JPH05262855A - Epoxy resin composition and use thereof - Google Patents

Abstract

PURPOSE:To prepare the title compsn. which is excellent in processibility and gives a cured article excellent in heat resistance, flexibility, and moisture resistance by compounding an epoxy resin with a specific arom. tetracarboxylic acid dianhydride. CONSTITUTION:An epoxy resin is compounded with a tetracarboxylic acid dianhydride of formula I (wherein Ya is a group of formula II or cyclohexylidene; Yb is -O- or a group of formula III; Yc is -O- or a group of formula IV; Xa, Xb, Xc, and Xd are each H, alkyl, alkenyl, or alkenoyl; and R1 and R2 are each H or 1-18C alkyl) to give the title compsn. Since the compsn. contains as a curative the above arom. dianhydride excellent in the compatibility with the resin, it has a good moldability until cured, gives a cured article contg. no void nor granular structure and excellent in heat resistance, flexibility, and moisture resistance, and thus greatly facilitates the molding operation in producing various apparatus.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention has a good workability and excellent heat resistance and flexibility of a cured product, and can greatly improve the reliability of electrical equipment, electronic equipment and structural industrial equipment. Epoxy resin composition and its use.

[0002]

2. Description of the Related Art Conventionally, in an acid anhydride-cured epoxy resin used in electrical equipment, electronic equipment and industrial equipment, the acid anhydride is used because of its compatibility with the epoxy resin and workability such as moldability. Usually, monofunctional ones (anhydrides of divalent carboxylic acids) are used. However, while the epoxy resin cured with a monofunctional acid anhydride has excellent workability, it has poor heat resistance and is limited in use at high temperatures. As a method of improving the heat resistance of an epoxy resin, a system in which a bifunctional anhydride (tetracarboxylic dianhydride) such as benzophenonetetracarboxylic acid anhydride and pyromellitic acid anhydride is added is known ( For example, JP-A-48-85699
And Japanese Patent Laid-Open No. 2-255828).

[0003]

However, these bifunctional aromatic anhydrides have poor compatibility with epoxy and have an extremely high melting point, and in order to obtain a good cured product, they cure at a temperature higher than the melting point. There are drawbacks that must be taken. Further, since the compatibility with the epoxy is poor, there is a problem in the moldability of the resin. A combination with a monofunctional anhydride can be considered, but the compatibility with the monofunctional anhydride is not sufficient, and workability during molding is not necessarily improved. In addition, the heat resistance and flexibility of the cured product are not sufficient, and the reliability of various devices using these resins was not always satisfactory. It is considered that this is due to the fact that a voidless and uniform molded product cannot be obtained. In the present invention, in order to improve the above-mentioned drawbacks, a novel difunctional aromatic anhydride having excellent compatibility with epoxy is used as a curing agent, so that a composition having good molding workability before curing is maintained. It is a thing and
It is an object to provide an epoxy resin composition that can obtain a cured product of an epoxy resin that is extremely excellent in heat resistance, flexibility, and moisture resistance without voids and inhomogeneities, and various applications using the same. To do.

[0004]

In order to solve the above problems, the present invention provides an epoxy resin composition containing an epoxy resin and a tetracarboxylic dianhydride represented by the following formula (1).

[Chemical 1] Each represents H, an alkyl group, an alkenyl group, and an alkenoyl group, and R ₁ and R ₂ are each H and an alkyl group having 1 to 18 carbon atoms. )

In the present invention, as the epoxy resin,
For example, when low viscosity is required for casting for insulating coils, various alicyclic compounds, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, hydantoin type epoxy, silicone epoxy, etc. are generally commercially available. Various epoxy materials with low viscosity are used. For semiconductor encapsulation and for prepregs for producing printed circuit boards, those having relatively high viscosity or solid ones are required. In this case, novolac type epoxy and diphenol of high molecular weight bisphenol A are required. Glycidyl ether or the like can be used. A plurality of these epoxies may be blended as necessary. Further, the acid anhydride may be used in combination with a generally commercially available monofunctional acid anhydride. Furthermore, conventionally known curing accelerators, additives, flexibilizers, various inorganic and organic fillers and the like may be blended and used as necessary. The mixing ratio of anhydrous acid to epoxy is
As conventionally known, 0.5 to 1.5 equivalents, preferably 0.7 to 1.2 equivalents, of the epoxy group 1 are used. As described above, the epoxy resin composition of the present invention can be selected by selecting an epoxy compound to be used and various additives, thereby producing an insulating varnish for an electric insulating coil, an FRP.
It can be used for various applications such as a resin for a matrix of a laminated material, a resin for an insulating layer of a printed board, and a resin for sealing a semiconductor element.

[0006]

In the anhydride-curable epoxy resin composition of the present invention, the novel bifunctional aromatic anhydride of Chemical Formula 1 used is an aromatic bifunctional aromatic anhydride which has been conventionally considered to have high heat resistance. The melting point is much lower than that of anhydrous acid, and the highly compatible ester or ether group is introduced in the molecular structure, so the solubility in epoxy is excellent, and the fluidity of the resin during molding is improved, and as a result, It is considered that the impregnation property was improved, a voidless and uniform molded product was obtained, and the moisture resistance was greatly improved. The cured product obtained from the acid anhydride-curable epoxy resin composition of the present invention has high heat resistance and good flexibility because the bifunctional anhydride represented by the chemical formula 1 used in the present invention has an aromatic ring. It is considered that this is due to the fact that a large amount of is included and a flexible group such as an ester or ether group is introduced into the molecular structure.

[0007]

〔Epoxy resin〕

Epicoat 828 (trade name manufactured by Yuka Shell Epoxy): Bisphenol type epoxy, viscosity 120 to 150 poise (at 25 ° C.) ELM-100 (trade name manufactured by Sumitomo Chemical Co., Ltd.): Amino epoxy, viscosity 11.2 poise (25 ° C.) CY-179 (trade name, manufactured by Ciba Geigy): alicyclic epoxy, viscosity 0.35 to 0.45 poise (at 25 ° C.) HP-4302 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.): naphthalene ring skeleton epoxy, Viscosity 14.2 poise (25 ℃
In) YL-932 (trade name of oiled shell epoxy): 1,
1,3-tris [p- (2,3-epoxypropoxy)
Phenyl] methane ECN1273 (Ciba Geigy product name): Cresol novolac type epoxy, softening point 65-75 ° C. GY280 (Ciba Geigy product name): Bisphenol type epoxy, semi-solid

[Anhydrous curing agent]

[Chemical 1] In the acid anhydride of, the following were used as the substituents. Xa, Xb, Xc, and Xd are -H, C: Ya is cyclohexylidene, Yb and Yc are -O-,
Xa, Xb, Xc, and Xd are -H, BTDA: Benzophenone tetracarboxylic dianhydride PMDA: Pyromellitic dianhydride TMEG (trade name of New Nippon Rika): Ethylene glycol bistrimellitate, melting point 64-72 ° C MHAC -P (trade name, manufactured by Hitachi Chemical Co., Ltd.): methyl nadic acid anhydride

[Curing accelerator] 2MZ-CN (trade name manufactured by Shikoku Kasei Kogyo): 1-cyanoethyl-2methylimidazole 2PZ-CN (trade name manufactured by Shikoku Kasei Kogyo): 1-cyanoethyl-2phenylimidazole

Examples 1 to 12 and Comparative Examples 1 to 6 In this example, various epoxy resins, the bifunctional anhydride (A, B or C) which is the object of the present invention, and conventionally known as comparative examples. Bifunctional anhydrous (BTDA, PMD
A, TMEG) and monofunctional acid anhydride (MHAC-P) were blended, and the state of the resin before curing and the properties of the cured product of the blended composition were examined. In this example, all the acid anhydrides were mixed in an amount of 1 equivalent to 1 equivalent of epoxy. or,
All systems mixed with solvent have a solid content concentration (NV) of 3
It was set to 0 wt%. Dissolution of the anhydrous acid in the solvent-unmixed system into the epoxy was heated to 70 to 100 ° C, and the solvent-mixed system was heated and stirred at room temperature to 50 ° C. The characteristics of the cured product are 2PZ- as a curing accelerator.
Add 0.5% of CN (Shikoku Kasei) to the solid content, and
50 ° C / 5 hours + 180 ° C / 10 hours + 200 ° C / 15
It measured using what was heat-cured for time. The characteristics of the cured product were measured by the following methods.

Bending characteristics: Using a universal tensilon device,
The measurement was performed at room temperature under a bending speed of 5 mm / min. Glass transition temperature: It was set as a point where the thermal expansion coefficient was changed by using a TMA apparatus and raising the temperature at a rate of 2 ° C./min. Pyrolysis initiation temperature: A temperature was raised at a rate of 5 ° C./min using a thermobalance, and the temperature was set to 10% reduction. The results are shown in Table 1.

[0012]

[Table 1]

From the results shown in Table 1, the systems containing the bifunctional anhydrides of Examples 1 to 12 were compared with the comparative examples containing conventional bifunctional anhydrides in the state of the resin before curing and the state of the cured product. It turns out that is extremely good. As for the bending properties of the cured products according to the examples of the present invention, it is understood that the elongation is large and the toughness is improved as compared with the comparative example using the conventional bifunctional anhydride and monofunctional anhydride alone. It can be seen that the glass transition temperature and the thermal decomposition temperature, which are indexes of heat resistance, are also improved in the examples of the present invention as compared with the comparative examples using the conventional bifunctional anhydride and monofunctional anhydride.

Examples 13 to 17 and Comparative Examples 7 to 9 In this example, the resin composition and the characteristics of the cured insulating coil were examined for use as an insulating varnish for a coil for a rotating machine. The compounding method was carried out according to the above-mentioned examples, and the curing accelerator was added at a ratio relative to the solid content. The method for producing an electrically insulated coil for a rotating machine will be described below. A glass-backed mica tape (insulating base material: tape having a width of 25 mm) was prepared by bonding an unfired soft laminated mica sheet and a glass cloth with a binder resin. The content of binder is non-volatile, 5
% By weight (based on the total weight of the insulating substrate). After winding the insulating base material on the semiconductor half-wrapped 5 times, the resin composition shown in Table 2 was impregnated under vacuum and 100 ° C./10 hours + 15.
It was cured by heating at 0 ° C./5 hours + 210 ° C./15 hours.
No peeling was observed in the insulating layer of the electrically insulated coil thus obtained. The characteristics of the cured product were measured by the following methods.

Heat resistance test (heat cycle test): 25
24 hours at 0 ° C, then 24 hours at 40 ° C, RH 95%
1 cycle of heating and moisture absorption test under the conditions
The cycle was repeated up to 0 cycles, and tan δ and insulation resistance were measured for each cycle. Weight reduction rate: Cut out only the insulating layer from the electrically insulated coil, and use a test piece of 50 mm × 50 mm to 270 ° C.
The rate of weight change after heat deterioration for 10 days was measured. Water resistance test: A test piece having a width of 10 mm and a length of 60 mm is cut out along the tape winding direction of the insulating layer of the electric insulating coil, and is supported at two points with a fulcrum distance of 40 mm and bent by a central load. Strength was measured at 25 ° C. Similarly,
The test piece was immersed in water at 40 ° C. for 24 hours, and the bending strength was measured to determine the retention rate from the initial stage. The results are shown in Table 2.

[0016]

[Table 2]

It can be seen that the characteristics of the insulating layer of the electrically insulating coil according to the embodiment of the present invention are improved in heat resistance and humidity resistance as compared with the comparative example using the conventional bifunctional anhydride and monofunctional anhydride. ..

Examples 18-22, Comparative Examples 10-12 In this example, the resin composition and the properties of the cured FRP laminate were investigated for use as a matrix resin for the FRP laminate. The compounding method is carried out according to Examples 1 to 12, and the curing accelerator is added in proportion to the solid content.
In Examples 18 to 22 and Comparative Example 12, glass cloth (E glass, thickness 0.1 mm) was impregnated with a resin, air-dried at room temperature, and further dried at 105 ° C. for 10 minutes to obtain a prepreg. .. 20 sheets of this prepreg are stacked and heated at a pressure of 50 kgf / cm ² and a temperature of 130 ° C. for 30 minutes,
Further, hot pressing was performed at 180 ° C. for 1 hour and 210 ° C. for 2 hours to obtain a laminated plate. In Comparative Examples 10 and 11, after air-drying, a solvent (DMF: N, N'-dimethylformamide) was used.
Since it has a high boiling point, the conditions are the same as those in Examples 18 to 22 except that it was dried at 140 ° C. for 3 minutes. The bending characteristics and the weight reduction rate were measured by cutting out a part of the molded product under the conditions outlined above.
For water resistance, the amount of water absorption was determined from the weight change after soaking for 24 hours at room temperature. The results are shown in Table 3.

[0019]

[Table 3]

The laminated materials according to the examples of the present invention have improved heat resistance and moisture resistance as compared with the conventional comparative examples using only bifunctional anhydrous acid and monofunctional anhydrous acid. Moreover, since a general low boiling point material can be used as a solvent for the resin, a good laminated product without voids was obtained.

Examples 23 to 27, Comparative Examples 13 to 15 Using the resin compositions shown in Examples 18 to 22 and Comparative Examples 10 to 12, prepregs were prepared under the same conditions as described above, and the surfaces of both sides of the prepregs were prepared. Roughened copper foil (thickness 3
5 μm), pressure 30 kgf / cm ² , temperature 1
Heat at 30 ℃ for 30 minutes, then at 170 ℃ for 1 hour, 21
A hot press was performed at 0 ° C. for 2 hours to obtain a copper-clad laminate.
An inner layer circuit pattern such as a signal layer, a power source layer, and a matching layer was formed on the obtained copper-clad laminate by a photoetching method, and the copper surface was pretreated for adhesion to produce a double-sided wiring unit circuit sheet.

The circuit sheets are laminated alternately with prepregs and the outermost layer is a copper foil, and the pressure is 40 kgf /
cm ^2, 1 hour at a temperature 170 ° C., to produce a prototype of a multilayer printed circuit board for 2 hours heating press at 200 ° C.. Further, a 0.3 mm or 0.6 mm hole was formed in the original form of the multilayer printed circuit board by a micro drill, and chemical copper plating was performed on the entire surface to form a through hole. Next, the outermost layer was formed by etching to produce a multilayer printed circuit board.
Table 4 shows a result of cutting out a part of the multilayer printed circuit board and measuring solder heat resistance and thermal shock resistance. In the table, regarding the solder heat resistance, ◯ indicates good, and x indicates peeling from the copper foil.

[0023]

[Table 4]

The solder heat resistance is 260 ° C. for 300 seconds, and the appearance is not abnormal. The thermal shock test is −60 ° C. to +125.
The cycle in which cracks were generated was measured with the temperature of 1 ° C as one cycle. The multilayer printed circuit boards according to the examples of the present invention are superior in solder heat resistance and thermal shock resistance to the comparative examples using the conventional bifunctional anhydride and monofunctional anhydride alone, and have improved reliability. Also, since a general low boiling point material can be used as a solvent for the resin, a good multilayer printed circuit board without voids was obtained.

Examples 28 to 32, Comparative Examples 16 to 18 In this example, in order to obtain a semiconductor encapsulating epoxy resin composition, each compound was mixed with a two-roll kneader.
After heating and kneading at 0 to 90 ° C. for 10 minutes, the mixture was cooled and coarsely pulverized. Then, using the epoxy resin composition, 4M
bit D. A RAM (dynamic random access memory) LSI was sealed using a transfer molding machine. Molding conditions: 180 ° C, 15 minutes, 70 kgf / cm
^{Is 2} . The obtained sealed product was put into a 121 ° C., 2-atmosphere supersaturated steam kettle (PCT kettle), taken out at predetermined intervals, and the electrical continuity of the LSI was checked to confirm corrosion breakage of aluminum wiring on the element. For each sealed product, 100 test pieces were introduced. Table 5 shows the composition of the formulation and the test results. The curing accelerator is the ratio of addition to the total amount of epoxy and anhydrous acid, and the other additives are the ratio to the total weight.

[0026]

[Table 5]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 23/29 23/31

Claims (5)

[Claims] 1. An epoxy resin composition comprising an epoxy resin and a tetracarboxylic acid dianhydride represented by the following formula 1. [Chemical 1] Each represents H, an alkyl group, an alkenyl group, and an alkenoyl group, and R ₁ and R ₂ are each H and an alkyl group having 1 to 18 carbon atoms. ) 2. A varnish for insulating an electrically insulating coil, which comprises using the epoxy resin composition according to claim 1. 3. A resin for a matrix of an FRP laminated material, which uses the epoxy resin composition according to claim 1. 4. An insulating resin for a printed circuit board, comprising the epoxy resin composition according to claim 1. 5. A resin for sealing a semiconductor element, which uses the epoxy resin composition according to claim 1.