Thermal spraying slurry and aggregation inhibitor used for the same

Abstract

To provide a thermal spraying slurry that inhibits aggregate from being generated even when being stored for a long term.SOLUTION: A thermal spraying slurry includes thermal spraying powder, a solvent, and an aggregation inhibitor including a triazine compound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a thermal spray slurry. [Background technology]

[0002] Techniques for imparting new functionality by coating the surface of a substrate with various materials have been used in various fields. For example, a thermal spraying method is known in which a thermal spray coating is formed by spraying a thermal spray powder made of a material such as ceramics onto the surface of a substrate in a molten state using combustion energy or electrical energy. In recent years, this thermal spraying method has also been carried out by supplying the thermal spray powder to a thermal spraying device in the form of a thermal spray slurry (including a suspension, a suspension, etc.) in which the thermal spray powder is dispersed in a solvent.

[0003] The type of thermal spray powder can be appropriately selected taking into consideration the desired function. For example, slurries using yttrium oxide have been found to be highly promising for protecting aluminum and aluminum alloy surfaces exposed to halogen-containing plasmas used in the manufacture of semiconductor devices (see, for example, Patent Document 1). Slurries using yttria-stabilized zirconia are known to be suitable for use in the environments used in semiconductor manufacturing equipment (see, for example, Patent Document 2). Slurries using aluminum oxide are used as protective coatings for various components because aluminum oxide exhibits high electrical insulation, wear resistance, and corrosion resistance (see, for example, Patent Document 3). Slurries using yttrium-aluminum composite oxides such as YAG are known to have excellent corrosion resistance and oxidation resistance and are therefore used as coating materials for components made of materials with poor corrosion resistance and oxidation resistance (see, for example, Patent Document 4).

[0004] As described above, there are many known thermal spray slurries that utilize thermal spray powder, although the present invention is not limited to those mentioned above. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 6,776,873 [Patent Document 2] Patent Publication No. 2021-042431 [Patent Document 3] Japanese Patent Publication No. 2022-94933 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-80954 Summary of the Invention [Problem to be solved by the invention]

[0006] However, it has been found that with conventionally known techniques, agglomerates may form in the thermal spray slurry when the thermal spray slurry is stored for a long period of time. If agglomerates form in the thermal spray slurry, there is a concern that, for example, clogging may occur in the supply pipe that sends the thermal spray slurry to the thermal spray torch, making it difficult to supply the thermal spray slurry to the thermal spray torch.

[0007] Therefore, an object of the present invention is to provide a thermal spray slurry that suppresses the generation of agglomerates even when stored for a long period of time. [Means for solving the problem]

[0008] One aspect of the present invention is a thermal spray slurry that includes a thermal spray powder, a solvent, and an agglomeration inhibitor that includes a triazine compound. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a thermal spray slurry that suppresses the generation of agglomerates even when stored for a long period of time. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an example of an optical microscope photograph when the result of the cohesion test was ⊚. [Figure 2]This is an example of an optical microscope photograph when the result of the coagulation test was good. [Figure 3] 1 is an example of an optical microscope photograph when the result of the cohesion test was △. [Figure 4] 1 is an example of an optical microscope photograph when the result of the cohesion test was ×. DETAILED DESCRIPTION OF THE INVENTION

[0011] In this specification, "X to Y" means "X or more and Y or less," with the preceding and following numerical values ​​(X and Y) being included as upper and lower limits. When multiple "X to Y" are used, for example, when "X1 to Y1" or "X2 to Y2" is used, the disclosure of each numerical value as an upper limit, the disclosure of each numerical value as a lower limit, and combinations of these upper and lower limits are all disclosed (i.e., they serve as legitimate grounds for amendment). Specifically, amendments to X1 or more, amendments to Y2 or less, amendments to X1 or less, amendments to Y2 or more, amendments between X1 and X2, and amendments between X1 and Y2, etc., must all be deemed legitimate. Furthermore, unless otherwise specified, operations and measurements of physical properties, etc., are performed at room temperature (20-25°C) and a relative humidity of 40-50% RH. Furthermore, when features or aspects of the present disclosure are described in terms of a Markush group, those skilled in the art will recognize that the present disclosure is thereby described in terms of any individual component or subgroup of components of the Markush group. Furthermore, it should be understood that all combinations of embodiments and descriptions disclosed in this specification are disclosed in the present application, and that they may be used as a basis for amendment.

[0012] <Thermal spray slurry> One aspect of the present invention is a thermal spray slurry containing a thermal spray powder, a solvent, and an aggregation inhibitor containing a triazine compound. This aspect makes it possible to provide a thermal spray slurry that suppresses the generation of aggregates even when stored for a long period of time.

[0013] (Aggregation inhibitor) The aggregation inhibitor of the present invention contains a triazine compound. The triazine compound is not particularly limited as long as it is a compound containing a six-membered ring structure containing three nitrogen atoms. That is, the triazine compound may contain a triazine ring or a hydrogenated triazine ring, and preferably contains a hexahydrotriazine ring. The positions of the nitrogen atoms in the six-membered ring structure may be 1,2,3 positions, 1,2,4 positions, or 1,3,5 positions. In view of providing a thermal spray slurry that suppresses the generation of aggregates even when the thermal spray slurry is stored for a long period of time, the positions are preferably 1,3,5 positions.

[0014] According to one embodiment of the present invention, the triazine compound has the following formula 1:

[0015] [ka]

[0016] In the above formula 1, R 1 ~R 3 are each independently an alkyl group having 1 to 4 carbon atoms or an acyl group having 2 to 4 carbon atoms, and the alkyl groups may each independently be substituted with at least one substituent selected from the group consisting of a hydroxyl group and an aryl group. This embodiment makes it possible to provide a thermal spray slurry that suppresses the generation of aggregates even when stored for a long period of time.

[0017] The aggregation inhibitor in the present invention has the effect of suppressing the generation of agglomerates (particularly those derived from the thermal spray powder) in the thermal spray slurry, but its effect is not limited to suppressing the generation of agglomerates, and there is no restriction on it having another additional effect.

[0018] According to one embodiment of the present invention, the number of carbon atoms in the alkyl group is 1 to 3, or 1 or 2. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a tert-butyl group.

[0019] According to one embodiment of the present invention, the acyl group is represented by "R-CO-* (* is the bonding position)", where R is an alkyl group having 1 to 3 carbon atoms. The above description of the alkyl group having 1 to 4 carbon atoms can be applied to the alkyl group having 1 to 3 carbon atoms.

[0020] According to one embodiment of the present invention, the number of carbon atoms in the aryl group is 6 to 12, or alternatively 6 to 8. Specific examples of the aryl group include a phenyl group and a naphthyl group.

[0021] In one embodiment of the present invention, when the alkyl group is substituted with a hydroxyl group, i.e., R 1 ~R 3 are each independently a hydroxyalkyl group, specific examples thereof include a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a 2-hydroxybutyl group, and a 4-hydroxybutyl group.

[0022] In one embodiment of the present invention, when the alkyl group is substituted with an aryl group, i.e., R 1 ~R 3 When each of the groups independently represents an arylalkyl group, specific examples thereof include a benzyl group, a phenylethyl group, a phenylpropyl group, and a phenylbutyl group.

[0023] According to one embodiment of the present invention, in the above formula 1, R 1 ~R 3 are each independently selected from the group consisting of an alkyl group, a hydroxyalkyl group, and a benzyl group.

[0024] According to one embodiment of the present invention, the hydroxyalkyl group is a hydroxyethyl group.

[0025] According to one embodiment of the present invention, the aggregation inhibitor is represented by the following formula 2:

[0026] [ka]

[0027] The present invention includes a compound represented by the formula:

[0028] According to one embodiment of the present invention, the aggregation inhibitor comprises at least one selected from the group consisting of 1,3,5-trimethylhexahydro-1,3,5-triazine, 1,3,5-tribenzylhexahydro-1,3,5-triazine, 1,3,5-triacetylhexahydro-1,3,5-triazine and 1,3,5-tributyrylhexahydro-1,3,5-triazine.

[0029] According to one embodiment of the present invention, the aggregation inhibitor may be one type or a combination of two or more types. According to one embodiment of the present invention, the mass concentration of the aggregation inhibitor in the thermal spray slurry is, for example, 0.001 mass% or more, 0.005 mass% or more, 0.01 mass% or more, 0.03 mass% or more, 0.05 mass% or more, or 0.07 mass% or more. When the mass concentration of the aggregation inhibitor in the thermal spray slurry is 0.001 mass% or more, the thermal spray slurry can be provided with long-term storage stability. According to one embodiment of the present invention, the mass concentration of the aggregation inhibitor in the thermal spray slurry is, for example, 3.0 mass% or less, 1.5 mass% or less, 1.0 mass% or less, or 0.08 mass% or less. When the mass concentration of the aggregation inhibitor in the thermal spray slurry is 5.0 mass% or less, the thermal spray slurry can be provided with long-term storage stability.

[0030] Thus, the present invention provides an agglomeration inhibitor for thermal spray slurries, which contains a triazine compound.

[0031] According to one embodiment of the present invention, a compound of formula 1:

[0032] [ka]

[0033] In the above formula 1, R 1 ~R 3and each independently represent an alkyl group having 1 to 4 carbon atoms or an acyl group having 1 to 4 carbon atoms, and the alkyl groups may each independently be substituted with at least one substituent selected from the group consisting of a hydroxyl group and an aryl group. The above description of the coagulation inhibitor can be applied.

[0034] (thermal spray powder) According to one embodiment of the present invention, the thermal spray powder contains spray particles made of ceramics, such as oxide-based ceramics made of oxides of various metals, carbide-based ceramics made of carbides of various metals, nitride-based ceramics made of nitrides of various metals, and non-oxide-based ceramics made of non-oxides such as borides, fluorides, hydroxides, carbonates, and phosphates of various metals.

[0035] The oxide ceramics are not particularly limited and may be oxides of various metals. Metal elements constituting such oxide ceramics include, for example, one or more selected from the following: semimetal elements such as B, Si, Ge, Sb, and Bi; typical metal elements such as Na, Mg, Ca, Sr, Ba, Zn, Al, Ga, In, Sn, Pb, and P; transition metal elements such as Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Ag, and Au; and lanthanoid elements such as La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tu, Yb, and Lu. Among these, one or more elements selected from Mg, Y, Ti, Zr, Cr, Mn, Fe, Zn, Al, Er, and Yb may be used. It is also preferable that the oxide ceramic contains a halogen element such as F, Cl, Br, or I in addition to the above metal elements.

[0036] More specifically, examples of oxide ceramics include alumina, zirconia, yttria, chromia, titania, cobaltite, magnesia, silica, calcia, ceria, ferrite, spinel, zircon, forsterite, steatite, cordierite, mullite, nickel oxide, silver oxide, copper oxide, zinc oxide, gallium oxide, strontium oxide, scandium oxide, samarium oxide, bismuth oxide, lanthanum oxide, lutetium oxide, hafnium oxide, vanadium oxide, niobium oxide, tungsten oxide, manganese oxide, tantalum oxide, terbium oxide, europium oxide, ytterbium oxide, and neodymium oxide. Examples of the rare earth silicate include tin oxide, tin oxide, antimony oxide, antimony-containing tin oxide, indium oxide, barium titanate, lead titanate, lead zirconate titanate, Mn-Zn ferrite, Ni-Zn ferrite, sialon, tin-containing indium oxide, zirconium oxide aluminate, hafnium oxide aluminate, lanthanum oxide aluminate, titanium oxide silicate, zirconium oxide silicate, tantalum oxide silicate, hafnium oxide silicate, yttrium oxide silicate, rare earth silicate, yttrium oxyfluoride, yttrium oxychloride, yttrium oxybromide, yttrium oxyiodide, etc. The rare earth silicate may be a compound represented by RE2SiO7 or RE2SiO5 (RE is a rare earth element). Examples include Yb2Si2O7, Yb2SiO5, ErSi2O7, Er2SiO5, Ho2Si2O7, Ho2SiO5, Dy2Si2O7, Dy2SiO5, Gd2SiO5, Gd2Si2O7, etc. Two or more of these may be appropriately combined to form composite oxide ceramics.

[0037] Examples of non-oxide ceramics include carbide ceramics such as tungsten carbide, chromium carbide, niobium carbide, vanadium carbide, tantalum carbide, titanium carbide, zirconium carbide, hafnium carbide, silicon carbide, and boron carbide; nitride ceramics such as silicon nitride and aluminum nitride; boride ceramics such as hafnium boride, zirconium boride, tantalum boride, and titanium boride; hydroxide ceramics such as hydroxyapatite; and phosphate ceramics such as calcium phosphate.

[0038] According to one embodiment of the present invention, the thermal spray powder contains yttrium oxide (YO) powder. Yttrium oxide (YO) is a preferred material for forming white thermal spray coatings that have environmental barrier properties and erosion resistance to common plasmas. For example, forming a yttrium oxide coating on the anodized surface of a high-purity aluminum alloy processing chamber or processing part surface provides excellent corrosion resistance.

[0039] According to one embodiment of the present invention, the thermal spray powder contains a powder made of a compound containing yttrium (Y) and a halogen element (X). Such a thermal spray powder contributes to the formation of a thermal spray coating with excellent plasma erosion resistance. Typical examples include yttrium fluorides (e.g., yttrium fluoride (YF)), chlorides (e.g., yttrium chloride (YCl)), bromides (e.g., yttrium bromide (YBr)), and iodides (e.g., yttrium iodide (YI)). Furthermore, the compound containing yttrium (Y) and a halogen element is not limited to binary compounds, but may be a ternary or higher compound containing any other element. Ternary or higher compounds are preferred, for example, yttrium oxyhalides containing oxygen (O) as a constituent element. Examples of yttrium oxyhalides include yttrium oxyfluoride, yttrium oxychloride, yttrium oxybromide, and yttrium oxyiodide.

[0040] Yttrium oxyfluoride is particularly preferred in that it can form a thermal spray coating that has excellent plasma erosion resistance against halogen-based plasma. Yttrium oxyfluoride can be a compound containing at least yttrium (Y), oxygen (O), and fluorine (F) as constituent elements. The ratio of yttrium (Y), oxygen (O), and fluorine (F) that constitute this yttrium oxyfluoride is not particularly limited.

[0041] For example, the molar ratio of fluorine to oxygen (F / O) is not particularly limited. As a preferred example, the molar ratio (F / O) may be, for example, 1 or greater than 1. Specifically, it may be, for example, 1, 1.1 or greater, 1.2 or greater, 1.3 or greater, or 1.4 or greater. The upper limit of the molar ratio (F / O) is not particularly limited, and may be, for example, 3 or less, 2 or less, 1.8 or less, or 1.7 or less. As the yttrium oxyfluoride, a compound whose chemical composition is represented by YOF, in which the ratio of yttrium, oxygen, and halogen elements is 1:1:1, is preferred. YOF is preferred because it is relatively thermodynamically stable. In addition, a compound represented by the general formula: YO 1-n F 1+2n (wherein n is, for example, 0.12≦n≦0.22) 17 O 14 F 23 etc. may also be used.

[0042] According to one embodiment of the present invention, the thermal spray powder contains a composite oxide made of yttrium oxide and aluminum oxide. Because composite oxides made of yttrium oxide and aluminum oxide have excellent corrosion resistance and oxidation resistance, they are suitable as coating materials for components made of materials with poor corrosion resistance and oxidation resistance. By appropriately adjusting the mixing ratio of yttrium oxide and aluminum oxide, the composite oxide made of yttrium oxide and aluminum oxide can be made into an yttrium-aluminum double oxide powder such as yttrium aluminum garnet (abbreviated as YAG), yttrium aluminum perovskite (abbreviated as YAP), or yttrium aluminum monoclinic (abbreviated as YAM), or a mixture of yttria powder and alumina powder. YAG, YAM, and YAP can be produced by mixing and firing the following proportions: (Y2O3: 57.1 mass%, Al2O3: 42.9 mass%), (Y2O3: 81.6 mass%, Al2O3: 18.4 mass%), and YAP (Y2O3: 68.9 mass%, Al2O3: 31.1 mass%), respectively.

[0043] According to one embodiment of the present invention, the thermal spray powder includes zirconia (ZrO2) powder doped with yttrium (Y) or calcium (Ca), or their oxides. Thus, according to one embodiment of the present invention, the thermal spray powder includes yttria-stabilized zirconia (YSZ) powder. The concentration (mol %) of yttrium in the Y-stabilized zirconia particles in the yttria-stabilized zirconia (YSZ) powder is defined as follows:

[0044]

number

[0045] The mole percent of yttrium can be determined by X-ray fluorescence (XRF) or any other method known in the art. According to one embodiment of the present invention, the concentration of yttrium in the Y-stabilized zirconia powder, calculated as yttria, can be, for example, 3 mole percent or more, 4 mole percent or more, 5 mole percent or more, 6 mole percent or more, or 7 mole percent or more. According to one embodiment of the present invention, the concentration of yttrium in the Y-stabilized zirconia powder, calculated as yttria, can be, for example, 15 mole percent or less, 13 mole percent or less, 11 mole percent or less, or 9 mole percent or less. According to one embodiment of the present invention, the Y-stabilized zirconia particles comprise a monoclinic phase (e.g., the yttrium in the Y-stabilized zirconia particles is at a concentration sufficient to provide a monoclinic phase). According to one embodiment of the present invention, the Y-stabilized zirconia particles comprise a tetragonal phase (e.g., the yttrium in the Y-stabilized zirconia particles is at a concentration sufficient to provide a tetragonal phase). In some embodiments, the Y-stabilized zirconia particles comprise a cubic phase (eg, the yttrium in the Y-stabilized zirconia particles is in a concentration sufficient to result in a cubic phase).

[0046] According to one embodiment of the present invention, the thermal spray powder contains ytterbium oxide (Yb2O3) powder. Ytterbium oxide has excellent wear resistance in high-temperature environments. Therefore, when used as a coating material by thermal spraying, it exhibits resistance to mechanical stress and friction. In addition, ytterbium oxide is resistant to corrosion, chemically stable, and has high thermal conductivity, making it suitable for use in high-temperature environments.

[0047] According to one embodiment of the present invention, the thermal spray powder contains ytterbium oxide silicate (Yb2Si2O7) powder. When Yb2Si2O7 is used as the rare earth silicate, the SiO component volatilizes during thermal spray coating formation and high-temperature heating, producing Yb2SiO5. Such coatings have excellent resistance in combustion or water vapor environments and can be suitably used, for example, as coatings for aircraft / turbines.

[0048] According to one embodiment of the present invention, the mass concentration of the thermal spray powder in the thermal spray slurry can be determined appropriately taking into consideration the thickness of the thermal spray coating produced from the thermal spray slurry per unit time, i.e., the thermal spray efficiency, and the need for a thermal spray slurry with the required fluidity suitable for good supply to a thermal spraying device, i.e., the required fluidity sufficient for forming a thermal spray coating. The lower limit of the mass concentration of the thermal spray powder in the thermal spray slurry can be, for example, 10 mass% or more, 13 mass% or more, 16 mass% or more, 19 mass% or more, 22 mass% or more, 25 mass% or more, 26 mass% or more, or 27 mass% or more. The upper limit of the mass concentration of the thermal spray powder in the thermal spray slurry can be, for example, 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, or 35 mass% or less.

[0049] According to one embodiment of the present invention, the cumulative 5% particle size (D5) in the volumetric particle size distribution of the thermal spray powder in the thermal spray slurry immediately after preparation may be 0.60 μm or more, 0.80 μm or more, or 1.00 μm or more. According to one embodiment of the present invention, the cumulative 5% particle size (D5) in the volumetric particle size distribution of the thermal spray powder in the thermal spray slurry immediately after preparation may be 2.00 μm or less, 1.50 μm or less, or 1.30 μm or less. The cumulative particle size in the volumetric particle size distribution can be measured by the method described in the Examples.

[0050] According to one embodiment of the present invention, the cumulative 50% particle size (D50) in the volumetric particle size distribution of the thermal spray powder in the thermal spray slurry immediately after preparation may be 2.50 μm or more, 3.00 μm or more, 4.00 μm or more, 5.00 μm or more, or 6.00 μm or more. According to one embodiment of the present invention, the cumulative 50% particle size (D50) in the volumetric particle size distribution of the thermal spray powder in the thermal spray slurry immediately after preparation may be 6.50 μm or less, 6.00 μm or less, or 5.50 μm or less.

[0051] According to one embodiment of the present invention, the cumulative 95% particle size (D95) in the volumetric particle size distribution of the thermal spray powder in the immediately prepared thermal spray slurry may be 5.00 μm or more, 7.00 μm or more, or 9.00 μm or more. According to one embodiment of the present invention, the cumulative 95% particle size (D95) in the volumetric particle size distribution of the thermal spray powder in the immediately prepared thermal spray slurry may be 18.00 μm or less, 16.00 μm or less, or 14.00 μm or less.

[0052] According to one embodiment of the present invention, the cumulative 5% particle size (D5) in the volumetric particle size distribution of the thermal spray powder in the thermal spray powder after storing the thermal spray slurry for 9 months under the conditions described in the examples may be 1.00 μm or more, 1.30 μm or more, or 1.50 μm or more. According to one embodiment of the present invention, the cumulative 5% particle size (D5) in the volumetric particle size distribution of the thermal spray powder in the thermal spray powder after storing the thermal spray slurry for 9 months under the conditions described in the examples may be 3.00 μm or less, 2.00 μm or less, or 1.80 μm or less.

[0053] According to one embodiment of the present invention, the thermal spray powder in the thermal spray powder after storing the thermal spray slurry for 9 months under the conditions described in the examples may have a cumulative 50% particle size (D50) of 2.00 μm or more, 3.00 μm or more, or 4.00 μm or more in the volumetric particle size distribution. According to one embodiment of the present invention, the thermal spray powder in the thermal spray powder after storing the thermal spray slurry for 9 months under the conditions described in the examples may have a cumulative 50% particle size (D50) of 7.00 μm or less, 6.50 μm or less, or 6.00 μm or less in the volumetric particle size distribution.

[0054] According to one embodiment of the present invention, after storing the thermal spray slurry for 9 months under the conditions described in the examples, the thermal spray powder in the thermal spray powder may have a cumulative 95% particle size (D95) of 6.00 μm or more, 7.00 μm or more, or 8.00 μm or more in the volumetric particle size distribution. According to one embodiment of the present invention, after storing the thermal spray slurry for 9 months under the conditions described in the examples, the thermal spray powder in the thermal spray powder may have a cumulative 95% particle size (D95) of 18.00 μm or less, 16.00 μm or less, or 14.00 μm or less in the volumetric particle size distribution.

[0055] The thermal spray slurry of the present invention contains an agglomeration inhibitor. Therefore, even if the thermal spray slurry is stored for an extended period of time, the particle size of the thermal spray powder contained in the thermal spray slurry changes little. In other words, the amount of change in the D5, D50, and D95 ​​values ​​during storage is small. An example of an index representing this amount of change is a value (slope, hereinafter sometimes referred to as "amount of change") calculated using the SLOPE function in Microsoft® Excel®. The SLOPE function returns the slope (b) of a regression line (y = bx + a) through data elements of known y and known x. This slope (b) is the vertical distance between two points on the line divided by the horizontal distance, and corresponds to the rate of change of the regression line. The slope of the regression line is expressed by the following formula (where x is the sample average (known x, storage period of the slurry), and y is the sample average (known y, D5, D50, or D95 value)):

[0056]

number

[0057] According to one embodiment of the present invention, the value of the variation in cumulative 5% particle size (D5) in the volumetric particle size distribution of the thermal spray powder contained in the thermal spray slurry is 0.05 or less, 0.04 or less, or 0.03 or less. According to one embodiment of the present invention, the value of the variation in cumulative 5% particle size (D5) in the volumetric particle size distribution of the thermal spray powder contained in the thermal spray slurry is not limited, but the lower limit is, for example, 0.01.

[0058] According to one embodiment of the present invention, the value of the variation in cumulative 50% particle diameter (D50) in the volumetric particle size distribution of the thermal spray powder contained in the thermal spray slurry is 0.05 or less, 0.04 or less, or 0.03 or less. According to one embodiment of the present invention, the lower limit of the correlation coefficient of cumulative 50% particle diameter (D50) in the volumetric particle size distribution of the thermal spray powder contained in the thermal spray slurry is not limited, but is, for example, 0.01.

[0059] According to one embodiment of the present invention, the value of the variation in cumulative 95% particle diameter (D95) in the volumetric particle size distribution of the thermal spray powder contained in the thermal spray slurry is 0.05 or less, 0.04 or less, or 0.03 or less. According to one embodiment of the present invention, the lower limit of the correlation coefficient of cumulative 95% particle diameter (D95) in the volumetric particle size distribution of the thermal spray powder contained in the thermal spray slurry is not limited, but is, for example, 0.01.

[0060] (solvent) According to one embodiment of the present invention, the solvent contained in the thermal spray slurry may be at least one of an aqueous solvent and a non-aqueous solvent. Note that, in this specification, the term "solvent" refers to a liquid that mediates the thermal spray powder, and may also be referred to as a "dispersion medium."

[0061] The aqueous solvent can be water or a mixture (mixed aqueous solution) of water and a water-soluble organic solvent. Examples of water that can be used include tap water, ion-exchanged water (deionized water), distilled water, and pure water. The organic solvent can be one or more organic solvents that are homogeneously miscible with water (e.g., lower alcohols or lower ketones having 1 to 4 carbon atoms). Suitable examples include organic solvents such as methanol, ethanol, n-propyl alcohol, and isopropyl alcohol. According to one embodiment of the present invention, the mass concentration of water in the aqueous solvent can be, for example, 80% by mass or more, 90% by mass or more, or 95% by mass or more (upper limit: 100% by mass).

[0062] Examples of non-aqueous solvents include organic solvents, such as alcohols such as methanol, ethanol, normal propyl alcohol, and isopropyl alcohol, toluene, and hexane.

[0063] The solvent may be selected appropriately depending on the spraying method of the thermal spray slurry. For example, when the thermal spray slurry is sprayed by a high-velocity flame spraying method, it is also preferable to use an aqueous solvent or a non-aqueous solvent. For example, when the thermal spray slurry is sprayed by high-velocity flame spraying, it is also preferable to use an aqueous solvent. When the thermal spray slurry is plasma sprayed, it is also preferable to use a non-aqueous solvent.

[0064] According to one embodiment of the present invention, the slurry for thermal spraying may contain, for example, a dispersant, a pH adjuster, a viscosity adjuster, a redispersibility improver, an antifoaming agent, an antifreeze agent, an antiseptic, and an antifungal agent. These additives may be used alone or in combination of two or more.

[0065] Therefore, according to one embodiment of the present invention, the thermal spray slurry may contain a dispersant. Here, the dispersant refers to a compound that can improve the dispersion stability of the thermal spray powder in the thermal spray slurry. The dispersant may be anionic, cationic, or nonionic. Examples of anionic dispersants include polycarboxylic acid-based dispersants such as sodium polycarboxylic acid salts, ammonium polycarboxylic acid salts, and polycarboxylic acid-based polymers; naphthalene sulfonic acid-based dispersants such as sodium naphthalene sulfonate and ammonium naphthalene sulfonate; alkyl sulfonic acid-based dispersants; and polyphosphate-based dispersants. Examples of cationic dispersants include polyalkylene polyamine-based dispersants, quaternary ammonium-based dispersants, alkyl polyamine-based dispersants, and imidazoline-based dispersants such as alkyl imidazolines. Examples of nonionic dispersants include alkylene oxide-based dispersants and polyhydric alcohol ester-based dispersants.

[0066] According to one embodiment of the present invention, the pH of the slurry for thermal spraying is not limited, but may be, for example, greater than 7.0 and equal to or less than 10, or 7.5 to 9.5. The pH of the slurry for thermal spraying can be measured in accordance with JIS Z8802:2011 using a glass electrode pH meter (for example, a benchtop pH meter (F-72) manufactured by HORIBA, Ltd.) and a certified pH standard solution (for example, a phthalate pH standard solution (pH: 4.005 / 25°C), a neutral phosphate pH standard solution (pH: 6.865 / 25°C), or a carbonate pH standard solution (pH: 10.012 / 25°C)).

[0067] According to one embodiment of the present invention, the thermal spray slurry can be produced by mixing the thermal spray powder, the solvent, the aggregation inhibitor, and, if necessary, additives such as a dispersant, by a conventionally known method. The order of addition is not particularly limited.

[0068] According to one embodiment of the present invention, the thermal spray slurry can be used as a thermal spray material for forming a thermal spray coating by being supplied to a thermal spraying device based on a known thermal spraying method. Suitable thermal spraying methods for spraying this thermal spray slurry include, for example, plasma spraying and high velocity flame spraying. [Example]

[0069] The present invention will be described in more detail below with reference to examples and comparative examples.

[0070] <Preparation of thermal spray slurry> Example 1 Water as a solvent, yttrium oxyfluoride (YOF: composition ratio YF3-13%YO3) powder as a thermal spray powder, and a dispersant shown in Table 1 were mixed so that the concentration of the thermal spray powder was 30 mass % and the concentration of the dispersant (polycarboxylic acid-based dispersant) was 0.05 mass %, and further, a solution of the compound represented by the following formula 2:

[0071] [ka]

[0072] A thermal spray slurry sample was prepared by mixing the agglomeration inhibitor consisting of the compound represented by the following formula (I) at 0.08 mass %. In order to confirm the agglomeration properties, a sufficient number of thermal spray slurry samples (within the same example) were prepared by carrying out the same procedure as in Example 1.

[0073] For some thermal spray slurry samples, the cumulative 5% particle size (D5), cumulative 50% particle size (D50), and cumulative 95% particle size (D95) of the volumetric particle size distribution were measured using a laser diffraction / scattering particle size analyzer (Spectris Corporation, Malvern Panalytical Division, Mastersizer 3000) within 30 minutes after the slurry was prepared (immediately after preparation). The results are listed in Table 1 under 0M (0 months) for D5, D50, and D95. The thermal spray slurry samples were then placed in a sealed container and stored in a thermostatic chamber at 25°C and 40% humidity for 9 months, after which D5, D50, and D95 ​​were measured again. The results are listed in Table 1 under 9M (9 months) for D5, D50, and D95. In addition, the change in particle size in the thermal spray slurry sample after slurry preparation and after 9 months of storage was calculated using the SLOPE function, and the results are shown in Table 1 as SD5, SD50, and SD95.

[0074] A plurality of thermal spray slurry samples prepared separately by the method of Example 1 were placed in sealed containers immediately after preparation and stored in a thermostatic chamber at a temperature of 25°C and a humidity of 40% (the volume of each thermal spray slurry sample in the container was 500 mL). Then, after the period shown in Table 1 had elapsed, some of the sealed containers containing the thermal spray slurry samples were removed, the lids were opened, and 500 mL of the thermal spray slurry sample was passed through a sieve with 38 μm openings. The presence or absence of aggregates on the sieve was then confirmed using the method described below. The results were evaluated based on the following evaluation indexes and are listed in Table 1.

[0075] <Evaluation method> The aggregates on the mesh were photographed at 50x magnification using an optical microscope (VHX-5000, manufactured by Keyence Corporation) to obtain an image. In the obtained image, any 1000 μm square area was divided into 24, the number of particles that could be confirmed within each divided area was counted, and the average number of particles contained in the 24 divided areas was calculated.

[0076] <Evaluation indicators> ◎: The average number of particles is 1 or less Good: The average number of particles is 5 or less, 2 or more △: The average number of particles is 20 or less and 6 or more ×: The average number of particles exceeds 20.

[0077] Examples of photographs showing results of the cohesion test (visual observation) as ⊚, ◯, △, and × are shown in Figs. 1 to 4, respectively.

[0078] (Comparative Example 1) A thermal spray slurry sample was prepared in the same manner as in Example 1, except that no aggregation inhibitor was added, and the aggregation properties were confirmed.

[0079] Example 2 A thermal spray slurry sample was prepared in the same manner as in Example 1, except that the thermal spray powder was changed to yttria (YO) powder and the D5, D50, and D95 ​​immediately after the slurry preparation were changed to those shown in Table 1, and the cohesion was evaluated. The results are shown in Table 1.

[0080] (Comparative Example 2) Except for not adding the aggregation inhibitor, a thermal spray slurry sample was prepared in the same manner as in Example 2, and the aggregation properties were confirmed. The results are shown in Table 1.

[0081] Example 3 A thermal spray slurry sample was prepared in the same manner as in Example 1, and its cohesion was evaluated, except that the thermal spray powder was changed to yttria-stabilized zirconia (YSZ; composition ratio: ZrO2-8%Y2O3) powder, the D5, D50, and D95 ​​immediately after slurry preparation were changed to those shown in Table 1, and the concentration of the thermal spray powder was changed to 25 mass%. The results are shown in Table 1.

[0082] (Comparative Example 3) Except for not adding the aggregation inhibitor, a thermal spray slurry sample was prepared in the same manner as in Example 3, and the aggregation properties were confirmed. The results are shown in Table 1.

[0083] Example 4 A thermal spray slurry sample was prepared in the same manner as in Example 1, and its cohesion was evaluated, except that the thermal spray powder was changed to yttrium aluminum garnet (YAG; composition ratio: Y2O3-45%Al2O3) powder, and the D5, D50, and D95 ​​values ​​immediately after the slurry preparation were changed to those shown in Table 1. The results are shown in Table 1.

[0084] Comparative Example 4 Except for not adding the aggregation inhibitor, a thermal spray slurry sample was prepared in the same manner as in Example 4, and the aggregation properties were confirmed. The results are shown in Table 1.

[0085] Example 5 A thermal spray slurry sample was prepared in the same manner as in Example 1, except that the thermal spray powder was changed to ytterbium (III) oxide (Yb2O3) powder and the D5, D50, and D95 ​​immediately after slurry preparation were changed to those shown in Table 1, and the cohesion was evaluated. The results are shown in Table 1.

[0086] (Comparative Example 5) Except for not adding the aggregation inhibitor, a thermal spray slurry sample was prepared in the same manner as in Example 5, and the aggregation properties were confirmed. The results are shown in Table 1.

[0087] Example 6 A thermal spray slurry sample was prepared in the same manner as in Example 1, except that the thermal spray powder was changed to Yb2Si2O7 powder (composition: Yb2O3-23%SiO2) and the D5, D50, and D95 ​​immediately after the slurry preparation were changed to those shown in Table 1, and the cohesion was evaluated. The results are shown in Table 1.

[0088] (Comparative Example 6) Except for not adding the aggregation inhibitor, a thermal spray slurry sample was prepared in the same manner as in Example 6, and the aggregation properties were confirmed. The results are shown in Table 1.

[0089] [Table 1]

Claims

1. A thermal spray powder; a solvent; an aggregation inhibitor containing a triazine compound; A thermal spray slurry comprising:

2. The triazine compound is represented by the following formula 1: 【Chemical 1】 In the above formula 1, R １ ~R ３ and each independently represent an alkyl group having 1 to 4 carbon atoms or an acyl group having 2 to 4 carbon atoms, and each of the alkyl groups may be independently substituted with at least one substituent selected from the group consisting of a hydroxyl group and an aryl group.

3. In the above formula 1, R １ ~R ３ The thermal spray slurry according to claim 2 , wherein each of is independently selected from the group consisting of an alkyl group, a hydroxyalkyl group, and a benzyl group.

4. The thermal spray slurry of claim 3 , wherein the hydroxyalkyl group is a hydroxyethyl group.

5. The triazine compound is represented by the following formula 2: 【Chemistry 2】 The thermal spray slurry of claim 1 , wherein

6. A flocculation inhibitor for thermal spray slurries comprising a triazine compound.

7. The triazine compound is Formula 1 below: 【Chemistry 3】 In the above formula 1, R １ ~R ３ and each independently represent an alkyl group having 1 to 4 carbon atoms or an acyl group having 2 to 4 carbon atoms, and each of the alkyl groups may be independently substituted with at least one substituent selected from the group consisting of a hydroxyl group and an aryl group.

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