Glaze composition, glaze slip, ceramic product and preparation method thereof

Abstract

The invention relates to a glaze composition, glaze slip, a ceramic product and a preparation method of the ceramic product. The glaze composition is prepared from the following components in parts by mass: 65 to 75 parts of potassium feldspar, 5 to 8 parts of calcined talc, 5 to 9 parts of kaolin, 12 to 20 parts of quartz sand, 0.5 to 2 parts of SrCO3, 0.2 to 1 part of Li2CO3, 0.1 to 0.6 part of K2CO3, 0.2 to 1 part of ZnO and 0.1 to 0.4 part of BaCO3; the fineness of the quartz sand meets the condition that the sieve residue K1 of ten thousand holes is greater than or equal to 0.02% and less than or equal to 0.06%; the fineness of the potassium feldspar meets the condition that the residue K2 on a sieve with ten thousand holes is greater than or equal to 0.1% and less than or equal to 0.5%. All the components act according to a specific proportion, so that the flatness and glossiness of a glaze surface formed by the glaze composition can be effectively improved, and the glaze composition is relatively high in whiteness and relatively good in attractiveness.

Description

Technical Field

[0001] The present application relates to the technical field of glazes, and in particular to a glaze composition, a glaze slurry, a ceramic product and a preparation method thereof. Background Art

[0002] Glaze is a layer of glass-like substance covering the surface of ceramics. It has some physical and chemical properties similar to glass, such as isotropy, no obvious melting point, gloss, high hardness, and resistance to acid and alkali corrosion (except hydrofluoric acid and hot alkali). 2 O 3 Ceramic tubes are used as vacuum switches, high-power thyristors, vacuum relays, vacuum capacitors, high-frequency high-power electron tubes and other vacuum devices. All of them need to be glazed on the outer surface of the ceramic shell. The glaze is used to cover the surface of the shell to protect the surface of the ceramic body from pollution, and is generally sintered in a hydrogen furnace together with the metallization layer. However, the traditional glaze formula has bubbles and is prone to produce glaze inequality like water ripples, which affects the appearance.

[0003] Therefore, it is necessary to improve the traditional technology. Summary of the invention

[0004] Based on this, the present application provides a glaze composition, glaze slurry, ceramic product and preparation method thereof with good aesthetics.

[0005] The technical solution of this application to solve the above technical problems is as follows.

[0006] On the one hand, the present application provides a glaze composition, which comprises the following components by weight:

[0007] Potassium feldspar 65-75 parts, calcined talc 5-8 parts, kaolin 5-9 parts, quartz sand 12-20 parts, SrCO 3 0.5~2 parts, Li 2 CO 3 0.2~1 parts, K 2 CO 3 0.1~0.6 parts, ZnO 0.2~1 parts and BaCO 3 0.1~0.4 parts; the fineness of the quartz sand meets the K of the 10,000-hole sieve 1 0.02%≤K 1 ≤0.06%; the fineness of the potassium feldspar meets the K 2 0.1%≤K 2 ≤0.5%.

[0008] In some embodiments, the glaze composition includes the following components by weight:

[0009] Potassium feldspar 68-72 parts, calcined talc 6-8 parts, kaolin 7-9 parts, quartz sand 12-15 parts, SrCO 3 1~2 parts, Li 2 CO 3 0.2~0.5 parts, K 2 CO 3 0.1~0.4 parts, ZnO 0.2~0.5 parts and BaCO 3 0.1~0.25 parts.

[0010] In some embodiments, in the glaze composition, the kaolin comprises at least one of raw kaolin and calcined kaolin.

[0011] In some embodiments, in the glaze composition, the potassium feldspar comprises calcined potassium feldspar.

[0012] On one hand, the present application provides a glaze slurry, comprising the above-mentioned glaze composition, a binder and water.

[0013] In some of the embodiments, in the glaze slurry, the viscosity of the glaze slurry is 0.15 Pa.S~0.25 Pa.S.

[0014] On the one hand, the present application provides a method for preparing a glaze slurry, comprising the following steps:

[0015] The above glaze composition, a binder and water are mixed to prepare a glaze slurry.

[0016] On one hand, the present application provides a ceramic product, including a ceramic substrate and a glaze layer on the surface of the ceramic substrate, and the raw materials for preparing the glaze layer include the above-mentioned glaze slurry.

[0017] In some embodiments, in the ceramic product, the glaze layer comprises the following components by mass percentage:

[0018] SiO 2 65%~70%,Al 2 O 3 15%~19%, CaO 0.15%~0.25%, MgO 2%~3%, Na 2 O 2%~3%, K 2 O 7%~9%, ZnO 0.2%~0.5%, SrO 0.3%~2%, Li 2 O 0.1%~0.6% and BaO 0.05%~0.3%.

[0019] In some embodiments, in the ceramic product, the Al 2 O 3 With the SiO 2 The molar ratio is 1:5~1:10.

[0020] On the one hand, the present application provides a method for preparing a ceramic product, comprising the following steps:

[0021] The glaze slurry is placed on the surface of the ceramic body to obtain a glazed body;

[0022] The glazed green body is subjected to glaze firing treatment to prepare a ceramic product.

[0023] In some of the embodiments, in the method for preparing ceramic products, the glaze firing treatment includes a first glaze firing and a second glaze firing performed sequentially, the temperature of the first glaze firing is 1220°C~1280°C, and the temperature of the second glaze firing is 1390°C~1430°C.

[0024] Compared with the prior art, the glaze composition of the present application has the following beneficial effects:

[0025] The glaze composition of the present application comprises potassium feldspar, calcined talc, kaolin, quartz sand, SrCO 3 , Li 2 CO 3 , K 2 CO 3 , ZnO and BaCO 3 , and control the fineness of quartz sand and potassium feldspar; by controlling the fineness of quartz sand, the glaze is effectively promoted to dissolve in the middle of the glaze body when it is melted, thereby effectively reducing the stress caused by the volume change of silicon oxide in the quartz sand, and effectively avoiding the glaze composition from causing dry glaze or glaze explosion during subsequent glaze firing; by controlling the fineness of potassium feldspar, the brightness of the glaze surface is effectively improved, and the glaze flow phenomenon is effectively avoided; the various components act in a specific proportion, which can effectively improve the flatness and glossiness of the glaze surface formed by the glaze composition, and the whiteness is higher and the appearance is better.

[0026] At the same time, the glaze composition of the present application has the characteristics of high surface resistivity, no moisture absorption, not easy to be polluted, easy to clean, good wear resistance and high mechanical strength. DETAILED DESCRIPTION

[0027] The present application will be further described in detail below in conjunction with the embodiments and examples. It should be understood that these embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0028] It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present application, and the equivalent forms obtained also fall within the scope of protection of the present application. For example, the features illustrated or described as part of one embodiment can be combined in another embodiment in a suitable manner to produce a new embodiment. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing implementation modes and embodiments and are not intended to limit this application.

[0030] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0031] In the present application, "plurality", "multiple", "multiple times", etc., unless otherwise specified, refer to a quantity greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0032] As used herein, "combination thereof", "any combination thereof", "any combination thereof" etc. include all suitable combinations of any two or more of the listed items.

[0033] Herein, the “suitable” mentioned in “suitable combination”, “suitable method”, “any suitable method”, etc., shall be based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0034] Herein, "preferred", "better", "more preferred", and "suitable" are only used to describe implementation methods or examples with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of this application. If multiple "preferred" items appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "preferred" item is independent.

[0035] In the present application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0036] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0037] In the present application, the terms "first", "second", "third", "fourth", etc. in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0038] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0039] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed herein should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including numerical interval types such as percentage intervals, ratio intervals, and ratio intervals.

[0040] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0041] In this application, the term "room temperature" or "normal temperature" generally refers to 4°C to 35°C, for example, 20°C ± 5°C. In some embodiments of this application, "room temperature" or "normal temperature" refers to 10°C to 30°C. In some embodiments of this application, "room temperature" or "normal temperature" refers to 20°C to 30°C.

[0042] In this application, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 3~5 h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0043] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the invention purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0044] The mass or weight of the relevant components mentioned in the specification of the embodiments of the present application may not only refer to the specific content of each component, but also indicate the proportional relationship of the mass or weight between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the specification of the embodiments of the present application, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass or weight described in the specification of the embodiments of the present application may be units known in the chemical industry such as μg, mg, g, and kg.

[0045] The traditional potassium feldspar-talc high-temperature transparent glaze contains bubbles. When observed under fluorescent light, due to the different refraction of light, it will appear similar to pig pores or orange peel features, with a rough appearance, which greatly affects the appearance; it is easy to produce water ripple-like glaze unevenness, that is, the glaze surface is not a straight line under the light, but tortuous, which greatly affects the appearance of the glazed parts, and thus affects the appearance quality of the whole tube after installation; it has poor matching with the current metallization sintering process. After metallization, there are many glaze layer quality problems such as glaze bubbles, dry glaze, glaze deficiency, ripple-like glaze unevenness, glaze explosion, glaze bubbles, glaze color difference, etc. After metallization, due to glaze layer quality problems The qualified product rate has been above 5%; the corrugated porcelain parts must be sprayed with glaze for the second time to ensure that the glaze on the corrugated side does not dry up after metallization sintering. The second glazing includes spraying glaze - wiping the sealing surface - primary glaze firing - second glazing - wiping the sealing surface - secondary glaze firing - metallization. This results in low production capacity of corrugated porcelain, difficult production organization, large energy loss in the second glazing firing, prolonged production cycle, and a significant increase in the glazing cost of corrugated porcelain parts. At the same time, the thickness of the second glaze spraying must be thicker to ensure that the glaze on the corrugated side does not dry up after metallization. However, the thick glaze layer on the peak is prone to glaze explosion, glaze bubbles and other problems after glazing, causing high cost losses to the company.

[0046] An embodiment of the present application provides a glaze composition, which comprises the following components by weight:

[0047] Potassium feldspar 65-75 parts, calcined talc 5-8 parts, kaolin 5-9 parts, quartz sand 12-20 parts, SrCO 3 0.5~2 parts, Li 2 CO 3 0.2~1 parts, K 2 CO 3 0.1~0.6 parts, ZnO 0.2~1 parts and BaCO 3 0.1~0.4 parts; the fineness of quartz sand meets the K of 10,000-hole sieve 1 0.02%≤K 1 ≤0.06%; the fineness of potassium feldspar meets the K content of the 10,000-hole sieve 2 0.1%≤K 2 ≤0.5%.

[0048] The glaze composition of the present application comprises potassium feldspar, calcined talc, kaolin, quartz sand, SrCO 3 , Li 2 CO 3 , K 2 CO 3 , ZnO and BaCO 3 , and control the fineness of quartz sand and potassium feldspar; by controlling the fineness of quartz sand, the glaze is effectively promoted to dissolve in the middle of the glaze body when it is melted, thereby effectively reducing the stress caused by the volume change of silicon oxide in the quartz sand, and effectively avoiding the glaze composition from causing dry glaze or glaze explosion during the subsequent glaze firing process; by controlling the fineness of potassium feldspar, the brightness of the glaze surface is effectively improved, and the glaze flow phenomenon is effectively avoided; each component acts in a specific proportion, which can effectively improve the flatness and glossiness of the glaze surface formed by the glaze composition, and the whiteness is high, and the appearance is good. Among them, the glaze surface is flat, free of bubbles, cracks, pinholes, color difference, and the glaze surface is bright and beautiful.

[0049] At the same time, the glaze composition of the present application has the characteristics of high surface resistivity, no moisture absorption, not easy to be polluted, easy to clean, good wear resistance and high mechanical strength.

[0050] The main component of quartz sand is silicon oxide, which is an indispensable acidic oxide in glaze. The researchers of this application found that the particle size of quartz sand is directly related to the amount and size of the remaining quartz sand in the glaze. The finer the quartz sand particles, the more it will dissolve in the middle of the glaze when the glaze melts. The less quartz sand is left, the smaller the volume change caused by the quartz sand due to the drop in glaze temperature after the glaze solidifies, and the smaller the stress caused by the volume change. However, if the quartz sand is too fine, the viscosity of the glaze liquid (i.e., high-temperature viscosity) will decrease at high temperatures, which is easy to cause dry glaze; if the quartz sand is too coarse, for example, the residual K of the 10,000-hole sieve reaches 0.1, a large amount of glaze explosion will occur during sintering of the glaze.

[0051] If potassium feldspar is too fine, for example, the K content on the 10,000-pore sieve reaches below 0.05%, glaze flow will occur. If potassium feldspar is too coarse, for example, the K content on the 10,000-pore sieve reaches above 2%, the glaze surface will become dull and not shiny.

[0052] Alkaline earth metal oxides with larger molecular weight and barium oxide (molecular weight is 153, through BaCO 3 Introduced), effectively improve the brightness of the glaze.

[0053] During the metallization sintering process, CaCO 3 Smoking can easily cause the glaze to turn black, and CaCO needs to be strictly controlled 3 proportion.

[0054] Calcium oxide can produce microcrystals on the glaze surface, and microcrystals make the glaze surface dull. This is mainly because the glaze cools down too slowly, and microcrystals are produced on the surface of the glaze, which promotes the growth of grains. In order to obtain a beautiful glaze with a strong sense of light, the glaze surface must be kept in a liquid state at high temperature as much as possible. Accelerating the cooling process is an ideal measure.

[0055] In addition, during the metallization sintering process, CaCO3 will easily produce smoke and cause the glaze to turn black. Therefore, we actually introduce a maximum of 0.5% CaCO3 or even no CaCO3 at all.

[0056] SrCO 3 It can effectively increase the firing resistance of the glaze, and the glaze is not easy to dry out when metallized at high temperature, which effectively solves the problem of side drying glaze of corrugated porcelain.

[0057] The glaze composition of the present application is formulated into a glaze slurry and is used on the ceramic surface. It has good compatibility with the metallization process. One-time glazing can ensure that the glaze on the corrugated side will not dry out after metallization sintering, fundamentally solving the problem that traditional sprayed corrugated porcelain pieces need to be glazed twice; and reducing the proportion of glazed pieces recycled due to glaze layer quality problems after metallization to less than 2%.

[0058] In addition, the glaze composition of the present application makes the ceramic body more impermeable to liquids and gases; prevents the tube from being contaminated, and even if it is contaminated, it can be easily cleaned with detergents, etc.; and improves the mechanical strength and dielectric properties of the ceramic body.

[0059] The glaze composition of the present application has a high-temperature viscosity, a surface tension and a thermal expansion coefficient within a suitable range.

[0060] It can be understood that in some of the examples, the glaze composition includes the following components by mass percentage:

[0061] Potassium feldspar 65%~75%, burned talc 5%~8%, kaolin 5%~9%, quartz sand 12%~20%, SrCO 3 0.5%~2%, Li 2 CO 3 0.2%~1%, K 2 CO 3 0.1%~0.6%, ZnO 0.2%~1% and BaCO 3 0.1%~0.4%.

[0062] It can be understood that in some of the examples, the compositions of potassium feldspar, calcined talc, raw kaolin, calcined kaolin, and quartz sand are as shown in Table 1:

[0063] Table 1

[0064]

[0065] SrCO 3 、ZnO、Li 2 CO3、K 2 CO 3 It is chemically pure.

[0066] It can be understood that in the glaze composition, by weight, potassium feldspar includes but is not limited to 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts; calcined talc includes but is not limited to 5 parts, 6 parts, 7 parts, 8 parts; kaolin includes but is not limited to 5 parts, 6 parts, 7 parts, 8 parts, 9 parts; quartz sand includes but is not limited to 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts; SrCO 3 Including but not limited to 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts; Li 2 CO 3Including but not limited to 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1; K 2 CO 3 Including but not limited to 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part; ZnO including but not limited to 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part; BaCO 3 Including but not limited to 0.1 part, 0.2 part, 0.3 part, 0.4 part; in some examples, any two of these point values ​​can be within the range formed by the end values, the same below.

[0067] In some of the examples, the glaze composition includes the following components by weight:

[0068] Potassium feldspar 68-72 parts, calcined talc 6-8 parts, kaolin 7-9 parts, quartz sand 12-15 parts, SrCO 3 1~2 parts, Li 2 CO 3 0.2~0.5 parts, K 2 CO 3 0.1~0.4 parts, ZnO 0.2~0.5 parts and BaCO 3 0.1~0.25 parts.

[0069] In some of the examples, the glaze composition includes the following components by weight:

[0070] Potassium feldspar 69-71 parts, calcined talc 6-7 parts, kaolin 7.5-8.5 parts, quartz sand 13-14 parts, SrCO 3 1~1.5 parts, Li 2 CO 3 0.2~0.3 parts, K 2 CO 3 0.2~0.3 parts, ZnO 0.3~0.4 parts and BaCO 3 0.15~0.2 portion.

[0071] The researchers of this application found that because raw talc has a flaky structure, it is easy to form a directional arrangement in the glaze and form an ordered state. When fired, it produces anisotropic shrinkage, which often easily causes cracks in the glaze surface. Therefore, burnt talc is used. In some examples, the preparation of burnt talc is to calcine raw talc at a high temperature; further, the calcination temperature is 1300~1350℃; in this way, the layered structure of raw talc can be destroyed.

[0072] In some examples, in the glaze composition, the kaolin includes at least one of raw kaolin and calcined kaolin. Further, the mass ratio of raw kaolin to calcined kaolin is 1 to 5: 1. Optionally, the mass ratio of raw kaolin to calcined kaolin is 1.2 to 2: 1.

[0073] Furthermore, the calcined kaolin is obtained by calcining raw kaolin; further, the calcination temperature is 850°C to 900°C; thus, it is more suitable for the current glaze spraying process.

[0074] In some examples, in the glaze composition, the potassium feldspar includes calcined potassium feldspar. Further, the calcined potassium feldspar is obtained by calcining potassium feldspar; further, the calcination temperature is 950°C to 1000°C.

[0075] One embodiment of the present application provides a glaze slurry, comprising the above-mentioned glaze composition, a binder and water.

[0076] In some of the examples, in the glaze slurry, the viscosity of the glaze slurry is 0.15 Pa.S~0.25 Pa.S.

[0077] It can be understood that the viscosity of the glaze slurry includes but is not limited to 0.15 Pa.S, 0.16 Pa.S, 0.17 Pa.S, 0.18 Pa.S, 0.19 Pa.S, 0.20 Pa.S, 0.21 Pa.S, 0.22 Pa.S, 0.23 Pa.S, 0.24 Pa.S, and 0.25 Pa.S.

[0078] The glaze slurry provided in the present application can solve the problem of secondary glaze spraying of corrugated porcelain with traditional glaze formulas and improve the glazing capacity; and it has a good match with the existing metallization sintering process, reduces the quality problem of the glaze layer after metallization, improves the one-time finished product rate after metallization, and reduces the proportion of glaze parts recycled due to glaze layer quality problems after metallization to less than 2%, effectively reducing the product quality cost loss of glaze parts.

[0079] The glaze layer formed by the glaze slurry provided in the present application has no change in the 800°C thermal shock resistance and the low-temperature minus 50°C impact test after 10 repeated tests, has high surface resistivity, does not absorb moisture, is not easily contaminated, and is easy to clean. At the same time, it is smooth, flat (a straight line observed under light), and beautiful, and its wear resistance and mechanical strength are also improved. Production tests of more than 50,000 pieces have shown that it matches the current glazing metallization and electroplating processes, and is adapted to the current glazing and metallization process technical conditions and vacuum switch tube installation processes.

[0080] The glaze slurry provided in this application is applicable to a wide range of applications, including but not limited to 95 porcelain; further, including but not limited to CaO—SiO 2 —Al 2 O 3Ternary 95 porcelain, quaternary CaO-MgO-SiO 2 —Al 2 O 3 System, zirconium-containing quaternary system CaO—MgO—SiO 2 —Al 2 O 3 —ZrO 2 , both can be glazed.

[0081] The glaze is fired in a hydrogen furnace simultaneously with the metallization process. In some of these examples, the binder in the glaze slurry includes polyvinyl alcohol.

[0082] It can be understood that the glaze slurry provided in the present application may also include additives commonly used in the art, including but not limited to at least one of a whitening agent and acid scarlet.

[0083] In this way, the appearance and texture of the glaze are improved.

[0084] An embodiment of the present application provides a method for preparing a glaze slurry, comprising the following steps:

[0085] The above glaze composition, a binder and water are mixed to prepare a glaze slurry.

[0086] In some of the examples, in the method for preparing the glaze slurry, the glaze composition and water are mixed and then ball-milled, and then a binder is added. It is understood that additives may be further added.

[0087] Furthermore, after ball milling, the product was sieved through a 100-mesh sieve.

[0088] An embodiment of the present application provides a ceramic product, including a ceramic substrate and a glaze layer on the surface of the ceramic substrate, and the raw materials for preparing the glaze layer include the above-mentioned glaze slurry.

[0089] In some of these examples, in the ceramic article, the glaze layer includes the following components by weight percentage:

[0090] SiO 2 65%~70%,Al 2 O 3 15%~19%, CaO 0.15%~0.25%, MgO 2%~3%, Na 2 O 2%~3%, K 2 O 7%~9%, ZnO 0.2%~0.5%, SrO 0.3%~2%, Li 2 O 0.1%~0.6% and BaO 0.05%~0.3%.

[0091] In some examples, Al 2 O 3 With SiO 2The molar ratio is 1:5~1:10.

[0092] Understandable, Al 2 O 3 With SiO 2 The molar ratio includes but is not limited to 1:5, 1:6, 1:7, 1:8, 1:9, 1:10.

[0093] By controlling Al 2 O 3 With SiO 2 The molar ratio can effectively improve the glossiness of the glaze.

[0094] Al 2 O 3 With SiO 2 When the molar ratio is 1:4, the glaze has poor glossiness, and when it is 1:3, it becomes a matte glaze.

[0095] In some examples, SiO 2 The glaze molar number is 5.5~7, Al 2 O 3 The glaze formula molar number is 0.8~1.1.

[0096] It can be understood that ceramic products include but are not limited to electric vacuum devices; further, electric vacuum devices include but are not limited to at least one of electric vacuum switches, electric vacuum relays, electric vacuum capacitors, high-frequency and high-power electron tubes, etc.

[0097] An embodiment of the present application provides a method for preparing a ceramic product, comprising the following steps:

[0098] The glaze slurry is placed on the surface of the ceramic body to obtain a glazed body;

[0099] The glazed body is subjected to a glaze firing process to prepare a ceramic product.

[0100] In some of the examples, in the method for preparing a ceramic product, the glaze firing process includes a first glaze firing and a second glaze firing performed sequentially, the temperature of the first glaze firing is 1220°C~1280°C, and the temperature of the second glaze firing is 1390°C~1430°C.

[0101] It can be understood that the temperature of the first glaze firing includes but is not limited to 1220℃, 1230℃, 1240℃, 1250℃, 1260℃, 1270℃, and 1280℃; the temperature of the second glaze firing includes but is not limited to 1390℃, 1400℃, 1410℃, 1420℃, and 1430℃.

[0102] The study found that the crystal transformation of quartz grains during firing is a key factor affecting the glaze. There are two types of crystal transformation of quartz grains: primary and secondary. The transformation between primary variants occurs at 1000°C, from α-quartz to α-phosphite, with a large volume change of about 16%, but due to its slow transformation speed and long time, the contradiction of volume effect is not prominent and has little effect; while in the secondary variant, β-quartz transforms into α-quartz at 573°C, with a volume change of about 0.82%, but due to the fast transformation speed, the actual effect of the volume change is very large, generating huge internal stress in a short time, which is very easy to cause glaze cracking and glaze explosion.

[0103] By carrying out the first and second glaze firings in sequence, the cracking and explosion of the glaze can be effectively avoided, while at the same time, the gas release reaction of the raw materials is promoted to be thorough.

[0104] In some of the examples, in the method for preparing the ceramic product, the first glaze firing time is 0.5 h~2 h.

[0105] It can be understood that the time for the first glaze firing includes but is not limited to 0.5 h, 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h, and 2 h.

[0106] In some of the examples, in the method for preparing the ceramic product, the second glaze firing time is 1 h to 3 h.

[0107] It can be understood that the time for the second glaze firing includes but is not limited to 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h, 2.8 h, and 3 h.

[0108] In some examples, in the method for preparing ceramic products, the method of applying the glaze slurry to the surface of the ceramic body includes spraying glaze. Furthermore, the pressure of spraying glaze is 0.3 MPa~0.5 MPa. In this way, the uniformity of the glaze surface can be effectively improved. It is understood that the pressure of spraying glaze includes but is not limited to 0.3 MPa, 0.4 MPa, and 0.5 MPa.

[0109] It can be understood that the second glaze firing is carried out in a hydrogen furnace synchronously with the existing metallization process.

[0110] The present application is further described in detail below in conjunction with specific implementation methods, but the implementation methods of the present application are not limited thereto.

[0111] Example 1

[0112] (1) The glaze composition comprises the following components in parts by mass:

[0113] 69.2 parts of potassium feldspar, 7 parts of calcined talc, 5 parts of raw kaolin, 3.4 parts of calcined kaolin, 13.2 parts of quartz sand, SrCO 3 1.2 parts, Li 2 CO 3 0.2 parts, K 2 CO 3 0.3 parts, ZnO 0.3 parts and BaCO 3 0.2 parts; the fineness of the quartz sand meets the K of the 10,000-hole sieve 1 The fineness of potassium feldspar meets the K content of 10,000-hole sieve. 2 It is 0.1%.

[0114] (2) The glaze composition and water are mixed and ball-milled, and the mixture is passed through a 100-mesh sieve, and then a binder of polyvinyl alcohol and acid scarlet are added to prepare a glaze slurry with a viscosity of 0.15 Pa.S;

[0115] (3) spraying the glaze slurry (spraying pressure 0.4 MPa) onto the surface of the ceramic body to obtain a glazed body;

[0116] (4) The glazed body is subjected to a first glaze firing treatment (maintaining temperature at 1250°C for 1 h) and a metallization firing (second glaze firing treatment, maintaining temperature at 1420°C for 2 h) to prepare a ceramic product.

[0117] Example 2

[0118] The same as Example 1, except that (1) the glaze composition is as follows:

[0119] The glaze composition includes the following components by weight:

[0120] Calcined potassium feldspar 70.2 parts, calcined talc 6.5 parts, raw kaolin 5 parts, calcined kaolin 2.9 parts, quartz sand 13.1 parts, SrCO 3 1.3 parts, Li 2 CO 3 0.25 parts, K 2 CO 3 0.25 parts, ZnO 0.32 parts and BaCO 3 0.18 portion.

[0121] Example 3

[0122] The same as Example 1, except that: (1) in the glaze composition, the fineness of the quartz sand satisfies the K 1 It is 0.06%.

[0123] Example 4

[0124] The same as Example 1, except that: (1) in the glaze composition, the fineness of potassium feldspar satisfies the K 2 It is 0.5%.

[0125] Example 5

[0126] The method is basically the same as Example 1, except that in (4), the first glaze firing treatment is omitted and the second glaze firing treatment is carried out at 1420°C for 3 h.

[0127] Comparative Example 1

[0128] The same as Example 1, except that: (1) in the glaze composition, the fineness of the quartz sand satisfies the K 1 It is 0.1%.

[0129] Comparative Example 2

[0130] The same as Example 1, except that: (1) in the glaze composition, the fineness of the quartz sand satisfies the K 1 It is 0.01%.

[0131] Comparative Example 3

[0132] The same as Example 1, except that: (1) in the glaze composition, the fineness of potassium feldspar satisfies the K 2 It is 0.01%.

[0133] Comparative Example 4

[0134] The same as Example 1, except that: (1) in the glaze composition, the fineness of potassium feldspar satisfies the K 2 It is 2%.

[0135] The ceramic products prepared in each embodiment have a smooth, flat (a straight line observed under light), beautiful glaze surface, good wear resistance, high mechanical strength, high whiteness and gloss, high surface resistivity, no moisture absorption, not easy to be contaminated, and easy to clean; among them, the glaze flatness and other properties of the ceramic products prepared in Examples 1 to 4 are better than those in Example 5; while a large amount of glaze explosion occurs in Comparative Example 1 during metallization firing; Comparative Example 2 causes dry glaze after metallization firing; Comparative Example 3 produces glaze flow when spraying glaze; Comparative Example 4 has a dull glaze surface after metallization firing.

[0136] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0137] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A glaze composition, characterized in that: By mass, it includes the following components: 65-75 parts of potassium feldspar, 5-8 parts of calcined talc, 5-9 parts of kaolin, 12-20 parts of quartz sand, 0.5-2 parts of SrCO3, 0.2-1 parts of Li2CO3, 0.1-0.6 parts of K2CO3, 0.2-1 parts of ZnO and 0.1-0.4 parts of BaCO3; the fineness of the quartz sand meets the 10,000-pore sieve residue K1 of 0.02%≤K1≤0.06%; the fineness of the potassium feldspar meets the 10,000-pore sieve residue K2 of 0.1%≤K2≤0.5%.

2. The glaze composition according to claim 1, characterized in that By mass, it includes the following components: 68-72 parts of potassium feldspar, 6-8 parts of calcined talc, 7-9 parts of kaolin, 12-15 parts of quartz sand, 1-2 parts of SrCO3, 0.2-0.5 parts of Li2CO3, 0.1-0.4 parts of K2CO3, 0.2-0.5 parts of ZnO and 0.1-0.25 parts of BaCO3.

3. The glaze composition according to any one of claims 1 to 2, characterized in that The kaolin comprises at least one of raw kaolin and calcined kaolin; and / or, The potassium feldspar includes calcined potassium feldspar.

4. A glaze slurry, characterized in that: The method comprises the glaze composition according to any one of claims 1 to 6, a binder and water.

5. The glaze slurry according to claim 4, characterized in that: The viscosity of the glaze slurry is 0.15 Pa.S~0.25 Pa.S.

6. A method for preparing a glaze slurry, characterized in that: The following steps are involved: The glaze composition according to any one of claims 1 to 3, a binder and water are mixed to prepare a glaze slurry.

7. A ceramic product, characterized in that: It comprises a ceramic substrate and a glaze layer on the surface of the ceramic substrate, and the raw materials for preparing the glaze layer include the glaze slurry as described in any one of claims 4 to 5.

8. The ceramic product according to claim 7, characterized in that The glaze layer comprises the following components in percentage by mass: SiO2 65%~70%, Al2O3 15%~19%, CaO 0.15%~0.25%, MgO 2%~3%, Na2O 2%~3%, K2O 7%~9%, ZnO 0.2%~0.5%, SrO 0.3%~2%, Li2O 0.1%~0.6% and BaO 0.05%~0.3%; optionally, the molar ratio of the Al2O3 to the SiO2 is 1:5~1:

10.

9. A method for preparing a ceramic product, characterized in that: The following steps are involved: Applying the glaze slurry as claimed in any one of claims 4 to 5 on the surface of a ceramic body to obtain a glazed body; The glazed green body is subjected to glaze firing treatment to prepare a ceramic product.

10. The method for preparing a ceramic product according to claim 9, characterized in that: The glaze firing process includes a first glaze firing and a second glaze firing performed sequentially, wherein the temperature of the first glaze firing is 1220°C to 1280°C, and the temperature of the second glaze firing is 1390°C to 1430°C.

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