JPH0329246B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] This invention relates to a method for producing a resin-impregnated product. [Background Art] Polyphenylene oxide has attracted attention in recent years due to its excellent high frequency properties (dielectric properties). There are various uses for polyphenylene oxide, and for example, there are uses for electronic materials. When polyphenylene oxide is used for electronic material applications, it can be particularly considered to be used for circuit boards such as printed circuit boards. Circuit boards are desired to have improved physical properties such as dimensional stability, heat resistance, and solvent resistance. Therefore, polyphenylene oxide is blended with a crosslinking agent, an initiator, etc., and the above-mentioned physical properties are improved by crosslinking. Further, physical strength has been increased by, for example, combining a glass base material with a resin.
In general, the performance required of a prepreg, which is a composite material of a base material and a resin, includes problems such as compatibility between the resin and the base material, adhesion of the resin, and voids. However, since crosslinking resin compositions containing polyphenylene oxide contain a large amount of high molecular weight resin, it is difficult to achieve a viscosity suitable for impregnation at a relatively low concentration (for example, about 15% by weight). Only solutions can be produced. When a prepreg is produced by impregnating a base material with such a solution and drying it, the amount of resin remaining is small and voids that remain after the solvent evaporates are observed. Even when such prepregs are laminated and molded, they tend to fade, making it difficult to obtain a good circuit board. For example, problems were often found in the water absorption, electrical insulation, etc. of circuit boards. [Object of the Invention] In view of the above circumstances, an object of the present invention is to provide a method for producing a resin-impregnated material that is well impregnated with a resin composition. [Disclosure of the Invention] In order to achieve the above object, the present invention impregnates a base material with a liquid in which a resin composition containing polyphenylene oxide, a resin with good crosslinking properties, a crosslinking aid, and an initiator is dissolved. In the method for producing a resin-impregnated product, the resin composition contains 30 to 30% of the crosslinking aid in 100% by weight of the total of polyphenylene oxide, a resin with good crosslinkability, a crosslinking aid, and an initiator.
The gist is a method for producing a resin-impregnated product characterized by containing 80% by weight. This invention will be explained in detail below. Examples of the crosslinking aid used in this invention include ester acrylates, epoxy acrylates, urethane acrylates, ether acrylates, melamine acrylates, alkyd acrylates, acrylates such as silicone acrylates, triallyl cyanurate,
Polyfunctional monomers such as triallyl isocyanurate, ethylene glycol dimethacrylate, divinylbenzene, diallyl phthalate, monofunctional monomers such as vinyltoluene, ethylvinylbenzene, styrene, paramethylstyrene, polyfunctional epoxies, diallyl phthalate prepolymers, etc. Each of them may be used alone or in combination of two or more, but the invention is not particularly limited to these. As a crosslinking aid, it is recommended to use either or both of triallyl cyanurate and triallyl isocyanurate because they have good compatibility with PPO and are effective in terms of impregnating the base material, crosslinking property, heat resistance, and dielectric properties. It's good because it's preferable. Triallyl cyanurate and triallyl isocyanurate are chemically structurally isomers and have almost the same impregnating properties, compatibility, solubility, reactivity, etc., so either one can be used individually. Or both can be used. Furthermore, it is preferable to use a diallyl phthalate monomer and/or a diallyl phthalate prepolymer as a crosslinking aid in terms of impregnating properties and is also advantageous in terms of cost. Furthermore, since the molding material flows very well during molding and penetrates into the base material well, it is possible to further reduce voids.
The diallyl phthalate monomer has the following formula For example, there are products such as ``Datsupu'' by Osaka Soda Co., Ltd. Although not particularly limited, diallylphthalate polymers used in this invention include:
A prepolymer having a molecular weight of about 50,000 to 60,000 or less is preferred. Note that at least one of triallyl cyanurate and triallyl isocyanurate and at least one of diallyl phthalate and diallyl phthalate polymer may be used in combination. In this invention, it is necessary that the crosslinking auxiliary agent accounts for 30% by weight or more and 80% by weight or less of the total 100% by weight of the polyphenylene oxide, the resin with good crosslinkability, the crosslinking auxiliary agent, and the initiator. If it is less than 30% by weight, voids will remain after the base material is impregnated with a solution of the resin composition and the solvent is evaporated, resulting in poor water absorption, electrical insulation, etc. of laminates, circuit boards, etc. using the resin impregnated material. A decrease in If it exceeds 80% by weight, the good dielectric properties, heat resistance, etc. of polyphenylene oxide will deteriorate. Note that the amount of the crosslinking aid is preferably 30 to 66% by weight out of the above 100% by weight. Polyphenylene oxide (also referred to as polyphenylene ether) used in this invention.Hereinafter,
``PPO'') is, for example, the following general formula: [Here, R represents hydrogen or a hydrocarbon group having 1 to 3 carbon atoms, and each R may be the same,
May be different. ] An example thereof is poly(2,6-dimethyl-1,4-phenylene oxide). Such PPO can be synthesized, for example, by the method disclosed in USP 4,059,568. For example, poly(2,6-dimethyl-1,4-phenylene oxide) is obtained by subjecting 2,6-xylenol to an oxidative coupling reaction with an oxygen-containing gas and methanol in the presence of a catalyst. , but is not limited to this method. Here, as a catalyst, a copper() compound, N,N'-di-tert
- Contains butylethylenediamine, butyldimethylamine and hydrogen bromide. Based on methanol, 2 to 15% by weight of water is added to the reaction mixture system, so that the total amount of methanol and water is 5 to 25% by weight as a polymerization solvent. For example, the weight average molecular weight (Mw) is 50000, the molecular weight distribution Mw/Mn=4.2 (Mn
(number average molecular weight) is preferably used. PPO is a resin with a low dielectric constant and low dielectric loss, so it is suitable for circuit boards used in ultra-high frequency ranges, but it may of course be used in other frequency ranges. It is also inexpensive. Examples of resins with good crosslinking properties include, but are not limited to, 1,2-polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, modified 1,2-polybutadiene (malein-modified, acrylic-modified, (epoxy-modified), rubbers, etc., and each may be used alone or in combination of two or more. Resins with good crosslinking properties and/or crosslinking aids are
By crosslinking (curing) it, it is used to improve heat resistance etc. without impairing the properties of PPO. These may be used alone or in combination, but their combined use is more effective in improving characteristics. In addition, an initiator is usually used in the resin composition. As an initiator, dicumyl peroxide, tert-butylcumyl peroxide, dicumyl peroxide,
tert-butyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-di-
(tert-butylperoxy)hexane, α,α′-
Peroxides such as bis(tert-butylperoxy-m-isopropyl)benzene [also referred to as 1,4 (or 1,3)-bis(tert-butylperoxyisopropyl)benzene], but not peroxides, As a commercially available initiator, the following formula Examples include Biscumil from NOF Co., Ltd., which is expressed by NOF Corporation, and each can be used alone or in combination of two or more, but is not limited thereto. Bisque mill has a one-minute half-life temperature of 330°C. The mixing ratio of the above raw materials is not particularly limited, but to 80 to 100 parts by weight of PPO, 20 to 40 parts by weight of a resin with good crosslinking properties, 40 to 130 parts by weight of a crosslinking aid,
Preferably, the proportion of initiator is from 0.5 to 5 parts by weight. Further, although not particularly limited, it is preferable to use a resin with good crosslinking properties in a ratio of 20 parts by weight or less per 1 part by weight of the crosslinking aid. Substrates for impregnation include, but are not particularly limited to, nonwoven or woven fabrics such as paper, glass fibers, and synthetic fibers, glass cloth, synthetic resin cloth, and paper. Glass cloth is preferable in terms of cost and performance. The method for preparing the liquid in which the resin composition is dissolved is as follows:
There are no particular limitations. For example, a resin composition containing PPO, a resin with good crosslinking properties, a crosslinking aid, and an initiator or its raw materials are placed in a solvent (solvent) at the desired blending ratio, and completely dissolved using a stirring device such as a disper. There is a way. However, the crosslinking aid should be contained in a proportion of 30 to 80% by weight out of the total 100% by weight of PPO, resin with good crosslinkability, crosslinking aid, and initiator. When considering impregnation into the base material, the viscosity of the solution is 50 to 50 when at least one of triallyl cyanurate and triallyl isocyanurate is used as a crosslinking auxiliary agent.
A range of 600 cP is preferable, and when at least one of a diallyl phthalate monomer and a diallyl phthalate polymer is used as a crosslinking aid,
A range of 600 to 1500 cP is preferable, and when at least one of triallyl cyanurate and triallyl isocyanurate and at least one of a diallyl phthalate monomer and a diallyl phthalate polymer are used together as a crosslinking auxiliary agent, a range between the above two ranges is preferable. preferable. The concentration of the resin composition is preferably 20 to 35% by weight. If the viscosity is below the lower limit of each of the above ranges, the amount of adhesion to the base material may be insufficient and the product may become blurred after molding.If the viscosity exceeds the upper limit of each of the above ranges, the amount of adhesion to the base material may be insufficient and the product may become blurry after molding. Burrs may appear. The concentration of the resin composition is
If it is less than 20% by weight, the amount adhered to the base material may decrease and whitening may occur after molding, and if it exceeds 35% by weight, the stability of the solution will deteriorate and the viscosity will increase significantly, making impregnation impossible. Sometimes. Examples of the above-mentioned solvent include halogenated hydrocarbons such as trichloroethylene, trichloroethane, chloroform, methylene chloride, tetrachloroethylene, and chlorobenzene, aromatic hydrocarbons such as benzene, toluene, and xylene, acetone, and carbon tetrachloride, and trichloroethylene is particularly preferred.
These can be used alone or in combination of two or more, but are not limited thereto. The method of impregnation is not particularly limited, such as a method of applying a liquid in which the resin composition is dissolved to the substrate, a method of immersing the substrate in a liquid in which the resin composition is dissolved, etc. The impregnation time is
About 5 to 60 seconds is preferable. After impregnation, it is best to scrape off the solution adhering to the surface (for example, with a glass rod). Thereafter, drying is performed to obtain a resin-impregnated product (prepreg). Although drying naturally varies depending on the type of solvent, it is preferable to dry at a low temperature of 50 to 60° C. for several minutes, and then dry for several minutes at a temperature higher than the boiling point of the solvent used. For example, when trichlorethylene is used as a solvent, a resin-impregnated product is obtained by drying at 50°C for 5 minutes, 90°C for 5 minutes, and 150°C for 5 minutes. When drying, it may be simply dried, or it may be semi-cured to a so-called B stage. The resin-impregnated product obtained as described above has a high resin solution concentration and a relatively low viscosity during impregnation, so the solution is sufficiently distributed into the gaps within the base material and has few voids. It is. Moreover, if the resin-impregnated material is produced as described above, the resin does not need to be melted, so it can be easily carried out at a relatively low temperature. The resin content of the resin-impregnated product is not particularly limited, but it is preferably about 30 to 60% by weight in order to prevent scratches and burrs from forming during molding. The method for molding the resin-impregnated product produced as described above is not particularly limited, but may include a method of laminating a predetermined number of sheets and pressing under pressure; A method of pressing, a method of laminating a specified number of sheets (including one sheet) in combination with a resin sheet, and pressing it under pressure, a method of laminating a specified number of sheets (including one sheet) in combination with a resin sheet, and placing metal on one or both sides of the sheet. There are various methods, such as a method of laminating metal foils and pressing them under pressure, and a method of laminating metal foils on one or both sides of a sheet and pressing them under pressure. Pressure pressing conditions are not particularly limited, but are preferably 160 to 300°C and 20 to 150 kg/cm ² , more preferably about 220°C, 100 kg/cm ² for about 30 minutes. Crosslinking is performed simultaneously with or after pressure pressing. Crosslinking is carried out by heating when the initiator used generates radicals upon heating, and by irradiation with ultraviolet rays when the initiator used generates radicals upon irradiation with ultraviolet rays. Alternatively, crosslinking may be performed by radiation irradiation. Molded products such as laminates obtained as described above contain a large amount of low molecular weight crosslinking aid in the resin component of the resin impregnated material, so the resin flows well during heat pressing, has few voids, and has good water absorption. , it has excellent electrical insulation properties. In addition, PPO provides good dielectric properties, and crosslinking improves dimensional stability, heat resistance,
The result is a laminate with excellent solvent resistance. Metal foils such as copper foils and aluminum foils are used as the conductor layers that form the circuit. It is preferable that the metal foil has a smooth adhesion surface and good conductivity in order to improve dielectric properties. Alternatively, the conductor layer may be formed by vapor deposition, etc. In addition, there are other methods such as subtractive method, additive method (full additive method, etc.).
It may be formed into a desired conductor (circuit, electrode, etc.) by a semi-destructive method, etc., and is not particularly limited. Note that the circuit board may be either a rigid board or a flexible board. Next, Examples and Comparative Examples will be described, but the present invention is not limited to the Examples. (Example 1) In the reactor equipped with a pressure reduction device in step 2, 100 g of PPO, 20 g of styrene-butadiene copolymer (Tuffrene A from Asahi Kasei Corporation), 40 g of triallyl isocyanurate (TAIC from Nippon Kasei Co., Ltd.), and diallyl phthalate were added. 40 g of Daisodap A from Osaka Soda Co., Ltd. and 4 g of dicumyl peroxide were added, followed by 500 g of trichlorethylene, and the mixture was thoroughly stirred until a homogeneous solution was obtained. Table 1 shows the resin composition concentration and viscosity of the obtained solution. Next, a glass cloth with a thickness of 100 μm was immersed in this solution for about 15 seconds, then taken out, and the surface was scraped with a bar coater. This was heated to 50°C for 5 minutes at 90°C.
Dry at ℃ for 5 minutes and 150℃ for 5 minutes.
I got 5 pieces of prepreg. Next, 18 μm thick copper foil, the prepreg 5
220℃, 100Kg/18μm copper foil
A laminate was obtained by pressing for 30 minutes at ^cm2 . The physical properties of this laminate are shown in Table 1. (Examples 2 to 8) A laminate was obtained in the same manner as in Example 1, except that the formulation of the resin composition and the amount of solvent were changed as shown in Table 1. Table 1 shows the physical properties of each impregnating liquid and each laminate. The diallyl phthalate polymer used in Example 6 had a molecular weight of about 5,000 to 10,000.

【table】

[Table] Weight of crosslinking aid

*=

Claims (1)

[Scope of Claims] 1. A method for producing a resin-impregnated product comprising a step of impregnating a base material with a solution in which a resin composition containing polyphenylene oxide, a resin with good crosslinking properties, a crosslinking aid, and an initiator is dissolved. , wherein the resin composition contains 30 to 80% by weight of a crosslinking auxiliary agent out of a total of 100% by weight of polyphenylene oxide, a resin with good crosslinkability, a crosslinking auxiliary agent, and an initiator. Manufacturing method. 2 The crosslinking aid is ester acrylates, epoxy acrylates, urethane acrylates,
Ether acrylates, melamine acrylates, alkyd acrylates, silicone acrylates, triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, divinylbenzene, diallyl phthalate, vinyltoluene, ethylvinylbenzene, styrene, paramethylstyrene, The method for producing a resin-impregnated product according to claim 1, which is at least one selected from the group consisting of polyfunctional epoxies and diallyl phthalate prepolymers. 3. A patent claim in which the resin with good crosslinking properties is at least one selected from the group consisting of 1,2-polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, modified 1,2-polybutadiene, and rubbers. A method for producing a resin-impregnated product according to item 1 or 2. 4 The resin composition contains polyphenylene oxide.
80 to 100 parts by weight, 20 to 40 parts by weight of a resin with good crosslinking properties, 40 to 130 parts by weight of a crosslinking aid, and 0.5 to 5 parts by weight of an initiator.
Claim 1 containing each in the proportion of parts by weight
A method for producing a resin-impregnated product according to any one of Items 1 to 3.