KR102486097B1 - Resin coated carbon fiber and manufacturing method thereof - Google Patents

Abstract

The resin-coated carbon fiber according to the present invention includes continuous carbon fiber and polymer resin, and the coefficient of variation of the yarn width in the resin-coated carbon fiber is 5% or less, and the resin coating method through melt extrusion and the liquid phase In order to solve the disadvantages of the resin treatment method, even though the liquid resin treatment method is applied, it has a uniform yarn width throughout the carbon fiber due to the low variation coefficient of the yarn width, thereby providing resin-coated carbon fiber suitable for grid fabric for earthquake-resistant reinforcement in a simple process. can

Description

Resin coated carbon fiber and its manufacturing method {RESIN COATED CARBON FIBER AND MANUFACTURING METHOD THEREOF}

The present invention relates to a resin-coated carbon fiber coated with a polymer resin, and relates to a resin-coated carbon fiber for grid fabric having a uniform yarn width with a low variation coefficient of yarn width, and a manufacturing method thereof.

In general, carbon fiber is a material having excellent mechanical properties, and is used by configuring carbon fiber reinforced plastic (CFRP) together with a matrix resin. CFRP is used as a new material to replace heavy metals because it is light in weight and has very high mechanical strength such as strength and elastic modulus compared to materials such as metal. As such, CFRP can achieve light weight and mechanical strength at the same time, so it is used in special applications such as aviation and space. is continuing to expand.

In addition, when carbon fiber is used as a reinforcing material for civil engineering or building based on the above-mentioned advantages, it is mainly used as a mesh-like grid fabric, which is different from fabrics having almost no voids. In particular, as earthquakes have recently subsided in Korea, research on applying carbon fiber reinforced concrete (CFRC), a concrete structure reinforced with carbon fiber, has been actively conducted to prevent chain collapse of buildings caused by earthquakes.

Grid fabrics are coated with resin to maintain their shape and bind between weft and warp yarns. In the case of the melt extrusion method, thermoplastic polymer resin is used and carbon fiber is passed through the supplied resin. In the case of the liquid resin treatment method, the liquid It is manufactured by using a resin and using a resin-soaked roll or a method of dipping fibers.

This melt extrusion method has the advantage that the shape is uniform because fibers are pulled out through a nozzle of a specific shape after resin coating, but a high temperature of 200 ° C or higher is required because the nozzle must be heated above the melting point of the resin, and carbon There is a problem in that the shear force acts on the fibers high and the frequency of fiber damage increases, and thus, process troubles often occur, and there is a disadvantage in that the process speed is lowered to prevent this. In addition, when a process trouble occurs, resin deterioration may occur. In order to prevent such deterioration of the resin, there is a significant disadvantage in that time and cost required to initialize and restart the resin extrusion device are consumed.

In addition, in the case of the liquid resin treatment method, the process temperature is relatively low, high-speed processing is possible, and trouble measures are simple. It may cause a problem that the quality of the fabric and the physical properties of each location are not uniform.

Korean Patent Publication No. 10-2001-0021631

The present invention is an invention proposed to solve the disadvantages of the resin coating method through the above-described melt extrusion method and the resin coating method through the liquid resin treatment method. It is intended to provide a resin-coated carbon fiber for grid fabric having a uniform yarn width with a very low modulus and a manufacturing method thereof.

The above and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

The above object is achieved by a resin-coated carbon fiber in which a polymer resin is coated on continuous carbon fiber, and the coefficient of variation of yarn width is 5% or less.

Preferably, the coefficient of variation of the yarn width may be measured at any 20 sections within a length of 100 m or more at a temperature of 0 ° C to 50 ° C for the resin-coated carbon fiber.

Preferably, the polymer resin may have a glass transition temperature of 20°C or higher.

Preferably, the resin-coated carbon fiber has a height difference of 30 to 70 mm at both ends when the length of the resin-coated carbon fiber is 300 mm at a temperature of 0 ° C to 50 ° C. can be

Preferably, the average yarn width of the resin-coated carbon fiber may be 4 to 8 mm at a temperature of 0 ° C to 50 ° C.

Preferably, the average thickness of the resin-coated carbon fiber may be 1.3 to 3 mm at a temperature of 0 ° C to 50 ° C.

Preferably, 20 to 40% by weight of the polymer resin based on the total weight of the resin-coated carbon fibers may be coated.

Preferably, the polymer resin may include at least one binder selected from caprolactam, hexamethylenediamine, adipic acid, and sebacic acid.

Preferably, the polymer resin may be coated on the carbon fiber using an aqueous dispersion coating solution containing the polymer resin dispersed in distilled water.

Preferably, the aqueous dispersion coating solution may further include a polyethylene acrylic acid copolymer.

Preferably, the aqueous dispersion coating solution may include 9 to 200 parts by weight of a polyethylene acrylic acid copolymer based on 100 parts by weight of the polymer resin.

Preferably, the aqueous dispersion coating solution may include 10 to 45 parts by weight of a polymer resin and 4 to 20 parts by weight of a polyethylene acrylic acid copolymer based on 100 parts by weight of distilled water.

In addition, the above object is to immerse and impregnate the continuous carbon fibers in a water dispersion coating liquid in which a polymer resin is dispersed in water, dry the carbon fibers impregnated with the water dispersion coating liquid to remove moisture, and dry the carbon fibers to 2 A method for producing resin-coated carbon fibers, comprising the steps of heating and opening fibers by passing them through at least one heating roll and cooling the carbon fibers heated through the heating rolls through two or more cooling rolls to adjust the yarn width of the carbon fibers. is achieved by

Preferably, the water-dispersed coating solution contains 10 to 45 parts by weight of at least one binder selected from caprolactam, hexamethylenediamine, adipic acid and sebacic acid and 4 to 20 parts by weight of a polyethylene acrylic acid copolymer based on 100 parts by weight of distilled water. may include

Preferably, the heating roll may be provided with a Π-shaped groove that limits the expansion range of the yarn width.

Preferably, the temperature of the heating roll may be a temperature between the glass transition temperature and the melting point of the polymer resin.

Preferably, the cooling roll may be provided as a nip roll to control the shape of the resin-coated carbon fiber.

Preferably, the temperature difference between the heating roll and the cooling roll may be 10 to 100 °C.

In addition, the above object is achieved by the above-described resin-coated carbon fiber used as a grid fabric for earthquake-resistant reinforcement.

According to the resin-coated carbon fiber and its manufacturing method according to an embodiment of the present invention, an effect such as having a uniform yarn width is obtained by using a liquid dipping method using a coating liquid in which a polymer resin having a glass transition temperature of 20 ° C or higher is dispersed in water. there is.

In addition, according to the resin-coated carbon fiber and its manufacturing method according to an embodiment of the present invention, the thread width is uniform during weaving of the grid fabric, so that the quality of the grid fabric and the physical properties of each position are uniform.

In addition, according to the resin-coated carbon fiber and its manufacturing method according to an embodiment of the present invention, it is easy to wind due to its excellent flexibility, and there is no fear of damage to the resin-coated carbon fiber even when the running angle is greatly bent during weaving a grid fabric. There is no, and the elasticity of the grid fabric is excellent, so the grid structure is not distorted, and the physical property expression rate of the grid fabric is excellent.

In addition, according to the resin-coated carbon fiber and the manufacturing method thereof according to an embodiment of the present invention, there are effects such as simple and safe manufacturing of the resin-coated carbon fiber for grid fabric for seismic reinforcement.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a flowchart showing a method for manufacturing a resin-coated carbon fiber according to an embodiment of the present invention.
2 is a schematic view of the structure and running process of a heating roll used in the method of manufacturing resin-coated carbon fibers according to an embodiment of the present invention.
FIG. 3 is a schematic view illustrating the opening of resin-coated carbon fibers in the Π shape of a heating roll used in the method of manufacturing resin-coated carbon fibers according to an embodiment of the present invention.
4 is a schematic view of the structure and driving process of a cooling roll used in the method of manufacturing resin-coated carbon fibers according to an embodiment of the present invention.
5 is a diagram explaining a method for measuring drapability of resin-coated carbon fibers.

With reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In the drawings, the thickness is shown enlarged to clearly express the various layers and regions. Like reference numerals have been assigned to like parts throughout the specification. When a part such as a layer, film, region, plate, etc. is said to be “on” another part, this includes not only the case where it is “directly on” the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. Also, although methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, suitable methods and materials are described herein.

The resin-coated carbon fiber according to an embodiment of the present invention is one in which a polymer resin is coated on continuous carbon fiber.

In one embodiment, the continuous carbon fibers preferably include at least one of PAN-based carbon fibers, pitch-based carbon fibers, and rayon-based carbon fibers.

Also, the number of filaments per tow of the carbon fiber tow is preferably 1,000 to 50,000. If the number of filaments is less than 1,000, there is a disadvantage in that the area ratio per volume is low and the manufacturing cost increases, and if the number exceeds 50,000, the number of filaments per carbon fiber tow increases, and the tensile strength of the grid fabric using the manufactured resin-coated carbon fiber A disadvantage occurs in that strength and/or compressive strength are lowered.

In one embodiment, the glass transition temperature of the polymer resin coated on the continuous carbon fibers is preferably 20 °C or higher. When the glass transition temperature of the polymer resin is less than 20 ° C, the yarn width of the resin-coated carbon fiber produced is likely to be distorted due to the fluidity of the resin at room temperature, that is, the coated fiber produced in the present invention is set to a specific yarn width, but the glass transition temperature If it is low, it is because the yarn width of the resin-coated carbon fiber is highly likely to be deformed from external forces such as tension due to resin fluidity and friction with guide rolls running during the winding process.

In one embodiment, the polymer resin may include at least one binder selected from caprolactam, hexamethylenediamine, adipic acid, and sebacic acid. Caprolactam, hexamethylenediamine, adipic acid and sebacic acid are precursor materials for polyamide resins, and these materials are suitable as carbon fiber coating agents because they are less likely to be removed from carbon fibers after coating than resins such as polypropylene and polyethylene. In addition, to use polyamide resin as it is, a melt extrusion method is required, the temperature conditions required for controlling the width of the yarn using a heating roll and a cooling roll can be severe, and since the elasticity is stronger than that of the precursor mixture, winding of resin-coated carbon fiber or grid fabric Since it may be unsuitable for the weaving process, in order to achieve the object of the present invention, it may include at least one binder among caprolactam, hexamethylenediamine, adipic acid, and sebacic acid, preferably all of them. can

In one embodiment, the polymer resin may be coated with 20 to 40% by weight of the polymer resin based on the total weight of the resin-coated carbon fiber. This is related to the concentration of the polymer resin solid content in the coating solution. If the polymer resin is less than 20% by weight, the yarn width of the resin-coated carbon fiber is easily changed by external force, and if it exceeds 40% by weight, the water dispersion stability is poor and excessive This is because there is a possibility that the resin-coated carbon fiber may be physically damaged due to the coating of the resin. For example, if the polymer resin exceeds 40% by weight, the tow may be damaged when the running angle is greatly bent in the grid fabric weaving process because the resin-coated carbon fiber has a hard property.

Resin-coated carbon fibers according to an embodiment of the present invention may be coated with a polymer resin on carbon fibers using a water dispersion coating solution containing a polymer resin dispersed in distilled water. That is, during the manufacture of resin-coated carbon fibers, the polymer resin is coated (impregnated) on the carbon fibers in the form of a coating liquid dispersed in distilled water.

In one embodiment, the water dispersion coating solution containing the polymer resin preferably further includes a polyethylene acrylic acid copolymer as a dispersant for water dispersion stability of the polymer resin.

In one embodiment, the aqueous dispersion coating solution preferably includes 9 to 200 parts by weight of a polyethylene acrylic acid copolymer based on 100 parts by weight of the polymer resin. If the content of the polyethylene acrylic acid copolymer is less than 9 parts by weight, the dispersion stability of the binder material is impaired and the resin coating amount in the longitudinal direction is not uniform, and if it exceeds 200 parts by weight, binding with carbon fibers may be inhibited.

In one embodiment, the aqueous dispersion coating solution in which the polymer resin is dispersed in water preferably contains 10 to 45 parts by weight of the polymer resin (binder material), more preferably 15 to 35 parts by weight, based on 100 parts by weight of distilled water. When the content of the polymer resin is dispersed in less than 10 parts by weight, the yarn width of the resin-coated carbon fiber is easily changed by external force, and when the content of the polymer resin is dispersed in more than 45 parts by weight, the water dispersion stability is deteriorated and an excessive amount of resin is coated. There is a possibility that the coated carbon fiber is physically damaged. For example, if the polymer resin solid content exceeds 45 parts by weight, the resin-coated carbon fiber has a hard property, and the resin-coated carbon fiber may be damaged when the running angle is greatly bent in the grid fabric weaving process.

In one embodiment, the aqueous dispersion coating solution in which the polymer resin is dispersed in water preferably contains 4 to 20 parts by weight of a polyethylene acrylic acid copolymer as a dispersing agent, more preferably 6.5 to 15 parts by weight, based on 100 parts by weight of distilled water. If the content of the polyethylene acrylic acid copolymer is less than 4 parts by weight, the dispersion stability of the binder material is impaired, so that the resin coating amount in the longitudinal direction is not uniform, and if it exceeds 20 parts by weight, binding with carbon fibers may be inhibited.

The resin-coated carbon fiber according to an embodiment of the present invention preferably has a coefficient of variation of 5% or less of yarn width representing a variation in yarn width. At this time, the coefficient of variation of the yarn width may be measured at any 20 sections within a length of 100 m or more at a temperature of 0 ° C to 50 ° C for the resin-coated carbon fiber. If the coefficient of variation of the yarn width exceeds 5%, it is preferable to set it within the above range because the variation of the yarn width increases and the yarn width is non-uniform, causing a problem in which the quality of the grid fabric and the physical properties of each position are not uniform.

In one embodiment, the resin-coated carbon fiber is the height of both ends ( It is preferable that the difference in sagging length) is 30 to 70 mm, and it is more preferable that the difference in height between both ends is 35 to 50 mm. If this height difference is less than 30 mm, it is difficult to wind the resin-coated carbon fiber due to lack of flexibility, and if the running angle is greatly bent during weaving the grid fabric, the resin-coated carbon fiber may be damaged. On the other hand, if it is greater than 70 mm, the grid Since the grid structure may be distorted due to insufficient elasticity of the fabric and the rate of physical property expression of the grid fabric may be lowered, the resin-coated carbon fiber preferably has a drape property within the above range.

In one embodiment, the resin-coated carbon fiber preferably has an average yarn width of 4 to 8 mm at a temperature of 0 ° C to 50 ° C. At this time, when the average yarn width of the resin-coated carbon fiber is less than 4 mm, the contact area with the matrix concrete is narrowed, resulting in a decrease in strength reinforcement efficiency. .

In one embodiment, the resin-coated carbon fiber preferably has an average thickness of 1.3 to 3 mm at a temperature of 0 ° C to 50 ° C. At this time, if the average thickness of the resin-coated carbon fiber is less than 1.3mm, the grid structure has a problem of distortion due to the decrease in elasticity of the grid fabric, and if it is more than 3mm, the contact area with the matrix concrete is narrowed and the strength reinforcement efficiency is lowered. have The meaning of limiting the thickness of the resin-coated carbon fiber is in line with the meaning of the average yarn width.

1 is a flowchart showing a method for manufacturing a resin-coated carbon fiber according to an embodiment of the present invention.

Referring to FIG. 1, a method for manufacturing resin-coated carbon fibers according to an embodiment of the present invention includes the steps of immersing and impregnating continuous carbon fibers in a water dispersion coating solution in which a polymer resin is dispersed (S101), Drying the impregnated carbon fiber to remove moisture (S102), heating and opening the dried carbon fiber by passing it through two or more heating rolls (S103), and heating the carbon fiber heated through the heating roll to two or more and adjusting the yarn width of the carbon fibers by cooling them through a cooling roll (S104).

First, in the step of immersing and impregnating continuous carbon fibers in a water dispersion coating solution in which a polymer resin is dispersed in water (S101), continuous carbon fibers are immersed and impregnated in a water dispersion coating solution formed by dispersing a polymer resin in distilled water. . At this time, the aqueous dispersion coating solution in which the polymer resin is dispersed in water preferably includes 10 to 45 parts by weight of a polymer resin (binder) and 4 to 20 parts by weight of a polyethylene acrylic acid copolymer based on 100 parts by weight of distilled water.

Next, in step S102 of drying the carbon fiber impregnated with the water dispersion coating liquid to remove water, the water is dried from the water dispersion coating liquid immersed in the carbon fiber so that only the carbon fiber polymer resin is coated on the carbon fiber. At this time, drying is preferably performed at 100° C. to 150° C., more preferably at 105° C. to 130° C. for 2 minutes to 5 minutes. If the drying temperature is less than 100 ° C., it is impossible to remove moisture, and if it exceeds 150 ° C., the coating liquid is scattered and uniform coating cannot be performed, and the polymer resin adheres to the rolls in the drying oven and causes fiber damage.

Next, in the step of heating and opening the dried carbon fiber by passing it through two or more heating rolls (S103), after completing the step of removing moisture (S102), it is heated by contacting the heating roll, and at the same time, the carbon fiber is opened. It is a step. At this time, the temperature of the heating roll is suitable for a temperature between the glass transition temperature and the melting point of the polymer resin. The heating roll heats the polymer resin above the glass transition temperature to provide fluidity, and by controlling the melting point below, it is possible to prevent fiber damage caused by melting and sticking of the polymer resin.

2 is a schematic view of the structure and running process of a heating roll used in the method of manufacturing resin-coated carbon fibers according to an embodiment of the present invention. Referring to FIG. 2 , two or more heating rolls 210 are disposed, and dried carbon fibers are heated and opened through the heating rolls 210 . In this case, heating rolls 210 having different diameters may be alternately disposed.

FIG. 3 is a schematic view illustrating the opening of resin-coated carbon fibers in the Π shape of a heating roll used in the method of manufacturing resin-coated carbon fibers according to an embodiment of the present invention. As shown in FIG. 3, the heating roll is preferably provided with a Π-shaped groove. The Π shape of the heating roll uniformly controls the yarn width by limiting the expansion range of the yarn width of the resin-coated carbon fiber provided in the present invention. The resin-coated carbon fiber is heated while passing through the heating roll, and the yarn width is expanded (301 to 304). Here, it will be commonly understood by those skilled in the art that the number and diameter of the heating rolls and the width and temperature of the Π shape may vary depending on the required opening width.

Next, in the step of adjusting the yarn width of the carbon fibers by cooling the carbon fibers heated through the heating rolls through two or more cooling rolls (S104), the resin-coated carbon fibers opened by the heating rolls are cooled by passing them through the cooling rolls. let it

4 is a schematic view of the structure and driving process of a cooling roll used in the method of manufacturing resin-coated carbon fibers according to an embodiment of the present invention. Referring to FIG. 4 , while the carbon fibers heated and opened through the heating roll 310 pass through the cooling roll 410 , the yarn width is narrowed due to thermal contraction of the polymer resin. At this time, the cooling roll 410 may be provided as a nip roll to control the shape of the resin-coated carbon fiber. The narrowing range of the yarn width is determined by the temperature difference between the temperature of the heating roll 410 and the cooling roll in this step, and two or more cooling rolls 410 may be provided depending on the cooling speed of the resin-coated carbon fiber. there is.

In addition, it is preferable that the temperature difference between the heating roll in step S103 and the cooling roll in step S104 is 10 to 100°C. At this time, if the temperature difference is less than 10 ℃, there is a problem that the heat shrinkage effect of the polymer resin is not well expressed because the temperature difference is too small. There is a narrowing problem.

The resin-coated carbon fiber produced by the above-described manufacturing method has a trapezoidal cross section, and the coated polymer resin is preferably 20 to 40% by weight of the total weight of the resin-coated carbon fiber. This is related to the concentration of the polymer resin solid content in the coating solution in which the polymer resin is dispersed in water. When the polymer resin is less than 20% by weight, the yarn width of the resin-coated carbon fiber is easily changed by external force, and when the polymer resin is greater than 40% by weight, the water dispersion There is a risk of physical damage to the resin-coated carbon fiber due to poor stability and excessive coating of the resin.

In addition, although not limited thereto, the resin-coated carbon fiber according to an embodiment of the present invention may be suitable for use as a grid fabric for seismic reinforcement.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through Examples and Comparative Examples. However, these examples are for explaining the present invention in more detail, and the scope of the present invention is not limited to these examples.

[Example]

[Example 1]

Preparation Example 1: Preparation of a coating solution in which a polymer resin is dispersed in water

Polyethylene acrylic acid copolymer (sigma-aldrich) is sufficiently pulverized to a particle diameter of 2 μm or less using bead mill equipment, and 651.98 g of the pulverized polyethylene acrylic acid copolymer is added to 10 L of distilled water, then the upper part of the container is covered with aluminum foil and a magnetic stirrer While the solution was mixed well using the ultrasonic disperser while heating to 80 ℃.

Next, after 10 hours, 956.24 g of caprolactam (Sigma-Aldrich), 239.06 g of hexamethylenediamine (Sigma-Aldrich), adip Add 217.33 g of acid and 130.40 g of sebacic acid, cover the top of the container with aluminum foil, mix the solution well using a magnetic stirrer, and operate the ultrasonic disperser for 24 hours while heating to 95 ° C to polymer resin and polyethylene acrylic acid copolymer. A coating solution completely dispersed in distilled water was prepared. At this time, the melting point of the mixed polymer resin was confirmed to be 155 ℃.

Preparation Example 2: Coating process

The coating solution in which the polymer resin prepared in Preparation Example 1 was dispersed in water was put into an impregnation tank, and a slope (running condition of the fiber in the process) was configured so that the carbon fiber (T700SC-50C-24k of Toray Advanced Materials) was immersed in the impregnation tank. The carbon fiber was immersed through an impregnation roll having a diameter of 260 mm, and the impregnation roll was managed to be immersed in the coating solution at least 100 mm from the bottom at all times. After passing through the impregnation bath, the carbon fibers were dried at 120° C. for 3 minutes to evaporate moisture. At this time, the tension of the process line was maintained at 700 gf and the speed at 6 m/min.

Preparation Example 3: Yarn Width Uniformization Process

The dried resin-coated carbon fibers obtained in Preparation Example 2 were opened by passing them through a heating roll having a Π shape having a width of 8 mm and a depth of 5 mm. At this time, the arrangement of the heating rolls was a three-stage structure of 150 mm in diameter - 70 mm in diameter - 150 mm in diameter, and the center of each roll was kept in a straight line (the diameter is based on the outer diameter of the heating roll in contact with the carbon fiber). The temperature of the heating roll was maintained at 95°C.

The resin-coated carbon fiber opened through the heating roll was cooled using a cooling roll, and then wound around the provided paper tube. At this time, one set of 150 mm diameter nip rolls and two single rolls were applied. In the case of the nip roll, a pressure of 1 kgf and a temperature of 60 ° C were maintained, and the subsequent cooling rolls were sequentially maintained at 35 ° C and room temperature. At this time, the tension of the process line was maintained at 700 gf and the speed at 6 m/min.

[Example 2]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that the temperature of the heating roll was applied at 120 ° C.

[Example 3]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that the temperature of the cooling roll was changed from 60 °C to 80 °C and from 35 °C to 40 °C.

[Example 4]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that the temperature of the cooling roll was changed from 60 °C to 50 °C and from 35 °C to 30 °C.

[Example 5]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that the structure of the heating roll was configured in a five-layer structure of [diameter 150 mm - diameter 70 mm - diameter 150 mm - diameter 70 mm - diameter 150 mm].

[Example 6]

A resin-coated carbon fiber was prepared in the same manner as in Example 5, except that the temperature of the heating roll was set at 80 °C.

[Example 7]

In the process of preparing the coating solution of Preparation Example 1, 1476.24 g of polyethylene acrylic acid copolymer, 2165.15 g of caprolactam, 541.29 g of hexamethylenediamine, 492.08 g of adipic acid, and 295.25 g of sebacic acid were used, but the same resin coating carbon as in Example 1. fibers were made.

[Example 8]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that the width of the Π-shaped groove of the heating roll was 5 mm.

[Example 9]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that 1396.33 g of caprolactam, 59.77 g of hexamethylenediamine, 54.33 g of adipic acid, and 32.60 g of sebacic acid were used in the preparation of the coating solution of Preparation Example 1.

[Comparative example]

[Comparative Example 1]

A resin-coated carbon fiber was prepared in the same manner as in Example 1, except that the heating roll and the cooling roll were not applied.

[Comparative Example 2]

A resin-coated carbon fiber was prepared in the same manner as in Example 1, except that the cooling roll was not applied and cooled to room temperature by exposing to air.

[Comparative Example 3]

A resin-coated carbon fiber was prepared in the same manner as in Example 1, except that the heating roll was not applied.

[Comparative Example 4]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that only one heating roll was applied at the time of fiber opening.

[Comparative Example 5]

A resin-coated carbon fiber was prepared in the same manner as in Example 1, except that the temperature of the heating roll was applied at 80 °C.

[Comparative Example 6]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that the temperature of the heating roll was applied at 170 ° C.

[Comparative Example 7]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that 197.03 g of polyethylene acrylic acid copolymer, 435.64 g of caprolactam, 108.91 g of hexamethylenediamine, 99.01 g of adipic acid, and 59.41 g of sebacic acid were used in the preparation of the coating solution. .

[Comparative Example 8]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that 2119.87 g of polyethylene acrylic acid copolymer, 3109.14 g of caprolactam, 777.29 g of hexamethylenediamine, 706.62 g of adipic acid, and 423.97 g of sebacic acid were used in the preparation of the coating solution. .

[Comparative Example 9]

Resin-coated carbon fibers were prepared in the same manner as in Example 1, except that 1445.23 g of caprolactam, 39.84 g of hexamethylenediamine, 36.22 g of adipic acid, and 21.73 g of sebacic acid were used in the preparation of the coating solution of Preparation Example 1.

For the resin-coated carbon fibers prepared in Examples 1 to 9 and Comparative Examples 1 to 9, physical properties were evaluated through the following experimental examples, and the results are shown in Table 1.

[Experimental Example]

(1) Measurement of polymer resin content of resin-coated carbon fiber

After cutting the prepared resin-coated carbon fiber into five samples of 5g each, the polymer resin was removed by putting it in an electric furnace heated to 500° C. for 40 minutes. The resin content of the resin-coated carbon fiber was measured by measuring the mass of the sample from which the resin was removed and calculating it using the formula below. The average value of the five samples was determined as the polymer resin content.

W ₀ : mass of resin-coated carbon fiber

W ₁ : mass of carbon fiber from which polymer resin is removed

RC: polymer resin content (%) of resin-coated carbon fiber

(2) Measurement of yarn width of resin-coated carbon fiber and calculation of coefficient of variation

The yarn width of the prepared resin-coated carbon fibers was measured for 20 sections at intervals of 5 m or more. It was measured (w ₁ ,w ₂ ,w ₃ ,w ₄ ,w ₅ ,…,w ₂₀ ) using an electronic vernier caliper capable of measuring up to 0.01 mm.

Average, standard deviation and coefficient of variation were calculated for the measured slope w ₁ to w ₂₀ .

AVG _w : Average of four widths

SD _w : Standard deviation of the square width

CV: coefficient of variation of sapok (%)

(3) Measurement of glass transition temperature of polymer resin solids

The glass transition temperature of the polymer resin solids used in the present invention was measured by differential scanning calorimetry (DSC). As the equipment, TA Instrument's Q2000 was used, and the temperature was measured from 30 °C to 300 °C by applying a heating rate of 10 °C per minute.

(4) Measurement of drape of resin-coated carbon fibers

As shown in FIG. 5, prepare a sample by cutting the prepared resin-coated carbon fiber by 320 mm, so that the thickness direction is in close contact with the floor, 20 mm is placed on a table, pressed with a finger, and the remaining 300 mm is suspended in the air. After pulling it out of the table edge, the end was grasped by hand. Then, the hand holding the resin-coated carbon fiber was removed from the area outside the table, and the drape at the end was measured after 30 seconds. The number of measurements was 10 times for each Example and Comparative Example, and the average value was calculated.

Resin coating amount
(wt%) Mean value of cross width (mm) four width
Coefficient of variation (%) Coating agent glass transition temperature (℃) drape
(mm) Example 1 24.6 7.3 2.2 45.3 46.4 Example 2 24.4 6.7 2.6 45.2 43.5 Example 3 23.7 7.4 3.1 44.1 43.4 Example 4 24.0 7.3 2.2 44.3 42.8 Example 5 24.0 7.3 3.1 45.9 47.9 Example 6 24.3 7.6 1.8 43.9 48.1 Example 7 34.8 6.9 3.9 45.2 35.1 Example 8 24.3 4.6 1.6 45.2 37.0 Example 9 25.0 7.5 4.7 20.6 51.1 Comparative Example 1 24.5 4.9 11.4 46.2 40.5 Comparative Example 2 24.3 3.2 10.1 45.4 41.1 Comparative Example 3 24.1 5.2 7.3 45.3 29.5 Comparative Example 4 24.1 5.3 7.2 44.9 31.0 Comparative Example 5 24.8 5.5 8.3 45.2 30.2 Comparative Example 6 22.8 not measurable not measurable 44.1 not measurable Comparative Example 7 16.8 6.9 9.8 45.9 73.3 Comparative Example 8 42.1 6.4 1.3 45.0 5.1 Comparative Example 9 25.3 7.6 5.9 18.7 53.1

As can be seen from Table 1 above, the coefficient of variation of the yarn width of the resin-coated carbon fibers according to Examples 1 to 10 of the present invention is managed within 5%, but the coefficient of variation of the yarn width of Comparative Examples 1 to 5 and Comparative Example 7 is 5 It can be seen that the % is exceeded.

In addition, Example 2 has a higher heating temperature than Example 1, and the difference between the temperature of the heating roll and the heating pin and the cooling temperature is larger, so the heat shrinkage effect of the resin-coated carbon fiber is also greater than that of Example 1. It can be seen that the average value of the slope is narrow. However, even at this time, it can be seen that the coefficient of variation of the slope width was uniformly managed at 2.6%. This shows that even if the required spool width is different, it can be achieved by a simple method of changing only the temperature settings of the heating roll and heating pin.

In addition, when the temperatures of the heating roll and the heating pin are the same through Examples 3 and 4 and Example 1, it can be seen that the relationship between the temperature of the cooling roll and the yarn width is not large, and the resin-coated carbon fiber is finally at room temperature. Since it is cooled by , it can be interpreted that the values at the time of measuring the slope width are almost identical.

In addition, Example 7 has a slightly narrower yarn width than Example 1, which can be interpreted as the fact that the heat shrinkage effect is relatively increased as the content of the polymer resin increases.

On the other hand, Comparative Example 2 did not use a cooling roll, and the yarn width was very narrow and the variation coefficient of the yarn width exceeded 5%, resulting in a large deviation. The cooling method in contact with the cooling roll changed the shape of the resin-coated carbon fiber. It can be confirmed that the cooling roll is an essential element in the present invention because it is suitable for holding and controlling the slant width constantly.

In addition, Comparative Example 3 did not use a heating roll, and the variation coefficient of the yarn width exceeded 5%, resulting in a large deviation, and the drape property was measured to be less than 30 mm, which was due to the fact that the resin-coated carbon fiber was not sufficiently stretched, so the yarn width It can be judged as narrow and thick. That is, it can be confirmed that the heating roll is an essential component in the present invention because the heating roll is suitable for limiting the yarn width by widening the resin-coated carbon fiber by a limited range.

As confirmed in Comparative Examples 2 and 3, the heating roll and the cooling roll are important elements for constantly controlling the yarn width, and it can be seen that Comparative Example 1, which does not include all of them, also shows a very large coefficient of variation of the yarn width.

In Comparative Example 4, only one heating roll was applied, and the coefficient of variation of the yarn width exceeded 5%, resulting in a large deviation. It can be seen that the limiting of the width is not achieved, and through this, it can be confirmed that two or more heating rolls are absolutely necessary.

In addition, Comparative Example 5 has the same process components as Example 1, but the temperature of the heating roll is low. In Example 1, it is possible to control the slope width, but in Comparative Example 5, it can be seen that the deviation is large. This is because the resin-coated carbon fibers in the heating roll of Comparative Example 5 were not sufficiently opened. On the other hand, Example 6 has the same heating roll temperature as Comparative Example 5, but the heating roll and heating pin are additionally applied to the process of Comparative Example 5 by one section, and it can be confirmed that the slope width is sufficiently controlled.

In addition, in the case of Comparative Example 6, the process was impossible because the temperature of the heating roll exceeded the melting point (155° C.) of the polymer resin and the polymer resin adhered to the heating roll.

In Comparative Example 7, it can be seen that the content of the binder and the polyethylene acrylic acid copolymer is insufficient, and the amount of the coated polymer resin is insufficient, so that the variation coefficient of the yarn width exceeds 5% and the drape property is also excessive.

In Comparative Example 8, it can be seen that the amount of the binder and the polyethylene acrylic acid copolymer is excessive, and the amount of the coated polymer resin is excessive, resulting in poor drape properties.

In addition, Comparative Example 9 has a low glass transition temperature, and it can be seen that, due to the fluidity of the polymer resin, the yarn width fluctuates from an external force such as tension or contact with a guide roll after the resin-coated carbon fiber passes through the cooling roll. can

As described above, according to the results of Examples and Comparative Examples in which the content of the coating agent matched in the case of drapability, it can be seen that the resin-coated carbon fiber according to an embodiment of the present invention has excellent workability in grid weaving.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also made according to the present invention. falls within the scope of the rights of

210: heating roll
410: cooling roll
301, 302, 303, 304: four-width expansion

Claims (19)

A resin-coated carbon fiber in which an aqueous dispersion coating solution containing a polymer resin dispersed in distilled water is coated on continuous carbon fibers,
Of the total weight of the resin-coated carbon fiber, 20 to 40% by weight of the polymer resin is coated,
The coefficient of variation of the slope is less than 5%,
The aqueous dispersion coating solution includes 10 to 45 parts by weight of a polymer resin and 4 to 20 parts by weight of a polyethylene acrylic acid copolymer based on 100 parts by weight of distilled water,
The resin-coated carbon fiber has a height difference of 30 to 70 mm at both ends when the length of the resin-coated carbon fiber is 300 mm at 0 ° C to 50 ° C. coated carbon fiber. According to claim 1,
The coefficient of variation of the yarn width is measured at any 20 sections within a length of 100 m or more at a temperature of 0 ° C to 50 ° C for the resin-coated carbon fiber, the resin-coated carbon fiber. According to claim 1,
The glass transition temperature of the polymer resin is 20 ℃ or more, resin-coated carbon fiber. delete According to claim 1,
The average yarn width of the resin-coated carbon fibers is 4 to 8 mm at a temperature of 0 ° C to 50 ° C, resin-coated carbon fibers. According to claim 1,
The average thickness of the resin-coated carbon fiber is 1.3 to 3 mm at a temperature of 0 ℃ to 50 ℃, resin-coated carbon fiber. delete According to claim 1,
The polymer resin comprises at least one binder selected from caprolactam, hexamethylenediamine, adipic acid and sebacic acid, resin-coated carbon fibers. delete delete delete delete immersing and impregnating continuous carbon fibers in an aqueous dispersion coating solution containing a polymer resin dispersed in distilled water;
drying the carbon fiber impregnated with the water dispersion coating liquid to remove moisture;
heating and opening the dried carbon fibers by passing them through two or more heating rolls; and
adjusting the yarn width of the carbon fibers by cooling the carbon fibers heated through the heating rolls through two or more cooling rolls;
A method for producing a resin-coated carbon fiber comprising a,
Of the total weight of the resin-coated carbon fiber, 20 to 40% by weight of the polymer resin is coated,
The aqueous dispersion coating solution includes 10 to 45 parts by weight of a polymer resin and 4 to 20 parts by weight of a polyethylene acrylic acid copolymer based on 100 parts by weight of distilled water,
The resin-coated carbon fiber has a height difference of 30 to 70 mm at both ends when the length of the resin-coated carbon fiber is 300 mm at 0 ° C to 50 ° C. Manufacturing method of coated carbon fiber. According to claim 13,
The water-dispersed coating solution comprises at least one binder selected from caprolactam, hexamethylenediamine, adipic acid and sebacic acid, a method for producing resin-coated carbon fibers. According to claim 13,
The heating roll is provided with a Π-shaped groove that limits the expansion range of the yarn width, the manufacturing method of the resin-coated carbon fiber. According to claim 13,
The temperature of the heating roll is a temperature between the glass transition temperature and the melting point of the polymer resin, the method for producing a resin-coated carbon fiber. According to claim 13,
The cooling roll is provided as a nip roll to control the shape of the resin-coated carbon fiber, the manufacturing method of the resin-coated carbon fiber. According to claim 13,
The temperature difference between the heating roll and the cooling roll is 10 to 100 ° C., the method of manufacturing a resin-coated carbon fiber. The resin-coated carbon fiber according to any one of claims 1 to 3, 5, 6 and 8, which is used as a grid fabric for earthquake-resistant reinforcement.

Images