JPH01204922A - Curable resin and its preparation and application - Google Patents

Abstract

PURPOSE:To attempt to prepare a base resin being easily curable, providing a coating film having excellent alkali resistance and being useful for preparing a circuit, by combining a novolak phenol resin with vinyl benzyl ether and epoxy groups at a specified equivalent ratio. CONSTITUTION:Vinyl benzyl groups are formed by dissolving a novolak phenol resin and chloromethylstyrene in a solvent and carrying out dehydrochlorination in the presence of an alkali at an equivalent ratio of chloromethylstyrene to phenolic hydroxyl groups of 0.2-0.9 and then epoxy groups are introduced by adding a large excess of epichlorohydrin and carrying out de hydrochlorination with remaining phenolic hydroxyl groups. In this case, the equivalent ratio of vinyl benzyl ether groups to epoxy groups is 90-20/10-80. The curable resin thus obtd. can be easily cured by means of an actinic radia tion such as an ultraviolet ray and heat.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a novel curable resin that is easily cured by active energy rays such as ultraviolet rays and heating, and whose cured coating film has excellent alkali resistance. With regard to its manufacturing method and its uses, curable resins are particularly useful as base resins for paints and inks for forming conductor circuits on printed wiring boards.

[Prior Art] In recent years, the conductor circuits of printed wiring boards used in the electronics industry have become increasingly finer and more precise.
There is a shift to full-additive methods, in which conductor circuits are created by simply applying electroless copper plating to laminates, and sub-additive methods in between.

Since the additive method uses an electroless copper plating method, it is necessary to use chemicals such as caustic soda, formalin, EDTA, etc. for copper precipitation, and to perform a reaction at high temperature and for a long time in an alkaline solution. Therefore, ordinary photosensitive films cannot withstand such conditions. - Generally, at present, we have no choice but to rely on screen printing methods using bake-curable epoxy resin paints or inks.

However, the screen printing method requires precision and
There are limits to high-precision circuit fabrication. Therefore, there is an extremely strong demand for the development of a photocurable resin that can be developed by photolithography, has alkali resistance, and is capable of electroless copper plating. (including screen printing methods), non-contact photolithography exposure-curing type resins, and contact photolithography exposure-curing type resins rely on acryloyl groups for photocuring, so their resin structure has the disadvantage of poor alkali resistance. was there. On the other hand, ultraviolet curing using an epoxy resin with excellent alkali resistance is also possible by using a photocationic catalyst, but it has the disadvantage that the conductor corrodes over time.

[Problems to be Solved by the Invention] In view of the current situation, the present invention provides a curable resin that does not have the drawbacks of photocurable acryloyl group-containing resins, that is, poor alkali resistance, and is also capable of photolithographic development. The object of the present invention is to provide a method for manufacturing the same, and uses thereof.

[Means for Solving the Problems] The first object of the present invention is to obtain a vinyl benzyl ether group and an epoxy group obtained by adding chloromethylstyrene and epichlorohydrin to the hydroxy group of a novolac type phenol resin. A curable resin based on a modified novolac type epoxy resin with an equivalent ratio of 90 to 20/10 to 80 has excellent curing properties such as alkali resistance, adhesion to substrates, thermal stability, and mechanical strength. This was achieved by discovering that the present invention can provide an object and completing the present invention.

The second object of the present invention is to prepare chloromethylstyrene and a novolac type phenolic resin in a solvent in the presence of an alkali so that the reaction ratio of chloromethylstyrene to phenolic hydroxy group is 0.2.
The equivalent ratio of vinyl benzyl ether groups to epoxy groups was reduced by reacting at ~0.9 (equivalent ratio) and then adding a large excess of epichlorohydrin to cause a dehydrochlorination reaction with the remaining phenolic hydroxy groups. is 90~20/
This was achieved by efficiently producing a curable resin mainly composed of a modified novolac type epoxy resin having a molecular weight of 10 to 80.

Furthermore, the third object of the present invention is that the equivalent ratio of the vinyl benzyl ether group to the epoxy group is 9.
A coating or ink for forming conductor circuits is prepared by blending a photopolymerization initiator, a curing agent for epoxy resins, and dyes and pigments with the curable resin of the present invention, which is mainly a modified novolac type epoxy resin having a molecular weight of 0 to 20/to to 80. This was achieved by obtaining.

[Function] The curable resin of the present invention has a specific proportion of vinylbenzyl ether groups and epoxy groups in the molecule, but since there is no (meth)acryloyl group, which has poor alkali resistance,
It has excellent alkali resistance and provides a cured product with excellent adhesion to substrates due to the presence of epoxy groups.

In addition, the curable resin of the present invention has two curing mechanisms: a crosslinking curing mechanism due to an addition reaction possessed by the vinyl group in the molecule, and a crosslinking curing mechanism due to a ring opening reaction possessed by the epoxy group in the molecule. Therefore, by appropriately combining these curing mechanisms, it is possible to adjust the curing speed at various curing temperatures, and there is an advantage that a cured product with high precision and high strength can be easily obtained. .

For example, as will be shown in detail in the Examples, the curable resin of the present invention is applied onto a substrate and then irradiated with light through a negative film to photocure the exposed areas. An initial cured product with a highly precise pattern is formed by the mechanism, and after washing and removing the unexposed uncured parts with a solvent, the initial cured product is heated and cured to form a strong cured product due to the ring-opening reaction of the epoxy group. is formed, so there is an advantage that a strong cured product having a highly accurate pattern with excellent alkali resistance that can withstand electroless copper plating can be easily obtained. Therefore, the curable resin of the present invention is optimal as a base resin for paints and inks for forming conductor circuits in additive methods.

The present invention will be explained in more detail below.

The curable resin of the present invention is mainly composed of a modified novolac type epoxy resin having a specific proportion of vinylbenzyl ether groups and epoxy groups in the molecule, and chloromethylstyrene and epichlorohydrin are added to the hydroxyl groups of the novopoc type phenolic resin. Obtained by dehydrochlorination reaction. A representative example is schematically shown.

(Left below) In formula [I] and formula (11), R and R' are hydrogen,
Methyl group or halogen, m+n and m'+n'
is 2~lO, m/n and m'/n' are 90~
The ratio of vinyl benzyl ether groups to epoxy groups in the resin is in the range of 20/10 to 80, i.e. the ratio of vinyl benzyl ether groups to epoxy groups in the resin is 90 to 20/
It is 10-80. If the ratio of the epoxy groups present is less than 10, curing by the epoxy groups will not be sufficiently effective, resulting in insufficient adhesion to the substrate. Moreover, when the amount is greater than 80, there is a drawback that the photocurability and developability due to the vinyl group are insufficient.

The curable resin of the present invention is obtained by dehydrochlorinating a mixture of chloromethylstyrene, an excess amount of epichlorohydrin, and a novolac type phenol resin with an alkali in a solvent, extracting with benzene, neutralizing with hydrochloric acid, It can be synthesized by repeated washing with water. However, in consideration of the reactivity of epichlorohydrin, first, chloromethylstyrene and novolac type phenol resin were mixed, and the reaction ratio of chloromethylstyrene to phenolic hydroxyl group was adjusted to 0.2.
The dehydrochlorination reaction is carried out at a ratio of ~0.9 (equivalent ratio), and then a large excess of e.g.
It is preferable to employ a two-stage reaction method in which twice as much epichlorohydrin (equivalent ratio) is subjected to a dehydrochlorination reaction.

The first reaction between chloromethylstyrene and novolac type phenolic resin is carried out by heating at 50 to 100° C. for 1 to 3 hours in a solvent such as dimethyl sulfoxide in the presence of a polymerization inhibitor and an alkali.

Next, epichlorohydrin is added, the temperature is raised to 100 to 120°C to azeotrope water-epichlorohydrin, and while returning only epichlorohydrin to the reaction system, alkali is added dropwise to carry out the second stage reaction. Implement.

The end point of the reaction is determined by the disappearance of the phenolic hydroxy group by infrared spectroscopy and chemical analysis.

Commercially available novolak phenolic resins used in the present invention are sufficient. For example, a novolac type phenol resin synthesized from phenol, cresol, bisphenol A1 bisphenol F, etc. is suitable.

The curable resin of the present invention can be photocured and heat cured, in which case a photopolymerization initiator and a curing agent are used.

Examples of the photopolymerization initiator used in the present invention include benzophenone, hydroxyisobutylphenone, acetophenone, 2,2-jethoxyacetophenone, benzoin, benzoin ethyl ether, benzyl, benzyl methyl ketal, benzoyl diphenylphosphine oxide,
Representative examples include carbonyl compounds such as ethyl anthraquinone, thioxanthone, chlorothioxanthone, and azobisisobutylnitrile. The amount used is 0.2 to IO parts by weight, preferably 0.5 to 7 parts by weight, per 100 parts by weight of the curable resin.

The curing agent that can be used in the present invention is one that is used as a curing agent for epoxy resins. Among these curing agents, amine curing agents are preferred because they satisfy alkali resistance. For example, aromatic amines such as diaminodiphenylmethane, diaminodiphenylsulfone, metaphenylenediamine, imidazole compounds such as 2-ethyl-4-methylimidazole, 2-methylimidazole, 1-benzyl-2-methylimidazole, dicyandiamide, N,N diallylmelamine, melamine, guanidine,
Typical examples of high-temperature curing agents include heterocyclic compounds such as phenylguanidine, tertiary amines represented by trisdimethylaminophenol, trimethylbenzylamine, and the like. Of course, aliphatic amine-based low temperature curing agents such as xylene diamine can also be used in some cases. The amount to be used is determined with reference to the amount corresponding to the epoxy equivalent. It is usually added in an amount of 1 to 25% by weight based on the curable resin.

The curable resin of the present invention can be widely used in adhesives, insulating materials, paints, composite structural materials, etc. by selecting its composition. In particular, when phenol or cresol novolac type phenolic resins with a softening point of 70°C or higher are used, cured products with excellent photocurability, adhesion to the coated surface, heat resistance, electrical properties, and pattern forming properties can be obtained, and contact Patterning by photolithographic exposure, that is, photocuring by light exposure, washing off the unexposed areas with a solvent,
If it is cured for ~10 minutes, it can withstand treatment in an electroless copper plating bath, so it is useful as a base resin for additive methods. It is also possible to pattern by non-contact photolithography instead of contact.

In addition, in order to improve the coating property of the curable resin of the present invention,
It can be used by dissolving it in an organic solvent to lower its viscosity.

In addition, in the curable resin of the present invention, other known monomers such as styrene, vinyltoluene, allylphenol, allyloxybenzene, diallylphthalate, acrylic ester, methacrylic ester, vinylpyrrolidone, etc., or epoxy It is possible to incorporate oligomers such as acrylates and acrylic urethanes without departing from the spirit of the present invention. Needless to say, hydroquinone, benzoquinone, copper salt, etc. can be added to adjust the curing, and a radical initiator can be added to accelerate the curing.

The curable resin of the present invention is processed by a kneader, blender, roll, etc., into fillers such as talc, barium sulfate, silica powder, glass peas, and Aeroseal, antifoaming agents and leveling agents such as silicone oil, dyes and pigments, and reinforcing agents. Fibers can be blended to be used as molding materials and composite materials, dissolved in solvents to be used in festivals, paints, and adhesives, and impregnated into reinforcing fibers such as glass fibers, carbon fibers, aromatic polyamide fibers, silicon carbide fibers, and alumina fibers. It can be used as a molding material or a structural material useful as a prepreg or as a filament winding.

[Examples] Next, reference examples and examples are shown to explain the present invention in detail, but the scope of the present invention is not limited by these. In addition, unless otherwise specified, parts and percentages in the examples are parts by weight/% by weight.

Reference example 1 Synthesis of phenol novolac vinyl benzyl ether glycidyl ether Phenol novolak BRG-55582 manufactured by Showa Kobunshi Co., Ltd.
(0.8 eq.), 16 parts (0.4 eq.) of sodium hydroxide were dissolved in 140 parts of dimethyl sulfoxide and 20 parts of water, and 62 parts of commercially available chloromethylstyrene (0.4 eq.
4 equivalents) and 0.1 part of hydroquinone dissolved in 40 parts of dimethyl sulfoxide were added dropwise at 70°C over 1 hour, and the reaction was continued at 70°C for another 1.5 hours.

Next, 555 parts of epichlorohydrin (6,θ equivalent) was added to the system.
was added, the temperature was raised to 115°C, water-epichlorohydrin was azeotroped, and while only epichlorohydrin was returned to the system, 40 parts of a 40% sodium hydroxide aqueous solution was added dropwise at 115°C over 2 hours. After the dropwise addition was completed, the mixture was stirred at 115° C. for 15 minutes to completely remove moisture.

After removing most of the excess epichlorohydrin by heating the system to 125° C. and distilling it, a large excess of water was added, and after stirring, the oil was extracted with benzene. The benzene layer was washed repeatedly with water until the pl+ of the aqueous layer reached 7, and the benzene layer was dried with anhydrous sodium sulfate. The yield after removing benzene and epichlorohydrin under reduced pressure is 96% (yield based on epichlorohydrin)
The epoxy equivalent was 552.

Reference example 2 Synthesis of phenol novolac vinyl benzyl ether glycidyl ether Phenol novolak BRG-55983 manufactured by Showa Kobunshi Co., Ltd.
, 2 parts (0.8 parts ff1), 16 parts of sodium hydroxide (
0.4 equivalents) in 140 parts of dimethyl sulfoxide and 20 parts of water.
Commercially available chloromethylstyrene 62
part (0.4 parts ff1), 0.1 part of hydroquinone dissolved in 40 parts of dimethyl sulfoxide was heated to 1 part at 70°C.
The mixture was added dropwise over a period of time, and the reaction was further continued at 70°C for 1.5 hours. Next, 555 parts (6.0 equivalents) of epichlorohydrin was added to the system and the temperature was raised to 115°C, and the water-epichlorohydrin was azeotropically distilled. 40 parts of an aqueous sodium hydroxide solution was added dropwise at 115°C over 2 hours, and after the dropwise addition was completed, stirring was continued at 115°C for 15 minutes to completely remove moisture. After removing most of the excess epichlorohydrin by heating the system to 125° C. and distilling it, a large excess of water was added, and after stirring, the oil was extracted with benzene.

The benzene layer was washed repeatedly with water until the pl+ of the aqueous layer reached 7, and the benzene layer was dried with anhydrous sodium sulfate. The yield after removing benzene and epichlorohydrin under reduced pressure was 96% (yield based on epichlorohydrin), and the epoxy equivalent was 560.

Reference example 3 Synthesis of cresol novolac vinyl benzyl ether glycidyl ether Cresol novolac CRG-95112 manufactured by Showa Kobunshi Co., Ltd.
4 parts (0,8 equivalents), 16 parts sodium hydroxide (0,4
equivalent) was dissolved in 180 parts of dimethyl sulfoxide and 20 parts of water, and 62 parts of commercially available chloromethylstyrene (0
.

Next, 555 parts (6.0 equivalents) of epichlorohydrin was added to the system.
was added, the temperature was raised to 115°C, water-epichlorohydrin was azeotroped, and while only epichlorohydrin was returned to the system, 40 parts of a 40% sodium hydroxide aqueous solution was added dropwise at 115°C over 2 hours. After the dropwise addition was completed, the mixture was stirred at 115° C. for 15 minutes to completely remove moisture.

After removing most of the excess epichlorohydrin by heating the system to 125° C. and distilling it, a large excess of water was added, and after stirring, the oil was extracted with benzene. The pH of the benzene layer and the water layer is 7.
The benzene layer was dried with anhydrous sodium sulfate. The yield after removing benzene and epichlorohydrin under reduced pressure was 96% (yield based on epichlorohydrin), and the epoxy equivalent was 598.

Reference example 4 Synthesis of bisphenol A-based novolak vinyl benzyl ether glycidyl ether Bisphenol A-based novolac MCM-8 manufactured by Showa Kobunshi Co., Ltd.
74122.4 parts (0.8 equivalents), sodium hydroxide 1
6 parts (0.4 equivalents) to 140 parts of dimethyl sulfoxide,
A mixture of 62 parts (0.4 equivalents) of commercially available chloromethylstyrene and 0.1 part of hydroquinone dissolved in 40 parts of dimethyl sulfoxide was added to 20 parts of water at 70°C.
The mixture was added dropwise over a period of time, and the reaction was further continued at 70°C for 1.5 hours. Next, 555 parts (6.0 equivalents) of epichlorohydrin was added to the system and the temperature was raised to 115°C, and the water-epichlorohydrin was azeotropically distilled. 40 parts of an aqueous sodium hydroxide solution was added dropwise at 115°C over 2 hours, and after the dropwise addition was completed, stirring was continued at 115°C for 15 minutes to completely remove moisture. After removing most of the excess epichlorohydrin by heating the system to 125° C. and distilling it, a large excess of water was added, and after stirring, the oil was extracted with benzene. The benzene layer was washed repeatedly with water until the pH of the aqueous layer became 7, and the benzene layer was dried with anhydrous sodium sulfate.

The yield after removing benzene and epichlorohydrin under reduced pressure is 96
The epoxy equivalent in % (yield based on epichlorohydrin) was 681.

Examples 1-4. Comparative Examples 4 to 5 Phenol novolak vinyl benzyl ether glycidyl ether, cresol novolac vinyl benzyl ether glycidyl ether, and bisphenol A-based novolac vinyl benzyl ether glycidyl ether produced in Reference Examples 1 to 4 were mixed with carpitol acetate to 70%
It was treated as a solid component. 2,4.61-limethylbenzoyldiphenylphosphine oxide as a photo-curing agent and 2-ethyl-4-methylimidazole as a curing agent were blended as shown in Table 1 for each Log. For comparison, phenol novolak vinyl benzyl ether (P
NVBE) alone and cresol novolac epoxy (C
NEP) alone was adjusted to 70% solid content with carpitol acetate solvent, and a photoinitiator and a curing agent were similarly blended with 1O[, respectively. Approximately 50 μm of these were coated on an epoxy resin glass laminate plate, and after the coating was dried at 80° C. for 30 minutes, the tackiness was examined. Thereafter, the negative film was exposed to light for about 8 seconds under a high-pressure mercury lamp (2 kW output), which is a photocuring light source. After washing off the unexposed area with the solvent, it was cured by heating at 150° C. for 45 minutes. This product was tested for adhesion and alkali resistance by being immersed in 10% caustic soda at 70° C. for 24 hours to confirm alkali resistance.

The results are shown in Table 1.

(The following is a blank space) [Effects of the Invention The curable resin according to the present invention has both photocurability and heat curability, so it can be used under various curing conditions,
The cured product has excellent adhesion to the surface to be coated, heat resistance, and electrical properties, and since it does not have a (meth)acryloyl group, it also has excellent alkali resistance.
It can be widely used in insulation materials, paints, inks, composite structural materials, etc. In particular, by combining photocuring that utilizes the excellent photocurability of vinylbenzyl ether groups and heat curing of epoxy groups, it is possible to form patterns with high precision and high strength that have excellent alkali resistance. It is extremely useful as a base resin for circuit fabrication by the method.

Claims (1)

[Claims] 1) Chloromethylstyrene and epichlorohydrin,
A curable resin mainly composed of a modified novolac-type epoxy resin having an equivalent ratio of vinylbenzyl ether groups to epoxy groups of 90-20/10-80, which is obtained by dehydrochlorination reaction with the hydroxyl group of a novolac-type phenol resin. 2) Chloromethylstyrene and novolac type phenolic resin are mixed in a solvent in the presence of an alkali, and the reaction ratio of chloromethylstyrene to phenolic hydroxy group is 0.
．． 2 to 0.9 (equivalent ratio), and then a large excess of epichlorohydrin is added to cause the dehydrochlorination reaction with the remaining phenolic hydroxy group. A method for producing a curable resin based on a modified novolac type epoxy resin having an equivalent ratio of 90 to 20/10 to 80. 3) A photopolymerization initiator, a curing agent for epoxy resin, and dyes and pigments are added to a curable resin mainly composed of a modified novolac type epoxy resin in which the equivalent ratio of vinyl benzyl ether groups to epoxy groups is 90 to 20/10 to 80. A paint for forming conductor circuits that is formulated with: 4) A photopolymerization initiator, a curing agent for epoxy resin, and dyes and pigments are added to a curable resin mainly composed of a modified novolac type epoxy resin in which the equivalent ratio of vinyl benzyl ether groups to epoxy groups is 90 to 20/10 to 80. An ink for forming conductor circuits containing the following.