JP5203127B2 - Equipment for modifying the film surface - Google Patents

Description

The present invention relates to an apparatus for modifying a film surface by causing charged fine particles of water, an aqueous solution or an aqueous dispersion to collide with the film.

  Gives plastic film functions such as adhesion, stain resistance, easy peelability, antireflection, antifogging, etc., and gives metal film functions such as corrosion resistance, adhesiveness, stain resistance, easy peelability, etc. For example, a resin or an inorganic substance is coated by a coating method or a vapor deposition method. However, the coating method cannot form a thin film, and the vapor deposition method is excellent in forming a thin film, but requires a vacuum device and is expensive.

  JP-A-2005-281679 (Patent Document 1), a plastic film is placed on a conductive plate, and a resin composition solution or dispersion is sprayed from a spray nozzle provided with a potential difference between the conductive plate, It describes a method of attaching to a plastic film by electrostatic force. However, since it is not possible to generate charged microparticles on the order of submicron from the spray nozzle, this method cannot form a thin film.

JP 2005-281679 A

Accordingly, an object of the present invention is to provide a low-cost apparatus for modifying the surface of a film by colliding charged fine particles of water, an aqueous solution or an aqueous dispersion.

  As a result of diligent research in view of the above object, when the present inventors collide charged fine particles of water, an aqueous solution or an aqueous dispersion with a film by an electric field, the molecules of water, an aqueous solution or an aqueous dispersion adhere firmly to the film surface. I discovered this and came up with the present invention.

The apparatus of the present invention for modifying the surface of a film comprises: (a) a roll for conveying the film; (b) a container for containing water, an aqueous solution or an aqueous dispersion ; and (c) an ultra-immersed in the container. and ultrasonic transducer, (d) the film of water, a means for providing a potential difference between the aqueous solution or dispersion, a first electrode disposed inside of the roll, the greater in the vessel Means comprising a second electrode located under a sonic vibrator and immersed in water, an aqueous solution or an aqueous dispersion; (e) the film in contact with the roll; and water, an aqueous solution or an aqueous dispersion. A DC power source connected to the first electrode and the second electrode so as to be charged in reverse polarity, the roll is located in a space surrounded by a cover covering the container, and the roll The distance from water, aqueous solution, or aqueous dispersion is set so that the electric field strength is 200 to 1,200 V / mm. Are characterized by having in water, charged particles generated by the ultrasonic vibration of the aqueous solution or dispersion adheres by impinging on the film on the roll.

  By causing charged fine particles of water, an aqueous solution or an aqueous dispersion to collide with a film surface such as plastic in an electric field, the charged fine particles can be firmly attached to the film surface even in the air. As a result, the charged fine particles adhere to the film surface as if they were deposited. The obtained surface modified film has excellent adhesiveness, stain resistance, easy peelability, antireflection property, antifogging property and the like depending on the components of the fine particles.

[1] Film The film whose surface is modified may be any of a plastic film, a metal film, and a plastic film having a metal thin film. The plastic film is not limited. For example, a film made of polyester (polyethylene terephthalate, etc.), polyamide, polyimide, polycarbonate, acrylic resin, polystyrene, polyolefin (polyethylene, polypropylene, etc.), polyvinyl chloride, or the like can be used. The metal film is not limited, and for example, a film made of aluminum, copper, stainless steel or the like can be used. The metal thin film can be formed by vapor deposition or plating of aluminum or copper. A primer layer such as a hydrophilic resin (eg, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer) is provided on the film surface to firmly adhere charged fine particles such as water. May be.

In order to firmly attach the charged fine particles, polar functional groups such as hydroxyl groups and carboxyl groups may be formed on the surface of the plastic film by corona discharge treatment or plasma discharge treatment. In addition, a large number of fine linear marks and / or holes may be formed in the film. The depth of the linear marks is preferably 1 to 40% of the thickness of the film, the average width is preferably 1 to 10 μm, and the average interval is preferably 1 to 100 μm. A linear trace can be formed by the method described in WO2003 / 091003, for example. The average opening diameter of the fine holes is preferably 0.5 to 20 μm, and the average density is preferably 500 holes / cm ² or more.

[2] Water, aqueous solution or aqueous dispersion The substances to be contained in the aqueous solution or aqueous dispersion are resins, metal fine particles, inorganic fine particles, inorganic salts, and the like, which are appropriately selected according to the application. The resin is preferably the same as that of the plastic film or primer layer. The inorganic fine particles are made of metal oxide, carbon, diamond or the like. The inorganic fine particles are preferably colloidal. The viscosity of the aqueous solution and aqueous dispersion is not limited as long as it can be atomized with an ultrasonic vibrator.

[3] Film surface modification FIGS. 1 to 3 show an example of a film surface modification apparatus. This apparatus includes an unwinding machine 1a for a film 10a, a roll 2 made of a dielectric (plastic or ceramics) for charging the film 10a, an electrode 2a disposed inside the roll 2, and a lower side of the roll 2. A container 5 containing the water 4, aqueous solution or water dispersion (hereinafter simply referred to as water) 4, an electrode 5 a and a plurality of ultrasonic vibrators 6 immersed in water 4 in the container 5, a roll 2, Winding of cover 7 covering container 5, DC power source 8 connected to electrode 3 and electrode 5a to provide a potential difference between film 10a and water 4, etc., drying furnace 9, and surface-modified film 10b Machine 1b.

  The plastic for roll 2 is preferably polyvinyl chloride or fluororesin having excellent corrosion resistance. The peripheral speed of the roll 2 is preferably 10 to 500 m / min, and more preferably 10 to 300 m / min.

The frequency of the ultrasonic transducer 6 is preferably 1 to 10 MHz. To generate as much as possible small charged fine particles 4a, preferable to use a plurality of ultrasonic transducer 6 as illustrated in FIG. Water 4 may be at room temperature, but may be heated as necessary.

  When a DC voltage is applied between the electrode 3 and the electrode 5a (in this example, a negative voltage is applied to the electrode 3 and a positive voltage is applied to the electrode 5a), the film 10a in contact with the roll 2 is charged with a polarity opposite to that of water 4 or the like. In order to obtain submicron-order charged fine particles 4a, the distance D between the roll 2 and water 4 is preferably set so that the electric field strength is 200 to 1,200 V / mm, more preferably 300 to 1,000 V / mm. preferable. The distance D is preferably 3 to 10 cm.

  When water 4 is vibrated by the ultrasonic vibrator 6 in this state, charged fine particles 4a of charged water 4 are generated. The particle diameter of 90% or more of the charged fine particles 4a is preferably 1 μm or less, more preferably 500 nm or less, for example, 1 to 100 nm. The particle diameter of the charged fine particles 4a can be obtained by Stokes' law from the electric mobility measured using a differential electric mobility analyzer. It is considered that the particles of water 4 and the like are refined by Rayleigh splitting due to ultrasonic vibration in an electric field.

  The charged fine particles 4a move at high speed in the electric field between the water 4 and the film 10a and collide with the surface of the film 10a. It is considered that the charged fine particles 4a are further refined by the collision. It is considered that the refinement of the charged fine particles 4a contributes to strong adhesion to the surface of the film 10a. Since the surface modification of the film 10a is not lost even after the electric field is removed, it is assumed that the charged fine particles 4a are chemically bonded to the surface of the film 10a. By drying in the drying furnace 9, only water adsorbed on the surface modified film 10 b is removed.

  Instead of the dielectric roll 2, a metal roll such as stainless steel may be used. In that case, the electrode 2a is brought into contact with a metal roll. A metal roll may be coated with a dielectric such as plastic or ceramic. In this example, water or the like 4 is positively charged and the film 10a is negatively charged.

It is the schematic which shows an example of the surface modification apparatus of the film of this invention. It is a partial expanded sectional view which shows the principal part of the surface modification apparatus of FIG. It is a top view which shows an example of arrangement | positioning of the ultrasonic vibrator in a container.

Explanation of symbols

1a ・ ・ ・ Unwinding machine
1b ... Winding machine 2 ... Roll
2a ... Electrode 4 ... Water etc.
4a ... charged fine particles 5 ... container
5a ... Electrode 6 ... Ultrasonic vibrator 7 ... Cover 8 ... DC power supply 9 ... Drying furnace
10a ・ ・ ・ Film
10b ・ ・ ・ Surface modified film

Claims (3)

An apparatus for modifying the surface of a film, comprising: (a) a roll for conveying the film; (b) a container for containing water, an aqueous solution or an aqueous dispersion ; and (c) an ultrasonic wave immersed in the container. A vibrator , and (d) means for providing a potential difference between the film and water, an aqueous solution or an aqueous dispersion , the first electrode disposed inside the roll, and the ultrasonic wave in the container Means comprising a second electrode located under the vibrator and immersed in water, an aqueous solution or an aqueous dispersion; and (e) the film in contact with the roll and the water, aqueous solution or aqueous dispersion are reversed. A DC power source connected to the first electrode and the second electrode so as to be charged to a polarity, and the roll is located in a space surrounded by a cover covering the container, and the roll and water The distance from the aqueous solution or aqueous dispersion is set so that the electric field strength is 200 to 1,200 V / mm. And which, with it water, apparatus characterized by charged fine particles generated by the ultrasonic vibration of the aqueous solution or dispersion adheres by impinging on the film on the roll. 2. The film surface modifying apparatus according to claim 1 , wherein 90% or more of the charged fine particles have a particle diameter of 1 [mu] m or less. 3. The film surface modification apparatus according to claim 1 , wherein a plurality of ultrasonic vibrators are immersed in the container.

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