KR102137918B1 - Corona treatment method - Google Patents

Abstract

A surface of the film comprising a step of generating a corona discharge between the discharge electrode 2 and the earth roll 3 and a step of moving the film 10 on the earth roll 3 under corona discharge. This is how it is treated. The discharge electrode 2 is covered with an electrode cover 4, and the electrode cover 4 has an opening 4c on the earth roll 3 side, and the opening 4c of the electrode cover 4 is transverse and inclined. Orientation, or upward direction.

Description

Corona treatment method {CORONA TREATMENT METHOD}

The present invention relates to a method of corona-treating the surface of a film-like pico-corona treatment.

Patent Documents 1 and 2 describe that a surface such as a polarizing film is activated by corona treatment. Corona treatment usually generates corona discharge by applying a high-frequency/high-voltage output supplied by a high-frequency power source between a discharge electrode and an earth roll provided in the corona treatment apparatus, and polarization under the corona discharge. It is carried out by passing a film such as a film (a picorona treated product).

However, when corona treatment is performed over a long period of time, there is a problem in that the yield is lowered due to adhesion of a crystalline foreign substance to the film (phycorona treatment).

On the other hand, it is known that ozone and nitrogen oxides (NOx) are generated by corona discharge (for example, see Patent Document 3). In Patent Document 3, the amount of ozone and nitrogen oxides (NOx) generated is reduced by using a corona treatment device having a predetermined structure.

However, the corona treatment apparatus described in Patent Literature 3 is not necessarily satisfactory from the viewpoint of suppressing adhesion of crystalline foreign substances when the above-mentioned corona treatment is performed for a long period of time. In addition, Patent Document 3 also has a problem in that corona treatment cannot be easily performed because it is necessary to make the corona treatment apparatus a predetermined structure.

Patent Document 1: Japanese Patent Publication No. 2005-213314 Patent Document 2: Japanese Patent Publication No. 2009-8860 Patent Document 3: Japanese Patent Publication No. 4194766

An object of the present invention is to provide a method capable of stably performing corona treatment over a long period of time.

The inventors of the present invention found the following knowledge as a result of repeated studies of the above-mentioned problems in order to solve the above problems.

That is, as a result of analyzing the crystalline foreign matter attached to the corona-treated film (picorona treated), the crystalline foreign matter was oxalic acid, oxalate, ammonium oxalate, aluminum nitrate, ammonium nitrate, and the like.

The present inventors have repeatedly studied the origin of these crystalline foreign substances. As a result, it was found that these crystalline foreign substances accumulate in the corona treatment apparatus as corona discharges, and this is dropped and adhered to the film (phycorona treatment). Further, based on this knowledge, as a result of further studies, when the corona treatment device is disposed so that the opening of the electrode cover provided in the corona treatment device is in a specific direction, the crystalline foreign matter accumulated in the corona treatment device is a film ( It has been found that it is possible to suppress the dropping and adhesion to the picorona treated product, and the present invention has been completed.

That is, the corona treatment method of the present invention has the following configuration.

(1) A corona discharge is generated between the discharge electrode and the earth roll provided in the corona treatment apparatus, and the corona discharge passes a film-like picorona treatment through the earth roll, and the surface of the picorona treatment object. As a method of corona treatment, the corona treatment apparatus covers the discharge electrode, and further includes an electrode cover having an opening on the earth roll side, so that the opening of the electrode cover becomes transverse to upward. A corona treatment method comprising disposing a corona treatment device.

(2) The corona treatment method according to (1) above, wherein the corona treatment apparatus is composed of a corrosion-resistant member.

(3) The corona treatment method as described in said (1) or (2) in which the surface of the said corona treatment apparatus is corrosion-resistant.

(4) The corona treatment method according to any one of (1) to (3), wherein the electrode cover is made of a transparent member.

(5) The corona treatment method in any one of said (1)-(4) in which the said film-form picorona processed material is at least 1 sort(s) selected from an optical film and a protective film.

(6) The corona treatment method according to any one of (1) to (5) above, wherein the length of the film-form picorona treated product is 10,000 m or more.

However, the "earth roll" in the present invention should just have a function of generating a corona discharge between the discharge electrodes and passing a film-shaped picorona treated substance under the corona discharge. It also includes what is referred to as a back roll.

The "film shape" in the present invention is not limited only to the film shape, and is a concept including a film shape to a sheet shape as long as the effects of the invention are not impaired.

Another aspect of the invention is a process for generating a corona discharge between the discharge electrode and the earth roll,

A method of corona-treating the surface of a film comprising the step of running a film on the earth roll under the corona discharge.

The discharge electrode is covered with an electrode cover,

The electrode cover has an opening on the earth roll side,

It is a method in which the opening of the electrode cover faces in the transverse direction, the inclined upward direction or the upward direction.

Here, it is preferable that at least one of the discharge electrode, the earth roll, and the electrode cover has a corrosion-resistant member.

Further, it is also preferable that at least one surface of the discharge electrode, the earth roll, and the electrode cover is subjected to corrosion resistance treatment.

It is also preferable that the gas in the space surrounded by the electrode cover is exhausted by the exhaust pipe, and the exhaust pipe has a corrosion-resistant member or the surface of the exhaust pipe is subjected to corrosion resistance treatment.

Further, it is also preferable that the discharge electrode is supported by an electrode holder, the electrode holder has a corrosion-resistant member, or the surface of the electrode holder is corrosion-resistant.

Moreover, it is preferable that the said electrode cover is transparent.

Moreover, it is preferable that the said film is at least 1 sort(s) chosen from an optical film and a protective film.

Moreover, it is preferable that the length of the said film is 10,000 m or more.

ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the crystalline foreign substance accumulating in the corona processing apparatus falls and adheres to a film (a picorona processed material), and therefore there is an effect that the corona treatment can be stably performed over a long period of time. Further, since a corona processing device having a general configuration can be employed, corona processing can be easily performed.

1 is a schematic explanatory diagram showing a corona processing apparatus according to an embodiment of the present invention.
2(a) to 2(c) are schematic explanatory diagrams for explaining the arrangement state of the corona processing device shown in FIG. 1.
3(a) and 3(b) are schematic explanatory diagrams for explaining the arrangement state of the corona processing device shown in FIG. 1.
4 is a schematic explanatory diagram showing a corona treatment method according to an embodiment of the present invention.

Hereinafter, an embodiment of the corona treatment method according to the present invention will be described in detail with reference to FIGS. 1 to 4. The corona treatment method of this embodiment is performed using the corona treatment apparatus 1 shown in FIG. 1.

The corona processing apparatus 1 includes a discharge electrode 2, an earth roll 3 disposed to face the discharge electrode 2, an electrode cover 4 covering the discharge electrode 2, and a discharge. The electrode holder 5 supporting the electrode 2 and the exhaust pipe 6 located on the other end surface 4b side opposite to the one end surface 4a located on the earth roll 3 side of the electrode cover 4 ).

The discharge electrode 2 has a substantially rod shape, and its tip portion 2a is located inside the electrode cover 4 than one end surface 4a of the electrode cover 4, and the rear end portion 2b is an electrode. It is supported by the holder (5). However, the shape of the discharge electrode 2 is not limited to a substantially rod shape as far as possible, and other shapes, such as a needle shape, a plate shape, and a column shape, may be sufficient.

While the earth roll 3 is earthed, it is arrange|positioned facing the discharge electrode 2 with a predetermined space|interval between the front-end|tip part 2a of the discharge electrode 2, and being. The earth roll 3 is connected to rotation drive means, such as a motor (not shown), and is comprised so that rotation is possible at a predetermined circumferential speed.

The electrode cover 4 has an opening 4c that opens on one end surface 4a located on the earth roll 3 side. In addition, the electrode cover 4 has a pair of side surfaces 4d and 4d. The pair of side surfaces 4d and 4d extend from one end surface 4a toward the other end surface 4b so as to be substantially parallel to each other.

In the exhaust pipe 6, a part of the outer circumference passes through the space surrounded by the electrode cover 4, and the outlet of the exhaust pipe (not shown) is connected to suction means such as a vacuum pump. Thereby, the gas in the space surrounded by the electrode cover 4 can be sucked through the exhaust pipe 6 and exhausted to the outside of the corona treatment apparatus 1. Therefore, ozone generated by corona treatment can be exhausted through the exhaust pipe 6 to the outside of the corona treatment apparatus 1. The air volume at the exhaust pipe outlet of the exhaust pipe 6 is preferably 0.1 m ³ /sec or more in order to reliably exhaust ozone.

The corona treatment method of this embodiment performed using the above-described corona treatment apparatus 1 is configured to connect high-frequency/high-voltage output supplied by a high-frequency power supply (not shown) to the discharge electrode 2 and the earth roll 3. By applying in between, corona discharge is generated between them, and under this corona discharge, the film-like picorona processed object 10 is passed through the earth roll 3, whereby the surface of the corona treated object 10 is This is how it is treated. That is, under corona discharge, the film is run on the earth roll, thereby corona-treating the surface of the film.

As the corona treatment intensity, a desired strength may be employed depending on the film (picorona treated material; 10), and is not particularly limited, but is usually about 200 to 2000 W. When the corona treatment strength is too low, it tends to be difficult to obtain a stable corona discharge over the entire width of the film (picorona treatment; 10), and if it is too high, it differs depending on the heat resistance characteristics of the film (picorona treatment; 10) However, there is a tendency that wrinkles or the like tend to easily occur in the film (picorona treated material 10) due to the heat generated, which is not preferable.

Here, in the corona treatment method of the present embodiment, as shown in Figs. 2(a) to 2(c), the corona so that the opening 4c of the electrode cover 4 described above becomes transverse to upward. The processing device 1 is disposed. That is, the opening 4c of the electrode cover 4 faces in the lateral direction, the inclined upward direction, or the upward direction. Thereby, it is possible to suppress the crystalline foreign matter accumulated in the corona treatment apparatus 1 from falling and adhering to the film (phycorona treated substance) 10, and the corona treatment can be stably performed over a long period of time. On the other hand, as shown in Figs. 3(a) and 3(b), if the corona treatment device 1 is arranged so that the opening 4c of the electrode cover 4 is inclined downward to downward in the transverse direction. , The crystalline foreign matter accumulated in the corona treatment apparatus 1 falls on the film (picorona treatment; 10) and is discarded.

On the other hand, in the general corona treatment apparatus, aluminum is often used for the members constituting the electrode holder 5, the exhaust pipe 6, and the like, but the foreign matter in the crystalline form tends to adhere to many members made of aluminum. Therefore, it is preferable that the corona processing apparatus 1 according to the present embodiment (for example, at least one of a discharge electrode, an earth roll, an electrode cover, an electrode holder, and an exhaust pipe) is made of a member other than aluminum, and corrosion resistance. It is more preferably made of a member. As a corrosion-resistant member, ceramics, stainless steel (SUS), etc. are mentioned, for example. In addition, instead of configuring the corona treatment device 1 itself as a corrosion-resistant member, the surface of the corona treatment device 1 (e.g., at least one of a discharge electrode, an earth roll, an electrode cover, an electrode holder, and an exhaust pipe) The same effect can be obtained also by coating with a corrosion-resistant member or subjecting the surface to corrosion resistance. Examples of the corrosion resistance treatment include an alumite treatment and the like. The above-described anticorrosive member or anticorrosion treatment may be applied to the entire corona treatment apparatus 1, or may be applied to a member or region in the corona treatment apparatus 1 to which crystalline foreign substances are easily attached.

Moreover, it is preferable to configure the electrode cover 4 with a transparent member. Thereby, since the electrode cover 4 becomes transparent, the states of the discharge electrode 2, the electrode holder 5, etc. can be visually confirmed through the electrode cover 4. As a transparency member, acrylic resin etc. are mentioned, for example. Transparent means that it is transparent to visible light (for example, 390 to 750 nm).

It is preferable that the inside of the side surface 4d of the electrode cover 4 is formed in a shape free from grooves and irregularities, etc. in which crystalline foreign matter is likely to accumulate.

As the film (corona treatment) 10 that is corona treated by the corona treatment apparatus 1, a desired film shape that requires corona treatment can be employed, but is not particularly limited, for example, optical such as polarizing film The film, the protective film which protects this optical film, the film provided with an adhesive layer or an adhesive layer, etc. are mentioned. Examples of the polarizing film include adsorption and orientation of a dichroic dye on a polyvinyl alcohol-based film, and examples of the protective film include acetylcellulose-based resin films such as triacetylcellulose and diacetylcellulose. And cycloolefin-based resin films.

As the length (hereinafter referred to as "throughput") of the film (picorona treated; 10), it is preferably 10,000 m or more, more preferably 30,000 m or more, and even more preferably 40,000 m to 60,000 m desirable. When conventional corona treatment is performed with respect to such a throughput, there is a tendency that a foreign substance in a crystalline form tends to adhere to the film (phycorona treated substance) 10. According to the corona treatment method of the present embodiment capable of stably performing corona treatment over a long period of time, the corona treatment can be stably performed even for the above-described throughput. However, the film having the above-described processing amount (picorona treated material; 10) may be released from one disc roll in which a long film (picorona treated material) is wound in a roll shape, each of which is prescribed. A plurality of films (picorona treated products) having a throughput may be connected.

The thickness of the film (phycorona treated; 10) is usually about 10 to 300 µm, and the width of the film (phycorona treated; 10) is usually about 300 to 2500 mm, but is not limited to these. .

Next, as an example in which a polarizing film and a protective film are used as a film (picorona treated product 10), for example, an embodiment in which the corona treatment of the present invention is performed on their surfaces will be described in detail with reference to FIG. 4. Explain.

As shown in the figure, first, two corona processing devices 1 and 1 are arranged at a predetermined position so that the opening 4c of the electrode cover 4 is in the lateral direction.

Subsequently, the polarizing film 11 and the protective film 12 are conveyed through the guide rolls 15a and 15b before corona treatment in arrows A and B, respectively. At this time, the polarizing film 11 and the protective film 12 are conveyed so that their respective surfaces contact the guide rolls 15a and 15b before corona treatment.

Then, by applying a high-frequency high-voltage output supplied by a high-frequency power supply (not shown) between the discharge electrode 2 and the earth roll 3, corona discharge is generated between them, and the earth roll ( The polarizing film 11 and the protective film 12 are passed through 3).

Thereby, while corona-treating the respective surfaces of the polarizing film 11 and the protective film 12, the corona treatment apparatus 1 is arrange|positioned so that the opening part 4c of the electrode cover 4 may become a transverse direction. Therefore, it is possible to suppress the crystalline foreign matters accumulated in the corona treatment apparatus 1 from falling and adhering to the polarizing film 11 and the protective film 12, and accordingly, the corona treatment can be stably performed over a long period of time.

On the other hand, in order to reduce the cost, before carrying the polarizing film 11 and the protective film 12, a low-cost film is previously conveyed as a lead film, and thereafter, the polarizing film 11 and the protective film 12 are conveyed. It is desirable to do. At this time, it is preferable to generate corona discharge when the polarizing film 11 and the protective film 12 pass over the earth roll 3 without generating corona discharge during lead film conveyance.

After the corona treatment, the polarizing film 11 and the protective film 12 are conveyed through the guide rolls 16a and 16b after the corona treatment in arrows C and D, respectively. Here, when the surfaces of the polarizing film 11 and the protective film 12 activated by the corona treatment contact the guide rolls 16a, 16b after the corona treatment, the guide rolls 16a, 16b after the corona treatment It tends to be contaminated. For this reason, oxalic acid produced by corona treatment exists on the surface of the polarizing film 11 and the protective film 12 after the corona treatment, and this is attached to the guide rolls 16a and 16b after the corona treatment. It is guessed. For this reason, in this embodiment, the polarizing film 11 after the corona treatment and the protective film 12 are conveyed so that the back surface opposite to the surface activated by the corona treatment contacts the guide rolls 16a, 16b after the corona treatment. .

Then, the surfaces of each other activated by the corona treatment are joined by a pair of left and right bonding rolls 17a, 17b, and taken out in the direction of the arrow E to obtain a polarizing plate 13. However, the layer structure of the polarizing plate 13 is a two-layer structure in which the protective film 12 is bonded to the surface of the polarizing film 11, but the protective film 12 is also bonded to the back surface of the polarizing film 11 to 3 You may make it into a layer structure.

Moreover, bonding of the polarizing film 11 and the protective film 12 can be performed using an adhesive, a pressure-sensitive adhesive (pressure sensitive adhesive), etc., for example, and is not specifically limited.

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

Example

Using the corona treatment apparatus 1 shown in FIG. 1 described above, the surface of the film (phycorona treated product 10) was corona treated. Then, the presence or absence of adhesion of a crystalline foreign substance to the film (phycorona treatment; 10) was visually observed and evaluated. The constitution of the used corona treatment apparatus 1, the film (picorona treated product 10), and the corona treatment conditions are shown below, and the results are shown in Table 1.

(Configuration of corona treatment device 1)

ㆍElectrode holder (5), exhaust pipe (6): made of aluminum with anodized (corrosion-resistant) surface

ㆍelectrode cover (4): made of transparent acrylic resin

ㆍDirection of the opening 4c of the electrode cover 4: inclined upward direction (see Fig. 2(b))

(Film (Ficorona treatment; 10) and Corona treatment conditions)

ㆍFilm (Picorona treated material; 10): Polarizing film, cycloolefin film, and triacetylcellulose film each having a predetermined throughput

ㆍCorona treatment intensity: 600W

ㆍThroughput: 49654m

[Comparative example]

A film (picorona treated material) was used in the same manner as in the above-described embodiment, except that the direction of the opening 4c of the electrode cover 4 was directed downward (see FIG. 3(b)) and the throughput was 49747 m. The surface of 10) was corona-treated, and the presence or absence of adhesion of a crystalline foreign substance to the film (picorona-treated product 10) was visually observed and evaluated. Table 1 shows the results.

The direction of the opening 4c of the electrode cover 4 Throughput Presence or absence of adhesion of crystalline foreign matter Example Slope upward 49654m none Comparative example Downward 49747m has exist

As is apparent from Table 1, the embodiment in which the direction of the opening 4c of the electrode cover 4 was inclined upward direction, the corona was stably over a longer period of time than the comparative example in which the direction of the opening 4c was downward. It can be seen that processing can be performed.

1 Corona treatment unit
2 discharge electrodes
3 Earth Roll
4 electrode cover
4a one side
4b Other section
4c opening
4d side
5 electrode holder
6 Exhaust pipe
10 film (picorona treated)
11 polarizing film
12 protective film
13 Polarizer
15a, 15b guide roll before corona treatment
Guide roll after 16a, 16b corona treatment
17a, 17b bonding roll

Claims (8)

A corona discharge is generated between the first discharge electrode provided with the first corona treatment device and the first earth roll, and under the corona discharge, a polarizing film is passed through the first earth roll, and the surface of the polarizing film is generated. Corona treatment process,
A corona discharge is generated between the second discharge electrode provided with the second corona treatment device and the second earth roll, and under the corona discharge, a protective film is passed through the second earth roll, and the surface of the protective film Corona treatment process,
In order to prevent oxalic acid produced on the surface of the polarizing film activated by the corona treatment from being attached to the first guide roll, the polarization after the corona treatment so that the back surface of the surface of the polarizing film contacts the first guide roll. The process of conveying the film,
In order to prevent oxalic acid produced on the surface of the protective film activated by the corona treatment from being attached to the second guide roll, the protection after corona treatment so that the back surface of the protective film contacts the second guide roll. The process of conveying the film,
And a step of bonding the surface of the polarizing film activated by corona treatment and the surface of the protective film activated by corona treatment using an adhesive or an adhesive,
The first corona processing apparatus further includes a first electrode cover having an opening on the first earth roll side while covering the first discharge electrode,
The first corona processing apparatus is disposed so that the opening of the first electrode cover is inclined upward to upward.
The second corona processing apparatus further includes a second electrode cover having an opening on the second earth roll side while covering the second discharge electrode,
The second corona processing apparatus is disposed so that the opening of the second electrode cover is inclined upward to upward.
The polarizing film is a polyvinyl alcohol-based film adsorbed and oriented dichroic,
The protective film is an acetyl cellulose-based resin film, or a cycloolefin-based resin film,
Corona treatment method characterized in that the corona treatment strength is 200 to 2000 W. The method according to claim 1, wherein the first corona treatment device and the second corona treatment device are made of a corrosion-resistant member. The method according to claim 1, wherein the surface of the first corona treatment apparatus and the surface of the second corona treatment apparatus are subjected to corrosion treatment. The method according to claim 1, wherein the first electrode cover and the second electrode cover are made of a transparent member. The method according to any one of claims 1 to 4, wherein the length of the polarizing film and the length of the protective film are 10,000 m or more. delete delete delete

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