JP2018167133A - Film deposition apparatus and film deposition method - Google Patents

Abstract

To provide a film deposition apparatus and a film deposition method which can suppress degradation of a film deposition rate in continuous film deposition.SOLUTION: A film deposition apparatus forms a film on a base film by an electrostatic spray method, and includes a conveyance mechanism for conveying the base film, and a plurality of nozzles which spray a charged raw material liquid and form the film on the base film conveyed by the conveyance mechanism. The plurality of nozzles include a nozzle for spraying the raw material liquid charged to positive polarity, and a nozzle for spraying the raw material liquid charged to negative polarity. The respective nozzles are aligned in a conveyance direction of the base film.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a film forming apparatus and a film forming method. Specifically, the present invention relates to a film formation apparatus and a film formation method that can suppress a decrease in film formation rate during continuous film formation.

  Conventionally, functional films represented by gas barrier films, conductive films, and the like have been used. In the functional film, a functional layer showing gas barrier properties, conductivity, and the like is formed on a base film. In order to protect the functional layer from external force, a protective layer may be formed on the functional layer. However, in order to sufficiently protect the functional layer, it is necessary to form a thick protective layer of, for example, 1 μm or more.

  For the formation of the thick film, an electrostatic spray method having a high film formation rate can be used (for example, see Patent Documents 1 and 2). In the electrostatic spray method, the membrane raw material liquid is charged and sprayed onto the base film, thereby creating a potential difference between the sprayed raw material liquid droplet and the base film, and the electrostatic force exerts the droplet on the base film. This is a film forming method for attracting and depositing.

  In the electrostatic spray method, droplets having the same polarity are deposited on the base film. Therefore, when the film is continuously formed, the potential difference between the droplets to be sprayed and the base film is gradually reduced. As the potential difference is reduced, the electrostatic force is weakened and the film formation rate is gradually reduced, making it difficult to form a film to the desired thickness. In particular, when forming a film under a reduced pressure such as a vacuum pressure, there is less charge movement in a reduced pressure environment than in an atmospheric pressure environment, and the charged state of the surface of the film on the base film tends to last for a long time. The formation of was more difficult.

JP2015-3301 Japanese Patent Laying-Open No. 2015-3293

  The present invention has been made in view of the above problems and circumstances, and an object of the solution is to provide a film forming apparatus and a film forming method capable of suppressing a decrease in film forming rate during continuous film formation.

  In order to solve the above-mentioned problems, the present inventor, in the process of examining the cause of the above-mentioned problems, on the base film, droplets of the raw material liquid charged not only with a positive or negative constant polarity but also with an opposite polarity. As a result of the deposition, it has been found that a decrease in film formation rate can be suppressed even if continuous film formation is performed, and the present invention has been achieved.

That is, the subject concerning this invention is solved by the following means.
1. A film forming apparatus for forming a film on a base film by an electrostatic spray method,
A transport mechanism for transporting the base film;
A plurality of nozzles for spraying a charged raw material liquid and forming the film on the base film transported by the transport mechanism;
The plurality of nozzles are composed of a nozzle that sprays a raw material liquid charged to a positive polarity and a nozzle that sprays a raw material liquid charged to a negative polarity, and the nozzles are arranged in the transport direction of the base film. A film forming apparatus characterized by being made.

  2. 2. The film forming apparatus according to claim 1, wherein the film is formed by spraying the raw material liquid with the plurality of nozzles under reduced pressure.

  3. The film forming apparatus according to claim 1 or 2, further comprising a heating device for the film formed using the plurality of nozzles.

4). A film forming method for forming a film on a base film by an electrostatic spray method,
Transporting the base film, spraying the charged raw material solution of the film with each of a plurality of nozzles to form the film on the base film,
The plurality of nozzles are arranged side by side in the transport direction of the base film, and at the time of forming the film, the raw material liquid charged to a positive polarity is sprayed by one or more of the plurality of nozzles, and negative A film forming method comprising spraying a polar charged material solution with the remaining one or a plurality of nozzles.

  5. The film forming method according to claim 4, wherein the film is formed by spraying the raw material liquid with the plurality of nozzles under reduced pressure.

  6). 6. The film forming method according to claim 4, wherein the film formed using the plurality of nozzles is heated.

  7). The film forming method according to any one of Items 4 to 6, wherein the film having a thickness of 1 μm or more is formed.

  By the above means of the present invention, it is possible to provide a film forming apparatus and a film forming method capable of suppressing a decrease in film forming rate during continuous film formation.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
When spraying a raw material liquid charged to a certain positive or negative polarity is repeated, charges of the same polarity accumulate on the surface of the film formed on the base film, and the potential difference between the newly sprayed raw material liquid and the base film Shrinks. Reduction of the potential difference weakens the electrostatic force (Coulomb force) that attracts the newly sprayed raw material liquid to the base film and lowers the film formation rate. It is possible to cancel the charge accumulated in the. It is surmised that the potential difference can be reduced by canceling out the electric charge, and the electrostatic force that draws the raw material liquid to the base film can be recovered to prevent the film formation rate from decreasing.

The front view which shows schematic structure of the film-forming apparatus of embodiment of this invention Side view showing nozzle and base film from base film transport direction Top view showing an arrangement example of a plurality of nozzles arranged in the width direction and the conveyance direction of the base film Graph showing the film thickness distribution in the width direction of the film formed using the nozzle of the arrangement example of FIG. Side view showing a film formed by spraying a raw material liquid charged to a positive polarity with a nozzle 5A is a side view showing a film formed by further spraying a raw material liquid charged to a positive polarity on the film of FIG. 5A. 5A is a side view showing a film formed by further spraying a negatively charged raw material liquid on the film of FIG. 5A. Front view showing a configuration example of a film forming apparatus using a back roller Front view showing a schematic configuration of a film forming apparatus for producing a functional film Sectional drawing which shows the structural example of a functional film

The film forming apparatus of the present invention is a film forming apparatus for forming a film on a base film by an electrostatic spray method, the transport mechanism transporting the base film, and spraying the charged raw material liquid, the transport mechanism A plurality of nozzles for forming the film on the base film conveyed by the nozzle, and the plurality of nozzles are charged with a negative polarity and a nozzle for spraying a raw material liquid charged with a positive polarity. It consists of nozzles for spraying the raw material liquid, and each nozzle is arranged in the transport direction of the base film.
The film forming method of the present invention is a film forming method in which a film is formed on a base film by an electrostatic spray method. The base film is transported and charged, and the raw material liquid of the film is respectively supplied by a plurality of nozzles. The film is formed on the base film by spraying, the plurality of nozzles are arranged side by side in the transport direction of the base film, and the raw material liquid charged to a positive polarity is formed when the film is formed. The raw material liquid sprayed by one or a plurality of nozzles among the nozzles and charged to a negative polarity is sprayed by the remaining one or a plurality of nozzles.
These features are technical features common to the inventions according to claims 1 to 7.

As an embodiment of the present invention, the film can be formed by spraying the raw material liquid with the plurality of nozzles under reduced pressure. By spraying the raw material liquid having the opposite polarity to the surface of the film, the charge on the surface of the film is canceled even under a reduced pressure at which charges are likely to accumulate, and a decrease in film formation rate can be suppressed.
Further, from the viewpoint of obtaining a uniform film thickness, it is preferable that an embodiment of the present invention includes a heating device for the film formed using the plurality of nozzles.
Since the decrease in the deposition rate is suppressed, a film having a thickness of 1 μm or more can be formed without using a large number of nozzles.

Hereinafter, the present invention, its components, and modes for carrying out the present invention will be described in detail.
In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

[Deposition system]
The film forming apparatus of the present invention is a film forming apparatus for forming a film on a base film by an electrostatic spray method. If the film-forming apparatus of this invention is on a base film, it can also form a film | membrane not only on the surface of a base film but on the other film | membrane already formed on the base film.

FIG. 1 shows a schematic configuration of a film forming apparatus 1 according to an embodiment of the present invention.
The film forming apparatus 1 is a roll-to-roll film forming apparatus, and as shown in FIG. 1, as a transport mechanism for the base film F, an unwinding device 31 for unwinding the base film F of the roll body, A plurality of rollers 32 for conveying the base film F, a winding device 33 for winding the base film F after forming the film to form a roll body, and the like are provided.
The film forming apparatus 1 can adjust the pressure environment in the film forming apparatus 1 to atmospheric pressure or reduced pressure by the vacuum pump 1a. Under reduced pressure refers to a pressure range of 0.1 Pa or more and less than atmospheric pressure.

The film forming apparatus 1 forms a film by an electrostatic spray method.
In the electrostatic spray method, a charged film raw material liquid is sprayed onto a base film, thereby generating a potential difference between the sprayed raw material liquid droplets and the base film, and the liquid droplets are caused by electrostatic force (Coulomb force). It is a film forming method for attracting and depositing on a base film.

As shown in FIG. 1, in the film forming apparatus 1, a plurality of nozzles 21 for spraying a film raw material liquid are arranged, and a roller 32 for transporting the base film F faces each nozzle 21 with the base film F interposed therebetween. Is arranged.
FIG. 2 is a side view showing one nozzle 21 and the base film F in FIG. 1 from the conveyance direction y.
As shown in FIG. 2, a power source 22 is connected to the nozzle 21, and a voltage is applied by the power source 22 during film formation in order to charge the raw material liquid sprayed by the nozzle 21. On the other hand, the roller 32 is grounded.

  As shown in FIG. 2, when the film 21 supplied from the supply unit 23 is sprayed by the nozzle 21, when a positive voltage is applied to the nozzle 21 by the power source 22, the nozzle 21 sprays as shown in FIG. 2. The prepared raw material liquid is charged to a positive polarity. The charged raw material liquid is repelled by electrostatic force (Coulomb force) and splits into droplets charged to a positive polarity. Since the positive charge density in the droplet rises due to the splitting, the droplet repeats splitting due to repulsion. On the other hand, since the base film F conveyed by the grounded roller 32 is almost non-polar, and a potential difference is generated between the droplet and the base film F, the droplets which have been finely divided by repeated splitting are electrostatically charged. It is attracted onto the base film F and deposited on the base film F.

If a potential difference can be generated between the droplet of the raw material liquid to be sprayed and the base film F, a voltage is applied by connecting the power source 22 to the raw material liquid supply unit 23 instead of the nozzle 21, The liquid can also be charged.
In addition, a potential difference may be generated between the droplets of the raw material liquid and the base film F by applying a voltage having a polarity opposite to that of the raw material liquid to the roller 32 that conveys the base film F.

In the film forming apparatus 1, a nozzle 21 for spraying a raw material liquid charged to a positive polarity and a nozzle 21 charged to a negative polarity are arranged side by side in the transport direction y of the base film F.
Thus, by arranging the nozzle 21 for spraying the raw material liquid charged to the positive polarity and the nozzle 21 for spraying the raw material liquid charged to the negative polarity in a mixed manner in the transport direction y, the film forming rate can be increased. A thick film can be formed while suppressing the decrease.
The arrangement order and the number of the nozzles 21 charged to the positive polarity and the nozzles 21 charged to the negative polarity are not particularly limited.

  When only the raw material liquid charged to a positive or negative constant polarity is sprayed in all the nozzles 21, charges having the same polarity accumulate on the surface of the film formed on the base film. The potential difference between the droplets to be sprayed and the base film F is gradually reduced. When the potential difference is reduced, the electrostatic force that attracts the droplets to the base film F is weakened, and the repulsive force between the droplets and the film formed on the base film F is also increased. Formation of the film becomes difficult.

On the other hand, if the nozzle 21 for spraying the raw material liquid charged to the positive polarity as described above and the nozzle 21 for spraying the raw material liquid charged to the negative polarity are mixed and arranged in the transport direction y, The positive or negative polarity charge accumulated on the surface of the film on the base film F can be canceled by the opposite polarity charge. The reduction in potential difference between the raw material liquid to be sprayed and the base film F can be suppressed, and the electrostatic force that attracts droplets to the base film F can be recovered. Since a decrease in film formation rate can be suppressed even during continuous film formation, a thick film of 1 μm or more can be formed.
In particular, under reduced pressure, the movement of electric charge is less than under atmospheric pressure, and the charged state of the surface of the film on the base film continues for a long time, and the potential difference tends to decrease. However, according to the film forming apparatus 1, the charge accumulated on the surface of the film can be canceled, so that it is possible to effectively suppress a decrease in the film forming rate not only under atmospheric pressure but also during continuous film formation under reduced pressure. Can do.

The raw material liquid for the film may be an inorganic material or an organic material, but a highly conductive material is preferable because it is easily charged and a sufficient electrostatic force is easily obtained for film formation. .
Even if it is a material with low electrical conductivity, it can be dissolved or dispersed in a highly polar solvent to prepare a raw material solution, or if conductive fine particles such as titanium oxide and tin oxide are added to the raw material solution of the film, the raw material solution It can be used because it can improve the chargeability of.
The raw material liquid for the film may contain a solvent, but in the electrostatic spray method, the solvent in the liquid droplets volatilizes when the liquid droplets of the raw material liquid break up, and the volatilized solvent lowers the degree of vacuum. Therefore, when the film is formed under reduced pressure, the content of the solvent is preferably small, and more preferably no solvent is contained.

  The voltage (V) applied by the power source 22 can be appropriately set according to the relationship between the distance between the nozzle 21 and the base film F and the spray amount of the raw material liquid. Although it does not specifically limit as a voltage to apply, Preferably it exists in the range of 5-20 kV, More preferably, it exists in the range of 10-15 kV.

The plurality of nozzles 21 are preferably arranged side by side not only in the transport direction y but also in the width direction perpendicular to the transport direction y from the viewpoint of increasing the film formation rate and forming a film with a uniform thickness.
FIG. 3 shows an arrangement example in which a plurality of nozzles 21 are arranged in the width direction x and the transport direction y of the base film F.
In the arrangement example shown in FIG. 3, five rows in which the three nozzles 21 are arranged at equal intervals in the width direction x are arranged in the transport direction y.

FIG. 4 shows the film thickness distribution in the width direction x of the film formed using the five rows of nozzles 21 shown in FIG. In FIG. 4, the solid line indicates the film thickness distribution of the film formed using the even-numbered nozzles 21 in the second and fourth rows from the upstream in the transport direction y. A dotted line indicates the film thickness distribution of the film formed by using the nozzles 21 in the odd-numbered first, third, and fifth rows.
As shown in FIG. 4, the positions of the nozzles 21 in the width direction x are shifted in units of columns so that the film thickness when the nozzles 21 are formed in each row is uniform in the width direction x as shown in FIG. ing.
In the arrangement example shown in FIG. 3, the positions of the nozzles 21 in each row in the width direction x are alternately shifted. However, as long as the film thickness is uniform in the width direction x, the position of any row may be shifted. . For example, the positions in the width direction x of the nozzles 21 in the first, second, and third rows may be the same position, and the positions in the width direction x of the nozzles 21 in the fourth and fifth rows may be shifted.

As shown in FIG. 1, the film forming apparatus 1 is preferably provided with a film heating device 24 formed using a plurality of nozzles 21 from the viewpoint of obtaining a uniform film thickness.
The viscosity of the film can be lowered by heating to achieve leveling of the film (surface smoothing), and the film thickness can be made uniform. Since it is only necessary to heat after forming the film, it is not necessary to lower the viscosity of the raw material liquid, and the raw material liquid can be adjusted to a high viscosity during spraying to prevent dripping from the nozzle 21.

FIG. 5A shows a film formed by spraying a raw material liquid charged to a positive polarity by a plurality of rows of nozzles 21 from the transport direction of the base film F.
As shown in FIG. 5A, since the positive charge density on the surface of the film increases and repels, the surface is not smooth, and film thickness unevenness occurs.

  When the raw material liquid charged with the same positive polarity as the membrane is further sprayed on the membrane shown in FIG. 5A, the potential difference between the surface of the membrane and the base film F is somewhat reduced and the repulsion is weakened. Thus, the effect of film leveling can be obtained.

  On the other hand, when the raw material liquid charged to the negative polarity which is the opposite polarity to the surface of the film is further sprayed on the film shown in FIG. 5A, the droplets are electrostatically attracted to the film surface, as shown in FIG. 5C. In addition, droplets are deposited while maintaining the surface shape of the original film having a large film thickness unevenness. Therefore, as shown in FIG. 5B, the same leveling effect as that in the case of depositing droplets having the same polarity cannot be expected. Even when droplets having such different polarities are deposited, by heating the film with the heating device 24 as described above, it is possible to obtain the effect of leveling by reducing the viscosity of the film.

When the raw material of the film is an ultraviolet curable resin or the like and is a film that needs to be cured, the film forming apparatus 1 can include a curing apparatus 25 as shown in FIG.
As the curing device 25, for example, an ultraviolet lamp, a xenon lamp, or the like can be used.

[Modification]
The configuration of the film forming apparatus 1 is not limited to the configuration shown in FIG. 1 and may be the configuration shown in FIG.
In the configuration example shown in FIG. 6, the base film F is transported by the back roller 34, and the plurality of nozzles 21 are arranged along the curved surface of the base film F transported by the back roller 34. If a back roller 34 incorporating a heater is used instead of the heating device 24, the film can be heated by the back roller 34.

  The film forming apparatus 1 is a roll-to-roll system that can continuously form a film on a long base film F. When the base film F is cut into a predetermined size, the base film F is supported. A conveyance method in which the plate is repeatedly rocked and conveyed may be used.

[Other Embodiments]
The film forming apparatus and film forming method of the present invention can be suitably used for the production of a functional film.
The functional film is a film having a functional layer on a base film. Functional films include, for example, a gas barrier film with a gas barrier layer that suppresses the ingress of gases such as oxygen and water, a conductive film with a conductive layer, an insulating film with an insulating layer, and a desired refractive index An optical film provided with a refractive layer having

When a film as a functional layer is formed by a roll-to-roll method, a protective layer may be provided on the functional layer in order to prevent the functional layer from being damaged when the film is wound. If this protective layer is continuously formed by the electrostatic spray method in a roll-to-roll system, the potential difference between the surface of the film and the base film decreases as described above, so the film formation rate decreases. However, according to the film forming apparatus and the film forming method of the present invention, since the decrease in the potential difference can be mitigated and the decrease in the film forming rate can be suppressed, a film sufficiently thick to protect the functional layer from external force can be formed. Can be formed.
In addition, when the functional layer is formed under reduced pressure, the roll-to-roll method has good production efficiency if the protective layer can also be formed under reduced pressure. However, the charge on the surface of the film is lower under reduced pressure than under atmospheric pressure. It is difficult to move, and the potential difference between the surface of the membrane and the base film is more likely to decrease. The film formation apparatus and the film formation method of the present invention can be optimally used for forming a protective layer because a decrease in film formation rate can be suppressed even under reduced pressure.

FIG. 7 shows a schematic configuration of the film forming apparatus 100 when a functional film is manufactured.
As shown in FIG. 7, the film forming apparatus 100 includes two film forming chambers 10 and 20, and a transport mechanism for the base film F as in the film forming apparatus 1 described above. The apparatus 33 etc. are provided.
The film forming apparatus 100 sequentially transfers the base film F to the film forming chambers 10 and 20 by the transfer mechanism, and after forming the functional layer on the base film F in the film forming chamber 10, the functional layer in the film forming chamber 20. A protective layer is formed on top.

  When the pressure difference between the two film formation chambers 10 and 20 is large, the film formation apparatus 100 may include a pressure adjustment chamber 40 between the film formation chamber 10 and the film formation chamber 20. The pressure adjustment chamber 40 can gradually adjust the pressure environment of the film formation chamber 10 to the pressure environment of the film formation chamber 20.

[Functional layer deposition chamber]
In the film forming chamber 10, a film as a functional layer is formed by an atomic layer deposition (ALD) method.
In the ALD method, a film forming process in which two or more kinds of raw materials are alternately supplied and each raw material is reacted is repeated a plurality of cycles, and one atomic layer (actually, a molecular layer of a compound) is formed for each cycle. It is a method of forming a film by depositing each one.
If it is ALD method, PE (Plasma Enhanced) ALD method, thermal ALD method, etc. which are 1 type of ALD method can be used.

FIG. 7 shows a configuration of the film forming chamber 10 using the PEALD method.
As shown in FIG. 7, the film forming chamber 10 includes three film forming chambers C1 to C3 in a chamber supplied with an inert gas. Each film forming chamber C1 to C3 is adjusted to a vacuum pressure by a vacuum pump or the like. The walls of the film forming chambers C1 to C3 are each provided with an opening on the transport path of the base film F so that the base film F can pass through.

The film forming chamber 10 supplies the material gas for the functional layer in each of the film forming chambers C1 and C2.
The film forming chamber 10 supplies a material gas for reforming treatment in the film forming chamber C3, generates plasma, and oxidizes, nitrides, and the like of the material adsorbed on the base film F in each film forming chamber C1 and C2. The reforming process is performed.

At the time of film formation, the base film F is transferred to the film formation chamber C1 by the transfer mechanism in the film formation chamber 10 to adsorb the raw material, and then the raw material transferred to the film formation chamber C3 is adsorbed. Thereby, a film having a thickness of one atom (molecule) can be formed. Furthermore, when the film forming chamber 10 transports the base film F to the film forming chamber C2 to adsorb the raw material, the film forming chamber 10 is folded and transported to the film forming chamber C3, and the adsorbed raw material is reformed. Thereby, a film having a thickness corresponding to one atom (molecule) can be formed.
According to the above procedure, when the same source gas is supplied in the film formation chambers C1 and C2, the same type of film can be stacked at a double film formation rate, and when different source gases are supplied, different types of films are formed. They can be stacked alternately.

  Excess source gas that could not be adsorbed onto the base film F in each film forming chamber C1 or C2 was transferred to the film forming chamber C3 from the film forming chamber C1 or C2 while being supplied into the film forming chamber C10. It can be removed (purged) by an active gas. As the inert gas, for example, a rare gas or the like can be used. If the reactivity with the raw material is low, a nitrogen gas or the like can also be used.

The film forming method in the film forming chamber 10 is not limited to the above-described ALD method, but sputtering methods such as magnetron sputtering method and RF (radio frequency) sputtering method, evaporation methods such as electron beam evaporation method and ion plating method, laser chemistry, etc. A CVD method such as a chemical vapor deposition (CVD) method, a thermal CVD method, or PE (Plasma Enhanced) CVD can be used.
In the case of forming a functional layer having a multilayer structure, a plurality of film formation chambers 10 can be provided, and the film formation method of each film formation chamber 10 can be varied.

[Protection layer deposition chamber]
In the film forming chamber 20, a film as a protective layer is formed by an electrostatic spray method.
The configuration of the film forming chamber 20 is the same as that of the film forming apparatus 1 described above.

[Pressure adjustment chamber]
The pressure adjusting chamber 40 gradually adjusts from the pressure environment of the film forming chamber 10 to the pressure environment of the film forming chamber 20 as described above.

[Functional film]
FIG. 8 is a cross-sectional view showing a configuration example of the functional film G that can be manufactured by the film forming apparatus 100.
As shown in FIG. 8, the functional film 1 includes a functional layer G <b> 1 and a protective layer G <b> 2 on the base film F.

[Base film]
The base film F is a functional film substrate.
As the base film F, a film-like resin, glass, metal, or the like can be used as long as it has flexibility. Especially, since it is lightweight, resin is preferable and resin with high transparency is preferable. When the transparency of the resin is high and the transparency of the base film F is high, a highly functional film can be obtained, and the functional film is preferably used for an electronic device such as an organic EL (Electro Luminescence) element. it can.

Examples of the resin that can be used as the base film F include methacrylate ester, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, polystyrene (PS), aromatic polyamide, and polyether ether. Ketone, polysulfone, polyethersulfone, polyimide (PI), polyetherimide and the like can be mentioned. Of these, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC) and the like are preferable from the viewpoint of cost and availability.
The base film F may be a laminated film in which two or more of the above resins are laminated.

  The resin base film F can be manufactured by a conventionally known general manufacturing method. For example, an unstretched resin base material that is substantially amorphous and not oriented can be produced by melting a resin as a material with an extruder, extruding it with an annular die or a T-die, and quenching. In addition, by dissolving the resin used as a material in a solvent, casting (casting) it onto an endless metal resin support, drying, and peeling, an unstretched film that is substantially amorphous and not oriented is used as a base. It can be obtained as film F.

  The unstretched film may be stretched in the film transport direction (MD: Machine Direction) or the width direction (TD: Transverse Direction) perpendicular to the transport direction, and the resulting stretched film may be used as the base film F. Examples of the stretching method include known methods such as uniaxial stretching, tenter sequential biaxial stretching, tenter simultaneous biaxial stretching, and tubular simultaneous biaxial stretching. Although a draw ratio can be suitably selected according to resin used as a raw material, both the conveyance direction and the width direction are preferably in the range of 2 to 10 times.

  The base film F may be the above-described unstretched film or a stretched film. A stretched film is preferable from the viewpoint of strength improvement and thermal expansion suppression. Since optical functions such as retardation of the base film F can be adjusted by stretching, it is preferable to use a stretched film when adjustment is necessary.

The base film F may be subjected to relaxation treatment, off-line heat treatment, and the like from the viewpoint of improving dimensional stability.
The relaxation treatment is preferably carried out in the tenter extending in the width direction after the heat setting in the stretching step, or in the step up to winding after exiting the tenter. The relaxation treatment is preferably performed at a treatment temperature in the range of 80 to 200 ° C, and more preferably in the range of 100 to 180 ° C.

  The method of off-line heat treatment is not particularly limited. For example, a roller transport method using a plurality of roller groups, an air transport method in which air is blown and floated on a film (specifically, heated air is supplied from a plurality of slits on one side of the film surface). Or a method of spraying on both surfaces), a method of using radiant heat by an infrared heater, a conveying method of hanging the film under its own weight and winding it down. Good dimensional stability can be obtained by making the conveyance tension during heat treatment as low as possible to promote thermal shrinkage. As the treatment temperature, a temperature range of (Tg + 50) to (Tg + 150) ° C. is preferable. Tg here refers to the glass transition temperature of the base film F.

  The thickness of the base film F is not particularly limited, and can be 200 μm or less when a thin functional film is obtained. From the viewpoint of obtaining a thinner functional film, the thickness is preferably 100 μm or less, and more preferably in the range of 20 to 100 μm.

The base film F can have a clear hard coat layer on its surface.
The clear hard coat layer can be formed, for example, by applying an ultraviolet curable resin and then irradiating it with ultraviolet rays to cure.

[Functional layer]
The functional layer G1 is, for example, a gas barrier layer, a conductive layer, an insulating layer, a refractive layer, or the like.
As a material for the functional layer G1, metal compounds such as metal oxides, metal nitrides, metal oxynitrides, metal oxycarbides, metal carbonitrides and the like can be used alone or in combination of two or more.
Examples of the metal in the metal compound that can be used for the functional layer G1 include aluminum (Al), titanium (Ti), silicon (Si), zirconium (Zr), hafnium (Hf), lanthanum (La), and niobium (Nb). Tantalum (Ta), magnesium (Mg), zinc (Zn), nickel (Ni), vanadium (V), copper (Cu), cobalt (Co), iron (Fe), yttrium (Y), and the like.
The functional layer G1 may be a layer obtained by modifying a silicon compound having a repeating structural unit such as polysilazane or polysiloxane.

When the functional layer G1 is a gas barrier layer, the gas barrier layer has a water vapor permeability (25 ± 0.5 ° C., relative humidity 90 ± 2%) measured by a method according to JIS-K-7129-1992. RH) preferably exhibits a gas barrier property of 0.010 (g / m ² · 24 h) or less, and more preferably 0.001 (g / m ² · 24 h) or less. Moreover, it is preferable that the oxygen permeability measured by the method based on JIS-K-7126-1987 is 1 * 10 < ^-3 > (ml / m < ² > * day * atm) or less. The water vapor permeability can also be measured by the MOCON method, the calcium corrosion method described in JP-A-2005-283561, and the like.

The functional layer G1 may have a single layer structure or a multilayer structure.
When the functional layer G1 is a gas barrier layer, the gas barrier layer has a multilayer structure including a second layer containing a metal compound on the first layer obtained by modifying polysilazane from the viewpoint of improving the gas barrier property. It is preferable. Among the metal compounds, transition metal compounds are preferable, and among the transition metal compounds, oxides of Group 5 elements Nb, Ta, and V are preferable. This is presumably because the Si barrier in the first layer and the transition metal such as Nb in the second layer are likely to be bonded, and the gas barrier property is enhanced by forming a dense structure.

The thickness of the functional layer G1 is preferably in the range of 3 to 200 nm.
When the thickness is 3 nm or more, sufficient functionality of the functional layer G1, such as gas barrier properties, can be obtained. Moreover, if thickness is 200 nm or less, durability under high temperature and high humidity will also improve, and sufficient functionality can be maintained over a long period of time.

[Protective layer]
The protective layer G2 can be provided on the functional layer G1 as a protective layer for preventing damage to the functional layer G1. In particular, when the functional layer G1 is formed as a gas barrier layer, gas such as water and oxygen penetrates through the damaged portion during winding, so that the protective layer G2 is formed in order to maintain high gas barrier performance. It is particularly effective.

  The material of the protective layer G2 is not particularly limited as long as the functional layer G1 can be protected from external force. From the viewpoint of forming a soft film that can be sufficiently protected, an ultraviolet curable resin, a thermoplastic resin, a heat A curable resin or the like can be used. It is preferable that the material has a large polarity and is easily charged because the film formation rate by the electrostatic spray method can be increased. Even if it is a material with a small polarity such as polysiloxane, the chargeability of the raw material liquid can be improved by dissolving it in a polar solvent or adding conductive fine particles to the raw material liquid. can do.

The thickness of the protective layer G2 can be 0.5 μm or more. From the viewpoint of enhancing the protective effect of the protective layer G2 and improving the durability of the functional layer G1 under high temperature and high humidity, the thickness of the protective layer G2 is preferably 1 μm or more.
Further, from the viewpoint of suppressing moisture absorption, the thickness of the protective layer G2 is preferably 10 μm or less.

  Since the protective layer G2 has a hardness measured by a nanoindenter of 1 GPa or less, the protective performance can be improved, which is preferable.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless there is particular notice, it represents "mass part" or "mass%".

[Film Formation Example 1]
In the film formation example 1, the gas barrier layer 1 is formed on the base film by the ALD method on the base film using the film formation apparatus 100 shown in FIG. 7, and the protective layer is electrostatically sprayed in the film formation chamber 20. A gas barrier film 1 was obtained by the method. Note that the configuration shown in FIG. 6 was used as the configuration of the film forming chamber 20.

Specifically, a base film roll body is set on the unwinding device 31 of the film forming apparatus 100, and the tip of the base film is transported to the winding device 33 to be wound and fixed, and then the base film is transported. Started.
As the base film, a Teijin Tetron film KDL8W (manufactured by Teijin DuPont Films) having a thickness of 50 μm, a length in the width direction of 1.3 m, and a length in the transport direction of 200 m was used.

(Gas barrier layer 1)
In the deposition chamber 10, an aluminum oxide (Al ₂ O ₃ ) film having a thickness of 5 nm was formed as the gas barrier layer 1 by the ALD method. The pressure environment during film formation was adjusted to a reduced pressure of 100 Pa.
Detailed film forming conditions are as follows.
(Deposition conditions)
Source gas supplied in film formation chambers C1 and C2: Trimethylaluminum Residence time in film formation chambers C1 and C2: 4.0 seconds / cycle Source gas for reforming process supplied in film formation chamber C3: Water Film formation Residence time in chamber C3: 4.0 seconds / cycle Inert gas used for purge: nitrogen gas Residence time in inert gas: 5.0 seconds / cycle Deposition rate of aluminum oxide film: 0.1 nm / cycle Cycle Base film transport speed: 5.0 m / min Base film temperature: 80 ° C.

(Protective layer)
In the film forming chamber 20, three nozzles 21 arranged in the width direction x of the base film were arranged in 10 rows in the transport direction y of the base film. Similarly to the arrangement example shown in FIG. 3, the positions of the nozzles 21 in each row in the width direction x are different from the nozzles 21 in the adjacent rows, and the film thickness distributions in the odd rows and even rows are shown in FIG. Arranged alternately to be distributed. Each row of the nozzles 21 is in the order of row numbers 1 to 10 in order from the row located upstream in the transport direction y. Represented by That is, column No. Column 1 is located at the uppermost stream, and column No. 1 Ten rows are located downstream.

  A raw material liquid was prepared by mixing 1% by mass of conductive fine particles SN-100P (manufactured by Ishihara Sangyo Co., Ltd.) with ultraviolet curable resin TB3042 (manufactured by Three Bond Co., Ltd.). The prepared raw material liquid is designated as column No. It supplied to the nozzle 21 of each row | line of 1-10, and sprayed the raw material liquid from the nozzle 21 of each row | line | column, and formed the film | membrane. The conveyance speed of the base film in the film forming chamber 20 was 5 m / min.

  At the time of film formation, among the 10 rows of nozzles 21, the raw material liquid charged with a positive voltage of +10 kV and charged to the positive polarity is row No. The raw material liquid sprayed by the nozzles 21 of Nos. 1 to 5 and charged with a negative voltage of −10 kV to be charged with a negative polarity is column No. Spraying was performed with 6 to 10 nozzles 21. The temperature of the back roller 34 at the time of film formation was 70 ° C. In addition, the pressure environment during film formation was adjusted to a reduced pressure of 1000 Pa.

After the film formation, the protective layer was cured by the curing device 25 to form a protective layer on the gas barrier layer 1. A mercury lamp was used as the curing device 25, and ultraviolet rays having an irradiation amount of 2000 mJ / cm ² were irradiated during the curing process.

[Deposition Examples 2 and 3]
In the film formation examples 2 and 3, when the protective layer is formed, the row numbers of the nozzles 21 in which the raw material liquid charged to the positive polarity and the raw material liquid charged to the negative polarity are sprayed, respectively. In addition, the gas barrier films 2 and 3 were obtained in the same manner as in the above-mentioned film formation example 1 except that the voltage applied to the nozzle 21 was changed as shown in Table 1 below and no heat treatment was performed.

[Film Formation Example 4]
In the film formation example 4, the film formation method in the film formation chamber 10 is changed to the slot die coating method, the polysilazane film is formed as the gas barrier layer 1, and the raw material liquid charged to the positive polarity or the negative polarity is sprayed. The row number of the nozzle 21. And the gas barrier film 4 was obtained like the film-forming example 2 except having changed the applied voltage to the nozzle 21 as shown in following Table 1, and having formed the protective layer. In the film formation example 4, the pressure environment of the film formation chamber 10 and the film formation chamber 20 was both atmospheric pressure.

(Gas barrier layer 1)
When the gas barrier layer 1 was formed, in the film formation chamber 10, the polysilazane film coating solution was applied by a slot die coating method so that the film thickness after drying was 150 nm.
The coating solution was a non-catalytic 20% by weight dibutyl ether solution of perhydropolysilazane (Aquamica NN120-20, manufactured by AZ Electronic Materials), and an amine catalyst (N, N, N ′, N′-tetramethyl-1, 6-diaminohexane) is mixed with a 20% by weight dibutyl ether solution of perhydropolysilazane containing 5% by weight of solid content (Aquamica NAX120-20, manufactured by AZ Electronic Materials) at a ratio of 4: 1, and In order to adjust the thickness, it was prepared by appropriately diluting with dibutyl ether.

After coating, the film was dried at 80 ° C. for 2 minutes, and the dried coating film was irradiated with vacuum ultraviolet rays having an irradiation energy of 3.0 (J / cm ² ) using a vacuum ultraviolet irradiation apparatus having a Xe excimer lamp having a wavelength of 172 nm. Thus, the gas barrier layer 1 was formed. At this time, the irradiation atmosphere was replaced with nitrogen, and the oxygen concentration was set to 0.1% by volume.

[Film Formation Example 5]
In the film forming example 5, the row No. of the nozzle 21 for spraying the raw material liquid charged to the positive polarity or the negative polarity. In addition, a gas barrier film 5 was obtained in the same manner as in the above film formation example 4 except that the applied voltage to the nozzle 21 was changed as shown in Table 1 below.

[Film Formation Example 6]
In the film formation example 6, after forming the gas barrier layers 1 and 2 on the base film using the film formation apparatus provided with the two film formation chambers 10 in the film formation apparatus 100 shown in FIG. A protective layer was formed on the gas barrier layer 2 to obtain a gas barrier film 6. The same base film as used in film formation example 1 was used. Note that the configuration shown in FIG. 6 was used as the configuration of the film forming chamber 20.

(Gas barrier layer 1)
The gas barrier layer 1 was formed in the first film formation chamber 10 under the atmospheric pressure by the slot die coating method in the same manner as in the film formation example 4.

(Gas barrier layer 2)
The gas barrier layer 2 was formed in the second film formation chamber by magnetron sputtering as follows.
A 5 nm-thick niobium oxide (Nb ₂ O ₅ ) film was formed by DC sputtering using an oxygen-deficient Nb ₂ O ₅ target as a target and Ar and O ₂ as process gases. The pressure environment during film formation was adjusted to a reduced pressure of 0.4 Pa. Further, the oxygen partial pressure was adjusted so that the composition of the film was Nb ₂ O ₅ . This oxygen partial pressure condition is a condition when a film was formed on a glass substrate with different oxygen partial pressures in advance, and the composition in the vicinity of a depth of 5 nm from the surface of the film was Nb ₂ O _5. .

(Protective layer)
When forming the protective layer, the row No. of the nozzle 21 for spraying the raw material liquid charged to positive polarity or negative polarity is used. A protective layer was formed in the same manner as in the above-mentioned film formation example 4 except that the voltage applied to the nozzle 21 and the presence or absence of heat treatment were changed as shown in Table 1 below. The pressure when forming the protective layer was adjusted to a reduced pressure of 1000 Pa.

[Film Formation Examples 7 and 8]
In the film formation examples 7 and 8, when forming the protective layer, the row No. of the nozzle 21 for spraying the raw material liquid charged to the positive polarity or the negative polarity is used. Gas barrier films 7 and 8 were obtained in the same manner as in the above-mentioned film formation example 6 except that the applied voltage and the presence or absence of heat treatment were changed as shown in Table 1 below.

[Deposition Example 9]
In the example 9 of film formation, after forming the gas barrier layers 1 and 2 on a base film using the film-forming apparatus which provided the two film-forming chambers 10 in the film-forming apparatus 100 shown in FIG. A protective layer was formed at 1 to obtain a gas barrier film 9. The same base film as used in film formation example 1 was used. Note that the configuration shown in FIG. 6 was used as the configuration of the film forming chamber 20.

(Gas barrier layer 1)
The gas barrier layer 1 was formed in the first film formation chamber 10 under the atmospheric pressure by the slot die coating method in the same manner as in the film formation example 4.
(Gas barrier layer 2)
The gas barrier layer 2 was formed under reduced pressure by the ALD method in the same manner as the gas barrier layer 1 of the film formation example 1 in the second film formation chamber 10.

(Protective layer)
The row No. of the nozzle 21 for spraying the raw material liquid charged to the positive polarity or the negative polarity. A protective layer was formed under reduced pressure in the same manner as in Example 1 except that the voltage applied to the nozzle 21 and the presence or absence of heat treatment were changed as shown in Table 1 below.

[Deposition Example 10]
In the film forming example 10, the row No. of the nozzle 21 for spraying the raw material liquid charged to the positive polarity or the negative polarity is used. A gas barrier film 10 was obtained in the same manner as in Example 9 except that the voltage applied to the nozzle 21 and the presence or absence of heat treatment were changed as shown in Table 1 below.

[Deposition Example 11]
In the film formation example 11, the film formation method in the film formation chamber 10 is changed to the PECVD method, the gas barrier layer 1 is formed, and the row number of the nozzles 21 for spraying the raw material liquid charged to the positive polarity or the negative polarity . The gas barrier film 11 was obtained in the same manner as in Example 1 except that the protective layer was formed by changing the voltage applied to the nozzle 21 and the presence or absence of heat treatment as shown in Table 1 below. In the film formation example 11, the pressure environments of the film formation chamber 10 and the film formation chamber 20 were both adjusted to a reduced pressure of 1.5 Pa.

(Gas barrier layer 1)
As the gas barrier layer 1, a 100 nm silicon oxycarbide (SiOC) film was formed by PECVD.
Detailed film forming conditions by the PECVD method are as follows.
(Deposition conditions)
Source gas 1: Hexamethyldisiloxane (HMDSO)
Source gas 1 supply: 50 sccm (standard cubic centimeter per minute) (0 ° C, 1 atm standard)
Source gas 2: Oxygen gas Supply amount of source gas 2: 500 sccm (0 ° C., 1 atm standard)
Applied power from the power source for plasma generation: 1.5 kW
Power supply frequency for plasma generation: 80 kHz

(Protective layer)
The row No. of the nozzle 21 for spraying the raw material liquid charged to the positive polarity or the negative polarity. A protective layer was formed in the same manner as in Example 1 except that the voltage applied to the nozzle 21 and the presence or absence of heat treatment were changed as shown in Table 1 below.

[Deposition Example 12]
In the film formation example 12, when forming the protective layer, the row numbers of the nozzles 21 in which the raw material liquid charged to the positive polarity and the raw material liquid charged to the negative polarity are sprayed, respectively. A gas barrier film 12 was obtained in the same manner as in Example 11 except that the voltage applied to the nozzle 21 and the presence or absence of the heat treatment of the protective layer were changed as shown in Table 1 below.

[Evaluation]
Using the gas barrier films 1 to 12 obtained in the respective film formation examples 1 to 12, the film formation rate of the protective layer formed in each of the film formation examples 1 to 12 and the protective effect by the protective layer are as follows. And evaluated.

(Average film thickness)
The average film thickness (micrometer) of the protective layer of the gas barrier films 1-12 was measured. Specifically, the film thickness of the protective layer of each of the gas barrier films 1 to 12 is measured at five points by changing the position in the transport direction at a position of 650 mm from the end in the width direction, and the average value is the average film thickness. As sought. A contact-type film thickness meter (manufactured by Mitutoyo Corporation) was used for the measurement.

(Average film formation rate)
The average film thickness (μm) of the protective layer of each gas barrier film 1 to 12 was divided by the film formation time (min) to obtain the average film formation rate (μm / min) of the protective layer. During the formation of the protective layer of each gas barrier film 1 to 12, the film formation time from the start of spraying by the first row nozzle to the end of spraying by the tenth row nozzle was 0.1 min.
The obtained average film formation rate was ranked as follows. Rank 3 or higher is an acceptable film formation rate.
4: Average film formation rate (μm / min) is 15 or more 3: Average film formation rate (μm / min) is 10 or more and less than 15 2: Average film formation rate (μm / min) is 5 or more and less than 10 1 : Average film formation rate (μm / min) is less than 5

(Protective effect)
In each of the film formation examples 1 to 12, a part of the gas barrier films 1 to 12 before being wound by the winding device 33 and after being wound are cut out to prepare samples, and the water vapor permeability of each sample (G / m ² / day) was measured by the Mocon method. The measurement was performed in an environment of a temperature of 38 ° C. and a relative humidity of 100% RH using a water vapor transmission rate measuring apparatus AQUATRAN (manufactured by Mocon).

The ratio of the water vapor transmission rate of the sample after winding to the water vapor transmission rate of the sample before winding (water vapor transmission rate after winding / water vapor transmission rate before winding) is determined, and the protective effect by the protective layer is determined from the obtained ratio Was evaluated as follows. Rank 4 or higher is a protection effect at an acceptable level.
5: Ratio is less than 1.5 times 4: Ratio is 1.5 times or more and less than 2.0 times 3: Ratio is 2.0 times or more and less than 5.0 times 2: Ratio is 5.0 times or more and 10.0 times Less than 1: Ratio is 10.0 times or more

Table 1 below shows the evaluation results.

  As shown in Table 1, according to the film formation example in which the polarities of the raw material liquids sprayed by the nozzles arranged in the transport direction of the base film are all the same, the film formation rate and It can be seen that the protective effect is high.

DESCRIPTION OF SYMBOLS 1,100 Film formation apparatus 21 Nozzle 22 Power supply 23 Raw material supply part 24 Heating apparatus 25 Curing apparatus 10, 20 Film formation chamber 31 Unwinding apparatus 32 Roller 33 Winding apparatus 34 Back roller G Functional film G1 Functional layer G2 Protective layer

Claims (7)

A film forming apparatus for forming a film on a base film by an electrostatic spray method,
A transport mechanism for transporting the base film;
A plurality of nozzles for spraying a charged raw material liquid and forming the film on the base film transported by the transport mechanism;
The plurality of nozzles are composed of a nozzle that sprays a raw material liquid charged to a positive polarity and a nozzle that sprays a raw material liquid charged to a negative polarity, and the nozzles are arranged in the transport direction of the base film. A film forming apparatus characterized by being made.   2. The film forming apparatus according to claim 1, wherein the film is formed by spraying the raw material liquid with the plurality of nozzles under reduced pressure.   The film forming apparatus according to claim 1, further comprising a heating device for the film formed using the plurality of nozzles. A film forming method for forming a film on a base film by an electrostatic spray method,
Transporting the base film, spraying the charged raw material solution of the film with each of a plurality of nozzles to form the film on the base film,
The plurality of nozzles are arranged side by side in the transport direction of the base film, and at the time of forming the film, the raw material liquid charged to a positive polarity is sprayed by one or more of the plurality of nozzles, and negative A film forming method comprising spraying a polar charged material solution with the remaining one or a plurality of nozzles.   The film forming method according to claim 4, wherein the film is formed by spraying the raw material liquid with the plurality of nozzles under reduced pressure.   The film forming method according to claim 4, wherein the film formed using the plurality of nozzles is heated.   The film forming method according to claim 4, wherein the film having a thickness of 1 μm or more is formed.

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