JP2021171687A - Roll and roll manufacturing method - Google Patents

Abstract

[Problem] To provide a roll which is less susceptible to static electricity than conventional rolls and is less susceptible to various inconveniences caused by static electricity, and a method for manufacturing said roll. [Solution] The roll of the present invention is a roll provided with a DLC film 2, and the DLC film 2 has an electrical resistivity of 1012 to 10-5 Ω·cm on the surface of a roll substrate 1. The roll of the present invention can also be provided with a DLC film 2 having an electrical resistivity of 109 to 10-5 Ω·cm as the DLC film. The roll manufacturing method of the present invention is a method for manufacturing a roll provided with a DLC film 2 on the surface of a roll substrate 1 by plasma treatment, and is a method for manufacturing a roll provided with a DLC film 2 having an electrical resistivity in the range of 1012 to 10-5 Ω·cm by adjusting the amount of a gas containing nitrogen or boron in addition to the main raw material gas of methane or acetylene used to form the DLC film. [Selected Figure] FIG.

Description

The present invention relates to a roll that can be used as a coating roll or a transport roll, and a method for manufacturing the roll.

A resin-made functional film (hereinafter referred to as "film") is used for displays such as organic EL TVs and smartphones. A manufacturing apparatus provided with a transport roll and a coating roll is used for manufacturing the film (for example, Patent Document 1).

During the production of the film by the manufacturing apparatus, static electricity may be generated due to the sliding friction between the film as an insulator and the roll. Since static electricity contributes to various obstacles, it is required to prevent static electricity in the production of films.

Japanese Unexamined Patent Publication No. 2004-344759

The present invention has been made in view of such circumstances, and a problem to be solved thereof is to provide a roll in which static electricity is less likely to be generated as compared with a conventional roll and various inconveniences caused by static electricity are less likely to occur, and a method for manufacturing the roll. There is.

[roll]
The roll of the present invention is a roll provided with a DLC film, and is provided with a DLC film having an electrical resistivity of 10 ¹² to 10 ^-5 Ω · cm on the surface of the roll base material.

[Roll manufacturing method]
The roll manufacturing method of the present invention is a method of manufacturing a roll having a DLC film on the surface of a roll base material by plasma treatment, and by adjusting the amount of nitrogen or boron-containing gas used for forming the DLC film. This is a method for producing a roll having a DLC film having an electrical resistivity in ^{the range of 10 12} to 10 ^{-5 Ω · cm.}

Since the roll of the present invention and the roll manufactured by the roll manufacturing method of the present invention ^{are provided with a DLC film having an electrical resistivity of 10 12} to 10 ^-5 Ω · cm, static electricity is unlikely to be generated, and adverse effects caused by static electricity. Is unlikely to occur.

(A) is a front view showing an example of the roll of the present invention, and (b) is an enlarged view of the Ib portion of (a). The present invention shows an example of the functional film manufacturing apparatus equipped with the roll of this invention. The flowchart which shows an example of the roll manufacturing method of this invention. It shows an example of the apparatus used for carrying out the roll manufacturing method of this invention.

(Roll embodiment)
An example of an embodiment of the roll of the present invention will be described with reference to the drawings. As an example, the roll shown in FIG. 1A is provided with a DLC film 2 having ^{an electrical resistivity of 10 12} to 10 ^{-5 Ω · cm on the surface of the roll base material 1.} In FIG. 1A, the case where the roll base material 1 is mounted on the outer periphery of the shaft 3 is taken as an example, but the roll base material 1 can also be mounted via a bearing attached to the flange.

The roll base material 1 is a tubular roll member that serves as a base for the roll. The roll base material 1 includes a metal roll (typically S25C, SS400, etc.), a stainless steel roll (typically austenitic, ferrite, martensite, double-layer stainless steel, super stainless steel, etc.), and a carbon steel roll (STKM13A). , Etc.), rubber rolls, plating rolls (HCr plating rolls, Ni plating rolls, etc.), resin rolls, sprayed rolls (WC sprayed rolls, etc.), aluminum alloy rolls, and the like can be used.

The thickness and length of the roll base material 1 are not limited and can be set arbitrarily, but when used as a coating roll, the diameter is preferably 4 mm or more. The roll base material 1 may be a tubular material (hollow material) or a solid material (solid material).

Although not shown, the surface of the roll base material 1 is formed with irregularities (cells) having various shapes such as diagonal lines, lattices, and pyramids. The depth and pitch of this cell are about several μm to several thousand μm. The cell shape, depth, and pitch are examples, and may be other than these. The cell may be provided on the entire surface or a part of the roll base material 1. The roll base material 1 may be a smooth one without cells.

The DLC film 2 is a film made of DLC (diamond-like carbon). DLC is amorphous with an intermediate crystal structure between diamond and graphite, and has high hardness, low coefficient of friction, abrasion resistance, electrical insulation, chemical resistance, antibacterial properties, hydrophilicity, water repellency, and ultraviolet resistance. , Has properties such as gas barrier properties.

The DLC film 2 of this embodiment is a film having an electrical resistivity of 10 ¹² to 10 ^-5 Ω · cm. Electrical resistivity of the DLC film 10 ¹⁰ Omega · cm or less, preferably 10 ⁹ to 10 ^-5 Omega · cm approximately, more preferably from 10 ⁷ 10 ^-2 Ω · cm or so.

The electrical resistivity of 10 ¹² to ¹⁰ Ω · cm is a region that has an effect of attenuating static electricity as compared with an insulator, and has an effect of preventing adsorption of dust and the like. From the electrical resistivity of 10 ⁹ to 10 ⁴ Omega · cm is antistatic region, the film is hardly region peeling occurred charging when detached from the roll. The electrical resistivity ^{from 10 3} to 10 ^-3 Ω · cm is the semiconductor region, and since the electrical resistivity is smaller than the antistatic region, it is a region in which peeling charge is less likely to occur. An electrical resistivity of 10 ^-4 Ω · cm or less is a conductive region, which can be used for static elimination purposes.

Since the semiconductor region ^{has a conductive property of about 10 -3} Ω · cm, static electricity can be released while controlling the conductivity, and the static electricity charged on the film surface during film transport is reduced to a certain ratio. Has the effect of reducing (static electricity elimination). For example, static electricity is generated by friction between the film and air in a portion that is not in contact with the roll during film transportation, and the film surface is charged. In this case, static electricity can be removed at once via a roll, but if this is done, static electricity wrinkles may occur at the same location, which may damage the film. On the other hand, in the case of the semiconductor region, such an adverse effect can be prevented by reducing (eliminating static electricity) the static electricity charged on the film surface at a constant rate.

Further, as described above, the conductive region has an effect of preventing defects due to electrostatic charge on the film surface by using the conductive region for the purpose of static elimination in a place where the most electrostatic charge is applied, such as around the winding portion of the film.

The DLC film 2 has a hardness of about 1000 to 7000 HV, preferably about 1500 to 7000 HV, and more preferably about 1500 to 2000 HV as measured by a Vickers hardness tester. The film thickness of the DLC film 2 is 0.5 to 100 μm, preferably about 0.5 to 50 μm.

(Example of use)
The roll of the present invention can be used as a transport roll, a coating roll, or the like for an apparatus used for producing a functional film (hereinafter referred to as "functional film manufacturing apparatus"). When the roll of the present invention is used as a transport roll for a functional film manufacturing apparatus or the like, it has the following merits as compared with a conventional transport roll.

In a conventional transport roll, so-called peeling charge may occur due to static electricity. Normally, since metal is used for the transport roll, static electricity is unlikely to be generated, but since it rotates via a bearing containing insulating oil, static electricity does not flow to the ground along the machine and charges the roll surface. As a result, peeling charge occurs.

On the other hand, in the roll of the present invention, the electrical resistivity of the DLC film can be adjusted in the range of ^{10 12} to 10 ^{-5 Ω · cm.} The electrical resistivity can be arbitrarily (optimally) adjusted according to the above), static electricity is less likely to be generated, and as a result, peeling charge is less likely to occur.

Further, when the roll of the present invention is used as a coating roll for a functional film manufacturing apparatus or the like, there are the following merits as compared with the conventional coating roll.

In conventional coating rolls, in addition to inorganic and organic materials that are indispensable for exerting functions, resin-based fillers and the like are used in the coating liquid. Since these fillers have insulating properties such as oxides and resins, they may aggregate due to static electricity.

In addition, the coating liquid is also agitated as the roll rotates, and the fillers in the liquid may rub against each other, resulting in static electricity (triboelectric charging) and agglutination. In addition, the roll is also charged with static electricity by contact with the film like the transport roll, so that the filler is easily adsorbed. If the filler adheres to the coating roll, there is a problem that scratch marks may be formed on the film during coating.

On the other hand, in the roll of the present invention, the electrical resistivity of the DLC film ^{is as small as 10 12} to 10 ^-5 Ω · cm, so that static electricity is less likely to be generated. As a result, the filler is less likely to adhere to the roll of the present invention, and when used as a coating roll, the harmful effect due to the filler adhering is less likely to occur.

FIG. 2 shows an example of a functional film manufacturing apparatus equipped with the roll of the present invention. In FIG. 2, 4 is a feeding roll, 5 is a winding roll, 6 is a transport roll, 7 is an impression cylinder roll, 8 is a coating container, 9 is a gravure roll, 10 is a touch roll, 11 is a blade, and 12 is a drying. It is a furnace.

In the example of FIG. 2, the roll having antistatic properties to the impression cylinder roll 7 and gravure roll 9 (roll from the electric resistivity of 10 ⁹ 10 ⁴ Ω · cm. Hereinafter the same.) And a roll (electrical resistance with semiconductor properties Rolls with a resistivity of 10 ³ to 10 ^-3 Ω · cm; the same shall apply hereinafter) can be used. The coating liquid in which the gravure roll is immersed is agitated by the rotation of the gravure roll, and the resin-based or oxide-based filler contained in the coating liquid may be triboelectrically charged. In a roll having conductive properties, static electricity charged on the film surface flows to the roll, but traces (whiskers) are generated in the flowing direction, and the smoothness of the coating film on the film surface may be impaired. On the other hand, according to the roll having antistatic characteristics and semiconductor characteristics, static electricity does not flow to the roll (it is difficult to flow), so that such an adverse effect is unlikely to occur.

Further, as the touch roll 10a on the delivery roll 4 side, which is most affected by the peeling charge, a roll having semiconductor characteristics or a roll having conductive characteristics (roll having an electrical resistivity of 10 ^-4 Ω · cm or less; the same applies hereinafter) is used. A roll having a conductive property can be used for the touch roll 10b on the winding roll 5 side, which needs to remove (eliminate static electricity) static electricity existing on the film surface at the time of winding.

As the transport roll 6, different types of rolls can be used depending on the installation location. For example, the transfer roll 6a immediately before the impression cylinder roll 7 and the gravure roll 9 has a roll having antistatic characteristics or a roll having semiconductor characteristics, and the transfer roll 6b in the drying furnace 12 having low humidity and easily generating static electricity has a semiconductor. A roll having a characteristic or a roll having a conductive property can be used, and a roll having an antistatic property can be used for the other transport roll 6c.

(Embodiment of Roll Manufacturing Method)
An example of the roll manufacturing method of the present invention will be described with reference to the drawings. The roll manufacturing method of the present invention is a method of manufacturing a roll having a DLC film 2 on the surface of a roll base material 1 by plasma treatment, and adjusts the amount of gas containing nitrogen (N) and boron (B). This is a method for producing a roll having a DLC film 2 having an electrical resistivity in ^{the range of 10 12} to 10 ^{-5 Ω · cm.}

As an example, the roll manufacturing method shown in FIG. 3 is a method of manufacturing a roll through a cleaning step S1, a mixing layer forming step S2, and a DLC film forming step S3. The cleaning step S1 and the mixing layer forming step S2 need to be performed only when necessary, and can be omitted when unnecessary.

The cleaning step S1, the mixing layer forming step S2, and the DLC film forming step S3 can be carried out by using an apparatus as shown in FIG. In FIG. 4, 13 is a vacuum chamber, 14 is an RF high frequency power supply, 15 is an RF electrode, 16 is a high voltage pulse power supply, and 17 is a gas inlet.

The cleaning step S1 is a step of cleaning the surface of the roll base material 1. In this step, the roll base material 1 is set in the RF electrode 15 of the vacuum chamber 13 and the inside of the vacuum chamber 13 is evacuated. In this state, the surface of the roll base material 1 is etched and cleaned with argon (Ar) for the purpose of cleaning the surface of the roll base material 1 and improving the adhesive force. The etching process can be performed by the same method as before. The cleaning step S1 may be performed as needed, and may be omitted when it is not necessary. Further, in the cleaning step, the oxide layer on the surface of the base material may be reduced by using hydrogen (H) ions in addition to Ar.

Cleaning of the roll base material 1 can be performed under the following conditions, for example.
Gas used: Ar, H ₂
Negative pulse voltage: -1 to -15 kV
RF output: 50-1500W

The mixing layer forming step S2 is a step of forming a mixing layer on the surface of the roll base material 1 in order to improve the bite of the DLC. In this step, the roll base material 1 is set in the RF electrode 15 of the vacuum chamber 13 and the inside of the vacuum chamber 13 is evacuated. In this state, the high voltage pulse power supply 16 applies a negative high voltage pulse to the roll base material 1. Raw material gas (for example, carbon (C) and silicon (Si)) is injected into the vacuum chamber 13 from the gas injection port 17 to generate C radicals to form a mixing layer on the surface of the roll base material 1 to form a DLC. Increases adhesion (adhesion). The mixing layer forming step S2 may be performed as needed, and may be omitted when it is not necessary.

When Si ions are injected as a raw material gas, Si can play the role of a primer. Further, as a raw material gas, _{a mixed gas such as N 2} , Ar, methane (CH ₄ ), acetylene (C ₂ H ₂ ), carbon tetrafluoride (CF ₄ ), C, H, and B can also be injected.

The mixing layer can be formed under the following conditions, for example.
Gas used: Hexamethyldisiloxane (HMDSO), Hexamethyldisilazane (HMDS), Tetramethylsilane (TMS), CH ₄ , C ₂ H ₂
Negative pulse voltage: -1 to -15 kV
RF output: 50-1500W

The DLC film forming step S3 is a step of forming the DLC film 2 on the surface of the roll base material 1 (when the mixing layer is formed, the surface thereof; the same applies hereinafter). The DLC film 2 can be formed by various methods such as a plasma CVD method and a PVD method, but here, the case where the plasma CVD method is used is taken as an example.

In this step, the inside of the vacuum chamber 13 in which the roll base material 1 is set is brought into a vacuum state at room temperature (preferably about 20 ° C. to 50 ° C.). In this state, a high-frequency voltage is applied by the RF high-frequency power supply 14, to generate plasma around the roll base material 1 (specifically, around the RF electrode 15 in the vacuum chamber 13), and the high-voltage pulse power supply 16 A negative high voltage pulse is applied to the roll base material 1.

After that, a raw material gas (for example, a gas containing boron such as N or triethylboron (B (C ₂ H ₅ ) _{3 ) together with CH 4} and C ₂ H ₂ ) is introduced into the vacuum chamber 13 from the gas inlet 17. The DLC film 2 is formed on the roll base material 1 by injecting the raw material gas into the roll base material 1 and reacting the raw material gas in the vacuum chamber 13 to deposit DLC on the surface of the roll base material 1. The DLC film 2 is not particularly specified, and may have a third element such as silicon or nitrogen in addition to carbon and hydrogen which are main elements to be composed. Further, the DLC film 2 may be a hydrophilic DLC film containing oxygen.

To form the DLC film 2, use raw material gas such as _{CH 4} or toluene (C ₇ H _{8 ), N 2} (nitrogen), or B (C ₂ H ₅ ) ₃ or triethoxyboron (B (OC ₂ H _5). ) ₃ ) and trimethyl borate (B (OCH ₃ ) ₃ ) can be added.

As the raw material gas, a hydrocarbon-based gas such as _{CH 4} , C ₇ H ₈ , C ₂ H ₂ , or C ₆ H _{6 (benzene) can be used.} Although the structure of the DLC film 2 is not particularly specified, _{it may contain a third element such as Si, O 2} (oxygen), B, N ₂ , Cr (chromium), and Ti (titanium) to relieve internal stress. ..

The DLC film can be formed under the following conditions, for example.
Gas used: _{Gas containing boron such as CH 4} , C ₂ H ₂ , N ₂ or B (C ₂ H ₅ ) ₃ Negative pulse voltage: −0.1 to -15 kV
RF output: 50-1500W

The DLC film 2 can also be formed in two or more steps. In this case, after the first film formation is performed under the above conditions, for example, the second film formation can be performed under the following conditions.
Gas used: _{Gas containing boron such as C 7} H ₈ , C ₂ H ₂ , N ₂ or B (C ₂ H ₅ ) ₃ Negative pulse voltage: −0.1 to -15 kV
RF output: 50-1500W

After forming the DLC film 2, no particular step such as polishing is required. In the roll of the present invention, the uneven shape of the surface of the roll base material 1 is almost the same as that before the film formation even after the DLC film 2 is formed, and the area ratio is 10% or less.

The rolls produced by the rolls and roll manufacturing methods of the present invention are suitably used as transport rolls and coating rolls for various devices, and in particular, as transport rolls and coating rolls for functional film manufacturing devices. Can be done.

1 Roll base material 2 DLC film 3 axes 4 Unwinding roll 5 Winding roll 6 Transfer roll 6a Transfer roll 6a (immediately before impression cylinder roll and gravure roll) Transfer roll 6b (in drying chamber) Transfer roll 6c (Other) transfer roll 7 Cage roll 8 Coating container 9 Gravure roll 10 Touch roll 10a (on the feeding roll side) Touch roll 10b (on the take-up roll side) Touch roll 11 Blade 12 Drying furnace 13 Vacuum chamber 14 RF High frequency power supply 15 RF electrode 16 High Voltage pulse power supply 17 Gas inlet

Claims (6)

In a roll provided with a DLC film on the surface of the roll base material,
As the DLC film, a DLC film having an electrical resistivity of 10 ¹² to 10 ^-5 Ω · cm was provided.
A roll characterized by that. In the roll according to claim 1,
As DLC film, electrical resistivity with a DLC film of from 10 ⁹ 10 ^-5 Ω · cm,
A roll characterized by that. In the roll according to claim 1,
As DLC film, electrical resistivity with a DLC film of 10 ⁷ to 10 ^-2 Omega · cm,
A roll characterized by that. In the role according to any one of claims 1 to 3.
As the DLC film, a DLC film having a hardness of 1000 to 7000 HV was provided.
A roll characterized by that. In the role according to any one of claims 1 to 3.
As the DLC film, a DLC film having a hardness of 1500 to 2000 HV was provided.
A roll characterized by that. In a method for producing a roll having a DLC film on the surface of a roll base material by plasma treatment,
By adjusting the amount of nitrogen or boron-containing gas used to form the DLC film, a roll having a DLC film having ^{an electrical resistivity in the range of 10 12} to 10 ^{-5 Ω · cm is produced.}
A roll manufacturing method characterized by that.

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