JP2710299B2 - 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 prepared by blending a polyphenylene ether resin and a polyfunctional cyanate ester resin, and further mixing other resins, adding a radical polymerization initiator, and performing a preliminary reaction (Japanese Patent Application Laid-Open No. 57-185350) ) Is known, but the decrease in the dielectric constant was insufficient.

Further, polybutadiene containing thermosetting 1,2-polybutadiene as a main component has a low dielectric constant, but has poor adhesiveness and insufficient heat resistance. Polyphenylene ether
A composition comprising 5 to 20 parts by weight of 1,2-polybutadiene, 5 to 10 parts by weight of a crosslinkable monomer and a radical crosslinking agent per 100 parts by weight (see JP-A-61-83224) is known. When 1,2-polybutadiene having a molecular weight of several thousand is used, stickiness remains when the solvent is removed from the composition, and the prepreg obtained by coating and impregnating on a glass substrate or the like cannot maintain a tack-free state. Therefore, there was 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 has a high 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). A low dielectric constant thermosetting resin composition comprising 50 to 200 parts by weight, and (c) 50 to 200 parts by weight of a brominated epoxy resin having a bromine content of 30% by weight or more.

Embedded image

[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). Specific examples include 1,3-dicyanatobenzene and 1,3-dicyanatebenzene. 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 phenolic compound used in the present invention include special phenolic resins PP-700-300, PP-700-180, and PP-1000-18 manufactured by Nippon Oil Co., Ltd.
There are 0 and the like, but it is not particularly limited to these. 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 the bromine content is preferably 30% by weight or more. If it 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) 50 to 200 parts by weight of component (b) and 50 to 200 parts by weight of component (c) per 100 parts by weight
It is preferably in parts by weight. Component (b) is Component (a)
If the amount is less than 50 parts by weight per 100 parts by weight, the effect on lowering the dielectric constant and the dielectric loss tangent is small, which is not preferable.If it exceeds 200 parts by weight, a large amount of unreacted phenolic hydroxyl groups remains in the cured resin. On the contrary, it is not preferable because dielectric properties are rather deteriorated. If the amount of the component (c) is less than 50 parts by weight based on 100 parts by weight of the component (a), the flame-retarding effect and the adhesion improving effect are poor.
It is not preferable because the dielectric properties are lowered.

Although the resin composition of the present invention is used in various forms, a solvent is often 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. Various types of monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, etc. Glycol ether solvent Solvent acetate, ethyl cellosolve acetate, butyl cellosolve acetate, ester solvents such as ethyl acetate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dialkyl glycol ether solvents such as diethylene glycol dibutyl ether, N, N-dimethylacetamide, N, N -There are amide solvents such as dimethylformamide and N-methyl-2-pyrrolidone, and alcohol solvents such as methanol and ethanol, and some of these can be used in combination.

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 oven at a temperature in the range 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. 100 parts by weight of brominated epoxy resin ESB-400, toluene /
A mixed solvent of methyl ethyl ketone 1: 1 was added to prepare a varnish solution so that the nonvolatile content concentration became 50%. A 10% nonylphenol solution of cobalt naphthenate was gradually added to the solution to adjust the gel time of the varnish on a hot plate at 170 ° C. to 4 minutes ± 15 seconds.
When 5 parts by weight was added, the time was 3 minutes and 58 seconds.

Thereafter, 100 parts of varnish is impregnated with 100 parts of a glass cloth (0.18 mm in thickness, E glass manufactured by Nitto Boseki Co., Ltd.) with a solid content using the varnish, and the varnish is placed in a drying oven at 150 ° C. for 4 minutes. It was dried to prepare a prepreg having a resin content of 50 wt%. The obtained prepreg was tack-free and excellent in workability. Lay 8 dried prepregs above and 35
μm electrodeposited copper foil, pressure 40kgf / cm ² , temperature 175 ℃
Heat and pressure molding was performed for 90 minutes to obtain a laminate having a thickness of 1.6 mm.
After the surface copper foil of this laminate is removed by etching,
For 20 hours under a pressure cooker condition at a pressure of 2.0 atm, 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 based on JIS C
The measurement was performed in accordance with 6481, and the capacitance at a frequency of 1 MHz was measured. JIS C for solder heat resistance and peel strength
The solder heat resistance was measured at 260 ° C. for 300 seconds to check for any abnormal appearance. Flame retardancy was evaluated by the vertical method according to 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, which is an industrial advantage. Is big.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C08L 9/00 C08L 9/00 63/00 63/00 79/04 79/04 // C08F 8 / 00 C08F 8/00 (56) References JP-A-61-126162 (JP, A) JP-A-3-148250 (JP, A) JP-A-50-116595 (JP, A) International publication 91/9062 (WO , A)

Claims (1)

(57) [Claims] (1) 100 parts by weight of a cyanate ester compound represented by the general formula (1) and / or a prepolymer thereof, and (b) a phenol compound 50 represented by the general formula (2).
A low dielectric constant thermosetting resin composition comprising 50 to 200 parts by weight of (c) a brominated epoxy resin having a bromine content of 30% by weight or more. Embedded image