JP2009195786A - Method and apparatus for treating porous base stock with ultraviolet ray - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for treating not only the surface of a porous base stock but also the insides of pores thereof efficiently with ultraviolet rays. <P>SOLUTION: The method for treating the porous base stock with ultraviolet rays includes a filling step of sucking a gaseous mixture containing a small amount of oxygen, which is in contact with the porous base stock, from the back surface of the porous base stock to fill the pores thereof with the gaseous mixture; and a modification step of treating the porous base stock, which is treated at the filling step, with ultraviolet rays to modify the insides of the pores, in the apparatus and method, includes the steps of: introducing the gaseous mixture containing a small amount of oxygen into a reaction chamber 100 through a pipeline 20; supporting the porous base stock 1 by a porous support 32; sucking the gaseous mixture from the back surface of the porous base stock 1; and irradiating the resulting porous base stock 1 with ultraviolet rays emitted from an ultraviolet lamp 10 to modify the insides of the pores of the porous base stock 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for ultraviolet treatment of a porous material, and more particularly to a method and an apparatus for ultraviolet treatment of the surface and pores of a porous plastic film.

  Ultraviolet treatment may be used as a method for hydrophilizing hydrophobic surfaces such as plastic, glass, ceramics, metals, and semiconductors. This is due to the effect of removing foreign substances on the surface by ultraviolet rays, and the chemical bond on the surface of the object to be treated is broken by the irradiation of ultraviolet rays, and a functional group showing hydrophilicity is generated there.

  On the other hand, porous materials are used in various fields such as battery separators, filters, gas separation, regenerative medicine culture media, and many porous materials are expected to be used in the future.

However, when it is necessary to hydrophilize not only the surface of the porous material but also the inside of the pores, most of the conventionally proposed surface treatment methods are methods for modifying only the surface of the object to be treated. Among a few reports, Patent Document 1 (Japanese Patent Laid-Open No. 2007-302806) attempts to treat the inside of the pores by plasma treatment in the atmosphere. In the future, it is considered that more treatment methods and treatment apparatuses aiming at treatment in the porous pores will be required.
JP 2007-302806 A

  Accordingly, an object of the present invention is to provide a method and an apparatus for efficiently modifying not only the surface of a porous material but also the inside of pores by ultraviolet irradiation.

The invention according to claim 1 is a method for ultraviolet treatment of a porous material, by sucking a mixed gas containing a small amount of oxygen from the back surface of the porous material in a state of being in contact with the porous material, Porous having a filling step of filling the mixed gas into the pores of the porous material, and a modifying step of modifying the inside of the pores by applying an ultraviolet treatment to the porous material after the filling step This is an ultraviolet treatment method for the material.
According to a second aspect of the present invention, in the method for ultraviolet treatment of a porous material, a mixed gas containing a trace amount of oxygen is sprayed onto the porous material, and the mixed gas is filled in the pores of the porous material. An ultraviolet treatment method for a porous material, comprising: a filling step; and a modification step of modifying the inside of the pores by subjecting the porous material to ultraviolet treatment.
The invention according to claim 3 is a reaction chamber, a gas introduction means for introducing a mixed gas containing a small amount of oxygen into the reaction chamber, a porous material supported in the reaction chamber, and from the back surface of the porous material. A support means for sucking the mixed gas; and an ultraviolet treatment means for irradiating the porous material with ultraviolet light, and the mixed gas introduced by the gas introduction means is in contact with the porous material. After sucking from the back surface of the porous material by means and filling the mixed gas into the pores of the porous material, the porous material is subjected to ultraviolet treatment by the ultraviolet treatment means, and the pores are modified. It is the ultraviolet processing apparatus of the porous material characterized by comprising so that it may quality.
The invention described in claim 4 includes a reaction chamber, a gas spraying means for introducing a mixed gas containing a small amount of oxygen into the reaction chamber and blowing the mixed gas onto a porous material, and a porous material in the reaction chamber. Supporting means and ultraviolet treatment means for irradiating the porous material with ultraviolet light, and filling the mixed gas into the pores of the porous material by the gas spraying means, and then the ultraviolet treatment means. The porous material ultraviolet treatment apparatus is characterized in that the porous material is subjected to ultraviolet treatment to modify the inside of the pores.
The invention according to claim 5 is configured such that the supporting means has a function of transporting the porous material and performs the ultraviolet treatment while continuously transporting the porous material to the reaction chamber. The ultraviolet ray processing apparatus according to claim 3 or 4, wherein

  According to the ultraviolet ray treatment method and treatment apparatus for a porous material of the present invention, not only the surface of the porous material but also the pores can be efficiently modified. In particular, the microporous plastic film that has been subjected to the ultraviolet treatment of the present invention is hydrophilicized not only on the surface but also in the pores, and is useful as a battery separator, various filters, a carrier for various functional materials and the like.

[1] porous material
The material of the porous material to which the ultraviolet treatment method of the present invention can be applied is not particularly limited, and examples thereof include porous plastic, glass, ceramics, metal, and semiconductor. The shape of the porous material is not particularly limited, but is preferably a film shape or a plate shape. Among these, a porous plastic film is preferable. Examples of the porous plastic film include a thermoplastic resin microporous film and a thermoplastic resin nonwoven fabric. Examples of the thermoplastic resin constituting the microporous film or the nonwoven fabric include polyolefin (PO), polyester, polyamide, polyarylene ether, polyarylene sulfide and the like.
Here, the porous material referred to in the present invention refers to a material having a porosity of 30 to 80% and an air permeability measured by JIS P8117 of 5 seconds to 2000 seconds. .

[2] UV treatment method and treatment equipment
In the method of the present invention, (a) a mixed gas containing a trace amount of oxygen is sucked from the back surface of the porous material in a state of being in contact with the porous material, whereby the mixed gas is introduced into the pores of the porous material. Filling (filling process), allowing the porous material to pass through the UV irradiation area and modifying the inside of the pores (modification process), or (b) spraying the mixed gas on the porous material at a predetermined flow rate, and mixing the gas Either is filled in the pores of the porous material (filling process), and the porous material is passed through the ultraviolet irradiation area to modify the pores (modification process). .

[3] Ultraviolet source In the present invention, the ultraviolet source is not particularly limited as long as a sufficient effect can be obtained.

[4] Mixed gas The mixed gas is appropriately selected according to the material of the porous material, but it is preferable that the main component is nitrogen used as a purge gas in a normal ultraviolet irradiation process. An inert gas other than nitrogen gas may be used, but is disadvantageous in terms of cost. The amount of oxygen is also selected as appropriate, but if it is mixed too much, the ultraviolet light is deprived of energy when changing from oxygen to ozone by ultraviolet irradiation, and sufficient ultraviolet light treatment becomes impossible. Therefore, the mixing ratio of oxygen is optimally about 1 vol% to 15 vol%.

[5] Processing time The processing time is not particularly limited as long as desired characteristics can be obtained. However, if the processing time is too short, a sufficient effect cannot be obtained.

  Hereinafter, a case where a film-like porous material is treated with ultraviolet rays will be described as an example with reference to the drawings. FIG. 1 is a schematic view showing an example of an apparatus for plasma processing a film-like porous material 1. In this example, the film-like porous material 1 is subjected to ultraviolet treatment in a batch manner. This apparatus supports a porous material 1 while supporting a porous material 1 in the reaction chamber 100, a tube 20 as a gas introducing means for introducing a mixed gas containing a small amount of oxygen into the reaction chamber 100, and the porous material 1. The plate-shaped porous support body 32 as a support means for sucking the mixed gas from the back surface thereof, and the ultraviolet lamp 10 as the ultraviolet treatment means for irradiating the porous material 1 with ultraviolet light. The porous support body 32 has pores communicating with each other in the thickness direction and the surface direction in contact with the porous material 1, and is connected to the decompression unit 34 through the pipe 33, so that the mixed gas is supplied from the back surface of the porous material 1. Can be aspirated. The sample stage 31 has a function of further supporting the porous support 32. The flow rate of the mixed gas is adjusted by the flow rate controller 21.

  The film-like porous material 1 is fixed on the porous support 32, the mixed gas is introduced into the reaction chamber 100 while adjusting the flow rate by the flow rate controller 21, and the ultraviolet lamp 10 is turned on. Since the porous material 1 is fixed on the porous support 32 and the mixed gas is sucked through the porous material 1 and the porous support 32 by the decompression means 34, the mixed gas is the porous material. 1 can pass through. Therefore, a very small amount of oxygen can be introduced into the entire surface and pores of the porous material 1, and by performing ultraviolet treatment, oxygen-derived functional groups are generated and modified in the pores. As described above, the mixed gas can be sprayed onto the porous material at a predetermined flow rate, and the mixed gas can be filled into the pores of the porous material. In this embodiment, in FIG. 1, a spraying means (not shown) may be separately set in the reaction chamber, and the mixed gas may be sprayed onto the surface of the porous material 1. In any form, it is preferable to remove the air in the reaction chamber 100, prevent the intrusion of air into the reaction chamber, and control the amount of oxygen and moisture in the reaction chamber 100. The flow rate of the mixed gas is, for example, 10 to 200 lsm. The flow rate of the mixed gas can be adjusted by, for example, the amount of mixed gas sucked from the back surface of the porous material 1. Although not clearly shown, the reaction chamber 100 may be configured to be kept airtight so that a gas other than the mixed gas is not mixed. However, this is not the case when an excessive amount of mixed gas is introduced into the reaction chamber 100.

  FIG. 2 is a schematic view showing an example of an apparatus for performing ultraviolet treatment on a roll-like film-like porous material 1. In FIG. 2, this apparatus includes a reaction chamber 100, a tube 20 as a gas introduction means for introducing a mixed gas containing a small amount of oxygen into the reaction chamber 100, and an ultraviolet treatment means for irradiating the porous material 1 with ultraviolet rays. 1 is provided with a roll unwinding mechanism 35 and a winding mechanism 36 for the porous material 1, and the porous material 1 is continuously placed in the reaction chamber 100. And can be subjected to ultraviolet treatment. As the conveying means, a porous roll 37 is used, and is installed at a position almost opposite to the ultraviolet lamp 10 in the reaction chamber 100. The porous roll 37 is connected to a decompression means 34 such as a vacuum pump through a pipe 33 and rotates while sucking the back surface of the porous material 1, and can transport the porous material 1. Although not clearly shown, the reaction chamber 100 may be configured to be kept airtight so that a gas other than the mixed gas is not mixed, as in FIG. However, this is not the case when an excessive amount of mixed gas is introduced into the reaction chamber 100.

  The winding speed (conveying speed of the porous material 1) varies depending on the flow rate of the mixed gas and the reforming speed, but approximately 1 m / min to 200 m / min is appropriate.

  By the ultraviolet treatment method and apparatus as described above, not only the surface of the porous material 1 but also the inside of the pores can be treated. When a polyolefin (PO) microporous membrane is treated, an oxygen-containing functional group such as a carboxyl group or a carbonyl group can be introduced to improve hydrophilicity. In particular, the PO microporous membrane subjected to the ultraviolet irradiation treatment of the present invention is useful as a battery separator, various filters, a carrier for various functional materials, and the like.

  Ultraviolet rays can be irradiated over the entire depth direction. Therefore, by filling the pores with a mixed gas containing oxygen, the pores can be modified to be hydrophilic throughout the depth direction.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1
Using the batch type apparatus shown in FIG. 1, a polyethylene (PE) microporous membrane [trade name: Cetilla, manufactured by Tonen Chemical Co., Ltd., 10 cm × 10 cm, thickness: 30 μm, porosity 60%, Air permeability (JIS P8117) 100 seconds] was subjected to ultraviolet treatment. The PE microporous membrane 1 was fixed on a sample table 30 made of a porous support in the treatment area. The ultraviolet lamp 10 (Iwasaki Electric Co., Ltd .: UEEX503) was turned on while supplying dry nitrogen gas mixed with 3% oxygen to the treatment area. Irradiation was performed for 3 minutes while sucking with a pump (pressure reduction means 34) connected to the porous support 32. The flow rate of the mixed gas was 100 lsm.

  When both sides of the PE microporous membrane 1 subjected to UV treatment were measured for the contact angle with pure water (hereinafter simply referred to as “water contact angle” unless otherwise specified), the top surface (surface on the UV lamp 10 side) was measured. The angle was 40 °, and the lower surface (the surface on the porous support 32 side) was 50 °. As a measuring machine, a contact angle meter manufactured by Kyowa Interface Science Co., Ltd. was used. Since the initial contact angle of the PE microporous membrane is 120 °, it can be said that it has been processed through the pores to the back surface.

Example 2
The PE microporous membrane was subjected to UV treatment under atmospheric pressure in the same manner as in Example 1 except that suction from the back surface of the PE microporous membrane was not performed. At this time, the flow rate of the mixed gas was set to 200 lsm, and the mixed gas was sprayed onto the PE microporous membrane. When the water contact angles on both sides of the obtained PE microporous membrane were measured, it was 40 ° on the upper surface and 70 ° on the lower surface. It was found that the bottom surface was effectively UV-treated.

Comparative Example 1
The PE microporous membrane was treated with ultraviolet rays in the same manner as in Example 1 except that only argon gas was used without using a mixed gas. When the water contact angle on both sides of the obtained PE microporous membrane was measured, it was 110 ° on the upper surface and 114 ° on the lower surface. Oxygen-derived functional groups were not introduced on both sides of the ultraviolet-treated PE microporous membrane, and the contact angle did not decrease.

It is the schematic which shows an example of the apparatus which plasma-processes a film-form porous material. It is the schematic which shows the example of the apparatus which ultraviolet-processes a roll-form film-form porous material.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Porous material, 10 UV lamp, 20 Tube as gas introduction means, 32 Porous support body, 34 Decompression means, 37 Porous roll, 100 Reaction chamber.

Claims (5)

  In the method for ultraviolet treatment of a porous material, the mixed gas containing a trace amount of oxygen is sucked from the back surface of the porous material while being in contact with the porous material. An ultraviolet treatment method for a porous material, comprising: a filling step for filling the pores; and a modification step for modifying the inside of the pores by subjecting the porous material to ultraviolet treatment after the filling step.   In the method for ultraviolet treatment of a porous material, a filling step of spraying a mixed gas containing a small amount of oxygen onto the porous material and filling the mixed gas into the pores of the porous material; An ultraviolet treatment method for a porous material, comprising an ultraviolet treatment and a modification step of modifying the inside of the pores.   A reaction chamber; gas introduction means for introducing a mixed gas containing a trace amount of oxygen into the reaction chamber; and support means for supporting the porous material in the reaction chamber and sucking the mixed gas from the back surface of the porous material; UV treatment means for irradiating the porous material with ultraviolet light, and the mixed gas introduced by the gas introduction means is brought into contact with the porous material from the back surface of the porous material by the support means. After being sucked and filled with the mixed gas into the pores of the porous material, the porous material is subjected to ultraviolet treatment by the ultraviolet treatment means to modify the inside of the pores. An ultraviolet treatment device for porous materials.   A reaction chamber; a gas blowing means for introducing a mixed gas containing a small amount of oxygen into the reaction chamber and blowing the mixed gas onto a porous material; a supporting means for supporting the porous material in the reaction chamber; Ultraviolet treatment means for irradiating the porous material with ultraviolet light, and after the mixed gas is filled in the pores of the porous material by the gas spraying means, the porous material is subjected to ultraviolet treatment by the ultraviolet treatment means. An ultraviolet treatment apparatus for a porous material, characterized in that it is configured to modify the inside of the pores.   The said support means has a function to convey the porous material, and is configured to perform the ultraviolet treatment while continuously conveying the porous material to the reaction chamber. 4. The ultraviolet treatment apparatus according to 4.

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