TW201431944A - Epoxy resin composition, cured product thereof, and light emitting diode - Google Patents

Abstract

An epoxy resin composition of the present invention contains an acid anhydride (A) and an epoxy resin (B), wherein (a) the acid anhydride (A) contains 30 to 90% by mass of cyclohexane-1, 2, 4-tricarboxylic acid-1, 2-anhydride, (b) the epoxy resin (B) contains 30 to 90% by mass of an a licyclic epoxy resin compound, and also contains a glycidyl ester-type epoxy resin compound, and (c) the mixing equivalence ratio between the acid anhydride and the epoxy resin represented by formula (1) shown below is within a range from 0.4 to 0.7. Mixing equivalence ratio between acid anhydride and epoxy resin = (X+Y)/Z (1) X: the number of acid anhydride functional groups contained within the acid anhydride (A) Y: the number of carboxyl functional groups contained within the acid anhydride (A) Z: the number of epoxy functional groups contained within the epoxy resin (B).

Description

Epoxy resin composition and hardened material thereof and light emitting diode

The present invention relates to an epoxy resin composition, a cured product thereof, and a light-emitting diode.

In recent years, a high-brightness blue or white light-emitting diode (hereinafter also referred to simply as a light-emitting diode "LED") has been developed, and it is widely used for use in a notice board, a full-color display, or a backlight of a mobile phone. Conventionally, an acid anhydride-cured epoxy resin is excellent in colorless transparency and is used as a sealing material for a photoelectric conversion element such as an LED.

As a curing agent for the epoxy resin used as the sealing material of the related photoelectric conversion element, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, and tetra are generally used. An alicyclic acid anhydride such as hydrogen phthalic anhydride.

Epoxy resin composition, when used in blue LED or white LED applications, since the epoxy resin hardened material is exposed to high temperature for a long time due to the strong luminescence energy of the LED, it is required that the epoxy resin hardened material is heated under a long time. Colorless transparency.

Since the colorless transparency of the cured product obtained by using the above-mentioned hardening agent is easily damaged, it is not applicable to a sealing material of a photoelectric conversion element such as a high-intensity LED.

Further, as a hardener for obtaining a colorless transparent epoxy resin cured product having improved light resistance and heat resistance, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride is also known (also called It is a hardener which hydrogenates the trimellitic anhydride, and is also abbreviated as "H-TMAn" hereinafter (for example, refer patent documents 1-4).

Further, an epoxy resin composition using H-TMAn is also known (for example, see Patent Document 5).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-36218

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-182961

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2007-39521

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2007-39522

[Patent Document 5] International Publication No. 2009/041389

However, the epoxy resin compositions described in Patent Documents 1 to 4 have high viscosity and high curing speed. Therefore, the epoxy resin composition described in Patent Documents 1 to 4 has a high viscosity increase ratio at room temperature during the daytime operation period, and the workability is deteriorated. Further, the epoxy resin compositions described in Patent Documents 1 to 4 are not preferable for colorless transparency (heat-resistant coloring property) under heating conditions in high-brightness LED applications.

The epoxy resin composition described in Patent Document 5 improves such a problem, and has low viscosity and improved workability. Further, the epoxy resin composition described in Patent Document 5 is greatly improved in colorless transparency (light coloring resistance) and heat-resistant coloring property under UV irradiation as compared with a composition using a general alicyclic acid anhydride. The level required for the resin used for the sealing material of the conversion element (hereinafter also referred to as "sealing resin") (150 ° C for 120 hours or 180 ° C for 48 hours) exhibits sufficient heat-resistant coloring property. However, the temperature at which the sealing resin is applied tends to increase due to the influence of higher power and higher current of the LED in the near future. As a result, in recent years, higher standards have been required for sealing resins. The table shows the heat-resistant coloring property at 150 ° C for 1000 hours. In such a case, the epoxy composition described in Patent Document 5 may have insufficient heat-resistant coloring properties, and there is still room for improvement.

An object of the present invention is to provide an epoxy resin composition having a property as the following (1) to (3) and suitable as a sealing material for a photoelectric conversion element such as a blue LED or a white LED, and a cured product thereof.

(1) The viscosity after blending is low, the viscosity increase ratio at room temperature is low, and the workability is excellent.

(2) The hardenability is good even if no hardening accelerator is added.

(3) The obtained cured product is colorless, transparent, and excellent in crack resistance, and is less colored when exposed to light for a long period of time and heated at 150 ° C for 1,000 hours.

In order to solve the above problems, the inventors of the present invention have been working hard to find an acid anhydride containing and containing a specific amount of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (H-TMAn). The epoxy resin of a specific amount of the alicyclic epoxy resin compound and the epoxy propyl ester type epoxy resin compound can achieve the above object by forming a resin composition having a specific concentration of the acid anhydride and the epoxy resin, and the present invention has been completed. .

That is, the present invention provides the following epoxy resin composition, cured product thereof, and light-emitting diode.

(1) An epoxy resin composition comprising an acid anhydride (A) and an epoxy resin (B), and: (a) the acid anhydride (A) contains 30 to 90% by mass of cyclohexane-1,2,4-tri a carboxylic acid-1,2-anhydride; (b) an epoxy resin (B) containing 30 to 90% by mass of an alicyclic epoxy resin compound, and containing a glycidyl ester type epoxy resin compound; (c) (1) The blending equivalent ratio of the anhydride to the epoxy resin is in the range of 0.4 to 0.7; the blending equivalent ratio of the anhydride to the epoxy resin is = (X + Y) / Z (1) X: in the anhydride (A) The number of functional groups Y of the acid anhydride group: the number of functional groups of the carboxyl group contained in the acid anhydride (A): the number of functional groups of the epoxy group contained in the epoxy resin (B).

(2) The epoxy resin composition according to (1), wherein the epoxy acrylate type epoxy resin compound in the epoxy resin (B) is contained in an amount of 10 to 60% by mass.

(3) An epoxy resin composition according to (1) or (2), wherein the epoxy propyl ester type epoxy resin compound It is selected from the group consisting of diglycidyl adipate, diglycidyl long-chain dibasic acid, diglycidyl tetrahydrophthalate and diglycidyl hexahydrophthalate. At least one of the groups.

(4) The epoxy resin composition according to any one of (1) to (3) wherein the alicyclic epoxy resin compound is 3,4-epoxycyclohexenylmethyl-3',4 '-Epoxycyclohexene carboxylate.

(5) The epoxy resin composition according to any one of (1) to (4), further comprising 0.1 to 5% by mass of a hindered phenol-based antioxidant.

(6) The epoxy resin composition according to any one of (1) to (5), further comprising 0.01 to 5% by mass of a phosphorus-based hardening accelerator.

(7) The epoxy resin composition according to any one of (1) to (6) further comprising a fluorescent substance which emits light from a light-emitting element having a main light-emitting peak wavelength of 550 nm or less At least a portion absorbs and emits fluorescence.

(8) An epoxy resin cured product obtained by hardening the epoxy resin composition according to any one of (1) to (7).

(9) A light-emitting diode in which a light-emitting element is sealed with an epoxy resin cured material as in (8).

The epoxy resin composition of the present invention exerts the following effects (1) to (3).

(1) The viscosity after the blending is low, and the viscosity increase ratio at room temperature during the daytime operation is low, so the workability is good.

(2) The hardenability is good even if no hardening accelerator is added.

(3) The obtained cured product is colorless, transparent, and excellent in crack resistance, and is rarely colored even under long-time light irradiation and heating at 150 ° C for 1,000 hours.

Further, in the epoxy resin composition of the present invention, the viscosity increase rate is increased by using a specific curing accelerator, but the coloring due to further heating is small, and a cured product excellent in heat resistance coloring property can be obtained.

Further, since the epoxy resin composition of the present invention exhibits the above effects, it is suitably used for a sealing material, a coating material, a coating, and an adhesive of a photoelectric conversion element such as a blue LED or a white LED. Agents and various molded articles, insulating members, decorative materials, etc., which are required to have heat-resistant coloring properties.

Hereinafter, embodiments of the present invention (hereinafter also referred to as "this embodiment") will be described in detail. Further, the following embodiments are illustrative of the invention, and the invention is not limited to the embodiments.

≪Epoxy resin composition≫

The epoxy resin composition of the present embodiment contains an acid anhydride (A) having a specific composition and an epoxy resin (B).

<Acid anhydride (A)>

The acid anhydride (A) used in the epoxy resin composition of the present embodiment contains 30 to 90% by mass of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride. When the acid anhydride (A) contains 30 to 90% by mass of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, the cured product of the obtained epoxy resin composition is excellent in crack resistance.

In the acid anhydride (A), the content of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (hereinafter also referred to as "H-TMAn") is 30 to 90% by mass, and 40 to 90% by mass. % is better, and 50 to 90% by mass is more preferable.

In the acid anhydride (A), if the content of H-TMAn is 30% by mass or more, the imparting property (crack resistance) originally possessed by H-TMAn to the cured product is further exhibited, and if the content of H-TMAn is When the amount is 90% by mass or less, the obtained epoxy resin composition is low in viscosity and workability is further improved.

In the acid anhydride (A), the content of H-TMAn can be appropriately selected in the range of 30 to 90% by mass in accordance with the use or performance of the epoxy resin composition. For example: if you pay attention to the hardened material of the epoxy resin composition The crack resistance is preferably 40% by mass or more of the H-TMAn content in the acid anhydride (A), more preferably 50% by mass or more, and still more preferably 60% by mass or more. In addition, the upper limit of the content of the H-TMAn in the acid anhydride (A) is preferably 85% by mass or less, more preferably 80% by mass or less, from the viewpoint of the viscosity of the epoxy resin composition.

Further, in the present embodiment, the content of H-TMAn of the acid anhydride (A) in the epoxy resin composition can be measured by component analysis by nuclear magnetic resonance (NMR) or gas chromatography (GC).

The acid anhydride (A) used in the present embodiment may contain an acid anhydride other than H-TMAn. The acid anhydride other than H-TMAn is not particularly limited, and examples thereof include tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Methyl nadic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexene tetracarboxylic dianhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, diphenylketone tetracarboxylate Acid dianhydride, ethylene glycol trimellitic anhydride, glycerin (trimellitic anhydride) monoacetate, dodecenyl succinic anhydride, aliphatic dibasic acid polybasic anhydride, chlorendic acid anhydride, and the like.

In particular, when considering the low viscosity and workability of the epoxy resin composition, and the crack resistance and light resistance of the cured product, it is preferable to use hexahydrophthalic anhydride as an acid anhydride other than H-TMAn. An acid anhydride having low viscosity and containing no double bond such as methylhexahydrophthalic anhydride is preferred. These anhydrides may be used alone or in combination with a plurality of anhydrides for dilution, for example: H-TMAn.

<Epoxy Resin (B)>

The epoxy resin (B) used in the epoxy resin composition of the present embodiment contains 30 to 90% by mass of an alicyclic epoxy resin compound and contains a glycidyl ester type epoxy resin compound. When the epoxy resin (B) contains 30 to 90% by mass of the alicyclic epoxy resin compound, the cured product of the epoxy resin composition is excellent in heat-resistant coloring property. On the other hand, when the epoxy resin (B) contains a glycidyl ester type epoxy resin compound, the softness of the cured product of the epoxy resin composition is increased, and generation of cracks due to thermal shock can be suppressed.

In the epoxy resin (B), the content of the alicyclic epoxy resin compound is 30 to 90% by mass, and the epoxy The content of the propyl ester type epoxy resin compound is preferably from 10 to 60% by mass.

Therefore, the epoxy resin (B) may be composed of only an alicyclic epoxy resin compound and a glycidyl ester epoxy resin compound, and may further contain other epoxy resin compounds. In the epoxy resin (B), the total content of the alicyclic epoxy resin compound and the glycidyl ester type epoxy resin compound is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more. In addition, the upper limit of the total content of the alicyclic epoxy resin compound and the glycidyl ester type epoxy resin compound in the epoxy resin (B) is not particularly limited, and is, for example, 100% by mass. When the total content of the alicyclic epoxy resin compound and the glycidyl ester type epoxy resin compound in the epoxy resin (B) is within the above range, the heat resistant coloring property and crack resistance of the cured product of the epoxy resin composition Better sex.

The alicyclic epoxy resin compound refers to an epoxy resin having an alicyclic ring in its molecule and forming a part of a carbon-carbon bond of the ring and an epoxy ring. The alicyclic epoxy resin compound is not particularly limited, and examples thereof include 3,4-epoxycyclohexenylmethyl-3', 4'-epoxycyclohexene carboxylate, and dicyclohexyloxycyclohexane. Vinylhexen diepoxide or the like. Among them, 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate is preferred from the viewpoint of low viscosity and economy.

The glycidyl ester type epoxy resin compound refers to an epoxy resin having a glycidyl ester moiety in its molecule. The glycidyl ester type epoxy resin compound is not particularly limited, and examples thereof include aliphatic systems such as diglycidyl adipate and diglycidyl long-chain dibasic acid, and diglycidyl phthalate. An alicyclic system such as an aromatic system such as diglycidyl terephthalate, diglycidyl tetrahydrophthalate or diglycidyl hexahydrophthalate. Among these, from the viewpoint of the viscosity of the epoxy resin composition or the coloring resistance of the cured product, it is preferably selected from the group consisting of diglycidyl adipate, diglycidyl long-chain dibasic acid, and tetrahydrogen. At least one of the group consisting of diglycidyl phthalate and diglycidyl hexahydrophthalate is preferred, and diglycidyl hexahydrophthalate is more preferred.

In the epoxy resin (B), the content of the alicyclic epoxy resin compound is 30 to 90% by mass, preferably 40 to 85% by mass, more preferably 50 to 80% by mass. In the epoxy resin (B), the more the content of the alicyclic epoxy resin compound, the more the coloring resistance of the cured product of the epoxy resin composition can be improved, and the content of the alicyclic epoxy resin compound is as described above. Above the limit, the hardening of the epoxy resin composition The heat-resistant coloring property of the object is more excellent. In the epoxy resin (B), when the content of the alicyclic epoxy resin compound is at most the above upper limit value, the cured product of the epoxy resin composition becomes softer, and cracking due to thermal shock can be suppressed. Moreover, the heat-resistant coloring property is also better.

On the other hand, the epoxy acrylate type epoxy resin compound in the epoxy resin (B) can improve the softness of the cured product of the epoxy resin composition, suppress the occurrence of cracks due to thermal shock, and the like. In the epoxy resin (B), the content of the glycidyl ester type epoxy resin compound is preferably from 10 to 60% by mass, more preferably from 15 to 50% by mass, even more preferably from 20 to 40% by mass. In the epoxy resin (B), when the content of the epoxy acrylate-based epoxy resin compound is at least the above lower limit value, the cured product of the epoxy resin composition is more excellent in crack resistance. In the epoxy resin (B), when the content of the epoxy acrylate-based epoxy resin compound is at most the above upper limit value, the cured product of the epoxy resin composition is more excellent in heat-resistant coloring property.

Further, in the present embodiment, in the epoxy resin composition (B) of the epoxy resin composition or the cured product thereof, the content of the alicyclic epoxy resin compound or the glycidyl ester epoxy resin compound can be utilized by nuclear magnetic resonance. (Component analysis analysis by (NMR) or gas chromatography (GC).

Further, the epoxy resin (B) may contain an epoxy resin compound other than the above-described alicyclic epoxy resin compound and glycidyl ester epoxy resin compound. The other epoxy resin compound is not particularly limited, and examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolak type epoxy resin, phenol novolac type epoxy resin, and biphenyl type epoxy. Resin, stilbene type epoxy resin, hydroquinone type epoxy resin, naphthalene skeleton type epoxy resin, tetrahydroxyphenylethane type epoxy resin, hydroxyphenylmethane type epoxy resin, two rings Pentadiene phenol type epoxy resin, diglycidyl ether of bisphenol A ethylene oxide adduct, diglycidyl ether of bisphenol A propylene oxide adduct, phenyl epoxidized ether, A A glycidyl ether having one epoxy group, such as a phenol-based glycidyl ether. Further, a nuclear hydrogenated epoxy resin which is a nuclear hydride of the epoxy resin may be mentioned.

In the epoxy resin (B), the content of the other epoxy resin compound is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less. In the epoxy resin (B), the lower limit of the content of the other epoxy resin compound is not particularly limited, and is, for example, 0% by mass. Other epoxy resin compounds may be used singly or in combination of two or more kinds within the above-mentioned range. In particular, nuclear hydrogenated epoxy trees The fat makes it possible to make the colorless transparency of the cured product of the epoxy resin composition good, and more preferably.

<Admixture of Anhydride (A) and Epoxy Resin (B)>

In the epoxy resin composition of the present embodiment, the blending amount of the acid anhydride (A) and the epoxy resin (B) is such that the blending equivalent ratio of the acid anhydride to the epoxy resin represented by the following formula (1) is 0.4 to 0.7. The amount of range.

The blending equivalent ratio of anhydride to epoxy resin = (X + Y) / Z (1)

X: number of functional groups of an acid anhydride group contained in the acid anhydride (A)

Y: the number of functional groups of the carboxyl group contained in the acid anhydride (A)

Z: number of functional groups of epoxy groups contained in epoxy resin (B)

In the above formula (1), the equivalent of the acid anhydride (A) is the total amount of the functional group number X of the acid anhydride group contained in the acid anhydride (A) and the functional group number Y of the carboxyl group. The reason is presumed that one acid anhydride group reacts with one epoxy group, and one carboxyl group reacts with one epoxy group.

For example, when the acid anhydride (A) is cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (H-TMAn), the number of functional groups of the acid anhydride group in one molecule is 1, and the number of functional groups of the carboxyl group It is 1, so the equivalent of the acid anhydride becomes 2. Further, in the case where the epoxy resin (B) is 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate, the number of functional groups of the epoxy group in one molecule is 2, so the equivalent weight of the epoxy resin becomes 2. The same applies to the case of the glycidyl ester type epoxy resin compound.

In the epoxy resin composition of the present embodiment, the number of functional groups X of the acid anhydride group contained in the acid anhydride (A) is the total of (the number of functional groups of the acid anhydride group of each acid anhydride compound) × (the molar fraction of the acid anhydride compound) The amount Y of the functional group Y of the carboxyl group contained in the acid anhydride (A) is the total amount of (the number of functional groups of the carboxyl group of each acid anhydride compound) × (the molar fraction of the acid anhydride compound). In the epoxy resin composition of the present embodiment, the functional group number Z of the epoxy group contained in the epoxy resin (B) is (the number of functional groups of the epoxy group of each epoxy resin compound) × (the epoxy The total amount of the molar fraction of the resin compound).

In the epoxy resin composition of the present embodiment, the blending equivalent ratio of the acid anhydride to the epoxy resin represented by the above formula (1) is in the range of 0.4 to 0.7, preferably in the range of 0.4 to 0.6, and preferably in the range of 0.4 to 0.5. .

In the epoxy resin composition of the present embodiment, the blending equivalent ratio of the acid anhydride to the epoxy resin represented by the above formula (1) is at least the above lower limit value, and the heat resistant coloring property of the cured product is improved. When the equivalent ratio is less than or equal to the above upper limit, the residual of the unreacted acid anhydride is suppressed, and the heat-resistant coloring property of the cured product is improved.

Further, in the epoxy resin composition or the cured product thereof, the blending equivalent ratio of the acid anhydride to the epoxy resin represented by the above formula (1) can be used to measure the equivalent (epoxy equivalent) of the epoxy resin and The equivalent of the hardener (anhydride equivalent) is calculated from the measured value. Further, the epoxy equivalent can be determined by measuring the potential difference using a 0.1 mol/L perchloric acid acetic acid standard solution in accordance with JIS K7236. Further, the acid anhydride equivalent can be subjected to component analysis by nuclear magnetic resonance (NMR) or gas chromatography (GC), and calculated based on the analysis result.

In the epoxy resin composition of the present embodiment, the total content of the acid anhydride (A) and the epoxy resin (B) is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and 90 to 100% by mass. Better.

The epoxy resin composition of the present embodiment is prepared by setting the blending amount of the acid anhydride (A) and the epoxy resin (B) to be in the range of the blending equivalent ratio of the acid anhydride to the epoxy resin, and adjusting the epoxy resin (B). The blending amount of the alicyclic epoxy resin compound, the glycidyl ester type epoxy resin compound, and other epoxy resin compounds enables the epoxy of the acid anhydride (A) and the epoxy resin (B) to be just prepared. The viscosity of the resin composition at 30 ° C is 5 Pa ‧ or less, and the viscosity-increasing ratio of the epoxy resin composition after standing for 7 hours at room temperature can be adjusted [(viscosity of epoxy resin composition after 7 hours) / (The viscosity of the epoxy resin composition just prepared)] is 3 times or less.

When the epoxy resin composition of the present embodiment is used as a sealing material for a photoelectric conversion element such as an LED, when the viscosity of the epoxy resin composition exceeds 5 Pa‧s or the adhesion increase ratio exceeds 3 times, high viscosity is used. The epoxy resin composition and the epoxy resin composition are further highly viscous during daytime operation, which deteriorates workability. When the viscosity increase ratio is within 2 times, it is preferable in terms of workability.

The epoxy resin composition of the present embodiment contains the acid anhydride (A) and the epoxy resin (B), and (a) the acid anhydride (A) contains 30 to 90% by mass of cyclohexane-1,2,4- Tricarboxylic acid-1,2-anhydride, (b) epoxy resin (B) contains 30 to 90% by mass of an alicyclic epoxy resin compound and contains a glycidyl ester type epoxy resin compound, (c) The blending equivalent ratio of the acid anhydride to the epoxy resin represented by the following formula (1) is in the range of 0.4 to 0.7, and the following effects (1) to (3) are exerted.

Further, in the epoxy resin composition of the present embodiment, the content of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (H-TMAn) in the acid anhydride (A) is 30 to 90. The mass%, the content of the alicyclic epoxy resin compound in the epoxy resin (B) is 30 to 90% by mass, and the content of the epoxy acrylate type epoxy resin compound is 10 to 60% by mass, further exerting the following ( 1) The effect of ~(3).

(1) The obtained epoxy resin composition has a low viscosity after compounding, and has a low viscosity-increasing ratio at room temperature during the daytime operation time, so that workability is excellent.

(2) The cured product of the obtained epoxy resin composition is colorless, transparent, and resistant to cracking, and the coloring is extremely small even under long-time light irradiation and heating at 150 ° C for 1,000 hours.

(3) The hardenability is good even if no hardening accelerator is added. Further, by using a specific curing accelerator, the viscosity increase rate of the epoxy resin composition is increased, but the coloring due to further heating is small, and a cured product excellent in heat resistance and coloring property can be obtained.

The epoxy resin composition which exhibits the effects of the above (1) to (3) is suitable as a sealing material for a photoelectric conversion element such as a blue LED or a white LED.

<antioxidant>

The epoxy resin composition of the present embodiment preferably contains an antioxidant when high heat resistance coloring property is required. The antioxidant is not particularly limited, and examples thereof include a hindered phenol-based antioxidant, a sulfur-based antioxidant (such as a mercaptopropionic acid derivative), and a phosphorus-based antioxidant (such as HCA). Particularly hindered phenolic antioxidants are effective. Specific examples of the hindered phenol-based antioxidant are not particularly limited, and examples thereof include 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester and triethylene glycol bis[3-( 3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methyl) Phenyl) propylene oxide 1,1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, 2,6-bis(1,1-dimethylethyl)- 4-methylphenol (BHT).

In the epoxy resin composition of the present embodiment, the content of the antioxidant is preferably from 0.1 to 5% by mass, more preferably from 0.1 to 4% by mass, still more preferably from 0.1 to 3% by mass. When the content of the antioxidant is at least the above lower limit value, the heat-resistant coloring property of the cured product of the epoxy resin composition is improved. Further, by setting the content of the antioxidant to be equal to or less than the above upper limit value, the cured product of the epoxy resin composition does not lose transparency due to bleeding of the antioxidant.

<fluorescent substance>

When the epoxy resin composition of the present embodiment is used as a material for sealing a light-emitting element of a white LED, it is preferable to contain light which emits at least a part of the light-emitting element having a wavelength of 550 nm or less from the main light-emitting peak portion and emits fluorescence. The fluorescent material is preferred. Such a fluorescent substance can emit light of various colors when combined with a light emitting diode (LED). For example, if a yellow phosphor is combined with a blue LED, white light can be emitted.

In the epoxy resin composition of the present embodiment, the content of the fluorescent substance is preferably 0.01 to 30% by mass, more preferably 0.01 to 20% by mass, still more preferably 0.1 to 10% by mass.

<hardening accelerator>

The epoxy resin composition of the present embodiment is hardened without using a curing accelerator, and has an advantage in cost. However, by adding a curing accelerator, the heat-resistant coloring property of the cured product of the epoxy resin composition can be further improved. . In the sealing material of a photoelectric conversion element such as an LED which is required to have heat-resistant coloring resistance, a curing accelerator can be suitably used in accordance with the required level of heat-resistant coloring property.

The curing accelerator is not particularly limited, and examples thereof include a tertiary amine such as benzyldimethylamine, dimethylaminomethyl phenol, and dimethylcyclohexylamine; 1-cyanoethyl-2-ethyl Imidazoles such as 4-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole; organophosphorus compounds such as triphenylphosphine and triphenyl phosphite; tetraphenyl a class 4 sulfonium salt such as ruthenium bromide or tetra-n-butyl bromide; a diazabicycloalkene such as 1,8-diazabicyclo[5.4.0]undecene-7 or an organic acid salt thereof Zinc octoate, tin octoate or B Organometallic compounds such as mercaptoacetone aluminum complex; tetra-ammonium salts such as tetraethylammonium bromide, tetrabutylammonium bromide, benzyltriphenylphosphonium bromide; boron trifluoride, triphenylene A boron compound such as a boric acid ester; a metal halide such as zinc chloride or tin (IV) chloride.

Further, the curing accelerator is not particularly limited, and examples thereof include a high melting point imidazole compound, dicyandiamide, and a high melting point dispersion type latent accelerator such as an amine addition accelerator which is obtained by adding an amine such as an epoxy resin; A microcapsule-type latent promoter obtained by coating a surface of an imidazole-based, phosphorus-based or phosphine-based accelerator; a high-temperature dissociation type such as an amine salt type latent hardening accelerator, a Lewis acid salt, and a Bendenide salt A latent hardening accelerator represented by a thermal cationic polymerization type latent hardening accelerator or the like.

Among these, a phosphorus-based hardening accelerator is preferred. Specific examples of the phosphorus-based hardening accelerator are not particularly limited, and examples thereof include an organophosphorus compound such as triphenylphosphine or triphenyl phosphite, tetraphenylphosphonium bromide, tetra-n-butylphosphonium bromide, and benzyltriamide. Grade 4 onium salts such as phenylphosphonium chloride and benzyltriphenylphosphonium bromide. When such a phosphorus-based hardening accelerator is used, a cured product excellent in heat-resistant coloring property can be obtained, and more preferably.

These hardening accelerators may be used alone or in combination of two or more.

In the epoxy resin composition of the present embodiment, the content of the curing accelerator is preferably 0.01 to 5% by mass, more preferably 0.05 to 4% by mass, still more preferably 0.1 to 3% by mass, still more preferably 0.1 to 1% by mass.

When the content of the hardening accelerator is at least the above lower limit, the heat-resistant coloring property of the cured product of the epoxy resin composition is improved. In addition, when the content of the hardening accelerator is less than or equal to the above upper limit, the cost of the epoxy resin composition is reduced, and the increase in viscosity of the epoxy resin composition can be suppressed, and workability is improved.

<Other additives>

In the epoxy resin composition of the present embodiment, an aliphatic polyol such as ethylene glycol or propylene glycol may be contained in a range that does not hinder the properties of the obtained epoxy resin composition and cured product, if necessary. A surface of a flexible agent such as a carbon dioxide gas generating agent or a polyalkylene glycol, a coupling agent such as a plasticizer, a slip agent or a decane, or an inorganic filler, such as an aliphatic or aromatic carboxylic acid compound or a phenol compound. Treatment agent, flame retardant, colorant, antistatic agent, coating agent, ion trapping agent, slidability improver, various rubber, organic polymer beads and other resistance improving agents, shake imparting agent, surfactant Additives such as surface tension reducing agent, antifoaming agent, anti-settling agent, light diffusing agent, ultraviolet absorber, mold release agent, conductive filler, and low viscosity solvent for viscosity adjustment.

<save method>

The epoxy resin composition of the present embodiment can be divided into two or more kinds of components. For example, the component containing the acid anhydride (A) and the component containing the epoxy resin (B) are stored in advance, and are prepared before curing. Further, it may be stored in the form of an epoxy resin composition in which the components are blended, and used directly for hardening. When it is stored in the form of an epoxy resin composition in which the components have been blended, it is preferably stored at a low temperature (usually -40 to 15 ° C).

≪Epoxy resin hardened ≫

The cured epoxy resin of the present embodiment is obtained by curing the epoxy resin composition.

The curing method of the epoxy resin composition is not particularly limited, and a curing method such as a conventionally known curing device such as a closed type curing furnace or a tunnel type furnace which can be continuously cured can be used. The heating method used for the curing is not particularly limited, and for example, it can be carried out by a conventionally known method such as hot air circulation, infrared heating, or high frequency heating. The heating method at the time of curing is not particularly limited, and for example, it can be carried out by a conventionally known method such as hot air circulation, infrared heating, or high frequency heating. The hardening temperature and the hardening time are preferably in the range of 30 to 10 hours at 80 to 250 ° C. When the internal stress of the hardened material is to be reduced, it is preferably post-hardened at 120 to 180 ° C for 0.1 to 5 hours after curing at 80 to 120 ° C for 0.5 to 5 hours. When the purpose is short-time hardening, it is preferably cured at 150 to 250 ° C for 30 seconds to 30 minutes.

The epoxy resin composition preferably has a weight retention ratio (ratio of the weight of the cured product to the weight of the epoxy resin composition before curing) of 97% or more. By appropriately selecting the kind and amount of the aforementioned low-viscosity acid anhydride compound (that is, an acid anhydride compound other than H-TMAn), and the acid anhydride (A) and The blending ratio of the epoxy resin (B) can obtain an epoxy resin composition having a high weight retention ratio.

≪Lighting diode ≫

The light-emitting diode of the present embodiment is a light-emitting diode in which the light-emitting element is sealed with the cured epoxy resin.

The cured epoxy resin is colorless, transparent, and resistant to cracking, and has less coloration under heating for a long period of time. For example, it can be suitably used as a sealing material for a light-emitting diode, in particular, a sealing material for a blue LED or a white LED.

≪Other uses≫

The epoxy resin composition of the present embodiment is not limited to the above-described use, and other light-emitting elements such as LEDs and semiconductor lasers, photoconductive elements, photodiodes, solar cells, photovoltaic crystals, and photothyristors (photo-Thyristor) may be used. An insulating sealing material for a photoelectric conversion element represented by an optical coupling element such as a light-receiving element, an optical coupler, or a photointerrupter, an adhesive such as a liquid crystal, a resin for forming a light, and a surface coating agent such as plastic, glass, or metal, Uses such as decorative materials that require transparency.

Further, the epoxy resin composition of the present embodiment may be an insulating seal or a molded article having a thickness of 2 mm or more by a conventionally known method such as potting, casting, filament winding, or lamination. Specifically, for example, a molded transformer, a molded transformer (converter (CT), a zero-layer converter (ZCT), a gauge transformer (PT), a set-type transformer (ZPT)) can also be used. , gas opening and closing parts (insulation spacers, supporting insulators, operating rods, sealed terminals, bushings, insulating columns, etc.), solid insulated switch parts, overhead distribution line automation equipment parts (rotary insulators, voltage detection elements, integrated capacitors, etc.) ), underground distribution line equipment parts (molded circuit breakers, power transformers, etc.), power capacitors, resin insulators, linear motor coils and other heavy-duty equipment related to insulation and sealing materials, various rotating equipment coils impregnated varnish (generator , motor, etc.).

Further, the epoxy resin composition of the present embodiment may be, for example, a potting resin such as a flyback transformer, an ignition coil, or an AC capacitor, an LED, a detector, or the like. An insulating sealing resin used in the weak electric field such as a transparent sealing resin such as a transmitter or a photocoupler, a film capacitor, or a resin impregnated with various coils.

The epoxy resin composition of the present embodiment can be used for various FRP molded articles, various coating materials, adhesives, decorative materials, and the like as a laminated plate or an application which does not necessarily require insulation.

[Examples]

Hereinafter, the present invention will be described in detail by way of examples and comparative examples, but the invention is not limited by the following examples.

Further, in the following examples and comparative examples, the physical properties of the obtained epoxy resin composition and the cured product thereof were measured and evaluated as follows.

(1) Viscosity of Epoxy Resin Composition The viscosity of the epoxy resin composition was measured by a dynamic viscoelasticity measuring apparatus (ARES manufactured by TA Instrument Co., Ltd.) with a 25 mm Φ aluminum plate at a distance between the plates of 0.05 mm and an internal temperature of 30 ° C. Determination.

Further, the viscosity-increasing ratio of the epoxy resin composition is defined as an epoxy resin composition in which the epoxy resin composition is subjected to room temperature (15 to 27 ° C) for 7 hours in a glass screw bottle with a cover. The viscosity is relative to the ratio of the viscosity of the epoxy resin composition.

[Adjusted viscosity evaluation]

○: The epoxy resin composition having a viscosity of 5 Pa‧s or less has just been prepared.

×: Epoxy resin composition with a viscosity of more than 5 Pa‧s just prepared.

[Evaluation of viscosity increase rate]

◎: An epoxy resin composition having a viscosity increase ratio of 2 times or less.

○: An epoxy resin composition having a viscosity increase ratio of more than 2 times 3 times or less.

×: An epoxy resin composition having a viscosity increase ratio of more than 3 times.

(2) Heat resistance coloring test

The quantitative sample (epoxy resin composition) was mixed in a beaker with a stirrer, and the dissolved passive gas in the epoxy resin composition was degassed under vacuum. Thereafter, the epoxy resin composition was cast into a 50 mm square and 3 mm deep ketone mold, and hardened in a hot air dryer at 100 ° C for 3 hours, and then cured at 150 ° C for 2 hours to obtain a cured product.

The hardened material obtained was heated at 150 ° C for 1000 hours. For the cured product before and after heating, the surface reflectance calculated from the spectrophotometer [Shimadzu Seiki Co., Ltd. spectrophotometer UV-3100] and the measured surface reflectance A light transmittance equivalent to 400 nm thicker than 1 mm is obtained. Then, the maintenance ratio of the light transmittance by the heat treatment was determined by the following formula.

(3) UV resistance test (light resistance test)

The cured product obtained in the same manner as the heat-resistant coloring property test was placed in a test furnace of EYE‧Super‧UVtester SUV-W11 manufactured by Dainippon Plastics Co., Ltd., and the wavelength range was 55 ° C / 50 RH %. Light of 295 to 450 nm (the peak having the highest intensity at 360 to 380 nm) was irradiated with UV light for 120 hours at an irradiation surface light intensity of 68 mW/cm ² .

For the cured product before and after the irradiation, the light transmittance measured by a spectrophotometer [Shimadzu Seiki Co., Ltd. spectrophotometer UV-3100] and the surface reflectance calculated from the additionally measured refractive index, A light transmittance equivalent to 400 nm thicker than 1 mm is obtained. Further, the following formula is used to calculate the retention rate of light transmittance due to UV irradiation.

[Number 2]

(4) Crack resistance test

The quantitative sample (epoxy resin composition) was mixed in a beaker with a stirrer, and the dissolved passive gas in the epoxy resin composition was degassed under vacuum. Thereafter, the epoxy resin composition was poured into the surface-package type light-emitting diode, hardened in a hot air dryer at 100 ° C for 3 hours, and then hardened at 150 ° C for 2 hours to obtain a cured product. Further, a light-emitting diode sealed with the cured product is obtained.

For this light-emitting diode, after 144 hours at 60 ° C 60% RH, the temperature range of 260 ° C and 230 ° 260 ° C was applied in a reflow furnace [XNB-738PC (C) manufactured by Furukawa Electric Co., Ltd.]. The 40-second heat history has a total of 3 times.

The above operation was carried out for each of 10 samples of each of the cured materials, and the crack resistance was evaluated in the following manner from the peeling of the cured product of the light-emitting diode after the heat history and the occurrence of cracking.

[Evaluation of crack resistance]

○: 0 samples produced peeling or cracking hardened material

△: 1 sample produces a cured product of peeling or cracking

×: a cured product which is peeled or cracked in more than 2 samples

In the examples and comparative examples, the following components were used as raw materials of the epoxy resin composition.

(1) Anhydride (A)

‧ Cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride [Mitsubishi Gas Chemical Co., Ltd., hereinafter referred to as "H-TMAn". ]

‧ Mixture of hexahydrophthalic anhydride and methylhexahydrophthalic anhydride [Nippon Chemical and Chemical Co., Ltd., MH700G, hereinafter referred to as "phthalic anhydride mixture"]

‧Methylhexahydrophthalic anhydride [New Japan Physical and Chemical Co., Ltd., MH, the following is also recorded as "MeHHPA". ]

(2) Epoxy resin (B)

(2-1) alicyclic epoxy resin compound

‧3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate [Daicel Co., Ltd., CEL2021P]

(2-2) Glycidyl ester type epoxy resin compound

‧ diglycidyl hexahydrophthalate [Sakamoto Pharmaceutical Industry Co., Ltd., SR-HHPA]

(2-3) Linear epoxy resin compound

‧Hexane-1,6-diglycidyl ether [Sakamoto Pharmaceutical Industry Co., Ltd., SR-16H]

(3) Antioxidants

‧Hindered phenolic antioxidant: AO-50 [made by ADEKA Co., Ltd., and AO-50" is also described below. ]

‧ Hindered phenolic antioxidant: 2,6-bis(1,1-dimethylethyl)-4-methylphenol [manufactured by Kanto Chemical Co., Ltd., and also referred to as "BHT" hereinafter. ]

(4) Hardening accelerator

‧The bromine salt of the fourth grade [[San-apro company, the following is also described as "U-CAT5003"]

(5) Fluorescent substances

‧ yttrium-doped yttrium aluminum oxide [Y ₃ Al ₅ O ₁₂ : Ce, yellow phosphor. ]

[Example 1]

21.0 parts by mass of H-TMAn [manufactured by Mitsubishi Gas Chemical Co., Ltd.], a mixture of hexahydrophthalic anhydride and methylhexahydrophthalic anhydride [MH700G, manufactured by Nippon Chemical and Chemical Co., Ltd.], 21.0 parts by mass, Alicyclic epoxy resin compound [3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexene carboxylate: CEL2021P manufactured by Daicel Co., Ltd.] 172 parts by mass, epoxy Propyl ester type epoxy resin compound hexahydrogen 73.9 parts by mass of succinyl phthalate [SR-HHPA manufactured by Sakamoto Pharmaceutical Co., Ltd.], 2.8 parts by mass of hindered phenol-based antioxidant AO-50 (made by ADEKA Co., Ltd.), and the fourth grade 鏻The bromine salt was mixed with 0.80 parts by mass of "U-CAT5003" manufactured by San-apro Co., Ltd. to obtain an epoxy resin composition. The physical properties of the epoxy resin composition obtained by the above method and the cured product thereof were measured and evaluated. The results are shown in Table 1.

[Examples 2 to 16 and Comparative Examples 1 to 9]

An epoxy resin composition was obtained in the same manner as in Example 1 except that the types and ratios of the raw material components were changed as shown in Tables 1 to 3. The physical properties of the epoxy resin composition obtained by the above method and the cured product thereof were measured and evaluated. The results are shown in Tables 1-3.

【Table 1】

【Table 2】

【table 3】

1), 2) A hardened material having insufficient hardness is not obtained. Therefore, the hardened material cannot be released from the ketone ketone mold and cannot be measured → not suitable as a sealing material

3) The obtained hardened material is in a soft state, and if cracking test is directly performed, cracking may occur further.

The following items are known from Tables 1 to 3 above.

An acid anhydride (A) and an epoxy resin (B), and the acid anhydride (A) contains 30 to 90% by mass of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, epoxy resin (B) An epoxy resin composition containing 30 to 90% by mass of an alicyclic epoxy resin compound and containing a glycidyl ester type epoxy resin compound, and an equivalent ratio of an acid anhydride to an epoxy resin of 0.4 to 0.7 The viscosity after the blending is low, the viscosity increase ratio at room temperature is low, the workability is excellent, and the cured product can be obtained without adding a hardening accelerator, and the hardenability is good. Further, the cured product was colorless and transparent, and was excellent in crack resistance, and was less colored under long-time light irradiation and heating at 150 ° C for 1,000 hours.

In particular, by controlling the content of H-TMAn in the acid anhydride (A) to be 30 to 90% by mass, the content of the alicyclic epoxy resin compound in the epoxy resin (B) is controlled to be 30 to 90% by mass, and the control is carried out. The epoxy acrylate type epoxy resin compound in the epoxy resin (B) is contained in an amount of 10 to 60% by mass, and the blending equivalent ratio of the acid anhydride to the epoxy resin is controlled to be 0.4 to 0.7, heat-resistant coloring property and UV-resistant coloring resistance. The properties are more excellent, and the workability of the epoxy resin composition is good, and a cured product having better crack resistance can be obtained.

Claims (9)

An epoxy resin composition containing an acid anhydride (A) and an epoxy resin (B), and: (a) the acid anhydride (A) contains 30 to 90% by mass of cyclohexane-1,2,4-tricarboxylic acid- (2) The epoxy resin (B) contains 30 to 90% by mass of an alicyclic epoxy resin compound and contains a glycidyl ester type epoxy resin compound; (c) the following formula (1) The ratio of the blending equivalent ratio of the anhydride to the epoxy resin is in the range of 0.4 to 0.7; the blending equivalent ratio of the anhydride to the epoxy resin is = (X + Y) / Z (1) X: the anhydride contained in the acid anhydride (A) The functional group number of the group Y: the number of functional groups of the carboxyl group contained in the acid anhydride (A): the number of functional groups of the epoxy group contained in the epoxy resin (B). The epoxy resin composition of the first aspect of the invention, wherein the epoxy acrylate type epoxy resin compound in the epoxy resin (B) is contained in an amount of 10 to 60% by mass. An epoxy resin composition according to claim 1 or 2, wherein the glycidyl ester type epoxy resin compound is selected from the group consisting of diglycidyl adipate and dimethyl epoxide of long-chain dibasic acid. At least one of the group consisting of diglycidyl tetrahydrophthalate and diglycidyl hexahydrophthalate. An epoxy resin composition according to claim 1 or 2, wherein the alicyclic epoxy resin compound is 3,4-epoxycyclohexenylmethyl-3',4'-epoxy ring Alkene carboxylate. The epoxy resin composition of claim 1 or 2 further contains 0.1 to 5% by mass of a hindered phenol-based antioxidant. The epoxy resin composition of claim 1 or 2 further contains 0.01 to 5% by mass of a phosphorus-based hardening accelerator. An epoxy resin composition according to claim 1 or 2, further comprising a fluorescent substance capable of absorbing and emitting at least a part of light emitted from a light-emitting element having a main light-emitting peak wavelength of 550 nm or less Light. An epoxy resin cured product obtained by hardening an epoxy resin composition according to claim 1 or 2. A light-emitting diode is obtained by sealing a light-emitting element with an epoxy resin cured material according to claim 8 of the patent application.