JP3317731B2 - 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 high heat-resistant thermosetting resin composition having a low dielectric constant, a low dielectric loss tangent, and excellent adhesion to a metal. It is suitably used for plates 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 prepared by blending a polyphenylene ether resin and a polyfunctional cyanate ester resin (see JP-A-56-141349), and further mixing other resins, adding a radical polymerization initiator, and performing a pre-reaction. Although a composition (see JP-A-57-185350) is known, 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 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 made as a result of intensive studies to obtain a thermosetting resin having low dielectric constant, high heat resistance, high adhesiveness and excellent workability. .

[0005]

The present invention relates to (a) 100 parts by weight of an epoxy resin containing an epoxy compound represented by the general formula (1) as a main component, and (b) a phenol compound represented by the general formula (2). 20 to 150 parts by weight, (c) 5 to 150 parts by weight of a polyphenylene ether represented by the general formula (3), and (d) a thermoplastic resin comprising at least two or more monomer components and having a polystyrene unit in any part. A low-dielectric constant thermosetting resin composition comprising 5 to 100 parts by weight of a copolymer.

Embedded image

[0006]

The epoxy resin used in the present invention has an epoxy compound represented by the general formula (1) as a main component, but has a bulky alkyl substitution in the molecule as compared with the conventional bisphenol A type epoxy resin. To have a group,
It is possible to reduce the value of the dielectric constant of the cured product. In addition to the compound (1), it is preferable that an epoxy resin having a halogen substituent in the molecule is contained for the purpose of imparting flame retardancy. The halogen substituent is not particularly limited, but examples include Cl, Br and the like. The amount of the halogen substituent is 15 to
Preferably it is 40% by weight. If it is less than 15% by weight, flame retardancy cannot be obtained, which is not preferred. On the other hand, if it exceeds 40% by weight, the heat resistance of the cured product decreases, which is not preferable.

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 thus functions as a curing agent for an epoxy resin. Furthermore, the molecular skeleton has an excellent property of having an aliphatic cyclized structure and also having a function of lowering the values of dielectric constant and dielectric loss tangent. The phenolic compound preferably has a hydroxyl equivalent of 100 to 2,000. If it is less than 100, the effect of improving the dielectric properties is undesirably reduced, and if it is more than 2,000, the crosslinking density of the epoxy resin curing agent decreases, and sufficient heat resistance cannot be obtained. Specific examples of the phenolic compound used in the present invention include Nippon Oil Co., Ltd. special phenolic resin PP-700-300, PP-700-180, PP-1000-200, and the like, but are not particularly limited thereto. Not something. In addition, other epoxy resin curing agents may be used in combination as long as the intrinsic properties of the composition of the present invention are not impaired.

The polyphenylene ether used in the present invention is a thermoplastic polymer by nature, but is a resin having excellent mechanical properties and electrical properties, especially dielectric properties, and good heat resistance. The polyphenylene ether of the present invention is
It may be a homopolymer using only one type of phenol compound or a copolymer in which two or more types are combined,
For example, poly (2,6-dimethyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2,6-dibromo-1,4-phenylene) Examples thereof include a homopolymer represented by ether, a copolymer derived from 2,6-dimethylphenol and 2,6-dibromophenol, and the like. Further, a phenol compound component containing a functional group such as an epoxy group or an unsaturated bond may be used as a part of the copolymer component. The molecular weight of the polyphenylene ether is preferably in the range of 3,000 to 20,000. 3000
If it is less than 2,000, the flexibility and mechanical properties are poor, which is not preferable.If it exceeds 20,000, the compatibility with the epoxy resin or phenolic compound decreases, the workability in the laminate manufacturing process decreases, and the adhesion to metal decreases. Is not preferred.

The thermoplastic copolymer used in the present invention has the effect of improving the compatibility of different polymers and significantly improving the properties of the resulting cured product, especially the solder heat resistance and solvent resistance. are doing. In the case where the different polymers are thermosetting resins, the compatibility of the polymers before crosslinking is improved, and the intermolecular distance can be reduced so that the interpenetrating network resin (IPN) can be more easily formed. Improve performance and chemical resistance. The same applies to the case of a combination of a thermoplastic polymer and a thermosetting polymer. Since the compatibility is increased, the thermoplastic polymer chains penetrate between the crosslinks of the thermosetting resin, and the semi-IPN structure is easily formed. In addition, various characteristics described above are improved.

Accordingly, the thermoplastic copolymer used in the present invention is not particularly limited as long as it can exhibit the ability to improve the compatibility between different polymers.
It is advantageous for the purpose of the present invention to have a component having a high affinity for each of the different polymers as a copolymer component. Furthermore, as long as a functional group incorporated into the crosslinked structure itself, such as an epoxy group, a carboxylic acid group, and a maleic anhydride group, is introduced, a heat resistance and a chemical resistance by adding and blending a thermoplastic copolymer. It is more preferable because the deterioration of the property can be prevented. Needless to say, it can be used in combination with a thermoplastic copolymer containing no functional group. Commercially available compatibilizers used in polymer alloys between thermoplastic resins can also be used for the purposes of the present invention. To give examples, `` Reseda '' series of comb-shaped graft polymers commercially available from Toa Gosei Chemical Industry Co., Ltd., `` Macromonomer '' series of reactive polymers, commercially available from NOF Corporation Although there are "Modiper" series and the like, it is more preferable for these purposes that a polystyrene unit having a high affinity for polyphenylene ether is contained in the molecule.

[0011] The low dielectric constant thermosetting resin composition of the present invention comprises:
(A) a specific epoxy resin, (b) a phenol compound,
(C) Polyphenylene ether and (d) a thermoplastic copolymer.
20 to 150 parts by weight of component (b), based on 100 parts by weight of component
It is preferable that the amount of component (c) is 5 to 150 parts by weight, and that the amount of component (d) is 5 to 100 parts by weight. If the amount of the component (b) is less than 20 parts by weight, the effect of lowering the dielectric constant is insufficient. If the component (c) is less than 5 parts by weight, the effect of improving the dielectric properties is small, which is not preferable. If it exceeds 150 parts by weight, the solvent resistance and heat resistance decrease, especially at a temperature of 260 ° C. or higher such as soldering. The dimensional change during processing is too large, which is not preferable. If the amount of the component (d) is less than 5 parts by weight, the effect of compatibilizing the polyphenylene ether and the thermosetting component is poor. Thus, if it exceeds 100 parts by weight, the heat resistance of the resin decreases, which is not preferable.

In addition, various additives can be added to the resin composition of the present invention in order to impart various properties, as long as the inherent properties of the composition are not impaired. Halogenated compounds for imparting flame retardancy, phosphorus compounds, nitrogen compounds, flame retardants such as inorganic compounds, various coupling agents for improving adhesion to glass cloth and copper foil, for accelerating curing Examples include catalysts, accelerators, coloring agents such as pigments, and fillers.

The thermosetting resin composition of the present invention contains a specific epoxy resin, a phenol compound, a polyphenylene ether and a thermoplastic copolymer.
A curing accelerator can be used to adjust the curing speed. As the curing accelerator, an imidazole compound, an organic phosphorus compound, a tertiary amine, a quaternary ammonium salt, or the like is used. Some of these accelerators can be used in combination. The compounding amount is 0.01 to epoxy resin.
5% by weight is preferred. If it is less than 0.01% by weight, the accelerating effect is small, and if it exceeds 5% by weight, the storage stability decreases.

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 -Amide solvents such as dimethylformamide and N-methyl-2-pyrrolidone,
There are alcohol solvents such as ethanol and ethanol, and these can be used in combination of several kinds.

The varnish obtained by dissolving the resin composition of the present invention in the above-mentioned solvent may be 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 thermosetting resin with excellent chemical resistance,
It is suitably used for laminates, metal-clad laminates and the like.

[0016]

The present invention will be described below 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, hereinafter the same)

Embedded image 34 parts of tetrabromobisphenol A is added to the mixture, and the mixture is heated and stirred at 120 ° C., and 0.01 parts of 2-methylimidazole is further added. The mixture is reacted at 150 ° C. for 4 hours. The solid epoxy having an epoxy equivalent of 400 and a bromine content of 20% A resin was obtained. Hereinafter, this is abbreviated as resin (A-1). Phenol resin P manufactured by Nippon Oil Co., Ltd. having an OH equivalent of 317 per 100 parts of resin (A-1)
79. In order to make the equivalent ratio of P-700-300 to resin (A-1) 1.0 (ratio of mole number of epoxy group to phenolic hydroxyl group), 79.
25 parts, 30 parts of poly (2,6-dimethyl-1,4-phenylene ether) having a molecular weight of 12,000 (hereinafter abbreviated as PPE), 10 parts of Reseda GP-300 manufactured by Toa Gosei Chemical Industry Co., Ltd., and Toluene was added to adjust the varnish solution to a non-volatile content of 50%. To this solution, 2-ethyl-4-methylimidazole was gradually added to adjust the gel time of the varnish on a hot plate at 170 ° C. to 4 minutes ± 15 seconds.

Thereafter, a glass cloth (0.18 mm in thickness, E-glass manufactured by Nitto Boseki Co., Ltd.) was impregnated with the varnish using the varnish so that the resin adhesion amount became 50 wt% of the total weight.
It was dried in a drying oven at 150 ° C. for 4 minutes to prepare a prepreg. The obtained prepreg was tack-free and excellent in workability. Lay 8 pieces of the dried prepreg, and put thickness on top and bottom
Overlaid 35μm electrolytic copper foil, pressure 40kgf / cm ² , temperature 175 ℃
For 1 hour to obtain a laminate having a thickness of 1.6 mm. After etching and removing the surface copper foil of this laminate, 12
The mixture was treated under a pressure cooker condition at 1 ° C. and a pressure of 2.0 atm for 20 hours, and the weight increase was measured. The same test piece was immersed in methylene chloride at room temperature for 10 minutes 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 9) Laminates were manufactured 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. .

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

As is clear from the results shown in Tables 1 and 2, the resin composition of the present invention has a low dielectric constant and a low dielectric loss tangent, and has excellent adhesiveness to metal, heat resistance and chemical resistance. It is a thermosetting resin composition. 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.

Continuation of the front page (56) References JP-A-6-192392 (JP, A) JP-A-6-1822 (JP, A) JP-A-5-320314 (JP, A) JP-A-3-115426 (JP) JP-A-2-269732 (JP, A) JP-A-2-222412 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 63/02 C08G 59/62 C08L 25/08 C08L 71/12

Claims (4)

(57) [Claims] (A) 100 parts by weight of an epoxy resin containing an epoxy compound represented by the general formula (1) as a main component, (b)
20 to 150 parts by weight of a phenolic compound represented by the general formula (2), (c) 5 to 150 parts by weight of a polyphenylene ether represented by the general formula (3), and (d) at least two or more monomer components. Characterized by comprising 5 to 100 parts by weight of a thermoplastic copolymer having a polystyrene unit in a portion thereof. Embedded image 2. The resin composition according to claim 1, wherein the epoxy resin has 15 to 40% by weight of the total weight of the epoxy resin. 3. A phenol compound having a hydroxyl equivalent of 350 to 2
2. The resin composition according to claim 1, wherein 4. The polyphenylene ether having a molecular weight of 3000
The resin composition according to claim 1, wherein the molecular weight is from 20,000 to 20,000.