JPH07138254A - Episulfide compound and thermosetting resin composition containing the same - Google Patents

Abstract

PURPOSE:To provide a new compound having a specific structure and low in dielectric constant, thus capable of giving copper-clad laminated boards suitable as multilayer printed wiring boards low in dielectric constant and excellent in heat resistance and low water-absorbency to be used for high-speed operation processing. CONSTITUTION:The objective episulfide compound of formula I (n is 0-10; R and R' are each H, 1-10C alkyl, etc.; R1 to R4 are each 1-10C alkyl, 5-7C cycloalkyl, etc.). The compound of the formula I can be obtained, for example, by dehydrohalogenating reaction of a bisphenol compound of formula II such as 1,1-bis(5-t-butyl-4-hydroxy-2-methylphenyl)butane with an epihalohydrin such as epichlorohydrin in the presence of a base to produce an epoxy compound of formula III which is, in turn, reacted with a thiocyanate such as potassium thiocyanate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an episulfide compound and a thermosetting resin composition thereof. A laminated board using the thermosetting resin composition of the present invention has a low dielectric constant and a low dielectric loss tangent, and is useful for printed wiring board applications, especially for a copper clad laminated board.

[0002]

2. Description of the Related Art A four- to ten-layer medium-layer copper-clad laminate is
Conventionally, a combination of a bisphenol type epoxy resin and dicyandiamide has been mainly used. In recent years, a resin having a low dielectric constant has been demanded for the purpose of improving a signal speed of a printed wiring board, and a method of combining a conventional epoxy resin with a thermoplastic resin having a low dielectric constant has been devised. For example, a method of modifying with a reactive polybutadiene resin, a method of dispersing a powder of polytetrafluoroethylene resin, a method of using aramid fiber as a base material, and the like. There are also reports of examples of using D-glass or quartz, which has a lower dielectric constant than conventional E-glass, as the base material.

[0003]

However, in these conventional techniques, since the epoxy resin has a high dielectric constant, the proportion of the thermoplastic resin to be combined is large in order to achieve a desired low dielectric constant. The heat resistance, dimensional stability, chemical resistance, etc. are impaired.
Further, when aramid fiber or quartz is used as the base material, there is a drawback that the wear of the drill is severe during drilling of the copper-clad laminate, and when D-glass is used, there is no problem of drilling workability, but the production of printed circuit boards. There is a problem of high cost. Therefore, there has been a strong demand for a thermosetting resin having a low dielectric constant such that a copper-clad laminate having a low dielectric constant can be obtained by the completely same method as the conventional method. The object of the present invention is to improve heat resistance compared to conventional products,
It is intended to provide a copper clad laminate having excellent physical properties such as low water absorption and excellent low dielectric constant, a thermosetting compound as a raw material thereof, and a composition thereof.

[0004]

Means for Solving the Problems The present inventors have focused their attention on an episulfide compound having a relatively low dielectric constant among thermosetting resins, and as a result of continuing diligent research on its skeletal structure, as a result, The compound was found to satisfy the low dielectric constant, and the present invention was completed. That is, the present invention is as follows. (1) The following general formula (1):

[0005]

[Chemical 2] (In the formula, n represents an average number of repetitions and takes a value of 0 or more and 10 or less. R and R ′ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and 5 to 7 carbon atoms. Indicates either an alkyl group having a carbon number of 5 to 20 including a cycloalkyl group or an aralkyl group having a carbon number of 7 to 20. R ₁ , R ₂ , R ₃ and R ₄ each independently have a carbon number of 1 or more. Any of an alkyl group having 10 or less, a cycloalkyl group having 5 to 7 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. The episulfide compound represented by. (2) A thermosetting resin composition containing the episulfide compound of (1) and a curing agent as essential components. (3) A copper-clad laminate obtained by dissolving the thermosetting resin composition of (2) in an organic solvent and impregnating it in a base material, and heat-molding a prepreg and a copper foil.

The episulfide compound of the present invention can be synthesized by the general formula (2):

[Chemical 3] (In the formula, n, R, R ′, R ₁ , R ₂ , R ₃ and R ₄ ,
It is defined similarly to the general formula (1). It can be carried out by a known method using an epoxy compound represented by the formula (1).

For example, a reaction between an epoxy compound and thiocyanates such as potassium thiocyanate and ammonium thiocyanate (British Patent No. 968424) and a reaction between an epoxy compound and thioureas (J. Polym. Sc).
i. , Symposium, No. 47,155 (19
74)) and the like, but not limited thereto. Furthermore, the synthetic method of the epoxy compound of the general formula (2) is as follows.

[0008]

[Chemical 4] (In the formula, R, R ′, R ₁ , R ₂ , R ₃ , and R ₄ are defined in the same manner as in the general formula (1).) The deprotection of the bisphenol compound represented by the general formula (1) and epihalohydrin with a base It can be synthesized by a known method such as a hydrogen halide reaction. The bisphenol compound may be obtained by any known method in addition to the methods described in US Pat. No. 4,560,808 and DE 2418975. As a general method for producing the bisphenol, it is exemplified that it can be obtained by reacting a disubstituted phenol with a carbonyl compound in the presence of an acid catalyst, but it is not limited to this.

The above-mentioned disubstituted phenols as raw materials of bisphenol are compounds in which two hydrogen atoms on the benzene ring of phenol are substituted, and exemplify xylenol, methylethylphenol, methylpropylphenol and methylisopropyl. Phenol, methylbutylphenol, methyl-t-butylphenol, methylamylphenol, methylhexylphenol, diethylphenol, dipropylphenol, dibutylphenol,
Various isomers of dialkylphenol typified by di-t-butylphenol and di-t-amylphenol, various isomers of alkylalkoxyphenol typified by methoxycresol, ethoxycresol, propoxycresol, and cyclo. Examples thereof include various isomers of alkylcycloalkylphenol typified by pentylcresol, cyclohexylcresol, and disubstituted phenols such as alkylarylphenol and alkylaralkylphenol. Among the disubstituted phenols, 2-t-butyl-5-methylphenol, more preferable one for lowering the dielectric constant,
2,6-xylenol, 2-t-butyl-4-methylphenol, 2,4-di (t-butyl) phenol, 2,
Examples thereof include 4-di (t-amyl) phenol and 2-cyclohexyl-5-methylphenol.

The above-mentioned carbonyl compound as a raw material of bisphenol is a compound having one carbonyl group, for example, formaldehyde and alkyl aldehydes such as acetaldehyde, propionaldehyde, butyraldehyde, pentyl aldehyde, and cyclopentane. Carbaldehyde, cyclohexanecarbaldehyde, methylcyclohexanecarbaldehyde, cyclohexylacetaldehyde, cycloheptanecarbaldehyde, and other cycloalkylaldehydes, benzylaldehyde, phenylpropionaldehyde, 2-methyl-3- (4-isopropylphenyl) propionaldehyde, Aralkyl aldehyde or acetone represented by 2-methyl-3- (4-t-butylphenyl) propionaldehyde Emissions, methyl ethyl ketone, ketones typified by methyl isobutyl ketone, cyclohexanone and the like. Among the carbonyl compounds, propionaldehyde, butyraldehyde, pentylaldehyde, cyclohexanecarbaldehyde and the like can be exemplified as more preferable ones for lowering the dielectric constant. Moreover, it is also possible to use the acetal of the said aldehyde instead of the said aldehyde.

In the episulfide compound of the present invention,
The average number of repetitions n in the general formula (1) can take any value of 0 or more and 10 or less, but n is 0 or more and 3 or less in order not to impair the operability of the episulfide compound and the curing reaction rate. preferable.

As the curing agent used in the thermosetting resin composition of the present invention, known epoxy resin curing agents can be used. Examples thereof include phenol novolac, cresol novolac, dicyclopentadiene-phenol reaction product, and phenol. Examples thereof include polyhydric phenols such as modified polybutadiene, amine curing agents such as aromatic amines and aliphatic amines, acid anhydrides, dicyandiamide, hydrazide compounds and the like. Aromatic amines and polyphenols are preferred. Further, the blending amount thereof is preferably 0.01 to 1.2 equivalents with respect to the episulfide group.

Further, to the extent that the effects of the present invention are not impaired,
Conventionally known bifunctional epoxy resin, polyfunctional epoxy resin,
It is also possible to use 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 novolac, glycidyl ether of brominated phenol novolac, cyanate resin, maleimide resin, glycidyl modified polybutadiene, anhydrous Examples include maleic acid-modified polyethylene.

In the present invention, known additives such as a curing accelerator, a flame retardant and a surface treatment agent may be added to the composition depending on the purpose. Examples of the curing accelerator include imidazoles, tertiary amines and phosphorus compounds, examples of the flame retardant include antimony trioxide, aluminum hydroxide and red phosphorus, and examples of the surface treatment agent include silane coupling agents.

The copper-clad laminate of the present invention can be prepared by a known method. That is, a base material is impregnated with a resin varnish obtained by dissolving the thermosetting resin composition of the present invention in an organic solvent, and after heat treatment to form a prepreg, a prepreg and a copper foil are laminated and heat-molded to form a copper-clad laminate. Is the way to do it.

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., alone or in combination of two or more. Is selected as a mixed solvent of.

The base material impregnated with the resin varnish is an inorganic fiber such as glass fiber, polyester fiber or polyamide fiber,
Woven cloth made of organic fibers, or non-woven cloth or mat,
Paper or the like may be used alone or in combination. The heat treatment conditions for the prepreg are appropriately selected depending on the solvent used, the catalyst added, 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. Heat molding conditions are exemplified 20 to 300 minutes of thermal press molding at a molding pressure of 10kg / cm ² ~100kg / cm ² at a temperature of 0.99 ° C. to 300 ° C..

[0018]

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 as the molecular weight of the epoxy resin per epoxy group, and the OH equivalent is defined as the molecular weight of the OH compound per OH group. Synthesis Example 1 This synthesis example relates to a method for producing an epoxy compound which is a raw material for the episulfide compound of the present invention. 1,1-
573 g of bis (5-t-butyl-4-hydroxy-2-methylphenyl) butane (3 OHmol, OH equivalent 19
1 g / eq. ), Epichlorohydrin 1942.5 g
(21 mol), dimethyl sulfoxide 976.5 g
Was charged into a 5 liter 4-necked flat bottom flask equipped with a thermometer, a stirrer, and a condenser with a separation tube, and the temperature was 48 ° C and 4
8.6% caustic soda solution 24 under 1 torr condition
6.9 g (3 mol) is added dropwise over 4 hours. During this time, while keeping the temperature at 48 ° C., the azeotropically-formed 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, 715.5 g of an epoxy compound was obtained. The epoxy equivalent of the epoxy compound thus obtained was 260 g / eq. Results of infrared absorption spectrum measurement Phenolic OH
Absorption 3200-3600Cm ^-1 disappeared, to have absorption 1240,910Cm ^-1 is the absorption of epoxide was confirmed. The average number of repetitions n determined by high performance liquid chromatography measurement was 0.10.

Example 1 This example relates to a method for obtaining an episulfide compound by reacting the epoxy compound obtained in Synthesis Example 1 with thiourea. 594.0 g (2.40 mol) of the epoxy compound obtained in Synthesis Example 1, 100 methylene chloride
0 g and 1000 g of methanol were charged into a 5 liter four-necked round bottom flask equipped with a thermometer, a condenser and a stirrer and dissolved at room temperature. After dissolution, thiourea 274.5g
(3.6 mol) was added and stirred for 4 hours to dissolve.
After continuously stirring for 3 hours, deionized water 1000
g was charged and washed with water, and the lower layer after liquid separation was concentrated to obtain an oily substance. Further, 500 g of toluene was added and cooled, and the precipitate was filtered off to obtain 118 g of a white solid. As a result of infrared absorption spectrum measurement, absorption of epoxide 1240 and 910
absorption of cm ^-1 is almost disappeared, it was confirmed that the absorption of the 620 cm ^-1 is the absorption of the episulfide.
Further, from the measurement of the mass spectrum, 526 fragment peaks were observed.

Comparative Synthesis Example Epoxy compound of bisphenol A (trade name Sumiepoxy
ELA-128, Sumitomo Chemical Co., Ltd., epoxy equivalent
187 g / eq) 500 g (2.69 mol), chloride
1000 g of ethylene, 1000 g of methanol, thermometer,
5 liter 4-neck round bottom with cooling tube and stirrer
It was placed in a Rasco and dissolved at room temperature. After dissolution, thiourea
Add 304.0 g (4.03 mol) and stir for 5 hours.
It was dissolved and reacted. Charge 1000g of deionized water
After washing with water and separating the lower layer, the lower layer was concentrated to obtain an oily substance. Furthermore
275 g of methylene chloride was added to and redissolved in n-hexa
450g of water was added for washing, and the upper layer after separation was concentrated to white.
145.7 g of a colored solid was obtained. Infrared absorption spectrum measurement
Result is the absorption of epoxide 1240, 910 cm ^-1of
Absorption almost disappeared, and it is absorption of episulfide 6
20 cm^-1It was confirmed to have absorption of. Again mass
From the spectrum measurement, 372,656 fragment fragments
Was observed.

Examples 2 to 5 The episulfide resin obtained in Example 1 and a phenol novolac resin (trade name: TAMANOR 758, manufactured by Arakawa Chemical Industry Co., Ltd.) or phenol-modified polybutadiene (trade name: PP-700-300, Japan) Table 1 with Petroleum Co., Ltd.
Were blended in the proportions shown in and dissolved in dimethylformamide. Further, 2-ethyl-4-methylimidazole in the amount shown in Table 1 was added and uniformly dissolved, and then heated while distilling dimethylformamide to obtain a resin-only cured product.
The glass transition temperature of the cured product and the dielectric constant and dielectric loss tangent at room temperature were measured, and the results are shown in Table 1. Glass transition temperature (Tg)
Was calculated from the inflection point of the thermal expansion curve using a thermal analyzer DT-30 manufactured by Shimadzu Corporation. Room temperature permittivity and loss tangent are 4275AM, manufactured by Yokogawa Hewlett-Packard Co., Ltd.
The value of the dielectric constant was calculated from the capacitance of the sample using an ultra-frequency LCR meter.

Comparative Example 1 The episulfide resin obtained in the comparative synthesis example and the phenol novolac resin (Tamanor 758, trade name mentioned above) were blended in the proportions shown in Table 1, and cured resin products were prepared in the same manner as in Examples 2-5. Got The glass transition temperature of the cured product, the dielectric constant at room temperature, and the dielectric loss tangent were measured in the same manner as in Examples 2 to 5, and the results are shown in Table 1.

Examples 6 and 7 The episulfide resin obtained in Example 1 and an epoxidized product of tetrabromobisphenol A (trade name Sumiepoxy ESB-400, manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent 398 g / eq), phenol Novolak resin (Tamanor 758, trade name above) or phenol-modified polybutadiene (PP-700-300, trade name above) and 2-ethyl-4-methylimidazole were mixed in the proportions shown in Table-2 and dissolved in dimethylformamide. To obtain a uniform resin varnish. Glass varnish (trade name KS-1600)
S962LP, 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. 5 sheets of prepreg and copper foil (TTAI treated 35μ thick, Furukawa Circuit Foil Co., Ltd.) are piled up and 170 ℃ × 50k
Hot press molding was performed for g / cm ² × 120 minutes to obtain a copper-clad laminate having a thickness of 1 mm. Solder heat resistance and boiling water absorption of laminated board are J
It was measured according to IS-C-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 room temperature dielectric constant and dielectric loss tangent are 42, manufactured by Yokogawa Hewlett-Packard Co., Ltd.
75A Multi-Frequency LCR m
The value of the dielectric constant was calculated from the capacitance of the sample by using eter. 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 472 g / eq) and cresol novolac type epoxy resin (Sumitomo Chemical Co., Ltd., Product name Sumi Epoxy ESCN-220, Epoxy equivalent 215g / e
q) and dicyandiamide and 2-ethyl-4-methylimidazole were mixed in the proportions shown in Table 2 and dissolved in a mixed solvent of methyl ethyl ketone and ethylene glycol monomethyl ether to form a uniform resin varnish. The varnish is glass cloth (trade name KS-1600S962L mentioned above).
P) was impregnated and treated with a hot air dryer at 150 ° C. for 5 to 10 minutes to obtain a prepreg. 5 sheets of prepreg and copper foil (TTA
I treatment of 35 μm thick, Furukawa Circuit Foil Co., Ltd. was overlaid and subjected to hot press molding at 170 ° C. × 50 kg / cm ² × 120 minutes to obtain a 1 mm thick copper clad laminate. The physical properties of the laminate were measured in the same manner as in Examples 6 and 7, and the results are shown in Table 2.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

The thus obtained copper clad laminate using the episulfide compound of the present invention has a lower dielectric constant than conventional ones, and is also excellent in heat resistance and low water absorption, and is therefore particularly suitable for high speed arithmetic processing. It is suitable for the multilayer printed wiring board.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichiro Kitayama 6 Kitahara, Tsukuba-shi, Ibaraki Sumitomo Chemical Co., Ltd. (72) Inventor Michio Suzuki 1 346 Miyanishi, Harima-cho, Kako-gun, Hyogo (72) Inventor Yoshihide Masuda No. 1 346 Miyanishi, Harima-cho, Kako-gun, Hyogo Sumitomo Seika Co., Ltd. (72) Inventor Kazuo Sakiyama 4-7 28 Kitahama, Chuo-ku, Osaka Sumitomo Seika Co., Ltd. Within

Claims (5)

[Claims] 1. General formula (1): (In the formula, n represents an average number of repetitions and takes a value of 0 or more and 10 or less. R and R ′ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and 5 to 7 carbon atoms. It represents either an alkyl group having 5 to 20 carbon atoms, including a cycloalkyl group, or an aralkyl group having 7 to 20 carbon atoms, wherein R ₁ , R ₂ , R ₃ , and R ₄ are each independently 1 or more carbon atoms. An alkyl group having 10 or less, a cycloalkyl group having 5 to 7 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and 1 carbon atom
It represents any of the above alkoxy groups of 10 or less. ) An episulfide compound represented by. 2. R ₁ and R ₃ in the general formula (1) are each independently an alkyl group having 4 to 10 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms, and R ₂ and R 3
The episulfide compound according to claim 1, wherein ₄ are each independently an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms. 3. The episulfide compound according to claim ₁ , wherein R ₁ and R ₃ in the general formula (1) are t-butyl groups, and R ₂ and R ₄ are alkyl groups having 1 to 10 carbon atoms. 4. A thermosetting resin composition comprising the episulfide compound according to claim 1, 2 or 3 and a curing agent as essential components. 5. A copper-clad laminate obtained by heat-molding a prepreg obtained by dissolving the thermosetting resin composition of claim 4 in an organic solvent and impregnating it in a base material and copper foil.