JP2003040970A - Method for producing silane-modified epoxy resin, resin composition, semicured material and cured material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid cured material which has excellent heat resistance and low-thermal-expansion property without causing a void, a crack and the like, and to provide a silane-modified epoxy resin composition which is easy for a molding processing in a semicured sate and a semicured material and a cured material obtained from the composition. SOLUTION: The silane-modified epoxy resin composition characterized by containing a silane-modified epoxy resin (A) obtained by a method for producing a methoxy group-containing silane-modified epoxy resin (A) and a curing agent for an epoxy resin (B) and an epoxy resin-silica hybrid cured material obtained by curing the epoxy resin composition are used. The methoxy group- containing silane-modified epoxy resin (A) is characterized by obtaining by a demethanolation condensation reaction of a bisphenol type epoxy resin (1), a novolak-type epoxy resin (2) and a methoxysilane partial condensate (3).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a methoxy group-containing silane-modified epoxy resin composition, a semi-cured product thereof, and a method for producing a cured product. INDUSTRIAL APPLICABILITY The epoxy resin composition of the present invention can be used in a wide range of applications such as coating agents for paints, adhesives, sealing agents, etc., and is particularly useful as an insulating coating agent, a printed wiring board material, an IC sealing material, an insulating sealing agent, etc. Is. The semi-cured product (sol-gel cured product) obtained from the epoxy resin composition of the present invention is flexible and has excellent moldability, and is therefore useful as an intermediate material such as a molding intermediate material, a prepreg, and a sealing agent. . The cured product (completely cured product) obtained from the epoxy resin composition of the present invention is transparent and has high hardness without cracks and the like. Further, it is excellent in adhesion, electric insulation, etc., and is also excellent in heat resistance (does not soften at high temperature, has a small expansion coefficient, and heat-resistant adhesion). Therefore, the wide-ranging applications mentioned above, especially electrical and electronic components,
It is useful as a molding material for automobile parts, civil engineering building materials, sports equipment materials, etc.

[0002]

2. Description of the Related Art Epoxy resins have hitherto been generally used as a composition in combination with a curing agent, and have been used in various fields such as electric and electronic materials. However, with the recent development of the electric and electronic materials field,
As a cured product of an epoxy resin composition is required to have higher performance, a material having particularly high heat resistance and low thermal expansion is desired.

In order to improve the heat resistance of a cured product of an epoxy resin composition, for example, a method using a composition in which a filler such as glass fiber, glass particles and mica is mixed in addition to an epoxy resin and a curing agent is used. There is. However, this method does not provide sufficient heat resistance. In addition, the transparency of the cured product obtained by this method is lost, and the adhesiveness at the interface between the filler and the epoxy resin is poor, so that mechanical properties such as elongation are insufficient.

Further, as a method for improving the heat resistance of a cured product of an epoxy resin composition, a method using a composite of an epoxy resin and silica has been proposed (JP-A-8-10).
No. 0107). The composite is prepared by adding hydrolyzable methoxysilane to a solution of a partially cured epoxy resin to further cure the cured product, hydrolyzing the methoxysilane to form a sol, and further polycondensing to form a gel. It is obtained by doing. However, the cured product obtained from such a composite has improved heat resistance to some extent as compared with the cured product of the epoxy resin alone, but due to water in the composite, water generated during curing, and alcohol, a cured product is obtained. Void inside
Occurs. Further, when the amount of methoxysilane is increased for the purpose of further improving heat resistance, the transparency of the cured product obtained by aggregation of silica generated by the sol-gel curing reaction is lost and whitening occurs, and a large amount of methoxysilane is added. A large amount of water is required to turn it into a sol, and as a result, warpage and cracks of the cured product are caused.

Further, a composition in which a silane-modified epoxy resin obtained by reacting an epoxy resin with a silicone compound and a phenol novolac resin as a curing agent are combined (Japanese Patent Laid-Open No. 3-201466), a bisphenol A type epoxy resin, A composition in which a silane-modified epoxy resin obtained by reacting tetrabisbromobisphenol A and a methoxy group-containing silicone intermediate is combined with a phenol novolac resin which is a curing agent (JP-A-61-27224).
No. 3, JP-A-61-272244, etc.) are also proposed. However, the cured products of these epoxy resin compositions have insufficient heat resistance because the main constituent units of the silicone compound and the methoxy group-containing silicone intermediate are diorganopolysiloxane units and cannot form silica. .

To date, the present inventors have found that a cured product obtained by curing a methoxy group-containing silane-modified epoxy resin obtained by subjecting a bisphenol type epoxy resin and a methoxysilane partial condensate to a methanol removal reaction has a glass transition point. It has been found that it disappears and becomes a high heat resistant material (Japanese Patent No. 3077695). In this method, in order to obtain a cured product, the solvent is volatilized from the resin composition and the methoxysilyl group is sol-gel cured and the epoxy group is epoxy cured to obtain an epoxy resin-silica hybrid cured product. There has been a problem that it is difficult to perform molding processing in a semi-cured state, which is indispensable for applications related to electronic materials.

[0007]

DISCLOSURE OF THE INVENTION The present invention is capable of obtaining a hybrid cured product which is excellent in heat resistance and low thermal expansion and does not cause voids, cracks, etc., and is easy to mold in a semi-cured state. It is an object of the present invention to provide a silane-modified epoxy resin composition which is, and a semi-cured product and a cured product obtained from the composition.

[0008]

As a result of intensive studies to solve the above problems, the present inventor has found that a methoxy group-containing silane-modified epoxy resin comprising a specific epoxy resin and a specific methoxysilane partial condensate, and an epoxy. It was found that an epoxy resin-silica hybrid cured product that meets the above purpose can be obtained with a composition comprising a curing agent for resins, and has completed the present invention.

That is, the present invention is characterized by being obtained by subjecting a bisphenol type epoxy resin (1), a novolak type epoxy resin (2) and a methoxysilane partial condensate (3) to a demethanol condensation reaction. The present invention relates to a method for producing a silane-modified epoxy resin (A). Further, the present invention relates to a silane-modified epoxy resin composition containing the silane-modified epoxy resin (A) obtained by the above-mentioned production method and a curing agent (B) for epoxy resin. The present invention also relates to an epoxy resin-silica hybrid cured product obtained by curing the epoxy resin composition.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The bisphenol type epoxy resin (1) which is a raw material of the methoxy group-containing silane-modified epoxy resin in the present invention is obtained by the reaction of bisphenols with haloepoxide such as epichlorohydrin or β-methylepichlorohydrin. It is a thing. As bisphenols, phenol or 2,6-dihalophenol and formaldehyde, acetaldehyde, acetone,
Examples thereof include those obtained by reaction with aldehydes or ketones such as acetophenone, cyclohexanone and benzophenone; those obtained by oxidation of dihydroxyphenyl sulfide with peracid; those obtained by etherification reaction of hydroquinones and the like.

The bisphenol type epoxy resin (1) is
It has a hydroxyl group capable of forming a silicate ester by a demethanol condensation reaction with the methoxysilane partial condensate (3). The hydroxyl group does not need to be contained in all the molecules constituting the bisphenol type epoxy resin (1), and these resins may have a hydroxyl group.

Among these bisphenol-type epoxy resins, the bisphenol A-type epoxy resin using bisphenol A as the bisphenol is most widely used, is inexpensive, and is preferable.

The bisphenol A type epoxy resin has the general formula (a):

[0014]

[Chemical 1]

Is a compound represented by:

The bisphenol type epoxy resin (1) used in the present invention has an epoxy equivalent of more than 230 g / eq.
It is less than 00 g / eq and has a number average molecular weight of about 460 to 2,000. When the bisphenol type epoxy resin (1) is a bisphenol A type epoxy resin, the average value of the repeating unit number m in the general formula (a) corresponds to 0.3 to 5.8. The epoxy equivalent is 230
When it is g / eq or less, the number of hydroxyl groups in the epoxy resin that reacts with the methoxysilane partial condensate (3) is small, and the number of repeating units m in the methoxy group-containing silane-modified epoxy resin (A) thus obtained is m = The proportion of epoxy compounds that do not have 0 hydroxyl groups has increased,
The thermal expansion coefficient of the silica hybrid cured product becomes high, which is not preferable. On the other hand, when the epoxy equivalent is 1000 g / eq or more, the number of hydroxyl groups in the bisphenol type epoxy resin (1) increases, and gelation tends to be caused by the reaction with the polyfunctional methoxysilane partial condensate (3). Not preferable. In addition, bisphenol type epoxy resin (1)
However, as long as the epoxy equivalent satisfies the above range, it may contain the one having a repeating unit number m of zero.

The novolac type epoxy resin (2), which is a raw material of the methoxy group-containing silane-modified epoxy resin (A) in the present invention, is a methanol removal reaction of the bisphenol type epoxy resin (1) and the methoxysilane partial condensate (3). In order to promote the reaction, it plays a role as a reaction medium for phase-dissolving both and a role for softening the semi-cured product. That is, the bisphenol type epoxy resin (1) and the methoxysilane partial condensate (3) have poor compatibility, and the silane-modified epoxy resin (A) cannot be produced without a reaction medium, but the novolac epoxy resin (2) is used as a reaction medium. If used,
This is preferable because the viscosity of the silane-modified epoxy resin composition does not drop too much as compared with organic solvents and the like. In general, the resulting silane-modified epoxy resin composition is finally completely cured (opening of the epoxy group in the epoxy group in the methoxy group-containing silane-modified epoxy resin (A) and the epoxy resin curing agent (B)). It is used for the intended purpose after curing by cross-linking reaction and sol-gel curing by hydrolysis and condensation in methoxy group-containing silane-modified epoxy resin (A). For specific applications represented by related applications, in the intermediate stage before complete curing,
In some cases, molding may be performed in the semi-cured state or the product may be commercialized. In such a case, the state of the semi-cured product (opening of the epoxy group of the epoxy group in the methoxy group-containing silane-modified epoxy resin (A) and the epoxy resin curing agent (B))
Sufficient flexibility is required in a methoxy group-containing silane-modified epoxy resin (A) in which only sol-gel curing by hydrolysis and condensation is allowed to proceed without a crosslinking reaction), but novolak type epoxy By using the resin (2) together in a predetermined ratio, the required performance can be satisfied.

Further, by using the novolac type epoxy resin (2), the coefficient of thermal expansion of the completely cured product becomes high, which is a problem when a bifunctional epoxy resin represented by a bisphenol type epoxy resin is used in combination. There is an advantage that it can be prevented. The average number of phenol nuclei in the novolac type epoxy resin is preferably 3 to 10, and more preferably 3 to 6. If the number of nuclides exceeds 10, the softening temperature becomes too high, so that the semi-cured product cannot be sufficiently provided with flexibility, which is not preferable. When the number of nuclei is less than 3, the coefficient of thermal expansion of the completely cured product tends to increase.

The novolac type epoxy resin (2) used in the present invention is obtained by reacting a novolac phenol resin with a haloepoxide such as epichlorohydrin. Examples of novolac resins include novolac phenolic resins, cresol novolac resins, bisphenol novolac resins, and poly-p-vinylphenol. Among these novolac resins, a phenol novolac type epoxy resin using a phenol novolac resin is particularly preferable because it is a polyfunctional epoxy but has a relatively low softening point and a low thermal expansion property of a cured product. As the novolac type epoxy resin (2), it is not necessary that all the hydroxyl groups of the constituent novolac resins are epoxy-modified with haloepoxide. The novolac epoxy resin partially having residual hydroxyl groups does not cause any problems because it undergoes a methanol removal reaction with the methoxysilane partial condensate (3) at the same time as the bisphenol type epoxy resin (1), but an epoxy resin with a low hydroxyl group content. Is preferred. This is because when a large number of hydroxyl groups are contained, the novolac type epoxy resin is silane-modified, so when the semi-cured product is produced,
This is because the sol-gel curing with the silane-modified bisphenol type epoxy resin may be carried out and the flexibility of the semi-cured product may be lowered.

The phenol novolac type epoxy resin is
General formula (b):

[0021]

[Chemical 2]

(In the formula, m represents an integer of 1 to 8).

In the present invention, it is essential to use the bisphenol type epoxy resin (1) and the novolac type epoxy resin (2) together in a predetermined ratio. By such combined use, a semi-cured product that is flexible and has excellent workability (sol-gel cured product)
This is because the object of the present invention that the can be easily prepared can be achieved. Bisphenol type epoxy resin (1)
Since the weight ratio of the epoxy resin composition and the novolac type epoxy resin (2) has a great influence on the performance of the resulting epoxy resin composition or semi-cured product, (2) / (1) should be in the range of 0.5 to 5. Is preferred, and more preferably 1 to 3. When the weight ratio exceeds 5, the amount of the methoxy group-containing silane-modified epoxy resin (A) becomes too small, and thus the heat resistance of the epoxy resin-silica hybrid cured product may be deteriorated. When the weight ratio is less than 0.5, the semi-cured product cannot be provided with sufficient flexibility, and the novolac epoxy resin (2) is a bisphenol epoxy resin (1) and a methoxysilane condensate ( The effect of compatibilizing with (3) is reduced, and the amount of solvent required for the reaction is increased, which is not preferable.

As the methoxysilane partial condensate (3), an oligomer obtained by partially hydrolyzing and condensing methoxysilane which is generally used in the sol-gel method can be used. For example, the general formula: R _p Si (OCH ₃ ) _4-p
(In the formula, p represents an integer of 0 or 1, and R represents a lower alkyl group having a carbon number of 6 or less or a phenyl group.) And the like. Note that p is 2 to
When it is 4, three-dimensional crosslinking does not occur, and it becomes difficult to impart desired high heat resistance to the finally obtained cured product.

Specific examples of the methoxysilane partial condensate (3) include tetramethoxysilane partial condensate; methyltrimethoxysilane, ethyltrimethoxysilane,
Partial condensates of trimethoxysilanes such as n-propyltrimethoxysilane, isopropyltrimethoxysilane, vinyltrimethoxysilane and phenyltrimethoxysilane can be mentioned. Among these, partial condensates such as tetramethoxysilane and methyltrimethoxysilane are preferable because they have a high sol-gel curing rate.

As the methoxysilane partial condensate (3), one kind or two or more kinds may be appropriately selected from the above substances, but the average number of Si per molecule is preferably 3 to 12. When the average number of Si is less than 3, the amount of toxic methoxysilanes flowing out of the system together with the by-product alcohol during the dealcoholization reaction with the bisphenol type epoxy resin (1) is not preferable. Again 1
When it exceeds 2, the compatibility with the bisphenol type epoxy resin (1) decreases, the amount of the novolac epoxy resin (2) and the large amount of organic solvent exceeding the above weight ratio are required, and the target methoxy group-containing silane-modified epoxy is required. Resin (A) is difficult to obtain.

In particular, the general formula (c):

[0028]

[Chemical 3]

(In the formula, Me represents a methyl group, and the average number of repeating units of n is 2 to 7.) A partial condensate of tetramethoxysilane represented by the general formula (c):

[0030]

[Chemical 4]

(In the formula, Me represents a methyl group, and the average number of repeating units of n is 2 to 7.) A partial condensate of methyltrimethoxysilane is preferable. The partial condensate is preferable from the viewpoint of reaction operation and safety and hygiene, since toxic tetramethoxysilane or methyltrimethoxysilane, which may flow out of the system together with by-product methanol, hardly exists in the demethanol reaction.

The methoxy group-containing silane-modified epoxy resin (A) according to the present invention comprises a bisphenol type epoxy resin (1), a novolac type epoxy resin (2) and a methoxysilane partial condensate (3) in the presence of a solvent. Alternatively, it can be obtained by carrying out a demethanol condensation reaction in the absence of a solvent. (Total equivalent of hydroxyl equivalents of bisphenol type epoxy resin (1) and novolac type epoxy resin (2)) /
(Methoxy group equivalent of methoxysilane partial condensate (3))
(Equivalent ratio) is not particularly limited, but is usually 0.01 to
It is 0.8, preferably 0.03 to 0.5. If the equivalence ratio is less than 0.3, the amount of unreacted methoxysilane partial condensate (3) will be too large. Therefore, if it exceeds 0.5 (stoichiometrically approaching equivalence), the progress of the demethanol reaction will proceed. It is not preferable because it easily gels.

When a high molecular weight bisphenol type epoxy resin (1) having an average epoxy equivalent of 400 or more is used, or a methoxysilane partial condensate (3) having an average number of Si of 7 or more per molecule (3) In the case of using as a raw material, when a demethanol condensation reaction is carried out until the hydroxyl groups of the bisphenol type epoxy resin (1) and the novolac type epoxy resin (2) are completely disappeared,
Easy to cause high viscosity and gelation. In such a case, it is possible to prevent the increase in viscosity and gelation by a method such as stopping the demethanol reaction during the reaction. For example, it is possible to employ a method of refluxing the methanol that flows out to adjust the amount of methanol distilled off from the reaction system, or cooling the reaction system to terminate the reaction when the viscosity increases.

The methoxy group-containing silane-modified epoxy resin (A) can be produced in the presence or absence of a solvent as described above. In the demethanol condensation reaction of the present invention, the reaction temperature is about 50 to 130 ° C, preferably 70 to 110 ° C, and the total reaction time is about 1 to 15 hours. This reaction is preferably carried out under substantially anhydrous conditions in order to prevent the polycondensation reaction of the methoxysilane partial condensate (3) itself. By the way, a methoxy group-containing silane-modified epoxy resin (A) produced without solvent
Has the advantage that it can be used as it is as a solventless application, for example, as a material for adhesives, molded products, sealing agents and the like. As an application to the solventless use, the organic solvent solution of the methoxy group-containing silane-modified epoxy resin (A) produced in the presence of a solvent may be depressurized to remove the solvent.

In the dealcoholization condensation reaction, a catalyst which does not open the epoxy ring can be used among the conventionally known catalysts in order to accelerate the reaction. Examples of the catalyst include lithium, sodium, potassium,
Metals such as rubidium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium, manganese; oxides of these metals, organic acids Examples thereof include salts, halides and methoxides. Among these, organic tin and organic acid tin are particularly preferable, and specifically dibutyltin dilaurate, tin octylate and the like are effective.

The methoxy group-containing silane-modified epoxy resin (A) of the present invention has a methoxy group derived from the methoxysilane partial condensate (3) in its molecule. The content of the methoxy group is necessary for the methoxy group to undergo a sol-gel reaction or a demethanol condensation by a heat treatment or a reaction with moisture (humidity) to form a hybrid cured product bonded to each other. Therefore, the methoxy group-containing silane-modified epoxy resin (A) is usually left unreacted with 40 to 95 mol%, preferably 50 to 90 mol% of the methoxy group of the methoxysilane partial condensate (3) used as a reaction raw material. It is good to keep it. Such a hybrid cured product has a gelled fine silica site (a higher-order network structure of siloxane bonds). The methoxy group-containing silane-modified epoxy resin (A) may contain the bisphenol type epoxy resin (1) and the methoxysilane partial condensate (3) in an unreacted state. The unreacted methoxysilane partial condensate (3) becomes silica by hydrolysis and polycondensation during sol-gel curing, and bonds with the methoxy group-containing silane-modified epoxy resin (A).

In the present invention, a silane-modified epoxy resin composition comprising a combination of a methoxy group-containing silane-modified epoxy resin (A) and a latent epoxy resin curing agent (B) is used. When the silane-modified epoxy resin composition of the present invention is applied to various uses, various epoxy resins can be used together depending on the use. As the epoxy resin which can be used in combination, the bisphenol type epoxy resin (1) described as a constituent of the present invention,
Novolac type epoxy resin (2); glycidyl ester type epoxy resin obtained by reacting polybasic acids such as phthalic acid and dimer acid and epichlorohydrin; polyamines such as diaminodiphenylmethane and isocyanuric acid, and epichlorohydrin Examples thereof include glycidyl amine type epoxy resins obtained by reaction; linear aliphatic epoxy resins and alicyclic epoxy resins obtained by oxidizing olefinic bonds with peracid such as peracetic acid.

Further, a curing agent (B) for latent epoxy resin
As the above, a conventionally known latent curing agent which is usually used as a curing agent for an epoxy resin can be used. Examples of the latent epoxy resin curing agent (B) include novolac resin-based curing agents, imidazole-based curing agents, and acid anhydride-based curing agents. Specifically, examples of the novolac resin-based resin include phenol novolac resin, bisphenol novolac resin, and poly-p-vinylphenol. Examples of the imidazole-based curing agent include 2-methylimidazole, 2-ethylhexylimidazole, 2-undecyl imidazole, 2-phenyl imidazole, 1-cyanoethyl-2-phenyl imidazolium trimellitate, 2
-Phenylimidazolium isocyanurate, etc., and as the acid anhydride-based curing agent, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, hexachloroendo Examples thereof include methylenetetrahydrophthalic anhydride and methyl-3,6-endomethylenetetrahydrophthalic anhydride, and examples of other curing agents include dicyandiamide and ketimine compounds. Among these, considering the storage stability of the silane-modified epoxy resin composition, a phenol novolac resin-based curing agent and an imidazole-based curing agent are preferable.

The latent epoxy resin curing agent (B) is usually used in such a proportion that the functional group having active hydrogen in the curing agent is 0 relative to 1 equivalent of the epoxy group in the methoxy group-containing silane-modified epoxy resin composition. It is prepared by blending it in a ratio such that it is about 2 to 1.5 equivalents.

The epoxy resin composition may contain a curing accelerator for promoting the curing reaction between the epoxy resin and the curing agent. For example, tertiary amines such as 1,8-diaza-bicyclo [5.4.0] undecene-7, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; 2 -Imidazoles such as methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole and 2-heptadecylimidazole; organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine; Tetraphenyl such as tetraphenylphosphonium / tetraphenylborate, 2-ethyl-4-methylimidazole / tetraphenylborate, N-methylmorpholine / tetraphenylborate Such as boron salt can be mentioned. The curing accelerator is preferably used in a proportion of 0.1 to 5 parts by weight with respect to 100 parts by weight of the epoxy resin.

If necessary, the epoxy resin composition may contain an organic solvent, a filler, a release agent, a surface treatment agent, a flame retardant, a viscosity modifier, a plasticizer, as long as the effects of the present invention are not impaired. Antibacterial agent, antifungal agent, leveling agent, defoaming agent, coloring agent,
You may mix | blend a stabilizer, a coupling agent, etc.

In order to obtain an epoxy resin-silica hybrid cured product from the above resin composition, it is necessary to carry out sol-gel curing of the methoxysilyl moiety of the methoxy group-containing silane-modified epoxy resin and epoxy curing of the epoxy group. However, when the epoxy curing precedes the sol-gel curing, the epoxy resin-silica hybrid cured product causes foaming and cracks due to the generation of methanol due to the sol-gel curing. In order to prevent this, when the film thickness of the epoxy resin-silica hybrid cured product exceeds 50 μm or when a novolac phenol resin is used as a curing agent, a catalyst for accelerating the sol-gel curing is added to the resin composition. It is preferable to mix them. Examples of the sol-gel curing catalyst include acid or basic catalysts, conventionally known catalysts such as metal-based catalysts, and tin octylate and dibutyltin dilaurate are particularly preferred because they have high activity and excellent solubility. . The amount of the catalyst used can be appropriately determined depending on the activity of the catalyst used, the film thickness, and the type of the latent epoxy resin curing agent (B). Normally, with respect to the methoxy group of the methoxy group-containing silane-modified epoxy resin used,
The molar ratio of paratoluenesulfonic acid or tin octylate having a high catalytic ability is about 0.01 to 5 mol%, and formic acid or acetic acid having a low catalytic ability is about 0.1 to 50 mol%.

Directly from the silane-modified epoxy resin composition,
In order to obtain a hybrid cured product, the above epoxy resin composition is cured at room temperature to 250 ° C. The curing temperature is appropriately determined by the latent epoxy resin curing agent (B).
When a phenol resin-based curing agent or a polycarboxylic acid-based curing agent is used as the curing agent (B), a sol-gel curing catalyst is used in combination with 0.1% or more in addition to the curing agent (B), It is preferred to cure at ~ 250 ° C. Because methanol is generated in the sol-gel curing reaction at the methoxysilyl site, ring opening / crosslinking of the epoxy group between the epoxy group in the methoxy group-containing silane-modified epoxy resin (A) and the epoxy resin curing agent (B). This is because if the methanol is generated after the curing by reaction proceeds, foaming or cracks will occur. Therefore, it is necessary to adjust the sol-gel curing reaction rate by appropriately selecting the catalyst.

To obtain a semi-cured film or an intermediate material for molding from the silane-modified epoxy resin composition, as the epoxy curing agent (B) of the above epoxy resin composition, a phenol resin curing agent, a polycarboxylic acid curing agent, Using latent curing agents such as imidazoles and ketimines, tin-based sol-
It is preferable to incorporate a gel curing catalyst. In order to produce a semi-cured film or an intermediate material for molding using the epoxy resin composition, it is preferable to heat the epoxy resin composition at 50 to 120 ° C. or less so that 70% of siloxane bonds due to sol-gel curing are contained in the epoxy resin composition. The sol-gel curing reaction needs to proceed so as to generate the above, preferably 90% or more. Because methanol is generated in the sol-gel curing reaction at the methoxysilyl site, if the progress of sol-gel curing during preparation of semi-cured product is small, curing shrinkage, cracks, and foaming may occur in the subsequent complete curing reaction. Because there is a nature.

Further, such a semi-cured product is subjected to thermoforming or thermocompression bonding, and is then completely cured at a temperature of usually 160 ° C. or higher and 250 ° C. or lower to be an epoxy resin-silica hybrid cured product.

[0046]

Industrial Applicability According to the present invention, there is provided an epoxy resin cured product which is excellent in heat resistance and low thermal expansion property, does not generate voids (air bubbles), etc., and has a flexible semi-cured state and is excellent in processability. You can Further, according to the present invention, the amount of the solvent used for producing the silane-modified epoxy resin can be reduced, so that the environmental load can be reduced.

[0047]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. In each example,% is based on weight unless otherwise specified.

Example 1 (Production of methoxy group-containing silane-modified epoxy resin) A bisphenol A type epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd.) was added to a reactor equipped with a stirrer, a water separator, a thermometer, and a nitrogen blowing port. Product name "Epicote 100
1 ", epoxy equivalent 472 g / eq, m = 2.1) 32
0g and novolac type epoxy resin (Tohto Kasei Co., Ltd.)
Product name, "Epototo YDPN-638P", epoxy equivalent 177 g / eq) 613.9 g, glycidol 8
Add 0.39 g and 450 g of methyl ethyl ketone, and add 90
Dissolved at ° C. Further, poly (methyltrimethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name "MTMS-A", average number of repeating units 3.5) 558.2 g and dibutyltin laurate 3.5 g as a catalyst were added, and under a nitrogen stream. At
The methanol removal reaction was carried out at 100 ° C. for 3 hours using a water divider. A methoxy group-containing silane-modified epoxy resin (hereinafter referred to as resin (A-1)) was obtained by replacing the water divider with a reflux tube and further reacting at 100 ° C. for 5 hours. The weight of the novolac type epoxy resin (2) at the time of preparation / the weight of the bisphenol type epoxy resin (1) = 1.9.
It is 2. Also, bisphenol type epoxy resin (1)
And the novolac type epoxy resin (2), the total of the hydroxyl equivalents / the alkoxy equivalent of the methoxysilane partial condensate (3) = 0.12. The epoxy equivalent of the resin (A-1) was 330 g / eq.

Example 2 A bisphenol A type epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd., trade name "Epicoat 1001", epoxy equivalent 472 g / e was added to the same reactor as in Example 1.
q, m = 2.1) 360 g and novolac type epoxy resin (manufactured by Tohto Kasei Co., Ltd., trade name “Epototo YDPN”)
-638P ", epoxy equivalent 177 g / eq) 502.
4 g, 120.6 g of glycidol and 250 g of methyl ethyl ketone were added and dissolved at 90 ° C. Furthermore, poly (tetramethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name “MS
-51 ", average repeating unit number 4) 772.4 g and dibutyltin laurate 0.5 g as a catalyst were added, and the methanol removal reaction was carried out using a water diverter at 100 ° C for 1.5 hours under a nitrogen stream. . Replace the water diverter with a reflux pipe and add another 100
A methoxy group-containing silane-modified epoxy resin (hereinafter referred to as resin (A-2)) was obtained by reacting at 6.5 ° C. for 6.5 hours. The weight of the novolac type epoxy resin (2) at the time of preparation / bisphenol type epoxy resin (1)
Weight = 1.40. Further, the sum of the hydroxyl equivalents of the bisphenol epoxy resin (1) and the novolac epoxy resin (2) / alkoxy equivalent of the methoxysilane partial condensate (3) was 0.067. Resin (A-2)
Had an epoxy equivalent of 350 g / eq.

Example 3 A bisphenol A type epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd., trade name "Epicoat 1001", epoxy equivalent 472 g / e was added to a reactor similar to that of Example 1.
q, m = 2.1) 150 g and novolac type epoxy resin (manufactured by Tohto Kasei Co., Ltd., trade name “Epototo YDPN”)
-638P ", epoxy equivalent 177 g / eq) 513.
9 g, 37.68 g of glycidol and 250 g of methyl ethyl ketone were added and dissolved at 95 ° C. Furthermore, poly (methyltrimethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name "MTMS-A", average number of repeating units 3.5) 26
1.7 g and 2 g of dibutyltin laurate as a catalyst were added, and a methoxy group-containing silane-modified epoxy resin (hereinafter, referred to as resin ( A-3)) was obtained. The weight of the novolac type epoxy resin (2) at the time of preparation / bisphenol type epoxy resin (1)
Weight = 3.43. Further, the sum of the hydroxyl equivalents of the bisphenol type epoxy resin (1) and the novolac type epoxy resin (2) / the alkoxy equivalent of the methoxysilane partial condensate (3) was 0.15. The epoxy equivalent of the resin (A-3) was 310 g / eq.

Example 4 A bisphenol A type epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd., trade name "Epicoat 1001", epoxy equivalent 472 g / e was added to the same reactor as in Example 1.
q, m = 2.1) 170 g and novolac type epoxy resin (manufactured by Tohto Kasei Co., Ltd., trade name “Epototo YDPN”)
-638P ", epoxy equivalent 177 g / eq) 489.
1 g, 42.71 g of glycidol and 225 g of methyl ethyl ketone were added and dissolved at 90 ° C. Furthermore, poly (methyltrimethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name “MTMS-A”, average number of repeating units 3.5) 29
6.5 g and 2 g of dibutyltin laurate as a catalyst were added, and a methanol removal reaction was carried out in a nitrogen stream at 100 ° C. for 2 hours using a water divider. A methoxy group-containing silane-modified epoxy resin (hereinafter referred to as resin (A-4) was used by replacing the water separator with a reflux tube and further reacting at 100 ° C. for 6 hours.
I got). The weight of the novolac type epoxy resin (2) / the weight of the bisphenol type epoxy resin (1) at the time of preparation was 2.88. Further, the total of the hydroxyl equivalents of the bisphenol type epoxy resin (1) and the novolac type epoxy resin (2) / the alkoxy equivalent of the methoxysilane partial condensate (3) was 0.14. The epoxy equivalent of the resin (A-4) was 310 g / eq.

Comparative Example 1 A bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., trade name "Epicoat 1001", epoxy equivalent 472 g / eq, m = 2.1) was used as it was. Hereinafter, the resin is referred to as resin (a-1).

Comparative Example 2 A bisphenol A type epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd., trade name "Epicoat 1001", epoxy equivalent 472 g / e was added to the same reactor as in Example 1.
q, m = 2.1) 320 g and novolac type epoxy resin (manufactured by Tohto Kasei Co., Ltd., trade name “Epototo YDPN”)
-638P ", epoxy equivalent 177 g / eq) 613.
9 g was added and dissolved at 80 ° C. After cooling to room temperature, further poly (methyltrimethoxysilane) (Tama Chemical Co., Ltd.)
Made, trade name "MTMS-A", average number of repeating units 3.
5) An epoxy resin composition was obtained by mixing 558.2 g. Hereinafter, the resin composition will be referred to as resin (a-2). The weight of the novolac type epoxy resin (2) / the weight of the bisphenol type epoxy resin (1) at the time of preparation was 1.92. Further, the sum of the hydroxyl equivalents of the bisphenol type epoxy resin (1) and the novolac type epoxy resin (2) / the alkoxy equivalent of the methoxysilane partial condensate (3) was 0.12. The epoxy equivalent of the resin (a-1) was 330 g / eq.

Comparative Example 3 A bisphenol A type epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd., trade name "Epicoat 1001", epoxy equivalent 472 g / e, was placed in the same reactor as in Example 1.
q, m = 2.1) 336.0 g and methyl ethyl ketone 268.8 g were added and dissolved at 70 ° C. Furthermore, poly (tetramethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name "MS-51", average number of repeating units 4) 360.4 g
Then, 0.3 g of dibutyltin dilaurate as a catalyst was added, the mixture was refluxed at 80 ° C. for 6 hours, cooled to 50 ° C., 33.6 g of methyl alcohol was added, and a methoxy group-containing silane-modified epoxy resin (hereinafter referred to as resin ( a-4)) was obtained. The hydroxyl equivalent of the bisphenol type epoxy resin (1) / alkoxy equivalent of the methoxysilane partial condensate (3) was 0.1. The obtained methoxy group-containing silane-modified epoxy resin solution had a curing residue of 50.8%, an epoxy equivalent of 1400 g / eq, and a silica content ratio of 36% in the curing residue.

Examples 5 and 6 and Comparative Examples 4 to 6 (Preparation of silane-modified epoxy resin composition and preparation of epoxy resin-silica hybrid semi-cured product) Obtained in Examples 1 and 2 and Comparative Examples 1 to 3. For each resin,
Novolac type phenolic resin (Arakawa Chemical Industry Co., Ltd.,
Trade name Tamanor 759) 50 with methyl ethyl ketone
% Of the epoxy equivalent / phenol equivalent, and tin octylate is added to 2% of the solid content.
% To make an epoxy resin composition.

(Evaluation of Epoxy Resin-Silica Hybrid Semi-Cured Product) Each epoxy resin composition obtained in Examples 5 and 6 and Comparative Examples 4 to 6 was coated with a fluorine resin-coated container (length × width × depth). = 10 cm x 10 cm x 1.5
cm) and heated at 80 ° C. for 1 hour to volatilize the solvent and cure the sol-gel to obtain an epoxy resin-silica hybrid semi-cured product. The state (appearance, shrinkage, foaming, flexibility) of the obtained semi-cured product was evaluated according to the following criteria. The results are shown in Table 1.

(Evaluation of appearance) ○: Transparent. Δ: There is cloudiness. X: Whitened.

(Evaluation of shrinkage) ◯: The cured product has no cracks or warpage. B: Warp exists in the cured product. X: The cured product has cracks.

(Evaluation of foaming) ◯: There are no bubbles in the cured product. Δ: There are less than 5 bubbles in the cured product. X: Five or more bubbles are present in the cured product.

(Evaluation of flexibility) ◯: Flexible and rich in moldability. X: Breaks when deformed.

[0061]

[Table 1]

As is clear from Table 1, each of Examples 5 and 6
In each of Comparative Examples 4 and 5, a transparent semi-cured product was obtained. However, the semi-cured product obtained in Comparative Example 5 was whitened due to phase separation of the epoxy resin and silica, and was extremely brittle. The semi-cured product obtained in Comparative Example 6 was transparent, but cracked when deformed.

Examples 7 and 8 and Comparative Examples 7 to 9 (Preparation and Evaluation of Epoxy Resin-Silica Hybrid Cured Product) The semi-cured product obtained above is further epoxy-cured by heating at 200 ° C. for 1 hour, A completely cured product was obtained.
The state (appearance, shrinkage, foaming, weight change from semi-cured product) of the obtained completely cured product was evaluated according to the following criteria. The results are shown in Table 2.

(Evaluation of appearance) ○: Transparent. Δ: There is cloudiness. X: Whitened.

(Evaluation of shrinkage) ◯: The cured product has no cracks or warpage. B: Warp exists in the cured product. X: The cured product has cracks.

(Evaluation of foaming) ◯: There are no bubbles in the cured product. Δ: There are less than 5 bubbles in the cured product. X: Five or more bubbles are present in the cured product.

(Evaluation of weight change from semi-cured product) ◯: Weight loss is less than 3%. Δ: Change in weight is less than 5%. X: Change in weight is 5% or more.

[0068]

[Table 2]

In Examples 7 and 8 and Comparative Example 9, transparent completely cured products were obtained, and the weight loss from the semi-cured products was slight. The weight of the completely cured product obtained in Comparative Example 7 was greatly reduced. The completely cured product obtained in Comparative Example 8 had unevenness, foaming, and cracks due to phase separation of the epoxy resin and silica, and was extremely brittle.

(Heat Resistance) Examples 7 and 8 and Comparative Examples 7 and 9
The cured film obtained in Step 5 was cut into 5 mm × 20 mm, and a viscoelasticity measuring instrument (Rheology Co., Ltd., trade name “DVE-V” was used.
4 ”, measurement conditions: amplitude 0.5 μm, frequency 10 Hz, slope 3 ° C./min) to measure the dynamic storage elastic modulus,
The heat resistance was evaluated. The measurement results are shown in FIG. In Comparative Example 2, a completely cured product could not be molded, and the evaluation could not be performed.

As is clear from FIG. 1, in Examples 7 and 8 and Comparative Example 9, the glass transition point of the cured film was higher than that in Comparative Example 7, and the elastic modulus did not decrease much even at high temperatures. It has excellent heat resistance.

(Linear Expansion) Examples 7 and 8 and Comparative Example 7
Using the cured film obtained in step 1, a thermal stress strain measuring device (manufactured by Seiko Electronics Co., Ltd., trade name TMA120
In C), the coefficient of linear expansion of 40 to 100 ° C. was measured. The results are shown in Table 3. In Comparative Example 9, a sample having a film thickness necessary for the measurement could not be prepared, and the examination could not be performed.

[0073]

[Table 3]

As is clear from Table 3, Examples 7 and 8 have lower thermal expansion properties than Comparative Example 7.

[Brief description of drawings]

FIG. 1 shows the evaluation results of heat resistance of the cured films obtained in Examples 7 and 8 and Comparative Examples 7 and 9.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4H017 AA04 AB08 AB15 AC01 AC03                       AC10 AC17                 4J036 AA02 AA05 AD08 AF06 AF08                       CC03 CD10 DA10 DB15 DB22                       DC28 DC31 DC40 FB07 JA01                       JA06 JA07 JA08

Claims (10)

[Claims] 1. A bisphenol type epoxy resin (1),
A process for producing a methoxy group-containing silane-modified epoxy resin (A), which is obtained by subjecting a novolac type epoxy resin (2) and a methoxysilane partial condensate (3) to a demethanol condensation reaction. 2. A bisphenol type epoxy resin (1)
However, the epoxy equivalent exceeds 230 g / eq and 1000 g /
The method for producing a methoxy group-containing silane-modified epoxy resin (A) according to claim 1, which is a bisphenol A type epoxy resin having an eq of less than eq. 3. The methoxy group-containing silane-modified epoxy resin (A) according to claim 1 or 2, wherein the novolac type epoxy resin (2) is a phenol novolac type epoxy resin.
Manufacturing method. 4. The silane-modified epoxy resin according to claim 1, wherein the methoxysilane partial condensate (3) is a methyltrimethoxysilane partial condensate and / or a tetramethoxysilane partial condensate. The production method of A). 5. The weight of the novolak epoxy resin / the weight of the bisphenol type epoxy resin (weight ratio) is 0.5 to 5.
The method for producing the silane-modified epoxy resin (A) according to any one of claims 1 to 4. 6. The total equivalent of hydroxyl groups of the bisphenol type epoxy resin (1) and the novolac type epoxy resin (2) / the equivalent of methoxy groups of the methoxysilane partial condensate (3) (equivalent ratio) is 0. It is 03-0.5, The manufacturing method of the silane modified epoxy resin (A) in any one of Claims 1-5. 7. A silane-modified epoxy resin containing the methoxy group-containing silane-modified epoxy resin (A) according to any one of claims 1 to 6 and a latent epoxy resin curing agent (B). Composition. 8. The latent epoxy resin curing agent (B) is phenol novolac resin, cresol novolac resin,
The silane-modified epoxy resin composition according to claim 7, which is at least one selected from the group consisting of acid anhydrides, imidazoles, ketimine compounds, and dicyandiamide. 9. An epoxy resin-silica hybrid semi-cured product obtained by drying and sol-gel curing the silane-modified epoxy resin composition according to claim 7 or 8 at 50 to 120 ° C. 10. The silane-modified epoxy resin composition or semi-cured product according to claim 7, which is at room temperature to 25.
An epoxy resin-silica hybrid cured product that is completely cured at 0 ° C.