JP2726483B2 - High heat-resistant flame-retardant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electric and / or thermoelectric material for providing a cured product having excellent heat resistance and flame retardancy.
The present invention relates to a high heat-resistant flame-retardant resin composition useful as an electronic component material.

[Prior art] Conventionally, epoxy resins have been used as electric and electronic component materials because of their excellent properties.
We have provided excellent cured products as materials for electric and electronic components such as IC sealants and laminates. In particular, cresol novolak epoxy resins are widely used from the viewpoint of ease of use in terms of melt viscosity or heat resistance of a cured product obtained.

On the other hand, for the purpose of imparting flame retardancy to the cured product, brominated epoxy resins such as bisphenol A type brominated epoxy resins and phenol novolak type brominated epoxy resins are generally used together with epoxy resins such as cresol novolak type epoxy resins. used.

[Problems to be Solved by the Invention] However, recent improvements in the integration density or higher integration of semiconductors have imposed new problems on resin compositions.

That is, in order to improve the integration density, use of a semiconductor by a surface mounting method has recently been demanded, and as a result, the sealing agent is immersed in a severe temperature condition of solder immersion (for example, 260 ° C.).
C.) has been required. For that reason,
In general, a method of increasing heat resistance by increasing the amount of filler used in the sealant is employed. This is an extremely effective method utilizing the fact that silica powder generally used as a filler is an inorganic substance and has heat resistance. However, increasing the amount of the filler, on the other hand, impairs the flow characteristics of the sealant, so that the amount of the increase was naturally limited. Moreover, even if the filler is increased as much as possible, from the viewpoint of heat resistance under the severe temperature condition of this solder immersion (for example, 260 ° C.), as long as the cresol novolac type epoxy resin is used, Not enough. Among brominated epoxy resins generally used for imparting flame retardancy, bisphenol A type brominated epoxy resin (ETBA
Is abbreviated in terms of heat resistance, and the phenol novolac type brominated epoxy resin used for the purpose of improving the heat resistance has a drawback that flow properties are impaired because the viscosity is too high.

Therefore, even if the amount of the filler is increased, providing a resin composition having a low viscosity so as not to impair the flow characteristics, and having flame retardancy and heat resistance can improve the integration density of the semiconductor or increase the integration. Is an extremely important issue.

[Means for Solving the Problems] The present inventors have conducted intensive studies on a resin composition having heat resistance without impairing flow characteristics, and consequently condensing hydroxybenzaldehyde and phenols,
Epoxy resin obtained by epoxidation and bromine content of 30
% By weight, and a resin composition comprising a brominated phenol novolak epoxy resin having a softening point of 70 ° C. or less in a specific ratio, has high heat resistance, has flame retardancy, and has flow characteristics. The inventors have found that the present invention is good, and have completed the present invention.

That is, the present invention provides: a) an epoxy resin which is a glycidyl ether of a condensate of hydroxybenzaldehyde and a phenol; b) a brominated phenol novolak having a bromine content of 30% by weight or more and a softening point of 70 ° C or less. An epoxy resin, and c) a curing agent, and 10 to 100 parts by weight of a brominated phenol novolak epoxy resin of b) are blended with 100 parts by weight of the epoxy resin of a), and a) and b) are totaled. A highly heat-resistant and flame-retardant resin composition comprising 0.5 to 1.5 equivalents of a curing agent of c) with respect to 1 equivalent of an epoxy resin, characterized by good heat resistance, flame retardancy and flow characteristics. To a resin composition to be formed.

In the present invention, salicylaldehyde and parahydroxybenzaldehyde are preferred as hydroxybenzaldehyde, and substituted or unsubstituted phenols such as phenol, cresol, 2,6-xylenol, and 2,4-xylenol are exemplified as phenols. And phenol, cresol and 2,6-xylenol are particularly preferred.

In the present invention, the use amount of the brominated phenol novolak epoxy resin per 100 parts by weight of the epoxy resin is 10 to 100 parts by weight, preferably 20 to 80 parts by weight. At this time, when the amount of the brominated phenol novolak epoxy resin is smaller, the flame retardancy is not provided, the flow characteristics are deteriorated, and when the amount is larger, the heat resistance is impaired.

According to the present invention, the heat resistance by the epoxy resin according to claim a), the flame retardancy and flow characteristics by the brominated phenol novolak epoxy resin according to b), and the IC due to good flow characteristics There is a surprising advantage that the heat resistance and the flame retardancy can be simultaneously imparted to the cured product due to the synergistic effect that the amount of the filler used in the sealant can be increased.

The epoxy resin used in the present invention can be obtained by epoxidizing a condensate obtained by reacting hydroxybenzaldehyde and a phenol with a known method in the presence of an acidic catalyst by a known method. Further, the brominated phenol novolak epoxy resin of the present invention can be obtained by brominating a phenol novolak resin having a softening point of 75 ° C. or lower by a known method (for example, see Japanese Patent Publication No. Sho 50-10635) and then epoxidizing it. .

Components other than these epoxy resins and brominated phenol novolak epoxy resins important in the composition of the present invention include polyamine-based curing agents such as aliphatic polyamines, aromatic polyamines, and polyamide polyamines, hexahydrophthalic anhydride, and methyltetrahydroanhydride. An acid anhydride based curing agent such as phthalic acid, a phenol based curing agent such as phenol novolak and cresol novolac, a Lewis acid such as boron trifluoride or a salt thereof, a curing agent such as dicyandiamide, etc. are epoxy resin and brominated phenol novolak. 0.5 to 1 equivalent of epoxy resin in total of epoxy resin
~ 1.5 equivalents, and if necessary, by adding 0.01 to 10 parts by weight of a curing accelerator to 100 parts by weight of the epoxy resin in total, a cured product excellent in heat resistance and flame retardancy can be provided. . Also, as described above, the good flow characteristics, which is an important feature of the present invention, allows for an increase in the amount of filler used in IC encapsulants, and therefore, the mixing of inorganic or organic fillers is also possible. It is extremely effective for improving heat resistance.

 An example will be described below.

Synthesis Example 1 A four-necked flask equipped with a thermometer and a stirrer was charged with 122 g (1 mol) of salicylaldehyde, 752 g (8 mol) of phenol, and 3.8 g of p-toluenesulfonic acid.
The reaction was carried out at 100100 ° C. for 2 hours, and further at 120-150 ° C. for 2 hours. After cooling to 70 ° C., 500 ml of methyl isobutyl ketone was added, and the mixture was washed with water until the washing water became neutral. The organic layer was separated and concentrated under reduced pressure to obtain 280 g of a condensate (A). The hydroxyl equivalent of the condensate (A) was 98 g / eq. Further, 98 g of the obtained condensate (A) was charged into a four-necked flask equipped with a thermometer, a stirrer, and a reflux device, and 650 g of epichlorohydrin was added.
Was dissolved. After dissolution, 48% aqueous sodium hydroxide solution 87.5
g was added dropwise over 6 hours. During this time, the water contained in the aqueous sodium hydroxide solution and the water generated by the reaction are removed under reduced pressure (15
0mmHg ~ 250mmHg) while azeotropically dehydrating the reaction temperature to 75 ℃ ~
It was kept at 80 ° C. After the completion of the dropwise addition of the aqueous sodium hydroxide solution, the mixture was further stirred at the same temperature for 1 hour. After completion of the reaction, by-produced salts were separated, and the solution was washed several times with water to make it neutral. Next, the organic layer was concentrated under reduced pressure to obtain 140 g of the epoxy resin (A1) used in the present invention. The epoxy equivalent of resin (A1)
It was 163 g / eq.

Synthesis Example 2 290 g of a condensate (B) was obtained in the same manner as in Synthesis Example 1, except that 864 g (8 mol) of orthocresol was used instead of phenol. The hydroxyl equivalent of the condensate (B) was 106 g / eq. Except for using 106 g of this condensate (B), the reaction with epichlorohydrin was carried out in the same manner as in Synthesis Example 1 to obtain 145 g of an epoxy resin (B1) used in the present invention. The epoxy equivalent of the resin (B1) was 170 g / eq.

Synthesis Example 3 Phenol novolak resin having a softening point of 73 ° C (hydroxyl equivalent weight)
106 g / eq.) 106 g and methanol 200 g were charged into a four-necked flask equipped with a thermometer and a stirrer, and dissolved while blowing nitrogen gas. In this, 176 g (1.1 mol) of bromine at 25 ° C
After dropwise addition at 3030 ° C., stirring was continued at the same temperature for 30 minutes. Next, a 30% aqueous sodium hydroxide solution was gradually added to neutralize by-produced hydrogen bromide. Further, the reaction solution was dropped into water 5 with vigorous stirring to obtain granular brominated phenol novolak resin. The obtained brominated phenol novolak resin was charged into a four-necked flask equipped with a stirrer and a reflux device, and dissolved in 650 g of epichlorohydrin. After dissolution, 87.5 g of a 48% aqueous sodium hydroxide solution was added dropwise over 6 hours. During this time, the water contained in the aqueous sodium hydroxide solution and the water generated by the reaction are reduced under reduced pressure (150 mmHg to 250 mmHg).
The reaction temperature was kept at 75 ° C to 80 ° C while azeotropic dehydration with.
After the completion of the dropping of the aqueous sodium hydroxide solution, one more
Stirred for hours. After completion of the reaction, by-produced salts were separated, and the solution was washed several times with water to make it neutral. Then the organic layer is separated,
It was concentrated under reduced pressure to obtain 215 g of a brominated phenol novolak epoxy resin (C) used in the present invention. The obtained epoxy resin (C) has an epoxy equivalent of 275 g / eq. And a softening point of 66.
° C, the bromine content was 35.2% by weight.

Examples 1 to 7 The epoxy resins obtained in Synthesis Examples 1, 2 and 3 and the brominated phenol novolak epoxy resin were mixed at the ratios shown in Table 1, and the glass transition temperature of the cured product was measured. As a curing agent, phenol novolak resin (Nippon Kayaku Co., Ltd.)
, A hydroxyl equivalent of 106 g / eq., A softening point of 84 ° C) and 2-methylimidazole as a curing accelerator in the proportions shown in Table 1, roll kneading at 70 to 80 ° C for 15 minutes, cooling, pulverizing, and tableting. After molding by a transfer molding machine, post-curing was performed to obtain a cured product for measuring a glass transition temperature.

 Table 3 shows the evaluation results of the cured products.

The glass transition temperature, transfer molding conditions and post cure conditions are as follows.

Glass transition temperature Thermomechanical analyzer (TMA): TM-7000, Vacuum Riko Co., Ltd. Heating rate: 2 ° C / min Transfer molding conditions Temperature: 150 ° C Molding pressure: 50 kg / cm ² hours: 3 minutes Post-curing Conditions Temperature: 180 ° C Time: 8 hours Comparative Examples 1 to 4 Orthocresol novolak epoxy resin (EOCN1020, epoxy equivalent 200,
Nippon Kayaku Co., Ltd.) and brominated phenol novolak epoxy resin (BREN-S, epoxy equivalent 280, bromine content 3)
5.0% by weight, softening point 85 ℃, Nippon Kayaku Co., Ltd.) or ETBA
(ETBA-100, epoxy equivalent: 356, bromine content: 48.1% by weight, softening point: 54 ° C., manufactured by Nippon Kayaku Co., Ltd.) and the same curing agent and curing accelerator as in Example 1, and molded by transfer molding To obtain a cured product.

 Table 3 shows the evaluation results of the cured products.

Examples 8 to 11 The resin compositions prepared in the amounts shown in Examples 2, 3, and 4 and Comparative Examples 1 and 2 were mixed with fused silica and a silane coupling agent (Tore. Silicone SH6040) and carnauba wax were blended, roll-kneaded at 70 to 80 ° C for 15 minutes, cooled, pulverized, and further tableted, and the flow characteristics in a spiral flow were evaluated by a transfer molding machine.

The spiral flow measurement was performed according to the method of EMMI 1-66.

Molding conditions for spiral flow measurement by the method of EMMI 1-66 Temperature: 180 ± 2 ° C Molding pressure: 70 ± 2 Kg / cm ² Transfer ram speed: 2.5 to 10 cm / sec Tablet weight: 20 g (However, 0.3 to 0.35 cull thickness) Preheat: None Spiral value: Read in 0.25 inch increments of continuous spiral Spiral flow: Average of 3 measurements (up, down ± 2%) [Effects of the Invention] As is clear from Table 3, according to the resin composition of the present invention, the glass transition temperature, which is an index of heat resistance, is higher than that of conventional resin compositions (Comparative Examples 1 to 4). As shown in Table 4, a high heat-resistant composition that can be used in a surface mounting method because it can be blended with a large amount of fused silica, that is, it can be filled at a high density. Very useful as a product.

Claims (1)

(57) [Claims] 1. An epoxy resin which is a glycidyl ether of a condensate of hydroxybenzaldehyde and a phenol, and b) a brominated phenol novolak epoxy having a bromine content of 30% by weight or more and a softening point of 70 ° C. or less. An epoxy obtained by adding 10 to 100 parts by weight of a brominated phenol novolak epoxy resin of b) to 100 parts by weight of the epoxy resin of the above a), which contains a resin and c) a curing agent, and a) and b) are totaled. A highly heat-resistant and flame-retardant resin composition comprising 0.5 to 1.5 equivalents of the curing agent (c) based on 1 equivalent of the resin.