JP2000007757A - New epoxy resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide epoxy resins low in viscosity, difficult in crystallization and capable of providing cured products excellent in heat resistance, moisture resistance, mechanical strength and the like. SOLUTION: These new epoxy resins are represented by the formula (wherein R1 is a 2-6C alkyl; R2 is H or a 1-3C alkyl; n is a real number of not less then 0) and have a number average molecular weight of 250-500 and a content of the component of n=0 of not less than 30% and a viscosity at 60 deg.C of 1-30,000 cP. A preferred epoxy resin is represented by said formula wherein R1 is tert- butyl and R2 is H and has a content of the component of n=1 of not less than 1% and a total chlorine content of not more than 2,000 ppm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel epoxy resin which provides a novel epoxy resin composition which has low viscosity, is hardly crystallized, and has excellent workability and storage stability. In detail, the present invention is a heat-resistant, moisture-resistant, excellent mechanical strength of the cured product, sealing materials for electrical and electronic parts such as semiconductor elements, laminated materials, structural materials, paints, Adhesives, novel epoxy resin compositions useful for casting materials, etc., and cured products thereof, for example, laminated articles such as laminates, laminated sheets, structural articles, coatings, films, cast articles,
Further, the present invention relates to a novel epoxy resin useful for providing a semiconductor sealing device or the like in which a semiconductor is sealed with a cured product of the epoxy resin composition.

[0002]

2. Description of the Related Art Conventionally, epoxy resins have been used in paints, since cured products thereof have excellent heat resistance, adhesiveness and mechanical properties.
It has been used as a casting material for electric parts, laminates, adhesives, sealants for electronic parts, and the like, but its required properties have been increasingly sophisticated in recent years. For example, epoxy resin is widely used as an encapsulant for semiconductors. In recent years, with the improvement in the degree of integration of semiconductor elements, package sizes have become larger and thinner, and mounting methods have also been changed to surface mounting. In order to develop better solder heat resistance, lower viscosity and lower moisture absorption are required.

[0003] Furthermore, due to the recent trend of low cost and high integration, a dual in-line package by transfer molding using a conventional mold has been replaced with a hybrid IC, chip-on-board, tape carrier package, plastic pin grid array, plastic Ball grid array, underfill type chip size package, globe top type chip size package,
A method of mounting a bare chip by spot sealing using a liquid sealing material without using a mold such as an overcoating type multi-chip module has been increasing.

[0004] However, in general, liquid sealing has a disadvantage that its reliability is lower than that of transfer molding. This is because, as a liquid epoxy resin for liquid materials, bisphenol F type epoxy resin is usually used. However, since its heat resistance is low or its viscosity is not low enough to satisfy the requirements, a sufficient amount of epoxy resin is used. The main reason is that an inorganic filler cannot be blended, and as a result, the cured product has a large water absorption coefficient and a large coefficient of linear expansion. In order to overcome these problems, the use of resorcinol diglycidyl ether having a lower viscosity than that of the bisphenol F type epoxy resin has been studied, but the cured product obtained by curing these epoxy resins has a glass transition temperature. And heat resistance is impaired.

Conversely, the use of diglycidyl ether of dihydroxynaphthalene has been studied to increase the heat resistance, but it is said that the viscosity is high, the amount of the filler is limited, and the workability and moldability are poor. There are drawbacks. On the other hand, studies have been made to use a low-molecular-weight, low-viscosity bisphenol F-type epoxy resin obtained by molecular distillation of a normal bisphenol F-type epoxy resin, but in that case, the viscosity of the composition decreases, Although heat resistance is slightly improved, neither viscosity nor heat resistance sufficiently satisfies the requirements.

[0006]

Accordingly, the present invention provides a cured product having excellent heat resistance, moisture resistance, mechanical strength, and the like when the epoxy resin is hardly crystallized in the epoxy resin composition and cured. It is an object of the present invention to provide an epoxy resin composition which is liquid at 25 ° C., a cured product thereof, and a semiconductor sealing device which is sealed with the epoxy resin composition having excellent reliability. It is another object of the present invention to provide an epoxy resin having the above-mentioned properties and providing an epoxy resin composition having low viscosity and thixotropy and excellent workability.

[0007]

As a result of various studies on the above problems, the present inventors have found that the number average molecular weight, viscosity, and content of the component of n = 0 in the general formula (1) (hereinafter referred to as “n = 0”)
By providing a hydroquinone-type epoxy resin in which only one alkyl group having a specific number of carbon atoms has been introduced into the benzene skeleton specified in the “content ratio”), the epoxy resin has a low viscosity, and Is difficult to crystallize, and the cured product has heat resistance, hygroscopicity, mechanical strength,
An epoxy resin composition that is liquid at 25 ° C. and has excellent electrical properties.
Furthermore, they have found that it is possible to provide a semiconductor sealing device excellent in reliability, moisture resistance reliability and the like, which is sealed with the cured product and the epoxy resin composition, and completed the present invention.

That is, the present invention provides the following general formula (1):

Embedded image (In the formula, R ¹ represents an alkyl group having 2 to 6 carbon atoms, R ²
Represents hydrogen or an alkyl group having 1 to 3 carbon atoms, and n represents 0
These represent the real numbers. ) Having a number average molecular weight of 25
0 to 500, the content of the component of n = 0 in the general formula (1) is 30% or more, and the viscosity at 60 ° C. is 1%.
Provides an epoxy resin that is ３０30,000 centipoise. Further, the present invention provides the epoxy resin described in the general formula (1), wherein R ¹ is a tert-butyl group. Further, the present invention provides the epoxy resin described in or above, wherein R ² is a hydrogen atom. The epoxy resin according to any one of the above, wherein the epoxy resin has a viscosity at 25 ° C. of 50 to 1,000,000 centipoise. Further, the present invention provides the epoxy resin according to any one of the above, wherein the content of the component of n = 1 in the general formula (1) is 1% or more. Further, the present invention provides the epoxy resin according to any one of the above, wherein the total chlorine content is 2000 ppm or less.

Hereinafter, the present invention will be described in detail. (i) Basic properties of the epoxy resin of the present invention The present invention provides the following general formula (1):

Embedded image (In the formula, R ¹ represents an alkyl group having 2 to 6 carbon atoms, R ²
Represents hydrogen or an alkyl group having 1 to 3 carbon atoms, and n represents 0
These represent the real numbers. ) Having a number average molecular weight of 25
0 to 500, the content of the component of n = 0 in the general formula (1) is 30% or more, and the viscosity at 60 ° C. is 1%.
It is an epoxy resin that is ３０30,000 centipoise.

1) Repeating unit n: In the structural formula of general formula (1), n represents the number of repeating units and is a real number of 0 or more.
This value is uniquely limited by the number average molecular weight. That is, n is 0 when focusing on one molecule of epoxy resin.
Although the above integer, the epoxy resin as a whole is generally used practically as a mixture having a molecular weight distribution, so that n has a number average value, and the value is preferably 0.
３3.9.

2) Substituent R ^{1 In} the structural formula of the general formula (1), R ¹ is an alkyl group having 2 to 6 carbon atoms. In this case, when the carbon number is 1 or less, the glass transition temperature indicating heat resistance is low, and the moisture absorption rate is undesirably high. In addition, the melting point and crystallinity of the epoxy resin are increased, and from the composition obtained by blending the epoxy resin with a curing agent or the like, quickly or during storage of the epoxy resin composition, Not only is the epoxy resin crystallized and the epoxy resin composition becomes non-uniform, but also the fluidity of the epoxy resin itself is lost, and the epoxy resin composition cannot be used as a liquid epoxy resin composition. On the other hand, when the number of carbon atoms is 7 or more, heat resistance represented by a glass transition temperature or the like is undesirably reduced. Therefore, R ¹
Is preferably an alkyl group having 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, and more preferably 4 carbon atoms. Among them, a tertiary butyl (tert-butyl) group has high heat resistance and low heat resistance. It is particularly preferable because it has a viscosity and an epoxy resin composition using the epoxy resin becomes a stable liquid.

In the epoxy resin of the present invention, the number of alkyl substituents directly bonded to the benzene ring represented by R ¹ is limited to one for each benzene ring. That is, an epoxy resin in which two substituents are directly bonded to each benzene ring, for example, 2,5-di-te
The rt-butylhydroquinone epoxy resin is a crystalline solid epoxy resin, and when it is mixed with a curing agent, it becomes a solid epoxy resin composition, or even if it is mixed with a low-viscosity curing agent. Can be liquefied,
Due to the high crystallinity of the epoxy resin, the epoxy resin crystallizes quickly or during storage from the composition,
The epoxy resin composition becomes uneven or the whole is solidified.

Although such an epoxy resin can be used as a molding material for low-pressure transfer molding as described above, a usual method for curing a liquid epoxy resin composition, for example, by filling a syringe into a dispenser. However, the method cannot be applied to a method of discharging using a liquid crystal, and the value as a liquid epoxy resin is significantly impaired. On the other hand, in the epoxy resin of the present invention, since only one substituent having a carbon number in a specific range (2 to 6) is directly bonded to each benzene ring, the symmetry of the molecular structure is lost. It is difficult to crystallize, and it is only by this that a stable liquid epoxy resin composition can be provided.

3) Number average molecular weight: The field of application of the epoxy resin of the present invention is a liquid epoxy resin composition and a cured product thereof. In order to provide such a liquid epoxy resin composition, The number average molecular weight of the epoxy resin of the invention must be specified. That is, the epoxy resin of the present invention has a number average molecular weight of 250 to 500. The lower the number average molecular weight is, the lower the viscosity is, and the improved properties of the cured product (heat resistance, moisture resistance, etc.) are also preferable, and are preferably 255 to 400, more preferably 260.
To 350, particularly preferably 270 to 300. If the molecular weight is greater than 500, the epoxy resin is at 25 ° C.
Thus, the solid or semi-solid in an amorphous state is formed. An epoxy resin composition containing such an epoxy resin loses fluidity at 25 ° C. and becomes solid or semi-solid, or has low heat resistance and low moisture resistance of a cured product.

Further, such an epoxy resin composition comprises:
For example, in the field of sealing a semiconductor device by low-pressure transfer molding, it can be used as a molding material by pulverizing it into an appropriate size and tableting it. Method, such as a method of filling a syringe and discharging using a dispenser, or a casting method of pouring into a predetermined mold, because the fluidity of the epoxy resin composition is lost, the method cannot be applied. I will.

4) Content of n = 0 component in formula (1) (n = 0 content): n = 0 of epoxy resin of the present invention
The content is preferably 30% or more, and the higher the content, the lower the viscosity of the epoxy resin, which is desirable. Therefore, preferably 50%
Or more, more preferably 80% or more, particularly preferably 90% or more.
% Or more, particularly preferably 95% or more. Note that n =
The 0 content is determined by gel permeation chromatography (hereinafter referred to as “GPC”).

5) Viscosity: (a) Viscosity at 60 ° C. The epoxy resin of the present invention has a viscosity of 1 to 3 at 60 ° C.
000 centipoise, preferably 5 to 3,0
00 centipoise, more preferably 8 to 500 centipoise, particularly preferably 10 to 100 centipoise, and particularly preferably 20 to 50 centipoise. If the viscosity at 60 ° C. is higher than 30,000 centipoise, the fluidity of the epoxy resin composition obtained by using the epoxy resin decreases, and the value as a liquid epoxy resin composition is significantly impaired. Furthermore, the workability of the kneading operation is deteriorated, so that a composition having a uniform composition cannot be obtained, or the mechanical strength of the cured epoxy resin obtained by curing the epoxy resin composition, and the moisture resistance are reduced. I get lost. When the epoxy resin composition is lower than 1 centipoise, the vapor pressure of the epoxy resin increases, and during the curing of the epoxy resin composition containing the epoxy resin, the epoxy resin vaporizes and voids are formed in the epoxy resin cured product. May be generated.

(B) Viscosity at 25 ° C. When the epoxy resin of the present invention has a viscosity at 25 ° C. of 50 to 1,000,000 centipoise, it can be mixed with various compounds such as a curing agent. This is desirable because the step of raising the temperature in advance can be omitted in some cases. Further, when the viscosity at 25 ° C. is higher than 1,000,000 centipoise, the fluidity of the epoxy resin composition obtained using the epoxy resin is reduced, and the value as a liquid epoxy resin composition is significantly impaired. There is. On the other hand, if it is lower than 50 centipoise, the vapor pressure of the epoxy resin increases, and during the curing of the epoxy resin composition containing the epoxy resin, the epoxy resin vaporizes and voids are formed in the cured epoxy resin. May be generated.

From such a viewpoint, the viscosity of the epoxy resin at 25 ° C. is preferably from 60 to 20,000, more preferably from 100 to 10,000, more preferably from 200 to 50,000.
000, particularly preferably 500 to 1500, particularly preferably 700 to 1200. 6) Regarding the substituent R ² : The substituent R ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a hydrogen atom is preferred because the viscosity tends to decrease.

(Ii) Content of n = 1 component in formula (1) (n = 1 content): The epoxy resin of the present invention is usually liquid at 25 ° C. For example, it may crystallize and become solid. The higher the n = 1 content of the epoxy resin of the present invention, the more difficult it is to crystallize, and n =
When the content is 1% or more and 70% or less, the epoxy resin becomes a stable liquid at 25 ° C. Therefore, it is preferably from 5% to 60%, more preferably from 10% to 50%.
% Or less. When the epoxy resin is liquid at 25 ° C., the step of heating when mixing with the curing agent or the like may be omitted in some cases. The crystallization tendency can be evaluated by a crystallization tendency test described later. The larger the numerical value obtained in this test, the more difficult it is to crystallize. In this test, it is preferably 0.5 or more. More preferably, it is 0 or more.

(Iii) “Liquid at 25 ° C.” In the present invention, “liquid at 25 ° C.” means the following 2 if the epoxy resin to be tested is not crystallized as it is.
One of the two conditions is satisfied.
Also, if the epoxy resin to be tested is crystallized,
After holding 100 g of the epoxy resin to be tested at a temperature of 80 ° C. for 24 hours, it is cooled to 25 ° C. within 0.5 hour,
For a test sample whose elapsed time after reaching 5 ° C. is within one hour, one of the following two conditions is satisfied.

(A) A test sample is placed in a vertical test tube (made of flat-bottomed cylindrical glass having an inner diameter of 30 mm and a height of 120 mm) and the height from the bottom of the test tube is 55 mm. When the test tube is leveled immediately after stirring for 1 minute with a stir bar while maintaining the temperature of the sample at 25 ° C., when the tip of the moving surface of the test sample extends from the bottom of the test tube, If the time required to pass through a portion having a distance of 60 millimeters is 90 seconds or less, the liquid is defined as “liquid at 25 ° C.”. (B) When the test sample is 3,000,000 centipoise or less when measured with a B-type viscometer at 25 ° C., it is regarded as “liquid at 25 ° C.”.

(Iv) Regarding chlorine content: Since the epoxy resin of the present invention is industrially produced also by using a chlorine-containing compound such as epichlorohydrin as an ordinary raw material, side reactions during the synthesis reaction may occur. As a cause, chlorine is often contained in the epoxy resin.
The epoxy resin can be used for various uses, but is particularly suitably used for a liquid sealing material for electronic parts such as semiconductors. In such applications, if the amount of chlorine contained in the epoxy resin is large, the aluminum wiring on the semiconductor element is corroded and disconnected, and the reliability of the semiconductor using the epoxy resin is reduced. There is. Therefore, the smaller the amount of chlorine contained in the epoxy resin, the better.

The chlorine contained in the epoxy resin is classified into inorganic chlorine, hydrolyzable chlorine, and total chlorine as defined by the measurement method described later. preferable. 5p inorganic chlorine content
pm or less, more preferably 1 ppm or less. Hydrolysable chlorine content is preferably 1500p
pm or less, more preferably 1000 ppm or less, further preferably 500 ppm or less, particularly preferably 100 ppm or less.
pm or less. The total chlorine content is 1% or less, more preferably 5000 ppm or less, further preferably 2000 ppm or less, particularly preferably 1000 pp.
m, more preferably 700 ppm or less. Further, the lower the total chlorine content, the lower the thixotropic property, and the more easily the resin flows during molding. The thixotropy is desirably smaller as the thixotropy index obtained by the method described later is smaller, preferably 5.0 or less, more preferably 2.0 or less.

(V) Production of Epoxy Resin 1) One Production Example The epoxy resin of the present invention has the general formula (2):

Embedded image (Wherein R ¹ is the same as in the case of formula (1)), and a catalyst comprising an epihalohydrin such as epichlorohydrin, 2-methyl-1-chlorohydrin, epibromohydrin and the like. After the addition reaction in the presence of, a dehydrohalogenation reaction is carried out using a dehydrohalogenation reactant, followed by washing with water, a separation step, and a step of recovering excess epihalohydrin.

(A) The amount of epihalohydrin used: In the general formula (1), in order to suppress the amount of a polymer having a repeating unit n of 1 or more and to suppress the increase in the number average molecular weight and the viscosity, The amount of the epihalohydrin to be used is usually 0.8 mol or more and 30 mol or less, preferably 1.0 mol or more and 20 mol or less, more preferably 2.5 mol or more and 10 mol or less, especially 1 mol of the phenolic hydroxyl group. Preferably it is 3 mol or more and 5 mol or less. If the amount of the epihalohydrin used is less than 0.8 mol, the molecular weight of the recovered epoxy resin becomes high, and the epoxy resin becomes solid. Also,
When the amount is more than 30 mol, the production amount of the epoxy resin produced in a reactor of a fixed volume decreases, or the concentration of the dehydrohalogenating reactant used decreases and the halogen content of the epoxy resin recovered decreases. May be higher.

(B) Catalyst: The catalyst used in the addition reaction includes tetramethylammonium chloride, benzyltrimethylammonium chloride, tetrabutylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, tetraethylammonium iodide, iodine Tetramethyl ammonium chloride, tetrapropyl ammonium chloride,
Ammonium salts such as benzyltrimethylammonium bromide, benzyltrimethylammonium iodide and choline chloride; alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide; Basic organic compounds such as tributylamine, triisopropylamine, benzyldiethylamine, 2-phenylimidazole, imidazole, N-methylimidazole; triphenylphosphine, trimethylphosphine, benzyltriphenylphosphonium bromide, amyltriphenylphosphonium bromide, iodide And phosphorus-based compounds such as benzyltriphenylphosphonium.

(C) Reaction temperature: The reaction temperature during the addition reaction is from 20 ° C to 160 ° C, preferably from 50 ° C to 140 ° C.
° C, more preferably 60 ° C to 130 ° C, particularly preferably 80 ° C to 120 ° C. If the reaction temperature is too low, less than 20 ° C., the progress of the reaction is too slow, the reaction is not completed or not industrially preferable, and the epoxy resin obtained due to an insufficient content of glycidyl groups is used. Problems such as low heat resistance of the cured product may occur. On the other hand, if the reaction temperature exceeds 160 ° C. and is too high, epihalohydrin may cause a hydrolysis reaction, and in the washing and separation steps after the completion of the reaction, the interface between the organic layer and the aqueous layer is unclear and separation is difficult. May be.

(D) Dehydrohalogenation Reactant: Examples of the dehydrohalogenation reactant used in the dehydrohalogenation reaction include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide. And alkaline earth metal hydroxides such as calcium hydroxide. The dehydrohalogenating reactant may be used as it is, or may be used after being dissolved in a solvent such as water, methanol, or ethanol. The present invention is not particularly limited by the amount of the dehydrohalogenating reactant used in this synthesis reaction, but it is 0.9 to 0.9 equivalent to 1 equivalent of phenolic hydroxyl group.
It is 3.0 equivalents, preferably 1.0 to 2.0 equivalents, particularly preferably 1.05 to 1.2 equivalents. If the amount is less than 0.9 equivalent, the content of hydrolyzable halogen contained in the recovered epoxy resin or the total content of halogen is not preferred. If the amount is more than 3.0 equivalents, a side reaction between the dehydrohalogenating agent and epihalohydrin occurs. As a result, in the water washing and separation steps after the completion of the reaction, the interface between the organic layer and the aqueous layer is unclear and separation occurs. It is difficult or industrially undesirable.

(E) Dehydrohalogenation reaction, etc .; (a) In the dehydrohalogenation reaction, water generated by the reaction or water entrained when the dehydrohalogenating reactant is added is removed to the outside of the reaction system. It is preferable to carry out while performing. Examples of the method for removing water include a method in which water in the reaction system is distilled off by azeotropic distillation with epihalohydrin, the distillate is separated into an aqueous phase and an organic phase, and then only the organic phase is returned to the reaction system. Is done. (B) Further, a reaction solvent may be used when performing both or both of the above addition reaction and dehydrohalogenation reaction. As a reaction solvent to be used, for example, toluene,
Non-polar solvents such as xylene; methyl isobutyl ketone,
Examples thereof include polar solvents such as dioxane and dimethyl sulfoxide. Among them, the use of dimersulfoxide is preferred because the content of hydrolyzable halogens or the total halogen content can be significantly reduced. (C) Further, the hydrolyzable halogen content of the epoxy resin of the present invention is obtained by adding the dehydrohalogenating reactant to the obtained epoxy resin in the presence or absence of the reaction solvent. The reduction can be achieved by performing a dehydrohalogenation reaction.

2) Other Production Examples of Epoxy Resin The epoxy resin of the present invention can also be obtained by the following glycidylation reaction. That is, a monoalkyl-substituted hydroquinone represented by the general formula (2), epihalohydrin represented by epichlorohydrin, and an alkali metal hydroxide or an alkaline earth metal hydroxide, in the presence or absence of a catalyst, It can also be obtained by reacting. The reaction is desirably performed at a temperature of, for example, 50 to 130 ° C., preferably 60 to 90 ° C. for 1 to 10 hours.

(A) Alkali metal hydroxide or alkaline earth metal hydroxide: The alkali metal hydroxide or alkaline earth metal hydroxide used herein is exemplified above as the dehydrohalogenating reactant. Sodium hydroxide, potassium hydroxide and their aqueous solutions are inexpensive and industrially preferred. These may be used as they are, or may be used after being dissolved in a solvent such as water, methanol, or ethanol. The present invention is not particularly limited by the amount of the alkali metal hydroxide or alkaline earth metal hydroxide used, but usually 0.8 to 3.0 equivalents, preferably 1 equivalent to 1 equivalent of phenolic hydroxyl group. 0.9 ~
2.0 equivalents, particularly preferably 1.0 to 1.2 equivalents. If it is less than 0.8 equivalent, the content of hydrolyzable halogen contained in the recovered epoxy resin or the total content of halogen may be increased. If the amount is more than 3.0 equivalents, a side reaction between the dehydrohalogenating reactant and epihalohydrin occurs. As a result, in the water washing and separation steps after completion of the reaction, the interface between the organic layer and the aqueous layer is unclear and separation is difficult. May be. When the alkali metal hydroxide or alkaline earth metal hydroxide used here is gradually added from the beginning of the reaction, the rise in temperature due to the heat of the reaction can be suppressed, and side reactions such as the hydrolysis reaction of epihalohydrin may occur. This is preferable because it reduces the number of the components.

(B) Catalyst: The catalyst used in the glycidylation reaction is exemplified as a catalyst used in an addition reaction between a monoalkyl-substituted hydroquinone represented by the general formula (2) and epihalohydrin. The same compounds can be used.

(C) Reaction Solvent A reaction solvent may be used in performing both or both of the above addition reaction and dehydrohalogenation reaction. Examples of the reaction solvent used include non-polar solvents such as toluene and xylene, and polar solvents such as methyl isobutyl ketone, dioxane, and dimethyl sulfoxide. The use of dimersulfoxide can significantly reduce the content of hydrolyzable halogens or the total halogen content.

(D) Removal of water from the reaction system during the reaction In this reaction, water generated by the reaction or water added when an alkali metal hydroxide or an alkaline earth metal hydroxide is added as an aqueous solution. It is preferable to carry out the reaction while removing the compound outside the reaction system. As a method of removing water, water in the reaction system is distilled off under reduced pressure or normal pressure by azeotropic distillation with epihalohydrin, and the distillate is separated into an aqueous phase and an organic phase. Returning to the reaction system is preferable because an epoxy resin having a low total halogen content or a low hydrolyzable halogen content is recovered.

3) Other Production Examples of Epoxy Resin: Further, the epoxy resin of the present invention is prepared by combining the epoxy resin of the present invention having a relatively low molecular weight synthesized by any one of the above-mentioned methods and the epoxy resin in the presence of a catalyst. It can also be synthesized by reacting with a monoalkyl-substituted hydroquinone represented by the formula (2). (a) Catalyst: The catalyst used here is a basic catalyst,
Examples include quaternary ammonium salt-based catalysts and phosphorus-based catalysts. (A) Examples of the basic catalyst include sodium hydroxide, potassium hydroxide, lithium hydroxide, tributylamine, triethylamine, triisopropylamine, benzyldiethylamine, 2-phenylimidazole, imidazole, N-methylimidazole, and 1,8. -Diazabicyclo
[5.4.0] undec-7-ene (commonly known as DBU).

(B) As the quaternary ammonium salt catalyst,
Examples include tetramethylammonium chloride, benzyltrimethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide and the like. (C) Examples of the phosphorus-based catalyst include triphenylphosphine, trimethylphosphine, benzyltriphenylphosphonium bromide, amyltriphenylphosphonium bromide, benzyltriphenylphosphonium iodide, triphenylphosphonium iodide and the like. (D) The present invention is not limited by the type of the catalyst, but among them, the use of a phosphorus-based catalyst such as triphenylphosphine is preferable since the corrosiveness of aluminum wiring is reduced when used as a sealant for semiconductors. .

(B) Amount of catalyst: The amount of the catalyst used is 1 ppm to 1%, preferably 5%, based on the glycidyl compound.
ppm to 1000 ppm, particularly preferably 10 ppm to
500 ppm. If the amount of the catalyst used is too small, less than 1 ppm, the reaction rate will be low. On the other hand, if it exceeds 1%, the amount of the catalyst remaining in the produced epoxy resin increases, and the physical and electrical properties of the cured epoxy resin deteriorate, or it is used as a sealing material for semiconductor sealing devices. In such a case, the corrosiveness of the aluminum wiring may increase.

(C) Reaction temperature The reaction temperature is 80 to 280 ° C., preferably 100 to 280 ° C.
220 ° C, more preferably 120 to 180 ° C. If the reaction temperature is too low, less than 80 ° C., the progress of the reaction is too slow, the viscosity of the reaction system increases, and the stirring of the reaction system becomes difficult, and the reaction is difficult to complete. Too much is not preferable because the resin starts to decompose thermally.

(D) Hydrolyzable halogen content: The content of the hydrolyzable halogen in the epoxy resin of the present invention is determined by subjecting the obtained epoxy resin to the dehalogenation in the presence or absence of the reaction solvent. The reduction can be achieved by adding a hydrogen reactant and performing the dehydrohalogenation reaction again.

4) Purification Example of Epoxy Resin; The epoxy resin of the present invention is synthesized under any of the above-mentioned production examples, and then is subjected to a normal pressure or a reduced pressure of 1 × 10 to 5 mmHg.
It can also be obtained by distillation at 80-280 ° C. The epoxy resin of the present invention obtained by the above distillation operation has various chlorine contents reduced and lower viscosity than the epoxy resin before distillation, and is industrially preferable.

5) Monoalkyl-substituted hydroquinone The monoalkyl-substituted hydroquinone which is a compound represented by the general formula (2) and which is used in the production examples of the epoxy resin described in the above (v) -1) to 3) is tert. -Butylhydroquinone, n-butylhydroquinone, n-propylhydroquinone, iso-propylhydroquinone, ethylhydroquinone, pentylhydroquinone,
Examples include n-hexylhydroquinone, isoamylhydroquinone, tert-amylhydroquinone, and the like.
Tert-butylhydroquinone is particularly preferred because the synthesized epoxy resin has a low viscosity and the cured product has excellent properties such as heat resistance.

(Vi) Mixing of other epoxy resins: 1) Other epoxy resins or epoxy compounds can be added to the epoxy resin of the present invention, if necessary, as long as the object of the present invention is not impaired. For example,
Bivalent phenols such as bisphenol A, bisphenol S, bisphenol F, hydroquinone, resorcin; tris- (4-hydroxyphenyl) ethane, 1,1,
3, such as 2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak and o-cresol novolak
Phenols of valency or higher;

Glycidyl ether derivatives derived from halogenated bisphenols such as tetrabromobisphenol A, or dihydric or trihydric phenols; alicyclic diepoxycarboxylate, alicyclic diepoxyacetal, alicyclic Cycloaliphatic epoxy resins such as diepoxy adipate and vinylcyclohexene diepoxide; and aliphatic epoxy compounds such as glycerin polyglycidyl compound and trimethylolpropane polyglycidyl compound. Further, phenyl glycidyl ether, cresyl glycidyl ether, p-tert-butylphenol glycidyl ether,
o-tert-butylphenol glycidyl ether, m-
Monoglycidyl compounds such as tert-butylphenol glycidyl ether and o-bromophenyl glycidyl ether are exemplified.

2) Mixing ratio of other epoxy resins: These epoxy resins can be used alone or as a mixture of two or more, but the amount of the epoxy resin of the present invention is not limited to the total epoxy resin. 5 to 100% by weight, preferably 20 to 100% by weight, more preferably 50 to 10% by weight.
It is desirably in the range of 0% by weight. It is preferable to mix these epoxy resins with the epoxy resin of the present invention, because the epoxy resin of the present invention becomes difficult to crystallize alone or from the epoxy resin composition, and becomes a more stable liquid.

(Vii) Application of the Epoxy Resin of the Present Invention The epoxy resin of the present invention is used alone or, if necessary, is mixed with a general-purpose epoxy resin or the like and a curing agent to form an epoxy resin composition. A cured product having high heat resistance and excellent mechanical properties, moisture resistance and the like can be obtained. Various compounds used in the epoxy resin composition include the following. 1) Curing agent An amine-based curing agent, a latent curing agent, an acid anhydride-based curing agent, a phenol-based curing agent, an imidazole-based curing agent, and a cationic curing agent are exemplified. An acid anhydride-based curing agent and a low molecular weight phenol-based curing agent are preferable in that they provide an epoxy resin composition having a low viscosity.

(A) Amine-based curing agent: (A) Examples of the amine-based curing agent include aliphatic amines such as ethylenediamine and triethylenetetramine, m-xylylenediamine, p-xylylenediamine, and 2,4-amine.
Aromatic amines such as diaminodiphenylmethane and 4,4'-diaminodiphenylmethane; and allylated aromatic amines such as monoallyldiaminodiphenylmethane and diallyldiaminodiphenylmethane are also preferable, and triethylenetetramine is preferable. (B) The amount of the amine-based curing agent used is not particularly limited, but the ratio of active hydrogen bonded to a nitrogen atom to 1 mol of the epoxy group in the epoxy resin is 0.7 to 1.5 mol,
It is desirable that the amount is preferably 0.9 to 1.2 mol.

(B) Latent curing agent: Examples of the latent curing agent include dicyandiamide and guanidine compounds. The amount of these compounds is one of the epoxy groups in the epoxy resin.
The ratio of active hydrogen bonded to a nitrogen atom to mole is 0.
It is preferable that the compounding amount is 4 to 0.9 mol, preferably 0.5 to 0.7 mol.

(C) Acid anhydride-based curing agent: (A) Examples of the acid anhydride-based curing agent include dodecenyl succinic anhydride, polyadipic anhydride, polyazeline anhydride, polysebacic anhydride, poly ( Ethyl octadecane diacid) anhydride, poly (phenylhexadecane diacid)
Anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhymic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexenedicarboxylic anhydride, phthalic anhydride, Examples include trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitate, heptic anhydride, tetrahydrophthalic anhydride and the like.

(B) It is preferable that the viscosity is low and the heat resistance of the cured product is high. Hexahydrophthalic anhydride and methyltetrahydrophthalic anhydride are preferable, and methyltetrahydrophthalic anhydride is particularly preferable. (C) The present invention is not particularly limited by the amount used, but from the viewpoint of high heat resistance and low water absorption, acid anhydride is used in an amount of 0.1 mol per 1 mol of epoxy groups in the epoxy resin.
It is desirable that it is 7 to 1.2 mol, preferably 0.75 to 1.1 mol, particularly preferably 0.8 to 1.0 mol.

(D) Phenolic curing agent: (a) Examples of the phenolic curing agent include phenol novolak, cresol novolak, resorcin, catechol, tert-butylcatechol, tert-butylhydroquinone, phloroglicinol, pyrogallol,
Hydroxyhydroquinone, tert-butyl pyrogallol, allylated pyrogallol, and the like can be mentioned. (B) Among them, when pyrogallol is used, a low-viscosity liquid epoxy resin composition is obtained, and the heat resistance and moisture resistance of the cured product are increased, which is preferable. (C) The present invention is not particularly limited by the use amount of the phenolic curing agent, but from the viewpoint of high heat resistance and low water absorption, the phenolic hydroxyl group is 0 to 1 mol of the epoxy group in the epoxy resin. 0.8-1.3 mol, preferably 0.9-1.2 mol, particularly preferably 1.0-1.0 mol
It is desirable to be blended so as to be 1.1 mol.

(E) Imidazole-based curing agent: Examples of the imidazole-based curing agent include 1-methylimidazole, 2
-Methylimidazole, 2-ethyl-4-methylimidazole and the like. (f) Cationic curing agent: Examples of the cationic curing agent include boron trifluoride, boron trifluoride-amine complex, and aromatic sulfonium salt.

2) Curing Accelerator: (A) As the curing accelerator which can be used when curing the epoxy resin of the present invention, an amine compound exemplified above as an amine curing agent or an imidazole curing agent, Examples thereof include an imidazole compound and a phosphorus compound. Examples of the phosphorus compound include phosphines such as triphenylphosphine, tributylphosphine, and triethylphosphine, and phosphonium salts such as n-butyltriphenylphosphonium bromide. (B) Among them, 2-ethyl-4-methylimidazole, triphenylphosphine, and benzyldimethylamine are preferred from the viewpoints of heat resistance, hygroscopicity, and reactivity. (C) The compounding amount of the curing accelerator is preferably 0.01 to 10 parts, more preferably 0.05 to 6 parts, per 100 parts of the epoxy resin.

3) Inorganic filler Examples of the inorganic filler include spherical or crushed silica powder such as fused silica and crystalline silica, alumina powder, mica, talc, calcium carbonate, alumina, hydrated alumina, asbestos, and oxidized powder. Examples include magnesium, diatomaceous earth, and graphite.

4) Use of other additives: In the present invention, if necessary, a thixotropy imparting agent such as fine silica powder, a defoaming agent, a flame retardant such as a phosphorus compound or a halogen compound, an antimony trioxide or the like. Flame retardant aids, colorants such as carbon black and iron oxide, elastomers such as modified nitrile rubber and modified polybutadiene, release agents, leveling agents, anti-cissing agents, antifoaming agents, etc. are also added. Glass fiber, glass cloth, carbon fiber and the like can be contained.

(Vii) Production of Epoxy Resin Composition The epoxy resin composition which is liquid at 25 ° C. using the epoxy resin of the present invention is prepared by thoroughly mixing the above-mentioned components according to a conventional method.
After kneading, it can be produced by defoaming under reduced pressure. 1) The production is not particularly limited by the method of mixing and kneading, but includes a reactor with a stirring blade, a planetary mixer, a kneader, a roll, a homodisper, an extruder, etc., and in particular, two to three rolls. Homodisper and the like are preferable in that an epoxy resin composition having a uniform composition can be obtained. 2) The mixing / kneading step is performed at room temperature or by heating, but the kneading temperature is 5 to 150 ° C., preferably 10 to 150 ° C.
To 140 ° C, more preferably 20 to 120 ° C.
If the kneading temperature is too high, exceeding 150 ° C., the curing reaction proceeds during kneading, and the viscosity of the obtained epoxy resin composition is undesirably increased. On the other hand, if the kneading temperature is too low, less than 5 ° C., the viscosity of the epoxy resin or the curing agent increases, making it difficult to knead, or moisture in the air adheres to the epoxy resin composition, and the moisture is hardened during curing. It is not preferable because it vaporizes and voids are generated in the cured product.

(Ix) Use of Epoxy Resin Composition, etc. 1) The liquid epoxy resin composition thus produced is subjected to a casting method, a potting method, a casting method, a dipping method, a dropping method, or the like. Can be cured. As a method of applying the dropping method, as shown in FIG. 1, a syringe (syringe) is filled with an epoxy resin composition, and a dispenser is used or manually, for example, an LSI package substrate, a printed wiring board, The epoxy resin composition was discharged onto the semiconductor chip mounted on TAB or carrier tape, or into the gap between the semiconductor chip and the above-mentioned substrates, and was heated and cured, and sealed with a cured liquid resin sealing material. A technique for manufacturing a semiconductor sealing device is preferred.

2) Curing The epoxy resin of the present invention is not particularly limited by curing conditions, but is reacted at a relatively low temperature until the epoxy resin composition gels and loses fluidity as a first step reaction. A method of post-curing at a temperature higher than the reaction temperature of the first stage as a two-stage reaction is preferred. That is, 70 ° C. to 150 ° C., preferably 100 ° C. to 1
40 ° C., more preferably 20 ° C. between 110 ° C. and 130 ° C.
Minutes to 2 hours, preferably 40 minutes to 1.5 hours, after which the reaction temperature is higher than the reaction temperature of the first stage and 220
A method of post-curing at a temperature of at most 190 ° C, preferably at most 190 ° C, is preferred.

3) Utilization of New Epoxy Resin Due to such characteristics, the epoxy resin of the present invention can be used as a sealing material or a casting material, a laminating material, various paints and adhesives for electric and electronic parts typified by semiconductor elements. And the like, and among them, it is suitably used for semiconductor sealing device applications.

[0060]

Hereinafter, the present invention will be described in detail with reference to examples. They do not limit the scope of the invention.
In the examples, "parts" indicates parts by weight. Also,
The evaluation of various physical properties in the examples was performed by the following methods. 1) Epoxy equivalent The epoxy resin is dissolved with benzyl alcohol and 1-propanol. An aqueous solution of potassium iodide and a bromophenol blue indicator were added to this solution, and titration was performed with 1 N hydrochloric acid. The point at which the reaction system turned from blue to yellow was defined as the equivalent point. From the equivalent point, the epoxy equivalent of the resin is calculated according to the following equation. Epoxy equivalent (g / eq.) = 1000 × W / (V × N
× F) W: Weight of sample (g) V: Titration (ml) N: Normality of hydrochloric acid used for titration (N) F: Factor of hydrochloric acid used for titration

2) Number average molecular weight The number average molecular weight is determined from the epoxy equivalent by the following equation. Number average molecular weight = epoxy equivalent × 2 3) Inorganic chlorine content 10 g of a sample was dissolved in 100 ml of toluene and 1 ml of methanol.
After adding and dissolving 00 ml and adding 2 ml of acetic acid, potentiometric titration was performed using an aqueous silver nitrate solution, the number of moles was determined from the detected inflection point, and the inorganic chlorine content was determined assuming that the total amount was chlorine.

4) Hydrolyzable chlorine content (HyCl) 0.1 to 3 g of a sample is dissolved in 50 ml of toluene,
After adding 20 ml of 0.1 N KOH-methanol solution and boiling for 15 minutes, the mixture was cooled, 2 ml of acetic acid was added, and potentiometric titration was performed using an aqueous silver nitrate solution, and the number of moles was determined from the detected inflection point. The chlorine content was determined assuming that the total amount was chlorine. The hydrolyzable chlorine content was determined by subtracting the inorganic chlorine content from the obtained chlorine content. 5) Total chlorine content (To-Cl) 0.1 to 3 g of a sample was dissolved in 25 ml of ethylene glycol monobutyl ether, and 20 ml of a 1N KOH-propylene glycol solution was added thereto. After boiling for 20 minutes, 100 ml of acetic acid was added. In addition, potentiometric titration was performed using an aqueous silver nitrate solution, the number of moles was determined from the detected inflection point, and the chlorine content was determined assuming that the total amount was chlorine. The total chlorine content was determined by subtracting the inorganic chlorine content from the obtained chlorine content.

6) Viscosity of epoxy resin (measuring temperature: 25)
℃) If the epoxy resin to be tested is not crystallized, keep it as it is. If the epoxy resin to be tested is crystallized, hold the epoxy resin at a temperature of 80 ° C. for 24 hours and then 0.5 hours It cooled to 25 degreeC within, and measured by the following methods within 0.5 hour after resin temperature reached 25 degreeC. The viscosity of the test sample was measured using a Canon Fenceke viscometer manufactured by Kusano Scientific Instruments Co., Ltd. at a resin temperature of 25 ° C, and the viscosity was determined by multiplying the viscosity at 25 ° C. When the measured value was greater than 20,000 centipoise by this method, the viscosity was determined by measuring using a B-type viscometer.

7) Viscosity of epoxy resin (measuring temperature: 60
℃) If the epoxy resin to be tested is not crystallized, keep it as it is. If the epoxy resin to be tested is crystallized, place the epoxy resin to be tested at a temperature of 80 ° C. for 1 hour.
After holding for 2 hours, it was measured within 0.5 hours by the following method. It was measured at 60 ° C. using a Cannon-Fenske viscometer manufactured by Kusano Kagaku Seisakusho Co., Ltd., and was obtained by multiplying the specific gravity at 60 ° C. If the measured value is greater than 20,000 centipoise by this method, use a B-type viscometer to measure
The viscosity was determined by measuring at ° C.

8) Viscosity of Epoxy Resin Composition (Measurement Temperature: 25 ° C.) The viscosity of the epoxy resin composition was determined by the following method within 0.5 hours after obtaining the epoxy resin composition. When the inorganic filler was not blended, first, the epoxy resin composition was measured at 25 ° C. using a Cannon-Fenske viscometer manufactured by Kusano Kagaku Kikai Seisakusho Co., Ltd., and multiplied by the specific gravity. When the measured value was greater than 20,000 centipoise by this method, the viscosity was determined by measuring at 25 ° C. using a B-type viscometer. All epoxy resin compositions containing an inorganic filler were measured at 25 ° C. using a B-type viscometer.

9) Specific Gravity The specific gravity of the epoxy resin and the epoxy resin composition at each temperature was measured using a floating-type specific gravity meter. 10) Softening point The softening point was measured by the ring and ball method described in JIS K7234. 11) Moisture Absorption A test piece having a thickness of 20 mm, 20 mm and a thickness of 2 mm obtained by heating and curing using a liquid epoxy resin composition was subjected to 121
The treatment was performed for 200 hours under the PCT conditions of 2 ° C., 2 atm and 100% relative humidity, and the weight increase after the treatment was determined as the moisture absorption rate.
The lower the moisture absorption, the better.

12) Glass transition temperature (Tg) Tg was determined by DSC. (Temperature rising rate: 10 ° C./min) 13) Storage stability test The epoxy resin composition was stored at 25 ° C. for 7 days, and the presence or absence of crystal precipitation was observed. 7 days after the crystal was not precipitated in the epoxy resin composition, ○, and when crystals were precipitated in the epoxy resin composition, ×. 14) Flexural strength 4 mm x 10 mm x 150 according to JIS-K6911
mm test piece, and the crosshead moving speed is 2 mm
/ Min.

15) Hydrolysis resistance test A 20 mm × obtained by heating and curing the epoxy resin composition.
A test piece of a cured epoxy resin product of 20 mm × 2 mm was prepared using 121
The treatment was performed under the PCT conditions of 2 ° C., 2 atm, and 100% relative humidity. When the time during which the weight of the test piece was smaller than the initial weight of the test piece by hydrolysis was less than 400 hours, it was evaluated as x. 16) Gel permeation chromatography (GP
C) 16,000 theoretical plates with exclusion limit molecular weight of 400,000 as column
Column with a length of 30 cm (Shodex KF-804, manufactured by Showa Denko KK)
) One column with a molecular weight of 70,000 and a theoretical plate number of 16,000 and a length of 30 cm (Shodex KF-803 manufactured by Showa Denko KK)
1 column and a 30 cm long column (Showa Denko, Shodex KF-802) 2 with an exclusion limit molecular weight of 5,000 and 16,000 theoretical plates
The books were connected in series, and the measurement was carried out at 25 ° C using tetrahydrofuran as a mobile phase at a flow rate of 1 ml / min using an ultraviolet detector having a wavelength of 280 nm. N = 0 in equation (1)
Ratio of the peak area of the molecule to the total peak area (n =
0), and the ratio of the peak area of the n = 1 molecule to the total peak area in the equation (1) (n = 1 content).

17) Melting Point Using a differential thermal analysis (DSC), the temperature was increased at a rate of 10 ° C./min and measured. The temperature at the top of the endothermic peak was defined as the melting point. 18) Thixotropicity evaluation test Methyltetrahydrophthalic acid (MeTH)
PA) was added in an amount of 0.9 mole based on 1 mole of the epoxy group, and a fused silica filler FB-48 (average particle size: 13 μm) manufactured by Denki Kagaku was used as a filler based on the total weight of the epoxy resin, the curing agent, and the filler. The epoxy resin composition obtained by blending so as to be 70% by weight was prepared, and two hours after blending the epoxy resin composition, a cone plate viscometer Rheomat 30 manufactured by Contrabass was used. hand,
It was measured by the following method. The viscosity was measured five times at 25 ° C. under the conditions of 0.12 revolutions per minute and 4.76 revolutions per minute, respectively, and the average value (V1) obtained at 4.76 revolutions per minute and 0 per minute were obtained. The thixotropy index was calculated from the average value (V2) of the data obtained at .12 rotations by the following formula, and evaluated by the average value of five samples. The smaller the thixotropy index, the higher the fluidity. [Thixotropic index] = [V2] / [V1]

19) Crystallization tendency test 20 g of a test sample of epoxy resin was weighed into a 100 ml sample bottle, covered, and kept at 80 ° C. for 24 hours.
Next, the test sample was returned to 25 ° C.
g and 2 g of ethanol, and stir with a glass rod for 2 minutes so that the mixture becomes uniform. Then cover the sample bottle and put it at 10 ℃
Check the crystallization of the test sample every 15 minutes under ± 2 ° C conditions. The state of the sample was classified into the following a, b, and c, and evaluated by the time until the state of c was reached. The unit is time, which indicates that the larger the value, the more difficult it is to crystallize. (a) When the test mixed resin has fluidity (b) When the fluidity is not seen when the sample bottle is turned over and left for 1 minute (c) When crystallization has progressed further than in the state of (b) and the resin has completely solidified.

20) Pressure Cooker (PCT) Reliability Test A liquid epoxy resin composition is filled in a syringe, and the liquid epoxy resin composition is discharged, sealed, and heated on a silicon chip having a circuit formed on a test board. The test board
The processing was performed under the PCT conditions of 21 ° C., 2 atm, and 100% relative humidity, and the evaluation was made based on the time until the occurrence of circuit failure. 21) Heat cycle (TC) reliability test A liquid epoxy resin composition is filled in a syringe, discharged and sealed on a silicon chip having a circuit mounted on a test board, and heated. The test is obtained by heating. The board was processed in the gas phase in a cycle of a temperature cycle at −50 ° C. for 30 minutes, a room temperature for 5 minutes, and 125 ° C. for 30 minutes as one cycle, and evaluated by the number of cycles until the occurrence of a circuit failure.

22) Discharge test As shown in FIG. 1, an epoxy resin composition was injected into a syringe (5 ml Terumo syringe, SS-05S, manufactured by Terumo Corporation).
And when the ejection was possible when extruded with a force of 5 kg, △ when the ejection was difficult, and X when the ejection was not possible.

(Example 1) 2 equipped with a stirrer and a thermometer
In a liter three-necked flask, 166 g (1 mol) of tert-butyl hydroquinone and epichlorohydrin 18 were added.
50 g (20 mol) and 0.55 g of tetramethylammonium chloride were charged and subjected to an addition reaction for 2 hours under heating and reflux. Next, the content was cooled to 60 ° C., and a water removing device was attached.
g (2.2 mol), water produced at a reaction temperature of 55-60 ° C. and a degree of vacuum of 100-150 mmHg is continuously azeotropically removed, and the ring closure reaction is performed while returning the epichlorohydrin layer of the distillate to the reaction system. Let it be done. 56.5 ml of generated water
Was reached as the reaction end point. Thereafter, filtration under reduced pressure and washing with water were repeated, and the remaining epichlorohydrin was recovered by distillation under reduced pressure to obtain an epoxy resin A (epoxy equivalent 146, epoxy equivalent).
Number average molecular weight 292, hydrolyzable chlorine content 1800p
pm, total chlorine content 9500 ppm, inorganic chlorine content 1
ppm, a viscosity at 25 ° C of 1070 centipoise, a viscosity at 60 ° C of 56 centipoise, n = 0 content: 87.1%, and n = 1 content: 8.5%). In the epoxy resin A, in the general formula (1), R ¹ is a tert-butyl group, R ² is a hydrogen atom, and the average value of n corresponds to 0.05 resin.

(Example 2) 2 equipped with a stirrer and a thermometer
A liter three-necked flask was charged with 166 g (1 mol) of tert-butylhydroquinone, 1110 g (12 mol) of epichlorohydrin, and dimethylsulfoxide 7
Dissolved in 49 g. At a temperature of 50 ° C., 169.2 g (2.05 mol) of 48.5% sodium hydroxide was continuously added dropwise over 1 hour, and the mixture was further reacted for 1.5 hours. During this time, while maintaining the temperature at 50 ° C., the pressure was reduced and the azeotropic epichlorohydrin and water were cooled and liquefied, and the reaction was performed while returning the organic layer into the reaction system. After completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, an epoxy resin containing a by-product salt and dimethylsulfoxide was dissolved in 1800 g of xylene, and the by-product salt and dimethylsulfoxide were removed by washing with water. Thereafter, xylene was distilled off under reduced pressure and epoxy resin B (epoxy equivalent 149, number average molecular weight 298, hydrolyzable chlorine content 300 ppm, total chlorine content 1520 ppm,
Inorganic chlorine content less than 1 ppm, viscosity at 25 ° C 12
(00 centipoise, viscosity at 60 ° C., 58 centipoise, n = 0 content: 88.2%, n = 1 content: 6.8%)
I got In the epoxy resin B, R ¹ in the general formula (1) is t
ert-butyl group, R ² is a hydrogen atom, and the average value of n is 0.
09 resin.

Example 3 In a 2.5-liter three-necked flask equipped with a stirrer and a thermometer, 166 g (1 mol) of tert-butylhydroquinone was charged, and 1480 g (16 mol) of epichlorohydrin and 1000 g of dimethyl sulfoxide were added. Dissolved. While maintaining the inside of the reaction system at 43 torr, 169.2 g (2.05 mol) of 48.5% sodium hydroxide was continuously dropped at a temperature of 48 ° C. in 5 hours. Meanwhile, while maintaining the temperature at 48 ° C., the azeotropic epichlorohydrin and water were cooled and liquefied, and the reaction was performed while returning the organic layer into the reaction system. After completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, and the epoxy resin containing by-product salt and dimethyl sulfoxide was removed from xylene 180.
0 g, and the by-product salt and dimethyl sulfoxide were removed by washing with water. Thereafter, xylene was distilled off under reduced pressure at 170 ° C. and 10 torr to obtain an epoxy resin X (epoxy equivalent: 14).
5, number average molecular weight 290, hydrolyzable chlorine content 300
ppm, a total chlorine content of 1520 ppm, an inorganic chlorine content of less than 1 ppm, and a viscosity of 1100 centipoise at 25 ° C.).

In a 2.5-liter three-necked flask equipped with a stirrer and a thermometer, 400 g of the epoxy resin X was charged and dissolved in 600 g of dimethyl sulfoxide. Keeping the temperature at 45 ° C., 1.55 g of 48.5% sodium hydroxide
(1.1 equivalents of the total chlorine content contained in the epoxy resin X) and reacted for 2 hours. After completion of the reaction, 800 g of xylene was added, and the by-product salt and dimethyl sulfoxide were removed by washing with water. Thereafter, xylene was distilled off under reduced pressure and the epoxy resin C (epoxy equivalent 145, molecular weight 290,
Hydrolyzable chlorine content 10 ppm, total chlorine content 680
ppm, an inorganic chlorine content of less than 1 ppm, a viscosity of 1300 centipoise at 25 ° C, a viscosity of 60 centipoise at 60 ° C, n = 0 content of 87.8%, and n = 1 content of 7.5%). The epoxy resin C corresponds to a resin in which R ¹ is a tert-butyl group, R ² is a hydrogen atom, and the average value of n is 0.05 in the general formula (1).

Example 4 A 2.5-liter three-necked flask equipped with a stirrer and a thermometer was charged with 166 g (1 mol) of tert-butylhydroquinone, 416 g (4.5 mol) of epichlorohydrin, and dimethyl sulfoxide. Dissolved in 750 g. At a temperature of 50 ° C., 169.2 g (2.05 mol) of 48.5% sodium hydroxide was continuously added dropwise over 1 hour, and the mixture was further reacted for 1 hour. During this time, while maintaining the temperature at 50 ° C., the azeotropic epichlorohydrin and water were cooled and liquefied, and the reaction was performed while returning the organic layer into the reaction system. After completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, an epoxy resin containing by-product salt and dimethyl sulfoxide was dissolved in 800 g of xylene, and the by-product salt and dimethyl sulfoxide were removed by washing with water. Thereafter, xylene was distilled off under reduced pressure and epoxy resin D (epoxy equivalent 157, number average molecular weight 315, hydrolyzable chlorine content 480 ppm, total chlorine content 1650 ppm, inorganic chlorine content less than 1 ppm, viscosity at 25 ° C of 5100 centipoise, 60 122 centipoise viscosity at ° C, n
= 0 content: 78.3%, n = 1 content: 13.1%). In the epoxy resin D, R ¹ in the general formula (1) is ter.
a t-butyl group, R ² is a hydrogen atom, and the average value of n is 0.17
Of resin.

Example 5 A 2.5-liter three-necked flask equipped with a stirrer and a thermometer was charged with 166 g (1 mol) of tert-butylhydroquinone, 1295 g (14 mol) of epichlorohydrin, and tetramethylammonium chloride. 1.1 g were added. 4 at 50 ℃
189.7 g of an 8.5% aqueous sodium hydroxide solution (2.3
Mol) was continuously added dropwise over 4 hours, and the reaction was further continued for 3 hours. During this time, while maintaining the temperature at 50 ° C., the azeotropic epichlorohydrin and water were cooled and liquefied, and the reaction was performed while returning the organic layer into the reaction system. After completion of the reaction, by-product salts were removed by washing with water, and unreacted epichlorohydrin was distilled off under reduced pressure to obtain an epoxy resin y-1 (epoxy equivalent: 145, hydrolyzable chlorine content: 1180 ppm, viscosity: 1,050 centipoise).

Next, 200 g of the epoxy resin y-1 was measured and 300 g of methyl isobutyl ketone (MIBK) was measured.
, And at 50 ° C., 0.82 g of a 48.5% aqueous sodium hydroxide solution (1.5 equivalents to the amount of hydrolyzable chlorine in the epoxy resin y-1) was added, and the mixture was further reacted at 50 ° C. for 4 hours. After washing with water, MIBK was distilled off under reduced pressure and the epoxy resin y-2 (epoxy equivalent 146, number average molecular weight 2
92, a hydrolyzable chlorine content of 30 ppm, and a total chlorine content of 1860 ppm). 100 parts of epoxy resin y-2
g, weigh out, put in a 500 ml eggplant-shaped flask, capillary tube, Claisen-type connecting tube, Liebig condenser,
Decompression type bifurcated distillation connecting tube, thermometer, eggplant type flask (2
) And set up a vacuum distillation apparatus, 500
The ml eggplant type flask was immersed in an oil bath, and vacuum distillation was performed using an oil rotary pump and an oil diffusion pump together.

Internal pressure 0.03 Torr, oil bath temperature 180
C., and the epoxy resin E (epoxy equivalent 141,
Number average molecular weight 282, hydrolyzable chlorine content 25 pp
m, total chlorine content 670ppm, inorganic chlorine content 1pp
m, viscosity at 25 ° C. 750 centipoise, 60
Viscosity at 40 ° C, n = 0 content 99.
5%, n = 1 content 0.2%). The epoxy resin E crystallized when stored at room temperature, and its melting point was 50 ° C. The epoxy resin E corresponds to a resin in which R ¹ is a tert-butyl group, R ² is a hydrogen atom, and the average value of n is 0.01 in the general formula (1).

(Example 6) In a 200 ml separable flask, 90 g of epoxy resin E and bisphenol A type epoxy resin [ARALDITE (r) AER (r) 260: manufactured by Asahi Ciba] 1
0 parts and stirred at 80 ° C. for 1 hour.
(Epoxy equivalent 145, number average molecular weight 290, hydrolyzable chlorine content 74 ppm, total chlorine content 840 ppm,
Inorganic chlorine content less than 1 ppm, viscosity at 25 ° C 90
0 centipoise, viscosity of 55 centipoise at 60 ° C., n = 0 content: 90.1%, n = 1 content: 0.9
%).

Comparative Example 1 200 g of epoxy resin C was charged into a 500 ml separable flask, and 0.5 g of triphenylphosphine was added at 80 ° C. and melted.
At 20 ° C., 58 g of tert-butylhydroquinone are added. Thereafter, the internal temperature was raised to 175 ° C. and reacted for 10 hours. At 25 ° C., a solid epoxy resin G (epoxy equivalent 360, number average molecular weight 720, hydrolyzable chlorine content 8
ppm, total chlorine content 530ppm, inorganic chlorine content 1
ppm, softening point 65 ° C, viscosity at 25 ° C 64,00
0,000 centipoise or more, viscosity at 60 ° C 3,200,000
(Centipoise, n = 0 content: 25.2%, n = 1 content: 5.1%). The epoxy resin G has the general formula (1)
R ¹ is a tert-butyl group, R ² is a hydrogen atom,
This corresponds to a resin having an average value of n of 2.0. The properties of the epoxy resins AG thus synthesized are summarized in Table 1.

[0083]

[Table 1] (Note) cps represents centipoise k represents x1000.

(Application Examples 1 to 7 and Application Comparative Examples 1 to
8) An epoxy resin and a curing agent were added to a metal petri dish at the ratios shown in Tables 2 to 4 and homogenized at 50 ° C, and then a curing accelerator was added to obtain an epoxy resin composition. However, in Examples 4 and 7, and Comparative Examples 1 and 6 to 8 were homogenized at 120 ° C. In Application Comparative Example 5, the temperature was made uniform at 140 ° C. After heating the obtained epoxy resin composition at 120 ° C. for 1 hour, it was cured by heating at 150 ° C. for 2 hours and further at 180 ° C. for 5 hours to obtain a cured epoxy resin product. However, for Application Comparative Example 5, the epoxy resin was cured by heating at 150 ° C. for 1 hour and further at 180 ° C. for 5 hours to cure. For the PCT and TC tests, the obtained liquid epoxy resin composition was filled in a syringe and discharged onto a silicon chip on which a circuit was formed, which was mounted on a test board using a dispenser, under the above conditions. Heat curing, sealing, and testing were performed. Tables 2 to 4 show the properties of the epoxy resin composition and the properties of the cured epoxy resin.

[0085]

[Table 2] (Note) MeTHPA: methyl tetrohydrophthalic anhydride (HN-2200 neutralization equivalent 83 g / eq., Manufactured by Hitachi Chemical Co., Ltd.)
, Liquid at 25 ° C., viscosity 60 cps (25 ° C.)) 2E4MZ: 2-ethyl-4-methylimidazole

[0086]

[Table 3]

(Note) k indicates x1000. Epoxy resin H: bisphenol F type epoxy resin, epoxy equivalent 177, viscosity (25 ° C.) 4420 centipoise, hydrolyzable chlorine content 150 ppm, total chlorine content 1
210 ppm epoxy resin I: 1,6-dihydroxynaphthalene type epoxy resin, epoxy equivalent 161, viscosity (25 ° C.) 2,800,00
0 centipoise, hydrolyzable chlorine content 10 ppm, total chlorine content 800 ppm Epoxy resin J: methylhydroquinone type epoxy resin,
Epoxy equivalent 125, viscosity (25 ° C) 250 centipoise, hydrolyzable chlorine content 24ppm, total chlorine content 78
0 ppm epoxy resin K: 2,5, -di-tert-butylhydroquinone type epoxy resin, epoxy equivalent 175, solid (melting point 12
9 ° C), hydrolyzable chlorine content 22ppm, total chlorine content 830ppm

[0088]

[Table 4] (Note) M indicates × 1,000,000. TPP: triphenylphosphine

[0089]

APPLICATION EXAMPLES 8-12 AND APPLICATION COMPARATIVE EXAMPLES 9-16 Epoxy resins, curing agents, curing accelerators and fillers were mixed and kneaded at 50 DEG C. using a roll in the proportions shown in Tables 5-6, and the epoxy resin was mixed. A resin composition was prepared. However, application example 11,
12, and 12 for Application Comparative Examples 9, 11, 14, and 16
At 0 ° C. in Application Comparative Example 13, kneading was performed at 140 ° C. using a roll to obtain an epoxy resin composition. After heating the obtained epoxy resin composition at 120 ° C. for 1 hour, it was cured by heating at 150 ° C. for 2 hours and further at 180 ° C. for 5 hours to obtain a cured epoxy resin product. However, for Application Comparative Example 13, the epoxy resin was cured by heating at 150 ° C. for 1 hour and further at 180 ° C. for 5 hours to cure. Also, PC
For the T and TC tests, the obtained liquid epoxy resin composition was filled in a syringe, discharged using a dispenser onto a silicon chip on which a circuit was formed and mounted on a test board, and heat-cured under the above conditions. , Sealed and tested. Tables 5 to 6 show the properties of the epoxy resin composition, the properties of the cured epoxy resin, and the test results of the semiconductor device sealed with each epoxy resin.

[0090]

[Table 5] (Note) * The epoxy resin composition could not be discharged from the dispenser, and a test board could not be obtained. ＊ Filling material: Fragmented fused silica manufactured by Tatsumori, trade name RD
-8 was used.

[0091]

[Table 6] (Note) * The epoxy resin composition could not be discharged from the dispenser, and a test board could not be obtained.

(Experimental Results) From the above experiments, (i) According to Tables 2 and 3, the epoxy resin compositions containing the epoxy resin of the present invention (Application Examples 1 to 6) have low viscosity and the discharge test It is clear that the cured product is excellent in heat resistance, moisture resistance represented by a moisture absorption test, and mechanical strength. On the other hand, (a) the epoxy resin composition comprising the conventional bisphenol F type epoxy resin (Application Comparative Example 2) has a low viscosity, but has a low glass transition temperature and is inferior in heat resistance.

The epoxy resin composition (b) of the naphthalene type epoxy resin (Application Comparative Example 3) has high heat resistance of the cured product, but has a high viscosity of the epoxy resin composition and poor workability. (C) In Application Comparative Example 4, during storage, crystals of the methylhydroquinone-type epoxy resin were precipitated from the epoxy resin composition, resulting in poor storage stability. Further, the epoxy resin composition was filled into a syringe and molded using a dispenser, but was crystallized in the syringe or needle, and could not be discharged. (D) In application comparative example 5, on a hot plate at 140 ° C.
A 2,5-di-tert-butylhydroquinone type epoxy resin and a curing agent were mixed, and 2E4Mz was added to homogenize the mixture. After returning to room temperature, 2,5-di-ter
The t-butyl hydroquinone type epoxy resin was precipitated, and the whole was solidified, and could not be filled in a syringe.

(Ii) According to Table 4, (a) The epoxy resin composition containing the epoxy resin of the present invention (Application Example 7) has a lower viscosity than the epoxy resin composition not according to the present invention. The cured product is excellent in heat resistance, hydrolysis resistance, and mechanical strength. On the other hand, (b) the epoxy resin compositions of Application Comparative Examples 6 and 8 have high viscosities at 25 ° C., and thus have extremely poor workability. The cured products obtained in Application Comparative Examples 6 to 8 are also inferior to Application Example 7 of the present invention in heat resistance and hygroscopicity.

(Iii) On the other hand, according to Tables 5 and 6, (a) the epoxy resin compositions of Application Examples 8 to 12 have low viscosity, excellent workability, good storage stability, and curing. The material is excellent in heat resistance, moisture resistance, hydrolysis resistance, and mechanical strength. Further, the semiconductor sealing device sealed with the epoxy resin is excellent in reliability evaluated by PCT or TC test. (B) The epoxy resin compositions of Application Comparative Examples 9, 11, 13, 14, and 16 have a high viscosity at room temperature, and thus have extremely poor workability. The cured product is also inferior to the applied examples of the present invention in heat resistance and hygroscopicity. (C) Application Comparative Examples 10 and 15 have good workability but are inferior in heat resistance, and Application Comparative Example 11 is inferior to the present invention in moisture resistance, TC and PCT.

[Thixotropy Evaluation Test, Crystallization Tendency Test] Table 7 shows the results of evaluation of the epoxy resin of the present invention in the thixotropy evaluation test and the crystallization tendency test.

[Table 7] * The viscosity was so high that a test sample could not be obtained.

[0097]

As described above, the epoxy resin of the present invention has low viscosity and thixotropy, and the epoxy resin composition containing the epoxy resin of the present invention has good storage stability and low viscosity, so that it can be discharged. Excellent in workability represented by the test, the cured product is excellent in heat resistance represented by the glass transition point, moisture resistance represented by the moisture absorption, mechanical strength represented by the bending strength, hydrolysis resistance Show characteristics. Furthermore, the semiconductor encapsulation device sealed using the epoxy resin composition containing the epoxy resin of the present invention exhibits excellent characteristics in reliability evaluated by TC and PCT tests.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating the state of a discharge test of an epoxy resin (composition) of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Syringe 2 Needle 3 Semiconductor chip 4 Substrate 5 Raw material (epoxy resin composition)

Claims (6)

[Claims] [Claim 1] The following general formula (1): (In the formula, R ¹ represents an alkyl group having 2 to 6 carbon atoms, R ²
Represents hydrogen or an alkyl group having 1 to 3 carbon atoms, and n represents 0
These represent the real numbers. ), Having a number average molecular weight of 25
0 to 500, the content of the component of n = 0 in the general formula (1) is 30% or more, and the viscosity at 60 ° C. is 1%.
An epoxy resin having a size of up to 30,000 centipoise. 2. The epoxy resin according to claim 1, wherein in the general formula (1), R ¹ is a tert-butyl group. 3. The epoxy resin according to claim 1, wherein R ² is a hydrogen atom. 4. A viscosity at 25 ° C. of 50 to 1,000,000.
The epoxy resin according to any one of claims 1 to 3, wherein the epoxy resin is centipoise. 5. The epoxy resin according to claim 1, wherein the content of the component where n = 1 in the general formula (1) is 1% or more. 6. The epoxy resin according to claim 1, wherein the total chlorine content is 2000 ppm or less.