KR20180110836A - A method of manufacturing fibrillated liquid crystal polyester short staple for synthetic paper and a method of manufacturing fibrillated liquid crystal synthetic paper using the same - Google Patents

Abstract

The present invention relates to a method of manufacturing a fibrillated liquid crystal polyester short fiber for synthetic paper and a method of manufacturing fibrillated liquid crystal synthetic paper using the same. More specifically, the present invention relates to a method of manufacturing a fibrillated liquid crystal polyester short fiber for synthetic paper which has a large specific surface area, has excellent internal bonding strength and tensile strength, has excellent mass productivity, workability and workability, and is capable of exhibiting the increased fiber content in the production of synthetic paper; and relates to a method of manufacturing fibrillated liquid crystal synthetic paper using the same.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for producing a fibrillated liquid crystal polyester staple fiber for synthetic fibers and a method for producing a fibrillated liquid crystal polyester synthetic paper using the same using the same}

The present invention relates to a process for producing a fibrillated liquid crystalline polyester staple fiber for synthetic fibers and a process for producing the fibrillated liquid crystal polyester synthetic paper using the same, and more particularly to a process for producing a fibrillated liquid crystalline polyester staple fiber having a large specific surface area, Which is excellent in productivity, workability and operability, and exhibits an effect that the fiber content can be increased in the production of synthetic paper, and a method for producing a fibrillated liquid crystalline polyester staple fiber for synthetic paper, .

Paper is traditionally defined as "a sheet-like, platelet-shaped fiber product that is formed by screening a suspension of fiber and water. However, in practice most non-fibrous additive materials are added during the manufacture of paper. For the production of special paper products, dry laver methods are also used recently. Pulp is a papermaking fiber raw material. Generally, pulp fibers are obtained from plants, but animal, mineral and synthetic fibers are used in small quantities for special applications.

Unlike conventional paper, synthetic fibers are used in addition to natural pulp for the purpose of imparting special functions, or paper is produced by using synthetic fiber alone, which is called synthetic paper. Synthetic papers are often compared with wet-raid nonwoven fabrics due to their commonality in the production process, and it is difficult to clearly distinguish between the two products. However, the fiber-to-fiber bond due to the fibrillation of natural pulp is a very important factor in the production of normal paper, and the wet nonwoven fabric is a major factor in the interfiber bonding when the heat treatment of the formed web is carried out. There is a difference in point.

Fibrillation is a very important factor in the production of paper. For this purpose, the process of dissociation, dispersion and beating is the most important process in the raw material composition process. In the entire paper manufacturing process, It is the most important process to determine the physical properties. The changes that occur in the fibers in the beating process are manifold in a wide variety of mechanical and hydrodynamic forces. Shear stresses are applied to the fibers by rolling, twisting and tensioning occurring between bars and in the grooves and passages of the refiner. Vertical stresses, such as tensile or compressive stresses, are applied to the chunks of fiber between the bar and bar surfaces by bending, grinding, pulling and pushing action. In order to summarize the effects that occur on individual fibers when a beating occurs, the primary walls are first partially removed. The primary walls are infiltrated by water but are not swollen, preventing the fibers from swelling. Once the primary wall is removed, the secondary wall is exposed, allowing water to penetrate into the molecular structure of the fiber. Eventually, if the internal structure is loosened, it promotes fiber swelling and makes the fiber soft and supple. Such internal fibrillation is generally considered to be the most important primary effect of defecation after removal of the primary wall. As the fibrillization further proceeds, the fibrils are loosened and the finer microfibrils are loosened on the fiber surface, greatly increasing the surface area of the cracked fibers. As the fibers become more flexible, the cell walls collapse into intracellular lumens and are made of ribbon-like fibers with greater conformity.

As described above, in the production of paper, fibrillation by defatting has various effects and contributes greatly to imparting physical properties of the paper. However, in the case of shredded fibers, it is difficult to add monofilization or fibrillation due to confinement, and it is difficult to add more than a certain amount because it interferes with the interfiber bonding in the normal case, and the strength of the synthetic paper may decrease as the addition amount increases . In general, natural pulp is used as a main raw material in the production of synthetic paper, and the amount of the shredded fiber is determined in consideration of the strength drop to the point where the strength of the paper is required, and a separate binder is used for adding the shredded fiber , And has been producing synthetic paper by a special treatment.

On the other hand, liquid crystal polyester fibers are mainly used in filament form and are used for applications requiring very strong strength and heat resistance, and are not processed in the form of short fibers. However, when it is processed into a short fiber form, it can be developed as a new characteristic synthetic paper when it is processed into a paper or nonwoven fabric form by utilizing the characteristics of the liquid crystal polyester fiber. Therefore, liquid crystal polyester fiber is made short fiber, It is necessary to develop a treatment method for use as a raw material of the present invention.

KR 10-2016-0132275 A

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method for producing a synthetic paper which is large in specific surface area, excellent in internal bonding strength and tensile strength, excellent in mass productivity, workability, The present invention is to provide a method for producing a fibrillated liquid crystal polyester staple fiber for synthetic fibers and a method for producing the fibrillated liquid crystal polyester synthetic paper through such a method.

In order to solve the above-mentioned problems, the present invention provides a method for producing a liquid crystal polyester filament fiber, comprising the steps of: (1) melt-spinning a liquid crystal polyester (LCP) (2) preparing the liquid crystalline polyester filament fibers as liquid crystalline polyester staple fibers; (3) dispersing the liquid crystalline polyester staple fibers in water to prepare a mixed slurry; And (4) fibrillating the mixed slurry. The present invention also provides a method for producing a fibrillated liquid crystalline polyester staple fiber for synthetic paper.

According to one embodiment of the present invention, the pulping process may be a defoaming process.

Further, the confusion can be performed for 3 to 13 minutes.

The liquid crystalline polyester staple fibers may have a fiber length of 2 to 12 mm.

The mixed slurry may contain 0.2 to 2.5% by weight of the liquid crystal polyester staple fibers based on the total weight of the mixed slurry.

The liquid crystal polyester staple fibers can be produced by shattering the liquid crystal polyester fibers.

In addition, the melt spinning can be performed at a temperature of 250 to 350 DEG C and a spinning speed of 150 to 1200 mpm.

On the other hand, the present invention relates to (1) a process for melt-spinning a liquid crystal polyester (LCP) to produce a liquid crystalline polyester filament fiber; (2) preparing the liquid crystalline polyester filament fibers as liquid crystalline polyester staple fibers; (3) dispersing the liquid crystalline polyester staple fibers in water to prepare a mixed slurry; (4) fibrillating the mixed slurry; And (5) dewatering and heat-treating the mixed slurry obtained by fibrillating the fibrillated liquid crystal polyester.

According to one embodiment of the present invention, the pulping process may be a defoaming process.

Further, the confusion can be performed for 3 to 13 minutes.

The heat treatment may be performed at 90 to 160 ° C.

On the other hand, the present invention provides fibrillated liquid crystal polyester short fibers for synthetic fibers having a freeness of 600 to 800 ml CSF measured by the following Measuring Method 1.

[Measurement method 1]

The freeness of the fibrillated liquid crystalline polyester staple fibers for synthetic paper was measured using a slurry prepared with 0.3% and 1000 mL of concentration, poured into a freeness measuring instrument, and water was passed through the orifice.

According to one embodiment of the present invention, the specific surface area measured by the following measurement method 2 may be 80 to 150 m ² / g.

[Measurement method 2]

The specific surface area was measured by measuring the amount of adsorbed nitrogen gas by adsorbing nitrogen gas on the surface of the fibrillated liquid crystal polyester staple fibers for synthetic paper, and calculating the surface area by BET equation.

On the other hand, the present invention provides a fibrillated liquid crystal polyester synthetic paper comprising the above-mentioned fibrillated liquid crystal polyester short fibers for synthetic paper.

According to one embodiment of the present invention, the tensile strength can be 10 Nm / g or more and the internal bond strength can be 200 J / m or more.

It may also contain no binder fibers.

INDUSTRIAL APPLICABILITY The method for producing a fibrillated liquid crystal polyester staple fiber for synthetic paper and the method for producing a fibrillated liquid crystal polyester synthetic paper according to the present invention have a large specific surface area and are excellent in internal bonding strength and tensile strength, And workability, and at the same time, the fiber content of the synthetic paper can be increased.

1 is a photograph of a fibrillated liquid crystalline polyester staple fiber for synthetic paper according to an embodiment of the present invention.
Figure 2 is a photograph of staple fibers that have not undergone fibrillation treatment.

Hereinafter, the present invention will be described in more detail.

As described above, in the past, the addition amount of the shredded fiber has been determined in consideration of the strength reduction to the point where the strength of the paper is required. To add the shredded fiber, a separate binder is used or a synthetic paper It had to be manufactured.

Accordingly, the present invention provides a method for producing a liquid crystal polyester filament fiber, comprising the steps of: (1) melt spinning a liquid crystal polyester (LCP) to produce a liquid crystalline polyester filament fiber; (2) preparing the liquid crystalline polyester filament fibers as liquid crystalline polyester staple fibers; (3) dispersing the liquid crystalline polyester staple fibers in water to prepare a mixed slurry; And (4) fibrillating the mixed slurry. The present invention has been made to solve the above-mentioned problems by providing a method for producing a fibrillated liquid crystalline polyester staple fiber for synthetic paper.

As a result, it has a large specific surface area, an excellent internal bonding strength and tensile strength, an excellent productivity, workability and workability, and an effect of increasing fiber content in the production of synthetic paper.

First, a step (1) of producing a liquid crystal polyester filament fiber by melt-spinning a liquid crystal polyester (LCP) is described.

The liquid crystal polyester resin (LCP) can be used without limitation as long as it is a liquid crystal polyester resin that can be usually produced in a filament form. Preferably, p-hydroxybenzoic acid, 6-hydroxy- But are not limited to, polycondensates of 2-naphthoic acid, biphenol, terephthalic acid, isophthalic acid and anhydrous acetic acid.

The melt spinning can be used without limitation as long as it is a melt spinning condition capable of producing filament type fibers in the art, and preferably at a temperature of 250 to 350 DEG C, at a spinning speed of 150 to 1200 mpm, At a temperature of 280 to 330 캜, and at a spinning speed of 200 to 1000 mpm. If the temperature of the melt spinning is less than 250 ° C., the polymer may not melt and spinning may occur. If the temperature exceeds 350 ° C., the polymer may be pyrolyzed or carbonized. If the spinning speed is less than 150 mpm, the spinning draft and the fineness can not be matched and the yarn can not be formed. If the spinning speed exceeds 1200 mpm, the spinning draft and the fineness can not be matched, A problem may arise.

Next, the step (2) of producing the liquid crystal polyester filament fiber with a liquid crystal polyester staple fiber will be described.

By producing the liquid crystalline polyester filament fiber with a liquid crystalline polyester staple fiber, a synthetic paper having characteristics of exhibiting strong strength and heat resistance of polyester can be produced.

The step (2) is not particularly limited as long as it is a method for producing short fibers which can be used in the art. Preferably, the step (2) can be performed by cutting or crushing. More preferably, But is not limited thereto.

On the other hand, the liquid crystal polyester staple fiber produced by the step (2) may be a short staple fiber of a usual length, preferably a fiber length of 2 to 12 mm, more preferably a fiber length of 3 to 10 mm Lt; / RTI > If the fiber length of the liquid crystalline polyester staple fiber is less than 2 mm, the contact surface area of the fiber is small, so that it may be difficult to form the water base which forms the basis of the paper. If the fiber length exceeds 12 mm, It can be difficult.

Next, the step (3) of producing a mixed slurry by dispersing the liquid crystalline polyester staple fibers in water will be described.

The mixed slurry is prepared for a fibrillating treatment to be described later.

The content of the liquid crystal polyester staple fibers contained in the mixed slurry is not limited as long as it is capable of performing the fibrillating treatment to be described later and is preferably 0.2 to 2.5 wt% By weight, more preferably 0.3 to 2.0% by weight. If the content of the staple fibers is less than 0.2% by weight, the yield of the fibrillated liquid crystal polyester staple fibers for synthetic fibers may be poor because the amount of staple fibers that can be treated at the same time is small. There is a problem that the high energy of the spent energy is excessively increased or the shear stress at the desired level can not be given.

Next, the step (4) of fibrillating the mixed slurry will be described.

Since the fibrillating treatment can increase the specific surface area of the synthetic paper to be described later and improve the tensile strength and internal bond strength, it is possible to produce paper of high strength without containing a separate binder.

The fibrillating treatment is not particularly limited as long as it can be used in the conventional fibrillating treatment in the art. As shown in Fig. 2, straight-line fibers can be fibrillated as shown in Fig.

On the other hand, the beating can be performed for 3 to 13 minutes, preferably 4 to 12 minutes, in order to improve the mechanical strength and physical properties of the fibrillated liquid crystal polyester short fibers and the fibrillated liquid crystal polyester synthetic paper for synthetic paper .

If the defatting time is less than 3 minutes, the fibrillated liquid crystal polyester staple fibers and fibrillated liquid crystal polyester synthetic papers for synthetic fibers may have low specific surface area, poor tensile strength and internal bond strength, Min, the specific surface area may be high, but the tensile strength and internal bond strength may be poor.

Accordingly, it is possible to perform the defoaming treatment for a time satisfying the above range, which is easy to manufacture a high strength paper without a binder.

On the other hand, the present invention carries out the step (5) of dewatering and heat-treating the mixed slurry obtained by fibrillating the slurry after the step (4) for producing the fibrillated liquid crystal polyester synthetic paper.

It is possible to produce a fibrillated liquid crystal polyester synthetic paper by using the fibrillated liquid crystal polyester short fibers for synthetic paper produced by the above-mentioned production method by performing dehydration and heat treatment after the dewatering, and to improve tensile strength and internal bond strength of synthetic paper .

The heat treatment may be performed at 90 to 160 ° C, preferably 100 to 150 ° C, in order to improve the tensile strength and internal bond strength of the synthetic paper. If the temperature of the heat treatment is less than 90 ° C, the tensile strength and internal bond strength of the synthetic paper may be poor. If the temperature exceeds 160 ° C, the productivity, workability and operability may not be good.

Meanwhile, the heat treatment can be performed for 10 minutes or less, preferably 8 minutes or less, more preferably 6 minutes or less, and further preferably 5 minutes or less, but is not limited thereto.

On the other hand, the fibrillated liquid crystalline polyester staple fiber for synthetic paper of the present invention may have a filtration degree of 600 to 800 ml CSF, preferably 660 to 740 ml CSF, as measured by the following measurement method 1.

[Measurement method 1]

The freeness of the fibrillated liquid crystalline polyester staple fibers for synthetic paper was measured using a slurry prepared with 0.3% and 1000 mL of concentration, poured into a freeness measuring instrument, and water was passed through the orifice.

The freeness degree of the fibrillated liquid crystal polyester staple fiber for synthetic paper can be indirectly known through the degree of freeness. If the degree of freeness measured by the above-mentioned method 1 is less than 600 ml CSF, the tensile strength and the internal bonding strength of the fibrillated liquid crystal polyester synthetic paper produced may be poor due to excessive heat treatment, Exceeds 800 ml CSF, the specific surface area may be remarkably low and the tensile strength and internal bond strength may not be good due to the failure of the beating treatment to a desired level.

On the other hand, the fibrillated liquid crystalline polyester staple fiber for synthetic paper of the present invention may have a specific surface area of 80 to 150 m ² / g, preferably 90 to 145 m ² / g, measured by the following measurement method 2.

[Measurement method 2]

The specific surface area was measured by measuring the amount of adsorbed nitrogen gas by adsorbing nitrogen gas on the surface of the fibrillated liquid crystal polyester staple fibers for synthetic paper, and calculating the surface area by BET equation.

The degree of briquetting of the fibrillated liquid crystal polyester staple fibers for synthetic paper can be indirectly known through the specific surface area. If the specific surface area measured by the above-mentioned measurement method 2 is less than 80 m ² / g, the specific surface area may be remarkably low, the tensile strength and the internal bonding strength may not be good, If the specific surface area exceeds 150 m ² / g, the high-temperature treatment may be excessive, and the tensile strength and internal bond strength of the fibrillated liquid-crystalline polyester synthetic paper produced may be poor.

On the other hand, the present invention provides a fibrillated liquid crystal polyester synthetic paper comprising the above-mentioned fibrillated liquid crystal polyester short fibers for synthetic paper.

The fibrillated liquid-crystalline polyester synthesis may have a tensile strength of 10 Nm / g or more, and preferably a tensile strength of 10 to 15 Nm / g. If the tensile strength of the fibrillated liquid crystalline polyester synthetic paper is less than 10 Nm / g, it can be considered that the fibrillated paper is not fibrillated to the desired level. Therefore, it is not possible to produce paper of high strength without containing a separate binder.

Further, the fibrillated liquid crystal polyester composition may have an internal bonding strength of 200 J / m or more, and preferably an internal bonding strength of 205 to 250 J / m. If the internal bonding strength is less than 200 J / m, the bonding strength between the fibrillated liquid crystal polyester short fibers for the synthetic paper contained in the synthetic paper of the fibrillated liquid crystal polyester is poor, and therefore, Paper can not be manufactured.

On the other hand, the fibrillated liquid crystal polyester composition of the present invention may not contain the binder fiber because it satisfies the above-described tensile strength and internal bonding strength range.

Hereinafter, the present invention will be described with reference to the following examples. The following examples are provided to illustrate the invention, but the scope of the present invention is not limited by the following examples.

<Preparation Example>

(1) Production of liquid crystal polyester resin

Hydroxybenzoic acid, 12 mol% of biphenol, 15 mol% of biphenol and 10 mol% of terephthalic acid were placed in a reaction vessel of 5 L capacity equipped with a stirrer, a nitrogen gas introducing tube and a thermometer, , 7 mol% of isophthalic acid and 1.1 equivalents of acetic anhydride (1.1 equivalents of phenolic hydroxyl group), and the mixture was heated to 150 ° C for 1 hour while stirring under a nitrogen atmosphere, and reacted at 150 ° C for 2 hours. Thereafter, the temperature was raised to 340 for 4 hours. The polymerization temperature was maintained, the pressure was reduced to 1 mmHg for 1.5 hours and the reaction was carried out to complete the polycondensation to prepare a liquid crystal polyester resin.

(2) Production of liquid crystal polyester staple fibers

The liquid crystalline polyester resin was put into a radiator (nozzle 0.3, L / D = 3, 16 holes) and melt-spun at a spinning speed of 310 캜 at a rate of 600 mpm to prepare a liquid crystal polyester filament fiber. The filament fibers were cut into a 5 mm ㎜ length of liquid crystal polyester staple fiber.

(3) Preparation of mixed slurry

230 g of the liquid crystalline polyester staple fiber thus prepared was added to 22.77 L of water and mixed to prepare a mixed slurry having a concentration of 1% by weight.

Example 1: Preparation of fibrillated liquid crystalline polyester synthetic paper

The mixed slurry according to the preparation example was placed in a beating machine (Lab Beater, TMI) and dispersed for 10 minutes in a no-load state and dispersed for 5 minutes under a dry condition to obtain a fibrillated liquid crystal poly Ester staple fibers. The filter paper was mounted on a funnel equipped with an aspirator and dehydrated by adding 100 ml of a mixed slurry to be treated, and then fibrillated liquid crystalline polyester staple fibers for synthetic paper laminated through dehydration was dipped in water at 120 ° C for 5 minutes Followed by heat treatment to prepare a fibrillated liquid crystal polyester synthetic paper.

&Lt; Examples 2 to 15 and Comparative Examples 1 to 5 >

The fibrillated liquid crystal polyester synthetic paper was prepared in the same manner as in Example 1 except that the defatting time and the heat treatment temperature were changed as shown in Tables 1 to 4 below.

<Experimental Example>

(1) Freeness measurement

A slurry of 0.3% of the fibrillated liquid crystalline polyester staple fibers prepared according to Examples and Comparative Examples was poured into a freeness tester (YASUDA) and the water passing through the orifice was collected, The results are shown in Tables 1 to 4 below.

(2) Measurement of specific surface area

The specific surface area of the fibrillated liquid crystalline polyester staple fibers prepared according to Examples and Comparative Examples was measured using a BET specific surface area analyzer and shown in Tables 1 to 4 below.

(3) Tensile strength measurement

The tensile strengths of the fibrillated liquid crystalline polyester synthetic paper prepared according to Examples and Comparative Examples were measured using a tensile strength tester (L & W), and the results are shown in Tables 1 to 4 below.

(4) Internal bond strength measurement

The internal bond strengths of the fibrillated liquid crystal polyester synthetic papers prepared according to Examples and Comparative Examples were measured using an internal bond tester (L & W), and the results are shown in Tables 1 to 4 below.

(5) Mass production, workability and operational evaluation

The productivity of the fibrillated liquid-crystalline polyester synthetic paper prepared according to the examples and the comparative examples was evaluated in terms of mass productivity, workability and operability, and it is shown in Tables 1 to 4 below. (◎) - When mass production, workability and operability are both excellent ○ - When mass production, workability and operability are excellent △ - When one of mass productivity, workability and operability is excellent , × - When mass productivity, workability and operation are not all good)

division Example 1 Example 2 Example 3 Example 4 Example 5 Break time (min) 5 1.5 4 10 12 Heat treatment temperature (캜) 120 120 120 120 120 Yeosu degree (ml CSF) 710 720 715 700 695 Specific surface area (m ² / g) 104 95 101 135 143 Tensile strength (Nm / g) 11.4 9.7 11.1 10.5 10.1 Internal bond strength (J / m) 233 197 212 218 202 Mass Production / Workability / Operation ◎ △ ◎ ◎ ◎

division Example 6 Example 7 Example 8 Example 9 Example 10 Break time (min) 15 5 5 5 5 Heat treatment temperature (캜) 120 75 100 140 150 Yeosu degree (ml CSF) 690 710 710 710 710 Specific surface area (m ² / g) 151 104 104 104 104 Tensile strength (Nm / g) 9.4 9.3 10.1 11.2 11.3 Internal bond strength (J / m) 196 185 212 239 248 Mass Production / Workability / Operation △ ○ ◎ ◎ ◎

division Example 11 Example 12 Example 13 Example 14 Example 15 Break time (min) 5 10 15 20 20 Heat treatment temperature (캜) 180 100 100 100 120 Yeosu degree (ml CSF) 710 700 690 680 680 Specific surface area (m ² / g) 104 135 151 178 178 Tensile strength (Nm / g) 11.4 10.3 9.8 8.8 9.7 Internal bond strength (J / m) 251 208 194 172 188 Mass Production / Workability / Operation × ○ △ △ △

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Break time (min) - - 5 10 - Heat treatment temperature (캜) 100 120 - - - Yeosu degree (ml CSF) 730 730 710 700 730 Specific surface area (m ² / g) 40 40 104 135 40 Tensile strength (Nm / g) 7.3 7.8 No synthetic paper No synthetic paper No synthetic paper Internal bond strength (J / m) 87 87 Mass Production / Workability / Operation △ △

As can be seen from Tables 1 to 4, the fibrillated liquid crystalline polyester staple fibers and fibrillated liquid crystal polyester synthetic fibers for synthetic fibers according to the present invention had a large specific surface area, excellent tensile strength and internal bonding strength, , Workability and workability were excellent.

Claims (16)

(1) melt spinning a liquid crystal polyester (LCP) to produce a liquid crystalline polyester filament fiber;
(2) preparing the liquid crystalline polyester filament fibers as liquid crystalline polyester staple fibers;
(3) dispersing the liquid crystalline polyester staple fibers in water to prepare a mixed slurry; And
(4) fibrillating the mixed slurry; and fibrillating the mixed slurry. The method according to claim 1,
Wherein the fibrillating treatment is a high-temperature treatment, and the fibrillating liquid crystal polyester staple fiber for synthetic paper. 3. The method of claim 2,
The method for producing a fibrillated liquid crystal polyester staple fiber for synthetic paper according to claim 1, wherein the beating is carried out for 3 to 13 minutes. The method according to claim 1,
Wherein the liquid crystalline polyester staple fiber has a fiber length of 2 to 12 mm. The method according to claim 1,
Wherein the mixed slurry contains 0.2 to 2.5% by weight of liquid crystal polyester staple fibers based on the total weight of the mixed slurry. The method according to claim 1,
Wherein the liquid crystalline polyester staple fibers are produced by shredding the liquid crystal polyester filament fibers. The method according to claim 1,
Wherein the melt spinning is carried out at a temperature of 250 to 350 占 폚 and at a spinning speed of 150 to 1200 mpm for producing a fibrillated liquid crystalline polyester staple fiber for synthetic fibers. (1) melt spinning a liquid crystal polyester (LCP) to produce a liquid crystalline polyester filament fiber;
(2) preparing the liquid crystalline polyester filament fibers as liquid crystalline polyester staple fibers;
(3) dispersing the liquid crystalline polyester staple fibers in water to prepare a mixed slurry;
(4) fibrillating the mixed slurry; And
(5) A method for producing a fibrillated liquid crystal polyester synthetic paper, which comprises dehydrating and heat-treating a fibrillated mixed slurry. 9. The method of claim 8,
Wherein the fibrillating treatment is a refining treatment. 10. The method of claim 9,
Wherein the beating is carried out for 3 to 13 minutes. 9. The method of claim 8,
Wherein the heat treatment is performed at 90 to 160 ° C. A fibrillated liquid crystalline polyester short fiber for a synthetic paper having a filtration degree of 600 to 800 ml CSF as measured by the following Measuring Method 1.
[Measurement method 1]
The freeness of the fibrillated liquid crystalline polyester staple fibers for synthetic paper was measured using a slurry prepared with 0.3% and 1000 mL of concentration, poured into a freeness measuring instrument, and water was passed through the orifice. 13. The method of claim 12,
A fibrillated liquid crystal polyester short fiber for a synthetic paper having a specific surface area of 80 to 150 m ² / g as measured by the following measurement method 2.
[Measurement method 2]
The specific surface area was measured by measuring the amount of adsorbed nitrogen gas by adsorbing nitrogen gas on the surface of the fibrillated liquid crystal polyester staple fibers for synthetic paper, and calculating the surface area by BET equation. 14. A fibrillated liquid crystal polyester synthetic paper comprising the fibrillated liquid crystal polyester short fibers for synthetic paper according to claim 12. 15. The method of claim 14,
A tensile strength of 10 Nm / g or more and an internal bonding strength of 200 J / m or more. 15. The method of claim 14,
Synthetic fibrillated liquid crystalline polyester without binder fibers.

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