JPH02302426A - Epoxy resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin composition suitable for use as a molding material, a powder coating material, a semiconductor encapsulating material, and the like.

Conventional epoxy resins and epoxy resin compositions containing inorganic fillers, etc., generally have better moldability, adhesiveness, and
Electrical properties 2 Because it has excellent mechanical properties, moisture resistance, etc., it is widely used as various molding materials, powder coating materials, electrical insulation materials, etc., and has recently attracted attention in particular as a semiconductor encapsulating material.

However, conventional epoxy resin compositions are often cranked during curing, which impairs the appearance of molded and painted surfaces and causes defects in semiconductor devices and other devices. , the present inventors previously proposed an epoxy resin composition with excellent crank resistance by adding a block copolymer consisting of an aromatic polymer and an organopolysiloxane to a curable epoxy resin ( JP-A No. 58-21417) has excellent crack resistance, a low expansion coefficient, a high glass transition point, and therefore a small amount of deformation during molding. There has been a desire for an epoxy resin composition that does not impair properties such as mechanical strength such as elastic modulus.

In addition, it has been said that injection molding of epoxy resins is difficult in the past, and the reason for this is that epoxy resin molding materials -
This is because JG hardens quickly in the initial stage and tends to gel when heated in the cylinder of an injection molding machine, and as a result, the nozzle is blocked by the gelled epoxy resin and cannot be injected into the mold.

The present invention was made in view of the above circumstances, and has improved bending strength, low expansion coefficient, and high glass transition point.
The object of the present invention is to provide an injection moldable epoxy resin composition that has excellent crack resistance, less deformation during molding, and good moisture resistance and electrical properties.

In order to achieve the above object, the present inventors have developed a block that is blended into an epoxy resin composition containing a curable epoxy resin and a curing agent, and which further provides an excellent effect on crank resistance. As a result of intensive studies on copolymer components, inorganic fillers, and curing accelerators, we found that novolak resin and the following formula (1) [However, in the formula, R1 is a hydrogen atom, or 1 having an amino group, an epoxy group, or a hydroxy group. A valent organic group, a hydroxy group, a halogen atom or a lower alkoxy group, R8 is the same or different alkyl group having 1 to 8 carbon atoms, a phenyl group, or C is 2 or 3. ), where a is 0.
b is a positive number of 001 to 0.1, b is a positive number of 1.9 to 2.2, and 1.9≦a+b≦2.3. Further, the number of silicon atoms in one molecule is 20 to 1000.

] In addition to the copolymer obtained by addition reaction with organopolysiloxane represented by formula (A) and (
It has been found that an epoxy resin composition containing a specific urea compound represented by B) has excellent properties.

That is, generally when a copolymer of a novolac resin and an organopolysiloxane is blended into an epoxy resin composition, the copolymer is uniformly distributed in the curable epoxy resin.
1. Because it contains the same or similar novolak resin segment, it has a high affinity for curable epoxy resins,
Therefore, microdispersion becomes possible, and an epoxy resin composition not only does not have a lower glass transition point but also has a low coefficient of expansion can be obtained.

In addition, by introducing glass fiber, the bending strength is improved and the crack resistance is dramatically improved, and furthermore, by using a specific urea compound as a curing accelerator, an injection moldable epoxy resin composition can be obtained. I discovered that
This has led to the completion of the present invention.

Therefore, in the present invention, a copolymer of a novolak resin and an organopolysiloxane is blended, glass fiber is preferably used as an inorganic filler, and urea compounds represented by formulas (A) and CB) are used as a curing accelerator. An injection moldable epoxy resin composition is provided.

The present invention will be explained in more detail below.

The epoxy resin constituting the composition of the present invention contains 2 epoxy resins per molecule.
An epoxy resin having 1 or more epoxy groups, this epoxy resin is not particularly limited in its molecular structure, molecular weight, etc., as long as it can be cured with various curing agents as described below, and is a conventionally known epoxy resin. Various materials can be used, including epoxy resins synthesized from epichlorohydrin and various novolak resins including bisphenol, alicyclic epoxy resins, and epoxy resins containing halogen atoms such as chlorine or bromine atoms. Examples include resins, epoxidized triphenolmethane, and the like.

Here, the above-mentioned epoxy resin is not necessarily limited to 111H when used, but two or more types may be mixed.

In addition, when using the above epoxy resin, there is no problem in using a monoepoxy compound as appropriate, and examples of this monoepoxy compound include styrene oxide, cyclohexene oxide, propylene oxide, methyl glycidyl ether, ethyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl. Examples include ether, octylene oxide, and dodecene oxide.

In addition, as a curing agent, an amine curing agent represented by diaminodiphenylmethane, diaminodiphenylsulfone, metaphenylene diamine, etc., an acid anhydride curing agent such as phthalic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, Alternatively, phenol novolak curing agents having two or more hydroxyl groups in one molecule such as phenol novolak and talesol novolak are exemplified.

The copolymer blended into the epoxy resin composition of the present invention is
Novolac resin and the following formula (1) % formula % (1) [However, R1 in the formula is a hydrogen atom, or a monovalent organic group having an amino group, an epoxy group, or a hydroxy group, a hydroxy group, a halogen atom, or a lower alkoxy The group R2 is the same or different alkyl group having 1 to 8 carbon atoms, phenyl group, or C is 2 or 3. ), where a is 0.
A positive number from 001 to 0.1, b is a positive number from 1.9 to 2.2, and 1.9≦a+b≦2.3. Further, the number of silicon atoms in one molecule is 20 to 1000.

It is a reaction product with an organopolysiloxane shown in

Here, examples of the novolak resin to be reacted with the organopolysiloxane include, in addition to known phenol novolak resins and epoxy novolak resins, alkenyl group-containing novolak compounds represented by the following formulas (1) to (2).

2〇 type■ Formula■ Formula■ 2〇2〇2〇 type■ (However, in the above formulas 0 to 0, p and q are usually l≦p≦20.
It is an integer satisfying 1≦9≦IO. ) These alkenyl group-containing novolac resins can be obtained by ordinary synthesis methods, such as epoxidizing an alkenyl group-containing phenol resin with epichlorohydrin, or partially reacting various known epoxy resins with 2-allylphenol, etc. can be easily obtained by the following method.

On the other hand, the organopolysiloxane represented by formula (1) used in the present invention includes a hydrogen atom represented by R' as a functional group capable of reacting with an epoxy group, hydroxy group, alkenyl group, etc. in the novolac resin; Hydroxy group, halogen atom such as chlorine, bromine, iodine, lower alkoxy group such as methoxy group, ethoxy group, propoxy group, butoxy group, or -(C11□), -Nllz (j! is an integer from 1 to 6) ,C11! -CI-(C11,), -1
CHz-CIICIIgO-(CIlg)-(m is 1-
\♂ \ge+IQ,.

having at least one monovalent organic group in one molecule containing an amine group, an epoxy group, or a hydroxy group such as If R' is a hydrogen atom, it can be used as hydrogen atom at both ends, hydrodiene methylpolysiloxane at both ends, hydrodiene methyl phenyl polysiloxane at both ends, hydrogen methyl at both ends (2-trimethoxysilylethyl)polysiloxane, etc. is preferable, and the number of hydrogen atoms directly bonded to silicon atoms in one molecule is preferably 1 to 5. On the other hand, R
When 1 is a monovalent organic group containing an amino group, the formula (1
) in which Rz is a methyl group and a phenyl group, the same <R'' is a methyl group and -CIIzCHxSi(OCH
3) Organopolysiloxanes having an s group or a γ-aminopropyldimethylsiloxy-blocked dimethylpolysiloxane structure are suitable. Specifically, compounds of the following formulas [phase] to (2) may be mentioned.

Formula [Phase] Formula ■ 2〇2〇 Formula ■ Formula ■ Formula ■ The degree of polymerization (n) of the organopolysiloxane represented by the above formula (1) is in the range of 20 to 1000, preferably 30 to 300, and n If n is less than 20, it will not be possible to impart sufficient flexibility or obtain a high glass transition point Tg, and if n exceeds 1000, it will be extremely difficult in terms of synthesis technology, and even if the copolymer Even if obtained, it cannot be easily dispersed in an epoxy resin, and the object of the present invention cannot be achieved.

In general, when the silicone content is the same, organopolysiloxanes give good results in crack resistance and high Tg as n increases, but on the other hand, dispersibility or adhesion with elements tends to decrease. . In order to improve the dispersibility and adhesion with devices, it is effective and desirable to introduce not only methyl groups but also groups such as propyl groups, phenyl groups, and alkoxy groups into the side chains of the polysiloxane skeleton.

Furthermore, it is desirable for the above-mentioned copolymer to be incompatible with the epoxy resin matrix and to have a fine seabird structure for an epoxy resin composition that has excellent crack resistance and adhesion to elements. , in equation (1),
When the functional group of organopolysiloxane is (X) and the molecular weight of novolak resin is (Y), 1.0< (X)
It is desirable to carry out the reaction within the range of / (Y) <25.

The addition reaction between the alkenyl group-containing novolac resin and the organopolysiloxane can be carried out using a conventionally known addition catalyst.
For example, platinum-based catalysts such as chloroplatinic acid can be used.

In addition, as a solvent, it is preferable to use an inert solvent such as benzene, toluene, or methyl isobutyl ketone.
In addition, the reaction temperature is not particularly limited, but is 60 to 120°C.
The reaction time is preferably 30 minutes to 24 hours.

For example, a copolymer of an epoxy resin and a polysiloxane having an organic group containing an amino group at both ends, or a copolymer of a phenol resin and a polysiloxane having an organic W containing an epoxy group at both ends. Coalescence is obtained by mixing at room temperature or high temperature and causing an addition reaction. During this reaction, in order to mix the two in a homogeneous or nearly homogeneous state, methyl isobutyl ketone, toluene, dioxane, methyl cellosolve, etc. are used. It is desirable to use a solvent, and to further accelerate the reaction, water, alcohols such as butanol, isopropyl alcohol, ethanol, and phenols are used, and tributylamine, 1,8-diazabicycloundecene-7 is used as a reaction catalyst. It is desirable to use amines such as , organic phosphines such as triphenylphosphine, and imidazoles such as 2-phenylimidazole.

The amount of the organopolysiloxane copolymer described above in the epoxy resin composition is 11 in total of the epoxy resin and the curing agent.
If the amount is less than 1 part by weight per 100 parts by weight, the effects of improving the glass transition point of the epoxy resin composition, improving crack resistance, inhibiting movement of aluminum wiring, etc. may become insufficient. If it exceeds 1 to 1, the mechanical strength of the epoxy resin composition tends to decrease.
It is preferably 100 parts by weight, particularly 2 to 60 parts by weight.

As the inorganic filler used in the present invention, various fillers commonly used in epoxy resin compositions such as adulterated materials, powder coating materials, semiconductor encapsulation materials, etc. may be added. It is preferable to use 10 to 90% by weight of whole shells of silica such as crystalline silica, fused silica, etc. in the filler.Furthermore, it is preferable to use inorganic fibers as other components in the inorganic filler, and this inorganic The fibers may be of any type as long as they are used to improve the mechanical strength such as bending strength of the resin, and it is preferable to use 10 to 90% by weight of the fibers in the filler. Examples of the fibers include glass fibers, asbestos fibers, gypsum fibers, ceramic fibers, steel fibers, titanium fibers, alumina fibers, boron fibers, and silicon carbide fibers, but it is preferable to use glass fibers.

The epoxy resin composition of the present invention comprises an isophorone bisurea compound represented by formula (A) and a urea compound represented by formula (B) (hereinafter referred to as urea compound (^)).
, urea compound (B)) as a curing accelerator, it has a long pot life at room temperature, quickly hardens at high temperatures, and improves electrical properties and moisture resistance. Urea compound (A) alone has a good pot life at room temperature, but has a problem in curability at high temperatures. On the other hand, the compound (B) alone has good curing properties at high temperatures, but since the compound contains chlorine, its use in large amounts may cause a decrease in moisture resistance and electrical properties. The weight ratio of urea compound (8) to urea metal compound (B) is preferably 3 to 9:1, particularly preferably 5:5 to 7:3.

It is preferable to use a urea compound (A) with a purity of 98% or more and an extracted water chlorine equivalent of IPP■ or less, and a urea compound (B) with a purity of 97% or more and an extracted water chlorine amount of 5 opp- or less. Especially for urea compound (B), the amount of chlorine in extracted water is 25p.
It is preferable to use a material with a particle diameter of pm or less, as the moisture resistance and electrical properties will be good. The total amount of the urea compound (^) and (B) added is 0.2 to 10.0 parts by weight based on 100 parts by weight of the epoxy resin and curing agent, especially from the viewpoint of curability and storage stability of the epoxy resin. The amount is preferably 1.0 to 5.0 parts by weight.

Although it is possible to add the urea compounds (A) and (B) as they are to the epoxy resin composition, they can be melted and mixed in advance with a phenol resin, etc., and then finely ground to obtain particles with a particle size of 150 to 75 microns. It is preferable to use

The composition of the present invention may further contain various additives depending on the purpose and use, for example, waxes, release agents such as fatty acids such as stearic acid and metal salts thereof, carbon There is no problem in blending pigments such as black, dyes, antioxidants, flame retardants, surface treatment agents (T-glycidoxypropyltrimethoxysilane, etc.), and other additives.

This epoxy resin composition can be prepared by stirring and mixing the above-mentioned ingredients uniformly, heating the mixture to 70 to 95°C, kneading it with a roller, extruder, etc., cooling it, and pulverizing it. You can get it at Note that there is no particular restriction on the order of blending the components.

The epoxy resin composition of the present invention can be suitably used as a molding material, a powder coating material, and also as an IC.

It can also be effectively used for sealing semiconductor devices such as LSIs, transistors, thyristors, and diodes, and for manufacturing printed circuit boards.

As explained above, the present invention uses an epoxy resin, a curing agent,
In addition to the inorganic filler, it is blended with a copolymer obtained by the reaction of novolak resin and organopolysiloxane, which has a low expansion coefficient, high glass transition point, and excellent crank resistance, and is preferably used as an inorganic filler. By using glass fibers, mechanical strength such as bending strength is increased, and by using a specific urea compound as a curing accelerator, an injection moldable epoxy resin composition can be obtained.

Next, an example of producing a copolymer used in the present invention will be shown using a synthesis example.

[Synthesis Example 1] 1 equipped with a Reflags condenser, a thermometer, a stirrer, and a dropping funnel! Alkenyl group-containing cresol novolak epoxy resin (115
00゜epoxy fft270, hydrolyzable chlorine 700
ppm) was obtained.

In a fourth flask similar to the above, add 120% of the alkenyl group-containing cresol novolac epoxy resin obtained by the above method.
g, methyl isobutyl ketone 1o.

g,) 200 g of toluene and 0.04 g of a 2-ethylhexanol-modified chloroplatinic acid solution with a 2% platinum concentration were added, and azeotropic dehydration was carried out for 1 hour, followed by 50 g of the organopolysiloxane shown in Table 1 at reflux temperature. was added dropwise for 30 minutes, and stirred at the same temperature for 4 hours to react.The resulting contents were washed with water and the solvent was distilled off under reduced pressure to produce the reactions shown in Table 1. Product (copolymer A~■
? and copolymer L-N) were obtained.

[Synthesis Example 2] ljl! equipped with a reflux condenser, thermometer, stirrer, and dropping funnel. After putting the cresol novolac resin and allyl glycidyl ether into the fourth flask and reacting them, add the alkenyl group-containing cresol novolac resin JJI (allyl equivalent 1500, 7 ethyl glycidyl ether)
10) was obtained.

In a four-bottle flask similar to the above, 120 g of alkenyl group-containing talesol novolak resin obtained by the above method, 100 g of methyl isobutyl ketone, 200 g of toluene, 2
Add 0.04 g of a 2-ethylhexanol-modified chloroplatinic acid solution with a platinum concentration of 2-ethylhexanol to each solution, perform azeotropic dehydration for 1 hour, and then dropwise add 50 g of organopolysiloxane shown in the following formula at reflux temperature over a 30-minute dripping time. Then, at the same temperature, 4
After stirring for a period of time and reacting, the obtained contents were washed with water,
By distilling off the solvent under reduced pressure, the reaction products (copolymer G) shown in Table 1 were obtained.

[Synthesis Example 3] 120 g of epoxidized Talesol novolac resin (epoxy ffi200) with a softening point of 70°C was placed in a four-bottle flask with an internal volume of 1 liter equipped with a reflux condenser, a thermometer, a stirrer, and a dropping funnel.

1.4-dioxane 150g, n-butanol 150g
was added, and while stirring at a temperature of 83° C., 50 g of an organopolysiloxane represented by the following formula was added dropwise over a 2-hour addition time, and the mixture was further stirred at the same temperature for 6 hours to react.

By distilling off the solvent from the resulting contents,
A reaction product (copolymer H) shown in Table 1 was obtained.

[Synthesis Example 4] 32 g of allylphenol, 200 E of toluene were added to a 1 liter four-bottle flask equipped with a reflux condenser, a thermometer, a stirrer, and a dropping funnel.

200 g of methyl isobutyl ketone, 2-
Add 0 and 04 g of ethylhexanol-modified chloroplatinic acid solution, perform azeotropic dehydration for 1 hour, and add 40 g of organopolysiloxane similar to that used in Synthesis Example 2 dropwise at reflux temperature for 30 minutes. After the mixture was added dropwise and reacted by stirring at the same temperature for 4 hours, the resulting content was washed with water, and unreacted allylphenol and the solvent were distilled off under reduced pressure to obtain the following compound.

In a fourth flask similar to the above, 50 g of phenolic OH-containing organopolysiloxane obtained by the above method and orthocresol novolak epoxy resin 7JR (12
00. Hydrolyzable chlorine 700pp+s) 120g,)
400 g of toluene was added and dissolved at reflux temperature, followed by stirring at the same temperature for 2 hours.

Thereafter, the solvent was distilled off under reduced pressure to obtain the reaction products shown in Table 1 (copolymer ■).

(Synthesis Example 5) 40 g of allyl glycidyl ether, 400 g of toluene, and 2-ethylhexanol-modified chloroplatinic acid with a platinum concentration of 2% were placed in a four-bottle flask equipped with a reflux condenser, a thermometer, a stirrer, and a dropping funnel. solution 0
．． 04 g each, and azeotropically dehydrated for 1 hour.
40 g of organopolysiloxane similar to that used in Synthesis Example 2 was added dropwise at reflux temperature for 30 minutes, and the mixture was further stirred at the same temperature for 4 hours to react, and the resulting contents were washed with water. , unreacted allyl glycidyl ether, and the solvent were distilled off under reduced pressure to obtain the following compound.

In a four-bottle flask similar to the above, 50 g of the epoxy group-containing organopolysiloxane obtained by the above method, 120 g of orthocresol novolak resin (OH equivalent 110), and MIB
400 g of K was added and dissolved at reflux temperature, followed by stirring at 110°C for 2 hours. Thereafter, the solvent was distilled off under reduced pressure to obtain the reaction products (copolymer J) shown in Table 1.

[Synthesis Example 6] 120 g of orthocresol crucible υ (OH equivalent: 110) was placed in a four-neck flask equipped with a reflux condenser, a thermometer, a stirrer, and a dropping funnel.
, 400 g of MIBK was added and dissolved under warm reflux, and then 16 g of 50% aqueous NaOH/Pi was added and water was removed by azeotropic dehydration. Thereafter, 50 g of the following organopolysiloxane was added dropwise over 30 minutes at reflux temperature. The reaction mixture was further stirred for 2 hours at 110"C. After that, the reaction product was washed with water and the solvent was distilled off to obtain the reaction product (copolymer K) shown in Table 1.

In Table 1, A- is a copolymer used in the present invention, and I and N are copolymers used as comparative products.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples. In addition, in the following examples, all parts indicate parts by weight.

[Examples, Comparative Examples] (Hereinafter, parts mean parts by weight.) Epoxidized cresol novolac resin with a weight of 11,200 parts per epoxy and phenol novolak resin with a weight of 1,110 parts per phenol were used in Tables 2-1 and 2-2, respectively. In addition to using the amounts shown in the table, 16 parts of each of the copolymers shown in Table 1 obtained in the synthesis examples were added, and the second-
The inorganic filler and curing accelerator shown in Table 1 and Table 2-2 were blended, and 10 parts of brominated epoxy novolac resin,
1.5 parts of glycidoxypropyltrimethoxysilane, 1.5 parts of wax E, and 1.0 part of carbon black were added, and the resulting mixture was uniformly melted and mixed with two hot rolls to make 2011 epoxy. Resin compositions (Examples 1 to 15 and Comparative Examples 1 to 5) were manufactured.

The obtained molding material was heated to a mold temperature of 180°C and a mold clamping pressure of 1 [
30kg r/cj, injection pressure 90kg r/cj
When injection molded using CD, a good molded product was obtained.

Regarding these epoxy resin compositions, the following (a) to (
G) tests were conducted.

(a) Using a test piece of 1 circular rotation, 1 round, 1 round, 4 InIlφ x 15-mm, the temperature was measured using a diradometer at a rate of 5°C per minute.

(b) Mechanical 1 Bending...P flexural modulus) 18
110X4X100 at 0℃ and 90kgf/cd
Measurements were made on a bendable rod that was molded and post-cured at 180°C for 4 hours.

(c) Crack resistance An enamelled coil wire was wound around an iron core measuring 150 x 200 x 250 mm to form a molded product measuring 155 x 205 x 255 cm. A current of 12 V and 150 A was passed through the coil, and the presence or absence of cracks that occurred when the enameled coil was broken was measured.

(d) Heat the Brabender Plastograph at 160°C or 80°C.
The gel was rotated at °C, the required torque was measured, and the time required to reach twice that torque was determined as the gel time. The gel time ratio was determined as gel time at 80°C/gel time at 160°C.

(E) A bending rod with a size of 10×4×100 − was molded, and the presence or absence of voids was determined from soft X-ray photographs.

(f) 1 sample molded into a moisture-resistant 14-pin DIP IC shape.
The wires were placed in a high-pressure oven at 21'C and 100% humidity for 100 hours, and the open failure rate of the wiring was investigated.

(g) Drawing 1s1 (1 Molded a disk with a diameter of 30 inches and a thickness of 3 mm, pulverized the molded product, mixed the fine powder Log with 50 g of distilled water, and heated it to 160°C.
The amount of chlorine in the extracted water after 120 hours was examined.

Table 2-2 * Curing accelerator (A) (B) From the results in Tables 2-1 and 2-2, the copolymer obtained by the reaction of the novolak resin and organopolysiloxane according to the present invention The epoxy resin composition blended with the copolymer has the following properties:
It can be seen that the crack resistance is excellent, and that the bending strength is increased by preferably using glass fiber, and that the gel time is increased and the moisture resistance is improved by using two types of urea compounds.

According to the injection-moldable epoxy resin composition of the present invention, epoxy resins that were difficult to injection mold in the past can be easily injection-molded, so they can be used for sealing electrical and electronic parts and structural members, and can be used in various industries. The above effect is extremely large.

Claims (1)

[Claims] 1. In an epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler, a novolac resin and a compound of the formula (1
) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・(1
) [However, in the formula, R^1 is a hydrogen atom, or a monovalent organic group having an amino group, an epoxy group, or a hydroxy group, a hydroxy group, a halogen atom, or a lower alkoxy group, R_2
is the same or different alkyl group having 1 to 8 carbon atoms, phenyl group, or a group represented by ▲Mathematical formula, chemical formula, table, etc.▼ (R^3 is a lower alkyl group, c is 2 or 3) and a is 0.
A positive number from 001 to 0.1, b is a positive number from 1.9 to 2.2, and 1.9≦a+b≦2.3. Further, the number of silicon atoms in one molecule is 20 to 1000. ] A copolymer obtained by reaction with an organopolysiloxane represented by the formula (A) and a urea compound represented by the formula (A) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(A) and the formula (B ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(B) An epoxy resin composition characterized by containing a urea compound represented by: