JPH0564992B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for impregnating an inorganic particle-dispersed resin. More specifically, the present invention is directed to impregnation with a resin solution in which inorganic particles are dispersed, which is useful for impregnating base materials such as laminates, enables uniform impregnation, and improves prepreg properties. It is about the method. (Prior art) In order to improve the performance of laminates, such as their insulation properties, dielectric properties, and strength, it has been widely practiced to impregnate a base material with a resin solution containing dispersed inorganic particles. There is. In this impregnation process, particles of inorganic substances such as silica, alumina, and magnesia are dispersed in resins such as epoxy resins, polyesters, phenolic resins, polyamides, and polyimides, and are impregnated into base materials such as glass cloth, glass sheets, glass mats, and paper. has been adopted as a general method. (Problems to be Solved by the Invention) However, in this conventional resin solution impregnation method, the inorganic particles dispersed in the solution result in non-uniform impregnation of the base material and also affect the performance of the base material. This issue remained unresolved due to its significant impact. In particular, when inorganic particles that affect the properties of the laminate are impregnated together with a resin, the influence of such non-uniform impregnation cannot be ignored. Such non-uniformity of impregnation is due to the size of the inorganic particles as determined by the inventors of the present invention.If the particle size is large, they will settle during the impregnation process, and the particles will settle at the beginning of the impregnation process. The content of inorganic particles in the resin solution differs greatly between the end and the end. On the other hand, if the particle size is too small, the physical properties of the inorganic particles and, by extension, the impregnated base material cannot be achieved as required, leading to increased costs associated with pulverization of the particles. Therefore, it has been desired to realize an appropriate impregnation method that can uniformly impregnate inorganic particle-dispersed resin and contribute to improving the performance of the base material or laminate. (Means for Solving the Problems) This invention was made in view of the above circumstances, and improves the drawbacks of the conventional resin impregnation method, and provides an impregnation treatment for a resin solution in which inorganic particles are dispersed. , the aim is to provide an improved method that allows uniform impregnation of these inorganic particles. Therefore, this invention has an average particle size of 2 μm or less,
The feature is that the base material is impregnated with a dielectric dispersed resin solution in which metal composite oxide dielectric powder with a maximum particle size of 7 μm or less is dispersed in a mixed resin solution of polyphenylene oxide, crosslinkable polymer, and monomer. It is said that Furthermore, the impregnation method of the present invention is particularly suitable for manufacturing laminates with high dielectric properties. In order to prevent the metal composite oxide dielectric particles from settling in the above resin solution, the average particle size of the particles must be 2 μm.
m or less, and the maximum particle size must be 7 μm or less. Although the smaller the particle size, the better the stability, it is not advantageous to make the particle size too small in terms of physical properties of the impregnated base material, particle physical properties, pulverization cost, etc. Since the precipitation of metal composite oxide dielectric particles is also related to the viscosity of the resin solution, it is preferable to adjust this viscosity appropriately. Generally, the higher the viscosity, the better; however, if the viscosity is too large, the permeation rate during impregnation will be slow, and sufficient impregnation will not be achieved before drying. When glass cloth is used as the base material, it is preferable to have a viscosity of about 100 to 700 csp. If it is less than 100 csp, the amount of resin adhering to the base material will be small, and the metal composite oxide dielectric particles will also settle quickly. In addition, the stability of metal composite oxide dielectric particles in solution is also related to the specific gravity of the particles and the specific gravity of the solution.
In this case, it is sufficient to have the particle size within the above range. As mentioned above, the impregnation method of the present invention is used to impregnate a resin solution in which metal composite oxide dielectric powder is dispersed in a mixed solution of polyphenylene oxide (PPO), a crosslinkable polymer, and a monomer. be. Examples of metal composite oxide derivative powders include metal titanate ceramics such as barium titanate, lead titanate, calcium titanate, magnesium titanate, and bismuth titanate, lead zirconate, and zirconate. Zirconate metal ceramics such as barium type, K ₂ O−PbO
−Lead composite oxide ceramics such as SiO ₂ type, Baf _0.5
Neodymium composite oxide ceramics such as Pb _0.5 Nd ₂ Ti ₅ O 14 series, BaNd ₂ Ti ₅ O ₁₄ series, or Ba(Zn _1/2
Examples include powders of niobium composite oxide ceramics such as Nb _2/3 ) O ₃ series, or mixed powders of two or more of these. These inorganic particles provide an impregnated base material with excellent dielectric properties and a laminate using the same. For example, polyphenylene oxide has the following chemical formula (1) (R represents hydrogen or a hydrocarbon group having 1 to 3 carbon atoms, and each R may be the same or different.) One example is poly(2,6-dimethyl -1,4-phenylene oxide). Examples of crosslinkable polymers include 1,2-
Examples include polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, modified 1,2-polybutadiene (malein-modified, acrylic-modified, epoxy-modified), rubbers, etc., and each can be used alone or in combination of two or more. .
These polymers may be in the form of elastomers or rubbers. Examples of crosslinking monomers include acrylates such as ester acrylates, epoxy acrylates, urethane acrylates, ether acrylates, melamine acrylates, alkyd acrylates, and silicone acrylates, triallyl cyanurate, and triallyl isocyanurate. , polyfunctional monomers such as ethylene glycol dimethacrylate, divinylbenzene, diallyl phthalate, monofunctional monomers such as vinyltoluene, ethylvinylbenzene, styrene, paramethylstyrene, and polyfunctional epoxies. Two or more can be used together. Among these, triallyl cyanurate and/or triallyl isocyanurate are preferred because they have good compatibility with polyphenylene oxide and improve film-forming properties, crosslinking properties, heat resistance, and dielectric properties. Triallyl cyanurate and triallyl isocyanurate are chemically structurally isomers and have almost the same film-forming properties, compatibility, solubility, reactivity, etc., and either one or Both can be used equally. An initiator can further be used when the polyphenylene oxide is made to contain the crosslinkable polymer, monomer, and metal composite oxide dielectric as described above. An appropriate initiator can be selected depending on whether the polyphenylene oxide resin composition is of an ultraviolet curing type or a thermosetting type. In the method of the present invention in which metal composite oxide dielectric particles are dispersed in a polyphenylene oxide resin solution for impregnation, the resin composition is usually dissolved in a solvent, dispersed, and mixed. In this case, an appropriate solvent can be used, such as halogenated hydrocarbons such as trichloroethylene, trichloroethane, chloroform, methylene chloride, and chlorobenzene, aromatic hydrocarbons such as benzene, toluene, and xylene, acetone, Carbon chloride and the like can be used, with trichlorethylene being particularly preferred. These can be used alone or in combination of two or more. As a method for impregnating a base material with a mixed resin solution in which metal composite oxide-based dielectric particles are dispersed, any suitable method including conventionally known methods can be employed. Generally, for example,
A resin composition including metal composite oxide-based dielectric particles is dispersed in a solvent, and a substrate is impregnated and adhered by dipping (dipping) in the solvent solution. Then, the solvent can be removed by drying or the like, or it can be semi-cured to bring it to the B stage. As the base material, resin-impregnated cloth materials such as glass cloth, aramid cloth, polyester cloth, and nylon cloth and/or fibrous materials such as nonwoven fabrics, paper such as kraft paper and linter paper, etc. can be used. It is not limited to. If the prepreg is produced in this way, it is not necessary to melt the resin, so it can be easily carried out at a relatively low temperature. A base material impregnated with resin and metal composite oxide-based dielectric particles can be laminated and integrated with a metal foil, for example, by a conventional method to form a laminate for a printed wiring board. (Function) The average particle size of the metal composite oxide dielectric particles is
By setting the particle size to 2 μm or less and the maximum particle size to 7 μm or less, the mixed resin solution of polyphenylene oxide, crosslinkable polymer, and monomer containing these particles can suppress the sedimentation of metal composite oxide dielectric particles. This enables uniform impregnation of the substrate. Metal composite oxide dielectric particles mixed into a resin solution for heat dissipation, dimensional stability, dielectric properties, etc. are stably and uniformly impregnated with the resin. This method makes it possible to obtain a resin-impregnated base material with high dielectric properties. Hereinafter, examples of the present invention will be shown and the present invention will be explained in more detail. Example 1 100g of polyphenylene oxide (PPO), 30g of styrene-butadiene copolymer (Asahi Kasei Corporation: Solprene T406),
Triallylisocyanurate (Nippon Kasei Co., Ltd.:
TAIC) 40g, 2,5-dimethyl-2,5-di-
2 g of (tert-butylperoxy)hexine-3 (Nippon Oil & Fats Co., Ltd.: Perhexine 25B) was added, followed by 750 g of trichlorethylene (Toagosei Chemical Co., Ltd.: Trichlene) and stirred thoroughly until a homogeneous solution was obtained. . After this, 150 g of barium titanate (BaTiO ₃ ) ceramic powder with an average particle size of 1 to 2 μm was prepared.
was added and stirred using a ball mill for about 24 hours to uniformly disperse the mixture. After that, defoaming is performed and the obtained PPO
A glass cloth (100 g/m ² ) was immersed in the resin composition, then taken out and heated at 50°C.
The prepreg was dried at 130°C for about 10 minutes and at 130°C for about 20 minutes. The four prepregs obtained were laminated,
A laminate was obtained by molding at 195° C. and 10 Kg/cm ² using a molding press. As shown in Table 1, the resin solution has excellent stability;
Uniform impregnation was achieved without particles settling. Examples 2 to 12 Impregnation was carried out in the same manner as in Example 1 using the formulations shown in Table 1. Examples 5, 7, and 8 used a mixture of two or more types of composite oxides. The resin solution was stable in both cases. Example 13 40 g of PPO and styrene-butadiene copolymer were placed in 800 g of trichlorethylene (Toagosei Kagaku Kogyo Co., Ltd.: Trichlene) in a 21 reactor equipped with a pressure reduction device.
40g, triallyl isocyanurate 120g, 2,
6 g of 5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3 (Nippon Oil Co., Ltd.: Perhexin 25B) was added and thoroughly stirred until a homogeneous solution was obtained. Next, 130 g of barium titanate (BaTiO ₃ ) ceramic powder was added and further stirred to uniformly disperse and defoam. A glass cloth (100 g/m ² ) was immersed in the resulting PPO resin composition to be impregnated with this solution, taken out, and dried at 50°C for about 10 minutes and at 130°C for about 20 minutes to obtain a prepreg. . Four sheets of the obtained prepreg were laminated and molded using a molding press at 195° C. and 10 kg/cm ² to obtain a laminate. Examples 14-25 Laminated plates were produced in the same manner as in Example 13 using the formulations shown in Table 1. Impregnation was uniform. Example 26 After immersing a glass cloth in the PPO resin composition solution of Example 1 for a while, it was taken out from the solution and dried at 50°C for about 10 minutes and at 130°C for about 20 minutes to completely remove the trichlorethylene. remove it
A glass cloth (prepreg) impregnated with a PPO resin composition was obtained. Two sheets of this prepreg and three sheets of Example 6 were laminated in this order: sheet and prepreg, and heat-pressed under the conditions of Example 1 to produce a laminate.

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[Table] Comparative Example 1 140 g of PPO, 40 g of styrene-butadiene copolymer (Asahi Kasei Corporation: Solprene T406), 40 g of triallyl isocyanurate (TATIC, Nippon Kasei Corporation), and dicumyl peroxide were placed in a 31 reactor equipped with a pressure reduction device. Then, 850 g of trichlorethylene (Toagosei Kagaku Kogyo Co., Ltd.: Trichlene) was added, and the mixture was thoroughly stirred until a homogeneous solution was obtained. After this,
Aluminum oxide powder with an average particle size of 5 to 6 μm (Sumitomo Aluminum Smelting Co., Ltd.: Aluminum oxide AM-
21) 280g was added and further stirred to uniformly disperse. Thereafter, defoaming was performed, and the resulting PPO-based resin composition solution was used for impregnation in the same manner as in Example 1 to produce a laminate. As shown in Table 2, the inorganic aluminum oxide powder precipitated and was not uniformly impregnated. Also, the appearance of the prepreg was not very good due to this non-uniformity. Comparative Examples 2 to 5 Laminated plates were produced in the same manner as in Example 1 using the formulations shown in Table 2. The solution was unstable. The content of the PPO resin composition in each of the above prepregs was 30 to 80% by weight. In all cases of impregnation with the resin solution of this invention, the solution was stable, there was no sedimentation of particles, and uniform impregnation was performed. The metal composite oxide dielectrics, aluminum oxide, and titanium dioxide powders of Examples 1 to 26 and Comparative Examples 1 to 5 were obtained by firing under the conditions shown in Table 3, respectively. The average particle size, particle size distribution, and type of each powder are also shown in Table 3.

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[Table] (Effects of the Invention) As explained in detail above, the present invention provides a stable and uniform solution of a mixed resin solution of polyphenylene oxide containing metal composite oxide dielectric particles, a crosslinkable polymer, and a monomer. It is possible to impregnate various base materials. Effective impregnation of metal composite oxide dielectric particles without sedimentation is achieved. A resin-impregnated base material with excellent dielectric properties can be obtained.

Claims (1)

[Claims] 1. A metal composite oxide dielectric powder having an average particle size of 2 μm or less and a maximum particle size of 7 μm or less is dispersed in a mixed resin solution of polyphenylene oxide, a crosslinkable polymer, and a monomer. A method for impregnating an inorganic particle-dispersed resin, the method comprising impregnating a base material with a dielectric-dispersed resin solution. 2. The metal composite oxide dielectric powder is a metal titanate ceramic, a metal zirconate ceramic,
2. The method for impregnating an inorganic particle-dispersed resin according to claim 1, wherein the impregnation method is a powder of lead composite oxide ceramic, neodymium composite oxide ceramic, or niobium composite oxide ceramic, or a mixed powder of two or more of these.