KR20120058837A - Floating Fiber and Method for manufacturing the same - Google Patents

Abstract

PURPOSE: A method for fabricating floating fiber is provided to prevent penetration of water into the fiber inside. CONSTITUTION: A floating fiber contains a core fiber and a coating layer. The specific gravity of the core fiber is larger than the specific gravity of the water. The core fiber contains an aramid fiber. The coating layer contains 99% or more of floatant on the outer layer of the core fiber. The floatant is silicon oil. The fiber contacts the surface of distilled water.

Description

Floating Fiber and Method for manufacturing the same

The present invention relates to a fiber floating in water and a method of manufacturing the same, and more particularly, to a fiber floating in water having an oil coating layer on the outer layer and a method of manufacturing the same.

Floating fibers can be applied to various water applications. For example, waterborne fibers can be used in a variety of water applications, such as tubes, swimwear, boats, life jackets, boats, warships, and ropes.

In order for an object to float, it must have a lower specific gravity than water, or a large buoyancy must act on the object. In particular, buoyancy refers to the force received from under an object by the weight of water corresponding to its volume when an object is submerged by the Archimedes principle.

Except for polyolefin fibers, ordinary fibers do not float well in water because they have a higher specific gravity than water. Accordingly, it is necessary to maximize buoyancy in order to float the fiber with a higher specific gravity than water.

However, in the related art, although the specific gravity is higher than that of water, technology development of the fiber floating in the water due to buoyancy has not been achieved at all. In addition, in the prior art, the development of technology for the fibers floating in water having excellent wear resistance was not made at all.

The present invention is to solve the above problems, because by coating a buoyancy agent such as silicone oil on the surface of the core fiber to prevent water from penetrating into the core fiber to maximize the air layer formed inside the core fiber It is an object of the present invention to provide a fiber and a method for producing the same, which can have a great buoyancy and excellent wear resistance, so that buoyancy characteristics can be maintained for a long time.

In one aspect of the present invention for achieving the above object, the core fiber having a specific gravity greater than water; And a coating layer containing 99% or more of a buoyancy agent on the outer layer of the core fiber.

In one aspect of the invention, the process for producing a core fiber having a specific gravity greater than water; And providing a coating layer containing 99% or more of a buoyancy agent on the outer layer of the core fiber.

The present invention has the following effects.

First, the fiber according to the present invention is coated with a buoyancy agent such as silicone oil on the outer layer, so that water does not penetrate into the fiber and has a great buoyancy as it has an air layer that is maximized inside the fiber to float in water easily.

Second, the fiber according to the present invention can be maintained for a long time because the buoyancy characteristics are excellent due to the use of a buoyancy agent such as silicone oil.

Such floating fibers can be used in various water applications such as tubes, swimwear, boats, life jackets, ships, warships, ropes, and the like.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

As used in the present invention, 'buoyant' refers to an oil-based compound having a lipophilic property that helps to float an object having a specific gravity higher than water.

As used herein, the term 'core fiber' refers to any type of fiber, such as multifilament, monofilament, staples, air entangled yarns, twisted yarns, etc. formed in the coating layer.

Hereinafter, an embodiment of the fiber floating in the water of the present invention will be described in detail.

The present invention includes core fibers having a higher specific gravity than water. As such, the core fiber having a specific gravity higher than that of the water sinks in water as time passes.

Fiber floating in the water of the present invention includes a coating layer containing at least 99% of the buoyancy agent in the outer layer. Since the buoyancy agent is an oil system, it has a lipophilic property with little affinity with water having a large polarity. Accordingly, the fiber coated on the outer layer of the buoyancy agent has the maximum buoyancy because water does not penetrate into the fiber and the air layer inside the fiber is not lost by the water. The fiber having a large buoyancy as described above has a specific gravity higher than that of water, but when it enters the water, it is floated in water because a large buoyancy is applied from below.

In order to maximize the buoyancy more, the coating layer may preferably comprise at least 99.9% buoyancy. In addition, in order to further maximize the buoyancy, the coating layer may preferably include at least 99.99% buoyancy agent. That is, when the coating layer is made of a buoyancy close to 100% because it can completely prevent the penetration of water, the fiber containing it has the maximum buoyancy.

In addition, the coating layer does not include a surfactant to maximize buoyancy. If the surfactant is included in the coating layer, the buoyancy decreases as the volume of the fiber in water decreases because water may penetrate into the fiber through the surfactant.

Silicone oil may be used as the buoyant having the above characteristics. Since the silicone oil is smooth, it has excellent friction resistance and fluidity, can easily form a thin film, and can be used in harsh environments because it has strong bonding strength and can be used in harsh environments, can have various viscosities, and can be used at a wide range of temperatures.

Such silicone oils can flow more easily than hydrocarbon oils of equal viscosity and can form a complete coating of thin films.

The silicone oil may comprise a polysiloxane compound. The polysiloxane compound may have a number average molecular weight of 500 to 50,000, if it has a molecular weight in this range may have an optimum viscosity. For example, the polysiloxane may be polydimethylsiloxane, polydibutylsiloxane, polymethylphenylsiloxane, or the like.

The core fiber may comprise aramid fiber.

Generally, wholly aromatic polyamides, collectively referred to as aramids, include para-aramids and meta-aramids having a structure in which the benzene rings are connected linearly through an amide group (CONH). Para-based aramis have excellent properties such as high strength, high elasticity, and low shrinkage.The 5mm thick thin thread manufactured therefrom has a strong strength enough to lift 2 tons of cars and is used for bulletproof applications. It is used in a variety of applications in the high-tech industry in the aerospace field. In addition, aramid is carbonized at 500 ° C or higher, and therefore has been in the spotlight in fields requiring high heat resistance.

Such aramid fibers may have a tensile strength of at least 20 g / d and an elastic modulus of at least 300 g / d. Such aramid fibers can be utilized in various fields requiring high strength and high heat resistance, such as bulletproof life suits, ropes, warships, and boats.

Fibers floating in the water of the present invention may be in contact with the surface of the distilled water when left for 30 days after falling at a height of 5 cm from the surface of distilled water at 25 ℃. In other words, the fiber floating in the water of the present invention has high buoyancy, so that when it is dropped in water, the fiber does not sink in water and is excellent in durability, so that it may be in contact with the surface of distilled water without sinking even if left in water for a long time.

Fibers floating in the water of the present invention may have a frictional recovery of 10000 or more until the cutting time measured by rubbing the fibers and the fiber at a load of 0.4 g / d. Such high friction recovery fibers can be used for marine ropes and the like which require excellent wear resistance.

Next, a method for producing a fiber floating in water according to an embodiment of the present invention.

First, a core fiber having a specific gravity higher than that of water is produced.

The core fiber may include all fibers having a specific gravity higher than water, such as polyester fibers, polyamide fibers, and polyacrylic fibers.

In particular, the core fibers may comprise aramid fibers.

The aramid fibers are prepared by dissolving the aromatic diamine in a polymerization solvent to prepare a mixed solution and polymerizing by adding an aromatic dieside to the prepared mixed solution, and preparing the aramid polymer by dissolving the aramid polymer in a sulfuric acid solvent to prepare a spinning dope and spinning it, It can be produced by coagulation and washing with water.

Next, a coating layer containing 99% or more of a buoyancy agent is formed on the outer layer of the core fiber.

The coating layer may have a content of 0.1 to 5.0% by weight based on the weight of the core fiber. If the content of the coating layer is less than 0.1% by weight, the content of the buoyancy agent is too low to obtain a high buoyancy and the coating layer is too thin may damage the buoyancy by friction for a long time. On the other hand, when the content of the coating layer exceeds 5.0% by weight, buoyancy may not be improved any more and tensile strength and bending strength may be lowered.

The process of imparting a buoyancy agent to the core fiber may be performed by various methods. For example, a buoyancy agent can be provided to a core fiber surface through methods, such as a kiss roll system, a jet nozzle system, and a immersion system.

The manufacturing process of the core fiber and the process of forming a coating layer on the outer layer of the core fiber may be performed continuously in the same apparatus. For example, during the manufacturing process of the core fiber consisting of a step of preparing a spinning dope using a polymer and then spinning the spinning dope through a spinning nozzle and then solidifying the spun spinning dope to produce a filament and winding up the obtained filament. In addition, a process of applying a buoyancy agent to the solidified filament before the winding process may be included.

As such, when the coating layer is formed on the outer layer of the core fiber in the manufacturing apparatus of the core fiber, the economic efficiency may be improved by simplifying the manufacturing apparatus, increasing the yield, and reducing the manufacturing cost.

The coating layer may not contain any surfactant such as a softening agent. However, core fibers in which only the buoyant such as silicone oil is applied to the outer layer without the softening agent may be frequently cut off due to severe friction during the manufacturing process, and thus, the production of the floating fiber may be difficult.

Thus, in order to prevent cutting due to severe friction during the fiber manufacturing process, aramid fibers can be used as the core fiber of the present invention. The aramid fiber has a high tensile strength and can be manufactured even at high speed because it can withstand friction without severe cutting even under severe friction.

In the case of using the aramid fibers it can be produced fibers floating in water through the following process.

First, an aramid polymer is prepared by dissolving an aromatic diamine in a polymerization solvent to prepare a mixed solution and adding the aromatic dieside to the prepared mixed solution to polymerize it.

Spinning dope is prepared by dissolving the aramid polymer in about 100% concentrated sulfuric acid solvent.

After spinning the spin dope using a spinneret, a filament is formed by coagulating in a coagulation bath in which a coagulating solution is received through an air gap.

When the radiation passed through the spinneret passes through the coagulating solution, the sulfuric acid in the emission is removed and filaments are formed. When sulfuric acid is rapidly removed from the surface, the surface is solidified before the sulfuric acid contained therein escapes. Since the problem of the uniformity of the filament may be lowered, sulfuric acid is added to the coagulating solution in order to prevent sulfuric acid from escaping rapidly from the surface of the radiant.

Next, sulfuric acid remaining in the obtained filament is removed. Sulfuric acid used in the manufacture of the spinning dope can remain but is not completely removed, although most of the emissions are passed through the coagulation bath. Moreover, when sulfuric acid is added to the coagulation liquid of a coagulation tank in order to make sulfuric acid escape | emit uniformly from a effluent, there is a high possibility that sulfuric acid will remain in the filament obtained. Since the amount of sulfuric acid remaining in the filament may adversely affect the aramid fiber properties no matter how small the amount, it is very important to completely remove the sulfuric acid remaining in the filament. Sulfuric acid remaining in the filament may be removed through a washing process using water or a mixed solution of water and an alkaline solution. The washing process may be carried out in a multi-step process, for example, after washing the filament containing sulfuric acid first with an aqueous caustic solution (caustic solution), the caustic soda thinner than the first aqueous caustic soda solution Secondary washing with an aqueous solution can be carried out.

Subsequently, the washed filaments are heat treated.

The heat treatment process may be performed after adjusting the moisture content of the filament. The step of adjusting the moisture content of the filament may be carried out by winding the filament on a predetermined dry roll. At this time, the moisture content of the filament can be adjusted by adjusting the time that the filament is in contact with the drying roll, or by controlling the temperature of the drying roll.

The heat treatment process may be performed after applying a buoyancy agent to the dried filament. That is, by applying the buoyancy agent to the filament having a low moisture content on the surface through the drying process it is possible to prevent the moisture contained in the buoyancy agent.

The process of treating the buoyant to the filament may be performed using a kiss roll or a spray nozzle.

The heat treatment process may be performed by winding a predetermined heated roll, and may be controlled by changing the contact time of the aramid filament and the heated roll or the temperature of the roll.

Subsequently, the heat treated aramid filament can be wound in a bobbin driven by a winder to complete the aramid fiber floating in water.

Meanwhile, the winding process may be performed after treating the buoyant to the heat treated aramid filament. That is, as described above, the aramid filament can be treated with the buoyancy agent immediately before the winding process, without treating the aramid filament with the buoyant agent before the heat treatment step. In particular, since silicone oil has affinity with aramid filaments, it may not need to undergo a separate heat treatment process.

In this way, in the aramid filament manufacturing apparatus to give a buoyancy agent to the surface of the aramid filament to form a coating layer to produce a fiber floating in the water manufacturing apparatus can be omitted, the production volume is increased and the economic cost can be improved as the manufacturing cost is reduced have.

However, as described above, the process of preparing the aramid filament and the process of forming the coating layer by applying a buoyancy agent to the outer layer of the aramid filament may not be continuously performed in the same apparatus, but may be performed through a separate apparatus. For example, a bobbin wound with aramid filament is mounted on a fixed part, and after dissolving the aramid filament from the bobbin mounted on the fixed part, a buoyant is applied to the dissimilar aramid filament surface using a kiss roll and dried to form a coating layer. The aramid fibers floating in water can be prepared through the process. However, in the case of manufacturing aramid fibers floating in the water through such a separate process, by installing a large-scale device may be economical because the investment cost is high and the production speed is low.

Aramid fibers floating in water prepared as described above for marine applications that require high tensile strength and wear resistance because friction recovery may have more than 10000 until the cut measured by rubbing the fiber and the fiber at a load of 0.4 g / d It can be used in a variety of fields, such as ropes, life jackets, warships, boats and boats.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. However, the following examples are only intended to help the understanding of the present invention, and the scope of the present invention is not limited thereto.

Example  One

CaCl ₂ was added to N-methyl-2-pyrrolidone (NMP) to prepare a polymerization solvent, and then para-phenylenediamine was dissolved in the polymerization solvent to prepare a mixed solution.

Thereafter, while stirring the mixed solution, terephthaloyl dichloride of the same mole as the para-phenylenediamine was added to the mixed solution in two portions to produce a poly (paraphenylene terephthalamide) polymer.

Thereafter, water and NaOH were added to the polymerization solution containing the polymer to neutralize the acid. Thereafter, after pulverizing the polymer, the polymerization solvent contained in the aromatic polyamide polymer was extracted using water, and finally, the aromatic polyamide polymer was obtained through a dehydration and drying process.

Thereafter, the obtained aromatic polyamide polymer was dissolved in 99% concentrated sulfuric acid to prepare a spinning dope. The polymer concentration in the spinning dope was adjusted to 20% by weight. Thereafter, the spinning dope was spun through a spinneret, passed through an air layer, and coagulated while passing through a coagulation bath containing a sulfuric acid aqueous solution and a coagulation tube below the coagulation bath to prepare a filament. Thereafter, the filament was washed with water to remove residual sulfuric acid.

Thereafter, the filaments were dried so as to be wound around a drying roll so that the water content of the filament was 5% by weight or less. Thereafter, the filaments were brought into contact with a kiss roll having a buoyancy agent containing 99.99% by weight of silicone oil (manufacturer, trade name) on the surface. At this time, the coating amount was adjusted so that the silicone oil corresponding to 2% by weight relative to the filament is coated on the filament.

Thereafter, the filaments were brought into contact with a heat treatment roll at 200 ° C. for heat treatment, and then wound up to obtain aramid fibers.

Example  2

In Example 1 described above, aramid fibers were obtained in the same manner as in Example 1 except that a buoyant having a content of silicone oil of 99.9% by weight was used.

Example  3

In Example 1 described above, aramid fibers were obtained in the same manner as in Example 1, except that a buoyant having a content of silicone oil of 99.0% by weight was used.

Comparative example

In Example 1, the composition liquid consisting of 2.0% by weight of the sorbitol-based polyglycidyl ether surfactant and 98.0% by weight of the silicone oil buoyant was used without using the buoyant containing 99.99% by weight of the silicone oil. Aramid fibers were obtained in the same manner as in Example 1 except that the filaments were coated to form a coating layer.

Physical properties of the aramid fibers obtained by the above Examples and Comparative Examples was measured by the following method and the results are shown in Table 1.

Measurement of Floating Aramid Fibers in Water

Floating degree of aramid fiber in the water of 25 ℃ at a height of 5 cm from the surface of distilled water at 25 ℃ and left for 30 days after leaving the sample in contact with the surface of distilled water buoyancy It was judged that.

Aramid  Wear resistance measurement of fiber

The abrasion resistance of the aramid fibers was a vertical movement of the load in one rotation of the crank and the friction between the fibers while moving the fiber as a sample at this time, it was determined by measuring the rotation speed until the fiber is cut. The samples were prepared by drying for 1 hour at a relative humidity of 70% and a temperature of 20 ° C.

division Buoyancy Wear Resistance (Recovery) Example 1 has exist 18000 Example 2 has exist 15000 Example 3 has exist 13000 Comparative example none 12000

As shown in Table 1, it can be seen that the aramid fiber according to the present invention floats in water for a long time as it has a great buoyancy, whereas the aramid fiber having a coating layer containing a surfactant does not have a great buoyancy You can see that it doesn't float.

In addition, it can be seen that the aramid fiber according to the present invention is very excellent in wear resistance as it contains a silicone oil. Accordingly, the waterborne fibers of the present invention will be applicable to a variety of water applications in which severe friction occurs frequently, requiring wear resistance.

Claims (13)

Core fibers with greater specific gravity than water; And
Fibers floating in water comprising a coating layer containing at least 99% buoyancy in the outer layer of the core fiber. The method of claim 1,
The coating layer is floating in water, characterized in that containing at least 99.9% buoyancy agent. The method of claim 1,
The coating layer is floating in water, characterized in that it does not contain a surfactant. The method of claim 1,
The buoyant agent is a fiber floating in water, characterized in that the silicone oil. The method of claim 1,
And the core fiber comprises aramid fiber. The method of claim 1,
The fiber which floats in water is dropped in a height of 5 cm from the surface of distilled water at 25 ℃ left for 30 days and then in contact with the surface of the distilled water. The method of claim 1,
The fiber which floats in water is a fiber floating in water, characterized in that the friction recovery until the cut off after the friction with the fiber at a load of 0.4 g / d is more than 10000. Preparing a core fiber having a specific gravity greater than that of water; And
A method for producing a fiber floating in water comprising the step of forming a coating layer containing 99% or more of the buoyancy in the outer layer of the core fiber. The method of claim 8,
The process of manufacturing the core fiber,
Preparing a spin dope;
Spinning the spinning dope through a spinning nozzle; And
The method of producing a fiber floating in water comprising the step of coagulating the spun spinning dope to produce a filament. The method of claim 8,
Process for forming a coating layer on the outer layer of the core fiber is a method of producing a fiber floating in water, characterized in that carried out continuously in the apparatus for producing the core fiber. The method of claim 8,
The process of manufacturing the spinning dope,
Preparing an aromatic polyamide polymer; And
A method for producing a fiber floating in water comprising the step of dissolving the aromatic polyamide polymer in sulfuric acid. The method of claim 8,
The buoyancy agent is a method of producing a fiber floating in water, characterized in that the silicone oil. The method of claim 8,
The coating layer is a method of producing a fiber floating in water, characterized in that it has a content of 0.1 to 5% by weight.