JPH11292954A - Liquid epoxy resin composition and its cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject low-toxic and low-viscosity composition capable of maintaining the liquid state for a long period and providing a highly heat resistant cured product having low water absorptivity by including a mixture of specific epoxy compounds and a liquid curing agent therein. SOLUTION: This composition is obtained by including (A) a mixture of epoxy compounds containing >=80 wt.%, preferably 90 wt.%, more preferably 100 wt.% of three kinds selected from an epoxy compound represented by formula I [G is glycidyl; R<1> is glycidyl ether, a 1-4C aliphatic, a 1-4C alkoxy, H or a halogen; (n) is 0, 1 or 2] (e.g. 2,5-di-tert-butylhydroquinone diglycidyl ether) and an epoxy compound represented by formula II (R<2> is a 1-4C aliphatic, a 1-4C alkoxy, H or a halogen) (e.g. 3,3',5,5'-tetramethyl-4,4'-biphenol diglycidyl ether) and (B) a liquid curing agent which is preferably a liquid acid anhydride- based curing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric / electronic material,
For example, it belongs to the technical field of manufacturing and using a liquid epoxy resin composition used as a semiconductor sealing material. More specifically, a low-toxicity, low-viscosity, liquid epoxy resin composition that can maintain a liquid state for a long time,
Also, it belongs to the technical field of producing and using a liquid epoxy resin composition whose cured product has high heat resistance and low water absorption.

[0002]

BACKGROUND OF THE INVENTION Epoxy resin compositions have excellent electrical properties and adhesiveness and are therefore used in various applications in the electric and electronic fields. In particular, the liquid epoxy resin composition is used during package assembly.
There are many advantages because the steps of high-temperature heating and pressurization can be omitted.

As the epoxy resin which is a main raw material of the liquid epoxy resin composition, various epoxy resins which are liquid at room temperature, such as bisphenol A epoxy resin, bisphenol F epoxy resin, and bisphenol AD epoxy resin, have been used. , Alicyclic epoxy resins, glycidylamine type epoxy resins, and the like are frequently used. Various diluents are added as needed.

However, cured products obtained from these epoxy resin-based compositions have various problems such as low glass transition temperature, insufficient heat resistance, and high water absorption of the cured products. And an epoxy resin composition having sufficient properties has not been obtained.

In many applications, a considerable amount of an inorganic filler is blended to improve various properties of the epoxy resin composition, but the amount of the filler is limited by the viscosity of the liquid component. Therefore, development of an epoxy resin composition having a lower viscosity, particularly an epoxy resin composition for encapsulation is desired.

In recent years, dihydroxynaphthalenediglycidyl ether has attracted attention as a material which can satisfy various characteristics such as low viscosity, high heat resistance and low water absorption. When a resin composition containing this epoxy resin as a main component is used, the amount of the liquid curing agent such as an acid anhydride increases due to a small epoxy equivalent, and the viscosity of the composition before curing becomes low. Have the advantages of high glass transition temperature, high heat resistance, and low water absorption of the cured product.

However, an epoxy resin having a naphthalene skeleton is a designated chemical substance, and when used, there are various regulations from the viewpoint of ensuring public health and safety.

On the other hand, an epoxy resin which is crystalline and therefore solid at ordinary temperature, has a relatively low viscosity when melted or dissolved in a liquid curing agent, and has excellent properties such as heat resistance and water absorption of the cured product. Also exists.

However, when these are used in the production of a liquid epoxy resin composition, the components are recrystallized in a short time after the production of the composition. It is difficult to provide properties such as high heat resistance and low water absorption.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a liquid epoxy resin composition having low toxicity, low viscosity, and capable of maintaining a liquid state for a long period of time. In this case, the purpose is to provide a cured product having high heat resistance and low water absorption.

That is, the present invention provides (A) a compound represented by the general formula (1):

[0012]

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Wherein G is a glycidyl group, R ¹ is a glycidyl ether group, a C _1-4 aliphatic group, a C _1-4 alkoxy group, a hydrogen atom or a halogen atom, and each R ¹ is the same And n is 0, 1 or 2) and an epoxy compound represented by the general formula (2):

[0014]

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Wherein G is a glycidyl group, R ² is C _1-4
Selected from the group consisting of epoxy compounds represented by the following formula: wherein R ¹ is an aliphatic group, a C _1-4 alkoxy group, a hydrogen atom or a halogen atom, and each R ² may be the same or different. A mixture of epoxy compounds containing at least 80% (% by weight, the same applies hereinafter) in all epoxy compounds, and a liquid epoxy resin composition containing (B) a liquid curing agent (claim 1), And claim 1
The present invention also relates to a cured product of the liquid epoxy resin composition obtained by thermally curing the liquid epoxy resin composition described above (claim 2).

Many of the epoxy compounds represented by the general formulas (1) and (2) contained in the liquid epoxy resin composition of the present invention have excellent properties, that is, low viscosity when dissolved, Although the material has characteristics such as high heat resistance and low water absorption, it also has high crystallinity. Therefore, when a liquid epoxy resin composition is manufactured by using the epoxy compound alone, recrystallization of the dissolved epoxy compound occurs in a short time after the preparation of the composition, so that a stable liquid epoxy resin composition can be obtained. Can not do. The present invention suppresses recrystallization of each component by mixing three or more kinds selected from the epoxy compounds, and obtains a low-viscosity liquid epoxy resin composition that exhibits a stable liquid state over a long period of time. As a matter of course, it is natural that an epoxy compound which is liquid at room temperature may be contained as a component. However, in order to lower the viscosity of the liquid resin composition or to obtain a cured product having the above-mentioned excellent properties, the mixture (A) (E) of the epoxy compound which is an essential component of the liquid epoxy resin composition of the present invention ( Hereinafter, 80% or more of the (A) component) must be an epoxy compound represented by the general formula (1) and / or (2).

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid epoxy resin composition of the present invention (hereinafter also referred to as a liquid resin composition) has a general formula (1):

[0018]

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Wherein G is a glycidyl group, R ¹ is a glycidyl ether group, a C _1-4 aliphatic group, a C _1-4 alkoxy group, a hydrogen atom or a halogen atom, and each R ¹ is the same And n may be 0, 1 or 2) (hereinafter also referred to as epoxy compounds (1)) and a general formula (2):

[0020]

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Wherein G is a glycidyl group, R ² is C _1-4
An epoxy group (hereinafter referred to as epoxy compounds (hereinafter referred to as epoxy compounds (2)), which is an aliphatic group, a C _1-4 alkoxy group, a hydrogen atom or a halogen atom, and each R ² may be the same or different. )), And a mixture (A) of an epoxy compound containing 80% or more, preferably 90% or more of the total epoxy compound in the total epoxy compound.

The compounds contained in the epoxy compounds (1) all have relatively low molecular weight, low viscosity when dissolved, and have various properties such as high heat resistance and low water absorption of the cured product. Therefore, from the viewpoint of lowering the viscosity of the liquid resin composition and increasing the heat resistance of the cured product, and reducing the water absorption, it is preferable.
Due to its high crystallinity, when used as a raw material of a liquid resin composition, it is used for a short time after production of the composition (usually 1 to 16
(Approximately time), which is an undesirable property that a stable liquid resin composition cannot be obtained.

On the other hand, the compounds contained in the epoxy compounds (2) have relatively low viscosities when dissolved.
Since the cured product has high heat resistance and low water absorption, rather than lowering the viscosity of the liquid resin composition, it exerts a great effect on increasing the heat resistance of the cured product and lowering the water absorption. Since it has high crystallinity like (1), when it is used as a raw material of a liquid resin composition, a short time after production of the composition (usually,
(At about 5 ° C. for about 5 to 24 hours), which has the undesirable property that recrystallization occurs and a stable liquid resin composition cannot be obtained.

In the present invention, since three or more compounds contained in the epoxy compounds (1) and (2) are used as a mixture, the epoxy compounds (1) and (2) In the case where the compound contained in the above is used alone, recrystallization in a short time after production of the liquid resin composition, which is a disadvantage of using the compound alone, is reduced. It should be noted that the use of a mixture of three or more as described above
In the seed, the effect of suppressing recrystallization of each component is small, and recrystallization occurs in a short time after the production of the liquid resin composition, but in the case of a mixture of three or more, preferably four or more, When the liquid resin composition of the present invention is inhibited from recrystallization, the mixture is allowed to stand at 5 ° C. under the condition of mixing 80% of an inorganic filler (for example, silica) which can be a crystallization nucleus, and then stored. This is because a stable state of the liquid resin composition can be maintained for 20 days or more, further for 60 days or more.

As described above, the proportion of three or more compounds selected from the epoxy compounds (1) and the epoxy compounds (2) used in the present invention is 80% or more, preferably 90%, of all epoxy compounds. % Or more. When the proportion of three or more compounds selected from the epoxy compounds (1) and the epoxy compounds (2) is less than 80% of the total epoxy compounds and the proportion of other epoxy compounds exceeds 20%. Is unfavorably affected by various properties of other epoxy compounds. That is, since other epoxy compounds have low viscosity and low toxicity before curing, and high heat resistance after curing, and a property that gives a cured product with low water absorption, there are no other epoxy compounds. If the viscosity of the compound is high,
The viscosity of the obtained liquid resin composition does not become sufficiently low.
Further, when the heat resistance of the cured product of the other epoxy compound is low, the cured product obtained from the liquid resin composition does not have sufficiently high heat resistance. Furthermore, if the water absorption of the cured product of other epoxy compounds is high,
The obtained cured product from the liquid resin composition does not have a sufficiently low water absorption.

In order for the obtained liquid resin composition to have sufficiently low viscosity and low toxicity, and for the cured product obtained from the liquid resin composition to have sufficiently high heat resistance and low water absorption, epoxy compounds are required. 80% or more, preferably 90% or more, of three or more compounds selected from (1) and epoxy compounds (2)
% Or more, more preferably 100%. Other epoxy compounds may be added as needed to further improve the stability of the liquid resin composition, but it is preferable that the amount is as small as possible.

The epoxy compounds (1) used in the present invention are, as described above, compounds represented by the general formula (1).

In the general formula (1), n is 0, 1 or 2. When n is 0, the molecular weight of the epoxy compound (1) becomes small. In the case of a compound in which n is 1 or 2, it is particularly preferable from the viewpoint of a large effect of suppressing recrystallization of a crystalline component. Further, among the compounds in which n is 1 or 2, in order to obtain a liquid resin composition having a lower viscosity,
It is preferable that n is 1 rather than 2, and it is preferable to use as little as possible. If n exceeds 3, the viscosity of the compound becomes too high, and it is not preferable from the viewpoint of obtaining a low-viscosity liquid resin composition even if recrystallization of the crystalline component can be suppressed.

When n in the general formula (1) is 0, the general formula (1) becomes the general formula (3):

[0030]

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## EQU1 ##

The two glycidyl ether groups (GO groups) contained in the general formula (3) may be present at any of ortho, meta and para positions, but some of the glycidyl ether groups may be present to some extent. It is preferred that they are apart from each other because there is no or little inhibition of the curing reaction due to steric hindrance, and the performance of the liquid resin composition can be sufficiently exhibited. Further, it is preferable to bond to a position having good symmetry from the viewpoint that a structure of a cured product having a linear and rigid skeleton and high heat resistance can be realized. Specifically, it is more preferable that two glycidyl ether groups are bonded to each other at the meta position and further at the para position, rather than bonded to each other at the ortho position.

Further, two R ^{1 s} contained in the general formula (3)
The group may be present in any of the ortho, meta and para positions with respect to one glycidyl ether group. For example, R ¹ other than two hydrogen atoms are in the meta position to each other, and It is more preferable that each glycidyl ether group and each R ¹ be bonded to positions other than ortho with each other than to a structure in which a glycidyl ether group is bonded, from the viewpoint that the curing reaction is hardly inhibited.

As a preferable structure of the general formula (3), for example,

[0035]

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And the like. In the case of having such a structure, it is preferable because there is no or little inhibition of the curing reaction, and the cured product tends to have high heat resistance.

When n in the general formula (1) is 1 or 2, one GO group in the general formula (3) is replaced by the general formula (4):

[0038]

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May be replaced by G in the general formula (4)
O group and two R ¹ and —O—CH ₂ —CH (OH) —CH ₂
The relationship with the —O— group may be in accordance with the relationship between one GO group when n is 0 and two GO groups after R ¹ .

A preferred structure of the general formula (1) when n is 1 is, for example,

[0041]

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And the like. It is preferable to have these structures because crystallinity is lower than when n is 0.

A preferred structure of the general formula (1) when n is 2 is, for example,

[0044]

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And the like. It is preferable to have these structures because the crystallinity is lower than when n is 1.

R ¹ in the general formula (1) represents a glycidyl ether group, a C _1-4 aliphatic group, a C _1-4 alkoxy group, a hydrogen atom or a halogen atom, and each R ¹ is the same. Or different.

R ¹ is preferably a hydrogen atom, an alkyl group, a trifluoromethyl group or an alkenyl group among C _1-4 aliphatic groups, from the viewpoint of low water absorption.
A halogen atom such as a chlorine atom is preferred from the viewpoint of flame retardancy.

When a plurality of R ¹ are the same, it is preferable from the viewpoint of cost reduction accompanying simplification of the synthesis process, and when they are different, it is preferable from the viewpoint of suppressing crystallization. .

Furthermore, the smaller or smaller the group to be bonded, the smaller the molecular weight, and the smaller the epoxy equivalent, the larger the mixing ratio of the liquid curing agent.
It is preferable for lowering the viscosity of the liquid resin composition, and the bulkier the bonding group is, the better from the viewpoint of improving the heat resistance of the cured product.

When R ¹ is a C _1-4 aliphatic group, C _1-4 alkoxy group or two halogen atoms bonded to one benzene ring, these groups do not participate in the curing reaction. Therefore, as described in the description of the glycidyl ether group, it is more preferable that the glycidyl ether group is bonded to a position having poor symmetry than to a position having good symmetry from the viewpoint of suppressing crystallization.

When a glycidyl ether group is selected as R ¹ , a GO group is further contained in addition to the two GO groups. The number of the GO groups is preferably large from the viewpoint of high heat resistance of the cured product of the liquid resin composition,
From the viewpoint of low water absorption, a smaller amount is preferred. When the number of GO groups contained in the general formula (1) is 5 or more, the water absorption of the cured product tends to increase. From the viewpoint of obtaining a cured product that can simultaneously satisfy high heat resistance and low water absorption, the number of GO groups in the molecule is preferably 4 or less, and more preferably 3 or less. Further, as described above, it is preferable that each glycidyl group be separated from each other to some extent because there is no inhibition of the curing reaction due to steric hindrance. It is preferable from the viewpoint of properties. Specifically, in one benzene ring, it is preferable that GO groups are bonded to each other at a para or meta position. In the case of a compound having a plurality of benzene rings, the GO groups are preferably dispersed in each benzene ring. And the GO group is preferably bonded.

More specifically, n in the general formula (1)
Is 0 and ^one of R ¹ is a glycidyl ether group,
For example, a structure in which three glycidyl ether groups are bonded to the 1, 3, and 5-positions of a benzene ring is preferable in terms of reactivity and high heat resistance of a cured product, and n in the general formula (1) is 1 or In the case of 2, for example, two or less glycidyl ether groups are bonded to two or three benzene rings, respectively, and the ether groups are bonded to each other at the para or meta position of the benzene ring. The structure is preferred.

Specific examples of the C _1-4 aliphatic group include:
For example, alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and tert-butyl group, halogen-substituted alkyl groups such as trifluoromethyl group, vinyl group, allyl group, and propenyl And alkenyl groups such as a group. Among these, a small group such as a methyl group or an ethyl group is preferred after a hydrogen atom from the viewpoint of lowering the viscosity, and a bulky group such as an isopropyl group or a tert-butyl group is preferred from the viewpoint of increasing the heat resistance.

Specific examples of the above-mentioned C _1-4 alkoxy groups include, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy and the like. Can be Among these, a methoxy group is preferred from the viewpoint of lowering the viscosity.

Specific examples of the halogen atom include a chlorine atom, a bromine atom and a fluorine atom. Among them, bromine atoms and chlorine atoms are preferable because they have a large effect of imparting flame retardancy to the cured product of the liquid resin composition of the present invention. However, in order to keep the molecular weight from increasing and keep the viscosity low, the number is preferably small.

As specific examples of the epoxy compounds (1), when n is 0, for example, hydroquinone diglycidyl ether, resorcin diglycidyl ether, 2,5-di-tert-butylhydroquinone diglycidyl ether, , 5-di-isopropylhydroquinone diglycidyl ether, phloroglucin triglycidyl ether, 2,5-di-tert-amylhydroquinone diglycidyl ether and the like when n is 1 or 2; one of GO groups in the compounds of Ai _{-O-CH 2 -CH (OH)} -CH 2 -O
And a binuclear body obtained by replacing and linking with a -group, and a trinuclear body obtained by replacing and linking two. The trinuclear compound is obtained by converting epoxy compounds (1) having n = 0 (for example, hydroquinone diglycidyl ether, resorcin diglycidyl ether, etc.) and corresponding phenols (for example, hydroquinone, resorcinol, etc.) to tetramethylammonium chloride or tetramethyl. It can be obtained easily by adducting at a molar ratio of 2: 1 in the presence of a catalyst such as ammonium tetrafluoroborate. These may be used alone or in combination of two or more.

Of the above catalysts, tetramethylammonium chloride is preferred from the viewpoint of low cost, and tetramethylammonium tetrafluoroborate is preferred from the viewpoint of high catalytic performance and low hygroscopicity.

The epoxy compounds (2) used in the present invention are compounds represented by the general formula (2) as described above.

R ² in the general formula (2) represents a C _1-4 aliphatic group, a C _1-4 alkoxy group, a hydrogen atom or a halogen atom, and each R ² is the same or different. You may.

[0060] Incidentally, an aliphatic group of the C _{1 to 4,} alkoxy group of C _{1 to 4,} specific examples of the halogen atom, and for example, those listed as specific examples of R ¹ in the general formula (1) Similar ones can be mentioned.

The epoxy compounds (2) contain two glycidyl groups in one molecule. For the same reason as described in the description of the epoxy compounds (1), it is preferable that each glycidyl group is bonded to a position separated from each other to some extent from the viewpoint of curing reactivity and has good symmetry. Bonding to the position is preferred from the viewpoint of high heat resistance of the cured product. Specifically, for example, a skeleton in which a glycidyl ether group is bonded to the 4 and 4 'positions of the biphenol skeleton or a skeleton in which a glycidyl ether group is bonded to the 3 and 3' positions is preferable.

When a plurality of R ² are the same, it is preferable from the viewpoint of cost reduction accompanying simplification of the synthesis process, and when they are different, suppression of crystallization due to a decrease in symmetry is preferred. Preferred from the point.

In addition, as described in the general formula (1), generally, the smaller or smaller the group to be bonded, the smaller the molecular weight, and the smaller the epoxy equivalent, the lower the mixing ratio of the liquid curing agent. Since the size is large, the liquid resin composition is preferable in terms of lowering the viscosity, and the bulky group to be bonded is more preferable in terms of the high heat resistance of the cured product.

When two C _1-4 aliphatic groups, C _1-4 alkoxy groups and halogen atoms are bonded to one benzene ring, these groups do not participate in the curing reaction. As described in the description of the glycidyl ether group, it is more preferable that the glycidyl ether group is bonded to a position having poor symmetry than to a position having good symmetry from the viewpoint of suppressing recrystallization.

When R ² is a halogen atom such as a bromine atom or a chlorine atom, the number is preferably small in order to suppress an increase in molecular weight and maintain a low viscosity.

As a preferable structure of the general formula (2), for example,

[0067]

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And the like. It is preferable to have these structures because they have relatively low viscosity and high heat resistance.

Specific examples of the epoxy compounds (2) represented by the general formula (2) include, for example, 4,4'-biphenol diglycidyl ether, 3,3 ', 5,5'-tetramethyl-4,4 '-Biphenol diglycidyl ether, 2,2'-biphenol diglycidyl ether and the like. These may be used alone or in combination of two or more. Of these,
2'-biphenol diglycidyl ether is preferred from the viewpoint of low viscosity, and 3,3 ', 5,5'-tetramethyl-
4,4'-biphenol diglycidyl ether is preferred from the viewpoint of high heat resistance.

The epoxy compounds (1) and (3) selected from the epoxy compounds (2) used in the present invention.
20% or less of the other epoxy compounds contained in the epoxy compound mixture (A) containing at least 80% or more of all kinds of compounds in the total epoxy compound is difficult to adjust viscosity, increase glass transition temperature (increase Tg), It is a component used for imparting flammability, reducing stress, and imparting toughness. Specific examples thereof include bisphenol F type epoxy resin used for viscosity adjustment, alicyclic epoxy resin, alicyclic epoxy resin used for high Tg, polyfunctional glycidylamine,
Brominated epoxy resin used for imparting flame retardancy,
An acrylic rubber-dispersed epoxy resin, an NBR-modified epoxy resin, a silicone-modified epoxy resin, and the like used for lowering stress and imparting toughness are exemplified. Examples of the alicyclic epoxy resin include Celloxide-202.
Examples of the bisphenol F type epoxy resin such as 1P (manufactured by Daicel Chemical Industries, Ltd.) and CY175 (manufactured by Ciba Specialty Chemicals) include EP
ICLON830LVP (Dainippon Ink and Chemicals, Inc.)
And RE-304S (manufactured by Nippon Kayaku Co., Ltd.).
-100 (manufactured by Sumitomo Chemical Co., Ltd.) and MY721 (manufactured by Ciba Specialty Chemicals), such as BREN-S (manufactured by Nippon Kayaku), Denacol EX- Eposet BPA328 (manufactured by Nippon Shokubai Co., Ltd.) as the acrylic rubber-dispersed epoxy resin, and R-1415 as an NBR-modified epoxy resin.
-1 (manufactured by Asahi Denka Kogyo Co., Ltd.), and silicone-modified epoxy resin include Blendur A-2130E (manufactured by NOF Corporation). These may be used alone or in combination of two or more.

The proportion of the other epoxy compound used is not particularly limited as long as it is 20% or less in the component (A), but in order to obtain the effect of use, it is 5% or more, and more preferably 10% or more. It is preferred to use.

The component (A) used in the present invention contains at least three types selected from the group consisting of epoxy compounds (1) and epoxy compounds (2). Is done.

The method of selecting three or more compounds forming the component (A) is not particularly limited as long as the liquid epoxy resin composition of the present invention can be obtained.
Alternatively, three or more types may be selected from only one of the epoxy compounds (2), and one or more types may be selected from each of the epoxy compounds (1) and the epoxy compounds (2) to obtain three or more types. Good.

In general, a compound having a small molecular weight and a good symmetry has relatively high crystallinity, so that it is preferable not to mix too many kinds. When a large number of compounds having high crystallinity are used, it is preferable to mix and use as many types of epoxy compounds as possible at a time in order to facilitate suppression of recrystallization.

Examples of such highly crystalline epoxy compounds include hydroquinone diglycidyl ether,
Examples thereof include 2,5-di-tert-butylhydroquinone diglycidyl ether and 4,4′-biphenol diglycidyl ether.

It is preferable to increase the amount of the compound containing three or more glycidyl groups in the molecule, from the viewpoint of the high heat resistance of the cured product. However, if the amount is too large, the cured product will have a sufficiently low water absorption. It is difficult to secure the property. The compounding amount of the compound containing three or more glycidyl groups is 50% or less, more preferably 40% or less, and 10% or more of all epoxy compounds.
Further, the content is preferably at least 20% from the viewpoint of obtaining a cured product having a good balance between high heat resistance and low water absorption. Examples of the epoxy compound containing three or more glycidyl groups include phloroglucin triglycidyl ether, pyrogallol triglycidyl ether, and 1,2,4-trihydroxybenzene triglycidyl ether.

When three or more compounds are selected from only the epoxy compounds (1), the epoxy equivalent of the mixture (A) tends to be small, and in particular, the liquid resin composition has the characteristic of having a low viscosity. When three or more compounds are selected from only the epoxy compounds (2), the mixture (A)
Epoxy equivalents are relatively large and it is difficult to obtain a low-viscosity liquid resin composition. However, epoxy compounds (1) are characterized in that a cured product excellent in high heat resistance and low water absorption is obtained. When one or more types are selected from each of the epoxy compound and the epoxy compound (2), and three or more types are selected, a composition having a well-balanced property, that is, a liquid resin composition having a low viscosity can be obtained. It is characterized in that a cured product having excellent heat resistance and low water absorption can be obtained.

Among these, epoxy compounds (1)
One or more types are selected from each of the epoxy compound and the epoxy compound (2), and three or more types are selected to obtain a composition having a good balance of the above-mentioned properties (heat resistance, moisture resistance and workability of the cured product). It is preferable because it is easy, and has high Tg, low water absorption, low viscosity, and low crystallinity.

Preferred combinations when two or more epoxy compounds (1) are selected as the mixture (A) and one or more epoxy compounds (2) are selected will be specifically described.

The combination and the mixing ratio of the specific components of the mixture (A) are, for example, at least 80%, preferably at least 90%, more preferably at least 100% in all the epoxy compounds so that the hydroquinone diglycidyl ether is contained. 5-15%, further 8-10%, 2,5-di-tert-butylhydroquinone diglycidyl ether 10-25%, further 15-20%, resorcin diglycidyl ether 10-30%, further 15-15% 20
%, 3,3 ', 5,5'-tetramethyl-4,4'-biphenol diglycidyl ether 40-65%, more preferably 50-60% (mixture (a)), hydroquinone diglycidyl ether 5 20%, and even 12
-15%, 2,5-di-tert-butylhydroquinone diglycidyl ether 10-25%, further 15-2
0%, resorcin diglycidyl ether 0 to 10%, further 5 to 8%, a reaction product of hydroquinone diglycidyl ether and hydroquinone at a ratio of 2: 1 (molar ratio) (n in the epoxy compound (1) is 2 Compound) 2 to 15%, further 5 to 10%, 3,3 ', 5,5'-tetramethyl-4,4'-biphenol diglycidyl ether 40 to
65%, furthermore a combination of 50-60% (mixture (b)), resorcin diglycidyl ether 5-20
%, Even 10-15%, phloroglucin triglycidyl ether 20-50%, even 35-40%,
3,3 ', 5,5'-tetramethyl-4,4'-biphenol diglycidyl ether 30 to 60%, and even 4
0-55% combinations (mixture (c)).

In the mixture (a), if the ratio of hydroquinone diglycidyl ether and resorcin diglycidyl ether is too small, it is difficult to obtain a liquid resin composition having a sufficiently low viscosity, and it is difficult to obtain other crystalline components. It becomes difficult to sufficiently suppress recrystallization of
If the amount is too large, it becomes difficult to obtain a cured product having sufficiently high heat resistance and low water absorption, and it tends to be difficult to sufficiently suppress recrystallization of these components. Also,
2,5-di-tert-butylhydroquinone diglycidyl ether and 3,3 ', 5,5'-tetramethyl-
If the respective proportions of 4,4'-biphenol diglycidyl ether are too small, it becomes difficult to obtain a cured product having sufficiently high heat resistance and low water absorption, and sufficient recrystallization of other crystalline components. If the amount is too large, it becomes difficult to obtain a liquid resin composition having a sufficiently low viscosity, and it tends to be difficult to sufficiently suppress recrystallization of these components.

In the mixture (b), if the ratio of the reactants is too small, it is difficult to sufficiently suppress recrystallization of hydroquinone diglycidyl ether. There is a tendency that it is difficult to obtain a liquid resin composition having a sufficiently low viscosity. Use of hydroquinone diglycidyl ether, resorcin diglycidyl ether, 2,5-di-tert-butylhydroquinone diglycidyl ether, 3,3 ', 5,5'-tetramethyl-4,4'-biphenol diglycidyl ether About a ratio, it is the same as that of mixture (a).

Further, in the mixture (c), when the proportion of phloroglucin triglycidyl ether is too small, the effects of lowering the viscosity of the liquid resin composition and increasing the heat resistance of the cured product are sufficiently exhibited. If it is too large, the water absorption of the cured product tends to increase. In addition, resorcin diglycidyl ether,
The proportion of 3,3 ', 5,5'-tetramethyl-4,4'-biphenol diglycidyl ether used is the same as in the mixtures (a) and (b).

Next, a preferred combination in the case where three or more types are selected from the epoxy compounds (1) alone as the mixture (A) will be specifically described.

The combination and the mixing ratio of the specific components of the mixture (A) may be, for example, 2,5-, so that 80% or more, preferably 90% or more, and more preferably 100% of the total epoxy compound is contained. Di-tert-butylhydroquinone diglycidyl ether 10-25%,
Further, 15-20%, resorcin diglycidyl ether 5-20%, further 10-15%, hydroquinone diglycidyl ether 5-15%, further 8-10%,
Phloroglucin triglycidyl ether 20-50%,
Further, a combination (mixture (d)) of 35 to 40%, 2,5-di-isopropylhydroquinone diglycidyl ether 10 to 25%, and further 15 to 20% is exemplified.

In the mixture (d), 2,5-di-t
If the proportion of tert-butylhydroquinone diglycidyl ether is too small, the Tg will be low, and if it is too large, the viscosity will increase and the crystallinity will increase, and if the proportion of resorcin diglycidyl ether is too small, Has a high viscosity, if it is too high, it will have a low Tg, if the proportion of hydroquinone diglycidyl ether is too low, it will have a high viscosity, if it is too high, crystallization will increase, If the proportion of glycine triglycidyl ether is too small, the Tg will be low, if it is too large, the water absorption will be high, and if the proportion of 2,5-di-isopropylhydroquinone diglycidyl ether is too small, In such cases, the Tg tends to be low, and if too large, the viscosity tends to be high and the crystallinity tends to increase.

The liquid resin composition of the present invention contains a liquid curing agent (B) together with the mixture (A).

Since the liquid curing agent (B) also functions as a solvent for the mixture (A) containing the epoxy compound having high crystallinity, the lower the viscosity of the curing agent itself and the larger the amount thereof, the longer the curing time. It is preferable from the viewpoint that a stable liquid resin composition that can be liquefied can be obtained, and also preferable from the viewpoint of reducing the viscosity of the liquid resin composition.

As the liquid curing agent (B), the conventionally known 5
Various curing agents that are liquid at a temperature of ° C. can be used, and examples thereof include a liquid acid anhydride-based curing agent, a liquid amine-based curing agent, and a liquid phenol-based curing agent. Among these, liquid acid anhydride-based curing agents are preferred from the viewpoint of lowering the viscosity. Also,
Since the reaction between the acid anhydride-based curing agent and the epoxy compound is relatively slow, the use of an appropriate latent curing agent also has the advantage that it can be easily one-packed.

The liquid acid anhydride-based curing agent generally has a lower viscosity than other liquid curing agents, and can be added in a large amount per 1 equivalent of an epoxy group.
Since a cured product having high glass transition temperature and high heat resistance can be obtained, it is widely used as a raw material for liquid epoxy resin compositions.

Specific examples of the above-mentioned liquid acid anhydride-based curing agents from which cured products having high heat resistance can be obtained include, for example, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhymic anhydride. , Trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride and the like. These may be used alone or in combination of two or more.

The liquid amine-based curing agent generally has two or more amino groups in the molecule and has a small active hydrogen equivalent, so that the amount that can be blended with the epoxy compound is generally small. Therefore, the mixture (A) having as low a crystallinity as possible, specifically, for example, 2,5-di-tert-
Butylhydroquinone diglycidyl ether / 3,3 ',
5,5'-tetramethyl-4,4'-biphenol diglycidyl ether / hydroquinone diglycidyl ether / resorcin diglycidyl ether / bisphenol A
Diglycidyl ether = 15/50/10/15/10
It is preferable to use them together. When the liquid amine-based curing agent is used, it is difficult to obtain a low-viscosity liquid resin composition as compared with the case where a liquid acid anhydride-based curing agent is used. ), The viscosity can be reduced to a level that cannot be obtained with a liquid resin composition using a conventional liquid amine-based curing agent.

The liquid amine-based curing agent is not particularly limited, but those which give a cured product having high heat resistance include, for example, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 1,3-diamino- 2,6-diethyl-4-
Methylbenzene, 1,3-diamino-4,6-diethyl-2-methylbenzene and the like can be mentioned. These may be used alone or in combination of two or more.

The liquid phenol-based curing agent has a higher viscosity than the liquid acid anhydride-based curing agent and has a smaller amount that can be blended per equivalent of epoxy group. It is preferred to use with a low mixture (A). Specifically, for example, 2,5-di-te
rt-butylhydroquinone diglycidyl ether / 3,
3 ', 5,5'-tetramethyl-4,4'-biphenol diglycidyl ether / hydroquinone diglycidyl ether / resorcin diglycidyl ether / bisphenol A diglycidyl ether = 15/50/10/15
/ 10 is preferably used. As described above for the liquid amine-based curing agent, it is difficult to obtain a liquid resin composition having a low viscosity as compared with the case where a liquid acid anhydride-based curing agent is used. By using the same, it is possible to reduce the viscosity to a level that cannot be obtained with a liquid resin composition using a conventional liquid phenol-based curing agent.

The liquid phenol-based curing agent is not particularly limited, but examples of low-viscosity ones include allylic compounds such as diallylbisphenol F, diallyldihydroxynaphthalene, and allylated phenol novolak resin. These may be used alone or in combination of two or more.

The amount of the liquid curing agent (B) is not particularly limited as long as it can exert the effect as a curing agent.
Usually, in the case of a liquid acid anhydride-based curing agent, the acid anhydride equivalent is 0.5 to 1 per equivalent of the epoxy group of the mixture (A).
1.5 equivalents, more preferably 0.7 to 1.1 equivalents, and in the case of a liquid amine-based curing agent, active hydrogen equivalents of 0.5 to 1.5 equivalents.
Equivalent, more preferably 0.7 to 1.1 equivalents, and in the case of a liquid phenolic curing agent, use in a ratio of 0.4 to 1.2 equivalents, more preferably 0.5 to 1.0 equivalent in hydroxyl equivalents. Preferably. If the amount of the liquid curing agent (B) is too small, the viscosity of the liquid resin composition tends to be high, and the crystalline epoxy compound tends to be recrystallized, while the amount is too large. In such a case, the properties inherent in the cured product cannot be exhibited, such as poor curing, and the beneficial effect of using a large amount tends not to be obtained.

The liquid resin composition of the present invention is prepared, for example, by dissolving the epoxy compound (1) and / or the epoxy compound (2) which is solid at room temperature in another liquid component to liquefy, and further mixing other raw materials. Can be manufactured. In that case, you may heat and stir as needed. The heating temperature may be within a range in which the solid epoxy compound (1) and / or the epoxy compound (2) are dissolved, self-polymerization of the epoxy group or a decomposition reaction due to high heat does not occur, and the viscosity does not increase. Usually, it is produced by heating in a temperature range from room temperature to about 150 ° C. to dissolve solid components.

The liquid resin composition of the present invention thus produced has an initial mixture viscosity at 25 ° C. of 200 to 100 when a liquid acid anhydride curing agent is used, for example.
It is kept liquid at 0 cP for a period of 20 days or more, and even 60 days or more. Further, the mixture (A) has low toxicity because it does not have a naphthalene skeleton, and is preferable from the viewpoint of securing public health and safety.

In the liquid resin composition of the present invention, various conventionally known curing accelerators may be used. When a latent curing accelerator is used, the working life of the liquid resin composition is prolonged, and there is an advantage that one-packing is possible.

The curing accelerator is FXE-1000.
(Manufactured by Fuji Chemical Industry Co., Ltd.), UCat3502T, UC
Urea-based curing accelerators such as at3503N (manufactured by San Apro Co.), amine adduct-based curing agents such as AMICURE MY24 (manufactured by Ajinomoto Co.), imidazoles such as 2-ethyl-4-methylimidazole and 2-methylimidazole And aliphatic phosphorus carboxylate compounds such as UCatSA102 (manufactured by San-Apro Co., Ltd.), and organic phosphorus compounds such as TPP-K (manufactured by Hokuko Chemical Industry Co., Ltd.), but are not limited thereto.

The amount of the curing accelerator varies depending on the type of the curing accelerator to be used and cannot be specified unconditionally. However, the amount is usually 1 to 100 parts of the mixture (A).
It is preferably 8 parts, more preferably 1 to 5 parts. When the compounding amount of the curing accelerator exceeds 8 parts with respect to 100 parts of the mixture (A), a decrease in the molecular weight between crosslinks of the cured product and a decrease in moisture resistance may occur. The effect of using the accelerator tends to be insufficient.

The liquid resin composition of the present invention may contain various conventionally known inorganic fillers. The type and amount of the inorganic filler may be appropriately selected according to the application and the viscosity of the liquid resin composition.

Specific examples of the inorganic filler include fused silica powder, quartz glass powder, crystalline silica powder, glass fiber, talc, alumina powder, calcium silicate powder, calcium carbonate powder, antimony oxide powder,
Examples include, but are not limited to, barium sulfate powder, titanium oxide powder, and aluminum hydroxide powder. When the use of the liquid resin composition is in the field of electronics and semiconductors, high purity products are obtained, and fused silica powder or quartz glass powder having a small linear expansion coefficient is suitable.

Further, the liquid resin composition of the present invention may contain various coupling agents, defoaming agents, low-stressing agents, rubber particles, pigments and the like within a range that does not adversely affect the viscosity, water absorption, and heat resistance. Various additives may be blended.

The cured product of the liquid resin composition of the present invention can be obtained by thermally curing the liquid resin composition of the present invention. The conditions for heat curing are not particularly limited as long as they are conditions capable of exhibiting the original performance of the liquid resin composition, but from the viewpoint of suppressing curing shrinkage and reducing residual stress, it is divided into several stages. Step hardening in which the temperature is gradually increased is generally adopted.

When a liquid acid anhydride-based curing agent is used, the curing temperature is usually from 100 to 200 ° C., preferably from 120 to 200 ° C.
When using a liquid amine-based curing agent, the curing temperature is usually 80 to 180 ° C, and more preferably 100 to 150 ° C.
° C, the curing temperature when a liquid phenolic curing agent is used is usually 120 to 220 ° C, furthermore 140 to 180 ° C.
C. is preferred.

The curing time is usually 30 minutes to 10 hours, and preferably 1 to 5 hours when any curing agent is used.

However, the present invention is not limited to these conditions.

The cured product obtained by heat-curing the liquid resin composition of the present invention thus obtained, for example, when cured with a liquid acid anhydride-based curing agent, has a glass transition temperature (DSC apparatus). (Temperature measured from the point at which the specific heat capacity changes by a differential scanning calorimeter) is 100 ° C. or more, further 150 ° C. or more, and the water absorption (pressure cooker test (hereinafter, also referred to as PCT) is 120 ° C., 2 atm. (Value after 700 hours of treatment under the conditions) is 3.0% or less, and furthermore, it shows excellent characteristics of 2.5% or less.

In a preferred embodiment of the liquid resin composition of the present invention, for example, the mixture (a), the mixture (b) or the mixture (c) and the various liquid anhydride-based curing agents are mixed with one equivalent of an epoxy group. 0.8-1.0 per acid anhydride
The liquid resin composition obtained by mixing at an equivalent ratio, stirring and dissolving at 120 ° C., cooling, adding a curing accelerator, an inorganic filler, a coupling agent, etc., and sufficiently kneading with a mixer is obtained. can give.

In a preferred embodiment of the cured product of the present invention, the liquid resin composition of the preferred embodiment is added at 100 ° C. for 1 hour, further at 150 ° C. for 2 hours, and further at 180 ° C.
And those having the performance obtained by curing for 2 hours.

[0112]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

The raw materials used in the examples and their abbreviations are as follows. These are not all designated chemical substances.

YDC-1312: 2,5-di-tert
-Butylhydroquinone diglycidyl ether (epoxy equivalent: about 176, manufactured by Toto Kasei Co., Ltd.) EX-201: Resorcinol diglycidyl ether (epoxy equivalent: about 112, manufactured by Nagase Kasei Co., Ltd.) EX-203: Hydroquinone diglycidyl ether (epoxy N2HQ: 2 mol of EX-203 and 1 m of hydroquinone (equivalent to about 114, manufactured by Nagase Kasei Co., Ltd.)
PGTE: phloroglucin triglycidyl ether (epoxy equivalent: about 100, manufactured by Nagase Kasei Co., Ltd.) IPHG: 2,5-di-isopropylhydroquinone diglycidyl ether (epoxy equivalent: about 160) YX4000: 3,3 ', 5,5'-tetramethyl4, manufactured by Nippon Steel Chemical Co., Ltd.
4'-biphenol diglycidyl ether (epoxy equivalent: about 186, manufactured by Yuka Shell Epoxy Co., Ltd.) Celloxide-2021P: alicyclic epoxy resin (epoxy equivalent: about 135, manufactured by Daicel Chemical Industries, Ltd.) EPICLON 830 LVP: bisphenol F type Epoxy resin (epoxy equivalent: about 162, manufactured by Dainippon Ink and Chemicals, Inc.) HN5500: methylhexahydrophthalic anhydride (acid anhydride equivalent: about 168, manufactured by Hitachi Chemical Co., Ltd.) 2E4MZ: 2-ethyl-4- Methyl imidazole (Shikoku Chemical Industry Co., Ltd.)

The evaluation in Examples and Comparative Examples was performed by the following method.

(1) Pot Life After the obtained liquid resin composition was left at 5 ° C. for a predetermined time, it was examined whether crystals had formed. When no crystal was formed even after standing for 240 hours, it was judged as ○, and when crystal was formed after standing for 24 hours, it was judged as x.

(2) Initial Viscosity The viscosity (cP (centipoise)) of the obtained liquid resin composition was measured at 25 ° C. using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

(3) Glass transition temperature (Tg) The obtained liquid resin composition was heated at 100 ° C. for 1 hour,
The glass transition temperature of the cured product obtained by curing at 50 ° C. for 1 hour and further at 180 ° C. for 1 hour was measured using a DSC device (manufactured by Seiko Instruments Inc.). 16 scans
The test was carried out under a heating condition of ° C./min, and the point at which the specific heat capacity changed was defined as the glass transition temperature.

(4) Water Absorption Rate 2 g of the obtained liquid resin composition was collected to a diameter of 40 mm and a thickness of 10 g.
The cured product obtained by casting in a 100 mm circular coin mold and curing at 100 ° C. for 1 hour, further at 150 ° C. for 1 hour, and further at 180 ° C. for 1 hour is subjected to a pressure cooker test (PCT). 120 ° C, 2 atm, relative humidity 100
% Water was absorbed by exposure for 700 hours, and the water absorption was calculated by the formula: water absorption (%) = (weight after water absorption−initial weight) ÷ initial weight × 100.

Examples 1 to 4 and Comparative Examples 1 to 3 The components shown in Table 1 were mixed in the proportions shown in Table 1 to obtain a liquid epoxy resin composition. The pot life and initial viscosity of the obtained resin composition, and the glass transition temperature and water absorption of a cured product from the obtained resin composition were measured.

Table 1 shows the results.

[0122]

[Table 1]

[0123]

The liquid epoxy resin composition of the present invention has a low viscosity and can maintain a liquid state for a long time without using a designated chemical substance as a raw material. Heat resistant and low water absorption. Therefore, the present invention can be applied to casting materials for many electric and electronic parts that require high heat resistance and low water absorption without being restricted by various regulations on public health.

Claims (2)

[Claims] (A) General formula (1): Wherein G is a glycidyl group, R ¹ is a glycidyl ether group, a C _1-4 aliphatic group, a C _1-4 alkoxy group, a hydrogen atom or a halogen atom, and each R ¹ is the same And n is 0, 1 or 2) and an epoxy compound represented by the general formula (2): (Where G is a glycidyl group, R ² is a C _1-4 aliphatic group,
A C _1-4 alkoxy group, a hydrogen atom or a halogen atom, wherein each R ² may be the same or different)
3 selected from the group consisting of epoxy compounds represented by
A liquid epoxy resin composition comprising a mixture of epoxy compounds containing at least 80% by weight of the total epoxy compound and at least 80% by weight of the total epoxy compound, and (B) a liquid curing agent. 2. A cured product of the liquid epoxy resin composition obtained by thermally curing the liquid epoxy resin composition according to claim 1.