JPH0473990A - Laminated board for electrical use - Google Patents

Abstract

PURPOSE:To obtain a laminated board for electrical use having excellent water resistance and punching workability by previously immersing a base material made of cellulose fiber with allyl alcohol modified melamine resin and drying it. CONSTITUTION:Kraft sheet is immersed with solution in which allyl alcohol modified melamine resin solution is diluted with aqueous methanol solution, squeezed by a roller, dried, and obtained sheet base material is adhered with allyl alcohol modified melamine resin. This material is floated on mixture solution of allyl ester resin composition, immersed with the resin solution from one side surface, seven materials are superposed, a copper foil with adhesive is further superposed on one side surface, both side surfaces are laminated with polyester films, heated, pressure molded by a press, and heated after pressing to obtain a copper foil-plated laminated board.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrical laminate for forming printed circuits used in electrical equipment, electronic equipment, communication equipment, etc.

[Conventional technology]

Various types of electrical laminates for forming printed circuits have been put into practical use. For those whose main component is cellulose fiber, a laminate is generally constructed of phenolic resin and paper, or unsaturated polyester resin and paper, and metal foil is laminated on one or both sides of this laminate. Regarding electrical laminates made of allyl ester resin and cellulose fibers, for example, Japanese Patent Application No. 1-25
No. 5038.

[Problem to be solved by the invention]

When manufacturing electrical laminates that are mainly composed of allyl ester resin and cellulose fibers, if cellulose fibers are used as they are, the resulting laminates have high water absorption, which may cause a decrease in electrical properties due to moisture absorption, or hardened allyl Mechanical strength and heat resistance are often unstable due to insufficient bonding strength between ester resin and cellulose fiber.

In order to improve these drawbacks, a method has been proposed in which cellulose fibers are pre-impregnated with melamine resin and dried and then used to manufacture laminates, but although this improves the water resistance of the laminates, it is still difficult to punch. Impact resistance performance such as workability deteriorates, and it is difficult to obtain a well-balanced laminate with excellent water resistance and punching workability, which is currently a major problem.

An object of the present invention is to provide an electrical laminate having both high water resistance and excellent punching workability.

[Means to solve the problem]

As a result of efforts to achieve these objectives, the present inventor has developed a metal foil-clad laminate consisting of an allyl ester resin, a base material mainly composed of cellulose fibers, and metal foil, in which the base material made of cellulose fibers is replaced with an allyl alcohol-modified melamine resin. The present invention has been completed based on the discovery that an electrical laminate with excellent water resistance and punching workability can be produced by pre-impregnating and drying the material.

Hereinafter, the content of the present invention will be explained in detail.

The allyl alcohol-modified melamine resin referred to in the present invention is
Refers to a product in which part or all of the methylol groups of an initial condensate of melamine or guanamines and formaldehyde are etherified with allyl alcohol. The amount of pormaldehyde to be reacted with melamine or guanamines can be selected appropriately, but usually melamine or guanamines 1
2.0 to 3.5 moles per mole is preferred.

There is no problem even if a part of the methylol group of the initial condensate of melamine or guanamines and formaldehyde is etherified with allyl alcohol and a lower alcohol having 5 or less carbon atoms other than allyl alcohol. Also,
There is no problem in using the allyl alcohol remaining as an unreacted product when producing the allyl alcohol-modified melamine resin together with the allyl alcohol-modified melamine resin.

The allyl alcohol-modified melamine resin can be impregnated into a cellulose fiber base material in the form of a solution or suspension using a single or mixed solvent such as water, alcohols, ketones, etc.

Examples of the base material containing cellulose fiber as a main component in the present invention include kraft paper, linter paper, cotton paper, etc., and from the viewpoint of impregnability and quality, the density when air-dried is 0.3.
-0.7 g/am3, such as kraft paper, is preferred.

The impregnating and drying treatment of these base materials is carried out by impregnating the cellulose fiber base material with the allyl alcohol-modified melamine resin and then drying it. The base material after impregnating and drying includes the base material 10 before impregnating and drying.
It is preferable to add 5 to 40 parts by weight, preferably 10 to 30 parts by weight of allyl alcohol-modified melamine resin to 0 parts by weight. If it is less than 5 parts by weight, the water resistance is insufficient, and if it exceeds 40 parts by weight, the punching workability is rather deteriorated.

The allyl ester resin as used in the present invention refers to a resin having an allyl ester group at the end of a saturated polyester composed of a saturated polybasic acid and a saturated polyhydric alcohol.

Examples of saturated polybasic acids include dibasic acids such as orthophthalic acid, orthophthalic anhydride, isophthalic acid, hepthalic acids such as terephthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, and methylendomethylenetetrahydro. phthalic acid,
Hexahydrophthalic acid, methyl hexahydrophthalic acid,
and hydrophthalic acids such as their acid anhydrides, aliphatic dibasic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, tetrabromophthalic acid, tetrachlorophthalic acid, chlorendic acid, and acid anhydrides thereof, etc. Examples include halogenated dibasic acids. Examples of trifunctional or higher-functional polybasic acids include trimellitic acid, pyromellitic acid, and acid anhydrides thereof. These can be used alone or in combination.

As the saturated polyhydric alcohol, ethylene glyconyl, 1
, 2-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexane dimethatol, baraxylene glycol, and other aliphatic, alicyclic or aromatic compounds. In addition to the dihydric alcohol containing, the general formula HO (CHRCH, O),
, H (R is H or CsH*s*+ s m is an integer of 1 to 5, n is an integer of 2 to 10), ethylene oxide, ethylene oxide, which is obtained by the addition reaction of alkylene oxides such as brobylene oxide, etc. Alcohols of high valence can be mentioned. Examples of the trihydric or higher polyhydric alcohol include aliphatic trihydric alcohols such as glycerin and trimethylolpropane, and tetrahydric or higher alcohols such as pentaerythritol and sorbitol. Further examples include aliphatic, alicyclic or aromatic halogenated polyhydric alcohols containing a halogen atom such as dibromneopentyl glycol and tetrabromobisphenol A ethylene oxide adduct. These can be used alone or in combination.

The method for producing allyl ester resins is already known and is described, for example, in Japanese Patent Application No. 6:3-262217. For example, an allyl ester resin is produced by charging a diallyl ester of a saturated dibasic acid such as diallyl terephthalate and a saturated polyhydric alcohol together with a transesterification catalyst into a reactor and reacting the allyl alcohol while distilling off the allyl alcohol. As an industrially more effective method, instead of diallyl terephthalate, a dialkyl ester of a saturated dibasic acid such as dimethyl terephthalate is charged into a reactor together with allyl alcohol, a polyhydric alcohol, and a transesterification catalyst, and a cleavable alcohol such as methanol is used. It can be obtained by reacting while distilling off.

Further, depending on the reaction temperature, a polymerization inhibitor such as hydroquinone may be allowed to coexist in the reaction solution. In this way, an allyl ester resin having an allyl ester group at the end of a saturated polyester can be produced.

In the present invention, the type of allyl ester resin that is impregnated into the base material that has been previously impregnated and dried with the allyl alcohol-modified melamine resin may be one type or a mixture of two or more types. By selecting various types of saturated polybasic acid and saturated polyhydric alcohol, it is possible to obtain an electrical laminate that meets the desired performance.

In the present invention, in addition to the allyl ester resin, the base material that has been pre-impregnated and dried with allyl alcohol-modified melamine resin may optionally contain a radically polymerizable crosslinking monomer or an additive flame-retardant compound containing bromine, chlorine, or phosphorus. It is also possible to impregnate and mold using a combination of inorganic flame retardants and the like.

Any known radically polymerizable crosslinking monomer can be used, but examples include diallyl phthalates such as diallyl orthophthalate, diallyl isophthalate, and diallyl terephthalate; styrene, α
- Methylstyrene, p-methylstyrene, p-chlorostyrene, bromstyrene, divinylbenzene, substituted styrenes: methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylate Acrylic acid or methacrylic esters such as 2-ethylhexyl acrylate, lauryl (meth)acrylate, benzyl (meth)acrylate, brominated phenyl (meth)acrylate; ethylene glycol di(meth)acrylate, 1 ,4-butanediol di(
meth)acrylate, trimethylolpropane tri(meth)acrylate, diacrylated incyanurate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerin di(meth)acrylate, neopentyl glycol di(meth)acrylate , bisphenol A di(meth)
Vinyl polyfunctional acrylic acid or methacrylic acid esters such as acrylate; polyurethane (meth)acrylate, polyether (meth)acrylate, epichlorohydrin-modified bisphenol A di(meth)acrylate,
Vinyl polyfunctional oligoesters such as ethylene oxide-modified bisphenol A di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate are included.

There is no problem in using two or more types of crosslinking monomers in combination depending on the purpose. In the present invention, by blending a crosslinking monomer, the viscosity of the allyl ester resin, which is originally a solid or viscous liquid, can be lowered, and a laminate can be manufactured without using a prepreg state using a solvent or the like. It is also possible to simplify the process.

Additive flame retardant compounds containing bromine, chlorine, or phosphorus include one or more bromine atoms, chlorine atoms,
Or, it refers to a compound having a phosphorus atom, and is an additive type aliphatic compound that does not undergo radical polymerization. Refers to alicyclic and aromatic hydrocarbon compounds.

For example, substituted benzenes such as monobromobenzene, dibromohensen, triflomobenzene, and bromochlorobenzene, substituted phenols such as bromophenol, dibromophenol, tribromophenol, and pentabromophenol, tetrabrom diphenyl ether, pentabrom diphenyl ether, Substituted diphenyl ethers such as hexabrom diphenyl ether, octabrom diphenyl ether, decabrom diphenyl ether, tetrabromo bisphenol A1, ethylene oxide adduct of tetrabromo bisphenol A, tetrachlorobisphenol A, brominated ethoxy compounds, ethyl bromide, propyl bromide, butyl Bromide, amyl bromide, hexyl bromide, octyl bromide, lauryl bromide, dibromopropane, dibromodecane, tetrabromomethane, tetrabromobutane, hexabromodicrotodecane, dibromoneopentyl glycol, bromobrovar/-ol, ebifuromohitrin, bromobromide Toluene, pentafluoromotoluene, bromoxylene, bromonaphthalene, chlorinated rough in, chlorinated polyethylene, chlorinated polypropylene, perchloropentaciflotican, chlorendic acid, tetrachlorophthalic anhydride, tetrachlorophthalic anhydride, bromine polystyrene, polydibromophenyl oxide, trimethyl phosphate,
triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate,
Examples include, but are not limited to, tricresyl phosphate, tris(chlorethyl) phosphate, tris(dichloropropyl) phosphate, cresyl diphenyl phosphate, triphenyl phosphite, and the like.

These can be used alone or in combination.

As the inorganic flame retardant, for example, antimony compounds such as antimony dioxide and antimony pentoxide, zinc borate, aluminum hydroxide, etc. can be used in combination.

In the present invention, the allyl ester resin can be cured using a general-purpose organic peroxide.
Known polymerization initiators such as polymerization initiators sensitive to electron beams can also be used.

Examples of organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide, 1.1-bis(t-butylperoxy)3.3.5-)limethylcyclohexane, n-
baroxyketals such as butyl-4,4-bis(t-butylperoxy)valerate, hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, -t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2゜5-di(t-butylperoxy), dialkyl peroxides such as beef san, lauroyl peroxide, hensyl peroxide, etc. Diacyl peroxides, peroxycarbonates such as di-1so-propyl peroxydicarbonate, cimilistyl peroxydicarbonate, bis(4-t-butylcyclohexyl)baroxydicarbonate, t-butylperoxydicarbonate, etc. Examples include peroxy esters such as oxypyhalate, t-butylperoxy-2-ethylhexanoate, and t-butylperoxybenzoate. These can be one type or a mixture of two or more types,
It can be used depending on the type of resin and curing conditions.

In the present invention, it is also possible to further enhance the performance of the laminate by using fillers, reinforcing materials, mold release agents, coloring agents, curing agents, accelerators, stabilizers, etc. in combination with the allyl ester resin as necessary. .

The electrical laminate of the present invention can be manufactured according to a known method. That is, a base material that has been previously impregnated and dried with an allyl alcohol-modified melamine resin is impregnated with the allyl ester resin, a plurality of impregnated base materials are laminated, and one or both sides of the metal foil are coated with an adhesive in advance, or are not coated. An electrical laminate can be produced by stacking them, heating, curing, and molding them without pressure or under pressure. At this time, the metal foil may be attached after the impregnated laminated base material is cured and molded.

As the metal foil, electrolytic steel foil intended for use in copper foil-clad laminates for electric circuits is commercially available.
It is preferable from the viewpoint of corrosion resistance, etching property, and adhesive property, but
The present invention is not limited to this. The thickness of the metal foil is preferably about 10 to 100 μm.

In order to effectively achieve adhesion between the metal foil and the resin-impregnated base material, it is preferable to use an adhesive, which is a liquid or semi-liquid adhesive that does not generate unnecessary side reaction products during the curing process. It is preferable that the shape is as follows. From this point of view, acrylate adhesives, epoxy adhesives, epoxy acrylate adhesives, incyanate adhesives, or modified adhesives of each type thereof are used.

The thickness of the electrical laminate of the present invention varies depending on the type of base material, the composition of the cured compound resin liquid, and the use of the laminate, but usually,
It is 0.5 to 5 mm. Further, the proportion of the resin composition in the electrical laminate is 30 to 8 Qwt%.

Thus, the electrical laminate i;t obtained according to the present invention
-tr Since the loose fiber base material is pre-impregnated and dried with allyl alcohol-modified melamine resin, the
/Alcohol-modified allyl group imparts flexibility to melamine resin and improves punching workability. Furthermore, because the affinity or reactivity between allyl groups and allyl ester resin is improved by allyl alcohol modification, the bonding strength between the cellulose fiber base material and the cured allyl ester resin is further increased, resulting in good water resistance and stable Mechanical strength is achieved.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples unless it departs from the gist of the present invention. Throughout this specification, all temperatures are in degrees Celsius, and parts and percentages are by weight unless otherwise specified.

〔Example〕

Production Example 1 Production of allyl ester resin (1) Diallyl terephthalate 600 was added to an IQ reactor equipped with a distillation device.
g (2,44moQ), propylene glycol 9
5.9 g (1,26 mod) and 01 g of dibutyltin oxide were charged and heated to 180° C. under a nitrogen stream to distill off the allyl alcohol produced. When 140g (2,41s+o) of allyl alcohol was distilled out,
The pressure inside the reactor was reduced to 50 mHg to accelerate the distillation rate. After allyl alcohol equivalent to propylene glycol was distilled off, unreacted diallyl terephthalate was distilled off at 1 miHg while maintaining the reaction solution at 200° C. using a thin film distiller. Pour the reaction solution into a tray, cool it,
It was pulverized to obtain a powdery allyl ester resin (1).

Production Example 2 Production of allyl ester resin (2) containing bromine Except for the conditions shown in Table 1, allyl ester resin (1
) to obtain a bromine-containing allyl ester resin (2).

Table 1 DATP raw material for allyl ester resin production
Nidialyl terephthalate DBNPG = dibromneopentyl glycol *l Halogen content in product resin ゛Production Example 3 Production of allyl alcohol-modified melamine resin solution (1) 126 g of melamine (1,00 moff,
), 37% formalin 276g (formaldehyde 3
゜4 mo(1), allyl alcohol 197g (3
,4m.

After reacting at 80°C under reflux for about 3 hours, cooling to room temperature, 250g of methanol (7°81oQ
) to obtain an allyl alcohol-modified melamine resin solution (1) with a solid content concentration of 27%.

Production example 4 Allyl alcohol modified melamine resin solution (2
) The solution of allyl alcohol-modified melamine resin (1) obtained in the same manner as in Production Example 3 was neutralized with sodium carbonate to pH 10, concentrated under reduced pressure of 20 mmHg to remove unreacted allyl alcohol, It was diluted with a 50% aqueous methanol solution to obtain an allyl alcohol-modified melamine resin solution (2) with a solid content concentration of 27%.

Example 1 50% allyl alcohol modified melamine resin bath M(1)
The mixture was diluted with an aqueous methanol solution to give a solid content concentration of 15%, and kraft paper with a tsubo jl of 155 g/m' and a thickness of 300 utr was soaked, squeezed with a roller, and dried to a thickness of 120'C13C1. 15 parts by weight of allyl alcohol-modified melamine resin was attached to the obtained paper base material.

This paper base material was floated in a blended solution of the resin composition shown in Table 2, impregnated with the resin liquid from one side, and the seven sheets were stacked, and one side was coated with copper foil (MK-61 manufactured by Mitsui Mining and Mining Co., Ltd.). After superimposing them and laminating a 50 μm polyester film on both sides, they were heated and pressure-molded using a press machine.

Heating and pressing conditions were 150℃, 5 minutes, 30 kg/am''
Met. After pressing, dry in hot air drying oven at 150'C52
Heating was carried out for a period of time to obtain a copper foil-clad laminate having a thickness of 1.6+am. The test results of the copper foil clad laminate are shown in Table 3.

Example 2 A laminate was produced in the same manner as in Example 1, except that allyl alcohol-modified melamine resin solution (2) was used instead of allyl alcohol-modified melamine resin bath 1 (1). The test results are shown in Table 3.

Comparative Example 1 Melamine resin (Nikaregin S-30 manufactured by Nippon Carbide Co., Ltd.)
5) in a 50% aqueous methanol solution to give a solid content concentration of 1.
5%, a basis weight of 155 g/'n+'' and a thickness of 300 μm was soaked and squeezed with a roller to produce a laminate in the same manner as in Example 1. The test results are shown in Table 3.

Comparative Example 2 A laminate was produced in the same manner as in Example 1 without impregnating and drying with an allyl alcohol-modified melamine resin. The test results are shown in Table 3.

As is clear from the results of Examples and Comparative Examples in Table 3, by pre-impregnating and drying cellulose fibers with allyl alcohol-modified melamine resin, electrical laminates with excellent water resistance and punching workability can be manufactured. It turns out that you can do it.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to obtain an allyl ester resin-based electrical laminate having high water resistance and excellent punching workability.

Claims (1)

[Claims] In a laminate consisting of an allyl ester resin, a base material mainly composed of cellulose fibers, and metal foil, the cellulose fibers that have been pre-impregnated and dried with an allyl alcohol-modified melamine resin are used as the cellulose fibers constituting the base material. An electrical laminate featuring: