JPH0632868A - Epoxy resin sealing agent - Google Patents

Abstract

PURPOSE:To obtain a sealing agent excellent in resistances to heat, moist heat, weather, etc. CONSTITUTION:This epoxy resin consists essentially of (A) an epoxy resin obtained by further epoxidizing a resin having vinyl groups obtained by reacting (a) a compound having one or more vinyl groups and one epoxy group in one molecule with (b) at least one kind selected from polymers containing a polybasic acid anhydride, a polybasic acid, an acid terminated polymer and carboxylic acid group and (c) at least one kind selected from compounds having one or more active hydrogens and (B) a curing agent for epoxy resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an epoxy resin sealant having excellent heat resistance, weather resistance and water resistance.

[0002]

2. Description of the Related Art Conventionally, a method of encapsulating an electronic component such as a diode, a transistor or an integrated circuit with a thermosetting resin has been performed. This resin encapsulation has been widely put into practical use because it is economically advantageous as compared with the hermetic seal system using glass, metal, or ceramic. As the encapsulating resin composition, an epoxy resin composition is most commonly used from the viewpoint of reliability and price among thermosetting resin compositions.

Recently, epoxy resin obtained by reacting phenol or novolac resin with epichlorohydrin has been used as a sealing resin for VLSI or the like. However, the resin contains several hundred ppm of chlorine, which is used for electrical parts. There are problems such as deterioration of electrical characteristics. Further, when a molded product is subjected to a hot and cold cycle test, resin cracks and pellet cracks occur, and there is a problem that the function as an electronic component cannot be fulfilled.

Further, when a flat package type molded product is prepared by using the same resin composition, the reliability is remarkably deteriorated when the solder is dipped in the assembling process.

[0005]

Therefore, it has been desired to develop a sealing material having excellent water resistance, heat resistance, and mechanical properties. The present invention provides a sealant having excellent water resistance, heat resistance, and mechanical properties.

Further, it has been clarified that the characteristics of the epoxy resin can be changed by giving various combinations of (a), (b) and (c) to be used, and a wide range of characteristics can be given.

[0007]

The present invention comprises (a) a compound having at least one vinyl group and one epoxy group in one molecule, (b) a polybasic acid anhydride, a polybasic acid, Vinyl obtained by reacting at least one selected from acid-terminated polymers and polymers containing carboxylic acid groups with at least one selected from (c) compounds having one or more active hydrogens. A sealant comprising an epoxy resin obtained by further epoxidizing a resin having a group and a curing agent for an epoxy resin as essential components.

Next, the present invention will be described in more detail.

The compound having one epoxy group and one or more vinyl groups in one molecule used in the present invention is (IV) << i is an integer of 1 to 5, R ¹ and R ⁴ are hydrogen atoms or alkyl groups having 1 to 50 carbon atoms or substituted phenyl groups,
R ² and R ³ are each a hydrogen atom or an alkyl group having 1 to 50 carbon atoms, and R ² and R ³ may be wrapped around a ring.

Examples of the compound represented by (IV) are the compounds shown below.

4-vinylcyclohexene-1-oxide, 5-vinylbicyclo [2.2.1] hept-2-ene-2-oxide, limonene monoxide, trivinylcyclohexane monoxide, divinylbenzene monoxide, butadiene monooxide. Oxide and 1,2-epoxy-
Examples include compounds represented by (I) such as 9-decene, compounds represented by (II) such as allyl glycidyl ether, and compounds such as glycidyl styryl ether.

Further, the following compounds can also be used.

[0013]

[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical 4] These may be used alone or in combination of two or more.

If desired, ethylene oxide,
Propylene oxide, cyclohexene oxide, styrene oxide, monoepoxides such as α-olefin epoxide, vinyl cyclohexene dioxide, 3,4-
A diepoxide such as epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate may be used together with the compound having one epoxy group and one or more vinyl groups in one molecule.

The polybasic acid anhydrides or polybasic acids (b) used in the present invention include aromatic polybasic acids and acid anhydrides thereof, and aliphatic polybasic acids and acid anhydrides thereof. Examples of aromatic polybasic acids and acid anhydrides thereof include:
Examples include phthalic anhydride, isophthalic acid, terephthalic acid and trimellitic anhydride. Examples of the aliphatic polybasic acid and its acid anhydride include tetrahydrophthalic acid, 4-methylhexahydrophthalic acid, hexahydrophthalic acid, adipic acid, maleic acid, and their acid anhydrides, fumaric acid and sebacic acid. , Dodecane diacid, and their acid anhydrides.

The acid-terminated polymer used in the present invention includes polyethylene glycol and polypropylene glycol.
Acid-terminated polyesters, acid-terminated polyesters, acid-terminated polybutadienes, acids obtained by reacting polybasic acids with poly (tetramethylene glycol), poly (butylene glycol), polycyclohexene glycol, polyvinyl cyclohexene glycol, etc. Examples include terminal polycaprolactone.

Further, an acrylic copolymer having a carboxylic acid group can be used instead of the acid terminal polymer, and it contains a polybasic acid anhydride, a polybasic acid, an acid terminal polymer, and a carboxylic acid group. These polymers may be used alone or in combination of two or more.

Next, as the compound (c) having active hydrogen used in the present invention, alcohols, phenols, carboxylic acids, amines, thiols, hydroxyl-terminated polymers, and hydroxyl groups can be used. The polymer etc. which are contained are mentioned. The alcohols are monovalent, divalent, trivalent or higher, and include, for example, methanol, ethanol, benzyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, and diethylene glycol. Examples thereof include propylene glycol, butanediol, hexanediol, glycerin, butanthol, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerol and triglycerol. In addition, neopentyl glycol, neopentyl glycol of hydroxy hivalic acid
Ester, dipentaerythritol, 1,4-cyclohexanedimethanol, trimethylpentanediol,
1,3,5-Tris (2-hydroxyethyl) cyanuric acid, hydrogenated bisphenol A, ethylene oxide adduct of hydrogenated bisphenol A, propylene oxide adduct of bisphenol A and the like can also be used.

Examples of the phenols are phenol, cresol, catechol, pyrogallol, hydroquinone,
Hydroquinone monomethyl ether, bisphenol A, bisphenol F, 4,4'-dihydroxybenzophenone, bisphenol S, ethylene oxide adduct of bisphenol A, propione oxide adduct of bisphenol A, phenol Resin and cresol-novolak resin.

The hydroxyl group-terminated polymer used in the present invention includes polyethylene glycol and polypropylene glycol.
Polyether polyols such as poly (tetramethylene glycol), poly (butylene glycol), poly (cyclohexene glycol) and poly (vinylcyclohexene glycol)
And hydroxyl-terminated polyesters, hydroxyl-terminated polybutadienes, hydroxyl-terminated polycaprolactones, and polycarbonate diols. Further, an acrylic copolymer having a hydroxyl group or the like can be used instead of the hydroxyl group-terminated polymer.

As carboxylic acids, formic acid, acetic acid, propionic acid, butyric acid, fatty acids of animal and vegetable oils, fumaric acid, maleic acid, adipic acid, dodecane diacid, trimellitic acid, pyromellitic acid, polyacrylic acid, phthalic acid, isophthalic acid. Acid, terephthalic acid, etc.

Further, compounds having both a hydroxyl group and a carboxylic acid, such as lactic acid, citric acid and oxycaproic acid, can also be mentioned.

The amines include monomethylamine, dimethylamine, monoethylamine, diethylamine, propylamine, monobutylamine, dibutylamine, pentylamine, hexylamine, cyclohexylamine,
Octylamine, dodecylamine, 4,4'-diaminodiphenylmethane, isophoronediamine, toluenediamine, hexamethylenediamine, xylenediamine, diethylenetriamine, triethylenetetramine, ethanolamine and the like.

As the thiols, methyl mercaptan,
Mercapto such as ethyl mercaptan, propyl mercaptan and phenyl mercaptan, mercaptopropionic acid or polyhydric alcohol ester of mercaptopropionic acid such as ethylene glycol dimercaptopropionic acid ester, trimethylolpropane trimercaptopropionic acid, pentaerythritol- Examples include rupentamercaptopropionic acid and the like.

Further, as the compound having active hydrogen, polyvinyl alcohol, polyvinyl acetate partial hydrolyzate, starch, cellulose, cellulose acetate
, Cellulose acetate butyrate, hydroxyethyl cellulose, acrylic polyol resin, styrene allyl alcohol copolymer resin, styrene-maleic acid copolymer resin, alkyd resin, polyester polyol resin,
Polyester carboxylic acid resins, polycaprolactone polyol resins, polypropylene polyols, polytetramethylene glycol, and the like.

Further, the compound having active hydrogen may have an unsaturated double bond in its skeleton, and specific examples thereof include allyl alcohol, acrylic acid, methacrylic acid,
2-hydroxyethyl methacrylate, 3-cyclohexene methanol, tetrahydrophthalic acid and the like.

Any compound having these active hydrogens can be used, and two or more kinds of them may be mixed.

The epoxy resin used in the present invention includes the compound (a) having at least one vinyl group and one epoxy group in the above molecule, a polybasic acid anhydride, a polybasic acid, and an acid terminal polymer. And a vinyl group-containing resin obtained by reacting at least one selected from the polymer (b) containing a carboxylic acid group and at least one selected from the compound (c) having active hydrogen. Obtained by epoxidation with an epoxidizing agent.

The starting materials (a), (b),
The charging ratio of (c) is 1 to 99 parts by weight of (a), preferably 30 to 80 parts by weight, 99 to 1 parts by weight of (b), preferably 20 to 70 parts by weight, and 0 of (c). To 99 parts by weight, preferably 0 to 30 parts by weight. The component (c) may not be used depending on the case. When the component (c) is not used, it is necessary to control the molecular weight while detecting the dehydration amount by controlling the reaction time, the degree of reduced pressure, the reaction temperature and the like.

When the amount of component (a) used is relatively small, the epoxy group content in the target epoxy resin is small.

The molar ratio of component (a) / component (b) is 0.
It is 4 to 5.0, preferably 0.5 to 3.0.

When the ratio of the component (a) is increased, the ratio of the terminal to be a hydroxyl group is increased, and when the terminal of the hydroxyl group and the terminal of the carboxyl group are present, all the terminals are hydroxyl groups as the dehydration reaction proceeds.

On the contrary, when the ratio of the component (b) is increased, the ratio of the terminal to be the carboxyl group is increased, and when the hydroxyl group terminal and the carboxyl group terminal are present, all the terminals become the carboxyl group as the dehydration reaction proceeds. . However, if the ratio of the component (a) becomes unnecessarily large, part of the component (a) will remain unreacted. Further, if the ratio of the component (b) becomes unnecessarily large, a part of the component (b) will remain without reacting.

In the reaction for synthesizing the resin having a vinyl group, a catalyst for promoting the ring-opening reaction of the epoxy group by the carboxyl group and, if necessary, a catalyst for promoting the (dehydration) esterification reaction may be used in combination. Good. .

As the catalyst for promoting the ring-opening reaction of an epoxy group with a carboxyl group which can be used in the present invention, a tertiary amine such as dimethylbenzylamine, triethylamine, tetramethylethylenediamine, tri-n-octylamine, or tetramethylammonium chloride is used. , Quaternary ammonium salts such as tetramethylammonium bromide and tetrabutylammonium bromide, alkylureas such as tetramethylurea, and alkylguanidines such as tetramethylguanidine.

The catalyst for promoting the ring-opening reaction that can be used in the present invention may be used alone or in combination of two or more kinds. This catalyst is 0.1 to 5.0 relative to the epoxy compound.
%, Preferably 0.5 to 3.0% by weight. The ring-opening reaction is 50 to 200 ° C, preferably
It is carried out at 100 to 180 ° C.

Examples of the catalyst for promoting the (dehydration) esterification reaction that can be used in the present invention include Sn compounds such as tin octylate and dibutyltin laurate, and Ti compounds such as tetrabutyl titanate. To be

The catalyst for promoting the (dehydration) esterification reaction used in the present invention may be used alone or in combination of two or more kinds. This catalyst is 0-100 with respect to the reaction system.
It is recommended to use 0 ppm, preferably 50 to 500 ppm. This (dehydration) ester reaction is 180-240 ° C.
Done in.

The epoxy group ring-opening reaction with a carboxyl group and the (dehydration) esterification reaction may be carried out sequentially, but after the raw materials and the catalyst have been charged all at once, the reaction temperature is raised stepwise according to the progress of the reaction. Method is preferred. If necessary, after the component (c) and the catalyst are charged in a batch, (a),
The component (b) may be dropped.

The resin having a cyclic olefin or vinyl group thus synthesized is reacted with an epoxidizing agent to synthesize the resin having an epoxy group of the present invention. As peracids,
Examples thereof include hydroperoxides.

Examples of peracids include formic acid, peracetic acid, perbenzoic acid and trifluoroperacetic acid. Of these, peracetic acid is industrially produced in large quantities and is available at low cost.
It is also a preferred epoxidizing agent because of its high stability.

The hydroper oxides include hydrogen peroxide, tertiary butyl hydroper oxide, cumene per oxide and the like.

In the epoxidation, a catalyst can be used if necessary.

For example, in the case of peracid, an alkali such as sodium carbonate or an acid such as sulfuric acid can be used as a catalyst.

In the case of hydroperoxides,
A mixture of tungstic acid and caustic soda with hydrogen peroxide,
Alternatively, a catalytic effect can be obtained by using an organic acid in combination with hydrogen peroxide or molybdenum hexacarbonyl in combination with tert-butyl hydroperoxide.

The epoxidation reaction is carried out by adjusting the presence or absence of a solvent and the reaction temperature according to the physical properties of the equipment and raw materials.

The reaction temperature range that can be used depends on the reactivity of the epoxidizing agent used.

Regarding the preferred epoxidizing agent, peracetic acid, 0 to 70 ° C. is preferable.

The reaction is slow below 0 ° C., and the decomposition of peracetic acid occurs at 70 ° C.

In the tertiary butyl hydroperoxide / molybdenum dioxide diacetylacetonate system, which is an example of hydroperoxide, for the same reason, 2
0 degreeC-150 degreeC is preferable.

The solvent can be used for the purpose of reducing the viscosity of the raw material and stabilizing it by diluting the epoxidizing agent.
In the case of peracetic acid, aromatic compounds, ethers, esters and the like can be used.

The charged molar ratio of the epoxidizing agent to the unsaturated bond can be changed according to the purpose such as the amount of the unsaturated bond to be left.

When a compound having a large number of epoxy groups is intended, the epoxidizing agent is preferably added in an equimolar amount or more with respect to the unsaturated group.

However, it is usually disadvantageous in excess of 2 times the molar amount in view of economical efficiency and side reaction, and in the case of peracetic acid, 1 to 1.5 times the molar amount is preferable.

The composition of interest can be removed from the reaction crude liquid by chemical engineering means such as concentration.

The epoxy resin (A) used in the encapsulant of the present invention can be used as a mixture with other epoxy resins as long as the characteristics of the composition are not impaired. Here, the other epoxy resin may be any as long as it is generally used, for example, epibis type epoxy, bisphenol-
Included are epoxy diluents such as Le F epoxy, novolac epoxy, cycloaliphatic epoxy and styrene oxide, butylglycidyl ether.

As the curing agent (B) used in the encapsulant of the present invention, known curing agents used in epoxy resins can be used as long as they do not impair the performance of parts after encapsulation. Examples include cationic catalysts such as resins, acid anhydrides, polymercaptan resins, novolac resins, dicyandiamide, and amine complexes of boron trifluoride.

Here, the amines include the following.

Diethylenetriamine, triethylenetetramine, metaxylylenediamine, bis (4-amino-)
Aliphatic polyamines such as 3-methylcyclohexyl) methane, adducts of the aliphatic polyamines with known epoxy compounds, reaction products with acrylonitrile, and reaction products with ketones.

Aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, diaminodiphenyl sulfide, and adducts of said aromatic polyamines with known epoxy compounds,
Secondary and tertiary amines and salts thereof such as tris (dimethylaminomethyl) phenol, piperidine, imidazole and its derivatives, and mixtures of said amines.

The polyamide resin includes a reaction product of a fatty acid such as fatty acid, dimer acid and trimer acid with an aliphatic polyamine.

The acid anhydride includes the following.

Phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylanhydride Acid anhydrides such as nadic acid, succinic anhydride, dodecenyl succinic anhydride, and mixtures of said acid anhydrides.

Novolak resins include low molecular weight resinous products made by condensation of phenol or a mixture of phenol and cresol, a mixture of dihydroxybenzenes and formaldehyde.

As the amine complex of boron trifluoride, monoethylamine, piperidine, aniline, butylamine,
A complex of boron trifluoride and a low molecular weight amine compound such as dibutylamine, cyclohexylamine, dicyclohexylamine, tributylamine, and triethanolamine is included.

Other curing agents include salts of super strong acids such as boron tetrafluoride, phosphorus hexafluoride and arsenic hexafluoride, such as diazonium salts, iodonium salts, bromonium salts and sulfonium salts. Among these curing agents, aliphatic polyamine, aromatic polyamine, polyamide resin,
The polymercaptan resin can be mixed and used at an arbitrary ratio, and can be used alone or in combination with a curing accelerator for the purpose of controlling the curing rate. Here, the secondary and tertiary amines can be used as the curing accelerator.

The acid anhydride can be used as it is, but it is also possible to use a curing catalyst and a curing accelerator together for the purpose of adjusting the curing rate and improving the physical properties of the cured product. Here, the curing catalyst is the secondary and tertiary amines and tin octylate. As a curing accelerator,
Water, alcohols such as ethanol, propanol, isopropanol, cyclohexanol and ethylene glycol, carboxylic acids such as acetic acid, propionic acid, succinic acid and hexahydrophthalic acid, and ethylenediamine, diethylenetriamine And amines having active hydrogen.

The novolak resin may be used alone or in combination with a curing catalyst for the purpose of controlling the curing rate. Here, the curing catalyst is the secondary and tertiary amines.

The dicyandiamide can be used alone or in combination with a curing catalyst for the purpose of adjusting the curing rate. Here, the curing catalyst is the secondary and tertiary amines.

The amine complex of boron trifluoride alone is
Alternatively, a curing rate adjusting agent can be used together for the purpose of adjusting the curing rate. Here, as the curing speed adjusting agent,
Any material may be used as long as it can be used for a conventional epoxy resin, and specifically, for example, carboxylic acids, amines, acetylacetone complex of metal, titanium,
Organometallic compounds of metals such as tin, glycols, organoboron compounds and the like are included.

The encapsulant of the present invention comprises the epoxy resin and the curing agent for the epoxy resin as defined in claims 1 to 11 as essential components, and if necessary, a filler, a flame retardant, a pigment, a coupling agent, etc. Can be used in combination, and it is particularly desirable to use a filler in combination.

Any filler can be used as long as it can be used as a filler for resins. Specific examples are silica sand, silica, alumina, diatomaceous earth, titanium white, talc, clay and red iron oxide. , Calcium carbonate,
There are magnesium carbonate, asbestos, glass, kaolin, glass fiber, carbon fiber, metal powder and the like. As for the shape,
Various materials such as fiber and flakes are used. Alumina and silica powder are particularly desirable. The blending ratio of the inorganic filler is preferably 25 to 90% by weight of the resin composition. If it is less than 25% by weight, the water resistance, heat resistance and mechanical properties are not improved, and if it exceeds 90% by weight, the bulkiness increases and the moldability deteriorates, which is not suitable for practical use.

As a general method for preparing the encapsulant of the present invention as a molding material, a raw material composition in which an epoxy resin, a curing agent and the like are selected in a predetermined composition ratio is sufficiently uniformly mixed by a mixer or the like. After that, a melt mixing treatment with a heat roll or a mixing treatment with a kneader or the like is further performed, and then the mixture is cooled and solidified and crushed to an appropriate size to obtain a molding material.

The sealant thus prepared was
Each molding method well known as a sealing method when used for a sealant for electronic parts such as a transistor, an integrated circuit, a capacitor, and a resistor, for example, a low-voltage transfer molding method,
There are injection molding method, compression molding method, etc., and it can be applied to almost all of these sealing molding techniques.

The encapsulant of the present invention has good water resistance, high heat resistance, excellent mechanical mechanical properties, and good molding workability. You can get credibility. Hereinafter, the present invention will be described in detail with reference to examples.

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Claims (11)

[Claims] 1. (A) (a) a compound having at least one vinyl group and one epoxy group in one molecule, (b) a polybasic acid anhydride, a polybasic acid, an acid terminal polymer, And a resin having a vinyl group obtained by reacting at least one selected from polymers having a carboxylic acid group and (c) at least one selected from compounds having one or more active hydrogens, Furthermore, an epoxy resin encapsulant comprising an epoxy resin obtained by epoxidation and (B) a curing agent for an epoxy resin as essential components. 2. The epoxy resin sealant according to claim 1, wherein the compound having one or more vinyl groups and one epoxy group in one molecule is 4-vinylcyclohexene-1-oxide. 3. The compound having one or more vinyl groups and one epoxy group in one molecule is 5-vinylbicyclo [2.2.1] hept-2-ene-2-oxide. 1. Epoxy resin encapsulant. 4. The epoxy resin sealant according to claim 1, wherein the compound having one or more vinyl groups and one epoxy group in one molecule is limonene monoxide. 5. A compound having at least one vinyl group and one epoxy group in one molecule is represented by the following (I): The epoxy resin sealant according to claim 1, which is a compound represented by << n is an integer of 0 to 30 >>. 6. A compound having one or more vinyl groups and one epoxy group in one molecule is represented by the following (II) The epoxy resin sealant according to claim 1, which is a compound represented by << n1 and n2 are integers from 0 to 30 >>. 7. A compound having one or more vinyl groups and one epoxy group in one molecule is represented by the following (III) The epoxy resin sealant according to claim 1, which is a compound represented by << Ph is a substituted phenyl group and n is an integer of 0 to 30. 8. A compound having one or more active hydrogens,
The epoxy resin sealant according to claim 1, which is an alcohol, a hydroxyl group-terminated polymer, and a polymer having a hydroxyl group. 9. The epoxy resin sealant according to claim 1, wherein the acid-terminated polymer is an acid-terminated polyester. 10. The epoxy resin sealant according to claim 8, wherein the hydroxyl group-terminated polymer is a hydroxyl group-terminated polyester. 11. The epoxy resin sealant according to claim 8, wherein the hydroxyl-terminated polymer is a hydroxyl-terminated polyether.