JPH1045921A - Prepreg - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the infiltration of a resin into the interstices among the filaments of a glass cloth to thereby provide a prepreg which gives a laminate scarcely containing voids remaining among the filaments of glass cloth. SOLUTION: This prepreg is obtained by impregnating a glass cloth with a thermosetting resin. In this process, the constituent solvent of a resin varnish used for impregnation comprises a nonaqueous organic solvent, and the glass cloth used comprises one having an activated surface. The surface activation is carried out by corona discharge treatment after chemical treatment of the glass cloth with a surface treating agent. Since no part unimpregnated with resin will occur in producing a prepreg, the infiltration of resin into the interstices among the filaments of glass cloth is improved so that this process is effective in obtaining a prepreg which produces a laminate containing no voids remaining among the filaments of glass cloth.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improvement of a glass cloth resin impregnated prepreg used for a glass cloth reinforced resin laminate. In particular, the present invention relates to a glass cloth resin-impregnated prepreg that can be effectively used for a printed wiring board that requires high mechanical strength, electrical characteristics, and heat resistance.

[0002]

2. Description of the Related Art Conventionally, a glass cloth reinforced resin laminate processed into a printed wiring board or the like has a high viscosity at room temperature or a resin having a low viscosity obtained by dissolving a solid epoxy resin composition or the like in an organic solvent. A prepreg manufacturing process in which a glass cloth is impregnated with a solution (hereinafter, referred to as a resin varnish), the organic solvent is dried, and a resin is impregnated into a semi-cured (B-stage) glass prepreg (hereinafter, referred to as a prepreg). , Laminating the prepreg,
It is manufactured by a laminate forming process of performing heat and pressure molding and curing the resin to obtain a glass cloth reinforced resin laminate (hereinafter referred to as a laminate).

[0003] However, in recent years, in terms of high productivity, performance and quality improvement, production conditions for glass cloth reinforced printed wiring boards have become more stringent, such as higher speeds and adoption of low-pressure molding, but the quality and performance have been higher than before. Are becoming increasingly demanding. Therefore, the production method and raw materials,
That is, there are many problems required for glass cloth and matrix resin.

For example, in the manufacturing process of a printed wiring board, the production speed of the prepreg is increased to the maximum for the purpose of improving the productivity, so that a resin-impregnated portion is generated. However, there is a problem that a resin-unimpregnated portion remains due to adoption of the low-pressure molding method. Furthermore, in recent years, from the aspect of global environmental protection and work environment improvement,
From a resin dissolved and diluted with a conventional organic solvent, an attempt has been made to improve the resin for prepreg production to a low-solvent or solventless resin, but the occurrence of a resin-impregnated portion of the prepreg due to the high viscosity of the resin has been attempted. There is a request for improvement.

[0005] As a solution to these problems, there has been proposed a method of subjecting a glass cloth to fiber opening processing or a method of slowing down the reactivity between a silane coupling agent and a matrix resin (Japanese Patent Laid-Open No. 4-178432). I have.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to improve the resin impregnation between filaments of glass cloth,
An object of the present invention is to provide a prepreg in which voids do not remain as much as possible between filaments of glass cloth in a laminate.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that the use of a glass cloth whose surface has been subjected to an activation treatment results in the generation of a resin-unimpregnated portion during the production of a prepreg. They have found that they do not, and have completed the present invention. That is, the present invention provides: a prepreg obtained by impregnating a thermosetting resin into a glass cloth, wherein the constituent solvent of the resin varnish is a non-aqueous organic solvent and the glass cloth whose surface has been activated is used. I do. Another feature is that the surface activation treatment is corona discharge machining. The activation treatment is also characterized in that it is performed after the glass cloth has been chemically treated with a surface treatment agent.

Hereinafter, the present invention will be described in detail. The activation treatment in the present invention is performed for the purpose of activating the glass surface and improving the penetration of the resin varnish into the inside of the yarn bundle of the glass cloth. By the activation, free radicals are stably present on the glass cloth surface for a considerably long time, and this surface reacts with oxygen in the air to eventually form hydroxyl groups, carboxyl groups, or amino groups. The nitro groups resulting from the oxidation are formed, which also improves the wettability. In addition, it is considered that the decomposition or cross-linking reaction of the organic compound due to ultraviolet rays generated during the activation treatment such as electric discharge machining also contributes to the improvement of wettability.

The activation treatment is performed by a method such as a corona discharge treatment or a plasma discharge treatment after the glass cloth is chemically treated with a surface treatment agent and before the resin varnish is applied. Preferably, it is a corona discharge treatment, and the processing condition is that the imprint power is 0.1 kW to 40.0 kW, preferably 0.3 kW to
20.0 kW; frequency is 1 kHz to 120 kHz, preferably 5 kHz to 50 kHz;
It is 0.05 seconds to 5 seconds, preferably 0.1 seconds to 3 seconds.

It is preferable that the glass cloth used in the present invention has been chemically treated with a surface treating agent in advance. Usually, a silane coupling agent is suitably used as the surface treatment agent. The silane coupling agent is used for the purpose of bonding or dissolving to the glass cloth and the matrix resin to improve the mutual adhesion. Therefore, it is preferable to select from the most suitable ones for the matrix resin used.

The following compounds or compositions are exemplified as the silane coupling agent. That is, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2
-Aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
γ-glycidoxypropyltrimethoxysilane, N-β
-(N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, N-β- (N-benzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride,

Γ-mercaptopropyltrimethoxysilane, vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-mercaptopropyl Dimethoxysilane, γ-glycidoxypropyldimethoxysilane, γ-ureidopropyltrimethoxysilane,
γ-methacryloxypropylmethyldimethoxysilane,

Β- (3,4-epoxycyclohexyl)
Ethyltrimethoxysilane, γ- (4- (3-aminopropoxy) butoxypropyl) aminopropyltrimethoxysilane, N-β- (N-benzylaminoethyl)-
N-vinylbenzyl-γ-aminopropyltrimethoxysilane hydrochloride, N-β- (N-vinylbenzylaminoethyl) -N-vinylbenzyl-γ-aminopropyltrimethoxysilane hydrochloride, N-β- (N- (Benzhydrylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, N-vinylbenzyl-γ-aminopropyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane and the like.

These may be used alone or in combination of two or more. In the present invention, a titanate coupling agent is also effectively used as a surface treatment agent. That is, since the filament surface of the glass cloth is coated with the titanate coupling agent, the fusion between the filaments is released, and the affinity with the resin is improved. Is improved. As a titanate coupling agent suitably used, isopropyl tridodecylbenzenesulfonyl titanate is exemplified. A mixed use or a combined use of a titanate coupling agent and a silane coupling agent may be used.

[0015] The application of the surface treatment agent to the glass cloth is performed by applying an aqueous solution of the surface treatment agent, a solution of an organic solvent, or a solution of a mixed solvent of water and the organic solvent at a temperature close to room temperature.
It can be performed by adhering to a glass cloth under normal pressure and then drying. At this time, the concentration of the component of the treating agent is desirably 0.01 to 5 wt%, preferably 0.2 to 2 wt%. When the concentration of the surface treatment agent is 0.
If it is less than 01% by weight, it is not preferable because the coating on the entire surface of the glass cloth is insufficient and heat resistance is not sufficiently exhibited,
On the other hand, if it exceeds 5% by weight, the effect of improving impregnation becomes insufficient, which is not preferable. To attach the solution of the coupling agent to the glass cloth, an immersion method, a spray method, a coater method, or the like can be applied. When a plurality of types of processing agents are used, they may be processed individually or with the same processing liquid.

The resin applied to the prepreg of the present invention includes:
For example, a compound having an epoxy group, a compound having an amino group, a compound having an isocyanate group, a compound having a phenol group, a compound having an imidazole group, dicyandiamide, a compound having a hydrazide group, an acid anhydride, Epoxy resins, epoxy acrylates and unsaturated polyesters cured with compounds having carboxyl groups, etc .; Resins cured with peroxides such as thermal polymerization and / or benzoyl peroxide; Compounds having hydroxyl and / or amino groups Resin, a melamine resin, a silicone resin, a polycarbonate resin, a polyimide resin, an aromatic polyamide resin, a polystyrene resin, a polyphenylene resin, a polysulfone resin, a polyphenylene oxide resin, etc. Is mentioned.

Further, in order to compensate for the brittleness of the resin and to improve the handleability of the glass fiber fabric, the glass transition temperature is set at 10%.
A resin at 0 ° C. or lower or a thermoplastic resin may be mixed. Although the glass composition of the glass cloth used in the present invention is not particularly limited, for example, as E glass, C glass, S glass, D glass, and high dielectric constant glass used as a reinforcing material of a glass fiber reinforced resin laminate. Known glass such as H glass and quartz can be used. Also,
The weaving density of the glass cloth is 10 to 20.
0/25 mm, preferably 15 to 100/25 mm, the mass (basis weight) is 5 to 400 g / m ² , preferably 10 to 300 g / m ² , and the weave is plain weave, satin weave, twill weave, Nanako weave can be used. Further, both or one of them may be a glass cloth woven with a textured glass fiber.

The prepreg can be prepared by using the glass cloth according to a conventional method. For example, a non-aqueous organic resin such as an epoxy resin, a polyimide resin, a sianate resin, a thermoplastic resin, etc. may be formed by a dipping method, a spray method or the like. It is obtained by impregnating the glass cloth of the present invention with a resin varnish having a resin component concentration of 20 to 90% by weight in a solvent, followed by drying and semi-curing at 100 ° C to 200 ° C. The non-aqueous organic solvent is not particularly limited. Isobutyl ketone, cyclohexanone, acetophenone, chloroform, chlorobenzene,
Examples thereof include toluene, xylene, N-methylpyrrolidone, dimethylformamide, and formamide.

Further, before and / or during drying, the resin varnish may be applied while being pressed by a press roll or a kiss roll, or may be subjected to forced impregnation such as defoaming in a decompression device. Further, a non-aqueous organic solvent may be pre-impregnated before applying the resin varnish. The laminate may be prepared according to a conventional method. For example, the laminate is prepared by laminating a predetermined number of the above-described prepregs and molding them under heat and pressure using a press machine. The laminate may have a conductive metal layer such as copper on one or both sides. Further, a conductive metal layer may be provided as an inner layer like a multilayer board.

[0020]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but these are not intended to limit the scope of the present invention. In addition, each physical property value was calculated | required as follows. (1) Impregnating property of prepreg The prepreg impregnated with the resin varnish described in Example 1 and cured to be in the B-stage state was visually observed and observed with an optical microscope to evaluate the impregnating property. ◎: extremely good, ：: good, Δ: normal, ×: bad. (2) Impregnating property of laminate The copper was removed from the 0.8 mm thick double-sided copper-clad laminate prepared by the method described in Example 1 by etching and visually observed to evaluate the impregnating property. ◎: extremely good, ：: good, Δ: normal, ×: bad.

(3) Moisture Absorbing Solder Heat Resistance Copper was removed from the 0.8 mm thick double-sided copper-clad laminate prepared by the method described in Example 1 by etching to remove the copper by 5 cm.
After cutting the corner test pieces, a moisture absorption solder heat test was performed.
For the epoxy resin laminate, the test piece was immersed in a 260 ° C. solder bath for 20 seconds to check for blisters. PCT-n / 121 in the table indicates that the test piece was exposed to moisture in a saturated pressure cooker at 121 ° C. for n hours. In the case of a polyimide resin laminate, PCT-5 /
After the moisture absorption treatment of No. 121, it was immersed in a solder bath at 300 to 360 ° C. to check for blisters. The evaluation results are shown in Tables 1 and 2.

Example 1 N-β- (N
-Vinylbenzylaminoethyl)-. Gamma.-aminopropyltrimethoxysilane hydrochloride (SZ6032, manufactured by Toray Dow Corning Silicone Co., Ltd.) was prepared in 0.5% by weight (component) aqueous solution, and the pH was adjusted to 4 by adding acetic acid. did. A 0.19-mm-thick glass cloth (style 7628, manufactured by Asahi Schwebel KK), which has been deoiled by heat cleaning in advance, is immersed in the above-mentioned processing liquid, and then the processing liquid retention rate is about 30% by weight based on the glass cloth. And then dried with hot air at 120 ° C.

The treated glass cloth was treated with a corona surface treatment device (two wire-electrode type, manufactured by Kasuga Electric Co., Ltd.) under the conditions of an imprint power of 1.5 kW, a frequency of 40 kHz and a treatment time of 1.0 second. For corona discharge treatment. Next, 85 parts by weight (solid) of brominated bisphenol A type epoxy resin E5046 (manufactured by Yuka Shell Epoxy), 15 parts by weight (solid) of cresol novolak type epoxy resin E180 (same as above), N, N′-dimethyl An epoxy resin varnish was prepared by blending 10 parts by weight of formamide, 10 parts by weight of methoxyethanol, 2.4 parts by weight of dicyandiamide, and 0.2 parts by weight of 2 ethyl 4-methylimidazole.

The treated glass cloth was impregnated with the resin varnish and dried to prepare a prepreg having a resin content of 42% by weight. The prepreg was observed under a microscope for transparency and the size of residual voids. Next, four prepregs were stacked, and a copper foil having a thickness of 18 μm was stacked on both surface layers of the prepregs.
Then, the mixture was heated and pressed at 175 ° C. under normal pressure for 60 minutes at 35 kg / cm ² to form a copper-clad laminate having a thickness of 0.8 mm. Further, the copper foil was entirely etched out with an etching solution, washed with water, and air-dried to obtain a laminate for a physical property test.

(Embodiment 2) In the corona discharge treatment of Embodiment 1, an imprinting power of 1.0 k was applied by using a corona surface treatment apparatus (two wire-electrodes type, manufactured by Kasuga Electric Co., Ltd.).
The operation was performed in the same manner as in Example 1 except that the corona discharge treatment was performed under the conditions of W, a frequency of 40 kHz, and a treatment time of 1.0 second. Example 3 In Example 1, the glass cloth subjected to the corona discharge treatment was allowed to stand in a room at a room temperature of 20 ° C. and a humidity of 60% for one month, and was evaluated in the same manner as in Example 1.

Example 4 In Example 1, as epoxy resin varnish, 35 parts by weight (solid) of bisphenol A type novolak epoxy resin E157 (manufactured by Yuka Shell Epoxy Co., Ltd.), and Hybromo type epoxy resin E5050 (same as above) ) 28 parts by weight (solid), bisphenol A type epoxy resin E828 (same as above) 6 parts by weight (solid), DPP type phenol resin YLH129 (same as above) 31 parts by weight (solid),
Except that 0.1 part by weight of 2-ethyl-4-methylimidazole and methoxyethanol were blended to prepare and use a phenol-cured epoxy resin varnish having a resin content of 67% by weight,
Evaluation was performed in the same manner as in Example 1.

Example 5 N-β- (N
-Vinylbenzylaminoethyl)-. Gamma.-aminopropyltrimethoxysilane hydrochloride (SZ6032, manufactured by Toray Dow Corning Silicone Co., Ltd.) was adjusted to a 0.5% by weight (component) aqueous solution, and acetic acid was added to adjust the pH to 4. did. A 0.19-mm-thick glass cloth (style 7628, manufactured by Asahi Schwebel KK), which has been deoiled by heat cleaning in advance, is immersed in the above-mentioned processing liquid, and the processing liquid retention rate becomes about 30% by weight with respect to the glass cloth. And then dried with hot air at 120 ° C.

The treated glass cloth was treated with a corona surface treatment device (two wire-electrode type, manufactured by Kasuga Electric Co., Ltd.) under the conditions of an imprinting power of 1.5 kW, a frequency of 40 kHz and a processing time of 1.0 second. For corona discharge treatment. Next, as a resin varnish, 50 parts by weight of Kelimide B601 (manufactured by Nippon Ciba Geigy) and 50 parts by weight of n-methylpyrrolidone were used. The resin varnish was impregnated into the treated glass cloth and dried to prepare a prepreg having a resin content of 42% by weight. The prepreg was observed under a microscope for transparency and the size of residual voids.

(Comparative Example 1) A comparative example was carried out in the same manner as in Example 1 except that the corona discharge treatment was not performed. (Comparative Example 2) A comparative example was carried out in the same manner as in Example 4 except that the corona discharge treatment was not performed. (Comparative Example 3) The same operation as in Example 5 was performed except that the corona discharge treatment was not performed, and the result was provided for comparison.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

As described above, in the present invention, by using a glass cloth whose surface is activated,
Since no resin-impregnated portion is generated during prepreg production, the effect of improving resin impregnation between filaments of glass cloth and obtaining a prepreg in which voids do not remain as much as possible between filaments of glass cloth in a laminated board can be obtained. There is.

Claims (3)

[Claims] 1. A prepreg obtained by impregnating a thermosetting resin into a glass cloth, wherein a constituent solvent of the resin varnish is a non-aqueous organic solvent, and a glass cloth whose surface is activated is used. Prepreg to do. 2. The prepreg according to claim 1, wherein the surface activation treatment is corona discharge machining. 3. The activation treatment according to claim 1, wherein the activation treatment is performed after the glass cloth is chemically treated with a surface treatment agent.
Or the prepreg according to 2.