Water-repellent film–forming chemical solution, chemical solution–filled container, storage method, and production method for water-repellent film–forming chemical solution

Abstract

A purified water-repellent film–forming chemical solution according to the present invention includes a silylating agent, a solvent having a carbonyl group, and an antioxidant, wherein the number of particles having a particle diameter of 0.2 μm or more in a liquid phase of the water-repellent film–forming chemical solution as determined by particle measurement using a light scattering liquid-borne particle detector is 10 particles or less per 1 mL.

Description

Chemical solution for forming water-repellent film, container containing chemical solution, storage method, and method for manufacturing chemical solution for forming water-repellent film

[0001] The present invention relates to a chemical solution for forming a water-repellent film, a container containing the chemical solution, a storage method, and a method for producing a chemical solution for forming a water-repellent film.

[0002] In recent years, the trend toward higher integration and miniaturization of semiconductor devices has intensified, resulting in increasingly finer resin patterns used as masks and inorganic patterns fabricated by etching processes with higher aspect ratios. However, this has also led to the problem of so-called pattern collapse. This pattern collapse occurs when multiple resin or inorganic patterns are formed in parallel on a substrate, resulting in adjacent patterns leaning against each other and, in some cases, causing the patterns to break or peel off from their base. When this pattern collapse occurs, the desired product cannot be obtained, resulting in reduced product yield and reliability.

[0003] It is known that this pattern collapse occurs due to the surface tension of the cleaning liquid when it dries during the cleaning process after pattern formation. In other words, when the cleaning liquid is removed during the drying process, stress based on the surface tension of the cleaning liquid acts between the patterns, causing pattern collapse. For this reason, it is expected that pattern collapse can be resolved by replacing the cleaning liquid with a chemical solution for forming a water-repellent film to form a water-repellent film on the pattern surface and reducing the stress acting on the pattern.

[0004] A water-repellent film-forming chemical liquid used for surface modification applications such as imparting water repellency in semiconductor device manufacturing processes is described, for example, in Patent Document 1. Patent Document 1 discloses a storage container having a storage section that contains a liquid composition containing an organic solvent with a water concentration of 400 mass ppm or less and a surface treatment agent, for the purpose of suppressing deterioration of the water repellency of the water-repellent film-forming chemical liquid before and after storage, wherein at least the portion of the inner wall of the storage section that comes into contact with the liquid composition has a contact angle θ with water of 10 degrees or more and 150 degrees or less, and a storage method for the liquid composition. Paragraph 0143 of Patent Document 1 also states that the organic solvent was purified using a distillation column before use.

[0005] International Publication No. 2017 / 217320

[0006] As a result of investigations by the present inventors, it was found that the color of a water-repellent film-forming chemical solution containing a silylating agent and a solvent having a carbonyl group may change before and after storage.

[0007] As a result of further investigation, the present inventors found that the degree of hue change before and after storage can be reduced by adding an antioxidant to a chemical solution containing a silylating agent and a solvent having a carbonyl group, and thus completed the present invention.

[0008] According to one aspect of the present invention, there are provided the following liquid chemical for forming a water-repellent film, a container containing the liquid chemical, a storage method, and a method for manufacturing the liquid chemical for forming a water-repellent film. 1. A liquid chemical for forming a water-repellent film, comprising a silylation agent, a solvent having a carbonyl group, and an antioxidant, wherein the number of particles having a particle size of 0.2 μm or more per mL is 10 or less when measured in the liquid phase of the liquid chemical for forming a water-repellent film using a light scattering liquid-borne particle detector. 2. A liquid chemical for forming a water-repellent film, comprising a silylation agent, a solvent having a carbonyl group, and an antioxidant, wherein the content of the antioxidant in the liquid chemical for forming a water-repellent film is 0.00001% by mass or more and 0.1% by mass or less. 3. A liquid chemical for forming a water-repellent film, comprising a silylation agent, a solvent having a carbonyl group, and an antioxidant, wherein the liquid chemical for forming a water-repellent film is a purified product. 4. 1. The water-repellent film-forming chemical solution according to any one of 1. to 3., wherein the difference in the Hazen color index before and after storage in a polyethylene container at 60°C in a nitrogen atmosphere in the dark for one month is 5 or less, and / or the difference in the Hazen color index before and after storage in a polyethylene container at 45°C in a nitrogen atmosphere in the dark for six months is 5 or less. 5. The water-repellent film-forming chemical solution according to any one of 1. to 4., wherein the solvent having a carbonyl group contains one or more selected from the group consisting of esters, ketones, carbonates, and polyhydric alcohol derivatives having no OH group. 6. The water-repellent film-forming chemical solution according to any one of 1. to 5., wherein the proportion of the solvent having a carbonyl group to the total solvent is 50 mass% or more. 7. The water-repellent film-forming chemical solution according to 1. to 6. 8. The liquid chemical for forming a water-repellent film according to any one of 1. to 7., wherein the content of the antioxidant in the liquid chemical for forming a water-repellent film is 0.00001 mass % or more and 0.1 mass % or less. 8. The liquid chemical for forming a water-repellent film according to any one of 1. to 7., wherein the antioxidant includes a phenol-based antioxidant.9. The liquid chemical for forming a water-repellent film according to any one of 1. to 8., wherein the silylating agent contains a silyl compound represented by the following general formula (1): R. １ ａ Si(H) ｂ X ４－ａ－ｂ [1] (In the above general formula [1], R １ are each independently an organic group containing a hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, and each X is independently a monovalent group in which an atom bonded to a silicon atom is nitrogen, oxygen, carbon, or a halogen, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 1 to 3. 10. A water-repellent film-forming chemical solution according to any one of 1. to 9., wherein the content of the silylating agent in the water-repellent film-forming chemical solution is 0.5% by mass or more and 20% by mass or less. 11. A chemical solution-containing container comprising: a water-repellent film-forming chemical solution containing a silylating agent, a solvent having a carbonyl group, and an antioxidant; a storage section that stores the water-repellent film-forming chemical solution; and a lid section installed on the storage section, wherein the void section of the storage section is filled with an inert gas. 12. 12. A method for storing a liquid chemical for forming a water-repellent film, wherein the liquid chemical for forming a water-repellent film contains a silylating agent, a solvent having a carbonyl group, and an antioxidant, and the method includes a storage step of storing the liquid chemical for forming a water-repellent film purified by filtration under a pure atmosphere, wherein the storage step is performed such that the difference in the Hazen color number value of the liquid chemical for forming a water-repellent film before and after the storage step is 5 or less. 13. A method for manufacturing a liquid chemical for forming a water-repellent film, the method including a step of mixing a silylating agent, a solvent having a carbonyl group, and an antioxidant and purifying the mixture. 14. A method for manufacturing a liquid chemical for forming a water-repellent film according to 13, wherein the purification is performed by filtration.

[0009] According to the present invention, there are provided a chemical solution for forming a water-repellent film, a container containing the chemical solution, a storage method, and a method for producing a chemical solution for forming a water-repellent film, which have a reduced degree of hue change before and after storage.

[0010] An outline of the water-repellent film-forming chemical solution of this embodiment will be described.

[0011] The chemical solution for forming a water-repellent film of this embodiment contains a silylating agent, a solvent having a carbonyl group, and an antioxidant.

[0012] In the first embodiment of the water-repellent film-forming chemical solution, the number of particles with a particle diameter of 0.2 μm or more measured in the liquid phase of the chemical solution using a light-scattering liquid-borne particle detector is 10 or less, preferably 7 or less, and more preferably 3 or less per mL. Note that, in this specification, particle measurement in the liquid phase of the chemical solution is performed using a commercially available light-scattering liquid-borne particle measurement system using a laser as a light source, and particle diameter refers to the light-scattering equivalent diameter based on PSL (polystyrene latex) standard particles. The number of particles in the liquid phase of the chemical solution can be reduced by a predetermined purification procedure. In this specification, the "number of particles with a particle diameter of 0.2 μm or more" refers to a value calculated using the following "measurement method." "Measurement method": Using a light-scattering liquid-borne particle measurement device, the liquid is irradiated with light with a wavelength of 830 nm, and the intensity of scattered light emitted by particles passing through the light is observed. As a reference, a dispersion of polystyrene latex standard particles with a particle diameter of 200 nm dispersed in pure water is used. When the intensity of scattered light in the sample is equal to or greater than the intensity (R) of scattered light from the polystyrene latex standard particles, it is determined that scattered light originating from "particles with a particle size of 0.2 μm or more" has been received. The number of times scattered light originating from "particles with a particle size of 0.2 μm or more" is received when the chemical solution is passed through is taken as the "number of particles with a particle size of 0.2 μm or more."

[0013] In the second embodiment, the chemical solution for forming a water-repellent film contains an antioxidant in an amount of 0.00001% by mass or more and 0.1% by mass or less. In this specification, "the chemical solution does not contain an antioxidant" means that the concentration of the antioxidant in the chemical solution measured using a gas chromatograph is below the detection limit. The detection limit varies depending on the device, but is, for example, 0.000005% by mass. In the third embodiment, the chemical solution for forming a water-repellent film is a purified product. The purified product in the third embodiment is preferably a product purified by filtration. Since the chemical solutions of the first to third embodiments contain an antioxidant, the degree of hue change before and after storage can be reduced. It has also been found that storing the chemical solution of this embodiment in an atmosphere substantially free of oxygen gas, preferably in a nitrogen environment, can further reduce the degree of hue change before and after storage.

[0014] According to the findings of the present inventors, it has been found that by selecting an appropriate purification method, it is possible to retain the antioxidant added when the raw materials are mixed in the chemical solution after purification. In purification methods such as distillation, the antioxidant added when the raw materials are mixed is not contained in the chemical solution after purification (specifically, the concentration of the antioxidant becomes below the detection limit). In contrast, by selecting an appropriate purification method such as filtration and performing the purification operation, the antioxidant remains in the chemical solution even after purification.

[0015] Furthermore, the inventors conducted storage tests in a dark, sealed space under varying conditions, depending on whether or not the atmosphere contained oxygen. This led them to believe that the discoloration of the solution was caused by dissolved oxygen in the solution. Therefore, it is believed that adding an antioxidant to the purified solution can prevent discoloration (e.g., yellowing) of the components in the solution caused by dissolved oxygen.

[0016] When we investigated the components that cause discoloration, we found that no change in hue was observed in solvents that did not contain a "carbonyl group-containing solvent," nor in "carbonyl group-containing solvents" that did not contain a "silylating agent." Based on these experimental results, we speculate that discoloration occurs when a "carbonyl group-containing solvent" and a "silylating agent" are included, or when a "carbonyl group-containing solvent," a "silylating agent," and an "accelerator" are included. Typically, silylating agents function as bases, and accelerators function as acids. However, hue changes occur whether the solvent is an acid or a base, and the hue change can be suppressed by adding an antioxidant. Therefore, it is believed that the composition described above is prone to oxidation. While the details of the hue change and its suppression mechanism are unknown, we speculate that the hue change occurs when a composition containing a carbonyl group-containing solvent, a silylating agent, and an accelerator is mixed, resulting in the oxidation of the solvent and the generation of coloring components.

[0017] The water-repellent film-forming chemical solution of this embodiment may be configured so that the difference in the Hazen color index before and after storage treatment in a polyethylene container at 60°C in a nitrogen atmosphere in the dark for one month is, for example, 5 or less, preferably 4 or less, and more preferably 3 or less. Furthermore, the water-repellent film-forming chemical solution of this embodiment may be configured so that the difference in the Hazen color index before and after storage treatment in a polyethylene container at 45°C in a nitrogen atmosphere in the dark for six months is, for example, 5 or less, preferably 4 or less, and more preferably 3 or less.

[0018] Hereinafter, each component of the chemical for forming a water-repellent film of this embodiment will be described in detail. In this specification, the chemical for forming a water-repellent film may also be simply referred to as the "chemical."

[0019] <Silylating Agent> The chemical solution of this embodiment contains a silylating agent. A known silylating agent can be used as the silylating agent. The silylating agent may contain one or more selected from the group consisting of silicon compounds represented by the following general formula [1] and cyclic compounds. These may be contained alone or in any combination of two or more.

[0020] R１ ａ Si(H) ｂ X ４－ａ－ｂ [1]

[0021] (In the above general formula [1], R １ are each independently an organic group containing a hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced with fluorine atoms or chlorine atoms, and each X is independently a monovalent group (functional group) in which the atom bonded to the silicon atom is nitrogen, oxygen, carbon, or halogen, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 1 to 3.) Note that the above hydrocarbon groups are still referred to as hydrocarbon groups even in cases in which all of the hydrogen atoms have been replaced with atoms other than hydrogen atoms.

[0022] R in the above general formula [1] １ may contain not only hydrogen, carbon, nitrogen, oxygen, a fluorine atom, or a chlorine atom, but also silicon, sulfur, a halogen atom (other than fluorine or chlorine), etc. １ R in the above general formula [1] may contain an unsaturated bond, an aromatic ring, or a cyclic structure. １ As each independently, C ｅ H ２ｅ＋１ (e=1 to 18), and C ｆ F ２ｆ＋１ CH ２ CH ２ (f=1 to 8).

[0023] R in the above general formula [1] １ When R contains a silicon atom, it may have a structure represented by the following general formula [1-1]: １ ｍ X ３－ｍ－ｎ (H) ｎ Si-(CH ２ ) ｐ -Si(H) ｎ X ３－ｍ－ｎ R １ ｍ [1-1] In the above general formula [1-1], R １ (However, this R １does not contain a silicon atom) and X are the same as those in the above general formula [1], m is an integer of 1 to 2, n is an integer of 0 to 1, the sum of m and n is 1 to 2, p is an integer of 1 to 18, and -(CH ２ ) ｐ The methylene chain represented by - may be substituted with a halogen.

[0024] In X in the above general formula [1], the monovalent organic group in which the atom bonded to the Si atom is nitrogen, oxygen, or carbon may contain not only hydrogen, carbon, nitrogen, or oxygen atoms, but also silicon, sulfur, halogen atoms, etc.

[0025] Examples of the monovalent organic group in which the atom bonded to the Si atom is nitrogen include an isocyanate group, an amino group, a dialkylamino group, an isothiocyanate group, an azide group, an acetamide group, and —NHC(═O)CF ３ , -N(CH ３ )C(=O)CH ３ , -N(CH ３ )C(=O)CF ３ , -N=C(CH ３ )OSi(CH ３ ) ３ , -N=C(CF ３ )OSi(CH ３ ) ３ , -NHC(=O)-OSi(CH ３ ) ３ , -NHC(=O)-NH-Si(CH ３ ) ３ , imidazole ring, triazole ring, tetrazole ring, oxazolidinone ring, morpholine ring, —NH—C(═O)—Si(CH ３ ) ３ , -N(S(=O) ２ R ４ ) ２ (where R ４ are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms, some or all of whose hydrogen atoms may be replaced by fluorine atoms, and a fluorine atom), and a substituent having a structure of the following general formula [1-2] (In the above general formula [1-2], R ５are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms), —N═C(NR ６ ２ ) ２ , -N=C(NR ６ ２ ) R ６ (where R ６ are each independently a hydrogen group, a —C≡N group, or —NO ２ and a hydrocarbon group in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and the hydrocarbon group may have oxygen atoms and / or nitrogen atoms. ａ１ ) (R ａ２ ) (wherein the above R ａ１ represents a hydrogen atom or a saturated or unsaturated alkyl group, and R ａ２ represents a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, or a saturated or unsaturated heterocycloalkyl group. ａ１ and R ａ２ may be bonded to each other to form a saturated or unsaturated heterocycloalkyl group having a nitrogen atom. ａ３ )-Si(R ａ４ ) (R ａ５ ) (R ａ６ ) (wherein the above R ａ３ represents a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, a trimethylsilyl group, or a dimethylsilyl group, and ａ４ , R ａ５ and R ａ６ each independently represents a hydrogen atom or an organic group, R ａ４ , R ａ５ and R ａ６ The total number of carbon atoms contained in —N(R ａ７ )-C(=O)R ａ８ (Here, the above R ａ７ represents a hydrogen atom, a methyl group, a trimethylsilyl group, or a dimethylsilyl group, and R ａ８ represents a hydrogen atom, a saturated or unsaturated alkyl group, a fluorine-containing alkyl group, or a trialkylsilylamino group.

[0026] Examples of the silylating agent in which X in the general formula [1] is a monovalent organic group in which the atom bonded to the Si atom is nitrogen include CH ３ Si(NH ２ ) ３ , C ２ H ５ Si(NH ２ ) ３ , C ３ H ７ Si(NH ２ ) ３ , C ４ H ９ Si(NH ２ ) ３ , C ５ H １１ Si(NH ２ ) ３ , C ６ H １３ Si(NH ２ ) ３ , C ７ H １５ Si(NH ２ ) ３ , C ８ H １７ Si(NH ２ ) ３ , C ９ H １９ Si(NH ２ ) ３ , C １０ H ２１ Si(NH ２ ) ３ , C １１ H ２３ Si(NH ２ ) ３ , C １２ H ２５ Si(NH ２ ) ３ , C １３ H ２７ Si(NH ２ ) ３ , C １４ H ２９ Si(NH ２ ) ３ , C １５ H ３１ Si(NH ２ ) ３ , C １６ H ３３ Si(NH ２) ３ 、C １７ H ３５ H ２ ) ３ 、C １８ H ３７ H ２ ) ３ 、(CH ３ ) ２ H ２ ) ２ 、C ２ H ５ H ３ ) ２ ) ２ 、(C ２ H ５ ) ２ H ２ ) ２ 、C ３ H ７ H ３ ) ２ ) ２ 、(C ３ H ７ ) ２ H ２ ) ２ 、C ４ H ９ H ３ ) ２ ) ２ 、(C ４ H ９ ) ２ H ２ ) ２ 、C ５ H １１ H ３ ) ２ ) ２ 、C ６ H １３ H ３ ) ２ ) ２ 、C ７ H １５ H ３ ) ２ ) ２ 、C ８ H １７ H ３ ) ２ ) ２ 、C ９ H １９H ３ ) ２ ) ２ 、C １０ H ２１ H ３ ) ２ ) ２ 、C １１ H ２３ H ３ ) ２ ) ２ 、C １２ H ２５ H ３ ) ２ ) ２ 、C １３ H ２７ H ３ ) ２ ) ２ 、C １４ H ２９ H ３ ) ２ ) ２ 、C １５ H ３１ H ３ ) ２ ) ２ 、C １６ H ３３ H ３ ) ２ ) ２ 、C １７ H ３５ H ３ ) ２ ) ２ 、C １８ H ３７ H ３ ) ２ ) ２ 、(CH ３ ) ３ H ２ 、C ２ H ５ H ３ ) ２ NH ２ 、(C ２ H ５ ) ２ H ３ )NH ２ 、(C ２ H ５ ) ３ H２ 、C ３ H ７ H ３ ) ２ NH ２ 、(C ３ H ７ ) ２ H ３ )NH ２ 、(C ３ H ７ ) ３ H ２ 、C ４ H ９ H ３ ) ２ NH ２ 、(C ４ H ９ ) ３ H ２ 、C ５ H １１ H ３ ) ２ NH ２ 、C ６ H １３ H ３ ) ２ NH ２ 、C ７ H １５ H ３ ) ２ NH ２ 、C ８ H １７ H ３ ) ２ NH ２ 、C ９ H １９ H ３ ) ２ NH ２ 、C １０ H ２１ H ３ ) ２ NH ２ 、C １１ H ２３ H ３ ) ２ NH ２ 、C １２ H ２５ H ３ ) ２ NH ２ 、C １３ H ２７H ３ ) ２ NH ２ 、C １４ H ２９ H ３ ) ２ NH ２ 、C １５ H ３１ H ３ ) ２ NH ２ 、C １６ H ３３ H ３ ) ２ NH ２ 、C １７ H ３５ H ３ ) ２ NH ２ 、C １８ H ３７ H ３ ) ２ NH ２ 、(CH ３ ) ２ H. ２ CH ３ H ２ NH ２ 、(C ２ H ５ ) ２ H. ２ 、C ２ H ５ H ２ NH ２ 、C ２ H ５ H ３ )(H)NH ２ 、(C ３ H ７ ) ２ H. ２ 、C ３ H ７ H ２ NH ２ CF ３ CH ２ CH ２ H ２ ) ３ 、C ２ F ５ CH ２ CH ２ H ２ )３ 、C ３ F ７ CH ２ CH ２ H ２ ) ３ 、C ４ F ９ CH ２ CH ２ H ２ ) ３ 、C ５ F １１ CH ２ CH ２ H ２ ) ３ 、C ６ F １３ CH ２ CH ２ H ２ ) ３ 、C ７ F １５ CH ２ CH ２ H ２ ) ３ 、C ８ F １７ CH ２ CH ２ H ２ ) ３ CF ３ CH ２ CH ２ H ３ ) ２ ) ２ 、C ２ F ５ CH ２ CH ２ H ３ ) ２ ) ２ 、C ３ F ７ CH ２ CH ２ H ３ ) ２ ) ２ 、C ４ F ９ CH ２ CH ２ H ３ ) ２ ) ２ 、C ５ F１１ CH ２ CH ２ H ３ ) ２ ) ２ 、C ６ F １３ CH ２ CH ２ H ３ ) ２ ) ２ 、C ７ F １５ CH ２ CH ２ H ３ ) ２ ) ２ 、C ８ F １７ CH ２ CH ２ H ３ ) ２ ) ２ CF ３ CH ２ CH ２ H ３ ) ２ NH ２ 、C ２ F ５ CH ２ CH ２ H ３ ) ２ NH ２ 、C ３ F ７ CH ２ CH ２ H ３ ) ２ NH ２ 、C ４ F ９ CH ２ CH ２ H ３ ) ２ NH ２ 、C ５ F １１ CH ２ CH ２ H ３ ) ２ NH ２ 、C ６ F １３ CH ２ CH ２ H３ ) ２ NH ２ , C ７ F １５ CH ２ CH ２ Si(CH ３ ) ２ NH ２ , C ８ F １７ CH ２ CH ２ Si(CH ３ ) ２ NH ２ , C.F. ３ CH ２ CH ２ Si(CH ３ ) (H) NH ２ aminosilanes such as aminodimethylvinylsilane, aminodimethylphenylethylsilane, aminodimethylphenylsilane, aminomethyldiphenylsilane, and aminodimethyl-t-butylsilane, or the amino group (—NH ２ group), -N=C=O, dialkylamino group (-N(CH ３ ) ２ , -N(C ２ H ５ ) ２ etc.), t-butylamino group, allylamino group, -N=C=S, -N ３ , -NHC(=O)CH ３ , -NHC(=O)CF ３ , -N(CH ３ )C(=O)CH ３ , -N(CH ３ )C(=O)CF ３ , -N=C(CH ３ )OSi(CH ３ ) ３ , -N=C(CF ３ )OSi(CH ３ ) ３ , -NHC(=O)-OSi(CH ３ ) ３ , -NHC(=O)-NH-Si(CH ３ ) ３(e.g., N,N'-bis(trimethylsilyl)urea, etc.), imidazole ring (e.g., N-trimethylsilylimidazole, etc.), triazole ring (e.g., N-trimethylsilyltriazole, etc.), tetrazole ring, oxazolidinone ring, morpholine ring, -NH-C(=O)-Si(CH ３ ) ３ , -N(S(=O) ２ R ４ ) ２ (R ４ is as described above. For example, N-(trimethylsilyl)bis(trifluoromethanesulfonyl)imide, etc.), and a substituent having the structure of the above-described general formula [1-2] (In the above general formula [1-2], R ５ is as described above.), -N=C(NR ６ ２ ) ２ , -N=C(NR ６ ２ ) R ６ (R ６ is as described above.), -N(R ａ１ ) R ａ２ (R ａ１ , R ａ２ is as described above.), -N(R ａ３ )-Si(R ａ４ ) (R ａ５ ) (R ａ６ ) (R ａ３ , R ａ４ , R ａ５ and R ａ６ is as described above.), -N(R ａ７ )-C(=O)R ａ８ (R ａ７ , R ａ８are as described above.) More specific examples of the silyl group include 2-trimethylsilyl-1,1,3,3-tetramethylguanidine, hexamethyldisilazane, N-methylhexamethyldisilazane, 1,1,3,3-tetramethyldisilazane, 1,3-di-N-ethyltetradimethyldisilazane, 1,3-di-N-propyltetradimethyldisilazane, 1,3-di-N-butyltetradimethyldisilazane, 1,3-di-N-octyltetramethyldisilazane, 1,3-di-N-decyltetramethyldisilazane, 1,3-divinyltetramethyldisilazane, heptamethyldisilazane, N-allyl-N,N-bis(trimethylsilyl)amine, 1,3-diphenyltetramethyldisilazane, 1,1, Examples thereof include 3,3-tetraphenyl-1,3-dimethyldisilazane, nonamethyltrisilazane, pentamethylethyldisilazane, pentamethylvinyldisilazane, pentamethylpropyldisilazane, pentamethylethyldisilazane, pentamethyl-t-butyldisilazane, pentamethylphenyldisilazane, trimethyltriethyldisilazane, N-trimethylsilylacetamide, N-trimethylsilyltrifluoroacetamide, N-methyl-N-trimethylsilylacetamide, N-methyl-N-trimethylsilyltrifluoroacetamide, bis(trimethylsilyl)acetamide, and bis(trimethylsilyl)trifluoroacetamide.

[0027] Examples of the silylating agent in which X in the general formula [1] is a monovalent organic group in which the atom bonded to the Si atom is oxygen include the amino group (—NH ２ group) by —O—C(═A)R ａ９ (wherein A is O, CHR ａ１０ , CHOR ａ１０ , C.R. ａ１０ R ａ１０ , or NR ａ１１ indicates R ａ９ , R ａ１０each independently represents a hydrogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, a fluorine-containing alkyl group, a chlorine-containing alkyl group, a trialkylsilyl group, a trialkylsiloxy group, an alkoxy group, a phenyl group, a phenylethyl group, or an acetyl group, and ａ１１ represents a hydrogen atom, an alkyl group, or a trialkylsilyl group.), —O—C(R ａ１２ ) = N(R ａ１３ ) (wherein the above R ａ１２ represents a hydrogen atom, a saturated or unsaturated alkyl group, a fluorine-containing alkyl group, or a trialkylsilylamino group; R ａ１３ represents a hydrogen atom, an alkyl group, or a trialkylsilyl group.), —O—C(R ａ１４ )=CH-C(=O)R ａ１５ (Here, the above R ａ１４ and R ａ１５ each independently represents a hydrogen atom or an organic group. For example, trimethylsilyloxy-3-penten-2-one, 2-trimethylsiloxypent-2-en-4-one, etc.), —OR ａ１６ (Here, the above R ａ１６ represents a saturated or unsaturated alkyl group, a saturated or unsaturated cycloalkyl group, or a fluorine-containing alkyl group; —O—S(═O) ２ -R ａ１７ (Here, the above R ａ１７ represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, a tolyl group, —O—Si(CH ３ ) ３ ), —O—P(—O—Si(CH ３ ) ３ ) ２More specific examples include trimethylsilyl acetate, dimethylsilyl acetate, monomethylsilyl acetate, trimethylsilyl trifluoroacetate, dimethylsilyl trifluoroacetate, monomethylsilyl trifluoroacetate, trimethylsilyl trichloroacetate, trimethylsilyl propionate, trimethylsilyl butyrate, trimethylsilyl sulfonate, trimethylsilyl benzenesulfonate, trimethylsilyl toluenesulfonate, bistrimethylsilyl sulfate, and tristrimethylsilyl phosphite.

[0028] Examples of silylating agents in which X in the general formula [1] is a monovalent organic group in which the atom bonded to the Si atom is oxygen include hexamethyldisiloxane, 1,3-diphenyl-1,3-dimethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, 1,1,1-triethyl-3,3-dimethyldisiloxane, 1,1,3,3-tetra-n-octyldimethyldisiloxane, bis(nonafluorohexyl)tetramethyldisiloxane, 1,3-bis(trifluoropropyl)tetramethyldisiloxane, 1,3-di-n-butyltetramethyldisiloxane, and the like. disiloxane, 1,3-di-n-octyltetramethyldisiloxane, 1,3-diethyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, hexa-n-butyldisiloxane, hexaethyldisiloxane, hexavinyldisiloxane, 1,1,3,3-tetraisopropyldisiloxane, vinylpentamethyldisiloxane, 1,3-bis(3-chloroisobutyl)tetramethyldisiloxane, hexaphenyldisiloxane, 1,1,1-triethyl-3,3,3-trimethyldisiloxane, 1,3-bis(chloromethyl)tetramethyldisiloxane ethyldisiloxane, 1,1,3,3-tetraphenyldimethyldisiloxane, pentamethyldisiloxane, 1,3-bis(3-chloropropyl)tetramethyldisiloxane, 1,3-dichloro-1,3-diphenyl-1,3-dimethyldisiloxane, n-butyl-1,1,3,3-tetramethyldisiloxane, 1,3-di-t-butyldisiloxane, vinyl-1,1,3,3-tetramethyldisiloxane, 1,1,1-trimethyl-3,3,3-triphenyldisiloxane, 3,3-diphenyltetramethyltrisiloxane, 3-phenylheptamethylenediamine n-propylheptamethyltrisiloxane, 3-ethylheptamethyltrisiloxane, 3-(3,3,3-trifluoropropyl)heptamethyltrisiloxane, 1,1,3,5,5-pentaphenyl-1,3,5-trimethyltrisiloxane, octamethyltrisiloxane, 1,1,5,5-tetraphenyl-1,3,3,5-tetramethyltrisiloxane, 1,1,1,5,5,5-hexamethyltrisiloxane, 3-phenyl-1,1,3,5,5-pentamethyltrisiloxane, 1,3,5-trivinyl-1,1,3,5,5-pentamethyltrisiloxane, 3-octylheptamethyltrisiloxane, 1,1,1,3,3,5,5-heptamethyltrisiloxane, 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,1,5,5,5-hexaethyl-3-methyltrisiloxane, furfuryloxytrisiloxane, tetrakis(dimethylsiloxy)silane, 1,1,3,3,5,5,7,7-octamethyltetrasiloxane, diphenylsiloxane-dimethylsiloxane copolymer, 1,3-diphenyl-1,3- Also included are siloxane compounds such as dimethyldisiloxane, 1,3-bis(trimethylsiloxy)-1,3-dimethyldisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, tetradecamethylhexasiloxane, polydimethylsiloxane, polyoctadecylmethylsiloxane, poly(3,3,3-trifluoropropylmethylsiloxane), trimethylsiloxy-terminated polydimethylsiloxane, and 1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane.

[0029] Examples of the silylating agent in which X in the general formula [1] is a monovalent organic group in which the atom bonded to the Si atom is carbon include the amino group (—NH ２ group) to -C(S(=O) ２ R ７ ) ３ (where R ７ are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and a fluorine atom. Examples include those in which hydrogen atoms are replaced by (trimethylsilyl)tris(trifluoromethanesulfonyl)methide, etc.

[0030] Furthermore, examples of the silylating agent in which X in the general formula [1] is a monovalent organic group in which the atom bonded to the Si atom is halogen include the amino group (—NH ２ group) is replaced with a chloro group, a bromo group, or an iodo group (for example, chlorotrimethylsilane, bromotrimethylsilane, etc.).

[0031] In the general formula [1], b is preferably 0. Furthermore, a is preferably 2 or 3, and particularly preferably 3. Furthermore, X is more preferably a monovalent organic group in which the atom bonded to the Si atom is nitrogen or oxygen. Furthermore, R １ As the group, an alkyl group is preferred, and a methyl group is particularly preferred. Therefore, the silicon compound represented by the general formula [1] is preferably a silicon compound having a trialkylsilyl group.

[0032] The silylating agent can contain a cyclic silazane compound, which further includes cyclic disilazane compounds such as 2,2,5,5-tetramethyl-2,5-disila-1-azacyclopentane and 2,2,6,6-tetramethyl-2,6-disila-1-azacyclohexane; cyclic trisilazane compounds such as 2,2,4,4,6,6-hexamethylcyclotrisilazane and 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane; and cyclic tetrasilazane compounds such as 2,2,4,4,6,6,8,8-octamethylcyclotetrasilazane.

[0033] More preferred specific examples of the silylating agent include one or more selected from the group consisting of hexamethyldisilazane, heptamethyldisilazane, N-(trimethylsilyl)dimethylamine, bis(dimethylamino)dimethylsilane, bis(trimethylsilyl)trifluoroacetamide, N-methyl-N-trimethylsilyltrifluoroacetamide, N-methyl-N-trimethylsilyldifluorochloroacetamide, N-trimethylsilylacetamide, N-trimethylsilylimidazole, trimethylsilyltriazole, bistrimethylsilyl sulfate, 2,2,5,5-tetramethyl-2,5-disila-1-azacyclopentane, 2,2,4,4,6,6-hexamethylcyclotrisilazane, hexamethyldisiloxane, trimethylsilyltrifluoroacetate, trimethylsilyldifluorochloroacetate, trimethylsilylbenzenesulfonate, and trimethylsilyltoluenesulfonate.

[0034] <Accelerator> The agent of this embodiment may contain, if necessary, an accelerator, which is a catalytic compound that accelerates the silylation reaction caused by the silylating agent, in combination with the silylating agent.

[0035] The accelerator is preferably one or more selected from the group consisting of Compound A (described below), acid imides, compounds having a guanidine skeleton, silicon-free nitrogen-containing heterocyclic compounds, and silylated heterocyclic compounds. Here, the accelerator is an accelerator that can accelerate the reaction between the pattern surface and the silylating agent or enhance the liquid-repellent properties of the formed water-repellent film, and may itself or a modified version thereof constitute a part of the water-repellent film.

[0036] The compound A may be at least one selected from the group consisting of a carboxylic acid represented by the following general formula

[16] , an anhydride of the carboxylic acid, a salt of the carboxylic acid, and a carboxylic acid derivative represented by the following general formula

[17] : ２９ —C(═O)OH

[16] (in the above general formula

[16] , R ２９ is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms, in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms. ２９’ -C(=O)O-Si(H) ３－ｈ (R ３０ ) ｈ

[17] (In the above general formula

[17] , R ２９’ is a monovalent hydrocarbon group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, and R ３０ are each independently a group selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, and h is an integer of 1 to 3.

[0037] The compound A may be at least one selected from the group consisting of sulfonic acids represented by the following general formula [3], anhydrides of the sulfonic acids, salts of the sulfonic acids, and sulfonic acid derivatives represented by the following general formula [4]: ８ -S(=O) ２ OH [3] (in the above general formula [3], R８ is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms and hydroxyl groups. ８’ -S(=O) ２ O—Si(H) ３－ｒ (R ９ ) ｒ [4] (In the above general formula [4], R ８’ is a monovalent hydrocarbon group having 1 to 8 carbon atoms, and R ９ are each independently a group selected from monovalent hydrocarbon groups having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, and r is an integer of 1 to 3.

[0038] Furthermore, the compound A may be at least one selected from the group consisting of sulfonate esters represented by the following general formula [5], sulfonimides represented by the following general formulas [6] and [7], sulfonimide derivatives represented by the following general formulas [8] and [9], sulfonmethides represented by the following general formula

[10] , and sulfonmethide derivatives represented by the following general formula

[11] . １０ -S(=O) ２ OR １１ [5] (In the above general formula [5], R １０ is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 8 carbon atoms and fluorine atoms, and R １１ is a monovalent alkyl group having 1 to 18 carbon atoms. １２ -S(=O) ２ ) ２ NH [6] (In the above general formula [6], R １２ are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms and a fluorine atom. (In the above general formula [7], R １３ is a divalent hydrocarbon group having 1 to 8 carbon atoms. １４ -S(=O) ２ ) ２ N) ｓ Si(H) ｔ (R １５ ) ４－ｓ－ｔ [8] (In the above general formula [8], R １４are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms and a fluorine atom, and R １５ are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, s is an integer of 1 to 3, t is an integer of 0 to 2, and the sum of s and t is 3 or less. (In the above general formula [9], R １６ are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms, and R １７ are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, u is an integer of 1 to 3, v is an integer of 0 to 2, and the sum of u and v is 3 or less. １８ -S(=O) ２ ) ３ CH

[10] (in the above general formula

[10] , R １８ are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms and a fluorine atom. １９ -S(=O) ２ ) ３ C) ｗ Si(H) ｘ (R ２０ ) ４－ｗ－ｘ

[11] (In the above general formula

[11] , R １９ are each independently a group selected from the group consisting of a monovalent hydrocarbon group having 1 to 8 carbon atoms and a fluorine atom, and R ２０ are each independently a monovalent hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, w is an integer of 1 to 3, x is an integer of 0 to 2, and the sum of w and x is 3 or less.

[0039] Specific examples of the compound A include trimethylsilyl trifluoroacetate, dimethylsilyl trifluoroacetate, butyldimethylsilyl trifluoroacetate, hexyldimethylsilyl trifluoroacetate, octyldimethylsilyl trifluoroacetate, decyldimethylsilyl trifluoroacetate, trimethylsilyl chlorodifluoroacetate, trimethylsilyl dichlorofluoroacetate, trimethylsilyl dichloroacetate, dimethylsilyl difluorochloroacetate, dimethylsilyl chloroacetate, dimethylsilyl dichloroacetate, and butyldimethylsilyl Examples of the chlorosilyl compounds include difluorochloroacetate, butyldimethylsilyl chloroacetate, hexyldimethylsilyl difluorochloroacetate, octyldimethylsilyl difluorochloroacetate, decyldimethylsilyl difluorochloroacetate, trimethylsilyl-2-chloropropionate, trimethylsilyl-3-chloropropionate, trimethylsilyl-2,2-dichloropropionate, trimethylsilyl-2,3-dichloropropionate, triethylsilyl-2-chloropropionate, and trimethylsilyl trichloroacetate, and the chlorosilyl compound may contain one or more compounds selected from among these. These compounds may be used alone or in combination of two or more.

[0040] By using the above-mentioned compound A, it is possible to realize a film-forming composition that has excellent in-plane uniformity of the water contact angle and is even more effective in suppressing the decrease in the water contact angle upon contact with or mixing with a protic liquid.

[0041] Although some of the above-mentioned Compound A fall under the category of the silylating agent, when it is used as an accelerator, it means that it is used in combination with another silylating agent other than Compound A. When used in combination, it is preferable to set the concentration of Compound A equal to or lower than the concentration of the other silylating agent, since this makes it easier for Compound A to act as an accelerator.

[0042] The compound A may be obtained by reacting a silicon compound represented by the following general formula [2] with one or more acetic acids selected from the group consisting of trifluoroacetic acid, trifluoroacetic anhydride, difluorochloroacetic acid, and difluorochloroacetic anhydride. The excess silicon compound represented by the following general formula [2] that remains unconsumed in this reaction can be used as the silylating agent together with the compound A obtained by the reaction. The silicon compound represented by the following general formula [2] may be reacted, for example, in a molar ratio of 0.2 to 100,000 times, preferably 0.5 to 50,000 times, and more preferably 1 to 10,000 times, the acetic acid or sulfonic acid.

[0043] R ２ ｃ (H) ｄ Si-X ４－ｃ－ｄ [2] (In the above general formula [2], R ２ is the above R １ X is the same as in the above general formula [1], c is an integer of 1 to 3, d is an integer of 0 to 2, and the sum of c and d is 1 to 3.

[0044] The sum of the above c and d is preferably 3, and more preferably d may be 0. In addition, in the above general formula [2], R ２ ｃ (H) ｄ Examples of Si- include (CH ３ ) ３ Si-, (CH ３ ) ２ (H)Si-, (C ４ H ９ ) (CH ３ ) ２ Si-, (C ６ H １３ ) (CH ３ ) ２ Si-, (C ８ H １７ ) (CH ３ ) ２ Si-, (C １０ H ２１ ) (CH ３ ) ２ Si- and the like.

[0045] Examples of the acid imide compounds include compounds having a chemical structure in which an acid such as a carboxylic acid or phosphoric acid is imidized.

[0046] The compound having a guanidine skeleton may be at least one of the compounds represented by the following general formulas

[12] and

[13] : ２１ -N=C(NR ２２ ２ ) ２

[12] R ２１ -N=C(NR ２２ ２ ) R ２２

[13] (In the above general formulas

[12] and

[13] , R ２１ represents a hydrogen group, a —C≡N group, or —NO ２ R is selected from a hydrocarbon group, an alkylsilyl group, and a hydrocarbon group in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and the hydrocarbon group may contain oxygen atoms and / or nitrogen atoms, but when it contains a nitrogen atom, it is considered to have a non-cyclic structure. ２２ are each independently a hydrogen group, a —C≡N group, or —NO ２ and hydrocarbon groups in which some or all of the hydrogen atoms may be replaced by fluorine atoms, and the hydrocarbon groups may contain oxygen atoms and / or nitrogen atoms, but when they contain nitrogen atoms, they are considered to have a non-cyclic structure.) Furthermore, examples of the compounds having a guanidine skeleton include guanidine, 1,1,3,3-tetramethylguanidine, 2-tert-butyl-1,1,3,3-tetramethylguanidine, 1,3-diphenylguanidine, 1,2,3-triphenylguanidine, N,N'-diphenylformamidine, and 2,2,3,3,3-pentafluoropropylamidine.

[0047] The silicon-free nitrogen-containing heterocyclic compound and silylated heterocyclic compound may include at least one of the compounds represented by the following general formulas

[14] and

[15] . (In the above general formula

[14] , R ２３ and R ２４are each independently a divalent organic group consisting of a carbon atom and / or a nitrogen atom and a hydrogen atom, and the total number of carbon atoms and nitrogen atoms is 1 to 9, and when there are 2 or more carbon atoms, there may be carbon atoms that do not constitute the ring. (In the above general formula

[15] , R ２５ represents an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a cycloalkyl group having 3 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a trialkylsilyl group having an alkyl group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an alkenyl group having 2 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an alkoxy group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a cycloalkyloxy group having 3 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an aliphatic acyl group having 2 to 7 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an aryl group having 6 to 20 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an aralkyl group having 7 to 20 carbon atoms in which a hydrogen atom may be replaced by a fluorine atom, an arylcarbonyl group having 7 to 20 carbon atoms in which a part or all of the hydrogen atoms may be replaced by a fluorine atom, a carboxyalkyl group having 2 to 7 carbon atoms in which a part or all of the hydrogen atoms may be replaced by a fluorine atom, an amino group, a monoalkylamino group having an alkyl group having 1 to 6 carbon atoms in which a part or all of the hydrogen atoms may be replaced by a fluorine atom, a dialkylamino group having an alkyl group having 1 to 6 carbon atoms in which a part or all of the hydrogen atoms may be replaced by a fluorine atom, an aminoalkyl group having 1 to 6 carbon atoms in which a part or all of the hydrogen atoms may be replaced by a fluorine atom, a nitro group, a cyano group, a hydrogen group, a hydroxyl group, a mercapto group, an alkylthio group having 1 to 6 carbon atoms in which a part or all of the hydrogen atoms may be replaced by a fluorine atom, or a halogen group; ２６ , R ２７ and R ２８are each independently an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, or a hydrogen group.

[0048] The above-mentioned R ２５ is preferably an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a cycloalkyl group having 3 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a trialkylsilyl group having an alkyl group having 1 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an alkenyl group having 2 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a cycloalkyloxy group having 3 to 8 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an aliphatic aryl group having 2 to 7 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a phenyl group, a phenyl group, a benzyl group, an arylcarbonyl group having 7 to 20 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an amino group, a monoalkylamino group having an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a dialkylamino group having an alkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, an aminoalkyl group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, a hydrogen group, an alkylthio group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms, or a halogen group.

[0049] The above-mentioned R ２５ The number of carbon atoms in the alkyl group having 1 to 6 carbon atoms in the formula (I) is preferably 1 to 4, and more preferably 1 or 2. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. Of these, a methyl group and an ethyl group are preferred, and a methyl group is more preferred. The alkyl group may also contain a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom.

[0050] The above-mentioned R２５ The number of carbon atoms in the cycloalkyl group having 3 to 8 carbon atoms is preferably 3 to 7, and more preferably 4 to 6. Specific examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

[0051] The above-mentioned R ２５ The number of carbon atoms in the trialkylsilyl group having an alkyl group having 1 to 8 carbon atoms is preferably 2 to 8, and more preferably 3 to 6. Specific examples of the trialkylsilyl group include a trimethylsilyl group, a propyldimethylsilyl group, and a butyldimethylsilyl group.

[0052] The above-mentioned R ２５ The number of carbon atoms in the alkenyl group having 2 to 6 carbon atoms is preferably 2 to 4, and more preferably 2 to 3. Specific examples of the alkenyl group include a vinyl group, a 1-propenyl group, and a 2-propenyl group.

[0053] The above-mentioned R ２５ The number of carbon atoms in the alkoxy group having 1 to 6 carbon atoms is preferably 1 to 4, and more preferably 1 or 2. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group, an n-pentyloxy group, and an n-hexyloxy group. Of these, a methoxy group and an ethoxy group are preferred, and a methoxy group is more preferred.

[0054] The above-mentioned R ２５ The number of carbon atoms in the cycloalkyloxy group having 3 to 8 carbon atoms is preferably 3 to 7, and more preferably 4 to 6. Specific examples of the cycloalkyloxy group include a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, and a cyclooctyloxy group.

[0055] The above-mentioned R ２５The number of carbon atoms in the aliphatic acyl group having 2 to 7 carbon atoms is preferably 2 to 5, and more preferably 2 or 3. Specific examples of the aliphatic acyl group include an acetyl group, a propionyl group, a butanoyl group, a pentanoyl group, a hexanoyl group, and a heptanoyl group. Of these, an acetyl group and a propanoyl group are preferred, and an acetyl group is more preferred. The aliphatic acyl group may also contain a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom.

[0056] The above-mentioned R ２５ In the above formula, the number of carbon atoms in the aryl group having 6 to 20 carbon atoms is preferably 6 to 12. Specific examples of the aryl group include a phenyl group, an α-naphthyl group, a β-naphthyl group, a biphenyl-4-yl group, a biphenyl-3-yl group, a biphenyl-2-yl group, an anthracen-1-yl group, an anthracen-2-yl group, an anthracen-9-yl group, a phenanthrene-1-yl group, a phenanthrene-2-yl group, a phenanthrene-3-yl group, a phenanthrene-4-yl group, and a phenanthrene-9-yl group. Of these, a phenyl group, an α-naphthyl group, a β-naphthyl group, a biphenyl-4-yl group, a biphenyl-3-yl group, and a biphenyl-2-yl group are preferred, with a phenyl group being more preferred.

[0057] The above-mentioned R ２５ In the above formula, the number of carbon atoms in the aralkyl group having 7 to 20 carbon atoms is preferably 7 to 12. Specific examples of the aralkyl group include a benzyl group, a phenethyl group, a 3-phenyl-n-propyl group, a 4-phenyl-n-butyl group, an α-naphthylmethyl group, a β-naphthylmethyl group, a 2-(α-naphthyl)ethyl group, and a 2-(β-naphthyl)ethyl group. Of these groups, a benzyl group and a phenethyl group are preferred, and a benzyl group is more preferred.

[0058] The above-mentioned R ２５ The number of carbon atoms of the arylcarbonyl group having 7 to 20 carbon atoms is preferably 7 to 13. Specific examples of the arylcarbonyl group include a benzoyl group, an α-naphthoyl group, and a β-naphthoyl group.

[0059] The above-mentioned R ２５The number of carbon atoms in the carboxyalkyl group having 2 to 7 carbon atoms is preferably 2 to 5, and more preferably 2 or 3. Specific examples of the carboxyalkyl group include a carboxymethyl group, a 2-carboxyethyl group, a 3-carboxy-n-propyl group, a 4-carboxy-n-butyl group, a 5-carboxy-n-pentyl group, and a 6-carboxy-n-hexyl group. Of these, a carboxymethyl group is preferred.

[0060] The above-mentioned R ２５ Specific examples of the alkyl group contained in the monoalkylamino group containing an alkyl group having 1 to 6 carbon atoms and the dialkylamino group containing an alkyl group having 1 to 6 carbon atoms are the same as the specific examples of the alkyl group described above. Specific examples of the monoalkylamino group are preferably an ethylamino group and a methylamino group, and more preferably a methylamino group. Specific examples of the dialkylamino group are preferably a diethylamino group and a dimethylamino group, and more preferably a dimethylamino group.

[0061] The above-mentioned R ２５ The number of carbon atoms of the aminoalkyl group having 1 to 6 carbon atoms in the formula (I) is preferably 2 to 4. Specific examples of the aminoalkyl group include a 2-aminoethyl group and a 3-aminopropyl group.

[0062] The above-mentioned R ２５ The number of carbon atoms in the alkylthio group having 1 to 6 carbon atoms is preferably 1 to 4, and more preferably 1 or 2. Specific examples of the alkylthio group include a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, an n-butylthio group, an isobutylthio group, a sec-butylthio group, a tert-butylthio group, an n-pentylthio group, and an n-hexylthio group. Of these, a methylthio group and an ethylthio group are preferred, and a methylthio group is more preferred.

[0063] The silicon-free nitrogen-containing heterocyclic compound may contain a heteroatom other than a nitrogen atom, such as an oxygen atom or a sulfur atom, in the ring, may have aromaticity, or may be a compound in which two or more rings are bonded together by a single bond or a polyvalent linking group having a valence of two or more. The compound may also have a substituent.

[0064] Among the polyvalent linking groups, divalent linking groups are preferred because they cause little steric hindrance between rings. Specific examples of the divalent linking group include an alkylene group having 1 to 6 carbon atoms, -CO-, -CS-, -O-, -S-, -NH-, -N=N-, -CO-O-, -CO-NH-, -CO-S-, -CS-O-, -CS-S-, -CO-NH-CO-, -NH-CO-NH-, -SO-, and -SO ２ The number of rings contained in a compound in which two or more rings are bonded by a polyvalent linking group is preferably 4 or less, more preferably 3 or less, and most preferably 2, from the viewpoint of ease of preparing a uniform film-forming composition. Note that, for example, in the case of a fused ring such as a naphthalene ring, the number of rings is 2.

[0065] Examples of nitrogen-containing heterocyclic compounds that do not contain silicon atoms include pyridine, pyridazine, pyrazine, pyrimidine, triazine, tetrazine, pyrrole, pyrazole, imidazole, triazole, tetrazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazole, thiadiazole, quinoline, isoquinoline, cinnoline, phthalazine, quinoxaline, quinazoline, indole, indazole, benzimidazole, benzotriazole, benzoxazole, benzisoxazole, benzothiazole, benzisothiazole, benzoxadiazole, benzothiadiazole, saccharin, pyrrolidine, and piperidine. Among these, pyrrole, pyrazole, imidazole, triazole, tetrazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazole, thiadiazole, indole, indazole, benzimidazole, benzotriazole, benzoxazole, benzisoxazole, benzothiazole, benzisothiazole, benzoxadiazole, benzothiadiazole, and saccharin are preferred, and imidazole, triazole, tetrazole, benzotriazole, and pyrazole are more preferred.

[0066] The silylated heterocyclic compounds include silylated imidazole compounds and silylated triazole compounds. Examples of silylated heterocyclic compounds include monomethylsilylimidazole, dimethylsilylimidazole, trimethylsilylimidazole, monomethylsilyltriazole, dimethylsilyltriazole, and trimethylsilyltriazole. Some of the silylated heterocyclic compounds fall under the category of the silylating agents described above, but when used as an accelerator, this means that they are used in combination with other silylating agents other than the silylated heterocyclic compounds.

[0067] The lower limit of the content of the silylating agent may be, for example, 1% by mass or more, preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more, based on 100% by mass of the chemical solution. This makes it possible to further suppress a decrease in the water-repellent effect even after the film-forming composition comes into contact with the protic liquid. On the other hand, the upper limit of the content of the silylating agent may be, for example, 90% by mass or less, preferably 50% by mass or less, and more preferably 30% by mass or less, based on 100% by mass of the chemical solution. This makes it possible to facilitate the replacement of the protic liquid mounded on the substrate surface with the film-forming composition.

[0068] The lower limit of the total content of the silylating agent and the accelerator may be, for example, 8% by mass or more, preferably 9% by mass or more, and more preferably 10% by mass or more, based on 100% by mass of the chemical solution. This facilitates improving the water contact angle CA5 when 5% by mass of 2-propanol is added, as measured by the coupon test described above. On the other hand, the upper limit of the total content of the silylating agent and the accelerator may be, for example, 95% by mass or less, preferably 50% by mass or less, and more preferably 30% by mass or less, based on 100% by mass of the chemical solution. This facilitates the replacement of the protic liquid mounded on the substrate surface with the film-forming composition.

[0069] <Solvent Having a Carbonyl Group> The chemical solution of this embodiment contains a solvent having a carbonyl group. The solvent having a carbonyl group can be an aprotic solvent having a carbonyl group. Specifically, the solvent having a carbonyl group may contain one or more solvents selected from the group consisting of esters, ketones, carbonates, and polyhydric alcohol derivatives that do not have an OH group.

[0070] The esters may be cyclic esters such as lactone compounds. Examples of lactone compounds include β-propiolactone, γ-butyrolactone, γ-valerolactone, γ-hexanolactone, γ-heptanolactone, γ-octanolactone, γ-nonanolactone, γ-decanolactone, γ-undecanolactone, γ-dodecanolactone, δ-valerolactone, δ-hexanolactone, δ-octanolactone, δ-nonanolactone, δ-decanolactone, δ-undecanolactone, δ-dodecanolactone, and ε-hexanolactone.

[0071] Examples of ketones include acetone, acetylacetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, cyclohexanone, and isophorone.

[0072] Carbonates include dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and propylene carbonate.

[0073] Examples of polyhydric alcohol derivatives that do not have an OH group include glycols (including ethylene glycols and diethylene glycols) and propylene glycols (including dipropylene glycols). Examples of glycols include diethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol diacetate, triethylene glycol dimethyl ether, ethylene glycol diacetate, ethylene glycol dimethyl ether, and 3-methoxy-3-methyl-1-butyl acetate. Examples of propylene glycols include propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol diacetate, dipropylene glycol dimethyl ether, dipropylene glycol methylpropyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, and dipropylene glycol diacetate.

[0074] The chemical solution of this embodiment may contain a solvent having a carbonyl group alone as a solvent, or may contain other solvents other than the solvent having a carbonyl group. The lower limit of the content of the solvent having a carbonyl group (ratio to the total solvent) is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, based on 100% by mass of the solvent. On the other hand, the upper limit of the content of the solvent having a carbonyl group (ratio to the total solvent) may be, for example, 95% by mass or less, or even 90% by mass or less, based on 100% by mass of the solvent.

[0075] As the other solvent, for example, an aprotic solvent other than a solvent having a carbonyl group can be used. Specifically, the other aprotic solvent refers to a solvent that does not contain a group in which a hydrogen atom is bonded to an oxygen atom or a nitrogen atom, such as a hydroxyl group or an amino group. The aprotic solvent is not particularly limited as long as it dissolves the silylating agent and catalytic compound. Examples of the aprotic solvent include organic solvents such as hydrocarbons, esters, ethers, ketones, halogen atom-containing solvents, sulfoxide solvents, carbonate solvents, polyhydric alcohol derivatives that do not have an OH group, nitrogen atom-containing solvents that do not have an N—H group, and silicone solvents. These may be contained alone or in any combination of two or more.

[0076] <Antioxidant> The chemical solution of this embodiment contains an antioxidant. As the antioxidant, an agent that suppresses the oxidation reaction of each component in the chemical solution can be used, but radical chain inhibitors such as phenolic antioxidants and light stabilizers (HALS) are preferred. Phenolic antioxidants are particularly preferred.

[0077] Examples of phenolic antioxidants include 2,6-di-t-butyl-4-methylphenol (BHT), butylhydroxyanisole (BHA), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), tetrakis(methylene-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate)methane, etc. These may be contained alone or in any combination of two or more.

[0078] The lower limit of the antioxidant content is, for example, 0.00001 mass%, preferably 0.00002 mass%, more preferably 0.00005 mass%, relative to 100 mass% of the chemical solution, while the upper limit of the antioxidant content is, for example, 0.1 mass%, preferably 0.05 mass%, more preferably 0.01 mass%, relative to 100 mass% of the chemical solution.

[0079] The chemical solution of this embodiment is preferably substantially free of water. Furthermore, a chemical solution that is substantially free of water, obtained by not adding water during preparation or by using raw materials for each component that contain no water or have a low water content, is more preferred. In this specification, "a chemical solution that is substantially free of water" means that the water content of the chemical solution is less than 5 ppm by mass. By using such a chemical solution, it is easy to exhibit excellent water repellency even when contacting or mixing with a protic liquid.

[0080] <Other Components> The chemical solution of the present embodiment may contain other components in addition to the components described above, if necessary, to the extent that the purpose of the present disclosure is not impaired. Examples of such other components include oxidizing agents such as hydrogen peroxide and ozone, and surfactants.

[0081] [Container containing chemical solution] An example of a container containing chemical solution of this embodiment includes the above-mentioned chemical solution for forming a water-repellent film, a storage section for storing the chemical solution for forming a water-repellent film, and a lid section installed on the storage section, and the void section of the storage section is filled with an inert gas.

[0082] The container is constituted by a container having an internal space surrounded by a wall, and at least a chemical solution for forming a water-repellent film is contained in the internal space. The container further has an inner surface as the outermost surface of the wall facing the internal space, and since the inner surface comes into contact with the chemical solution for forming a water-repellent film, it is desirable that the inner surface has resistance to the chemical solution for forming a water-repellent film, similar to the liquid-contacting member.

[0083] The wall portion may be made of one material or two or more materials as long as the inner surface is resistant to the chemical solution for forming a water-repellent film. Alternatively, a coating or lining that is resistant to the chemical solution for forming a water-repellent film may be formed on the inner surface of the wall portion, and a different material may be used on the outer side of the inner surface. Examples of materials used for the wall portion include corrosion-resistant metal materials, ceramic materials, and plastic materials. Examples of corrosion-resistant metal materials and ceramic materials include stainless steel (SUS), carbon steel, manganese steel, nickel steel, aluminum steel, steel, and tinplate. It is also preferable to use a plastic material, and in particular, at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE) and perfluoroalkoxyalkane (PFA) is more preferable, and at least one selected from the group consisting of polyethylene, polypropylene, polyether ether ketone, polytetrafluoroethylene and perfluoroalkoxyalkane is particularly preferable because it is resistant to the chemical solution for forming the water-repellent film even when used on the inner surface.

[0084] The container has at least one opening through which the water-repellent film-forming chemical solution can be supplied to and removed from the internal space. The position of the opening in the container is not particularly limited as long as it does not significantly interfere with the ease of supplying the water-repellent film-forming chemical solution and the ease of transporting and storing the chemical solution storage container.

[0085] The entire volume of the internal space of the container may be filled with the water-repellent film-forming chemical solution. However, for ease of storage and removal of the water-repellent film-forming chemical solution, the internal space may not be filled with the water-repellent film-forming chemical solution at 100% by volume, and a portion of the internal space may be filled with a gas. For example, the water-repellent film-forming chemical solution may be 95% by volume or less, preferably 90% by volume or less, of the total volume. The lower limit is not particularly limited, but may be 60% by volume or more. It is preferable that the interior of the container be a non-oxidizing atmosphere. Furthermore, if the gas is present, the gas may be composed of a gas. Since the gas comes into contact with the water-repellent film-forming chemical solution during storage, it is preferable to use a gas that can create a non-oxidizing atmosphere inside the container, and more preferably, an inert gas such as nitrogen gas or argon gas may be used.

[0086] The above-mentioned "non-oxidizing atmosphere" may refer to an atmosphere in which the oxygen concentration of the gas in the atmosphere is 10% by volume or less, preferably 5% by volume or less, and more preferably 1% by volume or less. Furthermore, it is more preferable that the atmosphere is substantially free of water. "Substantially free of water" may refer to, for example, an atmosphere in which the dew point is 0°C or less, preferably -10°C or less, and more preferably -20°C or less.

[0087] (Sealing Structure) The opening of the storage section has a sealing structure that can seal the storage section. The sealing structure may be any known container sealing member, such as a valve, stopper, or lid, and is not particularly limited in shape or number. The sealing member may apply pressure to increase airtightness, and the sealing structure may further increase airtightness by providing an elastic member between the storage section and the sealing structure.

[0088] [Method for storing the chemical solution] An example of a method for storing the chemical solution for forming a water-repellent film of the present embodiment includes a storage step of storing the chemical solution for forming a water-repellent film, which has been purified by filtration, preferably under a nitrogen atmosphere. The storage step is performed such that the difference in the Hazen color scale value of the chemical solution for forming a water-repellent film before and after the storage step is 5 or less.

[0089] The nitrogen atmosphere may be nitrogen alone or a mixed gas in which a gas other than nitrogen coexists. In the case of a mixed gas, it is sufficient that the oxygen concentration is the non-oxidizing atmosphere described above. Specifically, the nitrogen concentration in the atmosphere may be 90% by volume or more, preferably 98% by volume or more, and more preferably 99.5% by volume or more. Furthermore, the moisture content in the nitrogen atmosphere may be such that the dew point is 0°C or less, preferably -10°C or less, and more preferably -20°C or less. Furthermore, the storage temperature may be 50°C or less, preferably 30°C or less. Although a lower storage temperature can suppress an increase in hue, taking into account storage costs and the durability of the container, the storage temperature may be -30°C or more, preferably -10°C or more, and more preferably 0°C or more.

[0090] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0091] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the descriptions of these examples.

[0092] 1: Preparation of Water-Repellent Film-Forming Liquid Chemicals Water-repellent film-forming liquid chemicals for Examples 1 to 19, Comparative Examples 1 to 5, and Experimental Examples 1 to 2 listed in Table 1 were prepared according to the following procedure. In addition, water-repellent film-forming liquid chemicals for Examples 20 and 21 listed in Table 3 were prepared. In Examples 1 to 18, Comparative Examples 1 to 4, and Experimental Examples 1 and 2, the water-repellent film-forming liquid chemicals immediately after preparation were filled into polyethylene containers under a nitrogen atmosphere, sealed, and stored. In Example 19 and Comparative Example 5, the water-repellent film-forming liquid chemicals immediately after preparation were filled into polyethylene containers under an atmospheric (air) atmosphere, sealed, and stored. In addition, in Examples 20 and 21, the water-repellent film-forming liquid chemicals immediately after preparation were filled into polyethylene containers under a nitrogen atmosphere, sealed, and stored. In Table 1, "Me" represents a methyl group (CH ３ "-" indicates not measured, and "ND" indicates below the measurement limit. Table 2 lists the abbreviations of the components listed in Table 1 and the chemical names corresponding to the abbreviations.

[0093] (Examples 1 and 2) N-(trimethylsilyl)dimethylamine (TMSDMA), propylene glycol monomethyl ether acetate (PGMEA) as a solvent having a carbonyl group, and 2,6-di-t-butyl-4-methylphenol (BHT) were mixed at a liquid temperature of 25°C and stirred for 1 minute. Thereafter, a purification operation by filtration as shown in Table 1 was carried out to prepare a chemical solution for forming a water-repellent film.

[0094] Example 3 N-(trimethylsilyl)dimethylamine (TMSDMA), propylene glycol monomethyl ether acetate (PGMEA), and dibutylhydroxytoluene (BHT) were mixed at a liquid temperature of 25°C and stirred for 1 minute. Furthermore, trifluoroacetic acid (TFA) was mixed as a raw material component other than the solvent and antioxidant, and the mixture was stirred for 1 minute. The mixture was then purified by filtration as shown in Table 1 to prepare a chemical solution for forming a water-repellent film. In this example, a chemical solution for forming a protective film containing TMSDMA as a silylating agent and trimethylsilyl trifluoroacetate (TMSTFA) as an accelerator was obtained by the reaction of the following formula. The TMSDMA contained in the chemical solution of this example is a component that was not consumed in the reaction to obtain the accelerator, and this component functions as a silylating agent. The HN(CH ３ ) ２ is a by-product. (CH ３ ) ３ Si—N(CH ３ ) ２ +CF ３ COOH → (CH ３ ) ３ SiCOOCF ３ +HN(CH ３ ) ２

[0095] Examples 4 to 19 Liquid solutions for forming water-repellent films were prepared in the same manner as in Example 3, except that the raw materials listed in Table 1 were used.

[0096] Comparative Examples 1 to 3 A water-repellent film-forming chemical solution was prepared in the same manner as in Examples 1, 3, and 4, except that no antioxidant (BHT) was added to the raw materials.

[0097] Comparative Example 4 A water-repellent film-forming solution was prepared in the same manner as in Example 1, except that the purification procedure by distillation shown in Table 1 was carried out.

[0098] Comparative Example 5 A liquid chemical for forming a water-repellent film was prepared in the same manner as in Example 19, except that no antioxidant (BHT) was added to the raw materials.

[0099] Experimental Example 1 A liquid chemical for forming a water-repellent film was prepared in the same manner as in Example 10, except that no antioxidant (BHT) was added to the raw materials and decane was used as a solvent having no carbonyl group.

[0100] Experimental Example 2 Using only propylene glycol monomethyl ether acetate (PGMEA) as a raw material, the purification procedure by filtration shown in Table 1 was carried out to prepare a chemical solution for forming a water-repellent film.

[0101] Example 20 1,1,1,3,3,3-hexamethyldisilazane (HMDS), propylene glycol monomethyl ether acetate (PGMEA), and dibutylhydroxytoluene (BHT) were mixed at a liquid temperature of 25°C and stirred for 1 minute. Furthermore, trifluoroacetic anhydride (TFAA) was mixed as a raw material component other than the solvent and antioxidant, and the mixture was stirred for 1 minute. The resulting mixture was then purified as described in Table 3 to prepare a chemical solution for forming a water-repellent film. In this example, a chemical solution for forming a protective film was obtained, containing HMDS as a silylating agent and trimethylsilyl trifluoroacetate (TMSTFA) as an accelerator. The HMDS contained in the chemical solution in this example is a component that was not consumed in the reaction to obtain the accelerator described below, and this component functions as a silylating agent. The compound represented by the formula (CH ３ ) ３ NHCOOCF ３ is a by-product. (CH ３ ) ３ Si-NH-Si(CH ３ ) ３ + (CF ３ CO) ２ O → (CH ３ ) ３ SiCOOCF ３ + (CH ３ ) ３ NHCOOCF ３

[0102] Example 21 A water-repellent film-forming chemical solution was prepared in the same manner as in Example 20, except that chlorodifluoroacetic anhydride (CDFAA) was used as a raw material component other than the solvent and antioxidant. The purification procedure was as shown in Table 3, and the obtained chemical solution contained HMDS as a silylating agent and trimethylsilyl chlorodifluoroacetate (TMSCDFA) as an accelerator. The HMDS contained in the chemical solution of this example is a component that was not consumed in the reaction to obtain the accelerator, and this component functions as a silylating agent.

[0103] [Water Content] The water content of the purified water-repellent film-forming chemical solution was measured using a Karl Fischer moisture meter (ADP-511 model, manufactured by Kyoto Electronics Co., Ltd.). The water content of the chemical solutions of Examples 1 to 21 and Comparative Examples 1 and 4 was below the lower limit of quantitation (5 ppm by mass).

[0104] [Particle Count] The number of particles (particles / 1 mL) of "particles with a particle size of 0.2 μm or more" in the liquid phase of the water-repellent film-forming chemical solution immediately before and immediately after purification was measured using a light-scattering liquid-borne particle analyzer (KS-42AF model, manufactured by Rion Co., Ltd.). The flow rate of the chemical solution during measurement was fixed at 10 mL / min. The chemical solution immediately after purification, stored in a storage container, was used for measurement. The results are shown in Table 1. In the light-scattering liquid-borne particle analyzer, the liquid is irradiated with light of a wavelength of 830 nm, and the scattered light emitted when particles pass through the light is received by a light-receiving element and converted into an electrical signal. For calibration, a standard particle dispersion (NANOSPHERE manufactured by Thermo Scientific Co., Ltd.) with a particle size of 200 nm and traceable to NIST (National Institute of Standards and Technology) was used, in which polystyrene latex standard particles were dispersed in pure water. ＴＭ The magnitude of the electrical signal converted from scattered light when the standard particle dispersion was passed through was stored, and the number of times scattered light of a magnitude equal to or greater than this was received when the chemical solution was passed through was counted as the number of particles having a particle size of 0.2 μm or greater.

[0105] The content (mass%) of the antioxidant in the water-repellent film-forming chemical immediately after purification was measured using a gas chromatograph (GC-2014, manufactured by Shimadzu Corporation). The results are shown in Tables 1 and 3.

[0106]

[0107]

[0108]

[0109] The details of the purification procedures in Tables 1 and 3 are as follows: "One-pass purification using an ion exchange membrane and a particle removal membrane" An ion exchange resin membrane with a particle removal membrane having a particle removal diameter of 0.05 μm (Protegoplus LTX manufactured by Nippon Entegris Co., Ltd., membrane surface area 1.38 m) was used. ２ The solution was passed through a particle removal membrane (Microguard C manufactured by Nippon Entegris Co., Ltd., membrane surface area: 1.31 m) with a particle removal diameter of 0.01 μm at a flow rate of 2 L / min by one-pass filtration. ２ The solution was passed through one filter (number of filters: 1) at a flow rate of 1 L / min by one-pass filtration. "Simple distillation" Simple distillation was carried out under conditions of 80°C and 10 kPa.

[0110] The water-repellent film-forming liquid obtained above was evaluated for the following items.

[0111] <Evaluation 1 of Change in Hue Before and After Storage> Samples were taken from each purified water-repellent film-forming solution within 30 minutes after preparation, and the hue (Hazen color scale) of the solution was measured according to the [Hue Measurement] below. The results are shown in the "Initial" hue column in Table 1. Samples were also taken from each purified water-repellent film-forming solution within 30 minutes after preparation, and stored according to the [Storage Test 1] below, and the hue (Hazen color scale) of the solution was measured according to the [Hue Measurement] below. The results are shown in the "After 1 Month" hue column in Table 1.

[0112] [Storage Test 1] The water-repellent film-forming chemical solution was filled into a polyethylene storage container under a predetermined atmosphere and sealed. The storage container was then stored in a dark place at 60°C for one month. However, in Examples 1 to 18, Comparative Examples 1 to 4, and Experimental Examples 1 and 2, the water-repellent film-forming chemical solution was filled into the storage container under a nitrogen atmosphere, and in Example 19 and Comparative Example 5, the water-repellent film-forming chemical solution was filled into the storage container under an atmospheric (air) atmosphere.

[0113] <Evaluation of Hue Change Before and After Storage 2> Samples were taken from the purified water-repellent film-forming solutions of Examples 20 and 21 within 30 minutes after preparation, and the hue (Hazen color scale) of the solutions was measured according to the [Hue Measurement] below. The results are shown in the "Initial" hue column in Table 3. Samples were also taken from the purified water-repellent film-forming solutions of Examples 20 and 21 within 30 minutes after preparation, and stored according to the [Storage Test 2] below, and the hue (Hazen color scale) of the solutions was measured according to the [Hue Measurement] below. The results are shown in the "After 6 Months" hue column in Table 3.

[0114] [Storage Test 2] The water-repellent film-forming chemical solution was filled into a polyethylene storage container under a nitrogen atmosphere and sealed, and then the storage container was stored in a dark place at 45°C for 6 months.

[0115] [Color Measurement] Approximately 10 mL of the water-repellent film-forming chemical solution was collected, and the color was measured using a Hazen meter (OME-2000, manufactured by Nippon Denshoku Industries Co., Ltd.).

[0116] The results in Table 1 revealed the following findings: When stored under atmospheric conditions, Comparative Example 5, which did not contain an antioxidant, showed a very large change in hue before and after storage, whereas Example 19, which contained an antioxidant, showed results in which the hue change could be suppressed to a certain extent. Furthermore, when the results of Example 19, which was stored under atmospheric conditions, were compared with the results of Examples 1 to 18, which were stored under nitrogen, it was shown that Examples 1 to 18, which were stored under a non-oxidizing atmosphere, tended to be able to further suppress the hue change.

[0117] In Experimental Example 1, which did not use a "solvent having a carbonyl group" as a solvent, there was almost no change in hue before and after the storage test, even though it did not contain an antioxidant. Similarly, in Experimental Example 2, which contained a "solvent having a carbonyl group" as a solvent but did not contain a "silylating agent," there was almost no change in hue before and after storage, even though it did not contain an antioxidant. From these results, it is inferred that the cause of the change in hue of the chemical solution is the combined use of a "solvent having a carbonyl group" and a "silylating agent."

[0118] The solution of Comparative Example 4 shows that the antioxidant added to the raw material is not contained in the solution (the concentration is less than the detection limit of 0.000005% by mass), and therefore the hue change before and after storage cannot be sufficiently suppressed. The solutions of Comparative Examples 1 to 3 show that the raw material does not contain an antioxidant, and therefore the hue change before and after storage cannot be sufficiently suppressed. In contrast, the solutions of Examples 1 to 18 show that the antioxidant is contained in the solution, and therefore the hue change before and after storage can be suppressed. Furthermore, the results of Table 3 show that the solutions of Examples 20 and 21, which were stored in polyethylene storage containers for 6 months, both contain an antioxidant, and therefore the hue change before and after storage can be suppressed.

[0119] This application claims priority based on Japanese Patent Application No. 2024-010524, filed January 26, 2024, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A chemical solution for forming a water-repellent film, comprising a silylating agent, a solvent having a carbonyl group, and an antioxidant, wherein the number of particles having a particle size of 0.2 µm or more in the particle measurement by a light scattering type in-liquid particle detector in the liquid phase of the chemical solution for forming a water-repellent film is 10 or less per mL.

2. A chemical solution for forming a water-repellent film, comprising a silylating agent, a solvent having a carbonyl group, and an antioxidant, wherein the content of the antioxidant in the chemical solution for forming a water-repellent film is 0.00001% by mass or more and 0.1% by mass or less.

3. A chemical solution for forming a water-repellent film, comprising a silylating agent, a solvent having a carbonyl group, and an antioxidant, which is a purified product.

4. The chemical solution for forming a water-repellent film according to any one of claims 1 to 3, wherein the difference in the value of the Hazen unit color number before and after the storage treatment of storing in a polyethylene container at 60°C, in a nitrogen atmosphere, in the dark, for 1 month is 5 or less and / or the difference in the value of the Hazen unit color number before and after the storage treatment of storing in a polyethylene container at 45°C, in a nitrogen atmosphere, in the dark, for 6 months is 5 or less.

5. The chemical solution for forming a water-repellent film according to any one of claims 1 to 3, wherein the solvent having a carbonyl group contains one or more selected from the group consisting of esters, ketones, carbonates, and derivatives of polyhydric alcohols having no OH group.

6. The chemical solution for forming a water-repellent film according to any one of claims 1 to 3, wherein the ratio of the solvent having a carbonyl group to the total solvent is 50% by mass or more.

7. The chemical solution for forming a water-repellent film according to claim 1 or 3, wherein the content of the antioxidant in the chemical solution for forming a water-repellent film is 0.00001% by mass or more and 0.1% by mass or less.

8. The chemical solution for forming a water-repellent film according to any one of claims 1 to 3, wherein the antioxidant contains a phenolic antioxidant.

9. A chemical solution for forming a water-repellent film according to any one of claims 1 to 3, wherein the silylating agent contains a silyl compound represented by the following general formula (1). A chemical solution for forming a water-repellent film. R １ ａ Si(H) ｂ X ４－ａ－ｂ [1] (In the above general formula [1], R １ is each independently an organic group containing a hydrocarbon group having 1 to 18 carbon atoms in which some or all of the hydrogen atoms may be replaced by fluorine atoms or chlorine atoms, and X is each independently a monovalent group in which the atom bonded to the silicon atom is nitrogen, oxygen, carbon, or halogen, a is an integer of 1 to 3, b is an integer of 0 to 2, and the sum of a and b is 1 to 3.) 10. The chemical solution for forming a water-repellent film according to any one of claims 1 to 3, wherein the content of the silylating agent in the chemical solution for forming a water-repellent film is 0.5% by mass or more and 20% by mass or less.

11. A chemical solution for forming a water-repellent film, comprising a silylating agent, a solvent having a carbonyl group, and an antioxidant; a storage part for storing the chemical solution for forming a water-repellent film; and a lid part installed on the storage part, wherein an inert gas is filled in the void part of the storage part. A chemical solution container containing the chemical solution.

12. A method for storing a chemical solution for forming a water-repellent film, wherein the chemical solution for forming a water-repellent film contains a silylating agent, a solvent having a carbonyl group, and an antioxidant, and includes a storage step of storing the chemical solution for forming a water-repellent film purified by a filtration method under an inert atmosphere. The storage step is a storage method in which the difference in the Hazen unit color number value of the chemical solution for forming a water-repellent film before and after the storage treatment is 5 or less.

13. A method for producing a chemical solution for forming a water-repellent film, comprising a step of mixing and purifying a silylating agent, a solvent having a carbonyl group, and an antioxidant.

14. The method for producing a chemical solution for forming a water-repellent film according to claim 13, wherein the purification is by a filtration method.

Images