WO2015099504A1

WO2015099504A1 - Carbon fiber felt manufacturing method and method for manufacturing heat insulation material using same

Info

Publication number: WO2015099504A1
Application number: PCT/KR2014/012930
Authority: WO
Inventors: 박재흥; 윤광의; 장준현; 김학천
Original assignee: 오씨아이 주식회사
Priority date: 2013-12-27
Filing date: 2014-12-26
Publication date: 2015-07-02
Also published as: KR101523443B1

Abstract

The present invention relates to a carbon fiber felt manufacturing method and a method for manufacturing a heat insulation material using the same and, particularly, to a carbon fiber felt manufacturing method, which uses a carbon fiber mat orthogonal device for manufacturing, thereby making the surface density uniform and improving the orientation property of the carbon fiber, such that a carbon fiber felt is manufactured without separate fiber opening and carding processes, thereby providing more excellent process throughput and heat insulation performance than the prior art, and a method for manufacturing a heat insulation material using the same.

Description

Carbon fiber felt manufacturing method and insulation material manufacturing method using the same

The present invention is a method of manufacturing a carbon fiber felt and a method of manufacturing a heat insulating material using the same, specifically, by using a carbon fiber mat orthogonal apparatus, the surface density is uniform and the orientation of the carbon fiber is improved to improve the carbon fiber without any separate opening or carding process The present invention relates to a method for producing a carbon fiber felt and a method for producing a heat insulating material using the same, which is superior to the conventional process yield and heat insulating performance by producing a felt.

Carbon materials are materials having high thermal conductivity, electrical conductivity, and excellent mechanical strength, and have been widely used in industrial fields since ancient times. The carbon fiber processed in the form of fibrous carbon material refers to a fibrous material having a carbon content of 90% or more, and possesses excellent thermal conductivity, electrical conductivity, and mechanical properties.

Carbon fiber has a fibrous shape and is excellent in processability and has a wide range of applications. Carbon fiber has excellent properties especially at high temperatures. Unlike high-temperature metal materials, the mechanical strength of carbon fiber increases with high temperature. The carbon fiber has a low coefficient of thermal expansion and can be used up to 3000 ℃ in a non-oxidizing atmosphere. It is considered the only material.

Carbon fibers are largely classified according to raw materials, and are divided into PAN-based carbon fibers, rayon-based carbon fibers, and pitch-based carbon fibers. PAN-based carbon fiber is lighter than other materials and has excellent mechanical properties, so it is widely used in high-end sports and leisure goods such as golf clubs and fishing rods, and is currently used to replace metals in fields that have used conventional metal materials such as automobiles and ships. It is recognized as the material which can be. Rayon-based carbon fiber can be used as a general-purpose carbon fiber because of its relatively simple manufacturing method and easy mass production based on cheap raw materials. Pitch-based carbon fiber is based on coal coal tar and petroleum residue oil, and is classified into isotropic carbon fiber and anisotropic carbon fiber according to crystallinity, and is widely used as a general purpose material and a special functional material according to the use and manufacturing method.

In particular, pitch-based carbon fiber is manufactured from coal coal tar and petroleum residue, which are very inexpensive, and have a high modulus value and no thermal deformation at high temperatures. In addition, according to the manufacturing method can be manufactured with the desired physical properties, as well as general-purpose carbon fiber, it is characterized by a very wide range of applications as special fields and functional materials. Pitch-based carbon fiber is a situation in which the demand is rapidly growing in the industrial field based on these characteristics, especially the high temperature insulation field.

High-temperature insulation is a special industrial material used in furnaces of about 2000 ° C or higher. Currently, carbon fiber is the only material that can be used above 2000 ° C. The high temperature insulation material is an essential material for the production of polysilicon, which is a material of semiconductor and photovoltaic power generation, requires excellent insulation performance and high purity physical properties, and isotropic carbon fiber is suitable as a material raw material.

As a method of manufacturing a high temperature insulation material, there is a method in which carbon fibers of short length are dispersed in a dispersion solvent, impregnated with a binder, and molded using a mold. Insulating material manufacturing method is a method for producing a carbon fiber insulating material by dispersing the carbon fiber of about 1 ~ 5mm length in a dispersion solvent such as water or alcohol, it is not easy to disperse and requires a large amount of solvent dispersion. Since carbon fibers exist in the form of entangled with each other, it is very difficult to disperse using a dispersion solvent, and even if dispersed, it is not easy to obtain a high temperature insulating material having excellent heat insulation performance.

Another method of manufacturing high temperature insulation is to use carbon fiber felt. Carbon fiber felts are manufactured by collectively depositing spun carbon fibers through processes such as carding, carding, and needle punching, and impregnating them in a binder to laminate and pressurize to manufacture a heat insulating material. Unlike the above-mentioned method, it does not require a separate dispersion process, and is an efficient method for manufacturing insulation, but the trimming of edges is necessary due to uneven side density of the felt during the process of manufacturing carbon fiber felt. Since the opening and the carding process, the yield is reduced and the carbon fiber orientation is not good, there is a disadvantage that the production of a heat insulating material having excellent heat insulating performance is not easy.

The present invention solves the above problems, and by using a carbon fiber mat orthogonal apparatus, the surface density is uniform and the orientation of the carbon fiber is improved to produce a carbon fiber felt without a separate opening, carding process process yield and thermal insulation performance It is an object of the present invention to provide a method for producing a carbon fiber felt and a method for manufacturing a heat insulating material using the same compared to the prior art.

Carbon fiber felt manufacturing method according to an embodiment of the present invention for achieving the above object comprises the steps of (a) spinning a pitch for producing carbon fiber; (b) transferring the spun pitch fibers along a first conveying conveyor moving in a first direction; (c) collecting the conveyed pitch fibers in a tray reciprocating in the same direction as the first direction while lowering in the gravity direction; (d) forming a precursor web composed of a plurality of layers while lowering pitch fibers in a gravity direction in the tray; And (e) infusifying and carbonizing the precursor web while moving along the second transfer conveyor.

In addition, the method for producing a carbon fiber felt according to another embodiment of the present invention for achieving the above object (a) spinning a pitch for producing carbon fiber; (b) transferring the spun pitch fibers along a first conveying conveyor moving in a first direction; (c) collecting the conveyed pitch fibers in a tray reciprocating in the same direction as the first direction while lowering in the gravity direction; (d) forming a precursor web composed of a plurality of layers while lowering pitch fibers in a gravity direction in the tray; And (e) infusing and carbonizing the precursor web while moving along the second transfer conveyor; (f) impregnating a binder while transferring the carbon fiber felt; (g) laminating and curing the carbon fiber felt impregnated with the binder; And (h) carbonizing and graphitizing the cured carbon fiber felt.

According to the manufacturing method of the present invention, there is no separate opening and carding process, thereby simplifying the process and improving the yield of carbon fiber felt.

According to the production method of the present invention, the orientation of the carbon fibers in the felt is made constant, there is an excellent heat insulating performance of the heat insulating material prepared using the same.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the manufacturing apparatus of the carbon fiber felt for implementing the manufacturing method of this invention.

2 is a detailed schematic view of a carbon fiber mat orthogonal apparatus in the apparatus for producing carbon fiber felt for implementing the method of the present invention.

3 is a cross-sectional view of the carbon fiber felt prepared in Example 1.

4 is a cross-sectional view of the carbon fiber felt prepared by Comparative Example 1.

Advantages and features of the present invention, and methods for achieving the same will be apparent with reference to the embodiments described below in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims.

Hereinafter, a carbon fiber felt manufacturing method and a method of manufacturing a heat insulating material using the same according to a preferred embodiment of the present invention will be described in detail.

First, the carbon fiber felt manufacturing method will be described with reference to FIGS. 1 and 2.

Carbon fiber felt manufacturing method according to an embodiment of the present invention comprises the steps of (a) spinning a pitch for producing carbon fiber; (b) transferring the spun pitch fibers along a first conveying conveyor moving in a first direction; (c) collecting the conveyed pitch fibers in a tray reciprocating in the same direction as the first direction while lowering in the gravity direction; (d) forming a precursor web composed of a plurality of layers while lowering pitch fibers in a gravity direction in the tray; And (e) infusifying and carbonizing the precursor web while moving along the second transfer conveyor.

Spinning the pitch for producing carbon fiber through the spinning nozzle 100 in the step (a). Here, the pitch for producing carbon fiber may be a single or a mixture selected from the group consisting of coal coal tar pitch, petroleum residue oil pitch, but is not necessarily limited thereto.

According to a preferred embodiment of the present invention, the average length of the carbon fiber is 1 ~ 100mm, more preferably 50mm, the carbon fiber diameter may be 1 ~ 20㎛, more preferably 5 ~ 20㎛.

If the length of the carbon fiber is short, it is impossible to manufacture the felt. If the length of the carbon fiber is long, the carbon fiber is aggregated in a bent form, so that it is difficult to control the uniform apparent density during the manufacture of the felt, and the carbon fiber orientation is not good.

When the carbon fiber diameter is thin, there is a problem that the yield is low because the carbon fiber is easily broken during the felt manufacturing process, if too thick carbon fiber incompatibility is not properly made, heat fusion phenomenon occurs during the carbon fiber carbonization process.

The softening point of the pitch for producing carbon fibers is preferably 250 to 350 ° C. If the softening point is low, it is difficult to maintain the fiber shape due to the low viscosity during fiber spinning. If the softening point is high, the spinning temperature is high.

The spinning method of the pitch for producing carbon fibers is preferably a melt spinning method or a melt blown spinning method. Centrifugal spinning is difficult to collect and deposit carbon fibers in a certain direction. Winding spinning is easy to produce carbon fiber fabrics because of its long carbon fiber length, but is not suitable for producing carbon fiber felt.

Next, the steps (b), (c) and (d) are performed using the carbon fiber mat orthogonal apparatus 200. The carbon fiber mat orthogonal apparatus includes a first conveying conveyor 201, a tray 202, and a second conveying conveyor 203.

First, in step (b), the spun carbon fiber is pitched along the first transport conveyor 201 moving in the first direction.

The first conveying conveyor 201 serves to convey the pitch fibers radiated from the spinning nozzle in any first direction. In this case, the first direction is preferably a direction orthogonal to the direction in which the radiation nozzles are arranged.

Next, in step (c), the conveyed pitch fibers are collected in a tray 202 reciprocating in the same direction as the first direction while lowering in the gravity direction.

The tray 202 reciprocates in the same direction as the first direction of the set first conveying conveyor.

Next, in step (d), the pitch fibers are lowered to the second conveyor 203 moving in the second direction from the tray 202 to form a precursor web composed of a plurality of desired layers. It is preferable that the number of layers of the precursor web gathered in the 2nd conveyor 203 is 4-10. If the number of layers is less than 4, there is no great effect in eliminating the nonuniformity of surface density, and if the number of layers exceeds 10, the thickness becomes so thick that there is a problem that a long time is required for the subsequent process (incompatibility and carbonization process).

The second direction, which is the direction in which the second transport conveyor 203 moves, is preferably perpendicular to the first direction, which is the direction in which the first transport conveyor 201 moves. That is, at this time, the transfer direction of the precursor web is changed, thereby causing an effect that the non-uniformity of the left and right surface density of the precursor web is canceled.

In view of this point, the arrangement direction of the spinning nozzle radiating the pitch for producing carbon fibers may coincide with the moving direction of the second transfer conveyor.

In the manufacturing method of the present invention, in the steps (b), (c), (d), the moving speed of the first transfer conveyor 201 is V1, the moving speed of the second transfer conveyor is V2, When the number of layers of the precursor web is N, it is preferable that V1, V2, and N satisfy the following formula (1).

[Equation 1]

V2 = V1 / N

In the manufacturing method of the present invention, when the moving speed of the first transfer conveyor is V1 and the moving speed of the tray is V3, it is preferable that V1 and V3 satisfy the following expression (2).

[Equation 2]

V1 = V3

Next, in step (e) while moving the precursor web along the second conveying conveyor through the infusion furnace 300, the carbonization through the infusible, carbonization furnace 400 to produce a carbon fiber felt.

The incompatibility process proceeds under an oxygen atmosphere. Incompatibility is a process of increasing the molecular weight by crosslinking molecules with oxygen on the surface of the carbon fiber. If the incompatibility is not properly, there is a problem in that the carbon fiber carbonization process is thermally fused to the carbon fiber and entangled.

Incompatibility temperature is carried out between 150 ~ 400 ℃, the temperature rising rate is very important. The temperature increase rate is preferably 0.5 ~ 5 ℃ / min, there is a problem that the productivity is reduced when the temperature rising rate is low, when the temperature rising rate is high, the carbon fiber is thermally fused during the carbonization process. At this time, the oxygen content of the carbon fiber is increased, the oxygen content is appropriate 5 ~ 10%.

The infusible carbon fiber is subjected to a carbonization process. If the carbonization process is carried out in a non-oxidizing atmosphere, it is carried out at about 800 ~ 1000 ℃. Carbonized carbon fiber has a carbon content of 90% or more.

The carbon fiber felt produced by the manufacturing method of the present invention has a uniform surface density, and the difference between the surface density of the center and the surface density of the left and right is preferably 0.01% to 10%, but is not limited thereto, and is 0.02% to 5%. More preferably, it is not limited thereto.

A needle punching 500 process is performed to produce the carbonized carbon fiber mat into carbon fiber felt. By performing a needle punching process in the thickness direction of the carbon fiber mat, it is possible to obtain a three-dimensional stable carbon fiber felt.

The carbon fiber felt is generally wound in roll form through the winder 600 for ease of storage and transportation. Therefore, when the apparent density of the carbon fiber felt is low, the felt may be broken during winding. On the contrary, when the apparent density is high, the winding becomes difficult in the form of a roll. The apparent density of the carbon fiber felt is preferably 0.03 to 0.15 g / cm ³ .

Next, the manufacturing method of the heat insulating material using a carbon fiber felt is demonstrated first.

Method for producing a carbon fiber felt of the present invention comprises the steps of (a) spinning a pitch for producing carbon fiber; (b) transferring the spun pitch fibers along a first conveying conveyor moving in a first direction; (c) collecting the conveyed pitch fibers in a tray reciprocating in the same direction as the first direction while lowering in the gravity direction; (d) forming a precursor web composed of a plurality of layers while lowering pitch fibers in a gravity direction in the tray; (e) dissolving and carbonizing the precursor web while moving along the second transfer conveyor to produce carbon fiber felt; (f) impregnating a binder while transferring the carbon fiber felt; (g) laminating and curing the carbon fiber felt impregnated with the binder; And (h) carbonizing and graphitizing the cured carbon fiber felt.

Steps (a) to (e) have already been described in the carbon fiber felt manufacturing process, and a detailed description thereof will be omitted herein.

Impregnating the binder while transferring the carbon fiber felt produced through the roller in the step (f). Examples of the binder that can be used include at least one selected from phenol resins, furan resins, pitch for impregnation, epoxy resins, vinyl ester resins, polyimide resins, and sucrose.

Next, in step (g), the binder impregnated carbon fiber felt is cut to a predetermined size and laminated, and cured using a press. While maintaining the temperature at which the binder can be cured, pressure is applied such that the thickness of the carbon fiber felt can be compressed in half.

Next, the carbon fiber heat insulating material cured in step (h) is carbonized and graphitized at about 1000 ° C. and 2000 ° C., respectively, in a non-oxidizing atmosphere. Degreasing gas is generated as the binder is pyrolyzed during the carbonization process, and then pyrolysis gas is not generated through graphitization. After graphitization, the carbon fiber insulation is completed, and the apparent density is preferably 0.1 to 0.3 g / cm ³ . If the apparent density is high, the thermal conductivity is increased to lower the thermal insulation performance. If the apparent density is low, the thermal insulation performance is deteriorated because the radiant heat is not blocked at a high temperature.

Hereinafter, the present invention will be described in more detail with reference to preferred examples of the present invention and comparative examples.

실시예 1 Example 1

The coal-based high softening point isotropic pitch (SP: 280 ° C.) was spun through the spinning nozzle at a rate of 4 kg / hr, and carbon fibers were spun by melt blow spinning.

Six layers per m ² were collectively deposited again through the carbon fiber mat orthogonal apparatus of the present invention while depositing and transporting the spun pitch carbon fibers.

At this time, the width of the carbon fiber mat was 1.2m, the feed rate was 3m / min. The carbon fiber mat was transferred to an infusible furnace and a carbonization furnace at a rate of 0.5 m / min.

The carbon fiber mat infusified at 150 to 350 ° C. was carbonized at about 800 ° C. and needle punched to prepare a carbon fiber felt having an apparent density of 0.05 g / cm ³ .

비교예 1 Comparative Example 1

The coal-based high softening point pitch (SP: 280 ° C.) was spun through the spinning nozzle at a rate of 4 kg / hr, and carbon fibers were spun by melt blow spinning.

The spun pitch-based carbon fibers were transferred directly to an infusible furnace and a carbonization furnace without changing the process direction without using the carbon fiber mat orthogonal apparatus of the present invention.

At this time, the width of the carbon fiber mat was 1.2 m. The carbon fiber mat was transferred to an infusible furnace and a carbonization furnace through a conveyor belt, where the speed of the conveyor belt was 0.5 m / min.

The carbon fiber mat infusified at 150 to 350 ° C was carbonized at about 800 ° C. The carbonized carbon fiber mat was made of carbon fiber felt having an apparent density of 0.05 g / cm ³ by opening, carding and needle punching through a garnet cylinder.

평가evaluation

1. 탄소섬유 펠트의 수율 및 열전도도 평가1. Evaluation of yield and thermal conductivity of carbon fiber felt

The yield and thermal conductivity of the carbon fiber felt of Example 1 and Comparative Example 1 prepared above were measured and shown in Table 1 below.

Table 1

division	Example 1	Comparative Example 1
Carbon fiber felt yield (%) obtained from high softening point pitch	75	65
Carbon Fiber Felt Thermal Conductivity (at 20 ℃ (W / mK))	0.035	0.050

As can be seen in Table 1, according to the manufacturing method of the present invention, the non-uniformity of the left and right surface density of the carbon fiber mat is canceled, the amount of cutting the edge of the separate carbon fiber mat by the non-uniformity of the surface density is reduced It was found that there is an effect of increasing the process yield.

In addition, by arranging and re-depositing the carbon fiber pitch, it was excellent in the orientation of the carbon fiber pitch, it was confirmed that there is an effect that the yield of the carbon fiber felt remarkably improved because a separate opening and extruding process is unnecessary.

In addition, using the process of the present invention, the carbon fiber felt manufactured without a separate opening and carding process showed excellent characteristics with high process yield and low thermal conductivity.

The better the orientation of the fibers, the lower the thermal conductivity, but according to the method of the present invention through the thermal conductivity, it was confirmed that the orientation of the carbon fibers in the carbon fiber felt was excellent.

2. 탄소섬유 펠트의 단면 평가2. Evaluation of cross section of carbon fiber felt

The cross sections of the carbon fiber felts of Example 1 and Comparative Example 1 prepared above were compared and evaluated. The results are shown in FIGS. 3 and 4, respectively.

3 is a cross-sectional view of the carbon fiber felt prepared in Example 1, it was confirmed that the arrangement of the carbon fibers in the plane direction through the process through the carbon fiber mat orthogonal apparatus of the present invention.

Figure 4 is a cross section of the carbon fiber felt prepared in Comparative Example 1, there was no process of passing through the carbon fiber mat orthogonal apparatus of the present invention was confirmed that the arrangement of the carbon fibers irregular without direction.

3. 면밀도 평가3. Surface density evaluation

The surface density of each carbon fiber felt prepared by Example 1 and Comparative Example 1 was measured and shown in Table 2 below. Samples were taken at 10 × 10 cm by location.

TABLE 2

division	Surface density (left)	Surface density (center)	Surface density (right)
Example 1	490 g / m ²	495 g / m ²	493 g / m ²
Comparative Example 1	447 g / m ²	491 g / m ²	453 g / m ²

In Comparative Example 1, the difference between the median surface density (A), the left (B) and the right (C) surface densities was about 8% and about 7%, respectively, based on the median surface density. In contrast, the difference between the median surface density and the left and right surface densities of Example 1 was about 1% and about 0.4%, respectively. By using this method of manufacturing the carbon fiber felt of the present invention it is possible to produce a carbon fiber felt having an even surface density in the center, left and right.

4. 단열재 성능 평가4. Insulation performance evaluation

The carbon fiber felts prepared in Example 1 and Comparative Example 1 were impregnated in a resol-type phenolic resin, respectively, cured at 150 ° C. and carbonized, and then graphitized at 2000 ° C. to obtain a carbon fiber heat insulating material having an apparent density of 0.16 g / cm ³ . Prepared.

The thermal conductivity measurement results of the prepared insulation is shown in Table 3 below.

TABLE 3

	Example 1	Comparative Example 1
Carbon Fiber Insulation Apparent Density (g / cm ³ )	0.16	0.16
Carbon Fiber Insulation Thermal Conductivity at 20 ℃ (W / mK)	0.068	0.127

As can be seen from the above, the heat insulating material produced by the manufacturing method of the present invention is a constant orientation of the carbon fiber, it was confirmed that the excellent heat insulating performance of the heat insulating material prepared using this.

In the above description, the embodiment of the present invention has been described, but various changes and modifications can be made at the level of those skilled in the art. Such changes and modifications may belong to the present invention without departing from the scope of the present invention. Therefore, the scope of the present invention will be determined by the claims described below.

Claims

(a) spinning a pitch for producing carbon fiber;

(b) transferring the spun pitch fibers along a first conveying conveyor moving in a first direction;

(c) collecting the conveyed pitch fibers in a tray reciprocating in the same direction as the first direction while lowering in the gravity direction;

(d) forming a precursor web composed of a plurality of layers while lowering pitch fibers in a gravity direction in the tray;

(e) infusing and carbonizing the precursor web while moving along the second transfer conveyor;

Method of producing a carbon fiber felt comprising a.
The method of claim 1,

The second direction, which is the direction in which the second conveying conveyor moves, is perpendicular to the first direction, which is the direction in which the first conveying conveyor moves.
The method of claim 1,

When the moving speed of the first transfer conveyor is V1, the moving speed of the second transfer conveyor is V2, and the number of layers of the precursor web is N, V1, V2, and N satisfy Equation 1 below. Method for producing carbon fiber felt.

[Equation 1]

V2 = V1 / N
The method of claim 1,

When the moving speed of the first conveying conveyor is V1 and the moving speed of the tray is V3, V1 and V3 satisfy the following formula (2).

[Equation 2]

V1 = V3
The method of claim 1,

The arrangement direction of the spinning nozzle for spinning the pitch for producing the carbon fiber is the manufacturing method of the carbon fiber felt, characterized in that the same as the moving direction of the second conveying conveyor.
The method of claim 1,

Pitch for the carbon fiber manufacturing method of producing a carbon fiber felt, characterized in that the softening point is 250 ~ 350 ℃.
The method of claim 1,

The infusible temperature is 150 ~ 400 ℃, the temperature increase rate is 0.5 ~ 5 ℃ / min method for producing a carbon fiber felt.
The method of claim 1,

The carbonization temperature is a method for producing a carbon fiber felt, characterized in that 800 ~ 1000 ℃.
The method of claim 1,

The carbon fiber felt produced by the manufacturing method, the carbon fiber felt, characterized in that the left and right surface density of less than 0.01 ~ 5% based on the center of the felt.
(a) spinning a pitch for producing carbon fiber;

(b) transferring the spun pitch fibers along a first conveying conveyor moving in a first direction;

(c) collecting the conveyed pitch fibers in a tray reciprocating in the same direction as the first direction while lowering in the gravity direction;

(d) forming a precursor web composed of a plurality of layers while lowering pitch fibers in a gravity direction in the tray;

(e) dissolving and carbonizing the precursor web while moving along the second transfer conveyor to produce carbon fiber felt;

(f) impregnating a binder while transferring the carbon fiber felt;

(g) laminating and curing the carbon fiber felt impregnated with the binder;

(h) carbonizing and graphitizing the cured carbon fiber felt;

Method for producing a carbon fiber insulation comprising a.