JP2009235653A - Manufacturing method of water-repellent microfiber, water-repellent microfiber and article applied with water-repellent treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of water-repellent microfiber capable of giving water repellency to the surface of various articles. <P>SOLUTION: A method for manufacturing water-repellent microfiber which is formed on the surface of a body to be treated comprises the following processes: the process for preparing a polymer solution by adding an additive composed of a water-repellent material to a solution in which a polymer is dissolved; and the process for forming a laminated microfiber by an electrospinning method by applying high voltage to the polymer solution. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing water-repellent fine fibers using an electrospinning method.

Water repellent technology has been widely studied not only in the field of academic surface science but also in the semiconductor field as well as in industrial fields such as filters, building and building materials, and fiber processing. Various proposals have been made to improve the performance by providing the above. For example, Patent Document 1 discloses a technique in which dirt is less likely to adhere by coating the surface of a filter with a water repellent material, and the number of filter replacements is reduced, and the filter can be cleaned and reused. ing.
Japanese Utility Model Publication No. 56-66731

  In recent years, electrospinning techniques have attracted attention for these techniques. The electrospinning method is a method by which a nanofiber having a nano-order diameter can be made relatively easily. Recently, the demand for nano-order fiber has increased, and its importance has been reviewed. Technology. The electrospinning method is a method in which a high positive voltage is applied to a polymer solution, and fiber formation occurs in a process in which the polymer solution is sprayed onto a ground or negatively charged surface. By utilizing this electrospinning technology, it is desired to develop materials and applications with more functionality, and as one of them, the development of water repellent technology has become an issue.

  This invention is made | formed in view of such a subject, and provides the manufacturing method of the water-repellent fine fiber which can provide water repellency to the surface of various articles | goods by utilizing an electrospinning technique. Objective.

  In order to solve the above-mentioned problems, a method for producing water-repellent fine fibers according to the present invention is a method for producing water-repellent fine fibers formed on the surface of an object to be treated. The method includes a step of preparing a polymer solution by adding an additive made of a material, and a step of applying a high voltage to the polymer solution to form fine fibers laminated by an electrospinning method.

  In the method for producing the water-repellent fine fiber thus configured, the additive is preferably a fluorine-based water repellent.

  In the method for producing water-repellent fine fibers, the additive may be a silicon-based water repellent.

  Moreover, in the manufacturing method of the water repellent fine fiber comprised in this way, it is preferable that polymer is a polymer of a water repellent material.

  The water-repellent fine fiber according to the present invention is characterized by being produced using the method for producing a water-repellent fine fiber having the above-described configuration.

  Furthermore, the water-repellent treated article according to the present invention is characterized in that the water-repellent fine fiber is formed on the surface of the article using the method for producing a water-repellent fine fiber having the above-described configuration.

  According to the present invention, by using a polymer solution in which an additive of a water repellent material is added to a solution in which a polymer is dissolved, a water repellent fine fiber having an excellent water repellent effect is obtained using an electrospinning method. It can be formed relatively easily. Moreover, a water-repellent treatment article can be obtained by forming water-repellent fine fibers on various article surfaces regardless of the material.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The method for producing water-repellent fine fibers according to the present invention comprises laminating a fibrous material (nanofiber) by spraying a polymer solution obtained by adding an additive to a raw material (polymer) and a solvent under specific conditions by an electrospinning method. Thus, water-repellent fine fibers are formed.

  The electrospinning method is a known method as a fiberizing method (solution spinning) using the force of electricity, and is a method capable of making nanofibers relatively easily. A conceptual diagram of an electrospinning apparatus used in this embodiment is shown in FIG.

  The electrospinning apparatus E is mainly composed of a grounded target plate 1, a syringe 2 that holds a polymer solution (raw material solution or the like), a capillary 3 that is attached to the tip of the syringe, and a DC power source 4. In the electrospinning apparatus E, a polymer solution is applied by applying a positive DC voltage (high voltage) to the polymer solution side between the target plate 1 and the capillary 3 with a DC power source 4 to the polymer solution side. It sprays toward the target plate 1 from the tip of the capillary 3, and the solvent evaporates at the same time as the polymer solution becomes ultrafine. By this process, the liquid component in the solution is almost volatilized, and a deposited layer (nonwoven fabric) composed of uniform nanofibers 5 having a fiber diameter of the order of several tens to several hundreds of nanometers is formed on the target plate 1. The fiber film formed from this deposited layer is a water-repellent fine fiber.

  In this electrospinning method, nanofibers having a desired fiber diameter and fiber length are formed by appropriately selecting the applied voltage, the distance between the capillary 3 and the target plate 1, the discharge port diameter of the capillary 3, the composition of the polymer solution, and the like. can do.

  The applied voltage in the electrospinning method is not particularly limited, but for example, a range of about 5 to 30 kV is preferable. This is because many polymer solutions can be spun at a voltage exceeding 5 kV, and if it exceeds 30 kV, there is a risk of electric shock to the human body.

  The distance between the tip of the capillary 3 and the target plate 1 in the electrospinning method varies depending on the applied voltage, the viscosity of the polymer solution, etc., but is preferably in the range of about 40 to 150 mm, for example. If this distance is too close or too far away, good nanofibers cannot be formed. Here, the positional relationship between the capillary 3 and the target plate 1 is generally such that the syringe to which the capillary 3 is attached is vertical and the target plate 1 is placed directly below the syringe. However, when the viscosity of the solution is low, in order to prevent droplets from adhering to the formed nanofibers due to dripping, the target plate is slightly shifted from directly below the syringe while the syringe is inclined. It is preferable to set it at a different position.

  Although the discharge port diameter of the capillary 3 in the electrospinning method is not particularly limited, for example, a range of 0.3 to 1.0 mm is preferable.

  The polymer solution used in the electrospinning method in the present embodiment is obtained by mixing a raw material that is a polymer (polymer), a solvent that dissolves the polymer, and an additive having a water repellent effect.

  The raw material is not particularly limited as long as it is a polymer that can be electrospun, and examples thereof include polyethylene phthalate (PET), polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polylactic acid, nylon 6, and silk. It is done.

  A solvent is suitably selected according to the kind of the said raw material as what melt | dissolves the said raw material. Examples thereof include water, formic acid, hexafluoroisopropanol (HFIP), dimethylformaldehyde, chloroform, and acetone. Moreover, since the evaporation rate of the solvent is an important factor for forming nanofibers, a mixed solvent of a highly volatile solvent having a low boiling point and a volatile solvent having a higher boiling point may be used.

  As the additive, a water repellent material (water repellent) that is excellent in water repellency and insoluble or hardly soluble in the above-mentioned solvent is used. Examples of the water repellent include those using a fluorine-based or silicon-based water repellent or a combination thereof, but those containing fluorine are preferable because they have a large effect of reducing surface energy. Examples of the fluorine-based water repellent include fluorine resins such as polytetrafluoroethylene (PTFE), perfluoroalkyl compounds, and perfluoropolyether compounds.

  The concentration of the raw material (polymer) in the polymer solution is not particularly limited, but is preferably in the range of about 10 to 30% by weight. This is because if the concentration in the polymer solution is too low, it is sprayed in the form of mist and becomes particles, and if the concentration is too high, it cannot be injected from the capillary 3. The concentration of the water repellent in the polymer solution is not particularly limited, but is preferably in the range of about 5 to 20% by weight.

  According to the method for producing water-repellent fine fibers described above, the nanofibers 5 can be laminated by forming a water-repellent fine fiber (fiber film) by spraying the polymer solution toward the target plate 1 by electrospinning. it can. Further, in order to form the water-repellent fine fibers on the surface of the article, the article may be disposed near the target plate and the polymer liquid may be sprayed toward the article by the electrospinning method. In addition, by forming the target plate movably or using a rotatable drum instead of the target plate, a deposited layer composed of nanofibers is formed by electrospinning while moving or rotating the article. By doing so, uniform water-repellent fine fibers can be formed on the entire surface of the article. In addition, as an article that forms water-repellent fine fibers on the surface and the like, it can be applied regardless of the material, for example, filters, building and construction materials, fibers such as clothes, electronics members such as cables, Etc.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

[Example 1]
Using the electrospinning apparatus E of the principle shown in FIG. 1, a polymer solution in which 20 wt% of nylon 6 as a raw material, 70 wt% of formic acid as a solvent, and 10 wt% of a fluorine-based water repellent as an additive is applied When electrospinning was performed with a voltage of 20 kV and the distance from the capillary tip to the target plate (a copper plate with aluminum foil attached) adjusted to 56 mm, nanofibers with a fiber diameter of about 100 nm were formed on the target plate in a nonwoven fabric shape. Once formed, a fiber membrane could be made. Here, as the fluorine-based water repellent, Unidyne (containing 28.1 wt% fluorine-based polymer) manufactured by Daikin Industries is used. In this embodiment, after the fiber film is formed, the fiber film (water repellent) is cured by heating (curing) for 1 minute with 160 ° hot air.

  The result of measuring the contact angle of the fiber membrane thus formed is shown in FIG. FIG. 2 also shows the measurement results of the contact angle of the fiber film formed of the polymer solution to which the water repellent is not added and the contact angle of the aluminum foil itself (where no fiber film is formed). Has been. As can be seen from this result, the fiber membrane formed by adding a water repellent has a water repellency angle of 133.8 ° and a high water repellency (in general, a contact angle of 110 ° to 150 ° indicates “high repellency”. It is understood that it has an excellent water repellency effect. On the other hand, in the fiber film without the water repellent added, the contact angle was 50.7 °, and the effect of water repellency (generally, water repellency was achieved when the contact angle was 90 ° or more) was not shown.

[Example 2]
Using the electrospinning apparatus E of the principle shown in FIG. 1, a polymer solution in which 20 wt% of nylon 6 as a raw material, 70 wt% of formic acid as a solvent, and 10 wt% of a fluorine-based water repellent as an additive is applied When the voltage was 20 kV, the distance from the capillary tip to the target plate (copper plate with a filter medium attached) was adjusted to 56 mm, and the spinning time (spray time) was electrospun for 60 minutes, the fiber diameter was about 100 nm. Nanofibers were formed on the target plate in a non-woven form, and a fiber membrane could be formed on the filter medium surface. Here, Daikin Unidyne is used as the fluorine-based water repellent as in Example 1. Moreover, the pulp fiber is used as a filter medium. In this embodiment, after forming the fiber film, the fiber film (water repellent) is cured by heating with hot air at 160 ° C. for 1 minute.

  With respect to the fiber membrane formed on the surface of the filter medium in this way, the contact angle could not be measured because the fiber was too soft and water drops soaked into the filter medium. For this reason, as a measurement result in a present Example, the result of having measured the time until a water drop immerses in a filter medium is shown in FIG. FIG. 3 also shows the measurement results of the fiber membrane formed from the polymer solution to which the water repellent is not added. As can be seen from this result, in the fiber film without the water repellent added, the time for which the water droplets soaked was less than 1 second, whereas in the fiber film formed with the water repellent added, it was 53. The water repellent effect was confirmed in seconds.

  As described above, by using a polymer solution obtained by adding a water repellent to a mixed solution of raw materials and a solvent, and forming a fiber film by an electrospinning method, water repellent fine fibers having an excellent water repellent effect can be produced. it can. Moreover, the water-repellent effect can be obtained by forming the water-repellent fine fibers on various article surfaces regardless of the material.

It is a conceptual diagram of the electrospinning apparatus used for this embodiment. It is a table | surface which shows the measurement result of the contact angle of the film | membrane formed with the said electrospinning apparatus. It is a table | surface which shows the measurement result of time until a water drop immerses in a filter medium in the film | membrane formed on the filter medium surface by the said electrospinning apparatus.

Explanation of symbols

1 Target Plate 2 Syringe 3 Capillary 4 DC Power Supply 5 Nanofiber E Electrospinning Device

Claims (6)

A method for producing water-repellent fine fibers formed on the surface of an object to be treated,
A step of preparing a polymer solution by adding an additive made of a water repellent material to a solution in which a polymer is dissolved;
And a step of applying a high voltage to the polymer solution to form fine fibers laminated by an electrospinning method.   The method for producing water-repellent fine fibers according to claim 1, wherein the additive is a fluorine-based water repellent.   The method for producing water-repellent fine fibers according to claim 1, wherein the additive is a silicon-based water repellent.   The method for producing a water-repellent fine fiber according to any one of claims 1 to 3, wherein the polymer is a polymer of a water-repellent material.   A water-repellent fine fiber produced using the method for producing a water-repellent fine fiber according to any one of claims 1 to 4.   A water repellent treated article, wherein the water repellent fine fiber is formed on the surface of the article using the method for producing a water repellent fine fiber according to any one of claims 1 to 4.

Images