Method of making a Dalmatian pattern on a watch bezel

Abstract

The present invention relates to a method for forming a Dalmatian pattern on a watch bezel, comprising the steps of: (a) mixing zirconia powder and a color pigment in a solvent, ball-milling, and then drying to obtain a first composition; (b) mixing zirconia powder and alumina (Al2O3) in a solvent, ball-milling, and then drying to obtain a second composition; (c) introducing one of the first composition or the second composition into a mold and applying pressure to obtain an intermediate; (d) grinding and classifying the intermediate from step (c) to obtain a third composition; (e) mixing one of the first composition or the second composition that is not formed as an intermediate in step (c) with the third composition from step (d) and molding to obtain a molded article; and (f) sintering the molded article from step (e).

Description

Technology Field

[0001] The present invention relates to a method for forming a Dalmatian pattern on a watch bezel. Background Technology

[0002] A bezel refers to the rim that secures the glass to the watch face, and numbers or markings are displayed on the bezel to indicate minutes.

[0003] While metal has traditionally been the dominant material for bezels, ceramic materials are also being widely used recently. In particular, zirconium bezels are used in high-end wristwatches, and bezels with various differentiated colors and patterns are being developed to survive in a fiercely competitive market environment. Prior art literature

[0004] Republic of Korea Registered Patent No. 10-2454163 (Published on Oct. 12, 2022) The problem to be solved

[0005] The problem that the present invention aims to solve is to provide a method for forming a Dalmatian pattern on a watch bezel that not only possesses aesthetic appeal but also prevents defects such as micro-cracks. means of solving the problem

[0006] The present invention provides a method for forming a Dalmatian pattern on a watch bezel, comprising, in one embodiment: (a) a step of obtaining a first composition by mixing zirconia powder and a color pigment in a solvent and drying after ball milling; (b) a step of obtaining a second composition by mixing zirconia powder and alumina (Al2O3) in a solvent and drying after ball milling; (c) a step of obtaining an intermediate by introducing one of the first composition or the second composition into a mold and applying pressure; (d) a step of obtaining a third composition by grinding and classifying the intermediate from step (c); (e) a step of obtaining a molded article by mixing one of the first composition or the second composition that is not formed as an intermediate in step (c) with the third composition from step (d) and molding; and (f) a step of sintering the molded article from step (e).

[0007] In addition, in step (a), the first composition may include 0.1 to 10 parts by weight of color pigment based on 100 parts by weight of zirconia powder.

[0008] In addition, in step (b), the second composition may include 0 to 10 parts by weight of alumina based on 100 parts by weight of zirconia powder.

[0009] In addition, in steps (a) and (b), the solvent may be one or more selected from the group consisting of water, isopropyl alcohol, and lower alcohols having 1 to 4 carbon atoms, and specifically may be ethanol.

[0010] In addition, the first composition and the second composition may be ground after drying.

[0011] In addition, pressurization in step (c) can be performed at a pressure of 300 to 1,000 kg / cm².

[0012] In addition, in step (d), classification can be performed by sieving using a sieve.

[0013] In addition, there may be three types of sieves with mesh sizes of 10 mesh, 30 mesh, and 80 mesh.

[0014] In addition, in step (e), forming can be performed at a pressure of 800 to 2,000 kg / cm².

[0015] In addition, step (e) may mix one of the first composition or the second composition with the third composition in a weight ratio of 1 to 9:9 to 1.

[0016] In addition, sintering can be performed at a temperature of 1,200 to 1,600 ℃.

[0017] In another embodiment, the present invention provides a watch bezel having a Dalmatian pattern manufactured by the method described above. Effects of the invention

[0018] According to the present invention, a method for forming a Dalmatian pattern on a watch bezel can be provided, which not only has aesthetic appeal but also prevents the formation of micro-cracks.

[0019] In addition, watch bezels with various differentiated colors and patterns can be provided. Brief explanation of the drawing

[0020] FIG. 1 is a flowchart illustrating a method for forming a Dalmatian pattern on a watch bezel according to one embodiment of the present invention. FIG. 2 is an image of a watch bezel with a Dalmatian pattern formed according to Examples 1 and 2. Figure 3 is an image of a watch bezel with various colored Dalmatian patterns formed on it. Specific details for implementing the invention

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different embodiments and is not limited to the embodiments described herein. Throughout the specification, similar parts are denoted by the same reference numerals.

[0023] The term “Dalmatian” as used in this invention refers to a pattern of irregularly formed spotted spots of a color different from the background color.

[0024] FIG. 1 is a flowchart illustrating a method for forming a Dalmatian pattern on a watch bezel according to one embodiment of the present invention.

[0025] The present invention provides a method for forming a Dalmatian pattern on a watch bezel, comprising, in one embodiment: (a) a step of obtaining a first composition by mixing zirconia powder and a color pigment in a solvent and drying after ball milling (S100); (b) a step of obtaining a second composition by mixing zirconia powder and alumina (Al2O3) in a solvent and drying after ball milling (S200); (c) a step of obtaining an intermediate by introducing one of the first composition or the second composition into a mold and applying pressure (S300); (d) a step of obtaining a third composition by grinding and classifying the intermediate from step (c) (S400); (e) a step of obtaining a molded article by mixing one of the first composition or the second composition that is not formed as an intermediate in step (c) with the third composition from step (d) and molding; and (f) a step of sintering the molded article from step (e) (S600).

[0027] Step (a) of obtaining the first composition

[0028] First, as shown in FIG. 1, a step (S100) is performed to obtain a first composition by mixing 0.1 to 10 parts by weight of color pigment with 100 parts by weight of zirconia powder in a solvent, ball milling, and then drying.

[0029] Specifically, 1 to 5 parts by weight of color pigment can be mixed with 100 parts by weight of zirconia powder in a solvent.

[0030] The term zirconia powder used in this invention may be stabilized (ZrO2), and the commercially available brand name TZ3YSE (Tosoh Corporation) may be applied.

[0031] Color pigments can be applied in various colors such as red, orange, yellow, green, blue, indigo, and purple, and are not limited to these.

[0032] If the content of the color pigment is less than 0.1 parts by weight, the amount added is negligible and the desired color cannot be achieved, and if it exceeds 10 parts by weight, the content of the zirconia powder is relatively low, which may degrade the mechanical properties of the bezel. For example, cobalt oxide may be added to produce a blue color.

[0033] In step (a), the solvent may be one or more selected from the group consisting of water, isopropyl alcohol, and lower alcohols having 1 to 4 carbon atoms, and specifically may be ethanol.

[0034] In step (a), the ball mill is a wet ball mill using a solvent, wherein the balls may be zirconia balls, and the ball milling time may be 1 to 100 hours, specifically 12 to 72 hours.

[0035] Ball milling is performed to evenly disperse zirconia powder and color pigments, thereby producing a uniform color.

[0036] The drying method in step (a) is not limited, but specifically, spray drying using a spray dryer, etc., may be applied.

[0037] In step (a), the grinding process can be further carried out after drying. That is, the first composition obtained through step (a) may be a ground product that has undergone a grinding process.

[0038] The grinding method is not restricted, and is not restricted if it is applicable to the technology, such as low-speed grinders, high-speed grinders, etc.

[0040] Step (b) of obtaining the second composition

[0041] Next, as shown in FIG. 1, a step (S200) is performed to obtain a second composition by mixing 0 to 10 parts by weight of alumina (Al2O3) with 100 parts by weight of zirconia powder in a solvent, ball milling, and then drying.

[0042] The meaning of the alumina content being 0 parts by weight in step (b) is that the second composition can be used as zirconia powder alone.

[0043] Specifically, the second composition may include 0 to 10 parts by weight of alumina (Al2O3) in 100 parts by weight of zirconia powder, and more specifically, may include 0.1 to 10 parts by weight.

[0044] In step (b), alumina is added to achieve a white color in the second composition. If the alumina content is less than 0.1 parts by weight, the desired color cannot be obtained, and if it exceeds 10 parts by weight, the relative content of zirconia powder is lowered, which not only lowers mechanical properties but also exceeds the critical point required to achieve the desired color, making it uneconomical.

[0045] In step (b), the solvent, ball mill, drying, etc., can be performed in the same way as in step (a), so a description thereof is omitted.

[0046] Additionally, the grinding process can be further carried out after drying in step (b). That is, the second composition obtained through step (b) may be a ground product that has undergone a grinding process.

[0048] Step to obtain intermediate (c)

[0049] Next, as shown in FIG. 1, a step (S300) is performed to obtain an intermediate by introducing one of the first composition or the second composition into a mold and applying pressure.

[0050] Step (c) is a pretreatment step for granulating the first composition or the second composition, which can be performed under pressure conditions of 300 to 1,000 kg / ㎠, specifically under pressure conditions of 600 to 800 kg / ㎠, and more specifically under pressure conditions of 700 kg / ㎠.

[0051] In step (c), the pressurization condition is performed at a lower pressure than the pressurization condition in step (e), which will be described below, and this will be explained again in step (e).

[0052] In step (c), the intermediate can be manufactured by press forming, etc., and can also be produced by injection, extrusion, or tablet forming machine, but is not limited thereto.

[0053] Step (c) An intermediate can be formed using the first composition, and an intermediate can be formed using the second composition. That is, Step (c) can be carried out in two ways.

[0054] The reason for pressurizing one of the first composition or the second composition in step (c) is to ensure that the molding density is maintained at the same level when forming the Dalmatian pattern later, thereby preventing the formation of micro-cracks, cracks, etc.

[0055] These problems can be solved through step (c).

[0057] Step (d) of obtaining the third composition

[0058] Next, as illustrated in FIG. 1, a step (S400) is performed to obtain a third composition by crushing and classifying the intermediate of step (c).

[0059] Step (d) is a step of obtaining a third composition by grinding and classifying an intermediate obtained from either the first composition or the second composition, as previously explained.

[0060] The method of grinding in step (d) is not limited to any method applicable to the same technology.

[0061] In step (d), classification can be performed by sieving with a sieve.

[0062] In step (d), the sieve can be made of three types having 10 mesh, 30 mesh, and 80 mesh.

[0063] Briefly explain the term “classification” used in step (d).

[0064] In step (d), sifting is performed with the mesh size of the sieve, -10 mesh refers to passing through a 10-mesh sieve, and +10 mesh refers to what remains on the sieve.

[0065] The sieves used in step (d) with 10 mesh, 30 mesh, and 80 mesh meshes have mesh sizes of 2 mm, 0.6 mm, and 0.18 mm, respectively.

[0066] That is, +10 mesh particles have a size of 2 mm or more, +30 to -10 mesh particles have a size of 0.6 to 2 mm, +80 to -30 mesh particles have a size of 0.18 to 0.6 mm, and -80 mesh particles can have a size of 0.18 mm.

[0067] Here, +80 to -30 mesh refers to particles that pass through a 30 mesh sieve but not through an 80 mesh sieve.

[0068] In step (b), the third composition may contain particles of +10 mesh (2 mm or more), +30 to -10 mesh (0.6 to 2 mm), and +80 to -30 mesh (0.18 to 0.6 mm) in a weight ratio of 5:2.5:2.5 through classification.

[0069] That is, in step (d), the third composition is a mixture of crushed intermediates separated by size through classification, which can form a non-standardized Dalmatian pattern on the bezel.

[0070] In addition, the ground intermediate of +80 mesh obtained through sieving in step (d) is not used, as using it may result in mixed colors and thus cannot form a Dalmatian pattern.

[0071] Additionally, the third composition may further include a drying step after classification, and the method is not limited.

[0073] Step (e) of obtaining a molded product

[0074] Next, as illustrated in FIG. 1, a step (S500) is performed to obtain a molded product by mixing and molding one of the first composition or the second composition that is not formed as an intermediate in step (c) with the third composition of step (d).

[0075] Specifically, in step (e), the mixing may be performed by mixing one of the first composition or the second composition with the third composition in a weight ratio of 1 to 9:9 to 1, and more specifically, it is preferable to perform it in a ratio of 1:9 or 9:1, and if it is outside this range, a Dalmatian pattern cannot be formed.

[0076] In step (e), forming can be performed at a pressure of 800 to 2,000 kg / cm², specifically at a pressure of 900 to 1,500 kg / cm², and more specifically at 1,100 kg / cm².

[0077] The molding pressure in step (e) is set higher than the molding pressure in step (c) and the process is carried out.

[0078] This is to ensure that the molded product is densified by being molded at a lower pressure in step (c) than in step (e) and receiving a higher pressure once more in step (e), so that the third composition and the first or second composition have the same molding density, thereby narrowing the difference in shrinkage rates between the two compositions and preventing the formation of microcracks.

[0080] Sintering step (f)

[0081] Finally, as illustrated in FIG. 1, a step (S600) of sintering the molded product of step (e) is performed.

[0082] Step (f) can be carried out in a sintering furnace under an oxidizing atmosphere.

[0083] Sintering can be performed at a temperature of 1,200 to 1,600 ℃ for 1 to 10 hours, specifically at a temperature of 1,300 to 1,500 ℃ for 1 to 5 hours, and more specifically, sintering can be carried out for about 2 hours after raising the temperature of the sintering furnace to about 1,450 ℃.

[0085] In another embodiment, the present invention provides a watch bezel having a Dalmatian pattern manufactured according to the method described above.

[0087] The present invention will be described in more detail below using examples. These examples are solely for the purpose of more specifically explaining the present invention, and it is obvious to those skilled in the art that the scope of the present invention is not limited by them.

[0088] <Example>

[0089] Example 1

[0090] First, 100 parts by weight of zirconia powder (Doso, TZ3YSE) and 0.65 parts by weight of cobalt oxide, a blue pigment, were mixed in ethanol and wet ball milled for 24 hours. Afterward, the ball-milled slurry was dried and ground to prepare the first composition.

[0091] Next, 100 parts by weight of zirconia powder and 5 parts by weight of alumina were mixed in ethanol and wet ball-milled for 24 hours. Afterward, the ball-milled slurry was dried and ground to prepare the second composition.

[0092] Next, the manufactured second composition was filled into a press mold to granulate it and molded under a pressure condition of 700 kg / ㎠ to produce an intermediate.

[0093] Next, after grinding the manufactured intermediate, the lumps were sieved and classified according to particle size. Subsequently, the classified ground material was sieved through three types of sieves having mesh sizes of 10 mesh, 30 mesh, and 80 mesh, respectively, and a third composition was prepared to contain particles of +10 mesh (2 mm or more), particles of +30 to -10 mesh (0.6 to 2 mm), and particles of +80 to -30 mesh (0.18 to 0.6 mm) in a weight ratio of 5:2.5:2.5.

[0094] Finally, the first composition and the third composition were mixed in a weight ratio of 9:1 and filled into a press mold, molded at a pressure of about 1,100 kg / cm², and then sintered for 2 hours in an oxidizing atmosphere sintering furnace at a temperature of 1,450 ℃ to produce a watch bezel with a white Dalmatian pattern formed on a blue background.

[0096] Example 2

[0097] First, 100 parts by weight of zirconia powder (Doso, TZ3YSE) and 5 parts by weight of alumina were mixed in ethanol and wet ball-milled for 24 hours. Afterwards, the ball-milled slurry was dried and ground to prepare the first composition.

[0098] Next, 3.5 parts by weight of black pigment were mixed with ethanol in 100 parts by weight of zirconia powder (Doso, TZ3YSE) and wet ball milling was performed for 24 hours. Afterward, the ball-milled slurry was dried and ground to prepare the second composition.

[0099] Next, the manufactured second composition was filled into a press mold to granulate it and molded under a pressure condition of 700 kg / ㎠ to produce an intermediate.

[0100] Next, after grinding the manufactured intermediate, the lumps were sieved and classified according to particle size. Subsequently, the classified ground material was sieved through three types of sieves having mesh sizes of 10 mesh, 30 mesh, and 80 mesh, respectively, and a third composition was prepared to contain particles of +10 mesh (2 mm or more), particles of +30 to -10 mesh (0.6 to 2 mm), and particles of +80 to -30 mesh (0.18 to 0.6 mm) in a weight ratio of 5:2.5:2.5.

[0101] Finally, the first composition and the third composition were mixed in a weight ratio of 9:1 and filled into a press mold, molded at a pressure of about 1,100 kg / cm², and then sintered for 2 hours in an oxidizing atmosphere sintering furnace at a temperature of 1,450 ℃ to produce a watch bezel with a black Dalmatian pattern formed on a white background.

[0103] The present invention, as described above with reference to the attached drawings, is capable of various modifications and changes by a person skilled in the art, and such modifications and changes should be interpreted as being included within the scope of the rights of the present invention. Explanation of the symbols

[0104] S100: Step of obtaining the first composition S200: Step of obtaining the second composition S300: Step to obtain intermediate S400: Step of obtaining the third composition S500: Step to obtain molded product S600: Sintering stage

Claims

Claim 1 (a) a step of obtaining a first composition by mixing zirconia powder and a color pigment in a solvent, ball milling, and then drying; (b) a step of obtaining a second composition by mixing zirconia powder and alumina (Al2O3) in a solvent, ball milling, and then drying; (c) a step of obtaining an intermediate by introducing one of the first composition or the second composition into a mold and applying pressure; (d) a step of obtaining a third composition by grinding and classifying the intermediate from step (c); (e) a step of obtaining a molded article by mixing one of the first composition or the second composition that is not formed as an intermediate in step (c) with the third composition from step (d) and molding; and (f) a step of sintering the molded article from step (e), comprising a method for forming a Dalmatian pattern on a watch bezel. . Claim 2 A method for forming a Dalmatian pattern on a watch bezel according to claim 1, wherein in step (a), the first composition comprises 0.1 to 10 parts by weight of a color pigment based on 100 parts by weight of zirconia powder. . Claim 3 A method for forming a Dalmatian pattern on a watch bezel according to claim 1, wherein in step (b), the second composition comprises 0 to 10 parts by weight of alumina based on 100 parts by weight of zirconia powder. . Claim 4 A method for forming a Dalmatian pattern on a watch bezel according to claim 1, wherein in steps (a) and (b), the solvent is one or more selected from the group consisting of water, isopropyl alcohol, and lower alcohols having 1 to 4 carbon atoms. . Claim 5 A method for forming a Dalmatian pattern on a watch bezel, wherein, in claim 1, the solvent in steps (a) and (b) is ethanol. . Claim 6 A method for forming a Dalmatian pattern on a watch bezel according to claim 1, wherein the first composition and the second composition are ground after drying. . Claim 7 A method for forming a Dalmatian pattern on a watch bezel according to claim 1, wherein in step (c), the pressurization is performed at a pressure of 300 to 1,000 kg / cm². . Claim 8 A method for forming a Dalmatian pattern on a watch bezel, wherein in claim 1, the classification in step (d) is performed by sieving with a sieve. . Claim 9 A method for forming a Dalmatian pattern on a watch bezel according to claim 8, wherein the sieve is of three types having meshes of 10 mesh, 30 mesh, and 80 mesh. . Claim 10 A method for forming a Dalmatian pattern on a watch bezel according to claim 1, wherein in step (e), the forming is performed at a pressure of 800 to 2,000 kg / cm². . Claim 11 In claim 1, the method for forming a Dalmatian pattern on a watch bezel comprises, in step (e), mixing one of the first composition or the second composition with the third composition in a weight ratio of 1 to 9:9 to 1. . Claim 12 A method for forming a Dalmatian pattern on a watch bezel according to claim 1, wherein the sintering is performed at a temperature of 1,200 to 1,600 ℃. . Claim 13 A watch bezel having a Dalmatian pattern manufactured by the method of any one of claims 1 to 12. Claim 1

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