JPH05311070A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermosetting resin composition which has excellent workability and can give a laminate excellent in toughness, etc., by adding a polyphenylene ether to a resin obtained by reacting a specified dicyanate compound with a phenol-modified coal resin. CONSTITUTION:A modified cyanate resin is produced by reacting a phenol- modified coal resin with a dicyanate compound of formula I (wherein R1 is -CH2-, a group of formula II, a group of formula III, a group of formula IV, -O-, -S-or a direct bond; and R2 and R3 are each -H, -CH3, -C2H5 or CF3) [e.g. bis(4-cyanatophenyl)methane]. This resin is mixed with a polyphenylene ether [e.g. poly(2,6-dimethyl1,4-phenylene ether)] to produce a thermosetting resin composition. A laminate having low water absorption and low permittivity is produced by dissolving the above resin composition in a solvent, impregnating a glass cloth or the like with the solution, removing the solvent from the impregnated cloth by heating to produce a prepreg, laminating a plurality of such prepregs, and heating the assemblage under applied pressure.

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 which has good workability and is particularly useful for a low dielectric constant laminate having excellent heat resistance and toughness.

[0002]

2. Description of the Related Art In recent years, heat-resistant, low dielectric constant, low dielectric loss tangent resin for laminates has been desired for printed wiring boards used in a high frequency range. On the other hand, a thermoplastic resin such as a fluororesin or polyphenylene ether having a small dielectric constant has been proposed, but it has problems such as poor workability and adhesiveness and lack of reliability. Therefore, in order to improve workability and adhesiveness, an epoxy-modified polyphenylene ether resin or a polyphenylene ether-modified epoxy resin has also been proposed, but since the epoxy resin has a high dielectric constant and low heat resistance, satisfactory properties are obtained. Not obtained. Also,
Cyanate ester resin is known as a resin having a lower dielectric constant and better heat resistance than an epoxy resin, but a cured resin is brittle and its dielectric constant is still insufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosetting resin composition for a low dielectric constant laminate having good workability, heat resistance and toughness.

[0004]

The present invention provides a modified cyanate resin (A) obtained by reacting a dicyanate ester compound represented by the formula (1) with a phenol-modified coal resin.
And a polyphenylene ether (B).

[0005]

[Chemical 1]

[0006]

The dicyanate ester compound used in the present invention is represented by the formula (1). Formula (1)
Examples of preferred dicyanate ester compounds of bis (4-cyanatephenyl) methane, bis (3-methyl-4-cyanatephenyl) methane, bis (3-ethyl-4-cyanatephenyl) methane, bis (3,5 -Dimethyl-4-cyanatephenyl) methane, 1,1-bis (4-cyanatephenyl) ethane, 2,2-bis (4-cyanatephenyl) propane, 2,2-
Bis (4-cyanatephenyl) -1,1,1,3,3,3-hexafluoropropane, di (4-cyanatephenyl) ether, di
(4-Cyanatephenyl) thioether, 4,4-dicyanate-diphenyl and the like can be mentioned.

The phenol-modified coal resin used in the present invention is obtained by addition-polymerizing styrene, vinyltoluene, coumarone, indene and the like contained in the cracked oil fraction of coal with phenol, and a cyanate ester resin and polyphenylene ether. It is highly effective in improving workability, adhesiveness and toughness.

As the phenols, phenol, cresol, xylenol and the like are used. The content of the phenols is preferably 5% by weight or more and 50% by weight or less in the phenol-modified coal resin, and an average of 1 to 3 added per molecule is preferable. When the content of phenols is less than 5% by weight, Tg is low and good toughness cannot be obtained. On the other hand, when it exceeds 50% by weight, the dielectric constant and water absorption of the laminated plate increase.

The phenol-modified coal resin is preferably 5 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the dicyanate ester compound. If it is less than 5 parts by weight, the curability will be poor and the dielectric constant and water absorption of the laminate will be large. On the other hand, if it exceeds 50 parts by weight, the heat resistance is lowered and good toughness cannot be obtained.

It is desirable that the dicyanate ester compound and the phenol-modified coal resin are heated to 100 to 200 ° C. and pre-reacted to have a melting point of 50 ° C. or higher and 100 ° C. or lower to obtain a modified cyanate ester resin.

The polyphenylene ether used in the present invention is represented by the formula (2).

[0012]

[Chemical 2]

Poly (2,6-dimethyl-1,4-phenylene ether) is used as an example of the preferred polyphenylene ether of the formula (2). The molecular weight is not particularly limited, but a number average molecular weight of 3,000 or more and 200,000 or less is preferable. When the molecular weight is less than 3000, heat resistance and toughness are deteriorated, and when it exceeds 200,000, compatibility and workability are deteriorated.

The polyphenylene ether is preferably used in an amount of 5 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the modified cyanate ester resin. If it is less than 5 parts by weight, the toughness does not improve,
Cracks are likely to occur during drilling. If it exceeds 50 parts by weight, the viscosity of the varnish is extremely increased and the workability and adhesiveness are deteriorated.

The varnish solvent is not particularly limited, but aromatic hydrocarbons such as benzene, toluene and xylene are preferable.

In the composition of the present invention, a curing accelerator such as nonylphenol, cobalt naphthenate or zinc naphthenate may be used in combination, if necessary.

[0017]

【Example】

(Examples 1 and 2) A reaction vessel equipped with a stirrer, a vacuum distillation apparatus and a thermometer was charged with a dicyanate ester compound and a phenol-modified coal resin, and in Example 1, cobalt naphthenate was added according to the prescription of Table 1, To heat. The mixture was reacted under reduced pressure (about 20 mmHg) at 150 ° C so that the melting point was 70 to 80 ° C. The melting point of the produced resin is shown in Table 1.

[0018]

[Table 1]

Comparative Example 1 Only the dicyanate ester compound was reacted in the same manner as in Example 1. The melting point of the produced resin is shown in Table 1.

(Examples 3 to 4) The modified cyanate ester resin was dissolved in toluene according to the formulation shown in Table 2. The appearance of the varnish was good. This varnish was impregnated into a glass cloth that had been surface-treated and was dried in a dryer for 13
The solvent was removed by heating at 0 ° C. for 3 minutes to prepare a prepreg. Eight sheets of this prepreg were overlaid, a single-sided roughened copper foil (35 μm) was overlaid on both sides, and heated and pressed at 180 ° C. for 2 hours to obtain a copper-clad laminate. Table 2 shows the laminated plate properties of the product which was further cured at 180 ° C for 8 hours. Example 3, Example 4
Had a small dielectric constant and dielectric loss tangent, and had good adhesiveness, water absorption, and drill workability.

[0021]

[Table 2]

Comparative Example 2 Using the cyanate ester resin of Comparative Example 1, the same procedure as in Example 3 was carried out according to the formulation shown in Table 2. The dielectric constant and dielectric loss tangent are smaller than those of the epoxy resin of Comparative Example 5, but are larger than those of Example 3. Moreover, cracks occurred during drilling.

Comparative Example 3 Using the cyanate ester resin of Comparative Example 1, a varnish was prepared according to the formulation shown in Table 2.
The varnish became milky and separated after standing for several hours.

Comparative Example 4 Polyphenylene ether was not added to the modified cyanate ester resin of Example 1,
The same procedure as in Example 3 was carried out according to the formulation in Table 2. Some small cracks were generated by drilling.

(Comparative Example 5) Polyphenylene ether was added to an epoxy resin, and the same procedure as in Example 3 was carried out according to the formulation shown in Table 2. The dielectric constant, dielectric loss tangent and water absorption were large, and the glass transition temperature was low.

[0026]

EFFECTS OF THE INVENTION The thermosetting resin composition of the present invention has good workability, a laminated plate using the same has a high Tg, a low water absorption rate, excellent toughness, and no cracking during drilling. Moreover, the values of the dielectric constant and the dielectric loss tangent are also small. As a thermosetting resin for low dielectric constant laminated boards and low dielectric constant multilayer printed boards,
Very reliable and excellent.

Claims (1)

[Claims] 1. A thermosetting resin containing a modified cyanate resin (A) obtained by reacting a dicyanate ester compound represented by the formula (1) with a phenol-modified coal resin, and a polyphenylene ether (B). Resin composition. [Chemical 1]