TWI485513B - A photohardenable composition and a hardened product thereof - Google Patents

Description

Photocurable composition and cured product thereof

The present invention relates to a photocurable composition and a cured product thereof.

A photocurable composition containing a photopolymerization initiator as a component and hardened by irradiation with an active energy ray such as ultraviolet rays is used for a coating material, a resin insulating layer, and a solder resist because it has advantages such as excellent rapid curing property. A wide range of fields such as pastes for electrode formation (for example, Patent Documents 1 and 2).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2000-214584

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2001-075281

In recent years, in terms of productivity or workability, etc. Further, improvement in the hardenability of the photocurable composition is required. For the purpose of, for example, reduction in power consumption and running cost, etc., a conventional method of using an LED-UV lamp as a light source has been attracting attention. However, since the light emitted from the light source has a long wavelength, the hardening energy is low, and when compared with the case of using a conventional UV lamp, the photocurable composition cannot be sufficiently cured.

Therefore, an object of the present invention is to provide a photocurable composition excellent in curability and a cured product obtained by curing the same.

In view of the above problems and intensive studies, the present inventors have found that the above problems can be solved by using a combination of a specific photopolymerization initiator, and the present invention has been completed.

In other words, the photocurable composition for a printed wiring board of the present invention contains a photopolymerization initiator selected from the group consisting of an oxime ester photopolymerization initiator, an alkylphenone photopolymerization initiator, and a mercaptophosphine oxide. a photopolymerization initiator of at least one of the group of the initiator and the titanocene photopolymerization initiator; and a photopolymerization initiator represented by the following general formula (I); (In the formula, R represents a structure represented by the following formula (II), and l ₁ represents an integer of 2 to 4, and m ₁ represents an integer of 1 or more)

The photocurable composition for a printed wiring board of the present invention preferably further contains a photosensitive (meth) acrylate compound.

It is preferable that the photocurable composition for a printed wiring board of the present invention further contains an organic binder.

The cured product of the present invention is characterized in that the printed wiring board is cured with a photocurable composition.

According to the invention, it is possible to provide a curable superior photocurable composition and a cured product obtained by curing the same.

Fig. 1 is a graph showing a heating decrement curve obtained by simultaneous measurement of differential photothermal-thermal weight (TG/DTA measurement) of a photopolymerization initiator used in Reference Example. The horizontal axis represents the temperature (Cel: Celsius temperature), and the vertical axis represents the reduction ratio (%) of the thermal weight.

[Best Mode for Carrying Out the Invention]

Hereinafter, the photocurable composition of the present invention will be described in detail.

[Photopolymerization initiator]

The photocurable composition of the present invention contains a photopolymerization initiator selected from the group consisting of an oxime ester photopolymerization initiator, an alkylphenone photopolymerization initiator, a mercaptophosphine oxide photopolymerization initiator, and titanocene A photopolymerization initiator which is at least one selected from the group consisting of photopolymerization initiators.

As the oxime ester photopolymerization initiator, CGI-325, Irgacure OXE01, Irgacure OXE02, manufactured by BASF Japan Co., Ltd., N-1919 manufactured by ADEKA Co., Ltd., and the like can be exemplified.

In addition, a photopolymerization initiator having two oxime ester groups in the molecule can be suitably used. Specifically, an oxime ester compound having the carbazole structure represented by the following general formula (2) can be exemplified.

(wherein X represents a hydrogen atom, an alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, or a phenyl group (which is an alkyl group having a carbon number of 1 to 17 and carbon) a group of 1 to 8 alkoxy groups, an amine group, an alkylamino group having a carbon number of 1 to 8 or a dialkylamino group, and a naphthyl group (having a carbon number of 1 to 17) An alkyl group, an alkoxy group having 1 to 8 carbon atoms, an amine group, an alkylamino group having a carbon number of 1 to 8 or a dialkylamino group; wherein Y and Z are each represented as a hydrogen atom; An alkyl group having 1 to 17 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a halogen group, a phenyl group, and a phenyl group (having an alkyl group having 1 to 17 carbon atoms and an alkoxy group having 1 to 8 carbon atoms) a group, an amine group, an alkylamino group having a carbon number of 1 to 8 or a dialkylamino group, or a naphthyl group (having an alkyl group having a carbon number of 1 to 17 and a carbon number of 1~) Alkoxy, alkoxy, alkylamino or dialkylamino group of a C 1-8 alkyl group, fluorenyl, pyridyl, benzofuranyl, benzothienyl; Ar Is an alkylene group having a carbon number of 1 to 10, a vinyl group, a phenyl group, a phenyl group, a pyridine group, a naphthyl group, a thienyl group, a thiol group, a thienyl group, a furyl group, and 2, 5-pyridyl R-diyl, 4,4'-fluorene-diyl, 4,2'-styrene-diyl; n is an integer of 0 or 1.)

In particular, in the above formula, X and Y are each a methyl group or an ethyl group, Z is a methyl group or a phenyl group, n is 0, and Ar is an oxime ester group of a stretching phenyl group, a stretching naphthyl group, a thienyl group or a thienyl group. A photopolymerization initiator is preferred.

The oxime ester photopolymerization initiator may be used singly or in combination of two or more. The blending amount in the case of using the oxime ester photopolymerization initiator is preferably from 0.1 to 25% by mass, and more preferably from 5 to 15% by mass, based on the solid content of the photocurable composition. When it is 25% by mass or less, the coating film formation will be good. Moreover, when it is 0.1 mass % or more, sufficient photocurability can be obtained, and pattern formation property will be favorable.

The alkylphenone-based photopolymerization initiator may, for example, be a benzyldimethylketal photopolymerization such as 2,2-dimethoxy-1,2-diphenylethane-1-one. Starting agent; 1-hydroxy-cyclohexane-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)- Phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propenyl)-benzyl Α-hydroxyalkylphenone photopolymerization initiator such as phenyl}-2-methyl-propan-1-one; 2-methyl-1-[4-(methylthio)phenyl]- 2-morpholinylacetone-1,2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butan-1-one, 2-(dimethylamino) -2-[(4-methylphenyl)methyl]-1-[4- An α-aminoacetophenone photopolymerization initiator such as (4-m-decyl)phenyl]-1-butanone or N,N-dimethylaminoacetophenone. As a commercial item of the benzyl dimethyl ketal-based photopolymerization initiator, Irgacure 651 manufactured by BASF Japan Co., Ltd., etc. can be mentioned. As a commercial item of the α-hydroxyalkylphenone-based photopolymerization initiator, Irgacure 184, Darocur 1173, Irgacure 2959, Irgacure 127, etc., manufactured by BASF Japan Co., Ltd., may be mentioned. As a commercial item of the α-amino acetophenone-based photopolymerization initiator, Irgacure 907, Irgacure 369, Irgacure 379, etc. by BASF Japan Co., Ltd. are mentioned.

The mercaptophosphine oxide photopolymerization initiator may, for example, be 2,4,6-trimethylbenzimidyldiphenylphosphine oxide or bis(2,4,6-trimethylbenzhydrazide). Phenylphosphine oxide, bis(2,6-dimethoxybenzylidene)-2,4,4-trimethyl-pentylphosphine oxide, and the like. As a commercial item, Lucirin TPO, Irgacure 819, etc. by BASF Japan company are mentioned.

As the titanocene-based photopolymerization initiator, bis(cyclopentadienyl)-di-phenyl-titanium, bis(cyclopentadienyl)-di-chloro-titanium, bis(cyclopentadiene) can be exemplified. Bis(2,3,4,5,6 pentafluorophenyl)titanium, bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrol-1-yl)phenyl ) Titanium, etc. As a commercial item, Irgacure 784 by BASF Japan company, etc. are mentioned.

The alkylphenone-based photopolymerization initiator, the mercaptophosphine oxide-based photopolymerization initiator, and the titanocene-based photopolymerization initiator may be used singly or in combination of two or more. The blending amount in the case of using each of the above photopolymerization initiators is preferably in a photocurable composition in terms of solid content. It is 2 to 25% by mass, and preferably 5 to 15% by mass. When it is 25% by mass or less, the coating film formation will be good. In addition, when it is 2% by mass or more, sufficient photocurability is obtained and pattern formability is also excellent.

Further, the photocurable composition of the present invention contains the photopolymerization initiator represented by the following general formula (I).

(In the formula, R represents a structure represented by the following formula (II), and l ₁ represents an integer of 2 to 4, and m ₁ represents an integer of 1 or more)

The l ₁ in the above general formula (I) is preferably 2 or 4; the m ₁ is preferably 1 to 5, more preferably 1 to 3, and particularly preferably 1.

The photopolymerization initiator represented by the above general formula (I) is preferably liquid at room temperature. Here, the term "liquid at room temperature" means that a sample is added to a test tube having an inner diameter of 30 mm to a height of 55 mm at any temperature of 10 to 40 ° C, and the test tube is horizontally passed from the bottom to 85 mm. The part is within 90 seconds.

The photopolymerization initiator represented by the above general formula (I) is preferably a 5% reduction temperature of 260 ° C or higher. Further, the upper limit is preferably 500 ° C or lower. In the present specification, the 5% reduction temperature refers to a temperature at which the thermal weight is reduced by 5% in the heating loss curve obtained by simultaneous measurement of differential heat-heat weight (TG/DTA measurement) (measurement condition: 10 °C/min).

As an example of the photopolymerization initiator represented by the above general formula (I), a diester of carboxymethoxythioxanthone and polytetramethylene glycol 250 can be exemplified.

The chemical formula of a specific example of the photopolymerization initiator represented by the above general formula (I) is described. However, the present invention is not limited by the following compounds.

(wherein n represents an integer of 1 or more).

As an example of a commercial product of the photopolymerization initiator represented by the above general formula (I), Omnipol TX manufactured by IHT Co., Ltd., or the like can be exemplified.

The photopolymerization initiators of the above formula (I) may be used singly or in combination of two or more. The blending amount of the photopolymerization initiator represented by the above formula (I) is preferably from 0.01 to 15% by mass, and more preferably from 0.1 to 15% by mass, based on the solid content of the photocurable composition. When it is 15 mass% or less, formation of a coating film will become easy. In addition, when it is 0.01% by mass or more, sufficient photocurability can be obtained, and pattern formability will be good.

(Photosensitive (meth) acrylate compound)

The photocurable composition of the present invention preferably further contains a photosensitive (meth) acrylate compound. After the photosensitive (meth) acrylate compound is photocured by irradiation with an active energy ray, it contributes to insolubilizing or insolubilizing the carboxyl group-containing resin in an aqueous alkali solution. Sensitivity As the (meth) acrylate compound, a diluent which is a photocurable composition can also be used.

As the compound of the above-mentioned photosensitive (meth) acrylate compound, for example, conventional polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate may be used. , carbonate (meth) acrylate, epoxy (meth) acrylate, and the like. Specific examples thereof include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxy methacrylate; ethylene glycol and methoxy group; Diacrylates of diols such as tetraethylene glycol, polyethylene glycol, propylene glycol, diethylene glycol, etc.; N,N-dimethyl decylamine, N-methylol acrylamide, N,N- Acrylamines such as dimethylaminopropyl acrylamide; aminoalkyl groups such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate Acrylates; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, and para-hydroxyethyl isocyanurate or such ethylene oxide adducts, propylene oxide addition a polyvalent acrylate such as an ε-caprolactone adduct; a phenoxy acrylate, a bisphenol A diacrylate, and an oxirane ethylene oxide adduct of such a phenol or a propylene oxide Multivalent acrylates such as adducts; shrinkage of glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, etc. a polyvalent acrylate of a glyceryl ether; and not limited to the above, a polyol such as a polyether polyol, a polycarbonate diol, a hydroxyl terminated polybutadiene, or a polyether polyol is directly acrylated or Diisocyanate for urethane acrylated acrylates and melamine acrylates, and corresponding acrylic acid At least any one of the acrylates of the ester, and the like.

Further, the following resin may be used as a photosensitive monomer: an epoxy acrylate resin obtained by reacting a polyfunctional epoxy resin such as a cresol novolac epoxy resin with acrylic acid, or the epoxy An epoxy urethane acrylate compound obtained by reacting a hydroxyl group of an acrylate resin with a hydroxy acrylate such as pentaerythritol triacrylate or a diisocyanate compound such as isophorone diisocyanate. Such an epoxy acrylate-based resin not only does not lower the tackiness (touch dryness), but also improves the hardenability.

In particular, in the present invention, polyvalent acrylates such as polyhydric alcohols or such ethylene oxide adducts, propylene oxide adducts, or ε-caprolactone adducts, or phenols are used. Polyvalent acrylates such as ethylene oxide adducts or propylene oxide adducts, and (meth) acrylates containing urethane oligomers, which are low in warpage and bendability From the viewpoint, it can be suitably used.

The photosensitive (meth) acrylate compound may be used singly or in combination of two or more. The blending amount of the photosensitive (meth) acrylate compound is preferably from 1 to 30% by mass, more preferably from 2 to 20% by mass, particularly preferably from 5 to 20% by mass, based on the solid content. 15% by mass. When the content is 30% by mass or less, adhesion of the surface is not caused, and the dryness of the touch is good. In addition, when it is 1% by mass or more, sufficient photocurability can be obtained at the time of exposure, and pattern formability will be good.

(organic binder)

The photocurable composition of the present invention preferably further contains an organic binder resin. As the organic binder resin, a carboxyl group-containing resin is preferably used, and the photocurable composition can be used as an alkali-curable photocurable composition. In this case, a photocurable composition excellent in resolution can be obtained. The carboxyl group-containing resin is not particularly limited, and can be used as a conventional carboxyl group-containing resin used for a solder resist or a photocurable composition for an interlayer insulating layer.

Further, from the viewpoint of photocurability or developability, it is preferable to have an ethylenically unsaturated bond in the molecule in addition to a carboxyl group, but it may also be a carboxyl group-containing resin having no ethylenically unsaturated double bond. . When the carboxyl group-containing resin does not have an ethylenically unsaturated bond, in order to make the composition photocurable, a compound having one or more ethylenically unsaturated groups in the molecule (photoreactive monomer) is used in combination. It is better. As the ethylenically unsaturated double bond, acrylic acid or methacrylic acid or a derivative derived therefrom is preferred.

The carboxyl group-containing resin having a carboxyl group in the molecule and not containing an ethylenically unsaturated bond in the molecule may, for example, be as follows: (1) by having an unsaturated carboxylic acid (for example, acrylic acid, methacrylic acid, etc.) and having a compound having an unsaturated double bond (for example, styrene, α-methylstyrene, lower-order alkyl (meth) acrylate, isobutylene, etc.) obtained by copolymerization of a carboxyl group-containing resin; (2) having An epoxy group of a copolymer of an unsaturated double bond and a glycidyl (meth) acrylate having one carboxy group in one molecule An organic acid having no ethylenic unsaturated bond (for example, an alkyl carboxylic acid having 2 to 17 carbon atoms, an alkyl carboxylic acid having an aromatic group, etc.) is reacted, and the resulting secondary hydroxyl group is saturated with Or a carboxyl group-containing resin obtained by reacting an unsaturated polybasic acid anhydride; (3) a hydroxyl group-containing polymer (for example, an olefin-based hydroxyl group-containing polymer, an acrylic polyol, a rubber-based polyol, a polyvinyl acetal, a carboxyl group-containing resin obtained by reacting a styrene allyl alcohol resin, cellulose, or the like with a saturated or unsaturated polybasic acid anhydride; (4) a diepoxide compound (for example, a bisphenol A type epoxy resin, a double Phenol F type epoxy resin, bisphenol S type epoxy resin, brominated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, biphenol type epoxy resin, bisphenol type epoxy resin, etc. a reaction product of a dicarboxylic acid (for example, oxalic acid, malonic acid, succinic acid, phthalic acid, isophthalic acid, etc.), and a carboxyl group-containing resin obtained by reacting with a saturated or unsaturated polybasic acid anhydride; And (5) reacting a difunctional epoxy compound with a bisphenol (for example, bisphenol A, bisphenol F, etc.) , The carboxyl group-containing resin and a saturated or unsaturated polybasic acid anhydride is obtained.

Further, as the carboxyl group-containing photosensitive prepolymer having a carboxyl group and an intramolecular ethylenically unsaturated bond in the molecule, for example, (1) a polyfunctional epoxy having at least two epoxy groups in one molecule can be exemplified as follows: a hydroxyl group formed by reacting a compound (for example, a novolac type epoxy resin or the like) with an unsaturated monocarboxylic acid (for example, (meth)acrylic acid, etc.), and a saturated or unsaturated polybasic acid anhydride (for example, hexahydrophthalic acid) Anhydride or tetrahydroortylene (a) a carboxyl group-containing photosensitive prepolymer obtained after the reaction, and (2) a polyfunctional epoxy compound having at least two epoxy groups in one molecule (for example, a novolac type epoxy resin), and a monocarboxylic acid (for example, (meth)acrylic acid or the like) and a compound having one reactive group other than the alcoholic hydroxyl group reactive with an epoxy group in one molecule (for example, nonylphenol, etc.) / more preferably one molecule a compound having at least one alcoholic hydroxyl group and one reactive group other than an alcoholic hydroxyl group reactive with an epoxy group (for example, p-hydroxyphenylethanol), and then a saturated or unsaturated polybasic acid anhydride (for example, a hydroxy group-containing photosensitive prepolymer obtained after the reaction of hexahydrophthalic anhydride or tetrahydrophthalic anhydride; (3) an unsaturated carboxylic acid (for example, (meth)acrylic acid or cis a portion of a carboxyl group of a copolymer of a compound having an ethylenically unsaturated double bond (for example, a methyl (meth) acrylate or the like), and an epoxy group in one molecule; A carboxyl group-containing photosensitive precipitate obtained by reacting a compound having an ethylenically unsaturated double bond (for example, glycidyl (meth) acrylate, etc.) (4) an unsaturated carboxylic acid (for example, (meth)acrylic acid or maleic acid, etc.) and a compound having an ethylenically unsaturated double bond (for example, methyl (meth) acrylate, etc.) a copolymer which reacts with a compound having one epoxy group and an ethylenically unsaturated double bond in one molecule (for example, glycidyl (meth) acrylate, etc.), and then the resulting hydroxyl group is saturated or unsaturated. a carboxyl group-containing photosensitive prepolymer obtained by reacting an acid anhydride (for example, hexahydrophthalic anhydride or tetrahydrophthalic anhydride); and, (5) an unsaturated diproton anhydride (for example, cis Butylene anhydride And a copolymer of a compound having an ethylenically unsaturated double bond (for example, methyl (meth) acrylate, etc.), and a hydroxyalkyl (meth) acrylate (for example, 2-hydroxyethyl (methyl) A carboxyl group-containing photosensitive prepolymer obtained after the reaction, such as an acrylate or the like.

Further, the polyfunctional epoxy resin used for the synthesis of the above resin is a bisphenol A structure, a bisphenol F structure, a biphenol structure, a biphenol novolac structure, or a bisxylenol structure, and particularly has a biphenylphenol phenol structure. When the compound and the hydride thereof are used, the cured product of the photocurable composition is preferably low in warpage and bending resistance.

Here, the term "(meth)acrylate" is generally referred to as acrylate, methacrylate, and the like, and the following similar expressions are also the same.

Further, the acid value of the organic binder is preferably in the range of 20 to 200 mgKOH/g, and more preferably in the range of 40 to 150 mgKOH/g. When the acid value of the organic binder is 20 mgKOH/g or more, the adhesion of the coating film can be obtained, and in the case of the photocurable composition, the alkali solution development is good. In addition, when the acid value is 200 mgKOH/g or less, the dissolution of the exposed portion by the developer can be suppressed, the line can be made thinner than necessary, and the exposed portion and the unexposed portion can be suppressed from being indistinguishable. Since the developer is dissolved and peeled off, it is easy to obtain a normal resist pattern drawing.

The weight average molecular weight of the above organic binder varies depending on the resin skeleton, but is generally preferably 2,000 to 150,000. When the weight average molecular weight is 2,000 or more, the non-stick property is excellent, and the moisture resistance of the coating film after exposure is good, and no film reduction occurs during development. Less, so the resolution will be good. Moreover, when the weight average molecular weight is 150,000 or less, it is excellent in developability, and storage stability is also excellent. It is preferably 5,000 to 100,000.

(other ingredients)

In the photocurable composition of the present invention, conventional additives other than the above components may be blended as long as the effects of the present invention are not impaired. Examples of the additive include a thermal polymerization inhibitor, a UV absorber, a decane coupling agent, a plasticizer, a flame retardant, an antistatic agent, an antiaging agent, an antibacterial, an antifungal agent, an antifoaming agent, a leveling agent, and a filler. A tackifier, a tackifier, a shake imparting agent, a colorant, a photopolymerization initiator other than the above, a photoinitiating aid, a sensitizer, and the like. A solvent may also be used in the case of coating, drying, or photohardening on the surface of the substrate like a solder resist. Moreover, when it is used as a solder resist, it is preferable to mix a thermosetting component, such as a thermosetting resin, such as an epoxy compound.

(filler)

The photocurable composition of the present invention may further contain a filler (inorganic filler). The filler is used to suppress the hardening shrinkage of the cured product of the photocurable composition and to improve the properties such as adhesion and hardness. Examples of the filler include barium sulfate, amorphous vermiculite, molten vermiculite, globular vermiculite, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, tantalum nitride, aluminum nitride, and the like. Boron nitride, Neuburg Siliceous Earth, and the like.

The average particle diameter (D50) of the filler is preferably 1 μm or less, more preferably 0.7 μm or less, and still more preferably 0.5 μm or less. When the average particle diameter exceeds 1 μm, the photocurable composition is cloudy and turbid, and it is not suitable depending on the use. The average particle diameter (D50) can be measured by a laser diffraction/scattering method. When the average particle diameter is within the above range, the refractive index will approach the resin component and the permeability will be improved.

(thermosetting component)

In the photocurable composition of the present invention, a thermosetting component may be added in order to impart heat resistance. The thermosetting component used in the present invention may, for example, be a blocked isocyanate compound, an amine resin, a maleimide compound, or a benzo compound. A conventional thermosetting resin such as a resin, a carbodiimide resin, a cyclic carbonate compound, a polyfunctional epoxy compound, a polyfunctional oxetane compound, or an episulfide resin. Among these, a thermosetting component which is preferably one of a plurality of cyclic ether groups and a cyclic thioether group (hereinafter, simply referred to as a cyclic (thio)ether group) in one molecule is used. Hardening ingredients. The thermosetting component having such a cyclic (thio)ether group is commercially available in a variety of types, and various properties can be imparted depending on the structure.

A thermosetting component having a plurality of cyclic (thio)ether groups in the molecule, which is a cyclic ether group having two or more three, four or five-membered rings or a cyclic thioether group in the molecule. The compound of the two types of the group may, for example, be a compound having a plurality of epoxy groups in the molecule, that is, a polyfunctional epoxy compound; a compound having a plurality of oxetanyl groups in the molecule, that is, a polyfunctional oxy compound. Cyclobutane compound; having a plurality of thioethers in the molecule A compound such as an episulfide resin or the like.

The polyfunctional epoxy compound is a polyfunctional epoxy compound having two or more epoxy groups (oxirane rings) in one molecule, or a resin obtained by polymerizing the polyfunctional epoxy compound. Examples of the polyfunctional epoxy compound include epoxidized vegetable oil; bisphenol A type epoxy resin; hydroquinone type epoxy resin, bisphenol type epoxy resin, thioether type epoxy resin; and brominated epoxy resin. ; phenolic epoxy resin; phenolic phenolic epoxy resin; bisphenol F epoxy resin; hydrogenated bisphenol A epoxy resin; glycidylamine epoxy resin; Ring epoxy resin; trihydroxyphenylmethane type epoxy resin; dixylenol type or biphenol type epoxy resin or a mixture thereof; bisphenol S type epoxy resin; bisphenol A phenolic type epoxy resin ; tetraphenylolethane type epoxy resin; heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl xylyl ethane resin; naphthalene-containing epoxy resin Epoxy resin having a dicyclopentadiene skeleton; glycidyl methacrylate copolymerized epoxy resin; copolymerized epoxy resin of cyclohexane maleimide and glycidyl methacrylate; epoxy Modified polybutadiene rubber derivative, CTBN modified epoxy resin, etc. However, not limited thereto, and the like. These epoxy resins may be used alone or in combination of two or more. Among these, a bisphenol type epoxy resin is particularly preferable.

As the above polyfunctional oxetane compound, in addition to bis[(3-methyl-3-oxetanylmethoxy)methyl]ether, bis[(3-ethyl-3-oxetan) Alkyloxy)methyl]ether, 1,4-bis[(3-methyl-3-oxetanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-) 3-oxetane Methoxy)methyl]benzene, (3-methyl-3-oxetanyl)methacrylate, (3-ethyl-3-oxetane)methacrylate, (3- Methyl-3-oxetane)methacrylate, (3-ethyl-3-oxetane)methacrylate or polyfunctional oxalates of such oligomers or copolymers Examples of the cyclobutanes include oxetane, phenol resin, poly(p-hydroxystyrene), cardo type bisphenol, calixarene, resorcinol calixarene, or half. An etherified product of a resin having a hydroxyl group such as a decane or the like. Other examples thereof include a copolymer of an oxetane ring-unsaturated monomer and an alkyl (meth) acrylate.

Examples of the episulfide resin having a plurality of cyclic thioether groups in the above-mentioned molecule include YL7000 (bisphenol A type episulfide resin) manufactured by Mitsubishi Chemical Corporation, and YSLV-120TE manufactured by Tosho Kasei Co., Ltd., and the like. Further, an episulfide resin in which an oxygen atom of an epoxy group of a novolac type epoxy resin is substituted with a sulfur atom or the like can be used by the same synthesis method.

Moreover, in addition to the above-mentioned thermosetting component, the photocurable composition of the present invention may be a thermosetting component such as an amine resin such as a melamine derivative or a benzoguanamine derivative. Examples of such a thermosetting component include a methylol melamine compound, a methylol benzoguanamine compound, a methylol glycoluril compound, a methylol urea compound, an alkoxymethylated melamine compound, and the like. An alkoxymethylated benzoguanamine compound, an alkoxymethylated glycoluril compound, an alkoxymethylated urea compound, or the like. The type of the alkoxymethyl group is not particularly limited, and examples thereof include a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, and a butoxymethyl group. Especially for humans or the environment, the concentration of formalin is 0.2% or less. A melamine derivative is preferred. The thermosetting component may be used singly or in combination of two or more.

(solvent)

The photocurable composition of the present invention may contain an organic solvent in order to adjust the viscosity of the composition. As the organic solvent, as long as it is a photopolymerization initiator which can dissolve the present invention, a conventionally used type can be used. For example, toluene, xylene, ethyl acetate, butyl acetate, methanol, ethanol, isopropanol, isobutanol, 1-butanol, diacetone alcohol, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol single Methyl ether acetate, terpineol, methyl ethyl ketone, carbitol, carbitol acetate, butyl carbitol, butyl carbitol acetate, and the like. The solvent may be used singly or in combination of two or more.

The photocurable composition of the present invention is applied to a substrate or the like by, for example, the following coating method, followed by ultraviolet irradiation, preferably at a wavelength of 10 to 420 nm, preferably 250 to 420 nm. . The photocurable composition of the present invention is excellent in hardenability even when irradiated with ultraviolet rays having a long wavelength of 320 to 420 nm.

Examples of the ultraviolet light irradiation source include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a xenon lamp or a metal halide lamp, a laser, a UV-LED, and the like.

The coating method can be any method such as a dip coating method, a flow coating method, a roll coating method, a bar coating method, a screen printing method, a curtain coating method, a gravure coating method, or a lithography method. .

The photocurable composition of the present invention is preferably a solder resist. The solder resist is characterized in that the photocurable composition of the present invention is coated and cured on a substrate.

A conventional method can also be employed for the method of coating and hardening the photocurable composition for a solder resist. For example, the method can be as follows.

If necessary, it is diluted by a solvent to adjust the viscosity suitable for the coating method, and this is formed on a printed wiring board on which a loop is formed, for example, by screen printing, curtain coating, spray coating, roll coating. The coating is carried out by a method such as a method, and a non-stick coating film can be formed by volatilizing and drying the organic solvent contained in the composition at a temperature of, for example, about 60 to 100 °C. Thereafter, the active energy ray such as laser light is directly irradiated as in the form of a pattern, or is formed by a pattern mask and selectively exposed to ultraviolet light to be cured. When the photocurable composition is in the case of an alkali-developing type, the unexposed portion is developed by a dilute aqueous alkali solution to form a resist pattern. Further, as desired, a cured film (cured material) can be formed by heat curing or final hardening (true hardening) after irradiation with ultraviolet rays.

The photocurable composition of the present invention can be used for an interlayer insulating layer for a printed wiring board, a conductive display panel, and a conductive paste for forming an electrode of a touch panel, in addition to a solder resist. Further, the photocurable composition of the present invention may be used in the form of a dry film in addition to a method of applying a liquid directly onto a substrate, and the dry film has a photocurable composition coated in advance. And drying the coating layer formed on the film of the ethylene terephthalate film or the like.

[Examples]

Hereinafter, the present invention will be described in more detail by way of Examples and Comparative Examples. However, the present invention is not limited to the Examples and Comparative Examples. In addition, unless otherwise specified, "parts" means mass parts, and "%" means mass%.

[Reference example] (Measurement of 5% reduction temperature of photopolymerization initiator)

The 5% reduction temperature of Omnipol TX manufactured by IHT Co., Ltd. was measured by a differential thermal-thermal weight simultaneous measurement device (TG/DTA) under the following conditions at a constant rate to obtain a thermal weight of 5 The temperature at which % is reduced. The obtained heating loss curve is shown in Fig. 1. The 5% reduction temperature was 318 °C.

Assay sample: photopolymerization initiator (10 mg of this sample was metered on the sample vessel).

Measuring machine: TG/DTA6200 manufactured by Hitachi High-Tech Science Co., Ltd.

Measuring range: 30 ° C ~ 600 ° C. Heating rate: 10 ° C / min.

[Examples 1 to 5 and Comparative Examples 1 to 4] (modulation of photocurable composition)

Each component described in the following Table 1 was kneaded by a triaxial roll mill to prepare a photocurable composition. The unit of the blending amount in the table is part by mass. In addition, the photopolymerization initiator represented by the above general formula (I) is a photopolymerization initiator using the above Chemical Formula No. 1.

The following evaluation of the obtained photocurable composition was carried out. The evaluation results are shown in Table 2 below.

<hardenability>

The photocurable compositions of the examples and the comparative examples were applied by an applicator on a full copper substrate, and light having a wavelength of 395 nm and 405 nm from the LED light source was irradiated. The adhesion of the cured film was confirmed and evaluated based on the following criteria.

○: No adhesion.

△: There is a slight adhesion.

×: There is adhesion.

From the results shown in Table 1, it is known that the oxime ester system, alkyl group Photocurable composition of any of the benzophenone-based, mercaptophosphine oxide-based, and titanocene-based photopolymerization initiators in combination with the photopolymerization initiator represented by the above general formula (I) It is superior to hardenability.

Further, in an ink jet composition comprising a photo-sensitive monomer or the like as a main component and having a low viscosity, each of the initiators and DETX-S used in the present invention is prepared, and the ink jet is used. In the case of the printability, when the former is used, the printing can be performed without problems. In contrast, when the latter is used, the nozzle is clogged and the printing cannot be performed.

Such a cured product of the present invention is particularly suitable for the field of molded articles requiring the above characteristics, such as a button for a mobile phone, various casings, or the like, or a UV molded article material, a material for forming a light, a material for inkjet, and a 3D inkjet. The use of materials for printers, etc.

Claims (4)

A photocurable composition for a printed wiring board, comprising: an oxime ester photopolymerization initiator, an alkylphenone photopolymerization initiator, a mercaptophosphine oxide photopolymerization initiator, And at least one photopolymerization initiator of the group consisting of a titanocene-based photopolymerization initiator, and a photopolymerization initiator represented by the following general formula (I); (wherein R represents a structure represented by the following formula (II), and l ₁ represents an integer of 2 to 4, and m ₁ represents an integer of 1 or more), The photocurable composition for a printed wiring board according to claim 1, further comprising a photosensitive (meth) acrylate compound. The photocurable composition for a printed wiring board according to claim 1, further comprising an organic binder. A cured product obtained by curing the printed wiring board according to any one of claims 1 to 3 with a photocurable composition.