JPH061823A - Low-permittivity thermosetting resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermosetting resin which has high adhesion and excellent applicability and gives a cured resin having a low permittivity and high heat resistance by mixing a specific epoxy resin with a specific phenolic compound and a specific poly (phenylene ether). CONSTITUTION:The title composition comprises 100 pts.wt. epoxy resin consisting mainly of an epoxy compound represented by formula I, 20-150 pts.wt. phenolic compound represented by formula II or III, and 5-150 pts.wt. poly(phenylene ether) represented by formula IV. In the formulae, k is an integer of 0-100; R1 and R2 each is an alkyl such as methyl, ethyl, isopropyl, or t-butyl; X is an alkylene such as methylene, ethylene, isopropylidene, isobutylene, or hexafluoroisopropylidene or a group represented by formula V (wherein R3, R4, R5, and R6 each is a 1C or higher alkyl); m and n each is an integer of 1 or larger; R7 is methyl, ethyl, isopropyl, or t-butyl; and p is an integer of 1 or larger.

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 and a high heat resistance and excellent adhesion to a metal, such as a laminated plate and a metal foil-clad laminated plate. It is preferably used for.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a laminated wiring board resin having excellent heat resistance and low dielectric constant and low dielectric loss tangent for printed wiring used in a high frequency range. On the other hand, a thermoplastic resin such as a fluororesin or a polyphenylene ether resin having a small dielectric constant has been proposed, but it has 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 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 other resins, adding a radical polymerization initiator, and preliminarily reacting the mixture (JP-A-57-18535).
No. 0) is known, but the decrease in dielectric constant was insufficient.

Further, the polybutadiene resin containing thermosetting 1,2-polybutadiene as a main component has a low dielectric constant,
The adhesion was poor and the heat resistance was insufficient. A composition containing 5 to 20 parts by weight of 1,2-polybutadiene resin, 5 to 10 parts by weight of a crosslinkable monomer and 100 parts by weight of a polyphenylene ether resin, and a radical crosslinking agent (JP-A-61-8).
3224) is known, but it has a molecular weight of several thousand.
When the 1,2-polybutadiene resin is used, stickiness remains when the solvent is removed from the composition, and the prepreg obtained by coating and impregnating the glass substrate cannot maintain a tack-free state, which is a practical problem. was there. On the other hand, there is a method of using a high molecular weight 1,2-polybutadiene to eliminate stickiness, but this method causes a problem in practical use because the solubility in a solvent is lowered, the solution becomes highly viscous and the fluidity is lowered. It was

[0004]

The present invention has been made as a result of extensive studies to obtain a thermosetting resin having a low dielectric constant, high heat resistance, high adhesiveness and excellent workability. .

[0005]

That is, the present invention provides an epoxy resin (A) containing an epoxy compound represented by the following general formula [1] as a main component and a phenol compound represented by the general formula [2a] or [2b]. (B) and polyphenylene ether (C) represented by the general formula [3], and the ratio of each is epoxy resin (A) 100 parts by weight phenol compound (B) 20 to 150 parts by weight polyphenylene ether (C) 5 It is a low dielectric constant thermosetting resin composition characterized by being 150 parts by weight.

[0006]

[Chemical 1] Here, k represents an integer of 0 or 100 or less. R ₁ , R
₂ represents an alkyl group such as a methyl group, an ethyl group, an isopropyl group and a tertiary butyl group, which may be the same or different. X is a methylene group, an ethylene group,
Alkylene groups such as isopropylidene group, isobutylene group, hexafluoroisopropylidene group or

[Chemical 2] (R ₃ , R ₄ , R ₅ and R ₆ represent an alkyl group having 1 or more carbon atoms and may be the same or different.)
Indicates.

[0007]

[Chemical 3] m and n represent an integer of 1 or more.

[0008]

[Chemical 4] R ₇ is a methyl group, an ethyl group, an isopropyl group, or a tertiary butyl group, and p is an integer of 1 or more.

[0009]

The epoxy resin used in the present invention is mainly composed of the epoxy compound represented by the general formula [1]. It is possible to increase the molecular volume by introducing a bulky alkyl substituent or the like into the aromatic ring in the molecule or its connecting part, and as a result, the dielectric constant is smaller than that of a normal bisphenol A type epoxy resin. It is possible to do so, which is preferable. Further, k in the general formula [1] is 1
It is preferably 00 or less. A polymer having a high molecular weight of more than 100 is not preferable because it lowers the workability in the process of manufacturing a laminate. Further, the epoxy resin of the present invention preferably has a halogen substituent corresponding to 15 to 40% by weight of the total amount. If it is less than 15% by weight, flame retardancy cannot be obtained, which is not preferable, and if it exceeds 40% by weight, heat resistance is impaired, which is not preferable. The halogen substituent is not particularly limited, but examples thereof include bromine and chlorine. Further, a flame retardant aid may be added if necessary.

The phenol compound used in the present invention is represented by the general formula [2a] or [2b]. Since it has a phenolic hydroxyl group in the molecule, it functions as a curing agent for the epoxy resin. Furthermore, since the molecular skeleton has an aliphatic cyclized structure, it also has a function of lowering the values of dielectric constant and dielectric loss tangent, which is preferable. The hydroxyl equivalent of this phenol compound is preferably 100 to 2000. If it is less than 100, the effect of improving the dielectric properties is weakened, and if it exceeds 2000, it is not preferable because the crosslinking density of the epoxy curing agent is lowered and sufficient heat resistance cannot be obtained. Specific examples of the phenol compound used in the present invention include phenol resins IPP-500L, IPP-500M and IPP manufactured by Nippon Oil Co., Ltd.
There are, for example, -500H, but not limited to these. Further, another epoxy curing agent can be used in combination within a range that does not have an adverse effect.

The polyphenylene ether used in the present invention is represented by the general formula [3], but since it shows a low dielectric constant and a low dielectric loss tangent, it is preferable as a constituent component of the resin for a high frequency laminate. However, in chloroform at 25 ° C
Polyphenylene ether having an intrinsic viscosity of more than 2.0 measured in step 3 has a high molecular weight, which reduces its compatibility with epoxy resins and phenol compounds, resulting in reduced workability in the laminate manufacturing process and reduced adhesion with metals. It is not preferable because it invites. It is preferable that the intrinsic viscosity is 2.0 or less because the compatibility with the epoxy resin and the phenol compound is good and the resin for laminates has excellent dielectric properties without causing the above defects. The low dielectric constant thermosetting resin composition of the present invention comprises a specific epoxy resin (A), a phenol compound (B), and a polyphenylene ether (C).
Phenolic compound (B) 20 to 150 relative to 0 part by weight
It is desirable that the amount is 5 to 150 parts by weight of the polyphenylene ether (C). Phenol compound (B) is 2
If it is less than 0 parts by weight, the effect of lowering the dielectric constant is insufficient,
If it exceeds 150 parts by weight, the heat resistance is lowered, which is not preferable. When the amount of polyphenylene ether is less than 5 parts by weight, the effect of lowering the dielectric loss tangent is poor, and when it exceeds 150 parts by weight, the adhesion to metal is lowered and the solvent resistance is lowered, which is not preferable. The thermosetting resin composition of the present invention contains a specific epoxy resin, a phenol compound and polyphenylene ether, and a curing accelerator can be used to adjust the curing rate. As the curing accelerator, an imidazole compound, an organic phosphorus compound, a tertiary amine, a quaternary ammonium salt or the like is used. It is possible to use several kinds of these accelerators in combination. The blending amount is preferably 0.01 to 5% by weight with respect to the epoxy resin. If it is less than 0.01% by weight, the promoting effect is small, and if it exceeds 5% by weight, the storage stability is lowered.

The epoxy resin composition of the present invention is used in various forms, but a solvent is often used when coating and impregnating a substrate. The solvent used must have good solubility in some or all of the composition,
A poor solvent can also be used as long as it does not adversely affect. 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, mesitylene, methyl cellosolve, ethyl cellosolve butyl alsolve, isobutyl. Cellosolve, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene ghool monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether,
Various glycol ether solvents such as ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, and diethylene glycol monobutyl ether, ester solvents such as methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, ethyl acetate, ethylene glycol dimethyl ether, diethylene Gutacol dimethyl ether,
Dialkyl glycol ether type solvents such as diethylene glycol diethyl ether and diethylene glycol dibutyl ether, N, N-dimethylacetamide, N, N
There are amide-based solvents such as -dimethylformamide and N-methyl-2-pyrrolidone, and alcohol-based solvents such as methanol and ethanol, and these may be used in combination.

The varnish obtained by using the above-mentioned solvent with the epoxy resin composition of the present invention is applied to a base material such as a glass woven cloth, a glass non-woven cloth or paper, or a cloth containing a component other than glass, and impregnated in a drying oven. A prepreg for a printed wiring board can be obtained by drying in the range of 80 to 200 ° C. The prepreg is used for producing a printed wiring board by heating and pressurizing, but the epoxy resin composition of the present invention has a low dielectric constant, a low dielectric loss tangent, excellent workability, excellent adhesiveness to metal, and high heat resistance. It is a thermosetting resin and is preferably used for laminated plates, metal-clad laminated plates and the like.

[0015]

EXAMPLES The present invention will now be described in more detail with reference to examples. << Example 1 >> 66 parts of an epoxy compound represented by the following formula having an epoxy equivalent of 300 (parts by weight; the same applies hereinafter)

[0016]

[Chemical 5]

To 34 parts of tetrabromobisphenol A was added and heated and stirred at 120 ° C., 0.01 part of 2-methylimidazole was further added, and the mixture was reacted at 150 ° C. for 4 hours.
A solid epoxy resin having an epoxy equivalent of 400 and a bromine content of 20% was obtained. Hereinafter, this is abbreviated as resin (A-1). OH equivalent of 185 per 100 parts of resin (A-1)
Nippon Oil Co., Ltd. phenol resin IPP-50
46.25 parts of 0 L was added to the resin (A-1) so that the equivalent ratio (epoxy group mole number / hydroxyl group mole number) was 1, and the intrinsic viscosity measured at 25 ° C. in chloroform was 0. 36.56 parts of poly (2,6-dimethylphenylene ether) of 0.40 were added, and 0.8 parts of a curing accelerator 2-ethyl-4-methylimidazole was added to 100 parts of the total solid content of the three. In addition, the concentration of non-volatile components is 5 with toluene.
The varnish solution was adjusted to be 0%. Then, using this varnish, glass cloth (thickness 0.18 mm, Nitto Spinning Co., Ltd.
100 parts of E glass manufactured by Co., Ltd.) was impregnated with 43 parts of the varnish with a solid content and dried in a drying oven at 150 ° C. for 4 minutes to prepare a prepreg. The obtained prepreg was tack-free and had excellent workability. 8 pieces of the above dry prepregs are piled up, 35 μm thick electrolytic copper foils are piled up and down, pressure 40 kgf / cm
^2. Heat and pressure molding for 1 hour at 175 ℃
A 1.6 mm laminated plate was obtained. After removing the surface of the laminated plate by etching, the laminate was treated for 20 hours at 121 ° C. under a pressure cooker condition of 2.0 atm, and the weight increase was measured. The results are shown in Table 2.

The dielectric constant and dielectric loss tangent are measured according to JIS C.
According to 6481, the capacitance at a frequency of 1 MHz was measured and determined. JIS C 6 for solder heat resistance and peel strength
The solder heat resistance was measured at 260 ° C. for 300 seconds, and the appearance was checked for abnormality. The 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. The results are shown together in Table 2.

Example 2 To 66 parts of an epoxy compound represented by the following formula [5] having an epoxy equivalent of 250

[Chemical 6]

34 parts of tetrabromobisphenol A was added and reacted under the same conditions as in Example 1 to give an epoxy equivalent of 2
A solid epoxy resin having a bromine content of 75 and a bromine content of 20% was obtained. Hereinafter, this is abbreviated as resin (A-2). Resin (A-
2) 100 parts of IPP-50 used in Example 1
67.27 parts of 0 L was added, and 41.82 parts of the polyphenylene ether used in Example 1 was further added.
A laminated board was manufactured by the same method as described above and various characteristics were evaluated. The results are shown in Table 2.

<< Examples 3 to 6 and Comparative Examples 1 to 6 >> Laminated plates were produced in the same manner as in Example 1 except for the formulation shown in Table 1, and the results are shown in Table 2. .

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

As is clear from the results shown in Tables 1 and 2, the epoxy resin composition of the present invention has a low dielectric constant, a low dielectric loss tangent, an excellent adhesion to a metal, and a thermosetting property. It is a resin composition. Therefore, it is an optimal 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 laminate resin, which is an industrial advantage. Is large.

Front Page Continuation (72) Inventor Yozo Shiota 1-2-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Sumitomo Bakelite Co., Ltd.

Claims (4)

[Claims] 1. An epoxy resin (A) containing an epoxy compound represented by the following general formula [1] as a main component, a phenol compound (B) represented by the following general formula [2a] or [2b], and the following general formula: It consists of polyphenylene ether (C) represented by [3], and the ratio of each is epoxy resin (A) 100 parts by weight phenol compound (B) 20 to 150 parts by weight polyphenylene ether (C) 5 to 150 parts by weight. A characteristic low-dielectric-constant thermosetting resin composition. [Chemical 1] Here, k represents an integer of 0 or 100 or less. R ₁ , R
₂ represents an alkyl group such as a methyl group, an ethyl group, an isopropyl group and a tertiary butyl group, which may be the same or different. X is a methylene group, an ethylene group,
Alkylene groups such as isopropylidene group, isobutylene group, hexafluoroisopropylidene group or (R ₃ , R ₄ , R ₅ and R ₆ represent an alkyl group having 1 or more carbon atoms and may be the same or different.)
Indicates. [Chemical 3] m and n represent an integer of 1 or more. [Chemical 4] R ₇ is a methyl group, an ethyl group, an isopropyl group, or a tertiary butyl group, and p is an integer of 1 or more. 2. The resin composition according to claim 1, wherein the epoxy resin (A) has 15 to 40% by weight of the total amount of halogen substituents. 3. The resin composition according to claim 1, wherein the hydroxyl equivalent of the phenol compound (B) is 100 to 2000. 4. The resin composition according to claim 1, wherein the polyphenylene ether (C) has an intrinsic viscosity of 2.0 or less measured at 25 ° C. in a chloroform solution.