TWI598412B - Curable composition for inkjet, and method of manufacturing electronic parts - Google Patents

Description

Curable composition for inkjet and method for producing electronic component

The present invention relates to a curable composition for inkjet which is applied by an inkjet method, and relates to an inkjet curable composition suitable for forming a cured layer such as a resist pattern on a substrate, and A method of producing an electronic component having a cured layer formed of the inkjet curable composition.

Conventionally, a printed wiring board in which a solder resist pattern as a patterned solder resist film is formed on a substrate on which an upper surface is provided with wiring is used. With the miniaturization and high density of electronic equipment, printed wiring boards require a finer solder resist pattern.

As a method of forming a fine solder resist pattern, a method of applying a composition for a solder resist by an inkjet method has been proposed. The number of steps is reduced in the ink jet method as compared with the case where the solder resist pattern is formed by screen printing. Therefore, the ink jet method can form a solder resist pattern easily and efficiently.

In the case where the composition for a solder resist is applied by an inkjet method, the viscosity at the time of coating is required to be as low as a certain degree. On the other hand, in recent years, an ink jet apparatus capable of heating up to 50 ° C or higher has been developed. By increasing the temperature of the solder resist composition to 50° C. or higher in the ink jet apparatus, the viscosity of the solder resist composition is relatively low, and the discharge property of the solder resist composition using the ink jet apparatus can be further improved.

Further, Patent Document 1 listed below discloses a composition for a solder resist which can be applied by an inkjet method. Patent Document 1 listed below discloses a monomer comprising a (meth)acryl fluorenyl group and a thermosetting functional group, a photoreactive diluent having a weight average molecular weight of 700 or less, and a photopolymerization initiator. A curable composition for inkjet. The curable composition for inkjet has a viscosity at 25 ° C of 150 mPa ‧ s or less.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] WO2004/099272A1

The curable composition for inkjet described in Patent Document 1 has a relatively low viscosity. Therefore, the curable composition for inkjet described in Patent Document 1 can be applied onto a substrate by an inkjet method.

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

For example, when a curable composition for inkjet is ejected by an inkjet device, the curable composition for inkjet is usually left in the inkjet device after being supplied to the inkjet device for a certain period of time. On the other hand, in order to improve the discharge property, the temperature in the inkjet apparatus may be raised to 50 ° C or more. In the inkjet device for inkjet curing described in Patent Document 1, in the inkjet device which is heated to 50° C. or higher, the composition is hardened, the viscosity of the composition is increased, and the composition is difficult to be ejected.

An object of the present invention is to provide a curable composition for inkjet, and a method for producing an electronic component using the curable composition for inkjet, which is coated by an inkjet method, and is even added When the temperature is above 50 °C, the viscosity is not easy to change, and the pot life is longer.

According to a broad aspect of the present invention, there is provided a curable composition for inkjet which is applied by an inkjet method and which is cured by irradiation of light and heat, and includes two or more Photoreactivity of a compound containing a (meth) acrylonitrile group and a compound containing a (meth) acryl fluorenyl group, wherein a cyclic ether group of a cyclic ether group is converted into a (meth) acryl fluorenyl group The compound, a photopolymerization initiator, a compound having a cyclic ether group, and a latent curing agent have a viscosity at 25 ° C measured according to JIS K2283 of 160 mPa·s or more and 1200 mPa·s or less.

The compound containing a (meth) acrylonitrile group is preferably a bisphenol A type compound having two or more cyclic ether groups, or a bisphenol F type compound having two or more cyclic ether groups, and (meth) The reactant of acrylic acid. The compound having a cyclic ether group is preferably a bisphenol A epoxy compound or a bisphenol F epoxy compound.

In still another specific aspect of the curable composition for inkjet according to the present invention, the latent curing agent is dicyandiamide.

The photopolymerization initiator is preferably an α-aminophenanthrone type photoradical polymerization initiator. More preferably, the photopolymerization initiator is an α-aminophenanone type photoradical polymerization initiator having a dimethylamino group.

In another specific aspect of the curable composition for inkjet according to the present invention, the latent curing agent reacts dicyandiamide with a functional group-containing compound having a functional group reactive with the dicyandiamide. A reaction viscous material.

In another specific aspect of the curable composition for inkjet according to the present invention, the photoreactive material includes a polyfunctional compound having a polycyclic skeleton and having two or more (meth)acrylonium groups.

In still another specific aspect of the curable composition for inkjet according to the present invention, the photoreactive compound includes a monofunctional compound having a polycyclic skeleton and having one (meth)acryl fluorenyl group.

In still another specific aspect of the curable composition for inkjet according to the present invention, the photoreactive compound contains a polyfunctional compound having a polycyclic skeleton and having two or more (meth)acrylonium groups, and has a plurality of Both a ring skeleton and a monofunctional compound having one (meth)acryl fluorenyl group.

Moreover, according to a broad aspect of the present invention, there is provided a method of producing an electronic component, comprising the steps of: coating an inkjet curable composition according to the present invention by an inkjet method, and drawing it in a pattern; The above-mentioned inkjet curable composition drawn in a pattern is irradiated with light and heat is applied to be cured to form a cured layer.

In a specific aspect of the method for producing an electronic component according to the present invention, the method for producing a printed wiring board having an electronic component having a photoresist pattern is applied to the curable composition for inkjet by an inkjet method. In the form of a pattern, the inkjet curable composition drawn in a pattern is irradiated with light and heat is applied thereto to be cured to form a photoresist pattern.

The curable composition for inkjet according to the present invention contains a (meth)acrylonyl group-containing compound obtained by converting a cyclic ether group of a compound having two or more cyclic ether groups into a (meth) acrylonitrile group. A photoreactive compound, a photopolymerization initiator, a compound having a cyclic ether group, and a latent curing agent can be cured by irradiation of light and heat. Further, since the curable composition for inkjet according to the present invention has the above composition and has a viscosity of 160 mPa·s or more and 1200 mPa·s or less, it can be applied by an inkjet method. Further, since the curable composition for inkjet according to the present invention has the above-described composition, even if the temperature is raised to 50 ° C or higher, the viscosity does not easily change, and the pot life can be made longer.

Hereinafter, the details of the present invention will be described.

(curable composition for inkjet)

The curable composition for inkjet according to the present invention comprises a compound (A) containing a (meth) acrylonitrile group, a photoreactive compound (B), a photopolymerization initiator (C), and a compound having a cyclic ether group ( D), and latent hardener (E). The (meth)acrylonitrile group-containing compound (A) is a (meth)acryl fluorenyl group obtained by converting a cyclic ether group of a compound having two or more cyclic ether groups into a (meth) acrylonitrile group. Compound. The photoreactive compound (B) is a photoreactive compound other than the (meth) acrylonitrile group-containing compound (A). The term "(meth)acrylonitrile" means an acryloyl group and a methacryloyl group.

The curable composition for inkjet according to the present invention contains a (meth)acrylonium group-containing compound (A), a photoreactive compound (B), and a photopolymerization initiator (C), so that it can be irradiated with light. And hardened. Since the curable composition for inkjet according to the present invention contains the compound (D) having a cyclic ether group and the latent curing agent (E), it can be cured by the imparting of heat. Therefore, the curable composition for inkjet according to the present invention is an inkjet light and a thermosetting composition which can be cured by irradiation of light and heat. The curable composition for inkjet according to the present invention obtains a primary cured product by irradiation with light, and then is hardened by applying heat to the primary cured product, whereby a photoresist pattern as a cured product can be obtained. By performing primary hardening by irradiation of light, it is possible to suppress wettability of the curable composition for inkjet applied to a member to be coated such as a substrate. Therefore, a fine photoresist pattern can be formed with high precision.

Further, the curable composition for inkjet according to the present invention has a viscosity at 25 ° C measured according to JIS K2283 of 160 mPa ‧ s or more and 1200 mPa ‧ s or less. Since the curable composition for inkjet according to the present invention has the above composition and the viscosity is within the above range, it can be applied by an inkjet method.

Since the curable composition for inkjet according to the present invention has the above-described composition, the application period can be sufficiently long even in an environment in which the temperature is increased to 50 ° C or higher. In general, a curable composition for inkjet containing a compound having a cyclic ether group tends to have a relatively short pot life. However, by using the above composition, even if the compound (D) having a cyclic ether group and the latent curing agent (E) are contained, the viscosity change of the composition can be made small, and the pot life can be made long enough. When the curable composition for inkjet according to the present invention is heated to 50 ° C or higher, the viscosity is less likely to increase, and thermal hardening is less likely to proceed excessively. Therefore, the curable composition for inkjet is excellent in stability at a high temperature, and can be stably ejected from an inkjet nozzle.

Hereinafter, the details of each component contained in the curable composition for inkjet according to the present invention will be described.

[Compound (A) containing (meth)acrylinyl group]

The (meth)acrylonitrile group-containing compound (A) is a (meth)acryl fluorenyl group obtained by converting a cyclic ether group of a compound having two or more cyclic ether groups into a (meth) acrylonitrile group. Compound (A). Such compounds are themselves well known in the art. The compound (A) containing a (meth) acrylonitrile group may be used alone or in combination of two or more.

The compound (A) containing a (meth) acrylonitrile group can be obtained by, for example, a compound having two or more cyclic ether groups in the presence of a catalyst such as a basic catalyst (including a ring) The ether compound is reacted with (meth)acrylic acid. In this case, it is preferred that two or more cyclic ether groups are substantially converted into a (meth) acrylonitrile group. The compound obtained by this reaction usually has a hydroxyl group by a conversion reaction from a cyclic ether group to a (meth) acrylonitrile group. It is preferred that the compound (A) having a (meth) acrylonitrile group has a hydroxyl group. Preferably, the hydroxy group is produced by conversion of a cyclic ether group to a (meth) acrylonitrile group. The above terms "(meth)acrylic acid" mean acrylic acid and methacrylic acid. The term "(meth)acrylate" means acrylate and methacrylate.

It is preferably a compound containing (meth)acryl fluorenyl group which is partially (meth) acrylylated by conversion of 80% or more of a cyclic ether group to a (meth) acrylonitrile group (conversion ratio). More preferably, 90% or more of the cyclic ether group is converted into a (meth) acrylonitrile-containing compound containing a (meth) acrylonitrile group.

Examples of the cyclic ether group in the (meth)acryl fluorenyl group-containing compound (A) include an epoxy group and an oxetane group. Among these, the cyclic ether group is preferably an epoxy group from the viewpoint of improving the curability and obtaining a cured product which is more excellent in heat resistance.

Specific examples of the (meth)acryl fluorenyl group-containing compound (A) include bisphenol epoxy (meth) acrylate, cresol novolak epoxy (meth) acrylate, and carboxylic acid anhydride. Epoxy (meth) acrylate, phenol novolac type epoxy (meth) acrylate, and the like.

The compound (A) containing a (meth) acrylonitrile group is preferably a bisphenol type compound having two or more cyclic ether groups, from the viewpoint of further reducing the viscosity change at the time of temperature increase and further extending the pot life. The reaction product of a phenol novolak type compound having two or more cyclic ether groups and (meth)acrylic acid is more preferably a reaction product of a bisphenol type compound having two or more cyclic ether groups and (meth)acrylic acid. Examples of the bisphenol type compound include a bisphenol A type compound, a bisphenol F type compound, a bisphenol AD type compound, and a bisphenol S type compound. The (meth)acrylonitrile group-containing compound (A) is preferably a bisphenol A having two or more cyclic ether groups, from the viewpoint of further reducing the viscosity change at the time of temperature increase and further extending the pot life. A reaction of a type compound or a bisphenol F type compound having two or more cyclic ether groups with (meth)acrylic acid.

The (meth)acrylonitrile group-containing compound (A) is preferably a bisphenol type epoxy compound having two or more epoxy groups from the viewpoint of further reducing the viscosity change at the time of temperature increase and further extending the pot life. Or a reaction product of a phenol novolak type epoxy compound having two or more epoxy groups and (meth)acrylic acid, more preferably a bisphenol type epoxy compound having two or more epoxy groups and (meth)acrylic acid Reactant. Examples of the bisphenol type epoxy compound include a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol AD type epoxy compound, and a bisphenol S type epoxy compound. The compound (A) containing a (meth) acrylonitrile group is preferably a bisphenol A type having two or more epoxy groups, from the viewpoint of further reducing the viscosity change at the time of temperature increase and further extending the pot life. A reaction of an epoxy compound or a bisphenol F-type epoxy compound with (meth)acrylic acid.

In order to further reduce the change in viscosity at the time of temperature increase and to further extend the pot life, the compound having two or more cyclic ether groups for obtaining the (meth) acrylonitrile group-containing compound (A) is preferably Bisphenol A type epoxy compound or bisphenol F type epoxy compound.

The compounding amount of the (meth)acrylonitrile group-containing compound (A) is appropriately adjusted so as to be moderately hardened by irradiation of light and heat, and is not particularly limited. When the compounding amount of the compound (A) containing a (meth) acrylonitrile group is 100% by weight of the curable composition for inkjet, the content of the compound (A) is preferably 5% by weight or more and 70%. Below weight%. The content of the compound (A) is more preferably 10% by weight or more, and still more preferably 50% by weight or less, based on 100% by weight of the curable composition for inkjet. In the 100% by weight of the curable composition for inkjet, the upper limit of the content of the compound (A) is appropriately adjusted depending on the contents of the components (B) to (E) and other components.

[Photoreactive compound (B)]

The photoreactive compound (B) is a photoreactive compound other than the (meth) acrylonitrile group-containing compound (A). The photoreactive compound (B) can be hardened by irradiation with light. The photoreactive compound (B) may have a (meth) acrylonitrile group or a cyclic ether group. The photoreactive compound (B) preferably does not have both a (meth) acrylonitrile group and a cyclic ether group. As the photoreactive compound (B), a previously known photoreactive compound can be used. The photoreactive compound (B) may be used alone or in combination of two or more.

The photoreactive compound (B) may, for example, be a polyfunctional compound having two or more (meth)acrylonium groups and a monofunctional compound having one (meth)acrylonium group.

Examples of the polyfunctional compound include a (meth)acrylic acid addition product of a polyhydric alcohol, a (meth)acrylic acid addition product of an alkylene oxide modified product of a polyhydric alcohol, and a (meth)acrylic acid urethane type ester. And polyester (meth) acrylates and the like. Examples of the polyhydric alcohol include diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, trimethylolpropane, cyclohexane dimethanol, and tricyclodecane dimethanol. , an alkylene oxide adduct of bisphenol F, and pentaerythritol.

Specific examples of the polyfunctional compound in the photoreactive compound include triethylene glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, and the like. Dimethanol di(meth)acrylate, dicyclopentenyl dimethanol di(meth)acrylate, and the like.

Specific examples of the monofunctional compound in the photoreactive compound include (meth)acrylic acid. Ester, dihydroxycyclopentadienyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate And naphthyl (meth) acrylate.

The photoreactive compound (B) preferably contains a compound (B1) having a polycyclic skeleton and having a (meth)acrylinyl group. By using the compound (B1), the heat resistance of the cured product of the curable composition for inkjet can be improved. Therefore, the printed wiring board using the curable composition for inkjet of the present invention can be used for a long period of time, and the reliability of the printed wiring board can be improved.

The compound (B1) is preferably a polyfunctional compound (B1-1) having a polycyclic skeleton and having two or more (meth)acrylonium groups. Therefore, the photoreactive compound (B) preferably contains a polyfunctional compound (B1-1) having a polycyclic skeleton and having two or more (meth)acrylonium groups. The above compound (B1) is also preferably a monofunctional compound (B1-2) having a polycyclic skeleton and having one (meth)acryl fluorenyl group. Therefore, the photoreactive compound (B) is preferably a monofunctional compound (B1-2) having a polycyclic skeleton and having one (meth)acrylonium group. Among them, from the viewpoint of further improving the heat and humidity resistance of the cured product, a polyfunctional compound (B1-1) having a polycyclic skeleton and having two or more (meth)acrylonium groups is preferable.

Furthermore, it is more preferable that the photoreactive compound (B) contains a polyfunctional compound (B1-1) having a polycyclic skeleton and having two or more (meth)acryl fluorenyl groups, and has a polycyclic skeleton and has one Both (meth)acryloyl group-based monofunctional compounds (B1-2). In such a case, the heat resistance of the cured product of the curable composition for inkjet is further improved. Therefore, electronic components such as a printed wiring board using the curable composition for inkjet according to the present invention can be used for a long period of time, and the reliability of the electronic component is further improved. Moreover, by using the monofunctional compound (B1-2), not only the moist heat resistance of the cured product is improved, but also the discharge property of the curable composition is improved. Further, when a monofunctional compound (B1-2) having a polycyclic skeleton and having one (meth)acryl fluorenyl group is used, it has no polycyclic skeleton and has one (meth) In the case of a monofunctional compound of an acrylonitrile group, the heat and humidity resistance of the cured product is improved.

The polyfunctional compound (B1-1) is not particularly limited as long as it has a polycyclic skeleton and has two or more (meth)acrylonyl groups. As the polyfunctional compound (B1-1), a previously known polyfunctional compound having a polycyclic skeleton and having two or more (meth)acrylonium groups can be used. Since the polyfunctional compound (B1-1) has two or more (meth)acryl fluorenyl groups, it is polymerized by irradiation of light and hardened. The polyfunctional compound (B1-1) may be used alone or in combination of two or more.

Examples of the polyfunctional compound (B1-1) include a (meth)acrylic acid adduct of a polyhydric alcohol, an (meth)acrylic acid adduct of an alkylene oxide modified product of a polyhydric alcohol, and an amine group of (meth)acrylic acid. Formates, polyesters (meth) acrylates, etc. Examples of the polyhydric alcohol include diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, trimethylolpropane, and pentaerythritol.

Specific examples of the polyfunctional compound (B1-1) include tricyclodecane dimethanol di(meth)acrylate and different Dimethanol di(meth)acrylate, dicyclopentenyl dimethanol di(meth)acrylate, and the like. Among them, the polyfunctional compound (B1-1) is preferably tricyclodecane dimethanol di(meth)acrylate from the viewpoint of further improving the moist heat resistance of the cured product. The term "(meth)acrylate" means acrylate and methacrylate.

The monofunctional compound (B1-2) is not particularly limited as long as it has a polycyclic skeleton and has one (meth)acrylonyl group. As the monofunctional compound (B1-2), a previously known monofunctional compound having a polycyclic skeleton and having one (meth)acryl fluorenyl group can be used. The monofunctional compound (B1-2) may be used alone or in combination of two or more.

Specific examples of the above monofunctional compound (B1-2) include (meth)acrylic acid Ester, dihydroxycyclopentadienyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate And naphthyl (meth) acrylate. Among them, the monofunctional compound (B1-2) is preferably selected from (meth)acrylic acid from the viewpoint of further improving the heat and humidity resistance of the cured product. Ester, dihydroxycyclopentadienyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate and dicyclopentanyl (meth)acrylate At least one of the group consisting of.

The above "polycyclic skeleton" in the compound (B1) means a structure of a continuous plural number of cyclic skeletons. Examples of the polycyclic skeleton in the compound (B1) include a polycyclic alicyclic skeleton and a polycyclic aromatic skeleton.

Examples of the polycyclic alicyclic skeleton include a bicycloalkane skeleton, a tricycloalkane skeleton, a tetracycloalkane skeleton, and a different Base skeleton, etc.

Examples of the polycyclic aromatic skeleton include a naphthalene ring skeleton, an anthracene ring skeleton, a phenanthrene ring skeleton, and a naphthac ring skeleton. Ring skeleton, extended triphenyl ring skeleton, tetrafen ring skeleton, anthracene ring skeleton, pentacene ring skeleton, anthracene ring skeleton and anthracene ring skeleton.

The blending amount of the photoreactive compound (B) is appropriately adjusted so as to be moderately hardened by irradiation with light, and is not particularly limited. When the amount of the photoreactive compound (B) is 100% by weight, the content of the photoreactive compound (B) is preferably 20% by weight or more, and more preferably 30%. The weight% or more is preferably 90% by weight or less, more preferably 80% by weight or less. The upper limit of the content of the photoreactive compound (B) in 100% by weight of the curable composition for inkjet is appropriately adjusted depending on the content of the component (A), the components (C) to (E), and other components.

The content of the compound (B1) is preferably 5% by weight or more, more preferably 10% by weight or more, still more preferably 20% by weight or more, and preferably 95% by weight based on 100% by weight of the curable composition for inkjet. % or less, more preferably 90% by weight or less, still more preferably 70% by weight or less, and particularly preferably 60% by weight or less. The content of each of the compound (B1-1) and the compound (B1-2) is preferably 5% by weight or more, more preferably 10% by weight or more, and still more preferably 20% by weight based on 100% by weight of the curable composition for inkjet. The weight% or more is preferably 95% by weight or less, more preferably 90% by weight or less, still more preferably 70% by weight or less, particularly preferably 60% by weight or less, and most preferably 50% by weight or less. When the content of each of the compound (B1), the compound (B1-1), and the compound (B1-2) is at least the above lower limit, the moist heat resistance of the cured product is further improved. When the content of each of the compound (B1), the compound (B1-1), and the compound (B1-2) is at most the above upper limit, the curable composition can be efficiently cured by irradiation of light and heat.

[Photopolymerization initiator (C)]

In order to harden the curable composition by irradiation of light, the curable composition for inkjet according to the present invention contains a photopolymerization initiator (C). Examples of the photopolymerization initiator (C) include a photoradical polymerization initiator, a photocationic polymerization initiator, and the like. Preferably, the photopolymerization initiator (C) is a photoradical polymerization initiator. The photopolymerization initiator (C) may be used alone or in combination of two or more.

The photoradical polymerization initiator is not particularly limited. The photoradical polymerization initiator is a compound which generates a radical by irradiation of light and starts a radical polymerization reaction. Specific examples of the photoradical polymerization initiator include benzoin, benzoin alkyl ether, acetophenone, aminoacetophenone, anthraquinone, thioxanthone, and ketal. , 2,4,5-triaryl imidazole dimer, riboflavin tetrabutyrate, thiol compound, 2,4,6-tri-second-three , organohalogen compounds, diphenyl ketones, xanthone and 2,4,6-trimethylbenzimidyl diphenylphosphine. These photoradical polymerization initiators may be used alone or in combination of two or more.

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 and the like. As the above aminoacetophenones, 2-methyl-1-[4-(methylthio)phenyl]-2- Lolinylpropan-1-one, 2-benzyl-2-dimethylamino-1-(4- Polinylphenyl)-butan-1-one and N,N-dimethylaminoacetophenone and the like. Examples of the above hydrazines include 2-methylhydrazine, 2-ethylhydrazine, 2-tert-butylfluorene, and 1-chloroindole. Examples of the above thioxanthone include 2,4-dimethylthiaxanthone, 2,4-diethylthiaxanone, 2-chlorothiazinone, and 2,4-diisopropyl. Pyrithione and the like. Examples of the ketal include acetophenone dimethyl ketal and benzyl dimethyl ketal. Examples of the above thiol compound include 2-mercaptobenzimidazole and 2-mercaptobenzoene. Oxazole and 2-mercaptobenzothiazole. Examples of the organic halogen compound include 2,2,2-tribromoethanol and tribromomethylphenylhydrazine. Examples of the diphenyl ketones include diphenyl ketone and 4,4′-bisdiethylaminodiphenyl ketone.

The photoradical polymerization initiator is preferably an α-aminophenanthrone type photoradical polymerization initiator, more preferably an α-aminophenanone type photoradical polymerization having a dimethylamino group. Starting agent. By using this specific photoradical polymerization initiator, the curable composition for inkjet can be efficiently photocured even when the amount of exposure is small. Therefore, it is possible to efficiently suppress the wet spreading of the applied curable composition for inkjet by irradiation of light, and it is possible to form a fine photoresist pattern with high precision. Further, in the case where the photoradical polymerization initiator is an α-aminophenanthone type photopolymerization initiator having a dimethylamino group, the rate of thermal curing can be accelerated, and the composition can be irradiated with light. The material has good thermal hardening properties.

The present inventors have found that by using an α-aminophenytophenone type photoradical polymerization initiator having a dimethylamino group, not only photocurability but also thermosetting property can be changed. Good. The above-mentioned α-aminophenytophenone type photoradical polymerization initiator having a dimethylamino group is a component which contributes greatly to the improvement of thermosetting property. Further, by using an α-aminophenyl ketone type photoradical polymerization initiator having a dimethylamino group, heat resistance and insulation reliability of the cured product can be improved. When the insulation reliability is excellent, the electronic component such as a printed wiring board having the photoresist pattern formed of the curable composition for inkjet according to the present invention is used for a long period of time under high humidity conditions, and the insulation resistance is maintained sufficiently high. .

Specific examples of the α-aminophenanthrone type photoradical polymerization initiator include Irgacure 907, Irgacure 369, Irgacure 379, and Irgacure 379EG manufactured by BASF Corporation. An α-aminophenanone type photopolymerization initiator other than these may also be used. Among them, from the viewpoint of improving the photocurability of the curable composition for inkjet and the insulation reliability of the cured product, 2-benzyl-2-dimethylamino-1-(4) is preferred. - Oryl phenyl)-butanone-1 (Irgacure 369) or 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4- Phenyl)phenyl]-1-butanone (Irgacure 379 or Irgacure 379EG). These are α-aminophenenyl ketone type photoradical polymerization initiators having a dimethylamino group.

A photopolymerization initiation aid may also be used in combination with the above photoradical polymerization initiator. Examples of the photopolymerization initiation aid include ethyl N,N-dimethylaminobenzoate, isoamyl N,N-dimethylaminobenzoate, and pentyl-4-dimethylaminobenzoic acid. Acid esters, triethylamine and triethanolamine. Photopolymerization starters other than these may also be used. The photopolymerization initiation aid may be used singly or in combination of two or more.

Moreover, in order to promote a photoreaction, CGI-784 or the like (manufactured by Ciba Specialty Chemicals Co., Ltd.) having a absorption in the visible light region may be used.

The photocationic polymerization initiator is not particularly limited, and examples thereof include a phosphonium salt, a phosphonium salt, a metallocene compound, and a benzoin tosylate. The photocationic polymerization initiator may be used singly or in combination of two or more.

The content of the photopolymerization initiator (C) is preferably 0.1 part by weight or more, more preferably 100 parts by weight based on 100 parts by weight of the total of the (meth)acryloyl group-containing compound (A) and the photoreactive compound (B). 1 part by weight or more, more preferably 3 parts by weight or more, and still more preferably 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 (C) is at least the above lower limit and not more than the above upper limit, the curable composition is more efficiently cured by irradiation with light.

[Compound (D) having a cyclic ether group]

The compound (D) having a cyclic ether group is different from the compound (A) containing a (meth)acryl fluorenyl group and the photoreactive compound (B), and is not particularly specific as long as it has a cyclic ether group. limited. Examples of the cyclic ether group in the compound (D) include an epoxy group and an oxetane group. Among these, the cyclic ether group is preferably an epoxy group from the viewpoint of improving the curability and obtaining a cured product which is more excellent in heat resistance. The compound (D) having a cyclic ether group preferably has two or more cyclic ether groups. The compound (D) having a cyclic ether group preferably does not have a (meth) acrylonitrile group. The compound (D) which does not have a (meth) acryloyl group and has a cyclic ether group is different from the compound (A). The compound (D) having a cyclic ether group may be used alone or in combination of two or more.

Specific examples of the compound having an epoxy group include a bisphenol S-type epoxy compound, a diglycidyl phthalate compound, a heterocyclic epoxy compound such as triglycidyl isocyanurate, and a dimethicone. a phenol type epoxy compound, a biphenol type epoxy compound, a tetraglycidyl xylenyl ethane compound, a bisphenol A type epoxy compound, a hydrogenated bisphenol A type epoxy compound, a bisphenol F type epoxy compound, Bisphenol AD type epoxy compound, brominated bisphenol A type epoxy compound, phenol novolac type epoxy compound, cresol novolac type epoxy compound, alicyclic epoxy compound, bisphenol A novolak type ring Oxygen compound, chelate type epoxy compound, glyoxal type epoxy compound, amine group-containing epoxy compound, rubber modified epoxy compound, dicyclopentadiene novolac type epoxy compound, polyfluorene modified An epoxy compound and an ε-caprolactone modified epoxy compound.

The compound (D) having a cyclic ether group is preferably a bisphenol epoxy compound or a phenol novolak epoxy compound, from the viewpoint of further reducing the viscosity change at the time of temperature increase and further extending the pot life. It is a bisphenol type epoxy compound. Examples of the bisphenol type epoxy compound include a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol AD type epoxy compound, and a bisphenol S type epoxy compound. The compound (D) having a cyclic ether group is preferably a bisphenol A type epoxy compound or a bisphenol F type epoxy compound from the viewpoint of further reducing the viscosity change at the time of temperature increase and further extending the pot life. .

The compound (D) having a cyclic ether group preferably has an aromatic skeleton. By using a compound having an aromatic skeleton and a cyclic ether group, the curable composition is more excellent in heat stability during storage and at the time of discharge, and the curable composition is less likely to cause gelation during storage. Further, since the compound having an aromatic skeleton and a cyclic ether group is compared with a compound having no aromatic skeleton and having a cyclic ether group, the compound (A) containing a (meth) acrylonitrile group and a photoreactive compound (B) and the latent curing agent (E) are excellent in compatibility, so that insulation reliability is further improved.

A compound having an oxetane group is exemplified, for example, in Japanese Patent No. 3074086.

The compound (D) having a cyclic ether group is preferably liquid at 25 °C. The viscosity of the compound (D) having a cyclic ether group at 25 ° C is preferably more than 300 mPa ‧ s. The viscosity of the compound (D) having a cyclic ether group at 25 ° C is preferably 80 Pa‧s or less. When the viscosity of the compound (D) having a cyclic ether group is at least the above lower limit, the resolution at the time of forming the cured layer becomes more favorable. When the viscosity of the compound (D) having a cyclic ether group is at most the above upper limit, the discharge property of the curable composition is further improved, and compatibility of the compound (D) having a cyclic ether group with other components is obtained. Further improvement, insulation reliability is further improved.

The compounding amount of the compound (D) having a cyclic ether group is appropriately adjusted so as to be moderately hardened by the imparting of heat, and is not particularly limited. The content of the compound (D) having a cyclic ether group in 100% by weight of the curable composition for inkjet is preferably 3% by weight or more and 60% by weight or less. The content of the compound (D) having a cyclic ether group is preferably 5% by weight or more, and more preferably 50% by weight or less, based on 100% by weight of the curable composition for inkjet. When the content of the compound (D) is at least the above lower limit, the curable composition can be more efficiently cured by the application of heat. When the content of the compound (D) is at most the above upper limit, the heat resistance of the cured product is further improved, and the inkjet curable composition applied by the inkjet method can be further suppressed from being wet spread.

[latent hardener (E)]

The latent curing agent (E) is not particularly limited. As the latent curing agent (E), a previously known latent curing agent can be used. The latent curing agent (E) may be used alone or in combination of two or more.

Examples of the latent curing agent (E) include dicyandiamide and an anthraquinone compound.

The latent curing agent (E) is preferably dicyandiamide from the viewpoint of further reducing the change in viscosity at the time of temperature increase and further extending the pot life.

Specific examples of the latent curing agent (E) include latent hardening of triphenylphosphine (thermosetting agent) coated with an outer shell formed of a (meth)acrylic acid methyl ester resin or a styrene resin. Agents (such as "EPCAT-P" and "EPCAT-PS" manufactured by Nippon Kayaku Co., Ltd.), and latent hardening of a thermal hardener such as an amine coated with a shell formed of a polyurea polymer or a radical polymer. A latent hardener (Asahi Kasei E) obtained by dispersing a thermosetting agent such as modified imidazole in an epoxy resin and sealing it by re-pulverization (described in Japanese Patent No. 3031897 and Japanese Patent No. 3199818) - "Novacure HXA3792" and "HXA3932HP" manufactured by materails, a latent curing agent which disperses and contains a hardening agent in a thermoplastic polymer (described in Japanese Patent No. 3098061), and a tetraphenol compound. A coated imidazole latent curing agent (for example, "TEP-2E4MZ" and "HIPA-2E4MZ" manufactured by Japan's Soda". Latent hardeners other than those may also be used.

Preferably, the latent curing agent (E) is a reaction dope (E1) obtained by reacting dicyandiamide and a functional group-containing compound having a functional group reactive with the dicyandiamide. By using such a reactive dope (E1), the insulation reliability of the cured product can be improved. Further, the curable composition does not easily change even when the temperature is raised to 50 ° C or higher, and the pot life is increased.

In addition, the reactive dope (E1) may have a viscous property alone before being used for the curable composition for inkjet, and may not be viscous in the curable composition for inkjet. Further, when the reaction dope (E1) is taken out from the curable composition for inkjet, the reactive dope may be viscous.

Since dicyandiamide (dicyandiamide particles) which are solid at normal temperature (23 ° C) are present in a solid form in the liquid component, there is a possibility of precipitation during storage or clogging of the nozzle of the ink jet head. In order to solve such a problem, it is preferred to react dicyandiamide with a functional group-containing compound having a functional group reactive with the dicyandiamide to prepare a reactive dope (E1), which is then added to the composition. in. In other words, in the curable composition for inkjet according to the present invention, it is preferred to react the dicyandiamine with a functional group-containing compound having a functional group reactive with the dicyandiamide. The substance (E1) is used as a hardener (E). When the reactive dope (E1) is used, the pot life of the composition and the insulation reliability of the cured product become good.

It is preferred that the reaction dope (E1) before being formulated in the above-mentioned inkjet curable composition is not formulated in an organic solvent or blended in an organic solvent and is 100 parts by weight based on 100 parts by weight of the reaction dope (E1). The amount of the organic solvent to be formulated is 100 parts by weight or less. When the reaction viscous material (E1) is blended in an organic solvent, the amount of the organic solvent to be added to 100 parts by weight of the reaction viscous material (E1) is preferably 50 parts by weight or less, more preferably 20 parts by weight. The remainder is more preferably 10 parts by weight or less, particularly preferably 1 part by weight or less.

Preferably, the reaction viscous material (E1) is a reaction product obtained by reacting the functional group-containing compound with a part of active hydrogen of dicyandiamide. The functional group of the above functional group-containing compound which can be reacted with dicyandiamide is usually reacted with a part of the active hydrogen of dicyandiamide.

Preferably, the dicyandiamide which is reacted with the functional group-containing compound is in the form of a powder. By reacting the powdery dicyandiamide with the above functional group-containing compound, the above-mentioned reactive dope (E1) which is not powdery and viscous can be obtained.

From the viewpoint of easily synthesizing the above-mentioned reactive dope (E1) and further obtaining a curable composition having a long pot life, it is preferred that the functional group-containing compound which is reacted with the above dicyandiamide has a hydroxyl group selected from the group consisting of At least one functional group of the group consisting of a cyclic ether group, a carboxyl group, and an isocyanate group.

From the viewpoint of easily synthesizing the above reaction dope (E1) and further obtaining a curable composition having a long pot life, it is preferred that the functional group-containing compound which reacts with the above dicyandiamide has a cyclic ether. Base compound. The compound having a cyclic ether group which is reacted with dicyandiamide is preferably one having a cyclic ether group.

The above functional group-containing compound which reacts with the above dicyandiamide is preferably an epoxy group from the viewpoint of easily synthesizing the above reaction dope (E1) and further obtaining a curable composition having a long pot life. Compound. The epoxy group-containing compound which is reacted with dicyandiamide preferably has one epoxy group.

From the viewpoint of easily synthesizing the above-mentioned reaction dope (E1) and further obtaining a curable composition for inkjet which has a long pot life, and further improving the heat resistance of the cured product of the curable composition, The functional group-containing compound which reacts with the above dicyandiamide preferably has an aromatic skeleton, more preferably a compound having an aromatic skeleton and a cyclic ether group, and particularly preferably a compound having an aromatic skeleton and an epoxy group.

Specific examples of the functional group-containing compound include phenyl glycidyl ether, butyl glycidyl ether, o-cresyl glycidyl ether, m-cresol glycidyl ether, p-cresol glycidyl ether, and alkene. a glycidyl ether such as propyl glycidyl ether or p-tert-butylphenyl glycidyl ether, or glycidyl (meth)acrylate, and 3,4-epoxycyclohexylmethyl (meth)acrylate .

From the viewpoint of further improving the heat resistance of the cured product, the functional group-containing compound preferably has an aromatic ring phenyl glycidyl ether, o-cresyl glycidyl ether, m-cresol glycidyl ether, and a pair. Phenol glycidyl ether or p-tert-butylphenyl glycidyl ether.

In the reaction of the above dicyandiamide with the above functional group-containing compound, it is preferred to make 1 mole of dicyandiamide and preferably 0.2 mole or more, more preferably 1 mole or more, and more preferably 4 The above functional group-containing compound having a molar ratio of 3 moles or less is preferably reacted. That is, it is preferred that the above reaction dope (E1) is such that 1 mol of dicyandiamide is preferably 0.2 mol or more, more preferably 1 mol or more, and preferably 4 m or less or less. A reaction viscous material obtained by reacting the above functional group-containing compound of 3 mol or less. From the viewpoint of obtaining a curable composition having a more excellent pot life, it is particularly preferred that the above reaction dope (E1) is one mole of the above dicyandiamide and one mole or more and 3 moles or less of the above. A reaction dope comprising a functional group-containing compound. When the amount of the functional group-containing compound used is less than the above lower limit, there is an unreacted dicyandiamide precipitated. When the amount of the functional group-containing compound used exceeds the above upper limit, all of the active hydrogen in the reaction dope is deactivated, and the compound (D) cannot be cured. Further, in the reaction, it is preferred to carry out the reaction at 60 ° C to 140 ° C in the presence of a solvent or a reaction accelerator as needed.

When the dicyandiamide is reacted with the above functional group-containing compound, a solvent may be used in order to dissolve the dicyandiamide. The solvent may be any solvent which can dissolve dicyandiamide. Examples of the solvent that can be used include acetone, methyl ethyl ketone, dimethylformamide, and methyl cellosolve.

In order to promote the reaction of the above dicyandiamide with the above functional group-containing compound, a reaction accelerator may also be used. As the reaction accelerator, a known reaction accelerator such as a phenol, an amine, an imidazole or triphenylphosphine can be used.

In the curable composition for inkjet according to the present invention, the reactive dope (E1) is preferably a compound having a cyclic ether group (D) from the viewpoint of suppressing the decrease in the pot life and suppressing the unevenness of the hardening. It is compatible, preferably compatible with the (meth)acryloyl group-containing compound (A), preferably compatible with the photoreactive compound (B), and further preferably dissolved in the curable composition.

The above reaction dope (E1) is preferably compatible with the compound (D) having a cyclic ether group, and is preferably compatible with the compound (A) having a (meth)acryloyl group, preferably Compatible with the photoreactive compound (B).

The above reactive viscous material (E1) is a non-powdered reaction viscous material obtained by, for example, a reaction of a powdery dicyandiamide with the above functional group-containing compound. The reaction dope (E1) is preferably not a solid, and is preferably not crystalline, and is preferably not a crystalline solid, from the viewpoint of further improving the ink jet ejectability. Preferably, the reaction viscous material (E1) is liquid or semi-solid.

Preferably, the above reactive viscous material (E1) is transparent or translucent. Whether the above-mentioned reactive dope (E1) is transparent or translucent can be judged by judging whether the object can be recognized when the object is observed through the above-mentioned reactive dope (E1) having a thickness of 5 mm.

The compounding ratio of the compound (D) having a cyclic ether group to the latent curing agent (E) is not particularly limited. The content of the latent curing agent (E) per 100 parts by weight of the compound (D) having a cyclic ether group is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, and preferably 70 parts by weight or less or less. It is preferably 50 parts by weight or less.

[Other ingredients]

The curable composition for inkjet according to the present invention may contain a thermosetting agent other than the latent curing agent (E) while containing the latent curing agent (E). Further, the curable composition for inkjet according to the present invention may contain a curing accelerator.

Specific examples of the above-mentioned thermosetting agent include an organic acid, an amine compound, a guanamine compound, an anthraquinone compound, an imidazole compound, an imidazoline compound, a phenol compound, a urea compound, a polysulfide compound, and an acid anhydride. As the above-mentioned thermosetting agent, an amine-epoxy adduct or the like can be used to modify the polyamine compound.

Examples of the curing accelerator include a tertiary amine, an imidazole, a quaternary ammonium salt, a quaternary phosphonium salt, an organic metal salt, a phosphorus compound, and a urea compound.

The curable composition for inkjet according to the present invention may contain a solvent as needed in order to adjust the viscosity and the like. As the solvent, it is preferred not to react with the components in the curable composition. It is preferably a volatile solvent for heating in an oven or a hot plate before the hardening reaction of the curable composition, and drying by decompression in a decompression chamber. Further, the curable composition for inkjet according to the present invention may contain an organic solvent if the amount is small.

In the curable composition for inkjet according to the present invention, various additives can be formulated within a range not inhibiting the object of the present invention. The additive is not particularly limited, and examples thereof include a colorant, a polymerization inhibitor, an antifoaming agent, a leveling agent, and an adhesion imparting agent.

Examples of the coloring agent include phthalocyanine blue, phthalocyanine green, iodine green, bisazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black. Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, tert-butyl catechol, pyrogallol, and phenolthiophene. Wait. Examples of the antifoaming agent include a polyfluorene-based antifoaming agent, a fluorine-based antifoaming agent, and a polymer-based antifoaming agent. Examples of the leveling agent include a polyfluorene-based leveling agent, a fluorine-based leveling agent, and a polymer-based leveling agent. Examples of the adhesion imparting agent include an imidazole-based adhesion imparting agent, a thiazole-based adhesion imparting agent, a triazole-based adhesion imparting agent, and a decane coupling agent.

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 ejected from the inkjet head easily and with high precision. Further, even when the curable composition for inkjet is heated to 50 ° C or higher, the composition can be easily and accurately ejected from the inkjet head.

The above viscosity is preferably 1000 mPa‧s or less, and more preferably less than 500 mPa‧s. When the viscosity is more than the above-described upper limit, the discharge property is further improved when the curable composition is continuously discharged from the ink jet head. Further, from the viewpoint of further suppressing the wetting and spreading of the curable composition and further improving the resolution at the time of forming the cured layer, the viscosity is preferably 500 mPa·s or more.

Moreover, there is also a method of cooling the substrate during printing. When the substrate is cooled, the viscosity of the curable composition increases when it reaches the substrate, and the resolution is improved. At this time, it is preferable to dehumidify the air in the environment so that the cooling is not to be dew condensation or in a manner that does not condense. Moreover, since the substrate shrinks due to cooling, the dimensional accuracy can be corrected.

The curable composition for inkjet according to the present invention preferably contains no 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. The content of the organic solvent in the 100% by weight of the curable composition 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 above organic solvent, the more the resolution at the time of forming the cured layer becomes better.

The curable composition for inkjet according to the present invention preferably contains no organic solvent, or contains an organic solvent, and the content of the organic solvent is 50 parts by weight or less based on 100 parts by weight of the reactive viscous material (E1). The content of the organic solvent is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, even more preferably 1 part by weight or less based on 100 parts by weight of the reaction viscous material (E1). The smaller the content of the above organic solvent, the more the resolution at the time of forming the cured layer becomes better.

(Manufacturing method of electronic parts)

Next, a method of manufacturing the electronic component of the present invention will be described.

The method for producing an electronic component of the present invention is characterized in that the above-mentioned curable composition for inkjet is used. That is, in the method of producing an electronic component of the present invention, first, the curable composition for inkjet is applied by an inkjet method, and a pattern is drawn. In this case, it is particularly preferable to directly draw the above-mentioned curable composition for inkjet. The term "direct drawing" refers to drawing without using a mask. Examples of the electronic component include a printed wiring board and a touch panel component. The above electronic component is preferably a wiring board, more preferably a printed wiring board.

The above-mentioned inkjet hardenable composition is applied by using an ink jet printer. The ink jet printer has an ink jet head. The ink jet head has a nozzle. Preferably, the ink jet apparatus is provided with a temperature increasing portion for increasing the temperature in the ink jet apparatus or in the ink jet head to 50 ° C or higher. Preferably, the above-mentioned curable composition for inkjet is applied onto a member to be coated. Examples of the coating target member include a substrate and the like. Examples of the substrate include a substrate on which wiring or the like is provided on the upper surface. The above-mentioned curable composition for inkjet is preferably applied onto a printed substrate.

Moreover, according to the method of manufacturing an electronic component of the present invention, the substrate can be made into a glass-based member, and a glass substrate for a display device such as a liquid crystal display device can be produced. Specifically, a conductive pattern of ITO (Indium-Tin Oxide) or the like may be provided on the glass by a method such as vapor deposition, and then the inkjet method is applied to the conductive pattern by the manufacturing method of the electronic component of the present invention. A hardened layer is formed. If the conductive ink is used to be equal to the pattern provided on the cured layer, the cured layer becomes an insulating film, and in the conductive pattern on the glass, an electrical connection can be obtained between the specific patterns.

Then, the inkjet curable composition drawn in a pattern is irradiated with light and heat is applied to be cured to form a cured layer. In this way, an electronic component having a cured layer can be obtained. The cured layer may be an insulating film or a photoresist pattern. The insulating film may be in the form of a pattern. Preferably, the cured layer is a photoresist pattern. Preferably, the photoresist pattern is a solder resist pattern.

Preferably, the method of manufacturing an electronic component of the present invention is a method of manufacturing a printed wiring board having a photoresist pattern. It is preferable that the curable composition for inkjet is applied by an inkjet method and drawn into a pattern, and then the inkjet curable composition drawn in a pattern is irradiated with light and heat is applied thereto to be cured. Resistive pattern.

The primary curable composition can be obtained by irradiating light to the above-described curable composition for inkjet which is drawn in a pattern to be hardened once. Thereby, the wet spreading of the inkjet hardenable composition to be drawn can be suppressed, and a highly precise photoresist pattern can be formed. Further, when a cured product is obtained by irradiation of light, heat is applied to the primary cured product to be hardened, whereby a cured product can be obtained to form a photoresist pattern. The curable composition for inkjet according to the present invention can be cured by irradiation of light and heat. When photohardening and thermal hardening are used together, a photoresist pattern which is more excellent in heat resistance can be formed. The heating temperature at the time of hardening by heat application is preferably 100 ° C or more, more preferably 120 ° C or more, preferably 250 ° C or less, more preferably 200 ° C or less.

The irradiation of the light may be performed after the drawing, or may be performed simultaneously with the drawing. For example, the light may be irradiated while the curable composition is ejected, or may be irradiated immediately after the ejecting. As described above, since the light is irradiated at the same time as the drawing, the light source can be disposed such that the light irradiation portion is positioned at the drawing position by the ink jet head.

The light source for illuminating light is suitably selected depending on the light to be irradiated. Examples of the light source include a UV-LED (Ultraviolet-Light Emitting Diode), 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 light to be irradiated is usually ultraviolet rays, and may be an electron beam, an alpha ray, a beta ray, a gamma ray, an X ray, a neutron beam or the like.

The temperature at the time of application of the curable composition for inkjet is not particularly limited as long as the curable composition for inkjet is a temperature at which the viscosity can be ejected from the inkjet head. The temperature at the time of application of the curable composition for inkjet is preferably 50 ° C or more, more preferably 60 ° C or more, and is preferably 100 ° C or less. The viscosity of the curable composition for inkjet at the time of application is not particularly limited as long as it can be ejected from the inkjet head.

Moreover, there is also a method of cooling the substrate during printing. When the substrate is cooled, the viscosity of the curable composition increases when it reaches the substrate, and the resolution is improved. At this time, it is preferable to dehumidify the air in the environment so that the cooling is not to be dew condensation or in a manner that does not condense. Moreover, since the substrate shrinks due to cooling, the dimensional accuracy can be corrected.

Since the curable composition for inkjet according to the present invention contains the latent curing agent (E), the curable composition for inkjet is used when the curable composition for inkjet is heated, for example, in an inkjet head. The period of application is also long enough. And it can be sprayed stably. Further, since the curable composition for inkjet can be heated until it is suitable for application by the inkjet method, the inkjet curable composition of the present invention can be preferably used for printing. Electronic components such as circuit boards.

Hereinafter, the present invention will be specifically described by way of examples and comparative examples. The invention is not limited to the following examples.

(Synthesis Example 1)

To a three-necked flask equipped with a stirrer, a thermometer, and a dropping funnel, 50 g of methyl cellosolve, 15 g of dicyandiamide, and 2,4-diamino-6-[2'-undecylimidazolyl were added. -(1')]-ethyl-second-three 1 g and heated to 100 ° C to dissolve the dicyandiamide. After the dissolution, 130 g of butyl glycidyl ether was added dropwise from the dropping funnel over 20 minutes, and the mixture was allowed to react for 1 hour. Thereafter, the temperature was lowered to 60 ° C, and the solvent was removed under reduced pressure to obtain a yellow and translucent reaction viscous material. The reaction dope obtained is solvent free.

(Synthesis Example 2)

To a three-necked flask equipped with a stirrer, a thermometer, and a dropping funnel, 50 g of methyl cellosolve, 15 g of dicyandiamide, and 2,4-diamino-6-[2'-undecylimidazolyl were added. -(1')]-ethyl-second-three 1 g and heated to 100 ° C to dissolve the dicyandiamide. After the dissolution, 40 g of o-cresyl glycidyl ether was added dropwise from the dropping funnel over 20 minutes, and the mixture was allowed to react for 1 hour. Thereafter, the temperature was lowered to 60 ° C, and the solvent was removed under reduced pressure to obtain a yellow and translucent reaction viscous material. The reaction dope obtained is solvent free.

(Synthesis Example 3)

A yellow and translucent reaction viscous material was obtained in the same manner as in Synthesis Example 2 except that the dropwise addition amount of o-cresyl glycidyl ether was changed from 40 g to 95 g. The reaction dope obtained is solvent free.

The reaction dope obtained in Synthesis Examples 1 to 3 corresponds to a latent curing agent (E).

Further, the materials shown in Table 1 below were suitably used in the examples and comparative examples.

In the above Table 1, EBECRYL 3700, KRM 8570, and PNA-161H correspond to the compound (A) having a (meth)acrylonyl group and a cyclic ether group. DICY7 and SDH are equivalent to latent hardener (E).

(Example 1)

30 parts by weight of an epoxy acrylate ("EBECRYL 3700" manufactured by Daicel-Cytec Co., Ltd.) corresponding to a bisphenol A type epoxy compound containing a (meth) acrylonitrile group-containing compound (A), which corresponds to a photoreactive compound 40 parts by weight of (B) triethylene glycol diacrylate, corresponding to the acrylic acid of the photoreactive compound (B) 10 parts by weight of a bisphenol A type epoxy compound ("jER828" manufactured by Mitsubishi Chemical Corporation) corresponding to a compound (D) having a cyclic ether group, and an Irgacure equivalent to a photopolymerization initiator (C) 907 (α-aminoacetophenone type photoradical polymerization initiator, manufactured by BASF Japan Co., Ltd.) 4 parts by weight, and dicyandiamide equivalent to latent curing agent (E) (DICY7 manufactured by Mitsubishi Chemical Corporation) 1 part by weight of the mixture was mixed to obtain a curable composition for inkjet.

(Examples 2 to 32 and Comparative Examples 1 and 2)

A curable composition for inkjet was obtained in the same manner as in Example 1 except that the types and the amounts of the components to be formulated were changed as shown in the following Tables 2 to 4.

Further, in the curable composition for inkjet obtained in Examples 20 to 32, the reactive dope is compatible with a compound containing a (meth)acryl fluorenyl group, is compatible with a photoreactive compound, and has a ring shape. The ether group compound is compatible and further soluble in the curable composition.

(Evaluation)

(1) Viscosity

The viscosity of the obtained curable composition for inkjet at 25 ° C was measured using an E-type viscometer ("TVE22L" manufactured by Toki Sangyo Co., Ltd.) in accordance with JIS K2283.

(2) spouting

An inkjet head of a piezoelectric inkjet printer equipped with an ultraviolet irradiation device sprays a curable composition for inkjet onto a substrate. In the above-described drawing of the above-described ink jet printer, it was visually evaluated whether or not the curable composition was ejected, and the discharge property was determined based on the following criteria. Further, in the discharge test of the curable composition having a viscosity of 500 mPa ‧ or less, the temperature of the ink jet head was set to 80 ° C, and the spray test of the curable composition having a viscosity of more than 500 mPa ‧ was sprayed The head temperature was set to 95 °C.

[Judgement criteria for spouting]

○○: The curable composition can be continuously ejected from the inkjet head for more than 10 hours.

○: The curable composition can be continuously ejected from the inkjet head for 10 hours or more, but uneven discharge is slightly generated between 10 hours of continuous ejection.

Δ: The curable composition can be continuously ejected from the inkjet head, but it cannot be continuously ejected for more than 10 hours.

X: The curable composition cannot be ejected at the initial stage of ejecting from the inkjet head

(3) Wetting and spreading

An FR-4 substrate with a copper foil attached to a copper foil on the upper surface is prepared. The inkjet head for a piezoelectric inkjet printer equipped with an ultraviolet irradiation device has a line width of 80 μm and an interval between lines of 80 so as to cover the entire surface of the copper foil. The film was sprayed on the substrate in a μm manner and patterned in a pattern. In the discharge test of the curable composition for inkjet having a viscosity of 500 mPa·s or less, the inkjet head temperature was set to 80° C., and the curable composition for inkjet having a viscosity of more than 500 mPa·s was used. In the discharge test, the head temperature was set to 95 °C.

Ultraviolet rays having a wavelength of 365 nm were applied to the curable composition for inkjet (thickness: 20 μm) applied to the substrate so that the irradiation energy was 1000 mJ/cm ² .

After the ultraviolet ray was irradiated for 5 minutes, the wetting spread of the pattern was visually observed, and the wetting spread was judged by the following criteria.

[Determination criteria for wetting and spreading]

○○: The state of wet spreading is the target line width +40 μm or less

○: The state of the wetting spread exceeds the target line width +40 μm and is 75 μm or less.

×: The composition layer is wet-laid from the drawing portion, the interval between the lines disappears, or the state of wet spreading spread exceeds the target line width +75 μm

(4) Storage stability (length of pot life)

The obtained curable composition for inkjet was heated at 80 ° C for 12 hours.

An FR-4 substrate with a copper foil attached to a copper foil on the upper surface is prepared. An attempt was made to warm the substrate to 80 ° C and spray it on a substrate from a piezoelectric inkjet printer (jet head temperature: 80 ° C) with an ultraviolet irradiation device so as to cover the entire surface of the copper foil. In the head, the curable composition for inkjet was sprayed so as to have a line width of 80 μm and an interval between the lines of 80 μm, and was applied and drawn into a pattern. According to the discharge property from the ink jet head at this time, the storage stability was determined based on the following criteria.

[Criteria for the determination of storage stability]

○○○: The composition can be continuously ejected from the inkjet head for more than 10 hours.

○○: The composition can be continuously ejected from the inkjet head for 1 hour or more and less than 10 hours.

○: The composition can be continuously ejected from the inkjet head for 10 minutes or more and less than 1 hour.

Δ: The composition can be continuously ejected from the inkjet head for less than 1 minute.

×: The composition hardens before the ejection, or the viscosity of the composition rises, and the composition cannot be ejected from the inkjet head

(5) Insulation reliability (migration resistance)

Prepare the comb type test pattern B of IPC-B-25. The comb type test pattern B is warmed to 80 ° C, and is sprayed and coated by an ink jet head of a piezoelectric ink jet printer with an ultraviolet irradiation device so as to cover the entire surface of the comb type test pattern B. A curable composition for ink. In the discharge test of the curable composition for inkjet having a viscosity of 500 mPa·s or less, the inkjet head temperature was set to 80° C., and the curable composition for inkjet having a viscosity of more than 500 mPa·s was used. In the discharge test, the head temperature was set to 95 °C.

The coated inkjet curable composition (thickness: 20 μm) was irradiated with ultraviolet rays having a wavelength of 365 nm using a high-pressure mercury lamp so that the irradiation energy became 1000 mJ/cm ² . Then, the primary cured product was heated at 150 ° C for 60 minutes to be completely hardened, and a photoresist pattern as a cured product was formed to obtain a test piece.

The obtained test piece was subjected to a 500-hour humidification test at 85 ° C, a relative humidity of 85%, and a direct current of 50 V. The insulation resistance after the humidification test was measured, and the insulation reliability was determined based on the following criteria.

[Determination of insulation reliability]

○: Insulation resistance is 3 × 10 ¹⁰ Ω or more

Δ: Insulation resistance is 1 × 10 ⁹ Ω or more, and less than 3 × 10 ¹⁰ Ω

×: The insulation resistance is less than 1 × 10 ⁹ Ω

The results are shown in Tables 2 to 4 below. Furthermore, in Tables 2 to 4 below, "-" indicates that no evaluation was made.

Further, in the curable composition of Examples 1 to 17, 20 to 32 in which an α-aminoacetophenone type photopolymerization initiator is used, an α-aminoacetophenone type photopolymerization initiator is used. In addition to the curable composition of Examples 18 and 19 other than the photopolymerization initiator, the surface of the primary cured product after the light irradiation and before the thermal curing is less sticky, and the thermosetting property at the time of thermosetting is also excellent. Furthermore, the evaluation results of the insulation reliability were also good.

Further, Examples 1 to 8 using an α-aminophenytophenone type photoradical polymerization initiator having no dimethylamino group and starting with an α-aminophenanthone type photoradical polymerization were used. In Examples 18 and 19 of the photoradical polymerization initiator other than the agent, the evaluation results of the insulation reliability were all "Δ", but the α-aminophenylidene type optical free of dimethylamino group was used. Examples 18 and 19 of the values of the insulation resistance in Examples 1 to 8 of the base polymerization initiator and the photoradical polymerization initiator other than the α-aminophenyl ketone type photoradical polymerization initiator The value of the insulation resistance is relatively high.

Further, in Examples 9, 20, and 29, the evaluation results of the insulation reliability (migration resistance) were all "○", but the value of the insulation resistance of Example 29 was compared with the value of the insulation resistance of Example 9. The height is higher than the value of the insulation resistance of the embodiment 20.

Moreover, in the examples, the following heat and humidity resistance (heat resistance and moisture resistance) were evaluated.

(6) Humidity resistance (heat resistance and moisture resistance)

A glass epoxy substrate (100 mm × 100 mm) provided with copper wiring on the upper surface was prepared. An ink jet head of a piezoelectric ink jet printer equipped with an ultraviolet irradiation device ejects a curable composition for inkjet and applies it to the substrate in its entirety. Further, in the discharge test of the curable composition having a viscosity of 500 mPa ‧ or less, the temperature of the ink jet head was set to 80 ° C, and the spray test of the curable composition having a viscosity of more than 500 mPa ‧ was sprayed The head temperature was set to 95 °C.

The ultraviolet curable composition (thickness: 20 μm) applied to the substrate was irradiated with ultraviolet light having a wavelength of 365 nm, and then heated at 180 ° C for 1 hour so that the irradiation energy was 1000 mJ/cm ² . Hardened material (thickness 20 μm).

The obtained laminate of the substrate and the cured product was allowed to stand under conditions of 130 ° C and a relative humidity of 85% RH for 24 hours. Then, the adhesion of the cured product to the substrate was confirmed by a hundred-square test (JIS 5400 6.15), and the moist heat resistance was determined based on the following criteria. Using a cutter, 100 slits were formed on the hardened material at intervals of 1 mm in a grid shape, and then a cellophane tape (JIS Z1522) was attached to the cured product having the slit portion, and one end of the tape was 45 degrees. The angle is strongly peeled off and the peeling state is confirmed.

As a result, in the case of the curable composition of Example 32 containing the polyfunctional compound (A1-1) having a polycyclic skeleton and having two or more (meth)acryl fluorenyl groups, the cured product at the time of tape peeling Do not peel off. In the case of the curable composition of Examples 1 to 31 which does not contain the polyfunctional compound (A1-1) having a polycyclic skeleton and having two or more (meth)acrylinyl groups, the cured product is peeled off at the time of tape peeling. Part or all of it peeled off. However, in the case of the curable composition of Examples 1 to 31, the cured product before peeling of the tape was not peeled off.

Claims (12)

A curable composition for inkjet which is applied by an inkjet method and which is cured by irradiation of light and heat, and is used for forming a solder resist film which is irradiated with light. And imparting heat to form a cured layer containing 80% or more of an epoxy group of a compound having two or more epoxy groups and reacting with (meth)acrylic acid to introduce a (meth)acrylonitrile group (meth)acryloyl group-containing compound, photoreactive compound other than the above (meth)acryloyl group-containing compound, photoradical polymerization initiator, epoxy group-containing compound, and latent curing agent And the viscosity at 25 ° C measured according to JIS K2283 is 230 mPa. Above s, 1200mPa. s below. The curable composition for inkjet according to claim 1, wherein the compound containing a (meth)acryl fluorenyl group is a bisphenol A type compound having two or more epoxy groups or a bisphenol having two or more epoxy groups. A reaction of a F-type compound with (meth)acrylic acid. The curable composition for inkjet according to claim 1 or 2, wherein the compound having an epoxy group is a bisphenol A epoxy compound or a bisphenol F epoxy compound. The curable composition for inkjet according to claim 1 or 2, wherein the latent curing agent is dicyandiamide. The inkjet hardenable composition according to claim 1 or 2, wherein the photoradical polymerization initiator is an α-aminophenanthrone type photoradical polymerization initiator. The curable composition for inkjet according to claim 5, wherein the photoradical polymerization initiator is an α-aminophenanthrone type photoradical polymerization initiator having a dimethylamino group. The inkjet hardenable composition according to claim 1 or 2, wherein the latent hardener is obtained by reacting dicyandiamide with a functional group-containing compound having a functional group reactive with the dicyandiamide The reaction of the sticky substance. The curable composition for inkjet according to claim 1 or 2, wherein the photoreactive compound comprises a polyfunctional compound having a polycyclic skeleton and having two or more (meth)acrylonium groups. The curable composition for inkjet according to claim 1 or 2, wherein the photoreactive compound comprises a monofunctional compound having a polycyclic skeleton and having one (meth)acryl fluorenyl group. The curable composition for inkjet according to claim 1 or 2, wherein the photoreactive compound comprises a polyfunctional compound having a polycyclic skeleton and having two or more (meth)acrylonium groups, and has a polycyclic skeleton, And both have one (meth)acryl fluorenyl monofunctional compound. A method for producing an electronic component, comprising the steps of: coating the curable composition for inkjet according to any one of claims 1 to 10 by an inkjet method, and drawing the pattern into a pattern; The above-mentioned curable composition for inkjet is irradiated with light and imparts heat to be cured to form a cured layer. The method for producing an electronic component according to claim 11, which is a method for producing a printed wiring board having an electronic component having a photoresist pattern, wherein the curable composition for inkjet is applied by an inkjet method and patterned into a pattern. Then, the inkjet curable composition drawn in a pattern is irradiated with light and heat is applied to be cured to form a photoresist pattern.