JPH03115351A - Flame-retardant epoxy resin composition - Google Patents

Abstract

PURPOSE:To prepare an epoxy resin compsn. excellent in the mechanical properties, crack resistance, arc resistance, flame retardance, etc., and capable of preventing the generation of a toxic gas by compounding an epoxy resin, a curing agent, a brominated epoxy resin, antimony oxide, etc. CONSTITUTION:The title compsn. is prepd. by compounding: 100 pts.wt. resin component comprising an epoxy resin and a brominated epoxy resin; a curing agent (e.g. methyltetrahydrophthalic anhydride); 1-15 pts.wt antimony oxide; 10-100 pts.wt. aluminum hydroxide; and 100-500 pts.wt. composite filler comprising a shot glass fiber having a means aspect ratio of 2-20 and an inorg. filler having a mean particle diameter of 0.05-5mum. In the composite filler, the amt. of the glass fiber is pref. 30-80wt.% still pref. 40-70wt.%.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) FIELD OF THE INVENTION The present invention relates to flame retardant epoxy resin compositions.

(Prior Art) In recent years, there has been an increasing demand for flame retardant properties for various resin materials used for insulating members of electrical equipment, particularly electrical equipment in the nuclear field.

Various types of curable flame-retardant epoxy resin compositions have been studied as one of the resin materials that can meet such demands for flame retardancy.

Conventionally, flame-retardant epoxy resin compositions include: (1) those containing halogen compounds such as chlorine compounds and phosphorus compounds as flame retardants; (2) those containing brominated epoxy resins and antimony oxide as flame retardants; ■Those containing aluminum hydroxide as a flame retardant are known.

However, epoxy resin compositions containing these flame retardants have advantages and disadvantages, and pose problems in practical use.

That is, halogen compounds, phosphorus compounds, brominated epoxy resins,
A flame-retardant epoxy resin composition containing antimony oxide as a flame retardant exhibits a flame-retardant effect due to the gas generated in the gas phase due to the flame retardant during combustion. However, the flame retardance is accompanied by smoke containing harmful gases, which causes pollution problems, and furthermore, there are problems in that electrical properties such as arc resistance and tracking resistance are inferior.

On the other hand, the above-mentioned flame-retardant epoxy resin composition containing aluminum hydroxide as a flame retardant has a flame-retardant effect due to the water of crystallization contained in the aluminum hydroxide molecules, so it does not cause pollution problems. can be prevented, and electrical properties such as arc resistance are improved. However, there was a problem in that the mechanical strength such as bending strength and crack resistance of the cured product were significantly reduced, making it unsuitable especially as a casting resin composition for insulating structures.

(Problems to be solved by the invention) The present invention has been made to solve the conventional problems.
A flame-retardant epoxy resin composition that has excellent mechanical strength such as bending strength of a cured product, crack resistance, and electrical properties such as arc resistance, and can also provide sufficient flame retardancy and suppress the generation of harmful gases. This is what we are trying to provide.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides an epoxy resin (a), a curing agent (b), a brominated epoxy resin (C), antimony oxide (d), and aluminum hydroxide (e). , and a composite filler (f) consisting of short glass fibers having an average aspect ratio of 2 to 20 and an inorganic filler having an average particle size of 0.05 to 5 μm. It is a resin composition.

The epoxy resin (a) is not particularly limited, but includes, for example, bisphenol A type resin, bisphenol F type epoxy resin, novolak type epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol A type epoxy resin, triglycidyl isocyanate, and hydantoin. Examples include epoxy resins, and these may be used alone or as a mixture of two or more. Specifically, Ep1cotc815,81 manufactured by Shell Chemical Co., Ltd. is used as a bisphenol A type resin.
9,827,828, GY250 manufactured by Ciba-Geigi. G
Y252. GY280, DER3 manufactured by Dow Chemical Company
30, DER331, DER332, R manufactured by Mitsui Ishiura Co., Ltd.
-140, R-140P, and alicyclic epoxy resins include Chissonox 201, 221, 289, Araldite CY175. CY178. CY179 is mentioned. Among such epoxy resins, those that are liquid at room temperature are desirable.

The curing agent (b) is not particularly limited as long as it is a curing agent for epoxy resins, and examples thereof include novolac type phenolic resins having two or more phenolic hydroxyl groups such as phenol novolac resins and cresol novolak resins, phthalic anhydride, and hexahydrocarbons. Examples include acid anhydrides such as phthalic anhydride and tetrahydrophthalic anhydride, amines such as triethylenetetramine and metaphenylenediamine, and imidazole, and these may be used alone or as a mixture of two or more. Among such curing agents, acid anhydrides that are liquid at room temperature are desirable. Specifically, methyltetrahydrophthalic anhydride (New [MT-500 manufactured by Ippon Rika Co., Ltd., IIN-2200 manufactured by Hitachi Chemical Co., Ltd.), methylendomethylenetetrahydrophthalic anhydride (Kayahard MCD manufactured by Nippon Kapaku Co., Ltd.)
, HM-2200 manufactured by Hitachi Chemical Co., Ltd.), Methylnadic anhydride (HY-908 manufactured by Nippon Ciba-Geigi Co., Ltd.),
In addition to 4-methylhexahydrophthalic anhydride (M) l-700 manufactured by Shin Nihon Rika Co., Ltd.), modified acid anhydride (manufactured by Nippon Ciba Geigi Co., Ltd.) IY905, 915, 917, 919゜9
20, Epicure 103, 121, 1 manufactured by Yuka Shell Co., Ltd.
36), etc.

The brominated epoxy resin (C) is blended as one of the flame retardant components. As such a brominated epoxy resin, for example, Epiclon 152.1 manufactured by Dainippon Ink Co., Ltd.
65, bisphenol A-type brominated epoxy resin such as APR-755 manufactured by Asahi Kasei Co., Ltd., BREN- manufactured by Nippon Kapaku Co., Ltd.
Novolac type brominated epoxy resins such as No. 8 may be used, and these may be used alone or as a mixture of two or more. The bromine content of the brominated epoxy resin is based on the mixed component (hereinafter, the mixed component is referred to as the resin component), which is the epoxy resin (a), the curing agent (b), and the brominated epoxy resin (c). It is desirable that the content be in the range of 5 to 15%. The reason for this is that if the amount is less than 5% by weight, sufficient flame retardant effect may not be obtained, while if the amount exceeds 15% by weight, the electrical properties may deteriorate.
There is a risk of causing pollution problems due to the generation of harmful gases.

The antimony oxide (d) is blended as one of the flame retardant components. As such antimony oxide,
Examples include antimony trioxide, antimony tetroxide, antimony pentoxide, antimony trioxide, etc.
These may be used alone or as a mixture of two or more. These antimony oxides may be surface-treated with a silane coupling agent or the like. The amount of antimony oxide to be blended is preferably in the range of 1 to 15 parts by weight, more preferably 2 to 10 parts by weight, per 100 parts by weight of the resin component. The reason for this is that if the amount is less than 1 part by weight, sufficient flame retardant effect may not be obtained, whereas if the amount exceeds 15 parts by weight, the electrical properties may deteriorate or harmful gases may be generated. There is a risk of causing pollution problems.

The aluminum hydroxide (e) is blended to impart flame retardancy and improve arc resistance. Examples of such aluminum hydroxide include Hisilite H-31, 8-32, H-42, )l-43 manufactured by Showa Light Metal Company, and aluminum hydroxide B-52°8-103 manufactured by Nippon Light Metal Company.
．． B-700, etc., and these may be used alone or as a mixture of two or more. These antimony oxides may be surface-treated with a silane coupling agent or the like. The amount of aluminum hydroxide to be blended is preferably 10 to 100 parts by weight, more preferably 20 to 50 parts by weight, based on 100 parts by weight of the resin component. The reason for this is that if the amount is less than 10 parts by weight, it will be difficult to achieve sufficient flame retardant effect and arc resistance, while if the amount exceeds 100 parts by weight, the mechanical strength and resistance of the cured product will decrease. There is a risk that crack resistance may be reduced.

Short glass fibers, which are one of the components of the composite filler (f), improve the mechanical strength of the cured product due to the addition of the aluminum hydroxide (e) and improve crack resistance. It has an effect.

Such glass fibers are not particularly limited as long as they have an average aspect ratio within the above range, and specifically, Micro Glass Surf Knee Strand REV-1 manufactured by Nippon Sheet Glass Co., Ltd.
, REV-4, REV-8, REV-7, REV-8, and the like.

The inorganic filler, which is the other component of the composite filler (['), is used to provide low viscosity and good fluidity even when the glass fiber is blended. Examples of such inorganic fillers include silica, alumina,
Examples include talc, clay, and wollastonite, with silica being particularly preferred from the viewpoint of improving the fluidity of the resin composition.

The compounding amount of the composite filler (r) is 100% of the resin component.
It is desirable that the amount is in the range of 100 to 500 parts by weight, more preferably 100 to 400 parts by weight. The reason for this is that if the amount is less than 100 parts by weight, it will be difficult to improve the mechanical strength and crack resistance of the cured product, while if the amount exceeds 400 parts by weight, the viscosity of the composition will increase. Liquidity may decrease.

The content of the glass fiber in the composite filler (f) is preferably 30 to 80% by weight, more preferably 40 to 70% by weight. The reason for this is that if the amount of glass fiber occupied is outside the range of 30 to 80% by weight, the viscosity will increase and the fluidity may be inhibited.

The flame retardant epoxy resin composition according to the present invention includes the above (a)
In addition to the component (f), if necessary, the average particle size is 5 μm.
Inorganic fillers such as silica, alumina, talc, and wollastonite, catalysts, colorants, surfactants, silane coupling agents, and the like may be blended.

(Function) The flame-retardant epoxy resin composition of the present invention uses an epoxy resin as a base material, and contains a brominated epoxy resin (C), antimony oxide (d), and aluminum hydroxide (e). For this reason, the brominated epoxy resin (C)
and the synergistic effect of the flame retardant effect due to the gas caused by the antimony oxide (d) generated in the gas phase during combustion and the flame retardant effect due to the water of crystallization contained in the molecules of the aluminum hydroxide (e). Through this action, sufficient flame retardancy can be imparted. In addition, by blending the aluminum hydroxide as a flame retardant, the amount of the brominated epoxy resin and antimony oxide can be reduced, so that the brominated epoxy resin (e) and antimony oxide (d) are removed during combustion.
can reduce the generation of H poisonous gas caused by Furthermore, arc resistance can be improved by adding aluminum hydroxide.

Further, the flame retardant epoxy resin composition of the present invention comprises short glass fibers having an average aspect ratio of 2 to 20 and an average particle size of 0.0.
Because it contains a composite filler (f) consisting of 5 to 5 μl of fine inorganic filler, it compensates for the decrease in mechanical strength such as bending strength of the cured product and crack resistance due to the addition of aluminum hydroxide. can do. That is, by incorporating short glass fibers into a resin composition as a reinforcing material, the mechanical strength and crack resistance of the cured product can be improved. However, it is actually difficult to uniformly mix short glass fibers into a resin composition, and as the short glass fibers are added, the viscosity of the resin composition increases and fluidity decreases. Formability by molding methods etc. deteriorates. Therefore, when only short glass fibers are used as a filler, it is difficult to mix them in a sufficient amount to improve mechanical strength and the like. On the other hand, although a fine inorganic filler can improve the fluidity of a resin composition, it is difficult to improve the mechanical strength and crack resistance of a cured product using only this inorganic filler. From such a thing,
By blending into the resin composition a composite filler (f') consisting of short glass fibers with an average aspect ratio of 2 to 20 and an inorganic filler with an average particle size of 0.05 to 5 μm, the glass The effects of the short fibers and the inorganic filler complement each other, and the flow effect of the inorganic filler allows a sufficient amount of glass fiber to be blended, improving the mechanical strength (especially bending strength) and crack resistance of the cured product. It is possible to improve not only the properties but also the moldability by the casting method.

(Example) Examples of the present invention will be described in detail below.

Examples 1 to 7 and Comparative Examples 1 to 8 Flame retardant epoxy resin compositions having the compositions shown in Table 1 below,
A flame-retardant epoxy resin composition prepared by mixing under heating and vacuum using a Sanei Manufacturing Co., Ltd. universal mixer was heated and cured to form a sample, and the flame retardance, arc resistance, bending strength, and crack resistance were determined. I researched gender. The results are also listed in Table 1.

As is clear from Table 1, the flame retardant epoxy resin compositions of Examples 1 to 7 have better flame retardancy, arc resistance, bending strength and It can be seen that good results were obtained in a well-balanced manner in all evaluation items of crack resistance.

[Effects of the Invention] As detailed above, according to the present invention, the cured product has excellent electrical properties such as mechanical strength, crack resistance, and arc resistance, and also has sufficient flame retardancy and is resistant to harmful gases. It is possible to provide a flame-retardant epoxy resin composition that can suppress the occurrence of fire.

Claims (1)

[Scope of Claims] (a) epoxy resin, (b) curing agent, (c) brominated epoxy resin, (d) antimony oxide, (e) aluminum hydroxide, and (f) an average aspect ratio of 2 to 20. A flame-retardant epoxy resin composition comprising: a composite filler consisting of short glass fibers having the following properties and an inorganic filler having an average particle size of 0.05 to 5 μm.