JP2001114986A - Epoxy resin composition and cured product thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition that is excellent in moldability and, in spite of containing no halogen-containing flame retardant or antimony compound, can give a cured product being excellent in flame retardancy, having low hygroscopicity, and being excellent in mechanical strengths, heat resistance, solder reflow, etc., and is therefore suited for e.g. sealing electronic components. SOLUTION: This composition contains an epoxy resin and a curing agent and further contains 1-100 pts.wt. per 100 pts.wt. epoxy resin, polycyclic aromatic substance, such as a polycyclic aromatic compound, a pitch, or an aromatic resin, having a softening point of 10-250 deg.C, a carbon residue rate of at least 10 wt.% (as measured by heating to 700 deg.C in a nitrogen stream), and a fraction of aromatics (fa) of at least 0.85 in a 13C-nuclear magnetic resonance spectrum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is excellent in flame retardancy, excellent in moldability such as rapid curability and fluidity, and has excellent mechanical strength and heat resistance even without containing a halogen-based flame retardant or an antimony compound. The present invention relates to an epoxy resin composition which gives a cured product excellent in properties, low moisture absorption, solder reflow properties and the like.

[0002]

2. Description of the Related Art A resin composition containing an epoxy resin as a main component is widely used in electric and electronic fields such as casting, sealing, and laminates. Epoxy resin compositions used in the electric and electronic fields have flame retardant standards set around the world from the viewpoint of ensuring safety against fire.
A wide variety of flame retardants are used to satisfy this flame retardant standard.

[0003] In the field of semiconductors, in particular, the transition from the conventional pin insertion method to the surface mounting method is progressing as a method of mounting components on a printed circuit board. There is a demand for materials for parts sealing and materials for printed circuit boards. That is, in the surface mounting method, since the entire package and the entire printed board are heated to the solder temperature, package cracks due to thermal shock and poor reliability of the printed board are becoming serious problems. Furthermore, in recent years, high integration of semiconductor devices, increase in device size, and miniaturization of wiring width are also rapidly progressing.
These problems are becoming more serious.

In particular, epoxy resin compositions used for electronic materials satisfy flame retardant standards and are excellent in physical properties such as mechanical strength, heat resistance, low moisture absorption, and solder reflow properties. Conventionally, a brominated flame retardant or a combination of a brominated flame retardant and antimony trioxide has been mostly used as a flame retardant. However, in recent years, from the viewpoints of environment, safety, and improvement of reliability as a material, a flame-retarding method without using a halogen-based flame retardant and an antimony compound, that is, a flame retardant has been desired.

[0005] As a method of flame retardation without using a halogen-based flame retardant or an antimony compound, for example, JP-A-10-27
9813, there is a method using a hydrated metal compound such as aluminum hydroxide and magnesium hydroxide. However, in this method, the amount of the hydrated metal compound must be increased in order to satisfy the flame retardant specification. Therefore, physical properties such as solder reflowability and moisture resistance reliability are likely to be reduced. As another method, for example, Japanese Patent Application Laid-Open No. 9-2
As described in U.S. Pat. No. 35449, there is a method using an organic phosphoric acid ester. However, even in this method, the amount of addition must be increased in order to satisfy the flame retardant standard, and the solder reflow property and the moisture resistance There are problems such as deterioration of physical properties such as properties, mold contamination due to volatility, and generation of harmful gases such as phosphine gas. Also, in the method using a silicon compound, the addition amount must be increased in order to satisfy the flame retardant standard, and there is a problem in that physical properties such as solder reflowability and moisture resistance are deteriorated.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an epoxy resin composition having excellent flame retardancy and rapid curability, fluidity, etc., even without containing a halogen-based flame retardant or an antimony compound. It gives a cured product with excellent moldability and excellent mechanical strength, heat resistance, low moisture absorption, solder reflowability, etc., especially for sealing electronic parts such as surface mount type semiconductor elements, printed circuit boards, etc. An object of the present invention is to provide an epoxy resin composition.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and found that the softening point and the nitrogen gas flow under a nitrogen stream were reduced to 70%.
A polycyclic aromatic substance having a specific range of a residual carbon ratio at a temperature of 0 ° C. and an aromatic index (fa) in ¹³ C-nuclear magnetic resonance spectrum within a specific range is used as a flame retardant in an epoxy resin composition. It has been found that the above objects can be achieved by adding the components in a ratio, and the present invention has been completed.

That is, the present invention relates to an epoxy resin composition containing (A) an epoxy resin and (B) a curing agent, which has a softening point of 10 to 250 ° C. and a residual when heated to 700 ° C. in a nitrogen stream. The coal content is 10wt% or more, and ^13C
-Characterized in that it contains 1 to 100 parts by weight of a polycyclic aromatic substance having an aromatic index (fa) of 0.85 or more in a nuclear magnetic resonance spectrum as a flame retardant per 100 parts by weight of the epoxy resin. An epoxy resin composition and a cured product obtained by curing the epoxy resin composition.

The epoxy resin composition of the present invention contains (A) an epoxy resin and (B) a curing agent, but contains a polycyclic aromatic substance contained as a flame retardant. This polycyclic aromatic material has a softening point of 10 to 250 ° C. and a residual carbon ratio of 10 wt% when heated to 700 ° C. under a nitrogen stream.
That is, the aromatic index (fa) in the ¹³ C-nuclear magnetic resonance spectrum needs to be 0.85 or more, which can be a single compound, a mixture, or a resinous material.

The polycyclic aromatic substance (hereinafter also referred to as the present flame retardant) used as the flame retardant of the present invention is not limited as long as it satisfies the above requirements such as softening point. Polycyclic aromatic hydrocarbons, high-molecular-weight heteroheteropolycyclic aromatic compounds, or high-boiling substances or distillation residues mainly containing alkyl and hydroxy-substituted products thereof, or resins and oligomers obtained from these and a crosslinking agent And the like. Preferably, synthetic pitch obtained by polycondensation of coal-based heavy oil such as coal tar or coal liquefied oil, pitches as distillation residue, and condensed polycyclic hydrocarbons such as naphthalene using a catalyst, petroleum-based In addition to the heavy oil and distillation residue of the reformed oil, for example, asphalts and the like, there are polycyclic aromatic resins and oligomers obtained from a polycyclic aromatic compound and a crosslinking agent.

The present flame retardant is preferably an aromatic hydrocarbon or a substance mainly composed of an aromatic hydrocarbon or a raw material derived from the same. However, a hetero atom such as nitrogen, oxygen or sulfur is contained in the aromatic ring. Includes cases in which it is included. In the case of a mixture such as a distillation residue such as pitch, a component other than the aromatic compound may be mixed, or a heterocyclic compound may be mixed.

[0012] Pitches are obtained by removing coal tar generated during carbonization of coal, for example, by distillation at 300 to 370 ° C, and further distilling the residue under specified conditions or solvent separation. It is manufactured by removing specific components such as solvent-insoluble components by centrifugation or centrifugal sedimentation, or by performing heat treatment or other treatment. Petroleum heavy oil is a residue obtained by distilling and refining crude oil to remove components such as naphtha, gasoline, kerosene, and light oil.Furthermore, this residue or fraction is distilled or reformed under specified conditions. And the like. As the polycyclic aromatic resin or oligomer, a polycyclic aromatic substance such as naphthalene, anthracene, or pyrene can be used to form an oligomer by using a crosslinking agent such as p-xylene glycol or formaldehyde.
It is manufactured by, for example, For example, p-xylene glycol is charged under the condition of an excess of a polycyclic aromatic compound such as pyrene, and in the presence of an acid catalyst such as p-toluenesulfonic acid, 10 to 250 ° C, preferably 100 to 250 ° C.
A method of reacting at 200 ° C. for 1 to 10 hours is exemplified. After completion of the reaction, the target substance can be obtained by removing the catalyst by a method such as washing with water as necessary. The molecular weight of the polycyclic aromatic oligomer can be easily adjusted by changing the molar ratio of the polycyclic aromatic compound and the crosslinking agent when they are reacted. That is, the higher the molar ratio of the crosslinking agent to the polycyclic aromatic compound, the higher the softening point and viscosity of the obtained polycyclic aromatic oligomer. Also, as the molar ratio is smaller, the viscosity of the polycyclic aromatic oligomer decreases, but the amount of unreacted polycyclic aromatic compound during synthesis increases, and the production efficiency of the resin decreases. The above molar ratio must be practically 2 mol or less, and is preferably in the range of 0.2 to 0.7 mol. If the amount is less than 0.2 mol, the amount of unreacted polycyclic aromatic compound increases, which is not industrially preferable.

The flame retardant of the present invention has a softening point in the range of 10 to 250.
° C, preferably 30 to 150 ° C. Those having a softening point lower than this generally have a low molecular weight and are easily decomposed during combustion to generate a combustible substance, so that an epoxy resin composition excellent in flame retardancy and a cured product cannot be provided. . On the other hand, those having a higher softening point generally have a high molecular weight. For example, when used in an epoxy resin composition for sealing electronic components, the viscosity of the epoxy resin composition increases, so that an inorganic filler is used. Cannot be increased, and a cured product having excellent solder reflow properties cannot be obtained. Also, for example, when used in an epoxy resin composition for a printed circuit board, the dispersibility in the epoxy resin composition is reduced, thereby lowering workability, and an epoxy resin composition excellent in flame retardancy, and Can not give cured product.

When the temperature of the flame retardant is raised to 700 ° C. under a nitrogen stream, the range of the residual carbon ratio is at least 10 wt%, preferably at least 15 wt%. Those having a residual carbon ratio lower than this generally have a low molecular weight and are easily decomposed during combustion to easily generate a combustible substance, so that an epoxy resin composition having excellent flame retardancy and a cured product can be provided. Can not.

The flame retardant has an aromatic index range of at least 0.85, preferably at least 0.90, in the ¹³ C-nuclear magnetic resonance spectrum. Those having an aromatic index lower than this generally have a high proportion of aliphatic side chains and are easily decomposed during combustion to produce a combustible substance, so that an epoxy resin composition excellent in flame retardancy, and a cured product Can not give.

The content of the present flame retardant used as a flame retardant in the epoxy resin composition of the present invention is as follows.
The amount is 1 to 100 parts by weight, preferably 2 to 20 parts by weight with respect to 0 parts by weight. If it is less than this, the effect of improving the flame retardancy of the epoxy resin composition is small, and if it is more than this, molding such as deterioration of curability, mechanical strength, heat resistance, etc., bleeding on the surface of the cured molded product, etc. This leads to a decrease in sex. As the flame retardant, the flame retardant alone or may be used in combination with another flame retardant, but it is preferable that all or the main flame retardant component of the flame retardant component,
In addition, it is preferable that a halogen-based flame retardant and an antimony-based flame retardant are not used. The polycyclic aromatic substances used as the present flame retardant may be used alone or in combination. In addition, when the present flame retardant is a resin or an oligomer, etc., in addition to the function as the flame retardant, it may have other functions, but is understood to mean that it fulfills the main flame retardant function in the composition. .

The epoxy resin (A) used in the epoxy resin composition of the present invention is not particularly limited.
An epoxy resin having two or more epoxy groups in the molecule can be used. Examples include bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-
Bivalent phenols such as biphenol, hydroquinone and resorcin; or trivalent or higher valent such as tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane and phenol novolak There are glycidyl ether compounds derived from phenols and the like, but o-cresol-novolak epoxy resins and aralkyl epoxy resins are preferably used. These epoxy resins can be used alone or in combination of two or more.

The o-cresol-novolak type epoxy resin has a methylene group structure, and a polyhydric phenol resin is obtained by reacting o-cresol with formaldehyde as a crosslinking agent. It is produced by reacting with epichlorohydrin. The aralkyl-type epoxy resin is produced by reacting an aralkyl-type polyvalent phenol resin with epichlorohydrin. The aralkyl polyhydric phenol resin is obtained by reacting a phenolic hydroxyl group-containing compound having an alkyl-substituted or unsubstituted benzene ring or a naphthalene ring with a specific aromatic crosslinking agent. As the phenolic hydroxyl group-containing compound, for example,
Phenol, o-cresol, m-cresol, p-cresol, ethylphenols, isopropylphenols,
There are benzene ring-containing compounds such as tertiary butylphenol, phenylphenols, catechol, resorcin, hydroquinone, and naphthalene ring-containing compounds such as 1-naphthol, 2-naphthol and naphthalene diols.

(A) The preferred softening point of the epoxy resin is in the range of 50 ° C. to 120 ° C., and the more preferred softening point is in the range of 60 ° C. to 100 ° C. If it is lower than this, the heat resistance of the epoxy resin composition is reduced,
If it is higher than this, the workability is reduced due to the increase in viscosity.

The curing agent (B) used in the epoxy resin composition of the present invention is not particularly limited, and a known epoxy resin curing agent can be used, and is preferably a polyhydric phenolic compound. . As the polyvalent phenolic compound, a compound known as an epoxy resin curing agent can be used, and a polyvalent phenolic compound having an aralkyl-type structure can be used. The polyhydric phenolic compound having an aralkyl-type structure is produced by reacting a phenolic hydroxyl group-containing compound having an alkyl-substituted or unsubstituted benzene ring or a naphthalene ring with a specific aromatic crosslinking agent.

Specific examples of the curing agent (B) include bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol,
Divalent phenols such as 2'-biphenol, hydroquinone, resorcin, catechol, naphthalene diols, or tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane Phenols such as phenol novolak, o-cresol novolak, naphthol novolak, and polyvinyl phenol; and phenols, naphthols or bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, and 4,4 '. -Biphenols such as biphenol, 2,2'-biphenol, hydroquinone, resorcinol, catechol and naphthalene diols, and formaldehyde, acetaldehyde, benzaldehyde, p-
Polyvalent synthesized by reaction with a cross-linking agent such as hydroxybenzaldehyde, p-xylylene glycol, p-xylylene glycol dimethyl ether, divinylbenzene, diisopropenylbenzene, dimethoxymethylbiphenyls, divinylbiphenyl, diisopropenylbiphenyls Phenolic compounds are included. These curing agents can be used alone or in combination of two or more.

The preferred softening point range of the curing agent, for example, a polyhydric phenolic compound is in the range of 40 ° C. to 150 ° C., more preferably in the range of 50 ° C. to 120 ° C. If it is lower than this, the heat resistance of the epoxy resin composition will decrease, and if it is higher than this, the workability will decrease due to an increase in viscosity.

Specific aromatic cross-linking agents used to obtain polyhydric phenolic compounds include those having a benzene skeleton and those having a biphenyl skeleton. The compound having a benzene skeleton may be any of an o-form, an m-form and a p-form, but is preferably an m-form or a p-form. Specifically, p-xylylene glycol, α, α ′
-Dimethoxy-p-xylene, α, α'-diethoxy-
p-xylene, α, α′-diisopropoxy-p-xylene, α, α′-dibutoxy-p-xylene, m-xylylene glycol, α, α′-dimethoxy-m-xylene, α, α′- Diethoxy-m-xylene, α, α'-
Diisopropoxy-m-xylene, α, α′-dibutoxy-m-xylene, 1,4-di (2-hydroxy-2-
Ethyl) benzene, 1,4-di (2-methoxy-2-ethyl) benzene, 1,4-di (2-ethoxy-2-ethyl) benzene, 1,4-di (2-isopropoxy-2-
Ethyl) benzene, 1,4-di (2-hydroxy-2-
Propyl) benzene, 1,4-di (2-methoxy-2-
Propyl) benzene, 1,4-di (2-ethoxy-2-
Propyl) benzene, 1,4-di (2-isopropoxy-2-propyl) benzene, 1,3-di (2-hydroxy-2-ethyl) benzene, 1,3-di (2-methoxy-2-ethyl) ) Benzene, 1,3-di (2-hydroxy-2-propyl) benzene, 1,3-di (2-methoxy-2-propyl) benzene, 1,2-divinylbenzene, 1,3-divinylbenzene, 1,4-divinylbenzene, 1,2-di (2-propenyl) benzene, 1,3
-Di (2-propenyl) benzene, 1,4-di (2-propenyl) benzene and the like.

Further, those having a biphenyl skeleton include 4,4'-dihydroxymethylbiphenyl,
4'-dihydroxymethylbiphenyl, 2,2'-dihydroxymethylbiphenyl, 4,4'-dimethoxymethylbiphenyl, 2,4'-dimethoxymethylbiphenyl, 2,2'-dimethoxymethylbiphenyl, 4,4 '
-Diisopropoxymethylbiphenyl, 2,4'-diisopropoxymethylbiphenyl, 2,2'-diisopropoxymethylbiphenyl, 4,4'-dibutoxymethylbiphenyl, 2,4'-dibutoxymethylbiphenyl,
2,2'-dibutoxymethylbiphenyl, 4,4'-di (2-hydroxy-2-ethyl) biphenyl, 4,4 '
-Di (2-methoxy-2-ethyl) biphenyl, 4,
4′-di (2-ethoxy-2-ethyl) biphenyl,
4,4'-di (2-isopropoxy-2-ethyl) biphenyl, 4,4'-di (2-hydroxy-2-propyl) biphenyl, 4,4'-di (2-methoxy-2-propyl) Biphenyl, 4,4'-di (2-ethoxy-2
-Propyl) biphenyl, 4,4'-di (2-isopropoxy-2-propyl) biphenyl, 2,4'-di (2
-Hydroxy-2-ethyl) biphenyl, 2,4'-di (2-methoxy-2-ethyl) biphenyl, 2,4'-
Di (2-hydroxy-2-propyl) biphenyl, 2,
4′-di (2-methoxy-2-propyl) biphenyl,
2,4'-divinylbiphenyl, 2,2'-divinylbiphenyl, 4,4'-divinylbiphenyl, 2,4'-
Di (2-propenyl) biphenyl, 2,2′-di (2-propenyl) biphenyl, 4,4′-di (2-propenyl) biphenyl and the like. Substitution positions of a functional group such as a methylol group for biphenyl are 4,4′-positions,
Any of the 2,4'-position and the 2,2'-position may be used, but a desirable compound as the condensing agent is a 4,4'-isomer, and the total 4,4'-isomer is contained in 50% by weight or more in all the crosslinking agents. Are particularly preferred. If the amount is less than this, there are disadvantages such as a decrease in curing speed when curing the synthesized resin, and an obtained cured product becomes brittle.

The epoxy resin composition of the present invention can be obtained by mixing (A) an epoxy resin, (B) a curing agent and the present flame retardant by a known method. The present flame retardant may be added as it is at the time of compounding the epoxy resin composition, or may be melt-mixed in advance with a part of the compound such as an epoxy resin and a curing agent, and the composition may be added in the form of a molten mixture. It is used by the method of adding at the time of compounding. However, in order to improve various properties mainly on flame retardancy, it is desirable that the degree of dispersion of the present flame retardant in the epoxy resin composition is higher. It is desirable to melt-mix them in advance and add them in the form of a molten mixture when compounding the composition.

The resin composition of the present invention may further comprise a curing accelerator, an inorganic filler, a modifier,
Other additives can be blended.

Known curing accelerators can be used. Examples include amines, imidazoles, organic phosphines, Lewis acids and the like. Specifically, 1,8-diazabicyclo (5,4,0) undecene-7,
Tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris (dimethylaminomethyl) phenol, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-1-methylimidazole, and 2-hepta Imidazoles such as decyl imidazole, organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine, tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate, and tetrabutylphosphonium・ Tetra-substituted phosphonium such as tetrabutyl borate ・ Tetra-substituted borate, 2-ethyl-14-methylimidazole ・ Tetraf And tetraphenylboron salts such as phenylborate and N-methylmorpholine / tetraphenylborate. The addition amount is usually in the range of 0.2 to 10 parts by weight based on 100 parts by weight of the epoxy resin.

As the inorganic filler, silica, alumina,
Powders of zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, mullite, titania, etc., or spherical beads thereof, etc. Or two or more of them can be used in combination.

One of the objects of the present invention is to seal electronic components such as surface-mounted semiconductor elements. In such a case, it is desirable to contain a high content of an inorganic filler. From the viewpoint of increasing the filling of the inorganic filler, spherical fused silica is preferably used. Usually, silica is used in combination with one having several types of particle size distribution. The average particle size of the combined silica ranges from 0.5 microns to 100 microns. The blending amount of the inorganic filler is preferably at least 70 wt%, more preferably at least 80 wt%. If the amount is less than this, the effect of improving flame retardancy and solder reflowability is small.

Further, thermoplastic oligomers can be added to the resin composition of the present invention from the viewpoint of improving the fluidity during molding and improving the adhesion to lead frames, copper foils and the like. Examples of thermoplastic oligomers include C5 and C9 petroleum resins, styrene resins, indene resins,
Indene / styrene copolymer resin, indene / styrene /
Examples thereof include a phenol copolymer resin, an indene / coumarone copolymer resin, and an indene / benzothiophene copolymer resin. The addition amount is usually in the range of 2 to 30 parts by weight based on 100 parts by weight of the epoxy resin. Further, if necessary, the resin composition of the present invention, carnauba wax,
Release agents such as ester waxes, coupling agents such as epoxy silane, amino silane, ureido silane, vinyl silane, alkyl silane, organic titanate, aluminum alcoholate, coloring agents such as carbon black, low stress agents such as silicone oil, Lubricants such as higher fatty acids and metal salts of higher fatty acids can be blended.

In general, the raw material departments described above are sufficiently mixed by a mixer or the like with a predetermined blending amount of the raw material departments, kneaded with a mixing roll, an extruder, etc., and cooled and pulverized. , Molding material family can be prepared. As a method for sealing an electronic component using the molding material obtained by the present invention, a low pressure transfer molding method is the most common, but an injection molding method or a compression molding method is also possible.

[0032]

The present invention will be described more specifically with reference to the following examples. The measurement conditions of various physical properties are as follows.

(Softening Point) The softening point is a value measured by a ring and ball method, and the melting point is a value measured by a method using a capillary tube. (Residual carbon ratio) The residual carbon ratio is a value measured by a differential thermogravimetric simultaneous measuring device TG / DTA220 manufactured by Seiko-Electronic Industries. That is, 10 mg of the sample was added at 200 ml / min.
10 ° C./min in an atmosphere where nitrogen gas is flowed at
The ratio of the amount of residual carbonaceous material to the initial mass after heating from room temperature to 700 ° C. at the heating rate was defined as the residual carbon ratio.

(Aromatic Index) The aromatic index (fa) is a value measured by NMR ( ¹³ C-nuclear magnetic resonance spectrum) based on the NNE method using JNM-GX400 manufactured by JEOL Ltd. That is, 125 mg of a sample was dissolved in 0.5 ml of chloroform-d1 (CDCl ₃ ), and 6 mg of chromium (III) acetylacetonate, a paramagnetic relaxation reagent, was added to prepare a measurement sample. The observation frequency was 100 MHz and the pulse width was 45 °. The measurement was performed under the conditions of a pulse and a pulse waiting time of 2 seconds. About the obtained spectrum, 110-16
The range of 0 ppm was assigned as aromatic carbon and the range of 10 to 60 ppm was assigned as non-aromatic carbon, and the respective carbon fractions were determined from the integrated values. The aromatic index (f) is represented by the ratio of the aromatic carbon to the total carbon determined from the obtained carbon fraction.
a).

(Flame Retardancy) The flame retardancy was evaluated by molding a test piece having a thickness of 1/16 inch according to UL94V-0 standard. Pass means that the test passes the UL94V-0 standard. Quantitatively, the total frame in the test of n = 5
Mining time is shown as an index. (Hardness under heating) Hardness under heating was measured by a Barcol hardness tester on a test piece molded at 175 ° C. for 90 seconds. (Glass transition point) The glass transition point was determined by a thermomechanical measuring apparatus at a temperature rising rate of 10 ° C./min. (Water absorption) The water absorption was measured using the epoxy resin composition of 5%.
A 0mmφ × 3mm disk is formed and post-cured at 85 ℃
This is when moisture is absorbed for 100 hours under the condition of 85% RH. (Crack occurrence rate) The crack occurrence rate was QFP-80p
In (14 × 20 × 2.5 mm), after post-curing, after absorbing moisture for 85 hours at 85 ° C. and 85% RH under the same conditions as water absorption, immersed in a 260 ° C. solder bath for 10 seconds And the state of the package was observed and determined.

Examples 1 to 6 and Comparative Examples 1 to 4 Various aromatic substances are used as a flame retardant, and are added to an epoxy resin composition to impart flame retardancy, and at the same time, have rapid curability and fluidity. An attempt was made to obtain a cured product having excellent moldability such as moldability, and excellent in mechanical strength, heat resistance, low moisture absorption, solder reflowability and the like. In this evaluation, the content of these flame retardants, that is, the content of the polycyclic aromatic substance, was 10 parts by weight with respect to 100 parts by weight of the epoxy resin. Flame retardants used in Examples and Comparative Examples (A1 to A
The production method or origin of 8) is shown below. In addition, A1 to A5 correspond to the present flame retardant, and A6 to A8 do not correspond to the present flame retardant.

A1: Coal tar soft pitch, a residue obtained by distilling coal tar obtained by carbonizing coal at 300 to 370 ° C. A2: The product obtained by removing the quinoline-insoluble matter from A1 was further distilled under reduced pressure (330 to 350 ° C., 10,000 to 30,000).
Pa) A3: Distillation of A1 under reduced pressure (360-390 ° C, 9000-
15000 Pa). A4: Anthracene oligomer. 88 g (0.495 mol) of anthracene, 27.3 g (0.198 mol) of p-xylene glycol and 4.6 g of p-toluenesulfonic acid as a catalyst were charged, heated to 180 ° C. under a nitrogen stream, and then stirred. While reacting for 3 hours
6.5 g of generated water was recovered. After cooling, chlorobenzene was added as a diluting solvent, the catalyst was removed by washing with water, and the solvent chlorobenzene was distilled off under reduced pressure to obtain 38 g of an anthracene oligomer. A5: pyrene-based oligomer. Pyrene 100 g (0.495 mol), p-xylene glycol 27.3 g (0.198 mol), p-
Toluenesulfonic acid (5.1 g) was charged, and nitrogen
After heating to 80 ° C., the reaction was carried out for 3 hours while stirring, and 6 g of generated water was recovered. After cooling, chlorobenzene was added as a diluting solvent, the catalyst was removed by washing with water, and the solvent, chlorobenzene, was distilled off under reduced pressure to obtain 40 g of a pyrene-based oligomer. A6: Decant oil which is a heavy component of fluid catalytic cracking oil of petroleum. A7: Commercial naphthalene. A8: Commercially available anthracene.

Table 1 shows these basic characteristics.

[Table 1]

In order to evaluate characteristics such as flame retardancy of an epoxy resin composition for use in electronic parts and the like,
An epoxy resin composition for an electronic component sealing material was prepared and evaluated. The mixing conditions and evaluation conditions are as follows.

As the epoxy resin component, o-cresol novolak type epoxy resin (Epoxy resin A: EOCN-1020-65, manufactured by Nippon Kayaku; epoxy equivalent: 200, hydrolyzable chlorine)
Phenol novolak (curing agent A: manufactured by Gunei Chemical Co., PSM-4261; OH equivalent 103, softening point 80 ° C) or 1-naphtho-aralkyl-type resin (curing agent) B: Nippon Steel Chemical, SN-485; OH equivalent 21
0, softening point 85 ° C). Further, spherical silica (average particle size: 18 μm) as a filler, triphenylphosphine as a curing accelerator, carbon black as a coloring agent, carnauba wax as a release agent, and a flame retardant shown in Table 1 were mixed and kneaded. Thus, an epoxy resin composition was obtained. The mixing ratio was the same for 800 parts of spherical silica, 1.2 parts of curing accelerator, 5 parts of carbon black, and 3 parts of carnauba wax, except that the amounts of epoxy resin A and curing agent A or B were as shown in Table 2. And The curing agent component was blended in such a number that the equivalent weight of the curing agent component was equal to that of the epoxy resin component. The silica content at this time is 83 wt%. Table 2 shows the proportions of the main components. The blending of the flame retardant was performed in Example 3 except that the powder was mixed at the time of kneading. The epoxy resin composition was molded at 175 ° C., post-cured at 175 ° C. for 12 hours to obtain a cured product test piece, which was then subjected to various physical property measurements. Table 3 shows the measurement results of the physical properties.

[0041]

[Table 2]

[0042]

[Table 3]

Examples 1 to 6 satisfying the conditions of the present invention are all excellent in flame retardancy, excellent in moldability such as rapid curability and fluidity, and have good mechanical strength, heat resistance, low moisture absorption, and solderability. It can be seen that a cured product having excellent reflow properties and the like is provided. On the other hand, Comparative Examples 1 to 3 which do not satisfy the conditions specified in the present invention.
No. 4 is not as excellent in flame retardancy as the example. That is,
In Comparative Example 1, the flame retardant A6 used was 70 wt.
Since the residual carbon ratio and fa when the temperature was raised to 0 ° C. were out of the range of the present invention, the flame retardancy was not improved as much as in Examples 1 to 6. In Comparative Example 2, since the flame retardant A7 used had a residual carbon ratio outside the range of the present invention when the temperature was raised to 700 ° C. under a nitrogen stream, the flame retardancy was improved as in Examples 1 to 6. Absent. In Comparative Example 3, since the flame retardant A8 used was out of the range of the present invention when the temperature was raised to 700 ° C. under a nitrogen stream, the flame retardancy was improved as in Examples 1 to 6. Absent.
In Comparative Example 4, the flame retardant of the present invention was not used at all, and thus the flame retardancy was not improved as much as in Examples 1 to 6.

[0044]

The epoxy resin composition of the present invention has excellent flame retardancy and excellent moldability such as rapid curability and fluidity without containing a halogen-based flame retardant and an antimony compound.
Also provides a cured product with excellent mechanical strength, heat resistance, low moisture absorption, solder reflowability, etc., especially when applied to the sealing of electronic components such as surface mounted semiconductor elements, or printed circuit boards, etc. It shows flame retardancy and solder reflowability.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiko Nakahara 1st Tsukiji, Kisarazu-shi, Chiba Nippon Steel Chemical Co., Ltd.Electronic Materials Development Center (72) Inventor Yoichi Kawano 46 Nippon Steel Chemical Co., Ltd. at Nippon Steel Chemical Co., Ltd. (72) Inventor Tetsuo Fukuda Fukuta, Nippon Steel Chemical Co., Ltd. 4J002 AE05X AG00X CD04W CD05W CD06W EJ036 EJ046 FD010 FD13X FD130 FD156 GF00 GJ02 GQ00 4M109 AA01 BA01 CA21 EA02 EB02 EB04 EB06 EB07 EB08 EB09 EB12 EB18 EB19 EC09 EC03 EC05 EC05

Claims (2)

[Claims] 1. An epoxy resin composition containing (A) an epoxy resin and (B) a curing agent, having a softening point of 10 to 2
A polycyclic aromatic having a residual carbon ratio of 10 wt% or more when heated to 700 ° C. in a nitrogen stream at 50 ° C. and an aromatic index (fa) of 0.85 or more in ¹³ C-nuclear magnetic resonance spectrum An epoxy resin composition comprising a flame retardant as a flame retardant in an amount of 1 to 100 parts by weight based on 100 parts by weight of the epoxy resin. 2. A cured product obtained by curing the epoxy resin composition according to claim 1.