JP2862613B2 - Resin impregnated coated fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a composite material useful as a reinforcing material for molded articles or a reinforcing material in the civil engineering business.

<Prior art> Conventionally, as a method for producing a fiber-reinforced thermoplastic resin raw material, when producing pellets to be subjected to injection molding, generally,
A method of kneading and extruding a chopped strand obtained by cutting a fiber bundle to about 5 mm and a resin using an extruder is known.

However, according to this method, for example, in the case of aramid fiber which is an organic fiber, when the fiber is cut short, the fiber becomes cottony and becomes extremely bulky, so that it is difficult to bite into an extruder or a kneader, and carbon fiber which is an inorganic fiber is used. Fiber and glass fiber are pulverized by high shear force in the kneading process of the extruder.
0.5 mm or less, resulting in a problem that the mechanical properties of the obtained fiber-reinforced thermoplastic resin cannot be enhanced.

Also, in recent years, as reinforcement of heat-resistant resins such as PPS, PEEK, and PES has become necessary, the dispersibility of the fibers due to the thermal deterioration of the reinforcing fiber sizing agent during pellet preparation time and injection molding by the extruder has increased. There was a problem of getting worse.
Further, when the molded article is used at a high temperature, there is a problem that the heat resistance and mechanical properties of the obtained fiber-reinforced thermoplastic resin are reduced due to the water of the reinforcing fibers and the gas of the sizing agent which has been thermally degraded. To solve these drawbacks, Japanese Patent Application Laid-Open Nos. 62-240351 and 57-90020 have been proposed, but they are effective for biting properties and grinding of reinforcing fibers. The problem of gasification of reinforcing fibers due to water and thermally degraded sizing agent has not been solved. More importantly, it is necessary that each reinforcing fiber is covered with a fiber reinforcing resin. In the method of the above publication, the reinforcing fiber bundle is coated with a high-viscosity resin under normal pressure. For this reason, only the surface of the fiber bundle is mainly covered, and the individual reinforcing fibers are not covered, and thus a sufficient reinforcing effect is not obtained.

JP-A-61-40113 discloses resin-coated fibers obtained by coating continuous reinforcing fibers with a resin. In this method, since the fiber bundles are dispersed, the individual reinforcing fibers are coated, but since the reinforcing fiber bundles are not preheated at a temperature equal to or higher than the melting point of the thermoplastic resin, the fibers adhere to the reinforcing fibers. At the time of molding, the remaining sizing agent is thermally degraded at the molding temperature and gasified, thereby lowering the heat resistance and mechanical properties of the molded product. It is also an important required property that the continuous fibers are uniformly dispersed and mixed in the length direction. However, according to the method of this publication, resin-coated fibers in which the fibers are uniformly dispersed and mixed in the length direction are manufactured. I can't.

<Object of the Invention> An object of the present invention is to solve the problems of the related art as described above. That is, the biting and dispersing properties are good, the generation of gas due to thermal deterioration in the molding stage is small, and the fibers are uniformly dispersed and mixed throughout the molded product.
An object of the present invention is to provide a method for producing a resin-impregnated coated fiber capable of providing a molded product having good heat resistance and mechanical properties.

Specifically, in the method of coating the reinforcing fiber bundle with the thermoplastic resin, the reinforcing fiber bundle is pre-heated at a temperature equal to or higher than the melting temperature of the thermoplastic resin before being coated with the resin, thereby adsorbing or adhering to the reinforcing fiber. Evaporates and removes evaporating components such as moisture and oils to prevent gas generation during molding, and applies pressure when coating with a molten thermoplastic resin to reinforce high-viscosity thermoplastic resin. Pressing into a fiber bundle, and further molding using a molding nozzle at a melting temperature of the thermoplastic resin or higher, found that continuous fibers could be uniformly dispersed in the length direction, and this was also used as a raw material. The inventors have found that molded articles exhibit extremely good heat resistance and mechanical properties, and have reached the present invention.

<Constitution of the Invention> That is, the present invention provides: (1) a resin-impregnated coated fiber obtained by coating a reinforcing fiber bundle with a thermoplastic resin to form a sea-island cross section in which the reinforcing fiber bundle and the thermoplastic resin are dispersed in the fiber cross section. A resin-impregnated coated fiber characterized in that the single fiber group constituting the reinforcing fiber bundle also has a sea-island cross section as an independent island component of 10 to 70% of the single fiber.

(2) 10% under the 40% load of breaking strength of resin impregnated coated fiber
The resin-impregnated coated fiber according to claim 1, wherein the creep strain after the lapse of 00 hours is 5% or less.

(3) A high-strength civil material network formed by knitting the resin-impregnated coated fibers according to (1).

(4) In the method for producing a resin-impregnated coated fiber in which a reinforcing fiber bundle is coated with a thermoplastic resin, the reinforcing fiber bundle is heated to a temperature equal to or higher than the melting temperature of the thermoplastic resin before the reinforcing fiber bundle is coated with the molten thermoplastic resin. A method for producing a resin-impregnated coated fiber, characterized in that after heating in advance, the reinforcing fiber bundle is covered with a molten thermoplastic resin under a pressure of 25 kg / cm ² or more through a forming nozzle.

It is.

The reinforcing fibers used in the present invention are carbon fibers, glass fibers, aramid fibers, stainless fibers, copper fibers, amorphous fibers and the like. Further, the fibers may be subjected to an appropriate sizing treatment or surface treatment.

The thermoplastic resin for impregnated coating is polyamide, polyethylene, polyester, polyarylate, polysulfone,
Polyarylene sulfide, polyether sulfone,
Examples include polyetherimide, polyamideimide, polyacrylonitrile, polycarbonate, polyolefin, polyacetal, and polystyrene.

In order to improve the properties of these thermoplastic resins, various additives such as a heat-resistant agent, a weathering agent, an ultraviolet-ray deterioration inhibitor, an antistatic agent, a lubricant, a mold-retardant, a dye, a pigment, and a crystallization accelerator are added. , A flame retardant or the like may be added.

In the resin-impregnated coated fiber of the present invention, the reinforcing fiber bundle forms an island component and the thermoplastic resin forms a sea component in a fiber cross section. However, a structure in which the reinforcing fiber bundles are all gathered at the center of the resin-coated fiber cannot provide a sufficient effect (for example, FIG. 1). Whether the reinforcing fiber bundles individually form island components independently (FIGS. 2 (A) and (B)), or even if all the island components are in contact with each other, they all gather at the center of the resin-coated fiber. It is not in a proper form. The cross-sectional shape of the reinforcing fiber bundle itself may be circular as shown in FIG. 2 (A), but a non-circular shape as shown in FIG. 2 (B) is more preferable.

Next, the single fiber group constituting the reinforcing fiber bundle is also 10 to
70% of the islands form sea-island cross-sections as independent island components.

If all the single fibers constituting the reinforcing fiber are covered with the coating resin, that is, if all the single fibers are independent island components, the bending strength of the resin-impregnated coated fiber becomes too large. Since the handling efficiency is greatly deteriorated, the ratio of single fiber as an independent island component is 70% or less, preferably 60% or less.
%, It is necessary to be 10% or more, preferably 20% or more because the reinforcing fiber is easily removed from the resin if it is less than 10%.

 Next, the present invention will be described with reference to the drawings.

FIG. 1 shows a conventional resin-coated fiber.
FIG. 1 is a cross-sectional view of a resin-coated fiber in which five reinforcing fiber bundles composed of a large number of reinforcing single fibers have been aligned to form a reinforcing fiber bundle. It is sectional drawing in the case. The reinforcing fiber bundle is solidified in one place without being divided, and is almost circular.

FIG. 3 is a sectional view of one of the conventional reinforcing fiber bundles shown in FIG. 1 taken out. FIG. 3 shows a dispersion state of single fibers constituting a reinforcing fiber bundle in a thermoplastic resin. The thermoplastic resin for coating hardly penetrates into the single fiber, or even from the surface layer to at most several layers.

Such a dispersed state is a form obtained when a bundled fiber bundle is coated with a thermoplastic resin by an ordinary method, and the pulling force between the thermoplastic resin and the reinforcing fibers is extremely low.

FIGS. 2 (A) and 2 (B) show an example of an embodiment obtained by the present invention, and are cross-sectional views when five reinforcing fiber bundles are used. This shows a state in which a thermoplastic resin for impregnation coating as a sea component has entered between bundles.

FIG. 2 (A) shows a state in which each reinforcing fiber bundle is independently covered with a thermoplastic resin, and the contact area between the reinforcing fiber bundle and the thermoplastic resin increases as compared with FIG. Therefore, the pulling force has been greatly improved.

FIG. 2 (B) shows that each reinforcing fiber bundle is, for example, an ellipse,
It has a non-circular cross-section such as a flat, U-shaped, or star shape, and is covered with a thermoplastic resin. The contact area between the reinforcing fiber bundle and the thermoplastic resin is further larger than that in FIG. 2 (A). Due to the increase, the pull-out force is further improved.

The cross-sectional form of the reinforcing fiber bundle shown in FIG.
It is not necessary to be constant in the length direction, and these forms may be combined.

FIG. 4 shows an example of a dispersion state of a group of single fibers constituting one of the reinforcing fiber bundles, taken out of one of the reinforcing fiber bundles shown in FIG. 2 (A). In one reinforcing fiber bundle composed of single fibers, the single fibers form a dense portion and a dispersed portion, which are covered with a thermoplastic resin.

When all of the single fibers are dispersed in the thermoplastic resin, the contact area with the thermoplastic resin increases and the pull-out resistance improves, but the thermoplastic resin does not compress or expand during bending. Since the contact area with the metal is high, the degree of freedom is low and the bending resistance is poor. Therefore, in order to simultaneously satisfy the contradictory conditions of pull-out resistance and bending resistance, 30 to 90% of the single fiber group constituting the reinforcing fiber bundle is densely bundled, and the remaining 70 to 10% is coarsely dispersed. It is necessary to be.

 Next, the present invention will be described with reference to the drawings.

FIG. 6 shows an example of a production apparatus used in the method for producing a resin-impregnated coated fiber of the present invention. A plurality of continuous fiber bundles F for reinforcement are guided from the bobbin 1 to the preheater 3 via the guide 2, where they are heated to vaporize and vaporize harmful components during molding. Then, the fiber bundle is introduced from the introduction die 5 into the polymer reservoir 6. Here, it is coated with a molten thermoplastic resin that has been extruded through a throat 8 melted by a screw 9,
It is formed by a forming nozzle 11 heated to a temperature not lower than the melting temperature of the thermoplastic resin through an outlet die 7, and is taken up by a guide roll 12 via a guide guide roller 12 while being cooled by a cooling bath 13.
Picked up at 14. The strand-shaped resin-impregnated coated fiber is wound by a winder 15. Further, instead of the winding machine 15, the strand is cut to an arbitrary length by a strand cutter or a pelletizer.

The preheater 3 in FIG. 6 evaporates and vaporizes moisture, oils, fixing agents, and the like that are harmful during molding. In order to minimize damage to the fiber bundle, it is desirable to use a non-contact type heater. Further, it is desirable to provide a reflection plate for uniformly heating a plurality of fiber bundles, and to make the temperature of each fiber bundle uniform. If the temperature near the fiber bundle is higher than the melting temperature of the thermoplastic resin, the preheating temperature of the preheating heater 3 can suppress gas due to thermal deterioration, which is a problem at the time of molding. The preheating temperature is desirably 20 ° C. or higher than the melting temperature of the thermoplastic resin. However, if the temperature is too high, not only is the energy loss large, but also the fibers are damaged by heat, resulting in a decrease in mechanical strength and the like. Therefore, for example, in the case of aramid fibers, it is desirable to heat at a temperature of 150 ° C. or higher than the melting temperature of the thermoplastic resin, and in the case of inorganic fibers, it is desirable to heat at a temperature of 200 ° C. or lower than the melting temperature of the thermoplastic resin. The preheating time depends on the preheating temperature.
If the processing time is not less than seconds, it is possible to suppress gas generation during molding. In addition, the reinforcing fiber bundle preheat-treated in this way has improved adhesion between the fiber bundle and the molten thermoplastic resin. In other words, when the molten thermoplastic resin is attached to the fiber bundle that is not preheated, the resin cannot keep up when the take-up speed exceeds a certain value, and the resin adhesion unevenness occurs in the length direction of the fiber bundle. In the pre-heat treated fiber bundle, even when the take-up speed is 1.5 times or more as fast as that in the case where no pre-heating is performed, the resin spots do not occur. This is an effect that directly leads to improvement in productivity and quality. The introduction die 5 is fixed to the die head 10 by bolts. FIG. 7 shows the details of the die 5, and it is desirable to provide a taper at the upper portion, which is the entry side of the fiber bundle, in order to facilitate the passage of the fiber bundle. The reinforcing fiber introduction hole 16 facilitates pressurization in the polymer reservoir 6, and the molten thermoplastic resin introduces the introduction hole.
In order to prevent the fiber bundle from flowing out of the system, it is desirable that the cross-sectional area be close to the cross-sectional area of the fiber bundle. Since the drawing becomes difficult, the sectional area of the introduction hole is desirably 1.02 times or more of the sectional area of the fiber bundle. On the other hand, if the ratio is too large, not only the pressurization becomes difficult but also the molten thermoplastic resin easily flows out. Therefore, the ratio is desirably 1.7 times or less. In addition, introduction hole 16
The length is preferably long for pressurization and preventing the molten thermoplastic resin from flowing out, but is preferably 3 to 20 mm from the viewpoint of workability and handleability.

The exit die 7 is fixed to the die head 10 by bolts. FIG. 8 shows details of the die 7. It is desirable to provide a taper on the upper side, which is the entry side of the fiber bundle, and to pull out the molten thermoplastic resin adhering to and impregnating the reinforcing fibers while narrowing the resin in order to improve the impregnation property of the resin.

In addition, the outlet hole 17 of the reinforcing fiber bundle coated and impregnated with the molten thermoplastic resin has a cross-sectional area of the inlet hole 16 for the purpose of pressurizing the polymer reservoir 6 and preventing the molten thermoplastic resin from flowing out. Desirably the same or more. Also, outlet hole
The length of the hole 17 is desirably equal to or less than the length of the introduction hole 16 from the viewpoints of pressurization in the polymer reservoir 6 and prevention of the molten thermoplastic resin from flowing out.

By supplying the molten thermoplastic resin from the screw 9 using the inlet die 5 and the outlet die 7, pressurization in the polymer reservoir 6 becomes possible, eliminating bubbles in the reinforcing fiber bundle, and This makes it possible to impregnate the reinforcing fiber bundle with the thermoplastic resin. When the applied pressure is low, sufficient impregnation cannot be obtained due to the high viscosity of the molten thermoplastic resin, and the thermoplastic resin cannot enter the fiber bundle. However, 25 kg / cm ² or more, desirably 50 kg / cm ²
If pressurized at the above pressure, the melted thermoplastic resin enters the reinforcing fiber bundle, disperses in the resin, and a resin-impregnated coated fiber having good adhesion between the fiber and the resin can be obtained. . The higher the pressure, the more the molten thermoplastic resin can be impregnated into the fiber bundle within a short time. However, considering the rotational energy of the screw 9 for pressurization and the working accuracy of the dies 5, 6, 200 kg / cm. It is desirable to set the pressure to ² or less.

FIG. 9 shows the details of the forming nozzle 11, and it is desirable to provide a taper on the entry side of the reinforcing fiber bundle covered with the thermoplastic resin. By providing this taper, the thermoplastic resin is narrowed down, and the resin pool removed by narrowing down the tapered portion is used as a polymer reservoir, so that the thermoplastic resin can be more uniformly impregnated and coated in the length direction. Becomes possible. The forming hole 18 has a generally circular cross section, but a polygonal cross section such as a triangle or a square can be used arbitrarily. Further, what is important in the forming nozzle 11 is to heat the fiber bundle to a temperature higher than the melting temperature of the thermoplastic resin impregnated and coated. When the thermoplastic resin is squeezed below the melting temperature of the thermoplastic resin, not only a high drawing tension is required, but also the peeling between the thermoplastic resin and the reinforcing fibers already impregnated and coated on the reinforcing fibers. And the impregnation is significantly reduced. Further, when the temperature of the nozzle 11 is significantly higher than the melting temperature of the thermoplastic resin, the viscosity of the thermoplastic resin is reduced, so that not only the narrowing effect is reduced but also the deterioration of the thermoplastic resin is accelerated. In addition, the mechanical properties of the obtained resin-impregnated coated fiber are reduced. Outgoing die 7
Although the distance between the resin and the forming nozzle 11 can be freely set, it is desirable to make the distance as close as possible in order to prevent the cooling and solidification of the reinforcing fiber bundle covered with the thermoplastic resin.

<Effects of the Invention> According to the present invention, it is possible to provide a resin-impregnated coated fiber which is hard to slip out of the reinforcing fiber bundle from the thermoplastic resin for coating, has a small elongation until a maximum strength is obtained, and has excellent creep resistance. (Improvement in pullout resistance and flexibility).

Further, according to the present invention, it has become possible to suppress the generation of gas, which greatly affects the quality, in molding the resin-impregnated coated fiber.

In addition, the reinforcing civil engineering material network is buried in the soil and used to prevent the collapse of earth and sand. The reinforcing civil engineering material network and earth and sand are interlocking effects (anchor effect) between the stitches and the earth and sand. Prevents slippage. At this time, the internal stress of the earth and sand changes into a force to stretch the resin-impregnated coated fibers constituting the reinforcing civil engineering material network.

In particular, the stretching force is particularly strong for several years until it hardens after being buried in the soil, and this force causes the resin-impregnated coated fiber to creep. The force to stretch the resin-impregnated coated fiber is transmitted to the reinforcing fiber bundle via the thermoplastic resin, but if the pull-out resistance between the reinforcing fiber bundle and the thermoplastic resin is not sufficient, the characteristics of the reinforcing fiber bundle Is not utilized, and a satisfactory reinforcing effect cannot be obtained despite the use of the reinforcing fibers. When the resin-impregnated coated fiber of the present invention is used as such a reinforcing civil engineering material network, it has a sufficient pulling-out resistance, so that the reinforcing effect is remarkably excellent.

<Example> Hereinafter, the present invention will be specifically described with reference to examples. The measuring method used in the examples is as follows.

(1) Presence or absence of gas generation The temperature was measured by a gas chromatography method using a glass chromatography model G80 manufactured by Yanagimoto Seisakusho. Reinforcing fiber, thermoplastic resin and resin impregnated coated fiber not surface treated
The case where the decomposition peak of the resin-impregnated coated fiber is composed of the decomposition peak of the non-surface-treated reinforcing fiber and the decomposition peak of the thermoplastic resin, without gas generation, of the non-surface-treated reinforcing fiber Gas generation was defined as a case where the decomposition peak other than the decomposition peak and the decomposition peak of the thermoplastic resin was the decomposition peak of the resin-impregnated coated fiber.

Measurement conditions at this time are: Carrier gas: He, Inject temperature: Melting point + 15 ° C (PPS: 300 ° C) Column: Leave at 100 ° C for 10 minutes, then 300 ° C at a rate of 10 ° C / 1 minute.
After heating up, leave for another 10 minutes.

Strand uniformity Measure the diameter of the strand at 1m intervals under a microscope of 30x.
20 points were measured and indicated by CV% (σ /).

Example 1 According to the production method of the present invention, 1500 denier / 1000 filament technola (Teijin Co., Ltd. para-aramid fiber) was heated for 3 seconds with a preheater heated to 350 ° C., and then was 0.5 mm in inner diameter and 10 mm in length. The fiber is introduced into the polymer reservoir through the introduction hole, where the fiber is impregnated with a PPS resin that has been melted with a screw and controlled at 320 ° C under a pressure of 50 kg / cm ² , and then pulled out from a lead-out hole with an inner diameter of 0.6 mmφ and a length of 2 mm. 0.55mm inside diameter heated at 320 ℃, length 5mm
The molding was performed using a molding nozzle and cooled to obtain a Vf 57% strand.

The strand was cut into 3 mm by a strand cutter to obtain a master pellet for injection molding, and a PPS resin was added at the time of molding to prepare a sample for measuring Vf of 20%.

The injection molding conditions at this time are: cylinder temperature; 310 ° C. on the side containing pellets; 310 ° C. on the nozzle side;
° C, mold temperature; 130 ° C, injection pressure 800 kg / cm ² .

Comparative example 1 It carried out similarly to Example 1 except not using a preheating heater.

Comparative Example 2 The measurement was performed in the same manner as in Example 1 except that the molding nozzle was not used. As a result, a strand having a Vf of 35% was obtained.

Comparative Example 3 The inner diameter of the outlet hole of Example 1 was 0.8 mmφ, and the immersion pressure was 0 to 5
The same operation was carried out except that Kg / cm ² was used.

Table 1 shows the mechanical properties, the dispersibility of the reinforcing fibers, the presence / absence of gas generation, and the uniformity of the dispersion and mixing of the reinforcing fibers of the injection-molded article prepared using the obtained strands.

Example 2 Sample A fiber bundle for reinforcement was formed using a Technora yarn (para-aramid fiber of Teijin Limited), and a high-density polyethylene (melt index 0.25 gr / 10) was used as a thermoplastic resin for impregnation coating.
And a softening point of 128 ° C.), and a coating was used to prepare a civil engineering material net having a mesh of repeating units of 28 mm and a wire diameter of 4 mm by a predetermined method.

In the following examples, the reinforcing fiber bundle was used only in the vertical direction unless otherwise specified. In addition, the covering form of the reinforcing fiber bundle was changed by changing the method of supplying the reinforcing fiber and the melting condition of the thermoplastic resin to obtain a different form.

Measurement method (1) Tensile strength and elongation Repeat unit: 3 (84 mm) in the horizontal direction, 17 in the vertical direction
(476 mm), cut out the test piece, hold the horizontal wires at both ends in the vertical direction using a jig so that the clamping pressure of the chuck is not applied to the vertical wire, and then hold both ends in the middle of the vertical direction. Cut the vertical wire into a sample and use an Intesco tensile tester (type 2005) at a temperature of 23 ° C and a humidity of 50
The maximum strength and the elongation at that time were repeatedly measured 10 times under the conditions of% and take-off speed of 50 mm / min, and the pull-out property at this time was also examined.

(2) Single fiber covering condition Using a reflected light with an optical microscope, observe the dispersion state of the single fibers in the thermoplastic resin at a magnification of 100 times, and determine the number of single fibers surrounded by the thermoplastic resin. Measured.

(3) Handleability during construction As a typical characteristic of handleability during construction, judgment was made based on the presence or absence of breakage when the resin-impregnated coated fiber was bent 60 mm with a point 50 cm ahead of the fulcrum.

(4) Creep characteristics Repeating unit: 3 (84 mm) in the horizontal direction, 30 in the vertical direction
(840 mm), a test piece for creep property evaluation was cut out, a load of 200 kg corresponding to 40% of the breaking strength was applied, and the temperature was changed to 23.
The elongation after 1000 hours was measured under the conditions of a temperature of 50 ° C and a humidity of 50%.

As a reinforcing fiber, a Z fiber of 74 pieces / m is put into a 1500 denier / 1000 filament Technora yarn to form one reinforcing fiber bundle, and five reinforcing fiber bundles are 300
The resin-impregnated coated fiber having a cross-sectional shape shown in FIG. 2A was obtained by feeding into a high-density polyethylene resin melted and pressurized at 50 ° C. and 50 kg / cm ² .

As a result of a tensile test of this sample, it was found that the pull-out resistance was improved up to 88% of the breaking strength of the reinforcing fiber bundle.
Also, the creep strain was as good as 3%.

Example 3 Reinforcement fiber bundles were prepared by putting 74 strands / m of Z twist into 1500 denier / 1000 filament techno yarn as reinforcement fibers, and using separate nozzles to prevent five reinforcement fiber bundles from coming into contact with each other. Except for the above, coating was performed in the same manner as in Example 1 to obtain a resin-impregnated coated fiber having a cross-sectional shape as shown in FIG. 2 (A). As a result of a tensile test of this sample, it was found that the pull-out resistance was improved to 91% of the breaking strength of the reinforcing fiber bundle. Also, the creep strain was as good as 3%.

Example 4 As a reinforcing fiber bundle, a 750 denier / 500 filament Technora yarn was used, and 74 strands / m of Z twist was put into a reinforcing fiber bundle. Then, separate reinforcing nozzles were used to prevent the ten reinforcing fiber bundles from coming into contact with each other. Coating was performed in the same manner as in Example 2 except that the coating was performed. As a result of a tensile test of this sample, the reinforcing fiber bundle was broken without being pulled out. Also, the creep characteristics were almost the same as those of the reinforcing fibers.

Example 5 As a reinforcing fiber, impregnated coating was performed in the same manner as in Example 2 except that five techno yarns of 1500 denier / 1000 filaments without twisting were resin-impregnated and coated via five separate nozzles.

As a result of a tensile test of this sample, the reinforcing fiber bundle exhibited high breaking strength and low creep characteristics without being pulled out.

Comparative Example 4 1500 denier / 1000 fillant techno yarn was used as one reinforcing fiber bundle to form one reinforcing fiber bundle, and five fibers were collected.
// m S-twisted fiber bundle for reinforcement
A resin-impregnated coated fiber having a cross-sectional configuration shown in FIG. 1 was obtained in the same manner as in Example 2 except that the resin was put into the thermoplastic resin for impregnated coating melted at 300 ° C. without pressing.

As a result of a tensile test on this sample, only a low value of 50% of the breaking strength was obtained because the pull-out resistance was weak.
Even the creep strain under load was as large as 100%.

Comparative Example 5 Reinforcing fiber of 74 denier / 1000 filament techno yarn as a reinforcing fiber and 74 strands / m Z twist put into one reinforcing fiber bundle to collect 5 strands and 17 strands / m S twist A resin-impregnated coated fiber having a cross-sectional shape as shown in FIG. 1B was obtained in the same manner as in Comparative Example 1 using a nozzle and a nozzle.

As a result of a tensile test of this sample, the breaking strength of the reinforcing fiber bundle was as low as 65%, and even a creep strain under a load of 20% was 100%.
%.

Comparative Example 6 The same procedure was performed as in Example 3 except that the pressure was increased to 150 kg / cm ² . Although the drawing characteristics were good, breakage occurred during bending.

Table 2 shows the mechanical properties and the drawing conditions of the obtained resin-impregnated coated fibers.

Example 6 The procedure of Example 1 was repeated except that the PPS resin was changed to PBT resin, the resin temperature and the molding nozzle temperature were changed to 300 ° C., and a Vf 47% strand was obtained.

The injection molding conditions were as follows: Cylinder temperature: 260 ° C on the pellet side, nozzle side: 270
° C Nozzle temperature: 275 ° C, Mold temperature: 70 ° C Injection pressure was 870 Kg / cm ² . Table 3 shows the evaluation results.

Example 7 In Example 1, the PPS resin was changed to nylon 46 resin.
Change the resin temperature and molding nozzle temperature to 330 ° C, and
% Of strands was obtained in the same manner as in Example 1.

At this time, the injection molding conditions were as follows: cylinder temperature: 300 ° C on the pellet side, nozzle side: 320
C. Nozzle temperature: 320 ° C., mold temperature: 120 ° C. Injection pressure was 1000 kg / cm ² . Table 3 shows the evaluation results.

Example 8 The procedure of Example 1 was repeated except that the reinforcing fiber was changed to Kevlar 49 of 1420 de / 1000 fil, and a strand having a Vf of 39% was obtained.

The injection molding conditions were as follows: Cylinder temperature: 320 ° C on the pellet side, nozzle side: 330
° C Nozzle temperature: 335 ° C, Mold temperature: 130 ° C Injection pressure was 1000 kg / cm ² . Table 3 shows the evaluation results.

Comparative Examples 7 to 9 Examples 6 to 8 were carried out in the same manner as in Examples 6 to 8, except that the inner diameter of the lead-out hole was 0.8 mm and the pressure and impregnation pressure was 0 to 5 kg / cm ² . Table 3 shows the evaluation results.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a form of a conventional reinforcing fiber bundle and a thermoplastic resin. FIGS. 2 (A) and 2 (B) are cross-sectional views showing forms of a reinforcing fiber bundle and a thermoplastic resin according to the present invention. FIG. 3 is a cross-sectional view showing a dispersion state of single fibers in a thermoplastic resin in one reinforcing fiber bundle of FIG. 1 of a conventional example. FIG. 4 is a cross-sectional view showing a dispersion state of single fibers in a thermoplastic resin in one reinforcing fiber bundle of FIG. 2 according to the present invention. FIG. 5 is a plan view of a high-strength civil engineering material network produced using the resin-impregnated coated fiber of the present invention. FIG. 6 is a schematic view showing an example of the apparatus for producing a resin-impregnated coated fiber according to the present invention, FIG. 7 is a front view of an introduction side die, FIG. 8 is a front view of an exit side die, and FIG. Front view. ...... Reinforcing fiber bundle, Thermoplastic resin, Single fiber concentrated part, Single fiber dispersion part, Single fiber, F Supply fiber, 1, Bobbin, 2,4 Guide guide , 3 ... Preheater, 5 ... Inlet die, 6 ... Polymer pool, 7 ... Outlet die, 8 ... Throat, 9 ... Screw, 10 ... Die head, 11 ... Forming nozzle, 12 ... ... Guide guide roller, 13 ... Cooling bath, 14 ... Taking-up roll, 15 ... Winding machine, 16 ... Reinforcing fiber introduction hole, 17 ... Reinforcing fiber outlet hole, 18 ... Forming hole

Continuation of front page (72) Inventor Keiro Toshiro 3-4-1, Amihara, Ibaraki-shi, Osaka Teijin, Ltd. Osaka Research Center (56) References JP-A-49-102921 (JP, A) JP-A Sho 47-39714 (JP, A) JP-A-48-56993 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) D01F 8/04 D06M 15/00

Claims (4)

(57) [Claims] 1. A resin-impregnated coated fiber in which a reinforcing fiber bundle is coated with a thermoplastic resin, wherein the reinforcing fiber bundle and the thermoplastic resin form a sea-island cross section in which the fiber cross section is dispersed. Constituent single fiber group is 10 ~ 70% of single fiber
Has a sea-island cross-section as an independent island component. 2. The resin-impregnated coated fiber according to claim 1, wherein the creep strain of the resin-impregnated coated fiber after a lapse of 1000 hours under a load of 40% of the breaking strength is 5% or less. 3. A high-strength civil material net obtained by knitting the resin-impregnated coated fibers according to claim 1. 4. A method for producing a resin-impregnated coated fiber in which a reinforcing fiber bundle is coated with a thermoplastic resin, wherein the reinforcing fiber bundle is melted before the reinforcing fiber bundle is coated with the molten thermoplastic resin. A method for producing a resin-impregnated coated fiber, comprising heating a reinforcing fiber bundle with a molten thermoplastic resin under a pressure of 25 kg / cm ² or more through a forming nozzle after preheating at a temperature or higher.