JP2012082468A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film which can sufficiently suppress the deterioration of a gas barrier property even if the film is bent.SOLUTION: The laminated film has a base material and at least one layer of thin film layers which is formed on at least one surface of the base material. At least one layer of the thin film layers contains at least one or more kinds of oxygen, carbon and a nonmetal element (excluding silicon, oxygen and carbon). Furthermore, the laminated film is characterized by satisfying all of the following conditions (i) to (ii) that, in a carbon distribution curve which indicates a relationship between a distance from the surface of the layer in the film thickness direction of the layer and a ratio of carbon atoms (atom ratio of carbon) with respect to the total amount of silicon atoms, oxygen atoms and carbon atoms, (i) the carbon distribution curve is substantially continuous, and (ii) the carbon distribution curve has at least one extremal value.

Description

  The present invention relates to a laminated film excellent in gas barrier properties, which can be suitably used for flexible illumination using organic electroluminescence elements (organic EL elements), organic thin film solar cells, liquid crystal displays, pharmaceutical packaging containers, and the like.

  A laminated film, particularly a laminated film excellent in gas barrier properties, can be suitably used as a packaging container suitable for filling and packaging articles such as foods and drinks, cosmetics and detergents. In recent years, gas barrier films have been proposed in which a thin film of an inorganic oxide such as silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide is formed on one surface of a base film such as a plastic film.

As a method for forming an inorganic oxide thin film on the surface of a plastic substrate in this manner, physical vapor deposition (PVD) such as vacuum deposition, sputtering, ion plating, thermochemical vapor deposition, etc. A chemical vapor deposition method (CVD) such as a method (thermal CVD method) or a plasma chemical vapor deposition method is known.
In addition, as a laminated film using such a film forming method, for example, in Japanese Patent Laid-Open No. 4-89236 (Patent Document 1), two or more vapor-deposited silicon oxide films are formed on the surface of a plastic substrate. A laminated film provided with a laminated laminated vapor deposition film layer is disclosed.
In addition, for example, Patent Document 2 discloses a gas barrier film formed of carbon-containing silicon nitride (SiN _x C _y ) and having a continuously changing carbon content as a protective film of an organic EL element.

JP-A-4-89236 JP 2007-273094 A

  However, the gas barrier film as described in Patent Document 1 can be used as a gas barrier film for articles that are satisfactory even if the gas barrier property is relatively low, such as foods and drinks, cosmetics, and detergents. As a gas barrier film for an electronic device such as an EL element or an organic thin film solar cell, the gas barrier property is not always sufficient. In addition, the gas barrier film as described in Patent Documents 1 and 2 has a problem that when the film is bent, the gas barrier property against oxygen gas and water vapor is lowered, and the film is resistant to bending like a flexible liquid crystal display. As a gas barrier film that requires high properties, the film is not always sufficient in terms of gas barrier properties when the film is bent.

  The present invention has been made in view of the above-described problems of the prior art, has a sufficient gas barrier property, and can sufficiently suppress a decrease in gas barrier property even when the film is bent. An object of the present invention is to provide a laminated film.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have provided a laminated film including a base material and at least one thin film layer formed on at least one side of the base material. At least one of the layers contains at least one kind of silicon, oxygen, carbon, and nonmetallic elements (excluding silicon, oxygen, and carbon), and the thin film in the film thickness direction of the layer Surprisingly, sufficient gas barrier properties are obtained when the carbon distribution curve showing the relationship between the distance from the surface of the layer and the atomic ratio of carbon to the total amount of silicon atoms, oxygen atoms and carbon atoms satisfies the specific conditions. In addition, the present inventors have found that a laminated film that can sufficiently suppress a decrease in gas barrier properties even when the film is bent is obtained.

That is, the laminated film of the present invention is a laminated film comprising a substrate and at least one thin film layer formed on at least one surface of the substrate, and at least one of the thin film layers. Contains at least one kind of silicon, oxygen, carbon, and nonmetallic elements (excluding silicon, oxygen, and carbon), and the distance from the surface of the layer in the film thickness direction of the layer And carbon distribution curve showing the relationship between the ratio of the amount of carbon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms (carbon atomic ratio), the following conditions (i) to (ii):
(I) the carbon distribution curve is substantially continuous;
(Ii) the carbon distribution curve has at least one extreme value;
It is characterized by satisfying all of the above.

  In the laminated film of the present invention, the nonmetallic element is at least one selected from the group consisting of Group 15 elements of the Periodic Table, Group 16 elements excluding oxygen, and Group 17 elements. It is preferable that it is an element of these. In such a case, the nonmetallic element is preferably nitrogen.

  In the laminated film of the present invention, the thin film layer is preferably a layer formed by a plasma chemical vapor deposition method using a film forming gas containing nitrogen.

  Moreover, in the laminated | multilayer film of this invention, it is preferable in the said thin film layer that the said carbon distribution curve has a maximum value and a minimum value.

  In the laminated film of the present invention, in the thin film layer, the difference between the maximum value among the maximum values of the carbon distribution curve and the minimum value among the minimum values is preferably 5 at% or more.

  In the laminated film of the present invention, in the thin film layer, the distance from the surface of the layer in the thickness direction of the layer and the ratio of the amount of silicon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms ( In the silicon distribution curve showing the relationship with the atomic ratio of silicon, the difference between the maximum value and the minimum value of the silicon distribution curve is preferably 5% or less.

  In the laminated film of the present invention, when the non-metallic element is nitrogen, the ratio of the amount of nitrogen atoms to the total amount of silicon atoms, oxygen atoms, carbon atoms, and nitrogen atoms in the thin film layer is It is preferable that it is 1 at% or more.

  In the laminated film of the present invention, it is preferable that at least one carbon atom is directly bonded to a silicon atom in the thin film layer. In such a case, it is preferable that the carbon atom directly bonded to the silicon atom in the thin film layer is also bonded to the hydrogen atom.

  Further, in the laminated film of the present invention, the thin film layer is preferably a layer formed by a plasma chemical vapor deposition method using a nitrogen-containing compound gas or a deposition gas containing nitrogen gas. In such a case, it is also preferable that the film-forming gas contains a nitrogen-containing organosilicon compound gas or a compound gas containing oxygen and nitrogen.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the laminated | multilayer film which has sufficient gas barrier property and can fully suppress the fall of gas barrier property, even when a film is bent.

It is a schematic diagram which shows one Embodiment of the manufacturing apparatus which can be used suitably for manufacturing the laminated | multilayer film of this invention.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

The laminated film of the present invention is a laminated film comprising a substrate and at least one thin film layer formed on at least one surface of the substrate,
At least one of the thin film layers contains at least one kind of silicon, oxygen, carbon, and nonmetallic elements (excluding silicon, oxygen, and carbon), and
In the carbon distribution curve showing the relationship between the distance from the surface of the layer in the thickness direction of the layer and the ratio of the amount of carbon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms (carbon atomic ratio), The following conditions (i) to (ii):
(I) the carbon distribution curve is substantially continuous;
(Ii) the carbon distribution curve has at least one extreme value;
All of these are satisfied.

  As a base material used for this invention, the film or sheet | seat which consists of colorless and transparent resin is mentioned. Examples of the resin used for such a substrate include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefin resins such as polyethylene (PE), polypropylene (PP), and cyclic polyolefin; polyamide Polycarbonate resin; Polystyrene resin; Polyvinyl alcohol resin; Saponified ethylene-vinyl acetate copolymer; Polyacrylonitrile resin; Acetal resin; Polyimide resin. Among these resins, polyester resins and polyolefin resins are preferred, and PET and PEN are particularly preferred from the viewpoints of high heat resistance and linear expansion coefficient and low production cost. Moreover, these resin can be used individually by 1 type or in combination of 2 or more types.

  The thickness of the base material can be appropriately set in consideration of the stability when producing the laminated film of the present invention. The thickness of the substrate is preferably in the range of 5 to 500 μm from the viewpoint that the film can be conveyed even in a vacuum. Furthermore, when forming the thin film layer concerning this invention by plasma CVD method, since the thin film layer concerning this invention is formed, discharging through the said base material, the thickness of the said base material is in the range of 50-200 micrometers. More preferably, it is particularly preferably in the range of 50 to 100 μm.

  Moreover, it is preferable to perform the surface activation process for cleaning the surface of a base material to the said base material from an adhesive viewpoint with the thin film layer mentioned later. Examples of such surface activation treatment include corona treatment, plasma treatment, and flame treatment.

  The thin film layer concerning this invention is a layer formed in the at least single side | surface of the said base material. In the laminated film of the present invention, at least one of the thin film layers contains at least one kind of silicon, oxygen, carbon, and nonmetallic elements (excluding silicon, oxygen, and carbon). It needs to be a layer. In addition, at least one of the thin film layers may further contain aluminum.

  In the present invention, at least one of the thin film layers contains at least one other non-metallic element in addition to silicon, oxygen, and carbon, so that the film is bent. A laminated film having excellent gas barrier properties can be obtained. Non-metallic elements other than silicon, oxygen, and carbon contained in the layer include group 15 elements (nitrogen, phosphorus) in the periodic table, group 16 elements excluding oxygen (sulfur, selenium), and It is preferably at least one element selected from the group consisting of Group 17 elements (fluorine, chlorine, bromine, iodine). Among these, nitrogen is more preferable because good gas barrier properties can be obtained.

  In the present invention, a thin film containing at least one or more of the above silicon, oxygen, carbon, and nonmetallic elements (excluding silicon, oxygen, and carbon) (hereinafter referred to as “other nonmetallic elements”). At least one of the layers satisfies all of the above conditions (i) to (ii). That is, such a thin film layer first has a surface of the layer in the thickness direction of the layer (in the case where a thin film layer or the like is further laminated on the layer, the interface with the upper layer of the layer; The carbon distribution curve showing the relationship between the distance from the total amount of silicon atoms, oxygen atoms and carbon atoms (the ratio of carbon atoms) to the total amount of silicon atoms, oxygen atoms and carbon atoms (i) the carbon distribution curve Need to be substantially continuous. When the carbon distribution curve is substantially continuous, peeling due to a discontinuous interface or the like hardly occurs, and a laminated film having excellent gas barrier properties when the film is bent can be obtained.

In this specification, the carbon distribution curve being substantially continuous means that the carbon distribution curve does not include a portion where the atomic ratio of carbon changes discontinuously. Specifically, the etching rate and the etching rate are not included. The distance (x, unit: nm) from the surface of the layer in the film thickness direction of at least one of the thin film layers calculated from the time, and the atomic ratio of carbon (C, unit: at%) In the relationship, the following formula (F1):
| dC / dx | ≦ 1 (F1)
This means that the condition represented by

  In addition, such a thin film layer must then (ii) have the carbon distribution curve have at least one extreme value. In such a thin film layer, the carbon distribution curve more preferably has at least two extreme values, and particularly preferably has at least three extreme values. Among these, it is preferable to have at least one maximum value and at least one minimum value. When the carbon distribution curve does not have an extreme value, the gas barrier property when the resulting laminated film is bent is insufficient. Further, in the case of having at least three extreme values in this way, the surface of the thin film layer in the film thickness direction of the thin film layer at one extreme value and the extreme value adjacent to the extreme value of the carbon distribution curve ( Or the absolute value of the difference in distance from the interface) is preferably 200 nm or less, and more preferably 100 nm or less.

  In the present invention, the extreme value means the maximum value or the minimum value of the atomic ratio of the element to the distance from the surface of the thin film layer in the film thickness direction of the thin film layer. Further, in the present invention, the maximum value is a point where the value of the atomic ratio of the element changes from increasing to decreasing when the distance from the surface of the thin film layer is changed, and from the value of the atomic ratio of the element at that point This also means that the value of the atomic ratio of the element at a position where the distance from the surface of the thin film layer in the film thickness direction of the thin film layer is further changed by 20 nm from the point decreases by 3 at% or more. Furthermore, in the present invention, the minimum value is a point where the value of the atomic ratio of the element changes from decreasing to increasing when the distance from the surface of the thin film layer is changed, and from the value of the atomic ratio of the element at that point This also means that the atomic ratio value of the element at a position where the distance from the surface of the thin film layer in the film thickness direction of the thin film layer is further changed by 20 nm from that point increases by 3 at% or more.

  Further, in such a thin film layer, the difference (absolute value) between the maximum value of the maximum value and the minimum value of the minimum value of the carbon distribution curve is preferably 5 at% or more. In such a thin film layer, the absolute value of the difference between the maximum value of the maximum value of the atomic ratio of carbon and the minimum value of the minimum value is more preferably 6 at% or more, and 7 at% or more. It is particularly preferred that When the absolute value is 5 at% or more, the gas barrier property when the film of the obtained laminated film is bent is further improved.

  Further, it is preferable that at least one carbon atom contained in such a thin film layer is an organic carbon atom bonded to at least one hydrogen atom. In the present invention, since the organic carbon is contained in the thin film layer, the thin film layer is excellent in flexibility, and a laminated film excellent in gas barrier properties when the film is bent can be obtained.

  Further, it is preferable that at least one carbon atom contained in such a thin film layer is directly bonded to a silicon atom. In the present invention, since a direct bond between a carbon atom and a silicon atom exists in the thin film layer, a thin film layer having excellent flexibility is obtained, and a laminated film having excellent gas barrier properties when the film is bent is obtained. Obtainable. In the present invention, it is particularly preferable that the carbon atom directly bonded to the silicon atom existing in the thin film layer is also bonded to the hydrogen atom.

  In the present invention, the relationship between the distance from the surface of the thin film layer in the film thickness direction and the ratio of the amount of oxygen atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms (atomic ratio of oxygen) is The oxygen distribution curve shown preferably has at least one extreme value, more preferably has at least two extreme values, and particularly preferably has at least three extreme values. When the oxygen distribution curve does not have an extreme value, the gas barrier property tends to decrease when the resulting laminated film is bent. In the case of having at least three extreme values in this way, from the surface of the thin film layer in the thickness direction of the thin film layer at one extreme value and the extreme value adjacent to the extreme value of the oxygen distribution curve. The absolute value of the difference in distance is preferably 200 nm or less, and more preferably 100 nm or less.

  In the present invention, the absolute value of the difference between the maximum value and the minimum value of the oxygen atomic ratio in the oxygen distribution curve of the thin film layer is preferably 5 at% or more, more preferably 6 at% or more. , 7 at% or more is particularly preferable. When the absolute value is less than the lower limit, gas barrier properties tend to be lowered when the resulting laminated film is bent.

  In the present invention, the relationship between the distance from the surface of the thin film layer in the film thickness direction and the ratio of the amount of silicon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms (the atomic ratio of silicon) is The absolute value of the difference between the maximum value and the minimum value of the atomic ratio of silicon in the silicon distribution curve shown is preferably 5 at% or less, more preferably less than 4 at%, and particularly preferably less than 3 at%. When the absolute value exceeds the upper limit, the gas barrier property of the obtained laminated film tends to be lowered.

  In the present invention, the total amount of oxygen atoms and carbon atoms relative to the distance from the surface of the layer in the film thickness direction of at least one of the thin film layers and the total amount of silicon atoms, oxygen atoms, and carbon atoms. In the oxygen carbon distribution curve showing the relationship with the ratio (atomic ratio of oxygen and carbon), the absolute value of the difference between the maximum value and the minimum value of the total oxygen ratio of oxygen and carbon in the oxygen carbon distribution curve is less than 5 at%. Preferably, it is less than 4 at%, more preferably less than 3 at%. When the absolute value exceeds the upper limit, the gas barrier property of the obtained laminated film tends to be lowered.

In the present invention, as shown in the following formula, in the silicon distribution curve, silicon atoms are present in a region of 90% or more (more preferably 95% or more, particularly preferably 100%) of the film thickness of the thin film layer. Is preferably 30.0 at% or more and 37.0 at% or less. When the ratio of silicon atoms is within the range, the gas barrier property when the film of the obtained laminated film is bent is improved.
30at% ≦ (amount of silicon atom) / {(amount of oxygen atom) + (amount of carbon atom) + (amount of silicon atom)} ≦ 37at%

In the present invention, as shown in the following formula, the ratio of the total number of oxygen atoms and carbon atoms to the number of silicon atoms is preferably larger than 1.8 and not larger than 2.2. . When the ratio of the number of silicon atoms to the total number of oxygen atoms and carbon atoms is within this range, the gas barrier property when the film of the resulting laminated film is bent is improved.
1.8 <{(amount of oxygen atoms) + (amount of carbon atoms)} / (amount of silicon atoms) ≦ 2.2

In the present invention, in the region of 90% or more (more preferably 95% or more, particularly preferably 100%) of the thickness of the thin film layer, the atomic ratio of silicon, the atomic ratio of oxygen, and the atomic ratio of carbon are It is preferable that the condition represented by the following formula (1) or the following formula (2) is satisfied. When the atomic ratio of silicon, the atomic ratio of oxygen, and the atomic ratio of carbon satisfy the above conditions, the gas barrier property of the obtained laminated film becomes better.
(Atomic ratio of oxygen)> (atomic ratio of silicon)> (atomic ratio of carbon) (1)
(Atomic ratio of carbon)> (Atomic ratio of silicon)> (Atomic ratio of oxygen) (2)

  Further, in the silicon distribution curve, the oxygen distribution curve, and the carbon distribution curve, in the region where the atomic ratio of silicon, the atomic ratio of oxygen, and the atomic ratio of carbon are 90% or more of the film thickness of the layer, the above formula (1 ), The atomic ratio of the content of silicon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms in the thin film layer is preferably 25 to 45 at%, More preferably, it is ˜40 at%. The atomic ratio of the oxygen atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the thin film layer is preferably 33 to 67 at%, and more preferably 45 to 67 at%. Furthermore, the atomic ratio of the carbon atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the thin film layer is preferably 3 to 33 at%, and more preferably 3 to 25 at%.

  Further, in the silicon distribution curve, the oxygen distribution curve, and the carbon distribution curve, in the region where the atomic ratio of silicon, the atomic ratio of oxygen, and the atomic ratio of carbon are 90% or more of the film thickness of the layer, the above formula (2 ), The atomic ratio of the content of silicon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms in the thin film layer is preferably 25 to 45 at%, More preferably, it is ˜40 at%. The atomic ratio of the oxygen atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the thin film layer is preferably 1 to 33 at%, more preferably 10 to 27 at%. Furthermore, the atomic ratio of the carbon atom content to the total amount of silicon atoms, oxygen atoms and carbon atoms in the thin film layer is preferably 33 to 66 at%, and more preferably 40 to 57 at%.

  In the present invention, in the thin film layer, the ratio of the amount of atoms of other nonmetallic elements to the total amount of atoms of silicon atoms, oxygen atoms, carbon atoms and other nonmetallic elements (the atoms of other nonmetallic elements) Ratio) is preferably 1 at% or more. By satisfy | filling such conditions, the gas barrier property and bending resistance of the laminated film obtained can be further improved. The upper limit of the atomic ratio of the other nonmetallic elements is not particularly limited, but is preferably 20 at%.

  Furthermore, in the present invention, when the thin film layer contains nitrogen as another nonmetallic element, the ratio of the amount of nitrogen atoms to the total amount of silicon atoms, oxygen atoms, carbon atoms and nitrogen atoms is 1 at% or more. Preferably there is. In the present invention, in particular, the distance from the surface of the thin film layer in the film thickness direction and the ratio of the amount of nitrogen atoms to the total amount of silicon atoms, oxygen atoms, carbon atoms and nitrogen atoms (the atomic ratio of nitrogen) The nitrogen distribution curve showing the relationship with () is 90% or more (more preferably 95% or more, particularly preferably 100%) of the film thickness of the thin film layer, and the ratio of nitrogen atoms is 1 at% or more. Is preferred. When a sufficient amount of nitrogen is contained in the thin film layer, a thin film layer having excellent flexibility is obtained, and a laminated film having excellent gas barrier properties when the film is bent can be obtained.

The silicon distribution curve, the oxygen distribution curve, the carbon distribution curve, the oxygen carbon distribution curve, and the nitrogen distribution curve are measured by X-ray photoelectron spectroscopy (XPS) and rare gas ion sputtering such as argon. Can be used for so-called XPS depth profile measurement in which surface composition analysis is sequentially performed while exposing the inside of the sample. A distribution curve obtained by such XPS depth profile measurement can be created, for example, with the vertical axis as the atomic ratio (unit: at%) of each element and the horizontal axis as the etching time (sputtering time). In addition, in the element distribution curve with the horizontal axis as the etching time in this way, the etching time is generally correlated with the distance from the surface of the thin film layer in the film thickness direction of the thin film layer in the film thickness direction. As the distance from the surface of the thin film layer in the film thickness direction of the thin film layer, the distance from the surface of the thin film layer calculated from the relationship between the etching rate and the etching time employed in the XPS depth profile measurement may be adopted. it can. In addition, as a sputtering method employed for such XPS depth profile measurement, a rare gas ion sputtering method using argon (Ar ⁺ ) as an etching ion species is employed, and the etching rate (etching rate) is 0.05 nm / It is preferable to set to sec (SiO ₂ thermal oxide film conversion value).

  In the present invention, the thin film layer is substantially in the film surface direction (direction parallel to the surface of the thin film layer) from the viewpoint of forming a thin film layer having a uniform and excellent gas barrier property over the entire film surface. Preferably it is uniform. In the present specification, the thin film layer is substantially uniform in the film surface direction means that the oxygen distribution curve, the carbon distribution curve, and the carbon distribution curve at any two measurement points on the film surface of the thin film layer by XPS depth profile measurement. When an oxygen carbon distribution curve is created, the number of extreme values of the carbon distribution curve obtained at any two measurement points is the same, and the maximum and minimum values of the carbon atomic ratio in each carbon distribution curve The absolute value of the difference between the values is the same as each other or within 5 at%.

  The laminated film of the present invention comprises at least one thin film layer containing at least one kind of silicon, oxygen, carbon, and other non-metallic elements and satisfying all of the above conditions (i) to (ii). However, two or more layers satisfying such conditions may be provided. Further, when two or more such thin film layers are provided, the materials of the plurality of thin film layers may be the same or different. When two or more such thin film layers are provided, such a thin film layer may be formed on one surface of the base material, and is formed on both surfaces of the base material. May be. Moreover, as such a some thin film layer, the thin film layer which does not necessarily have gas barrier property may be included.

  The thickness of the thin film layer is preferably in the range of 5 to 3000 nm, more preferably in the range of 10 to 2000 nm, and particularly preferably in the range of 100 to 1000 nm. If the thickness of the thin film layer is less than the lower limit, the gas barrier properties such as oxygen gas barrier properties and water vapor barrier properties tend to be inferior. On the other hand, if the thickness exceeds the upper limit, the gas barrier properties tend to decrease due to bending.

  When the laminated film of the present invention includes a plurality of thin film layers, the total thickness of the thin film layers is usually in the range of 10 to 10,000 nm, preferably in the range of 10 to 5000 nm. More preferably, it is in the range of -3000 nm, and particularly preferably in the range of 200-2000 nm. If the total thickness of the thin film layer is less than the lower limit, the gas barrier properties such as oxygen gas barrier properties and water vapor barrier properties tend to be inferior. On the other hand, if the upper limit is exceeded, the gas barrier properties tend to decrease due to bending. .

  The laminated film of the present invention includes the base material and the thin film layer, but may further include a primer coat layer, a heat sealable resin layer, an adhesive layer, and the like as necessary. Such a primer coat layer can be formed using a known primer coat agent capable of improving the adhesion between the substrate and the thin film layer. Moreover, such a heat-sealable resin layer can be suitably formed using a well-known heat-sealable resin. Furthermore, such an adhesive layer can be appropriately formed using a known adhesive, and a plurality of laminated films may be bonded to each other by such an adhesive layer.

  In the laminated film of the present invention, the thin film layer is preferably a layer formed by a plasma chemical vapor deposition method. As a thin film layer formed by such a plasma chemical vapor deposition method, plasma chemistry in which the base material is disposed on the pair of film forming rolls and plasma is generated by discharging between the pair of film forming rolls. A layer formed by a vapor deposition method is more preferable. Further, when discharging between the pair of film forming rolls in this way, it is preferable to reverse the polarities of the pair of film forming rolls alternately. Further, as a film forming gas used in such a plasma chemical vapor deposition method, a gas containing an organosilicon compound, oxygen, and a compound containing atoms of nonmetallic elements other than silicon, carbon, and oxygen is preferable. The oxygen content in the film forming gas is preferably less than or equal to the theoretical oxygen amount required to completely oxidize the entire amount of the organosilicon compound in the film forming gas. Moreover, in the laminated | multilayer film of this invention, it is preferable that the said thin film layer is a layer formed of the continuous film-forming process.

  Next, a method for producing the laminated film of the present invention will be described. The laminated film of the present invention can be produced by forming the thin film layer on the surface of the substrate. As a method of forming such a thin film layer according to the present invention on the surface of the substrate, it is preferable to employ plasma chemical vapor deposition (plasma CVD) from the viewpoint of gas barrier properties.

  Further, when generating plasma in the plasma enhanced chemical vapor deposition method, it is preferable to generate a plasma discharge in a space between a plurality of film forming rolls, and a pair of film forming rolls is used, and the pair of film forming films is used. More preferably, the substrate is disposed on each of the rolls, and plasma is generated by discharging between the pair of film forming rolls. In this way, a pair of film forming rolls are used, a base material is disposed on the pair of film forming rolls, and discharge is performed between the pair of film forming rolls. In addition to forming the surface portion of the base material present on the other film, the surface portion of the base material existing on the other film forming roll can be formed at the same time. Since the film rate can be doubled and a film having the same structure can be formed, the extreme value in the carbon distribution curve can be at least doubled, and a layer that efficiently satisfies all the above conditions (i) to (ii) can be obtained. It becomes possible to form. Moreover, it is preferable that the laminated film of this invention forms the said thin film layer on the surface of the said base material by a roll-to-roll system from a viewpoint of productivity. Further, an apparatus that can be used when producing a laminated film by such a plasma chemical vapor deposition method is not particularly limited, and includes at least a pair of film forming rolls and a plasma power source, It is preferable that the apparatus has a configuration capable of discharging between the film forming rolls. For example, when the manufacturing apparatus shown in FIG. 1 is used, roll-to-roll using plasma chemical vapor deposition is used. It is also possible to manufacture by a roll method.

  Hereinafter, the method for producing the laminated film of the present invention will be described in more detail with reference to FIG. FIG. 1 is a schematic diagram showing an example of a manufacturing apparatus that can be suitably used for manufacturing the laminated film of the present invention. In the following description and drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

  1 includes a feed roll 11, transport rolls 21, 22, 23, 24, film forming rolls 31, 32, a gas supply pipe 41, a plasma generating power supply 51, a film forming roll 31, and 32 includes magnetic field generators 61 and 62 installed inside 32, and a winding roll 71. In such a manufacturing apparatus, at least the film forming rolls 31, 32, the gas supply pipe 41, the plasma generating power source 51, and the magnetic field generating apparatuses 61, 62 are arranged in a vacuum chamber (not shown). ing. Further, in such a manufacturing apparatus, the vacuum chamber is connected to a vacuum pump (not shown), and the pressure in the vacuum chamber can be appropriately adjusted by the vacuum pump.

  In such a manufacturing apparatus, each film-forming roll has a plasma generation power source so that the pair of film-forming rolls (film-forming roll 31 and film-forming roll 32) can function as a pair of counter electrodes. 51 is connected. Therefore, in such a manufacturing apparatus, it is possible to discharge into the space between the film forming roll 31 and the film forming roll 32 by supplying power from the plasma generating power source 51, thereby forming the film. Plasma can be generated in the space between the roll 31 and the film forming roll 32. In this way, when the film forming roll 31 and the film forming roll 32 are also used as electrodes, the material and design thereof may be appropriately changed so that they can also be used as electrodes. Moreover, in such a manufacturing apparatus, it is preferable that the pair of film forming rolls (film forming rolls 31 and 32) are arranged so that their central axes are substantially parallel on the same plane. Thus, by arranging a pair of film forming rolls (film forming rolls 31 and 32), the film forming rate can be doubled and a film having the same structure can be formed. Can be at least doubled. And according to such a manufacturing apparatus, it is possible to form a thin film layer on the surface of the film 100 by the CVD method, while depositing a film component on the surface of the film 100 on the film forming roll 31, Furthermore, since the film component can be deposited on the surface of the film 100 also on the film forming roll 32, the thin film layer can be efficiently formed on the surface of the film 100.

  Further, inside the film forming roll 31 and the film forming roll 32, magnetic field generators 61 and 62 fixed so as not to rotate even when the film forming roll rotates are provided, respectively.

  Further, as the film forming roll 31 and the film forming roll 32, known rolls can be appropriately used. As such film forming rolls 31 and 32, those having the same diameter are preferably used from the viewpoint of forming a thin film more efficiently. Further, the diameter of the film forming rolls 31 and 32 is preferably in the range of 5 to 100 cm from the viewpoint of discharge conditions, chamber space, and the like.

  Moreover, in such a manufacturing apparatus, the film 100 is arrange | positioned on a pair of film-forming roll (The film-forming roll 31 and the film-forming roll 32) so that the surface of the film 100 may oppose, respectively. By disposing the film 100 in this manner, each of the films 100 existing between the pair of film forming rolls is generated when the plasma is generated by performing discharge between the film forming roll 31 and the film forming roll 32. It becomes possible to form a film on the surface simultaneously. That is, according to such a manufacturing apparatus, the film component can be deposited on the surface of the film 100 on the film forming roll 31 and further the film component can be deposited on the film forming roll 32 by the CVD method. Therefore, the thin film layer can be efficiently formed on the surface of the film 100.

  Further, as the feed roll 11 and the transport rolls 21, 22, 23, and 24 used in such a manufacturing apparatus, known rolls can be appropriately used. Further, the winding roll 71 is not particularly limited as long as it can wind the film 100 on which the thin film layer is formed, and a known roll can be appropriately used.

  Further, as the gas supply pipe 41, a pipe capable of supplying or discharging the source gas or the like at a predetermined speed can be appropriately used. Furthermore, as the plasma generating power source 51, a known power source for a plasma generating apparatus can be used as appropriate. Such a power source 51 for generating plasma supplies power to the film forming roll 31 and the film forming roll 32 connected to the power source 51 and makes it possible to use them as a counter electrode for discharging. As such a plasma generation power source 51, it is possible to more efficiently carry out plasma CVD, so that the polarity of the pair of film forming rolls can be alternately reversed (AC power source or the like). Is preferably used. In addition, since the plasma generating power source 51 can perform plasma CVD more efficiently, the applied power can be set to 100 W to 10 kW, and the AC frequency can be set to 50 Hz to 500 kHz. More preferably, it is possible. As the magnetic field generators 61 and 62, known magnetic field generators can be used as appropriate. Furthermore, as the film 100, in addition to the base material used in the present invention, a film in which the thin film layer is formed in advance can be used. As described above, by using the film 100 in which the thin film layer is formed in advance, it is possible to increase the thickness of the thin film layer.

  Using the manufacturing apparatus shown in FIG. 1, for example, the type of source gas, the power of the electrode drum of the plasma generator, the pressure in the vacuum chamber, the diameter of the film forming roll, and the film transport speed are adjusted as appropriate. By doing so, the laminated film of the present invention can be produced. That is, by using the manufacturing apparatus shown in FIG. 1 to generate a discharge between a pair of film forming rolls (film forming rolls 31 and 32) while supplying a film forming gas (such as a raw material gas) into the vacuum chamber. The film forming gas (raw material gas or the like) is decomposed by plasma, and the thin film layer is formed on the surface of the film 100 on the film forming roll 31 and on the surface of the film 100 on the film forming roll 32 by the plasma CVD method. Is done. In such film formation, the film 100 is conveyed by the delivery roll 11, the film formation roll 31, and the like, respectively, so that the film 100 is formed on the surface of the film 100 by a roll-to-roll continuous film formation process. A thin film layer is formed.

  The source gas in the film-forming gas used for forming such a thin film layer can be appropriately selected and used according to the material of the thin film layer to be formed. As such a source gas, for example, an organosilicon compound containing silicon can be used. Examples of such organosilicon compounds include hexamethyldisiloxane, 1.1.3.3-tetramethyldisiloxane, vinyltrimethylsilane, methyltrimethylsilane, hexamethyldisilane, methylsilane, dimethylsilane, trimethylsilane, diethyl Examples thereof include silane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane, and tetramethylsilane. Among these organosilicon compounds, hexamethyldisiloxane and 1.1.3.3-tetramethyldisiloxane are preferable from the viewpoints of properties such as the handleability of the compound and the gas barrier property of the obtained thin film layer. Moreover, these organosilicon compounds can be used individually by 1 type or in combination of 2 or more types. Furthermore, it is good also as using as a silicon source of the thin film layer to contain monosilane other than the above-mentioned organosilicon compound as source gas.

  In addition to the source gas, a reactive gas may be used as the film forming gas. As such a reactive gas, a gas that reacts with the raw material gas to become an inorganic compound such as an oxide can be appropriately selected and used. As a reaction gas for forming an oxide, for example, oxygen or ozone can be used. These reaction gases can be used singly or in combination of two or more.

In the present invention, a thin film layer containing silicon, oxygen, carbon, and nitrogen can be obtained by using a gas containing nitrogen as the film forming gas. The gas containing nitrogen may be nitrogen-containing compound gas in addition to nitrogen gas. Examples of the nitrogen-containing compound gas include inorganic nitrogen-containing compound gases such as ammonia, nitrogen oxides {nitrogen monoxide (NO), nitrogen dioxide (NO ₂ ), nitrous oxide (dinitrogen monoxide) (N ₂ 0). , Dinitrogen trioxide (N ₂ O ₃ ), dinitrogen tetroxide (N ₂ O ₄ ), dinitrogen pentoxide (N ₂ O _5, etc.), and the like, and the like. Nitrogen gas, ammonia, oxygen, and a compound gas containing nitrogen can be used as a reaction gas. These gases containing nitrogen can be used singly or in combination of two or more. In addition, for example, an oxynitride can be formed in the thin film layer by using a combination of a reaction gas for forming an oxide and a reaction gas for forming a nitride. In addition, a nitrogen-containing organosilicon compound gas containing both silicon and nitrogen, such as hexamethyldisilazane, may be used as the source gas.

  As the film forming gas, a carrier gas may be used as necessary to supply the source gas into the vacuum chamber. Further, as the film forming gas, a discharge gas may be used as necessary in order to generate plasma discharge. As such carrier gas and discharge gas, known ones can be used as appropriate, for example, rare gases such as helium, argon, neon, xenon, etc .; hydrogen can be used.

  When such a film-forming gas contains a source gas and a reactive gas, the ratio of the source gas and the reactive gas is the reaction gas that is theoretically necessary for completely reacting the source gas and the reactive gas. It is preferable not to make the ratio of the reaction gas excessive rather than the ratio of the amount. If the ratio of the reaction gas is excessive, a thin film that satisfies all the above conditions (i) to (ii) cannot be obtained. In this case, excellent barrier properties and bending resistance cannot be obtained depending on the formed thin film layer. Further, when the film forming gas contains the organosilicon compound and oxygen, the amount is less than or equal to the theoretical oxygen amount required for complete oxidation of the entire amount of the organosilicon compound in the film forming gas. It is preferable.

Hereinafter, the film forming gas contains hexamethyldisiloxane (organosilicon compound: HMDSO: (CH ₃ ) ₆ Si ₂ O) as a source gas, and oxygen (O ₂ ) and nitrogen gas as reaction gases. The silicon-oxygen-based thin film is manufactured as an example, and a suitable ratio of the source gas to the reaction gas in the film forming gas will be described in more detail.

A film-forming gas containing hexamethyldisiloxane (HMDSO, (CH ₃ ) ₆ Si ₂ O) as a source gas and oxygen (O ₂ ) as a reaction gas is reacted by plasma CVD to form a silicon-oxygen-based material. When producing a thin film, the following reaction formula (1) is given by the film-forming gas:
(CH ₃ ) ₆ Si ₂ O + 12O ₂ → 6CO ₂ + 9H ₂ O + 2SiO ₂ (1)
The reaction as described in 1 takes place to produce silicon dioxide. In such a reaction, the amount of oxygen required to completely oxidize 1 mol of hexamethyldisiloxane is 12 mol. Therefore, when the film forming gas contains 12 moles or more of oxygen with respect to 1 mole of hexamethyldisiloxane and is completely reacted, a uniform silicon dioxide film is formed. ) To (ii) cannot be formed. Therefore, in the present invention, when forming the thin film layer, the oxygen amount is set to the stoichiometric ratio with respect to 1 mol of hexamethyldisiloxane so that the reaction of the above formula (1) does not proceed completely. It must be less than 12 moles. Note that in the actual reaction in the plasma CVD chamber, the raw material hexamethyldisiloxane and the reaction gas oxygen are supplied from the gas supply unit to the film formation region to form a film, so the molar amount of oxygen in the reaction gas ( Even if the flow rate is 12 times the molar amount (flow rate) of hexamethyldisiloxane as the raw material, the reaction cannot actually proceed completely. It is considered that the reaction is completed only when a large excess is supplied compared to the stoichiometric ratio (for example, in order to obtain silicon oxide by complete oxidation by CVD, the molar amount (flow rate) of oxygen is the raw material hexamethyldisiloxane. (It may be about 20 times or more of the molar amount (flow rate).) Therefore, the molar amount (flow rate) of oxygen with respect to the molar amount (flow rate) of the raw material hexamethyldisiloxane is preferably an amount of 12 times or less (more preferably 10 times or less) which is the stoichiometric ratio. . By including hexamethyldisiloxane and oxygen at such a ratio, carbon atoms and hydrogen atoms in hexamethyldisiloxane that have not been completely oxidized, and nitrogen atoms derived from nitrogen gas are taken into the thin film layer, It is possible to form a thin film layer containing silicon, oxygen, carbon, and nitrogen and satisfying all of the above conditions (i) to (ii), and the resulting laminated film has excellent barrier properties and flex resistance Can be exhibited. If the molar amount (flow rate) of oxygen with respect to the molar amount (flow rate) of hexamethyldisiloxane in the film forming gas is too small, carbon atoms and hydrogen atoms that have not been oxidized are excessively taken into the thin film layer. In this case, the transparency of the barrier film decreases, and the barrier film cannot be used for a flexible substrate for a device that requires transparency such as an organic EL device or an organic thin film solar cell. From such a viewpoint, the lower limit of the molar amount (flow rate) of oxygen relative to the molar amount (flow rate) of hexamethyldisiloxane in the film forming gas is more than 0.1 times the molar amount (flow rate) of hexamethyldisiloxane. Preferably, the amount is more than 0.5 times.

  Further, if the molar amount (flow rate) of nitrogen relative to the molar amount (flow rate) of hexamethyldisiloxane in the film forming gas is too small, a sufficient amount of nitrogen may not be taken into the thin film layer. For this reason, it is preferable that the molar amount (flow rate) of the nitrogen gas in the film forming gas is a value larger than 0.1 times the molar amount (flow rate) of hexamethyldisiloxane. For example, the molar amount (flow rate) of nitrogen gas in the film forming gas can be set to the same molar amount (flow rate) as the gas used as the carrier gas or the discharge gas.

  Moreover, although the pressure (vacuum degree) in a vacuum chamber can be suitably adjusted according to the kind etc. of source gas, it is preferable to set it as the range of 0.1 Pa-50 Pa.

  In such a plasma CVD method, in order to discharge between the film forming rolls 31 and 32, an electrode drum connected to the plasma generating power source 51 (in this embodiment, the film is installed on the film forming rolls 31 and 32). The electric power to be applied can be adjusted as appropriate according to the type of source gas, the pressure in the vacuum chamber, etc., and cannot be generally stated, but may be in the range of 0.1 to 10 kW. preferable. If the applied power is less than the lower limit, particles tend to be generated. On the other hand, if the applied power exceeds the upper limit, the amount of heat generated during film formation increases, and the temperature of the substrate surface during film formation increases. Therefore, the substrate loses heat and wrinkles occur during film formation. In severe cases, the film melts due to heat, and a large current discharge occurs between the bare film formation rolls. May cause damage.

  The conveyance speed (line speed) of the film 100 can be adjusted as appropriate according to the type of raw material gas, the pressure in the vacuum chamber, etc., but is preferably in the range of 0.1 to 100 m / min. A range of 5 to 20 m / min is more preferable. If the line speed is less than the lower limit, wrinkles due to heat tend to occur in the film. On the other hand, if the upper limit is exceeded, the thickness of the formed thin film layer tends to be thin.

  As described above, according to the present invention, it is possible to provide a laminated film that has a sufficient gas barrier property and can sufficiently suppress a decrease in gas barrier property even when the film is bent. Is possible.

  Therefore, the laminated film of the present invention can be suitably used for flexible lighting using organic electroluminescence elements (organic EL elements), organic thin film solar cells, liquid crystal displays, pharmaceutical packaging containers, and the like.

  DESCRIPTION OF SYMBOLS 11 ... Sending roll, 21, 22, 23, 24 ... Conveyance roll, 31, 32 ... Film-forming roll, 41 ... Gas supply pipe, 51 ... Power source for plasma generation, 61, 62 ... Magnetic field generator, 71 ... Winding roll , 100 ... film.

Claims (12)

A laminated film comprising a substrate and at least one thin film layer formed on at least one surface of the substrate,
At least one of the thin film layers contains at least one kind of silicon, oxygen, carbon, and a nonmetallic element (excluding silicon, oxygen, and carbon), and the thickness of the layer. In the carbon distribution curve showing the relationship between the distance from the surface of the layer in the direction and the ratio of the amount of carbon atoms to the total amount of silicon atoms, oxygen atoms and carbon atoms (the atomic ratio of carbon), the following condition (i) ~ (Ii):
(I) the carbon distribution curve is substantially continuous;
(Ii) the carbon distribution curve has at least one extreme value;
A laminated film characterized by satisfying all of the above.   The nonmetallic element is one or more elements selected from the group consisting of Group 15 elements of the Periodic Table, Group 16 elements excluding oxygen, and Group 17 elements. Item 2. The laminated film according to Item 1.   The laminated film according to claim 1 or 2, wherein the nonmetallic element is nitrogen.   The laminated film according to any one of claims 1 to 3, wherein the thin film layer is a layer formed by a plasma chemical vapor deposition method using a film forming gas containing nitrogen.   In the said thin film layer, the said carbon distribution curve has a maximum value and a minimum value, The laminated | multilayer film as described in any one of Claims 1-4 characterized by the above-mentioned.   The laminated film according to claim 5, wherein, in the thin film layer, a difference between a maximum value among the maximum values of the carbon distribution curve and a minimum value among the minimum values is 5 at% or more.   In the thin film layer, the relationship between the distance from the surface of the layer in the film thickness direction and the ratio of the amount of silicon atoms to the total amount of silicon atoms, oxygen atoms, and carbon atoms (the atomic ratio of silicon) is shown. In the silicon distribution curve, the difference between the maximum value and the minimum value of the silicon distribution curve is 5% or less, and the laminated film according to any one of claims 1 to 6.   8. The ratio of the amount of nitrogen atoms to the total amount of silicon atoms, oxygen atoms, carbon atoms, and nitrogen atoms in the thin film layer is 1 at% or more, according to claim 3. Laminated film.   In the said thin film layer, at least 1 carbon atom is couple | bonded directly with the silicon atom, The laminated | multilayer film as described in any one of Claims 1-8 characterized by the above-mentioned.   In the said thin film layer, the carbon atom directly couple | bonded with the silicon atom is also couple | bonded with the hydrogen atom, The laminated film as described in any one of Claims 1-9 characterized by the above-mentioned.   The thin film layer is a layer formed by plasma enhanced chemical vapor deposition using a nitrogen-containing compound gas or a film forming gas containing nitrogen gas. The laminated film according to item.   The laminated film according to claim 11, wherein the film forming gas includes a nitrogen-containing organosilicon compound gas or a compound gas containing oxygen and nitrogen.

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