JP2019011413A - Method for producing multilayer film - Google Patents

Abstract

An object of the present invention is to provide a production method capable of efficiently producing a high-quality multilayer film by suppressing the occurrence of uneven oxygen concentration in the film width direction that may occur during roll conveyance. A discharge treatment apparatus used in a discharge treatment process includes a step of performing a discharge treatment on a surface of a long substrate, and a step of forming a coating layer on the surface of the substrate after the discharge treatment. A processing unit, a housing that accommodates the discharge processing unit, a transport roll that is arranged with a gap between the housing so that the base material can be transported, and an inlet side on which the base material of the housing is loaded A blow-out device that blows a gas containing an inert gas and dry air onto a base material that is provided in the case wall and is carried into the gap, and the discharge treatment step includes inert gas and dry air into the case And at least one of supplying a gas containing inert gas and dry air from the gas outlet to the substrate carrying-in path to the surface of the substrate under predetermined conditions. The manufacturing method of a multilayer film including performing discharge processing. [Selection] Figure 3

Description

  The present invention relates to a method for producing a multilayer film.

  A coating film is formed by applying a coating solution on the surface of a traveling belt-like substrate to form a coating layer, and if necessary, drying the coating layer to produce a multilayer film having two or more layers. It has been done conventionally. And in order to apply | coat a coating liquid on the surface of a base material favorably, performing the corona discharge process to the surface of a base material prior to application | coating and modifying a base material surface is performed. As an apparatus for efficiently performing such discharge processing, an apparatus that performs continuous processing on a continuous film that is continuously conveyed is known (for example, Patent Document 1).

  Generally, corona discharge treatment requires the presence of a controlled concentration of oxygen in the discharge environment. For this reason, an apparatus for performing a discharge process on a long film surrounds a part of the film transport path with a chamber, and controls the oxygen concentration in the chamber. The oxygen concentration is controlled so that the oxygen concentration in the chamber becomes a specific value such as 0.2%. Such control is generally performed by adjusting the amount of inert gas such as nitrogen introduced into the chamber.

JP 2014-196454 A

  Here, the long film is conveyed by the roll into the corona discharge treatment apparatus while entraining external air, so that the oxygen concentration in the chamber becomes high. Furthermore, in the width direction of the film, since the air entrainment method is different, unevenness of the oxygen concentration may occur on the surface of the film that is corona-treated in the chamber. In the width direction, there may be a difference in characteristics such as wettability and peel strength.

  Accordingly, an object of the present invention is to provide a production method capable of producing a high-quality multilayer film by suppressing the occurrence of uneven oxygen concentration in the film width direction that may occur during roll conveyance.

The present inventor has studied to solve the above problems. As a result, by controlling the film conveyance speed and the pressure of the gas introduced into the chamber, the unevenness of the oxygen concentration on the film surface during the corona discharge treatment is eliminated, and the wettability of the film after the corona discharge treatment is improved. The manufacturing method which can be made uniform in the width direction was found. The present invention has been completed based on such findings.
That is, the present invention is as follows.

（上記式中、Ｐ_０は前記筐体の外側の気圧（Ｐａ）、Ｐ_１は前記筐体内へ供給されるガスの流入圧力（Ｐａ）、Ｐ_２は前記ガス吹き出し口から前記基材搬入路へ供給されるガスの流入圧力（Ｐａ）、ｖは前記搬送ロールの搬送速度（ｍ／秒）、ｈ_１は前記基材搬入路の幅の最小値（ｍ）、ｈ_２は前記ガス通路の幅の平均値（ｍ）、Ｌ_１は前記搬送ロールの前記基材搬入路に対応する部分の外周長さ（ｍ）、Ｌ_２は前記ガス通路の長さ（ｍ）、Ｌ_３は前記筐体の前記ガス吹き出し口が設けられている壁面の前記基材搬入口から前記ガス吹き出し口までの長さ（ｍ）、μ_１は前記筐体内に供給されるガスの粘度（Ｐａ・ｓ）、μ_２は前記基材搬入路へ供給されるガスの粘度（Ｐａ・ｓ）を示し、Ｈ_２は（ｈ_２Ｌ_２＋ｈ_１Ｌ_３）／（Ｌ_２＋Ｌ_３）である。）
〔２〕 前記放電処理工程において、連続走行する前記基材の前記面に、大気圧以上、酸素濃度０．０５重量％以上０．５５重量％以下、かつ水分含有量５ｍｇ／ｍ³以下の環境下でコロナ放電処理を行い、
前記塗工層形成工程において、前記基材のコロナ放電処理された面に塗工液を塗布して前記塗工層を形成する、〔１〕に記載の複層フィルムの製造方法。
〔３〕 前記放電処理工程を、コロナ放電処理装置を用いて行う、〔１〕または〔２〕に記載の製造方法。
〔４〕 前記放電処理工程において、５Ｗ・分／ｍ^２以上１００Ｗ・分／ｍ^２以下でコロナ放電処理を行う、〔１〕〜〔３〕のいずれか一項に記載の複層フィルムの製造方法。
〔５〕 前記放電処理工程において、前記筐体内へ不活性ガス及び乾燥空気を含むガスを供給することを含み、前記不活性ガスの流量をＸ（Ｌ／ｍｉｎ）、前記乾燥空気の流量をＹ（Ｌ／ｍｉｎ）としたときに、Ｙ／Ｘが０．００５以上０．０５０以下である、〔１〕〜〔４〕のいずれか１項に記載の複層フィルムの製造方法。
〔６〕 前記放電処理工程において、前記筐体内へ不活性ガス及び乾燥空気を含むガスを供給することを含み、前記筐体の幅をＷ（ｍｍ）、前記不活性ガスの流量をＸ（Ｌ／ｍｉｎ）としたときに、Ｘ／Ｗが０．０５以上０．３０以下である、〔１〕〜〔５〕のいずれか１項に記載の複層フィルムの製造方法。
〔７〕 前記放電処理工程において、前記筐体内へ不活性ガス及び乾燥空気を含むガスを供給することを含み、前記筐体の幅をＷ（ｍｍ）、及び前記筐体への前記ガスの流量Ｚ（Ｌ／ｍｉｎ）としたときに、Ｚ／Ｗが５．０５×１０^−２以上３．０３×１０^−１以下である、〔１〕〜〔６〕のいずれか１項に記載の複層フィルムの製造方法。
〔８〕 前記基材が脂環式構造含有重合体を含む樹脂のフィルムである、〔１〕〜〔７〕のいずれか１項に記載の複層フィルムの製造方法。
〔９〕 前記放電処理工程の後、前記塗工層形成工程の前に、前記基材を除電する工程をさらに含む、〔１〕〜〔８〕のいずれか１項に記載の複層フィルムの製造方法。 [1] A method for producing a multilayer film comprising a step of performing a discharge treatment on the surface of a long substrate, and a step of forming a coating layer on the surface of the substrate after the discharge treatment,
The discharge treatment apparatus used in the discharge treatment step includes a discharge treatment unit, a casing that houses the discharge treatment unit, and a transport roll that is arranged with a gap that allows the base material to be transported between the case and the case. And a blowing device that is provided in a housing wall on the carry-in side where the base material of the housing is carried in, and blows a gas containing an inert gas and dry air onto the base material carried into the gap, Have
The blowing device includes a gas supply unit that supplies a gas including an inert gas and dry air from the outside, a gas blowing port that opens in a wall surface facing the gap of the housing, and the gas blowing unit of the gas supply unit. A gas passage communicating from the mouth end to the gas outlet,
A gap between the transport roll and the wall surface of the housing where the gas outlet is provided is a base material carry-in path,
In the discharge treatment step, a gas containing an inert gas and dry air is supplied into the housing, and a gas containing an inert gas and dry air is supplied from the gas outlet to the substrate carry-in path. Among these, the manufacturing method of a multilayer film including performing an electrical discharge process on the surface of the said base material on the conditions shown to following formula (1)-(7) including at least one.

(In the above formula, P ₀ is the atmospheric pressure (Pa) outside the casing, P ₁ is the inflow pressure (Pa) of the gas supplied into the casing, and P ₂ is the base material carry-in path from the gas outlet). The inflow pressure (Pa) of the gas supplied to V, v is the conveyance speed (m / sec) of the conveyance roll, h ₁ is the minimum value (m) of the width of the substrate carrying-in path, and h ₂ is the gas passage The average width (m), L ₁ is the outer peripheral length (m) of the part of the transport roll corresponding to the substrate carrying-in path, L ₂ is the length of the gas passage (m), and L ₃ is the housing The length (m) from the base material inlet to the gas outlet of the wall surface of the body where the gas outlet is provided, μ ₁ is the viscosity (Pa · s) of the gas supplied into the housing, mu ₂ represents the viscosity (Pa · s) of the gas supplied to the substrate introduction passage, _{H 2} is _{(h 2 L 2 + h 1} L 3) / (L + _{L 3)} it is.)
[2] In the discharge treatment step, an environment having an atmospheric pressure or higher, an oxygen concentration of 0.05% by weight or more and 0.55% by weight or less, and a water content of 5 mg / m ³ or less is formed on the surface of the substrate that continuously runs. Under the corona discharge treatment,
The method for producing a multilayer film according to [1], wherein, in the coating layer forming step, the coating layer is formed by applying a coating solution to a surface of the substrate that has been subjected to corona discharge treatment.
[3] The manufacturing method according to [1] or [2], wherein the discharge treatment step is performed using a corona discharge treatment apparatus.
[4] The multilayer film production according to any one of [1] to [3], wherein in the discharge treatment step, corona discharge treatment is performed at 5 W · min / m ² or more and 100 W · min / m ² or less. Method.
[5] In the discharge treatment step, a gas containing an inert gas and dry air is supplied into the housing, the flow rate of the inert gas is X (L / min), and the flow rate of the dry air is Y The method for producing a multilayer film according to any one of [1] to [4], wherein Y / X is 0.005 or more and 0.050 or less when (L / min) is set.
[6] The discharge treatment step includes supplying a gas containing an inert gas and dry air into the housing, wherein the width of the housing is W (mm), and the flow rate of the inert gas is X (L / Min), the method for producing a multilayer film according to any one of [1] to [5], wherein X / W is 0.05 or more and 0.30 or less.
[7] In the discharge treatment step, a gas including an inert gas and dry air is supplied into the housing, the width of the housing is W (mm), and the flow rate of the gas to the housing The compound according to any one of [1] to [6], wherein Z / W is 5.05 × 10 ⁻² or more and 3.03 × 10 ⁻¹ or less when Z (L / min) is set. A method for producing a layer film.
[8] The method for producing a multilayer film according to any one of [1] to [7], wherein the base material is a resin film containing an alicyclic structure-containing polymer.
[9] The multilayer film according to any one of [1] to [8], further including a step of discharging the base material after the discharge treatment step and before the coating layer forming step. Production method.

  According to the manufacturing method of the multilayer film of this invention, generation | occurrence | production of the nonuniformity of the oxygen concentration in the film width direction which may arise in the case of roll conveyance can be suppressed, and a high quality multilayer film can be manufactured efficiently.

FIG. 1 is a schematic diagram schematically showing an example of a production apparatus for carrying out the production method for a multilayer film of the present invention and an operation of the production method of the present invention. FIG. 2 is a front view schematically showing a state in which the corona discharge treatment apparatus 100 shown in the example of FIG. 1 is observed from a direction perpendicular to the axis 112 of the roll 111. FIG. 3 is a cross-sectional view schematically showing a cross section of the corona discharge treatment apparatus 100 shown in FIGS. 1 and 2 taken along a plane perpendicular to the axis 112 of the roll 111. FIG. 4 is a cross-sectional view showing a main part of the corona discharge treatment apparatus 100 shown in FIG.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and its equivalent scope.

[Embodiment 1]
[1. Overview of manufacturing method]
The production method of the present invention includes a step of performing a discharge treatment on the surface of the elongated substrate (discharge treatment step), and a step of forming a coating layer on the surface of the substrate after the discharge treatment (coating layer forming step). )including.

  FIG. 1 is a schematic view schematically showing an example of a production apparatus for carrying out a production method for a multilayer film according to the present invention and an operation of the production method according to the present invention. In FIG. 1, the manufacturing apparatus 10 includes a corona discharge treatment apparatus 100, a coating apparatus 300, a scraping apparatus 400, and a stretching apparatus 500 in order from the upstream of the manufacturing line. In the operation of the manufacturing method of the present invention using the manufacturing apparatus 10, the elongated base material 30 is unwound from the film roll 60, transported in the direction of A <b> 1, and subjected to corona discharge processing by the corona discharge processing apparatus 100. The coating liquid is applied by the coating apparatus 300, the excess coating liquid is scraped by the scraping apparatus 400, and the stretching process is performed by the stretching apparatus 500. Thereby, the multilayer film 90 is obtained, wound up, and film roll 80.

[2. Discharge treatment process]
In the present embodiment, the discharge treatment process is performed by supplying a gas containing inert gas and dry air (also referred to as “first mixed gas”) into the housing, and from the gas outlet to the substrate carry-in path. And supplying a gas containing active gas and dry air (also referred to as “second mixed gas”). Details of the gas including the inert gas and the dry air will be described later.

  In the electric discharge treatment step, corona discharge treatment is performed on the surface of the continuously running substrate under a specific environment. Such a discharge treatment process is performed using a corona discharge treatment apparatus provided with means capable of forming such an environment. In the example shown in FIG. 1, this step is performed using a corona discharge treatment apparatus 100.

  In the present application, the corona discharge treatment is broadly understood and includes various discharge treatments called so-called glow discharge treatment and plasma discharge treatment.

[2.1. Discharge treatment device]
A more specific structure of the corona discharge treatment apparatus 100 shown in FIG. 1 is shown in FIGS.
FIG. 2 is a front view schematically showing a state in which the corona discharge treatment apparatus 100 shown in the example of FIG. 1 is observed from a direction perpendicular to the axis 112 of the transport roll 111.
FIG. 3 is a cross-sectional view schematically showing a cross section of the corona discharge treatment apparatus 100 shown in FIGS. 1 and 2 taken along a plane perpendicular to the shaft 112 of the transport roll 111.
FIG. 4 is a cross-sectional view showing a main part of the corona discharge treatment apparatus 100 shown in FIG.

  As shown in FIGS. 2 and 3, the corona discharge treatment apparatus 100 includes a corona discharge electrode 131 (an example of “discharge treatment unit”, hereinafter also referred to as “electrode”), a housing 120 that houses the electrode 131, A transport roll 111 arranged with a gap S1 capable of transporting the base material 30 between the housing 120 and the base material provided in the slit block 122F (inside the housing wall) and carried into the gap S1. 30 and a blowing device 125 that blows the second mixed gas. The transport roll 111 can rotate around the shaft 112.

  The housing 120 has a structure that surrounds the lower portion of the transport roll 111 and is close to the transport roll 111 via a slight gap S1. As a result, the inside chamber is defined by the surface of the transport roll 111 and the housing 120. A gap S1 between the transport roll 111 and the wall surface 122L of the housing 120 functions as a base material carry-in path.

  As shown in FIG. 3, a plurality of electrodes 131 are provided in the housing 120. Preferably, the electrode 131 is electrically connected to a high frequency generator (not shown) in a manner capable of adjusting the frequency and power, and is installed in a manner capable of adjusting the distance from the transport roll 111 in the casing 120. Thereby, the mode of discharge in the discharge treatment can be adjusted. The electrode 131 has a plate-like shape extending in parallel with the extending direction of the shaft 112 of the transport roll 111, whereby a partial area on the surface of the transport roll 111 (area indicated by an arrow A 201 in FIG. 2). The discharge treatment can be uniformly applied to the entire width direction of the substrate 30 guided in contact with the substrate. The transport roll 111 is connected to the ground as necessary, so that the discharge from the electrode 131 can be efficiently directed to the transport roll 111.

Inside the housing 120 of the corona discharge treatment apparatus 100, there is provided a blowout port (I) 141 that is electrically connected to a gas supply device (not shown) and opens into a chamber defined by the transport roll 111 and the housing 120. A gas containing an inert gas and dry air is supplied into the housing 120 via the blowout port 141. The inflow pressure P1 of the _first mixed gas supplied into the housing can be measured by a barometer 151 installed in the housing. Examples of the barometer 151 include a precision digital barometer.

  An oxygen concentration measuring device 153 that measures the oxygen concentration in the chamber is further provided inside the housing 120. As a result, the oxygen concentration in the vicinity of the electrode 131 during operation can be measured.

  An exhaust port 142 is provided at the bottom of the housing 120. The exhaust port 142 communicates with a conduit 143 that extends from the housing 120 and opens to the outside of the housing. From the exhaust port 142, the gas can be exhausted from the chamber at a positive pressure as required.

  The housing 120 includes a front wall 121F that is an upstream wall and a rear wall 121B that is a downstream wall. The front wall 121F has a slit block 122F at its upper end, and the rear wall 121B has a slit block 122B at its upper end.

  The front wall 121F and the rear wall 121B further include support members 124F and 124B, respectively, and the support members 124F and 124B support the slit blocks 122F and 122B, respectively. Each of the support members 124F and 124B is provided in such a manner that its position can be changed upward and downward, whereby the width of the gap between the substrate 30 to be carried in and the slit block 122F and the substrate 30 to be carried out are discharged. The width of the gap between the slit block 122B and the slit block 122B can be adjusted.

  The electrode 131 is provided in the housing 120 via a support member 134 in the chamber. The support member 134 is provided in such a manner that its position can be changed upward and downward, and thereby the width of the gap between the substrate 30 and the electrode 131 can be adjusted.

  As shown in FIG. 3, a blowing device that blows a gas containing an inert gas and dry air onto the base material 30 carried into the gap S1 inside the slit block 122F of the front wall 121F (inside the housing wall). 125 is provided. Therefore, the blowing device 125 is provided in a manner embedded in the slit block 122F of the front wall 121F.

  As shown in FIG. 4, the blowing device 125 includes a gas supply unit 125A that supplies a second mixed gas from the outside, a gas blowing port 123F that opens in a wall surface 122L facing the gap S1 of the housing, and a gas supply unit 125A. And a gas passage 123 communicating from the upper end portion (end portion 125B on the gas outlet side) to the gas outlet 123F.

  The gas outlet 123F (also referred to as an outlet (II) 123F) opens toward the transport roll 111 on the wall surface 122L facing the gap S1 of the housing 120. The gas supply unit 125A is electrically connected to a pipe 126 that supplies the second mixed gas from the gas supply device. The second mixed gas supplied from the pipe 126 enters the gas supply part 125A, and then is ejected from the gas outlet 123F through the gas passage 123, thereby forming a gas curtain. The blowout port (II) 123F is provided over the entire width direction of the housing 120, whereby reduction of the accompanying flow can be achieved over the entire base material carry-in port (122F1 in the drawing). The slit block 122F has a structure in which the width of the gas passage 123 can be varied. By adjusting the amount of the second mixed gas introduced from the pipe 126 and the width of the gas passage 123, the amount and speed of gas ejection from the outlet (II) 123F can be adjusted.

The inflow pressure P2 of the _second mixed gas supplied from the gas outlet 123F to the base material carry-in path (gap S1) can be measured by a barometer 152 installed in the gas supply unit 125A. Examples of the barometer 152 include a precision digital barometer.

  In the present embodiment, as shown in FIG. 3, the gap S3 (base material carry-out path) between the transport roll 111 and the slit block 112B also inside the slit block 122B (within the housing wall) of the rear wall 121B. A blowing device 225 for blowing gas onto the base material 30 conveyed inside is provided. The blowing device 225 has the same configuration as the blowing device 125. The gas blown to the substrate by the blowing device 225 is preferably a gas common to the second mixed gas blown to the substrate by the blowing device 125 (a gas containing inert gas and dry air). In the blowing device 225, the gas supplied from the pipe 226 enters the gas supply unit, and then is blown out from the gas blowing port 123B through the gas passage 223, whereby a gas curtain can be formed.

[2.2. Discharge treatment operation]
An example of the operation in the discharge treatment process using the corona discharge treatment apparatus 100 shown in FIGS. In the discharge treatment process of this example, an appropriate tension is applied to the base material 30 to bring it into contact with the transport roll 111, the transport roll 111 is rotated, and the base material 30 is transported in the direction indicated by the arrow A1. As a result, the gap S1 between the transport roll 111 and the slit block 122F serves as a base material inlet for carrying the base material 30 into the interior from the outside of the chamber, and the clearance S3 between the transport roll 111 and the slit block 122B. However, it functions as a substrate outlet for unloading the substrate 30 from the inside of the chamber to the outside. Further, the electrode 131 is energized to generate corona discharge toward the transport roll 111, thereby performing continuous corona discharge treatment on the substrate 30.

  In the discharge treatment process, the oxygen concentration and the water content in the environment where the corona discharge treatment is performed are adjusted to a specific range.

[Operation of discharge treatment equipment]
In the discharge treatment process, the oxygen concentration in the environment in the chamber is preferably adjusted to 0.05 wt% or more and 0.55 wt% or less. The oxygen concentration is more preferably 0.08% by weight or more, further preferably 0.2% by weight or more, more preferably 0.4% by weight or less, and further preferably 0.3% by weight or less. By the presence of oxygen in the discharge treatment environment, polar groups are imparted on the surface of the substrate subjected to the corona discharge treatment, and a desired reforming treatment is achieved. And by making oxygen concentration more than the said minimum, since provision of this polar group can be achieved in a short time, an efficient discharge process is attained. However, if the oxygen concentration is too high in an environment without decompression, non-uniform corona discharge can occur. On the other hand, when the oxygen concentration is too high, generation of unwanted foreign matters due to by-products increases. Therefore, by setting the oxygen concentration to be equal to or higher than the lower limit and equal to or lower than the upper limit, it is possible to achieve good corona discharge even in an environment without decompression, and to efficiently apply polar groups to the substrate surface. And the generation of foreign matter can be reduced.

The water content in the discharge treatment environment, that is, the amount of water contained in the gas in the discharge treatment environment is preferably adjusted to 5 mg / m ³ or less. The water content is more preferably 2 mg / m ³ or less, ideally zero mg / m ³ . When the oxygen concentration in the discharge treatment environment is within the specific range and the water content is within this range, generation of undesired by-products due to discharge can be suppressed.

  The discharge processing environment having such an oxygen concentration and moisture content uses a processing apparatus including a chamber surrounding the environment in which the discharge processing is performed, as in the examples shown in FIGS. And by adjusting the water content.

  In the present embodiment, in order to adjust the oxygen concentration in the chamber, a gas containing inert gas and dry air (containing oxygen at a lower concentration than the atmosphere) is supplied from the gas supply device to the outlet (I) 141 in the discharge treatment process. Therefore, the disturbance of the corona discharge due to the blown airflow can be reduced.

Examples of the inert gas include noble gases such as nitrogen and argon, but nitrogen is usually used from the viewpoint of cost. Dry air is air dried. As the dry air, one having a dew point of a predetermined low value can be used. The dew point of the dry air at atmospheric pressure is preferably −20 ° C. or lower, more preferably −30 ° C. or lower. Dry air with a dew point of −20 ° C. has a moisture content of about 1.07 g / m ³ under atmospheric pressure. By introducing this into the chamber, the moisture content in the chamber can be easily adjusted to a low value. it can.

Dry air can be prepared by compressing the atmosphere with a compressor to remove the condensed moisture. By such a preparation method, useful dry air can be easily prepared and pressure for pumping can be applied to the air. Specific examples of dry air include air having a dew point of −10 ° C. or lower under compression of 0.76 MPa (dew point of approximately −34.4 ° C. or lower at atmospheric pressure, moisture content of 0.314 g / m at atmospheric pressure) ³ or less) can be used. Prior to supplying air to the chamber, it is preferable to remove particles with a filter in order to perform a good discharge treatment. Specifically, it is preferable to set the amount of particles satisfying the requirements of class 5 of the ISO 14644-1 standard or a more stringent class.

  The supply of the gas containing the inert gas and dry air (first mixed gas) into the housing can be performed, for example, by the following operation. For example, the gas supplied from the nitrogen generator and the dry air supply device is stored in the buffer tank after it is confirmed by the oxygen concentration measurement device that the oxygen concentration is sufficiently low. The mixed gas is supplied from the buffer tank to the outlet 141 at a desired flow rate by a blower and a flow rate control device. By having such a blowout opening (I) 141 that is electrically connected to the gas supply device, the environment in the chamber can be easily adjusted to the desired range described above.

  In supplying the first mixed gas into the chamber (inside the casing), it is preferable that the flow rate X (L / min) of the inert gas and the flow rate Y (L / min) of the dry air are in a specific ratio. . Specifically, it is preferable that Y / X satisfies the relationship of 0.005 or more and 0.050 or less. Y / X is more preferably 0.01 or more, further preferably 0.015 or more, more preferably 0.045 or less, and still more preferably 0.04 or less. When X and Y satisfy such a relationship, the oxygen concentration and moisture content in the chamber can be easily adjusted to a desired range.

  When supplying the first mixed gas into the chamber, the flow rate of the supplied first mixed gas is preferably a specific amount. In addition, when supplying the first mixed gas into the chamber, the flow rate of the inert gas supplied into the chamber is preferably a specific amount. The flow rate is determined by the flow rate Z (L / min) of the first mixed gas per width W (mm) of the chamber and the flow rate X (L / min) of the inert gas per width W (mm) of the chamber, that is, It can be defined as Z / W and X / W. The width W of the chamber corresponds to the width A202 of the housing 120 in the examples shown in FIGS.

Specifically, it is preferable that Z / W is 5.05 × 10 ⁻² or more and 3.03 × 10 ⁻¹ or less. Z / W is more preferably 0.1 or more, further preferably 0.15 or more, more preferably 0.25 or less, and further preferably 0.22 or less. X / W is preferably 0.05 or more and 0.30 or less. X / W is more preferably 0.1 or more, further preferably 0.15 or more, more preferably 0.25 or less, and further preferably 0.22 or less.

When Z / W, X / W, or both satisfy such a relationship, the oxygen concentration and water content in the chamber can be easily and stably adjusted to a desired range.
For example, when only the inert gas (Y / X = 0) is supplied into the chamber, the oxygen supply source is only air flowing in from the gap between the chambers, and the main one is associated with the base material 30. The air flows from the gap S1. In this case, the oxygen concentration in the chamber is adjusted by adjusting the supply amount of the inert gas. At that time, the amount of inert gas supplied is relatively small and the inflow of oxygen becomes unstable. Therefore, when the oxygen concentration becomes higher than the set value in the discharge treatment operation, the inert gas is supplied. It is necessary to continuously perform control such as increasing the introduction amount of oxygen and decreasing the introduction amount of the inert gas when the oxygen concentration becomes lower than the set value. Moreover, when such gas supply is performed, the inflow of gas from the gap S1 between the casings constituting the chamber increases, and the generation of foreign matter may increase.
On the other hand, when Z / W or X / W satisfies the relationship described above, a relatively large amount of gas is supplied into the chamber. As a result, the degree to which the oxygen concentration in the chamber is affected by the air flowing from the gap of the chamber such as an accompanying flow is reduced. As a result, continuous control is not performed. For example, if the Y / X value is set to a certain value, even if only the operation of maintaining a fixed amount of gas supply without changing it in the discharge processing operation, It becomes possible to maintain the oxygen concentration inside at a desired value. Thereby, the oxygen concentration in the chamber can be easily and stably adjusted to a desired range. Also, the water content can be easily and stably adjusted to a desired range by the same principle.

  The flow rates of the inert gas and the dry air may be continuously controlled in parallel with the discharge treatment. For example, when Z / W, X / W or both values are within a specific range, In this case, after the value of Y / X is set to a certain value, it may be merely controlled to maintain it without changing it.

  The atmospheric pressure in the chamber is controlled to atmospheric pressure or higher, preferably atmospheric pressure + 20 Pa or higher. Thereby, the amount of outside air flowing into the chamber can be reduced, and an environment with a low oxygen concentration can be easily maintained. On the other hand, the atmospheric pressure in the chamber is preferably atmospheric pressure + 0.3 MPa or less, more preferably atmospheric pressure + 0.2 MPa or less, because it is possible to form a good corona discharge.

  When the atmospheric pressure of the environment in the chamber becomes higher than a set pressure, the pressure can be adjusted by opening a path from the exhaust port 142 to the outside and exhausting from the exhaust pipe 143. Further, when a substance such as a gas harmful to the discharge process is accumulated in the chamber by the discharge process, the substance can be excluded from the chamber by exhausting from the exhaust port 142 and the exhaust pipe 143. it can. In that case, in order to maintain the atmospheric pressure in the chamber, the flow rate of the first mixed gas blown out from the blowing port (I) can be increased as necessary.

  The oxygen concentration in the chamber (in the housing) is preferably adjusted based on the value measured by the oxygen concentration measuring device 153 provided in the vicinity of the electrode 131 in the housing. By providing such an oxygen concentration measuring device, it is possible to obtain an oxygen concentration value that accurately reflects the oxygen concentration in the discharge space and to adjust the oxygen concentration more appropriately.

  That is, when the oxygen concentration measuring device 153 in the enclosure determines that the oxygen concentration is higher than the set concentration, the amount of gas supplied from the nitrogen generator and the dry air supply device is appropriately controlled by the flow rate control device. By doing so, the oxygen concentration of the gas supplied to the outlet (I) 141 can be lowered, and thereby the oxygen concentration in the chamber can be lowered. Alternatively, the oxygen concentration in the chamber can also be lowered by increasing the flow rate of the gas supplied to the outlet (I) 141 and reducing the amount of outside air flowing from the gaps (for example, the gap S1 and the gap S3). it can.

  In the manufacturing method of the present embodiment, the blowing ports (II) 122F and 122B are provided at positions separated from the electrode 131, and the gas including the inert gas and the dry air is blown from there. Disturbance of corona discharge due to airflow can be reduced. Here, separating means that the distance between the outlets (II) 123F and 123B and the electrode 131 is 10 mm or more, preferably 50 mm or more.

  In the manufacturing method of the present embodiment, an inert gas and dry air are included in the base material carried into the base material carry-in path from the blowout port (II) 123F provided on the wall surface 122L of the slit block 122F of the housing 120. Supplying gas (hereinafter also referred to as “second mixed gas”). At the base material carry-in port 122F1, outside air can be introduced as the base material 30 is carried. If the introduction of the outside air is allowed, the oxygen concentration in the chamber easily approaches the outside air, and it becomes very difficult to maintain a predetermined low oxygen concentration in the chamber. However, in the present embodiment, such a blowout port (II) 123F is provided at the base material carry-in port 122F1, and by blowing such a second mixed gas, an air curtain is formed, and into the chamber. The introduction of outside air can be effectively reduced, and as a result, a predetermined low oxygen concentration can be easily maintained in the chamber.

  From the outlets (II) 123F and 123B, the second mixed gas is blown upward in FIG. At the position where the second mixed gas is blown to the base material 30 from the blow-out port (II) 123F on the base-material carry-in side into which the base material 30 is carried in, the blow-out direction (from the blow-out port (II) 123F to the base material 30) 4 is a traveling direction of the base material 30 (a direction indicated by an arrow Y in FIG. 4), which is parallel to a tangent to the surface of the transport roll 111 at the intersection of the surface of the transport roll 111 and the arrow Y. ) Is 0 ° and the direction opposite to the traveling direction of the substrate is 180 °, preferably 90 to 165 °. By providing the outlet at an angle in the range and spraying at an angle in the range, the inflow of outside air at the inlet can be effectively suppressed. However, the blowing direction and the direction of the tangent line of the transport roll 111 here are directions projected onto a plane perpendicular to the axis 112 of the transport roll 111.

  The second mixed gas supplied from the outlet (II) 123F and the gas supplied from the outlet (II) 123B are common to the first mixed gas introduced into the chamber from the outlet (I) 141. It is preferable to use gas from the viewpoint of low supply cost and easy control of the environment in the chamber.

  In the present embodiment, the discharge treatment step includes performing a discharge treatment on the surface of the substrate 30 under the conditions shown in the following formulas (1) to (7).

In the above formula, P ₀ is the atmospheric pressure (Pa) outside the casing 120, P ₁ is the inflow pressure (Pa) of the gas supplied into the casing 120, and P ₂ is the base material carry-in path S 1 from the gas outlet 123 F. Inflow pressure (Pa) of the gas supplied to V, v is the conveyance speed (m / sec) of the conveyance roll 111, h ₁ is the minimum value (m) of the width of the substrate carry-in path (gap S1), and h ₂ is the gas outer peripheral length of the average value of the width of the passage 123 (m), _{L 1} is the part corresponding to the substrate introduction passage of the transfer roll 111 (111P from 111F in FIG. 4) (m), _{L 2} is a gas passage 123 (FIG. length from 125B in _{4 123F1) (m), L} 3 is the length from the substrate entrance 122F1 wall 122L of gas housing 120 outlet 123F is provided to the gas outlet 123F (m), mixed gas mu ₁ is supplied to the housing 120 Viscosity (Pa · s), μ ₂ indicates a viscosity of the second mixture gas supplied to the substrate introduction passage _{S1 (Pa · s), H} 2 is _{(h 2 L 2 + h 1} L 3) / (L ₂ + L ₃ ).

  By performing the discharge treatment under the conditions shown in the formulas (1) to (7), the accompanying flow from the base material inlet 122F1 can be reduced, and the occurrence of uneven oxygen concentration in the width direction of the base material is suppressed. be able to. As a result, a clothing film having uniform wettability and peel strength can be obtained.

In the present _{invention, [(P 1 -P 0)} h 1 2 / 6μ 1 vL 1] + [(P 2 -P 0) H2 3 / 6μ 2 h 1 v (L 2 + L 3)] ( hereinafter "Z value Is greater than 1 and less than 20. The Z value is preferably 3 or more, more preferably 5 or more, preferably 18 or less, more preferably 15 or less.

The air pressure P ₀ outside the housing 120 includes an inflow pressure P _{1 of} gas supplied into the housing 120 and an inflow pressure (Pa) P _{2 of} gas supplied from the gas outlet 123F to the substrate carry-in path S1. It can be measured with a precision digital barometer as well.

The outer peripheral length L ₁ (m) of the part corresponding to the base material carry-in path of the transport roll 111 is preferably 0.03 or more, more preferably 0.05 or more, preferably 0.8 or less, more preferably 0.7 or less. The length L ₂ (m) of the gas passage 123 is preferably 0.03 or more, more preferably 0.05 or more, preferably 0.8 or less, more preferably 0.7 or less. L ₃ is preferably a length L ₃ (m) from the base material inlet 122F1 to the gas outlet 123F of the wall surface 122L where the gas outlet 123F of the housing 120 is provided, preferably 0.03 or more, more preferably 0. .05 or more, preferably 0.8 or less, more preferably 0.7 or less.

  The conveyance speed v (m / sec) of the conveyance roll 111 is preferably 0.05 or more, more preferably 0.1 or more, preferably 4.0 or less, more preferably 2.0 or less.

In the manufacturing method of the present invention, oxygen can be supplied to the chamber by introducing dry air into the chamber, so that the air flowing in along with the base material 30 from the gap S1 into which the base material 30 is carried in can be supplied. A small amount is preferable for forming a stable in-chamber environment.
Therefore, it is preferable that the width of the gap S1 (the width of the base material carry-in path, h ₁ shown in FIG. 4) is narrow to some extent. Specifically, h ₁ is preferably 0.002 m or less, more preferably 0.0015 m or less. On the other hand, from the viewpoint of carrying a smooth substrate, the lower limit of h ₁ can be set to 0.0008 mm or more, for example.
Moreover, it is preferable that the gas blowing speed from the blowing port (II) is higher than a certain level. Therefore, the width of the gas passage 123 (h ₂ shown in FIG. 4) is preferably narrowed to a certain level. Specifically, h ₂ is preferably 0.002 m or less, more preferably 0.0015 m or less, and the lower limit of h ₂ can be, for example, 0.002 m or more.

In the corona discharge treatment, the power applied to the electrode 131 can be adjusted as appropriate so that a good corona discharge is formed. From the viewpoint of further reducing the generation of foreign matter, it is preferable to perform corona discharge treatment at a relatively low output. The output of the specific discharge treatment is preferably 5 W · min / m ² or more, more preferably 7 W · min / m ² or more, preferably 100 W · min / m ² or less, more preferably 60 W · min / m 2. ² or less. Further, the distance between the substrate and the electrode is preferably 0.5 mm or more, and preferably 2 mm or less.

[3. Static elimination process]
In the manufacturing method of this invention, it is preferable to further include the process of neutralizing a base material after a discharge treatment process and before a coating layer formation process. In the example of FIG. 1, the static elimination process can be performed at an arbitrary position downstream of the discharge treatment apparatus 100 and upstream of the coating apparatus 300 in the production line.

  By performing the static elimination process, the electrostatic pressure on the surface of the base material can be reduced, preventing the base material and the coating liquid from repelling each other in the coating layer forming process, to the base material surface of the coating liquid Can be promoted.

  The static elimination step can be performed using a known static elimination device. For example, using a commercially available static eliminator (for example, SJ-H156A manufactured by Keyence Corporation), static eliminator can be performed under conditions of a static elimination pulse frequency of 1 to 68 Hz and a down flow of 0 to 0.3 m / s.

[4. Base material]
The base material that can be used in the production method of the present invention will be described. As the base material, a film-like member is usually used. Especially, it is preferable to use a resin film as a base material. Among the resins forming the base material, a preferable example includes a resin containing an alicyclic structure-containing polymer (hereinafter, referred to as “alicyclic structure-containing polymer resin” as appropriate). The alicyclic structure-containing polymer resin is excellent in transparency, low hygroscopicity, dimensional stability and light weight, and is suitable for an optical film. As a base material, the base material etc. which are disclosed by Unexamined-Japanese-Patent No. 2014-196454 etc. can be used, for example.

[5. State of base material after discharge treatment]
A polar group can be imparted to the surface of the base material subjected to the discharge treatment step and, if necessary, the static elimination step. The amount of polar groups on the treated substrate surface can be measured by X-ray photoelectron spectroscopy (XPS). The proportion of polar groups on the treated substrate surface is the sum of C—C bonds, C—O bonds, C═O bonds, C (═O) O bonds, and O—C (═O) O bonds. % Of the peak intensity derived from bonds other than the C—C bond in the case of%, preferably 20 to 100%.

  On the treated substrate surface, the presence of many polar groups increases the affinity for polar liquids, and the contact angle for polar liquids is smaller than before treatment. In addition, since uniform processing can be achieved, the standard deviation when the contact angle is measured at many points in the plane can be a small value. For example, even when a stretched resin film containing an alicyclic structure-containing polymer having a low affinity for water is used as a substrate, the average contact angle θ with respect to water is less than 50 °, and the standard deviation σ of θ Can achieve high hydrophilicity, such as less than 4.0.

[6. Coating layer forming process]
The manufacturing method of the present invention is a coating method in which a coating solution is applied to a surface of a substrate that has been subjected to a corona discharge treatment after the discharge treatment step or after the discharge treatment step and the subsequent neutralization step. Including a layer forming step.

  The coating layer forming step can be performed by a known coating apparatus such as a gravure coater, a transport roll coater, or a die coater. The coating layer forming step may also include an operation of scraping excess coating liquid by a scraping device equipped with a smoothing roll or the like in addition to the coating operation by the coating device. In the example shown in FIG. 1, the process is performed using a coating apparatus 300 and a scraping apparatus 400.

[7. Coating liquid]
The coating liquid that can be used in the production method of the present invention will be described.
As the coating liquid, a liquid that can improve the wettability of the base material with respect to the liquid by a discharge treatment step on the base material and that is suitable for providing a coating layer can be used as appropriate. In particular, as the coating liquid, a liquid containing a solvent and a substance that may remain in the coating layer after drying the coating liquid (hereinafter sometimes simply referred to as “solid content”) may be used. As the coating liquid, for example, a coating liquid disclosed in JP 2014-196454 A can be used.

  The viscosity of the coating liquid is preferably 10 mPa · s or less, and particularly preferably 8 mPa · s or less. Thereby, a coating liquid can be apply | coated thinly and uniformly.

[8. Other optional steps]
In the manufacturing method of the present invention, an optional step can be performed in addition to the steps described above. For example, an operation such as heating may be performed on the coating liquid layer, thereby curing the coating liquid layer and forming a coating layer. Further, the substrate can be stretched, and the area, thickness, and optical properties of the resulting multilayer film can be adjusted to a desired range. Such stretching step can be performed after the coating liquid layer curing step, or the stretching is usually performed at a temperature close to the glass transition temperature of the substrate by heating. The step of curing the coating liquid layer can be performed simultaneously.

[9. Description of multilayer film]
The multilayer film manufactured by the manufacturing method of this invention is equipped with a base material and the coating layer formed in this base material. Here, the dry thickness of the coating layer is preferably 10 nm or more, more preferably 20 nm or more, preferably 120 nm or less, more preferably 100 nm or less.

The multilayer film is usually used as an optical film. When the example of the optical film used as a multilayer film is given, a protective film, retardation film, an optical compensation film, etc. will be mentioned.
Moreover, you may use a multilayer film as a stretched film. That is, a coated film may be formed thereon using a stretched film as a base material, or a multilayer film formed by forming a coating layer on a base material (which may be a stretched film or an unstretched film). You may extend | stretch and use after manufacturing.

  Especially, the multilayer film obtained by the manufacturing method of this invention is suitable for a polarizing plate protective film. When the multilayer film obtained by the production method of the present invention is used as a polarizing plate protective film, such a polarizing plate protective film is, for example, the multilayer film itself obtained by the production method of the present invention alone as a polarizing plate protective film. The polarizing plate protective film may be a combination of the multilayer film obtained by the production method of the present invention and another film.

[10. Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above, You may implement it further changing.
(1) In the above embodiment, the oxygen concentration measuring device 151 is provided in the chamber and the oxygen concentration is measured. However, in the chamber, not only the oxygen concentration but also the concentration of other types of substances, etc. A measuring device that also measures this information may be provided, and the measurement may be performed in the discharge processing step. For example, a substance such as a gas harmful to the discharge process can be accumulated in the chamber by the discharge process, so a measurement device for measuring the amount of the substance is provided, and based on information obtained from the measurement device, When the amount of the substance exceeds a predetermined amount, control for opening the exhaust port 142 and exhausting air can be performed in the discharge treatment process.
(2) In the above embodiment, an example in which the blowing device 225 having the same mode as the blowing device 125 provided inside the front wall 122F of the housing 120 is also provided inside the rear wall 122B of the housing 120 is shown. However, the blowing device may be provided only on the carry-in port side. Further, the blowing device that blows the gas onto the substrate conveyed by the conveying roll may be provided outside the casing in a mode different between the carry-in port side and the carry-out port side, for example, the blow-out device on the carry-out port side.
(3) In the above-described embodiment, in the discharge treatment step, a gas containing an inert gas and dry air is supplied into the housing, and a gas containing the inert gas and dry air is supplied from the gas outlet to the substrate carry-in path. Although the manufacturing method including both of supplying was shown, even if the discharge treatment is performed on the surface of the base material under the conditions satisfying the formulas (1) to (7), only one of them may be included. Good.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples, and may be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and its equivalent scope. Further, in the following description, “%” and “part” representing amounts are based on weight unless otherwise specified. Further, in the following description, the operation was performed in an environment of normal temperature and pressure unless otherwise specified regarding temperature and pressure.

[Evaluation test]
[Measurement of contact angle]
The contact angle with respect to water was measured on the surface subjected to the discharge treatment and the charge removal treatment of the substrate 600 at the time obtained in the charge removal step of (1-3-2) below. For the measurement, a water contact angle was obtained by a θ / 2 method using a fully automatic contact angle meter (“LCD-400S” manufactured by Kyowa Interface Science Co., Ltd.). The water contact angles (θ) at 10 points were measured at equal intervals in the width direction of the base material 600, and the average value thereof was determined as the contact angle θ (unit) of the base materials of the examples and comparative examples (hereinafter also referred to as “each example”). : °). The standard deviation σ of the water contact angle was calculated from the 10 measured values.

[Evaluation of adhesive strength]
The surface of the urethane resin layer of the multilayer film produced in each example and one side of the polarizer produced in Production Example 1 described below are bonded with a roll laminator using the adhesive produced in Production Example 2. Thus, a polarizing plate was produced. The obtained polarizing plate was cut into a width of 10 mm, the polarizer and the film were pulled in the 90 ° direction, and the tensile force (90 ° peel strength) when peeling off was measured. The measurement was performed with a length of 20 mm, and the average value (average peel strength) and the standard deviation of the peel strength at that time were obtained. A universal tensile / compression tester (TCM-500CR: manufactured by Shinsei Tsushin Kogyo Co., Ltd.) was used as a measuring machine, and the test was performed at a tensile speed of 20 mm / min.

(Production Example 1: Production of polarizer)
A polyvinyl alcohol film having a thickness of 80 μm was dyed in a 0.3% iodine aqueous solution. Thereafter, the film was stretched 5 times in 4% boric acid aqueous solution and 2% potassium iodide aqueous solution, and then dried at 50 ° C. for 4 minutes to produce a polarizer.

(Production Example 2: Production of adhesive)
Water was added to goosephimer Z410 (manufactured by Nippon Synthetic Chemical Industry, polyvinyl alcohol containing an acetoacetyl group) to dilute to 3% solid content to produce an adhesive.

[Hajiki-mura]
The multilayer film produced in each example was irradiated with a video light VLG-301 manufactured by LPL. The reflected light of this film was visually observed from an oblique direction, and a portion that had a diameter of 0.5 mm or more and was transparently transparent in a circular shape was defined as repellency unevenness, and the presence or absence of repellency unevenness was confirmed in the width direction.

[Example 1]
(1-1. Production of coating liquid)
An aqueous dispersion of polyurethane ("Superflex 210" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) in an amount of polyurethane, 15 parts of an epoxy compound ("Denacol EX313" manufactured by Nagase ChemteX) as a crosslinking agent, and a non-volatile base 2 parts of adipic acid dihydrazide, 10 parts of silica particle water dispersion (“Snowtex ZL” manufactured by Nissan Chemical Co., Ltd .; average particle size 85 nm) as a lubricant, and acetylene surface activity as a wetting agent A liquid composition having a solid content concentration of 4% is prepared by blending 0.5% by weight of the agent (“Surfinol 440” manufactured by Air Products and Chemical Co., Ltd.) and water with respect to the total solid content. Got as. The viscosity of the coating solution was 1.2 mPa · s.

(1-2. Production of base material)
A pellet of an alicyclic olefin resin (“ZEONOR” manufactured by Nippon Zeon Co., Ltd .; glass transition temperature 126 ° C.) containing a norbornene polymer was dried at 100 ° C. for 5 hours. This pellet is supplied to an extruder, melted in the extruder, passed through a polymer pipe and a polymer filter, extruded from a T die into a sheet on a casting drum, cooled, and a long substrate having a thickness of 80 μm and a width of 2100 mm Got. Both ends and the width direction of the obtained base material were cut and removed, the width was set to 1700 mm, and the film was rolled to obtain a film roll.

(1-3. Production of multilayer film)
The multilayer film was manufactured using the manufacturing apparatus 10 schematically shown in FIG.

(1-3-1. Discharge treatment process)
The base material 30 was drawn out from the film roll 60 obtained in (1-2), conveyed in the direction of A1, and subjected to corona discharge treatment using a corona discharge treatment apparatus 100 (manufactured by Kasuga Denki Co., Ltd.). Subsequently, the coating liquid obtained in (1-1) is applied by the coating apparatus 300, the surplus coating liquid is scraped by the scraping apparatus 400, and the stretching process is performed by the stretching apparatus 500. A film 90 was obtained and wound up to form a film roll 90.

As the corona discharge treatment apparatus 100, an apparatus schematically shown in FIGS. The width A202 of the housing 120 was 2200 mm, and the length of the electrode 131 was 2000 mm. The width of the gap between the electrode 131 and the substrate 30 was 1 mm. The minimum value _{h 1} of the width of the gap S1 (base material introduction passage) between the slit blocks 122F and the base 30 of the front wall of the housing was 1 mm (0.001 m). The discharge amount of the corona discharge treatment apparatus 100 was 10 W · min / m ^2, and the conveyance speed v of the base material 30 introduced into the apparatus 100 was 0.5 m / s. The amount of nitrogen gas introduced into the chamber in the housing 120 was 300 L / min, and the amount of dry air introduced was 3 L / min (dry air volume / inert gas volume = 0.01).
The pressure P ₀ outside the casing 120 is 101325 Pa, the inflow pressure P ₁ of the first mixed gas supplied into the casing 120 is 101350 Pa, and the inflow of gas supplied from the gas outlet 123F to the base material carry-in path S1 the pressure _{P 2} was 101350Pa. The average width h ₂ of the gas passage 123 is 0.001 m, the outer peripheral length L ₁ of the portion corresponding to the base material carry-in path of the transport roll 111 is 0.1 m, and the length L ₂ of the gas passage 123 is 0.2 m. , the length _{L 3} from the substrate entrance 122F1 wall 122L of gas housing 120 outlet 123F is provided to the gas outlet 123F is 0.05 m, _{H 2} was 0.001 m. The first mixed gas supplied into the casing 120 and the second mixed gas supplied to the substrate carry-in path S1 are the same, and their viscosities μ ₁ and μ ₂ are 1.76 × 10 ⁻⁵ Pa.・ It was s.
During the discharge treatment, the oxygen concentration in the chamber was monitored by the oxygen concentration measuring device 153. As a result, the oxygen concentration in the chamber was stably reduced to 0.2% without particularly adjusting the amount of gas introduced. Kept. The atmospheric pressure in the chamber was maintained in the range of atmospheric pressure or higher and atmospheric pressure + 0.1 MPa or lower. Moreover, the water content of the environment in the chamber was 0.9 mg / m ³ .

(1-3-2. Static elimination process)
The corona-treated film was neutralized with a static eliminator (Keyence SJ-HA).

(1-3-3. Coating layer forming step)
As the coating apparatus 300, an apparatus provided with a coating roll was used. The coating roll 40 was rotated on the surface of the base material 30 by rotating the coating roll in the same direction as the transport direction of the base material 30 at a peripheral speed of 30 m / min.

  As the scraping device 400, a device provided with a scraping roll having a diameter of 40 mm was used. The scraping roll was rotated at a rotational speed of 8.5 rpm in the direction opposite to the conveying direction of the substrate 30 and operated so as to obtain a coating layer having a dry thickness of 45 nm.

  In the stretching apparatus 500, both ends in the width direction of the base material 30 were gripped, and the stretching process was continuously performed in the film width direction at a stretching temperature of 139 ° C. and a stretching ratio of 1.50. During the stretching process, the coating liquid layer was heated and cured on the substrate 30 to form a coating layer. Thereby, the multilayer film 90 provided with a base material and a coating layer was obtained.

  Both ends and the width direction of the multilayer film 90 thus obtained were cut and removed, and the remaining part was wound up to obtain a film roll 80.

  The obtained multilayer film 90 was evaluated and the results are shown in Table 1.

[Examples 2-6 and Comparative Examples 1-6]
In (1-3-1.), The pressure P ₀ outside the casing 120, the inflow pressure P ₁ of the first mixed gas supplied into the casing 120, and the gas outlet 123F to the substrate carry-in path S1. Corresponds to the inflow pressure P _{2 of the} gas to be supplied, the minimum width h ₁ of the gap S 1 between the slit block 122 F and the base material 30, the average value h ₂ of the width of the gas passage 123, and the base material carry-in path of the transport roll 111. The outer peripheral length L ₁ of the portion to be performed, the length L ₂ of the gas passage 123, and the length L ₃ from the base material inlet 122 F 1 to the gas outlet 123 F of the wall surface 122 L provided with the gas outlet 123 F of the housing 120. , and of H ₂ except that the as shown in Table 1 and Table 2, the same procedure as in example 1, examples 2 to 6 were prepared a multilayer film of Comparative example 1-6. Each example was evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

  From the results of Tables 1 and 2, according to the production method that satisfies all the requirements of the present invention, the variation in the contact angle and the peel strength in the film width direction is reduced, and a high-quality multilayer film free from repelling unevenness is efficiently produced. It turns out that it can be manufactured.

DESCRIPTION OF SYMBOLS 10 ... Manufacturing apparatus 30 ... Base material 60 ... Film roll 80 ... Film roll 90 ... Multi-layer film 100 ... Corona discharge treatment apparatus 111 ... Conveyance roll 112 ... Shaft 120 ... Housing 121B ... Rear surface wall 121F ... Front surface of housing Wall 122B, 122F ... Slit block 123, 223 ... Gas passageway 123F, 123B ... Gas outlet 124B, 124F ... Support member 125, 225 ... Outlet device 125A ... Gas supply part 125B ... End of gas supply part on the gas outlet side 126, 226 ... Tube 131: Electrode for corona discharge (discharge treatment part)
141 ... Outlet (I)
DESCRIPTION OF SYMBOLS 142 ... Exhaust port 143 ... Conduit 151, 152 ... Barometer 153 ... Oxygen concentration measuring device 300 ... Coating device 400 ... Scraping device 500 ... Stretching device A1 ... Conveyance roll conveyance direction A201 ... Area | region where a base material is guided A202 ... Housing Body width S1 ... Gap (base material loading path)
S3: Clearance (base material carry-out path)

Claims (9)

A process for producing a multilayer film comprising a step of performing a discharge treatment on the surface of a long substrate, and a step of forming a coating layer on the surface of the substrate after the discharge treatment,
The discharge treatment apparatus used in the discharge treatment step includes a discharge treatment unit, a casing that houses the discharge treatment unit, and a transport roll that is arranged with a gap that allows the base material to be transported between the case and the case. And a blowing device that is provided in a housing wall on the carry-in side where the base material of the housing is carried in, and blows a gas containing an inert gas and dry air onto the base material carried into the gap, Have
The blowing device includes a gas supply unit that supplies a gas including an inert gas and dry air from the outside, a gas blowing port that opens in a wall surface facing the gap of the housing, and the gas blowing unit of the gas supply unit. A gas passage communicating from the mouth end to the gas outlet,
A gap between the transport roll and the wall surface of the housing where the gas outlet is provided is a base material carry-in path,
In the discharge treatment step, a gas containing an inert gas and dry air is supplied into the housing, and a gas containing an inert gas and dry air is supplied from the gas outlet to the substrate carry-in path. Among these, the manufacturing method of a multilayer film including performing an electrical discharge process on the surface of the said base material on the conditions shown to following formula (1)-(7) including at least one.

(In the above formula, P ₀ is the atmospheric pressure (Pa) outside the casing, P ₁ is the inflow pressure (Pa) of the gas supplied into the casing, and P ₂ is the base material carry-in path from the gas outlet). The inflow pressure (Pa) of the gas supplied to V, v is the conveyance speed (m / sec) of the conveyance roll, h ₁ is the minimum value (m) of the width of the substrate carrying-in path, and h ₂ is the gas passage The average width (m), L ₁ is the outer peripheral length (m) of the part of the transport roll corresponding to the substrate carrying-in path, L ₂ is the length of the gas passage (m), and L ₃ is the housing The length (m) from the base material inlet to the gas outlet of the wall surface of the body where the gas outlet is provided, μ ₁ is the viscosity (Pa · s) of the gas supplied into the housing, mu ₂ represents the viscosity (Pa · s) of the gas supplied to the substrate introduction passage, _{H 2} is _{(h 2 L 2 + h 1} L 3) / (L + _{L 3)} it is.) In the discharge treatment step, corona is applied to the surface of the substrate that is continuously running under an environment of atmospheric pressure or higher, oxygen concentration of 0.05% by weight to 0.55% by weight, and water content of 5 mg / m ³ or lower. Discharge treatment,
2. The method for producing a multilayer film according to claim 1, wherein in the coating layer forming step, a coating solution is applied to a surface of the base material subjected to a corona discharge treatment to form the coating layer.   The manufacturing method according to claim 1 or 2, wherein the discharge treatment step is performed using a corona discharge treatment apparatus. Wherein the discharge treatment step, a corona discharge treatment at 5W · min / m ² or more 100W · min / m ² or less, the production method of the multilayer film according to any one of claims 1 to 3.   Supplying a gas containing an inert gas and dry air into the casing, wherein the flow rate of the inert gas is X (L / min) and the flow rate of the dry air is Y (L / The manufacturing method of the multilayer film of any one of Claims 1-4 whose Y / X is 0.005 or more and 0.050 or less when it is referred to as min).   The discharge treatment step includes supplying a gas containing an inert gas and dry air into the casing, wherein the width of the casing is W (mm), and the flow rate of the inert gas is X (L / min). 6. The method for producing a multilayer film according to claim 1, wherein X / W is 0.05 or more and 0.30 or less. The discharge treatment step includes supplying a gas containing an inert gas and dry air into the casing, the width of the casing is W (mm), and the flow rate Z (L of the gas to the casing) / Min), Z / W is 5.05 * 10 ^<-2 > or more and 3.03 * 10 ^{< -1} > or less, The manufacturing method of the multilayer film of any one of Claims 1-6 .   The manufacturing method of the multilayer film of any one of Claims 1-7 whose said base material is a film of resin containing an alicyclic structure containing polymer.   The manufacturing method of the multilayer film of any one of Claims 1-8 which further includes the process of neutralizing the said base material after the said discharge treatment process and before the said coating layer formation process.

Images