JPH03223314A - Photocurable resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a tack-free photosensitive coating film even with an actual exposure apparatus by mixing a specified modified resin with a product of modification of a normally solid epoxy resin with an alpha,beta-unsaturated monocarboxylic acid and a photopolymerization initiator. CONSTITUTION:An addition reaction between a conjugated diene (co)polymer of a number-average mol.wt. of 500-5000 and a vinyl content of 50mol% or more and an alpha,beta-unsaturated dicarboxylic acid anhydride is effected to obtain an adduct (a) having acid anhydride groups and a softening point (ring and ball softening point, JIS K 2531-60) of 70-200 deg.C. Component (a) is subjected of a reaction with an alcoholic hydroxyl-containing alpha,beta-unsaturated monocarboxylic ester (b) of the formula (wherein R1 and R2 are each H or CH3; and R3 is a 2C or higher hydrocarbon residue which may contain a heteroatom) to obtain a modified resin (A) in which at least 10mol% of the acid anhydride groups of component (a) are opened. 100 pts.wt. component A is mixed with 5-200 pts.wt. product (B) of modification of a normally solid epoxy resin with an alpha,beta-unsaturated monocarboxylic acid and 0.1-20 pts.wt. photopolymerization initiator (C).

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention uses a specific modified resin obtained by modifying a conjugated diene polymer or a conjugated diene copolymer, and an α,β-unsaturated epoxy resin that is solid at room temperature. This invention relates to a photocurable resin composition blended with a modified monocarboxylic acid. In particular, the present invention relates to a photocurable resin composition suitable for producing photocurable printed wiring boards.

[Prior art] Various methods have been developed for manufacturing printed wiring boards, but in recent years, a method using a photocurable photosensitive resin as an etching resist or plating resist has become mainstream in recent years. .

In the former method, a layer of a photocurable resin composition is created on a substrate by some method, then a negative circuit pattern mask is closely attached, the necessary parts are cured by irradiation with actinic rays, and the uncured parts are developed. In this method, a predetermined circuit pattern is obtained by removing and then etching.

For the latter, use a mask with a reverse pattern, remove the resin film in the necessary parts by development, apply etching-resistant solder plating to this part, peel off the resin film in the unnecessary parts, and then etch it to the desired shape. It is used to obtain a circuit pattern.

Here, the circuit pattern mask corresponds to a negative in photography, and a light blocking layer forming an appropriate pattern is formed on a transparent substrate. Although some substrates are made of glass, plastic films such as polyester are the most common. Metals such as Cr and Ag are often used as materials for the barrier layer.

The general composition of this photocurable resin composition is: (1) a binder polymer, (2) a photopolymerizable hexamer or oligomer (
(crosslinking agent), (1) photopolymerization initiator, (2) others (stabilizer, coloring agent, flame retardant), etc.

The role of the binder polymer is to give it a film shape, and acrylic polymers are mainly used, and are made by copolymerizing acrylic acid, acrylic esters, methacrylic acid, methacrylic esters, styrene, etc., and have a molecular weight of several hundred. be.

Photopolymerizable monomers/oligomers with acryloyl or methacryloyl groups are also used.

The principle is to use this composition and expose only the necessary areas to make them insolubilized.

[Problems to be Solved by the Invention] A method of using a photocurable resin composition using a specific maleated modified oil as a so-called photoresist such as an etching resist is described, for example, in Japanese Patent Publication No. 52-21526. However, since the composition described here is a mixture of a maleated modified oil and an ethylenically unsaturated compound having two or more unsaturated bonds in one molecule, the resulting coating film before irradiation with light is Tests conducted by the present inventors revealed that the film had tackiness at room temperature in a finger touch test.

That is, in the production of printed wiring boards, a circuit pattern mask is usually vacuum-adhered to the formed photosensitive coating film and exposed to UV light. At this time, if the photosensitive resin coating film has room temperature tackiness, the circuit pattern mask after exposure may When removing the mask, some of the paint film will stick to the mask. In order to prevent this, a cooling device or a cooling tank may be installed after exposure, but this is not preferable because it results in drawbacks such as high equipment costs, an additional step, and complexity. Applying a release agent or the like to a circuit pattern mask has an adverse effect on fine pattern formation. Therefore, the present inventors proposed in Japanese Patent Application No. 63-189596 that by adding an α,β-unsaturated dicarboxylic acid anhydride to a conjugated diene polymer or conjugated diene copolymer, -60 by ring and ball softening point measurement) in the range of 70 to 200°C, and then opened partially or completely with an α,β-unsaturated monodicarboxylic acid ester having an alcoholic hydroxyl group. It has been reported that a photosensitive resin coating formed from a modified resin produced by introducing a conjugated double bond has almost no room temperature tackiness in a finger touch test.

Here, the degree to which the photosensitive coating film adheres to the circuit pattern mask in actual equipment depends on various conditions such as temperature, pressure, and time. In both cases, the higher the temperature, the higher the pressure, and the longer the time, the better the adhesive will be. For example, in actual equipment, since it is used continuously, the temperature of the atmosphere itself tends to rise due to heat radiation from the light source, and pressure is applied to make the mask adhere to the mask in a vacuum, making it easier to adhere to the mask.

Therefore, the present inventors conducted an adhesion test of a photosensitive coating film under conditions closer to those of the actual machine, and found that
It has been found that the technique of No.-189598 is not necessarily satisfactory.

In other words, new tests have revealed that the patterned mask does not have complete tack-free properties, such as making a clear peeling sound when the patterned mask is peeled off after exposure. If this tack-free property is not sufficient, resin may adhere to the mask when the same pattern mask is used many times in industrial production, making the expensive pattern mask unusable, or in extreme cases. In this case, the resist pattern to be formed will be missing or short-circuited.

That is, in order to solve the above-mentioned problems, the present invention aims to provide a composition that provides a photosensitive coating film that is tack-free even in an actual exposure device.

[Means for Solving the Problems] The present invention provides (a) a softening material derived from a conjugated diene polymer or conjugated diene copolymer having a number average molecular weight of 500 to 5000 and a vinyl group content of 50 mol% or more. Point (JIS
An α,β-unsaturated dicarboxylic acid anhydride adduct having a temperature of 70 to 200°C (according to the ring and ball softening point measurement method of -2531-60) has the general formula RIR20(I) (wherein R1 and R2 is a hydrogen atom or methyl, R3
is a hydrocarbon residue having 2 or more carbon atoms which may contain a heteroatom) By reacting an α,β-unsaturated monocarboxylic acid ester having an alcoholic hydroxyl group represented by 100 parts by weight of a modified resin obtained by ring opening of 10 mol%, (b) 5 to 200 parts by weight of an α,β-unsaturated monocarboxylic acid modified epoxy resin that is solid at room temperature, and (C) initiation of photopolymerization. 0.1 to 20 parts by weight of a photocurable resin composition.

The invention will be further explained below.

In the present invention, the softening point (JIS-2531-60
A part of the acid anhydride group is obtained by using an α,β-unsaturated monocarboxylic acid ester having an alcoholic hydroxyl group. Alternatively, a modified resin (a) produced by completely ring-opening is used.

The conjugated diene polymer or conjugated diene copolymer used here refers to carbon atoms such as butadiene and isoprene.
-5 low polymers of conjugated diolefins, or one or more of these conjugated diolefins and monomers other than these conjugated diolefins having an ethylenically unsaturated bond, especially isobutylene, diisobutylene, styrene, α
- Low degree of polymerization copolymers with aliphatic or aromatic monomers such as methylstyrene, vinyltoluene, divinyltoluene. A mixture of two or more of these can also be used.

The above conjugated diene polymer or conjugated diene copolymer has a vinyl group content of 50 mol% or more and a number average molecular weight of 500 to 5.
A value in the range of 000 is used. At this time, those having a vinyl group content of less than 50 mol % are undesirable because of low crosslinking density. In addition, if the number average molecular weight is less than 500, the strength of the photosensitive coating film obtained is low;
Anything over 000 is not preferred because a smooth coating film cannot be obtained.

Here, the above-mentioned modified resin (a) can be produced as follows.

The conjugated diene polymer or conjugated diene copolymer is produced by a conventionally known method. That is, preferably 50% of the conjugated diolefin having 4 to 5 carbon atoms alone, a mixture of these diolefins, or a conjugated diolefin using an alkali metal or an organic alkali metal compound as a catalyst.
A typical manufacturing method is anionic polymerization of aromatic vinyl monomers such as styrene, α-methylstyrene, vinyltoluene, or divinylbenzene in amounts of up to mol % at temperatures from 0°C to 100°C. In this case, in order to control the molecular weight and obtain a light-colored low polymer with a low gel fraction, etc., an organic alkali metal compound such as sodium benzyl is used as a catalyst, and a compound having an alkylaryl group, such as toluene, is chained. Chain transfer polymerization using a transfer agent (U.S. Pat. Legal (Japanese Patent Publication No. 42-17485, Publication No. 43-27432), or toluene,
A polymerization method in which the molecular weight is controlled by using an aromatic hydrocarbon such as xylene as a solvent, a metal dispersion such as sodium as a catalyst, and adding an ether such as dioxane (Japanese Patent Publication No. 32-7448, 33-1245, 31-10188), etc. are suitable manufacturing methods.

Also, low polymers produced by coordination anionic polymerization using an acetylacetonate compound of a Group I metal in the periodic table, such as cobalt or nickel, and an alkyl aluminum halide (Japanese Patent Publication No. 45-507,
4B-30300) can also be used.

Next, an adduct of acid anhydride groups is produced by adding α,β-unsaturated dicarboxylic acid anhydride to these conjugated diene polymers or conjugated diene copolymers.

The α,β-unsaturated dicarboxylic acid anhydride referred to in the present invention includes maleic anhydride, citraconic anhydride, chloromaleic anhydride, and the like.

Usually, this addition reaction is carried out at a reaction temperature of 100 to 250 in an inert solvent that dissolves these alone or both.
It is carried out at ℃. At this time, 0.1 to 0.3 parts by weight of hydroquinone, catechols, p-phenylenediamine derivatives, etc. are added as antigelation agents.

In the present invention, the softening point of the resulting acid anhydride adduct (according to the method for measuring the ring and ball softening point) is 70 to 200.
It is important to add the α,β-unsaturated dicarboxylic acid anhydride so that the temperature is within the range of °C.

If the softening point is less than 70℃, the resulting coating film will become tacky,
If the temperature exceeds 200°C, a smooth coating film cannot be obtained, which is not preferable. This softening point mainly depends on the unsaturated bond content and molecular weight of the raw material conjugated diene polymer or conjugated diene copolymer, and the amount of α,β-unsaturated dicarboxylic acid anhydride added. For example, when using a liquid butadiene polymer with a number average molecular weight of 1000, the total acid value is 400 ■KOH/
A value greater than or equal to g is required.

Next, in the present invention, the adduct of the acid anhydride obtained as described above is reacted with an α,β-unsaturated monocarboxylic acid ester having an alcoholic hydroxyl group represented by the formula (1) above, and the acid (a) wherein at least a portion of the anhydride group is ring-opened;
The modified resin described in is produced.

The number of carbon atoms in the R3 group in the formula (I) is preferably 2
~20, and preferred heteroatoms that may be included are nitrogen and oxygen.

Specific α,β-unsaturated monocarboxylic acid esters having an alcoholic hydroxyl group represented by formula (I) include, for example, 2-hydroxyethyl acrylate, 2-
Hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, N-methylol acrylamide, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-phenoxypropyl methacrylate, etc., these may be used alone or in combination. It can be used as

The ring-opening reaction of the acid anhydride group by these is usually carried out in the presence of a base catalyst at a relatively low temperature of 100° C. or lower. Here, the ring-opening reaction does not necessarily need to be carried out on all of the acid anhydride groups; for example, 50% of the acid anhydride groups may be ring-opened and the remaining acid anhydride groups may be ring-opened with an alcohol or water that does not have an unsaturated group. Also included are imidized compounds containing -grade amines. Of course, all acid anhydride groups may be ring-opened. In addition, during this reaction, it is preferable to use a solvent that has no reactivity with these and dissolves both.

Examples include aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate, ethers without hydroxyl groups such as diethylene glycol dimethyl ether and triethylene glycol dimethyl ether, and diacetone alcohol. Examples include tertiary alcohols such as.

In any case, from the viewpoint of photocurability, the proportion of ring-opening by the α,β-unsaturated monocarboxylic acid ester having an alcoholic hydroxyl group is 10 mol% or more, preferably 30 mol% or more of the acid anhydride group. Appropriate. If it is less than 10 mol%, the photocurability will be insufficient, which is not preferable.

In this way, the modified resin (a) is produced.

To this modified resin (a), epoxy resin which is solid at room temperature is added α,
A modified product (b) obtained by modifying with β-unsaturated monocarboxylic acid is further blended.

The epoxy resin used as a modified raw material is solid at room temperature. A hot liquid epoxy resin is not preferred because the photosensitive coating film obtained will not be tack-free. Preferred epoxy resins are bisphenol A type epoxy resins or novolak type epoxy resins.

Bisphenol A type epoxy resin is 2,2-bis(4
°-Hydroxyphenyl)propane, 1,1-bis(4
“-Hydroxyphenyl)ethane, 1,1-bis(4”
It is produced by reacting a bisphenol compound such as -hydroxyphenyl)isobutane with epichlorohydrin. A more preferable bisphenol A epoxy resin is represented by the following formula (Il).

General formula (Il) (where n is an integer of 2 to 20, preferably 2 to 5, m is 1 or 0, preferably 1, R4 and R5 are hydrogen atoms or hydrocarbon residues having 1 to 10 carbon atoms) (preferably represents a methyl group or an ethyl group, respectively) Further, a novolak type epoxy resin is produced by reacting a novolak resin with epichlorohydrin. A preferred novolac type epoxy resin has the following formula (m)
It is expressed as

(In the formula, n is an integer of 3 to 10, R is a hydrogen atom or
The above epoxy resin (each representing a hydrocarbon residue of 1 to 1Ω) is heated at a temperature of 0 to 200°C, preferably 50 to 150°C.
℃ to react with α,β-unsaturated monocarboxylic acid to form (b
) to obtain a modified α,β-unsaturated monocarboxylic acid. α,
β-unsaturated monocarboxylic acids include acrylic acid, methacrylic acid and crotonic acid, and mixtures thereof can also be used.

Appropriate catalysts such as tertiary amines and quaternary ammonium salts can be used in the above modification reaction.

In the present invention, at least 50 mol% or more of the epoxy groups in the epoxy resin are reacted with an α,β-unsaturated monocarboxylic acid. However, when the photocurable resin composition of the present invention is used in a water-dispersed state, it is necessary to react with all the epoxy groups. In this case, if unreacted epoxy groups remain, they react with amines and the like added when dispersing the composition in water, giving the coating film excessive hydrophilicity, which is not preferable.

The α,β-unsaturated monocarboxylic acid modified product of (b) above is
It can be blended alone or as a mixture, and the blending amount is (a
) is in the range of 5 to 200 parts by weight per 100 parts by weight of the resin. If the amount is less than 5 parts by weight, it is substantially difficult to eliminate the desired tackiness, and if the amount exceeds 200 parts by weight, the photosensitivity will not be sufficient.

The photopolymerization initiator (c) that is further added in the present invention may be a conventionally known normal photopolymerization initiator, such as benzoin, benzoin methyl ether, benzoin methyl ether, benzoin isobutyl ether, benzyl, Michler's ketone, etc. - In addition to diethylthioxanthone etc., usually Irgacure 184, Irgacure 651, Irgacure 907 (Ciba Geigy), Flocure -
A commercially available product sold under a trade name such as 1173 (Merck & Co.) may also be used. These can be used alone or in combination. The amount of these used is 0.1 to 20 parts by weight per 100 parts by weight of the modified resin (a), and if it is less than 0.1 part by weight, the photocurability will decrease, so it is not preferable.
If the amount exceeds 1 part by weight, the strength of the resulting photosensitive coating will deteriorate, which is not preferable.

It is permissible to add an arbitrary fourth component to the resin composition within a range that does not cause tack on the coating film.

Examples of the fourth component include photopolymerizable monomers such as trimethylolpropane triacrylate and pentaerythritol triacrylate, and aminoacrylate.

In the present invention, a modified resin a), an α,β-unsaturated monocarboxylic acid modified product (b) and a photopolymerization initiator (C
) is dissolved in a conventionally known suitable solvent and used as a so-called varnish with a roll coater.
It may be used as a coating material for applicators and the like, or it may be used as an electrodeposition coating liquid after being made water-soluble or water-dispersed.

In the case of the latter electrodeposition coating, in order to make it water-soluble or water-dispersible, at least 1 of the acid content of the modified resin N (a) must be
A method of neutralizing 0% or more with a common basic compound can be preferably used. If the neutralization is low, water solubility or water dispersibility will be poor, making it undesirable as a water-based paint. Bases used for neutralization include ammonia, diethylamine, triethylamine, monoethanolamine, jetanolamine,
Amines such as N,N-dimethylethanolamine and N,N-dimethylbenzylamine, potassium hydroxide, and the like are used. Furthermore, various organic solvents can be used as necessary for the purpose of improving water solubility or water dispersibility or adjusting the flowability of the coating film. Examples of such organic solvents include ethyl cellosolve, butyl cellosolve, ethylene glycol dimethyl ether, diacetone alcohol, 4-methoxy-4-methylpentanone-2,
Examples include water-soluble organic solvents such as methyl ethyl ketone, and non-aqueous organic solvents such as xylene, toluene, methyl isobutyl ketone, and 2-ethylhexanol.

Furthermore, since the electrodeposition coating composition obtained by neutralization as described above is water-based, it has obvious advantages in terms of safety and production.

In the photocurable resin composition of the present invention, conventionally known thermal polymerization stabilizers such as hydroquinone, 2,6-di-tert-butyl para-cresol, parabenzoquinone, hydroquinone 7-methyl ether, phenothiazine, α-naphthylamine, etc. are appropriately added. Can be used in combination with

Although the photosensitive composition of the present invention can be applied to any substrate, the case where it is applied to a copper-clad laminate will be explained below as an example.

The coating may be applied to the copper-clad laminate using a water-based paint and an electrodeposition method in accordance with the usual methods of dip coating, roll coating, and curtain coating. Note that drying is usually carried out at 120°C or lower, preferably 100°C or lower for 5 to 20 minutes. At this time, if the temperature exceeds 120°C, the coating film will be thermally hardened, which is not preferable.

The coating film thus obtained has a smooth coating surface without tackiness at room temperature, making it ideal as a photosensitive coating film for producing circuit patterns.

The photosensitive coating film applied to this copper-clad laminate is exposed to active rays such as ultraviolet rays through a negative mask to harden the coating film in the exposed areas of the mask.

The active radiation for curing varies depending on the absorption wavelength of the photopolymerization initiator, but it is usually ultraviolet rays or electrons emitted from light sources such as xenon lamps, metal halide lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, and ultra-high-pressure mercury lamps. Active energy rays such as electron beams, α rays, β rays, and γ rays extracted from a ray accelerator. The light intensity of the light source, the irradiation time, etc. can be determined as appropriate. The atmosphere for irradiating active rays may be air or an inert atmosphere such as nitrogen.

After photocuring, by developing with an appropriate developer, the unexposed areas are eluted and the conductive coating on the circuit pattern area is exposed, which is removed with an etching solution, and then the cured coating is removed with an appropriate stripping solution. By removing this, an extremely high-resolution wiring pattern is completed. After development, in order to further improve the etching resistance, the remaining coating film may be further cured by UV irradiation or at a temperature of 120° C. or higher.

[Effects of the Invention] According to the present invention, a substantially tack-free photosensitive coating film can be obtained even in an actual exposure apparatus. Therefore, the photocurable resin composition of the present invention is suitable for the method of manufacturing a photosensitive type printed wiring board.

"Examples" The present invention will be described in detail below using Examples. Note that the present invention is not limited to the following examples.

Production Example 1 A viscosity of 14 poise at a number average molecular weight of 1000.25°C obtained by polymerizing butadiene at 30°C in the presence of a chain transfer agent toluene using benzyl sodium as a catalyst,
1. 322 g of liquid butadiene polymer with 65% bond, 245 g of maleic anhydride, 10 g of xylene, and 1.1 g of Antigen 6C (manufactured by Sumitomo Chemical ■, trade name) were placed in a 1J separable flask equipped with a reflux condenser and nitrogen blowing tube. and reacted at 190°C for 4.5 hours under a nitrogen stream. Next, unreacted maleic anhydride and xylene were distilled off to synthesize a maleated butadiene polymer with a total acid value of 480 try K OH/g. The softening point (ring and ball softening point JIS-2531-60) of this material was 128°C.

200 g of the maleated butadiene polymer obtained.

Diacetone alcohol 180g, hydroquinone 0.2g
The mixture was placed in an IJ separable flask equipped with a reflux condenser and air blowing tube, and soaked in an oil bath at 80°C.
The inside of the flask was lightly stirred to completely dissolve the maleated butadiene polymer.

Next, while blowing air into the reaction mixture little by little with a blowing tube, 2-hydroxypropyl acrylate was added.
117. Eig and 16 g of triethylamine were added and reacted at 70° C. for 6 hours to obtain modified resin A. The nonvolatile content concentration of modified resin A is 57%, and the acid value is 178y+y.
KOH/g of resin.

Production Example 2 In an IJ separable flask equipped with a reflux condenser, novolac epoxy resin (trade name YDCN 70
4. Manufactured by Tobu Kasei ■; average aromatic ring number 11) 310g1
104 g of acrylic acid, 310 g of diacetone alcohol
Then, 8 g of triphenylphosphine was taken and reacted at 100° C. for 12 hours to obtain modified resin B. This modified resin B
The nonvolatile content concentration was 57%, and the acid value was 3I1gKOH/g resin.

Production Example 3 The following compound was obtained by reacting bisphenol A and epichlorohydrin in the presence of an alkali catalyst in an IT separable flask equipped with a reflux condenser, and a bisphenol type epoxy resin (trade name Epicote' 1004) which is solid at room temperature. , manufactured by Yuka Shell Chemical ■) 500g,
38g acrylic acid 177g diacetone alcohol, 5g hydroquinone and 2 dimethylethanolamine
．． Take 5g and react at 100℃ for 4 hours to obtain modified resin C.
I got it. This modified resin C had a nonvolatile content concentration of 75% and an acid value of 41 FlyKOH/g of resin.

Production Example 4 Novolac epoxy resin (trade name: YDPN), which is a viscous liquid at room temperature, was placed in a lJ separable flask equipped with a reflux condenser.
638, manufactured by Tobu Kasei ■; average number of aromatic rings 4) 270 g, acrylic acid 108 g, diacetone alcohol 295 g and triphenylphosphine 8 g were taken and heated at 100°C for 12
The reaction was carried out for a period of time to obtain a modified resin.

The nonvolatile content concentration of this modified resin is 57%, and the acid value is 2my.
KOH/g of resin.

Example 1 Modified resin A obtained in Production Example 1 and modified resin B obtained in Production Example 2 were mixed so that the solid content weight concentration ratio was 6 = 4, and further 8% by weight based on the total solid content. A photocurable resin composition was prepared by adding the photopolymerization initiator benzoin isobutyl ether and stirring at 40° C. or lower for 1 hour while shielding from light.

This composition was applied with an applicator to a copper-clad laminate that had been previously brushed, washed and degreased, and dried at 80° C. for 20 minutes to obtain a coating film with a thickness of 15 μm.

The resulting coating film was subjected to a tack test and a photosensitivity test, which will be described later. The results are shown in Table 1.

Example 2 Modified resin A obtained in Production Example 1 and modified resin B obtained in Production Example 2 were mixed so that the solid content weight concentration ratio was 1021, and further 8% by weight based on the total solid content. A photocurable resin composition was prepared by adding the photopolymerization initiator benzoin isobutyl ether and stirring at 40° C. or lower for 1 hour while shielding from light.

This composition was applied with an applicator to a copper-clad laminate that had been previously brushed, washed and degreased, and dried at 80° C. for 20 minutes to obtain a coating film with a thickness of 15 μm.

The resulting coating film was subjected to a tack test and a photosensitivity test, which will be described later. The results are shown in Table 1.

Example 3 The modified resin A obtained in Production Example 1 and the modified material 11WB obtained in Production Example 2 were mixed at a solid content weight concentration ratio of 10:l, and further mixed at a concentration of 8% by weight based on the total solid content. Photopolymerization initiator Irgacure 907 (Ciba Geigy)
was added, triethylamine was added in an amount to neutralize 1/3 of the acid groups of resin A, and the mixture was dispersed in water using a conventional method to prepare a photocurable electrodeposition coating composition. The non-volatile content of this composition is 15%
, pH was 6.6, and electrical conductivity was 1.8 hS/cm.

Using this electrodeposition solution, electrodeposition was applied to a copper-clad laminate that had been previously brushed, washed and degreased under the conditions shown below, and after draining, it was dried at 100°C for 5 minutes to form a 15μ A coating film with a thickness of (3) was obtained.

The resulting coating film was subjected to a tack test and a photosensitivity test, which will be described later. The results are shown in Table 1.

(Electrodeposition conditions) Electrodeposition method: Anionic electrodeposition constant current method: 90-110mA/da+2* 3 minutes Example 4 Modified resin A obtained in Production Example 1 and modified resin C obtained in Production Example 3 were solidified. Mix so that the weight concentration ratio is 6 = 4, and further add photopolymerization initiator Irgacure 907 (Ciba Geigy) to 8% by weight based on the total solid content.
Triethylamine was added in an amount to neutralize 8/10 of the acid groups in Resin A, and the mixture was dispersed in water using a conventional method to prepare a photocurable electrodeposition coating composition. The non-volatile content of this composition is 15%, pH
was 7.0, and the electrical conductivity was 2.12 m5/cj.

Using this electrodeposition solution, under the conditions shown in Example 3, a copper-clad laminate that had been brushed in advance, washed and degreased was electrodeposition coated, and after draining, it was dried at 100°C for 5 minutes to form a 15μ intestine. A coating film with a thickness of .

The resulting coating film was subjected to a tack test and a photosensitivity test, which will be described later. The results are shown in Table 1.

Comparative Example 1 By adding the modified resin A obtained in Production Example 1 and the photopolymerization initiator benzoin isobutyl ether to 8% by weight based on the total solid content, and stirring at 40°C or less for 1 hour while shielding from light. , a photocurable resin composition was prepared.

This composition was applied with an applicator to a copper-clad laminate that had been previously brushed, washed and degreased, and dried at 80° C. for 20 minutes to obtain a coating film with a thickness of 15 μm.

The resulting coating film was subjected to a tack test and a photosensitivity test, which will be described later. The results are shown in Table 1.

Comparative Example 2 Modified resin A obtained in Production Example 1 and photopolymerization initiator Irgacure 907 (
(Ciba Geigy, Inc.), triethylamine in an amount to neutralize 1/3 of the acid groups of the resin, and water dispersion by a conventional method to prepare a photocurable electrodeposition coating composition. The non-volatile content of this composition is 15%, the pH is 6.6, and the electrical conductivity is 1.80a.
It was S/ctn.

Using this electrodeposition solution, electrodeposition was applied to a copper-clad laminate that had been brushed in advance, washed and degreased under the conditions shown in Example 3, and after draining, it was dried at 100°C for 5 minutes to form a 15 μm layer. A thick coating film was obtained.

The resulting coating film was subjected to a tack test and a photosensitivity test, which will be described later. The results are shown in Table 1.

Comparative Example 3 The modified resin A obtained in Production Example 1 and the modified resin resin obtained in Production Example 4 were mixed at a solid content weight concentration ratio of 6:4, and further mixed at 8% by weight based on the total solid content. A photocurable resin composition was prepared by adding a photopolymerization initiator benzoin isobutyl ether and stirring at 40° C. or lower for 1 hour while shielding from light.

This composition was applied with an applicator to a copper-clad laminate that had been previously brushed, washed and degreased, and dried at 80° C. for 20 minutes to obtain a coating film with a thickness of 15 μI.

The resulting coating film was subjected to a tack test and a photosensitivity test, which will be described later. The results are shown in Table 1.

(Tack test) A copper-clad laminate on which a photosensitive coating was formed was placed in a dark room with constant humidity and temperature at 35°C, and a negative mask (made of PET film) with a circuit pattern drawn was placed on top, and a 1.5 mm thick film was placed on top. A glass plate and a weight were placed on the mask, and a pressure of 0.2 to 1/ci was applied to the contact surface between the mask and the coated surface (this pressure was set as the pressure due to vacuum contact). After holding this state for 5 minutes, the glass plate and weight were removed, and the negative mask was peeled off, and the peeling state at this time was evaluated as follows. Note that each test device was preheated to ambient temperature before the test.

O: The mask can be peeled off without any resistance and without making a peeling sound.

×: When removing the mask, there was a feeling of resistance and a clear peeling sound was heard.

(Photosensitivity test) 30, 50. Using a circuit pattern mask for evaluation having pattern lines with a width of 100 μm, pattern lines were formed under the following exposure and development conditions, and pattern reproducibility was evaluated by microscopic observation.

O: A pattern is formed.

X: No pattern is formed.

(1) Exposure conditions Exposure device; Ushio Inc. UVC-2613 light source;
Metal halide lamp light amount: 170 mJ/cat (2) Development conditions Developing device: In-house spray device (spray pressure t, A5
Ny/cat) Developer: 1% sodium carbonate aqueous developer Temperature: 30°C

Claims (1)

[Scope of Claims] 1. (a) Softening point (JIS-K −
2531-60 according to the ring and ball softening point measurement method) is 70~
α,β-unsaturated dicarboxylic acid anhydride adducts in the range of 200℃ have general formulas, ▲mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 and R_2 are hydrogen atoms or methyl,
R_3 is a hydrocarbon residue having 2 or more carbon atoms which may contain a heteroatom) By reacting an α,β-unsaturated monocarboxylic acid ester having an alcoholic hydroxyl group, the acid anhydride group of the adduct is at least 100 parts by weight of a modified resin obtained by ring-opening 10 mol%, (b) 5 to 200 parts by weight of an α,β-unsaturated monocarboxylic acid modified epoxy resin that is solid at room temperature, and (c) initiation of photopolymerization. A photocurable resin composition comprising 0.1 to 20 parts by weight of an agent. 2. The composition according to claim 1, wherein the α,β-unsaturated dicarboxylic acid anhydride in (a) is maleic anhydride. 3. The α,β-unsaturated monocarboxylic acid ester in (a) above is 2-hydroxyethyl acrylate, 2-
The composition according to claim 1, selected from the group consisting of hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, and 2-hydroxy-3-phenoxypropyl methacrylate. 4. The composition according to claim 1, wherein the conjugated diene is butadiene. 5. According to claim 1, wherein the α,β-unsaturated monocarboxylic acid modified epoxy resin in (b) is an α,β-unsaturated monocarboxylic acid modified product of bisphenol A type epoxy resin or novolac type epoxy resin. Compositions as described.