JPH0866922A - Fiber reinforced plastic rod material and manufacture thereof - Google Patents

Abstract

PURPOSE: To improve adhesion to peripheral material by forming unevenness on the surface of a rod stock at the heat-curing of matrix resin by a method wherein the periphery of the uncured fiber reinforced plastic rod stock, which is made of one or more matrix resin-impregnated reinforced resin strands is covered with two kinds or more covering fibers having different factors of heat shrinkage from each other. CONSTITUTION: Uncured fiber reinforced plastic rod stock is made of one or more high strength and high elasticity inorganic or organic fiber strands impregnated with matrix resin consisting of thermoplastic resin or thermosetting resin. The uncured rod stock 1 is covered with two kinds or more covering fibers 2 and 3 having different factors of heat shrinkage from each other. Due to the difference between the factors of heat shrinkage of the respective covering fibers 2 and 3 developing at the thermal curing of the matrix resin, unevenness is formed at the surface of the rod stock 1. Thus, the fixing strength between the rod material and its peripheral material is enhanced by the improving action of adhesion through the interface of the uneven part, resulting in showing a high resistance against pulling-out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced plastic rod and a method for producing the same, and more specifically, the rod has irregularities due to the difference in heat shrinkage ratio of the coated fibers used in the production thereof. The present invention relates to a bar material made of fiber-reinforced plastic, which has improved adhesiveness with peripheral materials and is inexpensive, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, metal reinforcing bars and PC tension members are used as structural rods for cement or plastic, but these reinforcing bars and PC tension members rust during long-term use. This causes a decrease in strength and a decrease in adhesiveness and adhesion with peripheral materials such as cement, and there are problems of insufficient durability and dissociation of strength. The coefficient of thermal expansion is high, and there is also the problem that the thermal expansion causes cracks in the surrounding materials.Furthermore, metal has a large specific gravity, and its weight is large relative to its volume, so special equipment is required for transportation, etc. However, there is also the problem of high costs.

Therefore, in order to solve such a problem, a lightweight and high-strength rod which does not rust has been demanded. At present, a matrix of organic or inorganic fiber having high strength and high elasticity is required. Many bar materials made of fiber-reinforced plastic have been created and submitted by impregnating a resin, bundling a plurality of these fibers to obtain a predetermined thickness, and then heat-treating them. These bar rods made of fiber reinforced plastic have a specific gravity smaller than metal and are free from rusting and have strength higher than that of metal. Therefore, development for practical application is currently underway, and many types of fiber reinforced Plastic bars have been proposed.

However, a reinforcing bar or a PC tension member made of a fiber reinforced plastic rod is knurled or threaded on the surface like a metal rod, or is formed into a wedge shape or the like. Since it cannot be processed into a shape, there is a problem that the adhesiveness with peripheral materials such as cement is poor. This is because the bar material made of fiber reinforced plastic is fiber reinforced, so if the surface of the bar material is knurled or threaded, the fiber will be cut and the original strength cannot be exhibited. This is because the processing for forming a different shape such as a wedge shape is not generally performed because the molding method is complicated and the cost is high.

Further, in the case where the strands are simply converged, usually, the strands are disjointed in the uncured state and the shape cannot be maintained, and external pressure is required to cure the strand bundles. If there is no pressure, voids will be generated, and the matrix resin will sag during curing, making it unusable as a bar material. Therefore, the strands are generally coated on their outer circumference in some way, for example with a woven fabric called a blade. As a result, slight irregularities are formed on the surface of the bar, but the irregularities that provide an anchor effect to the peripheral material are not obtained.

For this reason, a method of winding a fiber bundle piece in a free end state is known (Japanese Utility Model Laid-Open No. 1-96925), but since it cannot be wound continuously, productivity is poor, and This is not sufficient because the number of steps for the reinforcing work increases and the cost increases. In addition, a method in which an aggregate obtained by bundling a plurality of long fibers is impregnated with an uncured binder, and particles such as sand are attached to the aggregate before the binder hardens to provide an anchor effect (JP Japanese Laid-Open Patent Publication No. 64-29560) is also known, but since the adhered matter is particles, continuous bonding is not performed, and particles are detached by impact or peeled during transportation, and the number of steps for reinforcement work is increased. As a result, the cost becomes high, and this has not yet solved the above-mentioned problems.

[0007]

Therefore, as a result of earnest studies to solve such problems, the present inventors have found that
When two or more kinds of coated fibers having different heat shrinkage ratios are coated around the uncured fiber-reinforced plastic rod material to form a fiber-reinforced plastic rod material, the above-mentioned coated fibers are heated to heat when cured. Differences in shrinkage occur and irregularities are formed on the surface, improving the adhesiveness with peripheral materials.
The inventors have completed the present invention by finding that the number of manufacturing steps for rods does not increase and the manufacturing cost is low.

Therefore, the object of the present invention is to improve the adhesiveness to the peripheral material by generating irregularities on the surface of the bar material without any special treatment, and to increase the number of manufacturing steps of the bar material and also in terms of cost. It is to provide a bar material made of fiber reinforced plastic at a low cost.

[0009]

That is, according to the present invention, one or a plurality of reinforcing fiber strands impregnated with a matrix resin are bundled to form an uncured fiber reinforced plastic rod material, and the heat shrinkage ratios around each other are formed around the rod material. Made of fiber-reinforced plastic, which is formed by coating two or more kinds of coated fibers having different types, and forming unevenness on the surface by the difference in heat shrinkage ratio of the coated fibers generated when the matrix resin is heat-cured. It is a bar.

Further, according to the present invention, a strand of reinforcing fiber having high strength and high elasticity is impregnated with a matrix resin,
An uncured fiber-reinforced plastic rod material constituted by bundling one or more of these strands is coated with two or more kinds of coated fibers having different heat shrinkage rates, and then the matrix resin of the rod material is heat-cured. The method for producing a fiber-reinforced plastic rod is characterized in that unevenness is formed on the surface due to the difference in the heat shrinkage rate of the coated fibers during the heat curing.

The present invention will be described in detail below. Strands constituting the uncured fiber-reinforced plastic rod material in the present invention is a fiber that retains strength, may be either high-strength and high-elasticity inorganic fiber or organic fiber, as the inorganic fiber carbon fiber, glass fiber, Carbon silicon fiber, stainless fiber, etc. can be used, and as the organic fiber, aramid fiber, vinylon fiber, high strength polyethylene fiber, etc. can be used. These strands are usually composed of fiber bundles that are bundled in the range of several tens of filaments to several hundreds of thousands of filaments, and are generally referred to as strands. When several to several tens of the strands are further converged into a so-called strand state and used as a bar, the bundle in the strand state is used alone or in plural. The single form is usually linear, and the plural forms are twisted or knitted.

The resin used in the present invention may be either a thermoplastic resin or a thermosetting resin, but is preferably a thermosetting resin, such as epoxy resin, urethane acrylate resin, vinyl ester resin, polyester resin, Phenol resin, polyimide resin or the like can be used. Further, as the thermoplastic resin, nylon, polypropylene, PEEK (polyether ether ketone), PES or the like can be used.

When the strand is impregnated with these resins, the content of the resin is preferably 20 to 50% by weight. When the content of this resin is less than 20% by weight, the adhesion between filaments in the wire is insufficient, and voids are generated in the pressure-heat-cured bar material to lower the strength of the bar material itself. . Also, when the resin content exceeds 50%,
At the time of curing, the resin oozes out to the surface layer, and the surface resin of the cured product increases, so that unevenness hardly occurs.

As the heat-shrinkable fiber for coating which can be applied in the present invention, polyester fiber, acrylic fiber, P
Examples thereof include PS fiber, aramid fiber, polypropylene fiber, vinylon fiber, TPX fiber and the like, and two or more kinds of these fibers are used to coat an uncured bar material.
The surface condition of the coated bar material is a braided shape, a tape shape, a cloth shape, a spiral shape, a spiral shape, or the like.

The coated fiber may be either filament yarn or spun yarn. Generally, in the case of filament yarn, the resin content of the strand is 20 to 30% by weight because the matrix resin has a good impregnation property. Is preferred,
In the case of spun yarn, the resin content of the strand is preferably 30 to 50% because the impregnating property of the matrix resin is poor.

Since the strength of the coated fiber hardly contributes to the rod material, it is not necessary to use a fiber having high strength and high elasticity. This means that in any of the above-mentioned surface states of the coated rod material, the coating angle is 10 ° or more when the longitudinal direction of the rod material is 0 ° and is 10 ° or less in the production. It is judged because it is impossible.
This is because the tensile strength of the fiber itself is usually significantly reduced when the coating angle is 10 ° or more.

The heat shrinkage of the coated fiber in the present invention is a value near the curing temperature of the matrix resin, and when the ratio of the maximum and the minimum heat shrinkage of the coated fiber is 1 to 70%, the surface of the bar material. The unevenness of is in a good state. When the heat shrinkage ratio of the coated fiber is less than 1%, surface irregularities are not recognized when the rod material is cured, and sufficient adhesive force with peripheral materials cannot be obtained. On the other hand, when it is more than 70%, the coated fiber having a small heat shrinkage does not shrink more than the fiber having a large heat shrinkage, and the fiber having a small heat shrinkage is not sufficiently impregnated with the matrix resin, that is, a so-called unimpregnated state. Therefore, it does not form a resin composite and the adhesive strength cannot be sufficiently exhibited.

The thickness of the coated fiber is 100 to 1,000.
0 denier is preferable, and the thickness of the coated fiber is 100
When it exceeds 0 denier, the matrix resin is not sufficiently impregnated, and especially the surface layer portion is not impregnated. On the other hand, when it is less than 100 denier, the matrix resin covers the surface layer, so that the surface of the bar material does not become uneven.

Further, the ratio of the heat shrinkage ratio of the coated fiber and the thickness of the coated fiber are different depending on the material of the peripheral material, and when the peripheral material is a resin system having a relatively low viscosity, In order to reduce the unevenness of the surface of the bar, the ratio of the heat shrinkage ratio of the coated fiber is 1 to 40%, and the thickness of the coated fiber is 1
Preferred is from 00 to 500 denier. On the other hand, when the peripheral material is cement in which a filler or the like is mixed, the ratio of the heat shrinkage ratio of the coated fiber is 40 to 70% in order to increase the unevenness of the surface of the rod material. Thickness is 5
00 to 1,000 denier is preferred.

Further, it is preferable that the coating fiber layer constituting the surface layer of the rod is as thin as possible. If the layer of the coated fiber becomes thick, the apparent cross-sectional area of the rod material becomes large, and the proportion of the relatively high-strength and high-elasticity portion becomes small.

[0021]

In the rod material made of fiber reinforced plastic according to the present invention, the strand formed by the reinforcing fiber impregnated with the matrix resin is coated with two or more kinds of coating fibers having different heat shrinkage rates, and the matrix resin is heat-cured. Irregularities are formed on the surface of the bar due to the difference in the heat shrinkage rate of each coated fiber that occurs when the rod is made. Therefore, the sticking strength of the bar material and the surrounding material is increased by the effect of improving the adhesiveness due to the interface of the concave and convex portions, and a high pulling resistance is exerted. Therefore, this bar has a special anchor effect,
For example, the anchor effect can be exerted without attaching particles to the bar material or providing a protrusion. Furthermore,
It is possible to expect a reduction in price without requiring a step of providing the uneven portion.

[0022]

EXAMPLES The fiber-reinforced plastic rod and the method for producing the same according to the present invention will be specifically described below with reference to examples.

Example 1 A matrix resin containing 60 parts by weight of bisphenol A type epoxy (Epicote 1001 manufactured by Yuka Shell Co., Ltd.) and 40 parts by weight of phenol novolac type epoxy (EPN-1138 Ciba-Geigy Co.) as a main component, and dicyandiamide as a curing agent. A resin composition containing 6 parts by weight and 4 parts by weight of 1-dimethylurea as a curing accelerator was prepared.
This epoxy resin composition is diluted with methyl cellosolve,
The diluted solution was impregnated with 6000 filaments of carbon fiber (ESKYNOS NT-35), and then methylcellosolve, which is a diluent, was evaporated with a hot air dryer to form a strand. The resin adhesion amount of this strand was 32% by weight.

Then, 20 strands are converged to form a strand bundle, and this strand bundle is
(A) and FIG. 2 (a)) or a bundle of seven (FIG. 1)
(B) and FIG. 2 (b)), the surface of which has a heat shrinkage of 1.75 (10 ⁻⁴ / ° C.) of 450 denier vinylon (filament yarn, coated fiber 3 in FIG. 2), and heat A shrinkage factor of 92 (10 ^-4 / ° C.) and 600 denier polypropylene (filament yarn, coated fiber 2 in FIG. 2)
A braided shape (plain weave, so that the braid angle is 45 ° at a ratio of 1 to
It was wrapped around a satin weave) to obtain a rod material made of fiber reinforced plastic.

The carbon fiber reinforced plastic rod material was heat-cured under pressure at 140 ° C. for 60 minutes under atmospheric pressure. Thus, an outer diameter of 4.4 mm as shown in FIGS. 1, 2 and 3.
A fiber reinforced plastic bar material having an uneven surface on φ was obtained. In addition, in FIG. 1, reference numeral B is an uneven portion, and in FIGS. 2 and 3, reference numeral 1 is a fiber reinforced plastic portion, and
Reference numerals 2 and 3 are coated fibers. Here, the heat shrinkage rate of the coated fiber 2 is larger than the heat shrinkage rate of the coated fiber 3. The above-mentioned FIG. 2 shows a typical constitution of the fiber-reinforced plastic rod material of the present invention, and this constitution can be changed within the scope of the present invention.

Fiber-reinforced plastic rods (FIGS. 1 (a) and 2) formed from one strand bundle as described above.
As shown in FIG. 4, (a) was embedded and fixed in the peripheral material of the anchor body, and the pull-out strength in concrete was measured. In FIG. 4, reference numeral 1 is a fiber reinforced plastic portion, reference numerals 2 and 3 are coated fibers, and
Reference numeral 4 is a peripheral material. Table 1 shows the measurement results of the pulling strength.

Example 2 A strand was prepared in the same manner as in Example 1 except that the carbon fiber to be impregnated was Torayca T-700 having 12,000 filaments. The amount of resin attached to this strand is 30
% By weight.

Next, 27 strands are converged into a bundle of strands, and one strand bundle (FIG. 5) is formed.
(C) and FIG. 6 (c)) or a bundle of seven (FIG. 5)
(D) and FIG. 6 (d)), and 500 denier polyester (filament yarn, coated fiber 3 in FIG. 2) having a heat shrinkage of 1.00 (10 ⁻⁴ / ° C.) on its surface, A 450 denier acrylic (spun yarn, coated fiber 2 in FIG. 2) having a heat shrinkage of 3.25 (10 ⁻⁴ / ° C.) and a winding angle of 8
The rod material made of fiber-reinforced plastic was obtained by winding it in a spiral shape (tape, thread, etc.) so as to be 0 °.

This carbon fiber reinforced plastic rod material was heated and cured under pressure at 120 ° C. for 20 minutes and at 150 ° C. for 40 minutes under atmospheric pressure. Thus, FIGS. 5, 6 and 7
A fiber reinforced plastic rod having an outer diameter of 5.0 mmφ and a surface having irregularities was obtained as shown in (4). In FIG. 5, reference numeral B
6 and 7, reference numeral 1 is a fiber reinforced plastic portion, and reference numerals 2 and 3 are coated fibers. Here, the heat shrinkage rate of the coated fiber 2 is larger than the heat shrinkage rate of the coated fiber 3. The above-mentioned FIG. 6 shows a typical constitution of the fiber-reinforced plastic rod material of the present invention, and this constitution can be changed within the scope of the present invention.

A fiber reinforced plastic rod formed from one strand bundle (see FIGS. 5 (c) and 6).
(C) was embedded in the peripheral material of the anchor body in the same manner as in Example 1, and the pull-out strength in concrete was measured. Table 1 shows the measurement results of the pulling strength.

Comparative Example 1 A strand was prepared in the same manner as in Example 1 except that the carbon fiber to be impregnated was 3000 filaments. The resin adhesion amount of this strand was 62% by weight.

Then, 36 strands of this strand are converged into a strand bundle, and 600 denier vinylon (filament yarn) having a heat shrinkage of 1.75 (10 ⁻⁴ / ° C.) is heat-treated on the surface of the strand bundle. Shrinkage rate is 92 (10 ^-4
/ ° C) and 600 denier polypropylene (spun yarn) were wound into a braid at a braiding angle of 45 ° to obtain a fiber-reinforced plastic rod material.

The carbon fiber reinforced plastic rod material was heat-cured under pressure at 140 ° C. for 60 minutes under atmospheric pressure. The fiber-reinforced plastic rod thus obtained was embedded in the peripheral material of the anchor body in the same manner as in Example 1, and the pull-out strength in concrete was measured. As a result, the obtained fiber reinforced plastic rod has an outer diameter of 4.7 mm.
At φ, there was no unevenness on the surface and the matrix resin oozes on the surface in a large amount. In concrete, the same results as in Example 1 were not obtained and the anchor effect was not recognized.
Table 1 shows the measurement results of the pulling strength.

Comparative Example 2 A strand was prepared in the same manner as in Example 2. The amount of resin attached to this strand was 30% by weight.

Then, 27 strands are converged to form a strand bundle, and 450 denier vinylon (filament yarn) having a heat shrinkage of 1.75 (10 ⁻⁴ / ° C.) is wound on the surface of the strand bundle. A rod material made of fiber-reinforced plastic was obtained by spirally winding it at an angle of 80 °.

The carbon fiber reinforced plastic rod material was heat-cured under pressure at 140 ° C. for 60 minutes under atmospheric pressure. The fiber-reinforced plastic rod thus obtained was embedded in the peripheral material of the anchor body in the same manner as in Example 2, and the pull-out strength in concrete was measured. As a result, the fiber reinforced plastic rod obtained had an outer diameter of 5.0 mm.
At φ, there was no unevenness on the surface and the matrix resin was uniformly blotted on the surface. In the resin, the same results as in Example 2 were not obtained and the anchor effect was not recognized. Table 1 shows the measurement results of the pulling strength.

[0037]

[Table 1]

[0038]

The fiber reinforced plastic rod obtained by the present invention has the surface of its strand covered with two or more kinds of coated fibers having different heat shrinkage rates.
Unlike the conventional bar material configured to provide the anchor effect, no special process is required, so that an excellent fiber-reinforced plastic bar material can be obtained at low cost. In addition, the rod material can generate appropriate irregularities on the surface according to each use of the peripheral material by changing the type of the coated fiber, and further, the fiber is thermally shrunk during curing. For this reason, the fiber-reinforced plastic bar material does not generate voids, and a high strength bar can be obtained. Therefore, the practical effect is extremely remarkable.

[Brief description of drawings]

FIG. 1 is an external view schematically showing a fiber-reinforced plastic rod material according to the present invention. FIG. 1 (a) is a single-wire linear rod material composed of a single strand bundle and covered fibers are assembled. It is a bar woven into a string (plain weave), and (b) is 7
It is a double-strand twisted rod or knitted rod-shaped rod made of a bundle of strands, and the coated fibers are rods knitted in a braided (plain weave) shape.

FIG. 2 is a cross-sectional view of FIG. 1 of the present invention.

FIG. 3 is an enlarged view of part A of FIG. 1 of the present invention.

FIG. 4 is a schematic view when the fiber-reinforced plastic rod of the present invention is used as a rod (tensile) of an anchor body, (e) is a vertical cross-sectional view, and ( f) is a cross-sectional view.

FIG. 5 is an external view schematically showing the fiber-reinforced plastic rod material of the present invention, and FIG. 5 (c) is a single-line linear rod material composed of one strand bundle and the coated fiber is spiral. It is a bar material knitted into a filament (thread), and (d)
Is a multi-strand twisted or knitted rod material composed of a bundle of seven strands, and the coated fiber is a rod material knitted in a spiral shape (thread shape).

6 is a cross-sectional view of FIG. 5 of the present invention.

FIG. 7 is an enlarged view of a portion of FIG. 5C of the present invention.

[Explanation of reference numerals] B ... uneven portion, 1 ... fiber reinforced plastic portion, 2, 3 ... coated fiber, 4 ... peripheral material.

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location B29L 31:06 (72) Inventor Hiroyuki Uchino 2-3-7 Hanazono, Hanamigawa-ku, Chiba, Chiba Prefecture Sharm Kamigawa 304 (72) Inventor Yasuo Nagata 4-12 T2 Building Kiyomi Tainan, Kisarazu City, Chiba Prefecture (72) Ino Morii Atsushi 7-5-1, Higashi Narashino, Narashino City, Chiba Prefecture Suzuki Metal Industry Co., Ltd.

Claims (4)

[Claims] 1. A rod material made of uncured fiber-reinforced plastic is formed by bundling one or more strands of reinforcing fiber impregnated with a matrix resin, and two or more kinds of coated fibers having different heat shrinkage rates are formed around the rod material. A fiber-reinforced plastic bar material, characterized in that the surface is made uneven by the difference in the heat shrinkage ratio of the respective coated fibers generated when the matrix resin is heat-cured. 2. The amount of resin adhered to the strand is 20 to 50.
The fiber reinforced plastic rod according to claim 1, which is in weight%. 3. A ratio t between the maximum value and the minimum value of the heat shrinkage rate in a plurality of coated fibers, where t = (a ₂ / a ₁ ) × 10.
0, a _1: thermal shrinkage maximum, a _2: fiber-reinforced plastic bar according to claim 1, wherein the thermal shrinkage minimum] is 1 to 70%. 4. A heat-shrinkage ratio between the uncured fiber-reinforced plastic rod material formed by impregnating a matrix resin into a strand of reinforcing fiber having high strength and elasticity and bundling one or a plurality of this strand. Characterized in that two or more kinds of different coated fibers are coated, then the matrix resin of the rod material is heat-cured, and unevenness is formed on the surface due to the difference in the heat shrinkage ratio of each coated fiber at the time of this heat-curing. A method of manufacturing a rod made of fiber reinforced plastic.