CN108290376B

CN108290376B - Gas barrier film

Info

Publication number: CN108290376B
Application number: CN201680067287.7A
Authority: CN
Inventors: 门马千明; 铃木一生
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 2015-11-18
Filing date: 2016-10-03
Publication date: 2020-04-07
Anticipated expiration: 2036-10-03
Also published as: JP6720980B2; CN108290376A; JPWO2017086035A1; WO2017086035A1

Abstract

The present invention addresses the problem of providing a gas barrier film that has excellent gas barrier properties and high bending resistance even under high temperature and high humidity conditions. The gas barrier film of the present invention is characterized by comprising a gas barrier layer on a base film, wherein the gas barrier layer contains Si atoms, O atoms, and C atoms, and has at least one maximum value at a position in a layer thickness direction of 75 to 100% based on a C-C bond distribution curve, which is analyzed by a waveform of C1s measured by X-ray photoelectron spectroscopy at a position of 0 to 100% in the layer thickness direction from a surface of the gas barrier layer opposite to the base film to a surface of the base film, and which indicates a ratio of a C-C bond to a total of C-C, C-SiO, C-O, C ═ O, and C ═ OO bonds.

Description

Gas barrier film

Technical Field

The present invention relates to a gas barrier film, and more particularly, to a gas barrier film having excellent gas barrier properties and high bending resistance even under high temperature and high humidity conditions.

Background

Conventionally, a light and highly flexible gas barrier film has been used for sealing electronic devices such as organic el (electro luminescence) devices, liquid crystal display devices, and solar cells. The gas barrier film is generally formed by forming a gas barrier layer on a base film made of resin, and can prevent the penetration of gas such as water, oxygen, or the like in the atmosphere.

A gas barrier film used in an electronic device is required to have excellent gas barrier properties, and also required to have high bending resistance so that the film can maintain excellent gas barrier properties even when used for a flexible substrate.

In order to improve the bending resistance of the gas barrier film, a method is known in which Hexamethyldisiloxane (HMDSO) is used as a raw material, and the distribution of carbon atoms in the layer thickness direction of the gas barrier layer is adjusted so as to satisfy a certain condition (for example, see patent document 1).

In order to achieve a long life, it is desirable to have high bending resistance even under high temperature and high humidity. Since the base film swells under high temperature and high humidity, a difference in film stress between the base film and the gas barrier layer occurs, and the adhesion between the two tends to decrease. If the adhesiveness is reduced, when deformation of the base film due to bending is transmitted to the gas barrier layer, damage such as cracks is likely to occur in the gas barrier layer, resulting in a reduction in the gas barrier property.

Documents of the prior art

Patent document

Patent document 1, Japanese patent laid-open No. 2012 and 96531

Disclosure of Invention

The present invention has been made in view of the above problems and circumstances, and an object of the present invention is to provide a gas barrier film having excellent gas barrier properties and high bending resistance even under high temperature and high humidity conditions.

The present inventors have made studies to solve the above problems and found that a gas barrier layer containing Si atoms, O atoms, and C atoms is excellent in gas barrier properties and that if the ratio of C — C bonds on the base film side in the gas barrier layer is high, high bending resistance can be obtained even under high temperature and high humidity, and thus the present invention has been completed.

That is, the problem according to the present invention is solved by the following means.

1. A gas barrier film comprising a base film and a gas barrier layer provided on the base film, wherein,

the gas barrier layer contains Si atoms, O atoms and C atoms,

the gas barrier layer has at least one maximum value at a position in the layer thickness direction of 75 to 100% based on a C-C bond distribution curve showing the ratio of C-C bonds to the sum of C-C, C-SiO, C-O, C ═ O, and C ═ OO bonds, which is analyzed by X-ray photoelectron spectroscopy at a position of 0 to 100% in the layer thickness direction from the surface on the opposite side of the base film to the surface on the base film side of the gas barrier layer, and which has been measured by X-ray photoelectron spectroscopy.

2. The gas barrier film according to claim 1, wherein the average value of the ratio of C-C bonds at positions in the thickness direction of 90 to 100% in the C-C bond distribution curve is in the range of 20 to 90%.

3. The gas barrier film according to the above 1 or 2, wherein the maximum value of the one or more maximum values of the C — C bond distribution curve is in the range of 20 to 90%.

The above aspect of the present invention can provide a gas barrier film having excellent gas barrier properties and high bending resistance even under high temperature and high humidity conditions.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.

The gas barrier layer containing at least Si atoms, O atoms and C atoms has a dense structure due to the formation of a network of high-density bonds such as Si — O — Si and Si — C — Si, and therefore, a high gas barrier property is obtained.

Further, it is presumed that if the ratio of C — C bonds on the base film side is high in the layer thickness direction of the gas barrier layer, the C — C bonds can relax the film stress of the base film swollen under high temperature and high humidity, and the decrease in the adhesion between the base film and the gas barrier layer can be suppressed, and the resistance to the load at the time of bending can be improved. Further, it is presumed that the C — C bond can also relax deformation of the base film at the time of bending and reduce deformation transmitted to the inside of the gas barrier layer, and therefore, high bending resistance can be obtained even under high temperature and high humidity.

Drawings

Fig. 1 is a sectional view showing a schematic configuration of a gas barrier film of the present embodiment.

FIG. 2 is a graph showing a C-C bond distribution curve of a gas barrier layer in examples.

FIG. 3 is a graph showing a C-C bond distribution curve of a gas barrier layer in examples.

FIG. 4 is a graph showing a C-C bond distribution curve of a gas barrier layer in a comparative example.

Fig. 5 is a front view showing a schematic configuration of a gas barrier film manufacturing apparatus.

Detailed Description

The gas barrier film of the present invention is a gas barrier film including a gas barrier layer on a base film, wherein the gas barrier layer contains Si atoms, O atoms, and C atoms, and has at least one maximum value at a position in a layer thickness direction of 75 to 100% based on a C-C bond distribution curve representing a ratio of a C-C bond to a total of C-C, C-SiO, C-O, C ═ O, and C ═ OO bonds, which is analyzed by a waveform of C1s measured by an X-ray photoelectron spectroscopy at a position of 0 to 100% in the layer thickness direction from a surface of the gas barrier layer opposite to the base film to a surface of the base film side. This feature is a feature common to the inventions of the respective embodiments.

In the embodiment of the present invention, from the viewpoint of obtaining higher bending resistance, the average value of the ratio of C-C bonds at positions of 90 to 100% in the layer thickness direction in the C-C bond distribution curve is preferably in the range of 20 to 90%.

From the same viewpoint, the maximum value of the one or more maximum values of the C — C bond distribution curve is preferably in the range of 20 to 90%.

The present invention, its constituent elements, and modes for carrying out the present invention will be described in detail below.

In the present application, "to" is used to include numerical values before and after the "to" as the lower limit value and the upper limit value.

[ gas-barrier film ]

Fig. 1 is a sectional view showing a schematic configuration of a gas barrier film F according to an embodiment of the present invention.

As shown in fig. 1, the gas barrier film F includes a base film (base film)1 and a gas barrier layer 2 formed on the base film 1.

(gas Barrier layer)

The gas barrier layer 2 has gas barrier properties.

In the present invention, the term "having gas barrier properties" means that the MOCON water vapor transmission rate is used as a measurement deviceThe water vapor permeability measured at 38 deg.C and 90% RH by Aquatran (MOCON corporation) is less than 0.1[ g/(m)²·24h)]. From the viewpoint of obtaining a higher gas barrier property, the water vapor permeability is preferably less than 0.01[ g/(m)²·24h)]。

The gas barrier layer 2 contains at least Si atoms, O atoms, and C atoms.

Such a gas barrier layer 2 can be obtained by, for example, reacting an organosilicon compound having an Si — C skeleton with oxygen to form a silicon oxycarbide (SiOC) film. In addition, during the film formation, a gas such as nitrogen or ammonia may be supplied to perform nitridation, thereby forming the gas barrier layer 2 further containing N atoms.

The organosilicon compound to be used is preferably an organosilicon compound having a small number of Si-C bonds in 1 molecule, and examples thereof include cyclic siloxanes such as tetramethylcyclotetrasiloxane (TMCTS) and Octamethylcyclotetrasiloxane (OMCTS) having a number of Si-C bonds of 2 or less per 1 Si atom in 1 molecule, and alkoxysilanes such as methyltrimethoxysilane (MTMS) and Tetramethoxysilane (TMOS). These organosilicon compounds may be used alone in 1 kind or in combination of 2 or more kinds.

Among them, from the viewpoint of increasing the ratio of C — C bonds in the gas barrier layer 2 to improve the bending resistance and decreasing the ratio of C ═ C bonds and C ═ OO bonds to improve the transparency, the number of Si — C bonds of 1 Si atom is preferably 1 or 0.

The following shows the structures of TMCTS, OMCTS and MTMS.

The gas barrier Layer 2 can be formed by a Physical Vapor Deposition (PVD) method such as a vapor Deposition method or a sputtering method, a CVD method such as a Plasma Enhanced Chemical Vapor Deposition (PECVD) method, or an Atomic Layer Deposition (ALD) method, and the PECVD method is preferred in terms of easy adjustment of the Atomic composition of the gas barrier Layer 2. Among them, the opposing-roll PECVD method in which plasma is generated between two opposing rolls and a gas barrier layer is formed in parallel on a base film conveyed by each roll is preferable because the atomic composition in the layer thickness direction can be continuously changed.

As shown in fig. 1, the gas barrier layer 2 has at least one maximum value at a position in the layer thickness direction of 75 to 100% based on a waveform analysis of C1s measured by an X-ray Photoelectron Spectroscopy (XPS) method at a position of 0 to 100% in the layer thickness direction from a surface Sa on the opposite side of the gas barrier layer 2 to a surface Sb on the base film 1 side, the C-C bond distribution curve indicating the ratio of the C-C bond to the total of the C-C, C-SiO, C-O, C ═ O, and C ═ OO bonds.

The maximum value is an inflection point at which the percentage of C-C bonds in the C-C bond distribution curve changes from increasing to decreasing, and is a point at which the percentage of positions 2 to 20nm from the inflection point in the layer thickness direction is lower by 5% or more than the percentage of the inflection point.

The minimum value is an inflection point where the ratio of C-C bonds changes from decrease to increase in the C-C bond distribution curve.

These maxima and minima are referred to as extrema.

In this way, in the gas barrier layer 2 having a high ratio of C — C bonds on the side of the base film 1 at positions in the layer thickness direction within the range of 75 to 100%, a large number of C — C bonds distributed on the side of the base film 1 can alleviate the film stress of the base film 1 swollen under high temperature and high humidity and the load transmitted to the gas barrier layer 2 by the deformation of the base film during bending. The adhesion between the base film 1 and the gas barrier layer 2 is improved even under high temperature and high humidity, the resistance to a load during bending is improved, and the reduction in gas barrier properties is suppressed, so that the gas barrier layer 2 having high bending resistance is obtained.

From the viewpoint of obtaining higher bending resistance, the average value of the ratio of C-C bonds at positions in the thickness direction of 90 to 100% in the C-C bond distribution curve is preferably in the range of 20 to 90%.

The ratio of C — C bonds is particularly high near the interface between the gas barrier layer 2 and the base film 1, and therefore higher bending resistance can be obtained.

The maximum value of the one or more maximum values of the C — C bond distribution curve is preferably in the range of 20 to 90%.

Such a gas barrier layer 2 can obtain higher bending resistance because C — C bonds that relax the film stress and strain of the base film 1 are abundant.

The above C — C bond distribution curve can be drawn by combining the XPS method and the rare gas ion sputtering. The XPS method is a method of analyzing the composition and chemical bonding state of atoms constituting a sample surface by measuring the kinetic energy of photoelectrons emitted from the sample surface irradiated with X-rays, and is also called ESCA (Electron Spectroscopy for chemical analysis: Electron Spectroscopy for chemical analysis).

Specifically, the XPS method is used to analyze the atomic composition and the chemical bonding state of the sample surface exposed by sputter-etching the sample with a rare gas ion, and thereby can grasp the change in the atomic composition and the chemical bonding state in the layer thickness direction of the sample.

An example of measurement conditions combining the XPS method and the rare gas ion sputtering is shown.

(measurement conditions)

Etching ion species: argon (Ar)⁺)

Etch Rate (SiO)₂Thermal oxide film conversion value): 0.05nm/sec

Etch Spacer (SiO)₂Conversion value): 2.5nm

X-ray photoelectron spectroscopy apparatus: model name "VG ThetaProbe" manufactured by Thermo Fisher Scientific Co., Ltd "

Single crystal energy spectrum AlK α irradiated with X-ray

Spot and size of X-ray: an ellipse of 800X 400. mu.m.

The ratio of C — C bonds in the gas barrier layer 2 was determined by waveform analysis of the peak of C1s in the spectrum obtained by measuring the binding energy of C atoms by the XPS method. Specifically, a peak derived from a C-C bond was extracted from the peak of C1s, and the ratio (Q2/Q1X 100) of the peak area of the C-C bond (Q2) to the peak area of the C1s peak (Q1) was calculated as the ratio of the C-C bond in the gas barrier layer 2. That is, the ratio of C — C bonds is equal to the ratio of the number of C — C bonds to the total (total number of bonds) of the bonds C-C, C-SiO, C-O, C ═ O, and C ═ OO forming the peak of C1 s. For waveform analysis (separation of peak, calculation of peak area, specification of peak position, and the like) required for calculation of the ratio, commercially available analysis software such as PeakFIT (manufactured by SYSTAT corporation) can be used.

When the gas barrier layer 2 is etched by the rare gas ion sputtering at the etching intervals, the ratio of C-C bonds at the positions in the layer thickness direction is obtained every time, and an approximate curve of the ratio of the positions in the layer thickness direction is obtained as a C-C bond distribution curve representing the ratio of C-C bonds at the positions in the layer thickness direction of 0 to 100%.

As shown in fig. 1, the position of the gas barrier layer 2 in the layer thickness direction is represented by 0 to 100% where the position of the surface Sa of the gas barrier layer 2 opposite to the base film 1 is 0% and the position of the surface Sb of the base film 1 is 100%.

That is, the position of the gas barrier layer 2 in the layer thickness direction can be represented by the ratio of the sputtering depth from the surface Sa to the distance from the surface Sa to the surface Sb of the gas barrier layer 2 (the layer thickness of the gas barrier layer 2).

The layer thickness of the gas barrier layer 2 can be determined by observing the cross section of the gas barrier film F with a Transmission Electron Microscope (TEM). Specifically, the cross section of the gas barrier film F was observed, and the distance from the surface Sa to the surface Sb of the gas barrier layer 2 was measured. The interface between the gas barrier layer 2 and the base film 1 is determined by the contrast difference therebetween. The distance was measured at 10 points different in position on the film surface, and the average value of the measured values was determined as the layer thickness of the gas barrier layer 2.

As a Focused Ion Beam (FIB) apparatus for preparing samples for TEM and TEM, the following apparatus was used.

(TEM)

The device comprises the following steps: JEM2000FX (made by Japanese electronic official)

Acceleration voltage: 200kV

(FIB device)

The device comprises the following steps: SMI2050(SII Co., Ltd.)

Processing ions: ga (30kV)

Thickness of the sample: 100 to 200nm

Fig. 2 and 3 show C — C bond distribution curves obtained by analyzing the gas barrier layer of the gas barrier film according to the example of the present invention.

FIG. 2 shows a C-C bond distribution curve of a gas barrier layer formed by a PECVD method using methyltrimethoxysilane (MTMS) and oxygen as raw materials, and FIG. 3 shows a C-C bond distribution curve of a gas barrier layer formed by a PECVD method using tetramethylcyclotetrasiloxane (TMCTS) as a raw material.

Fig. 4 shows a C — C bond distribution curve obtained by analyzing the gas barrier layer of the gas barrier film of the comparative example. The C-C bond distribution shown in FIG. 4 is a C-C bond distribution of a gas barrier layer formed by a PECVD method using Hexamethyldisiloxane (HMDSO) and oxygen as raw materials.

As shown in FIGS. 2 and 3, the C-C bond distribution curves in the examples each have a maximum value at a position of 75 to 100% in the layer thickness direction. The respective maximum values are located at positions of about 83% and about 85% in the layer thickness direction, and the ratio of C — C bonds on the base film side is high, so that the gas barrier layer has high bending resistance as described above.

On the other hand, as shown in fig. 4, the C — C bond distribution curve of the comparative example has a maximum value at a position less than 75% in the layer thickness direction, but has no maximum value at a position 75 to 100% in the layer thickness direction. Therefore, the distribution of C — C bonds on the substrate film side is small, and therefore, the film stress of the substrate film under high temperature and high humidity and the deformation of the substrate film during bending cannot be relaxed, and there is a possibility that damage of the gas barrier layer such as cracking occurs.

The average value of the ratio of C-C bonds in the range of 90 to 100% in the position in the layer thickness direction is about 35% in the C-C bond distribution curve shown in FIG. 2, and about 69% in the C-C bond distribution curve shown in FIG. 3, all of which are in the range of 20 to 90%. In addition, the C-C bond distribution curves in FIGS. 2 and 3 have a plurality of maximum values, and the maximum values thereof are in the range of 20 to 90%, respectively. Therefore, the ratio of C-C bonds in the vicinity of the interface with the base film is high, and the C-C bonds are abundant, so that high bending resistance is obtained.

On the other hand, in the C-C bond distribution curve shown in fig. 4, the maximum value of the maximum value is in the range of 20 to 90%, but the average value of the ratio of C-C bonds at positions in the layer thickness direction of 90 to 100% is less than 20%, which is low, and high bending resistance as in the example cannot be expected.

Fig. 2 to 4 also show bond distribution curves indicating the ratios of C — Si bonds, C — O bonds, C ═ O bonds, and C ═ OO bonds at positions in the layer thickness direction of 0 to 100% of the gas barrier layer 2. Similarly to the C — C bond, peaks derived from the respective bonds were extracted from the C1s peak, and the ratio of the peak area of the peak derived from the respective bonds to the peak area of the C1s peak was determined as the ratio of the respective bonds.

Comparing fig. 2 and 3 with fig. 4, the example has a lower ratio of C ═ O bonds and C ═ OO bonds than the comparative example. A gas barrier layer having a small number of C ═ O bonds and C ═ OO bonds, which are chromophoric groups, is preferable because yellowing is small and the gas barrier layer is highly useful for sealing electronic devices requiring high transparency.

The ratio of C — C bonds in the layer thickness direction of the gas barrier layer 2 can be adjusted by selecting 1 or more types of organosilicon compounds from those exemplified as the organosilicon compounds that can be used, depending on the ratio of C atoms, H atoms, and O atoms in the molecule.

The ratio of C-C bonds in the layer thickness direction can be adjusted not only by selecting raw materials but also by adjusting film formation conditions.

For example, when the gas barrier layer 2 is formed by supplying oxygen gas supplied as a source gas together with an organosilicon compound by the PECVD method, the ratio of C — C bonds in the gas barrier layer 2 can be adjusted by adjusting the supply amount of oxygen gas.

Further, it is also possible to adjust the ratio of the target C — C bond in the layer thickness direction of the gas barrier layer 2 by supplying an inert gas such as nitrogen, argon, or helium during the film formation and adjusting the supply amount of the inert gas to stabilize the plasma and control the oxidation reaction, deposition, or the like of the oxygen gas and the organosilicon compound.

Further, by continuously changing the distance between the electrodes for generating plasma, the ratio of C — C bonds in the layer thickness direction can be adjusted to a target ratio.

When the film is formed by the opposite-roll PECVD method, if the distance between the electrodes incorporated in the respective rolls is changed, the density of plasma generated on the surface of the base film 1 in contact with the rolls is continuously changed, and therefore the composition of the gas barrier layer 2 can also be continuously changed.

The thickness of the gas barrier layer 2 is preferably in the range of 50 to 500nm, and preferably in the range of 50 to 300 nm.

When the layer thickness is 50nm or more, sufficient gas barrier properties can be obtained, and when the layer thickness is 500nm or less, a thin gas barrier film F can be obtained.

(basilar membrane)

As the base film 1, resin, glass, metal, or the like molded into a film shape can be used. Among them, a resin is preferable, and a resin having high transparency is preferable. If the transparency of the resin is high and the transparency of the base film 1 is high, a gas barrier film F having high transparency can be obtained and is suitably used for electronic devices such as organic EL elements.

Examples of the resin that can be used for the base film 1 include methacrylate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Polycarbonate (PC), polyarylate, Polystyrene (PS), aromatic polyamide, polyether ether ketone, polysulfone, polyethersulfone, Polyimide (PI), polyetherimide, and the like. Among them, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Polycarbonate (PC), and the like are preferable in terms of cost and ease of availability.

The base film 1 may be a laminated film in which 2 or more kinds of the above resins are laminated.

The resin-made base film 1 can be produced by a conventionally known production method. For example, a resin as a material may be melted by an extruder, extruded through an annular die or a T-die, and then rapidly cooled, thereby producing a substantially amorphous and unoriented unstretched resin base material. Further, the base film 1 may be obtained by dissolving a resin as a material in a solvent, casting (casting) the solution on an endless metal resin support, drying, and peeling the casting.

The unstretched film may be stretched in a film conveyance (MD) Direction or a width Direction (TD) perpendicular to the film conveyance Direction, and the obtained stretched film may be used as the base film 1.

The thickness of the base film 1 is preferably in the range of 5 to 500 μm, and more preferably in the range of 25 to 250 μm.

The gas barrier film F may have other layers such as an anchor layer, a smoothing layer, and a bleed-out prevention layer, if necessary. As the anchor layer, the smoothing layer, and the anti-bleeding layer, the layers described in japanese patent application laid-open No. 2013-52561, etc. can be used.

(anchoring layer)

The gas barrier film F may include an anchor layer between the base film 1 and the gas barrier layer 2, from the viewpoint of improving the adhesion between the base film 1 and the gas barrier layer 2.

The anchor layer can be formed by, for example, applying a coating liquid containing a polyester resin, an isocyanate resin, a urethane resin, an acrylic resin, an ethylene vinyl alcohol resin, a vinyl-modified resin, an epoxy resin, a modified styrene resin, a modified silicone resin, an alkyl titanate, or the like and drying the coating liquid.

(smoothing layer)

The gas barrier film F may have a smooth layer as a lower layer of the gas barrier layer 2. The gas barrier layer 2 can be formed on a flat surface by the smooth layer, and the generation of pinholes and the like due to unevenness can be prevented, whereby the gas barrier layer 2 having high gas barrier properties can be obtained.

The smoothing layer can be formed by, for example, applying a coating liquid containing a photosensitive resin and performing curing treatment. Examples of the photosensitive resin include resin compositions containing acrylate compounds having radically reactive unsaturated compounds; a resin composition containing an acrylate compound and a thiol compound having a thiol group; and resin compositions obtained by dissolving a polyfunctional acrylate monomer such as epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polyethylene glycol acrylate, or glyceryl methacrylate.

(anti-exudation layer)

The gas barrier film F may be provided with a bleed-out preventing layer in order to suppress a bleed-out phenomenon in which unreacted oligomer or the like migrates from the surface of the base film 1 to contaminate the contacted surface. The anti-bleeding layer is provided on the surface of the base film 1 on the side opposite to the smoothing layer. The anti-bleeding layer may have substantially the same configuration as the smoothing layer as long as it has a function of suppressing bleeding.

[ light transmittance of gas barrier film ]

The gas barrier film F is preferably used as a sealing material for electronic devices because it has high transparency.

Specifically, the evaluation was carried out in accordance with JIS K7105: the light transmittance measured in 1981 is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.

[ gas Barrier film manufacturing apparatus ]

Fig. 5 shows a schematic configuration of a manufacturing apparatus 100 capable of manufacturing the gas barrier film F.

As shown in fig. 5, the gas barrier film manufacturing apparatus 100 conveys a base film 1 by a plurality of rollers 11 to 18 in a vacuum chamber 10, and supplies a source gas while applying a voltage between a pair of

rollers

13 and 16 facing each other. In this way, in the manufacturing apparatus 100, a plasma reaction of the raw material gas is generated, and a gas barrier layer is formed on the base film 1, thereby manufacturing the gas barrier film F.

As shown in fig. 5, the vacuum chamber 10 is provided with an exhaust port 41, and a vacuum pump 42 is provided at the end of the exhaust port 41.

Further, as shown in fig. 5, the roll 11 unwinds the base film 1, and the roll 18 winds the gas barrier film F obtained by the formation of the gas barrier layer.

The rolls 12 to 17 transport the base film 1 from unwinding from the roll 11 to winding up by the roll 18.

The pair of

rollers

13 and 16 are disposed so as to face each other, and a gas supply portion 21 for supplying a raw material gas between the

rollers

13 and 16 is provided adjacent to the

rollers

13 and 16.

The pair of

rollers

13 and 16 are connected to a power source 22, respectively, and a magnetic field generating device 23 is incorporated therein. By supplying a source gas from a gas supply unit 21 and applying a voltage between the

rollers

13 and 16 by a power supply 22, plasma is generated in a discharge space between the

rollers

13 and 16, and a plasma reaction of the source gas is performed to form a gas barrier layer on the base film 1 conveyed by the

rollers

13 and 16. At this time, since a racetrack-shaped magnetic field is formed by the magnetic field generating device 23 around each of the

rollers

13 and 16, plasma is generated along the lines of magnetic force of the magnetic field. The electric field and the magnetic field in the discharge space confine electrons in the film formation space to generate high-density plasma, thereby improving the film formation efficiency.

The gas supply unit 21 shown in fig. 5 is provided on the center line of the

rollers

13 and 16, but may be offset from the center line toward either of the

rollers

13 and 16. This makes it possible to vary the supply amount of the raw material gas to the

rollers

13 and 16, and to vary the atomic compositions of the film formed on the roller 13 and the film formed on the roller 16. Similarly, in order to make the atomic composition of the film different, the position of the gas supply portion 21 may be shifted on the center line so as to be distant from or close to each of the

rollers

13 and 16.

When the film forming conditions such as the supply amount of the raw material gas during film formation are changed, films having different atomic compositions are stacked every time the film forming conditions are changed, and the atomic composition in the layer thickness direction is continuously changed.

Specifically, if the base film 1 passes through the point a of the roller 13 and the point B of the roller 16, the ratio of the number of C atoms in the layer thickness direction in the gas barrier layer 2 increases from a decrease, and the ratio of the number of O atoms decreases from an increase.

In contrast, if the base film 1 passes through the sites C1 and C2 of the roller 13 and the sites C3 and C4 of the roller 16, the ratio of C atoms in the layer thickness direction in the gas barrier layer 2 is changed from increasing to decreasing, and the ratio of O atoms is changed from decreasing to increasing.

The presence of such an extreme value of the transition from decrease to increase or from increase to decrease indicates that the presence ratio of C atoms to O atoms in the gas barrier layer 2 is not uniform, and a portion with low density and few C atoms is locally present, so that the gas barrier layer 2 has a flexible structure and the bending resistance is improved.

Each of the

rollers

13 and 16 is preferably configured in the following manner: the rotation axes are parallel to each other on the same plane, and the surfaces of the base films 1 to be conveyed are opposed to each other, on which the gas barrier layers are formed. With this configuration, after the gas barrier layer is formed on the base film 1 by the rollers 13 upstream in the transport direction, the gas barrier layer can be further laminated by the rollers 16 downstream in the transport direction, and the film formation efficiency can be further improved.

From the viewpoint of improving the film forming efficiency, the diameters of the

rollers

13 and 16 are preferably the same.

The diameter of each of the

rollers

13 and 16 is preferably in the range of 100 to 1000mm, and more preferably in the range of 100 to 700mm, from the viewpoints of optimization of discharge conditions, reduction of space in the vacuum chamber 10, and the like.

If the diameter phi is 100mm or more, a sufficiently large discharge space can be formed, and a decrease in productivity can be prevented. In addition, a sufficient layer thickness can be obtained by short-time discharge, and heat applied to the base film 1 during discharge can be suppressed, thereby suppressing residual stress. If the diameter is 1000mm or less, the uniformity of the discharge space can be maintained, and the device is practically designed.

The gas supply unit 21 supplies the source gas of the gas barrier layer to the discharge space formed between the pair of

rollers

13 and 16. For example, when the gas barrier layer containing silicon oxycarbide is formed by oxidizing the organosilicon compound, the gas supply unit 21 supplies a gas of the organosilicon compound and a gas such as oxygen or ozone as the raw material gas. In the nitriding, a source gas such as nitrogen or ammonia may be supplied.

The gas supply unit 21 may use a carrier gas when supplying the source gas as needed, or may supply a plasma generation gas to promote the generation of plasma. Examples of the carrier gas include a rare gas such as helium, argon, neon, xenon, or krypton, and nitrogen, and examples of the plasma generating gas include hydrogen.

As the power source 22, a known power source for generating plasma can be used, and an ac power source capable of alternately reversing the polarity of each of the

rollers

13 and 16 is preferable, which can improve the film formation efficiency.

The amount of power supplied by the power source 22 may be in the range of 0.1 to 10.0 kW. If the amount is 0.1kW or more, generation of foreign matter called particles can be suppressed. In addition, if 10.0kW or less, the amount of heat generated can be suppressed, and the generation of wrinkles in the base film 1 due to a temperature increase can be suppressed. In the case of an ac power supply, the frequency of the ac power is preferably in the range of 50Hz to 500 kHz.

The pressure in the vacuum chamber 10, that is, the degree of vacuum can be adjusted by the vacuum pump 42 according to the kind of the raw material gas, and is preferably in the range of 0.5 to 100.0 Pa.

The transport speed (linear velocity) of the base film 1 may be determined depending on the type of raw material gas, the degree of vacuum, and the like, and is preferably in the range of 0.25 to 100.00m/min, and more preferably in the range of 0.5 to 20.0 m/min. Within this range, the occurrence of wrinkles in the base film 1 can be suppressed, and a gas barrier layer having a sufficient thickness can be formed.

Examples

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, "part" or "%" is used, and unless otherwise specified, "part by mass" or "% by mass" is used.

[ gas Barrier film 1 ]

"KB フィルム with a thickness of 125nm^TM"(registered trademark) G1SBF (manufactured by KIMOTO Co., Ltd.) was used as the base film.

In the "KB フィルム^TM"G1 SBF has a gas barrier layer formed thereon from Hexamethyldisiloxane (HMDSO) and oxygen.

The gas barrier layer was formed under the following film formation conditions using a manufacturing apparatus having the same configuration as that shown in fig. 5.

(film Forming conditions)

Raw material gas 1: HMDSO

Raw material gas 2: oxygen gas

Supply amount of raw material gas 1: 50sccm (Standard Cubic Centimeter per Minute)

Supply amount of raw material gas 2: 650sccm

Vacuum degree: 2Pa

Power supplied from the power supply for plasma generation: 0.8kW

Frequency of power supply for plasma generation: 80kHz

Conveying speed of the film: 2m/min

[ gas barrier films 2 to 7 ]

In the production of the gas barrier film 1, the gas barrier films 2 to 7 were produced in the same manner as the gas barrier film 1 except that the type of the raw material gas 1 and the supply amounts of the raw material gases 1 and 2 were changed as shown in table 1 below.

[ C-C bond distribution Curve ]

For each of the gas barrier films 1 to 7 produced, the C — C bond distribution curve in the layer thickness direction of the gas barrier layer was obtained as follows.

TEM samples of the gas barrier films 1 to 7 were prepared using the FIB apparatus described below. The sample was fixed to TEM described below, and the cross section of each of the gas barrier films 1 to 7 was observed, and the distance from the surface of the gas barrier layer opposite to the base film to the surface of the base film was measured. The interface between the gas barrier layer and the base film was confirmed by the difference in contrast between the two. The measurement was performed at 10 points different in position on the film surface, and the average value of the measured values was determined as the layer thickness (nm) of the gas barrier layer.

(TEM)

Acceleration voltage: 200kV

(FIB device)

The device comprises the following steps: SMI2050(SII Co., Ltd.)

Processing ions: ga (30kV)

Thickness of the sample: 100 to 200nm

In each of the gas barrier films 1 to 7, the bond energy spectrum of the C atom on the exposed surface is obtained by XPS method by etching the gas barrier layer from the surface opposite to the base film to the surface on the base film side by sputtering with a rare gas ion. The measurement conditions of the XPS method and the rare gas ion sputtering are as follows.

(measurement conditions)

Etching ion species: argon (Ar)⁺)

Etch Rate (SiO)₂Thermal oxide film conversion value): 0.05nm/sec

Etch Spacer (SiO)₂Conversion value): 2.5nm

Single crystal energy spectrum AlK α irradiated with X-ray

Spot and size of X-ray: an ellipse of 800X 400. mu.m.

The C1s peak in the spectrum obtained by the XPS method was extracted from the peak of the C-C bond, and the ratio (Q2/Q1X 100) of the peak area of the C-C bond (Q2) to the peak area of the C1s peak (Q1) was determined as the ratio of the C-C bond in the gas barrier layer 2.

The obtained ratio of C — C bonds is plotted against the position of the gas barrier layer in the layer thickness direction etched from the surface on the side opposite to the base film, to prepare a depth profile. In this depth profile, an approximate curve of the plotted ratio is obtained as a C — C bond distribution curve. In the depth profile, the position in the layer thickness direction of the surface opposite to the base film is represented by 0%, the position in the layer thickness direction of the surface on the base film side is represented by 100%, and the position in the layer thickness direction of the gas barrier layer from the surface opposite to the base film is represented by the ratio of the depth distance (nm) of etching to the layer thickness (nm) of the gas barrier layer determined by the TEM.

In the depth profile of each of the gas barrier films 1 to 7, the position (%) in the layer thickness direction of the maximum value of the C-C bond distribution curve at the position in the layer thickness direction of 65 to 100% was determined. The C-C bond distribution curve has one maximum value at a position of 65 to 100% in the layer thickness direction.

In addition, the average value (%) of the ratio of C-C bonds between the position (%) in the layer thickness direction of the maximum value among the one or more maximum values of the C-C bond distribution curve and the position (%) in the layer thickness direction of 90 to 100% is obtained. The results are shown in table 1 below.

[ evaluation ]

(gas Barrier Property)

The water vapor transmission rates [ g/(m) of the gas barrier films 1 to 7 at a temperature of 38 ℃ and a humidity of 90% RH were measured using an MOCON Water vapor Transmission Rate measuring apparatus Aquastran (manufactured by MOCON Co., Ltd.)²·24h)]。

The gas barrier property was evaluated on the basis of the measured water vapor permeability according to the following evaluation criteria. The smaller the value of the water vapor permeability, the higher the gas barrier property, and a gas barrier property of grade 3 or more is practically usable.

5: water vapor transmission rate of less than 0.005

4: water vapor permeability of 0.005 or more and less than 0.010

3: water vapor permeability of 0.010 to less than 0.100

2: water vapor permeability of 0.100 or more and less than 0.500

1: water vapor permeability of 0.500 or more

(bending resistance)

The water vapor transmission rate (g/m) of the gas barrier films 1 to 7 at a temperature of 38 ℃ and a humidity of 90% RH was measured using an MOCON water vapor transmission rate measuring apparatus Aquastran (manufactured by MOCON Co., Ltd.)²·24h)。

After the measurement, the bending test of each of the gas barrier films 1 to 7 was performed. In the bending test, the gas barrier films 1 to 7 are first stored at 60 ℃ and 90% RH for 100 hours under high temperature and high humidity conditions. Each of the gas barrier films 1 to 7 taken out from the high temperature and high humidity was cut into a size of 3cm × 10cm, wound around the circumferential surface of a metal rod (diameter 6mm) with the gas barrier layer as the outer side, and the winding operation was repeated 100 times. The water vapor permeability of each of the gas barrier films 1 to 7 after the bending test was measured in the same manner as in the case before the bending test.

From the water vapor transmittances measured before and after the bending test, the rate of change in the water vapor transmittance was calculated by the following equation.

Rate of change of Water vapor Transmission (%)

Not (water vapor permeability after bending test)/(water vapor permeability before bending test)

The bending resistance was evaluated on the basis of the calculated rate of change in the water vapor permeability in the following scale. The smaller the numerical value of the rate of change, the more excellent the bending resistance, and a grade of 3 or more is a practical bending resistance.

5: the rate of change of the water vapor permeability is 1.0 or more and less than 2.0

4: a change rate of water vapor permeability of 2.0 or more and less than 4.5

3: a change rate of water vapor permeability of 4.5 or more and less than 7.0

2: a change rate of water vapor permeability of 7.0 or more and less than 10.0

1: the rate of change of water vapor permeability is 10.0 or more

The evaluation results are shown in table 1 below.

In table 1 below, HMDSO, TMCTS, and MTMS are short names of hexamethyldisiloxane, tetramethylcyclotetrasiloxane, and methyltrimethoxysilane, respectively.

As shown in table 1, it is understood that the gas barrier films 2 to 7 having the C — C bond distribution curve having at least one local maximum value at a position in the layer thickness direction of 75 to 100% are not only excellent in gas barrier properties but also high in bending resistance with little decrease in gas barrier properties even after standing under high temperature and high humidity.

Industrial applicability

The gas barrier film of the present invention can be used for long-term use under high temperature and high humidity.

Description of the symbols

F gas barrier film

1 base film

2 gas barrier layer

A surface of the gas barrier layer on the side opposite to the base film Sa

Surface of Sb-based film-side gas barrier layer

100 gas barrier film manufacturing apparatus

11 to 18 rollers

22 power supply

Claims

1. A gas barrier film comprising a base film and a gas barrier layer provided on the base film,

the gas barrier layer is obtained by reacting an organosilicon compound with oxygen, contains Si atoms, O atoms and C atoms, and has a number of Si-C bonds of 2 or less per 1 Si atom in 1 molecule,

the gas barrier layer has at least one maximum value at a position in the layer thickness direction of 75 to 100% based on a C-C bond distribution curve showing the ratio of C-C bonds to the sum of C-C, C-SiO, C-O, C ═ O, and C ═ OO bonds, which is analyzed by X-ray photoelectron spectroscopy at a position of 0 to 100% in the layer thickness direction from the surface on the opposite side of the base film to the surface on the base film side of the gas barrier layer.

2. The gas barrier film according to claim 1, wherein an average value of the ratio of C-C bonds at positions of 90 to 100% in a layer thickness direction in the C-C bond distribution curve is in a range of 20 to 90%.

3. The gas barrier film of claim 1 or 2, wherein the C-C bond distribution curve has one or more maxima having a maximum value in the range of 20 to 90%.