JPS61197621A - Sealant - Google Patents

Abstract

PURPOSE:A sealant excellent in moisture and heat resistances and mechanical properties, comprising a specified epoxy resin and a curing agent. CONSTITUTION:A polycyclohexene oxide polymer having vinyl groups as side chains, obtained by polymerizing 4-vinylcyclohexene-1-oxide by ring opening at -70-200 deg.C in the presence of both of an active hydrogen-containing organic compound (e.g.allyl alcohol) as an initiator and a catalyst (e.g., methylamine) is epoxidized with an oxidizing agent to obtain an epoxy resin of a softening point of 60-120 deg.C, represented by formula I (where R1 is a residue of an organic compound having 1 active hydrogen groups, n1, n2...nl are each 0-100 and their sum is 1-100, l is 1-100, A is a substituted oxycyclohexane skeleton of formula II, X is one of formulas III-V, R2 is H, alkyl, carboalkyl or carboaryl and contains at least one group of formula III). The obtained resin is mixed with a curing agent (e.g., diethylenetriamine) and, optionally, a curing catalyst, a cure accelerator, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sealant having excellent moisture resistance, heat resistance, and mechanical properties.

(Prior Art) Conventionally, electronic components such as diodes, transistors, and integrated circuits have been sealed using a thermosetting resin. This resin sealing method is economically advantageous compared to hermetic sealing methods using glass, metal, or ceramic, and is therefore widely put into practical use.

Among thermosetting resin compositions, epoxy resin compositions are most commonly used as sealing resin compositions in terms of reliability and cost.

(Problems to be Solved by the Invention) As epoxy resins for sealing, epoxy resins made by reacting phenol or novolak resin with epichlorohydrin are used, but the resin usually contains impurities such as chlorine ( Since the 0 port Irpprfl content is kept at 9 degrees Celsius, there is a problem that the liberated subchlorine ions corrode internal wiring, patterns, etc. Therefore, sealing using conventional epoxy resin sealant The above-mentioned electronic components obtained by this process suffer from functional deterioration such as a decrease in insulation properties and an increase in leakage current during use, and have the drawbacks of poor moisture resistance and reliability.

Furthermore, when a molded product is subjected to a hot/cold cycle test, open bonding wires, resin cracks, and pellet cracks occur, resulting in the problem that the product cannot function as an electronic component. Also, using a similar Kasai composition *t-)2
When a tube cage type molded product is made, reliability will be significantly degraded if it is dipped in solder during the assembly process. For these reasons, there has been a desire to develop a sealant with excellent moisture resistance, heat resistance, and mechanical properties.

The present invention was made in view of the above-mentioned drawbacks, and its object is to provide a sealant having excellent moisture resistance, high heat resistance, and excellent mechanical properties.

The present inventors have conducted extensive research to achieve the above objective "t".
As a result of stacking the epoxy resin with the structure (I), it was found that the sealant made of epoxy resin has superior moisture resistance and heat resistance compared to conventional ones, and has excellent mechanical properties. The present invention was achieved by discovering that

(Structure of the Invention) That is, the present invention comprises [(a) an epoxy resin represented by general formula (I) (b)
A sealing agent characterized by containing a curing agent for epoxy resin as an essential component.

However, R1 is an organic compound residue containing one active hydrogen.

n+1n1...nt is 0 or an integer from 1 to 100, and the sum thereof is from 1 to 100.

represents an integer from 1 to 100.

A is an oxycyclohexane skeleton having a substituent,
It is given by the following formula.

X is CM C)l*, CH=CHtCM-CHt
'o' OH,, OR1'\1 Contains one or more in the resin.

In the epoxy resin represented by the uninvented formula (I),
R is an organic substance residue having active hydrogen, and its precursor organic substance having active hydrogen includes alcohols, phenols, and carboxylic acids.

Amines, thiols, etc. are affected.

The alcohol may be a monohydric alcohol or a polyhydric alcohol.

For example, aliphatic alcohols such as methanol, ethanol, propatool, butanol, pentanol, hexanol, octatool, aromatic alcohols such as benzyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, furopylene gellicol, Diethylene glycol, 1.
3-butanediol, 1,4-butanediol, betanediol, 1.6-hexanediol, neopentyl glycol, oxypivalic acid neopentyl glycol ester, cyclohexane dimetatool, glycerin, diglycerin, polyglycerin, trimethylolpropane, trimethylol Examples include polyhydric alcohols such as ethane, pentaerythritol, and dipentaerythritol.

Examples of phenols include phenol, cresol, catechol, pyrogallol, hydroquinone, hydroquinone monomethyl ether, bisphenol A, bisphenol F, 4,4'-dihydroxybenzophenone, bisphenol S, phenol resin, and cresol novolac resin.

Carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, fatty acids from animal and vegetable oils, fumaric acid, maleic acid, a7abic acid, dodecanoic acid, trimellitic acid, ζ°romellitic acid, polyacrylic acid, phthalic acid, and inphthalic acid. acids, terephthalic acid, etc. Also included are compounds containing both a hydroxyl group and a carboxylic acid, such as lactic acid, citric acid, and oxycaproic acid.

Examples of amines include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, cyclohexylamine, octylamine, dodecylamine, 4,4'-diaminodiphenylmethane, isophoronediamine, toluenediamine, hexamethylenediamine, xylenediamine, diethylenetriamine. , triethylenetetramine, ethanolamine, etc.

Examples of thiols include mercaptans such as methyl mercaptan, ethyl mercaptan, propyl mercaptan, and huminyl mercaptan, mercaptopropionic acid or polyhydric alcohol esters of mercaptopropionic acid, examples:
Examples include ethylene glycol dimethyl captopropionic acid ester, trimethylolpropane trimercabutogropionic acid ester, and pentaerythritol pentamercaftprobionic acid ester.

Furthermore, other active hydrogen-containing compounds include hapolyvinyl alcohol, polyvinyl acetate partial hydrolyzate, starch, cellulose, cellulose acetate, cellulose acetate butyrate, hydroxyethyl cellulose,
Examples include acrylic polyol resin, styrene allyl alcohol copolymer resin, styrene-maleic acid copolymer resin, alkyd resin, polyester polyol resin, polyester carboxylic acid resin, polycaprolactone polyol resin, polypropylene polyol, polyetramethylene glycol, and the like.

In addition, the compound having active hydrogen may have an unsaturated double bond in its skeleton, and specific examples include allyl alcohol, acrylic acid, methacrylic acid, 3-cyclohexenemethanol, and tetradolphthalic acid. There is. The unsaturated double bonds of these compounds may also have an epoxidized structure.

ntlnt in general formula (I)...nt is 0
Alternatively, it is an integer from 1 to 100, but if it is 100 or more, the resin will have a high melting point and will be difficult to handle and cannot be used in practice.

t is an integer from 1 to 100.

Among the substituents X of A in formula (I1, that is, in the present invention, the substituents X are mainly

Specifically, the epoxy resin (represented by formula I3) used as the sealing agent of the present invention is a polyamide resin obtained by ring-opening polymerization of 4-vinylcyclohexene-1-oxide using an organic compound having active hydrogen as an initiator. It can be produced by epoxidizing an ether resin, that is, a polycyclohexene oxide polymer having a vinyl group * with an oxidizing agent such as a peracid.

4-Vinylcyclohexene-1-oxide is obtained by partially epoxidizing vinylcyclohexene obtained by a dimerization reaction of butadiene with peracetic acid.

It is preferable to use a catalyst when polymerizing 4-vinylcyclohexene-1-oxide in the presence of active hydrogen.

Catalysts include amines such as methylamine, ethylamine, propylamine, and piperazine; organic basic acids such as pyridines and imidazoles; organic acids such as formic acid, acetic acid, and propionic acid; inorganic acids such as sulfuric acid and hydrochloric acid; and sodium methylate. Alcolades of alkali metals such as KOH, Na
Alkali such as OH, BFs, ZnC, A, C, SiC. Lewis acids such as or complexes thereof, and organometallic compounds such as triethylaluminum and diethylzinc.

These catalysts can be used in an amount of 0.01 to 10%, preferably 0.1 to 5%, based on the reactants. The reaction temperature is -70 to 200°C, preferably -30°C to 10°C.
It is 0°C.

The reaction can also be carried out using a solvent. A solvent containing active hydrogen cannot be used.

i.e., ketones such as acetone, methyl ethyl ketone, methyl imbutyl ketone, benzene, toluene,
Aromatic solvents such as xylene, ethers, aliphatic hydrocarbons, esters, etc. can be used.

Now, the polycyclohexene oxide polymer having a vinyl group side chain synthesized in this way is epoxidized, and in order to produce the epoxy resin of the formula (I1) which is the sealant of the present invention, peracids, hydroperoxides, Either can be used.

As peracids, performic acid, peracetic acid, perbenzoic acid, trifluoroperacetic acid, etc. can be used.

Among these, peracetic acid is a particularly preferred epoxidizing agent because it is industrially available at low cost and has high stability.

As the hydroperoxides, hydrogen peroxide, tert-butyl hydroperoxide, cumene peroxide, etc. can be used.

A catalyst can be used during epoxidation if necessary. For example, in the case of peracid, an alkali such as soda carbonate or an acid such as @acid can be used as a catalyst. In the case of hydroperoxides, the catalytic effect can be obtained by using a mixture of tungstic acid and caustic soda with hydrogen peroxide, an organic acid with hydrogen peroxide, or molybdenum hexacarbonyl with tert-butyl hydroperoxide. .

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

Depending on the conditions of the epoxidation reaction, at the same time as the epoxidation of the olefin bond, a side reaction occurs with the substituents in the raw materials or the epoxidizing agent, etc. As a result, modified substituents are generated, which are included in the target compound. The ratio of the three substituents in the compound is determined by the type of epoxidizing agent, the molar ratio of the epoxidizing agent to the bond, and the reaction conditions.

For example, when the epoxidizing agent is peracetic acid, the modified substituent mainly has the structure shown below, and is generated from the produced epoxy group and the by-produced acetic acid.

The target compound can be extracted from the reaction solution by ordinary chemical industrial means such as rough concentration.

Further, the epoxy resin used in the sealant of the present invention can be mixed with other epoxy resins as long as the properties of the composition are not impaired. Here, other epoxy resins may be any commonly used epoxy resins, such as epibis type epoxy, bisphenol F epoxy, novolac epoxy, alicyclic epoxy, and epoxy diluents such as styrene oxide and butyl glycidyl ether. is included.

Further, the epoxy resin represented by formula (I) alone or after being mixed with other epoxy resins preferably has a solid state at room temperature, preferably a softening point of 60 to 120°C.

The curing agent used in the present invention may be any curing agent used for known epoxy resins as long as it does not impair the performance of the nine parts after sealing, such as amines, polyamide resins, acid anhydrides, polymercaptan resins, and novolac resins. , dicyandiamide, and amine complexes of boron trifluoride.

Here, the amines include the following.

Aliphatic polyamines such as diethylenetriamine, triethylenenatamine, menzendiamine, metaxylylenediamine, bis(4-amino-3-methylcyclohexyl)methane, adducts of the aliphatic polyamines and known epoxy compounds, and acrylonitrile. reactant with ketone.

metaphenynondiamine, diaminodiphenylmethane,
Aromatic polyamines such as diaminodiphenylsulfone and diaminodiphenylsulfide, and adducts of the aromatic polyamines and known epoxy compounds.

Secondary and tertiary amines and salts thereof such as tris(dimethylaminemethyl)phenol, piperidine, imidazole and derivatives thereof.

Polyamide resins include reactants of fatty acids, such as fatty acids, dimer acids, trimer acids, and aliphatic polyamines.

Acid anhydrides include the following:

Phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl anhydride Acid anhydrides such as nadic acid, cono-phosphoric anhydride, dodecenylsuccinic anhydride, succinic anhydride, and mixtures of the above-mentioned acid anhydrides.

Novolac resins include low molecular weight resinous products made by the condensation of phenol or mixtures of phenol and cresol, dihydroxybenzene, and formaldehyde.

Amine complexes of boron trifluoride include monoethylamine, piperidine, aniline, butylamine, dibutylamine, cyclohexylamine, dicyclohexylamine,
Includes complexes of low molecular weight amine compounds such as tributylamine and triethanolamine and boron trifluoride.

Other curing agents include salts such as diazonium salts, iotonium salts, bromonium salts, and sulfinium salts of super strong acids such as boron tetrafluoride, phosphorus hexafluoride, and arsenic hexafluoride. Also, among these curing agents, aliphatic polyamines,
Aromatic polyamines, polyamide resins, and borimercagutan resins can be used as a mixture in any proportion, and can be used alone or in combination with a curing accelerator for the purpose of adjusting the curing rate. Here, the aforementioned secondary and tertiary amines can be used as the curing accelerator.

The acid anhydride can be used as it is, but a curing catalyst and a curing accelerator can also be used together for the purpose of adjusting the curing rate and improving the physical properties of the cured product.

Here, the curing catalysts used are the secondary and g3 amines, and the tin octylate curing accelerators include water, ethanol, glopanol, alcohols such as inglono(nol, cyclohexanol, and ethylene glycol), 6m, phlopionic acid, and tin octylate. )/[, carboxylic acids such as hexahydrophthalic acid, and amines having hydrogen saving properties such as ethylenediamine and diethylenetriamine.

The novolak resin can be used alone or in combination with a curing catalyst for the purpose of adjusting the curing rate. Here, the curing catalysts are the aforementioned secondary and tertiary amines.

Dicyandiamide can be used alone or in combination with a curing catalyst for the purpose of adjusting the curing rate. Here, the curing catalysts are the aforementioned secondary and tertiary amines.

The amine complex of boron trifluoride can be used alone or in combination with a curing rate regulator to adjust the curing rate.

...Here, any curing rate g regulator may be used as long as it can be used for conventional epoxy resins.
Specifically, for example, carboxylic acids, amines, acetylacetone complexes of metals, organometallic compounds of metals such as titanium and tin, glycols, organoboron compounds, and the like are included.

Although the curing agent used in the sealant of the present invention includes the above-mentioned curing agents, novolak-based curing agents are particularly preferred.

The uninvented sealing agent contains an epoxy resin represented by formula (I) and a curing agent for epoxy resin as essential components, and optionally a filler, a coupling agent, and a mold release agent.

Flame retardants, pigments, etc. can be used in combination, and it is particularly desirable to use fillers in combination.

Examples of the filler include alumina, silica powder, antimony trioxide, Merck, titanium white, calcium carbonate, clay, red iron oxide, asbestos mica, glass fiber, and carbon fiber, with alumina and silica powder being particularly preferred. The blending ratio of the inorganic filler is preferably 25 to 90% by weight of the resin. If it is less than 25% by weight, the moisture resistance, heat resistance and mechanical properties will not be improved, and the ζ bulk will be large compared to 90% by weight, and the moldability will be poor, making it unsuitable for practical use.

A general method for preparing the sealant of the present invention as a molding material is to sufficiently uniformly mix a raw material composition containing an epoxy resin, a curing agent, etc. in a predetermined composition ratio using a mixer, etc. Further, the mixture can be melt-mixed using hot rolls or mixed using a kneader, etc., and then cooled and solidified and pulverized to an appropriate size to obtain a molding material t-.

When the sealant prepared in this way is used for encapsulating electronic components such as diodes, transistors, integrated circuits, capacitors, and resistors, various molding methods are widely used, such as low-pressure transfer molding. There are many methods such as molding method, injection molding method, compression molding method, Shoya method, etc., and it is applicable to almost all of these soil molding techniques.

(Effects of the Invention) The sealant of the present invention has good moisture resistance, high heat resistance, excellent mechanical properties, and good molding workability, so when used for sealing electronic and electrical parts, etc. sufficient reliability can be obtained.

(Examples of the Invention) The present invention will be further explained in detail with reference to Examples below.

Synthesis Example 1 Allyl alcohol 58f (1 mol), 4-vinylcyclohexene-1-oxide 868f (7 mol) and B
Fs Nieteller) 4.7f were mixed at 60°C and reacted until the conversion of 4-vinylcyclohexene-1-oxide reached 98% or more as determined by gas chromatography analysis. Ethyl acetate was added to the resulting reaction crude liquid, washed with water, and then the ethyl acetate layer was concentrated to obtain a viscous liquid.

In the infrared absorption spectrum of the product, the absorption due to the epoxy group at 810,850 cm-, which was observed in the raw material, was eliminated, and the absorption due to the ether bond was present at 1080.11503''1. Gas chromatography analysis revealed that the product The allyl alcohol in the substance is in trace form, but the infrared absorption spectrum shows an OR of 3450 cIn-'.
Based on the absorption of the group, it was confirmed that this compound has the structure shown by the following formula.

492t of this compound was converted into ethyl acetate and charged into a reactor, and 395f of peracetic acid was added as an ethyl acetate bath solution.
dripped over time. During this time, the reaction temperature was maintained at 40°C. After the addition of peracetic acid, the mixture was further aged at 40°C for 6 hours.

Add 1!1:ethyl acid to the reaction crude solution and add 41% of sodium carbonate.
Wash with alkaline water containing 6t, then thoroughly wash with distilled water.

The ethyl acetate layer was concentrated to obtain a viscous transparent liquid.90 This compound had an oxirane oxygen content of 9.27% and a characteristic absorption due to the epoxy group at 1260C11 was observed in the infrared absorption spectrum. Furthermore, absorption due to residual vinyl groups was observed at 1640 cm-', and further, this compound 492t and peracetic acid g395f were reacted in the same manner as in Synthesis Example 1 to obtain a viscous, transparent liquid.

This compound had an oxirane oxygen content of 9.27%, and a characteristic absorption due to the epoxy group was observed at 1260 cm-' in the infrared absorption spectrum. Furthermore, since absorption due to residual vinyl groups is observed in 1640-1 and absorption due to CO- groups is observed, this compound has a structure of the general formula (R1: glycidyl group or allyl group).

It was confirmed that n=7 on average, including a group in which a portion of acetic acid was added to an epoxy group).

Synthesis Example 2゜By the same operation as in Example-1, trimethylol gopan x
s4t, 4-vinylcyclohexene-1-oxide 1
863f was reacted to obtain a viscous liquid product.

In the infrared absorption spectrum of the product, the absorption due to the epoxy group at 810.850ctn-' observed in the raw material has disappeared, the absorption due to the ether bond exists at 1080.1150t1*-', and the NMR
From the analysis, it was confirmed that this compound has the structure shown by the following formula111
, nt, n, = average 5 Further, this compound fE573f and peracetic acid 387f were reacted in the same manner as in Example 1 to obtain a viscous transparent liquid.

This compound had an oxirane oxygen enrichment rate of 9.03%, and a characteristic absorption due to the epoxy group was observed at 1260 cm-' in the infrared absorption spectrum. Furthermore, 1640an-'
Absorption due to residual vinyl groups is observed in 3450c.
This compound has the structure of general formula (I) (R1: iJ methylolpropane residue t=3, n
+, flu@nm=5 on average, containing one part of a group in which acetic acid was added to an epoxy group).

Example 2゜100 parts by weight of the epoxy resin synthesized in Synthesis Example-2, Novolakya Phenol LT Resin (PSF-4300゜Gunei Chemical Industry vII) 503, 2-Undecylimidazole (C, Z, Shikoku) Chemical Industries) 1 part by weight.

Mix 400 parts by weight of fused silica powder at room temperature to form 9G~9
After kneading and cooling at 5C, the mixture was pulverized to obtain a molding material.

The obtained molding material was made into a tablet, preheated, and injected into a metal molding chamber heated to 170° C. by transfer molding, and cured to obtain a molded product. The properties of this molded product were measured,
The results are shown in Table 1.

Comparative Example-1 Talesol novolac epoxy resin (epoxy equivalent: 20
1) 100 parts by weight of novolac type phenolic resin (PS
F-4300, Gunei Chemical Industry Co., Ltd.) 50 parts by weight, 2-cundecylimidazole (C1+Z.

1 part by weight of Shikoku Kasei Kogyo) and 400 parts by weight of fused silica powder were mixed at room temperature and the molding material was obtained under the same conditions as Example-1. The properties of the products were measured and the results are also shown in Table 1.

Example-2 100]i parts of the epoxy resin synthesized in Synthesis Example-2, 5.0 parts by weight of novolac type phenol resin (PSF'-4300° Gunei Chemical Industry Co., Ltd.), 2-undecylimidazole (CIIZ, Shikoku) Chemical Industries) 1 part by weight.

One part of fused silica powder 4001i was mixed at room temperature to obtain a molded article under the same conditions as in Example-1. The mechanical properties of this molded article were measured, and the results are also shown in Part 1.

Table 1 *1: The number of cracks was determined by embedding a 25x25x3m+1 copper plate in the bottom of a 30x25x5 molded product, and measuring -40°C and +2001? : The resin was placed in a constant temperature bath for 30 minutes each, and the number of resin cracks was measured after repeating 15 cycles.

*2: An electrical component having two aluminum wirings was transfer-molded at 170°C for 3 minutes using the soil-compatible resin composition, and then cured at 180°C for 8 hours. The 100 sealed electrical components obtained in this way were subjected to a moisture resistance test in high-pressure steam at 120°C.
The time required for 0% disconnection (occurrence of defects) was measured.

As is clear from Table 1, the uninvented sealant is excellent in moisture resistance, heat resistance, and crank resistance.

Claims (1)

[Claims] (a) Epoxy resin represented by general formula (I) (b)
A sealant characterized by containing a curing agent for epoxy resin as an essential component. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) However, R_1 is an organic compound residue with 1 active hydrogen. n_1, n_2... n_l is 0 or an integer from 1 to 100, and the sum thereof is from 1 to 100. l represents an integer from 1 to 100. A is an oxycyclohexane skeleton having a substituent,
It is expressed by the following formula. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ X has ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (R_2 is any one of H, alkyl group, carboalkyl group, carboaryl group), but ▲ mathematical formula, There are chemical formulas, tables, etc. At least one ▼ is contained in the resin represented by formula (I).