JPH0762103A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To produce a thermosetting resin of high resistance to heat, low dielectric constant and low dielectric loss tangent for printed boards by the hydrosilylation reaction in which a specified bisallylnadimide is reacted with a polysiloxane having at least 3 SiH groups. CONSTITUTION:A bisallylnadimide (A) represented by formula I wherein R1 is an organic group having an aromatic ring or aliphatic residue; and R<2> and R<3> are allyl groups one at the 1- to 4-position and another at the 1'-to 4'-position is reacted with a polysiloxane (B) having at least 3 SiH groups in the molecular structure in the presence of a hydrosilylation catalyst (C) to produce a thermosetting resin having a number-average molecular weight of 1000 to 4000. The compound (A) preferably has R1 represented by formula II for its low dielectric constant. The compound (B) is preferably a cyclic polysiloxane, such as tetramethylcyclotetrasiloxane, for its crosslink density. For the catalyst (C), a transition metal is useful in addition to chloroplatinic acid hexahydrate and a complex of palladium. The thermosetting resin thus produced shows good properties as laminated boards suited for printed wiring boards to be used in a high-frequency region.

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 high heat resistance, a low dielectric constant and a low dielectric loss tangent, which is useful for printed circuit boards and the like, and is widely known as an unsaturated hydrosilylation reaction. It is synthesized from bisallylnadimides and polysiloxane by utilizing the addition reaction between the bond and SiH group.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a resin for a laminated board which has excellent heat resistance, low dielectric constant and low dielectric loss tangent for printed wiring used in a high frequency region. Against this background, bisallylnadiimides are expected to have a low dielectric constant because of the symmetry of the structure and the norbornene ring that is an aliphatic ring, and the imide structure in the skeleton. Since it contains, it is expected to have high heat resistance. However, the bisallyl nadiimides are 25
A curing temperature of 0 ° C or higher was required, which was a major obstacle to practical use. Also in a system using a catalyst,
Only a metal corrosive catalyst, which is a serious drawback in electronic materials such as strong acid and onium salt, can be used, and final curing requires a temperature of around 250 ° C.

Looking further at low dielectric constant resins other than bisallylnadiimide, for example, thermoplastic resins such as fluororesins and polyphenylene ether resins have been proposed, but their workability and adhesiveness are poor and their reliability is high. There were problems such as lack of sex. 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 epoxy resin has a high dielectric constant, 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 another resin, adding a radical polymerization initiator and preliminarily reacting the mixture (JP-A-57-185350). However, the decrease in the dielectric constant was insufficient.

Although polybutadiene containing thermosetting 1,2-polybutadiene as a main component has a low dielectric constant, it has poor adhesiveness and insufficient heat resistance. Polyphenylene ether
There is known a composition containing 5 to 20 parts by weight of 1,2-polybutadiene, 5 to 10 parts by weight of a crosslinkable monomer and 100 parts by weight of a radical crosslinking agent (see JP-A-61-83224). 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 a glass substrate etc. cannot maintain a tack-free state. So there was a problem in practice. On the other hand, there is a method of using a high molecular weight 1,2-polybutadiene to eliminate stickiness, but this method has a practical problem because the solubility in a solvent is lowered, the solution becomes highly viscous and the fluidity is lowered. It was

[0005]

The present invention has a low dielectric constant,
As a result of intensive studies, a thermosetting resin composition having a low dielectric loss tangent and high heat resistance was completed.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a bisallylnadimide (A) represented by the following general formula.

[Chemical 1] (However, R ₁ is an organic group containing a divalent aromatic ring or a divalent aliphatic residue, and R ₂ and R ₃ are allyl groups, each of which is 1,2,3,4 in the formula. At any one position and at any one of the 1 ', 2', 3 ', 4' positions) and 3 in the molecule
A thermosetting resin composition having a number average molecular weight of 1,000 or more and 4,000 or less, which is obtained by reacting polysiloxane (B) having one or more SiH groups in the presence of a hydrosilylation catalyst (C).

[0007]

In the bisallylnadiimide (A) of the present invention, R ₁ may be an organic group containing a divalent aromatic ring or a divalent aliphatic residue, but it has a low dielectric constant and a low dielectric loss tangent property. Especially for

[Chemical 2] Is more preferable.

The polysiloxane used in the present invention may have three or more SiH groups in the molecule, but in consideration of cost, easiness of prepolymer synthesis, crosslink density, etc., the general formula

[Chemical 3] The cyclic polysiloxane represented by, for example, tetramethylcyclotetrasiloxane, trimethylcyclotrisiloxane, pentamethylcyclopentasiloxane and the like are preferable, and if necessary, two or more kinds may be used in combination.

Examples of the hydrosilylation catalyst include chloroplatinic acid hexahydrate, platinum compounds such as platinum-divinyldisiloxane complex, various complexes such as rhodium and palladium, and peroxides. ADVANCES IN ORGANOMETA
LLIC CHEMISTRY VOL.17 (1979) ”, as described by JLSPEIER, Ti, Zr, Hf, Cr, Mo, W, M
Many transition metals such as n, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd and Pt are useful as catalysts.

The number average molecular weight of the thermosetting resin composition obtained in the present invention is preferably 1,000 or more and 4,000 or less. If the number average molecular weight is less than 1000, it is difficult to solidify the resin, it is difficult to eliminate the tack of the prepreg during coating and drying in the production process of the laminate, and the curability is poor, leading to a decrease in the glass transition temperature. . On the other hand, when it is more than 4000, the resin viscosity is too high and the fluidity is lowered, so that the press formability is lowered.

Further, in the prepolymer synthesis reaction utilizing the hydrosilylation reaction, the molar ratio of the double bond and the SiH group is an important factor, but in this reaction, the bisallylnadiimide (A) The double bond in the norbornene ring is an internal olefin in the ring, and the reactivity is low due to the decrease in electron density due to the imide structure, and it is considered that only the allyl group reacts. The molar ratio of groups is preferably in the range 1: 2 to 2: 1. When the allyl group is less than 1: 2, or when the allyl group is more than 2: 1, the glass transition temperature sharply decreases,
Problems such as poor curing occur.

[0012]

EXAMPLES Examples will be shown below for illustrating the present invention in detail, but the present invention is not limited to these examples.

(Example 1) Diphenylmethane-4,4'-bisallylnadiimide 240.0 g and toluene 193.8 g 1 liter 4
The flask was charged into a single neck separable flask, equipped with a cooling tube and a thermometer, and heated to 90 ° C. After the internal temperature became stable, add 1.7 ml of isopropanolic chloroplatinate solution (weight concentration 10 mg / ml) and immediately add tetramethylcyclotetrasiloxane 50.6
g was added dropwise, and the reaction was carried out for 10 hours after the completion of the addition. The resulting resin has a number average molecular weight of 1500 and a gel time at 172 ° C of 4 minutes 1
It was 5 seconds. This resin was solidified to 50% with toluene.
% Varnish solution, glass cloth (E glass thickness
0.18 mm) so that the resin content is 50%
It was dried at ℃ 4 minutes to prepare a prepreg. After stacking 8 sheets of this dried prepreg, and stacking 35μm thick electrolytic copper foil on top and bottom, heat and pressure molding at a pressure of 40kgf / cm ² and a temperature of 170 ℃ for 1 hour, and after-baking at 190 ℃ for 4 hours. A laminated board having a thickness of 1.6 mm was obtained.

The measurement of dielectric constant and dielectric loss tangent is JIS C 6481
The electrostatic capacitance at a frequency of 1 MHz was measured and obtained. JIS C 648 for solder heat resistance and peel strength
The solder heat resistance was measured at 260 ° C. for 300 seconds, and the presence or absence of abnormality in the appearance was examined according to 1. The glass transition temperature was determined from the peak temperature of tan δ by the viscoelastic method. The results are shown together in Table 1.

(Example 2) 32,3 g of 2,2-bis (4-phenoxyphenyl) propane-4,4'-bisallylnadiimide, 250 g of toluene, and 2.5 ml of isopropanol chloroplatinate solution were all used in Example 1 By the same operation as, number average molecular weight
A resin having a gel time of 4 minutes and 5 seconds at 1800 and 172 ° C. was obtained. Further, a laminated board was prepared by the same operation as in Example 1. The results are shown in Table 1.

Comparative Example 1 The same operation as in Example 1 was carried out except that the reaction time was 3 hours.
A resin having a gel time of 6 minutes and 30 seconds at 0 and 172 ° C. was obtained. A laminated plate was prepared in the same manner as in Example 1.

(Comparative Example 2) The same operation as in Example 1 was repeated except that the reaction time was 15 hours.
However, this resin could not be measured because the gelation at 172 ° C. was too fast. An attempt was made to produce a laminated plate in the same manner as in Example 1, but the fluidity was poor and press molding was impossible.

Comparative Example 3 Tetramethyldisiloxane 5
6.5 g was used instead of tetramethylcyclotetrasiloxane, and the reaction time was 15 hours in the same manner as in Example 1. The obtained resin had a number average molecular weight of 1200, but this resin did not gel at all. All the above results are shown in Table 1.

[0019]

[Table 1]

[0020]

The laminate using the thermosetting resin composition according to the present invention has high heat resistance, low dielectric constant and low dielectric loss tangent, and has excellent characteristics as a resin composition for printed circuit boards. is doing.

Claims (5)

[Claims] 1. A bisallylnadimide (A) represented by the following general formula: (However, R ₁ is an organic group containing a divalent aromatic ring or a divalent aliphatic residue, and R ₂ and R ₃ are allyl groups, each of which is 1,2,3,4 in the formula. At any one position and at any one of the 1 ', 2', 3 ', 4' positions) and 3 in the molecule
A thermosetting resin composition having a number average molecular weight of 1,000 or more and 4,000 or less, which is obtained by reacting polysiloxane (B) having one or more SiH groups in the presence of a hydrosilylation catalyst (C). 2. The thermosetting resin composition according to claim 1, wherein R ₁ has the following structure. [Chemical 2] 3. The thermosetting resin composition according to claim 1, wherein the polysiloxane (B) has the following general formula. [Chemical 3] 4. The hydrosilyl catalyst (C) is Ti, Zr, H.
f, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Rh, I
The thermosetting resin composition according to claim 1, which is a metal catalyst and / or a peroxide catalyst containing at least one of r, Ni, Pd, and Pt. 5. The thermosetting resin composition according to claim 1, wherein the molar ratio of the allyl group of the bisallylnadiimide (A) and the SiH group of the polysiloxane (B) is 1: 2 to 2: 1.