KR100786678B1 - Woven or knitted oil/water separating fabric material comprising plasma coating layer, and oil/water separating filter comprising the same - Google Patents

Abstract

A material using plasma surface treatment and an oil/water separating filter comprising the oil/water separating material are provided to have excellent separating properties of separating water and oil, excellent durability properties and to be used for diesel engine, gasoline engine and so on. An oil/water separating material includes a plasma coating layer which has a surface tension of 3.0x10^-2 J/m^2 to 7.2x10^-2 J/m^2, and which is formed on a surface of a fabric comprising a polymer fiber. The plasma coating layer is formed by performing a plasma vapor deposition process of a mixed gas comprising a fluorocarbon gas with 1 to 3 carbon atoms and hydrogen carbon gas with 1 to 3 carbon atoms at a volume ratio of 50:50 to 90:10. The polymer fiber is selected from the group consisting of a polyamide fiber, and a polyester fiber. The fabric is a woven or knitted fabric including a polymer fiber with an average diameter of 5 to 200 mum. The polymer fiber has depressions and prominences formed thereon. The oil/water separating material has a contact angle relative to water of 120 degrees or more.

Description

Woven OR KNITTED OIL / WATER SEPARATING FABRIC MATERIAL COMPRISING PLASMA COATING LAYER, AND OIL / WATER SEPARATING FILTER COMPRISING THE SAME}

1 is an oil separation mechanism of the oil separation material of the present invention.

Figure 2 is a schematic view of the fiber surface showing a fine concavo-convex structure of the oil-water separation material of the present invention.

Figure 3 is a schematic diagram comparing the separation characteristics according to the lotus structure.

Figure 4 is a separation test photograph of the oil and water separation material prepared according to Example 2.

Figure 5 is a separation test photograph of the oil and water separation material prepared according to Comparative Example 2.

[Industrial use]

The present invention relates to an oil and water separation material including a plasma coating layer, and an oil and water separation filter including the same, and more specifically, to an oil and water filter that can be used as a fuel filter for various automobiles and industrial machines equipped with a diesel engine, a gasoline engine, and the like. A separation material, and an oil / water separation filter comprising the same.

[Private Technology]

Recently, as environmental problems are greatly highlighted, separation materials for removing contaminated materials are attracting attention, and demand is increasing due to diversification of active research and use fields for high performance and application of separation material functions.

According to the purpose of the separation material, depending on the purpose of separation, the target fluid is classified into dry filtration, which is a gas, and wet filtration, where the target fluid is a liquid, and classified into gas / liquid and liquid / liquid according to the separation function.

Among the separated materials, the largest market is in the field of transportation of automobiles and the like, and the amount of use of various industrial liquid filters, dust filters, air filters, and masks is also increasing.

In the case of liquid / liquid separation or gas / liquid multifunctional separation materials, pulp filters accounted for more than 80% of the existing media market in developed countries such as the United States and Europe, but the market share of synthetic filter media is gradually increasing.

Silicon treated pulp media appeared to provide oil separation function, but there were many problems in satisfying consumers.In case of 5 or more layers of non-woven composite media, better dust removal ability, filtration efficiency and oil separation than conventional pulp media It is known as a product having performance.

As the demand for clean environment is increasing, in-depth research on separation material manufacturing technology with high functionality by surface treatment technology is required.

Plasma surface treatment technology improves the performance of a material by changing the surface of the polymer material or imparts new functions. The plasma surface treatment technology does not affect the bulk properties of the polymer material, and the modification of the physical and chemical properties of the surface It is expected that the processing of inexpensive materials into expensive materials will increase the importance of plasma surface treatment technology in the future industry.

Since the temperature of ions and neutral particles in the plasma is kept at a low temperature, it is possible to use most polymers that are easily damaged by heat as a base material. Can be functionalized.

The present invention is to solve the above problems, it is an object of the present invention to provide a material having oil and water separation characteristics using the plasma surface treatment.

Another object of the present invention is to provide an oil / water separation filter including the oil / water separation material.

In order to achieve the above object, the present invention provides a surface tension of 3.0 × 10 ⁻² J / m ² to 7.2 × 10 ⁻² J / on the surface of a woven fabric or knitted fabric including polymer fibers (hereinafter, referred to as a fabric). Provided is an oil and water separation material having a plasma coating layer of m ² is formed.

The present invention also provides an oil separation filter including the oil separation material.

The present invention also includes preparing a fabric comprising at least one polymer fiber selected from the group consisting of polyamide fibers and polyester fibers; And plasma treating the surface of the fabric under a mixed gas atmosphere containing fluorocarbon gas having 1 to 3 carbon atoms and hydrocarbon gas having 1 to 3 carbon atoms at a volume ratio of 50:50 to 90:10. It provides a method of manufacturing.

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

Generally, particulate water components present in oil components of hydrocarbon components such as diesel and gasoline are dispersed in a suspension state or emulsified in an emulsion state due to surface tension difference. The particle size of the water component has a diameter of about 0.1 μm to 10 μm, and it is difficult to visually identify it unless it is opaque because it exists in high concentration.

Water present in oil components, such as automotive fuel, is easy to remove in the case of large particle suspensions, but is difficult to remove when emulsified.

In the present invention, oil-water separation refers to the ability to separate and remove water components present in oil components such as automobile fuel.

Nowadays, the biggest problem of refined fuel is not solid contaminant, but water dispersed inside, and water in fuel shows big problems such as rusting engine parts, clogging, corrosion of fuel tank bottom, and microorganisms growing. have. A water content of around 100 ppm alone will prevent the fuel from functioning.

In general, there is a problem that the interfacial tension between the fuel and water falls to a level that is difficult to separate due to the emulsification by various additives added to the fuel.

Factors affecting oil separation performance include interfacial tension, viscosity, relative density, and temperature.

The interface between the two phases is called the interface, and the force that reduces the area of the interface is called the interface tension. Although it has almost the same meaning as surface tension, interfacial tension refers to a general case, and surface tension is used especially when one phase is gas phase.

Nonpolar hydrocarbon compounds such as diesel and gasoline have a surface tension of 2.18 × 10 ^-2 J / m ² (equivalent to 21.8 dyne / cm, at 25 ° C.), while water is 7.3 × 10 ^-2 J / m ² (73 dyne / It corresponds to cm, based on 25 ℃). In particular, the interfacial tension between these two components is a very important factor in the liquid / liquid phase separation, such as fuel / water, in which small droplets dispersed in the fuel by a process called coalescence are stable droplet size. This is because it can be easily separated by growing.

In this case, coalescence is a process in which two or more droplets gather to change into a larger volume of droplets and change in a direction having a small area. Thermodynamically, a plurality of particles are aggregated together to form one large particle due to the fusion of particle interfaces. It is an irreversible process.

In general, when the interfacial tension is 2.0 × 10 ^-2 J / m ^{2 or more} (corresponding to 20 dyne / cm, based on 25 ° C), the size of the coalesced particles is easily separated, but is emulsified by additives in the fuel. If the tension is less than 2.0 × 10 ⁻² J / m ² , the size of the coalesced particles is so small that it becomes very difficult to separate them.

The oil / water separation mechanism of the present invention maximizes the surface collision mechanism of the water particles and the fibrous particles.

In general, the particles present in the fluid have a characteristic of reaching the solid surface, that is, the surface wetting does not occur when colliding, and the contact time between the water particles and the fibrous surface is too long even when a surfactant is included. Short enough to be bound (Hartley, GS, & Brunskill, RT in Surface Phenomena in Chemistry and Biology , p. 214, JF Danielli Ed., Pergamon Press, 1958; Richard, D., & Qu, r ㅹ, D Europhys . Lett. 50, 769-775 (2000); Aussillous, P., & Qu ㅹ r ㅹ, D. Nature 411, 924-927 (2001).

However, in the case of continuous flow, collisions of water particles in the fuel accumulate and eventually behave according to the unity mechanism on the fiber surface as described above. In particular, a hydrophilic polymer fiber material such as polyester or polyamide may be used. This probability is large.

In the present invention, by coating a material having a very high interfacial tension with water on the fibrous surface and using it as an oil and water separating material, water particles in the fuel are continuously bound without being bonded to the fiber surface as shown in FIG. It is intended to implement a mechanism that allows the particles to continue to grow and subsequently coalesce with subsequently entering water particles so that the particles continue to grow and then separate downward by gravity.

In addition, in the present invention, as shown in FIG. 2, fine irregularities are formed on the surface of the fiber, and then a material having a very large interfacial tension with water is coated to maximize the repulsion of water particles on the surface of the fiber as shown in FIG. In this case, it is possible to implement a very good oil and water separation characteristics compared to the flat structure without fine irregularities.

The present invention relates to a technique for imparting oil-separation characteristics of the surface by plasma surface treatment of the surface of the fabric. Furthermore, the present invention relates to a technique of forming irregularities on the surface of the polymer fiber constituting the fabric through plasma etching, and then subjecting the surface of the fabric to plasma surface treatment to provide oil and water separation characteristics of the surface.

As a conventional technology for providing separation performance by plasma treatment, only a single function separation performance surface treatment technology that simultaneously imparts water repellency and oil repellency by plasma surface treatment using a fluorine-based gas has been mainly performed. There is a need for a surface treatment technology for providing the same multi-functional resolution.

The surface of lotus leaf or taro leaf having high water repellency shows excellent water repellency due to the characteristics of the cells forming the leaves. That is, the surface cells of these leaves are composed of submicron microstructures and multi-structures composed of relatively large irregularities (several μm) and waxy components (aliphatic compounds having 20 to 50 carbon atoms) of the outer epidermis.

The surface structure of the lotus leaf exhibits super water repellency of about 170 ° due to the combination of low surface energy of the surface wax component and unevenness of multiple structures. The water repellency imparting effect according to the physicochemical structure is called a lotus effect. Super water-repellent generally means that the contact angle with respect to water is 140 degree or more.

Oil-water separation material of the present invention is characterized in that the plasma coating layer is formed on the surface of the fabric containing the polymer fibers.

In particular, in order for the oil-water separation material of the present invention to have super water repellency without changing the oil repellency of the surface, the surface tension of the plasma coating layer should have a value between water and oil surface tension, and specifically, the surface tension of the plasma coating layer It is preferable that it is 3.0 * 10 <^-2> J / m <^2> -7.2 * 10 <^-2> J / m <^2> based on 25 degreeC.

In order for the plasma coating layer to have such a surface tension, the plasma coating layer may be formed by plasma vapor deposition of a mixed gas containing fluorocarbon gas having 1 to 3 carbon atoms and hydrocarbon gas having 1 to 3 carbon atoms at a volume ratio of 50:50 to 90:10. It is preferable to form, and the volume ratio of the mixed gas is more preferably 70:30 to 80:20. Since the surface tension of the plasma coating layer decreases as the content of the fluorocarbon gas increases in the mixed gas of the present invention, the surface tension of the coating layer may be controlled by controlling the content ratio of the mixed gas. Examples of the fluorocarbon gas include C ₂ F ₆ , or C ₃ F ₆ , and CH ₄ may be used as the hydrocarbon gas.

The fabric included in the oil and water separation material of the present invention preferably comprises a fiber selected from the group consisting of polyamide fiber, and polyester fiber, the polyamide fiber is nylon 6, nylon 6.6, nylon 4.6, nylon 6.10 More preferably, at least one polyamide fiber selected from the group consisting of nylon 6.12, nylon 11, nylon 12, and two or more copolymers thereof, wherein the polyester fiber is polyethylene terephthalate, polybutylene terephthalate, More preferably, it is at least one polyester fiber selected from the group consisting of polyethylene naphthalate, and two or more of these copolymers.

However, the type of the polymer fiber in the present invention is not limited only to the above examples, and polyolefin fiber, polyacrylonitrile fiber, polyether sulfone fiber, polyfluorine fiber, etc. having excellent oil resistance may be used alone or mixed as necessary. Can be.

The polymer fiber is preferably an average diameter of 5 to 200 ㎛, more preferably a fiber of an average diameter of 10 to 100 ㎛.

In order for the fabric to be suitable for a fuel filter, the size of the pores measured by the bubble point method is preferably 2 to 40 µm, more preferably 2 to 20 µm.

It is preferable that the said fabric is a woven fabric or a knitted fabric, and the woven and knitted structure of the said woven fabric or a knitted fabric is not specifically limited in the range which satisfy | fills the said conditions.

The oil-separated raw material of this invention which has the said structure is a contact angle with respect to water 120 degree phase, Preferably it is 140 degree or more, More preferably, it is 150 degree or more.

The oil-separated material may be used as a material for liquid / liquid separation, and more preferably, an in-tank filter, or a spin-on filter, for electric vehicles, and the like. It can be used as a diaphragm material for the electronics industry, and can be used as an aerosol separation material for industrial machinery, and an air purification material for clean rooms as a material for gas / liquid separation. In addition, it can be used for various industrial filters.

The oil-water separation material of the present invention can be manufactured by a method of forming a plasma coating layer on the surface of a fabric using a low temperature low pressure plasma surface treatment apparatus using an RF plasma source. However, the manufacturing method of the present invention is not limited only to the above contents.

The fabric may be made by spinning a fiber or one or more fibers selected from the group consisting of polyamide fibers and polyester fibers, and then weaving or knitting them. The fabrication process of the fabric is not particularly limited and is in accordance with conventional methods in the art.

However, the fabric preferably has a pore size of 2 to 40 μm, more preferably 2 to 20 μm, measured by the bubble point method.

In addition, the step of plasma treating the surface of the fabric is preferably carried out in a mixed gas atmosphere containing a fluorocarbon gas of 1 to 3 carbon atoms and a hydrocarbon gas of 1 to 3 carbon atoms in a volume ratio of 50:50 to 90:10. .

Conventional method related to plasma surface treatment technology is a method of simultaneously imparting water and oil repelling performance by forming a fluorine compound having a low surface tension on the surface of a substrate using a Fluorine series, that is, C ₂ F ₆ or C ₃ F ₆ gas This has been used mainly. Therefore, when a specific performance of the oil / water separation function such as a fuel filter for a diesel vehicle is required, existing technologies for simultaneously providing water / oil repelling performance are not suitable.

However, the plasma coating layer of the present invention is to adjust the surface tension of the plasma coating layer by appropriately adjusting the mixing ratio of the fluorocarbon gas and hydrocarbon gas.

In the plasma surface treatment technology of the present invention, it is preferable to use a plasma surface treatment apparatus using an RF plasma source, and the plasma surface treatment apparatus includes a vacuum chamber, a gas injection apparatus, and a power generator capable of reaching a constant degree of vacuum. good.

More specifically, the plasma surface treatment step includes the steps of i) placing the fabric in the chamber, and then setting the initial pressure in the chamber to 20-30 mTorr; ii) injecting the mixed gas into a chamber; iii) stabilizing the pressure in the chamber to 50 to 150 mTorr; And iv) plasma treatment with a power of 200 to 600 W.

In addition, in the manufacturing method of the present invention, in order to control the capillary force of the fabric, it is preferable to further comprise the step of forming an unevenness by plasma etching the surface of the fabric between the electrospinning step and the plasma treatment step.

Hereinafter, preferred embodiments of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

EXAMPLE

Example 1

A mixture of C ₂ F ₆ and CH ₄ under an initial vacuum of 20 mTorr, 300 W power, using a low temperature low pressure plasma apparatus for fabrics containing 100% Nylon 6 fibers having an average diameter of 100 μm and weighing 160 GSM. Volume ratio 90:10) The plasma surface treatment for 1 minute under the atmosphere.

The size of the treated sample was 200 × 150 mm, the sample was placed in a tray between the electrodes, and when the initial vacuum was reached, the mixed gas was injected at a flow rate of 70 sccm, and then the plasma surface treatment was performed at a working vacuum of 100 mTorr. .

Example 2

Plasma surface treatment was carried out in the same manner as in Example 1, except that the volume ratio of the mixed gas of C ₂ F ₆ and CH ₄ was 80:20.

Example 3

Plasma surface treatment was performed in the same manner as in Example 1 except that the volume ratio of the mixed gas of C ₂ F ₆ and CH ₄ was 70:30.

Example 4

Plasma surface treatment was performed in the same manner as in Example 1 except that the volume ratio of the mixed gas of C ₂ F ₆ and CH ₄ was 60:40.

Example 5

Plasma surface treatment was performed in the same manner as in Example 1 except that the volume ratio of the mixed gas of C ₂ F ₆ and CH ₄ was 50:50.

Example 6

The fabric of Example 1 was subjected to plasma surface treatment for 1 minute under an atmosphere of argon gas under an initial vacuum of 20 mTorr, 300 W power using a low temperature low pressure plasma apparatus to impart irregularities to the fiber surface, and then to the method of Example 2 The plasma surface treatment was performed.

Comparative Example 1

100% Nylon 6 fabric without any treatment was used as it is.

Comparative Example 2

Plasma surface treatment was carried out in the same manner as in Example 1 except that C ₂ F ₆ was used alone instead of using a mixed gas of C ₂ F ₆ and CH ₄ .

The surface of the sample prepared according to Examples 1 to 6 and Comparative Example 2 was analyzed by ESCA to summarize the components of the plasma coating layer detected in Table 1 below.

TABLE 1

division Gas used Peak area F _1s / C _1s C _1s F _1s Example 1 C ₂ F ₆ + CH ₄ (9: 1) 76.145 9.623 0.12637 Example 2 C ₂ F ₆ + CH ₄ (8: 2) 77.041 8.301 0.10775 Example 3 C ₂ F ₆ + CH ₄ (7: 3) 73.173 5.694 0.07781 Example 4 C ₂ F ₆ + CH ₄ (6: 4) 74.466 5.696 0.07649 Example 5 C ₂ F ₆ + CH ₄ (5: 5) 74.406 4.634 0.06228 Example 6 C ₂ F ₆ + CH ₄ (8: 2) 73.189 7.886 0.10236 Comparative Example 1 - 77.374 - - Comparative Example 2 C ₂ F ₆ 66.228 14.886 0.22477

In addition, the oil repellency of the samples prepared according to Examples 1 to 6 and Comparative Examples 1 and 2 were evaluated according to the AATCC-118 Oil Repellency Test method, and the water repellency was evaluated according to the AATCC-22 Water Repellency Test method.

In addition, the surface tension of 25 ℃ was measured according to the Pendent Drop Method.

The evaluation results are summarized in Table 2 below.

TABLE 2

division Use gas Water repellency Oil repellent Surface tension (10 ^-2 J / m ² ) Example 1 C ₂ F ₆ + CH ₄ (9: 1) Grade 2 Grade 4 3.2 Example 2 C ₂ F ₆ + CH ₄ (8: 2) Grade 2 X 4.2 Example 3 C ₂ F ₆ + CH ₄ (7: 3) Grade 2 X 4.8 Example 4 C ₂ F ₆ + CH ₄ (6: 4) Grade 2 X 5.4 Example 5 C ₂ F ₆ + CH ₄ (5: 5) Grade 2 X 6.3 Example 6 C ₂ F ₆ + CH ₄ (5: 5) Grade 2 X 4.0 Comparative Example 1 - X X 20.0 Comparative Example 2 C ₂ F ₆ Grade 2 3 ratings 2.8

As shown in Table 2, when the nylon 6 fabric used as the fuel filter medium is plasma treated for several minutes in a C ₂ F ₆ gas atmosphere to measure the oil repellency and water repellency by the above evaluation method oil repellency grade 3 grade, water repellency grade 2 or more grades are given.

In this case, as in Examples 1 to 5, when the nylon 6 fabric is plasma-treated in the presence of a mixture gas of C ₂ F ₆ gas and CH ₄ gas, it is confirmed that the water repellency of two or more grades is provided with little or no change in oil repellency. Can be.

In addition, as shown in Example 6 to give a fine surface irregularities and then plasma treatment in the presence of a mixture gas of C ₂ F ₆ gas and CH ₄ gas, it is confirmed that excellent water repellency is expressed even if less expensive C ₂ F ₆ gas is used Can be.

In order to visually prove the effect of the present invention, the water and oil repellency test photographs after dropping water and diesel fuel on the surface of the sample prepared according to Example 2 and Comparative Example 2 are shown in Figs. 4 and 5, respectively. It was.

As shown in FIG. 4, the oil-separation material prepared according to Example 2 of the present invention selectively penetrates only diesel fuel without penetrating water, while prepared according to Comparative Example 2 as shown in FIG. 2. The sample does not penetrate both water and diesel fuel and thus cannot serve as an oil separation filter.

 Oil and water separation material of the present invention is excellent in the separation of water and oil separation, and excellent oil durability, can be used as a fuel filter of various automobiles and industrial machines equipped with diesel engine, gasoline engine, etc. .

Claims (8)

An oil-separated material having a plasma coating layer having a surface tension of 3.0 × 10 ⁻² J / m ² to 7.2 × 10 ⁻² J / m ² formed on a surface of a fabric including polymer fibers. The method of claim 1, The plasma coating layer is an oil-and-water separation material formed by plasma vapor deposition of a mixed gas containing fluorocarbon gas having 1 to 3 carbon atoms and hydrocarbon gas having 1 to 3 carbon atoms in a volume ratio of 50:50 to 90:10. The method of claim 1, The polymer fiber is oil-separated material selected from the group consisting of polyamide fibers, and polyester fibers. The method of claim 1, The fabric is oil-separated material that is a woven or knitted fabric comprising a polymer fiber having an average diameter of 5 to 200 ㎛. The method of claim 1, The fabric is oil or water separation material that is woven or knitted. The method of claim 1, The polymer fiber is oil-water separation material that is formed with irregularities on the surface. The method of claim 1, The oil-water separation material is a water-oil separation material having a contact angle of 120 ° or more. An oil-water separation filter comprising the oil-water separation material according to any one of claims 1 to 7.

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