JP5744010B2 - Epoxy resin composition and cured product thereof - Google Patents

Description

  The present invention is a glycidyl ether of trimethylolpropane, which is suitable for the electrical and electronic industries such as electrical insulating materials mainly for semiconductor encapsulating materials, has low viscosity, has a small amount of organic chlorine, and has high heat resistance. The present invention relates to a resin composition blended as an essential component and a cured product thereof.

There are various types of epoxy resins from liquid to solid, and epoxy resins are easy to handle because they are excellent in reactivity with curing agents, and when cured with curing agents, they become cured resins having a large crosslinking density and are excellent. It exhibits high heat resistance, moisture resistance, chemical resistance, electrical properties, etc., and is widely used in the electrical and electronic fields.

Epoxy resins have been used in a wide range of industrial applications, but their required performance has become increasingly sophisticated in recent years. For example, there is a semiconductor sealing material in a typical field of a resin composition mainly composed of an epoxy resin, but in recent years, as the integration degree of semiconductor elements has improved, the package size has become larger and thinner, and mounting The system is also shifting to surface mounting, and the development of materials with higher solder heat resistance is desired.

Recently, due to technological trends of high integration and high density mounting, it has been changed to a package by transfer molding using a conventional mold, hybrid IC, chip on board, tape carrier package, plastic pin grid array, plastic ball grid. A method of sealing and mounting using a liquid material without using a mold such as an array is increasing. However, in general, liquid materials have a drawback that they are less reliable than solid materials used for transfer molding. This is because the liquid material has an upper limit of viscosity, and there are restrictions on the epoxy resin, curing agent, filler, and the like to be used.

In order to overcome these problems, lowering of viscosity, lowering of moisture absorption, and higher heat resistance are desired for the epoxy resin and the curing agent as the main agent. As the low viscosity epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin and the like are generally widely known, but are not sufficient in terms of low viscosity. As an epoxy resin excellent in low viscosity, an epoxy resin of an alcohol raw material can be mentioned. Generally, an epoxy resin of an alcohol raw material has a large amount of chlorine, and the performance is low in terms of heat resistance and moisture absorption of a cured product. Therefore, an epoxy resin of trimethylolpropane is exemplified as an epoxy resin having excellent low viscosity and high heat resistance of the cured product.
Although there are YH-300 manufactured by Tohto Kasei Co., Ltd. and Denacol EX-318 manufactured by Nagase Chemtech Co., Ltd. as trimethylolpropane epoxy resins, the total amount of chlorine is as high as 5% or more, respectively. Moreover, there was a problem that the terminal group purity was low and the Tg of the cured product was low.

  The objective of this invention is providing the epoxy resin composition which gives the hardened | cured material which is low viscosity and excellent in heat resistance and moisture resistance, and its hardened | cured material.

That is, the present invention relates to an epoxy resin composition containing, as an essential component, a polyglycidyl ether of trimethylolpropane obtained by reacting trimethylolpropane and epichlorohydrin, and the polyglycidyl ether of trimethylolpropane is obtained by gas chromatography. n = 0 component in the analysis trimethylolpropane tri in (trimethylolpropane monoglycidyl ether (monoglycidyl body), trimethylolpropane diglycidyl ether (diglycidyl thereof) and mixtures of trimethylolpropane triglycidyl ether (triglycidyl member)) The ratio of glycidyl ether is 35% or more and 62% or less , the content of n = 0 in the gel permeation chromatography analysis is 50% or more and 98% or less, and the total chlorine content is 0.3% or less. An epoxy resin composition comprising, as an essential component, a polyglycidyl ether of trimethylolpropane having a viscosity at 25 ° C. of 300 mPa · s or less.
Moreover, this invention is the hardened | cured material formed by hardening | curing the said epoxy resin composition.

  The epoxy resin composition using the epoxy resin of the present invention has excellent low viscosity, and a cured product obtained by curing the epoxy resin composition has excellent performance in heat resistance and moisture resistance. , Powder coating, PCM coating, can coating, etc., civil engineering / construction, bonding, electrical insulation, electrical and electronic parts such as semiconductor chip temporary fixer, printed wiring board and carbon fiber reinforced plastic (CFRP) ) And various other composite materials, and in particular, it can be suitably used for insulating materials in the electric and electronic fields such as printed wiring boards and semiconductor encapsulation.

The present invention will be described in detail.
In the trimethylolpropane glycidyl ether (n = 0 component) according to the present invention, there are usually a monoglycidyl body, a diglycidyl body and a triglycidyl body. In the present invention, the triglycidyl body ratio is 35% or more. When the triglycidyl body ratio is 35% or less, the physical properties such as Tg of the cured product are lowered and the resin viscosity is increased, which is not preferable, preferably 50% or more, and more preferably 75% or more.

The trimethylolpropane glycidyl ether used in the present invention has a total chlorine content of 0.3% by weight or less, preferably 0.2% by weight or less. When the total chlorine amount exceeds 0.3% by weight, in the case of a composition using a basic curing accelerator, the curing reaction is inhibited, and as a result, the physical properties of the cured product are lowered. In addition, the insulation reliability is lowered, which is not preferable for applications in the electric / electronic field.

The polyglycidyl ether of trimethylolpropane used in the present invention has a viscosity at 25 ° C. of 300 mPa · s or less. If the viscosity at 25 ° C. exceeds 300 mPa · s, the dilution efficiency decreases, which is not preferable.

  From the viewpoint of low viscosity, the polyglycidyl ether of trimethylolpropane used in the present invention preferably has a content of n = 0 component of 50% or more, more preferably 70% or more, still more preferably 90% or more. It is.

The reaction of reacting trimethylolpropane with epichlorohydrin can be carried out in the same manner as a normal epoxidation reaction. For example, after mixing and dissolving an excess epichlorohydrin with respect to the hydroxyl group of trimethylolpropane, a method of reacting in the range of 40 to 120 ° C. for 1 to 10 hours in the presence of an alkali metal hydroxide can be mentioned. In this case, it is preferable to perform the reaction at 50 to 90 ° C. from the viewpoint of reducing hydrolyzable chlorine.

Examples of the alkali metal hydroxide used in the above reaction include lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide and the like, and sodium hydroxide and potassium hydroxide are particularly preferable. The alkali may be an aqueous solution or a solid, but it is preferable to use an aqueous solution for ease of handling. The usage-amount of an alkali metal hydroxide is 0.7-3.0 equivalent normally with respect to 1 equivalent of alcoholic hydroxyl groups, Preferably it is 0.8-2.0 equivalent. If the amount of the alkali metal hydroxide used is too large, the polymerization reaction and side reaction are promoted, resulting in poor productivity. On the other hand, if the amount is too small, the reaction between trimethylolpropane and epichlorohydrin becomes insufficient, and a chlorohydrin which is not glycidyl ether remains, so that the purity of the terminal epoxy group is lowered.

Moreover, the usage-amount of the said epichlorohydrin is 1-10 equivalent with respect to 1 equivalent of hydroxyl groups of a polyhydric alcohol, Preferably 2-6 equivalent is good. When the amount of epichlorohydrin used is less than 1 equivalent, the polymerization tends to proceed and the yield of the desired chlorohydrin ether decreases. On the other hand, when the amount is more than 10 equivalents, the ratio of polyhydric alcohols to the total charged amount becomes too small and productivity is lowered, which is not preferable.

In order to make the reaction proceed easily, a quaternary ammonium salt may be added as a catalyst if necessary. Examples of quaternary ammonium salts that can be used include tetramethylammonium chloride, tetramethylammonium bromide, benzyltrimethylammonium chloride, and benzyltriethylammonium chloride. The amount of the quaternary ammonium salt used is usually 0.05 to 10% by weight, preferably 0.1 to 1% by weight, based on the amount of polyhydric alcohol used.

  The reaction can be carried out in a solvent that does not react with the epoxy group. Specifically, aromatic hydrocarbons such as toluene, xylene, and benzene, and ketones such as methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, and acetone. Alcohols such as propanol and butanol, glycol ethers such as diethylene glycol methyl ether, propylene glycol methyl ether and dipropylene glycol methyl ether, aliphatic ethers such as diethyl ether, dibutyl ether and ethylpropyl ether, dioxane, tetrahydrofuran and the like Examples thereof include alicyclic ethers, dimethyl sulfoxide, and the like, and two or more kinds thereof can be mixed and used. The amount of these solvents used is 200 parts by weight or less, preferably 5 to 150 parts by weight, and more preferably 10 to 100 parts by weight with respect to 100 parts by weight of epihalohydrin.

The water content in the reaction system is preferably 0.1% or more and less than 2.0%. When the water content in the system is lower than 0.1%, the reaction proceeds slowly. This is because when the water content in the system is 2.0% or more, the glycidyl etherification reaction is inhibited by the influence of the water, and the chlorine content increases.

In order to isolate the glycidyl ethers produced by the above method from the reaction mixture, for example, unreacted epichlorohydrin and the solvent are distilled off under reduced pressure or atmospheric pressure, dissolved in an organic solvent and by-produced alkali metal salt and excess There is a method in which the alkali metal hydroxide is separated by washing, filtration, etc., and then the organic solvent used for dissolution is recovered to obtain glycidyl ethers. Examples of the organic solvent used here include methyl isobutyl ketone, toluene, xylene, cyclohexanone, methanol, ethanol, propanol, butanol, etc. Among them, methyl isobutyl ketone, toluene and xylene are preferable, and these mixed solvents are also used. good.

After completion of the reaction between trimethylolpropane and epichlorohydrin, excess epihalohydrin is distilled off, dissolved in a solvent, filtered, washed with water to remove inorganic salts, and then the trimethylol used in the present invention is distilled off. Polyglycidyl ether of propane can be obtained, but if the amount of hydrolyzable halogen is too large, from the viewpoint of reducing the amount of hydrolyzable halogen, the obtained epoxy resin is further added to the remaining amount of hydrolyzable halogen. After adding 1 to 30 times the amount of alkali metal hydroxide and carrying out a purification reaction at a temperature of 60 to 90 ° C. for 10 minutes to 2 hours, excess alkali metal hydroxide is obtained by a method such as neutralization or washing with water. And by-product salts are removed, and the solvent is distilled off under reduced pressure to obtain a further purified polyglycidyl ether of trimethylolpropane used in the present invention. Moreover, what refine | purified by molecular distillation the polyglycidyl ether of the trimethylol propane obtained by reaction can be used.

   The epoxy resin composition of the present invention is an epoxy resin composition comprising an epoxy resin and a curing agent as essential components, wherein the polyglycidyl ether of trimethylolpropane according to claim 1 is blended as an essential component as an epoxy resin component. It is.

  As the curing agent when the polyglycidyl ether of trimethylolpropane according to claim 1 is an essential component, any of those generally known as curing agents for epoxy resins can be used. Examples include dicyandiamide, polyhydric phenols, acid anhydrides, aromatic and aliphatic amines.

  Specifically, as polyhydric phenols, for example, bisphenol A, bisphenol F, biphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2′-biphenol, hydroquinone, resorcin, naphthalenediol Divalent phenols such as tris- (4-hydroxydiphenyl) methane, 1,1,2,2-tetrakis (4-hydroxydiphenyl) ethane, phenol novolak, o-cresol novolak, naphthol novolak, polyvinylphenol Trivalent or higher phenols represented by Further, phenols, naphthols or divalent phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2′-biphenol, hydroquinone, resorcin, naphthalenediol And polyhydric phenolic compounds synthesized from condensing agents such as formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, and p-xylylene glycol.

  Examples of the acid anhydride include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl hymic anhydride, nadic anhydride, and trimellitic anhydride.

Examples of amines include aromatic amines such as 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenylsulfone, m-phenylenediamine, and p-xylylenediamine, ethylenediamine, There are aliphatic amines such as hexamethylenediamine, diethylenetriamine, and triethylenetetramine.
The amount of the above-mentioned known and commonly used curing agent is preferably 0.4 to 2.0 equivalent of the functional group of the curing agent, and 0.5 to 1.5 equivalent of 1 equivalent of the epoxy group which is the functional group of the epoxy resin. More preferably, it is particularly preferably 0.5 to 1.0 equivalent. If the curing agent relative to the epoxy group 1 equivalent is less than 0.4 equivalent, or 2.0 if the equivalent Eru Yue, curing may not satisfactory cured product obtained become incomplete. In the epoxy resin composition of the present invention, one or two or more of these curing agents can be mixed and used.

  Moreover, you may mix | blend another kind of epoxy resin other than the polyglycidyl ether of the trimethylol propane in connection with this invention as an epoxy resin component in the epoxy resin composition of this invention. As the epoxy resin in this case, all ordinary epoxy resins having two or more epoxy groups in the molecule can be used. Examples include divalent phenols such as bisphenol A, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2′-biphenol, hydroquinone, resorcin, or tris- (4-hydroxydiphenyl) methane. Glycidyl derived from trivalent or higher phenols such as 1,1,2,2-tetrakis (4-hydroxydiphenyl) ethane, phenol novolak, o-cresol novolak, or halogenated bisphenols such as tetrabromobisphenol A Examples include etherified products, polyglycidyl ethers of alcohols such as polyethylene glycol and polypropylene glycol, polyglycidyl amines such as diaminodiphenylmethane, and alicyclic epoxy resins. These epoxy resins can be used alone or in combination of two or more. And in the case of the epoxy resin composition of the present invention, the blending amount of the polyglycidyl ether of trimethylolpropane related to the present invention should be in the range of 5 to 100%, preferably 60 to 100% in the whole epoxy resin. .

  Further, in the epoxy resin composition of the present invention, an oligomer or a polymer compound such as polyester, polyamide, polyimide, polyether, polyurethane, petroleum resin, indene coumarone resin, phenoxy resin may be appropriately blended, You may mix | blend additives, such as an inorganic filler, a pigment, a flame retardant, a thixotropy imparting agent, a coupling agent, and a fluidity improver. Examples of the inorganic filler include silica powder such as spherical or crushed fused silica and crystalline silica, alumina powder, glass powder, mica, talc, calcium carbonate, alumina, and hydrated alumina. Examples of the pigment include organic or inorganic extender pigments and scaly pigments. Examples of the thixotropic agent include silicon-based, castor oil-based, aliphatic amide wax, oxidized polyethylene wax, and organic bentonite-based. Further, if necessary, the resin composition of the present invention includes a release agent such as carnauba wax and OP wax, a coupling agent such as γ-glycidoxypropyltrimethoxysilane, a colorant such as carbon black, three A flame retardant such as antimony oxide, a low stress agent such as silicon oil, a lubricant such as calcium stearate, and the like can be used.

Furthermore, a known curing accelerator can be used in the resin composition of the present invention as necessary. Examples include imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, imidazolines such as 2-methylimidazoline and 2-ethyl-4-methylimidazoline, triazine salts of imidazole compounds, cyanoethyl salts, List various salts such as cyanoethyl trimellitic acid salt, metal compounds such as zinc acetate and sodium acetate, quaternary ammonium salts such as tetraethylammonium chloride, amide compounds, and organophosphorus compounds such as triphenylphosphine. Can do. The mixing ratio of the curing accelerator, relative to the epoxy resin 100 parts by weight of the present invention, 0.01 to 5 mass parts, more preferably 0.1 to 2 mass parts.

  The cured epoxy resin of the present invention can be obtained by heating the above epoxy resin composition. Casting, pouring, potting, dipping, drip coating, transfer molding, compression molding and the like are suitably used as methods for obtaining a cured product, and the temperature at that time is usually in the range of 100 ° C to 300 ° C. .

Hereinafter, examples and comparative examples of the present invention will be described in detail. The present invention is not limited to these examples. In addition, the part in an example means a mass part and% means the mass%. The physical property values were measured by the following methods.
The epoxy equivalent was measured in accordance with JIS K 7236.
The total chlorine amount was measured in accordance with JIS K 7243-3.
The viscosity was measured by JIS K-7233, single cylinder rotational viscometer method.
The gas chromatography measurement was performed under the following conditions.
The mono, di, and triglycidyl content represents the area% of the peak obtained as a result of gas chromatography analysis.
Apparatus: “GC-14B” manufactured by Shimadzu Corporation
Column: Glass packed column 1.1 m in length and 3.2 mm in diameter
Filler: silicone OV-17
Carrier: chromosorb W AW-DMCS
Flow controller: hydrogen 50kPa, air 50kPa, carrier 50kPa, primary 400kPa
Column flow rate: 50 ml / min
INJECTION temperature: 280 ° C., FID temperature: 320 ° C., column temperature: 160 ° C. × 2 min, heating rate: 20 ° C./min, final column temperature: 300 ° C. × 5 min
Sample: 5 wt% acetone solution injection amount: 2 μL

GPC measurement was performed under the following conditions. The content of n = 0 represents the peak area% obtained as a result of the GPC analysis.
Equipment: Tosoh Corporation GPC8220
Separation column: TSKgel G2000HXL, TSKgel G2000HXL
TSKgel: G10000HXL connecting column temperature at series: 40 ° C.
Eluent: Tetrahydrofuran at 1 ml / min Flow rate detector: RI detector

Example 1

In a 1 L glass flask equipped with a stirrer, thermometer, nitrogen gas introducing device, dropping device, cooling pipe and oil / water separator, 90 parts of trimethylolpropane (TMP), 652 parts of epichlorohydrin, 65.2 parts of diethylene glycol dimethyl ether, 6.5 parts of water was charged, and dissolved by heating to 60 ° C. while flowing nitrogen gas. After the temperature was raised to 60 ° C., 77.3 parts of 99% sodium hydroxide was added and the reaction was carried out at the same temperature for 6 hours. Except for the salt produced by filtration, epichlorohydrin was distilled off and dissolved in 500 parts of toluene. After the temperature was raised to 80 ° C., 0.32 parts of 49.1% aqueous sodium hydroxide solution and 1.25 parts of warm water were added and a purification reaction was carried out at the same temperature for 1 hour. Thereafter, 25 parts of warm water was added, stirred and separated, the resin solution was dehydrated and filtered, and toluene was distilled off to obtain 164.2 g of an epoxy resin. Epoxy equivalent of this resin is 128 g / eq, viscosity is 150 mPa · s / 25 ° C., total chlorine is 0.23%, n = 0 purity by GPC is 58%, and n = 0 component mono: di: triglycidyl by gas chromatography The body ratio was 0:60:40. Properties of the obtained resin are shown in Table 1.
Example 2

154.5 g of epoxy resin was obtained in the same manner as in Example 1 except that 99% sodium hydroxide was changed from 77.3 parts to 116.0 parts. The epoxy equivalent of this resin is 125 g / eq, the total chlorine content is 0.25%, the purity of n = 0 by GPC is 50%, and the ratio of mono: di: triglycidyl of n = 0 component by gas chromatography is 0:38. : 62. Properties of the obtained resin are shown in Table 1.
Comparative Example 1

Except for changing 6.5 parts of water to 0.65 parts, the same operation as in Example 1 was performed to obtain 148.2 g of an epoxy resin. This resin has an epoxy equivalent of 135 g / eq, a total chlorine content of 0.25%, a GPC n = 0 purity of 50%, and a gas chromatography n = 0 component mono: di: triglycidyl ratio of 0:75. : 25. Properties of the obtained resin are shown in Table 1.
Comparative Example 2

  YH-300 (trimethylolpropane glycidyl ether) manufactured by Tohto Kasei Co., Ltd. The epoxy equivalent of YH-300 is 142 g / eq, viscosity is 147 mPa · s / 25 ° C., total chlorine is 5.0%, n = 0 purity by GPC is 29%, and n = 0 component mono: di: tri by gas chromatography. The glycidyl body ratio was 0:81:19. The properties of the resin are shown in Table 1.

実施例３

Example 3

The epoxy resin obtained in Example 1 (hereinafter referred to as epoxy resin A) was subjected to molecular distillation at a pressure of 0.3 pa and a temperature of 125 to 135 ° C. using a thin film molecular distillation machine KDL-4 manufactured by Fintech Co., Ltd. Got. The properties of the obtained resin are shown in Table 2.
Example 4

The epoxy resin (hereinafter referred to as epoxy resin B) obtained in Example 2 was subjected to molecular distillation in the same manner as in Example 3 to obtain Epoxy Resin E. The properties of the obtained resin are shown in Table 2.
Comparative Example 3

The epoxy resin (hereinafter referred to as epoxy resin C) obtained in Example 1 was subjected to molecular distillation in the same manner as in Example 3 to obtain an epoxy resin F. The properties of the obtained resin are shown in Table 2.
Comparative Example 4

YH-300 manufactured by Tohto Kasei Co., Ltd. was subjected to molecular distillation in the same manner as in Example 3 to obtain an epoxy resin G. The properties of the obtained resin are shown in Table 2.

実施例５、６比較例５，６実施例７、８比較例７，８

Examples 5 and 6 Comparative Examples 5 and 6 Examples 7 and 8 Comparative Examples 7 and 8

 As an epoxy resin component, YD-8125 manufactured by Tohto Kasei Co., Ltd. was blended with 100 parts by weight of Epoxy Resin A to Epoxy Resin G and YH-300 at a ratio such that the mixed viscosity was 1000 mPa · s / 25 ° C. Ricacid MH-700 (Methylhexahydrophthalic anhydride, acid anhydride equivalent 168g / eq, manufactured by Shin Nippon Chemical Co., Ltd.) as a curing agent, and Hishicolin PX-4ET (organic phosphonium salt compound, manufactured by Nippon Kagaku) as a curing accelerator An epoxy resin composition was obtained using the composition shown in Table 3. In addition, the numerical value in a table | surface shows the weight part in mixing | blending.

The epoxy resin composition was molded at 100 ° C. for 2 hours, and further post-cured at 140 ° C. for 12 hours to obtain a cured product test piece, which was then subjected to various physical property measurements. The results are shown in Table 3.
In addition, the test method and evaluation method of hardened | cured material property are as follows.
(1) The cured product Tg was measured at a rate of temperature increase of 10 ° C./min using a thermomechanical measuring device (manufactured by Seiko Denshi).
(2) The water absorption was defined as the rate of change in weight increase after absorbing moisture for 50 hours at 23 ° C. and 100% RH using a circular test piece having a diameter of 50 mm and a thickness of 5 mm.
(3) The amount of ionic impurities was determined by measuring the chloride ion of the extracted ion content after performing a pressure cooker test at 105 ° C. for 20 hours and converting the extracted ion content into a solid content.

Examples 5 and 6 using epoxy resins A and B show a high cured product Tg and a low water absorption rate as compared with Comparative Example 5 using epoxy resin C. Moreover, the amount of PCT chlorine extraction is significantly smaller than that of Comparative Example 6 using YH-300.
Similarly, Examples 7 and 8 using epoxy resins D and E show a high cured product Tg and a low water absorption rate as compared with Comparative Example 7 using epoxy resin F. Further, the amount of PCT chlorine extraction is significantly smaller than that of Comparative Example 8 using epoxy resin G.

  When the epoxy resin according to the present invention is used, a cured product having excellent low viscosity and high Tg and excellent moisture resistance can be obtained. This makes it possible to produce hardened materials with sufficient heat resistance and excellent moisture resistance in the normal use range, for sealing electrical and electronic parts such as semiconductor elements, coating materials, laminated materials, composite materials, etc. Useful resin compositions can be obtained, and the technical meaning is significant.

Claims (2)

An epoxy resin composition comprising a polyglycidyl ether of trimethylolpropane obtained by reacting trimethylol propane and epichlorohydrin as essential components, polyglycidyl ethers of the trimethylol propane, n = 0 in the gas chromatography analysis The ratio of trimethylolpropane triglycidyl ether in the components ( a mixture of trimethylolpropane monoglycidyl ether, trimethylolpropane diglycidyl ether and trimethylolpropane triglycidyl ether ) is 35% or more and 62% or less , and gel permeation chromatography analysis In which n = 0 content is 50% or more and 98% or less, the total chlorine content is 0.3% or less, and the viscosity at 25 ° C. is 300 mPa · s or less. An epoxy resin composition comprising polyglycidyl ether of bread as an essential component.   Hardened | cured material formed by hardening | curing the epoxy resin composition of Claim 1.