Cobalt blue magnesia reinforced porcelain, its preparation method and application in gold decoration

Abstract

This invention discloses a cobalt blue magnesium-reinforced porcelain, its preparation method, and its application in gold decoration, belonging to the field of decorative ceramics technology. The cobalt blue magnesium-reinforced porcelain of this invention includes a magnesium-reinforced porcelain body, on the surface of which are sequentially provided a cobalt blue coloring layer, an F88 curing and isolation layer, and a high-boron transparent glaze layer. The raw materials of the cobalt blue coloring layer, by mass, include 28-30 parts of F88 glaze powder, 11-12 parts of cobalt oxide, 8-9 parts of cobalt blue encapsulated pigment, and 0.5-1 parts of adhesive powder. The cobalt blue magnesium-reinforced porcelain of this invention exhibits excellent color development: the zirconium-encapsulated structure makes the cobalt blue color fuller, more vibrant, uniform, and stable; the glaze surface is defect-free: completely eliminating problems such as pores, crystallization, and matte edges; thoroughly solving the problems of gold absorption and loss of gloss caused by thermochemical incompatibility; high glaze firing pass rate and high baking and gold decoration; and strong durability after gold decoration.

Description

Technical Field

[0001] This invention belongs to the field of decorative ceramics technology, specifically relating to a cobalt blue magnesium-reinforced porcelain, its preparation method, and its application in gold decoration. Background Technology

[0002] Magnesium-reinforced porcelain is a special type of daily-use porcelain with high magnesium oxide content, mainly made from talc and feldspar. The firing temperature is as high as 1280±5℃. The body is prone to deformation at high temperatures, so it is necessary to use a molded sagger for firing during production. Therefore, the industry's common process route is high-temperature bisque firing and low-temperature glaze firing, with the glaze firing temperature being 1110~1145℃.

[0003] To match the expansion compatibility of the low-temperature glaze firing process with the high-magnesium body, the transparent glaze of magnesia-reinforced porcelain is a high-boron, low-temperature transparent glaze. Boric acid is introduced into the formula to increase the surface tension at high temperatures, and alkaline oxides such as zinc oxide and lithium oxide are introduced as strong fluxing components, resulting in a smooth and glossy glaze surface without matte edges. However, this type of glaze has a low initial melting point, and when baking gold at 830~860℃, the glaze surface will exhibit weak melting behavior. The boron component in the glaze is very prone to interfacial reaction with the active cobalt ions in the cobalt blue material, causing the gold layer to lose its luster and metallic texture, resulting in an appearance of "gold absorption".

[0004] Traditional cobalt blue uses cobalt-based composite oxide spinel structure pigments, which have stable color, but cobalt ions have extremely high migration activity in high-temperature glaze melts, making them easy to diffuse and smudge, which in turn causes defects such as glaze pores, crystallization, matte edges, and gold plating defects.

[0005] Therefore, solving the problem of applying cobalt blue color to magnesia ceramic glaze is the key to preparing high-quality cobalt blue and gold-decorated magnesia-reinforced ceramics. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides a cobalt blue magnesium-reinforced porcelain, its preparation method, and its application in gold decoration. This invention constructs a three-layer synergistic structure: a zirconium-encapsulated cobalt blue coloring layer + an F88 curing isolation layer + a high-boron transparent glaze layer. It uses cobalt blue to encapsulate the colorant, utilizing zirconium silicate (ZrSiO4) crystals as a physical barrier to prevent cobalt color ions (Co...) from developing. 2+ The tightly sealed coating layer is extremely stable at 830-860℃, neither decomposing nor softening, firmly locking cobalt ions within the crystal lattice. A second barrier is formed by an F88 cured isolation glaze, doubly preventing the migration of cobalt ions to the glaze surface and gold layer, completely eliminating thermochemical incompatibility reactions. This solves the problem of cobalt blue color showing up on magnesia ceramic glaze, making it suitable for gold decoration, especially for the large-scale production of high-end daily-use magnesia ceramics and artistic magnesia ceramics.

[0007] The technical solution adopted by this invention to solve its technical problem is: This invention provides a cobalt blue magnesium-reinforced ceramic, comprising a magnesium-reinforced ceramic body, wherein a cobalt blue coloring layer, an F88 curing and isolation layer and a high boron transparent glaze layer are sequentially disposed on the surface of the magnesium-reinforced ceramic body. The raw materials for the cobalt blue color layer, by mass parts, include: 28-30 parts of F88 glaze powder, 11-12 parts of cobalt oxide, 8-9 parts of cobalt blue encapsulated pigment, and 0.5-1 parts of adhesive powder.

[0008] Preferably, the raw materials of the cobalt blue color layer include, by mass parts: 28-30 parts of F88 glaze powder, 11 parts of cobalt oxide, 9 parts of cobalt blue encapsulated pigment, and 0.5 parts of adhesive powder.

[0009] Preferably, the chemical composition of the magnesium-reinforced ceramic body by mass fraction includes: SiO2 63~65%, Al2O3 5~6%, CaO 2.5~3%, MgO 25~26%, K2O 1~2%, Na2O 0.5~1%.

[0010] Further preferred, the chemical composition of the magnesium-reinforced ceramic body by mass fraction includes: 65% SiO2, 35% Al2O, 2.5% CaO, 26% MgO, 1% K2O, and 0.5% Na2O.

[0011] Preferably, the raw material for the F88 cured isolation glaze layer includes F88 glaze powder.

[0012] Preferably, the chemical composition of F88 glaze powder by mass fraction includes: SiO2 65~68%, Al2O3 10~13%, CaO 13~16%, MgO 1~2%, K2O 2~3%, Na2O 2~3%, Li2O 0~0.8%, and loss on ignition 0.5~1%.

[0013] Further preferred, the chemical composition of F88 glaze powder by mass fraction includes: 66% SiO2, 11% Al2O3, 15% CaO, 1.4% MgO, 2.8% K2O, 2% Na2O, 0.8% Li2O, and 1% loss on ignition.

[0014] Preferably, the chemical composition of the high-boron transparent glaze layer by mass fraction includes: ZnO 3~4%, SiO2 55~57%, Al2O3 12~13%, CaO 9~10%, MgO 0.6~1%, K2O 3~3.4%, Na2O 2.2~2.8%, Li2O 0.8~1.2%, B2O3 6~6.2%, and loss on ignition 4~6%.

[0015] Further preferred, the chemical composition of the high boron transparent glaze layer by mass fraction includes: ZnO 3%, SiO2 57%, Al2O3 12%, CaO 9%, MgO 0.6%, K2O 3.4%, Na2O 2.8%, Li2O 1.2%, B2O3 6.2%, and loss on ignition 4.8%.

[0016] Preferably, the cobalt blue pigment is zirconium-coated cobalt blue pigment.

[0017] Further preferred, the zirconium-coated cobalt blue pigment is a zirconium silicate (ZrSiO4) coated cobalt aluminum spinel (CoAl2O4) pigment.

[0018] This invention provides a method for preparing the above-mentioned cobalt blue magnesium-reinforced ceramic, comprising the following steps; (1) Spray cobalt blue agent onto the surface of the magnesium-reinforced ceramic body and let it stand; (2) Spray F88 curing isolation glaze and sinter; (3) Spray high boron transparent glaze, sinter, and obtain cobalt blue magnesium-reinforced porcelain.

[0019] Preferably, in step (1), the magnesium-reinforced ceramic body is pre-polished, cleaned, and dried.

[0020] Preferably, the water absorption rate of the magnesium-reinforced ceramic body in step (1) is <0.5%.

[0021] Preferably, in step (1), the cobalt blue agent has a material-to-water ratio of 100:150~170, a residue of <0.05% on a 325-mesh sieve, a specific gravity of 1.34~1.36g / ml, and a flow rate of 35~50s / 100ml.

[0022] Preferably, in step (1), the cobalt blue agent is sprayed to a thickness of 0.15~0.3mm.

[0023] Preferably, in step (2), the material-to-water ratio of the F88 curing glaze is 100:150~170, the residue on a 325-mesh sieve is <0.05%, the specific gravity is 1.66~1.68g / ml, and the flow rate is 28~36s / 100ml.

[0024] Preferably, in step (2), the thickness of the F88 curing isolation glaze spray is 0.1~0.15mm.

[0025] Preferably, the sintering temperature in step (2) is 1125~1145℃ and the holding time is 30~40min.

[0026] Further preferred, the sintering temperature in step (2) is 1130℃.

[0027] Preferably, after sintering in step (2), the material is allowed to cool naturally.

[0028] Preferably, in step (3), the thickness of the high boron transparent glaze spray is 0.10~0.15mm.

[0029] Preferably, the sintering temperature in step (3) is 1110~1145℃ and the holding time is 25~35min.

[0030] Preferably, the specific gravity of the high boron transparent glaze in step (3) is 1.68~1.72g / ml, and the flow rate is 26~38s / 100ml.

[0031] The present invention provides a cobalt blue magnesium-reinforced porcelain with gold decoration as described above, comprising the cobalt blue magnesium-reinforced porcelain, wherein the surface of the cobalt blue magnesium-reinforced porcelain is provided with a gold decorative layer.

[0032] This invention provides a method for preparing the above-mentioned gold-decorated cobalt blue magnesium-reinforced porcelain, comprising the following steps; Gold decorations are applied to the surface of cobalt blue magnesium-reinforced porcelain, and then the gold is baked on to obtain cobalt blue magnesium-reinforced porcelain with gold decoration.

[0033] Preferably, the gold painting uses rhodium-containing gold solution with a gold content of 11.5~12.5wt% and a rhodium content of 0.18~0.25wt%.

[0034] Preferably, the thickness of the gold plating is 0.03~0.05mm.

[0035] Preferably, the baking temperature is 830~860℃, and the holding time is 15~20min.

[0036] Magnesium-reinforced ceramics utilize a high-boron, low-temperature transparent glaze, resulting in a high B2O3 content, strong high-temperature activity, and low melt viscosity. Traditional cobalt-based spinel colorants contain cobalt ions (Co...). 2+ Cobalt exhibits extremely high high-temperature migration activity. During glaze firing at 1100-1130℃, cobalt ions diffuse extensively into the glaze layer, undergoing a thermochemically incompatible reaction with boron components to generate low-melting-point cobalt-boron composite compounds. This leads to abnormal color development (cobalt ions are consumed and lost in the reaction, and the color lattice is destroyed, resulting in a lighter, grayer, or darker color, a weakened blue hue, and decreased saturation; the diffusion and diffusion of cobalt ions cause uneven color development, color spots, large batch-to-batch color differences, and poor stability) and glaze defects (precipitation of cobalt-boron compounds in the glaze layer, uneven melt flow, and gas escape directly lead to: glaze crystallization, roughness, opacity, pores, pinholes, and dense bubbles; boron accumulation at the edges and uneven melt tension result in matte edges, no gloss bands, orange peel texture, and poor smoothness). The essence of these defects is that the deterioration in color development, glaze crystallization, and matte finish during the glaze firing stage are direct products of the cobalt-boron thermochemical reaction, belonging to chemically formed defects rather than simply physical flaws.

[0037] During the baking process (830~860℃), the high-boron glaze undergoes weak melting, and the cobalt-boron reaction continues. The "gold absorbing" effect is caused by a combination of direct chemical reaction and glaze crystallization / matte finish mechanisms. Glaze defects are not merely an accompanying phenomenon but a significant contributing factor. Direct chemical reaction: Cobalt ions diffused into the glaze layer during firing continue to form cobalt-boron complex salts with boron components under the weak melting environment of the baking process. This compound migrates to the gold-glaze interface, directly damaging the gold crystal structure and oxidizing the metallic gold, leading to loss of gloss, blackening, loss of metallic luster, and decreased adhesion of the gold layer—the fundamental chemical cause of the "gold absorbing" effect. The inducing effect of glaze crystallization / matte finish: Glaze crystallization and edge matte finish formed during firing are not only physical defects but also significantly induce and exacerbate the "gold absorbing" reaction. The crystallization region has numerous lattice defects and high interfacial activity, becoming a preferential channel for the aggregation and migration of cobalt-boron complex salts. Gold plating is the result of the synergistic effect of the direct thermochemical reaction between cobalt and boron and the crystallization / matteness defects on the glaze surface. Glaze crystallization / matteness is a significant catalytic factor, significantly accelerating and amplifying the gold plating reaction, and is a key factor leading to intensified plating, expanded plating area, and decreased stability. Gold plating during baking originates from both the direct thermochemical incompatibility reaction between cobalt ions and boron components, and is further amplified by the crystallization and matteness defects generated during glaze firing. The combined effect of these two factors leads to the destruction of the gold layer.

[0038] The cobalt blue agent of this invention adopts a compound system of cobalt oxide + cobalt blue encapsulated pigment. The core design concept is: cobalt oxide lays the foundation for the main color tone and provides a high-saturation blue base; cobalt blue encapsulates the pigment and has the dual functions of high-temperature cobalt locking, diffusion blocking, inhibiting cobalt-boron reaction and standard color tone fine adjustment. The two work together to accurately balance the color purity and anti-gold absorption performance.

[0039] Cobalt oxide is a highly saturated, high-coloring-power primary chromophore, determining the blue hue. If the content is insufficient (<11 parts): the blue hue is weak, the color is light, grayish, and the saturation is low, failing to meet the standard cobalt blue color. If the content is too high (>12 parts): the color is darker, duller, blackish, and slightly reddish. During glaze firing, the amount of free cobalt increases, which can easily lead to glaze defects such as crystallization and matte finish.

[0040] The dual function of cobalt blue encapsulating pigments: Cobalt blue pigment not only locks in cobalt at high temperatures, blocks the diffusion of cobalt ions, inhibits the cobalt-boron thermochemical reaction, and prevents glaze defects and gold bleed, but also has the functions of fine-tuning standard tones, correcting color deviations, and softening color feel. Its tone is soft and leans towards neutral blue, which can neutralize the red and dark tones of oxidation, making the overall color purer, more stable, and in line with the standard cobalt blue requirements.

[0041] If the encapsulated pigment (cobalt oxide = 0) is used alone: ​​the coloring power is weak, the total cobalt content is low, the color is too light, grayish, and lacks blueness, and it cannot achieve the standard cobalt blue.

[0042] If the amount of pigment used is too small (<8 parts, cobalt oxide>12 parts); insufficient cobalt locking: too much free cobalt, resulting in crystallization during glaze firing, matte finish, etc.; intense cobalt-boron reaction during baking gold, resulting in severe gold absorption, blackening, and loss of gloss; insufficient color adjustment: cobalt oxide with a darker or redder hue cannot be corrected, resulting in a darker, duller, or redder color, a harsh hue, and deviation from the standard color. If too much colorant is used (>9 parts, cobalt oxide <11 parts); sufficient cobalt locking: smooth glaze, no crystallization, matte finish, no gold absorption during baking; excessive color mixing: the proportion of soft hues in the color coating is too high, diluting the main blue, the color is too light, too gray, insufficient saturation, weak blue feel, and does not meet the standard cobalt blue.

[0043] Cobalt oxide determines the basic saturation and tone of blue, while the encapsulated pigment serves a dual purpose: locking in cobalt to prevent diffusion and fine-tuning the standard tone. Deviations in dosage will simultaneously affect the purity of the color, the quality of the glaze, and the anti-gold-eating effect. Furthermore, glaze crystallization and matte finish are both reaction products and can induce or amplify gold-eating. This invention's cobalt oxide + encapsulated pigment compound system precisely balances color development, glaze quality, and anti-gold-eating effect by using cobalt oxide to define the main color and the encapsulated pigment to lock in cobalt and adjust the color, achieving stable industrial production. 11 parts cobalt oxide (determining the main color and stabilizing the tone) + 9 parts cobalt blue encapsulated pigment (locking in cobalt, adjusting the color, correcting color deviation, and softening the tone) ensures a pure, saturated, and standard-compliant cobalt blue while completely blocking cobalt ion diffusion, inhibiting the cobalt-boron reaction, and eliminating glaze defects and gold-eating, achieving optimal color development and anti-gold-eating.

[0044] The selection of F88 glaze powder requires both matching melting temperature and chemical inertness of the components; neither can be neglected.

[0045] (1) Matching the melting temperature (basic prerequisite) The firing temperature of magnesia porcelain glaze is 1100~1130℃, and the melting temperature of F88 glaze powder is 1080~1100℃, which is precisely matched with the firing temperature. If the melting temperature is too low, the glaze layer will be over-melted, flow, and have edge defects. If the melting temperature is too high, the glaze layer will not melt, be rough, and the isolation will fail. The melting temperature of F88 is slightly lower than the firing temperature by 20~30℃ to ensure that the glaze layer is properly melted and the color saturation is complete.

[0046] (2) Component chemical compatibility (core and key) F88 glaze powder is a zinc-free, low-alkali, high-silicon-aluminum system, which is chemically inert with cobalt blue components and has no adverse reactions; it is zinc-free (ZnO): zinc ions will form cobalt-zinc-boron complex salts with cobalt ions and boron components, which will aggravate the reaction, induce crystallization, and result in a matte finish and gold absorption; DF116 contains zinc, which is incompatible with the components, has high chemical activity, and is prone to triggering side reactions, so it is not suitable for use; it is low in potassium and sodium and high in silicon and aluminum: DF22 high-potassium feldspar contains a large amount of K2O and Na2O. The high-temperature fluxing properties of alkali metals are too strong, which reduces the viscosity of the glaze layer, accelerates the diffusion of cobalt ions, promotes the boron reaction, and causes isolation failure, resulting in a rough glaze surface and severe gold absorption.

[0047] F88 is selected for its precise matching of melting temperature and dual compatibility with chemical inertness of components; DF11 (containing zinc) and DF22 (high potassium) are not suitable because their components have excessively high chemical activity, which can lead to side reactions.

[0048] In the cobalt blue agent formulation of this invention, F88 glaze powder functions primarily as a flux, while also regulating the melting state of the colorant, improving color uniformity, and stabilizing the color effect. Its dosage must be strictly controlled within the range of 28-30 parts. Deviations in dosage will cause defects in three aspects: melting state, color depth, and color uniformity. The specific mechanism is as follows: If the amount of F88 glaze powder is too small (<28 parts): insufficient melting, poor color development, and unstable color: A. Insufficient fluxing and poor melting effect: The amount of F88 as a fluxing agent is insufficient, the overall melting temperature of the colorant is too high, the viscosity at high temperature is high, and the fluidity is poor. It cannot be fully spread and leveled at high temperature, and the structure of the color layer is loose, the density is poor, and the porosity is high.

[0049] B. Poor color development and dull color: Insufficient melting leads to uneven dispersion of cobalt ions, poor crystal development, weak coloring power, resulting in a light, grayish, dark color with insufficient saturation and an impure blue hue.

[0050] C. Uneven color development and easy color variation: Uneven melting causes local enrichment and local thinning of the colorant, inconsistent diffusion of cobalt ions, color variation at high temperature, large color difference, blurred boundaries, and poor batch stability.

[0051] D. Decreased cobalt-locking and isolation capabilities: Insufficient melting leads to poor bonding between the color layer and the isolation layer, making it easy for cobalt ions to leak and diffuse, indirectly inducing crystallization of the glaze, and increasing the risk of matte finish and gold plating during baking.

[0052] If too much F88 glaze powder is used (>30 parts): the color will be diluted, the color will be uneven, and the color will be unstable. A. Severe color dilution and drastic drop in saturation: F88 is a white transparent flux glaze powder. Excessive use will significantly dilute the cobalt blue coloring concentration, reduce the relative proportion of cobalt ions, and directly lead to a noticeably lighter, grayer color, loss of blue hue, significant decrease in saturation, and failure to meet the standard cobalt blue.

[0053] B. Excessive melting, excessive fluidity, and easy color variation: Excessive flux causes the colorant to melt at too low a temperature, have too low viscosity at high temperatures, and have excessive fluidity. It flows excessively and diffuses out of control at high temperatures, resulting in extremely uneven distribution of cobalt ions, severe color variation, flow lines, color rings, and boundary bleeds, and messy color with huge batch-to-batch color differences.

[0054] C. Unstable color and prone to color deviation: Excessive F88 will change the chemical environment around cobalt ions, and the color lattice is prone to distortion at high temperatures, resulting in a floating, grayish, bluish-white, and unstable color tone.

[0055] D. Exacerbation of glaze defects: Excessive melting causes the color layer to over-melt, blister, develop pinholes, and have matte edges. Poor bonding with the high boron glaze interface further amplifies glaze defects and the risk of gold erosion.

[0056] F88 glaze powder is used as a flux. If too little is used, the glaze will not melt properly, resulting in poor color development and color variations. If too much is used, the color will be diluted and the flowability will be out of control, leading to severe color variations.

[0057] The beneficial effects of this invention are: This invention produces a cobalt blue magnesium-reinforced ceramic with excellent color development: the zirconium-encapsulated structure makes the cobalt blue color fuller, brighter, more uniform and stable; the glaze surface is defect-free: completely eliminating problems such as pores, crystallization, and matte edges; The cobalt blue magnesium-reinforced ceramic of this invention adopts a three-layer synergistic barrier: a zirconium-encapsulated color-developing layer to lock cobalt + an F88 isolation layer to block diffusion + a high boron surface glaze to maintain gloss, which completely solves the problem of gold absorption and loss of gloss caused by thermochemical incompatibility; The cobalt blue magnesium-reinforced porcelain glaze of this invention has a firing pass rate of 85-90%, and the baking and gold decoration pass rate is 90-96%. The cobalt blue magnesium-reinforced ceramic gold decoration of this invention has strong durability: the gold layer has been continuously tested 50 times in an industrial dishwasher without peeling, discoloration, or blackening, meeting the standards for high-end daily-use ceramics. Detailed Implementation

[0058] The present invention will be further described below with reference to embodiments.

[0059] The following will clearly and completely describe the concept, specific solutions, and technical effects of the present invention with reference to embodiments, so as to fully understand the purpose, features, and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. The various technical features in the present invention can be combined interactively without contradicting each other.

[0060] Based on the characteristics of magnesium-reinforced ceramic high-temperature bisque firing, low-temperature glaze firing, and high-boron low-temperature transparent glaze system, this invention addresses the root cause of gold layer loss and gold erosion during baking (830~860℃)—the thermochemical incompatibility between cobalt ions and boron components—by providing a three-layer synergistic barrier technology solution: (1) Zirconium-encapsulated cobalt blue color layer: "locks in" cobalt ions from the source, which is equivalent to putting cobalt ions in a high-temperature resistant "protective suit" to prevent cobalt ions from being released outward; (2) F88 solidified isolation layer: as an intermediate chemical barrier, it prevents residual cobalt ions from migrating upward; (3) High boron low temperature transparent glaze: ensures that the glaze surface is flat and bright, with no matte edges, and is compatible with the sintering of magnesium blanks.

[0061] This invention completely blocks the diffusion path of cobalt ions through the synergistic effect of a three-layer structure, solving common technical problems such as uneven color development in cobalt blue decoration, glaze pores, crystallization, matte edges, and loss of gloss during baking. It achieves a glaze firing qualification rate of 85-90% and a low-temperature baking and baking gold decoration qualification rate of 90-96%.

[0062] This invention solves the process of applying cobalt blue color to magnesium ceramic glaze blanks, including four stages: pretreatment of the blank, preparation and curing of cobalt blue agent, high boron transparent glaze coating and firing, decal painting and low-temperature baking.

[0063] (1) Pretreatment of green body: The rough magnesia-reinforced ceramic green body is placed in a high-frequency vibration device for polishing and grinding, cleaning the surface stains and polishing dust particles, and then placed in a drying room for 3-4 hours and air-dried for later use; the chemical composition (mass fraction) of the green body is: SiO2 65%, Al2O 35%, CaO 2.5%, MgO 26%, K2O 1%, Na2O 0.5%, and water absorption rate <0.5%.

[0064] (2) Preparation and curing of cobalt blue agent: A fixed formula for cobalt blue agent is used, including: 28-30g of medium-temperature zinc-free F88 glaze powder, 11g of cobalt oxide, 9g of cobalt blue coated pigment, and 0.5g of adhesive powder; the material-to-water ratio is 100:150-170, ball milling is performed for 5-8 hours until the residue on a 325-mesh sieve is <0.05%, the specific gravity is 1.34-1.36g / ml, and the flow rate is 35-50s / 100ml. The F88 curing isolation glaze is used, including: medium-temperature zinc-free F88 glaze powder; material-to-water ratio 100:150~170, ball milling for 5~8 hours until the residue on a 325-mesh sieve is <0.05%, specific gravity 1.66~1.68g / ml, flow rate 28~36s / 100ml; The medium-temperature zinc-free F88 glaze powder is a frit powder with the following chemical composition by mass fraction: SiO2 66%, Al2O3 11%, CaO 15%, MgO 1.4%, K2O 2.8%, Na2O 2%, Li2O 0.8%, with the balance being loss on ignition. The melting temperature is 1080~1100℃. Spraying forms a zirconium-encapsulated cobalt blue coloring layer with a thickness of 0.15~0.3mm; after slight drying, spraying an F88 curing isolation layer with a thickness of 0.1~0.15mm; heating to 1130℃ at 5~8℃ / min, holding at that temperature for 30~40min for sintering and curing, and then allowing it to cool naturally.

[0065] (3) High boron transparent glaze coating and firing: The chemical composition of the high-boron low-temperature transparent glaze layer, by mass fraction, includes: ZnO 3%, SiO2 57%, Al2O3 12%, CaO 9%, MgO 0.6%, K2O 3.4%, Na2O 2.8%, Li2O 1.2%, B2O3 6.2%, with the balance being loss on ignition; specific gravity 1.68~1.72g / ml, flow rate 26~38s / 100ml, particle size ≤10μm, and melting temperature 1090~1110℃.

[0066] The coating thickness is 0.10~0.15mm. The temperature is increased to 1110~1145℃ at 6~9℃ / min, and the temperature is held for 25~35min before glazing and firing. The glaze is then naturally cooled to obtain a white body with a glaze color. The glaze firing qualification rate is 85~90%.

[0067] (4) Decal gold painting and low-temperature baking gold: In a dust-free environment, rhodium-containing anti-cobalt gold solution is used for decal gold painting. The gold solution includes resin gold salt, Rh resin acid salt (core high-temperature resistant component), bismuth resin (flux), organic rosin carrier, and organic solvent (with gold content of 11.5~12.5%, rhodium content of 0.18~0.25%, and bismuth content of 0.3~0.4%), and the gold layer thickness is 0.03~0.05mm. The temperature is raised to 830~860℃ at 4~6℃ / min, held at that temperature for 15~20min, and then baked at a low temperature to obtain the finished product by natural cooling. The qualified rate of baked gold decoration is 90~96%.

[0068] The following examples all use a fixed-formula cobalt blue agent and a zirconium-coated cobalt blue coloring layer + F88 curing isolation layer + high boron transparent glaze three-layer synergistic structure, with other parameters kept consistent to ensure the comparability of the experiments.

[0069] The chemical composition (mass fraction) of the magnesium-reinforced ceramic blank is as follows: SiO2 65%, Al2O3 35%, CaO 2.5%, MgO 26%, K2O 1%, Na2O 0.5%; The chemical composition of F88 glaze powder by mass fraction is: SiO2 66%, Al2O3 11%, CaO 15%, MgO 1.4%, K2O 2.8%, Na2O 2%, Li2O 0.8%, with the balance being loss on ignition, and the melting temperature is 1080~1100℃; The chemical composition of DF116 high-zinc frit glaze by mass fraction is: ZnO 8.25%, SiO2 54.5%, Al2O3 12%, CaO 8.7%, MgO 1.5%, K2O 5%, Na2O 3.9%, Li2O 3.1%, B2O3 1.2%, with the balance being loss on ignition; The chemical composition of DF22 high-potassium feldspar by mass fraction is as follows: SiO2: 67%, Al2O3: 17%, CaO: 0.22%, K2O: 11.2%, Na2O: 2.7%, with the balance being loss on ignition; The cobalt blue encapsulated colorant is a zirconium-encapsulated cobalt blue material, with cobalt aluminum spinel (CoAl2O4) as the coloring core and dense zirconium silicate (ZrSiO4) as the protective shell. The colorant is a raw material from Leiying Glaze Company, number 3712. The adhesive powder is sodium carboxymethyl cellulose; The chemical composition of the high boron low-temperature transparent glaze layer by mass fraction includes: ZnO 3%, SiO2 57%, Al2O3 12%, CaO 9%, MgO 0.6%, K2O 3.4%, Na2O 2.8%, Li2O 1.2%, B2O 36.2%, with the balance being loss on ignition; Rhodium-containing gold solution: LG9996, Shenzhen Ruiqiong Materials Technology Co., Ltd. Ordinary rhodium-free gold solution: LG9909 from Shenzhen Ruiqiong Materials Technology Co., Ltd.

[0070] Example 1 A method for preparing a magnesium-reinforced ceramic decorated with cobalt blue and gold, comprising the following steps: (1) Pretreatment of green blank: Select magnesia-reinforced ceramic green blank, polish it with high frequency vibration, clean it, dry it in the drying room for 3.5 hours, and cool it for later use; the water absorption rate of the green blank is 0.38%.

[0071] (2) Preparation of cobalt blue agent: 29g of F88 glaze powder, 11g of cobalt oxide, 9g of cobalt blue coated pigment, 0.5g of adhesive powder, material-to-water ratio of 100:160 (mass ratio), ball milling for 6 hours until the residue on a 325 mesh sieve is <0.05%, then adjust the specific gravity to 1.35g / ml and the flow rate to 42s / 100ml; Preparation of F88 curing isolation glaze: F88 glaze powder, material-to-water ratio 100:160 (mass ratio), ball milled for 6 hours until the residue on a 325 mesh sieve is <0.05%, then the specific gravity is adjusted to 1.67 g / ml and the flow rate is 32 s / 100 ml.

[0072] (3) Spraying color and isolation: Spray cobalt blue agent to obtain a color layer with a thickness of 0.2 mm. After standing for 25 minutes to dry slightly, spray F88 curing isolation glaze to obtain F88 curing isolation layer with a thickness of 0.12 mm. Heat to 1130℃ at 6℃ / min and keep warm for 35 minutes to cure. Let it cool naturally.

[0073] (4) High boron glaze spraying and firing: Spray high boron transparent glaze (specific gravity of high boron transparent glaze is 1.70 g / ml, flow rate is 32 s / 100 ml), thickness is 0.12 mm; heat up to 1130℃ at 8℃ / min and keep warm for 30 min, then cool naturally; the glaze firing qualification rate is 89%.

[0074] (5) Applying gold leaf and baking gold: Use gold solution containing rhodium (13.5% gold and 1.0% rhodium) with a gold layer thickness of 0.04 mm; heat up to 845℃ at 5℃ / min and hold for 18 min for baking gold, then cool naturally; the gold baking qualification rate is 95%.

[0075] Results: The cobalt blue is full and uniform, and the glaze is free of pinholes, crystallization, and matte finish; the gold plating is free of loss of gloss, gold absorption, and the gold layer is bright.

[0076] Example 2 The only difference between this example and Example 1 is that the cobalt blue agent formulation in step (2) is different from the gold baking process in step (5), while the rest is the same as Example 1.

[0077] Cobalt blue agent formula: 28g F88 glaze powder, 11g cobalt oxide, 9g cobalt blue coated pigment, and 0.5g adhesive powder.

[0078] Baking process: Baking temperature 860℃, hold for 20 minutes.

[0079] Results: The color was pure and the glaze was intact; the gold plating did not absorb the gold or lose its gloss; the glaze firing pass rate was 86%, and the gold plating pass rate was 92%.

[0080] Example 3 The only difference between this example and Example 1 is that the cobalt blue agent formulation in step (2) is different from the gold baking process in step (5), while the rest is the same as Example 1.

[0081] Cobalt blue agent formula: 30g F88 glaze powder, 11g cobalt oxide, 9g cobalt blue coated pigment, and 0.5g adhesive powder.

[0082] Baking process: Baking temperature 860℃, hold for 20 minutes.

[0083] Results: The cobalt blue saturation was high, and the glaze surface was smooth; the gold layer was bright and firm with no gold absorption; the glaze firing pass rate was 90%, and the gold firing pass rate was 96%.

[0084] Example 4 The only difference from Example 1 is the cobalt blue agent used in step (2), otherwise it is the same as Example 1.

[0085] Keeping the fixed formula (11g cobalt oxide, 9g cobalt blue pigment, 0.5g adhesive powder) unchanged, only the amount of F88 glaze powder was adjusted, and the results are shown in Table 1.

[0086] Table 1: Comparison Results of F88 Glaze Powder Addition Amount

[0087] Conclusion: When the amount of F88 glaze powder added is in the range of 28-30%, the cobalt blue color is the purest, the glaze surface is without defects, it does not absorb gold, the glaze firing qualification rate is in the standard range of 85-90%, and the gold baking qualification rate is in the standard range of 90-96%.

[0088] Example 5 F88 Glaze Powder Excess Comparison: 32g.

[0089] The only difference from Example 1 is the cobalt blue agent used in step (2), otherwise it is the same as Example 1.

[0090] The amount of F88 glaze powder in the cobalt blue agent was increased to 32g, while the rest of the formula remained unchanged.

[0091] Results: The cobalt blue color showed significant differences, with the color being noticeably lighter and uneven; the glaze had obvious pinholes and matte finish, and the gold plating showed slight loss of gloss; the glaze firing pass rate was 56%, and the gold plating pass rate was 78%, both below the standard and failing to meet the requirements.

[0092] Example 6 F88 Glaze Powder Excess Comparison: 33g.

[0093] The only difference from Example 1 is the cobalt blue agent used in step (2), otherwise it is the same as Example 1.

[0094] The amount of F88 glaze powder was increased to 33g, while the remaining components of the fixed formula remained unchanged.

[0095] Results: The cobalt blue color was significantly lighter and the color difference was large; the glaze surface showed severe crystallization and the edges were matte; the gold plating lost its gloss significantly; the glaze firing pass rate was 0% and the gold plating pass rate was 0%, so the result was deemed unqualified.

[0096] Example 7 Comparative experiment of decreasing cobalt oxide and increasing cobalt blue pigment.

[0097] The only difference from Example 1 is the cobalt blue agent used in step (2), otherwise it is the same as Example 1.

[0098] Keeping the amount of F88 glaze powder, adhesive powder and total addition unchanged, the cobalt oxide content was gradually reduced, and the cobalt blue coating pigment content was increased by an equal amount. The rest of the process was the same. The results are shown in Table 2.

[0099] Table 2: Comparison of results for decreasing cobalt oxide content and increasing cobalt blue pigment content

[0100] Conclusion: Cobalt oxide is the core coloring component of cobalt blue. The optimal ratio of 11g cobalt oxide to 9g cobalt blue pigment is to ensure full color, excellent glaze, and no gold absorption during baking.

[0101] Comparative Example 1 Cancel the isolation glaze layer for comparison.

[0102] The only difference from Example 1 is that step (3) cancels the F88 cured isolation glaze layer; the rest is the same as Example 1.

[0103] Results: Cobalt ions diffused upwards without obstruction; pinholes and matte finish appeared during glaze firing; gold plating resulted in severe gold erosion, graying of the gold layer, and poor adhesion; the glaze firing pass rate was 0% and the gold plating pass rate was 0%, proving that the F88 solidified isolation glaze layer is the core and necessary technical feature for solving the gold erosion defect.

[0104] Comparative Example 2 Comparison of ordinary rhodium-free gold solution.

[0105] The only difference from Example 1 is that the gold solution in step (5) is different. The rhodium-containing gold solution is replaced with ordinary rhodium-free gold solution. The rest is the same as Example 1.

[0106] Results: The gold plating was poor, the gold plating turned black, and the gold plating cracked; the pass rate for gold plating was 20%, and the rest were unqualified.

[0107] Comparative Example 3 Comparison of different fluxes.

[0108] The only difference from Example 1 is the cobalt blue agent formulation in step (2), otherwise it is the same as Example 1.

[0109] In the cobalt blue agent, F88 glaze powder flux was replaced with DF116 high-zinc frit glaze or DF22 high-potassium feldspar, while the other components and their amounts remained unchanged. The results are shown in Table 3.

[0110] Table 3: Comparison Results of Different Flux Substitutions

[0111] Conclusion: Only F88, which does not contain zinc glaze powder, can be stably matched with cobalt-based colorants.

[0112] Comparative Example 4 This invention provides a comprehensive comparison between the cobalt blue agent and traditional cobalt-based spinel colorants.

[0113] The cobalt blue agent formula of this invention is as follows: 28-30g of F88 glaze powder, 11g of cobalt oxide, 9g of cobalt blue coated pigment, and 0.5g of adhesive powder.

[0114] The comparative cobalt-based composite oxide spinel structure colorant formulation (traditional formulation) is as follows: 28-30g F88 glaze powder, 11g cobalt oxide, 9g CoAl2O4 (28CT822), 0.5g adhesive powder, and the rest is the same as in Example 1.

[0115] The comparison results are shown in Table 4.

[0116] Table 4: Comparison of the effects of the cobalt blue agent of the present invention and traditional spinel colorants

[0117] Conclusion: (1) The fixed formula cobalt blue agent of the present invention relies on cobalt oxide for coloring + cobalt blue to encapsulate the colorant to lock cobalt + F88 solidification isolation layer to block diffusion, forming a double protection, the glaze firing surface has excellent performance and no defects; the baking gold performance is excellent, with no gold absorption and no loss of gloss.

[0118] (2) Traditional cobalt-based composite oxide spinel structure pigments: without encapsulation or isolation, cobalt ions diffuse very easily, resulting in extremely poor glaze performance and poor gold plating performance, making them unusable.

[0119] (3) It is fully demonstrated that the zirconium-encapsulated cobalt blue color layer + F88 curing isolation layer is the core key to solving glaze defects and gold plating.

[0120] In summary, this invention employs a fixed formula of cobalt blue agent (28-30g F88 glaze powder, 11g cobalt oxide, 9g cobalt blue encapsulated pigment, and 0.5g adhesive powder) to construct a three-layer synergistic structure: a zirconium-encapsulated cobalt blue coloring layer, an F88 curing and isolating layer, and a high-boron transparent glaze. This fundamentally blocks cobalt ion diffusion, completely resolving the issues of gold absorption and loss of gloss caused by thermochemical incompatibility, while also eliminating defects such as glaze pores, crystallization, and matte edges. The glaze firing success rate of this invention is 85-90%, and the baking and gilding success rate is 90-96%, enabling stable industrial production of high-end magnesium-reinforced ceramic cobalt blue gilded products.

[0121] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A cobalt blue magnesium-reinforced porcelain, comprising a magnesium-reinforced porcelain body, characterized in that, The surface of the magnesium-reinforced ceramic body is sequentially provided with a cobalt blue coloring layer, an F88 curing and isolation layer, and a high-boron transparent glaze layer. The raw materials for the cobalt blue color layer, by mass parts, include: 28-30 parts of F88 glaze powder, 11-12 parts of cobalt oxide, 8-9 parts of cobalt blue encapsulated pigment, and 0.5-1 parts of adhesive powder.

2. The cobalt blue magnesium-reinforced ceramic according to claim 1, characterized in that, The chemical composition of magnesium-reinforced ceramic bodies, by mass fraction, includes: SiO2 63~65%, Al2O3 5~6%, CaO 2.5~3%, MgO 25~26%, K2O 1~2%, Na2O 0.5~1%; The raw materials for the F88 curing isolation glaze layer include F88 glaze powder; The chemical composition of F88 glaze powder by mass fraction includes: SiO2 65~68%, Al2O3 10~13%, CaO 13~16%, MgO 1~2%, K2O 2~3%, Na2O 2~3%, Li2O 0~0.8%, and loss on ignition 0.5~1%; The chemical composition of the high-boron transparent glaze layer, by mass fraction, includes: ZnO 3~4%, SiO2 55~57%, Al2O3 12~13%, CaO 9~10%, MgO 0.6~1%, K2O 3~3.4%, Na2O 2.2~2.8%, Li2O 0.8~1.2%, B2O3 6~6.2%, and loss on ignition 4~6%. The cobalt blue pigment is a zirconium-encapsulated cobalt blue pigment.

3. The cobalt blue magnesium-reinforced ceramic according to claim 2, characterized in that, The raw materials for the cobalt blue coloring layer, by weight, include: 28-30 parts F88 glaze powder, 11 parts cobalt oxide, 9 parts cobalt blue encapsulated pigment, and 0.5 parts adhesive powder; The chemical composition of the magnesium-reinforced ceramic body, by mass fraction, includes: SiO2 65%, Al2O 35%, CaO 2.5%, MgO 26%, K2O 1%, Na2O 0.5%; The chemical composition of F88 glaze powder by mass fraction includes: SiO2 66%, Al2O3 11%, CaO 15%, MgO 1.4%, K2O 2.8%, Na2O 2%, Li2O 0.8%, and loss on ignition 1%. The chemical composition of the high boron transparent glaze layer, by mass fraction, includes: ZnO 3%, SiO2 57%, Al2O3 12%, CaO 9%, MgO 0.6%, K2O 3.4%, Na2O 2.8%, Li2O 1.2%, B2O 36.2%, and loss on ignition 4.8%. The zirconium-coated cobalt blue pigment is a zirconium silicate-coated cobalt aluminum spinel pigment.

4. The method for preparing cobalt blue magnesium-reinforced ceramic according to any one of claims 1-3, characterized in that, Includes the following steps; (1) Spray cobalt blue agent onto the surface of the magnesium-reinforced ceramic body and let it stand; (2) Spray F88 curing isolation glaze and sinter; (3) Spray high boron transparent glaze, sinter, and obtain cobalt blue magnesium-reinforced porcelain.

5. The method for preparing cobalt blue magnesium-reinforced ceramic according to claim 4, characterized in that, Step (1) The magnesium-reinforced ceramic body is pre-polished, cleaned and dried; Step (1) The water absorption rate of the magnesium-reinforced ceramic body is <0.5%.

6. The method for preparing cobalt blue magnesium-reinforced ceramic according to claim 4, characterized in that, Step (1) The material-to-water ratio of cobalt blue agent is 100:150~170, the residue on a 325-mesh sieve is <0.05%, the specific gravity is 1.34~1.36g / ml, and the flow rate is 35~50s / 100ml; Step (1) Cobalt blue agent spraying thickness 0.15~0.3mm; Step (2) The material-to-water ratio of F88 curing isolation glaze is 100:150~170, the residue on a 325-mesh sieve is <0.05%, the specific gravity is 1.66~1.68g / ml, and the flow rate is 28~36s / 100ml; Step (2) Apply F88 curing isolation glaze with a thickness of 0.1~0.15mm; Step (2) Sintering temperature 1125~1145℃, holding time 30~40min; Step (2) After sintering, allow it to cool naturally.

7. The method for preparing cobalt blue magnesium-reinforced ceramic according to claim 4, characterized in that, Step (3) Apply a high boron transparent glaze with a thickness of 0.10~0.15mm; Step (3) Sintering temperature 1110~1145℃, holding time 25~35min; Step (3) The specific gravity of the high boron transparent glaze is 1.68~1.72g / ml, and the flow rate is 26~38s / 100ml.

8. A cobalt blue magnesium-reinforced porcelain with gold decoration, characterized in that, The cobalt blue magnesium-reinforced porcelain includes the cobalt blue magnesium-reinforced porcelain according to any one of claims 1-3 or the cobalt blue magnesium-reinforced porcelain prepared by the preparation method according to any one of claims 4-7, wherein the surface of the cobalt blue magnesium-reinforced porcelain is provided with a gold decorative layer.

9. The method for preparing the gold-decorated cobalt blue magnesium-reinforced porcelain according to claim 8, characterized in that, Includes the following steps; Gold decorations are applied to the surface of cobalt blue magnesium-reinforced porcelain, and then the gold is baked on to obtain cobalt blue magnesium-reinforced porcelain with gold decoration.

10. The method for preparing gold-decorated cobalt blue magnesium-reinforced porcelain according to claim 9, characterized in that, The gold painting process uses rhodium-containing gold solution with a gold content of 11.5~12.5wt% and a rhodium content of 0.18~0.25wt%. The thickness of the gold leaf is 0.03~0.05mm; The baking temperature is 830~860℃, and the holding time is 15~20 minutes.

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