JP2010059299A - Inkjet ink, and cured film obtained from the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet ink having resistance to a metal etching solution, peelability by a peeling liquid, or resistance to a plating solution. <P>SOLUTION: The inkjet ink includes a radically polymerizable monomer (A) including a 5 or more-membered cyclic ether, a radically polymerizable monomer (B) having a thermally reactive functional group, a photopolymerization initiator (C), and a thermally reactive resin (D). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inkjet ink used for manufacturing a liquid crystal display element, an EL display element, a printed wiring board, and the like. Furthermore, the present invention relates to a cured film (including a patterned cured film) obtained by the inkjet ink, a cured film forming method, an electronic circuit board, an electronic component, and a display element on which the cured film is formed.

  Compared to the photolithography method, the pattern formation by the ink-jet method is simpler and can be expected to reduce the amount of material used. Therefore, it is proposed to be used for the production of printed wiring boards used in electronic devices. (For example, refer to Japanese Patent Laid-Open No. 2003-302642 (Patent Document 1) and Japanese Patent Laid-Open No. 2005-68280 (Patent Document 2)).

  In recent years, electronic devices have been miniaturized, and electronic circuit boards using lightweight and flexible printed wiring boards are often used. Such an electronic circuit board is formed, for example, by forming a metal wiring portion having a predetermined circuit pattern by using an etching resist, and thereafter forming a plating pattern by the plating resist and a coverlay that is a protective film for protecting the metal layer surface. It is made through a coating process.

  When these steps are performed by the ink jet method, the storage stability of the ink for ink jet is required, and the stable ink discharge property is required. In addition, a cured film formed of ink jet ink is required to have various performances depending on each ink application.

  For example, an ink-jet ink cured film formed for an etching resist is required to have resistance to a metal etching solution and to be peelable to a peeling solution.

  For example, an ink-jet ink cured film formed for a plating resist is required to have resistance to the plating solution and to be peelable to the peeling solution.

  For example, an ink-jet ink cured film formed for a coverlay is required to have resistance to a plating solution and solder heat resistance.

  However, the cured film of the conventional ink-jet ink is not suitable for practical use because one or more of the above performances are insufficient.

JP 2003-302642 A JP 2005-68280 A JP 2008-50601 A JP-A-9-183929

  Under the above-described circumstances, for example, an ink-jet ink excellent in ink storage stability is desired. In addition, for example, there is a demand for ink-jet ink that can be stably ejected. And when ink-jet ink is used as a cured film, for example, for etching resists, it has resistance to a metal etching solution and peeling properties, and for example, for plating resists, it has resistance to plating solutions and peeling properties against peeling solutions. In addition, for example, for coverlays, there is a demand for inkjet inks having resistance to plating solutions and solder heat resistance. In addition, a highly reliable flexible wiring board is required.

  The present inventors have found that the use of the radical polymerizable monomer (A) having a predetermined structure for the ink-jet ink can effectively cope with the above problem, and based on this finding, the radical polymerizable monomer (A ), A radically polymerizable monomer (B) having a thermally reactive functional group, a photopolymerization initiator (C), and a thermally reactive resin (D), the present invention was completed. The present invention provides the following ink jet ink, a cured film obtained from the ink jet ink, a method for forming the same, and the like.

[1] Radical polymerizable monomer (A) containing a cyclic ether having 5 or more members, a radical polymerizable monomer (B) having a thermally reactive functional group, a photopolymerization initiator (C), and a thermally reactive resin (D) and an inkjet ink.

[2] The inkjet ink according to the above [1], wherein the radical polymerizable monomer (A) containing a cyclic ether having a 5-membered ring or more is a compound represented by the general formula (A).
(In the general formula (A), R ¹ is hydrogen or alkyl having 1 to 3 carbon atoms, and R ² has an alkylene having 1 to 3 carbon atoms or a branched structure which may have a branched structure. C ³ -C 5 glycol ethers may be used, and R ³ is a cyclic ether having 1 or 2 oxygens and 5 or more ring members which may be substituted with alkyl having 1 to ³ carbons.

[3] In the general formula (A), R ¹ is hydrogen, methyl or ethyl, R ² is alkylene having 1 to 3 carbon atoms, and R ³ is substituted with alkyl having 1 to ³ carbon atoms. The inkjet ink according to the above [2], which is a good 5- or 6-membered cyclic ether having 1 or 2 oxygen atoms.

[4] The inkjet according to [2], wherein in general formula (A), R ¹ is hydrogen or methyl, R ² is methylene, and R ³ is a 5-membered cyclic ether having 1 oxygen. For ink.

[5] In the general formula (A), R ¹ is hydrogen or methyl, R ² is methylene, R ³ is a cyclic ether 6-membered ring having 2 carbon oxygen substituted by alkyl having 1 to 3 carbon atoms The inkjet ink according to [2] above.

[6] Any of the above [1] to [5], wherein the radically polymerizable monomer (B) having a thermally reactive functional group has a thermally reactive functional group selected from the group consisting of hydroxy, carboxy, oxirane and oxetane. An ink for ink jet according to claim 1.

[7] The inkjet ink according to any one of [1] to [5], wherein the radical polymerizable monomer (B) having a thermally reactive functional group has a hydroxy or carboxy thermally crosslinkable functional group.

[8] The ink-jet ink according to any one of [1] to [7], wherein the radically polymerizable monomer (B) having a thermally reactive functional group has one thermally reactive functional group.

[9] Any of [1] to [8] above, wherein the radically polymerizable monomer (B) having a thermally reactive functional group is a compound represented by the general formula (B-1) or (B-2). An ink for ink jet according to claim 1.
(In the general formulas (B-1) and (B-2), R ⁴ is each independently hydrogen or alkyl having 1 to 3 carbon atoms, and R ⁵ is each independently having a cyclic structure. Good alkylene having 2 to 12 carbon atoms, and n is an integer of 1 to 30.)

[10] The radical polymerizable monomer (B) having a thermally reactive functional group is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl. The group consisting of (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, monohydroxyethyl (meth) acrylate phthalate, and mono- [2- (2-methylacryloyloxy) -ethyl] ester phthalate The inkjet ink according to any one of [1] to [5], wherein the inkjet ink is one or more selected from the group consisting of:

[11] The above [1] to [1], wherein the photopolymerization initiator (C) is bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide or 2,4,6-trimethylbenzoyldiphenylphosphine oxide. [10] The inkjet ink according to any one of [10].

[12] The inkjet ink according to any one of the above [1] to [11], wherein the heat-reactive resin (D) is a melamine resin.

[13] The inkjet ink according to any one of [1] to [11], wherein the heat-reactive resin (D) is a phenol resin.

[14] The inkjet ink according to any one of [1] to [12], further including a flame retardant (E).

[15] The inkjet ink according to any one of [1] to [14], further including a polyfunctional (meth) acrylate (F).

[16] A cured film forming method in which the inkjet ink according to any one of [1] to [15] is applied by an inkjet method, and a cured film is formed by irradiating the applied ink with light.

[17] The inkjet ink according to any one of [1] to [15] is applied by an inkjet method, and the applied ink is irradiated with light and heated simultaneously or in the order of 1) light irradiation and 2) heating. A cured film forming method of forming a cured film by performing.

[18] A cured film obtained by the method described in [16] or [17] above.

[19] The cured film according to [18], which is formed in a predetermined pattern.

[20] An electronic circuit board in which the cured film described in [18] or [19] is formed on a substrate.

[21] An electronic component having the electronic circuit board according to [20].

[22] A display device having the electronic circuit board described in [20] or the electronic component described in [21].

  In addition, in this specification, in order to show both an acrylate and a methacrylate, it may describe as "(meth) acrylate".

  The ink-jet ink according to a preferred embodiment of the present invention has, for example, excellent ink storage stability and enables stable ejection. Moreover, the cured film obtained from this inkjet ink has the tolerance with respect to a metal etching liquid, and the peelability with respect to peeling liquid, for example. For example, a cured film obtained from the ink jet ink has resistance to a plating solution and releasability to a peeling solution. For example, a cured film obtained from ink jet ink has resistance to a plating solution and solder heat resistance. Furthermore, by using the ink-jet ink according to a preferred embodiment of the present invention, it is possible to reduce the labor and time required for forming a protective film in the production of an electronic circuit board, and it is possible to reduce consumables.

1. Ink-jet ink of the present invention The ink-jet ink of the present invention comprises a radical-polymerizable monomer (A) containing a cyclic ether having 5 or more members, a radical-polymerizable monomer (B) having a thermally reactive functional group, and photopolymerization. An ink-jet ink comprising an initiator (C) and a thermally reactive resin (D). Note that “thermal reactivity” means, for example, a property of causing a crosslinking reaction by heat, but is not limited thereto. The inkjet ink of the present invention may be colorless or colored.

  The ink-jet ink of the present invention comprises a radical polymerizable monomer (A) containing a cyclic ether having 5 or more members, a radical polymerizable monomer (B) having a thermally reactive functional group, and a photopolymerization initiator (C ) And the thermally reactive resin (D), a flame retardant (E), a polyfunctional (meth) acrylate (F), and the like can be optionally included. Moreover, a solvent, an additive, a polymerization inhibitor, a colorant and the like can be further contained as desired.

1.1 Radical polymerizable monomer containing a cyclic ether having 5 or more members (A)
The radical polymerizable monomer (A) containing a cyclic ether having a 5-membered ring or higher is not particularly limited as long as it is a radical polymerizable compound and has a cyclic ether having a 5-membered ring or higher. “Radical polymerizability” is a property that initiates polymerization by free radicals generated by exposure to light.

  Examples of the functional group for allowing the radical polymerizable monomer (A) to have radical polymerization include a functional group such as acrylic, methacrylic, acrylamide, or methacrylamide. Although the number of these functional groups contained in the radical polymerizable monomer (A) may be plural, it is preferably 1 to 3, more preferably 1 to 2, and still more preferably 1.

<Radically polymerizable monomer>
The radical polymerizable monomer (A) containing a cyclic ether having a 5-membered ring or higher is one in which the radical polymerizable monomer has a cyclic ether having a 5-membered ring or higher as described above. For example, the following can be mentioned.

  When the radical polymerizable monomer is a polyfunctional polymerizable monomer having, for example, hydroxy, for example, isocyanuric acid ethylene oxide modified di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol di (meth) acrylate monostearate , Pentaerythritol tri (meth) acrylate, trimethylolpropane di (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, or dipentaerythritol penta Examples include (meth) acrylate.

When the radical polymerizable monomer is, for example, a monofunctional polymerizable monomer having no hydroxy, for example, glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, methyl glycidyl (meth) acrylate, 3-methyl -3- (meth) acryloxymethyl oxetane, 3-ethyl-3- (meth) acryloxymethyl oxetane, 3-methyl-3- (meth) acryloxyethyl oxetane, 3-ethyl-3- (meth) acryloxy Ethyl oxetane, p-vinylphenyl-3-ethyloxeta-3-ylmethyl ether, 2-phenyl-3- (meth) acryloxymethyl oxetane, 2-trifluoromethyl-3- (meth) acryloxymethyl oxetane, 4- Trifluoromethyl-2- (meth) acryloxymethyl Oxetane, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, iso-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl ( (Meth) acrylate, benzyl (meth) acrylate, styrene, methylstyrene, chloromethylstyrene, (3-ethyl-3-oxetanyl) methyl (meth) acrylate, N-cyclohexylmaleimide, N-phenylmaleimide, vinyltoluene, tricyclo [5 .2.1.0 ^2,6 ] decanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, glycerol mono (meth) acrylate Chryrate, polystyrene macromonomer, polymethyl methacrylate macromonomer, 5-tetrahydrofurfuryloxycarbonylpentyl (meth) acrylate, (meth) acrylate of ethylene oxide adduct of lauryl alcohol, (meth) acrylic acid, crotonic acid, α-chloroacrylic Acid, cinnamic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, ω-carboxypolycaprolactone mono (meth) acrylate, succinic acid mono [2- (meth) acryloyloxyethyl], maleic acid mono [2- (meth) acryloyloxyethyl], cyclohexene-3,4-dicarboxylic acid mono [2- (meth) acryloyloxyethyl], (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl ( Examples include meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-acryloylmorpholine, N-phenylmaleimide, and N-cyclohexylmaleimide.

  When the radical polymerizable monomer is, for example, a polyfunctional polymerizable monomer having no hydroxy, for example, bisphenol F type ethylene oxide modified diacrylate, bisphenol A type ethylene oxide modified diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, 1 , 4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,4-cyclohexanedimethanol diacrylate, 2-n-butyl-2-ethyl-1,3- Propanediol diacrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylol Lopantri (meth) acrylate, epichlorohydrin modified trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, glycerol tri (meth) acrylate, epichlorohydrin modified glycerol tri (meth) acrylate, diglycerin tetra (meth) acrylate, Pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, ethylene oxide-modified phosphoric acid tri (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, Caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate or urethane (meth) acrylate Such as theft and the like.

<Cyclic ether having 5 or more members>
The radical polymerizable monomer (A) containing a cyclic ether having a 5-membered ring or higher is one in which the radical polymerizable monomer has a cyclic ether having a 5-membered ring or more as described above. Examples of the ether include 5-membered cyclic ether, 6-membered cyclic ether, and 7-membered cyclic ether. The number of ether bonds contained in the ring is, for example, 1, 2, or 3. Etc. These cyclic ethers may be substituted with alkyl, preferably alkyl having 1 to 3 carbon atoms, more preferably methyl or ethyl. Furthermore, although the number of substituents of this substituted alkyl may be plural, it is preferably 1 to 2, more preferably 1. Although the number of these cyclic ethers contained in the radical polymerizable monomer (A) may be plural, it is preferably 1 to 2, more preferably 1.

Specific examples of the cyclic ether having 5 or more members include the following structures.

  The radical polymerizable monomer (A) containing a cyclic ether having 5 or more ring members is one in which any of the radical polymerizable monomers described above has any of the cyclic ethers having 5 or more member rings described above. This includes all possible combinations.

  The radically polymerizable monomer (A) containing a cyclic ether having 5 or more members is preferably a compound represented by the above general formula (A).

In the general formula (A), R ¹ is alkyl of 1 to 3 carbon hydrogen or carbon, specifically, hydrogen, methyl, ethyl, n- propyl, isopropyl and the like, preferably hydrogen or methyl.

In the general formula (A), R ² is an alkylene or optionally a glycol ether having 2 to 5 carbon atoms which may have a branched structure of carbon atoms 1 to 3 have a branched structure. The alkylene having 1 to 3 carbon atoms is specifically methylene, ethylene or propylene, and for example, an alkyl substituent (preferably having 1 to 3 carbon atoms) may be bonded to form a branched structure. . Moreover, the C2-C5 glycol ether which may have a branched structure is specifically ethylene glycol ether, 1,2-propylene glycol ether, 1,3-butylene glycol ether, or neopentyl glycol. Ether.

In general formula (A), R ³ is a cyclic ether having 1 or 2 oxygen atoms and 5 or more ring members which may be substituted with alkyl having 1 to ³ carbon atoms. Specific examples of the cyclic ether include those described above.

  Specific examples of the polymerizable monomer (A) represented by the general formula (A) include tetrahydrofurfuryl (meth) acrylate, cyclic trimethylolpropane formal (meth) acrylate, alkoxylated tetrahydrofurfuryl (meth) acrylate, and caprolactone. Modified tetrahydrofurfuryl (meth) acrylate etc. are mentioned.

  Among these, tetrahydrofurfuryl acrylate (the following structural formula (a1-1)), tetrahydrofurfuryl methacrylate (the following structural formula (a1-2)), cyclic trimethylolpropane formal acrylate (the following structural formula (a2-1)) Or cyclic trimethylolpropane formal methacrylate (the following structural formula (a2-2)) is preferred.

  Tetrahydrofurfuryl acrylate is commercially available as SR285 manufactured by Sartomer, and Light acrylate THF-A manufactured by Kyoeisha Chemical Co., Ltd. Tetrahydrofurfuryl acrylate is SR203 manufactured by Sartomer, Wright manufactured by Kyoeisha Chemical Co., Ltd. Commercially available as ester THF. Cyclic trimethylolpropane formal acrylate is commercially available as SR531 manufactured by Sartomer.

  The polymerizable monomer (A) contained in the inkjet ink may be one type of compound selected from the above-described compounds, or a mixture of two or more types thereof.

  When the radically polymerizable monomer (A) is contained in the ink-jet ink in an amount of 1 to 70% by weight, it is preferable because the ejection stability from the nozzle is improved at the time of ink jetting, more preferably 10 to 65% by weight. More preferably, it is contained in an amount of 20 to 60% by weight.

1.2 Radical polymerizable monomer (B) having a thermally reactive functional group
The radically polymerizable monomer (B) having a thermally reactive functional group is not particularly limited as long as it is a radically polymerizable compound and has a thermally reactive functional group. Note that “thermal reactivity” means, for example, a property of causing a crosslinking reaction by heat, but is not limited thereto.

  The heat-reactive functional group is not particularly limited as long as it is a functional group that reacts with heat (preferably a crosslinking reaction), and examples thereof include hydroxy, carboxy, oxirane, and oxetane. Among these, hydroxy and carboxy are particularly preferable. preferable. The number of the thermally reactive functional groups contained in the radical polymerizable monomer (B) may be plural, but is preferably 1 to 3, more preferably 1 to 2, and still more preferably 1. It is.

  The heat-reactive functional group contained in the radically polymerizable monomer (B) has an effect of increasing the compatibility with other components contained in the inkjet ink. In particular, when the thermally reactive functional group is hydroxy, the effect of increasing the compatibility with other components contained in the ink-jet ink is great. Moreover, when a heat-reactive functional group is carboxy, it has the effect of improving the peelability with respect to alkaline aqueous solution of the cured film obtained from the inkjet ink.

<Radically polymerizable monomer (B) whose thermally reactive functional group is hydroxy>
When the heat-reactive functional group of the radical polymerizable monomer (B) is hydroxy, preferred examples include a polymerizable monomer having a double bond between hydroxy and one radical polymerizable carbon, and between hydroxy and two radical polymerizable carbons. Examples thereof include a polymerizable monomer having a double bond, or a polymerizable monomer having hydroxy and three or more radically polymerizable carbon-carbon double bonds.

  Specific examples of the polymerizable monomer having hydroxy and one radical polymerizable carbon-carbon double bond include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Or 1, 4- cyclohexane dimethanol mono (meth) acrylate etc. can be mentioned.

  Specific examples of the polymerizable monomer having hydroxy and two radical polymerizable carbon-carbon double bonds include isocyanuric acid ethylene oxide-modified di (meth) acrylate, glycerol diacrylate, pentaerythritol di (meth) acrylate, pentaerythritol di (meta) ) Acrylate monostearate, trimethylolpropane di (meth) acrylate, or dipentaerythritol di (meth) acrylate.

  Specific examples of the polymerizable monomer having hydroxy and three or more radically polymerizable carbon-carbon double bonds include pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth). ) Acrylate, dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, or alkyl-modified dipentaerythritol tri (meth) acrylate.

  Among these, as a radical polymerizable monomer (B) having hydroxy as a heat-reactive functional group from the viewpoint of ejection stability from a nozzle when applied to a photocurable ink-jet ink, hydroxy and one radical A polymerizable monomer having a polymerizable carbon-carbon double bond is preferable, and 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, or 1,4-cyclohexanedimethanol monoacrylate is particularly preferable.

Moreover, it is preferable that the radically polymerizable monomer (B) which has a heat-reactive functional group is a compound represented by the said general formula (B-1). In general formula (B-1), R < ⁴ > is respectively independently hydrogen or a C1-C3 alkyl, and specifically, hydrogen, methyl, ethyl, n-propyl, and isopropyl are mentioned, Preferably Hydrogen or methyl. In general formula (B-1), each R ⁵ independently represents an alkylene having 2 to 12 carbon atoms which may have a cyclic structure, and among these, ethylene, propylene, butylene or the following structures: The group represented is preferred. Moreover, in general formula (B-1), n is an integer of 1-30, Preferably it is 1-10, More preferably, it is 1-3, More preferably, it is 1.

<Radically polymerizable monomer (B) whose thermally reactive functional group is carboxy>
When the heat-reactive functional group of the radical polymerizable monomer (B) is carboxy, preferred examples include a polymerizable monomer having a double bond between carboxy and one radical polymerizable carbon, and between carboxy and two radical polymerizable carbons. Examples thereof include a polymerizable monomer having a double bond, or a polymerizable monomer having carboxy and three or more radically polymerizable carbon-carbon double bonds.

  Specific examples of the polymerizable monomer having carboxy and one radical polymerizable carbon-carbon double bond include (meth) acrylic acid, α-chloroacrylic acid, crotonic acid, cinnamic acid, itaconic acid, citraconic acid, and mesaconic acid. , Maleic acid, fumaric acid, ω-carboxy-polycaprolactone monoacrylate, or monohydroxyethyl (meth) acrylate phthalate.

  Specific examples of the polymerizable monomer having carboxy and two radical polymerizable carbon-carbon double bonds include fatty acid-modified pentaerythritol diacrylate.

  Specific examples of the polymerizable monomer having carboxy and three or more radically polymerizable carbon-carbon double bonds include succinic acid-modified pentaerythritol tri (meth) acrylate or succinic acid-modified dipentaerythritol penta (meth) acrylate. Can be mentioned.

  Among these, when applied to a photocurable inkjet ink, carboxy is used as a thermally reactive functional group from the viewpoint of ejection stability from a nozzle and releasability of a cured film obtained from an inkjet ink to an alkaline aqueous solution. As the radical polymerizable monomer (B), a polymerizable monomer having carboxy and one radical polymerizable carbon-carbon double bond is preferable, and in particular, phthalic acid monohydroxyethyl acrylate or phthalic acid monohydroxyethyl methacrylate (Shin Nakamura) Chemical industry CB-1 (trade name)) is preferred.

Moreover, it is preferable that the radically polymerizable monomer (B) which has a heat-reactive functional group is a compound represented by the said general formula (B-2). In general formula (B-2), R < ⁴ > is respectively independently hydrogen or a C1-C3 alkyl, and specifically, hydrogen, methyl, ethyl, n-propyl, and isopropyl are mentioned, Preferably Hydrogen or methyl. In general formula (B-2), R < ⁵ > is C2-C12 alkylene which may have a cyclic structure each independently (a preferable example is R in the said general formula (B-1)). ⁵ is the same as the description of), n is an integer from 1 to 30, preferably 1 to 10, more preferably 1 to 3, more preferably 1.

  The radically polymerizable monomer (B) contained in the inkjet ink may be one compound selected from the above-described compounds, or may be a mixture of two or more of these.

  When the radically polymerizable monomer (B) is contained in the ink jet ink in an amount of 1 to 80% by weight, the photocurable ink jet ink is preferably used because the ejection from the ink jet nozzle is stabilized, and preferably 3 to 75% by weight. More preferably, it is more preferably 5 to 70% by weight.

1.3 Photopolymerization initiator (C)
A photoinitiator (C) will not be specifically limited if it is a compound which can generate | occur | produce a radical by irradiation of an ultraviolet-ray or visible light. Specific examples of the photopolymerization initiator (C) include benzophenone, Michler's ketone, 4,4′-bis (diethylamino) benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2 -Hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxyacetophenone, 2 , 2-dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzi 2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4′-di (t-butylperoxycarbonyl) benzophenone, 3,4,4′-tri (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t -Hexylperoxycarbonyl) benzophenone, 3,3'-di (methoxycarbonyl) -4,4'-di (t-butylperoxycarbonyl) benzophenone, 3,4'-di (methoxycarbonyl) -4,3'-di (T-butylperoxycarbonyl) benzophenone, 4,4′-di (methoxycarbonyl) -3,3′-di (t-butylpe) Ruoxycarbonyl) benzophenone, 1,2-octanedione, 1- [4- (phenylthio) phenyl]-, 2- (o-benzoyloxime), 2- (4′-methoxystyryl) -4,6-bis ( Trichloromethyl) -s-triazine, 2- (3 ′, 4′-dimethoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (2 ′, 4′-dimethoxystyryl) -4, 6-bis (trichloromethyl) -s-triazine, 2- (2′-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4′-pentyloxystyryl) -4,6 -Bis (trichloromethyl) -s-triazine, 4- [p-N, N-di (ethoxycarbonylmethyl)]-2,6-di (trichloromethyl) -s-triazine, 1,3-bis ( Lichloromethyl) -5- (2′-chlorophenyl) -s-triazine, 1,3-bis (trichloromethyl) -5- (4′-methoxyphenyl) -s-triazine, 2- (p-dimethylaminostyryl) benz Oxazole, 2- (p-dimethylaminostyryl) benzthiazole, 2-mercaptobenzothiazole, 3,3′-carbonylbis (7-diethylaminocoumarin), 2- (o-chlorophenyl) -4,4 ′, 5,5 '-Tetraphenyl-1,2'-biimidazole, 2,2'-bis (2-chlorophenyl) -4,4', 5,5'-tetrakis (4-ethoxycarbonylphenyl) -1,2'-bi Imidazole, 2,2′-bis (2,4-dichlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2 4-dibromophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4,6-trichlorophenyl) -4,4 ′, 5 , 5′-tetraphenyl-1,2′-biimidazole, 3- (2-methyl-2-dimethylaminopropionyl) carbazole, 3,6-bis (2-methyl-2-morpholinopropionyl) -9-n- Dodecylcarbazole, 1-hydroxycyclohexyl phenyl ketone, bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc. It can be.

  Among them, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (IRGACURE 819 (trade name) manufactured by Ciba Japan) or 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Ciba Japan) DAROCUR TPO (trade name) manufactured by 1), 1-hydroxycyclohexyl phenyl ketone (IRGACURE 184 (trade name) manufactured by Ciba Japan Co., Ltd.) and the like are highly compatible with other components contained in the ink-jet ink. The resulting inkjet ink is preferable because it cures with a small amount of UV irradiation.

  The photopolymerization initiator (C) may be a single compound or a mixture of two or more different compounds. When the photopolymerization initiator (C) is contained in the ink-jet ink in an amount of 0.2 to 20% by weight, the ink-jet ink is preferably highly sensitive to ultraviolet rays, and is preferably 1 to 20% by weight. And more preferably 1 to 15% by weight.

1.4 Thermally reactive resin (D)
Examples of the thermally reactive resin (D) include an epoxy resin, a melamine resin, a “polymer of a radically polymerizable monomer having a thermally reactive functional group (for example, a phenolic resin)”, or a “radical having a thermally reactive functional group”. And a copolymer of a polymerizable monomer and another radical polymerizable monomer. Among these, it is preferable to use a melamine resin from the viewpoints of heat resistance and chemical resistance. From the viewpoint of peelability of the cured film with respect to an alkaline aqueous solution and acid resistant aqueous solution, “the weight of a radically polymerizable monomer having a thermoreactive functional group” may be used. It is preferable to use “union (for example, phenol resin)”.

Specific examples of the melamine resin include melamine, methylol melamine, etherified methylol melamine, benzoguanamine, methylol benzoguanamine, etherified methylol benzoguanamine, and condensates thereof. Of these, etherified methylol melamine is preferable because of its good chemical resistance, and the mixture of the following compound (d-1) and its condensate is Nicalak MW-30 (trade name) manufactured by Sanwa Chemical Co., Ltd. ).

  Specific examples of the “polymer of radically polymerizable monomer having a thermoreactive functional group” include phenol resins such as polyvinyl alcohol and polyvinylphenol, poly (glycidyl (meth) acrylate), poly (3,4-epoxycyclohexyl ( (Meth) acrylate), poly (methylglycidyl (meth) acrylate), poly (3-methyl-3- (meth) acryloxymethyloxetane), poly (3-ethyl-3- (meth) acryloxymethyloxetane), poly (3-methyl-3- (meth) acryloxyethyl oxetane), poly (3-ethyl-3- (meth) acryloxyethyl oxetane), poly (p-vinylphenyl-3-ethyloxeta-3-ylmethyl ether) , Poly (2-phenyl-3- (meth) acryloxymethyloxetane) Poly (2-trifluoromethyl-3- (meth) acryloxymethyloxetane), poly (4-trifluoromethyl-2- (meth) acryloxymethyloxetane), poly (meth) acrylic acid and the like can be mentioned. . Among them, a phenol resin such as polyvinylphenol is preferable because it improves the peelability of the cured film from an alkaline aqueous solution, and is commercially available as Maruka Linker MS-2P (trade name) manufactured by Maruzen Petrochemical Co., Ltd.

  When the heat-reactive resin (D) is contained in the inkjet ink in an amount of 0.1 to 30% by weight, the chemical resistance of the cured film of the resulting ink is preferably increased, and 0.5 to 25% by weight is preferably contained. More preferably, it is more preferably 1 to 20% by weight.

1.5 Flame retardant (E)
A flame retardant (E) may be included to impart flame retardancy to the ink jet ink. This flame retardant (E) is preferable because the phosphorus compound has little influence on the environment.

  Specific examples of the phosphorus compound flame retardant (E) include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl phenyl phosphate, 2-ethylhexyl diphenyl phosphate, 9,10-dihydro-9-oxa- 10-phosphaphenanthrene-10 oxide, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, condensed 9,10-dihydro-9-oxa-10-phos Examples include faphenanthrene-10 oxide.

Among these flame retardants, condensed 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10 oxide which is a compound represented by the following formula (e-1) (HFA manufactured by Showa High Polymer Co., Ltd.) -3003 (trade name) is preferable because the flame retardant bleed-out does not occur even when the cured film obtained from the inkjet ink is exposed to a high temperature state.

The flame retardant (E) may be one compound selected from the above-described compounds, or may be a mixture of two or more of these. When the flame retardant (E) is contained in the ink-jet ink in an amount of 10 to 50% by weight, the cured film obtained from the ink-jet ink exhibits high flame retardancy (equivalent to UL flame test method V-0 standard).
1.6 Polyfunctional (meth) acrylate (F)

  The inkjet ink may contain a polyfunctional (meth) acrylate (F) from the viewpoint of increasing photosensitivity, and is particularly preferably a polyfunctional (meth) acrylate having no hydroxy. Here, even if polyfunctional (meth) acrylate having no hydroxy is mixed in or produced as a by-product during production, or polyfunctional (meth) acrylate having hydroxy as an unreacted substance is contained in polyfunctional (meth) acrylate having no hydroxy Since the content in such a case is extremely small, it can be regarded as a polyfunctional (meth) acrylate (F) having no hydroxy. The polyfunctional (meth) acrylate (F) may be one compound selected from the following compounds, or may be a mixture of two or more thereof.

  Specific examples of the polyfunctional (meth) acrylate (F) having no hydroxy include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth). Acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polypropylene glycol di (meth) ) Acrylate, bisphenol A type ethylene oxide modified di (meth) acrylate, bisphenol F type ethylene oxide modified di (meth) acrylate, trimethylo Rupropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, glycerol tri (meth) acrylate, 1,6-hexane Diol di (meth) acrylate, methoxylated cyclohexyl di (meth) acrylate, neopentyl glycol di (meth) acrylate, diglycerin tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, Caprolactone-modified dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,3 Butylene glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, and caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate, novolac epoxy acrylate, Examples thereof include bisphenol A type epoxy acrylate, bisphenol F type epoxy acrylate, and resorcinol type epoxy acrylate.

  Among these, bisphenol F type ethylene oxide-modified di (meth) acrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, and It is more preferable to contain one or more selected from caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate and bisphenol F type epoxy acrylate, since the chemical resistance of the cured film becomes high.

  As the bisphenol F type epoxy acrylate, ZFR 1122, 1401H, 1491H (trade name) manufactured by Nippon Kayaku Co., Ltd., Neopol 8477 (trade name) manufactured by Nippon Iupika Co., Ltd., and the like are commercially available.

  When the polyfunctional (meth) acrylate (F) is contained in the inkjet ink in an amount of 5 to 80% by weight, it becomes highly sensitive to light when used as an inkjet ink, and the plating solution resistance of the cured film is increased. Therefore, it is preferable and it is more preferable in it being 10 to 70 weight%.

1.7 Other components The ink for inkjet is a storage stability, the durability of the film to be formed, the film surface uniformity of the film to be formed, the flame retardancy of the film to be formed, the ejection characteristics of the ink, A solvent, a reactive diluent, a polymerization inhibitor, a surfactant, a colorant, an antistatic agent and the like can be included in order to improve the coating property. These components may be a single compound or a mixture of two or more compounds.
The amount of water in the inkjet ink is not particularly limited, but is preferably 10,000 ppm or less, and more preferably 5,000 ppm or less. These amounts of water are preferable because the viscosity of the inkjet ink is small and storage stability is excellent.

1.7.1 Solvent (G)
The inkjet ink may contain a solvent (G) in order to improve the ink ejection characteristics. This solvent is preferably a solvent having a boiling point of 100 ° C. or higher. When the viscosity of the inkjet ink at room temperature is 50 mPa · s or higher, it is preferable to increase the jetting temperature. In this case, the boiling point of the solvent contained is preferably 200 ° C. or higher.

  Specific examples of the solvent having a boiling point of 100 ° C. or more include butyl acetate, butyl propionate, ethyl lactate, methyl oxyacetate, ethyl oxyacetate, butyl oxyacetate, methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, ethoxyacetic acid Methyl, ethyl ethoxyacetate, methyl 3-oxypropionate, ethyl 3-oxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, 2- Methyl oxypropionate, ethyl 2-oxypropionate, propyl 2-oxypropionate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, methyl 2-ethoxypropionate, 2-ethoxy Ethyl lopionate, methyl 2-oxy-2-methylpropionate, ethyl 2-oxy-2-methylpropionate, methyl 2-methoxy-2-methylpropionate, ethyl 2-ethoxy-2-methylpropionate, pyruvic acid Methyl, ethyl pyruvate, propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl 2-oxobutanoate, ethyl 2-oxobutanoate, dioxane, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene Glycol, 1,4-butanediol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether Acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, cyclohexanone, cyclopentanone , Diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol Examples include ethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, toluene, xylene, anisole, γ-butyrolactone, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylimidazolidinone. The amount of water in these solvents is preferably adjusted so that the amount of water in the inkjet ink is in the above-described range.

  Among these solvents, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, 3- Use of ethyl ethoxypropionate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, or the like is preferable because ink ejection is stable.

  It is preferable that the solvent (G) is contained in the inkjet ink in an amount of 0 to 50% by weight because the ejection in the case of the photocurable inkjet ink is stabilized, and more preferably 0 to 20% by weight.

Furthermore, since the surface tension of the ink greatly affects the applicability of the inkjet ink, the surface tension of the ink is preferably 20 to 45 mN / m, more preferably 27 to 42 mN / m, and even more preferably 30 to 40 mN / m. adjust. When the surface tension is in the range of 20 to 45 mN / m, the ink meniscus at the ink discharge port becomes stable, and ink discharge is good.
In order to adjust the surface tension to a range of 20 to 45 mN / m, it is important to select a solvent. One solvent having a surface tension in the range of 20 to 45 mN / m may be used, but a solvent having a large surface tension (for example, γ-butyrolactone: 43 mN / m) and a solvent having a small surface tension (for example, diethylene glycol methyl) It is preferable to use a mixture of ethyl ether: 24 mN / m or ethylene glycol monobutyl ether: 32 mN / m because the surface tension can be finely adjusted by the solvent composition.

1.7.2 Reactive diluent (H)
The inkjet ink may contain a reactive diluent (H) in order to adjust the viscosity of the ink and control the degree of crosslinking of the cured film. When the reactive diluent (H) is used instead of the solvent or by replacing a part of the solvent, the solid content concentration of the ink is increased, so that a thick film can be formed. The reactive diluent (H) is a radical polymerizable monomer (A) containing a cyclic ether having 5 or more members, a radical polymerizable monomer (B) having a thermally reactive functional group, and a polyfunctional (meth) acrylate (F). And a different compound.

  Specific examples of the reactive diluent (H) include n-butyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, tridecyl (meth) acrylate, 2- ( 2-Ethoxyethoxy) ethyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, 2-phenoxyethyl acrylate and the like.

  Among these, it is preferable to use a small amount of n-butyl (meth) acrylate and cyclohexyl (meth) acrylate because the viscosity of the inkjet ink can be greatly reduced.

  When the reactive diluent (H) is contained in an inkjet ink in an amount of 5 to 60% by weight, the viscosity at 25 ° C. measured by an E-type viscometer is 2 to 500 mPa · s when a photocurable inkjet ink is used. Therefore, the content is preferably 10 to 50% by weight.

1.7.3 Polymerization inhibitor (I)
The ink for inkjet may contain a polymerization inhibitor in order to improve storage stability. Specific examples of the polymerization inhibitor include 4-methoxyphenol, hydroquinone, phenothiazine and the like. Among these, phenothiazine is preferably used as a polymerization inhibitor from the viewpoint of minimizing a change in the viscosity of the ink when the ink jet head is heated during jetting.

  The polymerization inhibitor is preferably contained in the inkjet ink in an amount of 0.01 to 1% by weight from the viewpoint of achieving both the storage stability of the inkjet ink and the high sensitivity to light.

1.7.4 Surfactant (J)
The inkjet ink may contain a surfactant in order to improve the uniformity of the film surface obtained from the inkjet ink. As the surfactant, a silicon surfactant, an acrylic surfactant, a fluorine surfactant, or the like is used. Specifically, silicon systems such as Byk-300, Byk-306, Byk-335, Byk-310, Byk-341, Byk-344, or Byk-370 (each trade name: manufactured by Big Chemie Co., Ltd.) Surfactants; acrylic surfactants such as Byk-354, Byk-358, or Byk-361 (each trade name: manufactured by Big Chemie); DFX-18, Aftergent 250, or Aftergent 251 ( Product name: Neos Co., Ltd.), Megafuck F-410, Megafuck F-443, Megafuck F-445, Megafuck F-470, Megafuck F-479, Megafuck F-484, Megafuck F Fluorine-based surfactants such as -490 (each trade name: manufactured by Dainippon Ink Co., Ltd.).

  The surfactant is preferably 0.01% by weight or more in the thermosetting composition because the film surface uniformity of the cured film is improved, and 0.01 to 1% by weight in consideration of the balance with other properties. Preferably there is.

1.7.5 Colorant (K)
The inkjet ink may contain a colorant. In this case, for example, when the state of the obtained cured film is inspected, it can be easily distinguished from the substrate. The colorant may be included in the inkjet ink in an amount of about 0.01 to 10% by weight, preferably about 0.1 to 5% by weight. From the viewpoint of compatibility of the ink raw material, the colorant is preferably a dye.

1.7.6 Antistatic agent (L)
The antistatic agent is not particularly limited, and a known antistatic agent can be used. Specific examples include metal oxides such as tin oxide, tin oxide / antimony oxide composite oxide, and tin oxide / indium oxide composite oxide, and quaternary ammonium salts. The antistatic agent is used to prevent electrification, and is preferably used by adding 0.01 to 1 part by weight to 100 parts by weight of the ink jet ink.

1.8 Preparation Method of Inkjet Ink Inkjet ink is preferably prepared by filtering a solution obtained by mixing necessary components. For the filtration, for example, a fluororesin membrane filter is used.

1.9 Inkjet Ink Viscosity Inkjet ink has a viscosity of 2 to 500 mPa · s at 25 ° C. as measured with an E-type viscometer, resulting in good coating characteristics (such as jetting accuracy) from the inkjet head. Therefore, it is preferable. The viscosity of the inkjet ink at 25 ° C. is more preferably 3 to 300 mPa · s, and still more preferably 5 to 200 mPa · s.
When the viscosity at 25 ° C. exceeds 30 mPa · s, more stable ejection can be achieved by lowering the viscosity during ejection by heating the inkjet head. When jetting by heating the inkjet head, the viscosity of the inkjet ink at a heating temperature (preferably 40 to 120 ° C.) is preferably 3 to 30 mPa · s, more preferably 5 to 25 mPa · s, and 7 ˜20 mPa · s is particularly preferred.

1.10 Storage of ink- jet ink When the ink-jet ink is stored at -20 to 20 ° C, the viscosity change is small and the storage stability is good.

2. Application of inkjet ink by inkjet method The inkjet ink of the present invention can be applied using a known inkjet application method. As an inkjet coating method, for example, a method in which mechanical energy is applied to ink to eject (apply) the ink from the head (so-called piezo method), and a coating method in which thermal energy is applied to the ink to apply the ink (so-called piezo method) So-called bubble jet (registered trademark) system.
By using the inkjet coating method, the inkjet ink can be applied in a predetermined pattern. As a result, ink can be applied only to necessary portions, and the cost can be reduced as compared with the photolithography method.

A preferable application unit for performing application using the ink-jet ink of the present invention includes, for example, an application unit including an ink storage unit for storing these inks and an application head. Examples of the coating unit include a coating unit that causes thermal energy corresponding to a coating signal to act on ink and generates ink droplets by the energy.
The coating head has, for example, a heating part wetted surface containing metal and / or metal oxide. Specific examples of the metal and / or metal oxide include metals such as Ta, Zr, Ti, Ni, and Al, and oxides of these metals.

  As a preferable coating apparatus for performing coating using the inkjet ink of the present invention, for example, energy corresponding to a coating signal is given to the ink in the chamber of the coating head having an ink storage section in which the ink is stored, An apparatus that generates ink droplets by energy is used.

  The ink jet coating apparatus is not limited to the one in which the coating head and the ink container are separated, and may be one in which they are integrated so as not to be separated. The ink container is integrated with the application head in a separable or non-separable manner and mounted on the carriage, and is provided at a fixed portion of the apparatus so that the ink is supplied to the application head via an ink supply member, for example, a tube. It may be in the form of supplying.

  In addition, the inkjet discharge (application) temperature is preferably 10 to 120 ° C., and the viscosity of the inkjet ink at the application temperature is preferably 3 to 30 mPa · s.

3. Formation of Cured Film The cured film of the present invention is obtained by irradiating the ink with light such as ultraviolet rays or visible rays after ejecting the ink-jet ink onto the surface of the substrate using a known ink-jet coating method. The ink in the portion irradiated with light is cured as a three-dimensional cross-linked body by polymerization of a radical polymerizable monomer, for example, a (meth) acryl monomer, and the spread of the ink can be effectively suppressed. Therefore, when the ink-jet ink is used, a high-definition pattern can be drawn. Although depending on the composition of the ink-jet ink, when ultraviolet rays are used as the light to be radiated, the amount of ultraviolet rays to be radiated is the integrated light meter UIT-201 equipped with a photoreceiver UVD-405PD manufactured by USHIO INC. in measured, preferably about 10~1,000mJ / cm ^2, more preferably about 10~800mJ / cm ^2, about 20~500mJ / cm ² is more preferred. Moreover, 200-450 nm is preferable, the wavelength of the ultraviolet-ray to irradiate is more preferable, 220-430 nm is more preferable, 250-400 nm is further more preferable.
In addition, if necessary, the cured film cured by light irradiation may be further heated and baked. In particular, it is preferable to heat at 120 to 250 ° C. for 10 to 60 minutes, and at 150 to 240 ° C. for 10 to 10 minutes. Heating for 60 minutes is more preferable, and heating at 180 to 230 ° C. for 10 to 60 minutes is more preferable.

  The substrate used in the present invention is not particularly limited as long as it can be a target to which the ink jet ink is applied. The shape is not limited to a flat plate shape, and may be a curved surface shape.

  The material of the substrate is not particularly limited. For example, polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, fluorine resins, acrylic resins, and polyamides. , Plastic film such as polycarbonate, polyimide, cellophane, acetate, metal foil, laminated film of polyimide and metal foil, glassine paper, parchment paper, or polyethylene, clay binder, polyvinyl alcohol, starch, carboxymethyl cellulose (CMC) ) And the like, and paper or the like treated with a filler.

  The substances constituting these substrates may be further added to pigments, dyes, antioxidants, deterioration inhibitors, fillers, ultraviolet absorbers, antistatic agents and / or electromagnetic waves, as long as the effects of the present invention are not adversely affected. An additive such as an inhibitor may be included. Further, a material different from the substrate may be formed on a part of the surface of the substrate.

  The use of the substrate is not particularly limited, but the cured film obtained from the ink jet ink of the present invention is excellent in etching solution resistance, plating solution resistance, peelability against alkaline aqueous solution, and heat resistance. It is preferably used for manufacturing an electronic circuit board having a circuit. Although the metal which forms a circuit is not specifically limited, Gold, silver, copper, aluminum, or ITO is preferable.

  Although the thickness of a board | substrate is not specifically limited, Usually, it is about 10 micrometers-2 mm, Although it adjusts suitably by the objective to use, 15-500 micrometers is preferable and 20-200 micrometers is more preferable.

  If necessary, the surface of the substrate on which the cured film is to be formed is subjected to water-repellent treatment, corona treatment, plasma treatment, blast treatment, etc., or an easy-adhesion layer or a color filter protective film is provided on the surface. Also good.

  In addition, by applying the inkjet ink only to a specific location, a cured film having a predetermined pattern can be formed, and the cost for forming the cured film can be reduced. In particular, for electronic circuit boards, the inkjet ink of the present invention, which is excellent in dischargeability and storage stability, is applied only to predetermined circuit portions when forming metal wiring patterns, plating patterns, and metal wiring protective films (coverlays). Therefore, a cured film corresponding to each purpose can be efficiently formed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited by these. In the following description, “part” means part by weight unless otherwise specified.

Each component used for the Example and the comparative example is as follows.

Radical polymerizable monomer containing cyclic ether having 5 or more members (A)
A1: Tetrahydrofurfuryl methacrylate (trade name “SR203”, manufactured by Sartomer; 5-membered ring compound)
A2: Cyclic trimethylolpropane formal acrylate (trade name “SR531”, manufactured by Sartomer; 6-membered ring compound)

Radical polymerizable monomer having heat-reactive functional group (B)
B1: 2-hydroxyethyl methacrylate B2: Monohydroxyethyl methacrylate phthalate (trade name “CB-1”, manufactured by Shin-Nakamura Chemical Co., Ltd.)
B3: 4-hydroxybutyl acrylate

Photopolymerization initiator (C)
C1: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (trade name “DAROCUR TPO”, manufactured by Ciba Japan Co., Ltd.)

Thermally reactive resin (D)
D1: Polyvinylphenol (trade name “Marcalinker MS-2P”, manufactured by Maruzen Petrochemical Co., Ltd.)
D2: A mixture of the compound represented by the above formula (d-1) and a condensate thereof (trade name “Nicalak MW-30”, manufactured by Sanwa Chemical Co., Ltd.)

Flame retardant (E)
E1: Condensed 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10 oxide (trade name “HFA-3003”, Showa Polymer Co., Ltd.)

Multifunctional (meth) acrylate (F)
F1: Bisphenol F-type epoxy acrylate (trade name “Neopol 8477”, manufactured by Nippon Upica Co., Ltd.)
F2: Bisphenol F-type ethylene oxide-modified diacrylate (trade name “M-208”, manufactured by Toagosei Co., Ltd.)
Reactive diluent (H)
H1: Cyclohexyl methacrylate H2: Butyl methacrylate

(Examples 1-2, Comparative Examples 1-3)
In this example, when the cured film of the ink-jet ink according to the present invention containing a five-membered ring compound as the radical polymerizable monomer (A) containing a cyclic ether having five or more members is used for an etching resist or a plating resist Verify about. Each ink-jet ink was prepared by blending at a ratio (parts by weight) described in Table 1, mixing and dissolving, and filtering through a fluororesin membrane filter (0.2 μm).
In addition, Comparative Examples 1 and 2 are examples in which the case where the radically polymerizable monomer (A) component containing a cyclic ether having 5 or more members is not included is mainly verified, and Comparative Example 3 is mainly the component (A). It is an example which verifies the case where the heat-reactive resin (D) component is not included even if it is included.

  In addition, in the ink jet inks of Examples 1 and 2 and Comparative Examples 1 to 3, 0.05 parts by weight of phenothiazine (total amount of ink jet ink excluding the polymerization inhibitor (I) is used as the polymerization inhibitor (I). 100 parts by weight) was added.

(1) Viscosity of ink and change in viscosity due to storage The viscosity at 25 ° C. of each ink-jet ink was measured with an E-type viscometer (VISCOMETER TV-22 manufactured by Toki Sangyo Co., Ltd.). The results are shown in Table 2.
A part (10 g) of each inkjet ink was put in a 30 mL sample bottle, sealed, and stored at 100 ° C. for 5 hours. And the change rate of the viscosity of the ink after storage with respect to the viscosity of the ink before storage was investigated. The viscosity of each ink increased after storage. When the rate of change was less than 10%, “◯” was assigned, and when it was 10% or more, “X” was given. The results are shown in Table 2.
It turns out that the ink for inkjet of Examples 1-2 is excellent in storage stability.

(2) Evaluation of jetting characteristics Each inkjet ink is injected into an inkjet cartridge, which is mounted on an inkjet apparatus (DMP-2800 manufactured by FUJIFILM Dimatix), and a discharge voltage (piezo voltage) using a head for 10 pl. ) The state of discharge was observed under the conditions of 16 V, a head temperature of 70 ° C., and a driving frequency of 5 kHz. The case where the liquid column during jetting was discharged in the vertical direction and no satellite was generated was indicated as “◯”, and the case where the liquid column was in contact with the adjacent liquid column or a satellite was generated was indicated as “X”. The results are shown in Table 2.

(3) Preparation of test substrate Each ink-jet ink was injected into an ink-jet cartridge, and this was installed in an ink-jet apparatus (DMP-2800 manufactured by FUJIFILM Dimatix). An ink-jet ink was applied (drawn) and then UV cured to produce a test substrate on which a cured film was formed. Using the test substrate thus prepared, the following resistances (4) to (6) were examined for the resistance to the etching solution of the cured film, the peelability to the alkaline aqueous solution (stripping solution), and the resistance to the plating solution. .
Substrate production condition substrate : Substrate in which copper foil is laminated on polyimide (thickness 35 μm)
[(Toyobo Co., Ltd.) Viroflex (trade name)]
Cured film thickness: 30 μm
Discharge condition: Discharge condition similar to (2) above UV exposure: 250 mJ / cm ²

(4) Evaluation of resistance of cured film to etching solution In order to evaluate the resistance of the cured film to the etching solution, the prepared test substrate was placed in a 50% FeCl ₃ aqueous solution (free hydrochloric acid concentration: 0.2%) at 60 ° C. for 15 minutes. After the immersion, washing was performed, and the surface state of the cured film was visually determined. The case where peeling or discoloration did not occur was indicated as “◯”, and the case where peeling or discoloration occurred was indicated as “x”. The results are shown in Table 2.

(5) Evaluation of peelability of cured film for alkaline aqueous solution (peeling solution) In order to evaluate the peelability of cured film for alkaline aqueous solution (peeling solution), the prepared test substrate was placed in an 8% NaOH aqueous solution at 50 ° C for 1 minute. After the immersion, washing was performed, and the peeled state of the cured film was visually determined. The case where it was completely dissolved or peeled was indicated as “◯”, and the case where it was not dissolved or peeled was indicated as “x”. The results are shown in Table 2.

(6) Evaluation of resistance of cured film to plating solution In order to evaluate the resistance of the cured film to the plating solution, an electroless nickel plating solution (trade name: Nimden NPR-4, Ni concentration 4 at 60 ° C.) was used. 0.5 g / L, manufactured by Uemura Kogyo Co., Ltd. for 20 minutes and washed with water, followed by 10 minutes in a 60 ° C. gold strike plating solution (trade name: Acid Strike, manufactured by Nippon High Purity Chemical Co., Ltd.) Dipping and washing with water, followed by plating with 100 ° C electroless gold plating solution (trade name: Goblite TAM-55, Au concentration 1 g / L, manufactured by Uemura Kogyo Co., Ltd.) for 30 minutes and washing with water A film was formed. In this process, the case where no penetration or separation of the plating solution into the cured film occurred was “◯”, and the case where the plating solution entered or peeled into the cured film was “x”. The results are shown in Table 2.

(Examples 3-4, Comparative Examples 4-6)
In this example, the case where the cured film of the ink-jet ink according to the present invention is formed for coverlay will be verified. Each ink-jet ink was prepared by blending, mixing and dissolving in the proportions (parts by weight) listed in Table 3, and filtering through a fluororesin membrane filter (0.2 μm).
In addition, Comparative Examples 4 and 5 are examples in which the case where the radically polymerizable monomer (A) component containing a cyclic ether having 5 or more members is not included is mainly verified, and Comparative Example 6 is mainly the component (A). It is an example which verifies the case where the heat-reactive resin (D) component is not included even if it is included.

  In addition, in the inkjet inks of Examples 3 to 4 and Comparative Examples 4 to 6, 0.05 parts by weight of phenothiazine (the total amount of inkjet ink excluding the polymerization inhibitor (I) was used as the polymerization inhibitor (I). 100 parts by weight) was added.

(1) Viscosity of ink / change in viscosity due to storage The viscosity at 25 ° C. of each inkjet ink was measured with an E-type viscometer. The results are shown in Table 4.
A part (10 g) of each inkjet ink was put in a 30 mL sample bottle, sealed, and stored at 100 ° C. for 5 hours. And the change rate of the viscosity of the ink after storage with respect to the viscosity of the ink before storage was investigated. The viscosity of each ink increased after storage. When the rate of change was less than 10%, “◯” was assigned, and when it was 10% or more, “X” was given. The results are shown in Table 4.
It turns out that the ink for inkjets of Examples 3-4 is excellent in storage stability.

(2) Evaluation of jetting characteristics Each inkjet ink is injected into an inkjet cartridge, which is mounted on an inkjet apparatus (DMP-2800 manufactured by FUJIFILM Dimatix), and a discharge voltage (piezo voltage) using a head for 10 pl. ) The state of discharge was observed under the conditions of 16 V, a head temperature of 70 ° C., and a driving frequency of 5 kHz. The case where the liquid column during jetting was discharged in the vertical direction and no satellite was generated was indicated as “◯”, and the case where the liquid column was in contact with the adjacent liquid column or a satellite was generated was indicated as “X”. The results are shown in Table 4.

(3) Preparation of test substrate Each ink-jet ink was injected into an ink-jet cartridge, and this was installed in an ink-jet apparatus (DMP-2800 manufactured by FUJIFILM Dimatix). An ink-jet ink was applied (drawn), and then UV cured and thermally cured to produce a test substrate on which a cured film was formed. Using the test substrate thus prepared, the resistance of the cured film to the plating solution and the solder heat resistance shown in (4) and (5) below were examined.
Substrate production condition substrate : Substrate in which copper foil is laminated on polyimide (thickness 35 μm)
[(Toyobo Co., Ltd.) Viroflex (trade name)]
Cured film thickness: 30 μm
Ejection conditions: Ejection conditions similar to (2) above UV exposure: 40 mJ / cm ²
Thermosetting conditions: 190 ° C x 30 minutes

(4) Evaluation of the resistance of the cured film to the plating solution In order to evaluate the resistance of the cured film to the plating solution, the produced test substrate was treated with a 30 ° C palladium aqueous solution (trade name: KAT-450, Pd concentration of 12 mg / L, Uemura). After immersion for 1 minute in Kogyo Co., Ltd. and washing with water, in an electroless nickel plating solution (trade name: Nimden NPR-4, Ni concentration 4.5 g / L, manufactured by Uemura Kogyo Co., Ltd.) at 80 ° C. Immerse for 30 minutes and wash with water, then soak in water for 10 minutes in an electroless gold plating solution (trade name: Goblite TAM-55, Au concentration 1 g / L, manufactured by Uemura Kogyo Co., Ltd.) at 80 ° C. Thus, a plating film was formed. “○” indicates that no penetration of the plating solution into the cured film or peeling of the cured film occurs during this process, and “×” indicates that the penetration of the plating solution into the cured film or peeling of the cured film occurs. It was. The results are shown in Table 4.

(5) Evaluation of Solder Heat Resistance of Cured Film In order to evaluate the solder heat resistance of the cured film, rosin flux (trade name: NS-829, manufactured by Nippon Superior Co., Ltd.) is applied to the cured film surface of the test substrate. It was applied and immersed in a solder bath at 260 ° C. for 30 seconds to check whether peeling or swelling occurred. The case where no peeling or swelling occurred was indicated by “◯”, and the case where slight peeling or swelling occurred was indicated by “X”. The results are shown in Table 4.

(Examples 5-6, Comparative Examples 7-9)
In this example, when a cured film of the ink-jet ink according to the present invention containing a 6-membered ring compound as a radical polymerizable monomer (A) containing a cyclic ether having 5 or more members is used for an etching resist or a plating resist Verify about. Each ink-jet ink was prepared by blending at a ratio (parts by weight) listed in Table 5, mixing and dissolving, and filtering through a fluororesin membrane filter (0.2 μm).
In addition, Comparative Examples 7 and 8 are examples in which the case where the radically polymerizable monomer (A) component containing a cyclic ether having 5 or more members is not included is mainly verified, and Comparative Example 9 is mainly the component (A). It is an example which verifies the case where the heat-reactive resin (D) component is not included even if it is included.

  In addition, in the inkjet inks of Examples 5 to 6 and Comparative Examples 7 to 9, 0.05 parts by weight of phenothiazine (total amount of inkjet ink excluding the polymerization inhibitor (I) was used as the polymerization inhibitor (I). 100 parts by weight) was added.

(1) Viscosity of ink / change in viscosity due to storage The viscosity at 25 ° C. of each inkjet ink was measured in the same manner as in Example 1. The results are shown in Table 6.
Further, the rate of change in the viscosity of the ink was examined in the same manner as in Example 1. The results are shown in Table 6.
It turns out that the ink for inkjet of Examples 5-6 is excellent in storage stability.

(2) Evaluation of jetting characteristics In the same manner as in Example 1, the state of ejection of each inkjet ink was observed. The results are shown in Table 6.

(3) Production of test substrate A test substrate on which a cured film was formed was produced in the same manner as in Example 1. Using the test substrate thus prepared, the following resistances (4) to (6) were examined for the resistance to the etching solution of the cured film, the peelability to the alkaline aqueous solution (stripping solution), and the resistance to the plating solution. .

(4) Evaluation of resistance of cured film to etching solution In the same manner as in Example 1, the resistance of the cured film to the etching solution was evaluated. The results are shown in Table 6.

(5) Evaluation of releasability of cured film with respect to alkaline aqueous solution (stripping liquid) In the same manner as in Example 1, the releasability of the cured film with respect to alkaline aqueous solution (stripping liquid) was evaluated. The results are shown in Table 6.

(6) Evaluation of resistance of cured film to plating solution The resistance of the cured film to the plating solution was evaluated in the same manner as in Example 1. The results are shown in Table 6.

(Examples 7-8, Comparative Examples 10-12)
In this example, the case where the cured film of the ink-jet ink according to the present invention is formed for coverlay will be verified. Each ink-jet ink was prepared by blending, mixing and dissolving in the proportions (parts by weight) described in Table 7, and filtering through a fluororesin membrane filter (0.2 μm).
In addition, Comparative Examples 10 and 11 are examples in which the case where the radically polymerizable monomer (A) component containing a cyclic ether having 5 or more members is not included is mainly verified, and Comparative Example 12 is mainly the component (A). It is an example which verifies the case where the heat-reactive resin (D) component is not included even if it is included.

  In addition, in the inkjet inks of Examples 7 to 8 and Comparative Examples 10 to 12, 0.05 parts by weight of phenothiazine (total amount of inkjet ink excluding the polymerization inhibitor (I) was used as the polymerization inhibitor (I). 100 parts by weight) was added.

(1) Viscosity of ink and change in viscosity due to storage The viscosity at 25 ° C. of each inkjet ink was measured in the same manner as in Example 3. The results are shown in Table 8.
Further, the rate of change in the viscosity of the ink was examined in the same manner as in Example 3. The results are shown in Table 8.
It turns out that the inkjet ink of Examples 7-8 is excellent in storage stability.

(2) Evaluation of jetting characteristics In the same manner as in Example 3, the state of ejection of each inkjet ink was observed. The results are shown in Table 8.

(3) Production of test substrate A test substrate on which a cured film was formed was produced in the same manner as in Example 3. Using the test substrate thus prepared, the resistance of the cured film to the plating solution and the solder heat resistance shown in (4) and (5) below were examined.

(4) Evaluation of resistance of the cured film to the plating solution The resistance of the cured film to the plating solution was evaluated in the same manner as in Example 3. The results are shown in Table 8.

(5) Evaluation of solder heat resistance of cured film The solder heat resistance of the cured film was evaluated in the same manner as in Example 3. The results are shown in Table 8.

  The present invention can be used for, for example, a protective film or insulating film used for an electronic circuit board, a resist for forming a metal pattern wiring, or a resist for forming a plating pattern.

Claims (22)

  Radical polymerizable monomer (A) containing a cyclic ether having 5 or more members, a radical polymerizable monomer (B) having a thermally reactive functional group, a photopolymerization initiator (C), and a thermally reactive resin (D) And an ink jet ink. The inkjet ink according to claim 1, wherein the radically polymerizable monomer (A) containing a cyclic ether having a 5-membered ring or more is a compound represented by the general formula (A).
(In the general formula (A), R ¹ is hydrogen or alkyl having 1 to 3 carbon atoms, and R ² has an alkylene having 1 to 3 carbon atoms or a branched structure which may have a branched structure. C ³ -C 5 glycol ethers may be used, and R ³ is a cyclic ether having 1 or 2 oxygens and 5 or more ring members which may be substituted with alkyl having 1 to ³ carbons. In the general formula (A), R ¹ is hydrogen, methyl or ethyl, R ² is alkylene having 1 to 3 carbon atoms, and R ³ is the number of oxygens optionally substituted by alkyl having 1 to ³ carbon atoms. The inkjet ink according to claim 2, wherein the inkjet ink is 1 or 2 cyclic ether having 5 or 6 members. The inkjet ink according to claim 2, wherein in general formula (A), R ¹ is hydrogen or methyl, R ² is methylene, and R ³ is a 5-membered cyclic ether having 1 oxygen. In the general formula (A), R ¹ is hydrogen or methyl, R ² is methylene, and R ³ is a 6-membered cyclic ether having 2 oxygen atoms substituted with alkyl having 1 to ³ carbon atoms. The ink-jet ink according to claim 2.   The radically polymerizable monomer (B) having a heat-reactive functional group has a heat-reactive functional group selected from the group consisting of hydroxy, carboxy, oxirane, and oxetane. ink.   The inkjet ink according to any one of claims 1 to 5, wherein the radically polymerizable monomer (B) having a thermally reactive functional group has a hydroxy or carboxy thermally crosslinkable functional group.   The inkjet ink according to any one of claims 1 to 7, wherein the radically polymerizable monomer (B) having a thermally reactive functional group has one thermally reactive functional group. The inkjet polymer according to claim 1, wherein the radically polymerizable monomer (B) having a thermally reactive functional group is a compound represented by the general formula (B-1) or (B-2). ink.
(In the general formulas (B-1) and (B-2), R ⁴ is each independently hydrogen or alkyl having 1 to 3 carbon atoms, and R ⁵ is each independently having a cyclic structure. Good alkylene having 2 to 12 carbon atoms, and n is an integer of 1 to 30.)   The radically polymerizable monomer (B) having a thermally reactive functional group includes 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth). Selected from the group consisting of acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, monohydroxyethyl (meth) acrylate phthalate, and mono- [2- (2-methylacryloyloxy) -ethyl] ester phthalate The inkjet ink according to claim 1, which is 1 or more.   The photopolymerization initiator (C) is bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide or 2,4,6-trimethylbenzoyldiphenylphosphine oxide. The ink for inkjet described.   The inkjet ink according to claim 1, wherein the heat-reactive resin (D) is a melamine resin.   The inkjet ink according to any one of claims 1 to 11, wherein the heat-reactive resin (D) is a phenol resin.   Furthermore, the ink for inkjets in any one of Claims 1-12 containing a flame retardant (E).   Furthermore, the ink for inkjets in any one of Claims 1-14 containing polyfunctional (meth) acrylate (F).   A cured film forming method, wherein the inkjet ink according to claim 1 is applied by an inkjet method, and a cured film is formed by irradiating the applied ink with light.   A cured film is formed by applying the inkjet ink according to any one of claims 1 to 15 by an inkjet method, and performing light irradiation and heating on the applied ink simultaneously or in the order of 1) light irradiation and 2) heating. A cured film forming method to be formed.   A cured film obtained by the method according to claim 16 or 17.   The cured film according to claim 18, which is formed in a predetermined pattern.   An electronic circuit board on which a cured film according to claim 18 or 19 is formed on a board.   An electronic component comprising the electronic circuit board according to claim 20.   A display element comprising the electronic circuit board according to claim 20 or the electronic component according to claim 21.