JP3310426B2 - Low dielectric constant thermosetting resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition having a low dielectric constant, a low dielectric loss tangent, excellent adhesion to metal, high heat resistance, and flame retardancy. Board,
It is suitably used for metal foil clad laminates and the like.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a resin for a laminate having excellent heat resistance, a low dielectric constant, and a low dielectric loss tangent for a printed wiring used in a high frequency range. On the other hand, thermoplastic resins such as fluororesins and polyphenylene ether resins having a small dielectric constant have been proposed, but have problems such as poor workability and adhesiveness and lack of reliability. Therefore, an epoxy-modified polyphenylene ether resin or a polyphenylene ether-modified epoxy resin has been proposed for the purpose of improving workability and adhesiveness. However, the dielectric constant of the epoxy resin is high and satisfactory characteristics have not been obtained. A curable resin composition obtained by blending a polyphenylene ether resin, a polyfunctional cyanate ester resin, and other resins, adding a radical polymerization initiator thereto, and performing a preliminary reaction (Japanese Patent Application Laid-Open No. 57-185)
No. 350 is known, but the decrease in the dielectric constant was insufficient.

Polybutadiene containing thermosetting 1,2-polybutadiene as a main component has a low dielectric constant, but has poor adhesiveness and insufficient heat resistance. 1,2-polybutadiene 5 to 100 parts by weight of polyphenylene ether
A composition containing 20 parts by weight, 5 to 10 parts by weight of a crosslinkable monomer and a radical crosslinking agent (see JP-A-61-83224) is known, but 1,2-polybutadiene having a molecular weight of several thousand is used. In this case, when the solvent is removed from the composition, stickiness remains, and the prepreg obtained by coating and impregnating a glass substrate or the like cannot maintain a tack-free state, and thus has a practical problem. On the other hand, in order to eliminate stickiness, there is a method using 1,2-polybutadiene having a high molecular weight. However, according to this method, the solubility in a solvent is reduced, the solution becomes high in viscosity, and the fluidity is reduced, which is a practical problem. Was.

[0004]

SUMMARY OF THE INVENTION The present invention has been the result of intensive studies to obtain a thermosetting resin having low dielectric constant, low dielectric loss tangent, high heat resistance, high adhesiveness and excellent flame retardancy. It was done.

[0005]

The present invention relates to (a) a cyanate ester compound represented by the general formula (1) and / or 100 parts by weight of a prepolymer thereof, and (b) a phenol compound represented by the general formula (2). 100 to 550 parts by weight,
(C) A low dielectric constant thermosetting resin composition comprising 250 to 550 parts by weight of a brominated epoxy resin having a bromine content of 30% by weight or more.

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[0006]

The cyanate ester compound represented by the general formula (1) and / or a prepolymer thereof used in the present invention means an organic compound having two or more cyanate ester groups in a molecule. In the present invention, the polyfunctional cyanate ester itself or a prepolymer derived therefrom can be used. These compounds, if necessary, may be zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octylate,
By using a catalyst such as tin octylate, lead acetylacetonate, dibutyltin maleate or the like, the cyanate ester group can be trimerized and the reaction can be appropriately adjusted to form a prepolymer. The cyanate ester group can form a sym-triazine ring in the molecule by trimerization, and can be finally heat-cured. The cured product of the cyanate ester compound and / or a prepolymer thereof alone has excellent heat resistance and relatively low dielectric constant and dielectric properties, but is still insufficient as a resin for a high-frequency substrate. Only by blending with (2) a phenolic compound or a brominated epoxy resin and heating and curing, is it excellent in heat resistance, flame retardancy, adhesion and chemical resistance,
In addition, it is possible to provide a resin excellent in dielectric properties required for a resin for a high-frequency board.

The cyanate ester compound used in the present invention is not particularly limited as long as it is represented by the general formula (1).
Dicyanatobenzene, 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,8- or 2,6- or 2,7-dicyanatonaphthalene, 4,
4'-dicyanatobiphenyl, bis (4-cyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, bis (3,5-dimethyl-4-cyanatophenyl) methane, 2, 2-bis (3,5-dimethyl-4-cyanatophenyl) propane, bis (4-cyanatophenyl) sulfone, tris (4-cyanatophenyl) phosphite, 1,1-bis (4-cyanatophenyl) ) Ethane, 2,2-bis (4-cyanatophenyl) hexafluoropropane and the like.

The phenol compound used in the present invention is represented by the general formula (2), but has a phenolic hydroxyl group in the molecule and therefore functions as a curing agent for an epoxy resin. Further, since the molecular skeleton has an aliphatic cyclized structure, it has a function of lowering the dielectric constant and the dielectric loss tangent, which is preferable. Specific examples of the phenol compound used in the present invention include special phenol resins PP-700-300 and PP-700-1 manufactured by Nippon Oil Co., Ltd.
80, PP-1000-180, etc., but are not particularly limited thereto. It is also possible to use a reaction accelerator such as imidazole for accelerating the reaction with the epoxy group.

The brominated epoxy resin used in the present invention has the high adhesiveness of the epoxy resin and the effect of imparting flame retardancy by bromine atoms, and its bromine content is preferably at least 30% by weight. . If the amount is less than 30% by weight, the effect of imparting flame retardancy becomes poor, which is not preferable.

The low dielectric constant thermosetting resin composition of the present invention comprises:
It comprises a component (a) of a cyanate ester compound and / or a prepolymer thereof, a component (b) of a phenol compound, and a component (c) of a brominated epoxy resin. a) 100 to 550 parts by weight of component (b), 100 parts by weight of component (c)
Is preferably 250 to 550 parts by weight. If the amount of the component (b) is less than 100 parts by weight based on 100 parts by weight of the component (a), the effect on lowering the dielectric constant and the dielectric loss tangent is small. This is not preferable because a large amount of the phenolic hydroxyl group remains to impair the dielectric properties. Component (c) is Component (a) 10
If the amount is less than 250 parts by weight with respect to 0 parts by weight, the flame-retarding effect and the adhesiveness improving effect are poor, which is not preferable.
Exceeding the parts by weight is not preferable because the dielectric properties are reduced.

Although the resin composition of the present invention is used in various forms, a solvent is usually used when coating and impregnating a substrate. The solvent used must have good solubility in part or all of the composition, but a poor solvent can be used as long as it does not adversely affect the composition. Examples of the solvent used include acetone, methyl ethyl ketone,
Methyl isobutyl ketone, ketone solvents such as cyclohexanone, aromatic hydrocarbon solvents such as toluene, xylene and mesitylene, methyl cellosolve, ethyl cellosolve,
Butyl cellosolve, isobutyl cellosolve, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene ghoul monomethyl ether,
Various glycol ether solvents such as propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, and ethyl acetate Ester solvents, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dialkyl glycol ether solvents such as diethylene glycol dibutyl ether,
There are amide solvents such as N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, and alcohol solvents such as methanol and ethanol, and these may be used in combination of several kinds. it can.

The varnish obtained by dissolving the resin composition of the present invention in the above-mentioned solvent is a woven glass cloth, a nonwoven glass cloth or paper,
Alternatively, a prepreg for a printed wiring board can be obtained by applying and impregnating a substrate such as a cloth containing a component other than glass and drying it in a drying furnace at a temperature of 80 to 200 ° C. The prepreg is used for producing a printed wiring board by heating and pressing, and the resin composition of the present invention has a low dielectric constant, a low dielectric loss tangent, excellent workability, excellent adhesiveness to metal, high heat resistance, and It is a flame-retardant thermosetting resin having excellent chemical resistance, and is suitably used for laminates, metal-clad laminates and the like.

[0013]

The present invention will be described below in more detail with reference to examples.

Example 1 100 parts by weight of 2,2-bis (4-cyanatophenyl) propane, 120 parts by weight of special phenol resin PP-700-180 manufactured by Nippon Oil Co., Ltd., manufactured by Sumitomo Chemical Co., Ltd. A mixed solvent of toluene / methyl ethyl ketone = 1: 1 was added to 100 parts by weight of the brominated epoxy resin ESB-400 to prepare a varnish solution so that the nonvolatile content concentration became 50%. To this solution was gradually added 10% nonylphenol solution of cobalt naphthenate to adjust the gel time of the varnish on a hot plate at 170 ° C. to 4 minutes ± 15 seconds. 3 minutes 5
8 seconds.

Then, using this varnish, a glass cloth
(0.18 mm thick, E-glass manufactured by Nitto Boseki Co., Ltd.) 100 parts of varnish was impregnated with 100 parts of a solid content and dried in a drying oven at 150 ° C. for 4 minutes to obtain a prepreg having a resin content of 50% by weight. It was created. The obtained prepreg was tack-free and excellent in workability. Eight dried prepregs were stacked, and an electrolytic copper foil having a thickness of 35 μm was stacked on top and bottom, and the pressure was set to 40.
Heat-press molding at kgf / cm ² at 175 ° C for 90 minutes.
A 1.6 mm thick laminate was obtained. After the surface copper foil of the laminate was removed by etching, the laminate was treated at 121 ° C. under a pressure cooker under a pressure of 2.0 atm for 20 hours, and the weight increase was measured. The same test piece was immersed in methylene chloride for 10 minutes at room temperature, and the appearance was checked to determine the solvent resistance. Table 2 shows the results.

The measurement of the dielectric constant and the dielectric loss tangent are described in JI
The measurement was carried out in accordance with SC6481, and the capacitance at a frequency of 1 MHz was measured. Solder heat resistance and peel strength were also measured in accordance with JIS C 6481, and the solder heat resistance was examined at 260 ° C. for 300 seconds for abnormal appearance. Flame retardancy was evaluated by the vertical method according to the UL-94 standard. The glass transition temperature was determined from the peak temperature of tan δ by the viscoelastic method. Table 2 shows the results together.

(Examples 2 to 6 and Comparative Examples 1 to 5) Laminates were produced in the same manner as in Example 1 except that the formulation was as shown in Table 1 and the results are shown in Table 2. .

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

As is clear from the results shown in Tables 1 and 2, the resin composition of the present invention has a low dielectric constant, a low dielectric loss tangent, adhesion to metal, flame retardancy, heat resistance, and chemical resistance. It is a thermosetting resin composition which is also excellent. Therefore, it is the most suitable resin for printed wiring boards that require low dielectric constant and low dielectric loss tangent, and copper-clad laminates can be manufactured in the same process as conventional resin for laminates. The merit is great.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-5-310673 (JP, A) JP-A-5-320314 (JP, A) JP-A-6-1822 (JP, A) JP-A-6-182 192392 (JP, A) JP-A-6-207709 (JP, A) JP-A-6-211964 (JP, A) JP-A-6-212071 (JP, A) JP-A-6-248074 (JP, A) JP-A-6-271669 (JP, A) JP-A-6-271778 (JP, A) JP-A-7-157539 (JP, A) Patent 2808187 (JP, B2) (58) Fields investigated (Int. . ^7, DB name) C08G 73/00 - 73/26 C08G 59/00 - 59/72

Claims (1)

(57) [Claims] (A) 100 parts by weight of a cyanate ester compound represented by the general formula (1) and / or a prepolymer thereof, (b) 100 to 550 parts by weight of a phenol compound represented by the general formula (2), (c) ) A low dielectric constant thermosetting resin composition comprising 250 to 550 parts by weight of a brominated epoxy resin having a bromine content of 30% by weight or more. Embedded image