JPH0572926B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical field to which the invention pertains] The present invention relates to a curable resin composition. More specifically, it is cured by light irradiation and heating, and has excellent electrical properties, solder heat resistance, adhesive properties, and the like. The present invention relates to a curable resin composition extremely useful as a solder resist for printed wiring boards. [Technical Background and Problems of the Invention] Conventionally, it has been known to use an image-shaped protective film (hereinafter referred to as solder resist) in printed wiring boards to protect circuits and prevent solder bridging during soldering of components. . Epoxy thermosetting resins, acrylate and/or methacrylate photocuring resins, and the like are generally used as solder resist resins. Among these resins, epoxy thermosetting resins have excellent electrical properties, soldering heat resistance, moisture resistance, adhesion, etc., but printing methods such as screen printing are used as a method for forming solder resist images. Since it is used, the dimensional accuracy is poor, and it has the disadvantage that it cannot be applied to printed wiring boards with high-density fine patterns. On the other hand, acrylate-based and/or methacrylate-based photocurable resins have excellent workability because they can be cured in a short time by light irradiation, and image forming methods include the above-mentioned printing method and photographic method, that is, lamination on printed wiring boards. After exposing the photocurable resin through a negative mask, unexposed areas are removed with a solvent and developed to form an image corresponding to the negative mask. The photographic method has excellent dimensional accuracy of images, so it is advantageous for manufacturing printed wiring boards with high-density fine patterns. However, acrylate-based and/or methacrylate-based photocurable resins are not necessarily fully satisfactory in terms of electrical properties, soldering heat resistance, moisture resistance, and the like. To improve the problems of epoxy thermosetting resins or acrylate and/or methacrylate photocuring resins, for example, Japanese Patent Laid-Open No. 58-62636 discloses a method for forming images using a photographic method. A resin composition for a solder resist using an epoxy resin having a photosensitive group is disclosed. However, since this is an oligomer with a photosensitive group introduced into the main chain of the molecule, its solubility in solvents is limited, and it cannot necessarily be said that it has excellent workability. For example, it is difficult to dissolve in general-purpose non-flammable developing solvents, such as halogen-containing 1,1,1-trichloroethane, trichlorethylene, and tetrachloroethane, which are preferred for ensuring safety during the production of printed wiring boards, and the solubility is low. It has problems such as a long time required for development due to poor quality, and cannot be said to be fully satisfactory. [Object of the Invention] The object of the present invention is to provide a curable resin composition that is useful as a solder resist for printed wiring boards, for example, and has excellent electrical properties, soldering heat resistance, developability, etc., and that is cured by light irradiation and heating. It is about providing. [Summary of the Invention] The curable resin composition of the present invention comprises a) a partially acrylated and/or methacrylated (hereinafter abbreviated as partial (meth)acrylated) epoxy resin, b an acryloyl group, a methacryloyl group, and an epoxy group. Compounds having at least one type of group selected from the group (excluding partially acrylated and/or methacrylated epoxy resins) c Sensitizers that initiate polymerization of acryloyl groups and/or methacryloyl groups upon irradiation with light d It is characterized by comprising a curing catalyst containing an organoaluminum compound and an organosilicon compound. The partially (meth)acrylated epoxy resin (a) used in the composition of the present invention may be any of those generally known as partially (meth)acrylated epoxy resins. .
This component (a) includes, for example, a resin obtained by combining an epoxy resin with acrylic acid and/or methacrylic acid in an amount equivalent to or less than the epoxy group in the epoxy resin. Can be mentioned. The epoxy resin used here is not particularly limited as long as it satisfies the above conditions and is generally known as an epoxy resin.Specific examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin. Examples include resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, hydrogenated bisphenol A type epoxy resins, and diglycidyl ester type epoxy resins of aromatic dicarphonic acids.
Among these components (a), at least 2
An epoxy resin having an average molecular weight of 150 to 1500 and having epoxy groups of 0.3 to 0.9 equivalents based on the equivalent of the epoxy groups in the epoxy resin and/or
Alternatively, a resin obtained by addition reaction with methacrylic acid is preferable. The average molecular weight of epoxy resin is 150
If the average molecular weight is less than 1,500, it is difficult to obtain a resin with excellent heat resistance, and if the average molecular weight is more than 1,500, a solvent such as 1,
Poor solubility in halogenated nonflammable solvents such as 1,1-trichloroethane. Preferably 200
~1200. In addition, if the amount of acrylic acid and/or methacrylic acid is less than 0.3, the resulting partially (meth)acrylated epoxy resin will have poor photocurability, and if it exceeds 0.9, the resulting cured resin will have poor photocurability. Poor physical properties, soldering heat resistance, etc. Preferably it is 0.4 to 0.8. Among these components (a), more preferred is a resin obtained by reacting an epoxy resin with acrylic acid and/or methacrylic acid in the presence of an organometallic compound. The partially (meth)acrylated epoxy resin obtained by this method has extremely excellent electrical properties. Here, as the organometallic compound, β-diketone,
Al, Ga, Sn, Zr, Cu, Fe, Co, etc. with β-ketoester, salicylaldehyde derivatives, etc.
Examples include complexes of Ni, Mn, Cr, V, Pt, Mo, Pd, etc. Specific examples of the ligand include acetylacetone, benzoylacetone, trifluoroacetylacetone, hexafluoroacetylacetone,

[Embodiments of the invention]

Example 1 750 parts of epoxy resin Epicoat 834 (trade name, manufactured by Yuka Ciel Epoxy Co., Ltd., bisphenol A type epoxy resin, average molecular weight: 470) and 16 parts of acrylic acid were mixed with 18 parts of trisacetylacetonatoaluminum and p-methoxy In the presence of 3 parts of phenol, 110
A partially acrylated epoxy resin (epoxy group/acryloyl group = 1/3) was synthesized by reacting at ℃ for 12 hours. 70 parts of this partially acrylated epoxy resin,
15 parts of 1,6-hexanediol diacrylate,
15 parts of 2-hydroxy-3-phenoxypropyl acrylate, 4 parts of (1-hydroxy-1-methylethyl) phenyl ketone, 1 part of tris(ethylacetoacetato)aluminum, 3 parts of diphenyldimethoxysilane, 2 parts of colloidal silica. 20 parts of silica powder, 0.6 parts of phthalocyanine green as a coloring pigment, and 0.5 parts of silicone oil as an antifoaming agent were mixed and kneaded with a roll to obtain a curable resin composition of the present invention. The viscosity of the resin composition is 130Poise at 25℃
It was hot. This resin composition was applied to the entire surface of an IPC-B-25 test circuit board using a 150-mesh screen, and then exposed to parallel light for 40 seconds using a high-pressure mercury lamp with an illuminance of 5 mW/cm ² through a negative mask. . Next, the film was developed using 1,1,1-toluchloroethane for 30 seconds and cured by heating at 150°C for 1 hour. A precise coating suitable for a negative mask was obtained. No peeling of the paint film was observed in the grid tape peel test of the paint film. The pencil hardness of the coating film was 4H. No change in appearance or adhesion was observed even after the coated surface was immersed in a solder bath at 260°C for 30 seconds. Further, the electrical resistance according to IPC-SM-840method2.5.23 was 2×10 ¹⁴ Ω under normal conditions. 50
After being kept in an atmosphere at 95% relative humidity for 7 days, the electrical resistance was 8×10 ¹² Ω, indicating high insulation. Example 2 Epoxy resin Epicoat 1001 (trade name, manufactured by Yuka Ciel Epoxy Co., Ltd., bisphenol A type epoxy resin, average molecular weight: 900) 700 parts, epoxy resin Epicoat 828 (trade name, manufactured by Yuka Ciel Epoxy Co., Ltd.,
Bisphenol A type epoxy resin, average molecular weight:
380) Partially acrylated epoxy resin (epoxy group/acryloyl group = 1 /3) was synthesized. 60 parts of this partially acrylated epoxy resin, 30 parts of the partially acrylated epoxy resin synthesized in Example 1, 10 parts of dibentaerythritol hexaacrylate, 5 parts of benzyl dimethyl ketal, 1 part of trisacetylacetonatoaluminum, tert-butylperoxytrifluoride. 4 parts of enylsilane, 40 parts of methyl cellosolve
1 part, 2 parts of colloidal silica, 20 parts of silica powder, 0.6 parts of phthalocyanine green, and 0.5 parts of silicone oil were mixed and kneaded with a roll to obtain the curable resin composition of the present invention. This resin composition was prepared in Example 1.
It was applied to the entire surface of a similar circuit board using a 150-mesh screen, and then dried at 80°C for 15 minutes. Next, a negative mask was attached and exposed for 5 seconds at an illuminance of 100 mW/cm ² using a high-pressure mercury lamp. After exposure, the film was developed for 1 minute using a mixed solvent of 1,1,1-trichloroethane and butyl cellosolve (volume ratio: 95:5), and cured by heating at 150°C for 1 hour. A precise coating suitable for a negative mask was obtained. No peeling of the paint film was observed in the grid tape peel test of the paint film. The pencil hardness of the coating film was 4H. No change in appearance or adhesion was observed even after the coated surface was immersed in a solder bath at 260°C for 30 seconds. The electrical resistance is 7×10 ¹³ Ω at room temperature, and at 50℃,
The electrical resistance after being kept in an atmosphere of 95% relative humidity for 7 days was 9×10 ¹² Ω, indicating high insulation properties. Example 3 Partially acrylated epoxy resin obtained by reacting 1000 parts of epoxy resin Epicoat 828 and 190 parts of acrylic acid at 110°C for 10 hours in the presence of 24 parts of trisacetylacetonatoaluminum and 4 parts of p-methoxyphenol ( Epoxy group/acroyl group = 1/1) 75 parts, dibropylene glycol dimethacrylate 25 parts, (1-hydroxy-1-methylethyl) phenyl ketone 4 parts, tris(ethyl acetoacetato) aluminum 1 part, diphenyl dimethoxysilane 3 parts of colloidal silica, 20 parts of silica powder, 0.6 parts of phthalocyanine green, and 0.5 parts of silicone oil were kneaded with a roll to obtain a curable resin composition of the present invention. This resin composition was applied to the same circuit board as in Example 1 in an image form using a 150 mesh screen, and then applied in Example 2.
Exposure was carried out for 5 seconds using a lamp similar to the above. Thereafter, heat curing was performed at 150°C for 1 hour. When the same test as in Example 1 was conducted, good adhesion and solder heat resistance were shown. The hardness was 4H, and the electrical resistance was 8×10 ¹³ Ω under normal conditions and 7×10 ¹² Ω after moisture absorption. Example 4 70 parts of the partially acrylated epoxy resin synthesized in Example 2, 20 parts of trimethylolpropane, 5 parts of benzyl dimethyl ketal, 1 part of trisacetylacetonatoaluminum, 4 parts of tert-butylberoxytriphenylsilane, methyl A curable resin composition of the present invention was obtained by mixing 10 parts of methacrylate styrene (2:1) copolymer, 2 parts of colloidal silica, 10 parts of silica powder, 0.6 parts of phthalocyanine green, 0.3 parts of silicone oil, and 150 parts of methyl ethyl ketone. Ta. This resin composition was applied onto a polyethylene terephthalate film with a thickness of 25 μm,
A photosensitive film having a resin layer of 50 μm thickness was produced by drying at 70° C. for 1 hour. This photosensitive film
It was pressed onto a circuit board similar to that in Example 1 at 100°C using a roll. Next, a negative mask was brought into close contact with the photosensitive film, and exposed for 5 seconds using the same lamp as in Example 2. Next, the negative mask and polyethylene terephthalate film were peeled off, and development was performed for 2 minutes using the same developing solvent as in Example 2, followed by heat curing at 150° C. for 1 hour. An accurate coating film suitable for a negative mask was obtained. Example 1
When similar tests were conducted, good adhesion and
Demonstrates solder heat resistance. The hardness was 4H, and the electrical resistance was 8×10 ¹³ Ω under normal conditions and 7×10 ¹² Ω after moisture absorption. Comparative Example 1 In place of the partially acrylated epoxy resin in Example 1, 750 parts of Epicote 834 and 215 parts of acrylic acid were used.
A diacrylate resin obtained by reacting 3.5 parts of dimethylbenzylamine and 3 parts of p-methoxyphenol at 110° C. for 4 hours was used. That is, 70 parts of the diacrylate resin, 1,6
-15 parts of hexanediol diacrylate, 2-hydroxy-3-phenoxybropylacrylate
A curable resin composition was obtained by mixing 15 parts of (1-hydroxy-1-methylethyl) phenyl ketone, 4 parts of colloidal silica, 20 parts of silica powder, 0.6 parts of phthalocyanine green, and 0.5 parts of silicone oil. Using this resin composition, a coating film was formed by applying, exposing, developing and curing by heating in the same manner as in Example 1. When the same test as in Example 1 was carried out, the adhesion was good and the hardness was 4H, but some blistering occurred in a small area above the circuit on the solder immersed surface. The electrical resistance was 5×10 ¹³ Ω under normal conditions, and decreased to 8×10 ¹¹ Ω after moisture absorption. Comparative Example 2 Instead of the partially acrylated epoxy resin in Example 1, a kneaded product of 79 parts of the diacrylate resin synthesized in Comparative Example 1 and 21 parts of Epicoat 834 (epoxy group/acryloyl group = 1/3) was used. A resin composition was prepared using the same formulation as in Example 1. When coating, exposure, development, and heat curing were carried out in the same manner as in Example 1, some blistering occurred on the circuit during heat curing. [Effects of the Invention] As detailed above, the curable resin composition of the present invention has the following properties: the resulting cured product has excellent electrical properties, soldering heat resistance, moisture resistance, and adhesiveness;
Because it has good photocurability, it is extremely useful as a material for solder resists, for example, and its industrial value is extremely large.

Claims (1)

[Scope of Claims] 1a Partially acrylic and/or methacrylated epoxy resin b Compound having at least one group selected from the group consisting of acryloyl group, methacryloyl group, and epoxy group (provided that partially acrylic and/or methacrylated epoxy resin (Excluding epoxy resins.) c. A sensitizer that initiates polymerization of acryloyl groups and/or methacryloyl groups upon irradiation with light. d. A curable resin composition comprising a curing catalyst containing an organometallic compound and an organosilicon compound. 2. A partially acrylated and/or methacrylated epoxy resin having an average molecular weight of 300 to 1500 and having at least two epoxy groups in the molecule;
Based on the equivalent weight of epoxy groups in the epoxy resin
The composition according to claim 1, which is a resin obtained by addition reaction of 0.3 to 0.9 equivalents of acrylic acid and/or methacrylic acid. 3. The composition according to claim 1 or 2, wherein the partially acrylated and/or methacrylated epoxy resin is a resin obtained by reacting in the presence of an organometallic compound. 4 The organometallic compound is aluminum (Al), gallium (Ga), tin (Sn), zirconium (Zr),
Zinc (Zn), copper (Cu), iron (Fe), nickel (Ni), cobalt (Co), manganese (Mn), chromium (Cr), panadium (V), platinum (Pt), molybdenum (Mo) and 4. The composition according to claim 3, which is a compound comprising at least one metal selected from the group consisting of palladium (Pd). 5 The ratio of a) partially acrylated and/or methacrylated epoxy resin and b) a compound having at least one group selected from the group consisting of an acryloyl group, a methacryloyl group, and an epoxy group is 40:60 to 95 by weight. :5, the proportion of each in the curable resin composition is within the range of a) and b), and the total of a) and b) is
c) 0.5-10% by weight of a sensitizer and d) 0.5-10% by weight of a curing catalyst comprising an organoaluminum compound and an organosilicon compound. . 6. The composition according to claim 1, wherein the organosilicon compound is a compound having an alkoxysilyl group and/or an aryloxysilyl group. 7. The composition according to claim 1, wherein the organosilicon compound is a compound that generates silanol groups upon irradiation with light. 8. The composition according to claim 1, wherein the compound that generates a silanol group upon irradiation with light is a peroxysilyl group and/or an α-ketosilyl group.