JPH05309800A - Laminated sheet - Google Patents

Abstract

PURPOSE:To enhance various durabilities and punching processability by using a drying oil modified phenol resin compounded with an unsaturated polyester resin as the resin of a surface layer and using a drying oil modified phenol resin compounded with a melamine resin as the resin of an inner layer. CONSTITUTION:A drying oil modified phenol resin compounded with an unsaturated polyester resin is used as the resin of the surface layer of a laminated sheet and a drying oil modified phenol resin compounded with a melamine resin is used as the resin of the inner layer of the laminated sheet. As drying oil, for example, tung oil or the like is used. As phenols, for example, phenol or the like is used and, as the melamine resin, a reaction product of melamine and formaldehyde is used. At the time of production, a drying oil modified phenol resin is formed into varnish using a solvent and this varnish is infiltrated in the base materials of a drying oil modified phenol resin laminated sheet and the impregnated base materials are molded to form the laminated sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated board having excellent tracking resistance, punching workability and flame retardancy.

[0002]

BACKGROUND OF THE INVENTION Phenolic resins are synthesized by the addition condensation reaction of phenols and formaldehyde. For the laminated plate, a resol type synthesized by an alkali catalyst is used. Phenol resin alone is hard and has no plasticity, so the phenol resin is modified to balance various properties such as punching workability, mechanical strength, heat resistance, flame retardancy, and electrical properties. In order to improve tracking resistance, aluminum hydroxide is added or unsaturated polyester is blended to give flexibility, and modified with a drying oil such as tung oil to improve punching workability and mechanical strength. However, a phosphate ester external plasticizer is added.

[0003]

When the phenol resin is modified with tung oil, unsaturated polyester resin or the like, a large amount of addition is required to satisfy the tracking resistance and punching workability, and flame retardancy and moisture resistance are required. Lower.
The addition of aluminum hydroxide improves the tracking resistance but decreases the heat resistance. The addition of an external plasticizer such as a phosphoric acid ester improves punching workability and flame retardancy, but requires a large amount of plasticizer and reduces heat resistance and moisture resistance. The present invention provides tracking resistance, punching workability,
It is intended to provide a laminate having excellent flame retardancy.

[0004]

According to the present invention, a resin for a surface layer is a dry oil-modified phenol resin containing an unsaturated polyester resin, and a resin for an inner layer is a dry oil-modified phenol resin containing a melamine resin. It is a resin.
The thickness of the surface layer is 1/20 to 1/3, preferably 1/8 to 1/4 of the total thickness.

As the drying oil, tung oil, linseed oil, dehydrated castor oil, and deer oil are used, and as the phenols, phenol, metacresol, paracresol, orthocresol, isobroth, etc. Bill Feno
, Para-tert-butylphenol, oligomers of paraisopropenylphenol, oligomers of nonylphenol, nonylphenol, pisphenol A and the like are used.

The unsaturated polyester resin is blended in an amount of 3 to 20 parts by weight based on 100 parts by weight of the drying oil-modified phenolic resin. If it is 20 parts by weight or more, the moisture resistance, flame retardancy and the like are deteriorated, and if it is 3 parts by weight or less, there is no effect.

As the melamine resin used for the inner layer, a reaction product of melamine, benzoguanamine and the like with formaldehyde and the like is used. The melamine resin is mixed in an amount of 2 to 15 parts by weight with respect to 100 parts by weight of the drying oil-modified phenol resin. If it is 15 parts by weight or more, the punching workability is deteriorated,
If it is 2 parts by weight or less, the flame retardancy is not improved.

A dry oil-modified phenolic resin containing a polyester resin and a melamine resin is mixed with toluene, alcohol,
Mold into a varnish using a solvent such as methyl ethyl ketone, acetone, dimethylformamide, styrene, etc., and impregnate a commonly used base material of a dry oil-modified phenolic resin laminate such as paper, glass cloth, glass nonwoven fabric, synthetic fiber cloth, etc. To obtain a laminated plate. The molding is performed by stacking one or more base materials impregnated with the drying oil-modified phenolic resin varnish and at a required temperature and pressure. As a flame retardant, if necessary, phosphates such as triphenyl phosphate, cresyl diphenyl phosphate, isopropyl phenyl diphenyl phosphate, and bromine such as brominated phenols, brominated epoxy compounds, brominated biphenyl ether compounds. A compound may be blended.

In the case of obtaining a metal-clad laminate, a metal foil is further overlaid and formed on the above-mentioned plurality of prepregs that have been overlaid. As the metal foil, copper foil, aluminum foil, nickel foil, iron foil, stainless steel foil and the like are used, but usually copper foil is used. The metal foil may be provided with an adhesive, which improves the adhesive strength. Molding of the laminated insulating plate and the metal-clad laminated plate is carried out at the usual temperature and pressure for the laminated molding.

The laminated plate and the metal-clad laminate thus obtained are subjected to circuit processing to obtain a printed wiring board. The metallic-clad laminate is subjected to etching processing to form a printed wiring board. Further, the laminated plate and the metal-clad laminated plate become a printed wiring board by electrolytic plating or electroless plating. In addition, component holes such as semiconductors and resistors of a printed wiring board are generally formed by punching as well as drilling.

[0011]

The anti-tracking property is good for a structure such as a benzene nucleus or a phenol nucleus which is easily carbonized, and is good for an aliphatic hydrocarbon because it is hard to be carbonized. Polyester resins generally have many aliphatic components and have good tracking resistance, and the higher the proportion of the aliphatic components, the better the tendency. Since the tracking resistance is particularly affected by the surface layer portion, the tracking resistance of the laminate is improved by blending the unsaturated polyester resin in the surface varnish. The unsaturated polyester resin has a reactive group such as a double bond in the molecule, and does not lower the heat resistance by reacting with the drying oil-modified phenol resin.

When a large amount of unsaturated polyester resin is used, flame retardancy and moisture resistance are lowered. Melamine resin is flame retardant,
Moisture resistance is reduced. Melamine resin has good flame resistance and moisture resistance, and has little deterioration in tracking resistance. Therefore, by using a dry oil-modified phenol resin knitted with a melamine resin as the inner layer varnish, a laminate having a good balance of tracking resistance, flame retardancy, moisture resistance and the like can be obtained.

The crack which is particularly problematic in punching workability is the strain energy generated in the surface layer of the laminated plate during punching.
Is considered to occur when the in-plane tensile energy, which is the critical value, is reached, and cracking is less likely to occur by increasing the in-plane tensile energy. The unsaturated polyester resin has many aliphatic components and is effective in increasing the in-plane tensile energy. Therefore, by blending the unsaturated polyester resin with the resin of the surface layer portion, the in-plane tensile energy of the surface layer portion of the laminated plate is increased and cracking is less likely to occur.

[0014]

【Example】

Example 1 Tung oil and metacresol were reacted under an acid catalyst, and then paraformaldehyde was reacted under an alkali catalyst to give a resonance.
100 parts of a phenolic resin having a modified content of 40% by weight of tung oil (parts by weight, the same applies hereinafter), 10 parts of an unsaturated polyester resin, and 15 parts of a halogenated epoxy resin were mixed to obtain a varnish A for impregnation. .. Separately, 100 parts of a phenol resin having a tung oil modification amount of 40% by weight, 10 parts of a melamine resin, and 20 parts of a halogenated epoxy resin were mixed to prepare an impregnating varnish B.

Kraft paper pretreated with a water-soluble phenol resin (12% by weight of resin) was impregnated with varnish A so that the amount of resin was 50% by weight. The dried product was designated as prepreg B. 6 sheets of prepreg B are used for the inner layer, 1 sheet of prepreg A is laminated on both sides of the surface layer, and 1 sheet of copper foil with adhesive is laminated on one side of the surface layer, and heated and pressurized to 1.6 mm.
A single-sided copper-clad laminate was obtained.

Example 2 A phenol resin having a tung oil modification amount of 35% by weight was obtained in the same manner as in Example 1, and 100 parts of the phenol resin, 20 parts of the unsaturated polyester resin, and 15 parts of the halogenated epoxy resin were mixed. Using the impregnating varnish C, a prepreg C was obtained in the same manner as in Example 1. Six prepregs B were used for the inner layer, and one prepreg C was laminated on each side of the surface layer.
A single-sided copper clad laminate having a size of mm was obtained.

Example 3 In the same manner as in Example 1, a phenol resin having a tung oil modification amount of 40% by weight was obtained. 100 parts of the phenol resin, 5 parts of the melamine resin,
A prepreg D was obtained in the same manner as in Example 1 except that 25 parts of a halogenated epoxy resin was mixed to form an impregnating varnish D. Six prepregs D were used for the inner layer, and one prepreg A was laminated on each side of the surface layer to obtain a 1.6 mm single-sided copper-clad laminate in the same manner as in Example 1.

Comparative Example 1 Using 8 sheets of prepreg A, the same as in Example 1, 1.6 mm
A single-sided copper-clad laminate was obtained.

Comparative Example 2 Using 8 sheets of prepreg B, the same as in Example 1, 1.6 mm
A single-sided copper-clad laminate was obtained.

[0020]

[Table 1]

Regarding the test items in Table 1, the test method is as follows. Tracking resistance: CTI value according to IEC method Punching workability: Presence or absence of cracks, peeling and whitening when a sample is punched using an 80 ton press at a hole pitch of 1.78 mm at 20 ° C. Good, △ means a little bad.

[0022]

[Table 2]

Regarding the test items in Table 2, the test method is as follows. Flame retardance: According to UL method. Solder heat resistance: According to JIS-C-6481. Moisture resistance: Pressure cooker, 121 ° C, 0.22M
Moisture absorption rate after holding at Pa for 8 hours.

[0024]

INDUSTRIAL APPLICABILITY In the laminated board of the present invention, the surface layer phenol resin is blended with the unsaturated polyester resin, and the inner layer phenol resin is blended with the melamine resin. Therefore, the unsaturated polyester resin and the melamine resin complement each other. Therefore, it has excellent tracking resistance, punching workability, and heat resistance.

Claims (1)

[Claims] 1. The resin for the surface layer is a dry oil-modified phenol resin containing an unsaturated polyester resin, and the resin for the inner layer is a dry oil-modified phenol resin containing a melamine resin. Laminated board.