JP4108811B2 - Surface treatment method for plastic film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface treatment method applied to improve the adhesion of polyolefin resin films such as polyethylene and polypropylene, and a packaging material such as a decorative sheet for building materials or a food packaging using these films or sheets. Available to:
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a decorative sheet used as an interior decoration such as a wall of a building or a ceiling, furniture, a surface decoration material such as a cabinet, is often used as a base sheet.
For example, there are prints in which a wood grain pattern or the like is printed on a polyvinyl chloride sheet and a transparent polyvinyl chloride sheet is laminated thereon, and further, a transparent polyvinyl chloride sheet is embossed.
In addition, decorative sheets using polyolefin resin sheets such as polyethylene (hereinafter referred to as PE) and polypropylene (hereinafter referred to as PP) are also used as an alternative to the polyvinyl chloride sheet.
Furthermore, PE and PP are very important materials used in various fields as various packaging materials such as food packaging. In particular, it is often used as a heat seal material for sealing the contents.
[0003]
[Problems to be solved by the invention]
However, since polyolefin resin films (or sheets) such as polyethylene and polypropylene do not have polar groups, the adhesive strength with printing inks and adhesives is not sufficient, and the surface of the polyolefin resin film is subjected to corona discharge treatment. The method, the method of forming a primer layer, etc. are taken.
In addition, as a surface treatment method for a polyolefin film, an ozone treatment method, an ultraviolet treatment method, or the like is also performed.
However, these methods have merits and demerits, and as a decorative sheet for building materials, sufficient adhesive force cannot be obtained.
In particular, the ozone treatment method and the ultraviolet treatment method are simple and can be performed at low cost, but the degree of oxidation of the polyolefin film surface is small, and sufficient adhesive strength cannot be obtained.
Therefore, in the present invention, by combining ozone treatment and ultraviolet treatment, it was found that the amount of generated active oxygen necessary for oxidizing the polyolefin film surface was increased, and this problem was solved.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the surface treatment method of the plastic film was as follows. A mixed gas composed of ozone, oxygen, and nitrogen is irradiated with ultraviolet rays having main wavelengths of 185 nm and 254 nm to generate ozone and a larger amount of active oxygen than the ozone, and a mixed gas containing the ozone and the active oxygen is generated. Move continuously Polyolefin resin Made of plastic fill Of The surface treatment method of a plastic film is characterized in that the surface treatment is performed by spraying on the surface.
[0005]
The mixed gas composed of ozone, oxygen, and nitrogen is introduced into an ultraviolet irradiation device equipped with an ultraviolet lamp that emits ultraviolet rays of 185 nm and 254 nm, and the mixed gas is irradiated with ultraviolet rays to generate ozone and More than the ozone Generate active oxygen, feed the mixed gas containing ozone and active oxygen into the gas blowing section, and move continuously from the discharge port of the gas blowing section Said Perpendicular to plastic film on the direction of film flow Or reverse Blowing on Said A plastic film surface treatment method is characterized in that the plastic film surface is continuously treated.
[0006]
Then, a mixed gas containing ozone and active oxygen generated in the ultraviolet irradiation device is transported by a pipe, from the discharge port of the gas blowing part. Said Spray on plastic film, Said A plastic film surface treatment method is characterized in that the plastic film surface is continuously treated.
[0007]
Furthermore, in the method of spraying the mixed gas containing ozone and active oxygen generated in the ultraviolet irradiation device from the discharge port of the gas spraying portion to the plastic film, the gas spraying portion and a part of the plastic film are covered with a shielding device. In a sealed state, Said Gas mixture containing ozone and active oxygen on the plastic film surface Blowing Tight The And Said A plastic film surface treatment method is characterized in that the plastic film surface is continuously treated.
[0008]
That is, when a mixed gas composed of ozone, oxygen, and nitrogen is irradiated with ultraviolet rays having main wavelengths of 185 nm and 254 nm, oxygen molecules (O ₂ ) To ozone (O _Three ) Is generated and this O _Three Is O by UV light of 254nm ₂ And active oxygen (O) are decomposed, and ozone (O _Three ) And a lot of active oxygen (O).
In particular, since the ultraviolet lamp used in the present invention emits a lot of ultraviolet rays of 254 nm, a large amount of active oxygen is generated.
Next, if a mixed gas containing a large amount of active oxygen (O) is blown onto the polyolefin film, the surface of the polyolefin film comes into contact with a large amount of active oxygen to promote oxidation, and polar groups such as carbonyl groups are generated. In addition, the adhesive strength with the printing ink and the adhesive is improved.
[0009]
In addition, when the polyolefin film surface comes into contact with active oxygen, the extremely thin organic material film adhering to the polyolefin film surface reacts with active oxygen and is removed as a volatile substance. The film surface becomes clean, wettability is improved, and adhesion with printing ink and the like is improved.
Therefore, a major point of the present invention is to generate active oxygen in the mixed gas as much as possible and spray it onto the polyolefin film surface before the active oxygen disappears.
[0010]
Therefore, in the present invention, ozone is irradiated by irradiating a mixed gas composed of ozone, oxygen, and nitrogen (hereinafter referred to as ozone mixed gas) with ultraviolet rays having main wavelengths of 185 nm and 254 nm immediately before spraying on the surface of the plastic film. And active oxygen is generated, and the mixed gas containing ozone and active oxygen (hereinafter referred to as active oxygen-containing mixed gas) is perpendicular to the flow direction of the film while continuously moving the long plastic film. A method of continuously treating the surface of the plastic film by spraying from the slit-shaped discharge port in the direction (the width direction of the film) or the direction opposite to the flow direction of the film was used.
[0011]
Further, as a method of irradiating the ozone mixed gas with ultraviolet rays, an ozone mixed gas is introduced into an ultraviolet irradiation device equipped with the ultraviolet lamp, and the ozone mixed gas is irradiated with ultraviolet rays in the device to generate ozone and active oxygen. Generate as much as possible, transport the mixed gas containing active oxygen through a pipe, and continuously move the long plastic film from the discharge port of the gas blowing part, while slitting in the width direction of the plastic film By spraying on the surface of the plastic film, the surface of the plastic film was continuously treated to improve the processing capacity.
[0012]
Furthermore, the gas blowing part and a part of the film are sealed with a shielding device, and the active oxygen-containing mixed gas is blown onto the film within the shielding device, thereby preventing the active oxygen-containing mixed gas from leaking into the work environment. In addition, since the contact time between the active oxygen-containing mixed gas and the plastic film can be increased, oxidation of the film surface can be further promoted.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing an outline of each step of the plastic film surface treatment method of the present invention.
FIG. 2 is a view showing the outline of the plastic film surface treatment method of the present invention, and is a schematic view when the gas blowing section and the ultraviolet irradiation device are directly connected.
FIG. 3 is a diagram showing an outline of the plastic film surface treatment method of the present invention, and is a schematic view when a gas blowing part and an ultraviolet irradiation device are connected by a pipe.
[0014]
As shown in FIG. 1, the plastic film surface treatment method of the present invention basically supplies an ozone mixed gas 1 composed of ozone, oxygen and nitrogen to a gas supply pipe 11 and introduces it into an ultraviolet irradiation apparatus. A step, a step of generating ozone and active oxygen by irradiating the ozone mixed gas 1 with ultraviolet rays 5 from the ultraviolet lamp 4 in the ultraviolet irradiation device 12, and a mixed gas 2 (active oxygen-containing mixed gas) containing ozone and active oxygen. 2) is composed of a step of spraying the plastic film 3 from the gas spraying portion 13.
[0015]
In the surface treatment method for a plastic film of the present invention, a mixed gas of ozone, oxygen, and nitrogen (hereinafter simply referred to as an ozone mixed gas) is used. Therefore, it is necessary to supply this ozone mixed gas.
The ozone mixed gas can be used by sending air to an ozone generator to generate ozone to produce a mixed gas of ozone, oxygen and nitrogen, which is directly supplied to a gas supply pipe.
Moreover, what filled the gas cylinder with the ozone mixed gas produced with the ozone generator can also be used.
If ozone is generated by sending oxygen to the ozone generator, a mixed gas of ozone and oxygen can be obtained. This mixed gas can be used, but the mixed gas of ozone and oxygen is flammable. In the present invention, a mixed gas of ozone, oxygen, and nitrogen is used because the substance is easy to burn and handling is inconvenient.
[0016]
Next, the surface treatment method for the plastic film of the present invention will be described.
As shown in FIG. 1, the ozone mixed gas 1 composed of ozone, oxygen, and nitrogen obtained as described above is supplied to a gas supply pipe 11 and introduced into an ultraviolet irradiation device 12.
The ultraviolet irradiation device 12 is equipped with an ultraviolet lamp 4 that emits ultraviolet rays of 185 nm and 254 nm, and the ozone mixed gas 1 introduced into the ultraviolet irradiation device 12 is irradiated with the ultraviolet rays 5.
When the ozone mixed gas 1 is irradiated with ultraviolet rays 5 of 185 nm and 254 nm from the ultraviolet lamp 4, as described above, oxygen (O ₂ ) To ozone (O _Three ) And ozone (O _Three ) To produce active oxygen (O), which becomes a mixed gas containing active oxygen (O) in addition to the initial ozone, oxygen, and nitrogen (hereinafter referred to as ozone (O) _Three ) And a mixed gas containing active oxygen (O) is a mixed gas containing active oxygen).
[0017]
Next, the active oxygen-containing mixed gas 2 is sent to the gas blowing unit 13 through the connection pipe 11 a and blown to the plastic film 3 from the discharge port 13 a of the gas blowing unit 13.
The plastic film 3 is usually supplied from the winding and is continuously sprayed with the active oxygen-containing mixed gas 2 while being continuously moved between the roll 14 and the roll 14a, and the surface is oxidized by the active oxygen.
Of course, when it is necessary to increase the contact time between the plastic film 3 and the active oxygen-containing mixed gas 2 in order to increase the degree of oxidation of the plastic film, as described later, the box containing the active oxygen-containing mixed gas 2 The plastic film and the active oxygen-containing mixed gas 2 are brought into contact with each other and processed.
[0018]
Although ozone is a gas that is easily decomposed, it shows toxicity when leaked into the work environment, so according to the US ACGIH, the allowable concentration of ozone in the working environment is 0.1 ppm, and this figure is respected in Japan as well. Has been.
Therefore, after the active oxygen-containing mixed gas 2 is sprayed on the plastic film 3, it cannot be released into the working environment. Therefore, it is necessary to spray the active oxygen-containing mixed gas 2 on the plastic film 3 in a closed system. There is.
If the active oxygen-containing mixed gas 2 is blown onto the plastic film 3 in an open state, immediately after the active oxygen-containing mixed gas 2 is blown onto the plastic film 3, the surrounding air is sucked using a suction device. It is necessary to prevent the active oxygen-containing mixed gas 2 from diffusing into the working environment.
[0019]
Below, the method of spraying ozone on a plastic film without leaking into a work environment is demonstrated.
As shown in FIG. 2A, the ozone mixed gas 1 is supplied from the gas supply pipe 11 and introduced into the ultraviolet irradiation device 12.
In the ultraviolet irradiation device 12, the ozone mixed gas 1 is irradiated with ultraviolet rays 5 of 185 nm and 254 nm from the ultraviolet lamp 4, and ozone and active oxygen are generated to become the active oxygen-containing mixed gas 2.
This active oxygen-containing mixed gas 2 is sent to the gas blowing unit 13 through the connection pipe 11a, and is perpendicular to the flow direction of the plastic film 3 from the discharge port 13a of the gas blowing unit 13 (the width direction of the film). Or sprayed in the opposite direction.
The direction in which the active oxygen-containing mixed gas 2 is sprayed from the discharge port to the plastic film does not necessarily have to be a right angle, and it is sufficient that the plastic film is uniformly sprayed in the width direction of the film.
Practically, it is effective to spray the active oxygen-containing mixed gas 2 from the direction opposite to the film flow direction because the contact time between the plastic film 3 and the active oxygen-containing mixed gas 2 becomes longer.
As shown in FIG. 2B, the discharge port 13a of the gas blowing unit 13 has the same width as the width of the plastic film (the width of the gas blowout), and the gap between the discharge ports is slit-like. It is narrowed and blown out to the surface of the plastic film.
[0020]
As shown in FIG. 2A, the gas blowing portion 13 and the portion of the plastic film 3 where the gas is blown are surrounded by a shielding device 15 and are a sealed system except for the inlet and outlet of the plastic film.
Also, the plastic film inlet and outlet are made of a soft material so that the plastic film can be pressed so that gas does not leak as much as possible.
Furthermore, a suction device is provided at the inlet and outlet portions of the plastic film so that the slightly leaked gas is sucked and discharged outside, so that the active oxygen-containing mixed gas 2 does not leak into the working environment. did.
[0021]
As shown in FIG. 2A, when the shielding device 15 is sized to have a certain length with respect to the flow direction of the film, the shielding device 15 is obtained when the active oxygen-containing mixed gas 2 is sprayed on the plastic film. Since the active oxygen-containing mixed gas 2 filled in 15 comes into contact with the plastic film while the plastic film 3 passes through the shielding device 15, the degree of oxidation of the plastic film can be adjusted relatively easily.
That is, since ozone and active oxygen having a constant concentration generated in the ultraviolet irradiation device are supplied into the shielding device, ozone and active oxygen in the shielding device are always maintained at a constant concentration. Therefore, if the time during which the plastic film 3 stays in the shielding device 15 is made constant, the oxidation degree of the plastic film is always constant.
[0022]
Therefore, the required degree of oxidation of the plastic film can be obtained by changing the residence time of the plastic film in the shielding device, that is, the moving speed of the plastic film.
Also, the method of treating the plastic film in the shielding device is more effective than the method of blowing the active oxygen-containing mixed gas directly on the plastic film and immediately exhausting the active oxygen-containing mixed gas. You can save a lot.
[0023]
Further, as shown in FIG. 3, the ultraviolet irradiation device 12 is installed apart from the gas blowing unit 13, and the active oxygen-containing mixed gas 2 generated by the ultraviolet irradiation device 12 is transported to the gas blowing unit 13 by the connection pipe 11a. There is also a method of spraying on the plastic film 3.
In this case, since the ultraviolet irradiation device 12 is separated from the gas blowing unit 13, the ultraviolet irradiation device 12 can be a high performance device including a large device. For example, a lot of ultraviolet lamps are installed side by side, the irradiation time of ultraviolet rays to the ozone mixed gas 1 is lengthened, more ozone and active oxygen are generated, and the activity of the active oxygen-containing mixed gas 2 is increased. The oxidation efficiency of can be improved.
[0024]
Further, if the flow rate of the ozone mixed gas to the ultraviolet irradiation device is increased, the ultraviolet irradiation time to the ozone mixed gas 1 is shortened and the necessary ozone concentration and active oxygen concentration cannot be obtained. When the apparatus 12 is installed separately, the arrangement of the ultraviolet lamps can be changed to lengthen the flow path of the ozone mixed gas. Therefore, even if the flow rate of the ozone mixed gas is increased, the necessary ozone concentration and active oxygen concentration are increased. Is easily obtained.
[0025]
Further, as shown in FIG. 4, a gas blowing device 10 is configured by incorporating an ultraviolet lamp in the gas blowing section 13, and the ozone mixed gas 1 is irradiated with ultraviolet rays from the ultraviolet lamp 4, and the ultraviolet rays are irradiated. There is also a method of spraying the active oxygen-containing mixed gas 2 onto the plastic film 3.
This method is effective for effective use of active oxygen because it is sprayed on plastic film before ozone and active oxygen generated by UV irradiation decrease, but there are many UV lamps in the gas spraying device. There is a problem in the space for incorporating the film, and the processing capacity of the plastic film is limited.
[0026]
As the ultraviolet lamp used in the present invention, a low-pressure mercury lamp that emits 185 nm and 254 nm as ultraviolet rays is used.
As the output of the ultraviolet lamp, there are various lamps such as 25 W (Watt), 40 W, 56 W, and 350 W. A high output lamp is preferable for the surface treatment of the plastic film because the production speed can be increased.
However, when there is sufficient space for the ultraviolet irradiation device, many low-power ultraviolet lamps may be used side by side.
In order to increase the speed of the surface treatment of the plastic film, several to several tens of UV lamps are usually used side by side in parallel.
The number of UV lamps used is selected according to the processing capacity of the plastic film.
[0027]
The surface treatment method of the present invention can be used for all plastic films that require a surface treatment, but a polyolefin resin film having no polar group is mainly used.
Examples of the polyolefin resin include polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / butene-1 copolymer, propylene / butene-1 copolymer, polybutene-1, butene-1 / propylene / ethylene / ternary copolymer. Examples thereof include a polymer, butene-1, hexene-1, octene-1, ternary copolymer, polymethylpentene, or a single resin or a mixture of two or more.
[0028]
In addition, an elastomer component can be used in combination with the resin for the purpose of improving flexibility and processability.
Examples of the elastomer component include thermoplastic elastomers such as polyolefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, and polyester-based thermoplastic elastomers. Of these, the polyolefin-based thermoplastic elastomer can be used alone or as a polyolefin-based thermoplastic resin.
[0029]
Examples of elastomers include various rubbers. Examples of rubbers include diene rubbers, hydrogenated diene rubbers, and olefin copolymer rubbers. Among these, hydrogenated diene rubbers are preferable.
The hydrogenated diene rubber is formed by adding a hydrogen atom to at least a part of a double bond of a diene rubber molecule, and has a role of suppressing crystallization of the polyolefin resin and improving flexibility and transparency.
In general, when a diene rubber is added to a polyolefin resin, the weather resistance and heat resistance are lower than those of a polyolefin resin without the addition of a diene rubber due to the double bond of the diene rubber. Since the double bond is saturated with hydrogen, the weather resistance and heat resistance of the polyolefin-based resin are not deteriorated, and it is satisfactory.
[0030]
Examples of the diene rubber include isoprene rubber, butadiene rubber, butyl rubber, propylene / butadiene rubber, acrylonitrile / butadiene rubber, acrylonitrile / isoprene rubber, and styrene / butadiene rubber.
The olefin copolymer rubber is an elastic copolymer to which at least one polyene that can be copolymerized with two or three or more olefins is added. As the olefin, ethylene, propylene, α-olefin, or the like is used. As the polyene, 1,4 hexadiene, cyclic diene, norbornane and the like are used. Preferred examples of the olefin copolymer rubber include elastic copolymers containing olefin as a main component such as ethylene-propylene copolymer rubber, ethylene-propylene non-conjugated diene rubber, and ethylene-butadiene copolymer rubber.
[0031]
The amount of rubber added is about 1 to 90 parts by weight with respect to 100 parts by weight of the polyolefin resin. If it is less than 1 part by weight, the elasticity, elongation and impact resistance due to the addition of rubber are insufficient, and cracks and cracks are likely to occur during bending such as V-cutting and drawing. On the other hand, if it is 90 parts by weight or more, the elasticity and the elongation rate become too large, and the examination adjustment at the time of printing becomes unfavorable. The thickness is about 50 to 500 μm, more preferably 50 to 200 μm, and any of stretched and unstretched sheets can be used. However, the unstretched sheet is better in terms of forming suitability such as V-cut processing.
[0032]
When polypropylene (PP) is used as the base sheet of the decorative sheet, a colorless or colored transparent soft polypropylene resin having a composite three-dimensional structure composed of a mixed system of isotactic polypropylene and atactic polypropylene is preferable.
The two-layer or three-layer laminate sheet made of the soft polypropylene resin having the above-mentioned composite three-dimensional structure is required for a decorative sheet, namely, (1) creep deformation resistance, (2) organic solvent resistance, (3) Elongation at break, (4) Impact strength, (5) Moderate flexural modulus, (6) Good transparency, (7) Whitening by recrystallization even when heating and cooling accompanying embossing, etc. A product that does not cause turbidity, satisfies (8) weather resistance, etc. is obtained.
[0033]
【Example】
Below, based on an Example, this invention is demonstrated in more detail.
(Example 1)
While producing a film having a film width of 1400 mm, a take-off speed of 50 m / min, and a thickness of 40 μm by a T-die method using polypropylene resin (manufactured by Idemitsu Petrochemical Co., Ltd.), as shown in FIG. Immediately after that, the active oxygen-containing mixed gas 2 was sprayed as follows to perform surface treatment on one side of the PP film.
As shown in FIG. 5, an ozone mixed gas 1 produced using an ozone generator 1 (21% by volume of oxygen, 79% by volume of nitrogen, 10 g / m of ozone). ^Three ) Is supplied to the gas supply pipe 11 using a compressor, and this ozone mixed gas 1 is sent to a gas blowing device 10 equipped with three 350 W low-pressure mercury lamps (ultraviolet lamp 4) that emit ultraviolet rays of 185 nm and 254 nm. Then, ozone and active oxygen are generated, and the active oxygen-containing mixed gas 2 is flown from the discharge port 13a (width 1400 mm, gap 10 mm) of the gas blowing device 10 at a flow rate of 12 m. ^Three The process was performed by spraying on the PP film 3a at / hour.
[0034]
A suction device was provided at the gas blowing portion of the PP film 3a, and the active oxygen-containing mixed gas 2 after being blown onto the film was sucked, exhausted after being treated with an ozonolysis and removal device.
In addition, ozone (O _Three ) Concentration is 6 g / m ^Three Met.
[0035]
(Example 2)
A PP film 3a having a thickness of 40 μm and a width of 600 mm was produced by the T-die method using the polypropylene used in Example 1.
Further, as shown in FIG. 6A, an ultraviolet irradiation device 12 equipped with 12 25 W low-pressure mercury lamps (ultraviolet lamp 4) that emit ultraviolet rays of 185 nm and 254 nm is manufactured, and ozone mixed gas 1 is supplied thereto. A gas supply pipe 11 is connected to the ultraviolet irradiation apparatus 12 and connected to the gas blowing section 13 with a connection pipe 11a to form the gas blowing apparatus 10.
FIG. 6A is a schematic cross-sectional view when the active oxygen-containing mixed gas 2 is sprayed on the PP film 3a in the shielding device 15 using the gas spraying device 10, and FIG. It is a top view of a figure.
[0036]
In the ultraviolet irradiation device 12, low pressure mercury lamps having an effective light emission length of 300 mm and a tube diameter of 18 mm were arranged in parallel at equal intervals, so that the effective irradiation range was 300 mm wide × 500 mm long. That is, the ultraviolet irradiation device 12 is configured such that ultraviolet rays are irradiated while the ozone mixed gas 1 passes through a rectangular parallelepiped having a length of 500 mm, a width of 300 mm, and a height of 10 mm in the length direction.
Moreover, as shown in FIG.6 (b), the shape of the spraying part 13 is the discharge port 13a so that the active oxygen containing mixed gas 2 sent from the connection pipe 11a may be sprayed to the whole width direction of a film. The width was 600 mm, the same width as the film, and the gap was 5 mm.
[0037]
Further, as shown in FIG. 6 (a), the gas blowing portion 13 and the portion of the PP film 3a to which the gas is blown are sealed with a shielding device 15 so that the active oxygen-containing mixed gas 2 does not leak into the working environment. In addition, the PP film 3a is subjected to surface treatment in contact with the active oxygen-containing mixed gas 2 in the shielding device 15.
The shielding device 15 has a size capable of shielding a 600 mm wide film and a 600 mm wide gas blowing portion, and has a length of 1000 mm.
[0038]
As in Example 1, the gas blowing method was performed using an ozone mixed gas 1 produced by an ozone generator at a flow rate of 12 m. ^Three Supply to the ultraviolet irradiation device 12 at a time to generate ozone and active oxygen, and send the active oxygen-containing mixed gas 2 to the gas blowing unit 13 to flow from the discharge port 13a to a flow rate of 12 m. ^Three Sprayed on the PP film 3a.
The PP film 3a was heated to 120 ° C. with a heater and passed through the shielding device 15 at a speed of 20 m / min. Therefore, the contact time between the PP film 3a and the active oxygen-containing mixed gas 2 was 3 seconds.
[0039]
(Example 3)
A PE film 3b having a thickness of 40 μm and a width of 600 mm was produced by an inflation method using a polyethylene resin (manufactured by Mitsubishi Chemical Corporation).
Further, as shown in FIGS. 7A and 7B, an ultraviolet irradiation device 12 equipped with six U-shaped 350 W low-pressure mercury lamps (ultraviolet lamps 4) that emit ultraviolet rays of 185 nm and 254 nm is manufactured. Similarly to Example 2, the gas supply apparatus 11 was configured by connecting the gas supply pipe 11, the connection pipe 11 a and the gas blowing section 13 to this.
FIG. 7A is a schematic cross-sectional view when the active oxygen-containing mixed gas 2 is sprayed onto the PE film 3b in the shielding device 15 using the gas spraying device 10, and FIG. It is a top view of a figure.
[0040]
By arranging the ultraviolet lamps as described above, the effective irradiation range of the ultraviolet irradiation device 12 becomes 300 mm wide × 350 mm long, so the ozone mixed gas 1 is in a rectangular parallelepiped having a length of 350 mm × width of 300 mm × height of 10 mm. The ultraviolet rays were irradiated while passing through in the length direction.
The shape of the gas blowing part 13 was the same as that in Example 2.
[0041]
Furthermore, as shown to Fig.7 (a), the part to which the gas spraying part 13 and PE film 3b spray the gas was shielded with the shielding apparatus 15. FIG. The size of the shielding device 15 was the same as in Example 2.
[0042]
As in Example 2, the gas spraying method was performed using an ozone mixed gas 1 produced by an ozone generator at a flow rate of 12 m. ^Three Supply to the ultraviolet irradiation device 12 at a time to generate ozone and active oxygen, and send the active oxygen-containing mixed gas 2 to the gas blowing unit 13 to flow from the discharge port 13a to a flow rate of 12 m. ^Three Sprayed on the PE film 3b.
The PE film 3b was heated to 100 ° C. and passed through the shielding device 15 at a speed of 20 m / min. Therefore, the contact time between the PE film and the active oxygen-containing mixed gas 2 was 3 seconds.
[0043]
The films treated in Examples 1, 2, and 3 were greatly improved in wettability as compared with conventional ozone treatment, and the adhesion after dry lamination was greatly improved.
[0044]
【The invention's effect】
According to the present invention, since the active oxygen concentration is increased and sprayed onto the plastic film as compared with the conventional ozone treatment, the plastic film surface is promoted to be oxidized and the wettability is greatly improved.
Therefore, even in the case of a polyolefin-based resin having no polar group, it is possible to improve the adhesive force with the printing ink and the adhesive.
Therefore, if the present invention is used for the production of a decorative sheet for building materials, even when a polyolefin resin sheet (or film) is used, the adhesive strength between the layers becomes strong. Therefore, in the post-process of the decorative member to which the decorative sheet is attached, the suitability for V-cutting and the suitability for bending can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an outline of each step of a plastic film surface treatment method of the present invention.
FIG. 2 is a diagram showing an outline of a plastic film surface treatment method according to the present invention, and is a schematic view when a gas blowing section and an ultraviolet irradiation device are directly connected.
FIG. 3 is a diagram showing an outline of a plastic film surface treatment method according to the present invention, and is a schematic view when a gas blowing part and an ultraviolet irradiation device are connected by a pipe.
FIG. 4 is a diagram showing an outline of a gas spraying apparatus used for the surface treatment of a plastic film of the present invention, and is a schematic view when an ultraviolet lamp is provided in the gas spraying part.
5 is an explanatory diagram when processing the surface of a plastic film according to Example 1. FIG.
6 is an explanatory view when a plastic film surface is treated according to Example 2. FIG.
7 is an explanatory diagram when processing the surface of a plastic film according to Example 3. FIG.
[Explanation of symbols]
1 Ozone mixed gas
2 Mixed gas containing active oxygen
3 Plastic film
3a PP film
3b PE film
4 UV lamp
5 UV
10 Gas spraying device
11 Gas supply pipe
11a Connection pipe
12 UV irradiation equipment
13 Gas blowing part
13a Discharge port
14 rolls
14a roll
15 Shielding device
21 T-die
22 Extruder
23 Cooling roll
24 Nip roll

Claims (4)

A mixed gas composed of ozone, oxygen, and nitrogen is irradiated with ultraviolet rays having main wavelengths of 185 nm and 254 nm to generate ozone and a larger amount of active oxygen than the ozone, and a mixed gas containing the ozone and the active oxygen is generated. the surface treatment method of a plastic film characterized by blowing the plastic film arm surface consisting of continuously moving polyolefin resin surface treatment.   The mixed gas composed of ozone, oxygen, and nitrogen is introduced into an ultraviolet irradiation device equipped with an ultraviolet lamp that emits ultraviolet rays of 185 nm and 254 nm, and the mixed gas is irradiated with ultraviolet rays so that ozone and a larger amount of ozone than the ozone are emitted. Generate active oxygen, send the mixed gas containing ozone and active oxygen to the gas blowing part, and from the discharge port of the gas blowing part to the long plastic film that moves continuously, the film flow direction The surface treatment method of a plastic film according to claim 1, wherein the plastic film surface is continuously treated by spraying in a direction perpendicular to or opposite to the surface of the plastic film.   The mixed gas containing ozone and active oxygen generated in the ultraviolet irradiation apparatus is transported by a pipe, and blown onto the plastic film from the discharge port of the gas blowing section, thereby continuously treating the plastic film surface. The method for surface treatment of a plastic film according to claim 2. In the method in which the mixed gas containing ozone and active oxygen generated in the ultraviolet irradiation device is blown to the plastic film from the discharge port of the gas blowing portion, the gas blowing portion and a part of the plastic film are sealed with a shielding device. in state, plastic film according to the plastic film surface care-blowing a mixed gas containing ozone and active oxygen, claim 2 or claim 3, wherein the processing the plastic film surface continuously Surface treatment method.

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