Method for producing a modified polysilazane cured coating, and modified polysilazane cured coating

Abstract

The present invention provides a method for producing a modified polysilazane cured coating that enables the rapid densification of a film made of a polysilazane compound, thereby producing a film with sufficiently low water vapor permeability in a short time, and a modified polysilazane cured coating obtained by this method. [Solution] In curing the polysilazane compound, the coating containing the polysilazane compound is irradiated with vacuum ultraviolet (VUV) light at a specific range of irradiation intensity. Specifically, the method includes a coating step of applying a solution containing the polysilazane compound represented by the following general formula (1) to a substrate to form a coating, and a curing step of irradiating the coating with Xe excimer light to modify the polysilazane compound and form a cured film of the modified polysilazane compound, wherein the irradiance of the Xe excimer light in the curing step is 280 to 450 mW / cm². 2 This will be within the range of [the specified range]. [Formula 1] TIFF2026046748000008.tif28168

Description

[Technical Field]

[0001] The present invention relates to a method for producing a modified polysilazane cured coating, and to a modified polysilazane cured coating. [Background technology]

[0002] Gas barrier films are used in a wide range of fields, including various types of packaging and electronics. Electronic products, in particular, require high barrier performance against water vapor. The indicator of water vapor barrier performance is the water vapor transmission rate (WVTR). For example, semiconductor devices such as organic EL elements and solar cells require a water vapor transmission rate of 10. -3 ~10 -6 g / m 2 A barrier performance of / day is required.

[0003] Inorganic barrier films fabricated using vacuum processes such as atomic layer deposition (ALD) and chemical vapor deposition (CVD) achieve very low water vapor permeability. To alleviate stress in such inorganic barrier films, barrier structures with an alternating inorganic / organic layer structure, where a polymer is introduced as a stress-relaxing layer, have also been proposed.

[0004] However, vacuum processes have low material utilization efficiency and, due to the repeated processes with atmospheric pressure / vacuum pressure differences, present problems such as the adhesion of foreign matter. Furthermore, the film deposition rate is slower compared to wet processes. Additionally, in alternating laminated structures, the polymer that forms the stress relaxation layer is generally produced by coating, requiring alternating vacuum and coating processes, which increases manufacturing costs.

[0005] On the other hand, gas barrier layers that produce both a stress-relaxing layer and an inorganic barrier film through a coating process have also been reported. Such gas barrier structures, which are entirely fabricated by solution processes, can achieve high resource efficiency and high processing capacity (throughput), while keeping manufacturing costs low.

[0006] However, the water vapor permeability of the film obtained by the all-solution process such as the general sol-gel method is about 3 to 350 g / m 2 / day, and its density and barrier property were lower than those of the vacuum process.

[0007] In the formation of the barrier film by the vacuum process, since the throughput such as the film formation rate is low, a film formation method combining the vacuum process and the wet process using perhydropolysilazane (PHPS) has been studied.

[0008] Perhydropolysilazane (PHPS) is a reactive polymer having a Si-N bond as a main skeleton, and film formation by a wet process such as coating is possible. When heated in the atmosphere, it is converted into a SiO2 film by reaction with oxygen, but it can also be converted into a SiO2 film by irradiating vacuum ultraviolet light (VUV) in the atmosphere without heating. The barrier property of the SiO2 film obtained from perhydropolysilazane is 10 -1 ~10 -2 g / m 2 / day, and depending on the production conditions, the water vapor permeability can be reduced to about 10 -3 g / m 2 / day.

[0009] However, the barrier property of the SiO2 film was not sufficient for application to electronic products sensitive to water vapor. Therefore, it has been proposed to irradiate the film of perhydropolysilazane (PHPS) with vacuum ultraviolet light (VUV) in a nitrogen atmosphere to convert it into a silicon nitride (SiN x )-based film (Patent Document 1). The silicon nitride (SiN x )-based film has a high water vapor barrier property.

[0010] Non-Patent Document 1 describes a gas barrier layer fabricated by an all-solution process using polydimethylsiloxane (PDMS) with a Si-O bond as the main backbone in the stress relaxation layer and perhydropolysilazane (PHPS) in the barrier layer. And, for the perhydropolysilazane (PHPS) film, by irradiating with vacuum ultraviolet light (VUV) in a nitrogen atmosphere, it is converted into a silicon nitride (SiN x )-based film, and the water vapor permeability of the obtained silicon nitride (SiN x )-based film is described to reach 10 -3 g / m 2 / day.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Non-Patent Documents

[0012]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0013] The low water vapor permeability of the perhydropolysilazane (PHPS) cured film is achieved by densifying the film through irradiation with vacuum ultraviolet light (VUV). When the perhydropolysilazane (PHPS) film is irradiated with vacuum ultraviolet light (VUV), not only Si-H bonds and N-H bonds are broken, but also the Si-N bonds in the main chain undergo repeated bond cleavage and recombination, causing atomic rearrangement. And, due to the reduction of the film porosity by this atomic rearrangement, the densification of the film progresses.

[0014] Conventionally, achieving high density in polysilazane-cured films required irradiation with a sufficient amount of vacuum ultraviolet (VUV) light, which, for example, required irradiation for several minutes or more. Therefore, from the standpoint of film productivity, accelerating the densification speed was desired.

[0015] The present invention has been made in view of the above, and aims to provide a method for producing a modified polysilazane cured coating that enables the densification of a film made of a polysilazane compound in a short time and the production of a film with sufficiently low water vapor permeability in a short time, and a modified polysilazane cured coating obtained by the production method. [Means for solving the problem]

[0016] The inventors diligently conducted research to achieve the above objective. They discovered that by irradiating a coating containing a polysilazane compound with vacuum ultraviolet (VUV) light within a specific range of irradiation intensities, a modified polysilazane cured film with equivalent gas barrier properties to conventional materials can be formed with a smaller integrated light dose compared to the previously required integrated light dose. As a result, a modified polysilazane cured film with equivalent gas barrier properties to conventional materials can be obtained in a short time, thus completing the present invention.

[0017] In other words, the present invention includes the following embodiments.

[0018] [1] A coating step in which a solution containing a polysilazane compound represented by the following general formula (1) is applied to a substrate to form a coated product, The process includes a curing step of irradiating the coated material with Xe excimer light to modify the polysilazane compound and form a cured film of the modified polysilazane compound, The illuminance of the Xe excimer light in the curing process is set to 280-450 mW / cm². 2 The scope is defined as A method for producing a modified polysilazane cured coating. [ka] (In general formula (1), x is an integer such that 20 < x ≤ 1,000, and y is an integer such that 0 ≤ y < (x / 10).) [2] The method for producing a modified polysilazane cured film according to Embodiment [1], wherein the modified polysilazane compound has a value of (N + O) / Si, which is the total value of the number of nitrogen atoms and the number of oxygen atoms with respect to the number of silicon atoms, in the range of 0.9 to 1.1. [3] The method for producing a modified polysilazane cured film according to Embodiment [1], wherein the polysilazane compound is perhydropolysilazane. [4] The method for producing a modified polysilazane cured film according to Embodiment [1], wherein the integrated light amount of the Xe excimer light irradiated on the coated material is in the range of 1,000 to 10,000 mJ / cm 2 of the range. [5] The method for producing a modified polysilazane cured film according to Embodiment [1], wherein the Xe excimer light is irradiated in a nitrogen atmosphere with an oxygen concentration of 0.1% or less. [6] The method for producing a modified polysilazane cured film according to Embodiment [1], wherein the substrate is an organic resin film. [7] The method for producing a modified polysilazane cured film according to Embodiment [1], wherein the substrate is a polyimide (PI) film or a polyethylene terephthalate (PET) film. [8] A modified polysilazane cured film obtained by the method for producing a polysilazane cured film according to any one of Embodiments [1] to [7].

Advantages of the Invention

[0019] According to the present invention, a modified polysilazane cured film having a gas barrier property equivalent to that of the conventional one can be produced in a short time.

[0020] Furthermore, the method for producing a modified polysilazane cured film of the present invention allows for the production of a modified polysilazane cured film with a higher level of gas barrier properties than conventional methods, using a smaller amount of integrated light compared to the amount of integrated light previously required. Therefore, a polysilazane cured film with gas barrier properties can be produced efficiently with less energy compared to conventional methods.

[0021] Furthermore, the method for producing a modified polysilazane cured coating of the present invention allows for the production of a modified polysilazane cured coating with the same cumulative light intensity as conventional methods, while having higher gas barrier properties compared to conventional methods.

[0022] Therefore, according to the method for producing a modified polysilazane cured film of the present invention, a silicon coating material with high gas barrier properties can be obtained in a short time through a coating process, while achieving high resource efficiency and high processing volume (throughput). [Brief explanation of the drawing]

[0023] [Figure 1] This figure shows the results of elemental analysis performed by the RBS / HFS method on the polysilazanes used in the examples and comparative examples. [Figure 2] This figure shows the results of elemental analysis of the modified perhydropolysilazane cured coating obtained in Comparative Example 1 at an integrated light intensity of 6 J / cm2. (See Figure 2.) [Figure 3] This figure shows the results of elemental analysis of the modified perhydropolysilazane cured coating obtained in Example 2 at an integrated light intensity of 6 J / cm2. [Figure 4] The results of the refractive index distribution obtained by spectroscopic ellipsometry of the modified polysilazane cured coatings of Comparative Examples 1 to 3 are shown. [Figure 5] This shows the refractive index distribution results obtained by spectroscopic ellipsometry of the modified polysilazane cured coatings of Examples 1 to 3. [Figure 6] This graph shows the relationship between the refractive index of the TOP layer of a modified polysilazane-cured coating and the lamp intensity (irradiation intensity). [Modes for carrying out the invention]

[0024] ≪Method for Producing Modified Polysilazane Cured Film≫ The method for producing a modified polysilazane cured film of the present invention includes a coating step of applying a solution containing a polysilazane compound to a substrate to form a coated object, and a curing step of irradiating the coated object with Xe excimer light to modify the polysilazane compound and form a cured film of the modified polysilazane compound. The illuminance of the Xe excimer light in the curing step is within a specific range. Further, if necessary, a drying step of volatilizing the solvent contained in the coated object produced in the coating step by heating or the like to form a dried coated object may be included between the coating step and the curing step. Each element will be described below.

[0025] <Polysilazane Compound> The polysilazane compound used in the method for producing a modified polysilazane cured film of the present invention is represented by the following general formula (1). As long as it is represented by the following general formula (1), it is not particularly limited and can be arbitrarily selected as long as the effects of the present invention are not impaired.

[0026] [Chemical formula] (In general formula (1), x is an integer of 20 < x ≤ 1,000, and y is an integer of 0 ≤ y < (x / 10).)

[0027] The polysilazane compound used in the method for producing a modified polysilazane cured film of the present invention may be used not only alone but also in combination of two or more kinds at the same time.

[0028] The mass average molecular weight of the polysilazane compound used in the present invention is, from the viewpoints of solubility in a solvent and reactivity, for example, 900 to 50,000, and more preferably 900 to 20,000. The mass average molecular weight referred to here is the mass average molecular weight in terms of polystyrene and can be measured by gel permeation chromatography.

[0029] In the general formula (1), x is preferably an integer such that 30 < x ≤ 600, more preferably an integer such that 60 < x ≤ 400, and particularly preferably an integer such that 100 < x ≤ 200.

[0030] The polysilazane compound used in the method for producing the modified polysilazane cured film of the present invention preferably has a total value of the number of nitrogen atoms and the number of oxygen atoms with respect to the number of silicon atoms, (N + O) / Si, in the range of 0.9 to 1.1. If it is within this range, a cured film having a sufficiently low water vapor transmission rate (WVTR) can be formed.

[0031] The total value of the number of nitrogen atoms and the number of oxygen atoms with respect to the number of silicon atoms, (N + O) / Si, of the modified polysilazane compound is more preferably in the range of 0.90 to 1.05, and particularly preferably in the range of 0.90 to 1.00.

[0032] As the polysilazane compound used in the method for producing the modified polysilazane cured film of the present invention, among others, perhydropolysilazane (PHPS) or a modified product thereof in which y = 0 in the general formula (1) above is preferable. Perhydropolysilazane (PHPS) is a silicon-containing polymer comprising Si-N bonds as repeating units and consisting only of Si, N, and H. In perhydropolysilazane (PHPS), all elements bonded to Si and N are H except for the Si-N bond, and other elements such as carbon and oxygen are substantially not contained.

[0033] In the general formula (1) above, polysilazane compounds other than y = 0 can be produced, for example, as follows. With respect to the total mass of chlorosilanes and an organic solvent, in a state where a specific amount of moisture is present, the chlorosilanes and the organic solvent are mixed in a nitrogen atmosphere, and then, after blowing ammonia, the produced salt is removed to obtain a solution in which the polysilazane compound is dissolved. By adjusting the amount of moisture in the reaction, a polysilazane compound represented by the general formula (1) having a desired composition can be produced. Specifically, it can be obtained, for example, by the following method.

[0034] (Examples of production of polysilazane compounds other than y=0) 0.19 mol of dichlorosilane with a purity of 99% or higher was blown into 300 ml of pyridine at -10°C containing 373 ppm water, while stirring with nitrogen gas. At this time (initial stage of reaction), the amount of water relative to the total mass of chlorosilanes and amines (initial water content) was 350 ppm.

[0035] Next, 0.57 mol of ammonia with a purity of 99% or higher was blown in, and the resulting salt was removed by pressure filtration to obtain a solution in which the polysilazane compound was dissolved. At this point (the final stage of the reaction), the total water content of the solution (final water content) was 412 ppm.

[0036] The solution containing the obtained polysilazane compound was heated to 150°C, and 150 ml of pyridine was removed by distillation. Subsequently, 300 ml of dibutyl ether was added, and the pyridine was removed by azeotropic distillation to obtain the polysilazane compound.

[0037] In the general formula (1) of the obtained polysilazane compound, x was 170 and y was 10.

[0038] <Modified polysilazane cured coating> The modified polysilazane cured coating obtained by the method for producing a modified polysilazane cured coating of the present invention is a coating formed on a substrate by curing the polysilazane compound described above.

[0039] The modified polysilazane cured film obtained by the method for producing a modified polysilazane cured film of the present invention has a refractive index distribution in the thickness direction. When there is no significant change in composition, the refractive index correlates with density, and the refractive index serves as an indicator of density. That is, the refractive index becomes higher in the region close to the surface irradiated with Xe excimer light because the densification of polysilazane progresses easily, while the refractive index becomes lower in the region close to the substrate because Xe excimer light does not easily reach it.

[0040] Specifically, the refractive index in the region near the surface irradiated with Xe excimer light is 1.6 to 2.0, preferably 1.65 to 1.85, and the refractive index in the region near the substrate is 1.50 to 1.6, preferably 1.50 to 1.54.

[0041] Furthermore, the refractive index distribution in the thickness direction of the modified polysilazane cured film can be determined by spectroscopic ellipsometry. The refractive index distribution can be analyzed using a four-layer model, for example, which includes a thin layer of SiO2 formed on the surface of the modified polysilazane cured film.

[0042] <Coating process> The coating step in the method for producing a modified polysilazane cured coating of the present invention is a step of applying a solution containing a polysilazane compound to a substrate to form a coated product.

[0043] [solvent] The solvent for dissolving the polysilazane compound is not particularly limited, but examples include aromatic compounds such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, and triethylbenzene; linear hydrocarbon compounds such as pentane, 2-methylbutane, hexane, 2-methylpentane, heptane, 2-methylhexane, octane, 2,2,4-trimethylpentane, nonane, decane, and 2-methylnonane; cyclic hydrocarbon compounds such as ethylcyclohexane, methylcyclohexane, cyclohexane, p-menthane, decahydronaphthalene, and dipentene; ethers such as dipropyl ether, dibutyl ether (DBE), and methyl-t-butyl ether (MTBE); and ketones such as methyl isobutyl ketone (MIBK). These may be used individually or in combination of two or more.

[0044] [concentration] The concentration of the polysilazane compound in a solution containing the polysilazane compound is usually 5 to 95% by weight, preferably 5 to 20% by weight, depending on the application method.

[0045] [Other ingredients] The solution containing the polysilazane compound may also contain other components besides the polysilazane compound, as long as they do not impair the effects of the present invention. Examples of other components include additives such as fillers, leveling agents, antistatic agents, and ultraviolet absorbers, as well as surfactants. When a filler is included, the amount is usually 0.05 to 10 parts by mass, preferably 0.2 to 3 parts by mass, per 1 part by mass of the polysilazane compound.

[0046] [Base material] The substrate used in the method for producing the modified polysilazane cured coating of the present invention is not particularly limited, but may be an organic resin film. Since organic resin films generally have high moisture permeability, the modified polysilazane cured coating obtained by the present invention can be provided with high gas barrier properties.

[0047] The substrate used in the method for producing the modified polysilazane cured film of the present invention may more preferably be a polyimide (PI) film or a polyethylene terephthalate (PET) film.

[0048] Furthermore, the substrate used in the method for producing the modified polysilazane cured film of the present invention may be a thin film glass with a thickness of about 10 to 150 μm, depending on the application. The thin film glass may be a single layer, or it may be a thin film glass laminated with metal foil such as aluminum foil or resin. In addition, the substrate used in the method for producing the modified polysilazane cured film of the present invention may be metal foil such as stainless steel foil, aluminum foil, or copper foil.

[0049] Furthermore, before applying the solution containing the polysilazane compound to the substrate, the surface of the substrate may be degreased or cleaned to facilitate the adhesion of the light- or heat-curing resin to the substrate. Examples of methods for degreasing or cleaning the surface of the substrate include excimer treatment, UV ozone treatment, atmospheric pressure plasma treatment, plasma treatment, and corona discharge treatment.

[0050] [Application Method] The method for applying a solution containing a polysilazane compound to a substrate is not particularly limited, and known methods can be applied. Examples of methods for applying a solution containing a polysilazane compound to a substrate include spin coating, roll coating, flow coating, inkjet, spray coating, dip coating, casting, bar coating, die coating, gravure coating, gravure printing, and screen printing.

[0051] Before applying the solution containing the polysilazane compound to the substrate, the surface of the substrate may be degreased or washed to facilitate adhesion of the polysilazane compound to the substrate.

[0052] The coating of the substrate may be carried out at room temperature under an inert atmosphere such as nitrogen, or under open air. Performing the coating at room temperature under open air is more labor-saving and cost-effective than performing it under an inert gas atmosphere which requires a sealed system.

[0053] Furthermore, the substrate to which the solution containing the polysilazane compound is applied may be surface-modified by ozone cleaning using vacuum ultraviolet light or ultraviolet light. The reactive oxygen species separated from the ozone generated by vacuum ultraviolet light or ultraviolet light collide with the surface of the substrate, decomposing and removing organic contaminants present on the substrate surface. Substrates surface-modified by ozone cleaning have improved wettability, making it easier for the solution containing the polysilazane compound to be applied to the substrate.

[0054] <Drying process> If the coating obtained in the coating step contains a large amount of solvent, a drying step may be performed before the curing step described later. The drying step in the method for producing a modified polysilazane cured film of the present invention is a step in which the coating obtained in the coating step is heated by heater heating or irradiation with energy rays such as infrared rays to volatilize the solvent remaining in the coating and obtain a dried coating.

[0055] There are no particular restrictions on the heating conditions for the coated material, as long as the temperature and time are sufficient for the remaining solvent to evaporate completely. However, heating above the boiling point of the solvent or the heat resistance temperature of the substrate can cause voids to form in the coating film, or shrinkage and distortion of the substrate, so care should be taken to control the heating temperature to avoid such problems.

[0056] <Curing process> The curing step in the method for producing a modified polysilazane cured coating of the present invention is a step of modifying the polysilazane compound by irradiating the coating obtained in the coating step with Xe excimer light to form a cured coating of the modified polysilazane compound.

[0057] [Xe excimer light] The Xe excimer light irradiated onto the coated material obtained in the coating process is vacuum ultraviolet (VUV) light with a wavelength of 172 nm. Vacuum ultraviolet (VUV) irradiation is usually performed using a commercially available excimer lamp (wavelength 172 nm).

[0058] [Illuminance] In the method for producing a modified polysilazane cured coating of the present invention, the irradiance of the Xe excimer light irradiated onto the coating obtained in the coating step is 280 to 450 mW / cm². 2 This is within the specified range. In the present invention, by using Xe excimer light with an illuminance within this range, it is possible to densify a film made of a polysilazane compound in a short time and produce a modified polysilazane cured film with sufficiently low water vapor permeability in a short time.

[0059] [Cumulative light output] The integrated amount of Xe excimer light irradiated onto the coated material obtained in the coating process is 1,000 to 10,000 mJ / cm². 2 It is preferable that it be within the range of (mJ / cm²). 2 ) is the illuminance (mW / cm²) of Xe excimer light. 2 It can be calculated by multiplying the curing time (sec) by the time of curing.

[0060] The cumulative light intensity is 10,000 mJ / cm². 2An integrated light quantity exceeding this value is also acceptable, but in that case, the effect obtained by the present invention will be diminished.

[0061] The present invention provides a method for producing a modified polysilazane cured film that not only yields a modified polysilazane cured film with sufficiently low water vapor permeability in a short time, but also enables the production of a modified polysilazane cured film with a higher level of gas barrier properties than conventional methods, using a smaller amount of integrated light compared to the amount of integrated light previously required. Therefore, it is possible to efficiently produce a polysilazane cured film with gas barrier properties using less energy than conventional methods.

[0062] Furthermore, the method for producing a modified polysilazane cured coating of the present invention allows for the production of a modified polysilazane cured coating with the same cumulative light intensity as conventional methods, while having higher gas barrier properties compared to conventional methods.

[0063] [atmosphere] The atmosphere in which the curing process is carried out is not particularly limited. However, when a coating containing a polysilazane compound is irradiated with vacuum ultraviolet (VUV) light, the Si-N bonds in the main chain are repeatedly broken and reformed, causing atomic rearrangement. This atomic rearrangement reduces the porosity of the film and promotes densification. Therefore, in order to facilitate film densification, it is preferable that the atmosphere in which Xe excimer light is irradiated is a nitrogen atmosphere.

[0064] Furthermore, in the method for producing a modified polysilazane cured film of the present invention, it is preferable to irradiate with Xe excimer light in a nitrogen atmosphere with an oxygen concentration of 0.1% or less. By irradiating with Xe excimer light in a nitrogen atmosphere containing almost no oxygen, the film densification progresses further, and a modified polysilazane cured film with a high level of gas barrier properties can be produced in a short time.

[0065] The temperature at which the curing process is carried out is not particularly limited; for example, it may be at room temperature (generally 15-40°C). For example, it may be carried out under heating conditions such as 100-120°C, but the same effect can be obtained even when carried out at room temperature.

[0066] <<Applications of Modified Polysilazane Cured Coatings>> The modified polysilazane cured coating obtained in this invention has excellent gas barrier properties and can therefore be applied as various gas barrier layers.

[0067] Furthermore, the cured film obtained from polysilazane possesses excellent heat resistance and insulating properties in addition to its gas barrier properties. Therefore, for example, by forming a modified polysilazane cured film on the surface of a resin film, it can be used as a encapsulant for organic EL elements. [Examples]

[0068] The present invention will be described in more detail below based on examples, but the present invention is as described in the following examples. It is not restricted.

[0069] <Examples 1-3, Comparative Examples 1-3> A solution containing perhydropolysilazane (PHPS) was coated onto a silicon wafer (Si), and the resulting coating was irradiated with Xe excimer light (VUV light) at six different lamp intensities (irradiation intensities) to produce a modified polysilazane-cured film.

[0070] The results of the elemental analysis of the perhydropolysilazane (PHPS) used are shown in Figure 1. The chart shown in Figure 1 analyzes the elemental ratios of the polymer using Rutherford backscatter spectroscopy (RBS) and hydrogen backscatter spectroscopy (HFS). Note that the analysis chart is before correction for desorbed hydrogen atoms.

[0071] Furthermore, Table 1 shows the elemental analysis results after creating a calibration curve and correcting for the detached hydrogen atoms. [Table 1]

[0072] From the obtained elemental analysis results, the elemental ratios to the number of silicon atoms were calculated and are shown in Table 2. [Table 2]

[0073] [Coating process] A 20% perhydropolysilazane (PHPS) dibutyl ether (DBE) solution was diluted with an anhydrous DBE solution under nitrogen to prepare a 10% PHPS DBE solution. The prepared 10% PHPS DBE solution was spin-coated onto a 30x30 mm silicon wafer (Si) in air (25°C, 25% humidity) to create a PHPS coated film / Si. Spin coating was performed at a rotation speed of 2000 rpm for 30 seconds.

[0074] [Curing process] The obtained PHPS-coated film / Si PHPS-coated film was irradiated with Xe excimer light (VUV light) to produce a modified polysilazane-cured film. Xe excimer light (VUV light) irradiation was performed using an MDCOM excimer irradiation device (wavelength = 172 nm).

[0075] (Irradiation atmosphere) Xe excimer light (VUV light) irradiation was performed under a nitrogen atmosphere (oxygen and water vapor concentration <0.01%).

[0076] (Irradiation intensity) The lamp intensity (irradiation intensity) is 103-328 mW / cm². 2 There are six types in between (103, 229, 259, 290, 309, 328 mW / cm²). 2 The distance between the lamp and the PHPS coated film / Si was set to 2 mm. Here, the lamp intensity (irradiation intensity) represents the actual irradiation intensity on the PHPS coated film. Specifically, using a Hamamatsu Photonics power meter (C9536, sensor head: H9535-172), the irradiation intensity of Xe excimer light (VUV light) was measured at a location where the distance between the sensor head and the lamp was 2 mm, similar to the distance between the lamp and the PHPS coated film.

[0077] Lamp intensity (irradiation intensity): 103 mW / cm² 2 Comparative Example 1, 229 mW / cm²2 Comparative Example 2, 259 mW / cm² 2 Comparative Example 3, 290 mW / cm² 2 Example 1, 309 mW / cm² 2 Example 2, 328 mW / cm² 2 This will be referred to as Example 3.

[0078] (Cumulative light intensity) The cumulative luminous intensity of Xe excimer light (VUV light) is 6-72 J / cm². 2 That's what I decided.

[0079] The lamp intensity (irradiation intensity) is 103 mW / cm². 2 In Comparative Example 1, the integrated light intensity was 6 J / cm². 2 Figure 2 shows the results of elemental analysis of the modified perhydropolysilazane cured coating obtained. The lamp intensity (irradiation intensity) was 309 mW / cm². 2 In Example 2, the integrated light intensity was 6 J / cm². 2 Figure 3 shows the results of elemental analysis of the modified perhydropolysilazane cured coating obtained.

[0080] In both Comparative Example 1 and Example 2, the elemental analysis results showed that although the surface (0 nm) of the cured film was oxidized, the interior of the cured film had a composition with a high proportion of nitrogen. The internal composition was almost the same in Comparative Example 1 and Example 2, with Si at approximately 56%, N at approximately 38%, and O at approximately 6%.

[0081] (Refractive index distribution measurement) The density of the modified polysilazane cured film was measured as the refractive index distribution in the film thickness direction using a spectroscopic ellipsometry (manufactured by J.A. Woollam Japan Co., Ltd., model: WoollamVASE32). Since refractive index correlates with density when there are no significant compositional changes, the refractive index serves as an indicator of density (tightness).

[0082] Spectroscopic ellipsometry measurements were performed at wavelengths ranging from 250 to 1000 nm, with the incident angle varied at seven different angles: 45, 50, 55, 60, 65, 70, and 75 degrees. The obtained results were fitted to a four-layer modified polysilazane cured film / Si structure.

[0083] Previous studies have shown that photodensified modified polysilazane cured films have a refractive index distribution in the thickness direction (Adv. Mater. Interfaces, 201517 (8pp.) (2022)). Therefore, the outermost layer was made a SiO2 layer formed by the spontaneous oxidation of perhydropolysilazane (PHPS), and the SiN layer region between the SiO2 layer and the Si layer was fitted with three layers (Top layer, Mid layer, Bottom layer) in the thickness direction. In particular, the thickness of the Top layer was fixed at 30 nm in order to quantitatively evaluate the Top layer, which is most strongly irradiated with Xe excimer light (VUV light) and where photodensification is most likely to occur.

[0084] The obtained results are shown in Figures 4 and 5. Furthermore, the integrated light quantity at each lamp intensity (irradiation intensity) is 6 J / cm². 2 , 12J / cm 2 , 24 J / cm 2 72 J / cm 2 The refractive index of the TOP layer (30 nm) at that time is shown in Table 3 and Figure 6, and the irradiation time required to reach the respective integrated light intensity is shown in Table 4.

[0085] [Table 3]

[0086] [Table 4]

[0087] [Consideration] At all lamp intensities (irradiation intensities), the refractive index of the TOP layer increased as the integrated light quantity increased.

[0088] Furthermore, it was confirmed that, for the same integrated light dose, increasing the lamp intensity (irradiation intensity) increased the refractive index of the TOP layer. In other words, it was shown that the photodensification reaction of polysilazane is highly dependent on the lamp intensity.

[0089] If the photodensification reaction of polysilazane were a one-photon reaction, the refractive index would be determined by the integrated light amount, regardless of the lamp intensity (irradiation intensity). However, this experiment showed that the photodensification reaction is highly dependent on the lamp intensity (irradiation intensity), indicating that the photodensification reaction of polysilazane is not a one-photon reaction but a multi-photon reaction.

[0090] It was shown that, for the same integrated light output, the refractive index of the TOP layer increases as the lamp intensity (irradiation intensity) increases. In particular, the increase in refractive index was observed at a lamp intensity of 290 mW / cm². 2 It was shown that there is a sharp acceleration effect at a certain point. From this, it was determined that the lamp intensity (irradiation intensity) was 290 mW / cm². 2 The above demonstrates that polysilazane can be effectively densified.

[0091] Furthermore, comparing the time required for the refractive index of the TOP layer to become equivalent at different lamp intensities (irradiation intensities), the lamp intensity (irradiation intensity) was 103 mW / cm². 2 The refractive index of the TOP layer in Comparative Example 1 is 1.78 (integrated light intensity 24 J / cm²). 2 When using the following conditions as a baseline, Comparative Example 1 requires 234 seconds, while the lamp intensity (irradiation intensity) is 328 mW / cm². 2 In Example 3, the refractive index of the TOP layer becomes 1.78 when the integrated light intensity is 3 J / cm². 2 Therefore, it takes only 19 seconds.

[0092] Therefore, by increasing the lamp intensity (irradiation intensity) by approximately 3.2 times, the irradiation time in Example 3 could be shortened to 1 / 12 of that in Comparative Example 1, meaning it was reduced to just 8% of the time in Comparative Example 1.

[0093] Furthermore, when comparing with the TOP layer, which has a higher refractive index of 1.81 due to the further densification of the cured film, Comparative Example 1 (integrated light intensity 72 J / cm²) 2 ) versus Example 3 (integrated light intensity 12 J / cm²) 2 The irradiation time was reduced to 1 / 19th of the original time, or 5% of the original time, resulting in a significant reduction in irradiation time compared to conventional methods.

Claims

1. A coating step in which a solution containing a polysilazane compound represented by the following general formula (1) is applied to a substrate to form a coated product, The process includes a curing step of irradiating the coated material with Xe excimer light to modify the polysilazane compound and form a cured film of the modified polysilazane compound, The illuminance of the Xe excimer light in the curing process is 280 to 450 mW / cm². ２ The scope is defined as A method for producing a modified polysilazane cured coating. 【Chemistry 1】 (In general formula (1), x is an integer such that 20 < x ≤ 1,000, and y is an integer such that 0 ≤ y < (x / 10).)

2. The method for producing a modified polysilazane cured film according to claim 1, wherein the modified polysilazane compound has a (N+O) / Si ratio, which is the sum of the number of nitrogen atoms and oxygen atoms relative to the number of silicon atoms, in the range of 0.9 to 1.

1.

3. The method for producing a modified polysilazane cured film according to claim 1, wherein the polysilazane compound is a perhydropolysilazane.

4. The integrated amount of Xe excimer light irradiated onto the coated material is 1,000 to 10,000 mJ / cm². ２ A method for producing a modified polysilazane cured coating according to claim 1, wherein the range is [specified range].

5. A method for producing a modified polysilazane cured film according to claim 1, wherein the Xe excimer light is irradiated in a nitrogen atmosphere with an oxygen concentration of 0.1% or less.

6. The method for producing a modified polysilazane cured film according to claim 1, wherein the substrate is an organic resin film.

7. The method for producing a modified polysilazane cured film according to claim 1, wherein the substrate is a polyimide (PI) film or a polyethylene terephthalate (PET) film.

8. A modified polysilazane cured film obtained by the method for producing a modified polysilazane cured film according to any one of claims 1 to 7.

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