JPH0299504A - Resin component for permanent protective film and production of the same permanent protective film - Google Patents

Abstract

PURPOSE:To provide the subject composition composed of a resin having carboxyl groups and photosensitive C=C bonds, epoxy compound and photoinitiator and capable of providing a protective film with a high density excellent in moisture resistance, chemical resistance, adhesion and curing characteristics of a thick film in excellent workability. CONSTITUTION:(A) A resin containing carboxyl groups and photosensitive C-C double bonds, (B) an epoxy compound (e.g., phenyl glycidyl ether) and (C) an photoinitiator are mixed to obtain the objective composition. In addition as the component (A) a modified resin prepared by adding an alpha,beta-unsaturated dicarboxylic anhydride such as maleic anhydride to a copolymer of a conjugated diene such as polybutadiene and then reacting an alpha,beta-unsaturated monocarboxylic acid ester having a photosensitive C-C double bond such as 2-hydroxyethyl acrylate with the resultant addition product is exemplified.

Description

Detailed Description of the Invention [Industrial Application Fields] The present invention relates to a resin composition suitable for solder resists, markings, and solder levelers used as permanent protective films for printed wiring boards, and a resin composition using the resin composition. The present invention relates to a method for manufacturing a protective film.

[Conventional technology] The density of printed wiring boards has been increasing year by year, and it has become necessary to run three or more lines between IC lands, and permanent protective films such as solder resists are also becoming denser and more reliable. There is a need to respond to the

However, the conventional method of forming a permanent protective film using a thermosetting composition requires pattern formation to be performed by silk screen printing, which has the problem of not being able to form a fine pattern due to deviations in positional accuracy caused by deflection of the silk. In recent years, ultraviolet curable compositions that can form fine patterns have been widely used. In addition, many products that can be developed with organic solvents have been used up until now, but from the viewpoint of improving the work environment and equipment, there is a simultaneous shift from conventional organic solvent-developable resin compositions to alkali-developable resin compositions. I'm about to be killed. Such a transition is also desired from the viewpoints of resource saving, energy saving, improved workability, and improved productivity.

[Problems to be Solved by the Invention] A resin composition that is UV-curable and alkaline-developable and has good workability and can form such a fine pattern is the most preferable material for forming a permanent protective film. There are expectations for its development. However, at present, no method has yet been found for producing a permanent protective film that simultaneously satisfies both high density and high reliability using an ultraviolet curable and alkaline developable resin composition.

There are several reasons for this, but one of them is that in alkaline developable resin compositions, the carboxylic acid groups in the resin that are essential for alkaline development remain in the coating film even after the protective film is formed, which reduces the moisture resistance of the coating film. , it has problems in chemical resistance, hydrolysis resistance, and adhesion. A more serious problem with printed wiring boards is that the carboxylic acid groups in the resin corrode the copper wiring, significantly impairing the performance of the board. Therefore, in order to avoid this, the carboxylic acid groups in the resin have a total acid value of 50 KOH.
Currently, it is used at a concentration of less than /g, and therefore, when it is exposed and developed, there is a problem that it lacks resolution. In addition, currently commercially available ultraviolet curable resin compositions have problems such as insufficient chemical resistance and solvent resistance, and low reliability for thick film curing. Furthermore, when manufacturing a permanent protective film using an ultraviolet curable resin composition, in order to obtain high resolution, it is necessary to bring the circuit pattern mask into close contact with the paint film during UV exposure, so the paint film does not have any tack. It is also needed. In other words, the coating film before irradiation with light is required to have no room temperature tackiness in a finger touch test.

The present invention was developed in view of the problems of the prior art, and provides a high-density protective film with excellent properties such as moisture resistance, chemical resistance, and adhesion, as well as excellent thick film curing properties. It is an object of the present invention to provide a resin composition for a permanent protective film and a method for manufacturing a permanent protective film that can be manufactured satisfactorily.

[Means for Solving the Problems] As a result of intensive research in order to solve the above problems, the present inventors used a resin having a carboxylic acid group and a photosensitive carbon-carbon double bond in combination with an epoxy compound. It has been found that by doing so, it is possible to manufacture a permanent protective film with good workability, high density, and high reliability without deteriorating the performance of the substrate.

That is, the present invention relates to a resin composition for a permanent protective film comprising (a) a resin having a carboxylic acid group and a photosensitive carbon-carbon double bond, (b) an epoxy compound, and (C) a photoinitiator.

The present invention also provides a method in which the resin composition is applied to a base material to form a photosensitive coating film, and this coating film is exposed to ultraviolet light through a circuit pattern mask to harden the coating film in the exposed areas of the mask. A method for producing a permanent protective film, which is characterized in that the unexposed areas of the coating film are then removed by alkaline development to create a circuit pattern, and then the carboxylic acid groups in the coating film are reacted with an epoxy compound by after-curing. Regarding.

The permanent protective film produced by the method of the present invention has superior moisture resistance, chemical resistance, hydrolysis resistance, and adhesion compared to the protective film produced using conventional UV-curable resin compositions that can be developed with alkali. It is a highly reliable membrane. Furthermore, since the permanent protective film produced by the method of the present invention reduces or completely removes carboxylic acid groups by reaction with an epoxy compound, it will not corrode the copper wiring on the printed board, and will not corrode the copper wiring on the printed board. Performance can be maintained over the long term.

Furthermore, when a polyvalent epoxy compound is used as the epoxy compound, it also has the characteristic that the thick film hardening characteristics are improved by after-curing.

This is because, during after-curing, in addition to cross-linking of photosensitive double bonds caused by ultraviolet rays, cross-linking occurs due to the reaction between epoxy groups and carboxylic acid groups, so the cured film becomes so-called IPN.
This is because it has a (interpenetrating polymer network) structure.

The present invention will be explained below.

Although various polymers can be used as the resin (a) having a carboxylic acid group and a photosensitive carbon-carbon double bond used in the present invention, the following modified resins can be used, for example. That is, a conjugated diene polymer and/or copolymer α,β-unsaturated dicarboxylic acid anhydride adduct has the general formula (wherein R1 and R2 are hydrogen atoms or methyl groups, R
3 represents an alkylene group having 2 or more carbon atoms, preferably 2 to 12 carbon atoms, particularly preferably 2 to 6 carbon atoms) having a photosensitive carbon-carbon double bond represented by
, β-unsaturated monocarboxylic acid ester (1) or the above compound (1) and the general formula % formula % () (wherein R4 is an alkyl group or cycloalkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms) , which represents an organic residue such as an aryl group) and an alcohol (II) represented by the following formula is reacted to open at least 80 mol% of the acid anhydride groups of the adduct. .

The conjugated diene polymer and/or copolymer used here refers to a low polymer of a conjugated diolefin having 4 to 5 carbon atoms such as butadiene or isoprene, or one or more of these conjugated diolefins and an ethylenic polymer. Low polymerization degree with aliphatic or aromatic monomers other than these conjugated diolefins having unsaturated double bonds, especially isobutylene, diisobutylene, styrene, α-methylstyrene, vinyltoluene, divinyltoluene. It is a copolymer. A mixture of two or more of these can also be used.

The above-mentioned conjugated diene polymer and/or copolymer preferably has a vinyl group content in unsaturated double bonds present in the polymer of 50% or more and a molecular weight in the range of 500 to 5,000. The vinyl group content is preferably 50 to 80%, particularly preferably 55 to 70%. If the vinyl group content is less than 50%, the crosslinking density after photocuring is low and is not preferred. Further, those having a molecular weight of less than 500 have a low coating film strength after photocuring, while those having a molecular weight of more than 5,000 are not preferred because a smooth coating film cannot be obtained.

These low polymers are produced by conventionally known methods. That is, a conjugated diolefin having 4 to 5 carbon atoms alone, a mixture of these diolefins, or a conjugated diolefin is preferably used in an amount of 50 mol % or less, preferably 1 to 30 mol %, using an alkali metal or an organic alkali metal compound as a catalyst. A typical manufacturing method is anionic polymerization of mol % of an aromatic vinyl monomer, such as styrene, α-methylstyrene, vinyltoluene, or divinylbenzene, usually at a temperature of 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 used as a chain transfer agent. (U.S. Pat. No. 3,789,090), or living polymerization using a polycyclic aromatic compound such as naphthalene as an activator and an alkali metal such as sodium as a catalyst in a tetrahydrofuran solvent. Legal (Tokuko Sho 42-17
No. 485, No. 43-27432), or by using an aromatic hydrocarbon such as toluene or xylene as a solvent, using a metal dispersion such as sodium as a catalyst, and adding an ether such as dioxane to increase the molecular weight. (Japanese Patent Publication No. 32-7448, No. 33-1245)
No. 31-10188) and the like 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, No. 4B-30300) (Japanese Patent Application Publication No. 2003-110000) can also be used.

These conjugated diene polymers and/or copolymers have α
, a β-unsaturated dicarboxylic acid anhydride to produce an acid anhydride group adduct.

The α,β-unsaturated dicarboxylic acid anhydride referred to in the present invention is
It is a compound represented by the following general formula (III), and specifically includes acid anhydrides such as maleic anhydride, citraconic anhydride, and chloromaleic anhydride.

Double RS R6 each represents hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen.

This addition reaction is usually carried out in an inert solvent that dissolves these alone or both at temperatures of 100°C to 250°C.
carried out at a temperature of At this time, as a gelling inhibitor, hydroquinone, catechols, p-phenylenediamine derivatives, etc. can be added in an amount of 0.5 parts by weight or less, for example, 0.1 to 0.3 parts by weight.

In the present invention, the α,β-unsaturated dicarboxylic acid is Addition of anhydride is desirable. This softening point mainly depends on the unsaturated bond content and molecular weight of the raw material conjugated diene polymer or 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,
A total acid value of 400 or more is required.

Next, α
, β-unsaturated monocarboxylic acid ester (1) or α,
The above modified resin is produced by reacting a mixture of β-unsaturated monocarboxylic acid ester (1) and alcohol (II) to open at least 80 mol% of the acid anhydride groups of the adduct.

Here, specific examples of the α,β-unsaturated monocarboxylic acid ester having an alcoholic hydroxyl group represented by formula (1) include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, etc. They can be used alone or in combination.

Further, specific examples of the alcohol (n) include ethyl alcohol, butyl alcohol, ethyl cellosolve, butyl cellosolve, cyclohexanol, benzyl alcohol, and phenol.

In this ring-opening reaction, ester (I) having a photosensitive double bond is essential, and when alcohol (II) is used, α,β-unsaturated monocarboxylic acid ester (
The molar ratio of I) to alcohol (II) (I):
(II) -1: Used in the range of o to 4, preferably (I) 2 (II) -1: 0 to 1.

The ring-opening reaction of the acid anhydride group is usually carried out in the presence of a basic catalyst at a relatively low temperature of 100°C or lower, for example 50 to 100°C, preferably 70 to 95°C. It is appropriate that the ring-opening ratio be 80 mol% or more, preferably 90 mol% or more of the acid anhydride groups, from the viewpoint of photocurability and long-term stability of the coating film. The ring-opening reaction is preferably carried out in the presence of a solvent. As the solvent, it is preferable to use a solvent that has no reactivity with these and can dissolve both. Examples of this include aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone,
Examples include esters such as ethyl acetate, ethers without a hydroxyl group such as diethylene glycol dimethyl ether, and tertiary alcohols such as diacetone alcohol. In this way, the modified resin described above is produced.

It is also possible to use a resin in which a portion of the residual acid anhydride groups of this modified resin is further imidized with an amine, or a portion of the carboxylic acid groups of this modified resin are previously esterified with a monoepoxy compound.

In addition, the resin (a) may include a polymer or copolymer of acrylic acid or methacrylic acid, a polymer or copolymer of fumaric acid or maleic acid, and the α,β-unsaturated monocarboxylic acid ester (1). Modified resins obtained by reacting can also be used. Furthermore, an α,β-unsaturated dicarboxylic acid anhydride adduct of the polymer and/or copolymer of the conjugated diene, a polymer or copolymer of acrylic acid or methacrylic acid, or a polymer of fumaric acid or maleic acid. Alternatively, a modified resin obtained by reacting a copolymer with an α,β-unsaturated monocarboxylic acid ester having an epoxy group can also be used.

Examples of such α,β-unsaturated monocarboxylic acid esters having an epoxy group include glycidyl (meth)acrylate.

Epoxy compounds used in the present invention include phenylglycidyl ether, bromophenylglycidyl ether, allylglycidyl ether, 2-ethylhexylglycidyl ether, 1,2-epoxy-n-hexane, 1,2-epoxy-cyclohexane, methyl 〉・
oxide, monoepoxy compounds such as limonene oxide,
0-phthalic acid diglycidyl ester, hexahydrophthalic acid glycidyl ester, dibromoneopentyl glycol diglycidyl ether, ■, S-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol A type epoxy resin , brominated bisphenol F type epoxy resin, jepoxytricyclo[5
, 2, 1, 02, 6] Jepoxy compounds such as decane, triglycidyl isocyanurate, tetraglycidyl diaminodiphenylmethane, epoxidized soybean oil, polyglycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, epoxidized polybutadiene, novolak glycidyl ether Examples include polyvalent epoxy compounds such as.

It is particularly appropriate to use polyvalent epoxy compounds when thick film curing properties are particularly required.

The equivalent ratio of the carboxylic acid group of the resin (a) to the epoxy group of the epoxy compound (b) is carboxylic acid group/epoxy group -1/
It is preferably 0.5 to 1/1.2.

If the amount of epoxy compound is less than this, the amount of residual carboxylic acid in the coating may increase and the performance of the board may be impaired.
Moreover, if it is too large, developability will deteriorate.

As the photoinitiator used in the present invention, a conventionally known normal photopolymerization initiator can be used. For example, in addition to benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, benzyl, Michler's ketone, Irgacure 184 (manufactured by Ciba Geigy),
Photoinitiators commercially available under trade names such as Irgacure 651 (manufactured by Ciba Geigy) and Darocure 1173 (manufactured by Merck & Co.) may also be used. The amount of these used is usually 0.1 to 10% by weight based on the resin (a), and if it is less than 0.1% by weight, the photocurability will decrease, and if it is more than iomx%, the strength of the resulting photosensitive coating will decrease. Both are undesirable because they cause deterioration.

In the photosensitive coating film in the present invention, as a thermal polymerization stabilizer,
Hydroquinone, 2,6-di-tertiarybutylvalacresol, rosebenzoquinone, hydroquinone monomethyl ether, phenothiazine, α-naphthylamine, etc. can also be included.

Further, a catalyst that promotes the reaction between the resin (a) and the epoxy compound (b) may be added. As such catalysts, tertiary amines, boric acid esters, isic acids, organometallic compounds, organometallic salts, imidazoles, phosphine compounds, etc. can be used, but specifically triethylamine, 2
-ethyl-4-methylimidazole, ■-benzyru2
-Methylimidazole, triphenylphosphine and the like.

The amount of the catalyst added is preferably 0 to 5% by weight, particularly 0.1 to 3% by weight, based on the resin composition.

Furthermore, any other components may be added as long as they do not cause tack to the coating film. Examples of these include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 1, 3-butanediol acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, 2-ethylhexyl methacrylate, 2- Conventionally known photopolymerizable monomers such as hydroxyethyl methacrylate, 1,3-butanediol methacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, and high melting point tri(acryloyloxyethyl) isocyanurate are used. Can be mentioned.

Next, a method for producing a permanent protective film using the resin composition will be explained.

First, the resin composition is diluted with an organic solvent and applied to a substrate. Examples of this organic solvent include ethyl cellosolve, butyl cellosolve, ethylene glycol dimethyl ether,
Water-soluble organic solvents such as diacetone alcohol, 4-methoxy-4-methylpentanone-2, methyl ethyl ketone,
or xylene, toluene, methyl isobutyl ketone,
Non-aqueous organic solvents such as 2-ethylhexanol are exemplified, but the solvent is not particularly limited to these, and any solvent can be used as long as it can uniformly dissolve the resin composition.

The diluted solution of the resin composition has a rotational viscosity of 0.1 at room temperature.
-1000 voids, particularly preferably about 1 to 500 voids.

Moreover, an inorganic filler can be added to the diluted solution of the resin composition, if necessary. Such inorganic fillers include:
Mica, clay talc, alumina white, diatomaceous earth,
Examples include bentonite, wollastonite, quartz, aluminum hydroxide, calcium hydroxide, barium sulfate, magnesium silicate, titanium oxide, zinc oxide, silica alumina, and silicon nitride.

The amount of the inorganic filler added is 0 to 180 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the resin composition.

In addition, dyes or pigments such as Phthalocyanine Blue, Phthalocyanine Green, Cyanine Green, Titanium White, Titanium Yellow, Carbon Black, Yellow Lead, Hansa Yellow, Lake Red, Methyl Violet, Brilliant Green, Victoria Blue, etc., and flame retardant are added as necessary. Antimony pentoxide or the like can be added to achieve this.

Application to the substrate is usually done by dip coating, roll coating,
This is done using a curtain coat, etc. The paint film is dried by hot air drying.
Usually 120℃ or less, preferably 80℃ or less by far infrared rays etc.
This is usually achieved by heating at 100°C for 10 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.

After drying, a negative film is placed on the coating and irradiated with ultraviolet light using, for example, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like.

Next, this is developed by spraying a developing solvent or immersing it in a developing solvent, and the unexposed areas are washed away.

As the developing solvent, an alkaline aqueous solution such as sodium carbonate having a concentration of about 1 to 5% can be used, but it is also possible to use a solution to which an appropriate surfactant or water-soluble solvent is added.

After that, after-curing is performed using methods such as hot air drying and far infrared drying. After cure is 100-100℃
It is preferably carried out at 120 to 140°C, usually for 10 to 60 minutes. If the after-cure is insufficient, the long-term stability of the coating film will be low, and if the after-cure is performed excessively, productivity will decrease.

[Effects of the Invention] Since the resin composition for a permanent protective film of the present invention is UV curable and can be developed with alkali, it is possible to produce a high-density protective film with good workability. Moreover, the permanent protective film produced by the method of the present invention is different from the conventional protective film made using an ultraviolet curable resin composition that can be developed with alkali.
It is a highly reliable membrane with excellent moisture resistance, chemical resistance, hydrolysis resistance, and adhesion. Furthermore, since the permanent protective film produced by the method of the present invention removes the carboxylic acid groups by reaction with an epoxy compound, it will not corrode the copper wiring on the printed board, and the performance of the board will be maintained for a long time. can be kept. Furthermore, after-curing increases the crosslinking density, resulting in excellent thick film curing properties.

"Examples" The present invention will be specifically described below based on Examples. Note that the present invention is not limited to the following examples.

Example 1 A liquid with a number average molecule ffi of 1000.14 voids and a viscosity of 1.2-bonds at 65% at 25°C obtained by polymerizing butadiene at 30°C using benzyl sodium as a catalyst and in the presence of toluene as a chain transfer agent. butadiene polymer 322
g, 178.8 g of maleic anhydride, 10 g of xylene, and 1.1 g of Antigen 8C (polymerization inhibitor, manufactured by Sumitomo Chemical ■, trade name) were placed in a 1J separable flask equipped with a reflux condenser and nitrogen blowing tube, and heated with a nitrogen stream. The mixture was reacted at 190° C. for 4.7 hours. Next, unreacted maleic anhydride and xylene were distilled off, and the total acid value was 40 gmyKOH.
/g of maleated butadiene polymer was synthesized. The softening point of this material (ring and ball softening point JIS-2531-(1
0) was 88°C.

200 g of the maleated butadiene polymer obtained.

Ciacent alcohol 400g, vitroquinone 0.2g
Transfer to an IJ separable flask equipped with a reflux condenser,
The flask was immersed in an oil bath at 80°C and the inside of the flask was gently stirred to completely dissolve the maleated butadiene polymer.

Then 2-hydroxyethyl acrylate 41.4
g, 38.6 g of benzyl alcohol, and 2 g of triethylamine were added, and the inside of the flask was stirred for 40 minutes. Next, the temperature of the oil bath was lowered to 60°C, and 122 g of shea 7-ton alcohol, 8 g of Irgacure 651 (manufactured by Ciba Geigy), 230 g of YDPN 638 (phenol novolac type epoxy resin, manufactured by Tobu Kasei ■), and 3.6 g of ) Lifurphosphine were added. was added and stirred for 1 hour. The non-volatile concentration of this composition was 50%.

A permanent protective film was created in the following manner using a diluted solution of the above resin composition.

First, the above diluted solution was applied to a glass epoxy copper-clad laminate using an applicator, and then placed in a hot air dryer at 80°C for 20 minutes to remove the solvent, resulting in a coating film with a thickness of 20 μm. After drying, this coating film was touched at room temperature, and there was no tack at all.

Next, a polyester-based negative circuit pattern mask with a pattern of up to 50 μm duck is attached to this coating film, and then a 1.5 IRI thick mask is placed on top! Apply the quartz glass of No. 1, and
V exposure device (Ushio Inc. high pressure mercury lamp irradiation device U V
C-2513), the exposure amount at 385 nm is 400 mJ/a
It was exposed to light as shown in A. During this exposure, the temperature is 40
℃, but the tightly attached mask could be easily peeled off after exposure.

When this coating film was developed using a 2% aqueous sodium carbonate solution, the resolution was less than 50 μm. Finally, the coating film was after-cured by placing it in an electric furnace at 130° C. for 20 minutes to produce a protective film.

Physical properties of the cured film were evaluated according to known methods. The pencil hardness was 4H when measured according to JIS-D-02028-10. Also, the adhesion is JIS-D-
02028-12 was conducted and evaluated, and it was found to be good. Solder heat resistance is measured using a molten solder bath (26
After being immersed in water (0°C), a substrate test was conducted and evaluated in accordance with JIS-D-02028-12, and it passed. Moisture resistance was evaluated by performing a substrate test in accordance with JIS-D-02028-12 after boiling for 2 hours, and the result was a pass.

Further, after performing a pressure couture test in which the product was left in steam at 120° C. for 48 hours, a substrate test was performed in the same manner as above, but no peeling of the coating film was observed, and no corrosion of the copper occurred.

Example 2 257 g of the liquid butadiene polymer obtained in Example 1, 193 g of maleic anhydride, 10 g of xylene, and 1.5 g of Antigen 6C (manufactured by Sumitomo Chemical ■, trade name) were placed in a lJ separator equipped with a reflux condenser and a nitrogen blowing tube. The mixture was charged into a blue flask 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 having a total acid value of 4BOm9 K OH/g. The softening point of this material is 128℃
Met.

200 g of the maleated butadiene polymer obtained.

Diacetone alcohol 400g, hydroquinone 0.2g
Transfer to an IJ separable flask equipped with a reflux condenser,
The flask was immersed in an oil bath at 80°C and the inside of the flask was gently stirred to completely dissolve the maleated butadiene polymer.

Next, 69.5 g of 2-hydroxyethyl acrylate
, 27.8 g of benzyl alcohol and 2 g of triethylamine were added, and the inside of the flask was stirred for 35 minutes. Next, the temperature of the oil bath was lowered to 60°C, 131.7 g of dibromophenyl glycidyl ether was added, and then the temperature was raised to 100°C and stirred for 30 minutes. After that, lower the temperature of the oil bath to 60℃ again, and add 153 g of diacetone alcohol, 6 g of benzoin isobutyl ether, 1 YDPN 838 1
15g, add 3.6g of trifelphosphine, 1
Stir for hours. The non-volatile content of this composition was 50%.

A permanent protective film was prepared in the same manner as in Example 1 using a diluted solution of the above resin composition. After coating and drying, this coating film was touched at room temperature, and there was no tackiness at all. The resolution of this coating film was 50g or less.

The physical properties of the cured film were evaluated in the same manner as in Example 1.

The pencil hardness was 4H, the adhesion was good, and the soldering heat resistance was acceptable. Moisture resistance: JIS-D-02028 after 2 hours of boiling
-12 was conducted and evaluated, and it passed. Further, after conducting a pressure squeegee test in which the film was exposed to water vapor at 120° C. for 48 hours, a substrate test was performed in the same manner as above, but no peeling of the coating film was observed.

Example 3 A number average molecular weight of 2000.
1.2-React 300 g of liquid butadiene with 66% bond and tie maleic anhydride to obtain a total acid value of 320 #IgK
A maleated butadiene polymer with OH/g was synthesized.

200 g of this maleated butadiene polymer was placed in a flask No. 11 together with 440 g of methyl isobutyl ketone and 0.2 g of hydroquinone, and the mixture was stirred and dissolved at 80°C. Then 37.0 g of 2-hydroxyethyl methacrylate
, benzyl alcohol 24.8g, butyl cellosolve 6
．． 7 g was added and reacted for 30 minutes. Next, lower the temperature of the oil bath to 60°C, and add 114 g of YDB-400 (brominated bisphenol type epoxy resin, manufactured by Tobu Kasei ■),
YDPN 63g 51g, Irgacure 651 1
0 g and 3 g of 2-ethyl-4-methylimidazole were added and stirred for 1 hour.

A permanent protective film was prepared in the same manner as in Example 1 using a diluted solution of the above resin composition. After coating and drying, this coating film was touched at room temperature, and there was no tackiness at all. The resolution of this coating film was 50 μm or less.

The physical properties of the cured film were evaluated in the same manner as in Example 1.

Pencil hardness was 5H, adhesion was good, and soldering heat resistance was acceptable. Moisture resistance: JIS-D-02028 after 2 hours of boiling
-12 was conducted and evaluated, and it passed. Further, after performing a pressure squeegee test in which the film was left in steam at 120°C for 48 hours, a substrate test was performed in the same manner as above, but no peeling of the coating film was observed.

Comparative Example 1 A maleated butadiene polymer (total acid value: 4001 nlKOH/g) was synthesized in the same manner as in Example 1, and the following 2-
Hydroxyethyl acrylate and benzyl alcohol were reacted to obtain a diacetone alcohol solution containing 298 g of the same modified resin as in Example 1.

To this, 6 g of Irgacure 651 (manufactured by Ciba Geigy) and diacetone alcohol were added so that the concentration of non-volatile matter in this composition was 50%, and the mixture was stirred at 60° C. for 1 hour.

A permanent protective film was prepared in the same manner as in Example 1 using a diluted solution of the above resin composition. After coating and drying, this coating film was touched at room temperature, and there was no tackiness at all. The resolution of this coating film was 50 μm or less.

The physical properties of the cured film were evaluated in the same manner as in Example 1.

The pencil hardness was 2H1 and the adhesion was good. However, when it was immersed in a molten solder bath (260° C.) for 30 seconds, the cured film peeled off. After boiling for 2 hours, JIS-D
-02028-12, a substrate test was performed and the cured film was? lJ in! was recognized. Another 120
When we conducted a pressure couture test in which the material was exposed to water vapor for 5 hours, the cured film completely peeled off and the copper was corroded.

Claims (2)

[Claims] 1. A resin composition for a permanent protective film comprising (a) a resin having a carboxylic acid group and a photosensitive carbon-carbon double bond, (b) an epoxy compound, and (c) a photoinitiator. 2. The resin composition according to claim 1 is applied to a substrate to form a photosensitive coating film, and the coating film is exposed to ultraviolet light through a circuit pattern mask to cure the coating film in the exposed areas of the mask. Afterwards, the coating film in the unexposed areas is removed by alkaline development to create a circuit pattern, and then the carboxylic acid groups in the coating film are reacted with an epoxy compound by after-curing.Production of a permanent protective film. Method.