JPH03137176A - Photo-setting electrodeposition coating composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a polymerizable photo- setting resin, water-insoluble photopolymerization initiator and specific nitrogen- containing compound and capable of readily removing unexposed parts of an electrodeposition film exposed through a negative or positive film to light by development. CONSTITUTION:The objective electrodeposition coating composition, containing (A) a photo-setting resin containing photosensitive groups and ionic groups capable of crosslinking or polymerizing by irradiation with light, (B) a water- insoluble photopolymerization initiator and (C) a nitrogen-containing compound expressed by formula I (X is H or hydroxyl group; R1 to R3 are H, Cl or 1-12C alkyl), formula II (R4 and R5 are H or 1-12C alkyl), formula III (R6 to R8 are H, hydroxyl group or 1-12C alkyl), formula IV or V (R9 to R12 are hydroxyl group, 1-12C alkyl, 1-12C alkoxyl or H) and/or formula VI (R13 and R14 are H or 1-12C alkyl; n is 1-3) with hardly any toxicity to human bodies or a danger of a fire.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an electrocoating composition for printed wiring photoresists, and more specifically, it is a composition that can easily coat unexposed areas of an electrostatic coating film exposed through a negative or positive film. The present invention relates to an electrodeposition coating composition for printed wiring photoresists that can be removed by development and form an excellent printed wiring circuit pattern.

[Prior art] Conventionally, in order to create a printed wiring board, copper plating is generally applied to a laminate plate covered with copper foil, a photosensitive film is laminated on top of the copper plating, and then a photographic negative is layered and exposed and exposed. After development, unnecessary copper foil other than the circuit pattern is etched, and then a photosensitive film is removed to form a printed circuit on the insulating laminate.

The photosensitive film used in the above method is generally thick, around 50P, so the circuit pattern formed by exposure and development is not sharp, and it is difficult to uniformly laminate the photosensitive film on the copper foil surface. There are problems such as it is difficult to use, and even though photosensitive film is expensive, it is almost wastefully removed during the development process.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems by using a photosensitive film when producing a printed wiring board. It was created for the purpose of using a photocurable coating film, and it is a coating film that meets this purpose, that is, a uniform coating film that can be developed on the surface of a copper-clad laminate, and that has excellent photosensitivity. An object of the present invention is to provide an electrodeposition coating composition for printed wiring photoresists that can form a printed wiring photoresist. Although some photocurable electrodeposition paints have been put into practical use as printed wiring photoresists, there is a desire to develop photoresists with higher resolution.

Conventional photocurable electrodeposited photoresists generally require a large amount of exposure in order to obtain a high-resolution resist, which poses the problem of long exposure times and poor productivity.

[Means for Solving the Problems] The present inventors have conducted intensive research to obtain an electrodeposition coating composition suitable for printed wiring photoresists, which does not have the above-mentioned problems. The present inventors have discovered that the problem can be solved by adding a specific nitrogen-containing compound to a photocurable electrodeposition coating composition containing a resin and a water-insoluble photopolymerization initiator as main components, and have completed the present invention.

Thus, according to the present invention, (a) a photocurable resin containing a photosensitive group and an ionic group that can be crosslinked or polymerized by light irradiation, (b) a water-insoluble photoinitiator, and (c) The following general formulas (1) to (6) In the formula, X represents a hydrogen atom or a hydroxyl group, and R1, R2, and R1 each have a hydrogen atom, a chlorine atom, or a carbon number of 1 to 1
In the formula, R4 and R5 each represent a hydrogen atom or a carbon number of 1 to 2.
represents a 12 alkyl group, represents a 12 alkyl group or an alkoxyl group having 1 to 12 carbon atoms, where R6, R7 and R each represent a hydrogen atom, a hydroxyl group or an alkyl group having 1 to 12 carbon atoms, In the formula, R9, Rlo and R11 are each a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or a carbon number 1 to 12
represents an alkoxyl group, in which R1□ is a hydrogen atom,
Hydroxyl group or carbon number 1 ~ In the formula, R + s and RI4 each represent a hydrogen atom or a carbon number 1 to 12 alkyl group,
Provided is a photocurable electrodeposition coating composition comprising at least one nitrogen-containing compound selected from the following, wherein n is an integer of 1 to 3.

Hereinafter, the photocurable electrodeposition coating composition of the present invention will be explained in more detail.

The photocurable resin (a) used in the present invention contains a photosensitive group that can undergo a crosslinking reaction or polymerization reaction when irradiated with light, and an ionic group, that is, an anionic or cationic group. A polymer that is soluble in an aqueous alkali solution or an aqueous acid solution and contains a group of the following, which undergoes a crosslinking reaction or polymerization reaction when irradiated with light, and becomes substantially insoluble or sparingly soluble in an aqueous alkali solution or an aqueous acid solution. Curable polymers are included.

The photosensitive group that may be present in the photocurable resin (a) is a group that can initiate crosslinking or polymerization reaction by light irradiation in the presence of the water-insoluble polymerization initiator (b); As a specific example of a photosensitive group having such characteristics, for example, a (meth)acryloyl group [CH, .CR-CO-(R
represents a hydrogen atom or a methyl group)] cinnamoyl group,
Examples include allyl group.

The photocurable resin (a) contains the above-mentioned anionic or cationic ionic group in addition to the photosensitive group. The amounts of such ionic groups and photosensitive groups can vary over a wide range depending on the type and molecular weight of the polymer used as the substrate.

In grains, anionic groups (e.g. carboxyl groups) are added in an amount such that the photocurable resin has an acid value of 20 to 300 (mgKOH/g resin, the same applies hereinafter), preferably in the range of 30 to 100, and cationic groups. (e.g. tertiary amino group or onium base) is usually in an amount of 0.2 to 5 mol/kg FM resin, preferably 0.3 to 2.0 mol/kg resin,
The photosensitive group is suitably contained in an amount of 0.2 to 5.0 mol/kg resin, preferably 0.7 to 4.5 mol/kg resin.

In addition, the photocurable resin (a) is generally 300 to 100.0
00, preferably 1,000 to 50,000, more preferably 3,000 to 30,000, and its glass transition temperature (Tg) is 0°C or higher, particularly Preferably, the temperature is within the range of 5 to 70°C.

If the number of ionic groups in the photocurable resin is less than the lower limit of the above range, the resin generally cannot be made water-soluble or water-dispersible, making it difficult to form an electrodeposition coating composition; If the amount exceeds 100%, it becomes difficult for the electrodeposition paint to be applied to the substrate, and there is a tendency that a large amount of electric power is required to increase the amount of coating.

In addition, if the number average molecular weight of the photocurable resin is less than 300, the coating film applied during electrodeposition coating tends to be easily destroyed, making it difficult to obtain a uniform coating film.
If it exceeds 00.000, the smoothness of the electrodeposition coating film tends to be poor, resulting in an uneven coating surface, and the image resolution tends to be poor.

Furthermore, if the Tg of the photocurable resin is less than 0° C., the electrodeposited coating film generally exhibits tackiness, and dirt and dust tend to adhere to the coating film, making it difficult to handle.

Hereinafter, the anionic photocurable resin (a) used in the present invention will be specifically explained.

(1) Photocurable resin containing a (meth)acryloyl group as a photosensitive group: This photocurable resin can be produced, for example, by adding a glycidyl group-containing unsaturated compound to a high acid value acrylic resin. can. The high acid value acrylic resin used in this case has α,β-ethylenically unsaturated acids such as acrylic acid and methacrylic acid as an essential component, and contains (
Esters of meth)acrylic acid, e.g. methyl(meth)
Acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate,
It can be obtained by copolymerizing 2-ethylhexyl (meth)acrylate, hydroxyethyl (meth)acrylate, etc., and at least one unsaturated monomer selected from styrene, (meth)acrylonitrile, (meth)acrylamide, etc. Here, α, β-ethylenically unsaturated acids are generally used when the acid value of the acrylic resin is 40 to 650.
, preferably in the range of 60 to 500. In addition, the number average molecular weight and glass transition temperature (Tg) of the high acid value acrylic resin are as follows. It is adjusted as appropriate to have the following.

On the other hand, specific examples of the glycidyl group-containing unsaturated compound C added to the high acid value acrylic resin include glycidyl acrylate and glycidyl methacrylate.

The above-mentioned addition reaction between the high acid value acrylic resin and the unsaturated compound containing a glycidyl group is carried out according to a method known per se, for example, by using a catalyst such as tetraethylammonium bromide at 80 to 120"C for 1 to 5 hours. This can be easily done by doing this.

The photocurable resin can also be produced by adding a reaction product of a hydroxyl group-containing polymerizable unsaturated compound and a diisocyanate compound to a high acid value acrylic resin having a hydroxyl group, which will be described in Section 1 of CM below. can.

Examples of the hydroxyl group-containing polymerizable unsaturated compound include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and N-methylolacrylamide, and examples of the diisocyanate compound include tolylene diisocyanate, Examples include xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, and the like.

(11) Photocurable resin containing a cinnamoyl group as a photosensitive group: This photocurable resin is composed of, for example, a high acid value acrylic resin containing a hydroxyl group and a substituted or unsubstituted cinnamic acid halide. , in the presence of a base, for example, in a lysine solvent. The hydroxyl group-containing high acid value acrylic resin used in this case contains the α,β-ethylenically unsaturated acid and the hydroxyl group-containing polymerizable unsaturated compound described in the previous section (1) as essential components, and these and At least one other unsaturated monomer
It can be obtained by copolymerizing with seeds.

In the production of such a hydroxyl group-containing high acid value acrylic resin, the a,β-ethylenically unsaturated acid is -1151
The hydroxyl group-containing polymerizable unsaturated compound can be used in an amount such that the resulting photocurable resin has an acid value of 20 to 300, preferably 30 to 100. It can be used in an amount ranging from 5 to 97 parts by weight, preferably from 20 to 75 parts by weight, per 100 parts by weight of the high acid value acrylic resin.

On the other hand, substituted or unsubstituted cinnamic acid halide is generally used in the above-mentioned hydroxyl group-containing high acid value acrylic resin 100
6 to 180 parts by weight, preferably 30 to 140 parts by weight
It can be used in such amounts as to fall within parts by weight.

Substituted or unsubstituted cinnamic acid halides that can be used include cinnamic acid halides which may have 1 to 3 substituents selected from nitro groups, lower alkoxyl groups, etc. on the benzene ring, More specifically, cinnamic acid chloride, p-nitrocinnamic acid chloride, p-methoxycinnamic acid chloride, p-ethoxycinnamic acid chloride and the like can be mentioned.

The reaction between these substituted or unsubstituted cinnamic acid halides and the above-mentioned hydroxyl group-containing acrylic resin can be carried out, for example, by adding 20-10 parts of pyridine to 100 parts by weight of the acrylic resin solution.
0 parts by weight of cinnamic acid chloride dissolved in 20 to 100 parts by weight of dimethylformamide is added dropwise at 10°C or lower, followed by stirring at 30 to 70°C for 3 to 8 hours. The purified product can be obtained by pouring the reaction solution into a large excess of methanol to precipitate the polymer, reprecipitating it with a mixture of tetrahydrofuran and water, and then reprecipitating it with a mixture of tetrahydrofuran and methanol.

(i) Photocurable resin containing an allyl group as a photosensitive group; This photocurable resin can be prepared by, for example, adding allylglycidyl to the high acid value acrylic resin used in the previous item, or
It can be produced by adding a reaction product of (meth)allyl alcohol and a diisocyanate compound to a hydroxyl group-containing high acid value acrylic resin.

The above-mentioned addition reaction between the high acid value acrylic resin and allyl glycidyl ether can be carried out in the same manner as described in the previous section (1).

Furthermore, in the photosensitive electrodeposition coating composition of the present invention, a conventionally known cationic resin can be used in addition to the anionic resin as the photocurable resin (a) to form a cationic electrodeposition coating composition. It is.

Such cationic resins include, for example, resins obtained by adding a reaction product of a hydroxyl group-containing polymerizable unsaturated compound and a diisocyanate compound to an acrylic resin having a hydroxyl group and a tertiary amino group; epoxy resins; A tertiary amine group-containing resin obtained by reacting with a secondary amine and then reacting the remaining epoxy group with a polymerizable unsaturated monocarboxylic acid or a hydroxy group-containing unsaturated compound; 3 obtained by reacting a polymerizable unsaturated monocarboxylic acid or a hydroxyl group-containing polymerizable unsaturated compound with a resin obtained by copolymerizing a grade amine group-containing unsaturated compound with another polymerizable unsaturated monomer.
grade amino group-containing resin; epoxy resin is reacted with a polymerizable unsaturated monocarboxylic acid or a hydroxyl group-containing unsaturated compound, and the remaining epoxy group is converted to an onium salt in the presence of a tertiary amino compound, thioether, phosphine, etc. and a carboxylic acid. These resins can be used alone or in combination of two or more.

b and heavy A repellent The photocurable electrodeposition coating composition of the present invention contains a water-insoluble polymerization initiator. This initiator is decomposed by irradiation with light and starts a crosslinking reaction or a polymerization reaction of the photosensitive groups of the photocurable resin.

Such a polymerization initiator is a compound that generates a group active for the crosslinking reaction or polymerization reaction of the photosensitive group by its own cleavage reaction due to photoexcitation or by a hydrogen abstraction reaction from other molecules. , in particular those which are substantially insoluble in water (for example those with a solubility in water below 2 g/100-water) are used in the present invention. By using such a water-insoluble polymerization initiator, it is efficiently precipitated and contained in the coating film during electrodeposition coating, and a highly sensitive coating film can be formed.

Specific examples of such polymerization initiators include the following.

Benzophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzyl, diphenyl disulfide, tetramethylthiuram monosulfide, diacetyl, eosin, thionin, Michler's ketone,
Anthraquinone, chloranthraquinone, methylanthraquinone, α-hydroxyisobutylphenone, p-isopropyl α-hydroxyisobutylphenone, α・α dichloro-4-phenoxyacetophenone, 1-hydroxy 1-cyclohexylacetophenone, 2,2 dimethoxy 2-phenylacetophenone , methylbenzoylformate, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propene, thioxanthone, and the like.

The amount of these polymerization initiators used is not critical;
It can be varied within a wide range depending on the type, etc.
-M is 0.1 to 25 parts by weight, preferably 0.2 to 10 parts by weight per 100 parts by weight of the solid content of the photocurable resin (a) described above.
It can be within the range of parts by weight. If the amount is less than 0.1 parts by weight, the curability tends to decrease, and if it exceeds 25 parts by weight, the stability of the resulting composition tends to decrease. Further, these polymerization initiators may be used alone or as a mixture of two or more.

A When the nitrogen-containing compounds represented by the general formulas (1) to (6) described above are blended into the photocurable electrodeposition coating composition of the present invention,
The sensitizing effect is improved and the sensitivity is extremely high. Similarly, the resolution of images obtained using this material is also improved.

Although the reason for the above-mentioned effect is not clear, these nitrogen-containing compounds (C) have a strong ability to form chelates with metal ions such as copper. ), this prevents metal ions from increasing the molecular weight and crosslinking of the precipitated resin, thereby maintaining the alkali solubility of unexposed areas during image formation and preventing exposure to light. It is thought that the difference in solubility between the exposed area and the unexposed area becomes large, resulting in improved resolution.

Examples of such nitrogen-containing compounds (C) represented by general formula (1) include pyrazoles such as the following.

Examples of those represented by general formula (3) include: etc. can be mentioned.

Examples of those represented by general formula (4) include: 0 benzotriazoles such as 0 benzotriazoles.

Examples of the compound represented by the general formula (2) include the following.

Examples of those represented by general formula (5) include: etc. can be mentioned.

Furthermore, as shown by the general formula (6), for example, can be mentioned.

Among the nitrogen-containing compounds (C) described above, particularly preferred in the present invention are benzotriazoles represented by the general formula (1).

The nitrogen-containing compound (c) can be used singly or in combination of two or more in the electrodeposition coating composition of the present invention.
) It is generally in the range of 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of solid content.

d The electrodeposition coating composition of the present invention may optionally contain a polymerizable unsaturated group-containing resin, for example, an ethylenically unsaturated group-containing resin, in addition to the above-mentioned photocurable resin (a) component. Polyester acrylate resins, polyurethane resins, epoxy resins, acrylic resins, etc.: Vinyl monomers, (meth)acrylic acid ester dioligomers, such as diethylene glycol di(meth)acrylate, etc., are combined with photocurable resins (
a) It is also possible to adjust the performance of the formed coating film as appropriate by blending it in an amount usually not more than 100 parts by weight, preferably not more than 50 parts by weight, per 100 parts by weight of the solid content.

The photosensitive electrodeposition coating composition of the present invention includes, for example, a water dispersion or water solubilization product of the photocurable resin (a), a polymerization initiator (b), a nitrogen-containing compound (c), and other components. (d
) can be prepared by blending.

Water dispersion or water solubilization of the photocurable resin (a) can be achieved by neutralizing it with an alkali (neutralizing agent) when an anionic group such as a carboxyl group is introduced into the resin (a). In addition, when a cationic group such as an amino group is introduced, it is carried out by neutralizing with an acid (neutralizing agent). Examples of alkali neutralizing agents used in this case include alkanolamines such as monoethanolamine, jetanolamine, and triethanolamine; alkylamines such as nitriethylamine, diethylamine, monoethylamine, diisopropylamine, trimethylamine, and diisobutylamine; Examples include alkyl alkanolamines such as dimethylaminoethanol; alicyclic amines such as cyclohexylamine; alkali metal hydroxides such as caustic soda and caustic potash: ammonia. Examples of acid neutralizers include monocarboxylic acids such as formic acid, acetic acid, lactic acid, and butyric acid. These neutralizing agents can be used alone or in combination. The amount of the neutralizing agent used is generally preferably 0.2 to 1.0 equivalents, particularly 0.3 to 0.8 equivalents, per mole of ionic groups contained in the resin (a).

In order to further improve the fluidity of the water-solubilized or water-dispersed resin component, if necessary, a hydrophilic solvent such as methanol, ethanol, isopropanol, n-butanol, t -Butanol, methoxyethanol, ethoxyethanol, butoxyethanol, diethylene glycol methyl ether, dioxane, tetrahydrofuran, etc. can be added.

The amount of such hydrophilic solvent used is generally determined based on the resin (a)
It can be up to 300 parts by weight, preferably up to 100 parts by weight per 100 parts by weight of solid component.

In addition, in order to increase the amount of coating on the object to be coated, hydrophobic solvents such as petroleum solvents such as toluene and xylene; ketones such as methyl ethyl ketone and methyl isobutyl ketone: Esters such as ethyl acetate and butyl acetate; alcohols such as 2-ethylhexyl alcohol and benzyl alcohol can also be added.

The blending amount of these hydrophobic solvents is 10% of the solid component of resin (a).
Usually up to 200 parts by weight, preferably 100 parts by weight
It can be less than 1 part by weight.

In addition to the above purposes, polymerization initiators (b) and nitrogen-containing compounds (
The above-mentioned solvent can also be used as a solvent for dissolving c).1 If the polymerization initiator (b) and nitrogen-containing compound (c) are difficult to dissolve in the resin solution after neutralization, they may be dissolved in advance in an appropriate manner. It is preferable to mix with the resin (a) after dissolving it in a hydrophilic or hydrophobic solvent. The solvent that can be used can be selected from those mentioned above, and the amount used depends on the polymerization initiator (b) and the resin (a). An amount sufficient to dissolve the nitrogen compound (c) is sufficient.

The electrodeposition composition can be prepared by a conventionally known method, in which the resin (a
), a polymerization initiator (b), a nitrogen-containing compound (c), and other components (d) are thoroughly mixed, and water is added.

The composition prepared in this way is diluted with water in a conventional manner, and the pH is within the range of 4 to 9, and the bath concentration (solid content concentration) is 3 to 25% by weight, preferably 5 to 15%. The electrocoating paint (or coating bath) can be within a range of % by weight.

The electrodeposition paint prepared as described above can be applied to the surface of a conductor to be coated in the following manner. As the conductor, conductive materials such as metal, carbon, tin oxide, etc., or materials made by laminating, plating, etc., and fixing these materials to the surface of plastic or glass can be used.

The bath temperature is controlled at 15 to 40°C, preferably 15 to 30°C, and the pH and bath concentration are controlled within the ranges described above. 6 Then, the electrodeposition coating bath thus controlled is coated with Use the conductor as an anode if the electrodeposition paint is anionic.
In the case of a cationic type, it is immersed as a cathode for 5 to 20 minutes.
Appropriate time for one application of 0V DC current is 30 seconds to 5 minutes, and the resulting film thickness is generally 0.5 to 0.5 to 5 minutes in dry film thickness.
50F, preferably 1 to IOF.

After electrodeposition coating, the object to be coated is taken out of the electrodeposition bath and washed with water, and then the moisture contained in the electrodeposition coating is dried and removed using hot air or the like.

In addition, if necessary at this time, a cover coat layer can be provided on the electrodeposition coating film by a method known per se (
(See Japanese Unexamined Patent Publication No. 63-60594, etc.).

The active light used for exposure in the present invention varies depending on the absorption wavelength of the photopolymerization initiator, but is usually 250 to 400 nm.
UV radiation having a wavelength in the range of m is suitable. Examples of light sources containing light of these wavelengths include sunlight, mercury lamps, xenon lamps, arc lamps, and various lasers having oscillation lines in the ultraviolet region. The coating film is cured by irradiation with actinic light within several minutes, usually within a range of 1 second to 20 minutes.

In the development process, the unexposed area on the coating surface is washed away using an alkaline aqueous solution if the electrodeposition paint is an anionic type, or with an acid aqueous solution with a pH of 5 or less if the electrodeposition paint is a cationic type. This is done by Alkaline aqueous solutions are usually
Used are caustic soda, soda carbonate, caustic potash, aqueous ammonia, and other substances that can neutralize free carboxylic acids present in the coating film and make it water-soluble. Further, as the acid aqueous solution, acetic acid, formic acid, etc. can be used.

After development, the coating film is washed with water and dried with hot air, etc., to form a desired image on the conductor. Further, after etching is performed to remove the exposed conductor portions as necessary, the resist film can be removed to manufacture a printed circuit board.

The electrodeposition coating composition of the present invention and the image forming method using the same can be applied to photoresists, plate-making materials for planography and letterpress,
It can be applied to a wide range of uses such as PS plates for offset printing, information recording materials, and relief image production materials.

[Effects of the Invention] By electrocoating using the electrodeposition coating composition of the present invention, a uniform and smooth ultraviolet light-sensitive coating film can be obtained with any thickness. Since the formation of the coating film does not require any advanced technology, workability is greatly improved compared to conventional coating film formation methods. In addition, thin films that could not be achieved with liquid paints or photosensitive films can be easily obtained by simply setting the electrodeposition conditions, and the images obtained by exposure are much clearer than conventional methods. . Furthermore, since the electrodeposition coating composition of the present invention uses less organic solvent than conventional liquid coatings, it is less harmful to the human body and has less risk of fire.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that 1 part and % are both based on weight.

Example 1 40 parts of methyl methacrylate, 40 parts of butyl acrylate
A mixture of 20 parts of acrylic acid and 2 parts of azobisisobutyronitrile was heated to 11 parts in a nitrogen gas atmosphere.
The mixture was added dropwise over 3 hours into 90 parts of propylene glycol monomethyl ether (hydrophilic solvent) maintained at 0°C.

After dropping, the mixture was aged for 1 hour, and a mixed solution consisting of 1 part of azobisdimethylvaleronitrile and 10 parts of propylene glycol monomethyl ether was added dropwise over 1 hour.
A solution of a high acid value acrylic resin (0M value 155) was obtained by aging for a period of time.Next, this solution was added with glycidyl methacrylate 2
4 parts, 0.12 parts of hydroquinone and tetraethylammonium broma number approximately 50, 1.35 mol/k of photosensitive base
g resin, number average molecular weight approximately 20,000) solution was obtained. After neutralizing this polymerizable unsaturated resin with 0.6 equivalents of triethylamine, 3 parts of IH-benzotriazole and 6 parts of α-hydroxyisobutylphenone as a photopolymerization initiator were added, and the solid content became 10%. Water was added to prepare an electrodeposition coating bath (pH 7.0).

Example 2 10 parts of trimethylolpropane triacrylate was added to 225 parts of the polymerizable unsaturated resin solution of Example 1, and 0.6 equivalents of trimethylolpropane triacrylate were neutralized with triethylamine, followed by 4 parts of IH-benzotriazole as a photopolymerization initiator. After adding 7 parts of α-hydroxyisobutylphenone, the solid content was 10%.
% of water to prepare an electrodeposition coating bath.

Example 3 40 parts of methyl methacrylate, 25 parts of butyl acrylate
15 parts of 2-hydroxyethyl methacrylate, 20 parts of acrylic acid, and 2 parts of azobisisobutyronitrile was heated at 105°C under a nitrogen gas atmosphere.
It was added dropwise over 2 hours to 100 parts of dioxane (hydrophilic solvent) held at
Add 200 parts of this solution to 200 parts of an equimolar adduct of 2-hydroxyethyl methacrylate and tolylene diisocyanate.
In addition, 5 parts at a temperature of 80°C in a nitrogen gas atmosphere
By reacting for a period of time, a solution of a polymerizable unsaturated resin (acid value: 120, photosensitive base: 0.56 mol/kg resin, number average molecular weight: about 20,000) which can be used in the present invention was obtained. After neutralizing this polymerizable unsaturated resin with 0.6 equivalents of dimethylaminoethanol, 5 parts of the compound (3,5-dimethylpyrazole) and 6 parts of benzoin ethyl ether as a photopolymerization initiator were added, and the solid content was added. Water was added so that the ratio was 10% to prepare an electrodeposition coating bath (pH 7.2).

Example 4 A mixed solution consisting of 25 parts of methyl methacrylate, 15 parts of n-butyl acrylate, 15 parts of acrylic acid, 45 parts of dihydroxyethyl methacrylate, and 2 parts of azobisisobutyronitrile was heated at 80°C under a nitrogen gas atmosphere. It took 3 hours to drop into 100 parts of DMF held at
After dropping, the solution was aged for 1 hour, and a mixed solution consisting of 1 part of azobisdimethylvaleronitrile and 5 parts of DMF (dimethylformamide) was added dropwise over the course of 1 hour, and aged for another 5 hours to form a high acid value acrylic resin (acid value 115) solution. I got it.

Add 120 parts of pyridine to 200 parts of this polymerization solution,
57 parts of cinnamic acid chloride dissolved in 150 parts of MF was added dropwise at below 10°C, and then stirred at 50°C for 4 hours.
The reaction solution was poured into methanol to precipitate the polymer, and TH
F (tetrahydrofuran) - reprecipitated with water and further THF
- It was purified by reprecipitation with methanol and dried under reduced pressure at room temperature.

The resulting photocurable resin having a cinnamoyl group as a photosensitive group had an acid value of 81, a Tg point of 51°C, and a number average molecular weight of 20.0.
It was 00.

A solution of 100 parts of this resin in a mixed solvent of 50 parts of propylene glycol methyl ether and 50 parts of n-butanol was neutralized with 0.6 equivalents of triethylamine, and then the compound ? After adding 5 parts of H (1-hydroxybenzotriazole), 5 parts of Michler's ketone as photosensitizer.

Water was added so that the solid content was 10% to prepare an electrodeposition coating bath (pH 6, 9).

Comparative Example 1 An electrodeposition coating bath was prepared in the same manner as in Example 1 except that the IH-benzotriazole used in Example I was omitted.

Comparative Example 2 An electrodeposition coating bath was prepared in the same manner as in Example 2 except that the IH-benzotriazole used in Example 2 was omitted.

Comparative Example 3 An electrodeposition coating bath was prepared in the same manner as in Example 3 except that 3,5-dimethylpyrazole used in Example 3 was removed.

Comparative Example 4 An electrodeposition coating bath was prepared in the same manner as in Example 4, except that the 1-hydroxybenzotriazole used in Example 4 was omitted.

Using the electrodeposition coating baths obtained in Examples 1 to 4 and Comparative Examples 1 to 4, a copper-clad stacked stone board measuring 250 mm x 300 mm, 1.6 mm thick, and having a through hole with a diameter of 0.30 mm was coated under the following conditions. Electrodeposition painting was performed.

Bath temperature: 25°C Current density: 60111A/dm” DC current Distance between electrodes: 10cm Pole ratio: Plate/coated plate = % Current application time: 3 minutes After electrodeposition coating, dry at 80°C for 10 minutes to obtain a film thickness of 15 mm. A coating film was obtained.

Next, the electrodeposition coated plates produced using the electrodeposition coating baths of Examples 1 to 4 and Comparative Examples 1 to 4 were coated with two 3KW ultra-high pressure mercury lamps (upper and lower).
Light was irradiated on both sides through a 200F thick negative film on which a pattern of lines/spaces=i00P/100#11 was drawn using a vacuum printer device that scanned the light once back and forth.

After irradiation, the unexposed areas were completely washed out with a 1% sodium carbonate solution and developed. After development, etching the copper with ferric chloride,
The coating film on the exposed areas was removed with a 5% caustic soda solution to obtain a printed circuit board.

For printed circuit boards obtained using each paint, 0.
The minimum irradiation amount is required to form a resist film inside the 3On+m through hole and leave copper completely behind after etching.
The results of testing the condition of the surface pattern at that time are shown in Table 1 below.

An ultraviolet light meter UV-350 manufactured by Oak Seisakusho was placed on the glass plate of a vacuum printer manufactured by LLG Co., Ltd. and measured.

View of pattern state 2, Observation was made using a microscope with a scale and a magnification of 100 times.

Claims (1)

[Claims] 1. (a) A photocurable resin containing a photosensitive group and an ionic group that can be crosslinked or polymerized by light irradiation, (b) a water-insoluble photoinitiator, and (c) the following general formulas (1) to (6). ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) In the formula, ▲There are mathematical formulas, chemical formulas, tables, etc.▼(2) In the formula, R_4 and R_5 each represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(3) In the formula , R_6, R_7 and R_5 are each a hydrogen atom,
There are ▲mathematical formulas, chemical formulas, tables, etc. that represent a hydroxyl group or an alkyl group having 1 to 12 carbon atoms▼(4) In the formula, R_9R_1_0 and R_1_1 are a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or a carbon number, respectively. ▲ There are mathematical formulas, chemical formulas, tables, etc. that represent 1 to 12 alkoxyl groups ▼ (5) In the formula, R_1_2 is a hydrogen atom, a hydroxyl group, or a carbon number of 1 to 1
▲There are mathematical formulas, chemical formulas, tables, etc. that represent an alkyl group of 2 or an alkyl group having 1 to 12 carbon atoms.▼(6) In the formula, R_1_3 and R_1_4 each represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. , n is an integer of 1 to 3. A photocurable electrodeposition coating composition comprising at least one nitrogen-containing compound selected from the following.