JP3497293B2 - Modified epoxy resin, epoxy resin composition and cured product thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a modified epoxy resin and an epoxy resin composition which give a cured product having excellent crack resistance and a cured product thereof.

[0002]

2. Description of the Related Art Conventionally, epoxy resin compositions containing epoxy resins, phenol novolac resins or acid anhydrides, and curing accelerators as main components have been widely used in the field of encapsulating materials for electric / electronic parts and ICs. There is. However, the conventional epoxy resin composition is often cracked in the cured product due to internal stress generated at the time of curing, so that the appearance of the molded or coated surface is impaired, or many defects are caused in semiconductor elements or devices. In order to solve the problems, resin compositions containing polybutadiene rubber, organopolysiloxane, etc. are used.

[0003]

However, when a polybutadiene rubber or an organopolysiloxane is added to a conventional epoxy resin composition, the stress of the cured product can be reduced, but the heat resistance and other physical properties are deteriorated. Problems have arisen and are not yet satisfactory.

[0004]

In view of these circumstances, the inventors of the present invention have earnestly studied for an epoxy resin composition having improved crack resistance while maintaining the conventional physical properties such as heat resistance. Epoxy resin composition containing a modified epoxy resin having a molecular structure of, in the cured product, it was found to provide excellent crack resistance while maintaining heat resistance, to complete the present invention It was.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Expression (1)

[0006]

[Chemical 4]

(In the formula (1), w, x, y and z are positive numbers and represent average values.)

An epoxy group-containing polybutadiene represented by the formula (1) and an organopolysiloxane having one or more --SiH groups in one molecule are subjected to an addition reaction to obtain a compound of the formula (2).

[0009]

[Chemical 5]

Or equation (3)

[0011]

[Chemical 6]

A modified epoxy resin having a bond represented by: (2) (a) an epoxy resin composition containing the epoxy resin (b) curing agent described in (1) above, and (3) a curing accelerator. Epoxy resin composition according to (2) above, (4) Epoxy resin composition according to (2) or (3) containing an inorganic filler, (5) Above (2), (3) or ( 4) to provide a cured product obtained by curing the epoxy resin composition as described above.

The modified epoxy resin in the present invention can be obtained by subjecting the double bond of polybutadiene having an epoxy group and the -SiH group of the organopolysiloxane to an addition reaction in the presence of a specific catalyst.

The polybutadiene having an epoxy group used in the present invention is a diene rubber polymer having at least one epoxy group capable of reacting with a curing agent in the molecule, and is expressed as the number of epoxy groups per molecule. Is usually 2
-20, preferably 3-15. Again 1
The number of double bonds per molecule is usually 3 to 30,
It is preferably 5 to 25. The number average molecular weight is usually 500 to 3,000, preferably 600.
~ 2,500 are used. Such epoxy group-containing polybutadiene may be, for example, E-1000-8, E-
Commercial products such as 1800-6.5 (manufactured by Nippon Oil Co., Ltd.) and Denarex R-45 EPI (manufactured by Idemitsu Petroleum Co., Ltd.) are easily available.

The organopolysiloxane used in the present invention includes at least one --S in one molecule.
It has an iH group and usually has a number average molecular weight of 4
It is from 00 to 3000, preferably from 500 to 2800. Specifically, for example, the following compounds may be mentioned.

[0016]

[Chemical 7]

[0017]

[Chemical 8]

[0018]

[Chemical 9]

In the formulas (4) to (6), l, m and n represent average values, and usually l + m + n = 3 to 500, preferably 1 + m + n = 5 to 400.

The modified epoxy resin of the present invention comprises a double bond of the polybutadiene having the above epoxy group and the --SiH group of the above organopolysiloxane and a conventionally known addition catalyst such as a platinum system such as chloroplatinic acid. It can be obtained by heating reaction in the presence of a catalyst. When the polybutadiene having an epoxy group and the organopolysiloxane are reacted, the ratio of the -SiH group in the organopolysiloxane is usually 0.001-1 with respect to one double bond in the polybutadiene having an epoxy group. The number is preferably 0.005 to 0.8.

The modified epoxy resin of the present invention has the following formula (7)

[0022]

[Chemical 10]

(In the formula, w, x, y and z have the same meanings as in the formula (1). A and B are the following formulas (8) and (9).

[0024]

[Chemical 11]

Respectively, ), The double bond of the epoxy group-containing polybutadiene and the -SiH group of the organopolysiloxane can be subjected to an addition reaction, so that
When the iH group is added to the double bond of the A portion in the formula (7), the bond represented by the formula (2) is formed, and when added to the B portion, the bond represented by the formula (3) is formed. It

In the addition reaction, 60 to 12 in an inert solvent such as benzene, toluene and methyl isobutyl ketone.
It is preferable to heat to 0 ° C. The amount of the solvent used is usually 30 to 400%, preferably 50 to 300% of the total weight of the epoxy group-containing polybutadiene and the organopolysiloxane. The reaction time is usually 1 to 15 hours, preferably 2 to 10 hours. After completion of the reaction, the modified epoxy resin of the present invention can be obtained by washing with water and distilling off the solvent under heating and reduced pressure.

The epoxy resin composition of the present invention can be obtained by using the modified epoxy resin of the present invention as an essential component and adding a curing agent and, if necessary, a curing accelerator. In the epoxy resin composition of the present invention described in (2), (3) and (4) above, the epoxy resin of the present invention can be used alone or in combination with other epoxy resins. When used in combination, the proportion of the epoxy resin of the present invention in the total epoxy resin is preferably 2% by weight or more, particularly preferably 4% by weight or more. In this case, the epoxy resin used is not particularly limited as long as it is a compound having two or more epoxy groups in one molecule and is generally used for electronic devices. Specific examples of epoxy resins that can be used include phenol novolac type epoxy resins, cresol novolac type epoxy resins, naphthol novolac type epoxy resins and other novolac type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD type epoxies. Resins, bisphenol S type epoxy resins, bisphenol I type epoxy resins, biphenyl type epoxy resins and other epoxy resins obtained from aromatic dihydric phenols, glycidyl obtained by the reaction of polybasic acids such as phthalic acid and dimer acid with epihalohydrin Ester type epoxy resins, glycidyl amine type epoxy resins obtained by reaction of polyamines such as diaminodiphenylmethane and isocyanuric acid with epihalohydrin can be mentioned. . These epoxy resins may be used alone or in combination of two or more.

Specific examples of the curing agent that can be used in the epoxy resin composition of the present invention include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, amine compounds such as isophoronediamine and dicyandiamide, and dimer of linolenic acid. Resin synthesized from the body and ethylenediamine, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hexahydrophthalic anhydride, Examples thereof include novolak resins such as methylhexahydrophthalic anhydride, phenol novolac and cresol novolac, and modified products thereof, imidazole, BF ₃ -amine complex, guanidine derivative and the like. These curing agents may be used alone or in combination of two or more.

The amount of the curing agent used in the epoxy resin composition of the present invention is preferably 0.7 to 1.2 equivalents relative to 1 equivalent of epoxy groups of the epoxy resin. If the amount is less than 0.7 equivalent or more than 1.2 equivalent to 1 equivalent of the epoxy group, the curing may be incomplete and good cured physical properties may not be obtained.

The epoxy resin composition of the present invention may contain a curing accelerator. Specific examples of the curing accelerator that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole and 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, 1,8-diaza-. Examples thereof include tertiary amines such as bicyclo (5,4,0) undecene-7, phosphines such as triphenylphosphine, and metal compounds such as tin octylate. The curing accelerator is epoxy resin 100
If necessary, 0.1 to 5.0 parts by weight is used based on parts by weight.

Further, the epoxy resin composition of the present invention is
If necessary, it contains an inorganic filler. Specific examples of the inorganic filler that can be used include silica, alumina, talc and the like. The inorganic filler is 0 to 0 in the epoxy resin composition.
An amount occupying 90% by weight is used if necessary. Furthermore, if necessary, various compounding agents such as a silane coupling agent, a release agent and a pigment may be added to the epoxy resin composition of the present invention.

The epoxy resin composition of the present invention can be obtained by uniformly mixing the components. The epoxy resin composition of the present invention can be easily made into a cured product by a method similar to a conventionally known method. For example, an epoxy resin composition is obtained by sufficiently mixing an epoxy resin with a curing agent, an inorganic filler, and other compounding agents as needed using an extruder, a kneader, a roll, etc. until uniform. After the epoxy resin composition is melted, it is molded by using a casting or transfer molding machine, and further 2 to 10 at 80 to 200 ° C.
The cured product can be obtained by heating for a time.

Further, the epoxy resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone and the like to prepare glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper and the like. A prepreg obtained by impregnating a base material with heating and drying can be hot-press molded to obtain a cured product. The solvent is used in an amount such that the proportion of the solvent in the mixture of the epoxy resin composition of the present invention and the solvent is usually 10 to 70% by weight, preferably 15 to 65% by weight.

[0034]

EXAMPLES Next, the present invention will be described more specifically by way of Examples and Comparative Examples. In the following, parts are parts by weight unless otherwise specified.

Example 1 An epoxidized polybutadiene represented by the above formula (1) (epoxy equivalent 203 g / eq, double bond equivalent) was placed in a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractionating tube and a stirrer. 83 g / eq, number average molecular weight of about 1000) 166
Parts, methyl isobutyl ketone 150 parts, toluene 300
Parts, 0.05 parts of a 2-ethylhexanol-modified chloroplatinic acid solution having a platinum concentration of 2%, respectively, and subjected to azeotropic dehydration for 1 hour, and at the reflux temperature, the organopolysiloxane represented by the formula (5) ( -SiH group equivalent 1370 g / eq, 50 parts of number average molecular weight 2740) was charged at a dropping time of 30 minutes, and the mixture was further reacted by stirring at the same temperature for 4 hours. The modified epoxy resin (A) part of the present invention was obtained by distilling off underneath. The obtained epoxy resin was liquid and had an epoxy equivalent of 26.
It was 4 g / eq.

Examples 2 to 4 and Comparative Example 1 Epoxy resin (A) obtained in epoxy resin as Examples 2 to 4 and Comparative Example 1 and liquid epoxy resin Epicoat 828 (epoxy equivalent 186 g / eq, oilification A mixture of Shell Epoxy Co., Ltd. was used in different ratios, and an acid anhydride type curing agent Kayahard MCD (Nippon Kayaku Co., Ltd.)
Methyl endomethylene tetrahydrophthalic anhydride), 2-ethyl-4-methylimidazole (2E4MZ) as a curing accelerator, and stearic acid as a compounding agent, a silane coupling agent, and silica powder as an inorganic filler. Epoxy resin compositions for the present invention and for comparison were obtained by compounding with the compositions shown in the composition column of Table 1. Then, a semiconductor element is resin-sealed by a casting method using this composition, and these are cured at 80 ° C. for 2 hours, then at 120 ° C. for 2 hours, and at 200 ° C. for 5 hours to assemble a simulated semiconductor device. The glass transition point and crack resistance were measured. The results are shown in Table 1. The conditions for measuring crack resistance are as follows. Further, in the table, the numerical values in the column of formulation indicate parts by weight.

Glass transition temperature thermomechanical measuring device (TMA): TM-70 manufactured by Vacuum Riko Co., Ltd.
00 Temperature rising rate: 2 ° C./min Crack resistance 9.0 × 4.5 × 0.5 mm size silicon chip is sealed in a 14 PIN-IC frame (42 alloy) with an epoxy resin composition, After curing under the above conditions-
A thermal cycle of 196 ° C. × 1 minute to 260 ° C. × 30 seconds was repeatedly added, and the crack generation rate of the cured product after 50 cycles was measured.

[0038]

[Table 1] Table 1 Actual examples Comparative examples 2 3 4 1 Composition of composition Epoxy resin (A) 40 30 20 0 Epicoat 828 140 150 160 180 Kayahard MCD 145 147 150 155 2E4MZ 1.8 1.8 1.8 1.8 Silica powder 800 800 800 800 Stearic acid 4 4 4 4 Silane coupling agent 5 5 5 5 Physical properties of cured product Glass transition temperature (℃) 163 165 165 166 Crack resistance 0/10 0/10 2/10 9/10 In Table 1, crack resistance With respect to the sex, X of the 10 test bodies in which cracks were generated were shown as X / 10 with respect to 10 test bodies.

From Table 1, the cured product of the epoxy resin composition of the present invention exhibited excellent crack resistance while maintaining heat resistance.

[0040]

The modified epoxy resin of the present invention can give a cured product having excellent crack resistance and is extremely useful for a wide range of applications such as molding materials, casting materials, laminating materials, paints, adhesives and resists. is there.

Claims (5)

(57) [Claims] 1. A formula (1): (In the formula (1), w, x, y, and z are positive numbers and represent average values.) Polybutadiene containing an epoxy group and an organopoly having one or more —SiH groups in one molecule. In the molecule obtained by the addition reaction with siloxane, the compound of the formula (2) Alternatively, formula (3): A modified epoxy resin having a bond represented by. 2. The epoxy resin according to claim 1, which is (a). (B) An epoxy resin composition containing a curing agent. 3. The epoxy resin composition according to claim 2, which contains a curing accelerator. 4. The epoxy resin composition according to claim 2, which contains an inorganic filler. 5. A cured product obtained by curing the epoxy resin composition according to claim 2, 3 or 4.