KR101477113B1 - Prous fabriclike aramid oil-water separation sheet composition and manufacturing method for prous fabriclike aramid oil-water separation sheet using the same - Google Patents

Abstract

The present invention relates to a sheet composition for oil-water separation of porous, fibrous aramid and a method for preparing a sheet for oil-water separation of porous, fibrous aramid by using the sheet composition. More particularly, the present invention relates to a sheet composition for oil-water separation of porous, fibrous aramid and a method for preparing a sheet for oil-water separation of porous, fibrous aramid by using the same, wherein, the sheet composition has a porous property, hydrophobicity, and a magnetic property, and thus can be used to separate oil and water and to recover magnetic ingredients included in processing water.

Description

TECHNICAL FIELD [0001] The present invention relates to a porous fibrous aramid oil-water separating sheet composition and a porous fibrous aramid oil-water separation sheet using the porous fibrous aramid oil-

The present invention relates to a porous sheet-like aramid water-dispersible sheet composition and a method for producing porous sheet-like aramid water-dispersible sheet using the same. More particularly, The present invention relates to a porous fibrous aramid water-dispersible sheet composition which can be used for recovering a magnetic component and a porous fibrous aramid water-dispersible sheet using the same.

Generally, polyamide-based synthetic resins are classified into aliphatic polyamides and aromatic polyamides. Aliphatic polyamides are generally known under the trade name Nylon, and aromatic polyamides are known under the trade name Aramid.

The aliphatic polyamide. Especially, nylon 6 and nylon 6,6 are the most common thermoplastic engineering plastics, and they are used not only as a fiber but also as a molding material in various fields. The nylon resin used in the molding industry is made of reinforced plastics which is reinforced with mineral or glass fiber to improve mechanical properties such as elasticity and lowering the price to have improved flame retardancy and impact resistance.

Aromatic polyamides, developed in the 1960s, were developed to improve the heat resistance of nylon, an aliphatic polyamide. Aromatic polyamides, well known for their trade names such as Nomex and Kevlar, And has excellent heat resistance and high tensile strength which can be used for fibers such as cord.

A typical aliphatic polyamide is a synthetic resin having an aliphatic hydrocarbon bonded between amide groups, and an aramid is a synthetic resin having an amide bond having 85% of benzene groups bonded to two aromatic rings between amide groups. The aliphatic hydrocarbon of the aliphatic polyamide easily undergoes molecular motion when heat is applied, whereas the benzene ring of the aromatic polyamide is stable to heat and has a high elastic modulus because the molecular chain is rigid and molecules do not easily move even when heat is applied. And there are many differences in characteristics.

The aromatic polyamide is classified into a para-aramid and a meta-aramid. The para-aramid is Kevlar developed by DuPont. The para-aramid is the benzene ring bound to the amide group at the para position. Since the molecular chain is very stiff and has a linear structure, it has a very high strength and a particularly high elastic modulus, and thus has a very excellent shock absorbing performance. It is used in armor, bulletproof helmet, safety gloves, boots and fire extinguisher. It is used for sports equipment such as sticks, fishing rods and golf clubs, and also for industrial use such as FRP (Fiber Reinforced Plastic) and asbestos replacement fibers. Meta-aramid is a representative example of Nomex developed by DuPont and Conex developed by Dejin. The meta-aramid is a combination of benzene ring and amide group at the meta position. Its strength and elongation are similar to ordinary nylon, but it has very good heat stability. It is light and sweat-absorbing compared to other heat resistant materials. have. In the early days, the color was limited to a few, but recently it has been made in various colors including fluorescent colors. It is used as heat-resistant clothes for fire-fighting uniforms, uniforms for racing motorists, uniforms for astronauts, and work clothes.

As described above, the aramid sheet which can be easily used for drying or ironing laundry by using meta-aramid fibers having different fineness is disclosed in Korean Patent No. 10-1226225 (Apr. .

On the other hand, liquid-repellent, gas-permeable porous materials that repel water, oil and other low surface tension fluids are used in waterproof and waterproof tent fabrics, breathable lining for gloves and clothing, breathable backsheet for diapers and disposable products, and biological indicators Protection cover and the like. The value of these porous materials lies in their ability to repel a wide range of fluids while moving water vapor at high speed through the material.

Commercial fabrics are known in which the hydrophobic liquid or polymeric material is treated with silicone or fluorocarbon oil or resin to repel the fluid and permeate the water vapor. While these materials can provide adequate repellency with good water vapor permeability, their durability is variable since some of the barrier treatment, particularly the treatment for the porous substrate, is broken when it is rubbed, contacted, abraded or otherwise refracted. In addition, these materials are problematic in that the repellency can not be maintained for a long period of time because they are easily contaminated by the sweat residues in the blocking treatment part when they are exposed to perspiration, typically in garment use.

As a result, it is urgently required to develop a water-borne sheet which can be used for separation of oil and water due to its porosity and hydrophobicity, and which is not easily broken due to its high mechanical strength.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a porous fibrous aramid which can be used for separating oil and water, And to provide a method for producing a porous fibrous aramid water-dispersible sheet using the same.

The present invention relates to a method for producing an aramid flock, comprising: a first solution containing an aramid floc, carbon nanotubes and magnetic particles; And a second solution containing short staple fibers in a volume ratio of 1: 1 to 5: 1.

According to a preferred embodiment of the present invention, the first solution contains 10 to 300 parts by weight of carbon nanotubes, 10 to 200 parts by weight of magnetic particles, 10 to 300 parts by weight of base catalyst, and 5,000 to 20,000 parts by weight Parts by weight of solvent.

According to another preferred embodiment of the present invention, the aramid flock may comprise at least one of the group consisting of a meta-aramid polymer, a para-aramid polymer, and a meta-para-aramid polymer.

According to another preferred embodiment of the present invention, the base catalyst is selected from the group consisting of Potassium Hydroxide, Potassium tert-butoxide, Potassium phosphate, Potassium permanganate, Potassium sulfate and sodium hydroxide, and the solvent is at least one selected from the group consisting of dimethyl formamide, dimethyl sulfoxide and dimethylacetamide, And the like.

According to another preferred embodiment of the present invention, the second solution may have a dispersion of staple fibers having a dispersion degree of 50 to 100%.

According to another preferred embodiment of the present invention, the carbon nanotubes may be unmodified.

According to another preferred embodiment of the present invention, the magnetic particles may be at least one kind selected from the group consisting of nickel, iron, cobalt, iron oxide and cobalt oxide.

The present invention also relates to a method for producing a porous fibrous aramid water-dispersible sheet composition, Drying the mixed solution to prepare a sheet; And heat-treating the sheet to produce an aramid fibrous sheet; The present invention provides a method for producing a porous fibrous aramid water-dispersible sheet.

According to a preferred embodiment of the present invention, the mixing may be performed at 500 to 5,000 rpm for 30 minutes to 1 hour.

According to another preferred embodiment of the present invention, the heat treatment may be performed at 100 to 300 ° C for 30 minutes to 1 hour.

Further, the present invention relates to a polymeric staple fiber; Carbon nanotubes; Magnetic particles; And an aramid flock, wherein the porous fibrous aramid water-dispersible sheet having magnetic properties is provided.

According to a preferred embodiment of the present invention, the short staple fiber may be a sheath / core fiber.

According to another preferred embodiment of the present invention, the short staple fibers may be at least one selected from the group consisting of polyethylene / polyethylene terephthalate (PE / PET) and copolymerized polyethylene terephthalate / polyethylene terephthalate (CO-PET / PET) .

According to another preferred embodiment of the present invention, the fibrous aramid water-dispersible sheet comprises 10 to 300 parts by weight of carbon nanotubes, 10 to 200 parts by weight of magnetic particles and 10 to 100 parts by weight of polymeric monomers per 100 parts by weight of the aramid flock Fibers.

According to another preferred embodiment of the present invention, the carbon nanotubes may be unmodified.

According to another preferred embodiment of the present invention, the carbon nanotubes may have an average diameter of 1 to 20 nm and an average length of 1 to 300 μm.

According to another preferred embodiment of the present invention, the magnetic particles may include at least one of the group consisting of nickel, nickel, iron, cobalt, iron oxide and cobalt oxide.

According to another preferred embodiment of the present invention, the magnetic particles may have an average diameter of 0.001 to 200 탆.

According to another preferred embodiment of the present invention, the aramid flock may comprise at least one of the group consisting of a meta-aramid polymer, a para-aramid polymer and a meta-para-aramid polymer.

According to another preferred embodiment of the present invention, the polymeric staple fibers may have an average length of 3 to 15 mm and a fineness of 0.3 to 15 denier.

According to another preferred embodiment of the present invention, the porous fibrous aramid water-dispersible sheet may have a weight increase rate of 35 to 60% after oil immersion for 5 minutes.

According to another preferred embodiment of the present invention, the porous fibrous aramid water-dispersible sheet may have a contact angle of 105 to 180 째.

According to another preferred embodiment of the present invention, the porous fibrous aramid water-dispersible sheet may have a porosity of 70 to 95%.

Hereinafter, terms of the present invention will be defined.

The term "flock " of the present invention means fibers of shorter length than short fibers, the length of the flocs is from about 0.5 to about 15 mm and the diameter is from 4 to 50 μm, preferably from 1 to 12 mm And the diameter may be 8 to 40 [mu] m. Aramid floc can be produced by cutting aramid fibers to short lengths without significant or optional fibrillization, such as those produced by the methods described in U.S. Patent Nos. 3,063,966, 3,133,138, 3,767,756 and 3,869,430 .

The present invention relates to a porous fibrous aramid water-dispersible sheet composition which can be used for separation of oil and moisture with its porous and hydrophobic properties and which can be used for recovering a magnetic component contained in treated water with magnetism and a porous fibrous aramid water- There is an effect of providing a sheet manufacturing method.

FIG. 1 is a flowchart showing a method for producing a sheet for porous fibrous aramid water hydration according to a preferred embodiment of the present invention.
2 is a SEM photograph of the surface of the porous aramid sheet prepared in Comparative Example 1. Fig.
3 is a cross-sectional SEM photograph of the porous aramid sheet prepared in Comparative Example 1. Fig.
4 is an electron micrograph of the surface of the porous aramid sheet prepared in Comparative Example 1. Fig.
5 is a photograph of the surface of the porous aramid sheet prepared in Comparative Example 2. Fig.
Fig. 6 is a photograph showing the method for measuring the hydrophobicity and the results of the hydrophobic measurement used in Experimental Example 1. Fig.
7 is a photograph showing the magnetic measurement method used in Experimental Example 2. Fig.
8 is a photograph of a cut porous aramid sheet for the experiment of measuring the magnetic and oil absorption rate in Experimental Example 2. FIG.
9 is a photograph showing an experiment for measuring the magnetic and oil absorption rate in Experimental Example 2. FIG.

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

As described above, the conventional porous substrate has a problem that it is easily broken by friction, contact, abrasion or other refraction.

Accordingly, the present invention provides a method of manufacturing a semiconductor device, comprising: a first solution containing aramid floc, carbon nanotubes and magnetic particles; And a second solution containing short staple fibers at a ratio of 1: 1 to 5: 5 by volume, in order to solve the above-mentioned problems. The present invention relates to a porous fibrous aramid water-dispersible sheet composition which can be used for separation of oil and water, which has porosity and hydrophobicity, and which can be used for recovering a magnetic component contained in treated water with magnetism and a porous fibrous aramid water- There is an effect of providing a sheet manufacturing method.

The present invention relates to a method for producing an aramid flock, comprising: a first solution containing an aramid floc, carbon nanotubes and magnetic particles; And a second solution containing short staple fibers in a volume ratio of 1: 1 to 5: 1.

The first solution is not particularly limited as long as the first solution includes aramid flocs, carbon nanotubes and magnetic particles and is usually added to the production of a fibrous aramid sheet. Preferably, the first solution is made of aramid flock, carbon nanotubes, magnetic particles, . ≪ / RTI >

The aramid flock of the present invention is not particularly limited as long as it is an amide floc which can be conventionally prepared and purchased, but preferably includes at least one of the group consisting of a meta-aramid polymer, a para-aramid polymer and a meta-para-aramid polymer .

As described above, when the aramid sheet was produced by using the aramid flock, which is not an aramid flock, by using the normal phase transfer method, as shown in Experimental Example 3, the weight increase rate even after oil immersion for 5 minutes It is difficult to use it as a sheet for separating oil and water and for separating magnetic component.

The meta-aramid polymer is not particularly limited as long as it is capable of being synthesized and / or commercially available, but is preferably a poly (metaphenylene isophthalamide), a poly (m-benzamide), a poly (m-phenylene isophthalate) Amide), poly (m, m'-phenylenebenzamide), and poly (1,6-naphthylene isophthalamide).

In addition, the para-aramid polymer is not particularly limited as long as it can be synthesized and / or commercially available, but is preferably poly (paraphenylene terephthalamide), poly (p-phenylene p, p'- Poly (p-phenylene 1,5-naphthylene dicarboxamide), poly (trans, trans-4,4'-dodecahydrobiphenylene terephthalamide), poly (Cinnamamide), poly (p-phenylene 4,8-quinolinedicarboxamide), poly (1,4- [2,2,2] -bicyclooctyleneterephthalamide), copoly (P-phenylene-4,4'-trans-stilbene carboxamide) and poly (p-phenylene acetylene dicarboxamide) ) May be included.

Further, the meta-para-aramid polymer is not particularly limited as long as it can be synthesized and / or commercially available, but may preferably include poly (metaphenylene terephthalamide).

The carbon nanotubes are not particularly limited as far as the carbon nanotubes can be conventionally purchased and / or manufactured. Preferably, unmodified carbon nanotubes can be used. More preferably, the carbon nanotubes are not modified, 20 nm and an average length of 1 to 300 占 퐉 may be used.

In general, carbon nanotubes added to a sheet or a separation membrane serve to enhance hydrophilicity by adding acid or plasma modified surface, but in the present invention, by using carbon nanotubes that are not physically and chemically modified, , The manufacturing cost and the cost reduction as well as the high hydrophobicity were maintained, and the effect of improving the water / water separation performance was confirmed.

If carbon nanotubes having an average diameter exceeding 20 nm are used, the tunneling distance between the carbon nanotubes may increase, which may result in a decrease in the oil adsorption capability.

If carbon nanotubes having an average length exceeding 300 mu m are used, there is a disadvantage in economical disadvantages due to difficulties in supplying.

In addition, the base catalyst contained in the first solution is not particularly limited as long as it is usually used in the production of an aramid sheet. Preferably, the base catalyst is selected from the group consisting of Potassium Hydroxide, Potassium tert-butoxide, Potassium Phosphate Potassium hydroxide, potassium phosphate, potassium permanganate, potassium sulfate, and sodium hydroxide.

In addition, the solvent contained in the first solution is not particularly limited as long as it is used in the production of the aramid sheet, but it is preferably used in the form of dimethyl formamide, dimethyl sulfoxide and dimethylacetamide And the like.

Further, the magnetic particles are not particularly limited as long as they are magnetic particles added to the magnetic sheet, but may preferably include at least one of the group consisting of nickel, iron, cobalt, iron oxide and cobalt oxide.

Further, the magnetic particles are not particularly limited as long as they can be added to the magnetic sheet, but may preferably include magnetic particles having an average diameter of 0.001 to 200 탆.

If magnetic particles having an average diameter of less than 0.001 탆 are used, it is economically disadvantageous and can not be easily handled. A sheet having a weak magnetic force is produced, which has a problem in recovering performance. When particles are used, uniform dispersion in the first solution is difficult due to the phenomenon of precipitation or the like, and problems such as partial dropout may occur after production into a sheet.

In addition, the content of the first solution is not particularly limited as long as it contains aramid flocs, carbon nanotubes, magnetic particles, a base catalyst and a solvent. Preferably, the amount of the first solution is 10 to 300 parts by weight per 100 parts by weight of the aramid flock Nanotubes, 10 to 200 parts by weight of magnetic particles, 10 to 300 parts by weight of a base catalyst and 5,000 to 20,000 parts by weight of a solvent.

If the amount of the carbon nanotubes is less than 10 parts by weight based on 100 parts by weight of the aramid flock, there may arise a problem that the oil absorption capacity is decreased. When the amount of the carbon nanotubes exceeds 300 parts by weight based on 100 parts by weight of the aramid flock, A problem may arise in that a nonuniform sheet such as a partial rejection is produced.

If 100 parts by weight of the aramid flock contains less than 10 parts by weight of magnetic particles, it may cause a problem of sheet recovery due to weak magnetic property, and may include magnetic particles exceeding 200 parts by weight based on 100 parts by weight of the aramid flock , There may arise a problem of precipitation without being dispersed in the solution.

If the amount of the base catalyst is less than 10 parts by weight based on 100 parts by weight of the aramid flock, there may arise a problem that the aramid polox is not uniformly dispersed and dissolved. When 100 parts by weight of the aramid flock is used, If the catalyst is included, the production process and economically disadvantageous problems such as the aramid floc being completely dissolved and not being made into the fibrous sheet or washing with excessive water to remove excess base catalyst may occur.

If the amount of the solvent is less than 5,000 parts by weight based on 100 parts by weight of the aramid flock, the problem may arise that the aramid polox is not uniformly dispersed and dissolved, and more than 20,000 parts by weight of the solvent may be added to 100 parts by weight of the aramid flock If it is included, an economical problem such as an excessive amount of solvent must be treated.

Further, the second solution is not particularly limited as long as it contains short staple fibers and is usually added to the production of an aramid sheet. Preferably, the second solution may be a solution in which low melting point short staple fibers are dispersed, It may be an aqueous solution in which the melting point polymer short fibers are dispersed.

The low melting point high molecular weight staple fiber is not particularly limited as long as it is usually used in the production of a sheet, but it may preferably be a high molecular weight staple fiber having a surface melting point of 90 to 200 ° C.

The solution in which the low-melting-point polymer staple fibers are dispersed is not particularly limited as long as the solution is a solution in which the low-melting polymer staple fibers are dispersed, but is preferably a solution in which short staple fibers having a surface melting point of 90 to 200 캜 are dispersed. The solution may be a solution having a degree of dispersion of 50 to 100%, more preferably an aqueous solution in which short staple fibers having a surface melting point of 90 to 200 DEG C are dispersed. The solution is an aqueous solution having a dispersion degree of 50 to 100% Lt; / RTI >

The "degree of dispersion" is a value obtained by assuming that staple fibers are present in a lump, that the dispersion is 0%, and that the staple fibers are dispersed in a solvent so that all the staple fibers are dispersed is 100% .

The polymer staple fiber is not particularly limited as long as it is a polymer staple fiber that can be usually manufactured and purchased, but it may be preferably a polyester staple fiber, more preferably a sheath / core polyester staple fiber More preferably at least one of the group consisting of polyethylene / polyethylene terephthalate (PE / PET) and copolymerized polyethylene terephthalate / polyethylene terephthalate (CO-PET / PET) in sheath / core form .

The short staple fibers are not particularly limited as long as they can be conventionally prepared and / or purchased, but they may preferably have an average length of 3 to 15 mm and a fineness of 0.3 to 15 denier.

If a short staple fiber having an average length of less than 3 mm is used, the adsorption area may be decreased due to the improved interfacial adhesion between the aramid fiber and the staple fiber, When short fibers are used, there is a problem that the mechanical strength is reduced due to nonuniform dispersion or the adsorption area is uneven and the oil absorption capacity is decreased.

If a staple fiber having a fineness of less than 0.3 denier is used, it is difficult to control the pore diameter due to the improved interfacial adhesion between the aramid fiber and the staple fiber. This may cause a decrease in the adsorption area, resulting in a decrease in the oil absorption capacity. , There is a problem that the mechanical strength is reduced due to nonuniform dispersion or the adsorption area is uneven and the oil absorption capacity is decreased.

The mixing ratio of the short staple fibers to water is not particularly limited, but may include 20,000 to 100,000 parts by weight of water per 100 parts by weight of the short staple fibers.

If the mixing volume ratio of the first solution and the second solution is less than 1: 1, that is, if the volume of the first solution is larger than the volume of the second solution, the uniform dispersion of the staple fibers in the aqueous solution may be difficult If the mixing ratio of the first solution and the second solution is more than 1: 5, the dispersion of the aramid flocs is weak and the flocculated flocs are formed, which may result in a decrease in the mechanical strength.

FIG. 1 is a flow chart showing a method for producing a porous fibrous aramid water-dispersible sheet according to a preferred embodiment of the present invention, and a method for producing porous fibrous aramid water-dispersible sheet according to the present invention will be described.

First, the porous fibrous aramid water-dispersible sheet composition is mixed to prepare a mixed solution (S1).

The mixing is not particularly limited so long as it is a method for mixing two or more kinds of liquid, but it can be preferably stirred.

The stirring may be carried out to uniformly disperse the aramid flocs, the carbon nanotubes, and the magnetic particles and the short staple fibers. The stirring speed is not particularly limited, but is preferably performed at 100 to 5,000 rpm for 5 to 30 minutes .

If the stirring speed is less than 100 rpm, it may be difficult to uniformly disperse the aramid flocs and the carbon nanotubes and the short staple fibers in the mixed solution, resulting in difficulty in producing a uniform sheet. If the stirring speed exceeds 5,000 rpm If you do, there may be disadvantages to manufacturing normal.

If the stirring time is less than 5 minutes, it may be difficult to uniformly disperse the aramid flocs and the carbon nanotubes and the polymer staple fibers in the mixed solution, so that it may be difficult to produce a uniform sheet. If the stirring time exceeds 30 minutes If you do, there may be disadvantages to manufacturing normal.

Next, the mixed solution is dried to prepare a sheet (S2).

The drying is not particularly limited as long as it is a condition for drying the aramid sheet, but it may preferably be dehydrated and dried, and more preferably, it may be dried at 20 to 60 ° C for 30 minutes to 1 hour.

If it is dried for less than 30 minutes, excessive water may be contained and it may be difficult to produce a sheet of the desired shape upon heat treatment, which may result in a problem of normal manufacturing. If drying is performed for more than 1 hour, Economic problems can arise.

If it is dried at a temperature lower than 20 캜, it may contain a large amount of water and thus it may be difficult to produce a sheet of the desired shape at the time of heat treatment. In case of drying at a temperature exceeding 60 캜, The sheet shape such as shrinkage may become uneven.

The thickness of the aramid fibrous sheet is not particularly limited as long as it is a typical thickness of the aramid sheet, but it may preferably be 50 to 500 탆 thick.

If an aramid sheet for water distillation is produced at a thickness of less than 50 탆, the mechanical strength is low, which may cause unfavorable problems such as bending to be deformed into various structures, and an aramid sheet for water- , The use of excess carbon nanotubes and magnetic particles is economically disadvantageous, and it is difficult to bend the magnetic nanotubes and the magnetic particles may be partially removed.

On the other hand, when the sheet is produced as described above, the weak bending property of the aramid is not improved, which is not suitable for use as a sheet.

Thus, there is an effect of providing a porous fibrous aramid water-dispersible sheet having the aramid fibrous sheet thermally treated after the production of the sheet, whereby the weak folding property of the aramid is remarkably improved.

The heat treatment is not particularly limited as long as it is a temperature condition of a heat treatment process used in a process for producing an aramid sheet. The heat treatment may preferably be performed at 100 to 200 ° C for 30 minutes to 2 hours, 100 MPa and 100 to 200 캜 for 30 minutes to 2 hours.

When treated at a temperature of less than 100 ° C., the interface strength between aramid fibers, carbon nanotubes, and magnetic particles and short fibers is weakened due to surface unmelting of short fibers, resulting in a problem of lowering the mechanical strength of the sheet. Deg.] C, there may arise a problem that flexibility and bending property are reduced due to reduction in porosity of the sheet.

If the heat treatment is performed for less than 30 minutes, the interface strength between the aramid fibers, the carbon nanotubes, and the magnetic particles and the short fibers is weakened due to the surface unmelting of the short fibers, which may cause a problem of lowering the mechanical strength of the sheet , When the heat treatment is performed for more than 2 hours, there may occur a problem that flexibility and bending property are reduced due to reduction of porosity of the sheet.

If the pressure is less than 5 MPa, the produced aramid water-dispersible sheet may not exhibit mechanical strength. If the pressure is higher than 100 MPa, There may arise a problem that the bending property is reduced.

In addition, the present invention relates to a polymeric staple fiber; Carbon nanotubes; Magnetic particles; And an aramid flock, wherein the porous fibrous aramid water-dispersible sheet having magnetic properties is provided.

The short staple fibers are not particularly limited as long as they can be conventionally prepared and / or purchased, but they may preferably have an average length of 3 to 15 mm and a fineness of 0.3 to 15 denier.

If a short staple fiber having an average length of less than 3 mm is used, there may arise a problem that an aramid fiber, a carbon nanotube, and an interfacial adhesion between magnetic particles and staple fibers are brittle due to strong interfacial adhesion, When the polymer short fibers exceeding 15 mm are used, the absorption performance may be reduced due to nonuniform dispersion and non-uniform pore increase.

If a polymeric staple fiber having a fineness of less than 0.3 denier is used, it may be difficult to control the pore due to the improved interfacial adhesion between the aramid fiber, the carbon nanotube, and the magnetic particles and the staple fiber, When the polymeric staple fibers exceeding denier are used, there is a problem that the absorption performance is decreased due to nonuniform dispersion and nonuniform pore increase.

Further, the short staple fibers are not particularly limited as long as they are short staple fibers that can be conventionally prepared and purchased, but they may be preferably short staple fibers, more preferably polyester staple fibers of sheath / core And more preferably at least one of the group consisting of polyethylene / polyethylene terephthalate (PE / PET) and copolymerized polyethylene terephthalate / polyethylene terephthalate (CO-PET / PET) in the form of a sheath / core.

The aramid flock of the present invention is not particularly limited as long as it is an amide floc which can be usually prepared and purchased, but preferably includes at least one polymer selected from the group consisting of meta-aramid polymer, para-aramid polymer and meta- para-aramid polymer can do.

The meta-aramid polymer is not particularly limited as long as it is capable of being synthesized and / or commercially available, but is preferably a poly (metaphenylene isophthalamide), a poly (m-benzamide), a poly (m-phenylene isophthalate) Amide), poly (m, m'-phenylenebenzamide), and poly (1,6-naphthylene isophthalamide).

In addition, the para-aramid polymer is not particularly limited as long as it can be synthesized and / or commercially available, but is preferably poly (paraphenylene terephthalamide), poly (p-phenylene p, p'- Poly (p-phenylene 1,5-naphthylene dicarboxamide), poly (trans, trans-4,4'-dodecahydrobiphenylene terephthalamide), poly (Cinnamamide), poly (p-phenylene 4,8-quinolinedicarboxamide), poly (1,4- [2,2,2] -bicyclooctyleneterephthalamide), copoly (P-phenylene-4,4'-trans-stilbene carboxamide) and poly (p-phenylene acetylene dicarboxamide) ) May be included.

Further, the meta-para-aramid polymer is not particularly limited as long as it can be synthesized and / or commercially available, but may preferably include poly (metaphenylene terephthalamide).

The carbon nanotubes are not particularly limited as far as the carbon nanotubes can be conventionally purchased and / or manufactured. Preferably, unmodified carbon nanotubes can be used. More preferably, the carbon nanotubes are not modified, 20 nm and an average length of 1 to 300 占 퐉 may be used.

Carbon nanotubes added to sheets or separation membranes generally serve to increase the hydrophilicity by adding acid or plasma modified surface, but in the present invention, by manufacturing using carbon nanotubes that are not physically and chemically modified, The surface of the carbon nanotubes, surface defects, hydrophilization, and the like, thereby maintaining the inherent hydrophobicity of the carbon nanotubes and improving the oil absorption performance.

If carbon nanotubes having an average diameter exceeding 20 nm are used, the tunneling distance between the carbon nanotubes may increase, which may result in a decrease in the oil adsorption capability.

If carbon nanotubes having an average length exceeding 300 mu m are used, there is a disadvantage in economical disadvantages due to difficulties in supplying.

The magnetic particles serve to recover a magnetic sheet, which is inserted into the sheet and adsorbed with oil or a heavy metal component, by magnetic force. The magnetic particles are not particularly limited as long as they are magnetic particles normally added to the magnetic sheet, but nickel, Iron oxide, and cobalt oxide.

Further, the magnetic particles are not particularly limited as long as they can be added to the magnetic sheet, but may preferably include magnetic particles having an average diameter of 0.001 to 200 탆.

If magnetic particles having an average diameter of less than 0.001 탆 are used, economical disadvantages may arise and handling may not be easy, magnetic sheets having weak magnetic properties may be produced, problems in recovering performance may occur, It is difficult to uniformly disperse in the first solution due to the phenomenon of precipitation and the like, and problems such as partial elimination after the production into a sheet form may occur.

The thickness of the aramid fibrous sheet is not particularly limited as long as it is a typical thickness of the aramid sheet, but it may preferably be 50 to 500 탆 thick.

If the aramid water-dispersible sheet is produced at a thickness of less than 50 탆, the mechanical strength is low, which may cause unfavorable problems such as bending to be deformed into various structures, and the sheet for oil- , The use of excess carbon nanotubes and magnetic particles is economically disadvantageous, and it is difficult to bend the magnetic nanotubes and the magnetic particles may be partially removed.

In addition, the content of the porous fibrous aramid water-dispersible sheet is not particularly limited as far as it contains short staple fibers, carbon nanotubes, magnetic particles and aramid flocs, but is preferably 10 to 300 parts by weight per 100 parts by weight of the aramid flock 10 to 200 parts by weight of magnetic particles and 10 to 100 parts by weight of polymeric staple fibers.

If less than 10 parts by weight of the carbon nanotubes are contained in 100 parts by weight of the aramid flock, the oil-absorbing performance of the oil-water separating sheet may be lowered. If the amount of the carbon nanotubes exceeds 300 parts by weight based on 100 parts by weight of the aramid flock Carbon nanotubes, it is economically disadvantageous.

If the amount of the magnetic particles is less than 10 parts by weight based on 100 parts by weight of the aramid flock, the magnetic properties may decrease to cause problems in the recovery of the sheet, and the magnetic particles may contain more than 200 parts by weight based on 100 parts by weight of the aramid flock , Precipitation in the solution may occur, resulting in the problem of producing a non-uniform sheet.

If 100 parts by weight of aramid flock contains less than 10 parts by weight of short staple fibers, the oil absorption capacity may be reduced due to the decrease of the absorption area. If 100 parts by weight of the aramid flock is used, , The oil absorption capacity may be reduced due to uneven pore distribution.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[ Example ]

Example  One.

1 g of Aramid flock (Arawin, poly (metaphenylene terephthalamide), 2 denier, 6 mm) as a base catalyst, 1 g of potassium hydroxide (KOH, Daejung product), 0.33 g of multiwalled carbon nanotube (Hanwha Chemical, CM250) 1.0 g of magnetic particles (INCO, average diameter 2.6 占 퐉) was added to 100 g of dimethylacetamide (DMAC, Daqing product) as a solvent and mixed at 500 rpm for 30 minutes using a stirrer to prepare a first solution .

On the other hand, as the second solution, 0.5 g of short staple fiber of polyethylene terephthalate / polyethylene terephthalate copolymer (Eslon, CO-PET / PET staple fiber, 1.5 denier, 6 mm) was added to 300 L of water, A second solution was prepared by uniformly dispersing the polymer staple fibers in water using a magnetic stirrer.

Thereafter, 100 L of the first solution and the second solution were mixed to prepare a mixed solution. The mixed solution was stirred for 10 minutes at 2,000 rpm using a stirrer, poured into a vacuum flask containing a cellulose porous support, An aramid sheet was prepared. The prepared aramid sheet was dried at 25 ° C. for 30 minutes, and then subjected to a heat treatment under pressure at 170 ° C. and 20 MPa for 1 hour to prepare a porous fibrous aramid water-dispersible sheet.

Example  2.

A porous fibrous aramid water-dispersible sheet was prepared in the same manner as in Example 1, except that 3.0 g of nickel was used.

Example  3.

A sheet for porous fibrous aramid water-jet splitting was prepared in the same manner as in Example 1, except that 5.0 g of nickel was used.

Example  4.

A porous fibrous aramid water-dispersible sheet was prepared in the same manner as in Example 1, except that 10.0 g of nickel was used.

Comparative Example  One.

A solution containing 12 g of aramid, 2.0 g of carbon nanotubes (average diameter of 10 to 15 nm, average length of 200 m), 1 g of nickel magnetic particles (average diameter of 2.6 m) and 88 g of dimethylacetamide was uniformly mixed After casting at 25 캜 and using a 200 탆 coated knife, the sheet was prepared and immediately dipped in tap water at room temperature to induce phase separation. Thereafter, the film was immersed in running water for 24 hours to remove the remaining solvent, and then dried in an atmosphere at room temperature for 12 hours to produce an aramid sheet.

SEM photographs of the surface of the prepared porous aramid sheet were taken using a scanning electron microscope (SEM, SNE-3000M) and are shown in FIG. 2. FIG. 2A is a front surface photograph of the porous aramid sheet, This is a photograph of the back surface of the sheet. SEM photographs of cross sections of the prepared porous aramid sheets were taken using an electron microscope (SEM, SNE-3000M) and are shown in FIG. Further, the surface of the prepared porous aramid sheet was observed with a scanning electron microscope (EM, SNE-3000M), and FIG. 4A shows the result of 500 magnification and FIG. 4B shows the result of 1500 magnification.

As can be seen in FIGS. 2A to 3, the porous aramid sheet thus prepared was found to have a good pore formation to the extent that the pores were visually confirmed.

4A to 4B, it was confirmed that the nickel nanoparticles were bonded to the carbon nanotubes inside the prepared porous aramid sheet.

Comparative Example  2.

A porous fibrous aramid sheet was prepared in the same manner as in Example 1, except that nickel was not added.

5A is a photograph of the front surface of the porous aramid sheet, and FIG. 5B is a photograph of the surface of the back surface of the polyamide sheet. Fig. 5A is a photograph of the front surface of the porous aramid sheet, to be.

As can be seen from Figs. 5A to 5B, it was confirmed that the carbon nanotubes were present inside the prepared porous aramid sheet.

Experimental Example  1. Evaluation of hydrophobicity

Hydrophobicity and hydrophilicity of the porous aramid water-dispersible sheet prepared in Example 1 of the present invention were evaluated.

Specifically, hydrophobic and hydrophilic properties were evaluated by dropping ISOPAR-H (Isoparaffinic Hydrocarbon Solvent) or water on the porous aramid water-dispersible sheet prepared in Example 1. The evaluation results are shown in FIG.

As can be seen from FIG. 6, the porous aramid water-dispersible sheet of Example 1 was found to have low hydrophilicity due to no absorption of water and high hydrophobicity due to the absorption of the isoparaffinic hydrocarbon solvent.

Experimental Example  2. Contact angle  Measure

The contact angles of the porous fibrous aramid water-dispersible sheet prepared in Examples 1 to 4 and the porous aramid sheet prepared in Comparative Examples 1 and 2 were measured.

Specifically, the porous aramid sheet was immobilized on a contact angle meter (KRUSS, CAM DSA100S1) measurement plate, and water droplets were dropped thereon. The water droplet was dropped at a speed of 250 fps per second Were measured with a camera. The measured contact angle results are shown in Table 1 below.

Experimental Example  3. Measurement of magnetic and oil absorption rate

The magnetic and oil absorption rates of the porous fibrous aramid water-dispersible sheet prepared in Examples 1 to 4 and the porous aramid sheets prepared in Comparative Examples 1 and 2 were measured.

Specifically, the magnetic properties were measured using the magnets in the porous fibrous aramid water-dispersible sheet prepared in Examples 1 to 4 and the porous aramid sheets prepared in Comparative Examples 1 and 2, and the magnetic measuring method was shown in FIGS. 7a to 7b . Further, the measured magnetic properties are shown in Table 1 below.

The porosity of the porous fibrous aramid water-dispersible sheet prepared in Examples 1 to 4 and the porous aramid sheet prepared in Comparative Examples 1 and 2 was calculated using the following equation 1 with theoretical density and actual density . The porosity calculation results are shown in Table 1 below.

At this time, theoretical density = weight ratio of aramid × 1.38 + weight ratio of polymer short fibers × 1.35 + weight ratio of carbon nanotubes × 0.02 + nickel weight ratio × 8.90.

In addition, the porous fibrous aramid water-dispersible sheet prepared in Examples 1 to 4 and the porous aramid sheet prepared in Comparative Examples 1 and 2 were cut into a size of 5 mm x 5 mm and shown in Fig. In addition, the porous aramid sheet as shown in Fig. 9 was weighed and measured before and after immersion in a solution containing 8 g of water and 0.2 g of oil, and after 5 minutes of immersion The weight increase rate is shown in Table 1 below.

division Contact Angle (°) Porosity (%) Presence or absence of magnetism Weight Growth Rate (%) Example 1 108.1 76.88 In Magnetic 45.00 3 Example 2 107.5 81.27 In Magnetic 53.02 6 Example 3 110.9 83.15 In Magnetic 51.82 ± 2 Example 4 144.6 79.84 In Magnetic 44.49 ± 5 Comparative Example 1 102.1 92.31 No magnetism 23.46 ± 2 Comparative Example 2 100.0 60.71 No magnetism 47.46 ± 5

As can be seen in Table 1, the porous aramid sheet of Comparative Example 1 produced using a conventional aramid solution and the magnetic particle of Comparative Example 2 containing no nickel did not have magnetism, The sheet was confirmed to have magnetism.

Further, it was confirmed that the porous aramid water-dispersible sheet of the present invention had significantly higher oil absorption than the porous aramid sheet of Comparative Example 1 produced using a common aramid solution.

Further, it can be seen that the contact angle is decreased and the hydrophobicity is increased with the increase of the nickel content through the change of the contact angle of Examples 1 to 4. The hydrophobicity is comparable to that of Comparative Example 1 produced using a conventional aramid solution, Which is lower than that of the porous aramid sheet of Comparative Example 2 which does not contain nickel.

Thus, the porous fibrous aramid water-dispersible sheet of the present invention has magnetic property and high oil absorption rate, which is suitable for use in oil / water separation and magnetic material separation.

As can be seen from the Examples, Comparative Examples and Experimental Examples, the fibrous aramid sheet of the present invention has porosity and hydrophobicity and can be used for oil / water separation. Since the magnetic aramid sheet has magnetic properties, The present invention provides a porous sheet-like aramid water-dispersible sheet composition which can be used for receiving a porous fibrous aramid water-dispersible sheet.

Claims (20)

A first solution comprising an aramid floc, a carbon nanotube and magnetic particles; And a second solution containing short staple fibers in a volume ratio of 1: 5 to 5: 1. The method of claim 1, wherein the first solution comprises 10 to 300 parts by weight of carbon nanotubes, 10 to 200 parts by weight of magnetic particles, 10 to 300 parts by weight of a base catalyst, and 5,000 to 20,000 parts by weight of a solvent relative to 100 parts by weight of the aramid flock By weight based on the weight of the porous fibrous aramid. The sheet composition according to claim 1, wherein the aramid flock comprises at least one member selected from the group consisting of a meta-aramid polymer, a para-aramid polymer and a meta-para-aramid polymer. The method of claim 2, wherein the base catalyst is selected from the group consisting of potassium hydroxide, potassium tert-butoxide, potassium phosphate, potassium permanganate, Sodium hydroxide, and the solvent is at least one member selected from the group consisting of dimethyl formamide, dimethyl sulfoxide and dimethylacetamide, and at least one member selected from the group consisting of dimethyl formamide, dimethyl sulfoxide, Based on the total weight of the porous fibrous aramid water-splitting sheet composition. The sheet composition according to claim 1, wherein the second solution has a dispersion degree of 50 to 100%, wherein the polymer staple fibers are dispersed. The sheet composition according to claim 1, wherein the carbon nanotubes are not modified. The sheet composition according to claim 1, wherein the magnetic particles comprise at least one member selected from the group consisting of nickel, iron, cobalt, iron oxide and cobalt oxide. Mixing the sheet composition for porous aramid hydrolysis of any one of claims 1 to 7;
Drying the mixed solution to prepare a sheet; And
Heat-treating the sheet to produce an aramid fibrous sheet;
By weight based on the weight of the porous fibrous aramid. The method according to claim 8, wherein the mixing is performed at 500 to 5,000 rpm for 30 minutes to 1 hour. The method according to claim 8, wherein the heat treatment is performed at 100 to 300 ° C for 30 minutes to 1 hour. Staple fibers; Carbon nanotubes; Magnetic particles; And an aramid flock, wherein the porous fibrous aramid sheet has magnetic properties. 12. The sheet for porous aramid water dispersion according to claim 11, wherein the short staple fibers are sheath / core fibers. [14] The method of claim 12, wherein the polymer staple fibers include at least one selected from the group consisting of polyethylene / polyethylene terephthalate (PE / PET) and copolymerized polyethylene terephthalate / polyethylene terephthalate (CO-PET / PET) Wherein the sheet is made of porous fibrous aramid water. [12] The sheet for water-dispersible fibrous aramid according to claim 11, wherein the sheet for water-resisting fibrous aramid comprises 10 to 300 parts by weight of carbon nanotubes, 10 to 200 parts by weight of magnetic particles and 10 to 100 parts by weight of polymeric staple fibers per 100 parts by weight of aramid flakes Wherein the sheet is made of a porous fibrous aramid. 12. The sheet for porous fibrous aramid water dispersion according to claim 11, wherein the carbon nanotubes are not modified. 16. The sheet for porous fibrous aramid water dispersion according to claim 15, wherein the carbon nanotubes have an average diameter of 1 to 20 nm and an average length of 1 to 300 占 퐉. 12. The sheet for porous fibrous aramid water-dispersible powder according to claim 11, wherein the magnetic particles comprise at least one member selected from the group consisting of nickel, iron, cobalt, iron oxide and cobalt oxide. 18. The sheet for porous fibrous aramid water dispersion as claimed in any one of claims 11 to 17, wherein the porous fibrous aramid water-dispersible sheet has a porosity of 70 to 95%. 18. The sheet for porous fibrous aramid water dispersion as claimed in any one of claims 11 to 17, wherein the porous fibrous aramid water-dispersible sheet has a contact angle of 105 to 180 째. 18. The sheet for porous fibrous aramid water dispersion as claimed in any one of claims 11 to 17, wherein the porous fibrous aramid water-dispersible sheet has a weight increase rate after oil immersion for 5 minutes of 35 to 60%.

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