Glaze composition, cement-based material with glaze layer, and method for manufacturing cement-based material with glaze layer

Abstract

Provided are a glaze composition capable of forming a glaze layer on the surface of a cement-based material by firing at a relatively low temperature without thermally deteriorating or damaging the cement-based material, a cement-based material with a glaze layer, and a method for producing the cement-based material with a glaze layer. A glaze composition comprising a Raku ware glaze, petalite, and lithium carbonate. The blending ratio of the Raku ware glaze, petalite, and lithium carbonate is preferably 46-72:12-38:7-17 by mass.

Description

[Technical Field]

[0001] The present invention relates to a glaze composition, a cement-based material with a glaze layer, and a method for producing a cement-based material with a glaze layer. [Background technology]

[0002] Cementitious materials such as mortar and concrete begin to dehydrate when heated above 100°C, with calcium hydroxide typically dehydrating at around 500°C. In contrast, the melting point of typical glazes is around 1200-1300°C, making it difficult to apply glaze to the surface of cementitious materials without thermal deterioration or damage using conventional glazing methods, in which the glaze is applied to the surface of the substrate and then fired together with the substrate.

[0003] A method for producing long, homogeneously glazed prestressed concrete components is known (see, for example, Patent Document 1), in which a plasma spraying device and a long prestressed concrete component are moved relative to one another while introducing a glassy powder having an average particle size of 1 μm to 400 μm into the high-temperature plasma flame of the plasma spraying device, causing the fully melted glassy fused particles to collide with the required surfaces of the prestressed concrete component by the injection force of the plasma flame, thereby plasma spraying the substrate without substantially thermal degradation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 63-100085 Summary of the Invention [Problem to be solved by the invention]

[0005] The manufacturing method for long, uniformly glazed prestressed concrete materials described in Patent Document 1 uses plasma spraying to apply a glaze to the concrete surface, making it impossible to control the thickness of the glaze layer. Therefore, as a method for controlling the thickness of the glaze without thermally deteriorating or damaging the surface of the cementitious material, a method has been investigated in which a glaze composition is applied to the surface of the cementitious material, dried to form a coating film, and then irradiated with laser light to fire the coating film formed on the surface of the cementitious material. However, when the coating film formed on the surface of the cementitious material is fired with laser light, considerable damage occurs due to the firing. Specifically, although the glaze vitrifies on the cementitious material, the adhesion strength of the glaze layer tends to be lower than that of a material not irradiated with laser light.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a glaze composition that can form a glaze layer on the surface of a cement-based material by firing at a relatively low temperature without thermally deteriorating or damaging the cement-based material, a cement-based material with a glaze layer, and a method for producing a cement-based material with a glaze layer. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] A glaze composition comprising a Raku ware glaze, petalite, and lithium carbonate. [2] The glaze composition according to [1], wherein the blending ratio of the Raku ware glaze, the petalite, and the lithium carbonate is 46-72:12-38:7-17 by mass. [3] The glaze composition according to [1] or [2], wherein the blending ratio of the Raku ware glaze, the petalite, and the lithium carbonate is 70-72:12-21:16.5-17 by mass. [4] The glaze composition according to any one of [1] to [3], which is used to form a glaze layer by laser firing a coating film made of the glaze composition. [5] a cement-based material; a glaze layer formed on at least a portion of one surface of the cementitious material, The glaze layer is a fired product of the glaze composition according to any one of [1] to [4]. [6] The cementitious material with a glaze layer according to [5], wherein the glaze layer has a Mohs hardness of 3 or more. [7] A step of applying a glaze composition to a surface of a cement-based material to form a coating film made of the glaze composition; and a step of firing the coating film by laser firing to form a glaze layer on the coating surface of the cement-based material, A method for producing a cement-based material with a glaze layer, wherein the glaze composition is the glaze composition according to any one of [1] to [4]. [8] The method for producing a cementitious material with a glaze layer according to [7], wherein the firing temperature of the coating film by laser firing is 800°C or higher and 1000°C or lower. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a glaze composition that can form a glaze layer on the surface of a cement-based material by firing at a relatively low temperature without thermally deteriorating or damaging the cement-based material, a cement-based material with a glaze layer, and a method for producing a cement-based material with a glaze layer. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view schematically showing a cement-based material with a glaze layer according to one embodiment of the present invention. [Figure 2] FIG. 10 is a cross-sectional view schematically showing an adhesion test of Experimental Example 2. [Figure 3] FIG. 10 is a plan view schematically showing the adhesion test of Experimental Example 2. [Figure 4] 10 is a diagram showing the relationship between the heat quantity of laser light and adhesive strength in Experimental Example 2. FIG. [Figure 5] FIG. 10 is a diagram showing the results of a scratch test using a Mohs hardness scale in Experimental Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Glaze composition] A glaze composition according to one embodiment of the present invention includes a Raku ware glaze, petalite, and lithium carbonate (Li2CO3).

[0011] The Raku ware glaze is not particularly limited, and any general Raku ware glaze can be used. For example, the glaze with the composition shown in Table 1 can be used.

[0012] [Table 1]

[0013] As the petalite, for example, one having the composition shown in Table 2 can be used.

[0014] [Table 2]

[0015] The blending ratio of the Raku ware glaze, petalite, and lithium carbonate is preferably 46-72:12-38:7-17 by mass, and more preferably 70-72:12-21:16.5-17 by mass. When the blending ratio of the Raku ware glaze, petalite, and lithium carbonate is 46-72:12-38:7-17 by mass, the glaze layer formed by firing a coating film made of the glaze composition can be semi-vitrified or vitrified. When the blending ratio of the Raku ware glaze, petalite, and lithium carbonate is 70-72:12-21:16.5-17 by mass, the glaze layer formed by firing a coating film made of the glaze composition can be vitrified. Note that vitrified refers to a state in which the glaze layer is amorphous and transparent. Semi-vitrified refers to a state in which the glaze layer contains both crystalline and amorphous materials and is not completely transparent.

[0016] The glaze composition of this embodiment is preferably an aqueous dispersion of a glaze comprising a Raku ware glaze, petalite, and lithium carbonate. The water content of the glaze composition of this embodiment is not particularly limited and is adjusted appropriately depending on the shape and surface condition of the cementitious material to which the glaze composition is applied.

[0017] The content of the glaze relative to the total amount (100% by mass) of the glaze composition is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less.

[0018] Examples of methods for firing a coating film formed using the glaze composition of this embodiment include firing by irradiating the coating film with laser light (laser firing). The coating film formed using the glaze composition of this embodiment can be fired at 1000°C or less by laser firing, which allows for a lower firing temperature. Therefore, the glaze composition of this embodiment is preferably for laser firing.

[0019] A method for producing the glaze composition of this embodiment will be described. The glaze composition of this embodiment is obtained by mixing Raku ware glaze, petalite, and lithium carbonate in a predetermined ratio, and adding water as needed. The method for mixing the Raku ware glaze, petalite, and lithium carbonate is not particularly limited. The above-mentioned method can also be used when adding water.

[0020] The glaze composition of this embodiment contains a Raku ware glaze, petalite, and lithium carbonate, and therefore a coating film formed from the glaze composition can be semi-vitrified or vitrified by laser firing at 1000° C. or less. Therefore, a glaze layer can be formed on the surface (coated surface) of a cementitious material without thermally deteriorating or damaging the cementitious material to which the glaze composition is applied.

[0021] [Glazed cement-based material] A cementitious material with a glaze layer according to one embodiment of the present invention includes a cementitious material and a glaze layer.

[0022] Hereinafter, the cement-based material with a glaze layer of this embodiment will be described with reference to the drawings. As shown in FIG. 1, the cementitious material with a glaze layer 1 of this embodiment includes a cementitious material 2 and a glaze layer 3.

[0023] The glaze layer 3 is formed on at least a part of one surface 2a of the cementitious material 2. That is, the glaze layer 3 may be formed so as to cover a part of one surface 2a of the cementitious material 2, or may be formed so as to cover the entire one surface 2a of the cementitious material 2.

[0024] The cement-based material 2 is not particularly limited, and examples thereof include materials made of mortar and concrete. The shape of the cement-based material 2 is not particularly limited, and may be in various shapes such as a block, tile, or plate.

[0025] The size (area) of the cementitious material 2 is not particularly limited. The thickness of the cementitious material 2 is not particularly limited.

[0026] The glaze layer 3 is a fired product of the glaze composition of the above embodiment.

[0027] The thickness of the glaze layer 3 is not particularly limited, but is preferably 0.1 to 3.0 mm, more preferably 0.2 to 2.0 mm, and even more preferably 1.0 to 2.0 mm.

[0028] The Mohs hardness of the glaze layer 3 is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more.

[0029] The Mohs hardness of the glaze layer 3 can be measured by a scratch test using a Mohs hardness tester.

[0030] According to the cementitious material with a glaze layer of this embodiment, since the glaze layer is a fired product of the glaze composition of the above embodiment, a cementitious material with a glaze layer can be obtained in which one surface of the cementitious material is free from thermal deterioration or damage.

[0031] [Method of manufacturing cement-based material with glaze layer] A method for producing a cementitious material with a glaze layer according to one embodiment of the present invention includes a step of applying a glaze composition to a coating surface of a cementitious material to form a coating film made of the glaze composition (hereinafter referred to as a "coating film forming step"), and a step of firing the coating film by laser firing to form a glaze layer on the coating surface of the cementitious material (hereinafter referred to as a "coating film firing step").

[0032] "Paint film formation process" In the coating film forming step, the glaze composition of the above embodiment is applied to the surface (one surface) of the cement-based material to be coated, thereby forming a coating film made of the glaze composition.

[0033] As a method for applying the glaze composition to the surface of the cement-based material to form a coating film of the glaze composition, for example, a conventionally known coating method such as spray coating, spin coating, or coating with a bar coater can be used.

[0034] The thickness of the coating film is not particularly limited, but is preferably 0.1 mm to 3.0 mm, more preferably 0.2 mm to 2.0 mm, and even more preferably 1.0 mm to 2.0 mm. The coating film thickness here refers to the thickness of the coating film immediately before it is irradiated with laser light in the coating film firing process. When the coating film thickness immediately before it is irradiated with laser light is 0.2 mm to 2.0 mm, the adhesion of the glaze layer to the coated surface of the cement-based material can be increased regardless of the scanning speed of the laser light. Furthermore, when the coating film thickness immediately before it is irradiated with laser light is 1.0 mm to 2.0 mm, the adhesion of the glaze layer to the coated surface of the cement-based material can be increased regardless of the scanning speed of the laser light.

[0035] "Coating baking process" In the coating firing step, the coating formed on the surface of the cementitious material is irradiated with laser light to fire the coating, thereby forming a glaze layer on the surface of the cementitious material.

[0036] The laser light irradiated onto the coating film formed on the surface of the cement-based material is not particularly limited, and may be any of a solid-state laser, a liquid laser, a gas laser, and a semiconductor laser. The wavelength of the laser light is not particularly limited, but is preferably 100 nm to 1000 nm, more preferably 300 nm to 700 nm, and even more preferably 400 nm to 500 nm. In this embodiment, the wavelength of the laser light is, for example, 455 nm.

[0037] The spot diameter of the laser beam is not particularly limited, but is preferably 10 μm to 2000 μm, more preferably 100 μm to 1000 μm, and even more preferably 800 μm to 1000 μm. In this embodiment, the spot size of the laser beam is, for example, 0.08 mm × 0.08 mm.

[0038] The output power of the laser beam is not particularly limited, but is preferably from 1 W to 100 W, more preferably from 2 W to 50 W, even more preferably from 8 W to 30 W, and particularly preferably from 8 W to 10 W. When the output power of the laser beam is within this range, thermal deterioration or damage to the coated surface of the cement-based material is unlikely to occur when the laser beam is irradiated onto the coating film.

[0039] The scanning speed of the laser beam is not particularly limited, but is preferably 10 mm / min to 2000 mm / min, more preferably 30 mm / min to 200 mm / min, and even more preferably 50 mm / min to 150 mm / min. When the scanning speed of the laser beam is within this range, thermal deterioration or damage to the coated surface of the cement-based material is unlikely to occur when the coating film is irradiated with the laser beam.

[0040] The scanning interval of the laser beam is not particularly limited, but is preferably 20 μm to 6000 μm, more preferably 20 μm to 1000 μm, even more preferably 100 μm to 1000 μm, and most preferably 500 μm to 800 μm. When the scanning interval of the laser beam is within this range, thermal deterioration or damage to the coated surface of the cement-based material is unlikely to occur when the laser beam is irradiated onto the coating film. In this embodiment, for example, the scanning interval of the laser beam is set to 0.5 mm.

[0041] The firing temperature of the coating film made of the glaze composition by laser firing is preferably 800°C or higher and 1000°C or lower, more preferably 800°C or higher and 900°C or lower, and even more preferably 800°C or higher and 850°C or lower. When the firing temperature of the coating film is above the lower limit, the coating film can be semi-vitrified or vitrified. When the firing temperature of the coating film is below the upper limit, thermal deterioration or damage is less likely to occur on the coated surface of the cement-based material.

[0042] By irradiating the coating with laser light, the coating can be locally heated to a temperature above the melting point of the glaze, allowing the formation of a glaze layer on the surface of the cementitious material without causing thermal deterioration or damage.

[0043] <Film thickness control process> The method for producing a cement-based material with a glaze layer of the present embodiment may further include a film thickness control step of controlling the thickness of the coating film formed in the coating film formation step after the coating film formation step and before the coating film firing step. The thickness of the coating film in the film thickness control step is not particularly limited, but is preferably controlled to 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less, and even more preferably 1.0 mm or more and 2.0 mm or less. The method for controlling the thickness of the coating film formed in the coating film forming step is not particularly limited, but examples thereof include a method in which part of the coating film is removed by cutting or the like.

[0044] <Surface treatment process> Before the coating film forming step, a surface treatment step of treating the surface of the cementitious material may be further carried out. Surface treatment methods include roughening the surface of the cementitious material by rubbing it with a file or brush, and water jetting. The surface treatment can improve the adhesion between the cementitious material and the glaze layer, and also remove the weak laitance on the surface of the cementitious material.

[0045] According to the method for producing a cementitious material with a glaze layer of the present embodiment, the glaze composition of the above-described embodiment is used as the glaze composition, so that a cementitious material with a glaze layer can be obtained on one side of the cementitious material without thermal deterioration or damage. [Example]

[0046] The present invention will be explained in more detail below by way of experimental examples, but the present invention is not limited to the following experimental examples.

[0047] [Preparation of Glaze Composition] A glaze composition was prepared by placing Raku ware glaze, petalite, and lithium carbonate in a crucible and mixing them with a stirring rod to obtain the composition shown in Table 3. In Table 3, the masses of the Raku ware glaze, petalite, and lithium carbonate are shown so that the total amount is 10 g.

[0048] [Table 3]

[0049] [Experimental Example 1] 10 g of each of the glaze compositions of Formulation Examples 1 to 12 was placed in a porcelain crucible having an outer diameter of 39 mm and a height of 29 mm. The glaze composition was then fired in a muffle furnace at 800°C, 900°C, or 1000°C. The temperature was raised at a rate of 10°C / min and held at the specified temperature (800°C, 900°C, or 1000°C) for 15 minutes, after which the porcelain crucible containing the fired product was allowed to cool naturally in the muffle furnace. The state of the fired products was classified into five types: "vitrified," "semi-vitrified," "discolored," "lumpy," and "bubbly," and these classifications are shown in Tables 4 to 6. Table 4 shows the results for a firing temperature of 1000°C. Table 5 shows the results for a firing temperature of 900°C. Table 6 shows the results for a firing temperature of 800°C. "Vitrified" refers to a glaze layer that is amorphous and transparent. "Semi-vitrified" refers to a glaze layer that contains both crystalline and amorphous materials and is not completely transparent. "Discolored" refers to a blue or brown discoloration. "Lumpy" refers to a white ceramic-like state. "Bubbly" refers to a sample that contains bubbles.

[0050] [Table 4]

[0051] [Table 5]

[0052] [Table 6]

[0053] From the results shown in Table 4, it was confirmed that when the firing temperature was 1000°C, Composition Examples 5, 6, 7, 8, 9, 10, and 11 were vitrified or semi-vitrified. From the results shown in Table 5, it was confirmed that when the firing temperature was 900°C, Composition Examples 5, 6, 8, 9, and 11 were vitrified or semi-vitrified. From the results shown in Table 6, it was confirmed that when the firing temperature was 800°C, Composition Examples 6, 8, and 9 were vitrified or semi-vitrified. From the results shown in Tables 5 and 6, it was confirmed that Blending Example 6 was vitrified at a firing temperature of 800°C to 900°C. From the above results, it is believed that since Composition Examples 6, 8, and 9 are vitrified or semi-vitrified even with low thermal energy of 800°C to 1000°C, similar effects can be expected with laser firing.

[0054] [Experimental Example 2] "Preparation of cement-based materials" A plastic formwork measuring 105mm long x 154mm wide x 14mm thick was used to prepare mortar boards with a cement:fine aggregate ratio of 1:3 and a water-cement ratio of 50%. The materials used to mix the mortar are listed in Table 1. The mixed mortar was left to stand in a space with a temperature of 20°C and humidity of 60%, and was removed from the form 24 hours after pouring. It was then cured in water for three days and in air for seven days.

[0055] [Table 7]

[0056] "Surface treatment of cement-based materials" The surface of the prepared mortar board on which the glaze layer was to be formed was polished with an 80 grit file.

[0057] "Formation of a coating film of a glaze composition on the surface of a cement-based material" 15 mm wide masking tape was attached to both ends of the surface of the surface-treated mortar board on the side where the glaze layer was to be formed, and the glaze composition of Formulation Example 6 above was spray-coated. The glaze composition used was a mixture of commercially available Raku ware glaze, petalite, and lithium carbonate in a mass ratio of 10:6 with water. After spray-coating the glaze composition on the surface of the mortar board, it was allowed to dry for at least one day, forming a coating of the glaze composition on the surface of the mortar board, which was then used as a test specimen.

[0058] "Film thickness control" The masking tape on the dried specimen was peeled off together with the coating film on the masking tape, and feeler gauges were fixed to both ends, after which a squeegee with sufficient rigidity was slid to control the coating thickness. The coating thickness was 0.5 mm.

[0059] "Laser light irradiation on coating film" A laser processing machine (S10 Pro 50W Laser Engraving Machine, manufactured by Atomstack) was used, and the laser light output was set to 8W to 10W. The coating film of the glaze composition was irradiated with laser light. The scanning speed of the laser light was changed according to the output (heat amount) of the laser light to adjust the amount of energy of the laser light applied to the surface of the mortar board. Table 8 shows the laser light irradiation conditions.

[0060] [Table 8]

[0061] "Adhesion test" An adhesion test was conducted using a Construction Research Institute adhesive strength tester in accordance with JIS A 6909:2014 "Architectural Finish Coating Materials." In this adhesion test, four points were taken, and the arithmetic mean value was used as the experimental value. Specifically, the tensile load (kN) of the glaze layer was measured using a Construction Research Institute-type adhesion tester shown in Figure 2. Figure 2 is a schematic cross-sectional view showing the adhesion test. Figure 3 is a schematic plan view showing the adhesion test. In Figures 2 and 3, reference numeral 10 denotes the Construction Research Institute-type adhesion tester, reference numeral 12 denotes an attachment, reference numeral 13 denotes an adhesive, reference numeral 21 denotes a mortar board, and reference numeral 22 denotes a glaze layer. An attachment 12 with a contact surface 12a measuring 20 mm x 20 mm was filed and wiped with a cloth soaked in acetone. An epoxy resin-based filled adhesive (two-part mixture type) was then applied as adhesive 13 to the contact surface 12a of the attachment 12. The attachment 12 was then bonded, via the adhesive 13, to a specified position on the glaze layer 12, which had been formed by firing with a laser beam. After approximately one hour, as shown in Figure 2, the adhesive 13 and glaze layer 22 were scraped off along the attachment 12 with a cutter, forming a gap 23 between the adhesive 13 and glaze layer 22 directly below the attachment 12 and the remaining adhesive 13 and glaze layer 22. The Construction Research Institute adhesive strength tester 10 was then set horizontally, and the attachment 12 was pulled up vertically to measure the tensile load (kN). From the results obtained, the bond strength (kN / mm 2 ) was sought.

[0062]

number

[0063] In formula (1), P is the tensile load (kN), S is the area of ​​the contact surface of the attachment (mm 2 )

[0064] The relationship between the heat quantity of the laser beam and the adhesion strength is shown in Figure 4. For comparison, a coating consisting of only Raku ware glaze was formed on the surface of a mortar board, and this coating was then laser fired in the same manner as above, and the same adhesion test was also carried out. From the results shown in Figure 4, the glaze composition of Blending Example 6 showed a tendency for the adhesive strength to increase as the heat quantity of the laser beam decreased. 2 and 70 J / mm 2 It was found that the adhesion strength was higher than that of ordinary glazes during firing. In this way, it was found that by formulating a glaze that can be fired at a low temperature, it is possible to reduce damage to the mortar board.

[0065] [Experimental Example 3] "Mohs hardness" Using the glaze compositions of Formulation Examples 1 to 12, glaze layers were formed on the surface of mortar plates in the same manner as in Experimental Example 2, and the glaze layers were subjected to a scratch test using a Mohs hardness tester. The glaze layer thickness was set to 0.5 mm. The results of the scratch test using the Mohs hardness tester are shown in Figure 5. The results shown in Figure 5 indicate that the Mohs hardness is 5 to 6. [Explanation of symbols]

[0066] 1. Glazed cement-based materials 2. Cement-based materials 3 Glaze layer

Claims

1. A glaze composition comprising a Raku ware glaze, petalite, and lithium carbonate.

2. The glaze composition according to claim 1, wherein the blending ratio of the Raku ware glaze, the petalite, and the lithium carbonate is 46 to 72:12 to 38:7 to 17 by mass.

3. The glaze composition according to claim 2, wherein the blending ratio of the Raku ware glaze, the petalite, and the lithium carbonate is 70 to 72: 12 to 21: 16.5 to 17 by mass.

4. The glaze composition according to claim 1 , which is used to form a glaze layer by laser firing a coating film made of the glaze composition.

5. A cement-based material; a glaze layer formed on at least a portion of one surface of the cementitious material, A cement-based material with a glaze layer, wherein the glaze layer is a fired product of the glaze composition according to any one of claims 1 to 4.

6. The cementitious material with a glaze layer according to claim 5 , wherein the glaze layer has a Mohs hardness of 3 or more.

7. a step of applying a glaze composition to a surface of a cement-based material to form a coating film comprising the glaze composition; and a step of firing the coating film by laser firing to form a glaze layer on the coating surface of the cement-based material, The method for producing a cement-based material with a glaze layer, wherein the glaze composition is the glaze composition according to any one of claims 1 to 4.

8. The method for producing a cementitious material with a glaze layer according to claim 7, wherein the firing temperature of the coating film by laser firing is 800°C or higher and 1000°C or lower.

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