KR102534975B1 - wet-laid nonwoven fabric comprising carbon fiber and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a wet-laid non-woven fabric containing carbon fiber and a method for manufacturing the same, and more particularly, to a wet-laid non-woven fabric that can be applied to various fields such as aviation, automobiles, and energy, and has excellent mechanical properties as well as excellent flame retardancy. It relates to a wet-laid nonwoven fabric containing fibers and a manufacturing method thereof.

Description

Wet-laid nonwoven fabric comprising carbon fiber and manufacturing method thereof

The present invention relates to a wet-laid non-woven fabric containing carbon fiber and a method for manufacturing the same, and more particularly, to a wet-laid non-woven fabric that can be applied to various fields such as aviation, automobiles, and energy, and has excellent mechanical properties as well as excellent flame retardancy. It relates to a wet-laid nonwoven fabric containing fibers and a manufacturing method thereof.

Nonwoven fabrics are currently used for various purposes and are replacing traditional knitted fabrics and woven fabrics. This is because nonwoven fabrics have functional uses that could not be achieved by conventional knitted fabrics and woven fabrics. has increased

Various types of nonwovens are known, typical known nonwovens are for example; A dry method composed of filaments obtained by directly spinning a fiber-forming polymer by a spunbond method or a flash spinning method, etc., simultaneously drawing the spun filaments in the presence of a gas such as air, and integrating the obtained filaments. Non-woven fabrics, composed of staple fibers having a relatively long fiber length, and dry-laid non-woven fabrics obtained by melt blowing, and composed of staple fibers, which are carded to open these staple fibers and then open the staple fibers. They are accumulated in a sheet form using a cross laying machine or an air laying machine, and the staple fibers constituting the sheet are needle punched, entangled by a columnar water stream, or tacky or dry-laid nonwoven fabrics obtained by bonding them to each other by an adhesive method using hot-meltible fibers, and the like are known.

On the other hand, wet-laid non-woven fabric is a non-woven fabric manufactured by partially changing the paper manufacturing process. It can be distinguished from paper using pulp in that it is made into a sheet by dispersing fibers in water. However, since pulp is also a kind of fiber in a broad sense, the distinction is can be said to be ambiguous.

However, since the main purpose of wet-laid nonwoven fabric is to produce a fiber structure having fabric characteristics such as flexibility and strength at a high speed, such as paper production speed, it can be differentiated from paper.

In the case of wet-laid nonwoven fabrics, application products are used in relatively diverse fields. That is, it can be applied to various fields such as aviation, automobiles, and energy, and in order to be applied to such various fields, mechanical properties required in each field must be satisfied. In addition, in the event of a fire, if the wet-laid nonwoven fabric is not able to withstand the heat caused by the fire and is lost, the flames are transmitted to the surroundings, resulting in great damage.

Therefore, it is necessary to develop a wet-laid non-woven fabric that not only has flame retardancy but also satisfies the physical properties that the wet-laid non-woven fabric should have so that it can be applied to various fields such as aviation, automobiles, and energy.

Republic of Korea Patent Registration No. 10-1604592 (Announced on March 14, 2016)

In order to solve the above problems, the present invention is to provide a wet-laid nonwoven fabric including carbon fibers having excellent mechanical properties as well as excellent flame retardancy and a manufacturing method thereof.

In order to solve the above problems, the wet-laid nonwoven fabric including carbon fibers of the present invention may include polyacrylonitrile (PAN)-based carbon fibers, heat-sealable fibers, glass fibers, and polyphenylene sulfide fibers.

In a preferred embodiment of the present invention, the wet-laid nonwoven fabric of the present invention is based on 100 parts by weight of PAN-based carbon fibers, 24 to 36 parts by weight of heat-sealable fibers, 20 to 30 parts by weight of glass fibers and 8 parts by weight of polyphenylene sulfite fibers ~ 12 parts by weight.

In a preferred embodiment of the present invention, the PAN-based carbon fiber may have a short fiber fineness of 0.78 to 1.18 denier.

In a preferred embodiment of the present invention, the number of filaments of the PAN-based carbon fiber may be 4,800 to 7,200.

In a preferred embodiment of the present invention, the PAN-based carbon fiber may have a strand tensile strength of 3.13 to 4.71 GPa, measured by conforming to the ASTM D4018 test standard.

In a preferred embodiment of the present invention, the heat-sealable fiber may be a core-sheath type heat-sealable fiber having a copolyester resin as a sheath and a polyethylene terephthalate resin as a core.

In a preferred embodiment of the present invention, the core-sheath type heat-sealable fiber may have a fiber length of 4 to 6 mm and a fineness of 3.0 to 4.6 denier.

In a preferred embodiment of the present invention, the copolyester resin is an ester compound prepared by esterifying an acid component including terephthalic acid and a diol component including 2-methyl-1,3-propanediol and ethylene glycol, and polyethylene. It may be prepared by polycondensation of glycol (PEG).

In one preferred embodiment of the present invention, the wet-laid nonwoven fabric may further include modacrylic flame retardant fibers.

In a preferred embodiment of the present invention, the wet-laid nonwoven fabric may include 4 to 6 parts by weight of modacrylic flame retardant fibers based on 100 parts by weight of PAN-based carbon fibers.

On the other hand, the method for producing a wet-laid nonwoven fabric containing carbon fiber of the present invention is the first step of preparing a fiber mixture in which PAN-based carbon fiber, heat-sealable fiber, glass fiber, polyphenylene sulfite fiber and modacrylic flame retardant fiber are mixed , The second step of dispersing the prepared fiber mixture in water, draining the water, and then drying to prepare a dried product, and the third step of producing a wet nonwoven fabric by calendering the prepared dried product at a temperature of 130 ~ 170 ° C. steps may be included.

In a preferred embodiment of the present invention, the fiber mixture of the first step is based on 100 parts by weight of PAN-based carbon fiber, 24 to 36 parts by weight of heat-sealable fiber, 20 to 30 parts by weight of glass fiber, polyphenylene sulfite fiber 8 to 12 parts by weight and 4 to 6 parts by weight of modacrylic flame retardant fibers may be mixed.

In a preferred embodiment of the present invention, the drying in the second step may be performed at a temperature of 85 to 108 °C.

The wet-laid nonwoven fabric comprising the carbon fiber of the present invention and its manufacturing method have excellent mechanical properties as well as excellent flame retardancy.

Hereinafter, 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. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein. In order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added to the same or similar components throughout the specification.

The wet-laid nonwoven fabric including the carbon fibers of the present invention includes PAN (polyacrylonitrile)-based carbon fibers. PAN-based carbon fibers are produced by carbonizing PAN (Poly-Acrylonitrile) fibers obtained by spinning after polymerization of acrylonitrile at a high temperature, and are fibers made through the processes of polymerization, spinning, and firing. Polymerization is the process of applying heat and pressure to acrylonitrile (AN: acrylonitrile) to make it into a polymer state, and spinning is the process by which the high-molecular polymer (PAN: Poly-Acrylonitrile) made through the polymerization process is reborn into acrylic fibers through the spinning process. Firing is a process of oxidizing and carbonizing the acrylic fiber at a high temperature of 1,200 ° C or higher. Finally, only the carbon (C) component of the acrylic fiber that has undergone the firing process remains to produce PAN-based carbon fiber.

The PAN-based carbon fiber of the present invention may have a single fiber fineness of 0.78 to 1.18 denier, preferably 0.88 to 1.08 denier. In addition, the number of filaments in the PAN-based carbon fiber of the present invention may be 4,800 to 7,200, preferably 5,400 to 6,600. In addition, the PAN-based carbon fiber of the present invention may have a strand tensile strength of 3.13 to 4.71 GPa, preferably 3.52 to 4.32 GPa, measured according to the ASTM D4018 test standard.

Meanwhile, the wet-laid nonwoven fabric including the carbon fibers of the present invention may further include thermally adhesive fibers. At this time, the wet-laid nonwoven fabric containing the carbon fiber of the present invention may include 24 to 36 parts by weight of the heat-sealable fiber, preferably 27 to 33 parts by weight, based on 100 parts by weight of the PAN-based carbon fiber. If it is out of the negative range, it may be difficult to achieve the desired mechanical properties.

The heat-sealable fiber of the present invention may be a core-sheath type heat-sealable fiber having a copolyester resin as a sheath and a polyethylene terephthalate resin as a core. At this time, the sheath and the core may have a weight ratio of 1:0.8 to 1.2, preferably 1.:0.9 to 1.1 parts by weight. In addition, the sheath-type heat-sealable fiber may have a fiber length of 4 to 6 mm, preferably 4.5 to 5.5 mm, and a fineness of 3.0 to 4.6 denier, preferably 3.4 to 4.2 denier.

In addition, the copolyester resin contains an acid component including terephthalic acid and a diol component including 2-methyl-1,3-propanediol and ethylene glycol. It may be prepared by polymerization and condensation of an ester compound prepared by esterification and polyethylene glycol (PEG). Specifically, the acid component and the diol component may be etherified at a ratio of 1: 1.0 to 1.5, preferably 1: 1.1 to 1.3 to prepare an ester reactant, and the diol component is 2-methyl-1,3- 48 to 54 mol% of propanediol and 56 to 62 mol% of ethylene glycol may be included. In addition, polyethylene glycol may have a weight average molecular weight of 2,000 to 6,000, preferably 3,000 to 5,000, and polyethylene glycol may be included in 1 to 10 parts by weight, preferably 3 to 7 parts by weight, based on 100 parts by weight of the ester reactant. there is.

In addition, the polyethylene tetraphthalate resin may have an intrinsic viscosity of 0.45 to 0.85 dl/g, preferably 0.55 to 0.75 dl/g.

Furthermore, the wet-laid nonwoven fabric including the carbon fibers of the present invention may further include glass fibers. At this time, the wet-laid nonwoven fabric including the carbon fibers of the present invention may include 20 to 30 parts by weight of glass fibers, preferably 22.5 to 27.5 parts by weight, based on 100 parts by weight of PAN-based carbon fibers, and if the range of parts by weight described If it is out of the range, it may be difficult to achieve the desired mechanical properties.

In addition, the glass fiber may have a fineness of 3.04 to 4.56 denier, preferably 3.42 to 4.18 denier, and a fiber length of 2.4 to 3.6 mm, preferably 2.7 to 3.3 mm.

Meanwhile, the wet-laid nonwoven fabric including the carbon fibers of the present invention may further include polyphenylene sulfide fibers. At this time, the wet-laid nonwoven fabric containing the carbon fibers of the present invention may include 8 to 12 parts by weight of polyphenylene sulfite fibers, preferably 9 to 11 parts by weight, based on 100 parts by weight of PAN-based carbon fibers. If it is out of the range of parts by weight, it may be difficult to achieve the desired mechanical properties.

In addition, the polyphenylene sulfite fiber may have a fineness of 1.2 to 1.8 denier, preferably 1.35 to 1.65 denier, and a fiber length of 2.4 to 3.6 mm, preferably 2.7 to 3.3 mm.

Furthermore, the wet-laid nonwoven fabric comprising the carbon fibers of the present invention may further include modacrylic flame retardant fibers. First, modacrylic fiber refers to an acrylic synthetic fiber made of a polymer that mainly includes a polymer having acrylonitrile residues, particularly 35% to 85% of acrylonitrile units, and can be modified by other monomers. Modacrylic fibers can also be produced by spinning from a wide range of acrylonitrile copolymers. In addition, modacrylic fibers may contain residues of monomers such as vinyl monomers, for example, vinyl chloride, vinylidene chloride, vinyl bromide, and vinylidene bromide, but are not limited thereto, and may contain residues of other monomers. Additionally, the types of modacrylic fibers that can be produced within this broad category can vary widely in properties depending on their composition.

The modacrylic flame retardant fiber of the present invention has a flame retardant performance of 20 or more, preferably 24 to 40, when measured by the limited oxygen index (LOI) method through the KS M3032 regulation by post-processing of the flame retardant. Acrylic fibers may be included, preferably Kaneka Corporation's PROTEX or KANECARON.

In addition, the wet-laid nonwoven fabric containing the carbon fibers of the present invention may include 4 to 6 parts by weight of modacrylic flame retardant fibers, preferably 4.5 to 5.5 parts by weight, based on 100 parts by weight of PAN-based carbon fibers, and if the described parts by weight If it is out of range, it may be difficult to achieve the desired mechanical properties.

In addition, the modacrylic flame retardant fiber may have a fineness of 1.2 to 1.8 denier, preferably 1.35 to 1.65 denier, and a fiber length of 4 to 6 mm, preferably 4.5 to 5.5 mm.

Meanwhile, the wet-laid nonwoven fabric including the carbon fibers of the present invention may have a basis weight of 100 to 140 g/m 2 , preferably 110 to 130 g/m 2 , but is not limited thereto.

Furthermore, the method for producing a wet-laid nonwoven fabric comprising carbon fibers of the present invention includes first to third steps.

First, the first step of the method for producing a wet-laid nonwoven fabric containing carbon fibers of the present invention is to prepare a fiber mixture in which PAN-based carbon fibers, heat-sealable fibers, glass fibers, polyphenylene sulfite fibers, and modacrylic flame retardant fibers are mixed. can do. At this time, PAN-based carbon fibers, thermally adhesive fibers, glass fibers, polyphenylene sulfite fibers, and modacrylic flame retardant fibers are each as described above, and the fiber mixture is based on 100 parts by weight of PAN-based carbon fibers, thermally adhesive fibers 24 to 36 parts by weight, preferably 27 to 33 parts by weight, glass fiber 20 to 30 parts by weight, preferably 22.5 to 27.5 parts by weight, polyphenylene sulfite fiber 8 to 12 parts by weight, preferably 9 to 11 parts by weight 4 to 6 parts by weight of part and modacrylic flame retardant fibers, preferably 4.5 to 5.5 parts by weight, may be mixed.

Next, in the second step of the method for producing a wet-laid nonwoven fabric containing carbon fibers of the present invention, the fiber mixture prepared in the first step may be dispersed in water, drained of water, and then dried to prepare a dry product. At this time, the water may have a temperature of 20 ~ 25 ℃, drying may be carried out at a temperature of 85 ~ 108 ℃, preferably at a temperature of 90 ~ 100 ℃.

Finally, the third system of the method for producing a wet-laid nonwoven fabric containing carbon fiber of the present invention is calendering the dried product prepared in the second step at a temperature of 130 to 170 ° C, preferably 140 to 160 ° C. A wet-laid nonwoven fabric can be produced.

In the above, the present invention has been described with a focus on embodiments, but this is only an example and does not limit the embodiments of the present invention, and those skilled in the art to which the embodiments of the present invention belong will appreciate the essential characteristics of the present invention. It will be appreciated that various modifications and applications not exemplified above are possible within a range that does not deviate. For example, each component specifically shown in the embodiment of the present invention can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

Preparation Example 1: Preparation of core-sheath type heat-sealable fiber

(1) An ester reactant was prepared by esterifying an acid component and a diol component at a ratio of 1:1.2 at a temperature of 240° C. and a pressure of 1140 torr. At this time, 100 mol% of terephthalic acid was used as an acid component, and a mixture of 51 mol% of 2-methyl-1,3-propanediol and 59 mol% of ethylene glycol was used as a diol component.

(2) The prepared ester reactant is transferred to a polycondensation reactor, polyethylene glycol (PEG) having a weight average molecular weight of 4,000, titanium isopropoxide as a polycondensation catalyst, and triphosphate as a thermal stabilizer in the polycondensation reactor. After adding ethyl (triethyl phosphate), the temperature was raised to 280° C. while gradually reducing the pressure to a final pressure of 0.5 Torr to perform a condensation polymerization reaction to prepare a copolyester resin. At this time, polyethylene glycol (PEG) was used in an amount of 5 parts by weight based on 100 parts by weight of the ester reactant.

(3) After melting the prepared copolyester resin and polyethylene terephthalate (PET) resin having an intrinsic viscosity of 0.65 dl/g, each was put into a core-sheath type spinneret, and then, at a temperature of 275° C., at a spinning speed of 1000 mpm, the core part and sheath were conjugated to have a weight ratio of 5:5, and stretched 2.8 times in hot water at 60 ° C. to prepare a core-sheath type heat-sealable fiber having a copolyester resin as a sheath and a polyethylene terephthalate resin as a core. The prepared core-sheath type heat-sealable fiber had a fiber length of 5 mm and a fineness of 3.8 denier.

Example 1: Preparation of wet-laid nonwoven fabric

(1) PAN (polyacrylonitrile)-based carbon fiber with a single fiber fineness of 0.98 denier, a filament number of 6,000, and a strand tensile strength of 3.92 GPa measured in compliance with the ASTM D4018 test standard, core-sheath type thermal bonding prepared in Preparation Example 1 synthetic fiber, glass fiber with a fineness of 3.8 denier and a fiber length of 3 mm, polyphenylene sulfite fiber with a fineness of 1.5 denier and a fiber length of 3 mm, and modacrylic flame retardant fiber with a fineness of 1.5 denier and a fiber length of 5 mm ( Kaneka Company, KANECARON) were prepared respectively.

(2) Based on 100 parts by weight of the prepared PAN-based carbon fiber, 30 parts by weight of the prepared core-sheath type heat-adhesive fiber, 25 parts by weight of the prepared glass fiber, 10 parts by weight of the prepared polyphenylene sulfite fiber, and 5 parts by weight of the prepared modacrylic flame retardant fiber After dispersing in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Example 2: Preparation of wet-laid nonwoven fabric

(1) PAN (polyacrylonitrile)-based carbon fiber with a single fiber fineness of 0.98 denier, a filament number of 6,000, and a strand tensile strength of 3.92 GPa measured in compliance with the ASTM D4018 test standard, core-sheath type thermal bonding prepared in Preparation Example 1 A polyphenylene sulfite fiber having a fineness of 3.8 denier and a fiber length of 3 mm and a glass fiber having a fiber length of 1.5 denier and a fiber length of 3 mm were respectively prepared.

(2) Based on 100 parts by weight of the prepared PAN-based carbon fiber, 30 parts by weight of the prepared core-sheath type heat-sealable fiber, 25 parts by weight of the prepared glass fiber, and 10 parts by weight of the prepared polyphenylene sulfite fiber were dispersed in water at 23 ° C. After draining, it was dried at 95 ° C., and then calendered at a temperature of 150 ° C. to prepare a wet-laid nonwoven fabric having a basis weight of 120 g / m 2 .

Example 3: Preparation of wet-laid nonwoven fabric

A wet-laid nonwoven fabric was prepared in the same manner as in Example 1. However, unlike Example 1, with respect to 100 parts by weight of the prepared PAN-based carbon fiber, 30 parts by weight of the prepared core-sheath type heat-sealable fiber, 25 parts by weight of the prepared glass fiber, 10 parts by weight of the prepared polyphenylene sulfite fiber, and the prepared modacrylic flame retardant After dispersing 2 parts by weight of the fiber in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Example 4: Preparation of wet-laid nonwoven fabric

A wet-laid nonwoven fabric was prepared in the same manner as in Example 1. However, unlike Example 1, with respect to 100 parts by weight of the prepared PAN-based carbon fiber, 30 parts by weight of the prepared core-sheath type heat-sealable fiber, 25 parts by weight of the prepared glass fiber, 10 parts by weight of the prepared polyphenylene sulfite fiber, and the prepared modacrylic flame retardant After dispersing 8 parts by weight of the fiber in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Example 5: Preparation of wet-laid nonwoven fabric

A wet-laid nonwoven fabric was prepared in the same manner as in Example 1. However, unlike Example 1, 20 parts by weight of the prepared core-sheath type heat-sealable fiber, 25 parts by weight of the prepared glass fiber, 10 parts by weight of the prepared polyphenylene sulfite fiber, and 100 parts by weight of the prepared PAN-based carbon fiber, prepared with respect to 100 parts by weight of the prepared PAN-based carbon fiber After dispersing 5 parts by weight of the fiber in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Example 6: Preparation of wet-laid nonwoven fabric

A wet-laid nonwoven fabric was prepared in the same manner as in Example 1. However, unlike Example 1, 40 parts by weight of the prepared core-sheath type heat-sealable fiber, 25 parts by weight of the prepared glass fiber, 10 parts by weight of the prepared polyphenylene sulfite fiber, and 100 parts by weight of the prepared PAN-based carbon fiber were prepared. After dispersing 5 parts by weight of the fiber in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Example 7: Preparation of wet-laid nonwoven fabric

A wet-laid nonwoven fabric was prepared in the same manner as in Example 1. However, unlike Example 1, based on 100 parts by weight of the prepared PAN-based carbon fiber, 30 parts by weight of the prepared core-sheath type heat-sealable fiber, 18 parts by weight of the prepared glass fiber, 10 parts by weight of the prepared polyphenylene sulfite fiber, and the prepared modacrylic flame retardant After dispersing 5 parts by weight of the fiber in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Example 8: Preparation of wet-laid nonwoven fabric

A wet-laid nonwoven fabric was prepared in the same manner as in Example 1. However, unlike Example 1, based on 100 parts by weight of the prepared PAN-based carbon fiber, 30 parts by weight of the prepared core-sheath type heat-sealable fiber, 32 parts by weight of the prepared glass fiber, 10 parts by weight of the prepared polyphenylene sulfite fiber, and the prepared modacrylic flame retardant After dispersing 5 parts by weight of the fiber in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Example 9: Preparation of wet-laid nonwoven fabric

A wet-laid nonwoven fabric was prepared in the same manner as in Example 1. However, unlike Example 1, based on 100 parts by weight of the prepared PAN-based carbon fiber, 30 parts by weight of the prepared core-sheath type heat-sealable fiber, 25 parts by weight of the prepared glass fiber, 6 parts by weight of the prepared polyphenylene sulfite fiber, and the prepared modacrylic flame retardant After dispersing 5 parts by weight of the fiber in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Example 10: Preparation of wet-laid nonwoven fabric

A wet-laid nonwoven fabric was prepared in the same manner as in Example 1. However, unlike Example 1, with respect to 100 parts by weight of the prepared PAN-based carbon fiber, 30 parts by weight of the prepared core-sheath type heat-sealable fiber, 25 parts by weight of the prepared glass fiber, 14 parts by weight of the prepared polyphenylene sulfite fiber, and the prepared modacrylic flame retardant After dispersing 5 parts by weight of the fiber in water at 23 ° C., draining the water, drying at 95 ° C., and then calendering at a temperature of 150 ° C. to prepare a wet nonwoven fabric having a basis weight of 120 g / m 2 .

Comparative Example 1: Preparation of wet-laid nonwoven fabric

(1) PAN (polyacrylonitrile)-based carbon fiber with a single fiber fineness of 0.98 denier, a filament count of 6,000, and a strand tensile strength of 3.92 GPa, measured in accordance with the ASTM D4018 test standard, a fineness of 3.8 denier, and a fiber length of 3 mm Glass fibers, polyphenylene sulfite fibers having a fineness of 1.5 denier and a fiber length of 3 mm, and modacrylic flame retardant fibers (Kaneka, KANECARON) having a fineness of 1.5 denier and a fiber length of 5 mm were prepared, respectively.

(2) Based on 100 parts by weight of the prepared PAN-based carbon fiber, 25 parts by weight of the prepared glass fiber, 10 parts by weight of the prepared polyphenylene sulfite fiber, and 5 parts by weight of the prepared modacrylic flame retardant fiber were dispersed in water at 23 ° C., and the water was drained. After that, it was dried at 95 ° C., and then calendered at a temperature of 150 ° C. to prepare a wet-laid nonwoven fabric having a basis weight of 120 g / m 2 .

Experimental Example: Measurement of physical properties of wet-laid nonwoven fabric

For each of the wet-laid nonwoven fabrics prepared in Examples 1 to 10 and Comparative Example 1, the following physical properties were measured and shown in Table 1 below.

(1) Measurement of stiffness

The stiffness of each of the wet-laid nonwoven fabrics prepared in Examples 1 to 10 and Comparative Example 1 in the MD (machine direction) direction was measured by applying the ISO 2493 test standard.

(2) Measurement of tensile strength

Tensile strengths in MD (machine direction) and CD (cross direction) directions of each of the wet-laid nonwoven fabrics prepared in Examples 1 to 10 and Comparative Example 1 were measured in accordance with the ASTM D828 test standard.

(3) Measurement of tear strength

TAPPI T414 test standard was applied, and the tear strength in the machine direction (MD) direction and the cross direction (CD) direction of each of the wet-laid nonwoven fabrics prepared in Examples 1 to 10 and Comparative Example 1 was measured.

(4) Flame retardant performance measurement

Each of the wet-laid nonwoven fabrics prepared in Examples 1 to 10 and Comparative Example 1 was subjected to KS M3032 regulations, and the flame retardancy performance was measured by the limiting oxygen index (LOI) method (if the flame retardance standard is 28 or more, it is judged to be excellent.) .

division Example 1 Example 2 Example 3 Example 4 Stiffness (Kn/M) 451 448 449 430 tensile strength
(N/cm) MD 45.7 45.8 45.7 45.0 CD 25.3 25.1 25.2 24.9 tear strength
(N) MD 0.99 1.01 1.00 0.95 CD 1.87 1.90 1.88 1.82 Flame retardant performance 30 23 28 31 division Example 5 Example 6 Example 7 Example 8 Stiffness (Kn/M) 401 433 425 440 tensile strength
(N/cm) MD 41.4 44.4 42.8 44.6 CD 21.5 24.1 22.4 24.5 tear strength
(N) MD 0.90 0.95 0.80 0.96 CD 1.78 1.82 1.66 1.86 flame retardant performance 29 26 27 25 division Example 9 Example 10 Comparative Example 1 Stiffness (Kn/M) 440 435 347 tensile strength
(N/cm) MD 44.8 44.5 35.8 CD 25.0 24.8 17.4 tear strength
(N) MD 0.99 0.97 0.81 CD 1.85 1.82 1.67 flame retardant performance 26 29 26

As shown in Table 1, it was confirmed that the wet-laid nonwoven fabric prepared in Example 1 had excellent flame retardancy as well as excellent mechanical properties.

Simple modifications or changes of the present invention can be easily performed by those skilled in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (7)

Based on 100 parts by weight of PAN (polyacrylonitrile)-based carbon fiber, 24 to 36 parts by weight of heat-sealable fiber, 20 to 30 parts by weight of glass fiber, 8 to 12 parts by weight of polyphenylene sulfide fiber and modacrylic ) Wet-laid nonwoven fabric containing carbon fibers, characterized in that it comprises 4 to 6 parts by weight of flame retardant fibers.
delete According to claim 1,
The PAN-based carbon fiber has a short fiber fineness of 0.78 to 1.18 denier, a filament number of 4,800 to 7,200, and a strand tensile strength of 3.13 to 4.71 GPa, measured by applying the ASTM D4018 test standard,
The heat-sealable fiber is a core-sheath type heat-sealable fiber having a copolyester resin as a sheath and a polyethylene terephthalate resin as a core,
The sheath-type heat-sealable fiber has a fiber length of 4 to 6 mm and a fineness of 3.0 to 4.6 denier,
The copolyester resin is a polycondensation reaction between an ester compound prepared by esterifying an acid component including terephthalic acid and a diol component including 2-methyl-1,3-propanediol and ethylene glycol and polyethylene glycol (PEG) Wet-laid nonwoven fabric comprising carbon fibers, characterized in that produced by.
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