanate compound that can react with the blocking agent include the polyisocyanate compounds described above.

Examples of isocyanate blocking agents include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-parellolactam, γ-butyrolactam and β-propiolactam; Active methylene blocking agents such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl alcohol-based blocking agents such as ether, methyl glycolate, butyl glycolate, diacetone alcohol, methyl lactate and ethyl lactate; mercaptan blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol and ethylthiophenol; acid amide blocking agents such as acetic amide and benzamide; imides such as succinimide and maleic imide system blocking agents; amine blocking agents such as xylidine, aniline, butylamine and dibutylamine; imidazole blocking agents such as imidazole and 2-ethylimidazole; imine blocking agents such as methyleneimine and propyleneimine; mentioned.

Blocked isocyanate compounds may be commercially available, such as Sumidur BL-3175, BL-4165, BL-1100, BL-1265, Desmodur TPLS-2957, TPLS-2062, TPLS-2078, TPLS-2117. , Desmotherm 2170, Desmotherm 2265 (both manufactured by Sumitomo Bayer Urethane Co., Ltd.), Coronate 2512, Coronate 2513, Coronate 2520 (both manufactured by Nippon Polyurethane Industry Co., Ltd.), B-830, B-815, B-846, B-870, B-874, B-882 (all manufactured by Mitsui Takeda Chemicals), TPA-B80E, 17B-60PX, E402-B80T (all manufactured by Asahi Kasei Chemicals), 7950, 7951, 7960, 7961, 7982, 7990, 7991 , 7992 (both manufactured by Baxenden chemicals). Sumidur BL-3175 and BL-4265 are obtained by using methylethyloxime as a blocking agent. Such compounds having a plurality of isocyanate groups or blocked isocyanate groups in one molecule may be used singly or in combination of two or more.

A blending amount of the thermosetting component is preferably 1 to 30 parts by mass per 100 parts by mass of the curable composition of the present invention. If the blending amount is 1 part by mass or more, the toughness and heat resistance of the coating film are further improved. On the other hand, if it is 30 parts by mass or less, deterioration of storage stability can be suppressed.

Furthermore, the curable composition of the present invention may contain a (meth)acrylate having a hydroxyl group. By containing a (meth)acrylate having a hydroxyl group, the adhesion of the obtained film to a conductor circuit metal or a plastic substrate is improved.

Examples of (meth)acrylates having a hydroxyl group include 2-hydroxy-3-acryloyloxypropyl (meth)acrylate, 2-hydroxy-3-phenoxyethyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, 2-hydroxypropyl (Meth)acrylate and the like. Commercially available products include Aronix M-5700 (trade name manufactured by Toagosei Co., Ltd.), 4HBA, 2HEA, CHDMMA (trade names manufactured by Nippon Kasei Co., Ltd.), BHEA, HPA, HEMA, HPMA (trade names manufactured by Nippon Shokubai Co., Ltd.). (trade name), Light Ester HO, Light Ester HOP, Light Ester HOA (all trade names manufactured by Kyoeisha Chemical Co., Ltd.), and the like. (B) A (meth)acrylate compound having a hydroxyl group can be used singly or in combination.

Among these, in particular 2-hydroxy-3-acryloyloxypropyl acrylate, 2-hydroxy-3-phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 1,4-cyclohexanedimethanol Monoacrylates are preferably used. Moreover, a monofunctional (meth)acrylate compound is preferably used from the viewpoint of ease of viscosity adjustment.

The amount of the (meth)acrylate compound having a hydroxyl group is preferably 1 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the curable composition of the present invention.

Additionally, the curable composition of the present invention may comprise a hyperbranched oligomer or hyperbranched polymer. In the present invention, a multibranched oligomer or polymer having an ethylenically unsaturated group is a multibranched oligomer or polymer (referring to an oligomer or polymer having a plurality of branched chains in one molecule) having an ethylenic structure in its skeleton. It is a compound having at least one unsaturated group. The ethylenically unsaturated group is derived from a functional group such as a (meth)acryloyl group, and may have multiple types of ethylenically unsaturated groups in one molecule. In addition, a (meth)acryloyl group is a concept including both an acryloyl group and a methacryloyl group.

As a multibranched oligomer and/or polymer having an ethylenically unsaturated group (hereinafter also simply referred to as a "multibranched oligomer or polymer"), a compound having a dendrimer structure (dendritic structure) (hereinafter simply dendrimer ), compounds having a hyperbranched (hyperbranched) structure (hereinafter also simply referred to as hyperbranched (oligomers, polymers)), compounds having a star structure (oligomers, polymers), and compounds having a graft structure (oligomers, It is preferably a compound that is a polymer) and has a functional group having an ethylenically unsaturated bond, such as a (meth)acryloyl group.

In the present invention, the dendrimer broadly refers to a compound having a structure in which branched chains spread radially. Specific types of dendrimers are not particularly limited, and one or more types can be selected from known dendrimers such as amidoamine-based dendrimers, phenyl ether-based dendrimers, and hyperbranched polyethylene glycol.

The multi-branched oligomer or polymer generally has a weight average molecular weight (Mw) of 1000-20000, preferably 1000-8000. The weight average molecular weight (Mw) is the polystyrene-equivalent molecular weight based on the molecular weight distribution curve based on gel permeation chromatography.

The number of functional groups having an ethylenically unsaturated bond, particularly the number of (meth)acryloyl groups, in one molecule of the multibranched oligomer or polymer of the present invention is preferably 3 or more, particularly in the range of 4 to 30. It is preferably selected within a range that does not impair the desired effect of the composition of the present invention. In particular, since the photocurable composition of the present invention is used for inkjet, one having a number of functional groups of 30 or less and having a viscosity of 150 mPa·s or less at room temperature (25° C.) is used.

The method for producing a dendrimer is not particularly limited, and includes a divergent method in which molecules are attached to a central core molecule for each generation to form branches, a convergent method in which pre-synthesized branch moieties are attached to a core molecule, and two or more reaction points. A known production method such as a method of synthesizing in one step using a monomer ABx having a branched portion having B and a linking portion having another reaction point A in one molecule can be employed.

A commercially available dendrimer can also be used, for example, Etercure 6361-100 (manufactured by Eternal Materials), Doublermer (DM) 2015 (manufactured by Double Bond Chemical), SP1106 (manufactured by Miwon Specialty Chemical), Viscoat #1000. (manufactured by Osaka Organic Chemical Industry Co., Ltd.).

In addition, dendrimers are available from Iris Biotech, Kanto Kagaku, Merk Millipore, QIAGEN, Sigma-Aldrich, Techno Chemical, Double Bond Chemical, Osaka Organic Chemical Industry, Hakuto, and others.

In the present invention, by using a multi-branched oligomer or polymer having an ethylenically unsaturated group, adhesion between the curable composition and the substrate can be improved, and high hardness can be imparted to the cured product. . In addition, it is possible to improve plating resistance under severe treatment conditions.
Furthermore, since the polybranched oligomer or polymer having an ethylenically unsaturated group has a relatively low viscosity even if the number of functional groups or the amount used is increased, it is significant for increasing the hardness of the curable composition. be.

The blending amount of the polybranched oligomer or polymer having ethylenically unsaturated groups is preferably 0.1 to 40% by mass with respect to the total mass of the curable composition. By making it 0.1 or more, the hardness of the coating film is improved, and by making it 40% by mass or less, it is possible to suppress an increase in the viscosity of the cured composition.

Moreover, the curable composition of the present invention may contain a tri- or more and hexa- or less (meth)acrylate compound. By containing a (meth)acrylate compound having a functionality of 3 or more and 6 or less, an improvement in the tackiness (dryness to the touch) of the composition after photocuring is expected.

Trimethylolpropane triacrylate, trimethylolmethane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane. Triacrylate, pentaerythritol tetraacrylate, tetramethylolmethane tetraacrylate, ethylene oxide-modified phosphoric acid triacrylate, propylene oxide-modified phosphoric acid triacrylate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, or these polyfunctional acrylates represented by silsesquioxane-modified products of , methacrylate monomers corresponding to these, and ε-caprolactone-modified trisacryloxyethyl isocyanurate. The amount of the tri- to hexa-functional (meth)acrylate compound is, for example, 1 to 20 parts by mass, preferably 1 to 10 parts by mass, per 100 parts by mass of the curable composition of the present invention.

The curable composition of the present invention may optionally contain additives such as antifoaming/leveling agents, thixotropy-imparting agents/thickening agents, coupling agents, dispersants, and flame retardants.

Compounds such as silicones, modified silicones, mineral oils, vegetable oils, fatty alcohols, fatty acids, metallic soaps, fatty acid amides, polyoxyalkylene glycols, polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters, etc. as antifoaming agents and leveling agents can be used.

Thixotropy-imparting agents and thickeners include clay minerals such as kaolinite, smectite, montmorillonite, bentonite, talc, mica, and zeolite, fine silica particles, silica gel, amorphous inorganic particles, polyamide additives, modified urea additives, A wax-based additive or the like can be used.

By adding an antifoaming/leveling agent, a thixotropy imparting agent/thickening agent, the surface properties of the cured product and the properties of the composition can be adjusted.

Coupling agents include alkoxy groups such as methoxy, ethoxy, and acetyl, and reactive functional groups such as vinyl, methacryl, acryl, epoxy, cyclic epoxy, mercapto, amino, diamino, acid anhydride, ureide, sulfide, vinyl silane compounds such as vinylethoxysilane, vinyltrimethoxysilane, vinyl-tris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, Ν -β-(aminoethyl)γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)γ-aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane and other amino-based silane compounds, γ-glycides Epoxy silane compounds such as xypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and mercapto silanes such as γ-mercaptopropyltrimethoxysilane compounds, silane coupling agents such as phenylamino silane compounds such as Ν-phenyl-γ-aminopropyltrimethoxysilane, isopropyl triisostearoylated titanate, tetraoctylbis(ditridecylphosphite) titanate, bis(dioctylpyrophosphate ) oxyacetate titanate, isopropyltridodecylbenzenesulfonyltitanate, isopropyltris(dioctylpyrophosphate)titanate, tetraisopropylbis(dioctylphosphite)titanate, tetra(1,1-diallyloxymethyl-1-butyl)bis-(ditridecyl) Phosphite titanate, bis(dioctyl pyrophosphate) ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl tristearoyl diacryl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, dicumylphenyl Titanate coupling agents such as oxyacetate titanate and diisostearoylethylene titanate, ethylenically unsaturated zirconate-containing compounds, neoalkoxyzirconate-containing compounds, neoalkoxytrisneodecanoylzirconate, neoalkoxytris(dodecyl) base benzenesulfonyl zirconate, neoalkoxytris(dioctyl)phosphate zirconate, neoalkoxytris(dioctyl)pyrophosphate zirconate, neoalkoxytris(ethylenediamino)ethylzirconate, neoalkoxytris(m-amino)phenylzirconate, tetra (2,2-diallyloxymethyl)butyl, di(ditridecyl)phosphitozirconate, neopentyl(diallyl)oxy, trineodecanoylzirconate, neopentyl(diallyl)oxy, tri(dodecyl)benzene-sulfonylzirconate, neopentyl (diallyl)oxy, tri(dioctyl)phosphatozirconate, neopentyl(diallyl)oxy, tri(dioctyl)pyro-phosphatozirconate, neopentyl(diallyl)oxy, tri(N-ethylenediamino)ethylzirconate, neopentyl ( diallyl)oxy, tri(m-amino)phenylzirconate, neopentyl(diallyl)oxy, trimethacrylzirconate (, neopentyl(diallyl)oxy, triacrylzirconate, dineopentyl(diallyl)oxy, di-para-aminobenzoylzirconate, dineopentyl (diallyl)oxy, di(3-mercapto)propionic zirconate, zirconium (IV) 2,2-bis(2-propenolatomethyl)butanolate, cyclodi[2,2-(bis2-propenolatomethyl) ) Zirconate coupling agents such as butanolate]pyrophosphato-O, O, and aluminate coupling agents such as diisobutyl(oleyl)acetoacetylaluminate and alkylacetoacetate aluminum diisopropylate can be used.

Dispersants include polycarboxylic acid, naphthalenesulfonic acid formalin condensation, polyethylene glycol, polycarboxylic acid partial alkyl ester, polyether, polyalkylenepolyamine, and other polymeric dispersants; alkylsulfonic acid; Low-molecular-weight dispersants such as ammonium-based, higher alcohol alkylene oxide-based, polyhydric alcohol ester-based, and alkylpolyamine-based dispersants can be used.

Flame retardants include hydrated metals such as aluminum hydroxide and magnesium hydroxide, red phosphorus, ammonium phosphate, ammonium carbonate, zinc borate, zinc stannate, molybdenum compounds, bromine compounds, chlorine compounds, and phosphate esters. , phosphorus-containing polyols, phosphorus-containing amines, melamine cyanurate, melamine compounds, triazine compounds, guanidine compounds, silicone polymers and the like.

In order to adjust the polymerization rate and degree of polymerization, it is also possible to add a polymerization inhibitor and a polymerization retarder.

Further, a solvent may be used in the curable composition of the present invention for viscosity adjustment, but the amount added is preferably small in order to prevent film thickness reduction after curing. Moreover, it is more preferable not to contain the solvent for viscosity adjustment.

A coloring pigment, dye, or the like may be added to the curable composition of the present invention for the purpose of coloring. As the coloring pigments, dyes, and the like, known and commonly used ones represented by a color index can be used. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 60, Solvent Blue 35, 63, 68, 70, 83, 87, 94, 97, 122, 136, 67, 70, Pigment Green 7, 36, 3, 5, 20, 28, Solvent Yellow 163, Pigment Yellow 24, 108, 193, 147, 199, 202, 110, 109, 139 179 185 93, 94, 95, 128, 155, 166, 180, 120, 151, 154, 156, 175, 181, 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, 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198, Pigment Orange 1, 5, 13, 14, 16, 17, 24, 34, 36, 38, 40, 43, 46, 49, 51, 61, 63, 64, 71, 73, Pigment Red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151, 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269, 37, 38, 41, 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, 171, 175, 176, 185, 208, 123, 149, 166, 178, 179, 190, 194, 224, 254, 255, 264, 270, 272, 220, 144, 166, 214, 220, 221, 242, 168, 177, 216, 122, 202, 206, 207, 209, Solvent Red 135, 179, 149, 150, 52, 207, Pigment Violet 19, 23, 29, 32, 36, 38, 42, Solvent Violet 13, 36, Pigment Brown 23, 25, Pigment Black 1, 7 and the like. These coloring pigments and dyes are preferably added in an amount of 0.01 to 5 parts by mass with respect to 100 parts by mass of the curable composition.

The curable composition of the present invention is applicable to printing by an inkjet method. In order to be applicable to printing by an inkjet method, it is preferable that the viscosity is such that it can be jetted by an inkjet printer.

Viscosity refers to viscosity measured according to JIS K2283. Further, the viscosity of the curable composition for inkjet described above is preferably 150 mPa·s or less at room temperature (25° C.). As described above, the viscosity of the ink used in the ink jet printer is preferably about 20 mPa·s or less at the temperature during application. However, if the viscosity is 150 mPa·s or less at room temperature, the above conditions can be satisfied by heating before or during application.

Therefore, the curable composition of the present invention can be used to directly print a pattern on a printed wiring board substrate or the like.

Furthermore, since the curable composition of the present invention does not undergo a polymerization reaction at room temperature, it can be stably stored as a one-component curable composition.

The curable composition of the present invention is supplied as ink to an inkjet printer and used for printing on a substrate. Since the ink viscosity of the composition of the present invention is very low, when printed or applied by an inkjet method, the pattern or characters printed or applied to the base material wet and spread over a long period of time, causing bleeding.

<Cured product of curable composition>
A cured product of the curable composition of the present invention can be obtained, for example, by irradiating the composition layer immediately after printing with light of 50 mJ/cm ² to 1000 mJ/cm ² to photocure the composition layer. Light irradiation is carried out by irradiation with active energy rays such as ultraviolet rays, electron beams and actinic rays, preferably ultraviolet irradiation.

Ultraviolet irradiation in an inkjet printer can be carried out by, for example, attaching a light source such as a high-pressure mercury lamp, a metal halide lamp, or an ultraviolet LED to the side of the print head and scanning by moving the print head or substrate. In this case, printing and ultraviolet irradiation can be performed almost simultaneously.

When the cured product after photocuring contains a thermosetting component, it is thermoset by using a known heating means such as a hot air furnace, an electric furnace, an infrared induction heating furnace, or the like. As for the heating conditions, it is preferable to heat at 130° C. to 170° C. for 5 minutes to 90 minutes.

<Electronic component using cured product of curable composition as insulating cured film>
When a film (cured product) made of a curable composition pattern-printed on a substrate such as a substrate is used as a solder resist, it is heated in a soldering process for mounting components. Soldering may be performed by hand soldering, flow soldering, reflow soldering, etc. For example, in the case of reflow soldering, preheating at 100° C. to 140° C. for 1 to 4 hours After that, it is subjected to a reflow process in which the solder is heated and melted by repeating heating at 240 to 280° C. for about 5 to 20 seconds several times (for example, 2 to 4 times). the part is completed.

In the present invention, electronic components refer to components used in electronic circuits, including active components such as printed wiring boards, transistors, light-emitting diodes, and laser diodes, as well as passive components such as resistors, capacitors, inductors, and connectors. Thus, the cured product of the curable composition of the present invention exhibits the effects of the present invention as these insulating cured coating films.

Further, when the substrate is a so-called rigid substrate, i.e., a double-sided board having wiring printed on both sides or a multilayer board formed by laminating substrates, the substrate having a coating made of the above curable composition is applied several times. It is subjected to a soldering process and repeatedly heated.

According to the curable composition of the present invention, the obtained coating (cured product) does not generate cracks on the coating even after being subjected to heat history assuming multiple times of soldering, and sufficient substrate It maintains the adhesion and hardness of the film, and has good mechanical properties expected as a solder resist applied on a rigid substrate.

The curable composition of the present invention should be excellent in plasticity, impact resistance, adhesion, chemical resistance, heat resistance (including crack resistance after heating, adhesion and hardness maintenance properties), and insulation properties. It can be applied to various uses from the above, and there is no particular limitation on the application target. For example, it can be used for the production of etching resists, solder resists, marking resists, etc. for printed wiring boards using an inkjet method, and it can be suitably used as a solder resist that requires high heat resistance.

It can also be used for applications such as UV molded product materials, stereolithography materials, and 3D inkjet materials.

The present invention is not limited to the configurations and examples of the above embodiments, and various modifications are possible within the scope of the gist of the invention.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited only to these Examples. In addition, "part" shall mean a mass part unless there is particular notice below.

[Examples 1-8 and Comparative Examples 1-2]
1. Preparation of Composition Each component was blended in proportions (unit: parts by mass) shown in Table 1, and stirred with a dissolver.
After that, dispersion was carried out with 1 mm zirconia beads using a bead mill for 2 hours to obtain compositions of the present invention (Examples 1 to 8) and comparative compositions (Comparative Examples 1 and 2).

Product names and abbreviations in Table 1 are as follows.

ABE-300: EO-modified bisphenol A diacrylate (3 moles of EO adduct), manufactured by Shin-Nakamura Chemical Co., Ltd.
BPE-4: EO-modified bisphenol A diacrylate (EO4 mol adduct), manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
HBPE-4: EO-modified hydrogenated bisphenol A diacrylate (EO4 mole adduct), manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
BPE-10: EO-modified bisphenol A diacrylate (EO 10 mol adduct), manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
DPGDA: Dipropylene glycol diacrylate, manufactured by Toyo Chemicals Co., Ltd.
A-NOD-N: 1,9-nonanediol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.
HDDA: 1,6-hexanediol diacrylate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
Laromer LR8863: EO modified trimethylolpropane triacrylate (EO 6 mole adduct)
Omnirad 379: 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone from IGM Resins
ITX: 2-isopropylthioxanthone, manufactured by Nippon Kayaku Co., Ltd.
TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide, manufactured by IGM Resins Viscoat #1000: Dendrimer polyester acrylate oligomer (a dendrimer composed mainly of multi-branched (dendrimer-type) polyester acrylate having acrylate groups at the ends), Osaka Made by Organic Chemical Industry Co., Ltd.
EA-1010LC: (meth)acryloyl group-containing bisphenol A type epoxy resin (monofunctional), manufactured by Shin-Nakamura Chemical Co., Ltd.
BI7982: trifunctional blocked isocyanate, manufactured by Baxenden chemical
4HBA: 4-hydroxybutyl acrylate, manufactured by Nippon Kasei Co., Ltd. Melamine: manufactured by Nissan Chemical Industries, Ltd. Phthalocyanine blue: phthalocyanine blue pigment,
Chromophthal Yellow AGR: Anthraquinone-based yellow pigment,
BYK-315N: Silicon-based surface conditioner, manufactured by BYK-Chemie Japan Co., Ltd. Composition viscosity: The viscosity at 50° C. measured according to JIS K2283 immediately after dispersion in a bead mill was evaluated according to the following criteria.

◎ Less than 15mPa・s ○ 15mPa・s or more and less than 150mPa・s × Viscosity exceeding 150mPa・s

2. Production and Evaluation of Test Substrate 2-1. Evaluation of crack resistance after high-temperature treatment

<Conditions for creating test substrate>
Base material: Copper clad laminate
Polishing: Buff polishing (Scotch brite SF (#600 equivalent) and UEF (#1000 equivalent))
Application: Applicator (manufactured by ERICHSEN), film thickness at application: 30 μm
Temporary curing conditions: 300 mJ/cm ² , high-pressure mercury lamp (HMW-713 manufactured by ORC) is used as the light source Thermal curing conditions: 150° C. for 60 minutes, heating device uses DF610 (manufactured by Yamato Scientific Co., Ltd.) UV bump: 1000 mJ/ cm ² , and a high-pressure mercury lamp (HMW-713 manufactured by ORC) was used as the light source.

Using NIS-20-82C manufactured by Eitec Tectron, the temperature in the reflow furnace was measured 5 times under the same conditions as the reflow conditions in advance according to the following conveyor speed and heat source setting temperature (see FIG. 1), and a large difference confirmed that there was no After that, under the same conditions, the test substrate obtained above was subjected to reflow treatment by air reflow.

Conveyor speed: 1.0 m/min ≈ 1 zone (about 35 cm) in about 20 seconds
Heat source setting temperature: A. 210°C, B.I. 190°C, C.I. ~F. 185°C, G.I. 265°C, H.I. 285°C, I.P. ~J. Cooling process by fan

The reflow treatment was performed up to 5 times, and the presence or absence of cracks in the cured film on the test substrate was checked each time the reflow treatment was performed after the second time. Table 2 shows the results.

As shown in Table 2, (A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide variable of 1 to 6, and (B1) no cyclic skeleton and two or more alkylene glycol structures. When used in combination with a bifunctional (meth) acrylate monomer having a (B2) cyclic skeleton and a bifunctional (meth) acrylate monomer having a monoalkylene glycol structure, after 5 reflow heat cycles The resulting film did not crack and had sufficient crack resistance. On the other hand, in Comparative Examples (Comparative Examples 1 and 2) having (A) a cyclic skeleton and no (meth)acrylate monomer having an alkylene oxide modification number of 1 or more and 6 or less, cracks occurred after reflow, The crack resistance after heating was unsatisfactory.

2-2. Evaluation of coating properties after high-temperature treatment Using the curable compositions of each example and comparative example obtained in “1.
Each test substrate was produced under the same conditions as in “2-1. Evaluation of crack resistance after high temperature treatment”.

The prepared sample was immersed in a solder bath at 260° C. for 10 seconds according to the method of JIS C-5012.

After that, each test substrate after the solder immersion treatment was evaluated for coating properties according to the following “2-2-1. Adhesion to copper-clad laminate” and “2-2-2. Pencil hardness”.

2-2-1. Adhesion to Copper-clad Laminate A cross-cut tape peel test (JIS K 5600) was carried out using each of the prepared test substrates. Table 3 shows the percentage of the coating film remaining after the test.

2-2-2. Pencil Hardness Pencil hardness on the surface of each prepared test substrate was measured according to JIS K 5600-5-4. Table 3 shows the pencil hardness of the coating film surface.

As shown in Table 3, (A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less, and (B1) an alkylene glycol structure having no cyclic skeleton and having 2 or more When used in combination with a bifunctional (meth) acrylate monomer having a (B2) cyclic skeleton and a bifunctional (meth) acrylate monomer having a monoalkylene glycol structure, after three reflow heat cycles The film obtained in the above also had good adhesion to the conductor on the substrate and sufficient film hardness. On the other hand, in Comparative Examples 1 and 2, the hardness of the coating decreased after the soldering process, and the adhesion of the coating to the conductor on the substrate decreased. There is a risk that peeling of the coating may occur. Therefore, it is judged that the soldering heat resistance of the film of the comparative example is lowered.

2-3. Evaluation of film properties after electroless plating treatment Furthermore, commercial electroless nickel plating and electroless gold plating baths were applied to each test substrate prepared in "2-1. Evaluation of crack resistance after high temperature treatment". was used to plate the hard coating under the conditions of 0.5 μm nickel and 0.03 μm gold.

After that, the coating properties were evaluated according to the above "2-2-1. Adhesion to copper clad laminate" and "2-2-2. Pencil hardness". Table 4 shows the results.

As shown in Table 4, Examples 1-8 show good adhesion of the formed coating to the conductor and sufficient hardness, while Comparative Examples 1-2 show adhesion of the formed coating to the conductor. was declining. That is, (A) a comparative example having a cyclic skeleton and not having a (meth)acrylate monomer having an alkylene oxide modification number of 1 or more and 6 or less (Comparative Example 1) and (A) having a cyclic skeleton and 1 or more It was found that Comparative Example 2, which differs from the (meth)acrylate monomer having an alkylene oxide modification number of 6 or less only in the alkylene oxide modification number (=modification number 10), has low chemical resistance.

Claims (5)

(A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less;
(B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures;
(B2) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having a monoalkylene glycol structure;
(C) a photoinitiator;
A curable composition for inkjet printing comprising
(B2) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having a monoalkylene glycol structure (B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures A curable composition for inkjet printing, wherein the mass ratio of is 1.0 or more and 3.0 or less . The amount of (A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less per 100 parts by mass of the curable composition is 5 parts by mass or more and 40 parts by mass or less. Item 2. The curable composition for inkjet printing according to item 1. (B1) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having two or more alkylene glycol structures and (B2) a bifunctional (meth)acrylate monomer having no cyclic skeleton and having a monoalkylene glycol structure 3. The mass ratio of (A) a (meth)acrylate monomer having a cyclic skeleton and an alkylene oxide modification number of 1 or more and 6 or less to the total amount of is 0.10 or more and 0.70 or less. curable composition for inkjet printing of. A cured product of the curable composition for inkjet printing according to any one of claims 1 to 3 . An electronic component comprising the cured product according to claim 4 .

Images