JPS62183340A - Fiber reinforced composite material - Google Patents

Abstract

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

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a fiber-reinforced material using a cured product of an epoxy resin composition containing a specific polyglycidyl derivative and an epoxy curing agent as essential components as a matrix and fiber as a reinforcing material. It concerns composite materials.

[Conventional technology]

Fiber-reinforced composite materials, which have a cured epoxy resin composition as a matrix and reinforced with carbon fibers, alumina fibers, polyamide fibers, etc., have excellent mechanical properties and are used for structural parts in various industries. It is also used in sports and leisure goods.

[Problem that the invention seeks to solve]

However, as the field of application of composite materials has expanded in recent years, there has been a demand for materials that maintain chemical stability and mechanical properties under harsher environments such as higher temperatures and temperatures than those in which they have been used up until now. It's here.

In fiber-reinforced composite materials, the resin used as a matrix is important to maximize the properties of the reinforcing fibers, and therefore, various epoxy resin compositions are being actively developed. As a fiber-reinforced composite material with a matrix of
No. 217 proposes a carbon fiber-reinforced composite material using an epoxy resin matrix consisting of triglycidylaminophenol and diphenyldiaminosulfone. This composite material has a relatively high glabellar shear strength, but depending on the application, the glabellar shear strength may be even higher.
Furthermore, given the current demand for composite materials with excellent heat resistance and water resistance, this is not necessarily satisfactory.

Furthermore, since these epoxy resins have a high viscosity, there are problems depending on the molding method.

An object of the present invention is to provide a fiber-reinforced composite material having higher glabellar shear strength, heat resistance, and water resistance.

[Means for solving problems]

The present invention uses a cured product of an epoxy resin composition containing a polyglycidyl derivative of an aminophenol compound whose aromatic ring is substituted with at least one alkyl group and an epoxy curing agent as essential components, and fibers as a reinforcing material. Provides a fiber-reinforced composite material with characteristics.

The present invention was developed as a result of intensive studies in view of the above-mentioned circumstances.The present invention has been developed as a result of intensive studies in which an epoxy resin composition in combination with a specific polyglycidyl derivative and an epoxy curing agent is used as a matrix material. It was discovered that a composite material can be obtained.

The present invention will be explained in detail below.

The polyglycidyl derivative used in the present invention is a polyglycidyl derivative of aminophenol in which the aromatic ring is substituted with one or more alkyl groups. Compared to polyglycidyl derivatives of aminophenols in which the alkyl group is unsubstituted, this polyglycidyl derivative does not require any particular purification during production and can be obtained with high purity, so it has a low viscosity and excellent moldability. Furthermore, a fiber-reinforced composite material with excellent interlaminar shear strength, heat resistance, and water resistance can be obtained. Particularly from the viewpoint of moldability, polyglycidyl derivatives having a viscosity at 25° C. of 15 voids or less are preferred.

The method for producing the polyglycidyl derivative is not particularly limited, but to give an example, an alkyl group-substituted aminophenol is prepared in an excess (for example, 5 times the mole, preferably 10 times or more) of epihalohydrin (e.g., epichlorohydrin) at 100% After the addition reaction of epihalohydrin to amino groups at a temperature below ℃, an aqueous solution of caustic alkali is added dropwise under reduced pressure at a temperature of 40 to 100 ℃, and at the same time water in the reaction system is distilled off azeotropically, resulting in epoxidation. Examples include a method of reacting. The above reaction is characterized in that side reactions other than the epoxidation reaction are extremely suppressed, unlike existing epoxidation reactions. Therefore, a low molecular weight polyglycidyl derivative with a high content of epoxy groups can be obtained.

Particularly preferably, a polyglycidyl derivative having a viscosity of 15 voids or less at 25° C. can be obtained by using about 15 moles or more of epihalohydrin. This is an extremely low value for a trifunctional polyglycidyl derivative.

The polyglycidyl derivative used in the present invention has about three polyglycidyl groups bonded to one aromatic ring, and has a higher epoxy group content than existing polyglycidyl derivatives, so its cured product has a higher crosslinking density,
It is thought to exhibit a high degree of heat resistance.

The alkyl group of the alkyl group-substituted aminophenol compound, which is the raw material for the polyglycidyl derivative used in the present invention, has 1 to 5 carbon atoms, and preferably has one alkyl group substitution.Specifically, 4-amino -m-cresol,
4-amino-0-cresol, 6-amino-m-cresol, 5-amino-m-cresol, 3-ethyl-4-
One or more of aminophenol, 2-ethyl-4-aminophenol and the like are preferably used. Particularly preferably 4-amino-m-cresol, 4-amino-0
-It is a cresol.

The polyglycidyl derivative used in the present invention can also be used in combination with existing epoxy resins. These epoxy resins include bisphenol F;

Hydroquinone, resorcinol, phloroglycin, tris-(4-hydroxyphenyl)methane, 1,1,2.2
- Glycidyl ether compound 2 derived from divalent or trivalent or higher hydric phenols such as tetrakis(4-hydroxyphenyl)ethane or halogenated bisphenols such as tetrabromobisphenol A, aniline, p
-aminophenol, m-aminophenol, 4.4°
-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)
Benzene, 1.3-bis(4-aminophenoxy)benzene, 1.3-bis(3-aminophenoxy)benzene, 2.2-bis(4-aminophenoxyphenyl)propane, p-phenylenediamine, m-phenylene Diamine, 2゜4-toluenediamine, 2,6-toluenediamine, p-xylylene diamine, m-xylylene diamine, 1,4-cyclohexane-bis(methylamine)
, 1,3-cyclohexane-bis(methylamine),
5-amino-1-(4'-aminophenyl)-1,3,
3-trimethylindane, 6-amino-1-(4”-aminophenyl)-1,3° Amine-based epoxy resin derived from 3-trimethylindane, p-oxybenzoic acid, m-oxybenzoic acid, terephthal Glycidyl ester compounds derived from acids, aromatic carboxylic acids such as isophthalic acid, hydantoin epoxy resins derived from 5,5-dimethyl hydantoin, etc.
bis(3,4-epoxycyclohexyl)propane,
212゛-bis(4-(2,3-epoxypropyl)cyclohexyl)propane, vinylcyclohexene dioxide, 3,4-epoxycyclohexylmethyl-3,
Examples include alicyclic epoxy resins such as 4-epoxycyclohexanecarboxylate, and one or more of triglycidyl isocyanurate, 2,4.6-)liglycidoxys-)lyazine, and the like.

When using a polyglycidyl derivative of aminophenol whose aromatic ring is substituted with one or more alkyl groups and another epoxy resin, the above polyglycidyl derivative
It is desirable that the content is at least 50% by weight, preferably at least 50% by weight.

The epoxy curing agent used in the present invention includes conventionally known epoxy curing agents, such as diaminodiphenylsulfone,
Diaminodiphenylmethane compound, dicyandiamide,
Tetramethylguanidine, phenol novolac resin,
Examples include acid anhydrides, aromatic amines, aliphatic amines, and boron trifluoride complexes.

Among these curing agents, diaminodiphenyl sulfone compounds, diaminodiphenylmethane compounds, and acid anhydrides are preferred.

Diaminodiphenylsulfone, diaminodiphenylmethane compounds include 4.4°-diaminodiphenylsulfone, 3.3'-diaminodiphenylsulfone, 4.4'
Examples of acid anhydrides include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahyphthalic anhydride, dodecenylsuccinic anhydride, and nadic anhydride. acids, methylnadic anhydride, phthalic anhydride, romellitic anhydride,
Benzophenonetetracarboxylic anhydride, methylcyclohexenetetracarboxylic anhydride, 3,4-di-carboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride, 1-methyl-3,4-dicarboxylic anhydride -Carboxy-1°2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride is exemplified. These may be used alone or in a mixture of two or more.

More preferred are diaminodiphenylsulfone and/or
or a diaminodiphenylmethane compound, and a curing agent containing 30% by weight or more, particularly 50% by weight or more of these is preferable.

The polyglycidyl derivative used in the present invention has particularly excellent affinity with diaminodiphenylsulfone and diaminodiphenylmethane compounds, and the resulting resin is easy to handle and has good homogeneity in terms of physical properties.

The usage ratio of the epoxy curing agent is 0.4 to 1.4, assuming that the amount theoretically calculated from the total amount of epoxy groups in the polyglycidyl derivative or the mixture of this and the epoxy resin is 1.
The amount is preferably in the range of 0.5 to 1.2 times.

Furthermore, if necessary, conventionally known tertiary amines, phenol compounds, imidazoles, Lewis acids, etc. may be added as curing accelerators.

For example, combination use with a boron trifluoride amine complex is preferred.

Examples of fibers used as reinforcing materials in the present invention include carbon fibers, graphite fibers, glass fibers, silicon carbide fibers, alumina fibers, titania fibers, boron nitride fibers, aromatic polyamide fibers, aromatic polyester fibers, and polybenzimidazole fibers. , tensile strength 0.5 GPa or more, Young's modulus 50 GPa
Examples include inorganic or nucleating fibers of a or more.

These fibers can be used in the form of continuous tows, woven fabrics, short fibers, voice cars, and the like.

Furthermore, depending on the purpose of use, it is also possible to use two or more types of fibers or fibers with different shapes. Furthermore, in addition to reinforcing fibers, mixing granular materials such as talc, mica, calcium carbonate, alumina hydrate, silicon carbide, carbon black, and silica improves the viscosity of the resin composition and makes it easier to mold the composite material. It is also effective for improving the physical properties of the resulting composite material, such as compressive strength.

As a method for manufacturing the composite material of the present invention, any method such as a method for manufacturing a fiber-reinforced composite material using an epoxy resin as a matrix can be employed.

- An example is a method of laminating a plurality of sheet prepregs and heating and pressurizing them in an autoclave to obtain a composite material.

The prepreg herein refers to reinforcing fibers impregnated with the resin composition, and is in the form of sheets, continuous tows, strands, yarns, or pellets. In sheet-like products, the reinforcing fibers are arranged in continuous tows,
It takes the form of a mat of short fibers or a woven fabric. Also useful are laminated sheet prepregs made by stacking several of these sheets with different structures, and a bundle of several continuous tow prepregs.

The fiber content of these prepregs is generally 5 to 70% by volume.
, particularly preferably 10 to 60% by volume.

A fiber-reinforced composite material can be obtained by forming these prepregs into a desired shape by stacking or winding them, and then heating and pressurizing them. Furthermore, when a low-viscosity polyglycidyl derivative is used, it is particularly effective in terms of moldability in the filament winding method.

〔Effect of the invention〕

As explained above, the fiber-reinforced composite material of the present invention has better heat resistance and water resistance than conventional fiber-reinforced composite materials using epoxy resin, and also has bending strength, bending modulus,
It also shows excellent properties in terms of glabella shear strength.

〔Example〕

Example 1 The epoxy resin and curing agent shown in Table 1 were blended in the proportions shown in Table 1 to prepare a methyl ethyl ketone solution with a solids content of 60% by weight. This resin solution was continuously impregnated with carbon fibers (Magnamite AS-4, manufactured by Sumika Harkieless), and then wound up on a drum wrapped with silicone release paper. The amount of resin solution deposited was controlled by sandwiching the impregnated carbon fiber between two stainless steel rods with an adjusted interval.

The resin solution-impregnated carbon fiber wound on release paper was cut open and removed from the drum, and dried in a hot air dryer for 12 hours.
A dried prepreg was produced by keeping it at 0°C for about 10 minutes.

The epoxy resin composition squeezed out of this carbon fiber prepreg is the triglycidyl-4-amino-cresol and diaminodiphenylsulfone (
Hereinafter referred to as DDS.

), all exhibit a low viscosity of 10 voids or less at 50°C, and prepregs with moderate flexibility can be easily obtained due to the easily controllable low-temperature reaction behavior, and the Tg is 265. ℃, and the pot life was more than 24 hours.

Note that the carbon fiber content in the prepreg was adjusted to 60% by volume.

The obtained prepreg was charged into a mantido die mold so that the carbon fiber content after molding was 60% by volume, and heated and pressure molded for 1 hour using a hot press heated to a predetermined temperature. Vostky air was performed under predetermined conditions in a hot air circulation oven. After that, the glabellar shear strength and bending strength were measured according to ASTM D-2344 and ASTM D.
-790. The results are shown in Table 1.

Example 2 A carbon fiber reinforced composite material was prepared in the same manner as in Example 1 except that the polyglycidyl compound and 4,4'-diaminodiphenylsulfone shown in Table 2 were used in the amounts shown in the same table, and its physical properties were evaluated. It was measured. The results are shown in Table 2.

Example 3 Table 3 shows the physical properties of a carbon fiber composite material molded article prepared in the same manner as in Example 2 using Shimezu epoxy resin and 4,4°-diaminodiphenylsulfone and immersed in boiling water for 48 hours. was measured.

The results are shown in Table 3.

Example 4 200 parts by weight of triglycidyl-4-amino-m-cresol and 94% of 4.4"-diaminodiphenylsulfone were mixed.
Mixed at a ratio of 4 parts by weight, stirred at 100°C for 30 minutes,
4,4'-diaminodiphenylsulfone was completely dissolved to obtain a homogeneous liquid composition.

This was used as a filament winding molding composition. This resin was a viscous liquid at room temperature, the viscosity measured with a cone-plate viscometer at 100° C. was less than 1O voids, and the pot life was 24 hours or more.

Next, the liquid resin composition maintained at 100° C. was continuously impregnated with carbon fibers (same as in Example 1) and wound around a cylindrical mandrel sufficiently coated with a mold release agent by a filament winding method. The winding angle was 90 degrees with respect to the mandrel axis. The effect was carried out for 4 hours while continuously rotating a tubular article made of carbon fiber and a mandrel impregnated with this resin composition in an open environment at 180°C. After slow cooling, the mandrel was removed to obtain a fiber-reinforced tubular body.

As a result of cutting the obtained cured product and observing its cross section with a scanning electron microscope, it was confirmed that there were no pores. Further, the volume content of carbon fiber was 58%. The obtained tubular body was cut at right angles to the axial direction of the mandrel and tested by the Norring method. The results are shown in Table 4.

Norring tensile strength measurement was based on ASTM D-2290.

Table 4 (21 completed)

Claims (3)

[Claims] (1) The matrix is a cured product of an epoxy resin composition containing a polyglycidyl derivative of an aminophenol compound whose aromatic ring is substituted with at least one alkyl group and an epoxy curing agent as essential components, and fibers are used as a reinforcing material. fiber-reinforced composite material. (2) The fiber reinforced composite material according to claim 1, wherein the aminophenol compound is 4-amino-m-cresol and/or 4-amino-o-cresol. (3) The fiber reinforced composite material according to claim 1 or 2, wherein the epoxy curing agent is a diaminodiphenylsulfone compound and/or a diaminodiphenylmethane compound.