JP2012201711A - Casting epoxy resin composition, and coil part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casting resin composition which prevents the generation of cracks due to thermal cycling and mechanical stress and is excellent in dielectric breakdown characteristics and heat resistance, and to provide a coil part using the casting resin composition.SOLUTION: The two-part casting epoxy resin composition is characterized by comprising a main agent component comprising (A) a non-flexible epoxy resin and (B) silica particles, and a curing agent component comprising (C) a flexible epoxy resin, (D) a curing agent and (E) a curing accelerator. The coil part is obtained by cast-molding the casting epoxy resin composition.

Description

  The present invention relates to a casting epoxy resin composition and a coil component.

  It is common knowledge that coils used in various devices such as automobiles, especially ignition coils, are cast and sealed with a resin composition from the viewpoint that electrical insulation must be ensured with respect to the surroundings. ing. For such a resin composition, high impregnation properties and high insulation properties are required. From such a viewpoint, an epoxy resin composition has been widely used as the resin composition.

  However, since a high voltage is applied to the coil parts as described above, simply using a normal epoxy resin composition may result in insufficient insulation, resulting in dielectric breakdown, etc. In some cases, the sealing resin may crack due to thermal stress or mechanical stress resulting from the thermal cycle of the object. If a crack occurs in the sealing resin, when a current is passed through the coil, abnormal discharge or the like occurs in the crack portion, and the coil component cannot be operated normally.

  Although the occurrence of cracks can be suppressed to some extent by blending a flexible epoxy resin with the epoxy resin composition, the glass transition temperature is lowered and the heat resistance is lowered, and the high temperature environment as described above. It cannot be used as a sealing resin for an ignition coil used below.

  In view of such a problem, in Patent Document 1, it is difficult to form a tree path by containing a predetermined amount of silica particles having a particle size in a specific range with respect to the epoxy resin composition, thereby insulating the epoxy resin composition. Attempts have been made to reduce the breakdown voltage and prevent dielectric breakdown even when a high voltage is applied to the coil component.

  Further, in Patent Document 2, by obtaining a spherical resin having a specific particle diameter, an A agent composed of an acid anhydride and a curing accelerator, and an epoxy resin composition containing an epoxy resin as a B agent, and reducing the linear expansion coefficient. Attempts have been made to improve heat cycle resistance and prevent the occurrence of cracks due to the above-described thermal stress.

  However, even in the prior art as described above, it is not possible to sufficiently prevent the occurrence of dielectric breakdown and cracking due to thermal cycle and mechanical stress of the cast-sealed resin composition, and further improvement has been demanded. .

JP 2008-195782 A JP-A-11-71503

  The present invention provides a casting resin composition that is excellent in dielectric breakdown characteristics and heat resistance, preventing cracking due to thermal cycling and mechanical stress, and a coil component using the casting resin composition. For the purpose.

In order to achieve the above object, the present invention provides:
A hardener component containing (A) a non-flexible epoxy resin and (B) a main ingredient component containing silica particles, (C) a flexible epoxy resin, (D) a curing agent, and (E) a curing accelerator. It is related with the epoxy resin composition for two-component casting characterized by consisting of.

  The present invention also relates to a coil component that is cast by the above-described casting epoxy resin composition.

  The present inventors have conducted intensive studies to solve the above problems. As a result, attention has been paid to the fact that epoxy resins are currently widely used as sealing resins in the field of coil insulation, and attempts have been made to solve the above problems by adding various ideas to the epoxy resins. As a result, the epoxy resin composition is a two-part epoxy resin composition comprising a main agent component containing a non-flexible epoxy resin and the like and a curing agent component for the main agent, and the flexible epoxy resin is a curing agent. It discovered that the said subject could be solved by mix | blending in a component.

  That is, in the finally obtained epoxy resin composition, when obtaining the same low elasticity and bending elongation to prevent the occurrence of cracks due to thermal cycle and mechanical stress, the flexible epoxy resin is contained in the main component. The amount blended in the curing agent component can reduce the blending amount. Therefore, deterioration of heat resistance due to a decrease in the glass transition temperature of the epoxy resin composition due to containing a large amount of the flexible epoxy resin can be suppressed.

  As a result, according to the epoxy resin composition of the present invention, the epoxy resin itself exhibits high insulating properties, and the epoxy resin composition contains a flexible epoxy resin composition to such an extent that its heat resistance is not deteriorated. The occurrence of cracks due to thermal cycles and mechanical stress can be prevented. As a result, the dielectric breakdown characteristics of the epoxy resin composition can be sufficiently ensured.

  Moreover, since the epoxy resin composition of the present invention also contains silica particles, it becomes difficult to form a tree path, and from this point, the dielectric breakdown characteristics of the epoxy resin composition can be sufficiently secured.

  As described above, according to the present invention, the occurrence of cracks due to thermal cycles and mechanical stress is prevented, and the casting resin composition having excellent dielectric breakdown characteristics and heat resistance, and the casting resin composition are used. Coil parts can be provided.

It is sectional drawing which shows the structure of the ignition coil in this embodiment.

  Hereinafter, other features and advantages of the present invention will be described in detail based on embodiments for carrying out the invention.

(Resin composition for casting)
The (A) non-flexible epoxy resin used in the present invention forms the base material of the epoxy resin composition of the present invention, and has a molecular weight as long as it has two or more epoxy groups in one molecule. In general, it is possible to use those which are generally used without being limited by the molecular structure, for example, aromatic epoxy resins such as bisphenol type, novolac type and biphenyl type, glycidyl ether of polycarboxylic acid, cyclohexane Examples include alicyclic epoxy resins obtained by epoxidation of derivatives and the like, and these can be used alone or in admixture of two or more.

  The (A) epoxy resin can be used in combination with a liquid monoepoxy resin in consideration of castability and the like.

  (A) It is preferable that a non-flexible epoxy resin contains an alicyclic epoxy resin in the ratio of 10-50 mass%. By containing an alicyclic epoxy resin, the viscosity of the epoxy resin can be reduced, and the castability of the finally obtained epoxy resin composition can be improved. Moreover, since the glass transition temperature can be improved, the heat resistance of the epoxy resin composition can be improved. Furthermore, since the alicyclic epoxy resin has a higher boiling point than other diluents, it has characteristics such that it is less likely to volatilize during vacuum molding at high temperatures.

  In addition, when the content ratio of the alicyclic epoxy resin is 10% by mass or less, the above-described effects may not be sufficiently obtained, and when the content ratio of the alicyclic epoxy resin exceeds 50% by mass, The bending elastic modulus, which is a mechanical property, is increased and a decrease in elongation is observed, and the toughness tends to be inferior and brittle.

  As described above, (B) silica used in the present invention makes it difficult to form a tree path, and as a result, has the effect of improving the dielectric breakdown characteristics of the epoxy resin composition of the present invention. Moreover, there exists an effect which improves the intensity | strength of the epoxy resin composition finally obtained.

  As such (B) silica, crystalline silica, fused silica, and fused spherical silica can be preferably used. For example, crystallite AA, crystallite C, fuserex RD-8, fuserex RD-120, fuserex E-1, fuserex E-2 MSR-15, MSR-3500 Name) etc., and these can be used alone or in combination of two or more.

  This (B) silica is preferably contained in a range of 200 to 250 parts by mass with respect to 100 parts by mass of the (A) non-flexible epoxy resin. If the content is less than 200 parts by mass, the effect of improving the strength cannot be sufficiently obtained. If the content exceeds 250 parts by mass, the viscosity increases and the workability may decrease.

  Silica particles can be surface-treated from the viewpoint of improving the adhesion with the thermosetting resin. Examples of the surface treatment agent include organic silane compounds, organic titanate compounds, and organic aluminate compounds, and these can be used alone or in combination of two or more.

  Examples of the organic silane compound include vinyltriethoxysilane, vinyl-tris- (2-methoxyethoxy) silane, γ-methacryloxypropylmethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)- γ-aminopropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ-glycidoxypropylmethoxysilane, γ-mercaptopropyltrimethoxysilane and the like may be mentioned. A mixture of more than one species can be used.

  Examples of the organic titanate compound include tetra-i-propyl titanate, tetra-n-butyl titanate, butyl titanate dimer, tetrastearyl titanate, triethanolamine titanate, titanium acetylacetonate, titanium lactate, octylene glycol titanate, isopropyl ( N-aminoethylaminoethyl) titanate etc. are mentioned, These can be used individually or in mixture of 2 or more types. Moreover, as an organic aluminate compound, acetoalkoxy aluminum diisopropinate etc. are mentioned, for example.

  As the (D) curing agent used in the present invention, any one can be used as long as it can be cured by reacting with (A) a non-flexible epoxy resin, such as methylhexahydrophthalic anhydride, Examples thereof include novolak phenol resins, cresol novolac phenol resins, phthalic anhydride derivatives, dicyandiamide, aluminum chelates, and amine complexes of Lewis acids such as BF3. These curing agents can be used alone or in admixture of two or more as long as they do not inhibit curing.

  In addition, the content rate of these hardening | curing agents is suitably set according to the quantity of (A) non-flexible epoxy resin and the flexible epoxy resin demonstrated below.

  Moreover, as (E) hardening accelerator used for this invention, it has the effect | action which accelerates | stimulates reaction of (A) non-flexible epoxy resin and the flexible epoxy resin demonstrated below, and (D) hardening agent. And is not particularly limited, and examples thereof include imidazoles such as 2-ethyl-4-ethylimidazole and 1-cyanoethyl-2-ethyl-4-ethylimidazole, benzyldimethylamine, 2,4,6-tris And tertiary amines such as (dimethylaminomethyl) phenol, 1,8-diazabicyclo [5.4.0] undecene-7 (DBU) and its octyl salt, triethylphosphine, triphenylphosphine, diphenylphosphine and the like. These can be used individually or in mixture of 2 or more types.

  In addition, the content rate of these hardening accelerators is suitably set according to the quantity of (A) epoxy resin, the flexible epoxy resin demonstrated below, and (D) hardening | curing agent.

  In the present invention, (C) a flexible epoxy resin is added to a curing agent component containing (D) a curing agent and (E) a curing accelerator. As described above, this is because the epoxy resin composition finally obtained has the same low elasticity and bending elongation, and is intended to prevent the occurrence of cracks due to thermal cycles and mechanical stress. If the resin is blended in the curing agent rather than in the main agent, the blending amount can be reduced. By containing a large amount of the flexible epoxy resin, the heat resistance of the epoxy resin composition due to a decrease in the glass transition temperature is reduced. This is because deterioration can be suppressed.

  In this case, cracks due to thermal cycles and mechanical stress of the finally obtained epoxy resin composition can be prevented, so that the dielectric breakdown characteristics of the epoxy resin composition can be sufficiently ensured.

  (C) The flexible epoxy resin includes bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy. Resin, bisphenol fluorene type epoxy resin, biscresol fluorene type epoxy resin, bisphenol S diglycidyl ether, halogenated bisphenol type epoxy resin, halogenated cresol novolac type epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated phenol novolak type epoxy Resin, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl Ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane polyglycidyl ether, glycerin polyglycidyl ether, diglycerin polyglycidyl ether, polyglycerin polyglycidyl ether, sorbitol polyglycidyl ether , Butyl glycidyl ether, phenyl glycidyl ether, triglycidyl isocyanurate, N, N'-diglycidyl derivatives of cyclic alkylene urea, diglycidyl phthalate, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, dimer acid diacid Glycidyl ester, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, bi (3,4-epoxycyclohexylmethyl) adipate, and the like.

［式中、Ｒ^１およびＲ^２はそれぞれ独立して水素原子または炭素数１〜４のアルキル基を意味し、Ｒ^３は水素原子またはメチル基を意味し、ｍおよびｎは、ｍとｎとの和が１〜３となる０〜２の数であり、ｐは０〜１の数である。］ In particular, those including a structure represented by the following general formula are preferable, and examples thereof include EP4000 and EP4005 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.).

[Wherein, R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ³ represents a hydrogen atom or a methyl group, and m and n represent m, n, Is a number from 0 to 2 where 1 is from 1 to 3, and p is a number from 0 to 1. ]

  In addition, it is preferable that content of (C) flexible epoxy resin is 3-20 mass parts with respect to 100 mass parts of (A) epoxy resin. If the content is less than 3 parts by mass, the low elasticity of the flexible epoxy resin and the occurrence of cracks due to mechanical stress due to bending elongation cannot be prevented, and the dielectric breakdown characteristics of the epoxy resin composition are sufficient. There are cases where it cannot be secured. Moreover, since glass transition temperature will fall when it exceeds 20 mass parts, heat resistance will deteriorate and it may become difficult to use in high temperature environments, such as an ignition coil.

  The epoxy resin composition for casting of the present invention contains alumina, talc, calcium carbonate, and titanium, which are generally blended in this type of composition in addition to the above components, as long as the effects of the present invention are not impaired. Antimony trioxide and the like can be blended as necessary as inorganic fillers such as white, clay, bengara and carbon powder, coupling agents, antifoaming agents, pigments and other additives and flame retardant aids. However, it is preferable not to include a fibrous filler from the viewpoint of impregnation into the coil.

In preparing the epoxy resin composition of the present invention as a casting material, (A) a non-flexible epoxy resin and (B) a main component containing silica, (C) a flexible epoxy resin, (D) It can be produced by sufficiently mixing and uniformly mixing the curing agent component including the curing agent, (E) the curing accelerator, and the components blended as necessary as described above. More preferably, the epoxy resin composition of the present invention has a resin viscosity of 0.1 to 12 Pa · s (60 ° C.), an initial heating temperature of DSC of 70 to 100 ° C., and a maximum heating value of 40 to 100 J / g. Furthermore, it is preferable that the bending elastic modulus after curing is 12500 N / mm ² or less.

The casting epoxy resin composition thus obtained can impart excellent characteristics and reliability when applied to sealing, coating, insulation, etc. of electrical equipment parts, particularly ignition coils. In order to be applied to these applications, the cured product obtained from the epoxy resin composition of the present invention has low elasticity and a bending strength of 125 (N / mm ² ) or more as a mechanical strength. preferable.

(ignition coil)
Next, an ignition coil will be described as an example of a coil component for casting the above-described casting epoxy resin composition.

  FIG. 1 is a cross-sectional view showing a configuration of an ignition coil as a coil component in the present embodiment.

  The ignition coil includes a magnetic core 1, an outer core 2, a primary bobbin 3, a primary coil 4, a secondary bobbin 5, a secondary coil 6, and a terminal 7. The primary coil is wound about 200 mm of enameled wire with a diameter of about 0.5 mm, for example, and the secondary coil is wound about 20000 times of enameled thin wire with a diameter of about 0.05 mm, for example. The primary coil is connected to the battery and a direct current flows, but the current is intermittently changed by the ignition timing adjusting electronic circuit component 8 and a power switch (not shown) to change the magnetic flux, and a primary voltage is obtained by a self-induction action. This primary voltage is set to a high voltage of 20 to 40 KV by the mutual induction action of the primary coil and the secondary coil, and spark discharge is caused in the spark plug connected to the terminal.

  The ignition timing adjustment electronic circuit component 8 takes a form in which an electronic component 81 is sealed with an epoxy resin 82.

  The above-described center core 1 and the like are accommodated in a case 9 made of, for example, polyphenylene sulfide (PPS), and the gap between the case 9 and the center core 1 and the like is sealed with the above-described casting resin composition 10. .

  In the ignition coil shown in FIG. 1, the primary voltage generated by the ignition timing adjusting electronic circuit component 8 and the power switch (not shown) is applied to the primary coil 4 and the secondary coil 6 as described above. In some cases, a high primary voltage is applied to the capacitor, and the inflow and stop of the current are frequently repeated.

  When a high voltage is instantaneously applied in this way, a high voltage is also instantaneously applied to the resin composition 10 sealing the ignition coil. However, the resin composition 10 has a dielectric breakdown characteristic as described above. Therefore, the resin composition 10 can ensure insulation against the ignition coil without causing dielectric breakdown.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

Production of epoxy resin composition for casting (Example 1)
First, 100 parts by mass of EP4100E (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) as a bisphenol A diglycidyl ether type epoxy resin, 230 parts by mass of MSR-15 (manufactured by Tatsumori Co., Ltd.) as spherical silica, and TSA720 as an antifoaming agent (Product name manufactured by Momentive Co., Ltd.) 0.1 parts by mass and 0.5 part by mass of A-187 (product name manufactured by Nihon Unicar Co., Ltd.) as a silane coupling agent were vacuum-mixed for 1 hour to produce a main ingredient component.

  Next, 100 parts by mass of HN7000 (trade name, manufactured by Hitachi Chemical Co., Ltd.) as the acid anhydride, 5 parts by mass of EP4000 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) as the flexible epoxy resin, and U-CAT2313 as the curing accelerator (Product name, manufactured by San Apro Co., Ltd.) 1.0 part by mass and 300 parts by mass of MSR-15 (manufactured by Tatsumori Co., Ltd.) as spherical silica were vacuum-mixed for 1 hour to produce a curing agent component.

  An epoxy resin composition for casting was prepared by mixing 105 parts by mass of the curing agent component with respect to 100 parts by mass of the main component.

(Example 2)
A casting epoxy resin composition was obtained in the same manner as in Example 1 except that the blending ratio of the curing agent component to the main component was changed to 110 parts by mass with respect to 100 parts by mass of the main component.

(Example 3)
A casting epoxy resin composition was obtained in the same manner as in Example 1 except that the mixing ratio of the curing agent component to the main component was changed to 115 parts by mass with respect to 100 parts by mass of the main component.

Example 4
The main component is 80 parts by mass of EP4100E (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) as a bisphenol A diglycidyl ether type epoxy resin, 20 parts by mass of ERL 4221 (manufactured by Dow Chemical Co., Ltd.) as an alicyclic epoxy resin, and spherical silica MSR-15 (manufactured by Tatsumori Co., Ltd.) 230 parts by mass, 0.1 part by mass of TSA720 (trade name, manufactured by Momentive Co., Ltd.) as an antifoaming agent, and A-187 (product name, manufactured by Nihon Unicar Co., Ltd.) 0 as a silane coupling agent .5 parts by mass, and the compounding ratio of the curing agent component to the main agent component was the same as in Example 1 except that the curing agent component was 125 parts by mass with respect to 100 parts by mass of the main agent component. Got.

(Example 5)
The main component is 60 parts by mass of EP4100E (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) as a bisphenol A diglycidyl ether type epoxy resin, 40 parts by mass of ERL 4221 (manufactured by Dow Chemical Co., Ltd.) as an alicyclic epoxy resin, and spherical silica MSR-15 (manufactured by Tatsumori Co., Ltd.) 230 parts by mass, 0.1 part by mass of TSA720 (trade name, manufactured by Momentive Co., Ltd.) as an antifoaming agent, and A-187 (product name, manufactured by Nihon Unicar Co., Ltd.) 0 as a silane coupling agent .5 parts by mass, and the compounding ratio of the curing agent component to the main component is the same as in Example 1 except that the curing agent component is 130 parts by mass with respect to 100 parts by mass of the main component. Got.

(Example 6)
The content of flexible epoxy resin EP4000 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) in the curing agent component is 10 parts by mass, and the curing agent component is 130 parts by mass with respect to 100 parts by mass of the main component. A casting epoxy resin composition was obtained in the same manner as in Example 1.

(Comparative Example 1)
A casting epoxy resin composition was obtained in the same manner as in Example 1 except that the flexible epoxy resin was not contained in the curing agent component.

(Comparative Example 2)
The curing agent component does not contain a flexible epoxy resin, and the main component is 60 parts by mass of EP4100E (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) as a bisphenol A diglycidyl ether type epoxy resin, an alicyclic epoxy resin. 20 parts by mass of ERL 4221 (manufactured by Dow Chemical Co., Ltd.), 20 parts by mass of flexible epoxy resin EP4000 (manufactured by Asahi Denka Kogyo Co., Ltd., trade name), 230 parts by mass of MSR-15 (manufactured by Tatsumori Co., Ltd.) as spherical silica Example 1 with the exception that 0.1 part by mass of TSA720 (trade name, manufactured by Momentive Co., Ltd.) was used as the defoaming agent, and 0.5 part by mass of A-187 (trade name, manufactured by Nihon Unicar Co., Ltd.) was used as the silane coupling agent. Similarly, an epoxy resin composition for casting was obtained.

(Comparative Example 3)
The curing agent component does not contain a flexible epoxy resin, and the main component component is 50 parts by mass of bisphenol A diglycidyl ether type epoxy resin, EP4100E (Asahi Denka Kogyo Co., Ltd., trade name), alicyclic epoxy resin 20 parts by mass of ERL 4221 (manufactured by Dow Chemical Co., Ltd.), 30 parts by mass of flexible epoxy resin EP4000 (manufactured by Asahi Denka Kogyo Co., Ltd., trade name), 230 parts by mass of MSR-15 (manufactured by Tatsumori Co., Ltd.) as spherical silica , 0.1 part by mass of TSA720 (trade name, manufactured by Momentive Co., Ltd.) as an antifoaming agent, 0.5 part by mass of A-187 (trade name, manufactured by Nihon Unicar Co., Ltd.) as a silane coupling agent, and 100 parts by mass of the main ingredient component Thus, an epoxy resin composition for casting was obtained in the same manner as in Example 1 except that the curing agent component was changed to 106 parts by mass.

(Comparative Example 4)
The curing agent component does not contain a flexible epoxy resin, and the main component is 40 parts by mass of EP4100E (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) as a bisphenol A diglycidyl ether type epoxy resin, an alicyclic epoxy resin. 20 parts by mass of ERL 4221 (manufactured by Dow Chemical Co., Ltd.), 40 parts by mass of flexible epoxy resin EP4000 (manufactured by Asahi Denka Kogyo Co., Ltd., trade name), 230 parts by mass of MSR-15 (manufactured by Tatsumori Co., Ltd.) as spherical silica , 0.1 part by mass of TSA720 (trade name, manufactured by Momentive Co., Ltd.) as an antifoaming agent, 0.5 part by mass of A-187 (trade name, manufactured by Nihon Unicar Co., Ltd.) as a silane coupling agent, and 100 parts by mass of the main ingredient component Thus, an epoxy resin composition for casting was obtained in the same manner as in Example 1 except that the curing agent component was changed to 102 parts by mass.

(Comparative Example 5)
The curing agent component does not contain a flexible epoxy resin, and the main component is 30 parts by mass of EP4100E (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) as a bisphenol A diglycidyl ether type epoxy resin, an alicyclic epoxy resin. 20 parts by mass of ERL 4221 (manufactured by Dow Chemical Co., Ltd.), 50 parts by mass of flexible epoxy resin EP4000 (manufactured by Asahi Denka Kogyo Co., Ltd., trade name), and 230 parts by mass of MSR-15 (manufactured by Tatsumori Co., Ltd.) as spherical silica , 0.1 part by mass of TSA720 (trade name, manufactured by Momentive Co., Ltd.) as an antifoaming agent, 0.5 part by mass of A-187 (trade name, manufactured by Nihon Unicar Co., Ltd.) as a silane coupling agent, and 100 parts by mass of the main ingredient component Thus, an epoxy resin composition for casting was obtained in the same manner as in Example 1 except that the curing agent component was changed to 92 parts by mass.

(Comparative Example 6)
The curing agent component is 95 parts by mass of HN7000 (trade name, manufactured by Hitachi Chemical Co., Ltd.) as an acid anhydride, and 5 parts by mass of HT-08 (trade name, manufactured by Shin Nippon Rika Co., Ltd.) as a flexible acid anhydride. U-CAT2313 (manufactured by San Apro Co., Ltd., trade name) 1.0 part by mass as an accelerator, MSR-15 (manufactured by Tatsumori Co., Ltd.) 300 parts by mass as spherical silica, and a curing agent component with respect to 100 parts by mass of the main component A casting epoxy resin composition was obtained in the same manner as in Example 1 except that the amount was changed to 104 parts by mass.

(Comparative Example 7)
Curing agent components are 90 parts by mass of HN7000 (trade name, manufactured by Hitachi Chemical Co., Ltd.) as an acid anhydride, and 10 parts by mass of HT-08 (trade name, manufactured by Shin Nippon Rika Co., Ltd.) as a flexible acid anhydride. U-CAT2313 (manufactured by San Apro Co., Ltd., trade name) 1.0 part by mass as an accelerator, MSR-15 (manufactured by Tatsumori Co., Ltd.) 300 parts by mass as spherical silica, and a curing agent component with respect to 100 parts by mass of the main component A casting epoxy resin composition was obtained in the same manner as in Example 1 except that the amount was 99 parts by mass.

(Comparative Example 8)
The curing agent component is 85 parts by mass of HN7000 (trade name, manufactured by Hitachi Chemical Co., Ltd.) as an acid anhydride, and 15 parts by mass of HT-08 (trade name, manufactured by Shin Nippon Rika Co., Ltd.) as a flexible acid anhydride. U-CAT2313 (manufactured by San Apro Co., Ltd., trade name) 1.0 part by mass as an accelerator, MSR-15 (manufactured by Tatsumori Co., Ltd.) 300 parts by mass as spherical silica, and a curing agent component with respect to 100 parts by mass of the main component Was cast in the same manner as in Example 1 except that 93 parts by mass was obtained.

Evaluation Next, the casting epoxy resin composition obtained as described above was subjected to bending strength, bending elastic modulus, bending elongation, glass transition temperature, and crack resistance test, thereby performing the above casting. The practical properties of the epoxy resin composition were evaluated.

Bending strength and flexural modulus: The resin composition was cured at 100 ° C./3 h + 150 ° C./3 h to prepare sample pieces (w 10 mm, h 4 mm, L 80 mm) and measured at a temperature of 25 ° C. according to JIS K 6911.
Bending elongation: The resin composition was cured at 100 ° C./3h+150° C./3h to prepare a sample piece (w10 mm, h4 mm, L 80 mm) described in JIS K 6911, and until the sample was broken by the test method of JIS K 6911 The displacement of was obtained.
Glass transition temperature: After the resin composition was cured at 100 ° C./3 h + 150 ° C./3 h, the temperature was increased from room temperature to 250 ° C. at a temperature increase rate of 15 ° C./min by the TMA method.
・ Crack resistance test: Put a flat copper wire (w40mm × h5mm × t2mm) on the spool material (w40mm × h20mm × t1.5mm) of PPE plate and connect both ends with copper wire (0.2mm diameter), then with resin The cover was cured at 100 ° C./3h+150° C./3h to obtain a plate with a resin having a thickness of 10 mm. This sample was evaluated by performing a cooling cycle as shown below.

  The evaluation results and cooling cycle of the epoxy resin composition for casting are shown in Tables 1, 2 and 3, respectively.

  As is apparent from Tables 1 and 2, in the epoxy resin composition for casting in the examples according to the present invention, bending elongation and glass transition were observed with almost no deterioration in bending elastic modulus and bending strength. It can be seen that it is excellent in temperature and crack resistance tests, prevents the occurrence of cracks due to thermal cycles and mechanical stress, and is excellent in dielectric breakdown characteristics and heat resistance.

  The present invention has been described in detail based on the above specific examples. However, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

1 Central Core 2 External Core 3 Primary Bobbin 4 Primary Coil 5 Secondary Bobbin 6 Secondary Coil 7 Terminal 8 Ignition Timing Control Circuit Component 9 Case 10 Resin Composition

Claims (7)

  A hardener component containing (A) a non-flexible epoxy resin and (B) a main ingredient component containing silica particles, (C) a flexible epoxy resin, (D) a curing agent, and (E) a curing accelerator. A two-component casting epoxy resin composition characterized by comprising:   The epoxy resin composition for two-part casting according to claim 1, wherein the epoxy resin is a liquid epoxy resin. 3. The casting epoxy resin composition according to claim 1 or 2, wherein the flexible epoxy resin has a structure represented by the following general formula:

[Wherein, R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ³ represents a hydrogen atom or a methyl group, and m and n represent m, n, Is a number from 0 to 2 where 1 is from 1 to 3, and p is a number from 0 to 1. ].   The epoxy resin composition for casting according to any one of claims 1 to 3, wherein the (A) epoxy resin contains an alicyclic epoxy resin in a proportion of 10 to 50% by mass. The epoxy resin for casting according to any one of claims 1 to 4, wherein the epoxy resin composition has a flexural modulus of 12500 N / mm ² or less after curing and a flexural elongation of 2.0 mm or more. Resin composition.  A coil component cast with the casting epoxy resin composition according to any one of claims 1 to 5.  The coil component according to claim 6, wherein the coil component is an ignition coil for an automobile.

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