JP2012184411A - Curable composition for ink-jet and method for producing electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition for ink-jet, long in pot life even in the inner environment of an ink-jet device heated at ≥50°C.SOLUTION: The present invention relates to a curable composition for ink-jet, which is coated by an ink-jet method and is cured by applying heat. The curable composition for ink-jet comprises a compound having a cyclic ether group, a thermosetting agent, and a pigment. The thermosetting agent is a compound having a nitrogen atom. The pigment is a pigment exhibiting pH ≥3.0 and <7.3, when heating a liquid obtained by adding 5g of the pigment to 100 mL of pure water, boiling the liquid for 5 minutes, leaving the liquid until reaching 23°C to obtain the boiling-treated liquid, adding water to the obtained boiling-treated liquid in a water amount evaporated by the boiling-treatment to give the liquid containing 100 mL of water, and then measuring the pH of the liquid.

Description

  The present invention relates to an ink-jet curable composition applied by an ink-jet method, an ink-jet curable composition suitably used for forming a cured layer such as a resist pattern on a substrate, and the ink-jet curing. The present invention relates to a method for manufacturing an electronic component having a cured product layer formed of a composition.

  Conventionally, a printed wiring board in which a solder resist pattern, which is a patterned solder resist film, is formed on a substrate on which wiring is provided on the upper surface is often used. With the miniaturization and high density of electronic devices, printed circuit boards are required to have a finer solder resist pattern.

  As a method for forming a fine solder resist pattern, a method of applying a solder resist composition by an ink jet method has been proposed. In the inkjet method, the number of steps is smaller than in the case of forming a solder resist pattern by a screen printing method. For this reason, the solder resist pattern can be easily and efficiently formed by the inkjet method.

  When the solder resist composition is applied by an inkjet method, it is required that the viscosity at the time of application is low to some extent. On the other hand, in recent years, an inkjet apparatus capable of printing by heating to 50 ° C. or higher has been developed. By heating the solder resist composition to 50 ° C. or higher in the ink jet apparatus, the viscosity of the solder resist composition becomes relatively low, and the ejectability of the solder resist composition using the ink jet apparatus is further enhanced. be able to.

  Also, a solder resist composition that can be applied by an ink jet method is disclosed in Patent Document 1 below. Patent Document 1 below discloses inkjet curing comprising a monomer having a (meth) acryloyl group and a thermosetting functional group, a photoreactive diluent having a weight average molecular weight of 700 or less, and a photopolymerization initiator. A sex composition is disclosed. The viscosity of the curable composition for inkjet at 25 ° C. is 150 mPa · s or less.

  Patent Document 1 describes that a colorant such as a phthalocyanine green pigment may be included.

WO2004 / 099272A1

  The viscosity of the curable composition for inkjet described in Patent Document 1 is relatively low. For this reason, the curable composition for inkjet described in Patent Document 1 can be coated on a substrate by an inkjet method.

  However, since the curable composition for inkjet described in Patent Document 1 contains a monomer having a (meth) acryloyl group and a thermosetting functional group, there is a problem that the pot life under an environment of 50 ° C. or higher is short. is there.

  For example, when an inkjet curable composition is ejected by an inkjet device, the inkjet curable composition generally remains in the inkjet device for a certain period of time after being supplied into the inkjet device. On the other hand, the temperature in the ink jet apparatus may be heated to 50 ° C. or higher in order to improve the ejection property. In the curable composition for inkjet described in Patent Document 1, the composition is cured in an inkjet apparatus heated to 50 ° C. or more, and the viscosity of the composition is increased. It can be difficult.

  An object of the present invention is a curable composition that is applied by an ink jet method, and includes a compound having a cyclic ether group, and is potted even in an environment in an ink jet apparatus that is heated to 50 ° C. or higher. It is providing the curable composition for inkjets with a long life, and the manufacturing method of an electronic component using the curable composition for inkjets.

  According to a wide aspect of the present invention, there is provided a curable composition for inkjet that is applied by an inkjet method and cured by application of heat, comprising a compound having a cyclic ether group, a thermosetting agent, and a pigment. The thermosetting agent is a compound having a nitrogen atom, and the pigment is heated by boiling a liquid obtained by adding 5 g of the pigment to 100 mL of pure water and boiling for 5 minutes. When a pH of a liquid obtained by adding a water amount of water evaporated by boiling to the obtained boiled processing solution and making the amount of water 100 mL was measured in the obtained boiled processing solution, a value of pH 3.0 or more and less than 7.3 An ink-jet curable composition is provided.

  In the present specification, a liquid obtained by adding 5 g of pigment to 100 mL of pure water is heated and boiled for 5 minutes, and then allowed to stand until reaching 23 ° C. to obtain a boiling treatment liquid, and then the obtained boiling treatment A method of measuring the pH of a liquid in which the amount of water evaporated by boiling is added to the liquid to bring the amount of water to 100 mL may be referred to as a boiling method.

  The above pigment is heated in a solution obtained by adding 5 g of the pigment to 100 mL of pure water, boiled for 5 minutes, and then allowed to stand until it reaches 23 ° C. to obtain a boiling treatment liquid, and then to the obtained boiling treatment liquid. When the pH of a solution obtained by adding water in an amount of water evaporated by boiling to 100 mL is measured, it is preferably a pigment having a pH of 3.0 or more and less than 6.3. That is, the pigment is preferably a pigment having a pH by the boiling method of 3.0 or more and less than 6.3.

  In a specific aspect of the curable composition for inkjet according to the present invention, the thermosetting agent is at least one selected from the group consisting of dicyandiamide, an imidazole compound, and a compound having a triazine ring.

  In another specific aspect of the curable composition for inkjet according to the present invention, the pigment is a phthalocyanine pigment or a carbon black pigment.

  In another specific aspect of the curable composition for inkjet according to the present invention, the curable composition for inkjet that is applied by an inkjet method and is curable by irradiation with light and application of heat, A compound having a (meth) acryloyl group and a photopolymerization initiator are further included.

  In the curable composition for inkjet according to the present invention, the viscosity at 25 ° C. measured according to JIS K2283 is preferably 160 mPa · s or more and 1200 mPa · s or less.

  Moreover, according to the wide aspect of this invention, the process for apply | coating the inkjet curable composition comprised according to this invention by the inkjet system, and drawing it in a pattern form, and the said inkjet use drawn in the pattern form A method for producing an electronic component is provided, comprising: applying heat to a curable composition and curing the composition to form a cured product layer.

  In a specific aspect of the method for manufacturing an electronic component according to the present invention, a method for manufacturing a printed wiring board, which is an electronic component having a resist pattern, the inkjet curable composition is applied by an inkjet method. Then, a resist pattern is formed by drawing in a pattern and applying heat to the curable composition for inkjet drawn in the pattern to be cured.

  In another specific aspect of the method for producing an electronic component according to the present invention, an inkjet curable composition comprising a compound having a (meth) acryloyl group and a photopolymerization initiator as the inkjet curable composition. In the step of forming the cured product layer, light and heat are applied to the ink-jet curable composition drawn in a pattern and cured to form a cured product layer.

  The curable composition for inkjet according to the present invention includes a compound having a cyclic ether group, a thermosetting agent that is a compound having a nitrogen atom, and a pigment, and further has a pH of 3.0 or more according to the boiling method of the pigment. Therefore, the pot life is sufficiently long even in an environment inside the ink jet apparatus heated to 50 ° C. or higher.

  Details of the present invention will be described below.

(Curable composition for inkjet)
The curable composition for inkjet according to the present invention is a curable composition for inkjet that is applied by an inkjet method and is cured by application of heat. The curable composition for inkjet according to the present invention includes a compound (A) having a cyclic ether group, a thermosetting agent (B), and a pigment (C). The thermosetting agent (B) is a compound having a nitrogen atom. The curable composition for inkjet according to the present invention is a thermosetting composition.

  The pigment (C) is obtained by heating a liquid obtained by adding 5 g of the pigment (C) to 100 mL of pure water, boiling for 5 minutes, and then standing until reaching 23 ° C. to obtain a boiling treatment liquid. When the pH of the liquid obtained by adding water in an amount of water evaporated by boiling to the boiling treatment liquid to adjust the water volume to 100 mL (pH by boiling method) is a pigment having a value of pH 3.0 or more and less than 7.3 is there.

  In the curable composition for inkjet having the above composition, the inside of the inkjet apparatus heated to 50 ° C. or higher despite containing the compound (A) having a cyclic ether group and the thermosetting agent (B). The pot life can be made sufficiently long even in this environment. Moreover, even if the curable composition for inkjet before the coating by the inkjet method is heated to 50 ° C. or higher, the viscosity does not easily increase and the thermal curing does not easily proceed. For this reason, the curable composition for inkjet is excellent in stability at high temperatures, and can be stably discharged from the inkjet nozzle. The thermosetting agent (B), which is a curing agent having a nitrogen atom, has a curable composition because it is coordinated to the pigment (C) having a pH of 3.0 or more and less than 7.3 by the boiling method. It is conceivable that the pot life of the object becomes longer.

  Moreover, since the curable composition for inkjet which concerns on this invention has the said composition and contains the compound (A) which has a cyclic ether group especially, it can improve the heat resistance of the hardened | cured material after hardening. Furthermore, since the curable composition for inkjet according to the present invention has the above composition, the insulation reliability of the cured product after curing can be increased.

  The curable composition for inkjet according to the present invention is preferably an curable composition for inkjet that is applied by an inkjet method and is cured by irradiation with light and application of heat. It is preferable that the curable composition for inkjet according to the present invention further includes a compound (D) having a (meth) acryloyl group and a photopolymerization initiator (E) so that it can be cured by light irradiation. Ink jet light and thermosetting compositions are preferred. In this case, when obtaining a cured product layer such as a resist pattern using the curable composition for inkjet according to the present invention, after obtaining a primary cured product by light irradiation, heat is applied to the primary cured product. Thus, a main cured product can be obtained to obtain a cured product layer such as a resist pattern which is a cured product. Thus, by performing primary curing by light irradiation, wetting and spreading of the curable composition for inkjet applied onto a coating target member such as a substrate can be suppressed. Therefore, a cured product layer such as a fine resist pattern can be formed with higher accuracy.

  Hereinafter, the detail of each component contained in the curable composition for inkjet which concerns on this invention is demonstrated.

[Compound having a cyclic ether group (A)]
The curable composition for inkjet according to the present invention contains a compound (A) having a cyclic ether group so that it can be cured by application of heat. By using the compound (A), the curable composition or the primary cured product of the curable composition can be further cured by applying heat. For this reason, by using the compound (A), the resist pattern can be formed efficiently and accurately, and further, the heat resistance of the cured product and the insulation reliability due to the cured product layer can be enhanced. Only 1 type may be used for the compound (A) which has a cyclic ether group, and 2 or more types may be used together.

  The compound (A) having a cyclic ether group is not particularly limited as long as it has a cyclic ether group. Examples of the cyclic ether group in the compound (A) include an epoxy group and an oxetanyl group. Among these, the cyclic ether group is preferably an epoxy group from the viewpoint of improving curability and obtaining a cured product that is more excellent in heat resistance and further enhancing the insulation reliability of the cured product. The compound (A) having a cyclic ether group preferably has two or more cyclic ether groups.

  Specific examples of compounds having an epoxy group include heterocyclic epoxy compounds such as bisphenol S type epoxy compounds, diglycidyl phthalate compounds, triglycidyl isocyanurates, bixylenol type epoxy compounds, biphenol type epoxy compounds, tetraglycidyl xylenoyl Ethane compound, bisphenol A type epoxy compound, hydrogenated bisphenol A type epoxy compound, bisphenol F type epoxy compound, brominated bisphenol A type epoxy compound, phenol novolac type epoxy compound, cresol novolac type epoxy compound, alicyclic epoxy compound, bisphenol A novolac-type epoxy compound, chelate-type epoxy compound, glyoxal-type epoxy compound, amino group-containing epoxy compound, rubber-modified epoxy compound , Dicyclopentadiene phenolic type epoxy compounds, silicone-modified epoxy compounds and ε- caprolactone-modified epoxy compounds and the like.

  The compound having an oxetanyl group is exemplified in, for example, Japanese Patent No. 3074086.

  The compound (A) having a cyclic ether group preferably has an aromatic skeleton. By using a compound having an aromatic skeleton and a cyclic ether group, the thermal stability during storage and ejection of the curable composition is further improved, and further gelation occurs during storage of the curable composition. It becomes difficult. Further, a compound having an aromatic skeleton and a cyclic ether group is superior in compatibility with other components as compared with a compound having no aromatic skeleton and having a cyclic ether group. For this reason, insulation reliability is further improved by using a compound having an aromatic skeleton and a cyclic ether group.

  The compound (A) having a cyclic ether group is preferably liquid at 25 ° C. The viscosity of the compound (A) having a cyclic ether group at 25 ° C. preferably exceeds 300 mPa · s. The viscosity at 25 ° C. of the compound (A) having a cyclic ether group is preferably 80 Pa · s or less. When the viscosity of the compound (A) having a cyclic ether group is not less than the above lower limit, the resolution when forming the cured product layer is further improved. When the viscosity of the compound (A) having a cyclic ether group is not more than the above upper limit, the dischargeability of the curable composition is further improved, and the compound (A) having a cyclic ether group and other components The compatibility is further increased, and the insulation reliability is further improved.

  The compounding quantity of the compound (A) which has a cyclic ether group is suitably adjusted so that it may harden | cure moderately by provision of heat, and is not specifically limited. In 100% by weight of the curable composition for inkjet, the content of the compound (A) having a cyclic ether group is preferably 3% by weight or more, more preferably 5% by weight or more, still more preferably 10% by weight or more, preferably 99%. % By weight or less, more preferably 95% by weight or less, still more preferably 80% by weight or less. When the compound (D) and the photopolymerization initiator (E) are used, the content of the compound (A) having a cyclic ether group is particularly preferably 50% by weight in 100% by weight of the curable composition for inkjet. Hereinafter, it is most preferably 40% by weight or less. When the content of the compound (A) is not less than the above lower limit, the curable composition can be more effectively cured by application of heat. When the content of the compound (A) is not more than the above upper limit, the heat resistance of the cured product is further increased.

[Thermosetting agent (B)]
The curable composition for inkjet according to the present invention contains a thermosetting agent (B) in order to be able to be efficiently cured by application of heat. The thermosetting agent (B) cures the compound (A) having a cyclic ether group. In the curable composition for inkjet according to the present invention, the thermosetting agent (B) is a compound having a nitrogen atom. The use of a compound having a nitrogen atom greatly contributes to curing the curable composition for inkjet at a low temperature. A conventionally known compound can be used as the compound having a nitrogen atom. As for a thermosetting agent (B), only 1 type may be used and 2 or more types may be used together. From the viewpoint of further extending the pot life of the curable composition for inkjet, the thermosetting agent (B) is preferably a latent thermosetting agent.

  The thermosetting agent (B) is preferably a basic thermosetting agent. Whether the thermosetting agent (B) is basic or not is determined by putting 1 g of the thermosetting agent in 10 g of a liquid containing 5 g of acetone and 5 g of pure water, and heating with stirring at 80 ° C. for 1 hour. Next, when an insoluble component in the liquid after heating is removed by filtration to obtain an extract, the pH of the extract is judged to be basic (exceeding 7).

  Examples of the thermosetting agent (B) include dicyandiamide, hydrazide compounds, imidazole compounds, and compounds having a triazine ring. Thermosetting agents other than these may be used.

  From the viewpoint of further reducing the viscosity change when heated and further extending the pot life, the thermosetting agent (B) is at least selected from the group consisting of dicyandiamide, an imidazole compound and a compound having a triazine ring. It is preferable that it is 1 type.

  Specific examples of the imidazole compound include 2-undecylimidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1 -Benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl- 2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2 ' Methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6 -[2'-ethyl-4'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- Triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-dihydroxymethylimidazole, etc. Is mentioned.

  Specific examples of the compound having a triazine ring include melamine, melamine cyanurate, TEPIC-S (manufactured by Nissan Chemical Industries), 2,4,6-tri (6′-hydroxy-1′-hexylamino) triazine, and the like. Is mentioned.

  In order to prevent sedimentation of dicyandiamide particles and nozzle clogging, dicyandiamide may be reacted with a compound having a cyclic ether group in advance and dissolved in the composition. Even in this case, the pot life of the composition is good.

  The compound having a cyclic ether group to be reacted with dicyandiamide is preferably a compound having one cyclic ether group.

  Specific examples of the compound having a cyclic ether group to be reacted with dicyandiamide include phenyl glycidyl ether, butyl glycidyl ether, orthocresyl glycidyl ether, metacresyl glycidyl ether, paracresyl glycidyl ether, allyl glycidyl ether, para-t- Examples thereof include glycidyl ethers such as butylphenyl glycidyl ether, glycidyl (meth) acrylate, and 3,4-epoxycyclohexylmethyl (meth) acrylate.

  In the reaction of dicyandiamide and the compound having a cyclic ether group, it is preferable to react 0.2 mol or more and 4 mol or less of the compound having a cyclic ether group with respect to 1 mol of dicyandiamide. In this reaction, it is preferable to carry out the reaction at 60 ° C. to 140 ° C. in the presence of a solvent and a reaction accelerator as necessary.

  When the compound having a cyclic ether group is less than 0.2 mol, unreacted dicyandiamide may be precipitated. When the amount of the compound having a cyclic ether group is 4 mol or less, the pot life of the curable composition is further improved.

  A solvent may be used to dissolve dicyandiamide. The solvent may be any solvent that can dissolve dicyandiamide. Usable solvents include acetone, methyl ethyl ketone, dimethylformamide, methyl cellosolve and the like.

  In order to accelerate the reaction between dicyandiamide and the compound having a cyclic ether group, a reaction accelerator may be used. Known reaction accelerators such as phenols, amines, imidazoles, and triphenylphosphine can be used as the reaction accelerator.

  The compounding ratio of the compound (A) having a cyclic ether group and the thermosetting agent (B) is not particularly limited. The content of the thermosetting agent (B) is preferably 1 part by weight or more, more preferably 3 parts by weight or more, still more preferably 5 parts by weight or more with respect to 100 parts by weight of the compound (A) having a cyclic ether group. Particularly preferred is 10 parts by weight or more, preferably 60 parts by weight or less, more preferably 50 parts by weight or less, and still more preferably 40 parts by weight or less.

[Pigment (C)]
The pigment (C) contained in the curable composition for inkjet according to the present invention has a pH by the boiling method of 3.0 or more and less than 7.3. If pH exists in this range, the pot life of the inkjet curable composition can be lengthened by using the thermosetting agent (B) which is a compound which has a nitrogen atom further. Use of this specific pigment (C) greatly contributes to prolonging the pot life of the curable composition for inkjet.

  In the boiling method, a liquid obtained by adding 5 g of pigment (C) to 100 mL of pure water is heated and boiled for 5 minutes, and then left to stand until reaching 23 ° C. to obtain a boiling treatment liquid. In this method, the amount of water evaporated at the time of boiling is added to the boiling treatment liquid, and the pH of the obtained liquid is measured with a total volume of 100 mL.

  In the above boiling method, specifically, a liquid obtained by adding 5 g of the pigment (C) to 100 mL of pure water is placed in a container having an opening. The liquid in the container is heated by heating the container, and the liquid in the container is boiled. Maintain boiling for 5 minutes after starting to boil. Thereafter, a stopper is attached to the opening of the container and left to reach 23 ° C. to obtain a boiling treatment liquid. The stopper is removed from the opening of the container, and the amount of water evaporated by boiling is added to the obtained boiling treatment liquid to make the amount of water 100 mL. A stopper is attached to the opening of the container, shaken for 1 minute, and allowed to stand for 5 minutes. In this way, a measurement liquid is obtained. The pH of the obtained measuring solution is JIS Z8802 7. Can be measured in accordance with the operation described in 1.

  From the viewpoint of further increasing the pot life of the curable composition for inkjet, the pH of the pigment (C) by the boiling method is preferably 3.0 or more and less than 6.3.

  Specific examples of the pigment (C) include phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black and naphthalene black. As for pigment (C), only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of further increasing the pot life of the curable composition for inkjet, the pigment (C) is preferably a phthalocyanine pigment or a carbon black pigment. When the pigment (C) is a phthalocyanine pigment or a carbon black pigment, and the pH of the phthalocyanine pigment or the carbon black pigment is not less than 3.0 and less than 7.3, the pigment (C) is a phthalocyanine pigment. And the other pigments different from the carbon black pigment, and the storage stability of the curable composition is higher than the case where the pH of the other pigment is not less than 3.0 and less than 7.3 by the above boiling method. Even better.

  The blending amount of the pigment (C) is not particularly limited, and is appropriately adjusted so that the cured product exhibits a desired color or considering the curability of the composition. As an example of the amount of the pigment (C), the content of the pigment (C) is preferably 0.01% by weight or more and preferably 3% by weight or less in 100% by weight of the curable composition for inkjet. .

[Compound (D) having (meth) acryloyl group]
In order to cure the curable composition by irradiation with light, the curable composition for inkjet according to the present invention preferably includes a compound (D) having a (meth) acryloyl group. The compound (D) is not particularly limited as long as it has a (meth) acryloyl group. As the compound (D), a conventionally known compound having a (meth) acryloyl group can be used. The compound (D) is preferably a polyfunctional compound having two or more (meth) acryloyl groups. Since the polyfunctional compound has two or more (meth) acryloyl groups, the polymerization effectively proceeds and cures when irradiated with light. For this reason, curing can be advanced by irradiating light after coating the curable composition, the applied shape can be maintained, and primary curing of the curable composition irradiated with light. It can suppress effectively that a thing and hardened | cured material spread out too much. As for a compound (D), only 1 type may be used and 2 or more types may be used together.

  Compound (D) includes polyhydric alcohol (meth) acrylic acid adducts, polyhydric alcohol alkylene oxide modified (meth) acrylic acid adducts, urethane (meth) acrylates, and polyester (meth) acrylates. Etc. Examples of the polyhydric alcohol include diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, trimethylol propane, cyclohexane dimethanol, tricyclodecane dimethanol, an alkylene oxide adduct of bisphenol A, and Examples include pentaerythritol. The term “(meth) acrylate” refers to acrylate and methacrylate. The term “(meth) acryl” refers to acrylic and methacrylic.

  The compounding quantity of a compound (D) is suitably adjusted so that it may harden | cure moderately by irradiation of light, and is not specifically limited. As an example of the compounding amount of the compound (D), the content of the compound (D) is 0% by weight or more, preferably 40% by weight or more, more preferably 60% by weight in 100% by weight of the curable composition for inkjet. % Or more, preferably 95% by weight or less, more preferably 90% by weight or less. In 100% by weight of the curable composition for inkjet, the upper limit of the content of the compound (D) is appropriately adjusted depending on the contents of the components (A) to (C), (E) and other components.

[Photoinitiator (E)]
In order to cure the curable composition by irradiation with light, the curable composition for inkjet according to the present invention preferably contains a photopolymerization initiator (E) together with the compound (D). Examples of the photopolymerization initiator (E) include a photoradical polymerization initiator and a photocationic polymerization initiator. The photopolymerization initiator (E) is preferably a radical photopolymerization initiator. As for a photoinitiator (E), only 1 type may be used and 2 or more types may be used together.

  The photo radical polymerization initiator is not particularly limited. The photo radical polymerization initiator is a compound for generating radicals upon light irradiation and initiating a radical polymerization reaction. Specific examples of the photo radical polymerization initiator include, for example, benzoin, benzoin alkyl ethers, acetophenones, aminoacetophenones, anthraquinones, thioxanthones, ketals, 2,4,5-triarylimidazole dimers, Examples include riboflavin tetrabutyrate, thiol compounds, 2,4,6-tris-s-triazine, organic halogen compounds, benzophenones, xanthones, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide. As for the said radical photopolymerization initiator, only 1 type may be used and 2 or more types may be used together.

  Examples of the benzoin alkyl ethers include benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether. Examples of the acetophenones include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone. Examples of the aminoacetophenones include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane. Examples include -1-one and N, N-dimethylaminoacetophene. Examples of the anthraquinones include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone. Examples of the thioxanthones include 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone. Examples of the ketals include acetophenone dimethyl ketal and benzyl dimethyl ketal. Examples of the thiol compound include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole. Examples of the organic halogen compound include 2,2,2-tribromoethanol and tribromomethylphenyl sulfone. Examples of the benzophenones include benzophenone and 4,4'-bisdiethylaminobenzophenone.

  The photo radical polymerization initiator is preferably an α-aminoalkylphenone type photo radical polymerization initiator. By using this specific radical photopolymerization initiator, the curable composition for inkjet can be efficiently photocured even if the exposure amount is small. For this reason, it can suppress effectively that the coated curable composition for inkjet by wet irradiation spreads, and can form a fine resist pattern with high precision.

  Specific examples of the α-aminoalkylphenone photoradical polymerization initiator include Irgacure 907, Irgacure 369, Irgacure 379, and Irgacure 379EG manufactured by BASF. Other α-aminoalkylphenone type photopolymerization initiators may be used.

  A photopolymerization initiation assistant may be used together with the photo radical polymerization initiator. Examples of the photopolymerization initiation assistant include N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine. Photopolymerization initiation assistants other than these may be used. As for the said photoinitiation adjuvant, only 1 type may be used and 2 or more types may be used together.

  In addition, a titanocene compound such as CGI-784 (manufactured by Ciba Specialty Chemicals) having absorption in the visible light region may be used to promote the photoreaction.

  It does not specifically limit as said photocationic polymerization initiator, For example, a sulfonium salt, an iodonium salt, a metallocene compound, a benzoin tosylate etc. are mentioned. As for the said photocationic polymerization initiator, only 1 type may be used and 2 or more types may be used together.

  The content of the photopolymerization initiator (E) is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, further preferably 3 parts by weight or more, preferably 100 parts by weight of the compound (D). 30 parts by weight or less, more preferably 15 parts by weight or less, still more preferably 10 parts by weight or less. When the content of the photopolymerization initiator (E) is not less than the above lower limit and not more than the above upper limit, the curable composition is more effectively cured by light irradiation.

[Other ingredients]
You may mix | blend various additives with the curable composition for inkjet which concerns on this invention in the range which does not inhibit the objective of this invention. The additive is not particularly limited, and examples thereof include a polymerization inhibitor, an antifoaming agent, a leveling agent, and an adhesion imparting agent.

  Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, pyrogallol and phenothiazine. Examples of the antifoaming agent include silicone-based antifoaming agents, fluorine-based antifoaming agents, and polymer-based antifoaming agents. Examples of the leveling agent include silicone leveling agents, fluorine leveling agents, and polymer leveling agents. Examples of the adhesion imparting agent include imidazole adhesion imparting agents, thiazole adhesion imparting agents, triazole adhesion imparting agents, and silane coupling agents.

  In the curable composition for inkjet according to the present invention, the viscosity at 25 ° C. measured in accordance with JIS K2283 is preferably 160 mPa · s or more and 1200 mPa · s or less. When the viscosity of the curable composition for inkjet is not less than the above lower limit and not more than the above upper limit, the curable composition for inkjet can be easily and accurately discharged from the inkjet head. Furthermore, even when the curable composition for inkjet is heated to 50 ° C. or higher, the composition can be easily and accurately discharged from the inkjet head.

  The viscosity is preferably 1000 mPa · s or less, more preferably 500 mPa · s or less. When the above viscosity satisfies the above preferable upper limit, when the curable composition is continuously ejected from the head, the ejectability becomes even better. Moreover, from the viewpoint of further suppressing the wetting and spreading of the curable composition and further increasing the resolution when forming the cured product layer, the viscosity preferably exceeds 500 mPa · s.

  The curable composition for inkjet according to the present invention does not contain an organic solvent, or contains an organic solvent, and the content of the organic solvent in 100% by weight of the curable composition is 50% by weight or less. preferable. In 100% by weight of the curable composition, the content of the organic solvent is more preferably 20% by weight or less, still more preferably 10% by weight or less, and particularly preferably 1% by weight or less. The smaller the content of the organic solvent, the better the resolution when forming the cured product layer.

(Method for manufacturing electronic parts)
Next, a method for manufacturing an electronic component according to the present invention will be described.

  The manufacturing method of the electronic component which concerns on this invention uses the above-mentioned curable composition for inkjets. That is, in the method for manufacturing an electronic component according to the present invention, first, the curable composition for inkjet is applied by an inkjet method to draw a pattern. At this time, it is particularly preferable to directly draw the curable composition for inkjet. “Direct drawing” means drawing without using a mask. Examples of the electronic component include a printed wiring board and a touch panel component. The electronic component is preferably a wiring board, and more preferably a printed wiring board.

  An ink jet printer is used for application of the ink jet curable composition. The ink jet printer has an ink jet head. The inkjet head has a nozzle. The ink jet device preferably includes a heating unit for heating the temperature in the ink jet device or the ink jet head to 50 ° C. or higher. It is preferable that the said inkjet curable composition is coated on the coating object member. A substrate etc. are mentioned as said coating object member. As this board | substrate, a printed circuit board, a glass substrate, etc. are mentioned. Further, examples of the substrate include a substrate having wirings provided on the upper surface. The inkjet curable composition is preferably applied onto a printed circuit board.

  In addition, the substrate can be changed to a glass-based member by the method for manufacturing an electronic component according to the present invention, and a glass substrate for a display device such as a liquid crystal display device can be manufactured. Specifically, a conductive pattern such as ITO is provided on glass by a method such as vapor deposition, and a cured product layer is formed on the conductive pattern by an inkjet method by the method for manufacturing an electronic component according to the present invention. Good. If a pattern is provided on the cured product layer with a conductive ink or the like, the cured product layer becomes an insulating film, and electrical connection is obtained between predetermined patterns in the conductive pattern on the glass.

  Next, heat is applied to the curable composition for inkjet drawn in a pattern and cured to form a cured product layer. Moreover, when using the inkjet curable composition containing the compound (D) which has a (meth) acryloyl group, and a photoinitiator (E) as an inkjet curable composition, the inkjet drawn in pattern shape The curable composition for use is irradiated with light and heated to be cured to form a cured product layer. In this way, an electronic component having a cured product layer can be obtained. The cured product layer may be an insulating film or a resist pattern. The insulating film may be a patterned insulating film. The cured product layer is preferably a resist pattern. The resist pattern is preferably a solder resist pattern.

  The method for manufacturing an electronic component according to the present invention is preferably a method for manufacturing a printed wiring board having a resist pattern. The inkjet curable composition is applied by an inkjet method, drawn in a pattern, and the inkjet curable composition drawn in a pattern is irradiated with light and heat, cured. It is preferable to form a resist pattern.

  The ink-jet curable composition drawn in a pattern may be primarily cured by irradiating light to obtain a primary cured product. Thereby, wetting and spreading of the drawn curable composition for inkjet can be suppressed, and a cured product layer such as a highly accurate resist pattern can be formed. In addition, when a primary cured product is obtained by light irradiation, the primary cured product may be subjected to main curing by applying heat to obtain a cured product, and a cured product layer such as a resist pattern may be formed. The curable composition for inkjet according to the present invention can be cured by light irradiation and heat application. When photocuring and thermosetting are used in combination, a resist pattern that is more excellent in heat resistance can be formed. The heating temperature for curing by applying heat is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower.

  The light irradiation may be performed after drawing or may be performed simultaneously with drawing. For example, light may be irradiated at the same time as or after the ejection of the curable composition. Thus, in order to irradiate light simultaneously with drawing, the light source may be arranged so that the light irradiation portion is positioned at the drawing position by the inkjet head.

  The light source for irradiating light is suitably selected according to the light to irradiate. Examples of the light source include a UV-LED, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, and a metal halide lamp. The irradiated light is generally ultraviolet rays, and may be an electron beam, α-ray, β-ray, γ-ray, X-ray, neutron beam, or the like.

  The temperature at the time of application | coating of the curable composition for inkjets will not be specifically limited if it is the temperature from which the curable composition for inkjets becomes the viscosity which can be discharged from an inkjet head. The temperature at the time of application of the curable composition for inkjet is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and preferably 100 ° C. or lower. The viscosity of the curable composition for inkjet at the time of coating is not particularly limited as long as it can be discharged from the inkjet head.

  Since the curable composition for inkjet according to the present invention has the specific composition described above, for example, even when the inkjet curable composition is heated in an inkjet head, the pot life of the curable composition for inkjet is Sufficiently long and stable discharge is possible. Furthermore, since the ink-jet curable composition can be heated to a viscosity suitable for coating by the ink-jet method, the use of the ink-jet curable composition according to the present invention suitably produces electronic components such as printed wiring boards. can do.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

  In Examples and Comparative Examples, the following pigment (C) was used. Moreover, the pH measured by the boiling method of the pigment (C) is also described.

Cyanine Blue 4930 (manufactured by Dainichi Seika Co., Ltd., phthalocyanine pigment, untreated, pH by boiling method = 6.5)
Cyanine blue 4966 (manufactured by Dainichi Seika Co., Ltd., phthalocyanine pigment, acid treatment, pH by boiling method = 5.2)
Cyanine Blue 4940 (manufactured by Dainichi Seika Co., Ltd., phthalocyanine pigment, basic treatment, pH = 7.5 by boiling method)
Toka Black # 8500 / F (manufactured by Tokai Carbon Co., Ltd., carbon black pigment, pH by boiling method = 5.5)
Toka Black # 7400 / F (manufactured by Tokai Carbon Co., Ltd., carbon black pigment, pH by boiling = 7.0)
Toka Black # 7360SB (manufactured by Tokai Carbon Co., Ltd., carbon black pigment, pH by boiling = 7.5)
Palliogen Red L 3875 (manufactured by BASF, perylene pigment, pH by boiling method = 5.0)

Example 1
20 parts by weight of a bisphenol A type epoxy resin (“YD-127” manufactured by Nippon Steel Chemical Co., Ltd.) corresponding to the compound (A) having a cyclic ether group, and a trimethylol corresponding to the compound (D) having a (meth) acryloyl group 80 parts by weight of methylolpropane triacrylate (“TMPTA” manufactured by Daicel Cytec Co., Ltd.) and 5 parts by weight of an α-aminoacetophenone type photoradical polymerization initiator (“Irgacure 907” manufactured by BASF) corresponding to the photopolymerization initiator (E) 1 part by weight of 2-ethyl-4-methylimidazole (“2E4MZ” manufactured by Shikoku Kasei Co., Ltd.) corresponding to the thermosetting agent (B), cyanine blue 4930 (manufactured by Dainichi Seika Co., Ltd., phthalocyanine pigment, untreated, boiled) PH = 6.5 by method) 0.2 part by weight was mixed to obtain a curable composition for inkjet.

(Examples 2-12 and Comparative Examples 1-2)
A curable composition for inkjet was obtained in the same manner as in Example 1 except that the types and contents of the blending components were changed as shown in Table 1 below.

(Evaluation)
(1) Viscosity Based on JIS K2283, the viscosity at 25 degreeC of the obtained curable composition for inkjets was measured using the viscometer ("TVE22L" by the Toki Sangyo company). The viscosity of the curable composition for inkjet was determined according to the following criteria.

[Criteria for viscosity]
A: Viscosity exceeds 1200 mPa · s B: Viscosity exceeds 1000 mPa · s C: Viscosity exceeds 500 mPa · s, 1000 mPa · s or less D: Viscosity is 160 mPa · s or more, 500 mPa · s or less E: Viscosity is less than 160 mPa · s

(2) Inkjet ejection property The ejection test of the obtained curable composition for inkjet was performed from the inkjet head of a piezo-type inkjet printer with an ultraviolet irradiation device, and evaluated according to the following criteria. The head temperature was set to 80 ° C. during the discharge test of the curable composition having a viscosity of 500 mPa · s or less, and the head temperature was set to 95 ° C. during the discharge test of the curable composition having a viscosity exceeding 500 mPa · s.

[Judgment criteria for ink jetting properties]
◯: The curable composition could be continuously discharged from the head for 10 hours or longer. ○: The curable composition could be discharged from the head continuously for 10 hours or longer, but during the continuous discharge of 10 hours. Slight discharge unevenness occurs Δ: The curable composition can be continuously discharged from the head, but cannot be discharged continuously for 10 hours or more. ×: The curable composition is discharged from the head at the initial stage. It was impossible to discharge

(3) Wetting and spreading An FR-4 substrate with copper foil having a copper foil attached to the upper surface was prepared. An ink-jet curable composition is coated on the substrate so as to cover the entire surface of the copper foil so that the line width is 80 μm and the line-to-line spacing is 80 μm from the ink-jet head of a piezo-type ink-jet printer with an ultraviolet irradiation device. It was discharged and applied to draw a pattern. In the ejection test of the curable composition for ink jet having a viscosity of 500 mPa · s or less, the head temperature is set to 80 ° C., and in the ejection test of the curable composition for ink jet having a viscosity exceeding 500 mPa · s, the head temperature is set to 95 ° C. C.

The curable composition for inkjet (thickness 20 μm) coated on the substrate was irradiated with ultraviolet rays having a wavelength of 365 nm so that the irradiation energy was 1000 mJ / cm ² . Five minutes after irradiation with ultraviolet rays, the wet spread of the pattern was visually observed, and the wet spread was determined according to the following criteria.

[Wetting and spreading criteria]
○○: Wet spread state is the target line width + 40 μm or less ○: Wet spread state exceeds the target line width + 40 μm and +75 μm or less ×: The composition layer is wet spread from the drawing portion, and between the lines The interval is lost or the wet spread condition exceeds the target line width +75 μm.

(4) Storage stability The viscosity of 80 degreeC of the obtained curable composition for inkjet was measured using the viscometer ("TVE22L" by the Toki Sangyo company).

  Next, the obtained curable composition for inkjet was heated in an oven at 80 ° C. for 12 hours. The viscosity at 80 ° C. of the obtained ink-jet curable composition after heating was measured using a viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.), and the viscosity change rate was measured based on the following calculation formula.

  Viscosity change rate = (viscosity at 80 ° C. after heating at 80 ° C. for 12 hours) / (viscosity at 80 ° C. before heating at 80 ° C. for 12 hours)

  From the obtained viscosity change rate, the storage stability was determined according to the following criteria.

[Criteria for storage stability]
○: Viscosity change rate is less than 1.5 ○: Viscosity change rate is 1.5 or more and less than 2 ×: Viscosity change rate is 2 or more

(5) Coloring uniformity of hardened | cured material The FR-4 board | substrate with copper foil in which the copper foil was affixed on the upper surface was prepared. On the copper foil on the substrate, the ink-jet curable composition was applied from the ink-jet head of a piezo-type ink-jet printer with an ultraviolet irradiation device so that the line width was 80 μm and the line-to-line spacing was 80 μm. , Drawn in a pattern. The head temperature was set to 80 ° C. during the discharge test of the curable composition having a viscosity of 500 mPa · s or less, and the head temperature was set to 95 ° C. during the discharge test of the curable composition having a viscosity exceeding 500 mPa · s.

The curable composition for inkjet (thickness 20 μm) drawn in a pattern was irradiated with ultraviolet rays having a wavelength of 365 nm so that the irradiation energy was 1000 mJ / cm ² to obtain a primary cured product. Next, the primary cured product was heated at 140 ° C. for 60 minutes to be fully cured to obtain a resist pattern as a cured product. The color uniformity of this resist pattern (cured product) was evaluated and judged according to the following criteria.

[Criteria for color uniformity of cured product]
○: No color irregularity △: Color irregularity is visually confirmed ×: Colored and non-colored parts are clearly confirmed

  The results are shown in Table 1 below.

  Examples 1 to 8 and Examples 10 to 12 in which the pigment (C) is a phthalocyanine pigment or a carbon black pigment, and the pH of the phthalocyanine pigment or the carbon black pigment is 3.0 or more and less than 7.3 by the above boiling method. Then, the pigment (C) is another pigment different from the phthalocyanine pigment and the carbon black pigment, and the pH of the other pigment by the boiling method is 3.0 or more and less than 7.3. Thus, the storage stability of the curable composition was even better.

  Further, in the curable compositions of Examples 1 to 4 and 6 to 10 using the α-aminoacetophenone type photopolymerization initiator, another photopolymerization initiator different from the α-aminoacetophenone type photopolymerization initiator is used. Compared with the curable compositions of Examples 11 and 12, there was less stickiness of the surface of the primary cured product after light irradiation and before thermosetting, and it was excellent in thermosetting at the time of thermosetting, and further insulation reliability It was confirmed that the evaluation results of were also good.

Claims (9)

A curable composition for inkjet that is applied by an inkjet method and cured by application of heat,
Including a compound having a cyclic ether group, a thermosetting agent, and a pigment,
The thermosetting agent is a compound having a nitrogen atom,
The pigment is heated in a solution obtained by adding 5 g of the pigment to 100 mL of pure water, boiled for 5 minutes, and allowed to stand until reaching 23 ° C. to obtain a boiling treatment liquid. A curable composition for inkjet, which is a pigment that exhibits a pH of 3.0 or more and less than 7.3 when the pH of a solution obtained by adding water in an amount of water evaporated by boiling to 100 mL is measured.   The pigment is heated in a solution obtained by adding 5 g of the pigment to 100 mL of pure water, boiled for 5 minutes, and then allowed to stand until reaching 23 ° C. to obtain a boiling treatment liquid. The inkjet curing according to claim 1, which is a pigment having a value of pH 3.0 or more and less than 6.3 when the pH of a liquid whose amount is 100 mL by adding water evaporated by boiling is measured. Sex composition.   The curable composition for inkjet according to claim 1 or 2, wherein the thermosetting agent is at least one selected from the group consisting of dicyandiamide, an imidazole compound, and a compound having a triazine ring.   The curable composition for inkjet according to any one of claims 1 to 3, wherein the pigment is a phthalocyanine pigment or a carbon black pigment. A curable composition for inkjet which is applied by an inkjet method and is curable by light irradiation and heat application,
The curable composition for inkjet according to any one of claims 1 to 4, further comprising a compound having a (meth) acryloyl group and a photopolymerization initiator.   The curable composition for inkjet according to any one of claims 1 to 5, wherein the viscosity at 25 ° C measured in accordance with JIS K2283 is 160 mPa · s or more and 1200 mPa · s or less. Applying the inkjet curable composition according to any one of claims 1 to 6 by an inkjet method, and drawing in a pattern;
A process for producing an electronic component, comprising: applying heat to the curable composition for inkjet drawn in a pattern and curing the composition to form a cured product layer. A method for manufacturing a printed wiring board, which is an electronic component having a resist pattern,
The ink-jet curable composition is applied by an ink-jet method, drawn in a pattern, and heat is applied to the ink-jet curable composition drawn in a pattern to be cured to form a resist pattern. The method of manufacturing an electronic component according to claim 7. As the inkjet curable composition, an inkjet curable composition containing a compound having a (meth) acryloyl group and a photopolymerization initiator,
In the process of forming the said hardened | cured material layer, light and heat are given to the said curable composition for inkjet drawn in pattern shape, it is made to harden | cure, The hardened | cured material layer is formed. The manufacturing method of the electronic component of description.