JP3385440B2 - Epoxy resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a FRP, particularly to a copper-clad laminate used for an electronic circuit board, which has low water absorption, excellent heat resistance, and excellent physical properties. The present invention relates to an epoxy resin composition obtained without impairing workability such as impregnation. [0002] Epoxy resins are widely used in electronic parts, electric equipment, automobile parts, FRP, sporting goods and the like because of their excellent adhesiveness, electrical properties and heat resistance. However, copper-clad laminates used for FRP, especially for electronic circuit boards, are becoming thinner with increasing number of layers, and epoxy resins used for this purpose are required to have lower water absorption and higher heat resistance than ever before. [0003] Conventionally, epoxy resins used for electronic circuit boards include tetrabromobisphenol A and epichlorohydrin or bisphenol A glycidyl ether.
And a brominated epoxy resin such as Epototo YDB-400 manufactured by Toto Kasei Co., Ltd. (epoxy equivalent: 380 to 420 g / eq, bromine content: 46 to 50 wt.
%), Epototo YDB-500 (epoxy equivalent 45
0 to 550 g / eq, bromine content: 18 to 22 wt%) is used as a general-purpose product, and dicyandiamide alone or in combination with a polyamine compound is used as a curing agent, and a tertiary amine or imidazole is used as a curing accelerator. Used in combination. Meanwhile, as a method for reducing the water absorption of the epoxy resin and improving the heat resistance, a method for improving the purity of the epoxy resin is known. For example, there is a method in which impurities such as a hydrolyzable chlorine component, an α-diol component or an unreacted phenol component contained in the epoxy resin are reduced to the utmost. As this type of epoxy resin, for example, Epototo YDB-530 (epoxy equivalent 530 g /
eq and bromine content of 21.7 wt%), but there was a limit to improvement in heat resistance. The present inventors have previously found a method of reducing the water absorption by adding a polyfunctional phenol compound to an epoxy resin composition (Japanese Patent Laid-Open No. 4-22).
No. 4820). That is, a brominated epoxy resin produced from tetrabromobisphenol A and epichlorohydrin or bisphenol A glycidyl ether, and an average of 2.5 or more phenolic hydroxyl groups in one molecule With an epoxy equivalent of 550-80.
By using an epoxy resin obtained by reacting to be in the range of 0 g / eq, it is possible to reduce the compounding amount of a nitrogen-based curing agent component such as dicyandiamide, polyamine compound, etc., thereby reducing the water absorption. Reduced. However, even in this method, when an epoxy resin having an epoxy equivalent of 800 g / eq or more or a compound having a high softening point of a compound having a phenolic hydroxyl group is used, the resin viscosity increases, Since the impregnating property of the glass cloth deteriorates, there is a limit in improving the water absorption rate. As described above, the method of reducing the intramolecular impurities of the epoxy resin or the method of using the polyfunctional phenol compound reduces the water absorption of the epoxy resin, heat resistance and adhesiveness. There is a limit in obtaining an epoxy resin having excellent properties such as these. The present inventor has made various studies to improve the above-mentioned drawbacks and obtain an epoxy resin having a low water absorption rate and excellent heat resistance and adhesiveness. Without affecting the present invention, the present invention was completed by finding a method of reducing the curing agent component causing the deterioration of the water absorption, and an object of the present invention is to reduce the intramolecular impurities as described above, or A method using a polyfunctional phenolic compound, which has limitations in reducing water absorption, and has excellent heat resistance and adhesiveness, and has no adverse effect on workability such as impregnation with a novel epoxy resin composition for a copper-clad laminate. It is provided by. [0011] The gist of the present invention is to provide an epoxy resin composition comprising an epoxy resin and a curing agent, wherein the epoxy resin comprises 9,9-bis (4-hydroxyphenyl) fluorene, Naphthalene diol, tetraphenyl ethane, phenol novolak, cresol novolak, naphtho novolak, bisphenol A
A polyfunctional epoxy resin produced from a bifunctional or higher phenol selected from the group consisting of novolaks and epihalohydrin, and a polyfunctional phenol compound, which is obtained by reacting an epoxy equivalent But 300-700g
/ Eq and a residual phenolic hydroxyl group equivalent of 500 to 3000 g / eq. That is, in the present invention, the polyfunctional epoxy resin produced from the above-mentioned specific bifunctional or higher-functional phenol and epihalohydrin has an epoxy equivalent of 3
In the range of 100 to 700 g / eq and the residual pheno-
By using an epoxy resin obtained by reacting a polyfunctional phenol compound such that the hydroxyl equivalent is in the range of 500 to 3000 g / eq, low water absorption, excellent heat resistance, excellent adhesion and impregnation. Thus, it was possible to provide an epoxy resin composition having excellent workability. Hereinafter, the present invention will be described in detail. In the present invention, it is selected from the group consisting of 9,9-bis (4-hydroxyphenyl) fluorene, naphthalenediol, tetraphenylolethane, phenol-novolak, cresol-novolak, naphtho-novolak, and bisphenol-A novolak. The epoxy equivalent of the polyfunctional epoxy resin produced from bifunctional or more phenols and epihalohydrin is about 110 to 400 g / eq. These epoxy resins can be used alone or in combination of two or more, and some epoxy resins produced from bisphenol A, bisphenol F, tetrabromobisphenol A and epihalohydrin are used in combination. You can also. Examples of the polyfunctional phenol compound include phenol represented by bisphenol A, bisphenol F, 9,9-bis (4-hydroxyphenyl) fluorene, and the like.
And the like. Further, bifunctional or more functional phenol novolak resins, phloroglycinols, polyparavinylphenols, tetraphenylols obtained by condensation of these phenols, phenols, cresols and aldehydes.
Examples thereof include reaction products of ethane, unsaturated compounds and phenols. Furthermore, these halides can also be mentioned. In the present invention, the above polyfunctional epoxy resin is reacted with a polyfunctional phenol compound so that the epoxy equivalent is in the range of 300 to 700 g / eq, and the residual phenolic hydroxyl group equivalent is 500 to 3000 g. An epoxy resin in the range of / eq is obtained, and a known catalyst can be used in the reaction. Conventional catalysts such as metal oxides, inorganic bases, organic bases and salts thereof, onium compounds and phosphines may be used. However, in the present invention, in order to leave a specific amount of a part of the phenolic hydroxyl group in the epoxy resin unreacted, it is necessary to adjust the amount of the catalyst, the reaction temperature and the like variously according to the raw materials used. is there. Also, with certain catalysts, the catalyst can be deactivated by various methods,
By this method, a target polyfunctional epoxy resin can be produced. As a method for deactivating the catalyst, there are methods such as lowering the reaction temperature, adding a deactivator, or raising the temperature to thermally decompose the catalyst. The desired polyfunctional epoxy resin can also be produced by a continuous synthesis method represented by a mixing device such as a uniaxial coneder or a biaxial rudder. In short, any method may be used as long as the terminal groups of the polyfunctional epoxy resin are a specific number of epoxy groups and phenolic hydroxyl groups. When the epoxy resin in the epoxy resin composition of the present invention has an epoxy equivalent of 300 g / eq or less, the amount of the curing agent used increases, resulting in poor water resistance. The impregnating property is deteriorated by the increase in the resin viscosity. The residual phenolic hydroxyl group equivalent is also determined to be 500 g / eq.
Below, the compounding ratio of the specific polyfunctional epoxy resin is reduced to deteriorate heat resistance. At 3000 g / eq or more, the amount of the curing agent used is increased, and as a result, the water resistance is inferior, and the impregnating property is increased due to an increase in resin viscosity. It gets worse. As the curing agent for the composition of the present invention, pheno-
Curing agents and acid anhydrides, amine resins and other commonly used curing agents for epoxy resins can be used, more preferably from the viewpoint of storage stability, adhesion and heat resistance,
Dicyandiamide is used alone or in combination with a polyamine compound or in combination with a tertiary amine or imidazole as a curing accelerator. The composition of the present invention may further contain conventional additives such as a curing accelerator, a filler and a diluent. As a result of examining the hygroscopicity of the epoxy resin composition, when a nitrogen-based curing agent, particularly dicyandiamide, is used, the smaller the epoxy equivalent of the resin, that is, the larger the amount of dicyandiamide used, the higher the water absorption. I know it's big. Therefore, if the epoxy resin is polymerized to increase the epoxy equivalent and the amount of the nitrogen-based curing agent used is reduced, the water absorption can be reduced. However, when the polymer is simply polymerized, the crosslink density decreases and the heat resistance deteriorates. . In addition, the alcoholic hydroxyl group generated in the molecule deteriorates the water absorption. Therefore, by using a compound having an average of 2.5 or more phenolic hydroxyl groups in one molecule and polymerizing without lowering the crosslink density, it is possible to lower the water absorption and improve the heat resistance. did. However, as the polymer becomes higher, the viscosity of the resin becomes higher, the impregnating property of the glass cloth becomes worse, and a good copper-clad laminate cannot be produced. For this reason, a specific amount of a phenolic hydroxyl group is left unreacted in an epoxy resin reacted with a specific polyfunctional epoxy resin,
The reaction is stopped at a molecular weight at which the resin does not thicken. The remaining phenolic hydroxyl group acts as a curing agent, thereby reducing the amount of dicyandiamide added as a curing agent. As a result, the water absorption is reduced, the heat resistance can be maintained, the adhesive strength between the copper foil and the interlayer is increased, and an epoxy resin composition having good impregnation with glass cloth can be obtained. The present invention will now be described specifically with reference to examples and comparative examples. The epoxy equivalent of the synthesized epoxy resin was measured according to JIS K7236. The phenolic hydroxyl group equivalents in Synthesis Examples 1 to 4 were obtained by measuring the acid value with potassium hydroxide and converting the value to the phenolic hydroxyl group equivalent. Phenolic properties of Synthesis Examples 5 to 7
Hydroxyl equivalent is measured with a 305 nm UV absorption spectrophotometer.
Was. Synthesis Example 1 In a four-necked flask equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas introducing device, Epototo YD-128 (bisphenol A type epoxy resin manufactured by Toto Kasei Co., Ltd., epoxy equivalent: 186 g / eq) 484 parts, 100 parts of ZX-1142L (α-naphthol-novolak epoxy resin epoxy equivalent 240 g / eq, manufactured by Toto Kasei Co., Ltd.) and 50 parts of bisphenol A were charged and heated and melted while flowing nitrogen gas. 0.05 parts of triphenylphosphine was added and reacted at 160 ° C. for 2.5 hours. Thereafter, 366 parts of tetrabromobisphenol A was added and melted. To this, 0.01 part of triphenylphosphine was added to add 160 parts.
The reaction was performed at 4 ° C. for 4 hours to obtain an epoxy resin. The epoxy equivalent of the obtained epoxy resin was 546.2 g / eq, and the phenolic hydroxyl group equivalent was 1510 g / eq. Synthesis Example 2 Using the same apparatus as in Synthesis Example 1, YD-128 314
Part, YDCN-702 (o-cresol novolak epoxy resin manufactured by Toto Kasei Co., Ltd., epoxy equivalent 204 g)
/ Eq) 300 parts and 62 parts of bisphenol A were charged and heated and melted while flowing a nitrogen gas, and then 0.05 part of triphenylphosphine was added and reacted at 160 ° C. for 2.5 hours. Thereafter, tetrabromobisphenol A
324 parts was added and melted. To this, 0.01 part of triphenylphosphine was added and reacted at 160 ° C. for 4 hours to obtain an epoxy resin. The epoxy equivalent of the obtained epoxy resin is 421.0 g / eq, and the phenolic hydroxyl equivalent is 1
It was 311 g / eq. Synthesis Example 3 Using the same apparatus as in Synthesis Example 1, YD-128 490
Part, YDG-414 (Tohto Kasei Co., Ltd., tetraphenylolethane epoxy resin, epoxy equivalent 188 g /
eq) 88 parts and bisphenol A 57 parts were charged and melted by heating while flowing a nitrogen gas, and then 0.05 parts of triphenylphosphine was added and reacted at 160 ° C. for 2.5 hours. Thereafter, tetrabromobisphenol A was added to 36
Six parts were added and melted. To this, 0.01 part of triphenylphosphine was added and reacted at 160 ° C. for 4 hours to obtain an epoxy resin. The epoxy equivalent of the obtained epoxy resin was 554.9 g / eq, and the phenolic hydroxyl equivalent was 171.
It was 9 g / eq. Synthesis Example 4 Using the same apparatus as in Synthesis Example 1, YD-128 476
Parts, YDG-414 88 parts 9,9-bis (4-hydroxyphenyl) fluorene 70 parts were charged and heated and melted while flowing a nitrogen gas. Then, 0.05 parts of triphenylphosphine was added, and added at 160 ° C. for 2.5 hours. The reaction was performed. Thereafter, tetrabromobisphenol A 366
Was heated and melted. To this, 0.01 part of triphenylphosphine was added and reacted at 160 ° C. for 4 hours to obtain an epoxy resin. The epoxy equivalent of the obtained epoxy resin was 489.1 g / eq, and the phenolic hydroxyl group equivalent was 1301 g / eq. Synthesis Example 5 (Comparative Example) YD-128 590 using the same apparatus as in Synthesis Example 1.
Parts, bisphenol A 45 parts and tetrabromobisphenol A 366 parts were charged and heated and melted. To this was added 0.5 part of triphenylphosphine and reacted at 160 ° C. for 4 hours to obtain an epoxy resin. The epoxy equivalent of the obtained epoxy resin was 709.4 g / eq, and the phenolic hydroxyl group equivalent was 375,100 g / eq. Synthesis Example 6 (Comparative Example) YD-128 575 using the same apparatus as in Synthesis Example 1.
, ZX-1236 (p Crezo manufactured by Toto Kasei Co., Ltd.)
59 parts of condensate of ru-dicyclopentadiene) and 366 parts of tetrabromobisphenol A were charged and melted by heating. To this, 0.5 part of triphenylphosphine was added and 1 part was added.
The reaction was carried out at 60 ° C. for 4 hours to obtain an epoxy resin. The epoxy equivalent of the obtained epoxy resin is 694.1 g / e.
q, phenolic hydroxyl equivalent is 471,200 g / eq
Met. Synthesis Example 7 (Comparative Example) YD-128 576 using the same apparatus as in Synthesis Example 1.
Part, D-5 (o-cresol novolak resin manufactured by Toto Kasei Co., Ltd.), 58 parts, tetrabromobisphenol A
366 parts were charged and heated and melted. To this was added 0.5 part of triphenylphosphine and reacted at 160 ° C. for 4 hours to obtain an epoxy resin. The epoxy equivalent of the obtained epoxy resin was 807.4 g / eq, and the phenolic hydroxyl group equivalent was 253,400 g / eq. The epoxy resin obtained by the above synthesis method was mixed with a curing agent, and a copper-clad laminate was manufactured using the obtained epoxy resin composition, and the laminate was evaluated. The copper-clad laminate was prepared under the following conditions. For each epoxy resin dissolved in methyl ethyl ketone,
A curing agent dicyandiamide (manufactured by Nippon Carbide Industrial Co., Ltd.) and a curing accelerator 2ethyl 4-methylimidazole (manufactured by Shikoku Chemical Industry Co., Ltd.) are added as a solution of methylcellosolve / dimethylformamide, and a glass cloth (WEA manufactured by Nittobo Co., Ltd.) is added. −116E-105F115-N) and dried at 150 ° C. for 6 minutes to form a B-stage. A 35 μm copper foil (3EC manufactured by Mitsui Mining & Smelting Co., Ltd.) is layered on and under the 8 plies of prepreg,
Molding was performed under curing conditions of × 20 kgf / cm ² × 2 hours to obtain a laminate having a thickness of 0.8 mm. The evaluation method is as follows. The impregnating property was evaluated by visually impregnating a glass cloth with the compounded resin varnish. Those with very good impregnation are indicated by a, and those with slightly better impregnation are indicated by b. Further, those which were close to the limit in the ordinary impregnation method were indicated by c marks. The water absorption was measured by removing the copper foil by etching in accordance with JIS C 6481 3.2, and then leaving it under a condition of 90% humidity × 60 ° C. for 96 hours with reference to JIS C 5023. It was measured. For the measurement of the glass transition temperature, a Tan 98 value was measured at a heating rate of 2 ° C./min using DMA 982 manufactured by DuPont. The copper foil peel strength was measured according to JIS C 6486 7.7. The interlaminar bond strength was measured by measuring the bond strength between one layer on the surface of the glass cloth and the seven lower layers with the copper foil still attached, in the same manner as the copper foil peel strength. Example 1 An epoxy resin Y was added to 90 parts of the epoxy resin obtained in Synthesis Example 1.
DCN-704 (Orthocreso manufactured by Toto Kasei Co., Ltd.)
Lunovolak epoxy resin Epoxy equivalent 215g / e
q) 10 parts were mixed, and 1.59 parts of dicyandiamide as a curing agent and 0.10 part of 2-ethyl 4-methylimidazole as a curing accelerator were blended, and the laminate was evaluated. Table 1 shows the performance of the obtained laminate. [Table 1] Example 2 To 100 parts of the epoxy resin obtained in Synthesis Example 2, 1.69 parts of dicyandiamide as a curing agent and 0.03 part of 2-ethyl-4-methylimidazole as a curing accelerator were blended. An evaluation was performed. Table 1 shows the performance of the obtained laminate.
Shown in Example 3 An epoxy Y was added to 90 parts of the epoxy resin obtained in Synthesis Example 3.
DCN-704 (10 parts) was mixed, dicyandiamide (1.64 parts) as a curing agent and 2-ethyl 4-methylimidazole (0.05 parts) as a curing accelerator were blended, and the laminate was evaluated. Table 1 shows the performance of the obtained laminate. Example 4 An epoxy resin Y was added to 90 parts of the epoxy resin obtained in Synthesis Example 4.
DCN-704 (10 parts) was mixed, and dicyandiamide (1.69 parts) as a curing agent and 2-ethyl 4-methylimidazole (0.05 parts) as a curing accelerator were blended, and the laminate was evaluated. Table 1 shows the performance of the obtained laminate. Comparative Example 1 Epototo YDB-500 (a brominated epoxy resin manufactured by Toto Kasei Co., Ltd., epoxy equivalent: 51 as an epoxy resin)
90 g of 4 g / eq) were mixed with 90 parts of YDCN-potato, 2.33 parts of dicyandiamide as a curing agent, and 0.03 of 2-ethyl-4-methylimidazole as a curing accelerator.
Five parts were mixed and the laminate was evaluated. Table 2 shows the performance of the obtained laminate. [Table 2] Comparative Example 2 YDCN-7 was added to 90 parts of the epoxy resin obtained in Synthesis Example 5.
The mixture was mixed with 1.8 parts of dicyandiamide as a curing agent and 0.07 parts of 2-ethyl 4-methylimidazole as a curing accelerator, and the laminate was evaluated. Table 2 shows the performance of the obtained laminate. Comparative Example 3 90 parts of the epoxy resin obtained in Synthesis Example 6 was added to YDCN-7.
04 parts were mixed, 1.85 parts of dicyandiamide as a curing agent and 0.10 parts of 2-ethyl 4-methylimidazole as a curing accelerator were blended, and the laminate was evaluated. Table 2 shows the performance of the obtained laminate. Comparative Example 4 YDCN-7 was added to 90 parts of the epoxy resin obtained in Synthesis Example 7.
04 10 parts, and 1.64 parts of dicyandiamide as a curing agent and 0.07 part of 2-ethyl 4-methylimidazole as a curing accelerator were blended, and the laminate was evaluated. Table 2 shows the performance of the obtained laminate. From the above results, the product of Example was good in all respects,
In Comparative Example 1, the impregnation property and the glass transition temperature are good,
The water absorption is higher than Examples 1 to 4. Comparative Example 8 has good water absorption and glass transition temperature, but is inferior to Examples 1 to 4 in impregnation, copper foil peel strength and interlayer adhesion strength. . As described above, an epoxy resin produced from a specific polyfunctional epoxy resin and a polyfunctional phenol compound has an epoxy equivalent of 300 to 700 g / eq.
And the residual phenolic hydroxyl equivalent is 50.
By using an epoxy resin obtained by reacting in the range of 0 to 3000 g / eq, the heat resistance, moisture resistance, and adhesion can be improved without impairing workability such as impregnation. Things.

Continuation of the front page (56) References JP-A-6-41277 (JP, A) JP-A-4-224820 (JP, A) JP-A-62-283969 (JP, A) JP-A-4-272919 (JP) JP-A-3-170521 (JP, A) JP-A-63-48324 (JP, A) JP-A-61-43614 (JP, A) JP-A-58-79011 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) C08G 59/20-59/30 C08G 59/14 C08J 5/24 CFC H05K 1/03 630 H

Claims (1)

(57) [Claim 1] In an epoxy resin composition comprising an epoxy resin and a curing agent, the epoxy resin comprises 9,9-bis (4-hydroxyphenyl) fluorene, naphthalenediol, tetra Phenylolethane, phenol novolak, cresol novolak, naphthol novolak,
2 selected from the group consisting of bisphenol A novolak
It is obtained by reacting a polyfunctional epoxy resin produced from a phenol having more than one functionality and epihalohydrin with a bifunctional phenol compound, wherein the epoxy equivalent is in the range of 300 to 700 g / eq, and An epoxy resin composition having a phenolic hydroxyl group equivalent in the range of 500 to 3000 g / eq.