JP3230025B2 - Episulfide compound, thermosetting resin composition containing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an episulfide compound and a thermosetting resin composition thereof. The laminate 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, particularly for copper-clad laminates.

[0002]

2. Description of the Related Art Four to ten middle-layer copper-clad laminates include:
Conventionally, a combination of a bisphenol-type epoxy resin and dicyandiamide has been mainly used. In recent years, there has been a demand for lowering the dielectric constant of a resin for the purpose of improving the signal speed of a printed wiring board. On the other hand, a method of combining a conventional epoxy resin with a thermoplastic resin having a low dielectric constant has been devised. For example, there are 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. Further, there has been reported an example in which D-glass or quartz having a lower dielectric constant than conventional E-glass is used as a substrate.

[0003]

However, in these prior arts, the proportion of the thermoplastic resin to be combined increases to achieve a desirable low dielectric constant because the dielectric constant of the epoxy resin is high. , Heat resistance, dimensional stability, chemical resistance, etc. are impaired.
In addition, when aramid fiber or quartz is used as a base material, there is a drawback that drill wear is severe during drilling of a copper-clad laminate, and when D-glass is used, there is no problem with drill workability, but production of printed circuit boards is difficult. The problem that cost becomes high arises. Therefore, a low-dielectric constant thermosetting resin that can obtain a low-dielectric-constant copper-clad laminate in exactly the same manner as in the past has been desired. The object of the present invention is heat resistance compared to conventional products,
An object of the present invention is to provide a copper-clad laminate having excellent 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 on episulfide compounds having a relatively low dielectric constant among thermosetting resins, and have conducted intensive studies on their skeletal structures. The inventors have found that the compound satisfies the low dielectric constant, and have completed the present invention. That is, the present invention is as follows. (1) The following general formula (1):

[0005]

Embedded image (In the formula, n represents the 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 or more and 10 or less carbon atoms, Any of an alkyl group having 5 to 20 carbon atoms, including a cycloalkyl group, and an aralkyl group having 7 to 20 carbon atoms, wherein R ₁ , R ₂ , R ₃ , and R ₄ each independently have 1 or more carbon atoms. 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 An episulfide compound represented by: (2) A thermosetting resin composition comprising 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 the same into a base material, and heat-forming a prepreg and a copper foil.

The method for synthesizing the episulfide compound of the present invention is represented by the following general formula (2):

Embedded image (Where n, R, R ′, R ₁ , R ₂ , R ₃ , R ₄ ,
It is defined similarly to the general formula (1). Can be performed by a known method using the epoxy compound represented by the formula (1).

For example, the reaction of an epoxy compound with a thiocyanate such as potassium thiocyanate or ammonium thiocyanate (GB 968424) and the reaction of an epoxy compound with a thiourea (J. Polym. Sc)
i. , Symposium, No. 47, 155 (19
74)) and the like, but not limited thereto. Further, a method for synthesizing the epoxy compound of the general formula (2) is as follows:

[0008]

Embedded image (Wherein, R, R ′, R ₁ , R ₂ , R ₃ , and R ₄ are defined in the same manner as in the general formula (1)). It can be synthesized by a known method such as a hydrogen halide reaction. The above-mentioned bisphenol compounds can be obtained by any known method other than the methods described in US Pat. No. 4,560,808 and German Patent 2,418,975. As a general production method of the above bisphenol, it is exemplified that the bisphenol can be obtained by reacting a disubstituted phenol with a carbonyl compound in the presence of an acid catalyst, but is not limited thereto.

The disubstituted phenols used as a raw material of the bisphenol correspond to compounds in which two hydrogen atoms on the benzene ring of the phenol are substituted. For example, xylenol, methylethylphenol, methylpropylphenol, methylisopropyl Phenol, methylbutylphenol, methyl-t-butylphenol, methylamylphenol, methylhexylphenol, diethylphenol, dipropylphenol, dibutylphenol,
Di-t-butylphenol, various isomers of dialkylphenol represented by di-t-amylphenol, etc., or various isomers of alkylalkoxyphenol represented by methoxycresol, ethoxycresol, propoxycresol, etc. Examples include various isomers of alkylcycloalkylphenols such as pentylcresol and cyclohexylresole, and disubstituted phenols such as alkylarylphenols and alkylaralkylphenols. Among the disubstituted phenols, 2-t-butyl-5-methylphenol, more preferred 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 carbonyl compound serving as a raw material of the bisphenol corresponds to a compound having one carbonyl group. Examples thereof include formaldehyde, alkylaldehyde represented by acetaldehyde, propionaldehyde, butyraldehyde and pentylaldehyde, and cyclopentane. Cycloalkyl aldehyde, benzyl aldehyde, phenyl propionaldehyde, 2-methyl-3- (4-isopropylphenyl) propionaldehyde represented by carbaldehyde, cyclohexane carbaldehyde, methyl cyclohexane carbaldehyde, cyclohexyl acetaldehyde, cycloheptane carbaldehyde, etc. Aralkyl aldehyde or acetyl represented by 2-methyl-3- (4-t-butylphenyl) propionaldehyde, etc. Emissions, methyl ethyl ketone, ketones typified by methyl isobutyl ketone, cyclohexanone and the like. Among these carbonyl compounds, propionaldehyde, butyraldehyde, pentylaldehyde, cyclohexane carbaldehyde and the like can be exemplified as those more preferable for lowering the dielectric constant. Moreover, it is also possible to use the acetal of the above-mentioned aldehyde instead of the above-mentioned aldehyde.

[0011] 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 preferably 0 or more and 3 or less in order not to impair the operability and curing reaction rate of the episulfide compound. preferable.

As the curing agent used in the thermosetting resin composition of the present invention, known epoxy resin curing agents can be used, for example, phenol novolak, cresol novolak, dicyclopentadiene-phenol reaction product, phenol Examples include polyhydric phenols such as modified polybutadiene, amine-based curing agents such as aromatic amines and aliphatic amines, acid anhydrides, dicyandiamide, and hydrazide compounds. Preferably, it is an aromatic amine or a polyhydric phenol. The amount is preferably 0.01 to 1.2 equivalents 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 novolak, glycidyl ether of cresol novolak, glycidyl ether of brominated phenol novolak, cyanate resin, maleimide resin, glycidyl-modified polybutadiene, anhydrous And maleic acid-modified polyethylene.

In the present invention, known additives such as a curing accelerator, a flame retardant and a surface treating agent may be added to the composition according to 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. Examples of the surface treatment agent include a silane coupling agent.

The preparation of the copper-clad laminate of the present invention can be carried out according to a known method. That is, a resin varnish obtained by dissolving the thermosetting resin composition of the present invention in an organic solvent is impregnated into a substrate, and then heat-treated to form a prepreg. How to

The organic solvent used may be one or more of acetone, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, toluene, xylene, N, N-dimethylformamide, dioxane, tetrahydrofuran and the like. Is selected as a mixed solvent.

The base material to be impregnated with the resin varnish is made of inorganic fiber such as glass fiber, polyester fiber, polyamide fiber, etc.
Woven or non-woven fabric or mat made of organic fibers,
Paper or the like is used alone or in combination. The heat treatment conditions for the prepreg are appropriately selected according to the type and amount of the solvent, the added catalyst, and the various additives to be used, but the heat treatment is usually performed 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 to these examples. In the examples, the epoxy equivalent is defined by the molecular weight of the epoxy resin per epoxy group, and the OH equivalent is defined by 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 as a raw material of the episulfide compound of the present invention. 1,1-
573 g of bis (5-t-butyl-4-hydroxy-2-methylphenyl) butane (3 OH mol, OH equivalent 19
1 g / eq. ), 1942.5 g of epichlorohydrin
(21 mol), 976.5 g of dimethyl sulfoxide
Was charged into a 5 liter four-necked flat bottom flask equipped with a thermometer, a stirrer, and a condenser with a separation tube.
8.6% caustic soda aqueous solution 24 under 1 torr condition
6.9 g (3 mol) are added dropwise over 4 hours. During this time, while keeping the temperature at 48 ° 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 completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, an epoxidized product containing by-product salt and dimethyl sulfoxide was dissolved in methyl isobutyl ketone, and the by-product salt and dimethyl sulfoxide 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. As a result of infrared absorption spectrum measurement, phenolic OH
3200-3600 cm ^-1 disappeared, and it was confirmed to have absorptions of 1240 and 910 cm ^-1 which are absorptions of epoxide. 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, methylene chloride 100
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, 274.5 g of thiourea
(3.6 mol) was added and stirred for 4 hours to dissolve.
After continuing stirring for 3 hours, ion-exchanged water 1000
g was 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 the mixture was cooled, and the precipitate was separated by filtration to obtain 118 g of a white solid. As a result of infrared absorption spectrum measurement, 1240 and 910 which are absorptions of epoxide
The absorption at cm ^-1 almost disappeared, and it was confirmed to have an absorption at 620 cm ^-1 which is the absorption of episulfide.
From the measurement of the mass spectrum, 526 fragment peaks were observed.

Comparative Synthesis Example Epoxidized product of bisphenol A (trade name Sumiepoxy)
ELA-128, manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent
187 g / eq) 500 g (2.69 mol), chloride
1000 g of styrene and 1000 g of methanol were added to a thermometer,
5 liter four-neck round bottom fan with cooling tube and stirrer
It was charged in Rusco and dissolved at room temperature. After dissolution, thiourea
304.0 g (4.03 mol) was added and stirred for 5 hours.
Dissolution and reaction. Charge 1000g of ion exchange water
, And the lower layer after separation was concentrated to give an oily substance. Further
275 g of methylene chloride was added to
After washing with 450 g of liquid, the upper layer after concentration is concentrated to white
145.7 g of a colored solid were obtained. Infrared absorption spectrum measurement
Results 1240, 910 cm epoxide absorption ^-1of
The absorption almost disappears, which is the absorption of episulfide 6
20cm^-1Was observed. Also trout
From the spectrum measurement, 372,656 fragment
A peak was observed.

Examples 2 to 5 The episulfide resin obtained in Example 1 and a phenol novolak resin (trade name: Tamanol 758, manufactured by Arakawa Chemical Industries, Ltd.) or a phenol-modified polybutadiene (trade name: PP-700-300, Japan Table 1
And dissolved in dimethylformamide. Further, 2-ethyl-4-methylimidazole in an amount shown in Table 1 was added and uniformly dissolved, and then heated while distilling off dimethylformamide to obtain a cured resin alone.
The glass transition temperature, the dielectric constant at room temperature, and the dielectric loss tangent of the cured product were measured, and the results are shown in Table 1. 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 dielectric loss tangent at room temperature are 4275AM, manufactured by Yokogawa Hewlett-Packard Co., Ltd.
Using the multi-frequency LCR meter, the value of the dielectric constant was calculated from the capacitance of the sample.

Comparative Example 1 The episulfide resin obtained in the Comparative Synthesis Example and the phenol novolak resin (trade name: Tamanol 758) were blended in the ratio shown in Table 1, and the cured resin was prepared in the same manner as in Examples 2 to 5. I got The glass transition temperature, the dielectric constant at room temperature, and the dielectric loss tangent of the cured product 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 (trade name: Tamanol 758) or phenol-modified polybutadiene (trade name: PP-700-300) and 2-ethyl-4-methylimidazole are blended in the proportions shown in Table 2 and dissolved in dimethylformamide. Thus, a uniform resin varnish was obtained. Apply the varnish to a glass cloth (trade name KS-1600).
S962LP, manufactured by Kanebo Co., Ltd.) and treated with a hot air drier at 150 ° C. for 5 to 10 minutes to obtain a prepreg. Five prepregs and copper foil (35 µm thick with TTAI treatment, manufactured by Furukawa Circuit Foil Co., Ltd.) are superimposed and 170 ° C x 50k
g / cm ² × 120 minutes hot press molding to obtain a 1 mm thick copper-clad laminate. The solder heat resistance and boiling water absorption of the laminate are J
It 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 dielectric constant and the dielectric loss tangent at room temperature 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 using eter. Table 2 shows the measurement results.

Comparative Example 2 A brominated epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumiepoxy ESB-500, epoxy equivalent: 472 g / eq) and a cresol novolac type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd.) Product name Sumiepoxy ESCN-220, epoxy equivalent 215g / e
Using q), dicyandiamide and 2-ethyl-4-methylimidazole were blended in the proportions shown in Table 2 and dissolved in a mixed solvent of methyl ethyl ketone and ethylene glycol monomethyl ether to obtain a uniform resin varnish. Apply the varnish to a glass cloth (trade name KS-1600S962L)
P) and impregnated with a hot air drier at 150 ° C. for 5 to 10 minutes to obtain a prepreg. Five prepregs and copper foil (TTA
I-processed 35 μm thick, Furukawa Circuit Foil Co., Ltd.) were superimposed and hot pressed 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 also has excellent heat resistance and low water absorption, so that it is particularly suitable for high-speed arithmetic processing. It is suitable for a multilayer printed wiring board.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichiro Kitayama 6 Kitahara, Tsukuba, Ibaraki Prefecture Sumitomo Chemical Co., Ltd. (72) Inventor Michio Suzuki 346 Miyanishi, Harima-cho, Kako-gun, Hyogo Sumitomo Seika Co., Ltd. (72) Inventor Yoshihide Masuda 346-1 Miyanishi, Harima-cho, Kako-gun, Hyogo Prefecture Within Sumitomo Seika Co., Ltd. (72) Inventor Kazuo Sakiyama 4-28 Kitahama, Chuo-ku, Osaka Sumitomo Seika Co., Ltd. (56) References JP-A-62-184027 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07D 331/02 C08G 75/06 CA (STN) REGISTRY (STN)

Claims (5)

(57) [Claims] 1. A compound represented by the general formula (1): (In the formula, n represents the 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 or more and 10 or less carbon atoms, Any of an alkyl group having a carbon number of 5 to 20 including a cycloalkyl group and 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. 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
Any of at least 10 and no more than 10 alkoxy groups are shown. ). Wherein a general formula (1) in R _1, R ₃ are each independently a number 4 to 10 alkyl group or having 5 to 7 carbon-carbon cycloalkyl group, R _2, R
The episulfide compound according to claim 1, wherein ₄ is 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 dissolving the thermosetting resin composition of claim 4 in an organic solvent and impregnating the substrate with a prepreg and a copper foil.