CN114651020A - Thermosetting composition and thermosetting inkjet ink - Google Patents

Abstract

The present invention addresses the problem of providing a thermosetting composition having excellent storage stability at high temperatures and excellent thermosetting properties on the surface of a cured film at high temperatures and high humidity, and a thermosetting inkjet ink using the same. The thermosetting composition of the present invention is a thermosetting composition containing a blocked isocyanate (a), and is characterized by containing: the composition comprises a compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (A), and a (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate, wherein the compound (B) is contained in an amount of 0.1 to 20 parts by mass and the blocked isocyanate (A) is contained in an amount of 0.1 to 20 parts by mass, based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C).

Description

Thermosetting composition and thermosetting inkjet ink

Technical Field

The present invention relates to a thermosetting composition and a thermosetting inkjet ink, and more particularly, to a thermosetting composition having excellent storage stability at high temperatures and excellent thermosetting properties on the surface of a cured film at high temperatures and high humidity, and a thermosetting inkjet ink using the same.

Background

Poly (meth) acrylate resins (hereinafter also referred to as "acrylic resins") have high transparency and impact resistance, and are easily thermoformed and colored, and therefore, they are used in various applications as substitutes for inorganic glass, for window materials for buildings and vehicles, and also as parts for electric and electronic devices, daily necessities, office supplies, and the like.

The acrylic resin can be produced by: a radical generator that generates radicals by irradiation with active energy rays such as ultraviolet rays or electron beams is added to the (meth) acrylate to perform radical polymerization (crosslinking reaction). The (meth) acrylate may be produced by radical polymerization by adding a peroxide to a (meth) acrylate and heating the mixture.

For example, patent document 1 describes a curable composition used in a method for producing a poly (meth) acrylate by polymerizing a monomer having a (meth) acrylate in the presence of an isocyanate.

A polyurethane composition containing an acrylate having a functional group reactive with isocyanate is reported in patent document 2.

It is also known that a resist, a solder resist, and a mark of a printed circuit board are formed by forming a coating film using the thermosetting composition and the photocurable composition by a photolithography development method or a screen printing method.

As a method for manufacturing a printed circuit board using an ink jet printer, it has been proposed to form a resist on a copper-clad laminate for a printed wiring board by drawing a conductor circuit pattern using an ink jet printer and then perform etching treatment (see, for example, patent document 3). This method can significantly reduce the number of steps and time compared to a photolithography development method requiring a photomask and a screen printing method using a resist ink or a marking ink requiring a screen plate, and can reduce consumables such as a developer, various inks, and a cleaning solvent, and can reduce waste water, and therefore environmental cleanliness can be expected.

For solder resists, it has been proposed to form a cured film by light and heat using an ink jet system (see, for example, patent documents 4, 5, 6, and 7).

Specifically, patent document 6 discloses a photocurable and thermosetting composition containing: an acryloyl group-containing monomer, a blocked polyisocyanate having a triazine skeleton, and a photopolymerization initiator are used for printing by an inkjet method.

Further, patent document 7 discloses a white curable composition for a printed wiring board, which comprises: titanium oxide, a hydroxyl group-containing (meth) acrylate, a photopolymerization initiator, a wetting dispersant having an acid value, and a specific 2-functional (meth) acrylate compound (excluding a hydroxyl group-containing compound) are applied to copper wiring and a substrate.

However, in these thermosetting compositions and thermosetting inkjet inks, particularly, storage stability at high temperatures and thermosetting property of the surface of a cured film at high temperatures and high humidity are not sufficient, and improvement is desired.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6259394

Patent document 2: japanese Kokai publication No. 2010-523775

Patent document 3: japanese patent No. 5731746

Patent document 4: japanese patent No. 4936725

Patent document 5: japanese patent No. 5969208

Patent document 6: japanese patent No. 6069300

Patent document 7: japanese patent No. 6488345

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above problems and circumstances, and an object of the present invention is to provide a thermosetting composition having excellent storage stability at high temperatures and excellent thermosetting properties on the surface of a cured film at high temperatures and high humidity, and a thermosetting inkjet ink using the same.

Means for solving the problems

In order to achieve the above object, the present inventors have found, in the course of research on the causes of the above problems and the like: the present inventors have found that by incorporating a specific amount of a compound (B) having a functional group capable of forming a hydrogen bond with a blocked isocyanate (a) into a thermosetting composition containing a blocked isocyanate (a) and a poly (meth) acrylate (C), the storage stability at high temperatures can be greatly improved, and the thermosetting property of the surface of a cured film at high temperatures and high humidity can be improved, and have completed the present invention.

That is, the above problem according to the present invention is solved by the following means.

1. A thermosetting composition containing a blocked isocyanate (A), characterized by containing: the composition comprises a compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (A), and a (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate, wherein the compound (B) is contained in an amount of 0.1 to 20 parts by mass and the blocked isocyanate (A) is contained in an amount of 0.1 to 20 parts by mass, based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C).

2. The thermosetting composition according to claim 1, which contains a photopolymerization initiator.

3. The thermosetting composition according to claim 1 or 2, wherein the compound (B) has at least one functional group capable of forming a hydrogen bond with the blocked isocyanate (A) selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group and a mercapto group.

4. The thermosetting composition according to claim 3, wherein the compound (B) is a monomer containing a (meth) acryloyl group.

5. The thermosetting composition according to any one of items 1 to 4, wherein the compound (B) is contained in an amount of 1 to 10 parts by mass based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C).

6. A heat-curable ink jet ink comprising the heat-curable composition according to any one of items 1 to 5.

7. The heat-curable inkjet ink according to claim 6, which contains a gelling agent and undergoes a sol-gel phase transition depending on the temperature.

8. The thermosetting inkjet ink according to claim 7, wherein the viscosity at 25 ℃ is 1 to 1X 10⁴Pa · s at a temperature of 40 ℃ or higher and less than 100 ℃ to cause the sol-gel phase transition.

9. The thermosetting inkjet ink according to claim 7 or 8, wherein the gelling agent is a compound having a structure represented by the following general formula (G1) or general formula (G2),

general formula (G1): r₁-CO-R₂

General formula (G2): r₃-COO-R₄

In the formula, R₁～R₄Each independently represents a linear chain portion having 12 or more carbon atoms and may have a branched alkyl chain.

10. The thermosetting inkjet ink according to any one of items 6 to 9, which is a thermosetting inkjet ink for forming a solder resist pattern for a printed circuit board.

ADVANTAGEOUS EFFECTS OF INVENTION

The above-described means of the present invention can provide a thermosetting composition having excellent storage stability at high temperatures and excellent thermosetting properties of the surface of a cured film at high temperatures and high humidity, and a thermosetting inkjet ink using the same.

The mechanism of the effect of the present invention, or the mechanism of action, is not clear, and is presumed as follows.

The stability of the blocked isocyanate (A) is illustrated by the following Structure 1. The structure 1 represents a structure in which a blocked isocyanate (a) in which a terminal isocyanate group is blocked with a blocking group and a compound (B) having an active hydrogen bond are hydrogen bonded.

It is presumed that the blocked isocyanate (a) and the compound (B) form a stable six-membered ring structure as shown in the following structure 1 by forming a hydrogen bond in the compound (B) having a functional group capable of forming a hydrogen bond (having an active hydrogen atom) with the blocked isocyanate (a) at a site of R — NHC (═ O) -Block (Block represents a blocking group) of the blocked isocyanate (a), and thus the storage stability at high temperature can be improved. Preferably, R represents a residue of a blocked isocyanate group, R' represents a residue of a functional group (XH) having an active hydrogen, and X represents an oxygen atom, a sulfur atom, or a nitrogen atom.

[ solution 1]

(Structure 1)

In addition, surprisingly, curability of the surface of the cured film under high temperature and high humidity is also improved. This is presumably because: when the blocking agent of the blocked isocyanate (a) is released during thermal curing, the isocyanate group reacts with the compound (B), and the R' site mainly composed of a hydrocarbon group of the compound (B) protrudes to the outside of the molecule, and is easily oriented on the surface of the cured film, whereby the hydrophobicity of the surface of the cured film is improved.

Detailed Description

The thermosetting composition of the present invention is a thermosetting composition containing a blocked isocyanate (a), and is characterized by containing: the composition comprises a compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (A), and a (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate, wherein the compound (B) is contained in an amount of 0.1 to 20 parts by mass and the blocked isocyanate (A) is contained in an amount of 0.1 to 20 parts by mass, based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C). This feature is a feature common to or corresponding to each embodiment (mode) described below.

In the embodiment of the present invention, a photopolymerization initiator is preferably contained from the viewpoint of improving curability of the surface of the cured film.

In addition, from the viewpoint of maintaining the curability of the film surface at a high level, it is preferable that the functional group of the compound (B) capable of forming a hydrogen bond with the blocked isocyanate (a) is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group and a mercapto group.

Further, in the present invention, it is preferable that the compound (B) is a (meth) acryloyl group-containing monomer. This can further increase the polymerization degree of the entire thermosetting composition, thereby improving the thermosetting property.

In the embodiment of the present invention, from the viewpoint of the effect of the present invention, it is preferable that the compound (B) is contained in an amount of 1 to 10 parts by mass based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C).

Further, an inkjet ink containing the thermosetting composition of the present invention is preferable.

Further, in the present invention, a thermosetting inkjet ink containing a gelling agent and undergoing a sol-gel phase transition depending on temperature is preferable. This improves the hydrophobicity of the cured film and provides an excellent curing property of the film surface under high temperature and high humidity.

The viscosity at 25 ℃ is preferably 1 to 1X 10 in view of the capability of ejecting the ink-jet ink at a low viscosity⁴The sol-gel phase transition is carried out at a temperature of 40 ℃ or higher and less than 100 ℃ in the range of Pa · s.

In addition, from the viewpoint of improving the hydrophobicity of the cured film and excellent curability of the film surface under high temperature and high humidity, it is preferable that the gelling agent is a compound having a structure represented by the general formula (G1) or the general formula (G2).

Further, the thermosetting inkjet ink of the present invention is preferably used for forming a solder resist pattern for a printed circuit board, from the viewpoint of obtaining a cured film having high surface hardness.

The present invention and its constituent elements, as well as the embodiments and modes for carrying out the present invention will be described in detail below. In the present application, "to" are used to include numerical values described before and after the "to" as the lower limit value and the upper limit value.

In the present invention, "(meth) acryloyl group" means an acryloyl group or a methacryloyl group, and "(meth) acrylate" means an acrylate or a methacrylate.

Outline of thermosetting composition

The thermosetting composition of the present invention is a thermosetting composition containing a blocked isocyanate (a), and is characterized by containing: the composition comprises a compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (A), and a (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate, wherein the compound (B) is contained in an amount of 0.1 to 20 parts by mass and the blocked isocyanate (A) is contained in an amount of 0.1 to 20 parts by mass, based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C).

The thermosetting composition and the thermosetting inkjet ink of the present invention use the blocked isocyanate (a) as a heat curing agent. The blocking agent for blocking the isocyanate (A) is removed by heating at a high temperature, for example, 110 to 180 ℃ for 10 to 60 minutes, thereby initiating thermal curing. However, in practice, the blocking agent is removed from the reaction mixture at a temperature of about 80 ℃ which is lower than the above temperature, and the reaction proceeds little by little, resulting in a problem of an increase in viscosity. This problem is improved by increasing the dissociation temperature of the end-capping agent, but if so, thermosetting properties become insufficient.

Therefore, in the present invention, by allowing the compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate to interact with the blocked isocyanate (a) having a dissociation temperature in the above temperature range, it has been successfully achieved to achieve both storage stability at high temperature and curability.

Further, it is preferable that the number of — NCO functional groups of the blocked isocyanate is the same as the number of sites having active hydrogen of the compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (the same mol number), and it is known that: for example, the effect of the present invention can be obtained even when 1mol of the compound (B) having 1 active hydrogen-containing site is used per 1mol of the 3-functional blocked isocyanate compound. This is presumably because when the compound acts on R — NHC (═ O) -Block, the charge balance of the whole blocked isocyanate molecule is lost.

On the other hand, since a large amount of the hydrophilic compound (B) having a functional group capable of forming a hydrogen bond is contained, and particularly, is easily affected by high temperature and high humidity, there is a possibility that the curability of the film surface is lowered, but in the present invention, the compound (B) having a functional group capable of forming a hydrogen bond with a blocked isocyanate is contained in an amount of 0.1 to 20 parts by mass relative to the (meth) acryloyl group-containing monomer (C) having no functional group capable of reacting with a blocked isocyanate, which is a majority of the thermosetting composition and the thermosetting inkjet ink, and the blocked isocyanate (a) is contained in an amount of 0.1 to 20 parts by mass relative to 100 parts by mass of the (meth) acryloyl group-containing monomer (C), thereby solving the problem of the lowered curability of the film surface.

In the present invention, it is preferable to use a photopolymerization initiator in combination. By using a photopolymerization initiator in combination, the polymerization degree of the cured film can be increased, and further, the curability of the surface of the cured film under high temperature and high humidity can be improved. This is presumably because, when the (meth) acryloyl group-containing monomer (C) is polymerized by light irradiation, the viscosity in the film increases, the low molecular weight blocked isocyanate (a) and the compound (B) are relatively extruded to the surface of the cured film, and then the blocking agent of the blocked isocyanate (a) is released at the time of thermal curing as described above, the isocyanate group reacts with the compound (B), the R 'site mainly composed of a hydrocarbon group of the compound (B) protrudes to the outside of the molecule, and the R' site is easily oriented on the surface of the cured film, whereby the hydrophobicity of the surface of the cured film is further improved.

In addition, the compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate according to the present invention is preferably at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group and a mercapto group. It is presumed that the compound has high nucleophilicity and acts efficiently on the R — NHC (═ O) -Block site of the blocked isocyanate (a) to effectively Block the isocyanate group.

In the present invention, a gelling agent is preferably included. The reason for this is presumed: the site of the gelling agent composed of a linear or branched long-chain hydrocarbon group is likely to be in affinity with R mainly composed of a hydrocarbon group of R — NHC (═ O) -Block of the blocked isocyanate, and thus the site of — NHC (═ O) -Block is likely to protrude to the outside of the molecule, and the compound (B) according to the present invention is likely to interact with each other. In addition, it is presumed that: since the hydrophobicity of the cured film is improved, the surface of the cured film under high temperature and high humidity is excellent in thermosetting property.

Details of thermosetting compositions

Hereinafter, the thermosetting composition of the present invention will be described in detail with respect to its constitution and the like.

[ blocked isocyanate (A) ]

In the present invention, a blocked isocyanate (a) having an isocyanate group protected with a thermally dissociative blocking agent is used. By using such a blocked isocyanate (a) in a thermosetting composition, the storage stability at high temperatures can be improved. The compound having an isocyanate group is preferably a polyfunctional isocyanate having 2 or more isocyanate groups in the molecule.

(polyfunctional isocyanate)

The polyfunctional isocyanate is not particularly limited as long as it is a compound having 2 or more isocyanate groups in the molecule.

Specific examples thereof include aromatic polyisocyanates such as 2, 4-tolylene diisocyanate (2, 4-TDI), 2, 6-tolylene diisocyanate (2, 6-TDI), 4 '-diphenylmethane diisocyanate (4, 4' -MDI), 2, 4 '-diphenylmethane diisocyanate (2, 4' -MDI), 1, 4-phenylene diisocyanate, Xylylene Diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), dimethylbiphenyl diisocyanate (TODI), and 1, 5-Naphthalene Diisocyanate (NDI); aliphatic polyisocyanates such as Hexamethylene Diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, and norbornane diisocyanate methyl ester (NBDI); alicyclic polyisocyanates such as trans-cyclohexane-1, 4-diisocyanate, isophorone diisocyanate (IPDI), H6XDI (hydrogenated XDI), H12MDI (hydrogenated MDI), and H6TDI (hydrogenated TDI); polyisocyanates such as polymethylene polyphenylene polyisocyanate; biuret, isocyanurate, and carbodiimide-modified products of these compounds.

In the present invention, any one of these isocyanates may be used alone, or two or more kinds thereof may be used.

(blocking agent)

Known blocking agents can be used. Examples thereof include alcohols such as ethanol, N-propanol, isopropanol, t-butanol and isobutanol, phenols such as phenol, chlorophenol, cresol, xylenol and p-nitrophenol, alkylphenols such as p-tert-butylphenol, p-sec-aminophenol, p-octylphenol and p-nonylphenol, basic nitrogen-containing compounds such as 3-hydroxypyridine, 8-hydroxyquinoline and 8-hydroxy, active methylene compounds such as diethyl malonate, ethyl acetoacetate and acetylacetone, amides such as acetamide, acrylamide and acetanilide, imides such as succinimide and maleimide, pyrazoles such as 2-ethylimidazole and 2-ethyl-4-methylimidazole, imidazoles such as pyrazole, 3-methylpyrazole and 3, 5-dimethylpyrazole, pyrazoles such as pyrazole, and the like, Lactams such as 2-pyrrolidone and epsilon-caprolactam, oximes of ketones or aldehydes such as acetone oxime, methyl ethyl ketone oxime, cyclohexanone oxime and acetaldehyde oxime, aziridine and bisulfite, and the like.

In terms of ink preservability and thermal releasability, the thermally releasable blocking agent is preferably at least one compound selected from the group consisting of oxime compounds, pyrazole compounds and active ethylene compounds.

Examples of the oxime compound include formamide oxime, acetaldoxime, acetoxime, methylethylketoxime, and cyclohexanone oxime.

Examples of the pyrazole compound include pyrazole, 3-methylpyrazole, 3, 5-dimethylpyrazole and the like.

Examples of the active ethylene compound include dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone.

Examples of the polyfunctional isocyanate compound having an isocyanate group protected with the blocking agent include 2- [ (3, 5-dimethylpyrazolyl) carbonylamino ] ethyl methacrylate, 2- [ (3-butylene) aminooxycarbonylamino ] ethyl methacrylate, 2- [ (3, 5-dimethylpyrazolyl) carbonylamino ] ethyl acrylate, and 2- [ (3-butylene) aminooxycarbonylamino ] ethyl acrylate.

The content of the blocked isocyanate (a) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C). When the amount of (a) is less than 0.1 part by mass, thermal curing is insufficient, and when it is more than 20 parts by mass, the storage stability at high temperatures of the thermosetting composition and the thermal ink-jet ink is lowered.

One or more of the blocking agents may be used alone or in combination, and a plurality of blocked isocyanates blocked with one or more of the blocking agents may be used.

Examples of commercially available products of the blocked isocyanate include BI7961, BI7992 (both manufactured by Baxenden Co., Ltd.), MF-K60X (manufactured by Asahi Kasei- ケミカルズ Co., Ltd.), VPLS2253, BL 423865 4265SN (both manufactured by Suzushi バイエルウレタン Co., Ltd.).

[ Compound (B) having a functional group capable of forming a hydrogen bond with a blocked isocyanate ]

The "functional group capable of forming a hydrogen bond with the blocked isocyanate" in the present invention is a functional group having an active hydrogen, and examples thereof include a hydroxyl group, a carboxyl group, an amino group and a mercapto group.

The hydroxyl group is preferably an alcohol having 1 to 18 carbon atoms, a phenol, or a (meth) acrylate having a hydroxyl group. Specific examples thereof include phenol, p-cresol, ethyl salicylate, ethyl p-hydroxybenzoate, propylene glycol, and propylene glycol monomethyl ether.

The carboxyl group is preferably an aliphatic carboxylic acid or an aromatic carboxylic acid having 1 to 18 carbon atoms. Specifically, benzoic acid and the like are listed.

The amino group is preferably a primary amine or a secondary amine, and examples thereof include aliphatic amines and aromatic amines having from C1 to C18. Specific examples thereof include aniline and acetanilide.

The mercapto group is preferably an aliphatic thiol or an aromatic thiol having 1 to 18 carbon atoms, and specifically, 1-butanethiol or thiophenol is exemplified.

Further, in the present invention, it is preferable that the compound (B) is a (meth) acryloyl group-containing monomer. The monomer having a (meth) acryloyl group is preferably an acrylate.

Examples of the monofunctional (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 1-methyl-2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxymethylcyclohexylmethyl (meth) acrylate, p-hydroxymethylphenylmethyl (meth) acrylate, 2- (hydroxyethoxy) ethyl (meth) acrylate, 2- (hydroxyethoxyethoxy) ethyl (meth) acrylate, and mixtures thereof, Methyl α -hydroxymethylmethacrylate, ethyl α -hydroxymethylmethacrylate, hydroxyalkyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and the like.

Examples of the polyfunctional (meth) acrylate having a hydroxyl group include 2-hydroxy-3-acryloyloxypropyl methacrylate, dipentaerythritol penta (meth) acrylate, ethylene oxide-added pentaerythritol tetra (meth) acrylate, trimethylolpropane diacrylate, glycerol di (meth) acrylate, glycerol acrylate methacrylate, pentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol propionate, hydroxypivalaldehyde-modified dimethylolpropane tri (meth) acrylate, sorbitol tetra (meth) acrylate, sorbitol penta (meth) acrylate, pentaerythritol tri (meth) acrylate and the like.

When the functional group capable of forming a hydrogen bond with the blocked isocyanate (a) is a hydroxyl group, the compound (B) is preferably a compound represented by the following general formula (1) or a polyfunctional acrylate having a hydroxyl group.

General formula (1) Z-R₄-OH

(in the general formula (1), Z represents CH₂＝CR₁-COO-。R₁Represents a hydrogen atom or a methyl group. R₄Represents an organic residue containing carbon atoms in the range of 2 to 20. )

In the above general formula (1), R is represented by₄The organic residue is preferably a C2-20 linear, branched or cyclic alkylene group, a C2-20 alkylene group having an oxygen atom in the structure thereof via an ether bond and/or an ester bond, or a C6-11 optionally substituted aromatic group. Among these, preferred are linear, branched or cyclic alkylene groups having 2 to 6 carbon atoms, and alkylene groups having 2 to 9 carbon atoms which have an oxygen atom in the structure thereof through an ether bond.

Specific examples of the compound (B) represented by the above general formula (1) include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 1-methyl-2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxymethylcyclohexylmethyl (meth) acrylate, p-hydroxymethylphenylmethyl (meth) acrylate, 2- (hydroxyethoxy) ethyl (meth) acrylate, 2- (hydroxyethoxyethoxy) ethyl (meth) acrylate, and mixtures thereof, 2-hydroxy-3-phenoxypropyl acrylate, and the like.

As the multifunctional acrylate having a hydroxyl group, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, and the like are included.

More preferred specific examples of the compound (B) include alicyclic carboxylic acid epoxy acrylates such as 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate or pentaerythritol triacrylate, and acrylic modifications of glycidyl hexahydrodiphthalate, and dipentaerythritol pentaacrylate, and among them pentaerythritol triacrylate is preferred from the viewpoint of curing speed.

Examples of the (meth) acryloyl group-containing monomer having a carboxyl group include acrylic acid and methacrylic acid.

The content of the compound (B) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, of the blocked isocyanate (a) per 100 parts by mass of the (meth) acryloyl group-containing monomer (C). When the content of the compound (B) is less than 0.1 part by mass, the storage stability at high temperature is poor, and when it is contained in an amount of more than 20 parts by mass, the curability of the thermosetting composition and the cured film of the thermal ink-jet ink under high temperature and high humidity is lowered.

[ monomer (C) containing a (meth) acryloyl group having no functional group reactive with a blocked isocyanate ]

In the present invention, the (meth) acryloyl group-containing monomer (C) having no functional group reactive with a blocked isocyanate has 1 or more (meth) acryloyl groups in 1 molecule.

The (meth) acryloyl group-containing monomer is a compound having no functional group reactive with isocyanate. The functional group reactive with isocyanate is described for the compound (B).

Examples of the (meth) acrylate used in the present invention include monofunctional (meth) acrylates such as 2- (2-ethoxyethoxy) ethyl (meth) acrylate, butyl (meth) acrylate, stearyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate, and 2-phenoxyethyl (meth) acrylate, and difunctional (meth) acrylates such as 1, 3-butanediol di (meth) acrylate, 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, and neopentyl glycol diacrylate, and the like, And polyfunctional (meth) acrylate compounds of trifunctional (meth) acrylates such as trimethylolpropane triacrylate and tetrafunctional or higher (meth) acrylates such as ditrimethylolpropane tetraacrylate and dipentaerythritol hexaacrylate.

The monomer having a (meth) acryloyl group may be used alone or in combination of 2 or more.

[ gelling agent ]

The gelling agent according to the present invention is preferably held in a state of being uniformly dispersed in a cured film cured by light and heat, whereby penetration of moisture into the cured film can be prevented.

Such a gelling agent is preferably at least one compound of the compounds represented by the following general formula (G1) or (G2) in order to disperse the gelling agent in a cured film without inhibiting the curability of the ink. Further, in the ink jet printing, it is preferable that the fixing property is good, that drawing of a thin line and a film thickness can be performed, and that the thin line reproducibility is excellent.

General formula (G1): r₁-CO-R₂

General formula (G2): r₃-COO-R₄

(in the formula, R₁～R₄Each independently represents an alkyl chain having a straight chain portion of 12 or more carbon atoms and may have a branch. )

Since the ketone wax represented by the general formula (G1) or the ester wax represented by the general formula (G2) has a linear or branched hydrocarbon group (alkyl chain) having 12 or more carbon atoms, the crystallinity of the gelling agent is further improved, the water resistance is improved, and a more sufficient space is created in the following barn structure. Therefore, it is easy to sufficiently enclose the ink medium such as the solvent and the photopolymerizable compound in the space, and the fixing property of the ink is further improved.

The number of carbons of the linear or branched hydrocarbon group (alkyl chain) is preferably 26 or less, and if 26 or less, the melting point of the gelling agent is not excessively increased, so that it is not necessary to excessively heat the ink when the ink is ejected.

From the above viewpoint, R is particularly preferable₁And R₂Or, R₃And R₄Is a linear hydrocarbon group having 12 to 23 carbon atoms.

In addition, from the viewpoint of increasing the gel temperature of the ink and gelling the ink more rapidly after the ink bounces, R is preferable₁Or R₂Any one of (1), or R₃Or R₄Any of the above is a saturated hydrocarbon group having 12 to 23 carbon atoms.

From the above viewpoint, R is more preferable₁And R₂Both of them, or, R₃And R₄Both of these are saturated hydrocarbon groups having 11 or more and less than 23 carbon atoms.

Examples of the ketone wax represented by the above general formula (G1) include ditosyl (tetracosyl) ketone (C24-C24), dibosyl (C22-C22), distearyl ketone (C18-C18), dieicosyl (C18-C18), dipalmityl ketone (C18-C18), dimyristyl ketone (C18-C18), dilauryl ketone (C18-C18), lauryl myristyl ketone (C18-C18), lauryl palmityl ketone (C18-C18), myristyl palmityl ketone (C18-C18), myristyl stearyl ketone (C18-C18), myristyl behenyl (C18-C18), palmityl stearyl ketone (C18-C18), palmityl behenyl ketone (C18-C18), and behenyl (C18-C18). The carbon number in the parentheses indicates the carbon number of each of the two hydrocarbon groups separated by the carbonyl group.

Examples of commercially available ketone waxes represented by the general formula (G1) include Stearone (manufactured by Alfa Aeser Co., Ltd.; ステアロン), 18-pentatricoutanon (manufactured by Alfa Aeser Co., Ltd.), Hentriacontan-16-on (manufactured by Alfa Aeser Co., Ltd.), and Kao wax T-1 (manufactured by Kao corporation).

Examples of the fatty acid or ester wax represented by general formula (G2) include behenyl behenate (C21-C22), eicosanoic acid eicosyl ester (C19-C20), stearyl stearate (C17-C18), palmityl stearate (C17-C16), lauryl stearate (C17-C12), cetyl palmitate (C15-C16), stearyl palmitate (C15-C18), myristyl myristate (C13-C14), cetyl myristate (C13-C16), octyldodecyl myristate (C13-C20), stearyl oleate (C17-C18), stearyl stearate (C21-C18), stearyl linoleate (C17-C18), behenyl oleate (C18-C22), and eicosyl linoleate (C17-C20). The carbon number in the parentheses indicates the carbon number of each of the two hydrocarbon groups separated by the ester group.

Examples of commercially available ester waxes represented by the general formula (G2) include ユニスター M-2222SL and スパームアセチ, manufactured by Nissan oil company ("ユニスター" is a registered trademark of this company), エキセパール SS and エキセパール MY-M, manufactured by Kao corporation ("エキセパール" is a registered trademark of this company), EMALEX CC-18 and EMALEX CC-10, manufactured by Japanese エマルジョン company ("EMALEX" is a registered trademark of this company), アムレプス PC, and manufactured by advanced アルコール industries ("アムレプス" is a registered trademark of this company).

Since many of these commercially available products are mixtures of 2 or more species, the ink can be separated and purified as necessary. Among these gelling agents, ketone waxes, ester waxes, higher fatty acids, higher alcohols, and fatty acid amides are preferable from the viewpoint of further improving the fixability.

The content of the gelling agent according to the present invention is preferably in the range of 0.5 to 5.0 mass% with respect to the total mass of the ink. When the content of the gelling agent is within the above range, the effect of the gelling agent on the solubility and immobilization of the solvent component is improved, and the water resistance when a cured film is formed is improved. From the above viewpoint, the content of the gelling agent in the inkjet ink is more preferably in the range of 0.5 to 2.5 mass%.

In addition, from the following viewpoint, it is preferable that the gelling agent is crystallized in the ink at a temperature equal to or lower than the gel temperature of the ink. The gelation temperature is a temperature at which a phase of a gelling agent changes from sol to gel when an ink that is melted or liquefied by heating is cooled, and the viscosity of the ink changes rapidly. Specifically, for a sol or liquid ink, a temperature at which the viscosity rapidly increases when the ink is cooled while measuring the viscosity using a viscoelasticity measuring apparatus (for example, MCR300, manufactured by Physica corporation) can be set as the gel temperature of the ink.

[ photopolymerization initiator ]

In the photopolymerization initiator according to the present invention, when the photopolymerizable compound is a radical polymerizable compound, a photo radical initiator is preferably used, and when the photopolymerizable compound is a cation polymerizable compound, a photoacid generator is preferably used.

The photopolymerization initiator may be contained in the thermosetting inkjet ink of the present invention alone, or may be contained in two or more kinds.

The photopolymerization initiator may be a combination of both a photo radical initiator and a photoacid generator.

The photo radical initiator includes a cleavage type radical initiator and a hydrogen abstraction type radical initiator.

Examples of the cleavage type radical initiator include acetophenone-based initiators, benzoin-based initiators, acylphosphine oxide-based initiators, benzil and methylphenylglyoxylate.

Examples of the acetophenone-based initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzildimethylketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone.

Examples of the benzoin-based initiator include benzoin, benzoin methyl ether, and benzoin isopropyl ether.

In the case of the acylphosphine oxide-based initiator, 2, 4, 6-trimethylbenzoin diphenylphosphine oxide is contained.

Examples of the hydrogen abstraction-type radical initiator include benzophenone-based initiators, thioxanthone-based initiators, aminobenzophenone-based initiators, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9, 10-phenanthrenequinone, and camphorquinone.

Examples of the benzophenone-based initiator include benzophenone, methyl o-benzoylbenzoate-4-phenylbenzophenone, 4, 4 ' -dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4 ' -methyl-diphenylsulfide, acrylated benzophenone, 3 ', 4, 4 ' -tetrakis (t-butylperoxycarbonyl) benzophenone, and 3, 3 ' -dimethyl-4-methoxybenzophenone.

Examples of the thioxanthone-based initiator include 2-isopropylthioxanthone, 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone and 2, 4-dichlorothioxanthone.

Examples of the aminobenzophenone-based initiator include Michler's ketone and 4, 4' -diethylaminobenzophenone.

Examples of the photoacid generator include compounds described in the institute of organic electronics materials, organic materials for imaging, Wen Xin publication (1993), pages 187 to 192.

The content of the photopolymerization initiator may be in a range in which the ink can be sufficiently cured, and for example, may be in a range of 0.01 to 10% by mass with respect to the total mass of the thermosetting inkjet ink of the present invention (hereinafter, also simply referred to as the ink of the present invention).

Examples of commercially available photopolymerization initiators include Irgacure TPO (manufactured by BASF), 819 (manufactured by BASF), Irgacure 379 (manufactured by BASF), Genocure ITX (manufactured by Rahn a.g.) Genocure EPD (manufactured by Rahn a.g.).

The ink of the present invention may further contain a photopolymerization initiator aid, a polymerization inhibitor, and the like as necessary.

The photopolymerization initiator assistant may be a tertiary amine compound, preferably an aromatic tertiary amine compound.

Examples of the aromatic tertiary amine compound include N, N-dimethylaniline, N-diethylaniline, N-dimethyl-p-toluidine, N-dimethylamino-ethyl-terephthalate, N-dimethylamino-isoamyl-terephthalate, N-dihydroxyethylaniline, triethylamine, N-dimethylhexylamine, and the like. Among them, N-dimethylamino-ethyl terephthalate and N, N-dimethylamino-isoamyl terephthalate are preferable. These compounds may be used alone or in combination of two or more.

[ coloring agent ]

The ink of the present invention may further contain a colorant as needed.

The colorant may be a dye or a pigment, and is preferably a pigment in view of good dispersibility in the constituent components of the ink and excellent weather resistance. The pigment is not particularly limited, and examples thereof include organic pigments and inorganic pigments of the following numbers described in the color index.

In the case of red or magenta pigments, pigments selected from pigment red 3, 5, 19, 22, 31, 38, 43, 48: 1. 48: 2. 48: 3. 48: 4. 48: 5. 49: 1. 53: 1. 57: 1. 57: 2. 58: 4. 63: 1. 81, 81: 1. 81: 2. 81: 3. 81: 4. 88, 104, 108, 112, 122, 123, 144, 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, pigment violet 3, 19, 23, 29, 30, 37, 50, 88, pigment orange 13, 16, 20, 36, or mixtures thereof, and the like.

In the case of blue or cyan pigments, pigments selected from the group consisting of pigment blue 1, 15: 1. 15: 2. 15: 3. 15: 4. 15: 6. 16, 17-1, 22, 27, 28, 29, 36, 60, mixtures thereof, and the like.

In the case of the green pigment, a pigment selected from pigment green 7, 26, 36, 50 or a mixture thereof is contained.

In the example of the yellow pigment, a pigment selected from pigment yellow1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193, a mixture thereof, or the like is contained.

Examples of the black pigment include pigments selected from pigment black 7, 28 and 26, mixtures thereof, and the like.

Examples of commercially available pigments include Black Pigment (manufactured by Mikuni corporation), CHROMOFINE YELLOW 2080, 5900, 5930, AF-1300, 2700L, CHROMOFINE ORANGE 3700L, 6730, CHROMOFINE SCARLET 6750, CHROMOFINE MAGENTA 6880, 6886, 6891N, 6790, 6887, CHROFINE VIOLET RE, CHROMOFINE D6820, 6830, CHROFINE BLUE HS-3, 5187, 5108, 5197, GREEN 5085N, SR-5020, 5026, 5050, 50520, 1103, 49327, 4937, 4824, 4933GN-EP, 4940, 4973, 2035, 5208, 2035214, 5221, 5000P, GREEN 2, GN 2, GO 550, GO 5310, 4970, 493, 4970, 4942, 5340, CHROFINE 5370, MAGE 533, 366370, MAGE 4742, CHROFINE SCARLE 4750, 366370, MAGENE 3, 366370, MAGE 3, 36638, MAGE 3, 366370, MAG 3, MAG-3, MAG 3, 366370, MAG 3, 36633, MAG 3, MAG, 1537B, GY, 4R-4016, 3820, 3891, ZA-215, SEIKAFAST CARMINE 6B1476T-7, 1483LT, 3840, 3870, SEIKAFAST BORDEAUX 10B-430, SEIKA LIGHT ROSE R40, SEIKA LIGHT VIOLET B800, 7805, SEIKAFAST MAROON 460N, SEIKAFAST ORANGE 900, 2900, SEIKA LIGHT BLUE C718, A612, CYANINE BLUE 4933M, 4933GN-EP, 4940, 4973 (manufactured by DAYI refining industries, Inc.); KET Yellow 401, 402, 403, 404, 405, 406, 416, 424, KET Orange 501, KET Red 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 336, 337, 338, 346, KET Blue 101, 102, 103, 104, 105, 106, 111, 118, 124, KET Green 201 (manufactured by DIC corporation); colortex Yellow 301, 314, 315, 316, P-624, 314, U10GN, U3GN, UNN, UA-414, U263, Finecol Yellow T-13, T-05, pigment Yellow 1705, Colortex Orange 202, Colortex Red101, 103, 115, 116, D3B, P-625, 102, H-1024, 105C, UFN, UCN, UBN, U3BN, URN, UGN, UG276, U456, U457, 105C, USN, Colortex Maroon601, Colortex Brown B610N, Colortex Violol 600, pigment Red 122, Colortex 516, 517, 518, 519, A818, P-908, 510, Colortex Green402, 403, Colortex Black 702, U905 (manufactured by Shanyang pigment Co., Ltd.); lionol Yellow1405G, Lionol Blue FG7330, FG7350, FG7400G, FG7405G, ES, ESP-S (manufactured by TOYOBO インキ Co., Ltd.), Toner Magenta E02, Permanent Rubin F6B, Toner Yellow HG, Permanent Yellow GG-02, and Hostapeam Blue B2G (manufactured by Hoechst Industry Co., Ltd.); novoperm P-HG, Hostaperm Pink E, Hostaperm Blue B2G (manufactured by Craine, supra); carbon blacks #2600, #2400, #2350, #2200, #1000, #990, #980, #970, #960, #950, #850, MCF88, #750, #650, MA600, MA7, MA8, MA11, MA100R, MA77, #52, #50, #47, #45L, #40, #33, #32, #30, #25, #20, #10, #5, #44, CF9 (manufactured by Mitsubishi chemistry, supra), and the like.

The dispersion of the pigment can be carried out using, for example, a ball mill, a sand mill, an attritor, a roll mill, a stirrer, a henschel mixer, a colloid mill, an ultrasonic homogenizer, a bead mill, a wet jet mill, a paint shaker, or the like.

The pigment is preferably dispersed so that the volume average particle diameter of the pigment particles is preferably in the range of 0.08 to 0.5. mu.m, and the maximum particle diameter is preferably in the range of 0.3 to 10 μm, and more preferably in the range of 0.3 to 3 μm.

The dispersion of the pigment is adjusted by selection of the pigment, the dispersant and the dispersion medium, dispersion conditions, filtration conditions and the like.

In order to improve the dispersibility of the pigment, the ink of the present invention may further contain a dispersant.

Examples of the dispersant include carboxylic acid esters having a hydroxyl group, salts of long-chain polyaminoamides and high-molecular-weight acid esters, salts of high-molecular-weight polycarboxylic acids, salts of long-chain polyaminoamides and polar acid esters, high-molecular-weight unsaturated acid esters, polymer copolymers, modified polyurethanes, modified polyacrylates, polyether ester type anionic active agents, naphthalenesulfonic acid formalin condensate salts, aromatic sulfonic acid formalin condensate salts, polyoxyethylene alkyl phosphate esters, polyoxyethylene nonylphenyl ether, and stearylamine acetate. Examples of commercially available dispersants include Solsperse series available from Avecia, PB series available from Aomoto ファインテクノ, and the like.

The ink of the present invention may further contain a dispersion aid as necessary. The dispersing aid may be selected according to the pigment.

The total amount of the dispersant and the dispersing aid is preferably in the range of 1 to 50% by mass relative to the pigment.

The ink of the present invention may further contain a dispersion medium for dispersing the pigment, as necessary. The ink may contain a solvent as a dispersion medium, and the photopolymerizable compound (particularly, a monomer having a low viscosity) is preferably used as the dispersion medium in order to suppress the solvent remaining in the formed image.

Examples of the dye include oil-soluble dyes.

The oil-soluble dyes include the following dyes. Examples of the Magenta dye include MS Magenta VP, MS Magenta HM-1450, MS Magenta HSo-147 (manufactured by Mitsui Chemicals Co., Ltd., above), AIZENSOT Red-1, AIZEN SOT Red-2, AIZEN SOTRed-3, AIZEN SOT Pink-1, SPIRON Red GEH SPECIAL (manufactured by Mitsui Chemicals Co., Ltd., above), RESOLIN Red FB 200%, MACROLEX Red Violet R, MACROLEX ROT5B (manufactured by Nippon Japan Co., Ltd., above), KAYASET Red B, KAYASET Red 130, KAYASET Red 802 (manufactured by Nippon Chemicals Co., Ltd., above), PHOXIN, ROSE BENGAL, ACID Red (manufactured by Nippon Kazaki corporation, Japan ダイワ), KAYASET Red B-31, DIARESRED K (manufactured by Mitsubishi corporation, and ZIP Red (manufactured by BASF corporation, Japan).

Examples of Cyan dyes include MS Cyan HM-1238, MS Cyan HSo-16, Cyan HSo-144, MS Cyan VPG (manufactured by Mitsui chemical Co., Ltd.), AIZEN SOT Blue-4 (manufactured by Baoku chemical Co., Ltd.), RESOLIN BR Blue BGLN 200%, MACROLEX Blue RR, CERES Blue GN, SIRIUS SUPRATURQ.blue Z-BGL, SIRIUS SUPRA TURQ.blue FB-LL 330% (manufactured by Bayer Japan), KAYASET Blue FR, KAYASET Blue N, KAYASET Blue 814, Turq.blue GL-5200, Light Blue BGL-5200 (manufactured by KANYASET corporation, supra), DAIWA Blue 7000, Oleosolsast Blue GL (manufactured by ダイワ corporation, supra), DIARESIN Blue P (manufactured by Mitsubishi corporation), SUDAN Blue 670, NEOPEN Blue 808, ZAPON Blue 806 (manufactured by BASF corporation, supra), and the like.

Examples of Yellow dyes include MS Yellow HSm-41, Yellow KX-7, Yellow EX-27 (manufactured by Mitsui Chemicals Co., Ltd.), AIZEN SOT Yellow-1, AIZEN SOT Yellow W-3, AIZEN SOT Yellow-6 (manufactured by Baogu Chemicals Co., Ltd.), MACROLEX Yellow 6G, MACROLEX FLUOR. Yellow 10GN (manufactured by Bayer Japan Co., Ltd.), KAYASET Yellow SF-G, KAYASET Yellow2G, KAYASET Yellow A-G, KAYASET Yellow E-G (manufactured by Nippon Chemicals Co., Ltd.), DAIWA Yellow 330HB (manufactured by ダイワ chemical Co., Ltd.), HSY-68 (manufactured by Mitsubishi chemical Co., Ltd.), SUDAN Yellow 146, NEOPEN Yellow (manufactured by BASF Japan Co., Ltd.), and the like.

Examples of the Black dye include MS Black VPC (manufactured by Mitsui chemical Co., Ltd.), AIZEN SOT Black-1, AIZEN SOT Black-5 (manufactured by Bao Tuo chemical Co., Ltd.), RESORIN Black GSN 200%, RESOLIN Black BS (manufactured by Japan Co., Ltd.), KAYASET Black A-N (manufactured by Japan chemical Co., Ltd.), DAIWA Black MSC (manufactured by ダイワ chemical Co., Ltd.), HSB-202 (manufactured by Mitsubishi chemical Co., Ltd.), NEPTUNE Black X60, NEOPEN Black X58 (manufactured by BASF Japan Co., Ltd.), and the like.

The colorant is contained in 1 kind or 2 or more kinds in the ink of the present invention, and can be toned to a desired color.

The content of the colorant is preferably in the range of 0.1 to 20% by mass, and more preferably in the range of 0.4 to 10% by mass, based on the total amount of the ink.

[ other ingredients ]

The ink of the present invention may further contain other components including a polymerization inhibitor and a surfactant, within a range in which the effects of the present invention are obtained. These components may be contained in the ink of the present invention in only 1 kind, or may be contained in 2 or more kinds.

(polymerization inhibitor)

Examples of the polymerization inhibitor include (alkyl) phenols, hydroquinones, catechols, resorcinols, p-methoxyphenols, t-butylcatechols, t-butylhydroquinones, pyrogallols, 1-picrylhydrazines, phenothiazines, p-benzoquinones, nitrosobenzenes, 2, 5-di-t-butyl-p-benzoquinones, dithiobenzoyl disulfides, picric acid, cupferron, N-nitrosophenylhydroxyaminoaluminum, tri-p-nitrophenylmethyl, N- (3-oxyanilino-1, 3-dimethylbutylene) aniline oxide, dibutylcresol, cyclohexanone oxime cresol, guaiacol, o-isopropylphenol, butyraldehyde oxime, methyl ethyl ketone oxime and cyclohexanone oxime.

Examples of commercially available polymerization inhibitors include Irgastab UV10 (manufactured by BASF), Genorad 18 (manufactured by Rahn a.g.).

The amount of the polymerization inhibitor can be arbitrarily set within a range in which the effects of the present invention are obtained. The amount of the polymerization inhibitor can be set to, for example, 0.001 mass% or more and less than 1.0 mass% with respect to the total mass of the ink.

(surfactant)

Examples of the surfactant include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates, and fatty acid salts, nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and polyoxyethylene-polyoxypropylene block copolymers, cationic surfactants such as alkylamine salts and quaternary ammonium salts, and silicone surfactants and fluorine surfactants.

Examples of the silicone-based surfactant include polyether-modified silicone compounds, specifically, Tego rad 2250, manufactured by Evonik, KF-351A, KF-352A, KF-642 and X-22-4272, manufactured by shin-Etsu chemical industries, BYK307, BYK345, BYK347 and BYK348, manufactured by Bick chemical (BYK is a registered trademark of this company), TSF4452, manufactured by Michigan high and New materials.

The fluorine-based surfactant means a product obtained by substituting a part or all of hydrogen bonded to carbon in place of a hydrophobic group of a conventional surfactant with fluorine.

Examples of the fluorine-based surfactant include Megafac F, manufactured by DIC ("Megafac" is a registered trademark of this company), Surflon, manufactured by AGC semiconductor ("Surflon" is a registered trademark of this company), Fluorad FC, manufactured by 3M ("Fluorad" is a registered trademark of this company), Monflor, manufactured by Imperial chemical industries, Zonyls, manufactured by イー, アイ, デュポン, ネメラス, アンド, カンパニー, Licowet VPF, manufactured by ルベベルケ, ヘキスト, and FTERGENT, manufactured by NEOS ("FTERGENT" is a registered trademark of this company).

The amount of the surfactant can be arbitrarily set within a range in which the effects of the present invention are obtained. The amount of the surfactant can be set to, for example, 0.001 mass% or more and less than 1.0 mass% with respect to the total mass of the ink.

(curing accelerators)

In the present invention, a curing accelerator may be contained as necessary. The curing accelerator is not particularly limited as long as it accelerates the thermal curing of the resin component.

Examples of the curing accelerator include imidazoles, dicyandiamide derivatives, dicarboxylic acid dihydrazide, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazole-tetraphenylborate, and 1, 8-diazabicyclo [5.4.0] undecene-7-tetraphenylborate.

(coupling agent)

In the present invention, various coupling agents may be contained as necessary. By including the coupling agent, adhesiveness to the copper foil can be improved.

Examples of the various coupling agents include silane-based, titanium-based, and aluminum-based coupling agents.

(ion scavenger)

In the present invention, an ion scavenger may be contained as required. The inclusion of the ion scavenger has advantages such as adsorption of ionic impurities and improvement of insulation properties under the condition that the cured film absorbs moisture.

Examples of the ion scavenger include inorganic ion adsorbents such as triazine thiol compounds, bisphenol-based reducing agents, zirconium compounds, antimony bismuth-based magnesium aluminum compounds, and the like.

(solvent)

In the thermosetting composition of the present invention and the ink of the present invention, it is preferable that no solvent is originally used from the viewpoint of curability, but they may be added to adjust the viscosity of the ink.

[ Properties ]

The ink of the present invention preferably contains a gelling agent. In this case, the ink of the present invention preferably has a viscosity of 1 to 1 × 10 at 25 ℃ in order to sufficiently gel the ink when it is dropped and cooled to room temperature and to improve fixability⁴Pa · s.

From the viewpoint of further improving the ejection property from the ink jet head, the viscosity of the ink of the present invention at 80 ℃ is preferably within a range of 3 to 20mPa · s, and more preferably within a range of 7 to 9mPa · s.

In addition, when the ink of the present invention contains a gelling agent, the ink preferably has a phase transition point in a range of 40 ℃ or higher and less than 100 ℃. If the phase transition point is 40 ℃ or higher, the ink rapidly gels after landing on the recording medium, and thus the fixability is further improved. If the phase transition point is less than 100 ℃, the ink handling properties become good and the ejection stability improves.

The phase change point of the ink of the present invention is more preferably in the range of 40 to 60 ℃ from the viewpoint of discharging the ink at a lower temperature and reducing the load on the image forming apparatus.

The viscosity at 80 ℃, the viscosity at 25 ℃ and the phase transition point of the ink of the present invention can be determined by measuring the temperature change of the dynamic viscoelasticity of the ink with a rheometer.

In the present invention, these viscosity and phase transition point are values obtained by the following method.

The ink of the present invention was heated to 100 ℃ and cooled to 20 ℃ at a shear rate of 11.7(1/s) and a temperature lowering rate of 0.1 ℃/s while measuring the viscosity at a shear rate of 1000(1/s) by a Physica MCR301 (manufactured by Anton Paar Co., Ltd.) to obtain a temperature change curve of the viscosity.

The viscosity at 80 ℃ and the viscosity at 25 ℃ can be determined by reading the viscosity at 80 ℃ and the viscosity at 25 ℃ respectively in a temperature change curve of the viscosity. The phase transition point can be determined as a temperature at which the viscosity becomes 200mPa · s in a temperature change curve of the viscosity.

From the viewpoint of further improving the ejection from the ink jet head, the average dispersed particle diameter of the pigment particles according to the present invention is preferably in the range of 50 to 150nm, and the maximum particle diameter is preferably in the range of 300 to 1000 nm. More preferably, the average dispersed particle diameter is in the range of 80 to 130 nm.

The average dispersed particle size of the pigment particles in the present invention means a value obtained by a dynamic light scattering method using データサイザーナノ ZSP and Malvern. Since the ink containing the colorant has a high concentration and is not optically transparent in the measurement device, the ink is diluted 200 times and measured. The measurement temperature was set to room temperature (25 ℃).

[ method for Forming solder resist ]

The thermosetting inkjet ink of the present invention is preferably an ink for forming a solder resist pattern used for a printed circuit board. When a solder resist pattern (solder resist) is formed using the thermosetting inkjet ink of the present invention, penetration into the moisture solder resist can be prevented, and as a result, adhesion between the copper foil in the printed circuit board and the solder resist interface becomes good, and migration of copper is prevented, and a decrease in insulation properties can be suppressed.

The method for forming a solder resist using the thermosetting inkjet ink of the present invention preferably includes: (1) a step of discharging the ink of the present invention from a nozzle of an ink jet head and landing the ink on a printed circuit board on which a circuit is formed; (3) and a step of heating the ink to perform main curing.

When the ink of the present invention contains a compound having a photopolymerizable functional group and a photopolymerization initiator, it is preferable to include a step of irradiating the dropped ink with active light to temporarily cure the ink ((step of (2)) between the steps (1) and (3).

< Process (1) >

In the step (1), the ink droplets of the present invention are discharged from the ink jet head, and landed at a position corresponding to a resist film to be formed on a printed circuit board as a recording medium, thereby patterning the ink droplets.

As for the discharge manner from the inkjet head, both an on-demand manner and a continuous manner are possible.

As for the on-demand type ink Jet head, an electric-mechanical conversion method such as a single chamber type, a double chamber type, a bent tube type, a piston type, a common mode type, and a common wall type, an electric-thermal conversion method such as a thermal ink Jet type and a Bubble Jet (registered trademark) (the Bubble Jet is a registered trademark of canon corporation), and the like are all possible.

By discharging droplets of ink from the inkjet head in a heated state, discharge stability can be improved. The temperature of the ink at the time of discharge is preferably in the range of 40 to 100 ℃, and more preferably in the range of 40 to 90 ℃ in order to further improve the discharge stability. In particular, the ejection is preferably performed at an ink temperature at which the viscosity of the ink is in a range of 7 to 15 mPas, more preferably in a range of 8 to 13 mPas.

In the sol-gel phase change type ink, in order to improve the ejection property of the ink from the ink jet head, it is preferable to set the temperature of the ink at the time of filling the ink jet head to (gel temperature +10) ° c to (gel temperature +30) ° c of the ink. If the temperature of the ink in the ink jet head is (gel temperature +10) ° c or higher, the ink does not gel in the ink jet head or on the nozzle surface and the ink discharging property is lowered. On the other hand, if the temperature of the ink in the inkjet head is within (gel temperature +30) ° c, the ink does not excessively become high temperature and deteriorate the ink components.

The heating method of the ink is not particularly limited. For example, at least one of an ink supply system such as an ink tank constituting the head holder, a supply tube and a front chamber ink tank in front of the head, a filter-equipped pipe, and a piezoelectric head can be heated by using a plate heater, a band heater, heat-retaining water, or the like.

The amount of ink droplets at the time of discharge is preferably in the range of 2 to 20pL from the viewpoint of recording speed and image quality.

The pc board is not particularly limited, but is preferably selected from phenolic paper (i.e., フェノール), epoxy paper (i.e., エポキシ), epoxy glass cloth (ガラス cloth エポキシ), glass polyimide, glass cloth/epoxy non-woven fabric, glass cloth/epoxy paper, epoxy synthetic fiber, copper-clad laminate of all grades (FR-4, etc.) in products using such materials as copper-clad laminate for high-frequency circuits such as fluoro-polyethylene-PPO-cyanate ester, polyimide film, PET film, glass substrate, ceramic substrate, wafer sheet, stainless steel sheet, etc.

< step (2) >

In the step (2), the ink dropped in the step (1) is irradiated with an active ray to temporarily cure the ink.

The active light can be selected from, for example, electron beam, ultraviolet ray, alpha ray, gamma ray, and X ray, and ultraviolet ray is preferable.

The irradiation of ultraviolet rays can be performed at a wavelength of 395nm using, for example, a water-cooled LED manufactured by Phoseon Technology. By using the LED as the light source, curing failure of the ink due to dissolution of the ink by the radiant heat of the light source can be suppressed.

Irradiating ultraviolet rays so that the peak illuminance at the surface of the resist film of the ultraviolet rays having a wavelength in the range of 370 to 410nm is preferably 0.5 to 10W/cm²More preferably 1 to 5W/cm²Within the range of (1). From the viewpoint of suppressing the irradiation of radiant heat to the ink, the amount of light irradiated to the resist film is preferably less than 500mJ/cm²。

The active light is preferably irradiated for 0.001 to 300 seconds after the ink is landed, and more preferably for 0.001 to 60 seconds in order to form a high-definition resist film.

< step (3) >

In the step (3), after the temporary curing in the step (2), the ink is further heated to perform main curing.

In the heating method, for example, it is preferable to put the glass plate into an oven set at 110 to 180 ℃ for 10 to 60 minutes.

The thermosetting inkjet ink of the present invention can be used as an adhesive for electronic components, a sealing agent, a circuit protecting agent, and the like, in addition to the above ink for forming a solder resist pattern.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the examples, "part(s)" or "%" are used, and unless otherwise specified, "part(s) by mass" or "% by mass" is used.

EXAMPLE 1

[ preparation of thermosetting compositions 1-1 to 1-44 ]

Each component of the compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (A) and the (meth) acryloyl group-containing monomer (C) having no functional group capable of reacting with the blocked isocyanate were blended in the proportions shown in tables I to III, and the mixture was stirred with a dissolver to obtain thermosetting compositions 1-1 to 1-44.

[ preparation of thermosetting composition 1-45 to 1-58 ]

The total of the components of the compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (a) and the (meth) acryloyl group-containing monomer (C) having no functional group capable of reacting with the blocked isocyanate was 96% by mass of the entire thermosetting composition. The addition amount ratio is shown in Table III. Further, the following amounts of photopolymerization initiator and photopolymerization initiator aid were mixed and stirred with a dissolver to obtain thermosetting compositions 1-45 to 1-58.

Photopolymerization initiator Irgacure TPO (manufactured by BASF corporation): 1.0% by mass

Photopolymerization initiator Genocure ITX (manufactured by Rahn a.g.: 3.0% by mass

[ formation of cured films 1-1 to 1-58 ]

Using the thermosetting compositions 1 to 58, films having a thickness of 30 μm were produced on BT substrates using an applicator (manufactured by ERICHSEN Co., Ltd.), and the thermosetting compositions 1-1 to 1-44 were cured at 160 ℃ for 30 minutes to form cured films 1-1 to 1-44.

Furthermore, the thermosetting compositions 1-45 to 1-58 were irradiated with LED lamps (395nm, 8W/cm) manufactured by Phoseon Technology²Water cooling unit) so as to become 500mJ/cm²Curing the film at 160 ℃ for 30 minutes to form a cured film 1-45-1-58.

Compounds shown in the following table are shown.

< blocked isocyanate (A) >

A-1: TrixeneBI7961 (biuret type, blocking agent manufactured by LANXESS Co., Ltd.; DMP (dimethylpyrazole))

A-2: TrixeneBI7982 (blocking agent manufactured by LANXESS corporation: DMP)

A-3: TrixeneBI7992 (blocking agent manufactured by LANXESS, Inc.; DMP/DEM (diethyl malonate) active ethylene series Compound)

A-4: BL4265SN (blocking agent MEKO (methyl ethyl ketoxime) oxime series compound manufactured by Suzuki バイエルウレタン Co.)

A-5: TrixeneBI7991 (biuret type, manufactured by LANXESS Co., Ltd.; blocking agent: DMP/DEM)

A-6: デスモジュール BL 1100/1 (product of Sunghua バイエルウレタン Co., Ltd., blocking agent;. epsilon. -caprolactam)

< Compound (B) having a functional group capable of forming a hydrogen bond with a blocked isocyanate >

B-1: salicylic acid ethyl ester

B-2: p-hydroxybenzoic acid ethyl ester

B-3: para-cresol

B-4: benzoic acid

B-5: aniline

B-6: n-acetanilide

B-7: thiophenol

B-8: 2-hydroxybutyl acrylate (ライトエステル HOB-A, product of Kyoeisha chemical Co., Ltd.)

B-9: alicyclic carboxylic acid epoxy acrylate (DA-722: ナガセケムテックス Co., Ltd.)

B-10: dipentaerythritol pentaacrylate (Miramer M500: manufactured by MIWON Co., Ltd.)

B-11: methacrylic acid

B-12: acrylic acid 2-hydroxy-3-phenoxypropyl ester (LIGHT ACRYLATE M-600A, manufactured by Kyoeisha chemical Co., Ltd.)

B-13: 2-hydroxy-3-acryloyloxypropyl methacrylate (ライトエステル G-201P, manufactured by Kyoeisha chemical Co., Ltd.)

< monomer (C) containing (meth) acryloyl group having no functional group reactive with blocked isocyanate >)

C-1: dipropylene glycol diacrylate (DPGDA, M222 Miwon Co., Ltd.)

C-2: TMP (EO)9TA (trimethylolpropane EO modified triacrylate) (EM2382 made by Changxing chemical Co., Ltd.)

C-3: phenyl glycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer (urethane acrylate AH-600, manufactured by Kyoeisha chemical Co., Ltd.)

Evaluation

The storage stability at high temperature and the pencil hardness of the cured film were evaluated.

[ storage stability at high temperature ]

The viscosity of the thermosetting compositions 1-1 to 1-58 prepared as described above was measured at 25 ℃, and then stored in a sealed container at 85 ℃ for 500 hours, and then cooled naturally until the temperature reached 25 ℃, and the viscosity after the high-temperature treatment was measured to calculate the thickening ratio (%), and the evaluation was made by the following criteria.

The viscosity was measured at a shear rate of 1000(1/s) using a Physica MCR301 (manufactured by Anton Paar).

Thickening ratio (%) (viscosity after 500 hours-initial viscosity)/initial viscosity × 100.

Very good: the thickening rate is less than 5 percent

O: the thickening rate is more than 5 percent and less than 10 percent

And (delta): the thickening rate is more than 10 percent and less than 20 percent

X: the thickening rate is more than 20 percent or the solidification

[ Pencil hardness ]

The pencil hardness test was conducted on each of the cured films 1-1 to 1-58 formed by the above-mentioned thermal curing or photo-curing in addition to the thermal curing, using Hi-uni manufactured by Mitsubishi pencil in accordance with JIS K5400.

Specifically, a wood portion of the pencil is sharpened to a core length of 5-6 mm. A pencil was used in which the tip end of the lead was smoothly ground with a grinding paper to obtain a circular cross section. The pencil was held at an angle of 45 degrees with respect to the sample surface, and the coating film was scraped at an angle of 45 degrees with a load of 1kg applied to the sample surface. The maximum hardness of the pencil, at which the coating film did not reach the substrate, was evaluated.

[ Pencil hardness under high temperature and high humidity ]

Each of the cured films 1-1 to 1-58 formed by the above-mentioned thermal curing or photo-curing in addition to the thermal curing was left to stand at 85 ℃ and a relative humidity of 85% for 500 hours. Then, the pencil hardness was evaluated in the same manner as above, and the state of peeling of the cured film was observed.

The results are shown in tables I to III. In the following table, the compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (a) and the (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate are represented as the compound (B) having a functional group capable of forming a hydrogen bond and the (meth) acryloyl group-containing monomer (C), respectively.

As is clear from the results shown in tables I to III, the compounds within the scope of the present invention are excellent in storage stability at high temperature storage, thermosetting properties, and thermosetting properties at high temperature and high humidity. Further, it is found that the thermosetting composition having 1 to 10 parts by mass of the compound (B) having a functional group capable of forming a hydrogen bond or 1 to 10 parts by mass of the blocked isocyanate (a) per 100 parts by mass of the (meth) acryloyl group-containing monomer (C) is more excellent in ink storage properties.

It is also found that when the compound (B) having a functional group capable of forming a hydrogen bond is a monomer containing a (meth) acryloyl group, the ink storage property and pencil hardness are excellent.

Further, it was found that the thermosetting composition irradiated with light using the photopolymerization initiator was excellent in pencil hardness.

EXAMPLE 2

[ preparation of ink-jet ink ]

< preparation of yellow pigment Dispersion >

The following dispersants 1 and 2 and a dispersion medium were placed in a stainless steel beaker, heated and stirred to dissolve for 1 hour on a 65 ℃ hot plate, and after cooling to room temperature, the following pigments were added thereto, and the mixture was put into a glass bottle together with 200g of zirconia beads having a diameter of 0.5mm, and then stoppered. The resulting mixture was dispersed with a paint shaker until the particles had a desired particle size, and then the zirconia beads were removed.

Dispersant 1: EFKA7701(BASF corporation) 5.6 parts by mass

Dispersant 2: solsperse22000 (manufactured by Japan ルーブリゾール Co., Ltd.)

0.4 part by mass

Dispersion medium: dipropylene glycol diacrylate (containing 0.2% UV-10)

80.6 parts by mass

Pigment: PY185 (manufactured by BASF corporation, パリオトールイエロー D1155)

13.4 parts by mass

Preparation of a cyan pigment Dispersion

The yellow pigment dispersion was prepared in the same manner as described above except that the dispersant, the dispersion medium and the pigment were changed as described below.

Dispersing agent: EFKA7701 (manufactured by BASF corporation) 7 parts by mass

Dispersion medium: 70 parts by mass of dipropylene glycol diacrylate (containing 0.2% UV-10)

Pigment: PB 15: 4 (Dari Jing Shi Jing, クロモファインブルー 6332JC)

23 parts by mass

< gelling agent >

As the gelling agent, the following gelling agents were used.

D-1: distearyl ketone

D-2: behenic acid behenate

< photopolymerization initiator >

The TPO and ITX described in example 1 were used.

< blocked isocyanate (A) >

A-1 to A-6 described in example 1 were used.

< Compound (B) having a functional group capable of forming a hydrogen bond with a blocked isocyanate >

The compounds B-1 to B-13 described in example 1 were used.

< monomer (C) containing (meth) acryloyl group having no functional group reactive with blocked isocyanate >)

The above-mentioned C-1 to C-3 are used.

[ preparation of thermosetting inkjet ink ]

Thermosetting inkjet inks were prepared by mixing the respective thermosetting inkjet inks with a dissolver and stirring the mixture, and the mixture was filtered through a 3 μm membrane filter made by ADVATEC corporation, Teflon (registered trademark) to prepare thermosetting inkjet inks 2-1 to 2-68.

Preparation of thermosetting ink-jet inks 2-1 to 2-41

The total of the blocked isocyanate (a), the compound (B) having a functional group capable of forming a hydrogen bond, and the (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate was 93.0 parts by mass of the entire composition. The addition amount ratios are shown in tables IV and V. Further contains the following components.

Yellow pigment dispersion: 1.0% by mass

Cyan pigment dispersion: 2.0% by mass

Photopolymerization initiator: TPO: 1.0% by mass

Photopolymerization initiator: ITX: 3.0% by mass

Preparation of thermosetting inkjet inks 2-42 to 2-56

The blocked isocyanate (a), the compound (B) having a functional group capable of forming a hydrogen bond, and the (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate were added in a total amount of 90.0 parts by mass of the entire composition. The addition amount ratio is shown in tables V and VI. Further contains the following components.

Yellow pigment dispersion: 1.0% by mass

Cyan pigment dispersion: 2.0% by mass

Gelling agent D-1: 2.0% by mass

Gelling agent D-2: 1.0% by mass

Photopolymerization initiator: TPO: 1.0% by mass

Photopolymerization initiator: ITX: 3.0% by mass

Preparation of thermosetting ink-jet inks 2-57 to 2-62

The total of the blocked isocyanate (a), the compound (B) having a functional group capable of forming a hydrogen bond, and the (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate was 97.0 parts by mass of the entire composition. The addition amount ratio is shown in Table VI. Further contains the following components.

Yellow pigment dispersion: 1.0% by mass

Cyan pigment dispersion: 2.0% by mass

Preparation of thermosetting ink-jet inks 2-63 to 2-68

The total of the blocked isocyanate (a), the compound (B) having a functional group capable of forming a hydrogen bond, and the (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate was 94.0 parts by mass of the entire composition. The addition amount ratio is shown in Table VI. Further contains the following components.

Yellow pigment dispersion: 1.0% by mass

Cyan pigment dispersion: 2.0% by mass

Gelling agent D-1: 2.0% by mass

Gelling agent D-2: 1.0% by mass

(measurement of viscosity and gel transition temperature)

For each of the prepared heat-curable inkjet inks, the 80 ℃ viscosity and gel transition temperature of each ink were measured at a shear rate of 1000(1/s) using a Physica MCR301 (manufactured by Anton Paar corporation).

Wherein the gel transition temperature is a temperature at which a complex viscosity coefficient (a 2 Pa · s (— hydrox) becomes 1Pa · s or more in a viscoelastic curve obtained by changing a temperature at a cooling rate of 0.1 ℃/s, a strain of 5%, an angular frequency of 10 rad/s, and a cooling rate of 0.1 ℃/s.

The ink added with the gelatinizing agent has viscosity of 1-1 multiplied by 10 at 25 DEG C⁴Pa · s, whereas no inks to which a gelling agent is added are less than 1Pa · s.

In addition, the gel transition temperature of the ink added with the gelatinizer is 40-100 ℃, but the gel transition phenomenon is not found in the ink without the gelatinizer.

< Pattern formation Using Heat-curable ink-jet ink >

Each of the prepared thermosetting inkjet inks was loaded into an inkjet recording apparatus having an inkjet recording head provided with piezoelectric inkjet nozzles. Using this apparatus, a pattern was formed on a copper-clad laminate for a printed wiring board (FR-4 thickness 1.6mm, size 150 mm. times.95 mm).

The ink supply system is composed of an ink tank, an ink flow path, a sub-tank in front of the ink jet recording head, a piping with a metal filter, and a piezoelectric head. From the ink tank to the head portion, the ink was heated to 90 ℃. The piezoelectric head also incorporates a heater to heat the ink in the recording head to 90 ℃. In the piezoelectric head, heads having a nozzle resolution of 360dpi were arranged in a staggered manner with a nozzle diameter of 22 μm, thereby forming a nozzle row of 720 dpi.

Using this ink jet apparatus, a voltage was applied so as to form dots with a droplet volume of 6.0pl, and solid patterns and lines of 20mm × 50mm were printed on the substrate&After forming a comb-shaped pattern with a gap of 100 μm so that the thickness of each pattern became 20 μm, an LED lamp (395nm, 8W/cm) manufactured by Phoseon Technology was used²Water cooling unit) so as to become 500mJ/cm²The ink layer is temporarily cured. Then, the resultant was put into an oven set at 150 ℃ for 60 minutes to perform main curing, thereby obtaining a print sample.

Evaluation

The ink jet ink prepared above and the formed coating film were evaluated for storage stability and pencil hardness of the formed coating film in the same manner as in the evaluation method described in example 1.

The results are shown in tables IV to VI.

As is clear from the results shown in tables IV to VI, the thermosetting inkjet ink of the present invention is a material excellent in storage stability and thermal and photo curability. Further, it is found that a composition having 1 to 10 parts by mass of the compound (B) having a functional group capable of forming a hydrogen bond or 1 to 10 parts by mass of the blocked isocyanate (a) per 100 parts by mass of the (meth) acryloyl group-containing monomer (C) is more excellent in ink storage properties.

It is also found that when the compound (B) having a functional group capable of forming a hydrogen bond is a specific functional group, the ink storage stability is more excellent. This is presumably because a hydrogen bond is easily formed at the blocked site of the blocked isocyanate.

It is also found that the addition of a gelling agent to the heat and photo-curable composition of the present invention further improves the ink storage stability and heat curing properties.

Industrial applicability

The thermosetting composition of the present invention is excellent in storage stability at high temperatures and thermosetting property of the surface of a cured film at high temperatures and high humidity, and can be suitably used for thermosetting inkjet inks.

Claims (10)

1. A thermosetting composition containing a blocked isocyanate (A), characterized in that,

comprises the following components: a compound (B) having a functional group capable of forming a hydrogen bond with the blocked isocyanate (A), and a (meth) acryloyl group-containing monomer (C) having no functional group reactive with the blocked isocyanate,

the compound (B) is contained in an amount of 0.1 to 20 parts by mass and the blocked isocyanate (A) is contained in an amount of 0.1 to 20 parts by mass based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C).

2. The thermosetting composition according to claim 1, comprising a photopolymerization initiator.

3. The thermosetting composition according to claim 1 or 2, wherein the functional group that the compound (B) has to form a hydrogen bond with the blocked isocyanate (A) is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group and a mercapto group.

4. The thermosetting composition according to claim 3, wherein the compound (B) is a (meth) acryloyl group-containing monomer.

5. The thermosetting composition according to any one of claims 1 to 4, wherein the compound (B) is contained in an amount of 1 to 10 parts by mass based on 100 parts by mass of the (meth) acryloyl group-containing monomer (C).

6. A heat-curable ink jet ink comprising the heat-curable composition according to any one of claims 1 to 5.

7. The heat-curable inkjet ink according to claim 6, wherein the inkjet ink contains a gelling agent and undergoes a sol-gel phase transition in response to temperature.

8. The thermosetting inkjet ink according to claim 7, wherein the viscosity at 25 ℃ is 1 to 1 x 10⁴Pa · s at a temperature of 40 ℃ or higher and less than 100 ℃ and the sol-gel phase transition.

9. The heat-curing inkjet ink according to claim 7 or 8, wherein the gelling agent is a compound having a structure represented by the following general formula (G1) or general formula (G2),

general formula (G1): r₁-CO-R₂

General formula (G2): r₃-COO-R₄

In the formula, R₁～R₄Each independently represents a linear chain portion having 12 or more carbon atoms and may have a branched alkyl chain.

10. The thermosetting inkjet ink according to any one of claims 6 to 9, which is a thermosetting inkjet ink for forming a solder resist pattern for a printed circuit board.