JPH09194570A - Epoxy resin composition, modified epoxy resin composition and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an epoxy resin composition, comprising a curable epoxy resin having a specific composition and an engineering plastic, dissolved in the resin and useful for modification, capable of forming a single phase after curing and having a high light transmissivity, etc.

SOLUTION: This resin composition comprises (A) a curable epoxy resin composed of (i) a fluoreneepoxy compound (e.g. bisphenolfluorene diglycidyl ether) and (ii) a fluorenamine and (B) an engineering plastic, dissolved in the component (A) and useful for modification. The modified epoxy resin composition is formed by curing the resultant composition and comprises a single phase formed by compatibilizing a cured product of the epoxy resin with the component (B).

COPYRIGHT: (C)1997,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified epoxy resin composition, and more specifically, regardless of the curing conditions such as curing temperature and curing time, the constituents are compatible and a single phase is formed after curing. The present invention relates to an improved modified epoxy resin composition which is formed, exhibits high light transmittance, and has both high heat resistance and high strength (toughness).

The modified epoxy resin composition of the present invention is useful in the technical field of, for example, molding materials, paints and adhesives, and in particular, the aircraft industry and automobiles where high heat resistance and high strength are required at the same time. It is suitable for use as a structural material used in industry or as an encapsulant for integrated circuits. The present invention also relates to methods for making such modified epoxy resin compositions, and preparative epoxy resin compositions useful as preparative or precursor compositions in making such resin compositions.

[0003]

2. Description of the Related Art Epoxy resins are known to be adhesives,
It is a resin that is used in various fields as a molding material and paint. Epoxy resin is usually formed by mixing an epoxy compound which is a main component with a curing agent thereof, and then curing the mixture by heat or radiation to form an epoxy cured product. It exhibits excellent performance. Usually, when such an epoxy resin is used as a molding material, a filler, a modifier (also generally called a "modifier"), etc. are added in order to improve properties such as mechanical strength and heat resistance. .

One of the universal goals in the research field of improving the properties of such epoxy resins (generally called "modification") is to improve both heat resistance and toughness. Here, the “heat resistance” of a resin including an epoxy resin is represented by its glass transition point (Tg), and its high heat resistance is represented by a high Tg. Also,
"Toughness" is the tenacity of a material, that is, the property of being less likely to break against an external force. As an example, it is represented by the breaking energy described in detail below. High breaking energy has high toughness (or toughness). Meaning).

Methods conventionally used for modifying epoxy resins typically include rubber modification and engineering plastic modification. The modification of the epoxy resin with rubber is usually carried out by using a rubber-like material such as nitrile rubber as a modifying agent, and the effect thereof is referred to the data described in representative publicly known documents. It will be readily understood from the "Comparative Examples" and "Reference Examples" in the "Examples" section below and FIG. That is, in FIG. 1, points 1 to 12 (.
The area A including the group consisting of (1) to (4) is an example of modification using liquid nitrile rubber as a modifier, which has many years of knowledge and experience. In such a modified epoxy resin, the epoxy resin and the liquid nitrile rubber are mixed to form a microphase-separated structure. In order to achieve a desired modification effect, the curing temperature, the curing time, etc. are set. It is necessary to strictly control the conditions and determine the phase separation size.
In addition, as can be seen from this example, heat resistance (T
g) and toughness (fracture energy G _1C ) are in inverse proportion. This is because when the crosslink density is increased by using a bifunctional or polyfunctional epoxy compound to increase heat resistance, the toughness of the cured resin is lowered.

In addition, the above-mentioned modification example and points 13 to 16 (+
From the comparison with the example of the unmodified epoxy resin shown in the region B including the group consisting of That is, for an epoxy resin having heat resistance of about 100 ° C. (generally, curing of a bifunctional epoxy compound), the effect of modification by the liquid nitrile rubber is high (points 1 to 9 showing a high breaking energy value. 20)
With an epoxy resin having a heat resistance of 0 ° C. or higher (generally, curing of a tetrafunctional epoxy compound), the toughening effect is significantly reduced (see points 10 to 12). This is a low Tg
It is considered to be the limit as a modifier of liquid nitrile rubber which has only this.

In order to solve the above-mentioned problems in modifying the epoxy resin with rubber, it is conceivable to use another type of epoxy resin instead. For example, epoxy resins that can be used include U.S. Pat. Nos. 4,524,181, 4,684,678, 4,769,399, 4,882,370 and U.S. Pat.
It is an epoxy resin containing a compound having a fluorene skeleton in the molecule (hereinafter referred to as "fluorene compound"), which is disclosed in JP-A-5,073,595. Since the fluorene compound has a rigid molecular skeleton, it has a high glass transition point of 200 ° C. or higher while being bifunctional.
This is expected to improve the heat resistance in the range where the crosslink density is low and the toughness does not decrease. However,
This fluorene compound-containing epoxy resin shows an example of its heat resistance and toughness, and as shown by point 17 (indicated by ♦) in FIG. However, there is still room for improvement in terms of toughness.

Therefore, for example, US Pat. No. 4,684,6
No. 78, No. 4,980, 234, No. 4,983.
672, 5,045,363, and 5,
As described in No. 073,595, it has also been attempted to modify an epoxy resin containing a fluorene compound with a rubber. The result of such modification is shown in FIG. 1, which is a region C including the group of points 18 (indicated by *) in the figure. As can be seen from this region, the modification with only the rubber is Although a dramatic improvement in toughness can be expected, it also causes a decrease in heat resistance, and therefore there is a strong tendency to sacrifice the high heat resistance originally possessed by the fluorene compound-containing epoxy resin.

Attempts have also been made to modify epoxy resins by using engineering plastics instead of rubber. For example, in recent years, there have been the following reports regarding the modification with engineering plastics such as polyetherimide and polyethersulfone (hereinafter, sometimes abbreviated as “engineering plastic component”). 1) A composition comprising an epoxy resin, a polyetherimide as a toughness imparting agent (modifier), and an imide oligomer (low molecular weight imide) as an admixture. In the case of this composition, by the action of the low molecular weight imide as an admixture, the epoxy resin and the polyetherimide can form a micro phase separation structure having an appropriate phase separation size (32nd Japan Adhesion Society Annual Meeting Abstracts, 65-
See page 66 (1994)).

2) A composition comprising an epoxy resin, polyether sulfone and nitrile rubber. In the case of this composition, polyether sulfone and nitrile rubber are used as modifiers of the epoxy resin, but when high toughness is exhibited, the rubber component becomes the matrix phase (continuous phase) and the continuous rubber component Epoxy resin particles and polyether sulfone particles are dispersed in the phase to form a phase-separated form (Horiuchi et al., Polymer Preprints, Japan,
vol.43, No.3, p.1229 (1994)).

As can be understood from these reported examples, the addition of the engineering plastic component to the epoxy resin makes it possible to improve the toughness of the epoxy resin without substantially lowering the heat resistance thereof. However, in any case, the modification of the epoxy resin with the engineering plastics causes a new problem because the phase separation of the constituent components in the obtained resin composition is inevitable in any case as described above.

The first problem is that the light incident on the resin composition is scattered in the dispersed phase, so that it is difficult to enhance the light transmittance. The low light transmittance limits the use of the resin composition as a molding material because it is difficult to form a colored resin material containing a coloring material and colored in a desired color. The second problem is that the curing conditions are limited because the phase separation size that is important for obtaining the desired performance depends on the curing conditions. Such a limitation requires, for example, a curing treatment at a relatively low temperature for a long time in order to obtain a resin composition having a relatively small phase separation size which is advantageous for exhibiting high toughness. Therefore, it is not suitable for continuous production, and improvement in productivity cannot be expected.

The third problem is that when it is difficult to cure the molded product as a whole under uniform conditions, such as when the molded product of the resin composition has a relatively large size or when the structure is complicated. In addition, uneven strength distribution is likely to occur due to uneven phase separation size. Further, the unevenness of the strength distribution in the molded product may lead to a decrease in toughness.

By the way, although not intended to solve the above-mentioned problems of the prior art, the applicant of the present application discloses the same in US Pat. No. 5,276,7 when disclosed for reference.
No. 06, No. 5,368,922 and No. 5,40
In 5,686, an epoxy resin composition containing a curable epoxy resin and an engineering plastic was disclosed. These U.S. Patents describe a mixture of fluorene epoxy and bisphenol A type epoxy, in which a liquid thermosetting resin before curing and solid particles of a thermoplastic resin such as polyetherimide are dispersed in the resin. An epoxy resin composition containing the same is disclosed. This epoxy resin composition is characterized in that the viscosity does not significantly decrease in the thermosetting process, is prepared without using an organic solvent, and in the composition before thermosetting, the thermoplastic resin has a certain average particle size. It is dispersed as particles with a diameter. That is, the particles of the thermoplastic resin are dissolved in the thermosetting resin when heated above a temperature specified by the thermal characteristics and particle diameter, the viscosity of the composition rapidly increases, and during the thermosetting process. Does not significantly reduce the viscosity.
However, these US patents show that epoxy-containing thermosetting resins are
Means for preparing a cured product having high transparency from an epoxy resin composition and effectively modifying the cured product (improvement of Tg and toughness), although it teaches that the cured product dissolves in the thermoplastic resin. Is not disclosed.

[0015]

SUMMARY OF THE INVENTION The object of the present invention is to improve the problems of the prior art as described above, to provide a resin composition with a uniform phase structure, high light transmittance, and high heat resistance. It is an object of the present invention to provide an improved modified epoxy resin composition which has both excellent properties and high strength (toughness).

Another object of the present invention is to provide a method for producing such a modified epoxy resin composition. Yet another object of the present invention is to provide a preparative epoxy resin composition useful as a preparative composition or a precursor composition in the production of the modified epoxy resin composition as described above.

Other objects of the present invention can be easily understood from the "embodiments of the invention" and "examples" described below.

[0018]

SUMMARY OF THE INVENTION A first object of the present invention is to:
According to the present invention, a modification obtained by curing an epoxy resin composition comprising a curable epoxy resin composed of a fluorene epoxy compound and a fluorene amine, and a modifying engineering plastic dissolved in the curable epoxy resin. It can be achieved by an epoxy resin composition. An epoxy resin composed of a fluorene epoxy compound and a fluorene amine can be cured without causing phase separation while the modifying engineering plastic is dissolved.

The engineering plastic (engineering plastic component) "dissolves in the curable epoxy resin" means that the engineering plastic component and the curable epoxy resin are mixed with each other up to a molecular level or a state close to a molecular level. It means that it is possible to exist in the state of being That is, this state does not mean a state in which the engineering plastic component has a specific average particle size and is dispersed in the curable epoxy resin. In other words, although details will be described later, in the composition after curing, the engineering plastic component and the curable epoxy resin are compatible with each other to form a single phase,
It can be defined as a state in which a uniform single phase is formed even before curing.

A second object of the present invention is to prepare a mixed solution containing an organic solvent, a curable epoxy resin having a combination of a fluorene compound and an engineering plastic for modification dissolved in the organic solvent. Step (b) of preparing an epoxy resin composition comprising (a), a solvent removed from the mixed solution thereof, and a curable epoxy resin and a modifying engineering plastic component dissolved in the curable epoxy resin. And a step (c) of curing the epoxy resin composition. In this manufacturing method, with the help of the dissolving power of the organic solvent, a state in which the curable epoxy resin and the modifying engineering plastic component are sufficiently compatible with each other in advance is created, so that the modifying engineering plastic component remains dissolved. The curable epoxy resin can be cured without phase separation. It is also essential that the curable epoxy resin has a combination of fluorene compounds.

For forming the single phase, the engineering plastic component is dissolved and contained in the curable epoxy resin having a combination of fluorene compounds in the epoxy resin composition before curing, that is, this curable epoxy resin. It is important that the and engineering plastic components are compatible with each other. By curing the composition from a state in which these two components are compatible with each other, a state in which the two components remain compatible after curing can be formed, and the above-mentioned problems can be solved.

Further, in order to form such a single phase, it is essential that the modifier is made of engineering plastic.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION In the modified epoxy resin composition according to the present invention, a curable epoxy resin having a combination of fluorene compounds is used as the first constituent component. Here, the “curable epoxy resin” includes only (A) an epoxy compound which is a main component, and a curing agent for the epoxy compound is added before or during curing, and when cured, an epoxy resin cured product is obtained. Or a material which contains (B) an epoxy compound and a curing agent therefor and can be cured to give an epoxy resin cured product. That is, the cured product of the "curable epoxy resin" always contains the epoxy compound cured by the curing agent.

Usually, if the effective potential of the combination of the curing agent and the epoxy compound cannot be expected, a composition containing the epoxy compound, that is, a precursor composition of the modified epoxy resin composition or a preparation composition is prepared. Store separately from the curing agent, mix the precursor composition with the curing agent immediately before use,
A cured epoxy resin composition is prepared by curing. Also,
In the case of using a combination of an epoxy compound and a curing agent, which have a latent potential to give a sufficient pot life, a curing agent may be added to the curable epoxy resin, that is, the precursor composition in advance. In addition, the term "epoxy compound", when used in the present specification, refers to both a single compound and a mixture of two or more compounds, as described below. Include.

The "curable epoxy resin having a combination of fluorene compounds" means that the fluorene compound and the curable epoxy resin can be used in various combinations, and therefore, for example, Three forms: a curable epoxy resin comprising an epoxy compound and a curing agent therefor, at least one of an epoxy compound and a curing agent containing a fluorene compound; a curable epoxy resin comprising an epoxy compound and a curing agent therefor,
However, neither the epoxy compound nor the curing agent contains a fluorene compound, and the fluorene compound is used as the third component; and the curable epoxy resin comprises the epoxy compound and the curing agent thereof, and the epoxy compound and the curing agent. At least one of them contains a fluorene compound, and in addition to this, a compound containing a fluorene compound as the third component; In addition, these curable epoxy resins are epoxy resin cured products (epoxy compounds cured by a curing agent) whose cured products contain a fluorene compound, that is, fluorene-containing epoxy resin cured products (hereinafter, referred to as “fluorene-epoxy cured products”). (Also referred to as “object”) can be defined as a material. Further, in any of the above cases, the “curable epoxy resin having a combination of fluorene compounds” is a cured product produced by curing it, that is, “fluorene-
"Epoxy cured product" itself acts so as to form a uniform single phase, and when this cured product is combined with the engineering plastic component of the second constituent, the engineering plastic component is made compatible with the cured product, and It can act to form a single phase of components.

As is well known, the "fluorene compound" to be used in combination with the curable epoxy resin is a compound having a fluorene skeleton in the molecule, and can have various structures. For example, taking the case of using a fluorene compound as the third component among the above-mentioned three forms, the fluorene compound as the third component is used as a compatibilizer for the cured epoxy compound and the engineering plastic component. Can act. Specifically, fluorene acrylate compounds (bisphenol fluor orange hydroxy acrylate, bisphenol fluor orange methacrylate, etc.), fluorene phenol compounds (bis phenol fluorene, bis cresol fluorene, bis ethyl phenol fluorene, bis xylenol fluorene, etc.) ) And the like. The fluorene compound as the third component has excellent affinity for the epoxy compound and its curing agent, and therefore, the engineering plastic component is made compatible with the fluorene-epoxy cured product consisting of these three components to form a single phase. can do.

The "fluorene compound" can be contained in at least one of the epoxy compound and the curing agent. Specific examples of the fluorene-containing compound suitable for such a purpose include a fluorene epoxy compound, a curing agent composed of a compound having a functional group capable of reacting with a fluorene skeleton and an epoxy group in a molecule and having three or more functional groups, and the like. included. In the case of these fluorene-containing compounds, the epoxy compound itself, which is cured by reacting with the curing agent, has a compatibilizing effect on the engineering plastic components. Specifically, suitable fluorene epoxy compounds include bisphenol fluor orange glycidyl ether, and fluorene-containing curing agents include fluorene amines (bisaniline fluorene, bistoluidine fluorene, bisdiaminophenylfluorene, bischloroaminophenylfluorene, etc. ) And the like.

Of the three forms described above for the "curable epoxy resin having a combination of fluorene compounds", the preferable form is the epoxy compound and the curing in the presence or absence of the fluorene compound as the third component. At least one of the agents is such that it contains a fluorene compound. In the case of such a fluorene-containing epoxy compound and / or a curing agent, light transmittance, heat resistance, and breaking energy can be easily increased at the same time. From such a viewpoint, it is particularly preferable to select the case where the fluorene compound as the third component is not contained, that is, the case where the curable epoxy resin is composed of the epoxy compound and the curing agent thereof.

When the curable epoxy resin having the fluorene compound in combination is composed of the fluorene epoxy compound and the fluorene amine, the solubility of the engineering plastic component is extremely excellent, and therefore the modified epoxy resin composition having a single phase. Can be obtained particularly easily. "Epoxy compound" constituting the curable epoxy resin of the first constituent in the modified epoxy resin composition of the present invention
As described above, is a material that reacts with the curing agent to form an epoxy cured product, and can be used as a single compound or as a mixture of two or more kinds. It is also possible to use difunctional or higher polyfunctional epoxy compounds to improve the crosslink density.

As the epoxy compound, in addition to the above-mentioned fluorene epoxy compound, an epoxy compound known as a main ingredient of ordinary epoxy resins can be used. Specific examples of such epoxy compounds include diglycidyl ether of bisphenol A (abbreviation “DGEBA”) and tetraglycidyl diaminophenylmethane (abbreviation “TGDD”).
M "), diglycidyl ether of bisphenol F, p
-Aminophenol triglycidyl ether and the like.

Although the epoxy equivalent of the epoxy compound affects the viscosity of the preparation composition, the epoxy equivalent suitable for improving the handleability of the preparation composition is generally 150 to 1,000, Particularly preferably, it is in the range of 170 to 500. Then, the "curing agent" that constitutes the curable epoxy resin together with the epoxy compound, as described above,
It is a material that cures an epoxy compound to produce an epoxy cured product, and a single substance or a mixture of two or more types can be used. As the curing agent, in addition to the above-mentioned fluorene amine, those known as a general curing agent for epoxy resins can be used. Specific examples of suitable curing agents include diaminophenyl sulfone (abbreviation “DDS”), dicyandiamide, diaminodiphenylmethane, and the like. As the curing agent, it is preferable to use the amines as described above, because a single phase is easily formed in the cured resin composition, and the reactivity and the latent property are excellent.

Further, fluorene amine has an excellent ability to make the cured epoxy compound and the engineering plastic component compatible with each other to form a single phase. Therefore, if necessary, a fluorene compound may be contained in addition to the fluorene compound. It is of course possible to prepare the modified epoxy resin composition according to the invention. Further, in addition to the heat-activatable curing agent as described above, a combination of a radiation-activatable epoxy compound and a curing agent can be used unless the effects of the present invention are impaired.

The "curable epoxy resin having a combination of fluorene compounds" used as the first constituent in the modified epoxy resin composition of the present invention has been described above. In connection with this description, in the practice of the present invention, the fluorene compound-containing epoxy resin described in each of the U.S. Patents cited in the above "Prior Art" may also be advantageously used as the first component. Please understand that.

The second constituent used in the modified epoxy resin composition according to the present invention together with the above-mentioned "curable epoxy resin having a combination of fluorene compounds" as the first constituent is a "modifier", above all, ,
It is "engineering plastic for modification". Here, the "modifier" is compatible with a curable epoxy resin, and a cured product containing a modifier has a more remarkable heat resistance than a cured product obtained only from the curable epoxy resin. It can be defined as a polymeric material that acts to improve toughness without degradation. Such modifiers in the present invention consist of engineering plastics,
It does not include modifiers composed of other polymeric materials such as rubber components.

"Engineering plastic (engineering plastics component)," as used herein, is defined to be identical to the high performance resin so-called in conventional technical terms. Useful engineering plastic components are preferably thermoplastics having a glass transition temperature of 100 ° C. or higher. The engineering plastic component may be a single plastic or otherwise a mixture of two or more plastics. Specific examples of suitable engineering plastic components include polyetherimide, polyimide, polyethersulfone, polysulfone, polyphenylene oxide, polycarbonate, polyarylate, polyacetal, polyamide (nylon), polyester, polyether, polyetherketone, polyamideimide or Examples thereof include polyblends and alloys.

The engineering plastic component, which is advantageously used as a modifier in the resin composition of the present invention, is a linear polymer having no cross-linking structure in its molecule, and therefore effectively reduces the cross-linking density of the epoxy cured product. That is, since the engineering plastic component itself is tough and forms the cured composition while being compatible with the epoxy resin, the toughness of the modified epoxy resin composition can be increased. Further, the engineering plastic component itself also exhibits relatively high heat resistance, and since it produces a cured composition in a state of being compatible with the epoxy resin as described above, it does not reduce the heat resistance of the modified epoxy resin composition. It is also possible to increase.

As the engineering plastic component, an aromatic polymer, that is, a polymer containing one or more aromatic rings in its molecule is preferable because it has excellent compatibility with a fluorene-epoxy cured product. As such an aromatic polymer, an aromatic ether, that is, a polymer having a structure having an ether group, that is, an oxygen atom, between two aromatic rings is particularly preferable. These polymers are particularly advantageous for effectively lowering the crosslink density of the epoxy cured product and increasing the fracture energy while maintaining a high level of heat resistance. As the polymer having such an aromatic ether structure, polyetherimide or polyether sulfone is particularly excellent in compatibility with a fluorene-epoxy cured product, and a modified epoxy resin composition having a single phase can be easily obtained. Therefore, it is preferable. Furthermore, since polyetherimide is excellent in three properties of transparency, toughness and heat resistance, a modified epoxy resin composition containing polyetherimide is mentioned as one of the best embodiments of the present invention. To be

In the modified epoxy resin composition according to the present invention, as described above, the fluorene-epoxy cured product and the modifier comprising the engineering plastic component are compatible with each other by the action of the fluorene compound to form a single phase. ing. Here, the "single phase" is defined as a state in which no phase separation between the phase of the epoxy cured product and the phase of the modifier comprising the engineering plastic component is observed in the modified epoxy resin composition.

To form such a single phase, the engineering plastic component is dissolved and contained in a curable epoxy resin having a combination of a fluorene compound in the epoxy resin composition before curing, that is, this curing. It is important that the water-soluble epoxy resin and the engineering plastic component are compatible with each other. By curing the composition from the state where these two components are compatible with each other, a state where they remain compatible after curing can be formed.

In the first preferred mode for preparing the epoxy resin composition in which the two components are compatible with each other, the curable epoxy resin having the fluorene compound in combination is composed of the fluorene epoxy compound and the fluorene amine. To do so. This is because the epoxy resin composed of the fluorene epoxy compound and the fluorene amine can be cured without the phase separation while the engineering plastic component is dissolved.

A second preferred form for preparing an epoxy resin composition in which the two components are compatible with each other in this manner is to combine an organic solvent and a fluorene compound dissolved in the organic solvent. A step of preparing a mixed solution containing a curable epoxy resin and an engineering plastic having, a solvent is removed from the mixed solution, and a curable epoxy resin and a modifying engineering plastic dissolved in the curable epoxy resin are prepared. Comprises,
It is a method of preparing an epoxy resin composition. Creating a state in which the curable epoxy resin and the engineering plastic component are sufficiently compatible with each other with the help of the dissolving power of the organic solvent means that the curable epoxy resin undergoes phase separation while the engineering plastic component is dissolved. This is because it can be cured without any treatment.

Observation of a single phase in the resin composition can be confirmed by transmission observation of the resin composition with an optical microscope.
For example, a film-shaped resin composition having a thickness of about 0.1 mm is applied onto a slide glass, and the applied composition is 400 to 1,000.
When phase separation is not observed when observing with transmission at × 2,
It can be defined as "a single phase is formed".
Usually, since the fluorene-epoxy cured product and the engineering plastic component have different refractive indexes, if they are phase-separated, these two phases can be easily confirmed by observation with an optical microscope.

Also, from the observation of the fracture surface of the resin composition with an electron microscope, it can be similarly confirmed that the resin composition has a single phase. Usually, the fracture surface of the material that is phase-separated is observed as a matrix surface having relatively small irregularities corresponding to the matrix phase and a protrusion from the matrix surface corresponding to the dispersed phase. However, the above-mentioned protrusions are not observed in the fracture surface of the single-phase material.

The formation of a single phase can also be confirmed by the fact that the resin composition exhibits high light transmittance. This is because in a resin composition in which phase separation is observed, incident light is scattered in the dispersed phase and the light transmittance is reduced. Such light transmittance can be evaluated by measuring the light transmittance. For example, it can be evaluated by using a film-shaped resin composition having a thickness of about 0.25 mm as a sample and measuring the light transmittance using a light transmittance measuring device such as a haze meter. In the case of the modified epoxy resin composition forming a single phase, when measured in this way, it is 400 to 800 nm.
The light transmittance of light is usually 90% or more. In one best embodiment of the present invention, a high light transmittance of 95% or more can be achieved by selecting the type and content ratio of each component.

The modified epoxy resin composition according to the present invention comprises
It can be prepared according to various techniques. Preferably, the modified epoxy resin composition of the present invention contains a curable epoxy resin having a combination of a fluorene compound and a modifier comprising an engineering plastic component, which will be described below. It can be prepared by subjecting the composition for preparation which is a precursor composition to a curing treatment to cure the curable epoxy resin. By the curing treatment, it is possible to easily prepare a resin composition in which a fluorene-epoxy cured product that is a cured product of the curable epoxy resin and an engineering plastic component that is a modifier are compatible to form a single phase. it can.

To further explain, the curable epoxy resin having a combination of epoxy compounds can be cured by the action of application of energy such as heat or radiation in the presence of a curing agent. The curable epoxy resin containing the above-mentioned fluorene epoxy compound and / or fluorene amine is suitable for heat curing. When performing thermosetting, the heating temperature is usually in the range of 100 to 300 ° C. This heat curing may be performed in a single step,
Otherwise, it may be carried out in two steps consisting of pre-curing and post-curing. Thermal curing in two steps is effective in avoiding charring of the cured product during curing. Because
The thermal curing is usually carried out at a temperature equal to or higher than the Tg of the cured product, but when the cured product has a relatively high Tg, heating the precursor composition at such a high temperature from the beginning causes internal curing accompanying This is because the cured product may be burnt due to heat generation. The two-step curing can avoid such an adverse effect and sufficiently cure the precursor composition while shortening the total curing time. In this case, it is advantageous to make the curing temperature in the post-curing higher than the curing temperature in the pre-curing, because it facilitates sufficient curing and formation of a single phase. Specifically, the pre-curing temperature is 130 ° C.
It is in the range of 200 ° C or higher and the post-curing temperature is 200 ° C
It is preferable that the temperature is in the range of 300 ° C or higher and lower than 300 ° C. If the pre-curing temperature is lower than 130 ° C, the total time for completing the curing tends to be long, while if it is 200 ° C or higher, formation of a single phase may be difficult. Also,
If the post-curing temperature is lower than 200 ° C, sufficient curing may not be performed and the heat resistance of the resin composition may not be sufficiently enhanced. On the contrary, if the post-curing temperature is 300 ° C or higher, coloring due to oxidative deterioration is remarkable. May occur, and the light transmittance may be reduced. From this point of view, particularly preferably, the pre-curing temperature is in the range of 160 ° C or higher and 190 ° C or lower, and the post-curing temperature is in the range of 230 ° C or higher and lower than 270 ° C. The curing treatment of the precursor composition is performed by applying the precursor composition to a predetermined site, coating the base material made of a material such as glass or metal to a predetermined thickness, and then heating the base material together. It can be done by For coating, a usual coating means such as knife coater or extrusion coater can be used. It is also possible to inject the precursor composition into a mold having an inner surface that has been subjected to a release treatment in advance, and then heat the entire mold.

A preparative epoxy resin composition according to the invention,
That is, the composition for preparing the modified epoxy resin composition of the present invention can be prepared, for example, as follows. Add an epoxy compound to a solution of engineering plastics dissolved in an organic solvent and leave it at room temperature (about 25 ° C;
Means that the operation is performed in an environment of about 25 ° C. unless otherwise specified), and the mixture is stirred and mixed until a uniform solution is obtained to obtain a premix. Then, a curing agent is added to the obtained preliminary mixture, and after stirring and mixing in the same manner as above for several tens of minutes to several hours, it is a uniform and transparent liquid.
A preparative composition containing an organic solvent can be obtained. As the stirring device, a commonly used stirring device, for example, a screw type mixer, a homogenizer, a kneader or the like can be used. When a coating film made of an epoxy resin composition is formed on the surface of a substrate such as a glass plate, the preparation composition containing the solvent can be used, and the coating composition can be applied and dried to form the coating film. The mold can be filled with a solid epoxy resin composition obtained by removing the solvent, and fluidized by a heat treatment such as a curing operation to be molded.

As the organic solvent, a good solvent for the engineering plastic component, for example, a chlorinated solvent such as methylene chloride is suitable, and it is easy to form an epoxy resin composition in which the curable epoxy component and the engineering plastic component are compatible with each other. . The amount of the organic solvent in the epoxy resin composition may be determined in such a range that the compatibility of the above two components and the handleability of the epoxy resin composition are good, and is, for example, in the range of 10 to 90% by weight. .

In the preparation composition according to the present invention, the epoxy equivalent of the epoxy compound and the equivalent of the curing agent are usually adjusted to be equal. Further, the content ratio of the engineering plastic component to 100 parts by weight of the curable epoxy resin is preferably 1 to 50 parts by weight, and particularly preferably 10 to 30 parts by weight. If the engineering plastic component exceeds 50 parts by weight, it may be difficult to form a single phase, and if it is less than 1 part by weight,
The effect of improving the breaking energy may be reduced. In addition, here, the weight part of curable epoxy resin is the sum total of an epoxy compound and a hardening | curing agent.

The content ratio of the fluorene compound in the whole curable epoxy resin having the fluorene compound in combination is preferably 5% by weight or more, and particularly preferably 30% by weight or more. When the content ratio of the fluorene compound is less than 5% by weight, the compatibilizing action is lowered, the formation of a single phase tends to be difficult, and the breaking energy may be lowered. The upper limit of the content ratio of the fluorene compound is not particularly specified, and for example, if it is 5% by weight or more, all of the curable epoxy resins (that is,
100% by weight may consist solely of the fluorene compound.

The modified epoxy resin composition according to the present invention and the preparation composition therefor can be prepared as described above. In addition, various additives may be added to these resin compositions, if necessary, as long as the effects are not impaired. For example, as long as the fluorene-epoxy cured product and the engineering plastic component form a single phase and do not reduce the improved level of light transmission, heat resistance, and toughness, a curing accelerator, a flow control agent, an antistatic agent. Additives such as a lubricant, an antioxidant, and an ultraviolet absorber can be optionally added. Further, since the modified epoxy resin composition of the present invention has high light transmittance as described above, a composition containing a coloring agent such as a pigment or a dye in its preparation composition is cured to obtain high heat resistance. It is also possible to prepare a colored resin material which is colored in a desired color and has high toughness and high toughness.

The modified epoxy resin composition according to the present invention comprises
As described above, it is useful in the technical field of molding materials, paints, adhesives and the like. For example, when the modified epoxy resin composition is used as a molding material, the modified composition is charged into the molding die or brought into contact with the molding die, and cured in that state to give a resin composition. It is possible to obtain a molded product made of a product. When used as a hard coat coating for surface protection of glass products, the composition for preparation can be applied on the surface of glass products and then cured to form a hard coat. Furthermore, the preparation composition can be handled and used as an adhesive in the same manner as an ordinary epoxy adhesive.

[0053]

The present invention will be described below with reference to its embodiments. However, it should be understood that the invention is not limited to only these examples. Further, in order to facilitate understanding of the present invention, comparative examples and reference examples will be described together. Reference Examples Epoxy Resin Compositions 1 to 16 Epoxy resin compositions can exhibit various properties depending on factors such as changes in the composition and the presence or absence of modification treatment. For reference, the relationship between the glass transition point (Tg) and the breaking energy (G _1C ) of cured products from 12 types of rubber-modified epoxy resin compositions and 4 types of unmodified epoxy resin compositions is shown. As shown in Table 1 below, and FIG. 1 is a plot of these data. In FIG. 1, the shaded area A corresponds to the rubber-modified epoxy resin composition, and the shaded area B is shown.
Corresponds to the unmodified epoxy resin composition.

[0054]

[Table 1]

In the above Table 1, DGEBA means diglycidyl ether of bisphenol A, TGDD
M means tetraglycidyl 4,4'-diaminodiphenylsulfone, DDM means 4,4'-diaminodiphenylmethane, DDS means 4,4'-diaminodiphenylsulfone, and CTBN contains a carboxyl end group. Butadiene-acrylonitrile copolymer of Also, the property data for each composition are from the references listed below, respectively.

[0056]Composition Reference name 1,2,16 AFYee and RAPerson, J. Mater.Sci., 21, 2462 (1986); ibid., 21, 2475 (1986). 3-5, 13 ARSiebert and CKRiew, Org, Coat. Plast.Chem., 31, 5 52 (1971). 6-8 S.Kunz-Douglass, PWR Beaumont and MFAshby, J. Material.Sci., 15, 1109 (1980). 9, 10, 14, PJ Pearce, BC Ennis and CE Morris, Poly.Commun., 29 15, 93 (1988). 11, 12 AFYee and RAPerson, J. Mater.Sci., 21, 2462, 2475 ((1986) .RAPerson and AFYee, J. Mater. Sci., 24, 2571 ( 1989). Epoxy resin composition 18 Epoxy resin composition containing rubber-modified fluorene compound
Glass transition point (Tg) and fracture energy of these cured products
(G_1C), And plotting with the point group 18 in FIG.
And is surrounded by the shaded area C. Note that this
These modified fluorene compound-containing epoxy resin composition,
Developed by the applicant, their characteristic data
In U.S. Pat. Nos. 4,684,678 and 4,98.
0,234, 4,983,672, 5,0
Description of No. 45,363 and No. 5,073,595
Based onExample 1 Epoxy Resin Composition 19 The modified epoxy resin composition according to the present invention is shown in Table 2 below.
By using the ingredients described in 1) in the blending amount described,
Prepared.

Polyetherimide (engineering plastic component; hereinafter referred to as "PEI";"UL manufactured by GE Plastics Co., Ltd."
TEM1000 ") was dissolved in methylene chloride into an engineering plastic solution, and bisphenol fluorenediglycidyl ether (fluorene epoxy compound; hereinafter referred to as" FEP ";" Epon HPT Re "manufactured by Ciel Chemical Co.
sin 1079 ”; epoxy equivalent = 231) was added, and the mixture was stirred and mixed at room temperature (about 25 ° C.) for about 30 minutes until a uniform engineering plastic-epoxy mixed solution was obtained. The obtained homogeneous mixed solution is referred to as a premix here. Bischloroaminophenylfluorene (fluorene-based tetrafunctional curing agent; hereinafter referred to as "C
AF ”; manufactured by 3M Co .; amine equivalent = 104) was added, and the mixture was stirred and mixed at room temperature for 30 minutes. A uniform and transparent liquid composition (solvent-containing preparative epoxy resin composition) was obtained. Epoxy and amine equivalents were equal for this composition. The stirring device used in the above stirring and mixing was a lab stirrer equipped with a single screw.

After the solvent-containing preparation composition prepared as described above was coated on a slide glass and dried, the resulting epoxy resin composition together with the slide glass was placed in a curing oven, and first about 180 It was pre-cured at 2 ° C for 2 hours and then post-cured at 250 ° C for 2 hours. The modified epoxy resin composition according to the present invention was obtained, which was composed of a film-shaped cured product having a thickness of about 0.1 mm.

Transmission observation of the modified epoxy resin composition of the present example prepared as described above by an optical microscope (magnification:
400 times and 1,000 times), and surface observation of the fracture surface of the resin composition by an electron microscope (magnification: 5,000)
It was confirmed from this result that the resin composition had a phase structure composed of a single phase in which the fluorene-epoxy cured product and the engineering plastic component were mutually compatible.

The light transmittance of the modified epoxy resin composition of this example was measured as follows. Using a haze meter (NDH-SENSOR manufactured by Nippon Denshoku Co., Ltd.) as a sample, a film-shaped resin composition having a thickness of about 0.25 mm formed on a slide glass having a thickness of about 1.0 mm was used to measure a wavelength of 400 to The transmittance for 800 nm light was measured. The measured light transmittance was 96.1%.

The heat resistance (evaluation regarding Tg) of the cured product of the modified epoxy resin composition of this example was measured as follows. Using a test piece of about 1 mm × about 5 mm × about 45 mm made of the resin composition prepared in the same manner as above, the viscoelasticity was measured under bending mode, frequency 3 Hz, and temperature rising conditions from room temperature to 300 ° C. The peak temperature of the loss tangent was defined as Tg (glass transition point). The measuring device is a dynamic viscoelasticity measuring device manufactured by Rheometrics,
(Model number) RSA-2. The measurement results obtained are shown in Table 2 below.

Further, the fracture energy (G _1C ) which is a measure of toughness was measured as follows. A precursor composition obtained by removing the solvent from the solvent-containing preparation composition, that is, an epoxy resin composition was injected into a mold subjected to a mold release treatment, and then cured under the same two-stage curing conditions as above. .
The obtained sample for measurement had a plate shape, and the size thereof was about 8 mm × about 21.5 mm × about 26.0 mm as measured according to the method specified in ASTM E-399-83. The fracture toughness value (K _1C ) of this plate-shaped sample was measured using a tensile tester, and the fracture energy (G _1C ) was determined from this fracture toughness value by the following equation (1). The measurement results obtained are shown in Table 2 below.

[0063]

[Equation 1]

Here, B is the compressive elastic modulus, and ν is the Poisson's ratio. The compressive elastic modulus (B) is a value determined from the above equation (2) from the storage elastic modulus and Poisson's ratio (ν) obtained by the above viscoelasticity measurement, and the Poisson's ratio (ν) is
An empirical value of 0.4, which is also used in many papers, is adopted. The Tg and G _1C measured in this example are plotted as point 19 in FIG. Example 2 Epoxy Resin Composition 20 By using a modified epoxy resin composition according to the present invention according to a procedure similar to that described in Example 1 above and using the components set forth in Table 2 below in the amounts described. , Prepared. In this example, the content of the engineering plastic component was increased from 11 parts by weight to 25 parts by weight with respect to 100 parts by weight of the curable epoxy resin (a component composed of an epoxy compound and fluorene amine). The results of the confirmation of the single phase, the breaking energy (G _1C ) and the glass transition point (Tg) are shown in Table 2 below. Moreover, the measured value of the light transmittance was 95.7%.

The Tg measured in this example and
G_1CIs plotted as point 20 in FIG.Comparative Example 1 Epoxy resin composition 17 The procedure described in Example 1 above was repeated. However, in this example,
For comparison, the use of engineering plastics component PEI is omitted.
Was. As a result of confirmation of the single phase, the breakdown energy (G _1C) And
And the glass transition point (Tg) measurement results are shown in Table 2 below.
Show. The measured light transmittance was 97.8%.

The Tg and G _1C measured in this example are plotted as point 17 in FIG.

[0067]

[Table 2]

As is apparent from the results shown in Table 2 above and the points 19, 20 and 17 plotted in FIG.
In the modified epoxy resin compositions of Example 1 and Example 2 in which the fluorene-epoxy cured product and the engineering plastic component are compatible with each other to form a single phase, the unmodified epoxy cured product (Comparative Example 1) is used. The toughness can be improved with almost no decrease in Tg as compared with This is an advantageous effect as compared with the conventional modification method using a rubber component at the expense of Tg. Comparative Example 2 Epoxy Resin Composition 21 The procedure described in Example 1 above was repeated. However, in this example,
For comparison, polyether sulfone (PES as engineering plastics component; “Victrex 4” manufactured by Mitsui Toatsu Chemicals, Inc.)
100G ") is dissolved in methylene chloride, and then diglycidyl ether of bisphenol A as an epoxy compound (DGEBA;" DER33 "manufactured by Dow Chemical Co., Ltd.).
2 ″; epoxy equivalent = 173), and then 4,4′-diaminodiphenyl sulfone (D
DS; amine equivalent = 62) was added and mixed with stirring for 30 minutes. A solvent-containing preparative composition was obtained.
In this composition, the epoxy equivalent and the amine equivalent are equal, PES in the composition is 20% by weight of the total weight of the composition, and the compounding ratio (parts by weight) of DER332, DDS and PES is 100 /. It was 35.9 / 34.0.

In the cured product obtained by removing the solvent from the solvent-containing preparation composition and then curing, a phase separation structure was confirmed after the curing, and the light transmittance was 84.3%.
It showed that its transparency was low. Comparative Example 3 Epoxy resin composition 22 The procedure described in Comparative Example 2 was repeated. However, in this example, instead of PES as an engineering plastic component, the same amount of polyetherimide (PEI; “UL manufactured by GE Plastics Co., Ltd.
TEM1000 ") was used. After the epoxy resin composition was cured, a phase-separated structure was confirmed, and the light transmittance was 85.6%, showing that the transparency was low. Comparative Example 4 Epoxy Resin Composition 23 The procedure described in Comparative Example 2 was repeated. However, in this example, instead of DGEBA as an epoxy compound, an equivalent amount of dicyandiamide (“CG-1200” manufactured by ACI Japan Limited; equivalent amount = 21) was used. After the epoxy resin composition was cured, a phase-separated structure was confirmed, and the light transmittance was 75.4%, showing that the transparency was very low. Comparative Example 5 Epoxy resin composition 24 The procedure described in Comparative Example 4 was repeated. However, in this example, the same amount of PE was used instead of PES as the engineering plastic component.
I, "ULTEM1000" was used. After the epoxy resin composition was cured, a phase-separated structure was confirmed, and the light transmittance was 61.6%, showing that the transparency was very low. Examples 3 to 13 Epoxy resin composition 25 to 35 The modified epoxy resin composition according to the present invention was blended according to the same procedure as described in Example 1 and the components shown in Table 3 below. Prepared by using in. In the table, FEP as an epoxy compound is bisphenol full orange glycidyl ether (shell.
Chemical company "Epon HPT Resin 10
79 "; epoxy equivalent = 231), and BAF as a curing agent is bisaminophenylfluorene (manufactured by 3M Co .;
Amine equivalent = 87), and CAF is bischloroaminophenylfluorene (3M; amine equivalent = 1)
04). In these examples, the modified epoxy resin compositions prepared were all homogeneous, single phase, showing no phase separation, indicating high transparency.

[0070]

[Table 3]

[0071]

[Table 4]

[0072]

According to the present invention, a fluorene-epoxy cured product produced from a curable component containing an epoxy resin,
Since a modifier composed of engineering plastic components is compatible with each other to form a single phase, which gives a resin composition without phase separation,
Light transmission is enhanced, curing conditions are not limited,
It is possible to provide a modified epoxy resin composition which does not cause nonuniform strength distribution due to nonuniform phase separation size. Further, according to the present invention, in addition to these remarkable effects, the improvement effect of heat resistance and toughness can be achieved at a sufficient level due to the modifying effect of the engineering plastic component.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between glass transition point (Tg) and breaking energy (G _1C ) in various epoxy resin compositions.

Claims (4)

[Claims] 1. An epoxy resin composition comprising a curable epoxy resin composed of a fluorene epoxy compound and a fluorene amine, and a modifying engineering plastic dissolved in the curable epoxy resin. 2. The epoxy resin composition according to claim 1 formed by curing, wherein the epoxy resin cured product and the modifying engineering plastic are compatible with each other to form a single phase. A modified epoxy resin composition characterized in that 3. An epoxy resin cured product formed by curing an epoxy resin composition comprising a curable epoxy resin having a combination of a fluorene compound and a modifying engineering plastic dissolved in the curable epoxy resin. A method for producing a modified epoxy resin composition in which the modified engineering plastic and the modifying engineering plastic are compatible with each other to form a single phase, which comprises the following steps: (a) an organic solvent; Preparing a mixed solution containing the curable epoxy resin and the modifying engineering plastic dissolved in a solvent, (b) removing the solvent from the mixed solution to form the curable epoxy resin, and A step of preparing an epoxy resin composition containing the modifying engineering plastic dissolved in a curable epoxy resin, And (c) curing the epoxy resin composition at a curing temperature sufficient to cause curing of the curable epoxy resin in the presence of a curing agent. Method for producing modified epoxy resin composition. 4. The step (c) of curing the epoxy resin composition comprises a step of pre-curing at a first curing temperature sufficient to cause curing of the curable epoxy resin, and a step of the pre-curing step. After completion, a step of post-curing at a second curing temperature higher than the first curing temperature is included, and the manufacturing method according to claim 3.