JPS5817492B2 - Hokiyouyoushiyobutsu Oyobi Sonoshiyorihouhou - Google Patents

Description

Detailed Description of the Invention The present invention provides a method of firmly bonding reinforcing fibers with high strength and high elasticity such as aromatic polyamide fibers and carbon fibers to thermosetting resins such as Epoquin resin and unsaturated polyester. The present invention relates to treated reinforcing fibers for obtaining fiber-reinforced plastics and a method for treating the same.

Fiber-reinforced plastics have attracted much attention in recent years as structural materials that are lightweight and have excellent strength, and are used in a variety of fields.

Most commonly, a composite material consisting of glass fiber and unsaturated polyester resin or glass fiber and Epoquine resin is used.

However, the strength, dimensional stability, etc. of the composite materials may not always be fully satisfactory depending on the use.

Examples include precision equipment, high-speed moving objects, aircraft, space equipment,
In fields such as golf soyafts, even better mechanical properties are required.

For these reasons, for applications that require light weight and excellent mechanical properties, Epokin resin and unsaturated polyester resin are used to increase strength and dimensional stability, and Epokin fiber is especially used as a reinforcing fiber. It has been used for its excellent adhesive properties.

Further, as for reinforcing fibers, materials with higher strength and higher modulus of elasticity are being developed, and aromatic polyamide fibers, carbon fibers, boron fibers, and the like are being put into practical use.

However, even when these new composite materials are used, there has been a problem that they have not been able to fully demonstrate their performance.

The main reason for this is that the mutual adhesion between the resin and the reinforcing fibers is not excellent, so the strength and durability of the composite material cannot be fully satisfied.

For this reason, attempts have been made to improve the adhesion of reinforcing fiber materials through various physicochemical surface treatments, but these are still insufficient, and these composite materials cannot be used in fields that require a high degree of reliability. The reality is that its uses are limited.

Therefore, by further improving the adhesion between the new high-strength, high-modulus fibers and the resin, the strength of fiber-reinforced composite materials can be improved.
If durability improves dramatically, it will become possible to apply it to new uses.

The present inventors have conducted extensive research into improving the adhesion between epoxy resins, unsaturated polyester resins, and high-strength, high-elastic reinforcing fiber materials. We discovered that by pre-treating the fibers with a mixture of a vinyl compound and an amine curing agent for epoxy resins, we could dramatically improve the adhesion between the fibers and the resin, and after making various improvements, we made this book. The invention was completed and the intended purpose achieved.

That is, the present invention uses 20-80% by weight of a vinyl compound monomer having a glycidyl group ( In the following, unless otherwise specified, weight percentages are indicated.

) and an amine curing agent for epoxy resin in advance at a rate of 0.1 to 2.5, preferably 0.3 to 2.5, of the fiber weight.
2.0% adhesion and 1 to 3 at a temperature of 100 to 300℃
It is heat-treated for 0 minutes to fix it and improve its affinity with the MAR-IJ resin.

The vinyl compounds having a glycidyl group as used in the present invention include glycidyl methacrylate, grindyl acrylate,
Allyl grindyl ether, an amine curing agent for epoxy resins, is a reaction product of aliphatic amines such as ethylene diamine, diethylene triamine, and diethylaminopropyl amine, polyamines, grindyl compounds, ethylene oxide, propylene oxide, and acrylonitrile. There are isolated amine adducts, various polyamides, aromatic amines such as meta-phenylene diamine, diaminodiphenylmethane, diaminodiphenylsulfone, quinrylene diamine, dianediamide mencundiamine, pyridine, piperidine, aminoethylpiperazine, imidazole, triethylamine, benzyldimethylamine , dimethylaminomethylphenol, trimethylaminomethylphenol, and trifluoroboronomonoethylamine.

Also effective are amine-based plan coupling agents such as N-β(aminoethyl)γ-aminopropylmethyldimethquinane and N-β(aminoethyl)γ-aminopropyltrimethoxylene.

In addition, the aromatic polyamide fiber referred to in the present invention refers to an aromatic polyamide fiber in which 15 or more moles of bonding units are amide bonds, and carbon fiber refers to organic fibers such as polyacrylnyl-IJ fibers and cellulose fibers. Although the carbonized fiber has a leaded carbon content of 80% or more, the present invention is not limited to aromatic polyamide fibers and carbon fibers, and may include glass fibers, boron fibers, etc. It is also effective for general reinforcing fibers.

Furthermore, the epoxy resin referred to in the present invention refers to so-called epoxy resins containing two or more epoxy groups in the molecule, and furthermore, so-called epoxy resins that are modified by adding phenolic resins, polyamide resins, fatty acid derivatives, etc. to these epoxy resins. Also includes modified epoxy resins.

In addition, unsaturated polyester resin is a resin obtained by dissolving alkyd resin obtained by the condensation reaction of polybasic acid and polyhydric alcohol in styrene and acrylic acid ester as crosslinking agents, and it can be modified with oil, fat, fatty acid, phenol resin, etc. It also includes modified resins.

The form of impregnation of the above-mentioned various glycidyl group-containing vinyl compound monomers and the curing agent for epoxy resin into the high elastic fibers into the high elastic fibers may be any of an aqueous solution, an emulsified dispersion, and an organic solution. Treatment may be done by coating or spraying, but natural drying, dry heat treatment,
It is preferable to dry it by high-temperature heat treatment or the like until it becomes a handleable state.

In this case, the amount of the treatment agent impregnated into the fibers is effectively within the range of 0.1 to 2.5%, and more preferably 0.3 to 1.5% based on the weight of the fibers.

If the content is less than 1%, the adhesion effect between the resin and the fibers will not be sufficiently exhibited, and on the other hand, if it is more than 2.5%, the adhesive strength will not necessarily be excellent and will not be substantial.

Next, the optimal range of drying temperature is 100 to 300℃.
The most preferred and common treatment time is 1 to 30 minutes at a temperature of .

It is also acceptable to raise the drying temperature to shorten the processing time, but heating at a high temperature of 500° C. or less may be performed for an extremely short period of time.

Although it is still not clear why a mixture of vinyl compound monomers containing glycidyl groups and amine curing agents for epoxy resins improves the adhesion between fibers and epoxy resins or unsaturated ester resins, these glycidyl group-containing vinyls The compound and amine curing agent are reactive with Epoquin resin and unsaturated polyester resin, and curing is thought to occur through the reaction between the two, but at this time, an extremely uniform and dense curing reaction occurs on the fiber surface. It is thought that this causes a so-called "wedge effect" between the resin and the fibers.

Therefore, it is considered that the bonding between the resin and the reinforcing fibers is more complete, resulting in a strong bonding state with extremely few defective parts, and the adhesive strength between the fibers and the resin increases.

Such a strong bonding state with few defective parts has a remarkable effect of improving adhesive strength, especially for reinforcing fibers such as aromatic polyamides and carbon fibers, which originally do not have a strong bonding strength with resins.

Examples of the present invention will be shown below.

Example 1 A filament of 1,500 denier of polyIJ-P-phenylene terephthalamide, a high-strength, high-elastic fiber, was soaked in an aqueous solution of 50 parts of acrylic glyphzyl ether and 50 parts of hexamethylenetetramine, and then heated at 180°C for 3 minutes. Dry.

At this time, the amount of adhesion to the fibers was adjusted to be 0.6 ratio ± 0.1 ratio.

The treated fibers were mixed with each resin solution having the following composition (1) Epoquin resin Epicoat 828 (manufactured by Neru Chemical) 100 parts borofluoromonoethylamine trifluoride 5 parts (2) unsaturated polyester resin Poly7-L 3308 (Takeda Pharmaceutical Co., Ltd.) ) 100 copies Kniper B
Two parts of O (manufactured by B Honyaku) were impregnated and cured by hot pressing with the fibers aligned in one direction.

In this case, the curing conditions are (1) Epoquine resin Press hardening at 150℃ for 1 hour After cure at 170℃ for 1 hour (2) Unsaturated polyester resin Press hardening at 130°C for 1 hour It was adopted.

A test piece with a length of 20 mm, a width of 6 mm and a thickness of 3 mm was prepared from the molded product obtained in this way (fiber content: 60 mm), and a span distance of 13 m, 7 mm was made using the three-point beam bending method.
L1 Interlaminar shear modulus was measured at a crosshead speed of 1.0 mm/min.

On the other hand, for comparison, an untreated filament not impregnated with a treatment agent was molded in the same manner, a test piece was prepared, and measurements were conducted. The results are shown in Table 1.

As is clear from Table 1, the molded products pre-cured with a treatment agent exhibit clearly superior shear strength compared to the untreated molded products.

Example 2 The same poly P-phenylene terephthalamide 1500 denier yarn and polyacrylonitrile fiber tow as in Example 1 were made flameproof at 250°C without applying tension so as to maintain the orientation of the fibers, and then heated at 1200°C. Each of the carbon fibers obtained by heat treatment and carbonization (average fiber diameter 85μ, number of single yarns 2700, tensile strength 240 kg/mm, tensile modulus 20,000 kg/7n17t) was treated under exactly the same conditions as in Example 1. Post-molding processing (however, the fiber content was 60% for the former and 65% for the latter).

The same test pieces as in Example 1 were taken from these molded products and the interlaminar shear strength was measured in the same manner. The results are shown in Table 2.

As is clear from Table 2, the pretreated fibers exhibit superior shear strength compared to the untreated molded products.

Example 3 A solution in which allyl grindyl ether was used as the chrycidyl group-containing vinyl compound 7mer, the type of amine curing agent for Epoquin resin was changed, and the mixing ratio was adjusted so that the Evoquin equivalent and the amine equivalent were the same. In, Example 1
Similarly, 1500 denier poly-P-phenylene telescope fibers were dipped, the adhesion amount was adjusted to 0.5%, and after heat treatment molded products were made with Evokin resin and unsaturated polyester resin.

(Fiber content: 60±2%) Test pieces were prepared from these molded articles in the same manner as in Example 1, and the shear strength was measured. Table 3 shows the results.

As is clear from Table 3, compared to untreated product A, treated product B,
In C and D, a large+iJ improvement in shear strength was observed.

Example 4 In the same manner as in Examples 1 and 2, polyJ-P-phenylene tereph clamide fibers and carbon fibers were immersed in an aqueous solution of 50 parts of allylglyphdyl ether and 50 parts of hexamethylenetetramine to determine the amount of adhesion. 01-25% of fiber weight
The resulting product was treated under the same conditions as in Example 1 to create a molded product with Epoquine resin (fiber weight: 60%).

Test pieces were prepared from these molded articles in the same manner as in Example 1, and the shear strength was measured. The results are shown in FIG.

As is clear from Figure 1, the amount of treatment agent applied is 03 to 20.
% range is effective in improving the large riJ of shear strength.

As shown in the examples above, conventionally, the durability as a composite material was not satisfactory due to poor adhesion with resins such as aromatic polyamide resin and carbon fiber.
By treating a new covering material with a mixture of a vinyl compound monomer having a grindyl group and an amine compound, strength and durability can be dramatically improved.
It has become possible to develop new uses.

[Brief explanation of drawings]

FIG. 1 shows the relationship between the amount of treatment agent deposited and the interlayer shear strength.

Claims (1)

[Claims] To obtain a fiber-reinforced resin consisting of reinforcing fibers such as aromatic wood-based polyamide cellulose fibers and a thermosetting resin, the fibers are added with a monomer of a vinyl compound having a glycidyl group. A reinforcing treated product made by adhering a mixture with an amine compound in an amount of 0.1 to 25% by weight of the fibers in advance. 2. Obtaining a fiber-reinforced resin made of reinforcing fibers such as aromatic polyamide fibers and carbon fibers and thermosetting fibers. At this time, the fiber material is coated with the mixture described in - in such a manner that a mixture of 20 to 80 weight percent of a vinyl compound monomer having a glycidyl group and an amine compound is adhered to the fiber material in an amount of 0.1 to 2.5% by weight of the fiber. 0) Treatment method for frequently used fibers, which involves contacting with a solution or dispersion of the fibers and then drying.