JP3383709B2 - Epoxy resin composition and copper-clad laminate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition having a low dielectric constant and a low dielectric loss tangent, and a copper-clad laminate comprising the composition.

[0002]

2. Description of the Related Art Among epoxy resins used for electric and electronic purposes, a combination of a bisphenol type epoxy resin and dicyandiamide has been mainly used as a material for a printed wiring board. In recent years, as printed wiring boards have become thinner and multi-layered, resin has a low dielectric constant for the purpose of improving signal speed and circuit impedance matching, and resin for the purpose of reducing signal transmission loss with higher signal frequencies. The low dielectric loss tangent is required. On the other hand, a method of combining a conventional epoxy resin with a thermoplastic resin having a low dielectric constant and a low dielectric loss tangent has been devised. For example, a method of modifying with a reactive polybutadiene resin, a method of dispersing powder of polytetrafluoroethylene resin, and the like. In addition, there have been reported examples of using D-glass or quartz having a lower dielectric constant than conventional E-glass as a base material.

[0003]

However, in these conventional techniques, since the basic epoxy resin has a high dielectric constant, the proportion of the thermoplastic resin to be combined in order to achieve the desired dielectric constant becomes large. However, the heat resistance, adhesiveness, dimensional stability, chemical resistance, etc. Further, when D-glass or quartz is used as the base material, there is a drawback that the wear of the drill is severe during drilling of the printed circuit board. An object of the present invention is to provide a printed circuit board having an improved low dielectric constant and low dielectric loss tangent without impairing the heat resistance, adhesiveness and processability of conventional epoxy printed circuit boards, and an epoxy resin composition capable of obtaining the same. It is to be.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies on the functional group structure and skeleton structure of a compound capable of undergoing a thermosetting reaction with an epoxy resin, and as a result, a compound having a specific functional group structure and skeleton structure has been obtained. It was found that the epoxy resin composition containing the above-mentioned compound satisfies the above-mentioned object, and has completed the present invention. That is, the present invention comprises (1) an epoxy resin,
(2) General formula (1)

[0005]

[Chemical 4] (In the formula, n represents the average number of repeating units and has a value of 1 to 10. R ₁ represents a hydrogen atom or an acyl group having 1 to 20 carbon atoms, and n + 1 R ₁ are all hydrogen atoms. R ₂ represents an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms, i represents an integer of 0 to 3. When i is 2 or more, R ₂ is the same ring. R ₃ may be the same or different, and R ₃ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms). A compound represented by (3) an epoxy resin composition containing a curing accelerator as an essential component, and a prepreg and a copper foil obtained by dissolving the composition in an organic solvent, impregnating the base material and drying the laminate. The present invention relates to a copper-clad laminate formed by molding. As a general method for synthesizing the compound represented by the general formula (1) used in the present invention, the general formula (4)

[0006]

[Chemical 5] (In the formula, n, R ₂ , R ₃ and i are defined in the same manner as in the general formula (1).) And a novolac type polyphenol compound and an organic acid or an organic acid halide, an organic acid anhydride, etc. Known methods such as an esterification reaction with an organic acid derivative in the presence of a basic compound can be mentioned.

Examples of organic acids and organic acid derivatives in that case include formic acid, acetic acid, propionic acid, butyric acid, valeric acid,
Aliphatic monocarboxylic acids such as lauric acid, stearic acid, phenylacetic acid and bromoacetic acid, and their acid chlorides, acid bromides and acid anhydrides, benzoic acid, methylbenzoic acid, naphthoic acid, biphenylcarboxylic acids and other aromatic monocarboxylic acids. Acids and their acid chlorides, acid bromides and acid anhydrides, cyclopentanecarboxylic acids, cyclohexanecarboxylic acids, cycloaliphatic monocarboxylic acids such as cycloheptanecarboxylic acid and their acid chlorides, acid bromides and acid anhydrides You can

Examples of the basic compound used here include inorganic base compounds such as sodium hydroxide and potassium hydroxide, organic base compounds such as pyridine, triethylamine, triphenylphosphine and imidazole compounds. The reaction rate of the esterification reaction,
That is, the ratio in which R _{1 in the} general formula (1) is an acyl group is
When all of R ₁ are hydrogen atoms (acylation rate 0%)
However, the acylation rate is preferably 30% or more, and more preferably 50% or more for low dielectric constant and low dielectric loss tangent, which are the effects of the present invention.

Further, the novolac type polyphenol compound represented by the general formula (4) is produced by a commonly used method for producing a novolac type phenol resin. For example, an inorganic acid such as hydrochloric acid, phosphoric acid or sulfuric acid, or benzenesulfonic acid or toluenesulfone. It is produced by polycondensation of phenols and aldehydes using an acid, an organic acid such as oxalic acid, or a metal salt such as zinc acetate as a catalyst.

As the phenols, various kinds of phenol and monoalkylphenols such as cresol, n-propylphenol, isopropylphenol, n-butylphenol, isobutylphenol, t-butylphenol, octylphenol and nonylphenol o
-, M-, p-isomer, xylenol, diisopropylphenol, methylbutylphenol, di-t-butylphenol, di-t-amylphenol, various isomers of polysubstituted alkylphenol typified by 2,3,5-trimethylphenol Body or various cycloalkylphenols represented by cyclopentylphenol, cyclohexylphenol, cyclohexylcresol, etc.
-, M-, and p-isomers are exemplified, and these may be used alone or as a mixture of two or more kinds. Examples of aldehydes include formaldehyde, and alkyl aldehydes represented by acetaldehyde, propionaldehyde, butyraldehyde, pentyl aldehyde, etc., aryl aldehydes such as benzaldehyde, naphthaldehyde, 2-methyl-3 (isopropenylphenyl) propionaldehyde, 2 Examples include aralkyl aldehydes such as -methyl-3 (t-butylphenyl) propionaldehyde.

In the general formula (4), the average number of repeating units n is preferably from 1 to 10, more preferably from 1 to 10.
It is 5. When the number of repeating units exceeds 10 on average, the viscosity of the whole system combined with the epoxy resin increases, and there is a drawback that the workability at the time of producing a laminated plate decreases. On the other hand, when the average value is less than 1, there is a high possibility that the curing reactivity with the epoxy resin will be poor, and even if they react, the heat resistance of the cured reaction product will be significantly impaired. The epoxy resin used in the present invention is a compound containing two or more epoxy groups in the molecule, and its chemical structure is not particularly limited. However, an epoxy resin represented by the general formula (2) can be mentioned as a particularly preferable structure because of the low dielectric constant and low dielectric loss tangent which are the features of the resin composition of the present invention. The general synthesis method of the epoxy resin of the general formula (2) is the general formula (5)

[0012]

[Chemical 6] (In the formula, m, R ₄ , R ₅ and j are defined in the same manner as in the general formula (2).) A known method such as a dehydrohalogenation reaction of a novolac type polyphenol compound represented by the formula and epihalohydrin with a base. Can be synthesized at.
The novolac-type polyphenol compound of the general formula (5) is
It is produced by polycondensation of a substituted phenol and an aldehyde in the same manner as the novolak type polyphenol compound represented by the general formula (4). Substituted phenols have 4 carbon atoms
A monophenol having at least one alkyl group having 10 to 10 or a cycloalkyl group having 5 to 7 carbon atoms in the molecule, and specifically, n-butylphenol, isobutylphenol, t-butylphenol, octylphenol, nonylphenol, Methylbutylphenol, di-
Various o-, m-, p-isomers of alkylphenols typified by t-butylphenol, di-t-amylphenol, etc., or cycloalkylphenols typified by cyclopentylphenol, cyclohexylphenol, cyclohexylcresol, etc. Various o-, m-, p-
The isomers are exemplified, and these may be used alone or as a mixture of two or more kinds.

Examples of aldehydes include alkyl aldehydes represented by formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, pentyl aldehyde and the like.

In the general formula (5), the average number of repeating units n is preferably 1-10, more preferably 1-5 on average. If the number of repeating units exceeds 10 on average, the viscosity of the epoxy resin increases, and there is a drawback that the workability during the production of a laminated plate decreases. Further, when the average value is less than 1, the curing reaction is significantly defective.

Specific examples of the halogen-containing bisphenol compound of the general formula (3) used in the present invention include tetrabromobisphenol A, tetrachlorobisphenol A, tetraiodobisphenol A, tetrabromobisphenol F and tetrachlorobisphenol. Examples thereof include F, and tetrabromobisphenol A is preferably used from the viewpoints of economical efficiency and efficient flame retardancy.

The reaction of the epoxy resin of the present invention with the halogenated bisphenol compound of the general formula (3) may be carried out by a known method. For example, the above components can be reacted in the presence of a basic catalyst such as triphenylphosphine or imidazole. By reacting, it is possible to control the glass transition temperature by changing the distance between cross-linking points and impart flame retardancy using a halogen-containing compound without volatilization of low molecular weight substances during curing. Further, the quantitative ratio of the above-mentioned two components may be any ratio, but the OH group in the halogenated bisphenol compound should be 0.05 to 0.75 mol with respect to 1 mol of the epoxy group in the epoxy resin. It is desirable to mix and react.

Further, the quantitative ratio between the epoxy resin and the compound represented by the general formula (1) in the present invention is such that the number of moles of the epoxy group in the epoxy resin and the functional group R ₁ of the general formula (1).
The ratio of R ₁ is 0. 1 with respect to 1 mol of the epoxy group.
It is preferable to mix it in an amount of 3 to 1.5 mol.
More preferably, it is in the range of 0.5 to 1.2 mol. R
_If the number of moles of ₁ is out of this range, curing failure will occur and a good cured product cannot be obtained.

The curing accelerator in the present invention is a general compound that accelerates the curing reaction between the epoxy resin and the curing agent, and examples thereof include imidazoles such as 2-ethyl-4-methylimidazole and 4-methylimidazole. , Tertiary ethylamines such as triethylamine and benzyldimethylamine, quaternary ammonium salts such as tetramethylammonium chloride and tetrabutylammonium bromide, and phosphorus compounds such as triphenylphosphine.
Further, it is desirable to add such that the quantitative ratio thereof is 0.05 to 3% by weight in the total resin. Further, to the extent that the effects of the present invention are not impaired, conventionally known bifunctional epoxy resins,
It is also possible to use a polyfunctional epoxy resin, another thermosetting resin, or a thermoplastic resin having a functional group in combination.
Specifically, glycidyl ether of bisphenol A,
Glycidyl ether of tetrabromobisphenol A,
Glycidyl ether of phenol novolac, glycidyl ether of cresol novolak, glycidyl ether of brominated phenol novolac, cyanate resin,
Examples thereof include maleimide resin, glycidyl-modified polybutadiene, and maleic anhydride-modified polyethylene. These may be used by reacting in advance in addition to being mixed in the resin composition of the present invention.

In the present invention, known additives such as flame retardants and surface treatment agents may be added to the composition depending on the purpose. Examples of the flame retardant include antimony trioxide, aluminum hydroxide, red phosphorus and the like, and examples of the surface treatment agent include a silane coupling agent. The copper-clad laminate of the present invention can be produced by a known method. That is, it is a method of impregnating a base material with a resin varnish prepared by dissolving the above resin composition in an organic solvent, heat-treating the prepreg and then heat-molding the prepreg and copper foil to form a copper-clad laminate. The organic solvent used is acetone, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, toluene, xylene, N, N-dimethylformamide, dioxane, tetrahydrofuran, etc., or a mixed solvent of two or more thereof. Is selected as. The base material with which the resin varnish is impregnated is a woven or non-woven fabric made of inorganic fibers such as glass fiber, polyester fiber, polyamide fiber or organic fiber, or non-woven fabric, mat or paper, and these are used alone or in combination. The heat treatment conditions for the prepreg are appropriately selected according to the solvent to be used, the added catalyst, and the types and amounts of various additives used, but are usually at a temperature of 80 ° C to 220 ° C for 3 minutes to 30 minutes. Thermoforming conditions are 150 ℃ -300 ℃
At a temperature of 10 kg / cm ^{2 to} 100 kg / cm ^{2 at} a molding pressure of 20 minutes to 300
Minute heat press molding is exemplified.

[0020]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. In the examples, the epoxy equivalent is defined by the molecular weight of the epoxy resin per one epoxy group, and the OH equivalent is defined by the molecular weight of the polyphenol compound per one OH group. Synthesis Example 1 This synthesis example relates to a method for producing a novolac-type polyphenol compound in which R ₂ is a cyclohexyl group, i is 1 and R ₃ is a hydrogen atom in the general formula (4). Cyclohexylphenol (o-, p-isomer mixture) 3
17.4 g (1.8 mol), toluene 300.0 g thermometer, stirrer,
A 0.5 liter four-neck round bottom flask equipped with a cooling tube was charged and the temperature was raised to 80 ° C. p-toluenesulfonic acid 20.6 g (0.1
(08 mol), 109.5 g (1.35 mol) of 37% formalin was added dropwise using a dropping tube over 3 hours to raise the temperature, and the mixture was kept at 90 ° C. for 9 hours. After the reaction, the mixture was allowed to stand and the aqueous layer was separated, and washed 6 times with 500 g of ion-exchanged water. Concentrate the organic layer after washing under reduced pressure
(170 ° C./5 mmHg / 0.5 hours) to obtain 305.4 g of a resinous material. The OH equivalent of the obtained resinous material was 185.9 g / eq.

Synthesis Example 2 This synthesis example relates to a method for producing a novolac-type polyphenol compound in which R ₂ is a t-octyl group, i is 1 and R ₃ is a hydrogen atom in the general formula (4). . 165.0 g (0.8 mol) of 4-t-octylphenol and 120.0 g of toluene were charged into a 0.5 liter 4-neck round bottom flask equipped with a thermometer, a stirrer and a condenser, and the temperature was raised to 80 ° C.
After adding 2.85 g (0.015 mol) of p-toluenesulfonic acid and 12.0 g of deionized water, 37% formalin 48.7 g (0.60 mol)
l) was added dropwise using a dropping tube over 2 hours, the temperature was raised, and the temperature was kept under reflux for 2 hours. After the reaction, the mixture was diluted with 120.0 g of toluene, neutralized with 6.0 g of 10% NaOH aqueous solution, and washed twice with 200 g of ion-exchanged water. The organic layer after washing was concentrated under reduced pressure (170
(° C / 5 mmHg / 0.5 hours) to obtain 136.2 g of a resinous material. The OH equivalent of the obtained resinous material was 216.0 g / eq.

Synthesis Example 3 In this synthesis example, in the general formula (1), R ₁ is an acetyl group or a hydrogen atom, and R ₂ is a cyclohexyl group,
The present invention relates to a method for producing a compound in which i is 1 and R ₃ is a hydrogen atom. 94.0 g (0.5 OHm) of the reaction product of Synthesis Example 1
ol), methyl isobutyl ketone 115.0 g, pyridine 0.47 g
Was charged into a 0.5 liter 4-neck round bottom flask equipped with a thermometer, a stirrer, a dropping tube, and a cooling tube, and the temperature was raised to 70 ° C.
After acetic anhydride 51 g (0.5 mol) was added dropwise over 1.5 hours, 90
The temperature was raised to 0 ° C. and the temperature was kept for 4 hours for reaction. It was diluted with 345 g of methyl isobutyl ketone, neutralized with a 5% aqueous sodium hydrogen carbonate solution, washed, and then washed twice with 200 g of ion-exchanged water. The organic layer after washing is concentrated under reduced pressure (150 ℃ / 5mmHg / 1
After 10 hours, 108.1 g of a resinous product was obtained. The average acetylation rate of the R ₁ portion was 54.9% as a result of ¹ HNMR measurement.

Synthesis Example 4 In this synthesis example, in the general formula (1), R ₁ is an acetyl group or a hydrogen atom, R ₂ is a t-octyl group, and i
Is 1 and R ₃ is a hydrogen atom. 109 g of the reaction product of Synthesis Example 2 (0.5 OHmo
l), methyl isobutyl ketone 130.0g, pyridine 0.55g
Was charged into a 0.5 liter 4-neck round bottom flask equipped with a thermometer, a stirrer, a dropping tube, and a cooling tube, and the temperature was raised to 70 ° C. Acetic anhydride 51g (0.5mol) was added dropwise over 1.5 hours, then at 90 ℃
The temperature was raised to 2, and the temperature was kept for 2 hours for reaction. It was diluted with 173 g of methyl isobutyl ketone, neutralized with a 5% aqueous sodium hydrogen carbonate solution, washed, and further washed with 200 g of ion-exchanged water. The washed organic layer was concentrated under reduced pressure (140 ° C./5 mmHg / 1 hour) to obtain 122.7 g of a resinous material. The average acetylation rate of the R ₁ portion was 70.1% as a result of ₁ HNMR measurement.

Synthesis Example 5 This synthesis example is a compound in which R ₁ is an acetyl group or a hydrogen atom, R ₂ is a methyl group, i is 1 and R ₃ is a hydrogen atom in the general formula (1). It relates to the manufacturing method of. o-cresol novolak 96.0 g (0.8 OHmol),
129.6 g of methyl isobutyl ketone and 0.48 g of pyridine were charged into a 0.5 liter 4-neck round bottom flask equipped with a thermometer, a stirrer, a dropping tube and a cooling tube, and the temperature was raised to 70 ° C. 81.6 g (0.8 mol) of acetic anhydride was added dropwise over 1.5 hours, and the mixture was kept warm for 4 hours for reaction. Methyl isobutyl ketone 172.8g
Was diluted with, neutralized with a 5% aqueous sodium hydrogen carbonate solution, washed, and further washed with 200 g of ion-exchanged water. The organic layer after washing was concentrated under reduced pressure (150 ° C / 5mmHg / 1 hour) to give a resinous material 11
I got 9.0g. The average acetylation rate of the R ₁ part is ¹ HN
The MR measurement result was 74.4%.

Synthesis Example 6 This synthesis example is a compound in which R ₁ is an acetyl group or a hydrogen atom, R ₂ is a hydrogen atom, i is 1 and R ₃ is a hydrogen atom in the general formula (1). It relates to the manufacturing method of. Phenol novolac 108.0 g (0.9 OHmol), methyl isobutyl ketone 135.0 g, and pyridine 0.49 g are attached to a thermometer, a stirrer, a dropping pipe, and a cooling pipe. 0.5 liter 4
The flask was charged into a double-necked round bottom flask and heated to 70 ° C. Acetic anhydride
After 96.9 g (0.95 mol) was added dropwise over 2 hours, the mixture was kept warm for 4 hours for reaction. It was diluted with 180.0 g of methyl isobutyl ketone, neutralized with a 5% aqueous sodium hydrogen carbonate solution, washed, and further washed with 200 g of ion-exchanged water. The organic layer after washing is concentrated under reduced pressure (150 ℃ / 10mmHg / 1 hour) to give a resinous material.
I got 7.0g. The average acetylation rate of R ₁ is ¹ HNM
The R measurement result was 96.5%.

Synthesis Example 7 In this synthesis example, R ₄ is a hydrogen atom in the general formula (5), j is 2 and one of R ₅ is a t-butyl group,
The remaining one relates to a method for producing a novolac type polyphenol compound in which a methyl group is present. 2-t-butyl-
5-methylphenol 2231.0 g (13.58 OHmol), p-toluenesulfonic acid 12.9 g (0.068 mol), ion-exchanged water 22
3.2g was equipped with a thermometer, stirrer, cooling tube and drip tube 5
Charge to a 4-liter round-bottomed flask and raise the temperature to 100 ° C. After 218.4 g (2.715 mol) of formaldehyde was added dropwise over 2 hours, the reaction was carried out by keeping the temperature at 100 ° C for 2 hours.
After that, it was cooled to 80 ℃, and 27.7g (0.069m) of 10% NaOH aqueous solution was added.
ol). The organic layer after liquid separation was washed twice with 700 g of ion-exchanged water. The organic layer after washing is concentrated under reduced pressure (180 ° C / 10
mmHg / 1 hour) to obtain 857.2 g of a resinous material. The OH equivalent of the obtained resinous material was 176.0 g / eq.

Synthesis Example 8 In this synthesis example, in the general formula (2), R ₄ is a hydrogen atom, j is 2, one of R ₅ is a t-butyl group, and the remaining one is a methyl group. The present invention relates to a method for producing an epoxy resin. 246.4 g (1.4 OHmo of the reaction product of Synthesis Example 7)
l), epichlorohydrin 906.5 g (9.8 mol), dimethyl sulfoxide 453.3 g, ion-exchanged water 14.0 g, thermometer,
A 2-liter, 4-neck, round-bottomed flask equipped with a stirrer and a cooling tube with a separation tube was charged, and 48.6% under the conditions of 49 ° C and 42 torr.
108.31g (1.316mol) of caustic soda solution was added dropwise over 5 hours. During this time, while keeping the temperature at 49 ° C., the azeotropic epichlorohydrin and water were cooled and liquefied, and the reaction was performed while returning the organic layer into the reaction system. After the reaction was completed, unreacted epichlorohydrin was removed by concentration under reduced pressure, the epoxidized product containing a byproduct salt and dimethylsulfoxide was dissolved in methyl isobutyl ketone, and the byproduct salt and dimethylsulfoxide were removed by washing with warm water. By removing the solvent under reduced pressure, 304.9 g of an epoxy resin was obtained. The epoxy equivalent of the epoxy resin thus obtained was 256 g / eq. Infrared absorption spectrum measurement results, phenolic
OH absorption 3200-3600 cm ^-1 disappears, epoxide absorption 12
It was confirmed to have an absorption of 40,910 cm ^-1 .

Synthetic Example 9 In this Synthetic Example, the epoxy resin obtained in Synthetic Example 8 was added to the diglycidyl ether of tetrabromobisphenol A and tetrabromobisphenol A to give
The present invention relates to a method for obtaining a terminal epoxy resin. 62.0 g of the epoxy resin obtained in Synthesis Example 5, diglycidyl ether of tetrabromobisphenol A (Sumitomo Chemical Co., Ltd., trade name Sumiepoxy ESB-400, epoxy equivalent)
403g / eq) 25.3g, tetrabromobisphenol A 12.7g
Was charged into a 300 ml four-neck round bottom flask equipped with a thermometer, a condenser and a stirrer, and was heated and melted at 110 ° C. Then, 40 mg of triphenylphosphine (vs. resin 4 × 10-4
wt%) dissolved in 2.25 g of methyl ethyl ketone,
The mixture was kept at 10 ° C for 4 hours to carry out an addition reaction between an epoxy group and a phenolic hydroxyl group. After the reaction, the system was cooled to 90 ° C and 22.75 g of methyl ethyl ketone was added dropwise to the resin solid content.
123.9 g of 80.62 wt% resin solution was obtained. The epoxy equivalent of the obtained resin adduct was 399.0 g / eq.

Examples 1 to 6 Diglycidyl ether of bisphenol A as an epoxy resin (Sumitomo Chemical Co., Ltd., trade name Sumiepoxy EL
A-128, epoxy equivalent 186 g / eq), using the epoxy resins obtained in Synthesis Examples 8 and 9 and the compounds obtained in Synthesis Examples 3 and 5, and 2-ethyl-4-methyl as a curing accelerator. Imidazole (manufactured by Shikoku Chemicals Co., Ltd., trade name Curezol 2E4MZ) was mixed in the proportions shown in Table 1 and dissolved in a solvent to form a uniform resin varnish. The resin mixture obtained by distilling off the solvent from the resin varnish by heating was press-molded to obtain a resin cured plate having a constant thickness. The dielectric constant and dielectric loss tangent of the resin cured plate at 1 GHz are measured by gold vapor deposition with electrodes on both sides of a coaxial resonator (Boonton Electronics Resonant Coa
xial Line, Model34A), and calculated by measuring the resonance frequency and the frequency of 6.02 dB down by Hewlett Packard's 8573A Network Analyzer via Hewlett Packard's 85046A S-parameter test set. The results are shown in Table 1.

Comparative Example 1 Diglycidyl ether of bisphenol A (Sumiepoxy ELA-128) was used as an epoxy resin, phenol novolac resin (Tamanor 758, trade name, manufactured by Arakawa Chemical Industry Co., Ltd.) was used as a curing agent, and a curing accelerator. 2-Ethyl-4-methylimidazole (Curezol 2E4MZ) was used to prepare a resin cured plate in the same manner as in Examples 1 to 6, and the dielectric constant and dielectric loss tangent at 1 GHz were measured. The composition and the results are shown in Table 1.

Examples 7 to 10 The epoxy resin which is the reaction product of Synthesis Example 9 was used as the epoxy resin, and diglycidyl ether of tetrabromobisphenol A (Sumiepoxy ESB-400) was used as necessary for adjusting the bromine content. The compounds obtained in Synthetic Examples 3, 4, 5 and 6 and 2-ethyl-4-methylimidazole as a reaction accelerator were mixed in the proportions shown in Table 2 and dissolved in a solvent to form a uniform resin varnish. Glass varnish (trade name)
KS-1600S962LP, manufactured by Kanebo Co., Ltd., was impregnated and treated with a hot air dryer at 150 ° C for 5 to 10 minutes to obtain a prepreg. Five prepregs and a copper foil (TSTO-treated 35 μm thick, manufactured by Furukawa Circuit Foil Co., Ltd.) were overlaid and heat-pressed at 170 ° C. × 50 kg / cm ² × 120 minutes to obtain a 1 mm thick copper clad laminate. The copper foil peeling strength, solder heat resistance, and boiling water absorption of the laminate are JIS-C-
Measured according to 6481. The glass transition temperature (Tg) was determined from the inflection point of the thermal expansion curve using a thermal analyzer DT-30 manufactured by Shimadzu Corporation. The dielectric constant and the dielectric loss tangent at 1 GHz are shown in Examples 1 to 1.
It measured by the method similar to 6. The measurement results are shown in Table 2.

Comparative Example 2 Epoxy resin with brominated epoxy resin (Sumitomo Chemical Co., Ltd., trade name Sumiepoxy ESB-500, epoxy equivalent)
472g / eq) and cresol novolac type epoxy resin (Sumitomo Chemical Co., Ltd., trade name Sumiepoxy ESCN-22)
0, epoxy equivalent 215 g / eq), dicyandiamide and 2-ethyl-4-methylimidazole were mixed in the proportions shown in Table 1 and dissolved in a mixed solvent of methyl ethyl ketone and ethylene glycol monomethyl ether to form a uniform resin varnish. Using the varnish, a copper-clad laminate was prepared in the same manner as in Examples 7 to 10, and its physical properties were measured in the same manner as in Examples. The measurement results are shown in Table 2.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

The copper-clad laminate using the epoxy resin composition of the present invention has a lower dielectric constant and a lower dielectric loss tangent than conventional ones and is also excellent in moisture resistance, so that it is a multilayer print especially for high frequency signal processing. Suitable for wiring boards.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-8-34835 (JP, A) JP-A-7-53675 (JP, A) JP-A-61-271321 (JP, A) JP-A-4- 159326 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 59/62 B32B 15/08 C08G 59/14 C08J 5/24 H01B 3/40

Claims (5)

(57) [Claims] 1. An epoxy resin (1) and a general formula (1) (2). (In the formula, n represents the average number of repeating units and has a value of 1 to 10. R ₁ represents a hydrogen atom or an acyl group having 1 to 20 carbon atoms, but all of R ₁ are hydrogen atoms. No. R ₂ is an alkyl group having 1 to 10 carbon atoms or 5 carbon atoms
~ 7 represents a cycloalkyl group, i represents an integer of 0-3. When i is 2 or more, R ₂ may be the same or different in the same ring. R ₃ is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms or 7 to 20 carbon atoms
Represents an aralkyl group of. ) And a compound (3)
An epoxy resin composition containing a curing accelerator as an essential component. 2. (1) General formula (2) (In the formula, m represents the average number of repeating units and has a value of 1 to 10. R ₄ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R ₅ represents an alkyl group having 1 to 10 carbon atoms or Represents a cycloalkyl group, and at least one in the same ring is an alkyl group having 4 to 10 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms, j is an integer of 1 to 3, and j is 2
In the above cases, R ₅ may be the same or different within the same ring. ) Epoxy resin represented by
(2) General formula (1) (In the formula, n represents the average number of repeating units, and a value of 1 to 10
Is. R ₁ is hydrogen atom or acyl having 1 to 20 carbon atoms
It represents a group, but R ₁ is not all hydrogen atoms.
Yes. R ₂ is an alkyl group having 1 to 10 carbon atoms or 5 carbon atoms
~ 7 represents a cycloalkyl group, i represents an integer of 0-3
You When i is 2 or more, R _{2 s} may be the same in the same ring.
It can be different. R ₃ is a hydrogen atom, having 1 to 10 carbon atoms
Alkyl group, aryl group having 6 to 20 carbon atoms or carbon
It represents an aralkyl group of the formula 7 to 20. ) Compound represented by
And (3) Epoxy resin set containing a curing accelerator as an essential component
A product. 3. The epoxy resin comprises an epoxy resin and a general formula (3). (In the formula, R ₆ represents a hydrogen atom or a methyl group, and two R ₆ may be the same or different from each other. X,
X ′ is a halogen atom, and they may be the same or different from each other. k and l are independently 1 to 4
Is an integer. The epoxy resin composition according to claim 1, which is a compound obtained by previously reacting with a halogen-containing bisphenol compound represented by (4). 4. The epoxy resin composition according to claim 2 , wherein the epoxy resin is a compound obtained by previously reacting the epoxy resin of the general formula (2) with the halogen-containing bisphenol compound of the general formula (3). 5. A copper obtained by laminating and molding a prepreg obtained by dissolving the epoxy resin composition according to claim 1, 2, 3 or 4 in an organic solvent, impregnating it in a substrate and drying it, and copper foil. Upholstered laminate.