WO2021117421A1

WO2021117421A1 - Active energy ray-curable coating composition

Info

Publication number: WO2021117421A1
Application number: PCT/JP2020/042624
Authority: WO
Inventors: 晴彦西田
Original assignee: 積水フーラー株式会社
Priority date: 2019-12-09
Filing date: 2020-11-16
Publication date: 2021-06-17
Also published as: TW202128783A; JPWO2021117421A1

Abstract

Provided is an active energy ray-curable coating composition containing the components (A), (B), and (C) indicated below.　(A) is an oligomer having a group represented by formula (1) and a substituted or unsubstituted acryloyl group, (B) is a (meth)acrylic acid ester monomer having one unsaturated bond per molecule thereof, and (C) is photopolymerization initiator (in formula (1), R₁ represents a perfluoroalkyl group having 4-6 carbon atoms).

Description

Composition for active energy ray-curable coating

The present invention relates to a composition for active energy ray-curable coating.

Conventionally, in electric / electronic parts, especially electronic circuit mounting boards, an insulating moisture-proof coating is applied with a coating agent for the purpose of protecting metal exposed parts of electronic parts such as IC chips and chip coils from moisture, dust, corrosive gas, etc. Is given.

In recent years, the mounting density of electronic components has increased, and coating agents have become a particularly important factor in order to ensure the reliability of electronic circuit mounting boards. As coating agents applied to electronic circuit mounting substrates, coating agents such as solvent-drying type, moisture-curing type, and ultraviolet-curing type are mainly known.

As the solvent-drying coating agent, a coating agent using a polyurethane resin, an acrylic resin, or a polyolefin resin is known. In addition, moisture-curable coating agents are also known.

Further, a photocurable coating agent has been proposed as a coating agent that can be particularly preferably used for electronic circuit substrates (Patent Document 1).

Japanese Patent Application Laid-Open No. 2007-308681 Japanese Patent Application Laid-Open No. 2017-179171 Japanese Patent Application Laid-Open No. 2008-159437 Japanese Patent Application Laid-Open No. 2014-159573 Japanese Patent Application Laid-Open No. 2017-155207

However, when a silicone resin is generally used as a moisture-curable coating agent, the curing time depends on the humidity, so that it may take several hours to cure, which poses a problem in workability.

In addition, the solvent-drying coating agent is inferior in productivity because it takes time to dry the solvent. In addition, since it contains a solvent, it is necessary to manage the working environment at the coating site (manufacturing line).

Therefore, in recent years, there has been a tendency to use an ultraviolet curable moisture-proof coating agent in order to solve these problems.

As the ultraviolet curable coating agent, a coating agent using an acrylic compound such as urethane (meth) acrylate oligomer or (meth) acrylate ester monomer is mainly used, and a radical polymerization type is particularly used for electronic parts. It has become mainstream. When the light source of such an ultraviolet curable coating agent is a high-pressure mercury lamp or a metal halide lamp, sufficient deep curability can be obtained by a combination of a photopolymerization initiator, but a UV-LED light source having a single wavelength is sufficient. There is a problem that a good deep curability cannot be obtained.

In particular, such a UV-LED light source has a cost advantage as a factory line facility because the light source life of the device is long and the irradiation device is relatively inexpensive. Therefore, since the lamps have become popular in recent years instead of high-pressure mercury lamps, the above-mentioned problems related to deep curability have become even more non-negligible.

Further, depending on the electronic circuit mounting board, a film thickness of 1 mm or more may be required to ensure insulation reliability, and in that case, if sufficient deep curability cannot be obtained, insulation reliability will decrease.

On the other hand, when the ultraviolet curable coating agent is used, the coating agent that has entered under the lead of the lead portion of the IC chip is shielded from ultraviolet rays by the lead portion, and the portion becomes a dark portion and remains in an uncured state. there is a possibility. Such an uncured state may have some effect on the electronic circuit board.

As a solution to these problems, a coating agent (Patent Document 2), which is a photocurable composition combined with moisture curing, has been proposed, but since curing proceeds when it comes into contact with moisture in the air, it is easy to handle at the coating site (factory line). Is expected to worsen, and delicate control of the coating agent is required during work, which is not realistic.

Furthermore, such a coating agent is required to have an appropriate viscosity that can be applied with a coating machine at a temperature of room temperature to 40 ° C. Patent Document 3 proposes a coating agent containing urethane (meth) acrylate as a main component using a polyester polyol containing a dimer acid component, but it has a high viscosity and is unlikely to be practical. It is considered that the water resistance and moisture permeability can be improved by containing the dimer acid component, but it is insufficient to ensure the insulation reliability.

Patent Document 4 proposes a coating composition based on a fluorine-based UV curable functional group-containing compound. The base resin has a fluorine skeleton, and it can be expected that it has excellent water resistance, but LEDs The deep curability, dark curability, thermal shock resistance, and insulation reliability of the light source are insufficient.

Further, Patent Document 5 proposes an LED curable moisture-proof insulating coating composition based on an oligomer having a butadiene skeleton, which can be expected to be excellent in water resistance and insulation reliability, but is deeply curable by an LED light source. And the dark part curability is insufficient.

In view of the above circumstances, an object of the present invention is to provide an active energy ray-curable coating composition having excellent deep curability, insulation reliability and thermostable impact resistance in a thick film. ..

As a result of intensive research to achieve the above object, the present inventor uses an active energy ray-curable coating having excellent deep curability, insulation reliability and thermal shock resistance in a thick film by using a predetermined oligomer. It has been found that a composition for use can be provided. The present inventor has completed the present invention by conducting further research based on such findings.

That is, the present invention provides the following composition for active energy ray-curable coating.

Item 1.
A composition for active energy ray-curable coating containing the following components (A), (B) and (C).
(A) Oligomer having a group represented by the following formula (1) and a substituted or unsubstituted acryloyl group,
(B) A (meth) acrylic acid ester monomer having one unsaturated bond per molecule,
(C) Photopolymerization initiator

[In formula (1), R ₁ represents a perfluoroalkyl group having 4 to 6 carbon atoms. ]
Item 2.
Further, a fluorescent whitening agent is contained as a component (D), and the component (D) is contained.
Item 2. The composition according to Item 1, wherein the fluorescent whitening agent is at least one selected from the group consisting of an oxazole-based compound, a coumarin-based compound, and a stilbene-based compound.
Item 3.
Item 2. The composition according to Item 1 or 2, further comprising a thiol compound as the component (E).
Item 4.
Item 3. The composition according to Item 3, wherein the thiol compound is a secondary thiol compound having 2 to 4 thiol groups.
Item 5.
The unsaturated group is a substituted or unsubstituted acryloyl group.
The component (A) is a segment derived from at least one selected from the group consisting of an aliphatic diisocyanate compound, an alicyclic diisocyanate compound and an aromatic diisocyanate compound, and a hydrogenated polyester polyol dimerate, a polyester dimerate polyol and a polycarbonate. Item 2. The composition according to any one of Items 1 to 4, which is an oligomer containing a segment derived from at least one selected from the group consisting of diols.
Item 6.
Item 2. The composition according to any one of Items 1 to 5, wherein the mass of the component (A) is 20 to 50% by mass with respect to the total mass of the component (A) and the component (B).
Item 7.
Item 2. The composition according to any one of Items 1 to 6, wherein the component (A) has a mass average molecular weight of 5000 to 30000.
Item 8.
Item 2. The composition according to any one of Items 1 to 7, wherein the component (A) has a perfluoroalkyl group content of 0.01 to 0.6 mol / kg.
Item 9.
Item 2. The composition according to any one of Items 1 to 8, wherein the component (B) is a (meth) acrylic acid ester monomer having a hydroxyl group as a molecule.
Item 10.
The component (C) is an acylphosphine oxide-based photopolymerization initiator.
Item 2. The composition according to any one of Items 1 to 9, wherein the component (C) is contained in an amount of 0.5 to 3.0 parts by mass with respect to a total of 100 parts by mass of the components (A) and (B).
Item 11.
Item 2. The composition according to any one of Items 1 to 10, wherein the component (C) is an acylphosphine oxide-based photopolymerization initiator represented by the following formula (2) or (3).

Item 12.
Item 2. The composition according to any one of Items 1 to 11, wherein the viscosity at 25 ° C. is 3000 mPa · s or less.

The composition for active energy ray-curable coating of the present invention is excellent in deep curability, insulation reliability and thermal shock resistance in a thick film.

Explanatory drawing of deep curability evaluation test. Explanatory drawing of dark part curability evaluation test. Explanatory drawing of thermal shock resistance evaluation test.

The active energy ray-curable coating composition of the present invention (hereinafter, also simply referred to as "the composition of the present invention") is a coating composition that is cured by being irradiated with active energy rays. The active energy ray is not particularly limited, and examples thereof include ultraviolet rays, visible rays, X-rays, and electron beams. Among them, it is preferable to use ultraviolet rays at the time of curing, and examples of the ultraviolet light source include high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, xenon lamps, electrodeless discharge lamps, LED lamps, etc., and high-pressure mercury lamps and metal halides. Lamps or LEDs are preferred.

The irradiation amount of ultraviolet rays is usually 2000 to 5,000 mJ / cm ² (preferably 3500 to 4500 mJ / cm ² ), but when the light source is an LED, a device that emits an emission wavelength of 365 nm to 405 nm is preferable. Irradiation with ultraviolet rays of 3,500 to 5000 ^{mJ / cm 2} (preferably 4000 to 4500 mJ / cm ^{2) may be performed.}

The composition of the present invention contains components (A), (B) and (C).

1. 1. Ingredient (A)
The component (A) is an oligomer having a group represented by the following formula (1) and a substituted or unsubstituted acryloyl group.

In formula (1), R ₁ is a perfluoroalkyl group having 4 to 6 carbon atoms. The perfluoro group may be linear or branched, but is more preferably linear. Further, the number of carbon atoms is more preferably 4 or 6.

The oligomer has a substituted or unsubstituted acryloyl group at one end, and the group is more preferably an acryloyl group represented by the following formula (4).

In the formula (4), R ₂ can be an arbitrary substituent, but is preferably a hydrogen atom or a methyl group. That is, it is preferably an unsubstituted acryloyl group or a meta-acryloyl group.

The oligomer of component (A) is preferably a linear oligomer, and may have a group represented by the above formula (1) at one end and a substituted or unsubstituted acryloyl group at the other end. preferable.

Further, the oligomer of the component (A) is a segment derived from at least one selected from the group consisting of an aliphatic diisocyanate compound, an alicyclic diisocyanate compound and an aromatic diisocyanate compound (hereinafter, also simply referred to as “Seg1”). Further, it is preferable to include a segment derived from at least one selected from the group consisting of a hydrogenated polyester polyol dimerate, a polyester dimerate polyol and a polycarbonate diol (hereinafter, also simply referred to as “Seg2”).

Specific examples of the compound from which Seg1 is derived include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), and methyl. Cyclohexane-2,4 (or 2,6) -diisocyanate, 1,3- (isocyanatemethyl) cyclohexane, isophorone diisocyanate, trimethylhexamethylene diisocyanate, dimerate diisocyanate, dianisidine diisocyanate, phenyldiisocyanate, methylene diisocyanate, ethylene diisocyanate, butylene Diisocyanate, propylene diisocyanate, octadecylene diisocyanate, 1,5-naphthalenediocyanate, polymethylene polyphenylenediocyanate, naphthalene diisocyanate, 3-phenyl-2-ethylene diisocyanate, cumene-2,4-diisocyanate, 4-methoxy-1,3- Phenylene diisocyanate, 4-ethoxy-1,3-phenylenediisocyanate, 2,4'-diisocyanate diphenyl ether, 5,6-dimethyl-1,3-phenylenediisocyanate, 2,4'-diisocyanate diphenyl ether, benzidine diisocyanate, 9,10- Anthracene diisocyanate, 4,4'-diisocyanate benzyl, 3,3'-dimethyl-4,4'-diisocyanate diphenylmethane, 2,6'-dimethyl-4,4'-diisocyanate diphenyl, 3,3'-dimethoxy-4 , 4'-diisocyanate diphenyl, 1,4-anthracene diisocyanate, phenylenediisocyanate, 2,4,6-tolylene triisocyanate, 2,4,4'-triisocyanate diphenyl ether, 1,4-tetramethylene diisocyanate, 1, 6-Hexamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 4,4'-methylene-bis (cyclohexylisocyanate) and the like can be mentioned. These may be used alone or in combination of two or more.

Among the above, isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and tolylene diisocyanate are particularly preferable, and isophorone diisocyanate is most preferable.

Seg2 is preferably a residue derived from at least one selected from the group consisting of hydrogenated polyester polyol dimerate, polyester dimerate polyol and polycarbonate diol.

More specifically, the oligomer of the component (A) is an oligomer represented by the following formula (5) or (6).

[In the formulas (5) and (6), R ₃ represents an alkenyl group having 1 to 6 carbon atoms, preferably 2 to 4 carbon atoms, and R ₄ represents a hydrogen atom or a methyl group. n is a real number from 3 to 7. ]

In such an oligomer, the group represented by the above formula (1) is, for example, 2- (perfluorohexyl) ethanol or 2- (perfluorobutyl) ethanol, and the above-mentioned alicyclic diisocyanate compound, aliphatic diisocyanate compound and At least one selected from aromatic diisocyanate compounds can be obtained by an addition reaction (also referred to as urethanization reaction) between an isocyanate group and a hydroxyl group.

Commercially available products may be used as 2- (perfluorohexyl) ethanol and 2- (perfluorobutyl) ethanol. Examples of commercially available products include product names "CHEMINOX FA-4" and "CHEMINOX FA-6" manufactured by Unimatec.

The unsaturated group present at the other end of the oligomer is at least selected from the group consisting of, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. It can be obtained as an acryloyl group by subjecting one type and the diisocyanate compound to an addition reaction (also referred to as a butylation reaction) between an isocyanate group and a hydroxyl group.

The dimer acid of the polyester polyol dimer acid in the production of Seg2 is produced by dimerization of C18 unsaturated fatty acids made from plant-based fats and oils, and has a dibasic acid of C36 dicarboxylic acid (38 carbon atoms). Typical compounds thereof are obtained by heating linoleic acid and oleic acid. Further, in the present specification, the dimer acid is a saturated dibasic acid obtained by reducing the double bond existing in the molecule by a hydrogenation reaction in addition to the one having a double bond in the molecule. It is defined as a concept that also includes.

Diomeric polyester polyols include, but are limited to, reaction products obtained by reacting the above-mentioned dimer acids with, for example, short-chain diols, polyalkylene glycols, long-chain polyols, or various other diols. It's not a thing.

The molecular weight of the polyester polyol dimerate is preferably 1000 to 3000, more preferably 1000 to 2000. Within such a numerical range, the molecular weight of the oligomer becomes an appropriate range, and a coating composition having excellent mechanical properties, thermal shock resistance, and insulation reliability can be obtained.

Further, the polycarbonate diol in the production of Seg2 is a compound obtained by reacting dialkyl carbonates, alkylene carbonates, and other carbonates with the diol, and a hydrocarbon group (C3 to C18) derived from the diol is formed via a carbonate bond. Examples thereof include those having a linked polymer chain and hydroxyl groups bonded to both ends of the polymer chain and having a structure represented by the following formula (7).

[In the formula (7), R ₅ indicates a residue obtained by removing the hydroxyl group from the diol that reacts with carbonates, and R ₅ and p are set so that the number average molecular weight of the carbonate diol is 500 to 3000. ]

Here, the number average molecular weight of the polycarbonate diol is preferably 500 to 2000 or less, and more preferably 500 to 1000. By adopting such a configuration, a coating composition having excellent mechanical properties, thermal shock resistance, and insulation reliability can be obtained.

The oligomer represented by the formula (5) or (6) is, for example, a compound derived from Seg1 and a compound derived from Seg2 (compound derived from Seg1) :( compound derived from Seg2) = 2: 1. It can be obtained by reacting with a molar ratio of 3: 2 to 3.5: 2. That is, Seg1 is derived at a ratio of 0.5 equivalent or 0.57 to 0.65 equivalent of the hydroxy group of the compound derived from Seg2 with respect to 1 equivalent of the isocyanate group of the compound derived from Seg1. It can be obtained by reacting a compound with a compound from which Seg2 is derived.

The mass average molecular weight of the oligomer represented by the formula (5) or (6) is preferably 5000 to 30,000. When the mass average molecular weight is 5000 or more, the hardness of the composition does not become too high, and excellent heat impact resistance as well as excellent flexibility can be obtained. On the other hand, when the mass average molecular weight is 30,000 or less, the viscosity of the coating composition does not become too high, and as a result, excellent coatability of the composition can be maintained.

Particularly when Seg2 is derived from polyester dimerate, it is preferably 8000 to 30000, and more preferably 10000 to 18000. Further, particularly when Seg2 is derived from a polycarbonate diol, the mass average molecular weight of the oligomer represented by the formula (5) or (6) is preferably 5000 to 10000.

In the present specification, the mass average molecular weight of the component (A) is defined as a measured value obtained by converting with standard polystyrene using a gel permeation chromatograph measuring device.

The mass average molecular weight of the component (A) can be measured, for example, with the following measuring device and measuring conditions.
Measuring equipment: HLC-8320 (Tosoh)
Measurement condition:
-Moving layer: THF
-Column: TSKgel Super Multipore HZ-M x 4
-Column temperature: 40 ° C
-Flow velocity: 0.35 ml / min
・ Standard substance: Polystyrene

The perfluoroalkyl group content of the component (A) is preferably 0.01 to 0.6 mol / kg, more preferably 0.1 to 0.5 mol / kg. The perfluoroalkyl group referred to here means CF ₃ (CF ₂ ) q- (where q is a natural number of 4 to 6). That is, it represents the number of moles of perfluorohexyl contained in 1 kg of oligomer, and when 2- (perfluorohexyl) ethanol was used to synthesize the component (A), the total amount of the charged raw materials was 1 kg. In the case, it is calculated by the amount of 2- (perfluorohexyl) ethanol charged (g) × 0.876 / 319 (mol) / kg. Similarly, when 2- (perfluorobutyl) ethanol is used to synthesize the component (A), it represents the number of moles of perfluorobutyl contained in 1 kg of the oligomer, and to synthesize the component (A). When the total amount of the charged raw materials is 1 kg, it is represented by the charged amount (g) of 2- (perfluorobutyl) ethanol × 0.829 / 219 (mol) / kg.

The content of the component (A) is preferably 20 to 50% by mass, preferably 30 to 40% by mass, based on the total mass of the component (A) and the component (B) described later. Is more preferable. By adopting such a structure, the viscosity of the coating composition does not become too high, and as a result, good coatability of the composition can be maintained. In addition, excellent insulation reliability of the coating composition can be maintained.

2. Ingredient (B)
The component (B) is a (meth) acrylic acid ester monomer having one unsaturated bond in the molecule. If a monofunctional (meth) acrylic acid ester monomer having one unsaturated bond in the molecule is not used, the flexibility and thermostable impact resistance of the coating agent composition will not be sufficient.

Specific examples of the (meth) acrylic acid ester monomer having one unsaturated bond in the molecule include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-. Butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 1-ethylheptyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, 1-butylamyl (meth) acrylate , Lauryl (meth) acrylate, chain alkyl (meth) acrylate such as octadecyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl ( Meta) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxy (meth) acrylate, phenoxyethyl (meth) acrylate, alkylphenoxy (meth) acrylate, alkyl (Meta) acrylate having a cyclic structure such as phenoxyethyl (meth) acrylate; hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) Acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 2-hydroxylauryl (meth) acrylate and other hydroxyl groups Hydroxyalkyl (meth) acrylate or 2-hydroxy-3-phenoxypropyl acrylate; and diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) ) Acrylate, trimethylene glycol mono (meth) acrylate, oligo or polyoxyalkylene glycol mono (meth) acrylate such as polypropylene glycol (meth) acrylate, and the like. These may be used alone or in combination of two or more.

Among these, a (meth) acrylic acid ester monomer having an alicyclic structure, a (meth) acrylic acid ester monomer having a cyclic structure such as an aromatic skeleton, and an ethylene oxide-modified (meth) having an aromatic skeleton. It is preferable to use at least one selected from the group consisting of an acrylic acid ester monomer and a (meth) acrylic acid ester monomer having a hydroxyl group as a molecule. Among these, it is particularly preferable to use a (meth) acrylic acid ester monomer having a hydroxyl group as a molecule because good adhesion of the coating agent to the surface to be treated can be obtained.

Examples of the (meth) acrylic acid ester monomer having an alicyclic structure include isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentanyl (meth) acrylate. can do. The (meth) acrylate having an aromatic skeleton and modified with ethylene oxide includes a cyclic structure (meth) such as phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, and an aromatic skeleton. ) As the acrylic acid ester monomer, phenoxyethyl (meth) acrylate can be exemplified.

Among these, phenoxypolyethylene glycol (meth) acrylate, isobornyl (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate and the like are particularly preferable.

Examples of the (meth) acrylic acid ester monomer having a hydroxyl group in the molecule include 4-hydroxybutyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl acrylate, and 2-hydroxy-3-phenoxypropyl acrylate. Is particularly preferable. By containing these, the adhesiveness of the electronic circuit mounting substrate to the solder resist and electronic components without impairing the flexibility of the coating film, and the adhesiveness to the surface to be treated by the coating agent even when there is a flux residue. Is improved, and the reliability of the electronic circuit mounting board can be further maintained.

Further, as the acrylic acid ester monomer of the component (B), a commercially available product can be used. As commercially available products, for example, Kyoeisha Chemical Co., Ltd. product name "Light Acrylate P-200A" as phenoxypolyethylene glycol acrylate, Toa Synthetic Chemical Co., Ltd. product name "Aronix M-111" as nonylphenoxypolyethylene glycol acrylate, as isobornyl acrylate. Is a product name "IBXA" manufactured by Osaka Organic Chemical Co., Ltd., and Hitachi Kasei Co., Ltd. "FA-513M" is mentioned as a dicyclopentanyl methacrylate. As phenoxyethyl acrylate, product name "Viscoat 192" manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "Light acrylate PO-A" manufactured by Kyoeisha Chemical Co., Ltd., and as 2-hydroxy-3-phenoxypropyl acrylate, manufactured by Toa Synthetic Chemical Co., Ltd. Examples include the product name "Aronix M-5700" and the product name "Epoxyester M-600A" manufactured by Kyoeisha Chemical Co., Ltd.

The content of the component (B) is preferably 50 to 80% by mass, more preferably 60 to 70% by mass, based on the total mass of the components (A) and (B). .. By adopting such a structure, the viscosity of the coating composition does not become too high, and as a result, good coatability of the composition can be maintained. In addition, excellent insulation reliability of the coating composition can be maintained.

3. 3. Ingredient (C)
The photopolymerization initiator used as the component (C) may be one that generates radicals by light and the radicals efficiently initiate radical polymerization of unsaturated group-containing oligomers and (meth) acrylic acid ester monomers. However, there is no particular limitation, and a known photopolymerization initiator can be widely used.

Specific examples of such photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and benzyl dimethyl ketal. , 1-Hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, phenylbis (2,4,6-trimethylbenzoyl) -phosphenyl oxide, diphenyl (2,4,6-trimethylbenzoyl) phosphenyl oxide, benzophenone, o-benzoyl methyl benzoate, hydroxybenzophenone, 2-isopropylthioxanthone, 2,4 -Dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 2,4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6-bis (trichloro) -S-triazine , 2- (4-Methenylphenyl) -4,6-bis (trichloromethyl) -S-triazine, and the like. These photopolymerization initiators can be used alone or in combination of two or more.

Among the above, the acylphosphine oxide-based photopolymerization initiator represented by the following formula (2) or (3), which has absorption in the long wavelength region of UV light (phenylbis (2,4,6-trimethylbenzoyl)). -Phosphine oxide, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide) is most preferable. Here, the long wavelength in UV light mainly represents UV-A, represents a wavelength of 315 to 400 nm, and particularly means having an absorption peak wavelength in the vicinity of 375 nm.

The content of the component (C) is preferably 0.5 to 3.0 parts by mass, preferably 1.0 to 2.0 parts by mass, based on 100 parts by mass of the total of the components (A) and (B). It is more preferable to do so. By adopting such a configuration, excellent deep curability can be obtained.

A commercially available product may be used as the photopolymerization initiator of the component (C). Examples of commercially available products include IGM Resin product names "Omnirad 819" and "Omnirad TPO-H".

4. Ingredient (D)
It is also preferable that the composition of the present invention further contains a fluorescent whitening agent as the component (D). As the fluorescent whitening agent, known ones can be widely adopted, and there is no particular limitation. Examples of the fluorescent whitening agent include oxazole-based, coumarin-based, triazole-based, imidazole-based, virazolone-based, naphthalimide-based, and stillbenzene-based fluorescent whitening agents. Among these, 2,2'-(2,5-thiophenidiyl) bis (5-tert-butylbenzoxazole), which is an oxazole-based fluorescent whitening agent represented by the following formula (8), can be used. Especially preferable.

The oxazole-based fluorescent whitening agent is excited by absorbing ultraviolet light having a wavelength of 320 to 400 nm (peak wavelength 370 nm), and emits purple-blue to blue-green fluorescence (visible light) having a wavelength of 400 to 460 nm (peak wavelength 430 nm). It is a thing. 2,2'-(2,5-thiophenidiyl) bis (5-tert-butylbenzoxazole), which is an oxazole-based fluorescent whitening agent represented by the formula 8, is a photopolymerization initiator of the component (C). When used in combination with, the photosensitivity is further increased in ultraviolet irradiation emitting an emission wavelength of 365 nm to 405 nm, which contributes to the acquisition of more excellent deep curability and dark curability of the coating composition.

The blending amount of the component (D) is preferably 0.1 to 0.5 parts by mass, preferably 0.1 to 0.2 parts by mass, based on 100 parts by mass of the total of the components (A) and (B). It is more preferable to do so. By using the fluorescent whitening agent, the photosensitivity is further increased in the ultraviolet irradiation emitting an emission wavelength of 365 nm to 405 nm, and the deep curability and the dark curability of the coating composition can be improved.

As the fluorescent whitening agent for component (D), a commercially available product may be used. Examples of commercially available products include BASF's product name "TINOPAL OB".

5. Ingredient (E)
It is also preferable that the composition of the present invention further contains a thiol compound as a component (E). The thiol compound may be any of a primary, secondary and tertiary thiol compound. Above all, it is preferable to use a secondary thiol compound. By using the secondary thiol compound, an appropriate storage stability period can be maintained without affecting the storage stability of the coating composition. Further, among the secondary thiol compounds, a compound having 2 to 4 thiol groups is preferable, and a compound having 4 thiol groups is particularly preferable.

Specifically, 1,4-bis (3-mercaptobutylyloxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 ( 1H, 3H, 5H) -Trione, Trimethylol Propantris (3-mercaptobutyrate) Trimethylol Propantris (3-mercaptopropionate), Pentaerythritol Tetrakiss (3-Mercaptobutyrate), Pentaerythritol Tetrakiss (3- Mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate) and the like. These may be used alone or in combination of two or more.

Among the above, pentaerythritol tetrakis (3-mercaptobutyrate) and trimethylolpropane tris (3-mercaptobutyrate), which are secondary thiol compounds, are particularly preferable.

The blending amount of the component (E) is preferably 1.0 part by mass or less, preferably 0.3 to 0.5 part by mass, based on 100 parts by mass of the total of the components (A) and (B). More preferred. By setting the blending amount of the component (E) to 1.0 part by mass or less with respect to a total of 100 parts by mass of the components (A) and (B), the coating composition is crosslinked by ultraviolet irradiation emitting an emission wavelength of 365 nm to 405 nm. The degree is improved and a coating having a high degree of curing can be formed. These degrees of curing can be confirmed by the gel fraction. Further, by setting the blending amount of the component (E) to 0.3 parts by mass or more with respect to 100 parts by mass of the total of the components (A) and (B), sufficient dark part curability can be obtained.

6. Other Ingredients The composition of the present invention may contain a filler as appropriate depending on its purpose and the like. As the filler, an inorganic filler used in a normal curable resin composition can be used. The filler is preferably in the form of fine particles. For example, as the inorganic filler, fused silica, crystalline silica, fumed silica, quartz fine powder, calcium carbonate, mica, talc, etc. can be used, but it is more preferable to use fumed silica. The average primary particle size of fumed silica is preferably 5 nm to 50 μm. By using such fumed silica, good thixophilicity can be imparted to the composition of the present invention, and it can be suitably used as a coating on a portion where a thick film needs to be secured. Further, a composition that is almost transparent can be obtained, and sufficient curability can be obtained even when irradiated with ultraviolet rays.

In addition, if necessary, a polymerization inhibitor, an adhesion imparting agent, a leveling agent, an antifoaming agent, an antioxidant, a flame retardant, etc. can be appropriately added as long as the effects of the present invention are not impaired.

The composition of the present invention preferably has a viscosity at 25 ° C. of 50 to 3000 mPa · s, and has a viscosity of 100 to 2000 mPa · s. s is preferable. The viscosity can be measured and calculated by using a Brookfield rotational viscometer.

The method for producing the composition of the present invention is not particularly limited, and the composition can be produced by a conventional method. For example, the above-mentioned components (A) to (C) and, if necessary, other components can be mixed using a kneader whose temperature can be adjusted, for example, a planetary mixer, a twin-screw mixer, a high-shear mixer, a butterfly mixer, or the like. Can be manufactured by kneading

Further, the method of coating the electronic circuit mounting substrate using the composition of the present invention is not particularly limited, and coating can be performed by a conventionally known method, and a method of coating using a dispenser device is particularly preferable. ..

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail based on Examples, but the present invention is not limited thereto.

Component (A-1): Synthesis Example 1
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 500 g of polyester polyol dimerate (Crawder preplast 1838, hydroxyl value: 56 mgKOH / g, number average molecular weight: 2,000) and isophorone diisocyanate (ebonic). VESTNAT IPDI) 111.12 g was added, and the mixture was stirred and reacted at 80 ° C. for 3 hours under reflux with nitrogen, and then 45.51 g of 2- (perfluorohexyl) ethanol and 43.54 g of 2-hydroxyethyl acrylate were added. The reaction was carried out with stirring at 80 ° C. for 15 hours, and the completion of the reaction was confirmed by the disappearance of the isocyanate residue by the titration according to JIS K7301. As a result, component (A-1) (mass average molecular weight 14,900, perfluorohexyl group content: 0.18 mol / kg) was obtained.

Component (A-2): Synthesis Example 2
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 500.0 g of polyester polyol dimerate (Crawder's preplast 1838, hydroxyl value: 56 mgKOH / g, number average molecular weight: 2,000) and isophorone diisocyanate. (Ebonic VESTNAT IPDI) 111.12 g was added, and the mixture was stirred and reacted at 80 ° C. for 3 hours under reflux with nitrogen, and then 91.03 g of 2- (perfluorohexyl) ethanol and 29.03 g of 2-hydroxyethyl acrylate were added. The mixture was charged and stirred at 80 ° C. for 15 hours to react, and the completion of the reaction was confirmed by the disappearance of isocyanate residues by titration according to JIS K7301. As a result, component (A-2) (mass average molecular weight: 15200, perfluorohexyl group content: 0.34 mol / kg) was obtained.

Component (A-3): Synthesis Example 3
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 500.0 g of polyester polyol dimerate (Crawder's preplast 1838, hydroxyl value: 56 mgKOH / g, number average molecular weight: 2,000) and isophorone diisocyanate. (Ebonic VESTNAT IPDI) 111.12 g was added, and the mixture was stirred and reacted at 80 ° C. for 3 hours under reflux with nitrogen, and then 66.02 g of 2- (perfluorobutyl) ethanol and 29.03 g of 2-hydroxyethyl acrylate were added. The mixture was charged and stirred at 80 ° C. for 15 hours to react, and the completion of the reaction was confirmed by the disappearance of isocyanate residues by titration according to JIS K7301. As a result, component (A-3) (mass average molecular weight: 14900, perfluorohexyl group content: 0.35 mol / kg) was obtained.

Component (A-4): Synthesis Example 4
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 400 g of polycarbonate diol (Nipporan 965 from Toso, hydroxyl value: 112 mgKOH / g, number average molecular weight: 1000) and isophorone diisocyanate (VESTNAT IPDI from Ebonic) 177.83 g was added and stirred at 80 ° C. for 3 hours under reflux with nitrogen to react, then 72.82 g of perfluorohexyl alcohol and 78.08 g of 2-hydroxypropyl acrylate were added and stirred at 80 ° C. for 15 hours for reaction. The reaction was completed by confirming that the isocyanate residue had disappeared by the titration according to JIS K7301. As a result, component (A-4) (mass average molecular weight: 7300 perfluorohexyl group content: 0.27 mol / kg) was obtained.

Component (A-5): Synthesis Example 5
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 400 g of polycarbonate diol (Nipporan 965 from Toso, hydroxyl value: 112 mgKOH / g, number average molecular weight: 1000) and isophorone diisocyanate (VESTNAT IPDI from Ebonic) 177.83 g was added, and the mixture was stirred and reacted at 80 ° C. for 3 hours under reflux with nitrogen, then 145.64 g of perfluorohexyl alcohol and 52.06 g of 2-hydroxypropyl acrylate were added, and the mixture was stirred at 80 ° C. for 15 hours. The reaction was carried out, and the completion of the reaction was confirmed by the disappearance of the isocyanate residue by the titration according to JIS K7301. As a result, component (A-5) (mass average molecular weight: 7700, perfluorohexyl group content: 0.52 mol / kg) was obtained.

Component (A-6): Synthesis Example 6
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 500 g of polyester polyol dimerate (Crawder's preplast 1838, hydroxyl value: 56 mgKOH / g, number average molecular weight: 2,000) and isophorone diisocyanate ( Ebonic VESTNAT IPDI) 83.36 g was added, and the mixture was stirred and reacted at 80 ° C. for 3 hours under reflux with nitrogen, and then 9.10 g of 2- (perfluorohexyl) ethanol and 26.12 g of 2-hydroxyethyl acrylate were added. Then, the mixture was stirred and reacted at 80 ° C. for 15 hours, and the completion of the reaction was confirmed by the disappearance of the isocyanate residue by the titration according to JIS K7301. As a result, component (A-6) (mass average molecular weight 16,000 perfluorohexyl group content: 0.04 mol / kg) was obtained.

Component (A-7): Synthesis Example 7
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 500 g of polyester polyol dimerate (Crawder's preplast 1838, hydroxyl value: 56 mgKOH / g, number average molecular weight: 2,000) and isophorone diisocyanate ( Ebonic VESTNAT IPDI) 83.36 g was added, and the mixture was stirred and reacted at 80 ° C. for 3 hours under reflux with nitrogen, and then 22.76 g of 2- (perfluorohexyl) ethanol and 21.77 g of 2-hydroxyethyl acrylate were added. Then, the mixture was stirred and reacted at 80 ° C. for 15 hours, and the completion of the reaction was confirmed by the disappearance of the isocyanate residue by the titration according to JIS K7301. As a result, component (A-7) (mass average molecular weight 16,300 perfluorohexyl group content: 0.10 mol / kg) was obtained.

Component (A-8): Synthesis Example 8
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 500 g of polyester polyol dimerate (Crawder Preplast 1838, hydroxyl value: 56 mgKOH / g, number average molecular weight: 2,000) and isophorone diisocyanate (ebonic). VESTNAT IPDI) 111.12 g was added, and the mixture was stirred and reacted at 80 ° C. under reflux with nitrogen for 3 hours, then 58.05 g of 2-hydroxyethyl acrylate was added, and the mixture was stirred and reacted at 80 ° C. for 15 hours for reaction. The termination was confirmed by the disappearance of the isocyanate residue by the titration according to JIS K7301. As a result, the component (A-8) (mass average molecular weight: 14,600) was obtained.

Component (A-9): Synthesis Example 9
In a 1 L 4-neck flask equipped with a thermometer, a cooling tube, and a stirrer, 400 g of a hydrogenated polybutadiene polyol (Tosoh GI-1000, hydroxyl value: 70 mgKOH / g, number average molecular weight: 1,000) and isophorone diisocyanate ( 177.83 g of Ebonic VESTNAT IPDI) was added, and the mixture was stirred and reacted at 80 ° C. for 3 hours under reflux with nitrogen, then 92.88 g of 2-hydroxyethyl acrylate was added, and the mixture was stirred and reacted at 80 ° C. for 15 hours. The completion of the reaction was confirmed by the disappearance of the isocyanate residue by the titration according to JIS K7301. As a result, component (A-9) (mass average molecular weight: 20,500) was obtained.

Ingredient (B): Acrylic acid ester monomer (B-1) Monofunctional acrylate (Nonylphenoxypolyethylene glycol acrylate)
Aronix M-111 manufactured by Toagosei Co., Ltd.
(B-2) Monofunctional Acrylate (Phenoxy Polyethylene Glycol Acrylate) Kyoeisha Chemical Light Acrylate P-200
(B-3) Monofunctional acrylate (isobornyl acrylate)
Osaka Organic Chemical Industry IBXA
(B-4) Monofunctional acrylate (2-hydroxy-3-phenoxypropyl acrylate)
Toagosei Aronix M-5700

Ingredient (C): Photopolymerization Initiator Acylphosphine Oxide Compound (C1) IGM Resin Omnirad 819
(C2) IGM Resin Omnirad TPO-H

Component (D): Fluorescent whitening agent Oxazole-based fluorescent whitening agent BASF TINOPAL OB

Ingredient (E): Thiol compound 4-functional secondary thiol Showa Denko Karens MTPE1

(Examples and comparative examples)
Based on the formulations shown in Tables 1 and 2, the above components (A) to (E) are evaluated by producing a composition for active energy ray-curable coating using a stirring mixer equipped with a heating device. It was.

(Viscosity measurement)
Using a Brookfield B-type viscometer (Type DVE), (Spindle SC4-No. 29) and Thermocell were prepared, the chamber was filled with 13 cc of the coating composition, and the viscosity at 25 ° C. was measured.

(Deep curability evaluation test)
A peeling PET was attached to a stainless steel plate (5 cm × 5 cm) with double-sided tape so that the peeling surface was facing up, and a base base material for coating was prepared. Prepare silicon rubber sheets with thicknesses of 1 mm, 1.5 mm, 2 mm, and 3 mm, respectively, cut them into 2 cm x 2 cm, cut out so that the filling part of the coating agent is 15 mm x 15 mm as shown in Fig. 1, and use a spacer. did. The spacer was set on the prepared base material for coating, and the coating composition was filled to the height of the spacer. The packed coating composition was cured with a UV irradiation device (Aure UJ30 head wavelength 365 nm ANUJ6186 manufactured by Panasonic Corporation) at an integrated irradiation amount of 4500 mJ / cm2. The UV illuminance and the integrated irradiation amount were adjusted using an illuminance meter (UV Power PackII, Heraeus). The cured coating film was peeled off, placed on high-quality paper so that the peeled coating film was on the bottom, and cured for 1 hour. After curing, the coating film was removed and evaluated according to the following evaluation criteria. The back surface of the cured coating composition was confirmed, and if an uncured portion was not observed in the model having a film thickness of 1.5 mm of the silicon rubber sheet, the result was passed. Then, the models having a film thickness of 1 mm, 1.5 mm, 2 mm, and 3 mm obtained by each thickness of the silicon rubber sheet were judged according to the following evaluation criteria.
⊚: Uncured product cannot be confirmed even in the coating model with a film thickness of 2 mm and the coating model with a film thickness of 3 mm. Uncured product is confirmed in the coating model of (dark area curability evaluation test)
By the same method as the above-mentioned deep curability evaluation, a 1 mm spacer was used, the coating agent was filled, the film thickness was set to 1 mm, and then half the area of the filled part was made into an aluminum foil as shown in FIG. It was covered with UV light so that it would be a non-irradiated part. The irradiated part is cured with the same UV irradiation device and integrated irradiation amount as in the deep curable, the aluminum foil is removed, and the distance from the end face to the curing is observed with reference to the end face of the irradiated part. Judged by.
⊚: A distance of 5.0 or more and 7.5 mm or less from the end face of the irradiation part leads to curing ○: A distance of 2.5 or more and less than 5.0 mm from the end face of the irradiation part leads to curing Δ: 1.0 or more from the end face of the irradiation part A distance of less than 2.5 mm leads to curing ×: Only the irradiated part is cured. There is no curing on the non-irradiated part covered with aluminum foil.

(Heat and shock resistance evaluation test)
A coating device (Applicator (Unity IC30 PLUS) manufactured by Nordson, 3-axis robot (w / 4XP robot), Unity controller, nozzle 1.35 mm) was prepared. A silicon rubber sheet having a thickness of 2 mm was prepared, cut into 2 cm × 3.5 cm, and cut out so that the filled portion of the coating agent became 15 × 30 mm as shown in FIG. 3, and used as a spacer. The above spacer is set on the prepared copper-clad laminate, the coating composition is filled to the spacer height with the coating device, and the applied active energy ray coating composition is UV-irradiated in the same manner as in the deep curability evaluation. And the same integrated irradiation dose, the spacers were removed to obtain a coated coating film with a thickness of 2 mm, then the coating composition was applied, and the cured test piece was put into a thermal shock tester for 30 minutes at -40 ° C. The repetition of / 80 ° C. for 30 minutes was regarded as one cycle, and 500 cycles were carried out and evaluated according to the following evaluation criteria.
⊚: No peeling from the copper-clad laminate was caused.
◯: When the coating area is 100%, the peeling is less than 10%. Δ: When the coating area is 100%, there is 10 to 30% peeling.
X: When the coating area is 100%, there is peeling of 30% or more.

(Insulation reliability evaluation test)
The coating composition is applied to a comb-shaped electrode substrate (electrode spacing 0.318 mm) conforming to JIS Z3197 8.5.3e with the same coating device used in the measurement of thermal shock resistance so that the thickness is 1 mm. Then, the coating composition was cured with the same UV irradiation device and integrated irradiation amount used for the deep curability evaluation, and the test was performed for 500 hours using a migration tester under the conditions of 85 ° C. and 87.5% RH. Was evaluated according to the following evaluation criteria.
○: the insulation resistance is not generated dendrite 10 ⁸ Omega more △: the insulating resistance of at least 10 ⁸ Ω, × dendrite occurs: insulation resistance is less than 10 ⁸ Omega

(Adhesion evaluation)
A coating composition was applied to a copper-clad laminate (70 mm × 90 mm × 1.6 mm) in an area of 45 mm × 45 mm so as to have a thickness of 500 μm. Next, after curing the coating composition with the same UV irradiation device and integrated irradiation amount used for deep curability evaluation, the coating composition was left at room temperature for 24 hours, and a cross-cut method conforming to JIS K5400 (cut interval 2 mm, mass). The number of eyes 25) was evaluated according to the following evaluation criteria.
⊚: 25 remaining squares
〇: Remaining squares are 20 or more and less than 25 Δ: Remaining squares are 15 or more and less than 20 ×: Remaining squares are less than 15

Claims

A composition for active energy ray-curable coating containing the following components (A), (B) and (C).
(A) Oligomer having a group represented by the following formula (1) and a substituted or unsubstituted acryloyl group,
(B) A (meth) acrylic acid ester monomer having one unsaturated bond per molecule,
(C) Photopolymerization initiator

[In formula (1), R 1 represents a perfluoroalkyl group having 4 to 6 carbon atoms. ]
Further, a fluorescent whitening agent is contained as a component (D), and the component (D) is contained.
The composition according to claim 1, wherein the fluorescent whitening agent is at least one selected from the group consisting of an oxazole-based compound, a coumarin-based compound, and a stilbene-based compound.
The composition according to claim 1 or 2, further containing a thiol compound as the component (E).
The composition according to claim 3, wherein the thiol compound is a secondary thiol compound having 2 to 4 thiol groups.
The unsaturated group is a substituted or unsubstituted acryloyl group.
The component (A) is a segment derived from at least one selected from the group consisting of an aliphatic diisocyanate compound, an alicyclic diisocyanate compound and an aromatic diisocyanate compound, and a hydrogenated polyester polyol dimerate, a polyester dimerate polyol and a polycarbonate. The composition according to any one of claims 1 to 4, which is an oligomer containing a segment derived from at least one selected from the group consisting of diols.
The composition according to any one of claims 1 to 5, wherein the mass of the component (A) is 20 to 50% by mass with respect to the total mass of the component (A) and the component (B).
The composition according to any one of claims 1 to 6, wherein the mass average molecular weight of the component (A) is 5000 to 30000.
The composition according to any one of claims 1 to 7, wherein the component (A) has a perfluoroalkyl group content of 0.01 to 0.6 mol / kg.
The composition according to any one of claims 1 to 8, wherein the component (B) is a (meth) acrylic acid ester monomer having a hydroxyl group as a molecule.
The component (C) is an acylphosphine oxide-based photopolymerization initiator.
The composition according to any one of claims 1 to 9, wherein the component (C) is contained in an amount of 0.5 to 3.0 parts by mass with respect to a total of 100 parts by mass of the components (A) and (B). ..
The composition according to any one of claims 1 to 10, wherein the component (C) is an acylphosphine oxide-based photopolymerization initiator represented by the following formula (2) or (3).
The composition according to any one of claims 1 to 11, which has a viscosity at 25 ° C. of 3000 mPa · s or less.