JPS62283853A - Fiber for reinforcement - 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 3. Detailed Description of the Invention (a) Field of Industrial Application This invention relates to reinforcing Il miscellaneous materials. For more details,
It relates to reinforcing fibers that are mixed into various structural materials such as concrete and plastics.

(b) Prior Art Conventionally, glass fibers have been widely used as reinforcing materials for unsaturated polyester resins, concrete, and the like. These glass fibers are usually mixed with resin liquid or cement before hardening, or are laminated with these and then hardened, and are generally considered to increase the strength of the material. These glass fibers can be yarn, cloth, roving,
It is used in various U & miscellaneous body forms such as chopped strands, but in all cases, the single fibers that make up the fiber body are long fibers with an approximately circular cross section that does not have any twist or unevenness. It is being

(c) Problems to be solved by the invention However, in these various materials reinforced with conventional glass fibers, the compatibility and adhesion between the single glass fibers and the material material are insufficient, resulting in poor integrity. However, when an external stress is applied to the material, the stress is difficult to be sufficiently dispersed throughout the fiber body, resulting in insufficient reinforcement. In fact, on the fracture surface of a fractured fiber-reinforced plastic, although the material is broken, the single glass fibers are not cut and are often detached or pulled out from within the material.

The present invention has been made in view of these problems and their causes, and particularly aims to provide reinforcing fibers that have excellent integrity with materials.

(d) Means for Solving the Problems According to the present invention, the fibrous body is made of a glass-like substance, and the single fibers of the fibrous body are characterized by having a twist with a period of 1 to 10 mm. A reinforcing fiber is provided.

The most distinctive feature of this invention is that the taMi body made of a glass-like material is constructed from an AAA string having a predetermined twist. Here, the twist period of the single fiber is 0.1 to 10
This means, for example, that in a single fiber of 11 Il, it is twisted 100 to 100 times. Those with a period of less than 0.1 mm are not suitable because they are difficult to manufacture and cracks occur in the fibers themselves due to extreme twisting, resulting in a decrease in mechanical strength. Moreover, if it exceeds 40 mm, the improvement of the integrity with the material to be strengthened will be insufficient and it is not suitable. These twists are preferably continuous throughout the single IN, but may be intermittent without twisting in parts.

The thickness of the above-mentioned FF1w4 fibers is sufficient to be a single fiber of normal reinforcing glass tlN, and usually about 10 to 100 mm is appropriate. Note that the cross section of the single fiber itself is usually twisted due to twisting.
It tends to take on a flat circular shape, an elliptical shape, and especially a cocoon-like shape, and in this case, the thickness means the long width of the cross section.

The glassy substance that is the raw material for the fibers of this invention may be porous glass or nonporous glass, or may be a so-called glassy porous substance made of metal hydroxide or a low condensate thereof. It may also be a gel.

In the reinforcing fiber of the present invention, the twisted single fibers may be in the form of cotton, wear, yarn, cross, or strand, or may be in the form of a single fiber.

The reinforcing uAM of the present invention is, for example, an aqueous solution of a metal alkoxide and/or a substituted metal alkoxide in which at least one alkoxy group of the metal alkoxide is substituted with an aliphatic or aromatic hydrocarbon group, an amine group, or an alkylamino group. A hydrolysis catalyst is added to the sol to produce a sol, which is then heated and concentrated, and the concentrated sol is stretched while being twisted into a thread, or released and dried, or stretched into a thread, or It can be efficiently produced by twisting and drying after release.

The above-mentioned metal alkoxide may be any metal that can be obtained by heat treatment and dehydration, such as silicon alkoxide, aluminum alkoxide, titanium alkoxide, boron alkoxide, sodium alkoxide, calcium alkoxide, etc. , titanium alkoxide is preferred.

In addition, a lower alkoxy group is suitable for the alkoxy group,
Examples include methoxy group, ethoxy group, propioxy group, and the like.

Examples of the above metal alkoxides include tetraethoxysilane S+ <○C2H3)4, triethoxyaluminum A12 (○C2H3)3, and tetraisopropylene titanium! (0-!C3H7)4, Tetraethoxyzirconium Zr (OC2H't
)z, etc., with tetraethoxysilane being preferred.

The substituted metal alkoxide is a metal alkoxide substituted with at least one alkoxy group, an aliphatic or aromatic hydrocarbon group, an amino group, or an alkylamino group.

Examples of substituted aliphatic hydrocarbon groups include lower alkyl groups and vinyl groups. Examples of substituted metal alkoxides substituted with lower alkyl groups include Si (
OC2Hs ) R(CH3), Si (○C2Hs
)2 1cH3)2,Si (OC2toIs>
3 (C2Hs), Si (○C2H
s)2 (C2Hs)2, S! (OC2Hs)
3 (! C3H7), Si (OC2Hs
)2 (!C3H) )2 ,B (○C2
H5)2 (C2Hs), T! (0-i
C3Hy)3 (C2H5), Ti (
〇-i C3H7)2 (C2Hs)2,
Ca (OC2Hs) (C2H5), A
Q (○-: C3H7)2 (CH3), 8ρ (○-! 03 H7)2 (C2Hs)
, 8ρ(0!C3Hy)(CH3)2, and the like.

The aromatic hydrocarbon group substituted with the alkoxy group of the metal alkoxide includes a phenyl group substituted with a phenyl group or a lower alkyl group such as methyl, ethyl or propyl group.

Examples of the alkylamino group substituted with the alkoxy group of the metal alkoxide include amino groups substituted with lower alkyl groups such as methyl, ethyl, or propyl groups.

Each of the metal alkoxide and/or substituted metal alkoxide is used as an aqueous solution.

Generally, it is preferable to use a mixture of these, and in this case, the mixing weight ratio of metal alkoxide and substituted metal alkoxide is 1:1 from the viewpoint of the spinnability of the concentrated sol obtained later.
1 to 5:1 is preferred.

As the solvent for the aqueous solution, a mixed solution of water and a lower alcohol such as methanol, ethanol, propatool, etc. is used, as in the conventional method.

Further, as the hydrolysis catalyst, hydrochloric acid, sulfuric acid, ammonia aqueous solution, etc. are used as in the conventional method.

When an aqueous solution of a metal alkoxide and/or a substituted metal alkoxide is hydrolyzed to form a sol, it can be done by adding the above-mentioned hydrolysis catalyst to the aqueous solution and stirring at room temperature. The reaction may be accelerated. Further, the above hydrolysis reaction may be carried out by simultaneously adding and mixing a metal alkoxide, a substituted metal alkoxide, an aqueous solvent, and a hydrolysis catalyst.

The concentration of the sol is carried out at a viscosity rate that allows it to be stretched or released into threads, and is appropriately determined depending on the intended thickness of the single fibers. Twisting can be caused by stretching or releasing the fibers by rotating the stretching shaft itself or by rotating the outlet or concentrated sol supply tank, or by applying twisting force to the stretched or released single fibers in the axial direction before drying and hardening. It can be granted by giving .

The male bodies from the concentrated sol are made of glassy porous gels made of metal hydroxides and their low condensates;
This may be further heat-treated to form a fibrous body made of porous glass (at an even higher temperature, e.g., 1000°C or higher).
A fiber body made of non-porous glass may be obtained by heat treatment at a temperature of 1,000 ml, and both are within the scope of the present invention.

The reinforcing fiber of the present invention that can be produced in this manner can be appropriately cut into predetermined lengths or in a predetermined form and used as reinforcing fibers for various plastics, concrete, and the like.

However, it is also possible to produce it by a method other than the above-mentioned production method, and it is sufficient that it has at least the above-mentioned specific twist.

(e) Function Since the reinforcing fiber of this invention has a twisted thread-like structure, when mixed with plastics or cement to make a fiber-reinforced material, it has excellent integration with these materials. Therefore, for example, even if the fibers are subjected to strong stress in the longitudinal direction, they are unlikely to separate from the material.

(f) Example Example 1゜ S! (OC2Hs) 440yf.

Si (OC2H5) 3 (CH3) 10xl
, ethanol 50yi, water 811 and LON-HC
A'111 was mixed to prepare an aqueous solution of about 3, and this solution was stirred for 1 hour to hydrolyze and obtain a homogeneous sol. Next, this sol was kept at 60° C. and stirred for about 6 hours to concentrate, and the viscosity of the concentrated sol at this time was about 100 poise. Next, a container with an inner diameter of 0.5 mm and an outer diameter of 11T was placed in this concentrated sol container.
A 1 m glass tube was inserted and the container was rotated at 3 Orpm while the glass tube was pulled upward to obtain a twisted fibrous alkoxide gel.

This JIM-like gel was heat-treated at 1000° C. for 4 hours in a nitrogen atmosphere to obtain reinforcing fiber 1 of the present invention as shown in FIG. The cross-sectional shape of this fiber was flat circular (cocoon-like), its long width was 1 ridge, and its twist period was about 500.

Next, reinforcing fiber N (fiber length 40o) obtained as above
was mixed in cement at a ratio of 7% by weight, and a predetermined amount of water was added to harden it.
x 60mm) was produced. The cement used above was Portland cement JIS R5210.

The tensile strength of the above-mentioned reinforcing fibers and the bending strength of the slate board were measured according to the JIS A1048 bending test method for architectural boards, and the relationship between the two was compared for each ladder! It is shown in FIG. 2 along with an example of IM. In the figure, A is reinforcing mM of this invention, B is polyacrylonitrile fiber,
C indicates polyester fiber, and D indicates commercially available glass mu. In addition, regarding A, even when observing the cross section after destruction, no pullout or detachment of the fibers was observed, and it was confirmed that the fibers were sufficiently integrated with the material.

From these results, the reinforced tJA fiber of the present invention is excellent as a reinforcing material, and in particular, although its own tensile strength is slightly inferior to that of general glass fiber, it can impart significantly superior bending strength to the material. I understand.

Example 2゜ S! (OC2H5)t 113y/.

S! (OC2H5)3 (cH3)101if.

Ti (0+ C3H7) 415tf and ethanol 801! and add 50% ethanol to this mixture.
A mixed solution of 11 and INIi (:, (130'll) and 41! of water was added dropwise over about 30 minutes while stirring, and the stirring was continued for an additional hour to perform hydrolysis. This sol solution was kept at a constant temperature of 80°C. It was left in the tank for about 3 hours, and when the viscosity reached 10 poise, it was cooled to 0°C, and the concentrated sol was placed in a container with a convex discharge port (tip: diameter 1.5 mm, protrusion height 5 poise). The sol of this invention is made of a twisted fibrous alkoxide gel as shown in FIGS. 3 and 4 by blowing hot air at 80°C with a dryer. A reinforcing!1i strip (approximately 50 points in the long width of the cross section, with a twist period of 350*z) was obtained. By changing the speed at which the hot air is blown, single fibers with a twist period of 0.1 to 10 mm can be obtained. This was also confirmed.

(g) Effects of the Invention Since the reinforcing fiber of the present invention has excellent integrity with plastics and concrete, the mechanical strength of a composite material containing the reinforcing fiber is improved compared to the conventional one. Therefore, various FRP (fiber reinforced plastics) and FRC (
It is useful as a reinforcing fiber for fiber-reinforced concrete.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the reinforcing fiber of the present invention, FIG. 2 is a graph diagram showing the effects of a composite material using the reinforcing fiber of the present invention together with a comparative example, and FIGS. Each figure is for reinforcement of this invention! It is an enlarged photograph which replaces a drawing and shows the shape of the fiber of 1 miscellaneous other Examples. 1... Reinforcing fiber. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A reinforcing fiber comprising a fibrous body made of a glass-like substance, wherein the single fibers of the fibrous body have a twist period of 0.1 to 10 mm. 2. The reinforcing fiber according to claim 1, wherein the single fiber has a thickness of about 10 to 100 μm. 3. The reinforcing fiber according to claim 1, wherein the glassy substance is porous glass, nonporous glass, or glassy porous gel. 4. The reinforcing fiber according to claim 1, wherein the single fiber has a flat circular cross-sectional shape.