JP2000273290A - Production of epoxy resin varnish, production of epoxy resin prepreg and production of epoxy resin laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an epoxy resin laminate excellent in heat resistance to soldering. SOLUTION: This method for producing epoxy resin varnish comprises dissolving combined epoxy resin as an essential component into a solvent to previously blend the combined resin with the solvent and adding other component thereto and mixing the mixture with other component in a method for producing an epoxy resin varnish by using a combination of two or more kinds of epoxy resins as an essential component. This method for producing an epoxy resin prepreg comprises impregnating the varnish into a fiber substrate and drying the varnish. This method for producing an epoxy resin laminate comprises laminating the prepreg.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an epoxy resin varnish, a method for producing an epoxy resin prepreg, and a method for producing an epoxy resin laminate.

[0002]

2. Description of the Related Art Epoxy resin laminates have become an indispensable material for electrical equipment, especially industrial electronic equipment, personal computers, small communication equipment and the like. In this specification, the term “laminate” includes a copper-clad laminate having copper foil on one or both sides.

[0003] This epoxy resin laminate is manufactured as follows. First, an epoxy resin varnish is manufactured by dissolving and dispersing an epoxy resin, a curing agent, and various components necessary for imparting various properties in a solvent. Next, the epoxy resin varnish is impregnated into a fiber base and dried to produce an epoxy resin prepreg. Next, one or two or more prepregs are stacked according to the thickness of the prepreg, and the prepreg is charged between hot plates of a press, and heated and pressed to produce an epoxy resin laminate.
When manufacturing a copper-clad epoxy resin laminate used as a material for a printed wiring board, one side or two or more prepregs are laminated on both sides (when manufacturing a double-sided copper-clad epoxy resin laminate) or one side (one side copper). Copper foil is put on the hot platen of the press with copper foil laminated when producing a laminated epoxy resin laminate).

As an epoxy resin, bisphenol A
There are various variations such as a type epoxy resin and a novolak type epoxy resin, and they are used alone or in combination of two or more types according to the characteristics required as an epoxy resin laminate. For example, in the production of a general-purpose epoxy resin laminate, bisphenol A type epoxy resin is used alone, and a curing agent, a curing accelerator, a filler, a flame retardant and the like are dissolved and dispersed in a solvent to form an epoxy resin varnish. To manufacture. Further, for example, a flame retardant is imparted using a brominated bisphenol A type epoxy resin, and a novolak type epoxy resin is combined to further improve heat resistance, and this is combined with a curing agent, a curing accelerator, a filler and the like as a solvent. To make an epoxy resin varnish.

The epoxy resin varnish has been manufactured by putting necessary components such as an epoxy resin and a curing agent and a solvent into a varnish tank and mixing them. The same was true even when different types of epoxy resins were used in combination.

[0006]

In recent years, epoxy resin laminates have been required to have higher quality. The present inventor has studied a process of charging and mixing various necessary components such as an epoxy resin and a curing agent and a solvent into a varnish tank, and producing an epoxy resin varnish containing two or more types of epoxy resins as essential components. The present inventors have found that, when a different kind of epoxy resin is preliminarily blended by dissolving in a solvent and then other components are added, the solder heat resistance is improved.

An object of the present invention is to provide a method for producing an epoxy resin varnish capable of producing an epoxy resin laminate excellent in solder heat resistance. Another object of the present invention is to provide a method for manufacturing an epoxy resin prepreg, which can manufacture an epoxy resin laminate having excellent solder heat resistance. Another object of the present invention is to provide a method of manufacturing an epoxy resin laminate having excellent solder heat resistance.

[0008]

According to a first aspect of the present invention, there is provided a method for producing an epoxy resin varnish comprising two or more types of epoxy resins as an essential component. A method for producing an epoxy resin varnish, comprising preliminarily blending by dissolving in water and then adding and mixing other components.

The invention described in claim 2 is the first invention.
A method for producing an epoxy resin prepreg in which an epoxy resin varnish produced by the production method described in 1) is impregnated into a fiber base and dried.

[0010] Further, the invention described in claim 3 is based on claim 2.
A method of manufacturing an epoxy resin laminate, in which a predetermined number of epoxy resin prepregs manufactured by the manufacturing method described in 1) are stacked and heated and pressed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a known epoxy resin can be used as the epoxy resin, and there is no particular limitation. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, alicyclic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, Hydantoin-type epoxy resins, isocyanurate-type epoxy resins, halides and hydrogenated products thereof are used, and two or more of these are appropriately combined and used as an essential component so as to obtain necessary properties as an epoxy resin laminate.

For example, when manufacturing an epoxy resin laminate having flame retardancy and heat resistance, 80 to 90 parts by weight of a brominated bisphenol A type epoxy resin is added to 20 to 10 parts by weight of a cresol novolak type epoxy resin, for a total of 100 parts by weight. Combine so that As for the cresol novolak type epoxy resin, it is preferable to use a resin having a softening point of 75 to 85 ° C. from the viewpoint of workability such as uneven coating during coating operation.

The epoxy resin used in combination is previously blended by dissolving in a solvent. As the solvent used, acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate,
Examples include ethylene glycol monomethyl ether, N, N dimethylformamide, N, N dimethylacetamide, methanol, ethanol and the like. These may be used alone or in combination of two or more.

Some epoxy resins are synthesized by reacting raw material compounds in a solvent (eg, methyl isobutyl ketone). As described above, the epoxy resin using a solvent for the synthesis reaction is usually supplied without the solvent, but if the solvent used for the synthesis reaction is omitted, the epoxy resin is omitted because the solvent removal step is omitted. It is preferable because it is supplied at a cost and the cost can be reduced.

After the epoxy resin to be used in combination is dissolved in a solvent and previously blended, a curing agent, a curing accelerator, and other components such as a filler are added and dissolved and dispersed to produce an epoxy resin varnish.

The curing agent is blended to cure the epoxy resin, but the curing agent is not particularly limited, and a known curing agent is used. Examples of the curing agent include resole resins, novolak type phenol resins, acid anhydrides, amines, dicyandiamide, phosphines, and the like. In addition, a curing accelerator is added as necessary to accelerate the curing reaction. The curing accelerator is not particularly limited, and a known curing accelerator is used. Examples of the curing accelerator include imidazoles.

In addition, various components may be blended as required. For example, better mechanical strength,
When it is necessary to adjust the viscosity of the varnish, an inorganic filler is blended. Examples of the inorganic filler include alumina, finely divided silica, aluminum hydroxide, zirconium silicate, and talc which have been conventionally used for such a purpose.

The mixing ratio of each component is not particularly limited, and is appropriately selected within a range in which the purpose of mixing each component is best achieved. When these components are blended, a solvent may be added as necessary.

The epoxy resin varnish produced as described above is impregnated into a fiber base and dried to produce an epoxy resin prepreg. As the fiber base material, known fiber base materials such as glass woven fabric, glass nonwoven fabric, paper, and aramid fiber woven fabric can be used, and there is no particular limitation. Also,
The step of impregnating and drying the epoxy resin varnish is not particularly limited and can be performed.

The epoxy resin prepreg thus manufactured is stacked in a required number in accordance with the thickness of the laminate to be manufactured, and heated and pressed to manufacture an epoxy resin laminate. There is no particular limitation on the step of manufacturing the epoxy resin laminate, and a conventionally known method can be used. The copper-clad epoxy resin laminate is manufactured by placing copper foil on one or both sides of the prepreg.

[0021]

EXAMPLES Example 1 Brominated bisphenol A type epoxy resin (epoxy equivalent: 480 g / eq, softening point: 70 ° C., manufactured by Dainippon Ink and Chemicals, Inc., Epicron 1120-80M (trade name);
90 parts by weight (solvent: methyl ethyl ketone) with a solid content of 80% by weight (solvent: methyl ethyl ketone) 90 parts by weight (solid content equivalent) and ortho-cresol novolak type epoxy resin (epoxy equivalent 220 g / eq, softening point 80 ° C, Dainippon Ink and Chemicals, Ltd.) Co., Ltd., using Epicron N-670 (trade name))
10 parts by weight were blended. Next, dicyandiamide 2
Parts by weight, 0.2 parts by weight of 2-ethyl-4-methylimidazole, and the above-mentioned blended brominated bisphenol A-type epoxy resin and ortho-cresol novolak-type epoxy resin were charged and dissolved to prepare an epoxy resin varnish.

The epoxy resin varnish was impregnated and dried on a 7628 type glass cloth so that the resin adhesion after drying was 42% by weight, thereby producing a glass cloth base epoxy resin prepreg.

Eight prepared prepregs were stacked, and an electrolytic copper foil having a thickness of 18 μm was placed on both sides thereof.
A 1.6 mm-thick double-sided copper-clad epoxy resin laminate was produced by heating and pressing at 4 ° C. and a pressure of 4 MPa for 90 minutes.

EXAMPLE 2 15 parts by weight of an ortho-cresol novolak type epoxy resin synthesized in methyl isobutyl ketone and provided with methyl isobutyl ketone (product of the same grade as used in Example 1, resin solids 10%). Example 1 except that ethylene glycol monomethyl ether was used in an amount of 25 parts by weight.
An epoxy resin varnish was prepared in the same manner as described above. Hereinafter, a glass cloth base epoxy resin prepreg was produced in the same manner as in Example 1, and a double-sided copper-clad epoxy resin laminate was produced.

Comparative Example 90 parts by weight of brominated bisphenol A type epoxy resin (using the same product as in Example 1), 10 parts by weight of orthocresol novolak type epoxy resin (using the same product as in Example 1), 2 parts by weight of dicyandiamide And 2-ethyl-4-
An epoxy resin varnish was prepared by simultaneously charging and dissolving 0.2 parts by weight of methyl imidazole in 30 parts by weight of ethylene glycol monomethyl ether. Thereafter, a glass cloth base epoxy resin prepreg was produced and produced in the same manner as in Example 1, and a double-sided copper-clad epoxy resin laminate was produced.

The solder heat resistance of the double-sided copper-clad epoxy resin laminate obtained above was examined. Solder heat resistance is
A 50 mm x 50 mm test piece etched over the entire surface
1 hour in a pressure cooker tester at 21 ° C., 1215.9 hPa, saturated steam pressure (PCT in Table 1)
-1), 2 hours (PCT-2 in Table 1), 3 hours (PCT-3 in Table 1), 4 hours (P in Table 1
CT-4) After each holding, 2
It was immersed for 0 seconds and examined by visual observation. The number of test pieces was five each. The meanings of the symbols in Table 1 are as follows. ○: No abnormality △: Slight swelling ×: Severe swelling

[0027]

[Table 1]

[0028]

According to the present invention, an epoxy resin laminate having excellent solder heat resistance can be manufactured.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhiro Murai 1500 Oji Ogawa, Shimodate-shi, Ibaraki F-term in the Shimodate Plant of Hitachi Chemical Co., Ltd. AB17B AB33B AG00A AK53A AL05A BA01 BA02 BA11 DG01A DG11A DH01A EH072 EJ821 EJ861 GB43 JJ03 4J002 CD00W CD00X CD02W CD02X CD05W CD05X CD06W CD06X CD08W CD08X CD12W CD12X CD13W CD13X006 EA17

Claims (3)

[Claims] 1. A method for producing an epoxy resin varnish in which two or more epoxy resins are combined as an essential component, wherein the epoxy resin as an essential component is combined and dissolved in a solvent in advance, and then blended with other components. A method for producing an epoxy resin varnish, comprising adding and mixing. 2. A method for producing an epoxy resin prepreg, wherein the epoxy resin varnish produced by the production method according to claim 1 is impregnated into a fiber base and dried. 3. A method of manufacturing an epoxy resin laminate, wherein a predetermined number of epoxy resin prepregs manufactured by the manufacturing method according to claim 2 are stacked and heated and pressed.