Coating materials and laminates

Abstract

The present invention provides a functional coating material for the surface of a substrate that is resistant to peeling even when subjected to repeated thermal stress, improves wear resistance, and also has high mechanical strength. The coating material of the present invention is a layered coating material that is to be applied to a substrate, and is characterized by comprising inorganic particles, inorganic fibers, and an inorganic binder.

Description

[Technical Field]

[0001] This invention relates to coating materials and laminates. [Background technology]

[0002] It is known that functional coatings are applied to the surface of a substrate to impart specific functions to its surface.

[0003] For example, a non-stick coating material may be applied to the substrate to improve its liquid-repellent properties or to make it difficult for certain substances to adhere to the substrate's surface.

[0004] Fluorine-containing resins are known as materials for such non-stick coatings. Furthermore, because fluororesins contain PFAS (Per- and PolyFluoroAlkyl Substances), which are not easily decomposed in the environment, they have become subject to regulations in recent years. Furthermore, Non-Patent Documents 1 and 2 describe silicone resins and the like as alternative materials to fluororesins. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] "Development Trends and Performance Evaluation of Non-Fluorine-Based Water-Repellent and Oil-Repellent Technologies," 1st Edition, 1st Printing, April 30, 2025, Published by: Technical Information Association Co., Ltd. [Non-Patent Document 2] "Development Trends of Water-Repellent, Oil-Repellent, and Hydrophilic Materials," First Edition published March 12, 2021, Publisher: CMC Publishing Co., Ltd. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] A non-adhesive coating material (functional coating material) containing a fluororesin or a silicone resin exhibits high non-adhesiveness, but has problems that it peels off from a base material when repeatedly subjected to thermal stress and has low abrasion resistance.

[0007] The present invention has been made to solve the above problems. An object of the present invention is to provide a functional coating material formed on the surface of a base material, which is less likely to peel even when repeatedly subjected to thermal stress, can improve abrasion resistance, and also has high mechanical strength. [Means for Solving the Problems]

[0008] The coating material of the present invention is a layered coating material to be coated on a base material, characterized by comprising inorganic particles, inorganic fibers, and an inorganic binder.

[0009] Since the coating material of the present invention contains inorganic particles and inorganic fibers, friction occurs at the contact points between these components. Therefore, even when stress is applied to the coating material of the present invention, the inorganic particles and the inorganic fibers are less likely to move. That is, the coating material becomes hard as a whole and has high mechanical strength.

[0010] Further, the coating material of the present invention is formed by applying a coating composition containing inorganic particles, inorganic fibers, and an inorganic binder to a base material, and viscosity adjustment of the coating composition containing these components is easy. Therefore, when forming the coating material of the present invention, the coating composition can be easily applied to the base material.

[0011] Furthermore, another functional coating material is formed on the upper layer of the coating material of the present invention. Since the coating material of the present invention contains inorganic particles and inorganic fibers, the surface of the coating material becomes an appropriately roughened surface. Therefore, the adhesion between the coating material of the present invention and the functional coating material is improved. Accordingly, even if the functional coating material is repeatedly subjected to thermal stress, the functional coating material is less likely to peel off. In addition, the abrasion resistance of the functional coating material can also be improved.

[0012] The coating material of the present invention may further contain an organic binder. When the coating material contains an organic binder, the adhesion strength between inorganic particles and inorganic fibers can be improved, and the mechanical strength of the coating material is further enhanced. When the coating material contains an organic binder, it means that during the production of the coating material, the coating material has not been exposed to heat sufficient to thermally decompose the organic binder. Examples of such a coating material include a dried product of a mixture of inorganic particles, inorganic fibers, an inorganic binder and an organic binder.

[0013] In the coating material of the present invention, the coating material is a porous body having a plurality of pores, and it is preferable that at least a part of the pores communicate with each other. As described above, another functional coating material is formed on the upper layer of the coating material of the present invention. When the coating material is a porous body, the coating material has high flexibility, can alleviate volume change even when heated, and is less prone to generate thermal stress. Therefore, another functional coating material formed on the coating material is less likely to peel off.

[0014] In the coating material of the present invention, the porosity of the coating material is preferably 20 to 80%. When the porosity of the coating material is within the above range, thermal stress can be suitably alleviated. When the porosity of the coating material is less than 20%, it becomes difficult to alleviate thermal stress. When the porosity of the coating material exceeds 80%, the mechanical strength of the coating material becomes weak, and the coating material is prone to damage.

[0015] In the coating material of the present invention, the surface roughness Ra of the coating material is preferably 1 to 10 μm. When the surface roughness Ra of the coating material of the present invention falls within the above range, the friction coefficient between the coating material of the present invention and the functional coating material increases. Therefore, the functional coating material is less likely to shift at the interface between the functional coating material and the coating material of the present invention. As a result, the functional coating material becomes less prone to peeling. That is, the wear resistance of the functional coating material can be further improved.

[0016] In the coating material of the present invention, the inorganic particles comprise fine particles and an average particle diameter larger than that of the fine particles (D 50 ) that is larger than that of the fine particles. It is preferable that the inorganic particles contain coarse particles When the coating material of the present invention contains fine particles and coarse particles, the fine particles can enter between the coarse particles, thereby increasing the contact area between the inorganic particles. In this case, the inorganic particles are less likely to shift relative to each other, and the mechanical strength of the coating material of the present invention is improved.

[0017] In the coating material of the present invention, the average particle diameter of the fine particles (D 50 ) of the coarse particles relative to the average particle diameter (D 50 ) ratio ([average particle diameter of coarse particles (D 50 )] / [average particle diameter of fine particles (D 50 )]) is preferably 2 to 470. average particle diameter of fine particles (D 50 ) of the coarse particles relative to the average particle diameter (D 50 ) when the ratio falls within the above range, the mechanical strength of the coating material is further improved.

[0018] In the coating material of the present invention, the weight ratio of the coarse particles to the fine particles ([weight of coarse particles] / [weight of fine particles]) is preferably 10 to 90 wt%. When the weight ratio of coarse particles to fine particles falls within the above range, the mechanical strength of the coating material is further improved.

[0019] In the coating material of the present invention, the inorganic particles have an average particle diameter (D 50 ) of 0.2 to 4 µm. It is preferable that the inorganic particles include fine particles The inorganic particles have an average particle diameter (D 50Including fine particles with a size of 0.2 to 4 μm allows the porosity and mechanical strength of the coating material to be within a suitable range.

[0020] In the coating material of the present invention, the inorganic particles have an average particle size (D) that is smaller than the fine particles. 50 Preferably, the mixture further contains coarse particles with larger sizes. When a coating material contains both fine and coarse particles, the fine particles can fill the spaces between the coarse particles, increasing the contact area between the inorganic particles. In this case, the inorganic particles become less likely to shift from one another, improving the mechanical strength of the coating material.

[0021] In the coating material of the present invention, the inorganic particles have an average particle diameter (D 50 It is preferable that the material contains coarse particles with a diameter of 4 to 150 μm. Inorganic particles have an average particle diameter (D 50 Including coarse particles with a size of 4 to 150 μm allows the porosity and mechanical strength of the coating material to be within a suitable range.

[0022] In the coating material of the present invention, the inorganic particles have an average particle size (D) that is smaller than the coarse particles. 50 Preferably, the material further contains small fine particles. When a coating material contains both fine and coarse particles, the fine particles can fill the spaces between the coarse particles, increasing the contact area between the inorganic particles. In this case, the inorganic particles become less likely to shift from one another, improving the mechanical strength of the coating material.

[0023] In the coating material of the present invention, it is preferable that the inorganic particles include at least one selected from the group consisting of silicon carbide, silicon oxide, aluminum oxide, silicon nitride, and boron nitride. Silicon carbide, silicon oxide, aluminum oxide, silicon nitride, and boron nitride are hard and strong. Therefore, when inorganic particles contain these materials, the mechanical strength of the coating material of the present invention is further improved. Furthermore, since these inorganic particles are stable substances, the chemical resistance of the coating material of the present invention is improved. In addition, since these inorganic particles undergo little volume change with temperature, thermal stress is less likely to occur in the coating material of the present invention. Therefore, the coating material of the present invention becomes less susceptible to damage due to heat, and its heat resistance is improved.

[0024] In the coating material of the present invention, it is preferable that the ends of some of the inorganic fibers are exposed so as to protrude from the surface of the coating material. When another functional coating material is formed on top of the coating material of the present invention, the ends of the inorganic fibers protruding from the surface of the coating material will be located inside the functional coating material. Therefore, even when stress is applied to the coating material of the present invention and the functional coating material, the inorganic fibers act as support, making it difficult for the coating material of the present invention and the functional coating material to peel off.

[0025] In the coating material of the present invention, it is preferable that the inorganic fiber includes at least one selected from the group consisting of alumina, silica, mullite, aluminum borate, and biosoluble materials. The mechanical strength of the coating material of the present invention can be improved by including inorganic fibers such as alumina, silica, mullite, and aluminum borate. Furthermore, if the inorganic fibers contain biosoluble materials, even if a living organism inhales the inorganic fibers during the manufacturing of the laminate of the present invention, no health damage will occur.

[0026] In the coating material of the present invention, it is preferable that the weight ratio of the inorganic particles, inorganic fibers, and inorganic binder ([weight of inorganic particles]:[inorganic fibers]:[inorganic binder]) = 10 to 90:1 to 70:1 to 20. When the weight ratio of inorganic particles, inorganic fibers, and inorganic binder is within the above range, the adhesion of the coating material of the present invention to the substrate is further improved. In addition, the mechanical strength of the coating material of the present invention is further improved.

[0027] The coating material of the present invention is preferably used as the first coating layer in a laminate in which a substrate, a first coating layer, and a second coating layer are sequentially laminated. In this case, the first coating layer exhibits increased adhesion to the substrate and also higher mechanical strength. Furthermore, since the first coating layer contains inorganic particles and inorganic fibers, the surface of the first coating layer becomes moderately roughened. As a result, the adhesion between the first coating layer and the second coating layer is improved. Therefore, even if the second coating layer is subjected to repeated thermal stress, the functional coating material becomes less likely to peel off. Furthermore, the abrasion resistance of the second coating layer can also be improved.

[0028] The laminate of the present invention is characterized in that a substrate and a first coating layer made of the coating material of the present invention are laminated in order.

[0029] As described above, the coating material of the present invention exhibits high adhesion to the substrate and high mechanical strength. Therefore, in the laminate of the present invention, if the first coating layer is the coating material of the present invention, the first coating layer will have higher adhesion to the substrate and also higher mechanical strength.

[0030] In the laminate of the present invention, it is preferable that a second coat layer is further laminated on top of the first coat layer. In the laminate of the present invention, since the first coat layer is the coating material of the present invention, the adhesion between the first coat layer and the second coat layer is improved. Therefore, even if the second coat layer is repeatedly subjected to thermal stress, it becomes less likely to peel off. Furthermore, the abrasion resistance of the second coat layer can also be improved.

[0031] In the laminate of the present invention, the second coating layer preferably contains at least one material selected from the group consisting of ceramic materials, metal materials, carbon materials, silicon materials, resin materials, and organic materials. Even if the second coat layer is made of these materials, the first coat layer will adhere firmly to the second coat layer. In other words, it is possible to obtain the effect of improving the wear resistance of the second coating layer.

[0032] In the laminate of the present invention, it is preferable that the ends of the inorganic fibers protrude from the surface of the first coating layer, and that some of the ends of the inorganic fibers are located inside the second coating layer. In such a laminate, even when stress is applied to the first and second coat layers, the inorganic fibers provide support, making it difficult for the first and second coat layers to separate. [Effects of the Invention]

[0033] According to the present invention, it is possible to provide a functional coating material formed on the surface of a substrate that is resistant to peeling even when subjected to repeated thermal stress, has improved abrasion resistance, and also has high mechanical strength. [Brief explanation of the drawing]

[0034] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of the laminate of the present invention. [Figure 2] Figure 2 is a graph showing the relationship between the weight ratio (wt%) of coarse particles, density (g / cm3), and weight loss percentage (%) of the first coat layer relative to the total weight of inorganic particles in the example. [Modes for carrying out the invention]

[0035] The coating material and laminate of the present invention will be described in detail below. However, the present invention is not limited to the following configurations and can be modified and applied as appropriate without changing the gist of the invention. Furthermore, a combination of two or more of the individual preferred configurations of the present invention described below also constitutes the present invention.

[0036] Figure 1 is a schematic cross-sectional view showing an example of the laminate of the present invention. As shown in Figure 1, the laminate 10 of the present invention is constructed by sequentially laminating a base material 20, a first coating layer 30, and a second coating layer 40. Such a first coating layer 30 is also one embodiment of the coating material of the present invention. The following details each component.

[0037] (First coat layer) The first coating layer 30 is a layered coating material containing inorganic particles, inorganic fibers, and an inorganic binder.

[0038] Since the first coating layer 30 contains inorganic particles and inorganic fibers, friction occurs at their contact points. Therefore, even if stress is applied to the coating material of the present invention, the inorganic particles and inorganic fibers are less likely to move. In other words, the coating material as a whole becomes harder and its mechanical strength increases.

[0039] Since the first coating layer 30 contains inorganic particles and inorganic fibers, the surface of the first coating layer becomes a moderately roughened surface. As a result, the adhesion between the first coating layer 30 and the second coating layer 40 is improved. Therefore, even if the second coat layer is repeatedly subjected to thermal stress, it becomes less likely to peel off. Furthermore, the abrasion resistance of the second coat layer can also be improved.

[0040] The first coating layer 30 may be a dried or fired body of a composition containing inorganic particles, inorganic fibers, and an inorganic binder.

[0041] The first coating layer 30 may further contain an organic binder. When the first coating layer 30 contains an organic binder, the adhesive strength of the inorganic particles and inorganic fibers can be improved, and the mechanical strength of the first coating layer 30 is further enhanced. Furthermore, if the first coating layer 30 contains an organic binder, it means that when the laminate 10 is manufactured, the first coating layer 30 is not subjected to heat that would cause the organic binder to decompose. Examples of such a first coating layer 30 include a dried mixture of inorganic particles, inorganic fibers, an inorganic binder, and an organic binder.

[0042] The density of the first coating layer 30 is 0.5 to 5.0 g / cm³. 3 Preferably, it is 1.0 to 3.0 g / cm³. 3It is preferable that it be so. When the density of the first coating layer 30 is within the above range, the mechanical strength of the first coating layer 30 increases.

[0043] The first coating layer 30 is a porous material having multiple pores, and it is preferable that at least some of these pores are in communication with each other. When the first coating layer 30 is a porous material, the first coating layer 30 is highly flexible, and even when heat is applied, it can mitigate volume changes and is less likely to generate thermal stress. Therefore, the second coating layer 40 formed on top of the first coating layer 30 is less likely to peel off.

[0044] The porosity of the first coat layer 30 is preferably 20-80%, and more preferably 30-50%. If the porosity of the first coat layer 30 is within the above range, thermal stress can be suitably relieved. If the porosity of the first coat layer is less than 20%, it becomes difficult to relieve thermal stress. If the porosity of the first coat layer exceeds 80%, the mechanical strength of the first coat layer weakens, making it more susceptible to damage.

[0045] The porosity of the first coat layer 30 can be calculated from the weight and density of the material constituting the first coat layer and the volume (apparent volume) of the first coat layer based on the following formula (1). Porosity of the first coat layer (%) = 100 × [1 - {(Total weight of the material constituting the first coat layer) × (Logical density of the material constituting the first coat layer)] -1 / (Volume of the first coat layer)}]···(1) Note that in equation (1), "logical density of the material constituting the first coat layer" refers to the logical density when no pores are formed in the first coat layer.

[0046] The inorganic particles constituting the first coating layer 30 include silicon carbide, silicon oxide, aluminum oxide, silicon nitride, boron nitride, and the like. Silicon carbide, silicon oxide, aluminum oxide, silicon nitride, and boron nitride are hard and strong. Therefore, when inorganic particles contain these materials, the mechanical strength of the first coating layer 30 is further improved. Furthermore, since these inorganic particles are stable materials, the chemical resistance of the first coating layer 30 is improved. In addition, since these inorganic particles undergo little volume change with temperature, thermal stress is less likely to occur in the first coating layer 30. As a result, the first coating layer 30 becomes less susceptible to damage from heat, improving its heat resistance.

[0047] In the first coating layer 30, the inorganic particles consist of fine particles and particles with an average particle diameter (D) that is larger than the fine particles. 50 It is preferable that the particles include coarse particles with larger sizes. When the first coating layer 30 contains both fine and coarse particles, the fine particles can penetrate between the coarse particles, thereby increasing the contact area between the inorganic particles. In this case, the inorganic particles are less likely to shift from one another, and the mechanical strength (rigidity, deformation resistance, etc.) of the first coating layer 30 is improved compared to the case where only coarse inorganic particles are included.

[0048] The weight ratio of coarse particles to the total weight of inorganic particles may be 60 wt% or less. When the proportion of coarse particles in inorganic particles decreases, the density of the first coat layer increases, and the mechanical strength of the first coat layer improves. When the proportion of coarse particles in inorganic materials increases, the porosity of the first coat layer increases, and the proportion of air in the first coat layer increases. As a result, the thermal insulation of the first coat layer improves. In addition, when the proportion of coarse particles in inorganic materials increases, the manufacturing cost of the first coat layer decreases. In other words, the weight ratio of coarse particles is preferably set appropriately according to the purpose of the first coating layer.

[0049] In the first coating layer 30, the average particle size (D) of the above fine particles 50 ) with respect to the average particle diameter (D 50 ) ratio ([average particle size of coarse particles (D 50 )] / [Average particle size of fine particles (D50 )]) is preferably 2 to 470, and more preferably 3 to 40. Average particle size of fine particles (D 50 ) with respect to the average particle size of coarse particles (D 50 When the ratio of ) is within the above range, the mechanical strength of the coating material is further improved.

[0050] Average particle size of coarse particles (D 50 The particle size is preferably 4 to 150 μm, more preferably 8 to 125 μm, and even more preferably 10 to 30 μm. Average particle size of fine particles (D 50 The particle size is preferably 0.2 to 4 μm, and more preferably 0.8 to 3.2 μm.

[0051] Average particle size of coarse particles (D 50 ) and the average particle size of the fine particles (D 50 ) can be measured by laser diffraction and scattering methods.

[0052] If the inorganic particles include fine particles and coarse particles, the fine particles and coarse particles may be composed of the same material or of different materials. The first coating layer 30 may contain only coarse particles or only fine particles.

[0053] If the inorganic particles include fine particles and coarse particles, the fine particles and coarse particles may be composed of the same material or of different materials.

[0054] In the first coating layer 30, there may be only one peak in the particle size distribution of inorganic particles, or there may be two or more. For example, if there are two peaks in the particle size distribution of inorganic particles, one may be classified as a coarse particle and the other as a fine particle. Furthermore, in the first coating layer 30, the particle size distribution of inorganic particles may have two or more peaks in the range of 0.2 to 4 μm, and may also have two or more peaks in the range of 4 to 150 μm.

[0055] The weight percentage of inorganic particles contained in the first coating layer 30 is preferably 10 to 90 wt%, and more preferably 20 to 70 wt%.

[0056] The inorganic fibers constituting the first coating layer 30 include alumina, silica, mullite, aluminum borate, and biosoluble materials. If the inorganic fibers include alumina, silica, mullite, and aluminum borate, the mechanical strength of the first coating layer 30 can be improved. Furthermore, if the inorganic fibers contain biosoluble materials, even if a living organism inhales the inorganic fibers during the manufacturing of the laminate of the present invention, no health damage will occur. The first coating layer 30 may contain one type of inorganic fiber, or it may contain two or more types of inorganic fibers.

[0057] The average length of the inorganic fibers is preferably 10 to 100 μm, and more preferably 20 to 70 μm. The average diameter of the inorganic fibers is preferably 1 to 10 μm, and more preferably 3 to 7 μm.

[0058] In the first coating layer 30, it is preferable that the ends of some of the inorganic fibers are exposed so as to protrude from the surface of the first coating layer 30. In this case, the ends of the inorganic fibers protruding from the surface of the first coating layer 30 will be located inside the second coating layer 40. In such a laminate 10, even when stress is applied to the first coat layer 30 and the second coat layer 40, the inorganic fibers provide support, making it difficult for the first coat layer 30 and the second coat layer 40 to peel off.

[0059] The weight percentage of inorganic fibers contained in the first coating layer 30 is preferably 1 to 70 wt%, and more preferably 1 to 50 wt%.

[0060] As the inorganic binder included in the first coat layer 30, silica sol, alumina sol, aluminum phosphate, borate, zirconia sol, titania sol, etc., can be used. The inclusion of an inorganic binder in the first coating layer 30 makes the first coating layer 30 harder, improving its mechanical strength.

[0061] The weight percentage of the inorganic binder contained in the first coat layer 30 is preferably 1 to 30 wt%, and more preferably 10 to 20 wt%.

[0062] The first coating layer 30 may further contain an organic binder. The organic binder included in the first coat layer 30 can be methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyethylene glycol, phenolic resin, epoxy resin, polyvinyl alcohol, etc. The inclusion of an organic binder in the first coating layer 30 ensures that the first coating layer 30 adheres firmly to the substrate 20.

[0063] When the first coating layer 30 contains an organic binder, the adhesive strength of the inorganic particles and inorganic fibers can be improved, and the mechanical strength of the first coating layer 30 is further enhanced. Furthermore, if the first coating layer 30 contains an organic binder, it means that when the laminate 10 is manufactured, the first coating layer 30 is not subjected to heat that would cause the organic binder to decompose. Examples of such a first coating layer 30 include a dried mixture of inorganic particles, inorganic fibers, an inorganic binder, and an organic binder.

[0064] The weight percentage of the organic binder contained in the first coat layer 30 is preferably 0.1 to 10 wt%, and more preferably 0.1 to 5 wt%.

[0065] In the first coating layer 30, the weight ratio of inorganic particles, inorganic fibers, and inorganic binder ([weight of inorganic particles]:[inorganic fibers]:[inorganic binder]) is preferably 10 to 90:1 to 70:1 to 20, and more preferably 20 to 70:1 to 50:1 to 10. When the weight ratio of inorganic particles, inorganic fibers, and inorganic binder is within the above range, the adhesion of the first coating layer 30 to the substrate 20 is further improved. In addition, the mechanical strength of the first coating layer 30 is further improved.

[0066] The first coating layer 30 may also contain other components such as plasticizers, lubricants, pH adjusters, and surfactants.

[0067] (Second coat layer) The second coating layer 40 is preferably made of a functional coating material. Examples of functional coating materials include non-adhesive coatings, conductive coatings, insulating coatings, corrosion-resistant coatings, water-resistant coatings, antibacterial coatings, and antiviral coatings.

[0068] The second coating layer 40 may contain ceramic materials, metal materials, carbon materials, silicon materials, resin materials, and organic materials, etc. Even if the second coat layer 40 is made of these materials, the first coat layer 30 adheres firmly to the second coat layer 40. In other words, it is possible to obtain the effect of improving the wear resistance of the second coating layer 40.

[0069] Examples of ceramic materials constituting the second coating layer 40 include oxide ceramic materials such as silicon oxide, aluminum oxide, titanium oxide, and zirconium oxide; nitride ceramic materials such as titanium nitride and zirconium nitride; and carbide ceramics such as silicon carbide and boron carbide.

[0070] Examples of metal materials that make up the second coating layer 40 include copper, aluminum, and stainless steel.

[0071] Examples of carbon materials that make up the second coating layer 40 include diamond-like carbon and carbon nanotubes.

[0072] Examples of silicon materials constituting the second coating layer 40 include silicon oxide, silicon carbide, and polysilane.

[0073] Examples of resin materials constituting the second coating layer 40 include acrylic resin, urethane resin, fluororesin, and silicone resin.

[0074] (base material) The base material 20 may be composed of materials such as metal materials, ceramic materials, glass materials, or resin materials. The first coating layer 30 can adhere firmly to the substrate 20, which is composed of these materials.

[0075] The base material 20 may be used in parts prone to thermal stress, such as molds, industrial rolls, machine parts, sliding parts, and engine parts. As explained above, since the second coat layer 40 is formed on top of the first coat layer 30 of the laminate 10, the second coat layer 40 is less likely to peel off even if repeated thermal stress is applied to it.

[0076] Next, the method for manufacturing the laminate of the present invention will be described.

[0077] (Preparing materials) First, prepare the substrate, the composition for forming the first coat layer, and the composition for forming the second coat layer.

[0078] The composition for forming the first coating layer comprises inorganic particles, inorganic fibers, and an inorganic binder. The composition may optionally contain an organic binder. The preferred materials for inorganic particles, inorganic fibers, and inorganic binders are as described above, so their explanation is omitted here.

[0079] The composition for forming the first coating layer may contain, in addition to inorganic particles, inorganic fibers, inorganic binders, and organic binders, water, viscosity modifiers, plasticizers, lubricants, and the like.

[0080] The composition for forming the first coat layer, which contains these materials, is easy to adjust in viscosity. As will be described later, the composition for forming the first coat layer will be applied to the substrate. It is preferable to adjust the viscosity of the composition for forming the first coat layer so that it can be applied properly.

[0081] As described above, the second coating layer is preferably a functional coating material. As the composition for forming the second coating layer, a conventionally known composition for forming a functional coating material can be used.

[0082] The materials used for the base material are as described above, so we will omit further explanation here.

[0083] (Application of the composition for forming the first coat layer) Next, a composition for forming the first coat layer is applied to the surface of the substrate. Note that a primer treatment may be performed on the surface of the substrate before this application.

[0084] The composition for forming the first coat layer may be applied with a brush or with a coater. Examples of coaters include roll coaters, spin coaters, dip coaters, and slit coaters.

[0085] (Drying of the composition for forming the first coat layer) Subsequently, the composition for forming the first coat layer is dried to obtain the first coat layer. The drying conditions are not particularly limited, but examples include drying at 25-700°C for 30-120 minutes.

[0086] Furthermore, the first coat layer may be fired if necessary. Although the organic binder decomposes due to the firing process, the dehydration condensation of the silica sol is promoted, which can improve the mechanical strength of the first coat layer.

[0087] Furthermore, a laminate in which a first coating layer is formed on the surface of a substrate is also one embodiment of the present invention. The laminate, in which a first coat layer is formed on the surface of the substrate, may be transported to another location, and a second coat layer may be formed on the surface of the first coat layer.

[0088] The surface roughness Ra of the first coating layer formed in this manner is preferably 1 to 10 μm, and more preferably 2 to 8 μm. When the surface roughness Ra of the first coat layer is within the above range, the coefficient of friction between the first and second coat layers increases. As a result, the second coat layer becomes less likely to shift at the interface between the first and second coat layers. Consequently, the second coat layer becomes less likely to peel off. In other words, the wear resistance of the second coat layer can be further improved.

[0089] The surface roughness Ra is an arithmetic mean roughness measured according to JIS B 0601:2001, and can be measured, for example, using HANDYSURF [(manufactured by Tokyo Seimitsu Co., Ltd.)]. In this specification, the surface roughness Ra of the first coat layer refers to the average value of three measurements taken of the surface of the first coat layer in accordance with JIS B 0601:2001.

[0090] (Application of the composition for forming the second coat layer) Next, a composition for forming the second coat layer is applied to the surface of the first coat layer. The composition for forming the second coat layer may be applied with a brush or with a coater. Examples of coaters include roll coaters, spin coaters, dip coaters, and slit coaters.

[0091] If the ends of the inorganic fibers protrude from the surface of the first coating layer, the composition for forming the second coating layer will come into contact with the surface of these inorganic fibers.

[0092] Furthermore, if the first coat layer is a porous material having multiple pores, applying the composition for forming the second coat layer causes the composition for forming the second coat layer to impregnate the pores of the first coat layer.

[0093] In such cases, when the second coat layer is formed through a subsequent process, the adhesion between the first coat layer and the second coat layer is improved.

[0094] (Drying and firing of the composition for forming the second coat layer) Subsequently, the composition for forming the second coat layer is dried to form the second coat layer. The second coat layer may also be fired if necessary.

[0095] Through the above process, a laminate of the present invention can be manufactured, in which a base material, a first coating layer, and a second coating layer are sequentially laminated.

[0096] This specification contains the following information:

[0097] (1) of this disclosure is a layered coating material to be applied to a substrate, characterized in that it comprises inorganic particles, inorganic fibers, and an inorganic binder.

[0098] Disclosure (2) is the coating material described in Disclosure (1), further comprising an organic binder.

[0099] Disclosure (3) is the coating material according to Disclosure (1) or (2), wherein the coating material is a porous body having a plurality of pores, and at least some of the pores are in communication with each other.

[0100] This disclosure (4) is the coating material described in this disclosure (3), wherein the porosity of the coating material is 20 to 80%.

[0101] Disclosure (5) is a coating material according to any one of Disclosures (1) to (4), wherein the surface roughness Ra of the coating material is 1 to 10 μm.

[0102] This disclosure (6) states that the inorganic particles are fine particles and have an average particle diameter (D) that is larger than the fine particles. 50 The coating material is one of the materials described in any of (1) to (5) of this disclosure, which includes coarse particles with large size.

[0103] This disclosure (7) specifies the average particle size (D) of the fine particles. 50 ) with respect to the average particle diameter (D 50 ) ratio ([average particle size of coarse particles (D 50 )] / [Average particle size of fine particles (D 50 The coating material described in (6) of this disclosure is such that )) is 2 to 470.

[0104] Disclosure (8) is a coating material according to Disclosure (6) or (7), wherein the weight ratio of coarse particles to fine particles ([weight of coarse particles] / [weight of fine particles]) is 10 to 90 wt%.

[0105] This disclosure (9) states that the inorganic particles have an average particle diameter (D 50 The coating material is one of the descriptions (1) to (5) of this disclosure and contains fine particles having a diameter of 0.2 to 4 μm.

[0106] This disclosure (10) states that the inorganic particles have an average particle diameter (D) greater than the fine particles. 50 The coating material according to disclosure (9) further contains coarse particles with larger size.

[0107] This disclosure (11) states that the inorganic particles have an average particle diameter (D 50 The coating material is one of the claims (1) to (5) of this disclosure and contains coarse particles having a diameter of 4 to 150 μm.

[0108] This disclosure (12) states that the inorganic particles have an average particle diameter (D) greater than the coarse particles. 50 The coating material described in (11) further comprises small fine particles.

[0109] Disclosure (13) is a coating material according to any one of Disclosures (1) to (12), wherein the inorganic particles include at least one selected from the group consisting of silicon carbide, silicon oxide, aluminum oxide, silicon nitride, and boron nitride.

[0110] Disclosure (14) is a coating material according to any of Disclosures (1) to (13), wherein the ends of some of the inorganic fibers are exposed so as to protrude from the surface of the coating material.

[0111] This disclosure (15) is a coating material according to any one of disclosures (1) to (14) wherein the inorganic fiber comprises at least one selected from the group consisting of alumina, silica, mullite, aluminum borate, and biosoluble materials.

[0112] Disclosure (16) is a coating material according to any of Disclosures (1) to (15), wherein the weight ratio of the inorganic particles, the inorganic fibers, and the inorganic binder ([weight of inorganic particles]:[inorganic fibers]:[inorganic binder]) = 10 to 90:1 to 70:1 to 20.

[0113] The present disclosure (17) is a coating material according to any one of the present disclosures (1) to (16) used as the first coating layer in a laminate in which a substrate, a first coating layer, and a second coating layer are sequentially laminated.

[0114] The present disclosure (18) is a laminate characterized in that a substrate and a first coating layer made of a coating material described in any of the present disclosures (1) to (16) are sequentially laminated.

[0115] The present disclosure (19) is a laminate according to the present disclosure (18), wherein a second coat layer is further laminated on the first coat layer.

[0116] The present disclosure (20) is a laminate according to the present disclosure (19), wherein the second coating layer comprises at least one selected from the group consisting of ceramic materials, metal materials, carbon materials, silicon materials, resin materials, and organic materials.

[0117] The present disclosure (21) is a laminate according to the present disclosure (19) or (20), wherein the ends of inorganic fibers protrude from the surface of the first coating layer, and some of the ends of the inorganic fibers are located inside the second coating layer. [Examples]

[0118] The following are examples that more specifically disclose the present invention. However, the present invention is not limited to these examples.

[0119] (Example 1) Silicon carbide - fine particles (average particle size (D 50 A composition for forming the first coat layer was prepared by mixing 35 parts by weight of (1.5 μm), 30 parts by weight of biosoluble fibers (average length: 60 μm, average diameter: 6 μm), 15 parts by weight of silica sol, 0.5 parts by weight of carboxymethylcellulose, 2 parts by weight of polyvinyl alcohol, 0.1 parts by weight of lactic acid, and 17 parts by weight of ion-exchanged water. In addition, a 1mm thick ceramic plate was prepared as the base material.

[0120] Next, a composition for forming a first coat layer was applied to the surface of the substrate using a coater. In this process, the thickness of the composition for forming the first coating layer was set to 2 mm.

[0121] Subsequently, drying was performed at 120°C for 1 hour to form the first coating layer according to Example 1 on the surface of the substrate.

[0122] The surface roughness Ra of the formed first coating layer was measured according to JIS B 0601:2001 and was found to be 3.05 μm.

[0123] The volume of the formed first coat layer was measured, and the density and porosity of the first coat layer were calculated from the total weight of the materials constituting the first coat layer and the logical density of the materials constituting the first coat layer. The results are shown in Table 1.

[0124] (Examples 2) to (Examples 7) and (Comparative Example 1) Except for changing the proportions of each material as shown in Table 1, the first coating layers according to Examples 2 to 7 and Comparative Example 1 were formed in the same manner as in Example 1. Note that the composition values ​​in Table 1 refer to "parts by weight".

[0125] [Table 1]

[0126] (Rubbing test) Using a simple reciprocating abrasion tester (manufacturer: AS ONE Corporation, model number: 4-4557-01), a bit was brought into contact with the surface of the first coat layer in each example and comparative example, and the bit was moved back and forth under the following conditions. The weight loss of the first coat layer was measured, and the weight loss percentage (%) of the first coat layer was calculated. The results are shown in Table 1. Furthermore, the weight ratio (wt%) of coarse particles to the total weight of inorganic particles and the density (g / cm³) of the first coating layer in Examples 1 to 4 are also provided. 3 Figure 2 shows a graph plotting the weight loss percentage (%) and the percentage of weight reduction. Figure 2 shows the weight ratio (wt%) of coarse particles to the total weight of inorganic particles in the first coat layer according to the example, and the density (g / cm³). 3 This graph shows the relationship between weight and weight reduction percentage (%).

[0127] <Conditions for the rubbing test> Bit: Diamond bit, spherical shape (diameter: 5mm) Weight: 100g Travel stroke: 22mm (44mm round trip) Movement speed: 40 round trips / min Number of rubbing strokes (back and forth): 50

[0128] As shown in Table 1, the first coating layer in each example, which includes inorganic particles, inorganic fibers, and an inorganic binder, was found to have a small weight loss in the rubbing test. This is thought to be because the first coating layer in each example has high mechanical strength and is resistant to wear.

[0129] Furthermore, as shown in Table 1 and Figure 2, it was found that a higher density in the first coat layer resulted in less weight loss in the rubbing test. [Explanation of Symbols]

[0130] 10 Laminate 20 Base material 30. First coat layer 40. Second coat layer

Claims

1. A layered coating material that will be applied to a substrate, It comprises inorganic particles, inorganic fibers, and an inorganic binder. The coating material is a porous body having a plurality of pores, and is characterized in that at least some of the pores are in communication with each other.

2. The coating material according to claim 1, further comprising an organic binder.

3. The coating material according to claim 1 or 2, wherein the porosity of the coating material is 20 to 80%.

4. The coating material according to claim 1 or 2, wherein the surface roughness Ra of the coating material is 1 to 10 μm.

5. The inorganic particles consist of fine particles and an average particle diameter (D) that is larger than the fine particles. ５０ The coating material according to claim 1 or 2, comprising large coarse particles.

6. The average particle size (D) of the aforementioned fine particles ５０ ) with respect to the average particle diameter (D ５０ ) ratio ([average particle size of coarse particles (D ５０ )] / [Average particle size of fine particles (D ５０ The coating material according to claim 5, wherein the value of the )) is 2 to 470.

7. The coating material according to claim 5, wherein the weight ratio of the coarse particles to the fine particles ([weight of coarse particles] / [weight of fine particles]) is 10 to 90 wt%.

8. The inorganic particles have an average particle diameter (D ５０ The coating material according to claim 1 or 2, comprising fine particles having a diameter of 0.2 to 4 μm.

9. The inorganic particles have a larger average particle size (D) than the fine particles. ５０ The coating material according to claim 8, further comprising coarse particles with larger size.

10. The inorganic particles have an average particle diameter (D ５０ The coating material according to claim 1 or 2, comprising coarse particles having a diameter of 4 to 150 μm.

11. The inorganic particles further comprise fine particles having an average particle diameter (D ５０ ) smaller than that of the coarse particles, according to claim 10. The coating material

12. The coating material according to claim 1 or 2, wherein the inorganic particles include at least one selected from the group consisting of silicon carbide, silicon oxide, aluminum oxide, silicon nitride, and boron nitride.

13. The coating material according to claim 1 or 2, wherein some of the ends of the inorganic fibers are exposed so as to protrude from the surface of the coating material.

14. The coating material according to claim 1 or 2, wherein the inorganic fiber comprises at least one selected from the group consisting of alumina, silica, mullite, aluminum borate, and biosoluble materials.

15. The coating material according to claim 1 or 2, wherein the weight ratio of the inorganic particles, the inorganic fibers, and the inorganic binder ([weight of inorganic particles]:[inorganic fibers]:[inorganic binder]) = 10 to 90:1 to 70:1 to 20.

16. A coating material according to claim 1 or 2, used as the first coating layer in a laminate in which a base material, a first coating layer, and a second coating layer are sequentially laminated.

17. A laminate characterized by having a base material and a first coating layer made of the coating material described in claim 1 or 2, laminated in order.

18. The laminate according to claim 17, wherein a second coat layer is further laminated on the first coat layer.

19. The laminate according to claim 18, wherein the second coating layer comprises at least one selected from the group consisting of ceramic materials, metal materials, carbon materials, silicon materials, resin materials, and organic materials.

20. The ends of the inorganic fibers protrude from the surface of the first coating layer, The laminate according to claim 18, wherein some of the ends of the inorganic fibers are located inside the second coating layer.

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