JP7298080B2 - Curable composition for inkjet printing, cured product and printed wiring board - Google Patents

Description

TECHNICAL FIELD The present invention relates to a curable composition for inkjet, a cured product and a printed wiring board, and more particularly to a curable composition for inkjet, a cured product and a printed wiring board which are cured by a photopolymerization reaction.

UV curable compositions used for solder resists for inkjet printing are designed mainly with low-viscosity monomers in order to be applicable to inkjet printing, and a large amount of acrylate monomer is used as a diluent component to reduce viscosity. include.

Compared to these acrylate monomers, methacrylate monomers have a low viscosity, a high glass transition temperature (Tg), and are highly hydrophobic. expensive. However, methacrylate monomers have low reactivity and are difficult to cure.

It is known to add a thiol compound to improve reactivity in UV curing. Patent Document 1 discloses an ink composition comprising a radically polymerizable compound, a photopolymerization initiator, and a polyfunctional thiol as a chain transfer agent having a predetermined weight average molecular weight.

In the examples, only monomers and compounds having an acryloyl group were employed as the radically polymerizable compound. It exhibited ejection stability and UV curability.

Japanese Patent No. 5405174

According to Patent Document 1, as described above, good characteristics of the ink composition were obtained by containing a thiol-based compound. not done. In this respect, when a monomer containing a methacryloyl group is used as a photopolymerizable compound in the ink composition and a thiol compound is included, the reactivity is improved, but the stability under the heating conditions during inkjet printing is poor. It has been found by the studies of the present inventors that there is a problem that the properties are remarkably lowered.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a curable composition for inkjet printing using a methacrylate monomer, while maintaining stability under heating conditions and achieving good photocurability. It is to provide a curable composition for inkjet printing that exhibits A further object of the present invention is to provide a cured product of the curable composition for inkjet printing of the present invention, and a printed wiring board comprising the cured product.

The inventors of the present invention conducted intensive studies to achieve the above object. As a result, even if a methacrylate monomer was used in the curable composition for inkjet printing, by adding a polyfunctional thiol and a polymerization inhibitor, the reactivity of photocuring was improved, and the plating resistance and hardness were improved. The inventors have found that the problem of high-temperature stability of the composition can be solved while forming a coating film, and have completed the present invention.

That is, the above object of the present invention is
(A) a polyfunctional thiol;
(B) a bifunctional methacrylate monomer;
(C) a polymerization inhibitor;
(D) a photoinitiator;
It has been found that this is achieved by a curable composition for inkjet printing characterized by comprising:

The curable composition for inkjet printing of the present invention includes (B) a bifunctional methacrylate monomer, (B1) a low viscosity bifunctional methacrylate monomer having a viscosity of 150 mPa s or less at 25 ° C., and (B2) 25 ° C. and a high-viscosity difunctional methacrylate monomer having a viscosity greater than 150 mPa·s.

In addition, it is preferable that (E) a thermosetting component is further included, and it is more preferable that the (E) thermosetting component includes two or more thermosetting functional groups.

Moreover, the curable composition for inkjet printing of the present invention preferably has a viscosity of 150 mPa·s or less at 25°C.

It is also preferable to have (F) a photothermally reactive compound (excluding (E) a thermosetting component) having at least one photopolymerizable functional group and at least one thermosetting functional group.

The above object of the present invention can also be achieved by a cured product of the curable composition for inkjet printing of the present invention and a printed wiring board comprising this cured product.

According to the present invention, (C) the polymerization inhibitor improves the storage stability of the curable composition for inkjet printing, (A) the polyfunctional thiol improves photocuring reactivity, and (B) the bifunctional meta Coupled with the use of acrylate monomers, photocuring enables good curing of coatings printed by the inkjet method.

<Curable composition for inkjet printing>
The curable composition for inkjet printing of the present invention is
(A) a polyfunctional thiol;
(B) a bifunctional methacrylate monomer;
(C) a polymerization inhibitor;
(D) a photoinitiator;
including.

[(A) polyfunctional thiol]
(A) Polyfunctional thiol is used as a chain transfer agent for improving the reactivity of photopolymerization reaction.

(A) Polyfunctional thiols include, for example, hexane-1,6-dithiol, decane-1,10-dithiol, dimercaptodiethyl ether, aliphatic thiols such as dimercaptodiethylsulfide, xylylene dimercaptan, 4, Aromatic thiols such as 4′-dimercaptodiphenyl sulfide and 1,4-benzenedithiol; ), trimethylolethane tris (mercaptoacetate), trimethylolpropane tris (mercaptoacetate), pentaerythritol tetrakis (mercaptoacetate), dipentaerythritol hexakis (mercaptoacetate) and other poly(mercaptoacetates) of polyhydric alcohols; Ethylene glycol bis(3-mercaptopropionate), polyethylene glycol bis(3-mercaptopropionate), propylene glycol bis(3-mercaptopropionate), glycerol bis(3-mercaptopropionate), trimethylolethane Polyvalent tris (mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), etc. Poly(3-mercaptopropionates) of alcohols; 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5- Triazine-2,4,6(1H,3H,5H)-trione, poly(mercaptobutyrate) such as pentaerythritol tetrakis(3-mercaptobutyrate), and the like.

These commercially available products include, for example, BMPA, MPM, EHMP, NOMP, MBMP, STMP, TMMP, PEMP, DPMP, and TEMPIC (manufactured by Sakai Chemical Industry Co., Ltd.), Karenz MT-PE1, Karenz MT-BD1, and Karenz -NR1 (manufactured by Showa Denko KK) and the like.

Moreover, the polyfunctional thiol which has a heterocyclic ring can also be used as (A) polyfunctional thiol. Polyfunctional thiols having a heterocyclic ring include, for example, 2,4,6-trimercapto-s-triazine (manufactured by Sankyo Kasei Co., Ltd.: trade name Disnet F), 2-dibutylamino-4,6-dimercapto-s- Examples thereof include triazine (manufactured by Sankyo Kasei Co., Ltd.: trade name DISNET DB) and 2-anilino-4,6-dimercapto-s-triazine (manufactured by Sankyo Kasei Co., Ltd.: trade name DISNET AF).

In particular, from the viewpoint of the reactivity of the photopolymerization reaction of the curable composition for inkjet printing, it is preferable to use a polyfunctional thiol having 3 or more thiol groups. These (A) polyfunctional thiols may be used alone or in combination of two or more.

(A) The compounding amount of the polyfunctional thiol is preferably 0.5 to 10 parts by mass in terms of solid content per 100 parts by mass of the curable composition for inkjet printing. If the blending amount of the polyfunctional thiol is within such a range, the high-temperature stability of the curable composition for inkjet printing will be good, and the quality of the resulting coating film will also be good.

[(B) Bifunctional methacrylate monomer]
(B) The bifunctional methacrylate monomer is a component that is cured by photopolymerization and added to form a cured product.

(B) The bifunctional methacrylate monomer includes (B1) a low-viscosity bifunctional methacrylate monomer having a viscosity of 150 mPa s or less at 25°C and (B2) a high-viscosity bifunctional methacrylate monomer having a viscosity of 150 mPa s or more at 25°C. and acrylate monomers.

(B1) A low-viscosity bifunctional methacrylate monomer having a viscosity of 150 mPa·s or less at 25° C. is used as a diluent component to reduce the viscosity so as to be applicable to inkjet printing.

(B1) The low-viscosity bifunctional methacrylate monomer having a viscosity of 150 mPa s or less at 25°C preferably has a viscosity of 50 mPa s or less at 25°C from the viewpoint of reducing viscosity, and a viscosity of 20 mPa at 25°C. ·s or less, and most preferably, the viscosity at 25°C is 10 mPa·s or less.

(B1) The low-viscosity bifunctional methacrylate monomer having a viscosity at 25° C. of 150 mPa·s or less includes, for example, an ester of mono-, di- or trialkylene glycol and methacrylic acid, or an alicyclic ring having two methacryloyl groups. and difunctional methacrylate monomers such as formula compounds. Specific examples of this bifunctional methacrylate monomer include 1,3-butylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate. , 1,10-decanediol dimethacrylate, 1,16-hexadecanediol dimethacrylate, diethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, dibutylene glycol dimethacrylate, triethylene glycol dimethacrylate, tripropylene glycol Dimethacrylate, tributylene glycol dimethacrylate, tricyclodecanedimethanol dimethacrylate and the like.

These commercial products include, for example, NOD-N, DOD-N, 2G, 3G, 4G, NPG, DCP (manufactured by Shin-Nakamura Chemical Co., Ltd.), Miramer M231 (manufactured by Toyo Chemicals), B1065, T0948 ( (manufactured by Tokyo Kasei Kogyo Co., Ltd.), and the like.

(B2) A high-viscosity bifunctional methacrylate monomer having a viscosity of more than 150 mPa s at 25° C. provides a cured product obtained by curing the curable composition for inkjet printing of the present invention by a photopolymerization reaction, and plating resistance, hardness, etc. It is a component that imparts the functionality of

(B2) The high-viscosity bifunctional methacrylate monomer having a viscosity of more than 150 mPa s at 25°C includes, for example, polyhydric phenol methacrylate, EO (PO) adduct of polyhydric phenol methacrylate, and hydrogenation thereof. Including things.

(B2) Specific examples of the high-viscosity bifunctional methacrylate monomer having a viscosity at 25°C of more than 150 mPa s include dimethacrylate of bisphenol A EO (PO) adduct, bisphenol A diglycidyl ether methacrylic acid adduct (epoxy ester 3000MK, manufactured by Kyoeisha Chemical Co., Ltd.), isocyanuric acid EO-modified dimethacrylate, and the like.

These commercial products include, for example, BPE-80N, BPE-100, BPE-200, BPE-500, BPE-900, BPE-1300N (manufactured by Shin-Nakamura Chemical Co., Ltd.), BPEM-4, BPEM-10. , and HBPEM-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

(B) The amount of the bifunctional methacrylate monomer to be blended may be an amount that allows the curable composition for inkjet printing of the present invention to be cured by a photopolymerization reaction. Specifically, the amount of the bifunctional methacrylate monomer (B), in terms of solid content, is 30 parts by mass or more and 80 parts by mass or less per 100 parts by mass of the curable composition for inkjet printing, preferably for inkjet printing It is 40 parts by mass or more and 70 parts by mass or less per 100 parts by mass of the curable composition.

(B1) The blending amount of the low-viscosity bifunctional methacrylate monomer having a viscosity of 150 mPa s or less at 25° C. is, from the viewpoint of reducing the viscosity of the curable composition for inkjet printing, the curable composition for inkjet printing in terms of solid content. It is 5 parts by mass or more, preferably 10 parts by mass or more, per 100 parts by mass of the composition.

(B2) The blending amount of the high-viscosity bifunctional methacrylate monomer having a viscosity at 25° C. of more than 150 mPa s is, from the viewpoint of improving the plating resistance and hardness of the cured product obtained by the photopolymerization reaction of the curable composition for inkjet printing, In terms of solid content, it is 30 parts by mass or more, preferably 40 parts by mass or more per 100 parts by mass of the curable composition for inkjet printing.

[(C) polymerization inhibitor]
(C) The polymerization inhibitor is added in order to improve the storage stability of the curable composition for inkjet printing, especially during storage at high temperatures.

Specifically, if the curable composition for inkjet printing is stored for a long period of time in a high temperature environment (for example, 50° C.), the stability of the photopolymerization initiator is lowered, and the reaction of the photocurable component tends to proceed. For this reason, gelation of the photocurable component of the curable composition for inkjet printing tends to proceed, but gelation of the composition can be prevented by adding the polymerization inhibitor (C).

(C) Polymerization inhibitors include, for example, phenothiazine, hydroquinone, N-phenylnaphthylamine, chloranil, pyrogallol, benzoquinone, t-butylcatechol, hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, naphthoquinone or naphthoquinone derivatives, such as , 4-methoxy-1-naphthol, 2-hydroxy-1,4-naphthoquinone, etc. Among them, naphthoquinone or a naphthoquinone derivative is preferred.

(C) The amount of the polymerization inhibitor to be blended is 0.01 parts by mass or more, preferably 0.05 parts by mass or more in terms of solid content, per 100 parts by mass of the curable composition for inkjet printing. (C) The curable composition for inkjet printing is improved when the polymerization inhibitor is 0.01 parts by mass or more per 100 parts by mass of the curable composition for inkjet printing in terms of solid content.

[(D) Photoinitiator]
As the photopolymerization initiator (D), any compound that initiates a radical polymerization reaction by generating radicals by light, laser, electron beam, or the like can be used. Examples of the photopolymerization initiator (D) include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2, Acetophenones such as 2-diethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2- Aminoacetophenones such as dimethylamino-1-(4-morpholinophenyl)-butan-1-one and N,N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1- Anthraquinones such as chloroanthraquinone; Thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; ,4,5-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; 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole -3-yl]-, 1-(O-acetyloxime) and other oxime esters.

The photopolymerization initiator (D) may be used alone or in combination of two or more. 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. A titanocene compound such as Omnirad 784 (manufactured by IGM Resins B.V.) having absorption in the visible light region can also be added to (D) the photopolymerization initiator in order to promote the photoreaction. The components to be added to the radical photopolymerization initiator are not limited to these, and include those that absorb light in the ultraviolet or visible light region and radically polymerize ethylenically unsaturated groups such as (meth)acryloyl groups. If there is, it can be used alone or in combination without being limited to the photopolymerization initiator and the photoinitiation aid.

(D) The amount of the photopolymerization initiator is 0.5 to 25 parts by weight, more preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the curable composition for inkjet printing, in terms of solid content. It is preferably 1 to 15 parts by mass.

Examples of product names of commercially available photopolymerization initiators include TOE-04-A3 (manufactured by Nippon Kagaku Kogyosho), Omnirad 907, Omnirad 127, and Omnirad 379EG (all manufactured by IGM Resins B.V.). , and LUNACURE 2-ITX (manufactured by DKSH Japan).

[(E) thermosetting component]
Moreover, it is preferable that the curable composition for inkjet printing of this invention contains (E) thermosetting component. By containing a thermosetting component, it is possible to further improve functionality such as hardness and plating resistance of the coating film obtained after curing.

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.; Epototo YD-011 manufactured by Kasei Co., Ltd.; E. R. 317, bisphenol A type epoxy resin such as Sumie-Epoxy ESA-011 (both trade names) manufactured by Sumitomo Chemical Co., Ltd.; hydroquinone type epoxy resin, bisphenol F type epoxy resin such as YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. , Nippon Steel & Sumikin Chemical Co., Ltd. YSLV-120TE thioether epoxy resin; E. R. 542, Sumitomo Chemical Co., Ltd. Sumie-epoxy ESB-400, etc. (both are trade names); Mitsubishi Chemical Co. jER152, Dow Chemical Co. D.I. E. N. 431, EPICLON N-730 manufactured by DIC, Epotato YDCN-701 manufactured by Toto Kasei Co., Ltd., EPPN-201 manufactured by Nippon Kayaku Co., Ltd., Sumie-Epoxy ESCN-195X manufactured by Sumitomo Chemical Co., Ltd. (all trade names) Novolak type epoxy resin; Biphenol novolac type epoxy resin such as NC-3000 manufactured by Nippon Kayaku; EPICLON830 manufactured by DIC; jER807 manufactured by Mitsubishi Chemical; Bisphenol F type epoxy resin such as 2004 (both trade names); Hydrogenated bisphenol A type epoxy resin such as Epotato ST-2004 (trade name) manufactured by Tohto Kasei; jER604 manufactured by Mitsubishi Chemical Co., Ltd.; Epototo YH-434, Sumitomo Chemical Co., Ltd. Sumi-Epoxy ELM-120, etc. (all trade names) glycidylamine type epoxy resins; hydantoin type epoxy resins; Daicel Chemical Industries Co., Ltd. Celoxide 2021, etc. ); Trihydroxyphenylmethane type epoxy resins such as EPPN-501 (all trade names) manufactured by Nippon Kayaku; YL-6056, YX-4000, YL-6121 manufactured by Mitsubishi Chemical Corporation ( bixylenol-type or biphenol-type epoxy resins such as (all are trade names) or mixtures thereof; EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by ADEKA, and bisphenols such as EXA-1514 (trade name) manufactured by DIC. S-type epoxy resin; bisphenol A novolac type epoxy resin such as jER157S (trade name) manufactured by Mitsubishi Chemical; tetraphenylolethane type epoxy resin such as jERYL-931 (trade name) manufactured by Mitsubishi Chemical; Nissan Chemical Heterocyclic epoxy resins such as TEPIC (both trade names) manufactured by Kogyosha; diglycidyl phthalate resins such as BLEMMER DGT manufactured by NOF Corporation; tetraglycidyl xylenoyl ethane resins such as ZX-1063 manufactured by Toto Kasei Co. ESN-190 manufactured by Nittetsu Chemical Co., Ltd., naphthalene group-containing epoxy resins such as HP-4032 manufactured by DIC; epoxy resins having a dicyclopentadiene skeleton such as HP-7200 manufactured by DIC; Glycidyl methacrylate copolymer epoxy resin such as 50M; further copolymer epoxy resin of cyclohexyl maleimide and glycidyl methacrylate; (YR-102, YR-450, etc. manufactured by Kasei Co., Ltd.) and the like, 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, oligomers or copolymers thereof, and other polyfunctional oxetanes, as well as oxetane alcohol and Novolak resins, poly(p-hydroxystyrene), cardo-type bisphenols, calixarenes, calixresorcinarenes, etherified products with resins having a hydroxyl group such as silsesquioxane, and the like can be mentioned. Other examples include copolymers of unsaturated monomers having an oxetane ring and alkyl (meth)acrylates.

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 MX-032. , MX-270, MX-280, MX-290, and MX-706 (all manufactured by Sanwa Chemical Co., Ltd.). Such (E) thermosetting component may be used alone 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 above 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), BI7950, BI7951, BI7960, BI7961, BI7982, BI7990, BI7991 , BI7992 (both manufactured by Baxenden Chemicals), and the like. 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.

(E) The amount of the thermosetting component is preferably 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the curable composition for inkjet printing of the present invention, in terms of solid content, and 5 parts by mass or more and 20 parts by mass or less. It is even more preferable to have (E) The amount of the thermosetting component, in terms of solid content, is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the curable composition for inkjet printing of the present invention, so that the hardness of the coating film after curing And the deterioration of the storage stability of the curable composition for inkjet printing can be suppressed while further improving functionality such as plating resistance.

[(F) Photothermally reactive compound having at least one photopolymerizable functional group and at least one thermosetting functional group (excluding (E) thermosetting component)]
The curable composition for inkjet printing of the present invention further includes (F) a photothermally reactive compound having at least one photopolymerizable functional group and at least one thermosetting functional group (hereinafter simply referred to as (also referred to as a photothermally reactive compound).

(F) The photopolymerizable functional group of the photothermally reactive compound reacts with (B) the bifunctional methacrylate monomer, and the thermosetting functional group reacts with (E) the thermosetting component to form (B) the bifunctional methacrylate. The monomer and (E) the thermosetting component are bonded via (F) the photothermally reactive compound to form a stronger coating film.

In the present invention, the photopolymerizable functional group means an ethylenically unsaturated group. The ethylenically unsaturated group is a substituent having an ethylenically unsaturated bond, and examples thereof include a vinyl group and a (meth)acryloyl group. Here, a (meth)acryloyl group is a generic term for an acryloyl group and a methacryloyl group.

In the present invention, the thermosetting reactive group consists of an epoxy group and a group thermally reactive to the epoxy group (hereinafter also referred to as an epoxy reactive group). Therefore, (F) a photothermally reactive compound having at least one photopolymerizable functional group and at least one thermosetting functional group is composed of (F1) at least one photopolymerizable functional group and at least and (F2) a compound containing at least one photopolymerizable functional group and at least one hydroxyl group.

Here, the epoxy group includes, for example, an epoxy group, an alicyclic epoxy group, and a glycidyl group.

(F1) Compounds containing at least one photopolymerizable functional group and at least one epoxy group include bisphenol A type epoxy (meth)acrylate resin, bisphenol F type epoxy (meth)acrylate resin, bisphenol E type epoxy (Meth)acrylate resins, cresol novolak-type epoxy (meth)acrylate resins, phenol novolac-type epoxy (meth)acrylate resins, aliphatic epoxy (meth)acrylates, and the like.

(F1) Commercially available compounds containing at least one photopolymerizable functional group and at least one epoxy group include EBECRYL 600, EBECRYL 605, EBECRYL 648, EBECRYL 3700, and EBECRYL 3703 (manufactured by Daicel Allnex). (trade names), Epoxy Ester EX-0205, Epoxy Ester 3000A, Epoxy Ester 3002A (N) (trade names manufactured by Kyoei Chemical Co., Ltd.), 8026, 8101, 8125, 8197, 8250 L MH, 8260, 8355, 8360 BR , 8327, 8351 (manufactured by Nippon U-Pica Co., Ltd.), Hytaloid 7851 (manufactured by Hitachi Chemical Co., Ltd.), Viscoat #540 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), CN104, CN104A80, CN104B80, CN120, CN120A60, CN120A75, CN120B60, CN120B80, CN120C60, CN120C80, CN120D80, CN120E50, CN120M50, CN151 (manufactured by Arkema), Miramer PE210 (manufactured by MIWON) product name), NK Oligo EA-1010N, EA -1010LC, EA-1010NT, EA-1020, EA-1020LC3, EMA-1020 (trade names manufactured by Shin-Nakamura Chemical Co., Ltd.), 8475, 8476 (trade names manufactured by Japan U-Pica Co., Ltd.), NK Oligo EA-7120 / PGMAC, EA-7140 / PGMAC, EA-7420 / PGMAC (manufactured by Shin-Nakamura Chemical Co., Ltd.), 8400, 8411 L H (manufactured by Nippon U-Pica), Hitaroid 7663 (manufactured by Hitachi Chemical Co., Ltd.) (trade names), NK Oligo EA-6320/PGMAC, EA-6340/PGMAC (trade names manufactured by Shin-Nakamura Chemical Co., Ltd.), EBECRYL 3500, EBECRYL 3608, EBECRYL 3702 (trade names manufactured by Daicel Allnex) , Miramer PE230 (trade name manufactured by MIWON), and the like.

(F1) By including a compound containing at least one photopolymerizable functional group and at least one epoxy group, in addition to being able to form a strong coating film, it is possible to form a coating film on a metal such as copper on a substrate. The adhesion of is improved.

(F2) Compounds containing at least one photopolymerizable functional group and at least one hydroxyl group include hydroxyalkyl (meth)acrylates.

(F2) Commercially available compounds containing at least one photopolymerizable functional group and at least one hydroxyl group include Aronix M-5700 (manufactured by Toagosei Co., Ltd.), 4HBA, 2HEA, and CHDMMA (manufactured by Mitsubishi Chemical Co., Ltd.). (manufactured by Nippon Shokubai Co., Ltd.), BHEA, HPA, HEMA, HPMA (manufactured by Nippon Shokubai Co., Ltd.), Light Ester HO, Light Ester HOP, Light Ester HOA (manufactured by Kyoeisha Chemical Co., Ltd.), and the like.

(F2) A compound containing at least one photopolymerizable functional group and at least one hydroxyl group has a low viscosity. It becomes easy to adjust the viscosity of the composition.

(F) A photothermally reactive compound having at least one photopolymerizable functional group and at least one thermosetting functional group is added to 100 parts by mass of the curable composition for inkjet printing in terms of solid content. On the other hand, the total amount is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 5 parts by mass or more and 15 parts by mass or less.

(F) Photothermally reactive compounds having at least one photopolymerizable functional group and at least one thermosetting functional group, (F1) at least one photopolymerizable functional group and at least one The compound containing epoxy groups is preferably 1 part by mass or more and 10 parts by mass or less in terms of solid content with respect to 100 parts by mass of the curable composition for inkjet printing,
(F2) The compound containing at least one photopolymerizable functional group and at least one hydroxyl group is, in terms of solid content, 3 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the curable composition for inkjet printing. is preferably

(F1) a compound comprising at least one photopolymerizable functional group and at least one epoxy group, and (F2) a compound comprising at least one photopolymerizable functional group and at least one hydroxyl group. Although it is preferable that both compounds are contained, only one of the compounds may be contained.

[Other ingredients]
Furthermore, the curable composition for inkjet printing of the present invention preferably contains a trifunctional or higher photopolymerizable compound in order to improve the curability of the photopolymerization reaction.

A trifunctional or higher photopolymerizable compound is a compound containing three or more ethylenically unsaturated groups.

Trimethylolpropane triacrylate, trimethylolmethane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane triacrylate, penta Erythritol tetraacrylate, tetramethylolmethane tetraacrylate, ethylene oxide-modified phosphoric acid triacrylate, propylene oxide-modified phosphoric acid triacrylate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, or their silsesquioxylates Examples include polyfunctional acrylates represented by san-modified products, methacrylate monomers corresponding to these, and ε-caprolactone-modified trisacryloxyethyl isocyanurate. These may be used singly or as a mixture of two or more.

The amount of the trifunctional or higher photopolymerizable compound is 1 to 20 parts by mass, preferably 1 to 15 parts by mass, per 100 parts by mass of the curable composition for inkjet printing of the present invention in terms of solid content. .

The curable composition for inkjet printing of the present invention contains additives such as antioxidants, antifoaming/leveling agents, thixotropy-imparting agents/thickening agents, coupling agents, dispersants, and flame retardants as necessary. can be made

Antioxidants include hindered phenol compounds such as 3-(N-salicyloyl)amino-1,2,4-triazole, sulfur-based antioxidants such as zinc salt of 2-mercaptobenzimidazole, and triphenyl phosphite. phosphorus-based antioxidants, aromatic amine-based antioxidants such as di-tert-butyldiphenylamine, heteroatom-containing heteroatoms such as melamine, benzotriazole, tolyltriazole, etc. (excluding sulfur-based antioxidants) etc. Among them, melamine is preferred.

When the curable composition for inkjet printing of the present invention is applied on a metal substrate, the antioxidant is used to improve adhesion between the substrate and the curable composition by suppressing oxidation of the metal. added.

The content of the antioxidant is preferably 0.1 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the curable composition for inkjet printing of the present invention in terms of solid content, and 0.5 parts by mass or more. It is more preferably not more than parts by mass.

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, neoalkoxytrisneodecanoylzirconates, neoalkoxytris(dodecyl)benzenesulfonyl zirco 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) phenyl zirconate, neopentyl (diallyl) oxy, trimethacryl zirconate (, neopentyl (diallyl) oxy, triacryl zirconate, dineopentyl (diallyl) oxy, di-para-aminobenzoyl zirconate, dineopentyl (diallyl) oxy, di(3-mercapto)propionic zirconate, zirconium (IV) 2,2-bis(2-propenolatomethyl)butanolate, cyclodi[2,2-(bis-2-propenolatomethyl)butanolate] Zirconate coupling agents such as pyrophosphato-O, O, etc., aluminate coupling agents such as diisobutyl(oleyl)acetoacetylaluminate, alkylacetoacetate aluminum diisopropylate, etc. 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.

A polymerization retardant may be further added in order to adjust the polymerization rate and degree of polymerization.

Furthermore, a solvent may be used in the curable composition for inkjet printing of the present invention to adjust the viscosity, but the amount added is preferably small in order to prevent a decrease in film thickness 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 for inkjet printing 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 in terms of solid content with respect to 100 parts by mass of the curable composition for inkjet printing.

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

Viscosity refers to viscosity measured according to JIS Z8803. Further, the viscosity of the curable composition for inkjet described above is preferably 150 mPa·s or less at room temperature (25° C.). The viscosity of the ink used in the inkjet 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 for inkjet printing of the present invention can be used to directly print a pattern on a printed wiring board substrate or the like by an inkjet printing method.

Furthermore, since the curable composition for inkjet printing 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 for inkjet printing of the present invention is supplied as ink to an inkjet printer and used for printing on a substrate.

<Cured product of curable composition for inkjet printing, printed wiring board comprising the cured product>
The cured product of the curable composition for inkjet printing of the present invention can be obtained, for example, by irradiating the composition layer immediately after printing with light at 50 mJ/cm ² to 1000 mJ/cm ² to photocure the composition layer. can get. 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.

Thus, a printed wiring board provided with the cured product is produced by curing the film (cured product) made of the curable composition for inkjet printing pattern-printed on a substrate such as a substrate.

According to the curable composition for inkjet printing of the present invention, despite containing both (A) a polyfunctional thiol and (B) a bifunctional methacrylate, the stability is impaired even under heating conditions during inkjet printing. there is nothing In addition, the cured product of the curable composition for inkjet printing of the present invention and the printed wiring board comprising the cured product have improved reactivity of the photopolymerization reaction and have a coating film that is well cured after photocuring.

The curable composition for inkjet printing of the present invention can be applied to various uses, and there are no particular restrictions on the application. For example, the inkjet method can be used to prepare etching resists, solder resists, and marking resists for printed wiring boards.

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 to 5 and Comparative Examples 1 to 4]
1. Preparation of Curable Composition for Inkjet Printing Each component was blended in proportions (unit: parts by mass) shown in Table 1, and stirred with a dissolver. Then, using a bead mill, dispersion was performed with zirconia beads of 1 mm for 2 hours, and the curable composition for inkjet printing of the present invention (Examples 1 to 5) and the composition not according to the present invention (Comparative Examples 1 to 4). got

*1: Pentaerythritol tetrakis (3-mercaptobutyrate) (Karens MT (registered trademark) PE1: manufactured by Showa Denko)
*2: 1,6-hexanediol dimethacrylate (HD-N: manufactured by Shin-Nakamura Chemical Co., Ltd.)
*3: 1,9-nonanediol methacrylate (NOD-N: manufactured by Shin-Nakamura Chemical Co., Ltd.)
*4: Ethoxylated bisphenol A dimethacrylate (BPE-200: manufactured by Shin-Nakamura Chemical Co., Ltd.)
*5: A quinone-based polymerization inhibitor (Kinopower (registered trademark) QS-30: manufactured by Kawasaki Kasei Kogyo Co., Ltd.)
*6: Oxime ester-based photopolymerization initiator (TOE-04-A3: manufactured by Nippon Kagaku Kogyosho)
*7: 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (Omnirad 379: manufactured by IGM Resins B.V.)
*8: 2-Isopropylthioxanthone (LUNACURE 2-ITX: manufactured by DKSH Japan)
*9: Dimethylpyrazole block HDI trimer (BI7982: manufactured by Baxenden chemical)
*10: Monomer with acryloyl group and glycidyl ether (EA-1010LC: manufactured by Shin-Nakamura Chemical Co., Ltd.)
*11: 2-hydroxyethyl methacrylate (M0085: manufactured by Tokyo Chemical Industry Co., Ltd.)
*12: Pentaerythritol tri and pentaacrylate (M-306: manufactured by Toagosei Co., Ltd.)
*13: Dipentaerythritol penta and hexaacrylate (M-404: manufactured by Toagosei Co., Ltd.)
*14: Melamine (Melamine: manufactured by Nissan Chemical Industries, Ltd.)
*15: Phthalocyanine blue (FASTOGEN BLUE series: manufactured by DIC)
*16: Chromophthale Yellow (Cromophthale Yellow GR: manufactured by BASF)

2. Evaluation 2-1. High temperature stability 1 kg of the curable composition for inkjet printing of the present invention (Examples 1 to 5) and the composition not according to the present invention (Comparative Examples 1 to 4) are each sealed in a light-shielding bottle and kept at a constant temperature of 50 ° C. Stored in tank for 4 weeks. Then, the presence or absence of gelation was checked every week. Table 2 shows the results.

In addition, the evaluation criteria are as follows.

○: Not gelled even after 4 weeks ×: Gelation occurs after 1 week

2-2. Dryness to the touch (tackiness) of the coating film after temporary curing
When applying the curable composition for inkjet printing of the present invention (Examples 1 to 5) and the composition not according to the present invention (Comparative Examples 1 to 4) using an applicator (manufactured by ERICHSEN) on a copper clad laminated substrate Each coating is applied so that the film thickness is 25 μm, and the coating film is temporarily cured by irradiating ultraviolet rays with a metal halide lamp with an integrated light amount of 100 mJ / cm ² , and the dryness to the touch of the coating film after temporary curing is evaluated. bottom. Table 2 shows the results.

In addition, the evaluation criteria are as follows.

○: No tackiness on the surface of the coating film △: The surface of the coating film is sticky and fingerprints remain ×: The coating film is not partially cured, leaving a liquid part

2-3. Pencil hardness of the coating film after main curing Hot air heated to 150 ° C. for a copper-clad laminate having a coating film provisionally cured in item “2-2. Dryness to the touch (tackiness) of the coating film after provisional curing” It was placed in a circulating drying oven and heated for 60 minutes for final curing. A pencil hardness test according to JIS K 5600-5-4 was performed on the coating film after the main curing to evaluate the hardness of the coating film. Table 2 shows the results.

2-4. State of coating film after electroless plating treatment For the coating film that has been fully cured in item “2-3. Pencil hardness of coating film after main curing”, commercially available electroless nickel plating and electroless gold plating baths , nickel 0.5 μm, and gold 0.03 μm. After that, the state of the coating film after the electroless plating treatment was evaluated. Table 2 shows the results.

In addition, the evaluation criteria are as follows.

○: No abnormality in the coating film △: Whitening occurred on the coating film surface.
×: Peeling occurred in the coating film

As shown in Table 2, Examples 1 to 5 according to the present invention, from the results of the pencil hardness of the coating film after main curing and the high temperature stability test of the composition, while maintaining stability under heating conditions The object of the present invention, which is to exhibit good photocurability, was able to be achieved.

Further, from a comparison between Example 2 and Example 5, it was found that the dryness to the touch (tackiness) of the coating film after temporary curing was further improved by including a trifunctional or higher photopolymerizable compound. . Further, from a comparison between Example 2 and Example 3, (F1) a compound containing at least one photopolymerizable functional group and at least one epoxy group and (F2) at least one photopolymerizable functional group and at least one hydroxyl group, the state of the coating film after electroless plating is further improved. Further, by increasing the ratio of (A) the polyfunctional thiol, the hardness of the coating film after main curing was further improved.

On the other hand, in Comparative Example 1 in which the composition does not contain (A) a polyfunctional thiol and (C) a polymerization inhibitor, the hardness of the coating film after the main curing and the state of the coating film after the electroless plating treatment are poor. The high temperature stability of the composition was also unfavorable. In addition, in Comparative Example 2 in which (A) the polyfunctional thiol was not contained in the composition, the dryness to the touch of the coating film after temporary curing was deteriorated. In Comparative Examples 3 and 4, in which the composition did not contain (C) a polymerization inhibitor, although the performance of the film after temporary curing was good, the composition had poor high-temperature stability. ) When a polyfunctional thiol was added, the stability under the heating conditions during inkjet printing was remarkably lowered.

Claims (7)

(A) a polyfunctional thiol,
(B) a bifunctional methacrylate monomer,
(C) a polymerization inhibitor, and (D) a photoinitiator ,
(B) the bifunctional methacrylate monomer comprises (B1) a low-viscosity bifunctional methacrylate monomer having a viscosity of 150 mPa s or less at 25°C, and (B2) a high-viscosity bifunctional methacrylate having a viscosity of 150 mPa s or more at 25°C. A curable composition for inkjet printing , comprising: an acrylate monomer . The curable composition for inkjet printing according to claim 1 , further comprising (E) a thermosetting component. 3. The curable composition for inkjet printing according to claim 2 , wherein (E) the thermosetting component contains two or more thermosetting functional groups. 4. The curable composition for inkjet printing according to any one of claims 1 to 3 , wherein the viscosity at 25°C is 150 mPa·s or less. (F) a photothermally reactive compound (excluding ( E ) a thermosetting component) having at least one photopolymerizable functional group and at least one thermosetting functional group; The curable composition for inkjet printing according to any one of the items. A cured product of the curable composition for inkjet printing according to any one of claims 1 to 5 . A printed wiring board comprising the cured product according to claim 6 .