Stress mitigating gas barrier film

Abstract

To provide a gas barrier film capable of being uniformly applied to a film or a polysilazane resin and having stress relaxation properties not damaging workability.SOLUTION: A stress relaxation gas barrier film obtained by alternately laminating one or more cured coating layers obtained by curing a composition containing a polysilazane compound of the following formula (1) and one or more stress relaxation layers (film thickness: 0.1 to 15.0 μm) obtained by curing a composition containing a linear organopolysiloxane of the following formula (a- 1).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a gas barrier film having stress relaxation properties. [Background technology]

[0002] Advanced electronic materials such as organic light-emitting diodes (OLEDs), all-solid-state batteries, and perovskite solar cells are highly susceptible to moisture, and therefore require a high level of water vapor barrier treatment to ensure the durability of the devices. Specifically, a water vapor permeability of 10 -3 ~10 -6 A high level of gas barrier performance is required. Various methods have been proposed to achieve this high gas barrier performance, such as sealing by sandwiching between glass plates or sealing with metal foil, but no complete solution has been found from the standpoints of flexibility, transparency, and cost.

[0003] Meanwhile, a method has been proposed in which an organic film that has been treated with a high gas barrier is used to laminate the glass or metal foil instead (Patent Document 1). In this method, an inorganic film such as SiO2 or Si3N4 is formed by CVD on a film that is optically transparent and flexible, such as polyethylene terephthalate (PET). Compared to direct sealing with inorganic glass or metal, this method is preferable in terms of properties, as it can ensure optical transparency and flexibility, but it is very costly and has issues such as weakness when subjected to strong bending, so it has been proposed to use polysilazane instead of CVD film formation (Patent Document 2).

[0004] Before curing, polysilazane is a polymer that is soluble in solvents, and after curing, it becomes SiO2 or SiO x N y Wet coating is possible to form an inorganic film using polysilazane. Wet coating has better manufacturing costs and yields than CVD, so forming an inorganic film using polysilazane is preferred.

[0005] However, inorganic polysilazanes are prone to cracking due to volumetric shrinkage during curing, making them unable to be coated at a thickness of more than approximately 1 μm, even without bending. A technique of laminating thin films of several hundred nanometers thick has also been used, but this has little effect in reducing cracking. This is thought to be due to the cumulative effect of residual stress generated during curing of the inorganic polysilazane in the lower layer and stress generated during curing of the inorganic polysilazane in the upper layer. To solve this problem, a method has been proposed in which inorganic polysilazane is coated on both sides of the film (Patent Document 3). Because there is a limit to the thickness of inorganic polysilazane that can be coated on one side, coating on both sides can roughly double the total barrier layer thickness, but even this method fails to achieve the required gas barrier performance.

[0006] To address this issue, a method has been reported in which a stress relief layer is inserted between layers of inorganic polysilazanes to relieve residual stress (Patent Document 4). This method significantly increases the total thickness of the inorganic polysilazane layers, thereby improving gas barrier performance. However, the material used for the stress relief layer has not yet been optimized, and existing materials are simply used. In particular, the stress relief layer is cured by crosslinking via UV irradiation. However, with UV crosslinking, the curing reaction progresses gradually after UV irradiation, resulting in variations in the surface condition and crosslinking state of the coating film over time. This makes it difficult to determine the timing for applying the next inorganic polysilazane. While applying the next inorganic polysilazane is relatively easy once the layer has fully cured, it requires leaving the layer to stand for about a day after UV irradiation, making it unsuitable for mass production. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-87815 [Patent Document 2] Japanese Patent Application Publication No. 2018-177859 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-161891 [Patent Document 4] Japanese Patent Publication No. 2023-088514 Summary of the Invention [Problem to be solved by the invention]

[0008] In conventional gas barrier films having a stress relaxation layer, there were problems in that the stress relaxation layer could not be applied uniformly and the curing reaction of the stress relaxation layer took time, making it unsuitable for mass production. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a gas barrier film that can be uniformly applied to a film or a polysilazane resin and has stress relaxation properties that do not impair workability. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention A cured coating layer obtained by curing a polysilazane composition containing a polysilazane compound represented by the following formula (1): [ka] (In the formula, R is independently a hydrogen atom or a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms; and n is an integer of 2 to 20,000.) and a stress relaxation layer, which is obtained by curing a silicone resin composition containing a linear organopolysiloxane represented by the following formula (A-1), and which has a thickness of 0.1 to 15.0 μm per layer. [ka] (In the formula, R 1 are independently an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. 2 are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 3are independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms; a is an integer of 1≦a<200, and b is an integer of 0≦b<200, with the proviso that a+b is 10≦a+b<200. The present invention provides a stress-relieving gas barrier film characterized by being formed by laminating one or more layers of each of the above alternately.

[0010] Such a stress-relieving gas barrier film can be uniformly coated on a film or polysilazane resin. Furthermore, the use of the stress-relieving layer stabilizes the film quality by simply drying the solvent, allowing the film to proceed to the next step, significantly improving mass productivity and film quality stability compared to conventional methods.

[0011] The silicone resin composition further comprises a compound represented by the following formula (A-2): [ka] (In the formula, R 3 is the same as above, and R 4 are independently an alkyl group having 1 to 4 carbon atoms or a phenyl group; c is an integer of 0≦c<30; and d is independently 2 or 3. and (B) a hydrosilylation catalyst. It is preferred that the compound contains:

[0012] By containing such an organohydrogenpolysiloxane represented by formula (A-2) and (B) a hydrosilylation catalyst, the silicone resin composition is cured, which is preferable because the stress relaxation layer is less likely to be redissolved in a solvent when a cured coating layer or the like is applied in the next step.

[0013] The silicone resin composition further comprises a compound represented by the following formula (A-3): [ka] (In the formula, R 1 are independently the same as above, and R 5are independently selected from alkyl groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 3 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms, provided that at least two of them in one molecule are alkenyl groups, and e is an integer satisfying the conditions of 200≦e<500. It is preferable that the organopolysiloxane contains a linear organopolysiloxane represented by the following formula:

[0014] By including such a linear organopolysiloxane represented by formula (A-3), the value of e can be adjusted, thereby adjusting the physical properties of the stress relaxation layer, such as wettability and spreadability on the substrate and flexibility after curing.

[0015] In the formula (1), it is preferable that all of the R's are hydrogen atoms.

[0016] Such a polysilazane composition is preferable because it can form a dense silica glass layer after curing and has high gas barrier properties.

[0017] The polysilazane composition preferably further contains a surfactant.

[0018] The wettability can be improved by adding a surfactant to the polysilazane composition.

[0019] The silicone resin composition preferably further contains a surfactant (C).

[0020] Such a silicone resin composition is preferable because it improves the wettability of the substrate and the cured layer of the polysilazane composition, thereby reducing defects such as pinholes.

[0021] The silicone resin composition preferably further contains (D) an adhesion promoter.

[0022] Such a silicone resin composition is preferable because it has good adhesion to the substrate and the cured layer of the polysilazane composition. [Effects of the Invention]

[0023] As described above, the stress relaxation gas barrier film of the present invention can provide a uniform gas barrier film with excellent stress relaxation properties and good gas barrier properties. Furthermore, since the gas barrier film of the present invention is excellent in coatability and workability when produced, the gas barrier film can be provided with stable quality. DETAILED DESCRIPTION OF THE INVENTION

[0024] As described above, there has been a demand for the development of a gas barrier film with excellent stress relaxation properties and stable film quality.

[0025] As a result of extensive research into the above-mentioned problems, the present inventors have discovered that a gas barrier film formed on a substrate, in which one or more cured coating layers are alternately stacked on the surface side and one or more stress relaxation layers on the substrate side, exhibits excellent stress relaxation properties and excellent film stability, and have completed the present invention.

[0026] The stress-relieving gas barrier film of the present invention has one or more, preferably 4 to 8, alternating cured coating layers and stress relief layers made of a specific material. The alternating lamination of the cured coating layers and stress relief layers results in a gas barrier film with superior adhesion between the layers.

[0027] That is, the present invention provides: A cured coating layer obtained by curing a polysilazane composition containing a polysilazane compound represented by the following formula (1): [ka] (In the formula, R is independently a hydrogen atom or a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms; and n is an integer of 2 to 20,000.) and a stress relaxation layer, which is obtained by curing a silicone resin composition containing a linear organopolysiloxane represented by the following formula (A-1), and which has a thickness of 0.1 to 15.0 μm per layer. [ka] (In the formula, R 1 are independently an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. 2 are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 3 are independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms; a is an integer of 1≦a<200, and b is an integer of 0≦b<200, with the proviso that a+b is 10≦a+b<200. The stress relaxation gas barrier film is characterized by being formed by laminating one or more layers of each of the above alternately.

[0028] The present invention will be described in detail below, but the present invention is not limited thereto.

[0029] [Stress relaxation gas barrier film] The stress relaxation gas barrier film of the present invention comprises a cured coating layer obtained by curing a polysilazane composition containing a polysilazane compound represented by the following formula (1): [ka] (In the formula, R is independently a hydrogen atom or a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms; and n is an integer of 2 to 20,000.) and a stress relaxation layer, which is obtained by curing a silicone resin composition containing a linear organopolysiloxane represented by the following formula (A-1), and which has a thickness of 0.1 to 15.0 μm per layer. [ka] (In the formula, R 1 are independently an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. 2 are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 3are independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms; a is an integer of 1≦a<200, and b is an integer of 0≦b<200, with the proviso that a+b is 10≦a+b<200. These are stacked alternately in one or more layers.

[0030] [Cured film layer] The cured coating layer of the present invention is intended to impart gas barrier properties to a stress relaxation gas barrier film. The polysilazane composition forming the cured coating layer is characterized by containing a polysilazane compound represented by the following formula (1): [ka] (In the formula, R is independently a hydrogen atom or a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms; and n is an integer of 2 to 20,000.)

[0031] In the formula (1), R is independently a hydrogen atom or a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a cyclohexyl group. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Examples of the aralkyl group include a benzyl group, a 2-phenylethyl group, and a 2-phenylpropyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group. Among these, a hydrogen atom, a methyl group, and a phenyl group are preferred, and it is more preferred that all R are hydrogen atoms.

[0032] In the formula (1), n ​​is an integer of 2 to 20,000, and preferably 50 to 400.

[0033] Examples of the silazane unit of the polysilazane compound include the following. [ka]

[0034] The cured coating layer can be obtained by applying a polysilazane composition containing the polysilazane compound to a substrate and curing the composition. The polysilazane composition may contain an organic solvent.

[0035] Examples of the organic solvent include linear saturated aliphatic hydrocarbons such as n-hexane, n-octane, and n-nonane; unsaturated aliphatic hydrocarbons such as 1-octene, 1-nonene, and 1-decene; cyclic saturated aliphatic hydrocarbons such as cyclohexane, methylcyclohexane, and dimethylcyclohexane; ester compounds such as n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, isoamyl acetate, and ethyl caproate; and ether compounds such as diethyl ether, dibutyl ether, and ethylene glycol diethyl ether. Among these, ether compounds or ester compounds are preferred, with dibutyl ether and butyl acetate being particularly preferred, from the viewpoints of the solubility of the polysilazane compound and its wettability to inorganic and organic materials. The mixing ratio of the polysilazane compound to the organic solvent, in terms of mass ratio, is preferably in the range of 0.1 / 99.9 to 20 / 80, more preferably 1 / 99 to 20 / 80, and even more preferably 2.5 / 97.5 to 20 / 80. Within this range, storage stability and coatability are good, and a thick coating can be achieved at one time, which is preferable.

[0036] A surfactant may be added to the polysilazane composition to improve wettability. Examples of surfactants include acetylene glycol surfactants such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-dimethoxy, 2,4,7,9-tetramethyl-5-decyne-4,7-di(ethylene glycol), and 2,4,7,9-tetramethyl-5-decyne-4,7-di(ethylene glycol monomethyl ether). The amount of surfactant added can be determined as desired depending on the desired wettability and defoaming properties. However, adding too much surfactant can adversely affect gas barrier properties. Therefore, the amount of surfactant added is preferably within a range of 0.01 to 5% by mass, and more preferably within a range of 0.1 to 1% by mass, based on the total polysilazane composition.

[0037] Examples of methods for applying the polysilazane composition to a substrate include roll coating using a chamber doctor coater, a single-roll kiss coater, a reverse kiss coater, a bar coater, a reverse roll coater, a forward rotation roll coater, a blade coater, a knife coater, and the like; spin coating; dispensing; dipping; spraying; transfer; and slit coating.

[0038] The substrate is not particularly limited, but considering its application as a gas barrier, a flexible resin substrate is preferred. Specific examples include general-purpose plastics such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc), polyurethane (PUR), polytetrafluoroethylene (PTFE), acrylonitrile butadiene styrene resin (ABS), and acrylic resin (PMMA); engineering plastics such as polyamide (PA), nylon, polycarbonate (PC), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT); and super-engineering plastics such as amorphous polyarylate (PAR), polysulfone (PSF), thermoplastic polyimide (PI), and polyetherimide (PEI). Among these, PET and PC, which are widely used industrially, are more preferred due to their cost, light transmittance, and processability.

[0039] It is preferable to perform a drying process before curing the coating of the polysilazane composition applied by the above method in terms of post-curing properties, but this process may be omitted if the volatile components, such as the solvent used, have sufficiently evaporated by the time of the curing process. Furthermore, in the case of a heat curing process, the organic solvent evaporates before the polysilazane compound in the composition cures during the curing process, so this process may also be omitted. Conversely, if the curing process is performed before the organic solvent has sufficiently evaporated, the organic solvent may remain in the cured coating, which may deteriorate the physical properties of the cured coating. Furthermore, the solvent may evaporate when reheated, leading to poor appearance such as voids and cracks.

[0040] Although heat or energy ray irradiation is the most common method for curing polysilazane coatings, this is not necessarily limited to these methods. Furthermore, in the case of heat curing, the curing reaction temperature of the polysilazane compound itself is so high that it is expected that the base thermoplastic resin would not be able to withstand this. Therefore, it is preferable to add a heat curing catalyst to the polysilazane composition in advance. Without a catalyst, the curing time is approximately one day at 150°C. With the addition of a catalyst, however, sufficient curing occurs in approximately one to three hours at 150°C, depending on the amount added. In the case of energy ray irradiation, a photoradical generator may be added in advance, but curing proceeds sufficiently even without the addition. In particular, wavelengths of 200 nm or less, such as xenon excimer light, are absorbed almost entirely by polysilazane, allowing for rapid curing.

[0041] The thickness of the coating film is not particularly limited as long as it does not crack due to cure shrinkage of the polysilazane during curing, but it is preferably in the range of 0.01 to 20 μm. A film thickness of 0.01 μm or more is preferred because it can fully exhibit the effect of suppressing oligomer precipitation by polysilazane, gas barrier properties, and solvent resistance. Furthermore, a film thickness of 20 μm or less is preferred because it has excellent flexibility and is less likely to crack or peel when applied to a flexible substrate such as a thermoplastic resin film.

[0042] [Stress relief layer] The stress relaxation layer of the present invention is intended to relieve stress generated in a cured coating layer applied to a stress-relieving gas barrier film. The silicone resin composition forming the stress relaxation layer is characterized by containing a linear organopolysiloxane represented by the following formula (A-1) (hereinafter sometimes referred to as component (A-1)): [ka] (In the formula, R 1 are independently an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. 2 are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 3are independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms; a is an integer of 1≦a<200, and b is an integer of 0≦b<200, with the proviso that a+b is 10≦a+b<200.

[0043] In the formula (A-1), R 1 are independently an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. Specific examples include methyl, ethyl, propyl, vinyl, and allyl groups. Of these, methyl, ethyl, and vinyl groups are preferred. Furthermore, when component (A-2), which will be described later, is also included, it is preferable that each molecule contains two or more alkenyl groups. The presence of alkenyl groups allows them to react with the hydrosilyl groups of component (A-2) to form a cured coating.

[0044] In the formula (A-1), R 2 are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably a methyl group or an ethyl group.

[0045] In the formula (A-1), R 3 are independently selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a cyclohexyl group. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Examples of the aralkyl group include a benzyl group, a 2-phenylethyl group, and a 2-phenylpropyl group. Of these, a methyl group and a phenyl group are preferred.

[0046] In the formula (A-1), a is an integer satisfying 1≦a<200, and preferably 10≦a≦50. b is an integer satisfying 0≦b<200, and preferably 0≦b≦30. However, a+b satisfies 10≦a+b<200, and preferably 10≦a+b≦100. If a+b is less than 10, film loss due to evaporation may occur during solvent drying, and if it is 200 or more, solvent solubility decreases, which is undesirable.

[0047] The silicone resin composition for forming the stress relaxation layer of the present invention preferably contains, in addition to the linear organopolysiloxane (A-1) described above, an organohydrogenpolysiloxane represented by the following formula (A-2) (hereinafter sometimes referred to as component (A-2)), and a hydrosilylation catalyst as component (B): [ka] (In the formula, R 3 is the same as above, and R 4 are independently an alkyl group having 1 to 4 carbon atoms or a phenyl group; c is an integer of 0≦c<30; and d is independently 2 or 3.

[0048] In the formula (A-2), R 3 is the same as that shown in the formula (A-1) above, and preferred embodiments are also exemplified as those in (A-1).

[0049] In the formula (A-2), R 4 are independently an alkyl group having 1 to 4 carbon atoms or a phenyl group, and are preferably a methyl group or a phenyl group.

[0050] In the formula (A-2), c is an integer of 0≦c<30, and preferably 0≦c≦10. Within this range, it is preferable because it is easy to adjust the solvent solubility and the hardness of the cured product.

[0051] In the formula (A-2), d is independently 2 or 3.

[0052] When the component (A-2) is contained, the component (A-1) preferably has two or more alkenyl groups in one molecule.

[0053] The amount of component (A-2) blended is preferably such that the number of moles of hydrosilyl groups in component (A-2) is 0.8 to 2.0 moles, and more preferably 1.0 to 1.5 moles, per mole of the total amount of alkenyl groups in component (A-1) and component (A-3) described below.

[0054] The hydrosilylation catalyst (component (B)) is used to promote the curing reaction of the silicone resin composition. Examples of hydrosilylation catalysts include platinum group metal complexes. Specific examples include platinum (including platinum black), platinum chloride, chloroplatinic acid, platinum-olefin complexes such as platinum-divinylsiloxane complexes, and platinum-carbonyl complexes, with platinum-divinylsiloxane complexes being preferred.

[0055] The amount of component (B) to be added is in the range of 0.01 to 1.0% by mass, preferably 0.05 to 0.2% by mass, relative to the silicone resin composition, which is preferable because it provides good storage stability and curing speed.

[0056] By including the component (A-2), the silicone resin composition is cured, which is preferable because the stress relaxation layer is less likely to be redissolved in a solvent when a cured coating layer or the like is applied in the next step.

[0057] The silicone resin composition forming the stress relaxation layer of the present invention preferably further contains a linear organopolysiloxane represented by the following formula (A-3) (hereinafter sometimes referred to as component (A-3)). [ka] (In the formula, R 1 are independently the same as above, and R 5are independently selected from alkyl groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 3 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms, provided that at least two of them in one molecule are alkenyl groups, and e is an integer satisfying the conditions of 200≦e<500.

[0058] In the formula (A-3), R 1 are independently the same as those shown in the formula (A-1), and preferred embodiments thereof are also exemplified as those in (A-1).

[0059] In the formula (A-3), R 5 are independently selected from an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a cyclohexyl group. Examples of the alkenyl group include a vinyl group and an allyl group. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Examples of the aralkyl group include a benzyl group, a 2-phenylethyl group, and a 2-phenylpropyl group. Among these, a methyl group, a vinyl group, and a phenyl group are preferred. However, two or more of these groups in one molecule are alkenyl groups.

[0060] In the formula (A-3), e is an integer satisfying 200≦e<500, and preferably 300≦e<450. When e is 200 or more, the flexibility of the film is improved and cracks are less likely to occur, which is preferable, and when it is less than 500, the solvent solubility is good, which is preferable. Furthermore, by adjusting the value of e, the physical properties of the stress relaxation layer, such as wettability and spreadability on the substrate and flexibility after curing, can be adjusted.

[0061] The silicone resin composition preferably further contains (C) a surfactant. Examples of surfactants include those similar to those used in the cured coating layer. The amount of surfactant added is preferably 0.01 to 5% by mass, and more preferably 0.05 to 0.2% by mass, based on the total mass of the silicone resin composition.

[0062] The silicone resin composition preferably further contains (D) an adhesion promoter. Examples of adhesion promoters include vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and bis(2,2-dimethylethyl)acrylate. Examples of suitable adhesives include N-(2,2-dimethylethylene)(5-ethyl-1,3-dioxane-2,5-diyl)methylene, N-2(aminoethyl)3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, trimethoxysilane, tetramethoxysilane, and oligomers thereof. Among these, preferred is bis(2,2-dimethylethylene)(5-ethyl-1,3-dioxane-2,5-diyl)methylene bisacrylate. The amount of the adhesive aid blended is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 1 part by mass, per 100 parts by mass of the combined total of the (A-1) to (A-3) components.

[0063] The silicone resin composition forming the stress relaxation layer of the present invention may contain additives and fillers as needed, such as UV absorbers, UV scattering agents, antioxidants, heavy metal deactivators, flame retardants, and antistatic agents.

[0064] Examples of fillers include reinforcing inorganic fillers such as fumed silica, fumed titanium dioxide, and fumed alumina, and inorganic fillers such as fused silica, alumina, zirconium oxide, calcium carbonate, calcium silicate, titanium dioxide, ferric oxide, and zinc oxide, and these can be added in any desired ratio.

[0065] Furthermore, in order to accelerate the curing of the silicone resin composition, a condensation catalyst that accelerates the condensation reaction of alkoxy groups or hydroxy groups may be added in addition to the hydrosilylation catalyst, which is component (B). Although known condensation catalysts can be used, it is best to avoid those that may act as catalyst poisons for the hydrosilylation catalyst (B).

[0066] The stress relaxation layer of the present invention can be obtained by diluting the silicone resin composition with an organic solvent as needed, coating the composition on a substrate, and then heating and drying.Examples of the organic solvent include linear saturated aliphatic hydrocarbons such as n-hexane, n-octane, and n-nonane; unsaturated aliphatic hydrocarbons such as 1-octene, 1-nonene, and 1-decene; cyclic saturated aliphatic hydrocarbons such as cyclohexane, methylcyclohexane, and dimethylcyclohexane; aromatic hydrocarbons such as toluene, xylene, and anisole; ester compounds such as n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, isoamyl acetate, and ethyl caproate; ether compounds such as diethyl ether, dibutyl ether, and ethylene glycol diethyl ether; silicone oils such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, decamethyltetrasiloxane, and dodecamethylpentasiloxane; and among these, n-hexane and dodecamethylpentasiloxane are preferably used.

[0067] The thickness of the coated film must be within the range of 0.1 to 15.0 μm per layer, preferably 0.1 to 5 μm, and more preferably 0.1 to 1.0 μm. If the thickness is less than 0.1 μm, it is difficult to obtain the effect of alleviating the stress of the cured coating layer, and if it exceeds 15.0 μm, flexibility may be impaired.

[0068] The substrate may be the same as the substrate used to form the cured coating layer.

[0069] The heat drying temperature is determined based on the heat resistance temperature of the substrate and the boiling point of the organic solvent, but is generally preferably within the range of 20 to 100° C. This range increases the variety of substrates that can be used, and also prevents film roughening due to boiling of the organic solvent.

[0070] Furthermore, there are no particular limitations on the coating method as long as it can be applied to the desired location. Examples of coating methods include roll coating methods using a chamber doctor coater, single-roll kiss coater, reverse kiss coater, bar coater, reverse roll coater, forward rotation roll coater, blade coater, knife coater, etc., spin coating methods, dispensing methods, dipping methods, spraying methods, transfer methods, slit coating methods, etc. Coating can be performed by an appropriate method depending on the size and shape of the substrate. Furthermore, if necessary, the substrate may be subjected to a surface modification treatment before coating. Examples of surface modification treatments include inert modification treatments such as argon plasma treatment, xenon excimer treatment, and UV treatment, and active modification treatments such as oxygen plasma treatment and ozone treatment.

[0071] After coating, the organic solvent is dried using the above-mentioned method, and then the coating film is typically cured by heat curing. However, in the case of the stress relief layer of the present invention, the silicone resin composition cures during the drying process, eliminating the need for a separate curing step. Resin compositions used as stress relief layers are typically cured by heating or UV irradiation after the solvent dries. However, heat curing takes anywhere from several tens of minutes to several hours, significantly impacting mass productivity. While UV curing requires only a few seconds to a few minutes, it is undesirable because it requires a separate UV irradiation step in addition to the heating step for solvent drying. While UV irradiation itself is completed in a short time, the stress relief layer resin requires standing for several tens of minutes to a day for complete curing. Proceeding to the next step before complete curing is likely to result in significant variations in the film quality of the stress relief layer and should be avoided. By using the stress relief layer proposed in the present invention, film quality can be stabilized by the solvent drying step alone, allowing for the next step. This significantly improves mass productivity and film quality stability compared to conventional methods.

[0072] Furthermore, when laminating a cured coating layer on the stress relaxation layer, the surface of the coating of the stress relaxation layer may be subjected to the above-mentioned surface modification treatment before applying the polysilazane composition. In particular, xenon excimer treatment is preferred because it makes the outermost surface inorganic, thereby improving adhesion. [Example]

[0073] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited thereto. In the following examples and comparative examples, parts refer to parts by mass.

[0074] [Examples 1 to 9 and Comparative Examples 1 to 6] The structures of the linear organopolysiloxane components (A-1) to (A-3) contained in the silicone resin compositions used in the Examples and Comparative Examples are shown below. [ka] [ka] [ka] [ka]

[0075] Next, the components of the silicone resin composition other than the components (A-1) to (A-3) and the components of the polysilazane composition for forming a cured coating layer are listed. (B) Hydrosilylation catalyst 1: Platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (C) Surfactant 1...2-methyl-3-butyn-2-ol Surfactant 2...2,4,7,9-tetramethyl-5-decyne-4,7-diol (D) Adhesion aid...bis(2,2-dimethylethylene)(5-ethyl-1,3-dioxane-2,5-diyl)methylene bisacrylate Organic solvent D5...Decamethylcyclopentasiloxane Polysilazane composition for forming a cured coating layer: a solution obtained by dissolving 10 parts by mass of perhydropolysilazane in which all R's are hydrogen atoms and n=170 in the formula (1) above in 90 parts by mass of dibutyl ether.

[0076] The silicone resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4 were prepared using the above components and organic solvent in the amounts shown in Table 1. Next, stress relief layers and cured coating layers were prepared under the conditions below, and evaluations of coatability and water vapor permeability were carried out. The evaluation results and film thicknesses are shown in Table 1. In Comparative Example 5, component (A) was not dissolved in toluene, making it impossible to prepare a silicone resin composition, so further evaluation was not carried out. In Comparative Example 6, evaluation was carried out using a three-layer laminate of only the cured coating layers. The results are shown in Table 1.

[0077] [Evaluation of Coatability] In the present invention, the coatability was evaluated based on whether a uniform film could be formed in a short time through the processes of coating, drying, and curing. The evaluation was carried out under the following conditions. 1. The surface of a 75 μm thick polyimide (PI) film was modified with Ar plasma under the following Ar plasma treatment conditions: Ar flow rate: 10cc / min. Output: 100W Processing time: 30 seconds 2. The silicone resin composition of the example or comparative example was applied to the PI film using a spin coater under the following spin coater conditions: Rotation speed: 2,500 rpm Slope: forward and backward 5 seconds Rotation time: 30 seconds 3. Dry and harden on a hot plate to obtain a stress relaxation layer. The drying and hardening conditions are as follows: Temperature: 100℃ Time: 4 minutes 4. The surface of the formed PI film is observed with a white light interferometer (Keyence Corporation, VK-X3000) to check for surface roughness and the presence of defects such as pinholes.

[0078] [Evaluation of water vapor permeability] In the present invention, it is assumed that the stress relaxation layers are laminated alternately with cured coating layers made of inorganic polysilazane cured films. The water vapor permeability of a PI film laminated with a total of six layers, three of each of stress relaxation layers and cured coating layers, was measured. The evaluation sample was prepared using the following method. 1. The surface of a 75 μm thick polyimide (PI) film is modified with Ar plasma. The surface modification method is the same as that used to evaluate coatability. 2. The silicone resin composition of the example or comparative example is applied to the PI film using a spin coater under the same conditions as in the surface modification method. 3. Dry and harden on a hot plate to obtain a stress relaxation layer. The drying and hardening conditions are the same as those for the evaluation of coatability. 4. Xenon excimer light 4,000 mJ / cm in a nitrogen atmosphere 2 Irradiate. 5. The inorganic polysilazane solution (polysilazane composition) is applied using a spin coater under the same application conditions as those used to evaluate the coatability. 6. Dry on a hot plate to obtain a cured coating layer. The drying conditions are the same as those for the evaluation of coatability. 7. Xenon excimer light 4,000 mJ / cm in a nitrogen atmosphere 2 Irradiate. 8. Repeat steps 2 to 7 two more times to coat a total of six layers. 9. The water vapor permeability is measured under the following conditions: Temperature: 85℃ Humidity: 70%RH

[0079] [Table 1]

[0080] The results in Table 1 show that in Examples 1 to 9, in which a gas barrier film was formed by laminating a cured coating layer of the present invention and a stress relief layer on a substrate, the evaluation of both coatability and water vapor permeability showed good results. On the other hand, the water vapor permeability was inferior to that of the Examples in Comparative Examples 1, 3, and 4. In particular, the coatability was inferior in Comparative Examples 1 and 4, which is thought to be because the film thickness of the stress relaxation layer exceeded 15 μm, impairing flexibility. Comparative Example 2, which did not contain the linear organopolysiloxane that is a component of the silicone resin composition of the present invention, had good coatability but resulted in poor water vapor permeability. Comparative Example 6, in which only the cured coating layer was laminated, resulted in poor water vapor permeability.

[0081] As described above, the stress relaxation gas barrier film of the present invention can be uniformly coated on films and polysilazane resins without impairing workability, and is therefore useful as a gas barrier film for use in electronic materials, etc.

[0082] The present specification includes the following aspects. [1] A cured coating layer obtained by curing a polysilazane composition containing a polysilazane compound represented by the following formula (1): [ka] (In the formula, R is independently a hydrogen atom or a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms; and n is an integer of 2 to 20,000.) and a stress relaxation layer, which is obtained by curing a silicone resin composition containing a linear organopolysiloxane represented by the following formula (A-1), and which has a thickness of 0.1 to 15.0 μm per layer. [ka] (In the formula, R 1 are independently an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. 2 are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 3 are independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms; a is an integer of 1≦a<200, and b is an integer of 0≦b<200, with the proviso that a+b is 10≦a+b<200. A stress relaxation gas barrier film characterized by being formed by laminating one or more layers of each of the above alternately. [2] The silicone resin composition further comprises a compound represented by the following formula (A-2): [ka] (In the formula, R 3 is the same as above, and R 4 are independently an alkyl group having 1 to 4 carbon atoms or a phenyl group; c is an integer of 0≦c<30; and d is independently 2 or 3. The stress relaxation gas barrier film according to [1], characterized in that it contains an organohydrogenpolysiloxane represented by the following formula: and (B) a hydrosilylation catalyst. [3] The silicone resin composition further comprises a compound represented by the following formula (A-3): [ka] (In the formula, R 1 are independently the same as above, and R 5are independently selected from alkyl groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 3 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms, provided that at least two of them in one molecule are alkenyl groups, and e is an integer satisfying the conditions of 200≦e<500. The stress relaxation gas barrier film according to [1] or [2], characterized in that it contains a linear organopolysiloxane represented by the following formula: [4] The stress relaxation gas barrier film according to any one of [1] to [3], wherein in the formula (1), all of the R's are hydrogen atoms. [5] The stress relaxation gas barrier film according to any one of [1] to [4], wherein the polysilazane composition further contains a surfactant. [6] The stress relaxation gas barrier film according to any one of [1] to [5], wherein the silicone resin composition further contains (C) a surfactant. [7] The stress relaxation gas barrier film according to any one of [1] to [6], wherein the silicone resin composition further contains (D) an adhesive aid.

[0083] The present invention is not limited to the above-described embodiments, which are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that provides similar effects is included within the technical scope of the present invention.

Claims

1. A cured coating layer obtained by curing a polysilazane composition containing a polysilazane compound represented by the following formula (1): 【Chemistry 1】 (In the formula, R is independently a hydrogen atom or a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms; and n is an integer from 2 to 20,000.) and a stress relaxation layer, which is obtained by curing a silicone resin composition containing a linear organopolysiloxane represented by the following formula (A-1), and which has a thickness of 0.1 to 15.0 μm per layer. 【Chemistry 2】 (In the formula, R １ are independently an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. ２ are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ３ are independently a group selected from an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms; a is an integer of 1≦a<200, and b is an integer of 0≦b<200, with the proviso that a+b is 10≦a+b<200.

1. A stress relaxation gas barrier film comprising one or more layers of the above alternately laminated together.

2. The silicone resin composition further comprises a compound represented by the following formula (A-2): 【Transformation 3】 (In the formula, R ３ is the same as above, and R ４ are independently an alkyl group having 1 to 4 carbon atoms or a phenyl group; c is an integer of 0≦c<30; and d is independently 2 or 3. and (B) a hydrosilylation catalyst.

2. The stress relaxation gas barrier film according to claim 1, comprising:

3. The silicone resin composition further comprises a compound represented by the following formula (A-3): 【Chemistry 4】 (In the formula, R １ are independently the same as above, and R ５ are independently selected from alkyl groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 3 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms, provided that at least two of them in one molecule are alkenyl groups, and e is an integer satisfying the conditions 200≦e<500.

2. The stress relaxation gas barrier coating according to claim 1, which comprises a linear organopolysiloxane represented by the formula:

4. 2. The stress relaxation gas barrier film according to claim 1, wherein in the formula (1), all of the R's are hydrogen atoms.

5. 5. The stress relaxation gas barrier coating according to claim 1, wherein the polysilazane composition further contains a surfactant.

6. 5. The stress relaxation gas barrier film according to claim 1, wherein the silicone resin composition further comprises (C) a surfactant.

7. 5. The stress relaxation gas barrier film according to claim 1, wherein the silicone resin composition further comprises (D) an adhesion promoter.

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