JPH047321A - Curable resin and photocurable resin composition containing the same - Google Patents

Abstract

PURPOSE:To prepare the title resin which cures rapidly in the presence of a photopolymn. initiator and gives a cured article excellent in heat resistance, soldering resistance, and hardness by reacting a specific polyepoxy compd. with (meth)acrylic acid and then with a polycarboxylic anhydride. CONSTITUTION:A product obtd. by reacting a polyepoxy compd. of the formula (wherein R is 1-18C alkyl or methoxy; (n) is 0-4; X is H or halogen; Z is H or 1-10C alkyl; and (m) is a mean value and 0-3) with (meth)acrylic acid is made to react with a polycarboxylic acid anhydride (e.g. tetrahydrophthalic anhydride) to give the title resin.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a curable resin, particularly a curable resin suitable for photoresists and solder resists, and a curable resin that has excellent photocurability and heat resistance using the same resin. The present invention relates to a photocurable resin composition which provides an excellent photocured product and whose uncured portion has excellent alkali solubility.

In printed circuit boards, a protective pattern is formed on the surface of the board using solder resist resin in order to protect the circuitry and to prevent solder from adhering to areas other than the intended areas when soldering components onto the board. ing.

In order to form such a protective pattern, a method of screen printing a solder resist resin composition has conventionally been used. However, as printed circuit boards become more densely packed, photographic methods that can form finer protective patterns are being considered, and the photocurable solder resists needed for this purpose have been developed, such as cresol. A solder resist composition containing a novolak type epoxy resin or a phenol novolank type epoxy resin as a main component has been proposed (Japanese Patent Application Laid-Open No. 63-258975).

Although these solder resist resins have excellent photocurability, adhesion, and electrical properties, they do not have sufficient soldering heat resistance or hardness, and in recent years, they have been particularly difficult to seal IC chips and M boards using surface mounting methods. There has been a demand for improvements in productivity, and in particular there has been a strong demand for improvements in soldering heat resistance.

(Problems to be solved by the invention) The present invention aims to solve the above-mentioned drawbacks of conventional solder resist resins, and provides a curable resin for solder resists that is particularly excellent in heat resistance, hardness, and photocurability; The object of the present invention is to provide a photocurable resin composition using the same resin.

(Means for Solving the Problems) The curable resin of the present invention has the formula -i (wherein R is an alkyl group or methoxy group having 1 to 18 carbon atoms, n is an integer of O to 4, and X is A hydrogen atom or a halogen atom, Z is a hydrogen atom or has 1 to 1 carbon atoms
There are 0 alkyl groups, and m is a number from 0 to 3 on average. ) is a resin made by reacting a polybasic carboxylic acid anhydride with a reaction product of a polyepoxy compound represented by (meth)acrylic acid and (meth)acrylic acid.

Moreover, the photocurable resin composition of the present invention is a composition formed by containing a photopolymerization initiator and a diluent in such a curable resin.

The polyepoxy compound represented by the above general formula (1) of the present invention is a polyfunctional novolac resin obtained by condensing phenols and aromatic aldehydes having a phenolic hydroxyl group in the presence of an acidic catalyst, and epichlorohydrin. It is synthesized by reacting epihalohydrins such as

The curable resin in the present invention is a resin obtained by further reacting a polybasic carboxylic acid anhydride with the reaction product of the polyepoxy compound (1) and (meth)acrylic acid. The (meth)acrylic acid is a general term for acrylic acid and methacrylic acid, and it is possible to react only acrylic acid, only methacrylic acid, or any combination of acrylic acid and methacrylic acid. It is also possible to react mixtures in proportions of . The polyepoxy compound (
The reaction ratio of I) and (meth)acrylic acid is preferably 0.8 to 1 chemical equivalent of epoxy in the polyepoxy compound.
It is 1.2 chemical equivalents.

In this way, when (meth)acrylic acid is reacted with a polyepoxy compound, an ester bond is formed by the reaction between the epoxy group and the carboxyl group, and (meth)acrylic acid is formed at the site where the epoxy group of the polyepoxy compound was. ) Acrylic acid is connected via an ester bond, and at the same time as the ester bond is formed, the same number of hydroxyl groups are also generated.

Therefore, when a polybasic carboxylic anhydride is reacted with the reaction product of this polyepoxy compound and (meth)acrylic acid, the hydroxyl group of the reaction product and the polybasic carboxylic anhydride react, The reaction product is further increased in molecular weight to become a high molecular weight curable resin.

The polybasic carboxylic anhydride to be reacted with the reaction product of the polyepoxy compound and (meth)acrylic acid may be a saturated polybasic carboxylic anhydride or an inorganic acid anhydride having a polymerizable double bond. It may also be a saturated polybasic carboxylic acid anhydride. Specific examples of the polybasic carboxylic anhydride include succinic anhydride, maleic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride,
Dibasic acid anhydrides such as hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, hetacetic anhydride; trimellitic anhydride, anhydride Examples include aromatic polycarboxylic acids such as pyromellitic acid and benzophenonetetracarboxylic dianhydride.

The reaction ratio between the reaction product of the polyepoxy compound and (meth)acrylic acid and the polybasic carboxylic anhydride is as follows: is 0.05 to 1.00 chemical equivalent,
The acid value of the product is preferably about 40 to 150.

The thus obtained curable resin of the present invention can be heat-cured with a radical initiator such as an organic peroxide or an azo compound, to give a cured product with excellent heat resistance and hardness. When a photopolymerization initiator is blended and photopolymerized, a cured product with excellent heat resistance, hardness, adhesiveness, etc. can be obtained.

In particular, when this curable resin of the present invention is blended with a photopolymerization initiator and a diluent, it can be suitably used as a solder resist resin that can provide a cured product with excellent photocurability, heat resistance, and hardness. A photocurable resin composition is obtained.

Examples of the photopolymerization initiator include benzoin alkyl ethers such as benzoin, benzoin ethyl ether, and benzoin butyl ether, acetophenone, 2,2-diethoxyacetonenone, and 4'-phenoxy-2,2-dichloroacetophenone. Acetophenone type, ketal type such as acetophenone dimethyl ketal, benzyl dimethyl ketal, 2-
Anthraquinone-based products such as ethylanthraquinone and 2-chloroanthraquinone, thioxanthone-based products such as 2-chlorothioxanthone and 2,4-diethylthioxanthone, and propiophenone-based products such as 2-hydroxy-2-methylpropiophenone. , benzophenone-based compounds such as benzophenone, and xanthone-based compounds such as xanthone. These photopolymerization initiators may be used alone or in combination of two or more, and may be used in combination with known photopolymerization accelerators such as benzoic acid-based or tertiary amine-based photopolymerization promoters. You can also do that.

The amount of photopolymerization initiator used is in the range of 0.1 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the curable resin.

The diluent is added to reduce the viscosity of the resin composition. Specific examples of the diluent include various organic cuttings, aromatic hydrocarbons such as toluene and xylene, cellosolves such as cellosolve and butyl cellosolve,
Carpitol, carpitols such as butyl carpitol, ethyl acetate, butyl acetate, cellosolve acetate,
Examples include acetic acid esters such as carpitol acetate. Furthermore, various photopolymerizable monomers can also be used as a diluent that also serves as a monomer. Specific examples of the monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, cyclohexyl (meth)acrylate, and tetrahydrofuryl (meth)acrylate. Monofunctional (meth)acrylates such as furyl (meth)acrylate; diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dibut Difunctionality such as propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, bisphenol A/ethylene oxide adduct di(meth)acrylate (Meth)acrylates; polyfunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; and the like. These diluents may be used in 1.1 types, or 2.
You may use more than one species in combination. Note that the above-mentioned "(meth)acrylate" is a general term for acrylate and methacrylate.

The amount of diluent used in the photocurable resin composition of the present invention is 10 to 20 parts by weight per 100 parts by weight of the curable resin of the present invention.
0 parts by weight, preferably in the range of 20 to 100 parts by weight.

Various additives can be added to the photocurable resin composition of the present invention, if necessary. For example, inorganic fillers such as talc, silica, alumina, barium sulfate, and magnesium oxide, thixotropic agents such as Aerosil, leveling agents and antifoaming agents such as silicone and fluorine, and coloring agents such as cyanine green can be added. can.

The photocurable resin composition of the present invention can be photocured by irradiation with ultraviolet rays, electron beams, and various other types of radiation according to a conventional method. It is desirable to heat and harden at 'C.

(Examples etc.) Below, polyepoxy compound production examples, examples, and comparative examples are given and explained in detail. In these examples, "part" and "1%" are by weight.

The tests described in Examples and Comparative Examples were conducted as follows.

(2) Tackiness to the touch After applying the resist resin composition, the tackiness of the coating film was judged by touching it with the finger during temporary drying at 70°C for 30 minutes.

(2) The photocurable coating film was irradiated with ultraviolet rays under an 8kW high-pressure mercury lamp at a distance of 100 mm from the light source, and the time was expressed as the time until the coating film was not scratched by a fingernail.

(2) Glass transition temperature (Tg) was measured using a heat-resistant differential scanning calorimeter (DSC).

■ Solder resistance The state of the coating film after being immersed in molten solder at 260°C for 1 minute was judged according to the following criteria.

O: There is no abnormality in the appearance of the coating film.

×... There is blistering and peeling in the coating film.

■ Hardness Measured using a pencil hardness tester according to JIS K-6911.

■ Adhesion Measured by square stripping test according to JIS K-5400 4 ■ After exposure to alkaline solubility, melt the unexposed area with 2% NazCO3 aqueous solution,
The solubility upon removal was evaluated using the following criteria.

○・・・・・・Fast dissolution rate×・・・Example for producing polyepoxy compounds that do not dissolve or have a very slow dissolution rate Three-neck flask with a capacity of 1 liter equipped with a thermometer, stirrer, and condenser Contains 210 g of phenol and 6 g of salicylaldehyde.
Pour 2 g of og, p-toluenesulfonic acid and heat to 100°C.
After reacting for 4 hours, unreacted phenol was removed. Next, 750 g of epichlorohydrin and tetraethylammonium chloride Ig were added, and the reaction was carried out under reflux at 117°C for 2 hours, then cooled to 60°C, a water separator was attached, 142 g of Nap) was added, and 40 to 100 g of
While controlling the temperature to 50-70°C under reduced pressure of mmHg,
The produced water was removed from the system, and the reaction was continued for about 2 hours.

After adding 2.5 l of methyl isobutyl ketone to the obtained reaction solution and washing off the salt and NaDH in the solution with a large amount of water, epichlorohydrin and methyl isobutyl ketone were heated using an evaporator to 100 - 0,1 m
mHg and 60-150°C to obtain a pale yellow transparent solid polyepoxy compound with a yield of 178g, a softening point of 65°C, and an epoxy equivalent of 197. In this polyepoxy compound, the value of m in the general formula (1) was 0.3.

Polyepoxy compound production example 2 O-cresol 2 was used instead of phenol in production example 1 above.
Using 40 g, the reaction was otherwise carried out in accordance with the method of Production Example 1, followed by post-treatment to obtain a pale yellow, transparent solid polyepoxy compound with a yield of 201 g, a softening point of 72° C., and an epoxy equivalent of 210. This compound has m in the general formula (1) above.
The value was 0.3.

Example 1 Capacity 1 with thermometer, stirrer, water separator, nitrogen inlet tube
! In a four-bottle flask, 179 g of the polyepoxy compound obtained in Production Example 1 was added.

After stirring and dissolving 100 g of methyl isobutyl ketone, Ig of hydroquinone methyl ether, and 4 g of triphenylphosphine, the temperature was raised to 90°C, and 72 g of acrylic acid was dissolved.
g was added dropwise over 30 minutes, and after the completion of the addition, the same temperature was maintained for 4 hours to allow reaction.

Then, this reaction product was added with tetrahydrophthalic anhydride 7
7 g and 20 g of toluene were added and reacted for 10 hours while heating to 95°C to obtain 402 g of the desired curable resin as a pale yellow viscous liquid.

3 parts of benzoin butyl ether was added to 100 parts of this curable resin, and the mixture was stirred and mixed uniformly.
The degassed product was degassed under reduced pressure of mHg, then applied onto a copper-clad laminate using a 100μ applicator and heated at 70°C.
After drying for 30 minutes, the tackiness to the touch was examined. Next, the film was exposed through a negative mask under an 8 kW high-pressure mercury lamp.

Next, the unexposed areas were dissolved in a 2% Na2CO aqueous solution, and then heated and cured at 140°C for 1 hour to obtain a highly accurate resist pattern faithful to the negative mask. The results are shown in Table 1.

Example 2 Instead of 77 g of tetrahydrophthalic anhydride in Example 1, 30 g of phthalic anhydride was used, and the rest was as in Example 1.
In the same manner as above, 350 g of a curable resin was obtained as a pale yellow viscous liquid.

Using 100 parts of this curable resin, a highly accurate resist pattern was formed in the same manner as in Example 1 except for the above. The results are shown in Table 1.

Example 3 50 g of succinic anhydride was used in place of 77 g of tetrahydrophthalic anhydride in Example 1, and the rest was as in Example 1.
In the same manner as above, 365 g of a curable resin was obtained as a pale yellow viscous liquid.

Using 100 parts of this curable resin, a highly accurate resist pattern was formed in the same manner as in Example 1 except for the above. The results are shown in Table 1.

Example 4 Instead of 179 g of the polyepoxy compound used in Example 1, 210 g of the polyepoxy compound obtained in Production Example 2 above was used.
410 g of a curable resin was obtained as a pale yellow and viscous liquid in the same manner as in Example 1.

Using 100 parts of this curable resin, a highly accurate resist pattern was formed in the same manner as in Example 1 except for the above. The results are shown in Table 1.

Comparative Example 1 In place of 179 g of the polyepoxy compound in Example 1, 172 g of a phenol novolac type epoxy resin (trade name Epicote 152, manufactured by Yuka Shell Epoxy Co., Ltd.) was used, and 395 g of the curable resin was otherwise prepared in the same manner as in Example 1.
g was obtained as a pale yellow viscous liquid.

Using 100 parts of this curable resin, a resist pattern was formed in the same manner as in Example 1 except for the above. The results are shown in Table 1.

Comparative Example 2 In place of 179 g of the polyepoxy compound used in Example 1, 210 g of Talesol novolak type epoxy resin (Nippon Kayaku Co., Ltd. trade name EOCN-102) was used, and the other conditions were the same as in Example 1, but curable 431 g of resin was obtained as a pale yellow viscous liquid.

Using 100 parts of this curable resin, a resist pattern was formed in the same manner as in Example 1 except for the above. The results are shown in Table 1.

The following thread (@+ Effect of the invention) The photocurable resin composition using the curable resin of the present invention has a fast curing speed (and can provide a cured product with excellent heat resistance, solder resistance, and hardness). .

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (In the formula, R is an alkyl group or methoxy group having 1 to 18 carbon atoms, n is an integer from 0 to 4, and is a hydrogen atom or a halogen atom, Z is a hydrogen atom or has 1 to 1 carbon atoms
There are 0 alkyl groups, and m is a number from 0 to 3 on average. ) A curable resin obtained by reacting a polybasic carboxylic acid anhydride with a reaction product of a polyepoxy compound represented by the following formula and (meth)acrylic acid. (2) A photocurable resin composition comprising the curable resin according to claim 1 containing a photopolymerization initiator and a diluent.