JPH06206981A - Epoxy resin composition for electrical laminated board - Google Patents

Abstract

PURPOSE:To provide an epoxy resin composition comprising a specific epoxy resin, a curing agent and a curing accelerator, excellent in impregnating property, stability, heat resistance, adhesion, etc., and useful for copper-clad epoxy resin laminated boards, etc. CONSTITUTION:The composition comprises (A) an epoxy resin obtained by reacting (i) a difunctional epoxy resin having the bisphenol compound skeletons of bisphenol A and/or bisphenol F with (ii) a polyfunctional phenol compound and (iii) a bisphenol compound such as bisphenol A, bisphenol F and/or tetrabromobisphenol A, (B) a curing agent (e.g. an aromatic polyamine), and (C) a curing accelerator (e.g. benzyldimethylamine). The reaction time of the component A is preferably 60-200min at 100-200C, and the component ii is preferably used in an amount of 1-20wt.%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition for epoxy resin laminates, particularly when impregnating glass cloth or the like, good impregnation property into glass cloth and the like, good stability of prepreg, and heat resistance. It can give cured products with excellent heat resistance, measling resistance, drilling workability, adhesion to metals, etc. Therefore, it can be used for the production of printed wiring boards, etc., especially copper-clad epoxy resin laminated boards for multilayer printed wiring. It relates to an epoxy resin composition which is advantageously used.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic devices, the density of printed wiring has increased. Therefore, it is desired to improve the heat resistance and measling resistance of the base material.

In order to improve the heat resistance of the cured epoxy resin, it is possible to add a polyfunctional epoxy resin such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, or triglycidyl ether of paraaminophenol to the epoxy resin used. Although it is carried out, the sufficient heat resistance improving effect of the cured product cannot be obtained.

It is also known that the heat resistance of the produced epoxy resin is improved by reacting the polyfunctional epoxy resin with the bisphenol compound or by reacting the polyhydric phenol compound with the bisphenol type epoxy resin with the bisphenol compound. However, the epoxy resin produced in these cases has a high resin content because of the high content of the high molecular weight component, the impregnability into glass cloth is poor, and the stability of the prepreg is also poor. is there.

Further, when a laminate obtained by using these known heat-resistant epoxy resins is treated in a solder bath after boiling, phenomena such as blistering, peeling, measling and crazing of the laminate may occur. In addition, since the hardened material is hard and brittle, the drill workability is deteriorated.

[0006]

The present invention is suitable for the production of copper-clad epoxy resin laminates used for printed wiring boards and the like, and particularly has a good impregnation property for glass cloth and the like, and has a stable prepreg. It is possible to give a cured product that is good and has excellent heat resistance, resistance to measling, drill workability, and adhesion to copper foil, etc., that is, the physical properties before and after curing are well balanced. Another object of the present invention is to provide an epoxy resin composition.

[0007]

As a result of various studies to solve the above-mentioned problems, the present inventors were able to achieve the object by using a specific epoxy resin.

That is, the epoxy resin composition of the present invention is an epoxy resin composition containing an epoxy resin, a curing agent, and a curing accelerator, and the epoxy resin a containing the following epoxy resin a as a main component. It is the composition characterized by using.

Epoxy resin a: (I) Bifunctional epoxy resin having at least one bisphenol compound skeleton selected from bisphenol A and bisphenol F, (II) polyfunctional phenol compound, and (III) bisphenol A, bisphenol It is an epoxy resin obtained by reacting at least one bisphenol compound selected from F and tetrabromobisphenol A, and has a dispersity (Mw / Mn value) of 3 in the molecular weight distribution of the resin. Epoxy resin having a value of 0.0 or less.

The bifunctional epoxy resin (I) having a bisphenol compound skeleton, which is a raw material for producing the epoxy resin a in the present invention, is a bifunctional epoxy resin (I) having at least one bisphenol compound skeleton selected from bisphenol A and bisphenol F. Although it is a functional epoxy resin,
This type of bifunctional epoxy resin is already widely known,
Moreover, since it is widely marketed under various trade names, its detailed description is omitted.

As the polyfunctional phenol compound (II) which is a raw material for producing the epoxy resin a in the present invention, an aldehyde compound or a ketone compound having a hydroxyl group-substituted phenyl group and a phenol compound in the presence of an acid catalyst are used. A polyfunctional phenol compound obtained by reacting a polyfunctional phenol compound, a phenol dimethylol compound or a phenol novolak dimethylol compound and a phenol compound obtained by reacting with a phenol compound in the presence of an acid catalyst, a phenol compound and formaldehyde. Examples thereof include polyfunctional phenol compounds obtained by reacting in the presence of an acid catalyst.

Examples of the aldehyde compound or ketone compound having a hydroxyl group-substituted phenyl group used in the production of the above compounds include salicylaldehyde and p-
Examples thereof include hydroxybenzaldehyde and p-hydroxyacetophenone. Examples of the phenolic compound used for the production of the compound or or, for example, phenol, o-cresol, m-cresol, p
-Cresol, p- (t-butyl) phenol, bisphenol A and the like can be mentioned.

Examples of the phenol dimethylol compound or the phenol novolac dimethylol compound used for producing the above-mentioned compound include o-
Cresol dimethylol compound, m-cresol dimethylol compound, p-cresol dimethylol compound, dimethylolphenol compound, and the following general formula (i)
And various phenols binuclear dimethylol compounds, that is, o-cresol binuclear dimethylol compound, m-cresol binuclear dimethylol compound, p-cresol binuclear dimethylol compound, phenol binuclear dimethylol compound and the like. To be

[0014]

[Chemical 1] R in formula (i) is H or CH ₃ .

The bisphenol compound (III) which is a raw material for producing the epoxy resin a in the present invention is at least one bisphenol compound selected from bisphenol A, bisphenol F and tetrabromobisphenol A. Since various kinds of bisphenol compounds are already widely known and generally commercially available, detailed description thereof will be omitted.

The above-mentioned difunctional epoxy resin (I), polyfunctional phenol compound (II) and bisphenol compound (II
I) and, preferably in the presence of a reaction catalyst, usually 100 to
The reaction is carried out at a temperature of 200 ° C. for 60 to 200 minutes to obtain an epoxy resin a having a molecular weight distribution dispersity (Mw / Mn value) of 3.0 or less.

In the production reaction of the epoxy resin a, a reaction catalyst is usually used. The reaction catalyst is
For example, 1,2-dimethylimidazole, imidazoles such as 2-methylimidazole, trimethylamine,
Amines such as triethylamine, ammonium salts such as tetramethylammonium bromide and tetramethylammonium chloride, phosphines such as triphenylphosphine, phosphonium salts such as benzyltriphenylphosphonium chloride and ethyltriphenylphosphonium bromide Known catalysts are listed.

Generally, a conventional polyfunctional epoxy resin or a polyphenol compound such as a phenol novolac compound or a cresol novolac compound and a bisphenol type epoxy resin are reacted with a bisphenol compound or the like to produce an epoxy resin Since a large amount of high molecular weight components are contained in the resin, the resin viscosity is high, the impregnability into glass cloth is poor, and the stability of the prepreg was not sufficient, but the epoxy resin produced as described above, In particular, when the epoxy resin a in which the dispersity of the molecular weight distribution is maintained at 3.0 or less is used, an epoxy resin composition having a low viscosity, a good impregnation property for glass cloth and a good prepreg stability can be obtained. When the dispersity of the molecular weight distribution of the epoxy resin exceeds 3.0, the amount of high molecular weight components in the epoxy resin increases, impairing the impregnation into the glass cloth remarkably, and the stability of the prepreg also deteriorating. Become.

Regarding the reaction ratio of the bifunctional epoxy resin (I) with the polyfunctional phenol compound (II) and the bisphenol compound (III), the polyfunctional phenol compound (II) is 1 to 1 with respect to the total amount of the three. A range of 20% by weight is preferred.
That is, if the proportion of the polyfunctional phenol compound (II) is too low, the performance of the produced epoxy resin a cannot be sufficiently improved, and if the proportion is too high, the dispersity of the molecular weight distribution of the produced epoxy resin a is high. When it is more than 3.0, the workability such as impregnating ability of the glass cloth is deteriorated as described above.

In the epoxy resin composition of the present invention, a specific epoxy resin called the epoxy resin a obtained as described above is used as the epoxy resin. This epoxy resin a is used by itself. It is also possible to use this together with another epoxy resin having two or more epoxy groups in one molecule. Other epoxy resins that can be used in combination include, for example, glycidyl ether type epoxy resins such as hisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin,
Examples include various polyfunctional epoxy resins such as linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, halogenated epoxy resin and the like. The combined amount of these other epoxy resins should be 50% by weight or less with respect to the total amount of the epoxy resin, that is, 100 parts by weight of the total amount of the epoxy resin a and the other epoxy resin used in combination therewith.
If the amount of other epoxy resin used in combination is too large, the performance as a laminated plate is deteriorated, which is not preferable.

A hardener is added to the epoxy resin composition of the present invention. Examples of the hardener include aromatic polyamines, dicyandiamide, acid anhydrides and various phenol type novolac resins.

A curing accelerator is added to the epoxy resin composition of the present invention, and various curing accelerators can be used. For example, benzyldimethylamine,
Examples include amines such as various imidazole compounds, and tertiary phosphines such as triphenylphosphine.

When glass cloth is impregnated with the epoxy resin composition of the present invention, the resin composition may be dissolved in a solvent for impregnation in order to further improve the impregnation property. Examples of the solvent include acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N, N-dimethylformamide, N, N-dimethylacetamide, methanol and ethanol. These solvents can be appropriately used as a mixed solvent of two or more kinds.

If desired, the epoxy resin composition of the present invention may further contain various other additives such as flame retardants and fillers.

The production of, for example, a copper-clad epoxy resin laminate using the epoxy resin composition of the present invention can be carried out by a conventional method. For example, a glass cloth or the like is impregnated and coated with this epoxy resin composition, and then dried by heating to form a prepreg. One or more prepregs are laminated with copper foil on one or both sides,
Then, heating and pressurization are carried out according to a conventional method to form a laminate.

[0026]

The present invention will be described in more detail below with reference to synthesis examples of polyfunctional phenol compounds, examples and comparative examples, but the present invention is not limited to these examples. "Parts" and "%" described in these Examples and Comparative Examples mean "parts by weight" and "% by weight", respectively.

Synthesis Example A of Polyfunctional Phenolic Compound A A glass container equipped with a thermometer, a stirrer and a freezer was charged with 564 g of phenol, 122 g of salicylaldehyde and 0.3 g of concentrated hydrochloric acid and reacted at a temperature of 100 ° C. for 30 minutes. Further, 0.5 g of p-toluenesulfonic acid was added, a distillation apparatus was attached, the temperature was raised to 180 ° C, and the reaction was carried out at 180 ° C for 2 hours while distilling off excess phenol.

After the reaction was completed, the product was dissolved by adding 500 g of methyl isobutyl ketone, washing with 1000 g of a 3% NaHCO ₃ aqueous solution and then 1000 g of distilled water to remove the catalyst, and then using a rotary evaporator to remove the solvent and unreacted phenol. Was removed under reduced pressure to give polyfunctional phenol compound 2
60 g (softening point 115 ° C., hydroxyl equivalent 98 g / eq.)
Got This is called "polyphenol compound A".

Polyfunctional Phenolic Compound Synthesis Example B 2,4 in a glass container equipped with a thermometer, stirrer and freezer.
-Bishydroxymethyl-o-cresol 168 g and o-cresol 324 g were added, and oxalic acid 2 g was further added.
Was added and reacted at 75 ° C. for 4 hours, then dehydrated under reduced pressure to remove unreacted o-cresol by steam distillation to give 230 g of a polyfunctional phenol compound (softening point 65 ° C., hydroxyl group equivalent 118 g / eq.). Got This is called "polyphenol compound B".

Polyfunctional Phenolic Compound Synthesis Example C 228 g of bisphenol A, 24 g of 37% formalin, and 1 g of oxalic acid were placed in a glass container equipped with a thermometer, a stirrer and a freezer, and the reaction was carried out at the reflux temperature for 3 hours. Dehydration under reduced pressure 230
g (softening point 68 ° C., hydroxyl group equivalent 118 g / eq.) was obtained. This is called "polyphenol compound C".

Example 1 Bisphenol A type epoxy resin (Yukaka Shell Epoxy Co., Ltd. trade name Epicoat 828, epoxy equivalent 18
7 g / eq. ) 64.5 parts and polyphenol compound A
5 parts and 30.5 parts of tetrabromobisphenol A were added to the catalyst (1,2-dimethylimidazole) 0.03
The reaction was carried out at 150 ° C for 180 minutes in the presence of parts to obtain an epoxy resin. This epoxy resin has an epoxy equivalent of 551.
g / eq. And the polydispersity of the molecular weight distribution was 2.5. Hereinafter, this epoxy resin is referred to as "epoxy resin 1".

To 100 parts of this epoxy resin, 2.5 parts of dicyandiamide as a curing agent and 2 parts as a curing accelerator.
0.15 parts of -ethyl-4-methylimidazole was mixed, and a mixed solvent of methyl ethyl ketone / ethylene glycol monomethyl ether (mixing weight ratio 1/1) was added to prepare a varnish having a nonvolatile content of 55% by weight.

Then, this varnish was impregnated into a glass cloth.
Apply and dry at 130 ° C. for 7 minutes, 8 prepregs with a nonvolatile content of 45% of the epoxy resin composition are overlaid, 35 μm thick copper foil is overlaid on both sides, temperature 170 ° C., pressure 40 Kg / cm Heat-molded at ² for 1 hour and thickness is 1.6m
m copper clad glass epoxy laminate was produced.

The resin composition excluding the solvent of the epoxy resin composition (varnish) of this Example 1 is shown in Table 1, and the physical properties of the resin before curing after the evaporation of the solvent and the physical properties after curing (the physical properties of the cured laminate) are shown. Shown in 2.

The method for measuring the degree of dispersion of the molecular weight distribution and the method for testing the storage stability of the prepreg described in this specification were as follows.

Method for Measuring Dispersion of Molecular Weight Distribution By gel permeation chromatography (GPC), number average molecular weight (Mn) and weight average molecular weight (Mw)
Is measured and the value of the Mw / Mn ratio is taken as the dispersity. The column used for this measurement is TSK gel G4 manufactured by Tosoh Corporation.
A total of four 000Hxl, two G3000Hxl and one G2000Hxl were used in series. Further, as a solvent, tetrahydrofuran (TH
F) was used.

Test method for storage stability of prepreg The prepreg was stored in an atmosphere of 40 ° C. for 14 days, and the gel time retention of the prepreg with respect to the initial value was measured.

Example 2 62.5 parts of bisphenol A type epoxy resin (Epicoat 828 used in Example 1), 7 parts of polyhydric phenol compound B, and 30.5 parts of tetrabromobisphenol A.
And other parts were reacted in the same manner as in Example 1 to obtain an epoxy resin. This epoxy resin has an epoxy equivalent of 615 g / eq. And the polydispersity of the molecular weight distribution was 2.3. Hereinafter, this epoxy resin is referred to as “epoxy resin 2”.

A varnish was prepared in the same manner as in Example 1 except that this epoxy resin 2 was used, and a copper-clad glass epoxy laminated plate was manufactured in the same manner. The resin composition excluding the solvent in this case is shown in Table 1, and the resin physical properties of the resin composition before curing and the physical properties of the cured laminate are shown in Table 2.

Example 3 61.5 parts of bisphenol A type epoxy resin (Epicoat 828 used in Example 1), 8 parts of polyhydric phenol compound C, and 30.5 parts of tetrabromobisphenol A.
And other parts were reacted in the same manner as in Example 1 to obtain an epoxy resin. This epoxy resin has an epoxy equivalent of 673 g / eq. And the dispersity of the molecular weight distribution was 2.7. Hereinafter, this epoxy resin is referred to as "epoxy resin 3".

A varnish was prepared in the same manner as in Example 1 except that this epoxy resin 3 was used, and a copper clad glass epoxy laminated plate was manufactured in the same manner. The resin composition excluding the solvent in this case is shown in Table 1, and the resin physical properties of the resin composition before curing and the physical properties of the cured laminate are shown in Table 2.

Comparative Example 1 90 parts of brominated bisphenol type epoxy resin (Okaka Shell Epoxy Co., Ltd., trade name Epicoat 5049, epoxy equivalent 748 g / eq., Bromine content 28%) and orthocresol novolac type epoxy resin (oil type Shell Epoxy Co., Ltd., trade name Epicoat 180S70, and epoxy equivalent of 208 g / eq.) Were mixed with 10 parts. The dispersity of the molecular weight distribution of this mixed epoxy resin was 1.7.

A varnish was prepared in the same manner as in Example 1 except that this mixed epoxy resin was used, and a copper-clad glass epoxy laminated plate was manufactured in the same manner. The resin composition excluding the solvent in this case is shown in Table 1, and the resin physical properties of the resin composition before curing and the physical properties of the cured laminate are shown in Table 2.

Comparative Example 2 61.5 parts of bisphenol A type epoxy resin (Epicoat 828 used in Example 1) and orthocresol novolak (softening point 100 ° C., hydroxyl equivalent 118 g / e)
q. ) 8 parts and tetrabromobisphenol A 30.
5 parts were used and the other reaction was carried out in the same manner as in Example 1 to obtain an epoxy resin. This epoxy resin has an epoxy equivalent of 680 g / eq. And the polydispersity of the molecular weight distribution was 3.4. Hereinafter, this epoxy resin is referred to as "epoxy resin 2 '".

A varnish was prepared in the same manner as in Example 1 except that this epoxy resin 2'was used, and a copper-clad glass epoxy laminated plate was produced in the same manner. The resin composition excluding the solvent in this case is shown in Table 1, and the resin physical properties of the resin composition before curing and the physical properties of the cured laminate are shown in Table 2.

Comparative Example 3 54.5 parts of bisphenol A type epoxy resin (Epicoat 828 used in Example 1) and bisphenol A novolak type epoxy resin (trade name Epicoat 157S70 of Yuka Shell Epoxy Co., epoxy equivalent 208 g)
/ Eq. ) 15 parts and 30.5 parts of tetrabromobisphenol A were used, and other than that were reacted in the same manner as in Example 1 to obtain an epoxy resin. This epoxy resin has an epoxy equivalent of 400 g / eq. And the polydispersity of the molecular weight distribution was 3.2. Hereinafter, this epoxy resin is referred to as "epoxy resin 3 '".

A varnish was prepared in the same manner as in Example 1 except that this epoxy resin 3'was used, and a copper-clad glass epoxy laminated plate was manufactured in the same manner. The resin composition excluding the solvent in this case is shown in Table 1, and the resin physical properties of the resin composition before curing and the physical properties of the cured laminate are shown in Table 2.

[0048]

[Table 1]

Note to Table 1 * 1 Yuka Shell Cepoxy Co., Ltd. trade name Epicoat 5049 * 2 Yuka Shell Cepoxy Co. Ltd. trade name Epicoat 180S70

[0050]

[Table 2]

Note in Table 2 * 1 Gel time measurement temperature 160 ° C * 2 Judgment by visual inspection during impregnation / application of glass cloth * 3 Measurement by dynamic viscoelasticity * 4 Pressure cooker treatment at 120 ° C, 2 atmospheres, 4 hours After that, after immersing in a solder bath at 260 ° C. for 30 seconds, the presence or absence of blistering or peeling of the plate was checked and evaluated. The results are shown by the following abbreviations. ○ There is no swelling or peeling of the plate. △ There is slight swelling or peeling of the plate. × There is swelling or peeling of the plate. * 5 Visual inspection of resin smear. Drill 0.4mmφ, rotation speed 60,000rpm, feed 1.0m / min.

[0052]

The epoxy resin composition of the present invention is excellent in impregnating ability for glass cloth and the like, stability of prepreg, and also in heat resistance, measling resistance, drilling workability, copper foil adhesion, etc. It is possible to provide a well-balanced and excellent electric laminate (for example, a copper-clad epoxy resin laminate).

Claims (1)

[Claims] 1. An epoxy resin composition containing an epoxy resin, a curing agent, and a curing accelerator, wherein an epoxy resin containing the following epoxy resin a as a main component is used as the epoxy resin. Resin composition. Epoxy resin a: (I) Bifunctional epoxy resin having at least one bisphenol compound skeleton selected from bisphenol A and bisphenol F, (II) polyfunctional phenol compound, and (III) bisphenol A, bisphenol F and tetra An epoxy resin obtained by reacting three members with at least one bisphenol compound selected from bromobisphenol A, and having a resin polydispersity (Mw / Mn value) of 3.0 or less. Is an epoxy resin.