JP3494755B2 - Fluororesin film and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluororesin film having titanium oxide particles having a photocatalytic action fixed on the surface, which is effective for sterilization, deodorization and decomposition of organic substances, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, for the purpose of preventing nosocomial infection (MRSA), which is a problem in hospitals, it has been considered to apply bactericidal paint to walls. However, with this method, there is a concern that chemicals may harm the body, and the bactericidal action may decrease over time, and it is necessary to repaint once every several years. On the other hand, the photocatalytic action of titanium oxide has been widely known, and patents have been submitted such as baking coating on the surface of tiles for the purpose of deodorizing and bactericidal action, and decomposition of organic substances in a perfluoroinert liquid. (JP-A-6-63178, JP-A-6-199524). Convert this titanium oxide into a paint and apply it to walls, etc.
Although application to the decomposition of oil, hand dust, etc., deodorization, and removal of various bacteria is being studied, there are the following problems. In the conventional method of dispersing titanium oxide in the paint, the titanium oxide surface is not exposed from the paint unless the volume fraction of the titanium oxide in the paint exceeds at least 70% by volume, so that the photocatalytic action is sufficient. It was not demonstrated. Further, in a coating material having a volume fraction of titanium oxide of more than 70% by volume, although the photocatalytic action is exhibited, the viscosity of the coating material is extremely high, and the adhesive strength of the coating material to the base material is extremely low, It wasn't practical. Further, as a method of supporting titanium oxide on these films, a method of mixing titanium oxide using an extruder can be considered, but when titanium oxide is added until the film surface is exposed, film forming is impossible, When the amount of titanium oxide added is such that molding is possible, titanium oxide is not exposed from the film surface, and the photocatalytic action is hardly exhibited.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and a fluorine resin film having titanium oxide particles having a function of deodorizing, sterilizing and decomposing organic substances exposed and fixed on the surface, and It is an object to provide a manufacturing method thereof.

[0004]

The present invention has been made to solve the above-mentioned problems, and sprays titanium oxide particles heated with a combustion gas onto the surface of a fluororesin film having a melting point of 320 ° C. or less. By this, it is possible to immobilize the titanium oxide particles, and a suspension in which the titanium oxide particles are suspended is coated on the surface of the fluororesin film having a melting point of 320 ° C. or less and then dried, and heated near the melting point of the fluororesin. It was found that the titanium oxide particles can be firmly fixed to the surface of the fluororesin film by press-bonding with a rolled roll, and the falling of the titanium oxide particles can be prevented.
The present invention has been completed based on this finding.

That is, according to the present invention, titanium oxide particles having a photocatalytic action are fixed on the surface of a fluororesin film having a melting point of 320 ° C. or less so that a part of each particle is exposed.
There is provided a fluororesin film, wherein the that. The present invention also sprays titanium oxide particles heated using combustion gas onto the surface of a fluororesin film having a melting point of 320 ° C. or lower, embedding a part of each particle of the titanium oxide on the surface of the fluororesin film, It is intended to provide a method for producing a fluororesin film (hereinafter referred to as a thermal spraying method), characterized in that a part of each particle of titanium oxide is exposed and fixed. Further, in the present invention, a suspension of titanium oxide particles suspended in a dispersion medium is coated on the surface of a fluororesin film having a melting point of 320 ° C. or less, dried, and then heated to near the melting point of the fluororesin. A method for producing a fluororesin film, which comprises press-bonding with a roll, embedding a part of each particle of the titanium oxide on the surface of the fluororesin film, and exposing and fixing a part of each particle of the titanium oxide ( Hereinafter referred to as a crimping method).

The present invention will be described in detail below. The material of the film used in the present invention is a fluororesin having a melting point of 320 ° C. or less. Specific examples of the fluororesin film include, for example, vinyl fluoride resin film, vinylidene fluoride resin film, ethylene-tetrafluoroethylene resin film, chlorotrifluoroethylene resin film,
Chlorotrifluoroethylene-ethylene resin film,
Examples thereof include a tetrafluoroethylene-hexafluoropropylene resin film and a tetrafluoroethylene-perfluoro (alkyl vinyl ether) resin film. Among these fluororesin films, particularly, the fluororesin films of ethylene-tetrafluoroethylene resin film, tetrafluoroethylene-hexafluoropropylene resin film, tetrafluoroethylene-perfluoro (alkyl vinyl ether) resin film are titanium oxide particles. It is preferable in terms of immobilization and durability against oxidizing power. The thickness of the fluororesin film is not particularly limited, but is usually in the range of 5 to 500 μm, preferably 1
It is in the range of 0 to 200 μm.

In the present invention, the titanium oxide particles are fixed on the surface of the fluororesin film, but the fixed surface may be one side or both sides of the fluororesin film. When the fluororesin film having the titanium oxide particles of the present invention fixed on the surface is attached to a wall or other adherend, the titanium oxide particles are fixed only on one surface. As the titanium oxide particles fixed to the fluororesin film, those having a photocatalytic action may be used, and titanium oxide particles having various particle diameters, shapes, surface areas and the like can be used.
Alternatively, surface-treated titanium oxide particles may be used. Further, the titanium oxide particles may be particles of other materials whose surfaces are coated with titanium oxide. As titanium oxide to be used, rutile type and anatase type are adopted, but anatase type is particularly preferable. The particle size of titanium oxide particles is
Although not particularly limited, it is usually desirable that the primary particle diameter is in the range of 1 to 500 nm. Within this range, the photocatalytic action is good. The shape of the titanium oxide particles is, for example, acicular, spherical, cubic, rectangular parallelepiped, prismatic, cylindrical, spindle-shaped, scale-shaped, etc., but is particularly needle-shaped, spherical, cubic, or rectangular parallelepiped. The shape of is preferably adopted. The surface area of the titanium oxide particles is preferably 0.1 to 400 m ² / g.

The amount of titanium oxide particles fixed on the surface of the fluororesin film is not particularly limited, but is 0.1-40 g.
/ M ² is preferred. In the present invention, titanium oxide particles are fixed on the surface of the fluororesin film by exposing a part of each particle. The degree of exposure of the titanium oxide particles is not particularly limited, but the exposed portion has a catalytic action, so that the exposure rate is preferably high. To fix the titanium oxide particles, specifically, the degree of adhesion of the titanium oxide particles to the fluororesin film was 6 or more in the evaluation prescribed in JIS-K-5400 chalkiness degree, and the titanium oxide particles were firmly fixed with almost no falling off. Is preferably provided.

Next, the thermal spraying method and the pressure bonding method, which are the methods for producing the fluororesin film of the present invention, will be described respectively.
As the combustion gas used in the thermal spraying method of the present invention,
For example, various fuel gases such as city gas and acetylene gas can be used. In the thermal spraying method, the titanium oxide particles heated by using the combustion gas are sprayed onto the surface of the fluororesin film having a melting point of 320 ° C. or less. Specifically, the titanium oxide particles are gasified in the flame in which the combustion gas is burned. The titanium oxide particles are sprayed onto the surface of the fluororesin film placed in front of the flame. The distance between the flame of the combustion gas and the fluororesin film is not particularly limited, but it is preferably 20 cm or less from the tip of the normal flame, and the flame of the combustion gas may hit the fluororesin film.

The temperature of the combustion gas is not particularly limited, and is generally 1000 ° C to 5 ° C.
The range of about 000 ° C. is effective, but if the temperature is too high, the surface area of titanium oxide is reduced, which may reduce the photocatalytic activity. Therefore, it is desirable to suppress the temperature to 3000 ° C. or lower. The speed at the time of spraying the titanium oxide particles sprayed on the surface of the fluororesin film is not particularly limited,
It is usually in the range of 100 to 1,000 m / sec, and preferably in the range of 300 to 650 m / sec. The spraying amount of titanium oxide particles is not particularly limited, but 0.1-40 g / m ² is suitable. If the amount is too small, the photocatalytic action will be insufficient, and if it is too large, it will be useless. Therefore, the optimum amount may be appropriately selected for each application. Also,
If necessary, titanium oxide may be granulated to use particles having improved fluidity. The temperature of the surface of the fluororesin film on which the particles of titanium oxide are sprayed is usually preferably in the range from the glass transition point to a temperature higher by 50 ° C. than the glass transition point. For example, 120 to 170 ° C. for ethylene-tetrafluoroethylene resin film, 100 to 150 ° C. for tetrafluoroethylene-perfluoro (alkyl vinyl ether) resin, and tetrafluoroethylene-hexafluoropropylene resin film. Is preferably 80 to 130 ° C.

The dispersion medium used in the pressure bonding method of the present invention includes water, hydrocarbons, alcohols and the like, with water being preferred. In the pressure bonding method, the suspension of titanium oxide particles suspended in the dispersion medium is adjusted, but the concentration of the titanium oxide particles suspended in the dispersion medium is not particularly limited and is 1 g to 1 kg / A concentration of 1 liter is common. In addition, there is no limitation on adding a dispersant, a surfactant, and various surface treatment agents when preparing this suspension. In the pressure bonding method, this suspension is then coated on the surface of a fluororesin film having a melting point of 320 ° C. or lower and dried. The coating amount of the suspension is preferably such that the amount of titanium oxide particles is 0.1 to 40 g / m ² . The surface of the fluororesin film is preferably hydrophilized by a method such as corona discharge treatment, plasma etching treatment, or flame treatment before coating with the suspension. The coating can be performed by a method such as applying a suspension.

Drying may be natural drying, hot air spray drying, heat drying, or the like. The dried fluororesin film is then pressure-bonded with a heated roll near the melting point of the fluororesin. The vicinity of the melting point of the fluororesin, which is the roll temperature, is usually in the range of 150 ° C lower than the melting point of the fluororesin to the melting point of the fluororesin, preferably 100 ° C lower than the melting point of the fluororesin to the melting point of the fluororesin. The range is up to. Specific examples of the roll temperature include, for example, 150 ° C. to 250 ° C. for the ethylene-tetrafluoroethylene resin film and 150 for the tetrafluoroethylene-hexafluoropropylene resin film.
C to 260 C, 2 for tetrafluoroethylene-perfluoro (alkyl vinyl ether) resin film
A temperature of 00 ° C to 310 ° C is suitable. Roll pressure is usually 10
It is preferably 150 kg / cm ² . Regarding the surface of this roll, there is no limitation on applying a ceramic coat or a fluororesin coat, but it is desirable that the roll be coated with a fluororesin for the purpose of preventing stickiness, and the fluororesin used here means polytetrafluoro It is more preferable that the main component is ethylene resin.

[0013]

EXAMPLES Next, the present invention will be described more specifically by way of Examples and Comparative Examples. The present invention is not limited to these examples.

[Example 1] Anatase type titanium oxide particles having a primary particle diameter of 300 nm, a surface area of 10 m ² / g and a rectangular parallelepiped shape and having a photocatalytic activity were prepared by acetylene-oxygen gas spraying with ethylene- A sample was sprayed on one surface of a tetrafluoroethylene resin film (trade name: Aflex film, melting point 260 ° C., thickness 100 μm, manufactured by Asahi Glass Co., Ltd.). The spraying amount of titanium oxide particles is about 1 g / m ² , the combustion temperature of acetylene-oxygen gas is about 3000 ° C., the spraying speed of the titanium oxide particles sprayed is 300 m / sec, and the flame of the combustion gas is The distance between the tip of the fluororesin film and the fluororesin film was 1 cm, and the temperature of the surface of the fluororesin film at the time of spraying the titanium oxide particles was 135 ° C. The rate of decomposition of acetaldehyde was measured using this fluororesin film, and the results are shown in Table 1. In the measurement, 25 cm ² of the sample fluororesin film and acetaldehyde were placed in a Pyrex glass closed container having a volume of 2.8 liters, a black light of 1 mW / cm ² was applied, and the residual gas concentration was measured using a gas chromatogram. The primary particle diameter of the titanium oxide particles on the fluororesin film is 300 nm, and a part of each particle of the titanium oxide particles is embedded in the fluororesin film due to the energy at the time of thermal spraying. JIS-K-5400 score is 6-7
That is, the titanium oxide particles did not fall off, and a sufficiently practical fluororesin film was obtained.

[Example 2] Under the same conditions as in Example 1, the titanium oxide particles were subjected to tetrafluoroethylene-
Perfluoro (alkyl vinyl ether) resin film (brand name Aflex PFA film, melting point 310 ° C,
A sample having a thickness of 100 μm, manufactured by Asahi Glass Co., Ltd.) was sprayed on one surface, and the same evaluation as in Example 1 was performed. The primary particle size of titanium oxide particles on this film is 3
It is 00 nm, and a part of each particle of the titanium oxide particles sunk into the inside of the fluororesin film by the energy at the time of thermal spraying. The score of JIS-K-5400 is 6 points or more,
A fluororesin film was obtained in which titanium oxide particles did not fall off and which was sufficiently practical.

Example 3 A suspension is prepared by suspending, in water, anatase-type titanium oxide particles having a primary particle size of 20 nm, a surface area of 50 m ² / g and a rectangular parallelepiped shape and having a photocatalytic activity. Regarding the concentration of titanium oxide particles, 100 g of titanium oxide particles was added to 1 liter of water. Ethylene-tetrafluoroethylene resin film subjected to corona discharge treatment (brand name Aflex film, melting point 2
This suspension was applied onto one surface of 60 ° C., thickness 100 μm, manufactured by Asahi Glass Co., Ltd.) and then dried at 110 ° C. Fluororesin film coated with these titanium oxide particles,
Roll pressure of 100kg / cm with polytetrafluoroethylene resin coated roll heated to 220 ℃
^{In step 2} , the titanium oxide particles were fixed on the fluororesin film by pressure bonding. The same evaluation as in Example 1 was performed using the fluororesin film thus produced. The results are shown in Table 1. The amount of titanium oxide particles carried on the fluororesin film was about 1 g / m ² . The primary particle diameter of titanium oxide on this film is 20 nm, and a part of each particle of titanium oxide particles is embedded in the film due to the pressure applied from the roll. JIS-K
The score of -5400 was 6 to 7, and titanium oxide particles did not fall off, and a sufficiently practical fluororesin film was obtained.

[Example 4] The suspension used in Example 3 was
Corona discharge treated tetrafluoroethylene-perfluoro (alkyl vinyl ether) resin film (brand name Aflex PFA film, melting point 310 ° C.,
It was applied on one side of a 100 μm thick Asahi Glass Co., Ltd.) and dried at 110 ° C. The fluororesin film coated with the titanium oxide particles was pressure-bonded with a polytetrafluoroethylene resin-coated roll heated to 280 ° C. to immobilize the titanium oxide particles on the fluororesin film. The same evaluation as in Example 1 was performed using the film thus prepared. The results are shown in Table 1. The amount of titanium oxide supported on the film was about 1 g / m ² . The primary particle diameter of titanium oxide on this film is 20 nm, and a part of each particle of titanium oxide particles is embedded in the film due to the pressure applied from the roll. According to JIS-K-5400, the rating was 6 to 7, and titanium oxide particles did not fall off, and a sufficiently practical fluororesin film was obtained.

[Embodiment 5] Escherichia coli was placed on the fluororesin film produced in Embodiment 4, and a fluorescent lamp of 20 W
It was installed at a place separated by cm. When the number of E. coli remaining after one hour was measured, the E. coli was completely destroyed.
The number of E. coli treated similarly on the glass plate remained unchanged.

[Comparative Example 1] The titanium oxide particles used in Example 1 were mixed with ethylene-tetrafluoroethylene resin 100.
Add 20 parts to 1 part to make a thickness of 1 using an extruder.
A fluororesin film having a size of 00 μ was prepared and evaluated in the same manner as in Example 1. When this film was exposed to ultraviolet rays, titanium oxide was hardly exposed on the film surface, and the photocatalytic action was not exhibited.

Comparative Example 2 A coating material was prepared by adding 70% by volume of the titanium oxide particles used in Example 1 in solid content to a fluororesin-based coating material (trade name: Lumiflon LF-200, manufactured by Asahi Glass Co., Ltd.). . This paint was applied to a glass plate and then dried to obtain a sample, and the same evaluation as in Example 1 was performed. This paint has good photocatalytic activity, but JIS-K
The score of -5400 was 1 to 2 and a practical fluororesin film could not be obtained. The primary particle size of titanium oxide on this film was 20 nm, and the amount of titanium oxide particles exposed on the surface was about 3 g /
It was m ² . Even if the titanium oxide particles were used, the ratio of actually contributing to the photocatalytic action among the added titanium oxide particles in the coating with the conventional paint was extremely low, but in the present invention, the titanium oxide particles are almost exposed on the surface. It is highly efficient and leads to cost reduction. The fluororesin films formed in the examples show a good photocatalytic action, and the adhesion of titanium oxide particles to the fluororesin film is JIS-
It has 6 or more points in the chalkiness evaluation of K-5400.
As a result, it can be applied to various applications using the photocatalytic action of titanium oxide.

[0021]

[Table 1]

[0022]

EFFECTS OF THE INVENTION When the fluororesin film having titanium oxide particles exposed on the surface of the present invention is used, in addition to the deodorizing and bactericidal effect, it is possible to remove the stains on the hands and cigarettes if there is ultraviolet light emitted from a fluorescent lamp. It is possible to provide an epoch-making stain removing method that can disassemble and remove stains on the tars without bothering hands and expect labor saving effect. The fluororesin film of the present invention can be adhered to iron, aluminum, vinyl chloride resin and the like, and can be applied to various uses. Further, the fluororesin film of the present invention has an ultraviolet ray amount of 0.01 mW /
cm ² or more, in particular even at a distance 30cm from the fluorescent lamp of 20W, it is possible to sufficiently exhibit its function, is very useful from the viewpoint of energy saving. Furthermore, according to the manufacturing method of the present invention, it is possible to provide the fluororesin film of the present invention having excellent durability.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification FI B32B 3/14 B32B 3/14 7/02 105 7/02 105 27/30 27/30 D (72) Inventor Nobuyuki Miyazaki Kanagawa Asahi Glass Co., Ltd., Central Research Laboratory, 1150, Hazawa-machi, Kanagawa-ku, Yokohama (56) Reference JP-A-9-76395 (JP, A) JP-A-5-253544 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 B05D 1/00-7/26

Claims (8)

(57) [Claims] To 1. A surface of the melting point of 320 ° C. or less of the fluorine resin film, a fluororesin film, characterized by comprising titanium oxide particles having a photocatalytic action and fixed by exposing a portion of the respective particles. 2. The fluororesin film according to claim 1, wherein the fluororesin is an ethylene-tetrafluoroethylene resin. 3. The fluororesin is tetrafluoroethylene-
The fluororesin film according to claim 1, which is a perfluoro (alkyl vinyl ether) resin. 4. The fluororesin is tetrafluoroethylene-
The fluororesin film according to claim 1, which is a hexafluoropropylene resin. 5. A titanium oxide particle having a primary particle diameter of 1 to 500.
The fluororesin film according to claim 1, wherein the fluororesin film has a thickness of nm. 6. The fluororesin according to claim 1, wherein titanium oxide particles are fixed on the surface of the fluororesin film at a rate of 0.1 to 40 g / m ^2. the film. 7. Titanium oxide particles, which are heated by using combustion gas, are sprayed onto the surface of a fluororesin film having a melting point of 320 ° C. or lower, and a part of each particle of the titanium oxide is embedded in the surface of the fluororesin film to form titanium oxide. 2. A method for producing a fluororesin film, which comprises exposing a part of each of the particles and fixing. 8. A suspension of titanium oxide particles suspended in a dispersion medium is coated on the surface of a fluororesin film having a melting point of 320 ° C. or lower, dried, and then heated by a roll heated near the melting point of the fluororesin. A method for producing a fluororesin film, which comprises press-bonding, embedding a part of each particle of the titanium oxide on the surface of the fluororesin film, and exposing and fixing a part of each particle of the titanium oxide.