JP7218387B2 - Photosensitive resin composition for inkjet and printed wiring board - Google Patents

Description

The present invention relates to a photosensitive resin composition for inkjet and a printed wiring board.

A photosensitive resin composition for forming a solder resist film or the like on a printed wiring board is required to have various properties such as solder heat resistance and adhesion to an insulating base material or a conductor layer. This photosensitive resin composition has been conventionally applied by a screen printing method or the like, but in recent years, application by an inkjet method has also been considered.
Examples of the photosensitive resin composition suitable for the inkjet method include (A) a photobase generator, (B) a (meth)acrylate compound having an epoxy group, (C) a photopolymerization initiator, and (D) a thermosetting A curable composition containing a component ((B) excluding a (meth)acrylate compound having an epoxy group) has been proposed (see Patent Document 1).

On the other hand, since a printed wiring board may be mounted with a heating element, the solder resist film may be required to be flame retardant. In order to stably eject a flame-retardant photosensitive resin composition using an inkjet method, a flame retardant having a fine particle size, for example, an average particle size of 1 μm or less, is blended into the photosensitive resin composition. I needed it. Therefore, in order to apply a photosensitive resin composition using an inkjet method, it is often practiced to grind a powdery flame retardant into fine particles and add it to the photosensitive resin composition. be.

However, even if the powdery flame retardant is pulverized, it cannot be sufficiently finely divided, and the inkjet method is used to stably eject the flame retardant photosensitive resin composition. There was room for improvement. Moreover, depending on the type of flame retardant, the flame retardant may bleed out from the solder resist film, and there is a problem with the bleeding resistance of the cured coating film.

JP 2015-110765 A

The present invention provides a photosensitive resin composition for inkjet that is excellent in coatability by an inkjet method and capable of forming a cured product that is excellent in electrical insulation, flame retardancy and bleeding resistance, and the same. It aims at providing the printed wiring board which used.

The inkjet photosensitive resin composition according to one aspect of the present invention includes (A) a (meth)acrylic resin having a weight average molecular weight of 500 or more, and (B) a (meth)acrylic compound having a weight average molecular weight of less than 500. , (C) a phosphorus-containing compound, and (D) a photopolymerization initiator, and a photosensitive resin composition, wherein the component (C) is a compound other than a phosphate ester, and in one molecule has a functional group capable of reacting with radical photopolymerization or cationic photopolymerization.

In the inkjet photosensitive resin composition according to one aspect of the present invention, the component (C) preferably has an unsaturated double bond or an oxirane ring in one molecule.
In the inkjet photosensitive resin composition according to one aspect of the present invention, the component (C) is at least one selected from the group consisting of compounds represented by the following formulas (1) to (3). Preferably.

In the inkjet photosensitive resin composition according to one aspect of the present invention, it is preferable to use two or more of the components (C) in combination.
In the inkjet photosensitive resin composition according to one aspect of the present invention, the component (B) preferably has a cyclic skeleton in one molecule.
In the inkjet photosensitive resin composition according to one aspect of the present invention, the component (D) preferably has a phosphorus atom in one molecule.
The inkjet photosensitive resin composition according to one aspect of the present invention preferably further contains (E) a bisallyl nadimide compound.

A printed wiring board according to one aspect of the present invention is characterized by comprising a solder resist film made of the inkjet photosensitive resin composition according to one aspect of the present invention.

According to the present invention, a photosensitive resin composition for inkjet that is excellent in coatability by an inkjet method and can form a cured product that is excellent in electrical insulation, flame retardancy and bleeding resistance, and A printed wiring board using it can be provided.

[Photosensitive resin composition for inkjet]
First, the inkjet photosensitive resin composition of the present embodiment (hereinafter also simply referred to as “photosensitive resin composition”) will be described.
The photosensitive resin composition of the present embodiment includes (A) a (meth)acrylic resin having a weight average molecular weight of 500 or more, (B) a (meth)acrylic compound having a weight average molecular weight of less than 500, and (C ) a phosphorus-containing compound, and (D) a photopolymerization initiator.

[(A) Component]
The (A) (meth)acrylic resin having a weight average molecular weight of 500 or more used in the present embodiment is not particularly limited in chemical structure as long as it is a (meth)acrylic resin having a weight average molecular weight of 500 or more. As used herein, the term "weight average molecular weight" means a weight average molecular weight measured at room temperature using gel permeation chromatography (GPC) and calculated in terms of polystyrene.

Component (A) includes polymers of monomers containing (meth)acrylic acid, polymers of monomers containing (meth)acrylate, polymers of monomers containing (meth)acrylic acid and (meth)acrylate, and epoxy resins. Epoxy (meth)acrylates obtained by reacting (meth)acrylic acid, urethane (meth)acrylates, and the like. Among these, epoxy (meth)acrylates and urethane (meth)acrylates are preferable from the viewpoint of further improving coatability using an inkjet method and obtaining a cured product having even more excellent bleeding resistance. .

Epoxy (meth)acrylate can be obtained by reacting (meth)acrylic acid with at least part of the epoxy groups of an epoxy resin having one or more epoxy groups in one molecule. The epoxy resin is not particularly limited, but biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, rubber-modified epoxy resin (such as silicone-modified epoxy resin). , ε-caprolactone modified epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, cycloaliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidylamine polyfunctional epoxy resins, heterocyclic polyfunctional epoxy resins, bisphenol-modified novolak-type epoxy resins, and polyfunctional-modified novolak-type epoxy resins.
This epoxy (meth)acrylate has no free carboxyl groups.

Urethane (meth)acrylates include, for example, urethane (meth)acrylates obtained by reacting urethane with (meth)acrylic acid. Urethane is a resin obtained by reacting a compound having two or more isocyanate groups in one molecule with a polyol compound having two or more hydroxyl groups in one molecule.

The compound having two or more isocyanate groups in one molecule is not particularly limited, but hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), methylenebiscyclohexyl isocyanate, trimethylhexa methyl diisocyanate, hexane diisocyanate, hexamethylamine diisocyanate, methylenebiscyclohexyl isocyanate, toluene diisocyanate, 1,2-diphenylethane diisocyanate, 1,3-diphenylpropane diisocyanate, diphenylmethane diisocyanate, and dicyclohexylmethyl diisocyanate. These may be used individually by 1 type, and may use 2 or more types together.

Polyol compounds having two or more hydroxyl groups in one molecule are not particularly limited, but aliphatic diols (ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, 2 , 2-diethyl-1,3-propanediol, 3,3-dimethylolheptane, 2-ethyl-2-butyl-1,3-propanediol, 1,12-dodecanediol, 1,18-octadecanediol, etc. alkane diols having 2 to 22 carbon atoms, alkenediol such as 2-butene-1,4-diol and 2,6-dimethyl-1-octene-3,8-diol), alicyclic diols (1,4 -cyclohexanediol, and 1,4-cyclohexanedimethanol), aliphatic triols (glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1 , 2,6-hexanetriol, trimethylolethane, trimethylolpropane, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-(hydroxymethyl)pentane, and 2,2 -bis(hydroxymethyl)-3-butanol, etc.), polyols (tetramethylolmethane, pentaerythritol, dipentaerythritol, xylitol, etc.), and the like. These may be used individually by 1 type, and may use 2 or more types together.
This urethane (meth)acrylate does not have a free carboxyl group.

Further, as another urethane (meth)acrylate, for example, epoxy (meth)acrylate is obtained by reacting (meth)acrylic acid with at least part of the epoxy group of an epoxy resin having one or more epoxy groups in one molecule. urethane (meth)acrylates obtained by subjecting the resulting hydroxyl group to addition reaction with a compound having one or more isocyanate groups in one molecule.

The epoxy resin is not particularly limited, and the same epoxy resin as used in the epoxy (meth)acrylate described above can be used.

The compound having one or more isocyanate groups in one molecule is not particularly limited, but hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), methylenebiscyclohexyl isocyanate, trimethylhexa methyl diisocyanate, hexane diisocyanate, hexamethylamine diisocyanate, methylenebiscyclohexyl isocyanate, toluene diisocyanate, 1,2-diphenylethane diisocyanate, 1,3-diphenylpropane diisocyanate, diphenylmethane diisocyanate, and dicyclohexylmethyl diisocyanate. These may be used individually by 1 type, and may use 2 or more types together.
This urethane (meth)acrylate does not have a free carboxyl group.

The weight-average molecular weight of component (A) is 500 or more, preferably 550 or more, particularly preferably 1000 or more, from the viewpoint of further improving ejection properties in the inkjet method. On the other hand, the upper limit of the weight-average molecular weight of component (A) is not particularly limited, but from the viewpoint of reliably preventing an increase in the viscosity of the photosensitive resin composition and obtaining excellent coatability even by an inkjet method, 5000 is preferred and 4000 is particularly preferred.

[(B) Component]
The chemical structure of (B) the (meth)acrylic compound having a weight average molecular weight of less than 500 used in the present embodiment is not particularly limited as long as it is a (meth)acrylic compound having a weight average molecular weight of less than 500.
Component (B) includes monofunctional (meth)acrylate monomers and bifunctional or higher (meth)acrylate monomers. By blending the component (B) in the photosensitive resin composition of the present embodiment, the viscosity of the photosensitive resin composition at 25° C. is reduced, so a non-reactive diluent (eg, an organic solvent) is blended. Even without it, it can be used for inkjet.
In addition, the component (B) preferably has a cyclic skeleton in one molecule from the viewpoint of compatibility with the component (C), which will be described later. The cyclic skeleton includes a benzene ring, an alicyclic ring (isobornyl group, cyclohexane ring, etc.), and the like. Among these, a benzene ring is preferred.

The viscosity of the component (B) at 25° C. is not particularly limited, but is 1 mPa·s or more and 300 mPa·s or less from the viewpoint of obtaining more excellent bleeding resistance while further improving coatability in the inkjet method. more preferably 2 mPa·s or more and 50 mPa·s or less, and particularly preferably 3 mPa·s or more and 20 mPa·s or less.

Component (B) includes monofunctional (meth)acrylate compounds, bifunctional (meth)acrylate compounds, trifunctional (meth)acrylate compounds and the like.
Monofunctional (meth)acrylate compounds include benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenol (meth)acrylate, phenoxyethyl (meth)acrylate, diethylene glycol mono(meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate.
Examples of bifunctional (meth)acrylate compounds include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, Triethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, and isocyanurate di(meth)acrylate (Meth)acrylate and the like.
Examples of tri- or higher functional (meth)acrylate compounds include trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipenta erythritol hexa(meth)acrylate and the like.
These may be used individually by 1 type, and may use 2 or more types together.

The amounts of the components (A) and (B) to be blended in the photosensitive resin composition are not particularly limited. However, from the viewpoint of reliably imparting strength to the cured product of the photosensitive resin composition, the amount of component (A) to be blended is preferably 5 parts by mass or more with respect to 100 parts by mass of component (B). , more preferably 10 parts by mass or more, and particularly preferably 15 parts by mass or more. On the other hand, from the viewpoint of further improving coatability in the inkjet method, the blending amount of component (A) is preferably 50 parts by mass or less, such as 40 parts by mass, per 100 parts by mass of component (B). It is more preferably 30 parts by mass or less, and particularly preferably 30 parts by mass or less.

[(C) component]
The (C) phosphorus-containing compound used in the present embodiment is a compound containing a phosphorus atom, but is a compound other than a phosphate ester, and has a functional group capable of reacting by photoradical polymerization or photocationic polymerization in one molecule. It has a group. The component (C) can impart flame retardancy to the photosensitive resin composition. Moreover, this component (C) does not adversely affect the electrical insulation and bleeding resistance, nor does it adversely affect the coatability in the ink jet method.

Functional groups capable of reacting by photoradical polymerization or photocationic polymerization include functional groups having unsaturated double bonds and functional groups having oxirane rings.
Functional groups having unsaturated double bonds include vinyl groups, allyl groups, acryloyl groups, and methacryloyl groups. Among these, an acryloyl group or a methacryloyl group is preferred.
A glycidyl group etc. are mentioned as a functional group which has an oxirane ring.

Component (C) is preferably a compound represented by the following general formula (C1).

In Formula (C1), X is a monovalent group having at least one group selected from the group consisting of a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, and a glycidyl group. X is more preferably an acryloyl group, a methacryloyl group, or a glycidyl group.
Y is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and these groups may have a substituent. A cyclic structure may be formed by these groups and a benzene ring bonded to phosphorus.
Compounds represented by (C1) include compounds represented by the following formulas (1) to (3).

Component (C) includes phosphine oxides ((meth)acryloylmethyldiphenylphosphine oxide, 2-(3,4-epoxycyclohexyl)ethyldiphenylphosphine oxide, etc.), compounds having a phosphaphenanthrene ring (10-(3 -glycidyloxypropyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (compounds represented by formula (2)), and compounds represented by formula (3), etc.), 10-[2-(3,4-epoxycyclohexyl)ethyl]-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3-glycidyloxypropyl)-9,10- dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 9,10-dihydro-9-oxa-10-vinyl-10-phosphaphenanthrene-10-oxiro, and phenylvinylphosphinic acid. Among these, methacryloylmethyldiphenylphosphine oxide (compound represented by formula (1)) and 10-(3-glycidyloxypropyl)-9 are used from the viewpoint that a cured product having even better bleeding resistance can be obtained. ,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (the compound represented by formula (2)) or the compound represented by formula (3) is preferred.
These may be used singly or in combination of two or more. From the viewpoint of the balance between flame retardancy and other physical properties, it is preferable to use two or more in combination.

The amount of component (C) is not particularly limited, but it is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and 15 parts by mass or more relative to 100 parts by mass of component (B). is particularly preferred. (C) If the compounding quantity of a component is more than the said minimum, flame retardancy can be reliably provided to the photosensitive resin composition. On the other hand, the amount of component (C) is 100 parts by mass of component (B) from the viewpoint of imparting flexibility to the cured product of the photosensitive resin composition and making it applicable to flexible substrates. It is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and particularly preferably 35 parts by mass or less.

[(D) component]
The (D) photopolymerization initiator used in the present embodiment is not particularly limited, and known ones can be used as appropriate. Component (D) includes bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether. , benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-methyl-4'-(methylthio)- 2-morpholinopropiophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1 -one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4'-bis(diethylamino)benzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethyl thioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, and p-dimethylaminobenzoic acid ethyl ester. These may be used individually by 1 type, and may use 2 or more types together.
From the viewpoint of preventing discoloration of the cured coating film, the component (D) preferably has a phosphorus atom in one molecule.

The amount of component (D) is not particularly limited, but it is preferably 5 parts by mass or more and 30 parts by mass or less, and 10 parts by mass or more and 20 parts by mass or less per 100 parts by mass of component (B). is particularly preferred.

[(E) component]
The photosensitive resin composition of the present embodiment may further contain (E) a bisallyl nadiimide compound. This (E) component can be substituted as part of the (A) component.
Component (E) is preferably a compound represented by the following general formula (E1).

In formula (E1), R ¹ represents an alkylene group having 2 to 18 carbon atoms, -R ² -phenylene group -R ³ -, or -phenylene group -R ⁴ -phenylene group-. R ² , R ³ and R ⁴ each independently represent an alkylene group having 1 to 5 carbon atoms. R ¹ is preferably -R ² -phenylene group -R ³ - or -phenylene group -R ⁴ -phenylene group-. Also, R ² , R ³ and R ⁴ are each independently preferably an alkylene group having 1 to 3 carbon atoms.
Examples of compounds represented by formula (E1) include Maruzen Petrochemical Co., Ltd. BANI-M (R ¹ is -phenylene group -methylene group -phenylene group-) and BANI-X (R ¹ is -methylene group -phenylene group -methylene group-). These may be used individually by 1 type, and may use 2 or more types together.

When component (E) is used, its blending amount is not particularly limited, but it is preferably 5 parts by mass or more and 35 parts by mass or less, and 10 parts by mass or more and 20 parts by mass with respect to 100 parts by mass of component (B). Part or less is particularly preferred.

In the photosensitive resin composition of the present embodiment, in addition to the above components (A) to (E), other components such as colorants, various additives, and non-reactive diluents may be added as necessary. can be blended.

Colorants include, but are not limited to, pigments and dyes. Further, the colorant may be any of white colorant, blue colorant, green colorant, yellow colorant, purple colorant, and black colorant, depending on the color to be imparted to the cured product of the photosensitive resin composition. Colors can also be used. Examples of the coloring agent include titanium oxide as a white coloring agent, inorganic coloring agents such as carbon black as a black coloring agent, phthalocyanine green as a green coloring agent, phthalocyanine blue as a blue coloring agent, and a yellow coloring agent. Examples include chromophthal yellow and anthraquinone colorants. These may be used individually by 1 type, and may be used in mixture of 2 or more types.

Various additives include, for example, antifoaming agents (silicone antifoaming agents, hydrocarbon antifoaming agents, and acrylic antifoaming agents), inorganic fillers (talc, barium sulfate, alumina, aluminum hydroxide, mica, and silica, etc.), and organic fillers (powder urethane resin, (meth)acrylic polymer, vinyl polymer, modified polymer containing carboxyl group, carboxylic acid ester, etc.). These may be used individually by 1 type, and may be used in mixture of 2 or more types.

A non-reactive diluent is optionally added to adjust the viscosity and drying properties of the photosensitive resin composition. Organic solvents, for example, can be used as non-reactive diluents. Examples of organic solvents include ketones (e.g., methyl ethyl ketone, cyclohexanone), aromatic hydrocarbons (e.g., toluene, xylene), alcohols (e.g., methanol, isopropanol, cyclohexanol), alicyclic hydrocarbons (e.g., cyclohexane, methylcyclohexane), petroleum solvents (e.g., petroleum ether, petroleum naphtha), cellosolves (e.g., cellosolve, butyl cellosolve), carbitols (e.g., carbitol, butyl carbitol), and esters (e.g., , ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, ethyl diglycol acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate) and the like. These may be used individually by 1 type, and may be used in mixture of 2 or more types.

The method for producing the photosensitive resin composition of the present embodiment is not limited to a specific method. For example, after blending each of the above components in a predetermined ratio, at room temperature, a three-roll mill, a ball mill, a bead mill, a sand mill, etc. It can be produced by kneading or mixing with a kneading means or a stirring means such as a super mixer and a planetary mixer. Moreover, prior to the kneading or mixing, pre-kneading or pre-mixing may be performed as necessary.

Next, usage examples of the photosensitive resin composition of the present embodiment will be described. The photosensitive resin composition of the present embodiment uses an inkjet printing method to form a cured product (e.g., a solder resist film, marking, etc.) on a substrate (e.g., a printed wiring board having a predetermined circuit pattern). can be used for

[Printed wiring board]
Next, the printed wiring board of this embodiment will be described.
The printed wiring board of the present embodiment includes a solder resist film made of the photosensitive resin composition of the present embodiment described above. And the printed wiring board of this embodiment can be manufactured as follows.
First, the photosensitive resin composition of the present embodiment is applied in a desired pattern onto a printed wiring board by an inkjet method (for example, an inkjet method using a jet dispenser). After coating, the coated film is photo-cured by laser direct drawing using LDI (Laser Direct Imaging) or active energy rays such as ultraviolet rays. When photocuring treatment is performed with active energy rays such as ultraviolet rays, the amount of irradiation light is, for example, in the range of 100 to 2000 mJ/cm ² . After the photo-curing treatment of the coating film, post-cure (heat curing treatment) for 20-80 minutes in a hot air circulating dryer at 130-170°C to print a solder resist film with a desired pattern. It can be formed on a substrate.

Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

((A) component)
Epoxy acrylate A: functional group number 2, weight average molecular weight 1500, trade name "EBECRYL 3708", manufactured by Daicel Cytec Co., Ltd. Epoxy acrylate B: functional group number 2, weight average molecular weight 520, trade name "Miramer
PE210", epoxy acrylate C manufactured by Miwon: functional group number 2, weight average molecular weight 550, trade name "Miramer
PE250", epoxy acrylate D manufactured by Miwon: number of functional groups 2, weight average molecular weight 850, trade name "EBECRYL 3703", urethane acrylate A manufactured by Daicel Cytec: number of functional groups 4, weight average molecular weight 2700, trade name "EBECRYL 8405" , Urethane acrylate B manufactured by Daicel Cytec Co., Ltd.: 2 functional groups, weight average molecular weight 1000, trade name "EBECRYL 8402", Urethane acrylate C manufactured by Daicel Cytec Co., Ltd.: 2 functional groups, weight average molecular weight 2600, trade name "Miramer PU210" , manufactured by Miwon

((E) component)
Bisallyl nadimide compound: trade name "BANI-M", manufactured by Maruzen Petrochemical Co., Ltd.

((B) component)
(Meth) acrylic compound A: benzyl acrylate, number of functional groups: 1, viscosity: 3 to 8 mPa s, trade name “Viscoat #160”, Osaka Organic Chemical Co., Ltd. (meth) acrylic compound B: 1,4-butanediol diol methacrylate, functional group number 2,
Viscosity 5 mPa s, trade name “Light Ester 1,4 BG”, Kyoeisha Chemical Co., Ltd. (meth) acrylic compound C: polypropylene glycol diacrylate, functional group number 2, viscosity 8 to 16 mPa s, trade name “Aronix M-220” ”, Toagosei Co., Ltd. (meth) acrylic compound D: 1,6-hexanediol diacrylate, functional group number 2, viscosity 7 mPa s, trade name “HDDA”, Daicel Cytec Co., Ltd. (meth) acrylic compound E : Diethylene glycol dimethacrylate, 2 functional groups, viscosity 2 mPa s, trade name "Light Ester 2EG", Kyoeisha Chemical Co., Ltd. (meth)acrylic compound F: Tetrahydrofurfuryl acrylate, 1 functional group, viscosity 3 mPa s, trade name "Viscoat #150", Osaka Organic Chemical Co., Ltd. (meth) acrylic compound G: isobornyl acrylate, functional group number 1, viscosity 8 mPa s, trade name "IBXA", Osaka Organic Chemical Co., Ltd. (meth) acrylic compound H: phenol acrylate, number of functional groups: 1, viscosity: 8 to 20 mPa s, trade name: "Miramer M140", manufactured by Miwon (component (C))
Phosphorus-containing compound A: methacryloylmethyldiphenylphosphine oxide (compound represented by formula (1)), trade name “MC-4”, manufactured by Katayama Chemical Industries, Ltd. Phosphorus-containing compound B: 10-(3-glycidyloxypropyl)- 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (compound represented by formula (2)), trade name "E-10g", phosphorus-containing compound C manufactured by Katayama Chemical Co., Ltd.: formula Compound represented by (3), trade name "FRM-1000", manufactured by Nippon Kayaku Co., Ltd.

(other ingredients)
Phosphorus-containing compound D: phosphinate metal salt, trade name "OP-935", manufactured by Clariant Phosphorus-containing compound E: phosphazene derivative, trade name "FP-110", manufactured by Sanko Phosphorus-containing compound F: bis(2-methacryloyl Oxyethyl) phosphate, trade name “PM-2”, manufactured by Nippon Kayaku Phosphorus-containing compound G: triphenyl phosphate, trade name “TPP”, manufactured by Daihachi Chemical Industry Co., Ltd.

((D) component)
Photoinitiator A: 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, trade name "IRGACURE 907", manufactured by BASF Photoinitiator B: 2-benzyl-2 -Dimethylamino-1-(4-morpholinophenyl)-butanone-1, trade name "IRGACURE 369E", BASF photopolymerization initiator C: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, trade name "LUCIRIN TPO", BASF photopolymerization initiator D: bis (2,4,6-trimethylbenzoyl)-phenylphosphine oxide, trade name "IRGACURE 819", BASF photopolymerization initiator E: diethylthioxanthone, commercial product Name "Chemcure DETX", manufactured by Chembridge International

(other ingredients)
Coloring pigment A: trade name “Lionol Blue FG-7351”, Toyo Color Co., Ltd. coloring pigment B: trade name “Chromophthal Yellow AGR”, Ciba Specialty Chemicals Co., Ltd. Additive A: trade name “Floren G-700”, Kyoeisha Chemical Co., Ltd. additive B: trade name "UVX-189", Kusumoto Kasei Co., Ltd. additive C: trade name "BYK-361N", BYK Chemie Japan Co., Ltd. additive D: trade name "BYK-168", BIC Organic solvent manufactured by Chemie Japan: Diethylene glycol monoethyl ether acetate, trade name "EDGAC", manufactured by Shinko Organic Chemical Industry Co., Ltd.

[Example 1]
15 parts by mass of epoxy acrylate A, 73 parts by mass of (meth)acrylic compound A, 20 parts by mass of phosphorus-containing compound A, 5 parts by mass of photopolymerization initiator A, 5 parts by mass of photopolymerization initiator C, 1 part by mass of color pigment A, and 1 part by mass of color pigment B After the parts were put into a container and premixed with a stirrer, they were mixed and dispersed at room temperature using a triple roll to obtain a photosensitive resin composition for inkjet.

[Examples 2 to 12]
A photosensitive resin composition for inkjet was obtained in the same manner as in Example 1, except that each material was blended according to the composition shown in Table 1.

[Examples 13 to 24]
A photosensitive resin composition for inkjet was obtained in the same manner as in Example 1, except that each material was blended according to the composition shown in Table 2.

[Examples 25 and 26]
A photosensitive resin composition for inkjet was obtained in the same manner as in Example 1, except that each material was blended according to the composition shown in Table 3.

[Comparative Examples 1 to 5]
A photosensitive resin composition for inkjet was obtained in the same manner as in Example 1, except that each material was blended according to the composition shown in Table 4.

<Evaluation of photosensitive resin composition for inkjet>
Evaluations (coatability, adhesion, flame retardancy, electrical insulation, bleeding resistance) of the photosensitive resin composition for inkjet were performed by the following methods. The results obtained are shown in Tables 1-4.
In addition, the test body preparation process is as follows.
(Test body preparation process)
Substrate: Copper-clad laminate (thickness 1.6 mm)
Surface treatment: buff scrubbing Printing method: inkjet printing (inkjet device: "MJP2013F1-DU", Microcraft)
DRY film thickness: 20 to 23 μm
Exposure: 1000 mJ/cm ² on the coating film, Eye Graphics Co., Ltd. "UB093-5AM"
Post-cure: 60 minutes at a temperature of 150°C in a BOX-type drying oven

(1) Coatability Using the above inkjet device, apply a 100 x 100 dot pattern, and then observe the substrate with a magnifying glass (30x) to check whether the same coating as the pattern is performed. bottom. In addition, when the same application as the pattern was performed, it was judged as "good", and when there was a problem such as ejection failure, it was judged as "poor".
(2) Adhesion Adhesion to copper was evaluated according to JIS K 5400 for the test specimens produced in the test specimen production process described above, and the remaining number of grids was evaluated as follows.
◎: 100/100
○: 70/100 to 99/100
△: 10/100 to 69/100
×: 0/100 to 9/100
(3) Flame Retardancy The substrate was changed from a copper-clad laminate to a polyimide substrate with a thickness of 25 μm. After forming, it was evaluated according to the UL94VTM test standard.
(4) Electrical insulation A cured coating film was formed according to the above-described test body preparation process, except that the substrate was changed from a copper-clad laminate to a comb-shaped test pattern (line width 100 μm, line spacing 100 μm), and the temperature was 85 ° C. , DC 30 V was applied in an atmosphere of 85% humidity and left for 100 hours.
(5) Bleed resistance After the test piece prepared in the above test piece preparation process was pressed at 150°C, 3 MPa, and 300 seconds, the state of exudation from the test piece was checked visually and with a magnifying glass (30x ) and evaluated as follows.
⊚: No seepage that can be determined with a magnifying glass after pressing.
◯: Exudation that can be determined with a magnifying glass after pressing.
Δ: There is bleeding that can be visually determined after pressing.
x: Exudation was observed after the preparation of the test specimen.

As is clear from the results shown in Tables 1 to 4, when the photosensitive resin composition for inkjet of the present invention was used (Examples 1 to 26), coatability, adhesion, flame retardancy, It was found that the electrical insulation and bleed resistance results were all good. Therefore, according to the photosensitive resin composition for inkjet of the present invention, it is possible to form a cured product which is excellent in coatability by an inkjet method and which is excellent in electrical insulation, flame retardancy and bleeding resistance. was confirmed.
On the other hand, when the inkjet photosensitive resin composition that does not contain the component (C) according to the present invention is used (Comparative Examples 1 to 5), the coatability, flame retardancy, electrical insulation, and at least one of bleed resistance.

The inkjet photosensitive resin composition of the present invention can be suitably used as a technique for forming an insulating coating film having a pattern on a printed wiring board or the like.

Claims (6)

(A) a (meth) acrylic resin having a weight average molecular weight of 500 or more, (B) a (meth) acrylic compound having a weight average molecular weight of less than 500, (C) a phosphorus-containing compound, and (D) photopolymerization initiation A photosensitive resin composition that contains an agent and does not contain a phosphate ester ,
The component (A) is at least one selected from the group consisting of epoxy (meth)acrylate and urethane (meth)acrylate,
the component (C) is a compound other than a phosphate ester, and has a functional group capable of reacting by photoradical polymerization or photocationic polymerization in one molecule,
A photosensitive resin composition for inkjet, wherein the component (C) is at least one compound selected from the group consisting of compounds represented by the following formulas (1) and (2).

In the inkjet photosensitive resin composition according to claim 1,
A photosensitive resin composition for inkjet, characterized in that two or more of the components (C) are used in combination. In the inkjet photosensitive resin composition according to claim 1 or 2,
A photosensitive resin composition for inkjet, wherein the component (B) has a cyclic skeleton in one molecule. In the inkjet photosensitive resin composition according to any one of claims 1 to 3,
A photosensitive resin composition for inkjet, wherein the component (D) has a phosphorus atom in one molecule. In the inkjet photosensitive resin composition according to any one of claims 1 to 4,
(E) A photosensitive resin composition for inkjet, further comprising a bisallyl nadimide compound. A printed wiring board comprising a solder resist film made of the inkjet photosensitive resin composition according to any one of claims 1 to 5.