TWI538964B - Ink for inkjet - Google Patents

Description

Inkjet ink

The present invention relates to an ink for ink jet which can be peeled off using an alkaline aqueous solution, and more particularly to an electronic circuit substrate suitable for use as a printed circuit board or the like. An inkjet ink such as an etching resist having an etching resistance or a plating resist having a plating resistance.

Conventionally, in the manufacture of an electronic circuit board such as a printed wiring board, a flexible print circuit board, or a semiconductor package substrate, a photolithography method using a photoresist has been used. In the method of manufacturing an electronic circuit board using the photolithography method, for example, when a wiring board is printed, a photoresist layer is formed on a copper foil of a copper foil laminate, and the surface thereof is exposed through a mask or the like, and then removed. An uncured portion forms a resist pattern. By bonding, the copper foil of the portion not covered by the photoresist pattern is removed by etching, and the photoresist pattern is removed, whereby a printed wiring board can be obtained.

However, the method for manufacturing a printed wiring board described above requires a long time and a large cost in the production of the photomask, so that the amount of investment in equipment increases. In addition, since the pattern exposure of the photomask is required, the steps are complicated and the operation is cumbersome.

In order to solve these problems, a method of forming a photoresist pattern by directly applying an impedance material to a substrate by using an inkjet method has been developed (see, for example, Japanese Laid-Open Patent Publication No. SHO 56-66089 (Patent Document 1) Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. This method does not require the pattern exposure required previously, so the investment amount of the equipment is small, and in view of the high yield of the material, it is expected.

The resist material used in the above-described inkjet method may, for example, be a resist or a plating resist. Generally, the resist is required to have etching resistance, and the plating resist has plating resistance. Various kinds of ink compositions which can be used for the ink jet method have been proposed so far (Japanese Patent Laid-Open No. Hei 7-170053 (Patent Document 5), Japanese Patent Laid-Open No. 2004-353027 (Patent Document 6), Japanese Patent JP-A-2005-057018 (Patent Document 7)), but the resist film formed of these inks does not have sufficient etching resistance or plating resistance, and does not have excellent alkali peelability.

On the other hand, a resist of a polyvinyl phenol and a derivative thereof is used (Japanese Patent Laid-Open Publication No. SHO 61-291606 (Patent Document 8), Japanese Patent Laid-Open No. Hei 8-211610 (Patent Document No. 9), and Japanese Patent Special Publication No. Plating resistance, alkali, etc., in Japanese Patent Laid-Open Publication No. SHO 60-17739 (Patent Document 11), and Japanese Patent Laid-Open Publication No. SHO 60-17740 (Patent Document No. 12) Excellent in peelability and can be used in photolithography. However, when high molecular weight polyvinyl phenol and its derivative are used as inkjet inks, ejection failure occurs.

[Patent Document 1] Japanese Patent Laid-Open No. 56-66089

[Patent Document 2] Japanese Patent Laid-Open No. 62-181490

[Patent Document 3] Japanese Patent Laid-Open No. Hei 6-237063

[Patent Document 4] Japanese Patent Laid-Open No. Hei 7-131135

[Patent Document 5] Japanese Patent Laid-Open No. 7-170053

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2004-353027

[Patent Document 7] Japanese Patent Laid-Open Publication No. 2005-057018

[Patent Document 8] Japanese Patent Laid-Open Publication No. SHO 61-291606

[Patent Document 9] Japanese Patent Laid-Open No. Hei 8-211610

[Patent Document 10] Japanese Patent Laid-Open Publication No. SHO 60-15636

[Patent Document 11] Japanese Patent Laid-Open No. 60-17739

[Patent Document 12] Japanese Patent Laid-Open No. 60-17740

Under the above circumstances, a resist film which achieves a balance between etching resistance, plating resistance, alkaline peelability, and the like, and an ink jet ink which can form a resist film having the above characteristics are required.

As a result of various studies on the constituent components of the inkjet ink, the inventors of the present invention have found that the inkjet ink containing the resin (A) having a weight average molecular weight of 1,000 to 8,000 represented by the general formula (1) is excellent. characteristic. Further, it has been found that, in addition to the resin (A), an inkjet ink containing a monomer or oligomer (B) having at least one carboxyl group, a diluent (C), and a photopolymerization initiator (D) is particularly included. It is excellent in jetting property, etching resistance, and plating resistance, and can form a cured film which can be alkaline-peeled, and the present invention has been completed based on this finding. The present invention provides an inkjet ink as described below, a cured film obtained from the inkjet ink, a method for forming the same, and the like.

The present invention encompasses the following items.

[1] An ink for inkjet comprising a resin (A) having a weight average molecular weight of 1,000 to 8,000 represented by the following general formula (1):

(In the formula (1), X is a constituent unit derived from a radical polymerizable monomer, m is an integer of 1 or more, and n is a number of 0 to 100).

[2] The ink for inkjet according to [1], wherein n is 0 in the resin (A).

[3] The inkjet ink according to any one of [1] to [2] wherein the resin (A) has a weight average molecular weight of 1,600 to 6,000.

[4] The inkjet ink according to any one of [1] to [3] further comprising: a monomer or oligomer (B) having a carboxyl group of at least one or more, and a diluent (C) And photopolymerization initiator (D).

[5] The ink for inkjet according to [4], wherein the content of the resin (A) is from 0.5 wt% to 20 wt%.

[6] The inkjet ink according to [4] or [5] wherein the monomer or oligomer (B) having one or more carboxyl groups is a monofunctional (meth) acrylate or polyfunctional ( Methyl) acrylate.

[7] The ink for inkjet according to any one of [4] to [6] wherein the monomer or oligomer (B) having one or more carboxyl groups is an acid-modified epoxy (methyl) )Acrylate.

[8] The ink for inkjet according to any one of [4], wherein the monomer or oligomer (B) having one or more carboxyl groups is a weight average molecular weight of 300 to 12,000. Acid modified epoxy acrylate.

[9] The ink for inkjet according to any one of [4] to [8] wherein the monomer or oligomer (B) having one or more carboxyl groups is a bisphenol F type acid modified ring. Oxy acrylate.

[10] The ink for inkjet according to any one of [4] to [9] wherein the diluent (C) has a viscosity of 0.1 mPa at 25 ° C. s~100 mPa. s.

[11] The ink for inkjet according to any one of [4] to [10] wherein the diluent (C) is a monofunctional (meth) acrylate or polyfunctional (methyl) having no carboxyl group. Acrylate.

[12] The ink for inkjet according to any one of [4], wherein the diluent (C) is a monofunctional (methyl) group having no carboxyl group represented by the formula (2). Acrylate:

(In the formula (2), R ¹ is hydrogen or an alkyl group having 1 to 3 carbon atoms, and R ² is an alkylene group having 1 to 12 carbon atoms which may have a cyclic structure, and n is 1 to 30. Integer).

[13] The ink for inkjet according to any one of [4], wherein the resin (A) is a polyvinylphenol having a weight average molecular weight of 4,000 to 6,000, and has a single or more carboxyl group. The bulk or oligomer (B) is a bisphenol F type acid modified epoxy acrylate having a weight average molecular weight of 500 to 11,000, and the diluent (C) is 2-hydroxyethyl (meth)acrylate, which is photopolymerized. The starting agent (D) is 2,4,6-trimethylbenzimidyldiphenylphosphine oxide.

[14] The ink for inkjet according to any one of [1] to [13] which has a viscosity at 25 ° C of 2 mPa. s~200 mPa. s.

[15] A method of forming a cured film by applying an inkjet ink according to any one of [1] to [14] onto a substrate by an inkjet method, and coating the applied ink Light is irradiated, thereby forming a cured film.

[16] A cured film obtained by the inkjet ink according to any one of [1] to [14].

[17] The cured film according to [16], which is formed in a pattern shape.

[18] A method of producing a substrate, comprising: a step of forming a resist film or a plating resist film using the cured film according to [17]; an etching step or a plating step thereafter; and thereafter The step of peeling off the above film.

[19] An electronic component having a substrate obtained by the method according to [18].

[20] A display element having the electronic component according to [19].

In addition, in the present specification, in order to show both an acrylate and a methacrylate, it is a case where it is labeled with "(meth)acrylate.

According to a preferred embodiment of the inkjet ink of the present invention, it is possible to provide an inkjet ink which can be subjected to alkaline peeling, which is excellent in ink discharge property, film curability, etching resistance, and plating resistance.

The above described features and advantages of the present invention will be more apparent from the following description.

1. Invented inkjet ink

The inkjet ink of the present invention is not particularly limited as long as it contains the resin (A) having a weight average molecular weight of 1,000 to 8,000 represented by the formula (1). Further, a monomer or oligomer (B) having at least one carboxyl group, a diluent (C), and a photopolymerization initiator (D) may be contained as needed. The ink for inkjet of the present invention may be colorless or colored.

The inkjet ink of the present invention may further contain an epoxy resin, a surfactant, a colorant, a polymerization inhibitor, or the like, in addition to the above components.

Here, the weight average molecular weight in the present specification is a THF-based column manufactured by Polymer Laboratories as a column by GPC (gel permeation chromatography) method (column temperature: 35 ° C, flow rate: 1) The value obtained in polystyrene obtained by ml/min). In addition, the weight average molecular weight of the commercial item in this specification is a catalogue value.

1.1 Resin (A)

The inkjet ink of the present invention contains the resin (A) represented by the above formula (1). The resin (A) is a polymer obtained from a monomer containing a vinyl phenol, and is a polyvinylphenol-based polymer in which OH is in a para, ortho or meta position with respect to the main chain.

In the formula, X is a constituent unit derived from a radical polymerizable monomer, m is an integer of 1 or more, and n is a number of 0 to 100. When m is 2 or more, the repeating unit of the constituent unit in [ ] of the formula (1) may have the same structure or may have a different structure. It can be a repetition of a number of different structures of n, or a repetition of a structure of the same number of n. n is preferably 0 to 10, more preferably 0 to 5, and particularly preferably n = 0.

In the present invention, the radical polymerizable monomer used as a raw material of X is not limited, and various compounds having a polymerizable unsaturated bond can be used. Examples thereof include styrene monomers such as styrene and α-methylstyrene, (meth)acrylonitrile, (meth)acrylic acid, (meth)acrylic acid ester (meth)acrylate, and the like. An acrylic monomer such as an amine, a vinyl ether such as ethyl vinyl ether, maleic anhydride, vinyl acetate or vinyl pyridine.

The above polyvinylphenol-based polymer can be obtained commercially. For example, Maruka Lyncur M (poly-p-vinylphenol) manufactured by Maruzen Petrochemical, Maruka Lyncur CMM (p-vinylphenol/methyl methacrylate copolymer), Maruka Lyncur CHM (p-vinylphenol/methacrylic acid-2) - hydroxyethyl ester copolymer), Maruka Lyncur CST (p-vinylphenol/styrene copolymer). Further, the resin (A) may be used in combination of two or more.

The polystyrene-equivalent weight average molecular weight of the resin (A) of the present invention is preferably from 1,000 to 8,000, more preferably from 1,600 to 6,000, and still more preferably from 4,000 to 6,000. When it is this range, the film has good hardenability, and is excellent in film characteristics, such as etching resistance and plating resistance, and is excellent in ejection characteristics. Further, the obtained cured film also has good solubility in alkali.

When the content of the resin (A) is from 0.1 wt% to 50 wt% of the solid content of the ink for inkjet, the balance between the etching resistance and the plating resistance, the alkaline peelability, and the ejection property is improved, so that it is preferable. Preferably, it is 0.5 wt% to 20 wt%, and further preferably 0.5 wt% to 10 wt%, particularly preferably 1 wt% to 10 wt%.

1.2 A monomer or oligomer having one or more carboxyl groups (B)

In order to improve the alkali peelability, the inkjet ink of the present invention may contain a monomer or oligomer (B) having a carboxyl group. Here, the "oligomer having a carboxyl group" is a compound having at least one carboxyl group or more among the polymerizable compounds in which two or more monomers are bonded.

The monomer having a carboxyl group or the oligomer (B) is not particularly limited as long as it has a carboxyl group. For example, it is excellent in etching resistance and plating resistance, and in order to further improve alkali peelability, an acid modified ring is preferred. Oxy (meth) acrylate.

The acid-modified epoxy (meth) acrylate of the present invention is a compound having two or more polymerizable double bonds and one or more carboxyl groups in one molecule. Here, the polymerizable double bond means a carbon-carbon double bond which can be polymerized. Examples of the group having a polymerizable double bond include an acryloyl group, a methacryl group, an allyl group, a vinyl group, or a maleimine group. The polymerizable double bond may be thermally polymerizable or photopolymerizable, and is preferably a photopolymerizable double bond.

The polystyrene-equivalent weight average molecular weight of the acid-modified epoxy (meth) acrylate is preferably from 300 to 12,000, more preferably from 500 to 11,500, and further preferably from 900 to 11,000, particularly preferably 900. ~8,000, especially good is 900~6,000. When it is this range, film characteristics, such as etching resistance and plating resistance, are excellent, and injection characteristics are also favorable. Further, the obtained cured film also has good solubility in alkali.

Specific examples of the acid-modified epoxy (meth) acrylate include an epoxy group obtained by reacting a (meth) acrylate having a carboxyl group and (meth) acrylic acid with an epoxy compound, and then reacting the epoxy group. A substance obtained by reacting an acrylate with a polybasic acid or a polybasic acid anhydride.

Examples of the epoxy compound include a phenol novolak type, a cresol novolak type, a bisphenol A type, a bisphenol F type, a bisphenol S type, a trisphenol methane type, and a tetraphenol ethane type epoxy resin. Among them, preferred are phenol novolak type, cresol novolac type, bisphenol A type, and bisphenol F type, and further preferably bisphenol A type and bisphenol F type, in terms of plating resistance, special Good is bisphenol F type.

Examples of the (meth) acrylate having a carboxyl group and (meth)acrylic acid include (meth)acrylic acid, β-carboxyethyl (meth)acrylate, and ω-carboxypolycaprolactone mono(meth)acrylate. , succinic acid mono [2-(methyl) propylene methoxyethyl] ester, maleic acid mono [2-(methyl) propylene methoxyethyl] ester, phthalic anhydride and (methyl) A reactant of hydroxyethyl acrylate (e.g., phthalic acid mono(hydroxyethyl methacrylate)) or a reaction of hexahydrophthalic anhydride with hydroxyethyl (meth)acrylate.

Examples of the polybasic acid or polybasic acid anhydride include phthalic acid, pyromellitic acid, succinic acid, trimellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, and itaconic acid (itaconic). Acid), citraconic acid, methylhexahydrophthalic acid, hexahydrotrimellitic acid, endomethylenetetrahydrophthalic acid, methyl endomethylenetetrahydrophthalic acid Or a polybasic acid such as a styrene-maleic acid copolymer; phthalic anhydride, pyromellitic anhydride, succinic anhydride, trimellitic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, horse Anhydride, itaconic anhydride, citraconic anhydride, methylhexahydrophthalic anhydride, hexahydrotrimellitic anhydride, trimellitic anhydride, endomethylenetetrahydrophthalic anhydride, methylene A polybasic anhydride such as a tetrahydrophthalic anhydride or a styrene-maleic anhydride copolymer.

The epoxy compound, the (meth) acrylate having a carboxyl group, the polybasic acid or the polybasic acid anhydride used in the present invention may be one compound or a mixture of two or more compounds.

Commercially available products of the acid-modified epoxy (meth) acrylate include KAYARAD CCR-1159H (molecular weight: 7,500, acid value: 101 mgKOH/g) manufactured by Nippon Kayaku Co., Ltd., KAYARAD CCR-1285H (acid Value: 82 mgKOH/g), KAYARAD ZFR-1401H (molecular weight: 12,000, acid value: 99 mgKOH/g), KAYARAD ZFR-1491H (acid value: 100 mgKOH/g), KAYARAD ZFR-1492H (acid value: 102 mgKOH) /g), KAYARAD TCR-1310H (molecular weight: 4500, acid value: 104 mgKOH/g); NEOPOL 8430 (molecular weight: 10000, acid value: 88 mgKOH/g) manufactured by Japan U-pica Co., Ltd., NEOPOL 8432 ( Molecular weight: 8000, acid value: 92 mgKOH/g), NEOPOL 8470 (molecular weight: 10000, acid value: 100 mgKOH/g), NEOPOL 8472 (molecular weight: 7000, acid value: 105 mgKOH/g), NEOPOL 8475 (molecular weight: 10000, acid value: 101 mgKOH/g), NEOPOL 8476 (molecular weight: 5000, acid value: 101 mgKOH/g), NEOPOL 8477 (molecular weight: 10000, acid value: 94 mgKOH/g), NEOPOL 8371, NEOPOL 8316, NEOPOL 8317, NEOPOL 8310 (molecular weight: 1000, acid value: 104 mgKOH/g), and the like. In addition, "molecular weight" in this paragraph means a weight average molecular weight.

Other monomers or oligomers (B) having a carboxyl group include the following.

Examples of the monomer having a carboxyl group include (meth)acrylic acid, (meth)acrylic acid dimer, crotonic acid, α-chloroacrylic acid, cinnamic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid. , mesaconic acid, β-carboxyethyl (meth) acrylate, ω-carboxy polycaprolactone mono (meth) acrylate, succinic acid mono [2-(methyl) propylene a reaction of a methoxyethyl]ester, a mono[2-(methyl) propylene methoxyethyl] maleate, a phthalic anhydride with a hydroxyethyl (meth) acrylate (eg, phthalic acid) A reaction product of formic acid mono(hydroxyethyl methacrylate) or hexahydrophthalic anhydride with hydroxyethyl (meth)acrylate.

When the content of the monomer having a carboxyl group or the oligomer (B) is from 1 wt% to 70 wt% of the solid content of the ink for inkjet, the etching resistance or plating resistance is balanced with the alkali peelability and the ejection property. It is better, so it is better, more preferably 2 wt% ~ 65 wt%, and further preferably 3 wt% ~ 60 wt%, particularly preferably 4 wt% ~ 55 wt%.

The monomer or oligomer (B) having a carboxyl group may be one compound or a mixture of two or more different compounds.

1.3 thinner (C)

In order to improve various characteristics, the ink for inkjet of the present invention may contain a diluent (C). The diluent (C) of the present invention is not particularly limited, and it is preferred that the viscosity at 25 ° C is 0.1 mPa. s~100 mPa. The s may be a monomer or a solvent having a radical polymerizable property. As the monomer having a radical polymerizable property, a monofunctional (meth) acrylate or a polymonofunctional (meth) acrylate having no carboxyl group is preferred, and it is more preferably represented by the above formula (2). Monofunctional (meth) acrylate.

1.3(1) Monofunctional polymerizable monomer

When the compound having a radical polymerizable property is a monofunctional polymerizable monomer, it is particularly preferable because it has good sprayability.

Specific examples of the monofunctional polymerizable monomer include a compound of the formula (2): 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and (meth)acrylic acid. -4-hydroxybutyl ester; other compounds may be exemplified by 1,4-cyclohexanedimethanol mono(meth)acrylate, N-hydroxyethyl(meth)acrylamide, glycidyl (meth)acrylate , (meth)acrylic acid-3,4-epoxycyclohexyl ester, methyl glycidyl (meth)acrylate, 3-methyl-3-(methyl)propenyloxymethyloxetane , 3-ethyl-3-(methyl)propenyloxymethyloxetane, 3-methyl-3-(methyl)propenyloxyethyloxetane, 3-B 3-(methyl)propenyloxyethyloxetane, p-vinylphenyl-3-ethyloxetan-3-ylmethylether, 2-phenyl-3- (Meth) propylene methoxymethyl oxetane, 2-trifluoromethyl-3-(methyl) propylene methoxymethyl oxetane, 4-trifluoromethyl-2- (Meth) propylene methoxymethyl oxetane, (meth)acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, (methyl ) Butyl olefinate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, styrene, methylstyrene, chlorine Methylstyrene, (3-ethyl-3-oxetanyl)methyl (meth)acrylate, N-cyclohexylmaleimide, N-phenylmaleimide, vinyl toluene , (meth) acrylate, tricyclo [5.2.1.0 ^2,6] decyl (meth) acrylate, dicyclopentenyloxyethyl acrylate, (meth) acrylate, (meth) acrylate, phenyl Glycerol mono (meth) acrylate, polystyrene macromonomer, polymethyl methacrylate macromonomer, (meth)acrylic acid-5-tetrahydrofurfuryloxycarbonylpentyl ester, lauryl alcohol ring Oxyethane adducts of (meth) acrylate, (meth) acrylate, crotonic acid, α-chloroacrylic acid, cinnamic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, methyl Fumaric acid, ω-carboxypolycaprolactone mono(meth)acrylate, succinic acid mono[2-(methyl)propenyloxyethyl]ester, maleic acid mono[2-(methyl ) propylene methoxyethyl] ester, cyclohexene-3,4-dicarboxylic acid mono [2-(methyl) propylene Oxyethyl]ester, (meth) acrylamide, N,N-dimethyl(meth) acrylamide, N,N-diethyl(meth) decylamine, N,N-di Methylaminopropyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-propenyl morpholine, N-phenyl maleimide, N-cyclohexyl Come to imine.

These monofunctional polymerizable monomers may be one type of compound or a mixture of two or more different compounds.

Wherein, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 1,4-cyclohexanedimethanol In the case of a single (meth) acrylate or the like, the compatibility of the ink and the solubility of the solid content of the ink can be improved, and the diffusion of the liquid after the ink is sprayed onto the substrate is small, so that high definition can be achieved, which is preferable.

These monofunctional polymerizable monomers having a hydroxyl group may be one type of compound or a mixture of two or more different compounds.

When the content of the monofunctional polymerizable monomer as the diluent (C) is from 1 wt% to 70 wt% of the total amount of the ink for inkjet, it can be adjusted to conform to the viscosity of the use to be used, so it is preferable if considering To the balance with other characteristics, it is better from 2 wt% to 65 wt%, and further preferably from 3 wt% to 60 wt%, particularly preferably from 4 wt% to 55 wt%.

1.3(2) Polyfunctional polymerizable monomer

The diluent (C) may also be a polyfunctional polymerizable monomer.

Specific examples of the polyfunctional polymerizable monomer include bisphenol F ethylene oxide modified diacrylate, bisphenol A ethylene oxide modified diacrylate, and isomeric cyanuric acid ethylene oxide modified Acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol diacrylate monostearate, 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, trihydroxyl Methyl propane diacrylate, dipentaerythritol diacrylate, modified iso-cyanuric acid ethylene oxide modified di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol di(meth)acrylic acid Ester monostearate, pentaerythritol tri(meth)acrylate, trimethylolpropane di(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, two Pentaerythritol tetra(meth) acrylate, dipentaerythritol penta (meth) acrylate, bisphenol F oxirane Diacrylate, bisphenol A ethylene oxide modified diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol Acrylate, 1,9-nonanediol diacrylate, 1,4-cyclohexanedimethanol diacrylate, 2-n-butyl-2-ethyl-1,3-propanediol diacrylate, trishydroxyl Propane tri(meth)acrylate, ethylene oxide modified trimethylolpropane tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, epichlorohydrin (epichlorohydrin) modified trimethylolpropane tri (meth) acrylate, di (trimethylolpropane) tetra (meth) acrylate, glycerol tri (meth) acrylate, epichlorohydrin modified glycerol (Meth) acrylate, diglycerin tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate Ethylene oxide modified tris(meth)acrylate, tris[(meth)propenyloxyethyl]isocyanate, caprolactone modified tris[(methyl)propene oxime Base B ] Iso cyanurate, (meth) acrylate, urethane.

These polyfunctional polymerizable monomers may be one type of compound or a mixture of two or more different compounds.

When the content of the polyfunctional polymerizable monomer as the diluent (C) is from 0.1 wt% to 60 wt% of the total amount of the ink for inkjet, the balance between the adjustment of the viscosity in accordance with the use used and the other characteristics is good. More preferably, it is 0.5 wt% to 55 wt%, and further preferably 0.8 wt% to 50 wt%, particularly preferably 1 wt% to 45 wt%.

1.3 (3) solvent

A solvent can also be used as the diluent (C). When the ink jet head is heated, if the ink contains a solvent having a low boiling point, the solvent volatilizes, and the viscosity of the ink rises, which may cause the nozzle opening of the ink jet head to clog. Therefore, a solvent having a boiling point of from 100 ° C to 300 ° C is particularly preferred.

Specific examples of the solvent having a boiling point of 100 ° C to 300 ° C include water, butyl acetate, butyl propionate, ethyl lactate, methyl hydroxyacetate, ethyl hydroxyacetate, butyl glycolate, and methoxyacetate. Ester, ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, 3-methoxy Methyl propyl propionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate Ester, propyl 2-hydroxypropionate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, methyl 2-ethoxypropionate, Ethyl 2-ethoxypropionate, methyl 2-hydroxy-2-methylpropanoate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-methoxy-2-methylpropanoate , 2-ethoxy-2-methylpropionic acid ethyl ester, methyl pyruvate, ethyl pyruvate, propyl pyruvate, methyl acetate, ethyl acetate, 2-butoxybutyric acid Ester, ethyl 2-oxobutanoate, dioxane, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene Alcohol, 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 monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, cyclohexanone, cyclopentane Ketone, 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 diethyl ether, diethylene glycol methyl ethyl ether, toluene, xylene, benzene Ether, γ-butyrolactone, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, or dimethylimidazolidone.

These solvents may be one compound or a mixture of two or more different compounds.

When the content of the solvent of the diluent (C) is from 0.1 wt% to 10 wt% of the total amount of the ink for inkjet, the balance between the jetting property and other characteristics is good, and more preferably 0.2 wt% to 8 wt%. Further preferably, it is 0.5 wt% to 6 wt%, and particularly preferably 1 wt% to 5 wt%.

The diluent (C) may be one compound or a mixture of two or more different compounds. For example, it may be a mixture of a monofunctional polymerizable monomer and a solvent.

1.4 Photopolymerization initiator (D)

In order to impart photocurability to the inkjet ink of the present invention, it may contain a photopolymerization initiator (D). The photopolymerization initiator (D) is not particularly limited as long as it is a compound which generates a radical by irradiation with ultraviolet rays or visible light.

Specific examples of the photopolymerization initiator (D) include benzophenone, Michler's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone (xanthone), thioxanthone, isopropyl oxazinone, 2,4-diethylthiaxanone, 2-ethyl hydrazine, acetophenone, 2-hydroxy-2-methyl Phenylpropiophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxy Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphoroquinone, benzantrone, 2-methyl-1-[4-(methylthio) Phenyl]-2-morpholinylpropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, 4-dimethyl Ethyl benzyl benzoate, isoamyl 4-dimethylaminobenzoate, 4,4'-di(t-butylperoxycarbonyl)benzophenone, 3,4,4'-three (t-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetrakis(t-butylperoxycarbonyl)benzophenone, 3,3',4,4' -tetrakis(t-hexylperoxycarbonyl)benzophenone, 3,3'-bis(methoxycarbonyl)-4,4'-di(t-butyl Oxycarbonyl)benzophenone, 3,4'-bis(methoxycarbonyl)-4,3'-bis(t-butylperoxycarbonyl)benzophenone, 4,4'-di Methoxycarbonyl)-3,3'-bis(t-butylperoxycarbonyl)benzophenone, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzylidene hydrazide), 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 (three Chloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxystyrene -4,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-bis(ethoxycarbonylmethyl)]-2,6-di(trichloromethyl)- Triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(4'-A Oxyphenyl)-s-triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzothiazole, 2-mercaptobenzoquinone Thiazole, 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'-biimidazole, 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-morpholinylpropanyl)-9-n-dodecylcarbazole, 1-hydroxycyclohexyl phenyl ketone, bis(η ⁵ -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-benzene Titanium, bis(2,4,6-trimethylbenzylidene)phenylphosphine oxide, or 2,4,6-trimethylbenzimidyldiphenylphosphine oxide.

The photopolymerization initiator (D) may be one compound or a mixture of two or more compounds.

When the content of the photopolymerization initiator (D) is from 0.5% by weight to 20% by weight based on the total amount of the ink for inkjet, it is preferable because it is highly sensitive to ultraviolet rays when it is used as an ink for inkjet. 1 wt% to 20 wt%, and further preferably 2 wt% to 20 wt%.

1.5 other ingredients

In order to further improve various characteristics of the inkjet ink of the present invention, it may contain an epoxy resin, an epoxy hardener, a surfactant, a colorant, a polymerization inhibitor, and the like.

1.5 (1) epoxy resin

The inkjet ink of the present invention may contain an epoxy resin, for example, in order to improve etching resistance or plating resistance.

Specific examples of the epoxy resin include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a glycidyl ester type epoxy resin, or an alicyclic epoxy resin.

Commercial products of the epoxy resin include Epikote 807, Epikote 815, Epikote 825, Epikote 827, Epikote 828, Epikote 190P, Epikote 191P (trade name; manufactured by Yuka Shell Epoxy Co., Ltd.); Epikote 1004, Epikote 1256 (product) Name; manufactured by Japan Epoxy Resin Co., Ltd.; Araldite CY177, Araldite CY184 (trade name; manufactured by Japan Ciba Geigy Co., Ltd.); Celloxide 2021P, EHPE-3150 (trade name; manufactured by Daicel Chemical Industries, Inc.); or Techmore VG3101L (trade name; manufactured by Mitsui Chemicals, Inc.).

The epoxy resin used in the inkjet ink may be one type of compound or a mixture of two or more compounds.

When the content of the epoxy resin is from 1 wt% to 20 wt% of the solid content of the ink for inkjet, the etching resistance or the plating resistance is improved, so that it is preferably 1 wt% to 10 wt%, and further Good is 1 wt% to 7 wt%.

1.5(2) surfactant

The inkjet ink of the present invention may contain a surfactant, for example, in order to improve the wettability to the base substrate and the film surface uniformity of the cured film. Examples of the surfactant include a ruthenium-based surfactant, an acrylic surfactant, and a fluorine-based surfactant.

Commercial products of the surfactants include Byk-300, Byk-306, Byk-335, Byk-310, Byk-341, Byk-344, and Byk-370 (trade name; manufactured by Byk-Chemie Co., Ltd.). Isocyanic surfactant; Acrylic surfactant such as Byk-354, Byk-358, and Byk-361 (trade name; manufactured by Byk-Chemie Co., Ltd.); DFX-18, Ftergent 250, or Ftergent 251 (commodity A fluorine-based surfactant such as a product manufactured by NEOS Co., Ltd., Megafac F-479 (trade name; manufactured by DIC Corporation).

The surfactant used in the ink for inkjet may be one compound or a mixture of two or more compounds.

When the content of the surfactant is 0.001 wt% to 1 wt% of the solid content of the ink for inkjet, the film surface uniformity of the cured film is improved, so that it is preferable to consider the balance with other characteristics. 0.001 wt% to 0.1 wt%, and further preferably 0.001 wt% to 0.05 wt%.

1.5(3) colorant

The inkjet ink of the present invention may contain a coloring agent, for example, in order to easily recognize the substrate when the cured film is inspected. The colorant is preferably a dye or a pigment.

The coloring agent used in the inkjet ink may be one type of compound or a mixture of two or more compounds.

When the content of the colorant is from 0.1 wt% to 5 wt% of the solid content of the ink for inkjet, it is easy to inspect the cured film, and therefore it is preferably 0.1 wt% in consideration of balance with other characteristics. ~1 wt%, and further preferably 0.1 wt% to 0.5 wt%.

1.5 (4) polymerization inhibitor

The inkjet ink of the present invention may contain a polymerization inhibitor, for example, in order to improve storage stability. Specific examples of the polymerization inhibitor include 4-methoxyphenol, hydroquinone, or phenothiazine. Among these polymerization inhibitors, phenothiazine is preferred even if the change in viscosity for long-term storage is small.

The polymerization inhibitor used in the inkjet ink may be one type of compound or a mixture of two or more compounds.

When the content of the polymerization inhibitor is 0.01 wt% to 1 wt% of the solid content of the ink for inkjet, the change in viscosity for long-term storage is small, so it is preferable, and it is better to consider the balance with other characteristics. It is 0.01 wt% to 0.5 wt%, and further preferably 0.01 wt% to 0.1 wt%.

1.6 Viscosity of inkjet ink

The inkjet ink of the present invention has a viscosity of 2 mPa at 25 ° C as measured by an E-type viscometer. s~200 mPa. In s, the coating characteristics (ejection accuracy, etc.) by inkjet printing are good, which is preferable. The inkjet ink at 25 ° C has a viscosity of 10 mPa. s~180 mPa. s, and thus better is 20 mPa. s~150 mPa. s.

The viscosity at 25 ° C is greater than or equal to 50 mPa. In the case of s ink, if the ink jet head is heated to lower the viscosity at the time of ejection, a more stable discharge can be achieved. When the inkjet head is sprayed, the viscosity of the ink for inkjet at a heating temperature (preferably 40 ° C to 120 ° C) is preferably 1 mPa. s~30 mPa. s, better is 2 mPa. s~25 mPa. s, especially good is 3 mPa. s~20 mPa. s.

When the ink jet head is heated, it is preferred to use a solvent-free ink. In this case, the viscosity of the ink is preferably adjusted by appropriately selecting the type and content of the diluent (C). When the ink jet head is not warmed, the viscosity of the ink can be adjusted by adding a solvent of 10 wt% or less equal to or less than the total amount of the ink.

1.7 Preservation of ink for inkjet

When the ink for inkjet of the present invention is stored at -20 ° C to 20 ° C, the change in viscosity during storage is small, and the storage stability is good.

2. Coating of ink for inkjet by an inkjet method

The inkjet ink of the present invention can be applied by a known inkjet coating method. The inkjet coating method includes, for example, a method of applying mechanical energy to the ink to eject (coat) the ink from the inkjet head (so-called piezo method); and applying thermal energy to the ink, The coating method of the applied ink (so-called bubble-jet (registered trademark) method).

By using an inkjet coating method, the ink for inkjet can be applied in a predetermined pattern. Thereby, the ink can be applied only to a desired portion, and the cost can be reduced as compared with the photolithography method.

As a coating unit which is preferably used for coating with the inkjet ink of the present invention, for example, an inkjet unit including an ink containing portion for storing the ink and an inkjet head can be cited. The ink jet unit may, for example, be an ink jet unit that applies thermal energy corresponding to a coating signal to the ink and generates ink droplets by the energy.

The ink jet head is, for example, an ink jet head having a liquid contact surface of a heat generating portion containing a metal and/or a metal oxide. Specific examples of the metal and/or metal oxide include metals such as lanthanum (Ta), zirconium (Zr), titanium (Ti), nickel (Ni), and aluminum (Al), and oxides of these metals. .

In the coating apparatus which is preferably used for the application of the inkjet ink of the present invention, for example, energy corresponding to the coating signal is supplied to the ink in the ink jet head having the ink containing portion for storing the ink, and A device that produces ink droplets from the above energy.

The inkjet coating device is not limited to a device in which the inkjet head is separated from the ink containing portion, and these devices that are inseparable and integrated may be used. Further, the ink accommodating portion may be provided in a fixed portion of the device in addition to the form in which the ink jet head is detachable or inseparable and integrated in a carriage, and may be provided via an ink supply member such as a tube (tube). The form of supplying ink to the inkjet head.

In addition, the inkjet ejection (coating) temperature is preferably from 10 ° C to 120 ° C, and the viscosity of the inkjet ink at the coating temperature is preferably 1 mPa. s~200 mPa. s.

3. Formation of hardened film

The cured film of the present invention can be obtained by applying the ink for inkjet onto the surface of the substrate by an inkjet method, and then irradiating the ink with light such as ultraviolet rays or visible rays, as needed.

When the ultraviolet ray is irradiated, the amount of the ultraviolet ray to be irradiated is determined by the composition of the inkjet ink, and is measured using an integrated photometer UIT-201 equipped with a light receiver UVD-365PD manufactured by Ushio Denki Co., Ltd., preferably 10 mJ/cm ² to 1,000 mJ/cm ² or so, more preferably 20 mJ/cm ² to 800 mJ/cm ² or more, preferably 40 mJ/cm ² to 500 mJ/cm ² or so. Further, the wavelength of the ultraviolet ray to be irradiated is preferably from 200 nm to 450 nm, more preferably from 220 nm to 430 nm, and further preferably from 250 nm to 400 nm.

Further, the cured film which is hardened by irradiation with light may be further heated and calcined as needed, and it is particularly preferably heated at 100 ° C to 250 ° C for 10 minutes to 60 minutes, more preferably at 120 ° C to 230 ° C. The heating is carried out for 10 minutes to 60 minutes, and it is preferably heated at 150 ° C to 200 ° C for 10 minutes to 60 minutes.

The "substrate" which can be used in the present invention is not particularly limited as long as it can be a target for applying ink for inkjet printing, and the shape thereof is not limited to a flat plate shape, and may be a curved shape.

In addition, the material of the substrate is not particularly limited, and examples thereof include polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). Polyolefin resins such as ethylene and polypropylene, plastic films such as polyvinyl chloride, fluororesin, acrylic resin, polyamide, polycarbonate, and polyimide, cellophane, acetate, metal foil, a laminate film of polyimide and metal foil, a glasse paper with a filling effect, a parchment paper, or a polyethylene, a clay binder, polyvinyl alcohol, starch, carboxymethyl cellulose (CMC, Carboxymethyl cellulose), etc., which is filled with paper, glass.

Among the substances constituting the substrate, pigments, dyes, antioxidants, anti-deterioration agents, fillers, ultraviolet absorbers, antistatic agents, and/or anti-electromagnetic waves may be further contained within a range that does not adversely affect the effects of the present invention. Additives such as agents. 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, and the cured film obtained by the inkjet ink of the present invention is excellent in etching liquid resistance, plating resistance, and peeling property to an alkaline aqueous solution, and therefore is preferably used for manufacturing on a substrate. An electronic circuit board or the like having a metal circuit on its surface. The metal forming the circuit is not particularly limited, and is preferably gold, silver, copper, aluminum or indium tin oxide (ITO).

The thickness of the substrate is not particularly limited, but is usually about 10 μm to 2 mm, and is appropriately adjusted depending on the purpose of use, and is preferably 15 μm to 500 μm, more preferably 20 μm to 200 μm.

It is also possible to perform an easy adhesion treatment such as water repellent treatment, corona treatment, plasma treatment, or blast treatment on the surface on which the cured film is formed on the substrate, or it is easy to adhere to the surface. A protective film for the layer or color filter.

[Examples]

Hereinafter, the present invention will be further illustrated by the examples, but the present invention is not limited by these examples.

<Production of Inkjet Ink and Substrate Forming Cured Film Pattern>

First, the inkjet inks of Examples 1 to 2 and Comparative Examples 1 to 3 and the substrate on which the cured film pattern is formed will be described.

[Example 1]

Mixed and dissolved in the following composition ratio: Maruka Lyncur M S-1G (trade name; manufactured by Maruzen Petrochemical Co., Ltd., weight average molecular weight: 1,600-2,400) used as the resin (A), used as having 1 or more carboxyl groups Monomer or oligomer (B) bisphenol F type acid-modified epoxy acrylate, NEOPOL 8476 (trade name; manufactured by Japan U-pica Co., Ltd., weight average molecular weight: 5000), used as a diluent ( C) 2-hydroxyethyl methacrylate, butyl methacrylate, 2,4,6-trimethylbenzhydryldiphenylphosphine oxide as photopolymerization initiator (D), DAROCUR TPO (trade name; manufactured by Ciba Specialty Chemicals Co., Ltd.), and phenothiazine as a polymerization inhibitor, and then filtered using a membrane filter (1 μm) made of polytetrafluoroethylene (PTFE). Inkjet ink 1 was prepared.

The viscosity of the inkjet ink 1 at 25 ° C was measured using an E-type viscometer (TV-22 manufactured by Toki Sangyo Co., Ltd., the same applies hereinafter), and the result was 40 mPa. s.

The inkjet ink 1 was injected into an ink jet cartridge, and it was mounted in an inkjet apparatus (DMP-2811 manufactured by FUJIFILM Dimatix Co., Ltd.), and a discharge nozzle was used at a discharge voltage of 10 pl ( Copper with a thickness of 35 μm formed by laminating copper foil on polyimide by a piezoelectric voltage of 16 V, a nozzle temperature of 70 ° C, a driving frequency of 5 kHz, and a coating number of one shot. A specific pattern is formed on the copper surface of a foil laminate, that is, Vyloflex (trade name; manufactured by Toyobo Co., Ltd.).

The substrate on which the inkjet ink 1 is patterned is irradiated with ultraviolet rays having a wavelength of 365 nm at a UV exposure amount of 250 mJ/cm ^{2 to} cure the inkjet ink 1 to thereby obtain a cured film having a thickness of 10 μm. Patterned substrate 1.

[Embodiment 2]

The same procedure as in Example 1 was carried out except that Maruka Lyncur M S-2G (trade name; manufactured by Maruzen Petrochemical Co., Ltd., weight average molecular weight: 4,000-6,000) was used as the polyvinyl phenol, and the following composition ratio was used. The inkjet ink 2 was prepared in a manner.

The viscosity of the inkjet ink 2 at 25 ° C was measured using an E-type viscometer (TV-22 manufactured by Toki Sangyo Co., Ltd., the same applies hereinafter), and the result was 45 mPa. s.

Using the inkjet ink 2, a substrate 2 on which a cured film pattern having a thickness of 10 μm was formed was obtained in the same manner as in Example 1.

[Comparative Example 1]

The resin containing the polymer using vinyl phenol was removed, and the inkjet ink 3 was prepared in the same manner as in Example 1 in the same manner as in Example 1.

The viscosity of the inkjet ink 3 at 25 ° C was measured using an E-type viscometer (TV-22 manufactured by Toki Sangyo Co., Ltd., the same applies hereinafter), and the result was 66 mPa. s.

Using the inkjet ink 3, a substrate 3 on which a cured film pattern having a thickness of 10 μm was formed was obtained in the same manner as in Example 1.

[Comparative Example 2]

A resin comprising a polymer of vinyl phenol, which is a phenolic resin-based phenol resin, which is a phenolic resin, is used as a resin, and is a composition ratio of the following composition ratio. An inkjet ink 4 was prepared in the same manner as in Example 1.

The viscosity of the inkjet ink 4 at 25 ° C was measured using an E-type viscometer (TV-22 manufactured by Toki Sangyo Co., Ltd., the same applies hereinafter), and the result was 92 mPa. s.

Using the inkjet ink 4, a substrate 4 on which a cured film pattern having a thickness of 10 μm was formed was obtained in the same manner as in Example 1.

[Comparative Example 3]

The same procedure as in Example 1 was carried out, except that Maruka Lyncur M S-4G (trade name; manufactured by Maruzen Petrochemical Co., Ltd., weight average molecular weight: 9,000-11,000) was used as the polyvinyl phenol, and the following composition ratio was used. The inkjet ink 5 was prepared in a manner.

The viscosity of the inkjet ink 5 at 25 ° C was measured using an E-type viscometer (TV-22 manufactured by Toki Sangyo Co., Ltd., the same applies hereinafter), and the result was 47 mPa. s.

Using the inkjet ink 5, a substrate 5 on which a cured film pattern having a thickness of 10 μm was formed was obtained in the same manner as in Example 1.

<Evaluation of inkjet ink and patterned cured film>

Next, the discharge property of the inkjet ink, the curability of the cured film, the etching resistance, the plating resistance, and the alkali peelability were evaluated. Each test method is as follows, and the evaluation results are shown in Table 1.

Ink ejection test

The disorder of the pattern on the obtained substrates 1 to 5 and the scratches of the printing were observed, and the discharge property of the ink was evaluated. The evaluation criteria are as follows.

◎: completely without pattern confusion, printed scratches.

○: There is almost no pattern of confusion and printed scratches.

△: There is a slight confusion in the pattern and a scratch on the print.

×: The pattern is confusing, and the printed scratches are many.

Membrane hardening test

The surface of the substrate was touched by a finger, and the surface state of the cured film was observed with a microscope. The evaluation criteria are as follows.

○: There is no trace of finger contact on the surface of the cured film.

△: There are few traces of finger contact remaining on the surface of the cured film.

×: The trace of the finger contact completely remains on the surface of the cured film.

Etch resistance test

The substrate was immersed in a 13% FeCl ₃ aqueous solution at 50 ° C for 2 minutes, and the surface state of the cured film was observed with a microscope. The evaluation criteria are as follows.

◎: There was no change at all on the cured film.

○: Less discoloration was observed on the cured film, but no peeling was observed at all.

△: The cured film was completely discolored, and less peeling was also observed.

×: The cured film was completely peeled off.

Plating resistance test

The substrate was immersed in a commercially available electroless nickel plating solution (trade name: Nimden NPR-4, Ni concentration: 4.5 g/L, manufactured by Uemura Kogyo Co., Ltd.) at 60 ° C for 15 minutes, and the cured film was observed by a microscope. Surface state. Further, the same observation was carried out by immersing in an electroless gold plating solution (trade name: Goblite TAM-55, Au concentration: 1 g/L, manufactured by Uemura Industrial Co., Ltd.) at 90 ° C for 20 minutes. The evaluation criteria are as follows.

◎: There was no change at all on the cured film.

○: Less discoloration was observed on the cured film, but no peeling was observed at all.

△: The cured film was completely discolored, and less peeling was also observed.

×: The cured film was completely peeled off.

Alkaline stripping test

The substrate after the evaluation of the etching resistance was immersed in an aqueous NaOH solution having a concentration of 5% at 50 ° C for 1 minute, and the peeling property of the cured film was observed by a microscope. Further, at 50 ° C, the nickel plating resistance was first evaluated, and then the substrate after the gold plating resistance was evaluated was immersed in an aqueous NaOH solution having a concentration of 5% for 1 minute, and the peeling property of the cured film was observed by a microscope. The evaluation criteria are as follows.

◎: Completely peeled off.

○: Partial peeling.

×: Not peeled at all.

As is clear from the results shown in Table 1, in the substrates 1 to 2 of the present invention, almost no pattern turbulence or printing scratches were observed, and the ink ejection property was good. Moreover, the hardenability of the film which contacted the finger on the board|substrate 1 - 4 was evaluated, and the trace of the finger contact was not left in the surface of the cured film, and the hardenability of the film was favorable.

Further, the substrates 1 to 2 are excellent in etching resistance, nickel plating resistance, gold plating resistance, and alkali peeling resistance, and in particular, the substrate 2 is excellent in etching resistance, nickel plating resistance, and gold plating resistance, and the substrate 1 is additionally provided. 2 is excellent in alkaline peelability.

On the other hand, in Comparative Example 1 containing no resin (A), nickel plating resistance and gold plating resistance were poor, and discoloration was observed on the surface of the substrate after evaluation of nickel plating resistance and evaluation of gold plating resistance. Further, the alkali peelability was extremely poor, and it was not peeled at all.

In Comparative Example 2 in which a novolak-based phenol resin was used in place of the resin (A), the basic peeling property was extremely poor, and it was not peeled at all.

Further, in Comparative Example 3 in which polyvinylphenol having a molecular weight of 9,000 to 11,000 was used as the resin (A), the discharge property of the ink was inferior, and the printed pattern on the substrate 5 was disordered and scratched, and a uniform film could not be obtained. Therefore, the evaluation other than the discharge property of the ink is interrupted.

As described above, according to the present invention, it is possible to obtain an inkjet ink which can be subjected to alkaline peeling, which is excellent in ink discharge property, film curability, etching resistance, and plating resistance.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

Claims (19)

An ink for inkjet comprising a resin (A) represented by the following general formula (1) and a monomer or oligomer (B) having one or more carboxyl groups, and the weight of the resin (A) The average molecular weight is 1,000~8,000: (In the formula (1), X is a constituent unit derived from a radical polymerizable monomer, m is an integer of 1 or more, and n is a number of 0 to 100), wherein the single having a carboxyl group of 1 or more The bulk or oligomer (B) is an acid-modified epoxy (meth) acrylate. The ink for inkjet according to claim 1, wherein n is 0 in the resin (A). The inkjet ink according to the first or second aspect of the invention, wherein the resin (A) has a weight average molecular weight of 1,600 to 6,000. The inkjet ink according to the first or second aspect of the invention, further comprising: a diluent (C) and a photopolymerization initiator (D). The ink for inkjet according to item 4 of the patent application, wherein the tree The content of the lipid (A) is from 0.5% by weight to 20% by weight. The ink for inkjet according to claim 1, wherein the monomer or oligomer (B) having one or more carboxyl groups is a monofunctional (meth) acrylate or a polyfunctional (meth) acrylate. . The ink for inkjet according to claim 1, wherein the monomer or oligomer (B) having one or more carboxyl groups is an acid-modified epoxy acrylate having a weight average molecular weight of 300 to 12,000. The ink for inkjet according to claim 1, wherein the monomer or oligomer (B) having one or more carboxyl groups is a bisphenol F-type acid-modified epoxy acrylate. The ink for inkjet according to claim 4, wherein the diluent (C) has a viscosity of 0.1 mPa at 25 ° C. s~100mPa. s. The ink for inkjet according to Item 4, wherein the diluent (C) is a monofunctional (meth) acrylate or a polyfunctional (meth) acrylate having no carboxyl group. The inkjet ink according to Item 4, wherein the diluent (C) is a carboxyl group-free monofunctional (meth) acrylate represented by the formula (2): (In the formula (2), R ¹ is hydrogen or an alkyl group having 1 to 3 carbon atoms, and R ² is an alkylene group having 1 to 12 carbon atoms which may have a cyclic structure, and n is 1 to 30. Integer). The inkjet ink according to Item 4, wherein the resin (A) is a polyvinylphenol having a weight average molecular weight of 4,000 to 6,000, and the monomer or oligomer (B) having one or more carboxyl groups is a bisphenol F type acid-modified epoxy acrylate having a weight average molecular weight of 500 to 11,000, a diluent (C) of 2-hydroxyethyl (meth)acrylate, and a photopolymerization initiator (D) of 2, 4 , 6-trimethylbenzimidyldiphenylphosphine oxide. The ink for inkjet according to claim 4, wherein the viscosity at 25 ° C is 2 mPa. s~200mPa. s. A method of forming a cured film by applying an inkjet ink according to any one of claims 1 to 13 to a substrate by an inkjet method, and irradiating the applied ink Light, thereby forming a cured film. A cured film obtained by the inkjet ink according to any one of claims 1 to 13. The cured film according to claim 15, which is formed into a pattern. A method for producing a substrate comprising: a step of forming a resist film or a plating resist film using a cured film as described in claim 16; an etching step or a plating step thereafter; and a subsequent peeling The step of the above film. An electronic component having a substrate obtained by the method of claim 17 of the patent application. A display element having the 18th item of the patent application scope The electronic parts described.