Ceramic slurry and ceramic sheet

Abstract

This invention provides a ceramic slurry, comprising ceramic powder and a ceramic binder; the ceramic powder contains B2O3, and the mass content of B2O3 in the ceramic powder is 20wt%~40wt%; the ceramic binder comprises a polymer, wherein the polymer contains polar structural units, hard structural units, and flexible structural units; the glass transition temperature Tg1 of the hard structural units is above 80℃; the glass transition temperature Tg2 of the flexible structural units is below 0℃; the polar structural units include hydroxyl-containing structural units, and simultaneously contain any one or a combination of at least two of carboxylic acid structural units, amide structural units, and sulfonic acid structural units; in the ceramic slurry, the content of hydroxyl-containing structural units in the polymer is 0.2%~1% of the B2O3 content in the ceramic powder. The ceramic slurry provided by this invention has stable viscosity, and the ceramic sheets prepared from it have high tensile strength and good flexibility.

Description

Technical Field

[0001] This invention belongs to the field of low-temperature co-fired ceramics technology, specifically relating to a ceramic slurry and ceramic sheets. Background Technology

[0002] Low-temperature co-fired ceramics (LTCC), as an important branch of modern electronic packaging, play an irreplaceable role in the construction of high-frequency, high-speed, and high-density electronic systems due to their excellent electrical properties, mechanical strength, thermal stability, and machinability.

[0003] The manufacturing process of LTCC typically includes the following steps: First, ceramic powder is dispersed by ball milling, followed by the addition of plasticizers and binders, and further ball milling and mixing. After degassing, a ceramic slurry composition with a suitable viscosity is obtained. Next, it is cast using equipment such as a doctor blade or reverse roller coater. After removing volatile components such as solvents by heating, ceramic sheets are peeled off from the base film. Conductive paste for forming internal electrodes is applied to the obtained ceramic sheets using a screen printing process. Multiple layers of coated ceramic sheets are alternately overlapped and heated and pressed together to form a laminate. Subsequently, the binder resin components in the laminate are thermally decomposed (i.e., degreasing) to remove these components. After this, a firing process is performed to obtain a sintered ceramic body, and external electrodes are sintered on its end faces, ultimately producing a multilayer ceramic capacitor.

[0004] In the field of LTCC (Low-Temperature Ceramic Carbide) technology, glass / ceramic composite systems are currently the most widely used systems. Among them, borate glass systems with B2O3-SiO2 as the main component have attracted much attention due to their ability to significantly reduce sintering temperature. However, in traditional preparation processes, polyvinyl butyral resin (PVB) is generally used as the binder. But when PVB binder is used in borate glass systems, the resulting slurry has low stability, and the key properties such as tensile strength of the cast ceramic sheets are insufficient.

[0005] Therefore, developing a ceramic binder suitable for borate casting is of great significance for improving the production efficiency and product quality of LTCC. Summary of the Invention

[0006] To address the problem of low stability and easy thickening of ceramic slurries prepared by existing PVB ceramic binders when used in borate glass systems with B2O3-SiO2 as the main component, this invention provides a ceramic slurry and ceramic sheets.

[0007] The objective of this invention is achieved through the following technical solution.

[0008] In a first aspect, the present invention provides a ceramic slurry, comprising ceramic powder and a ceramic binder; the ceramic powder contains B2O3, and the mass content of B2O3 in the ceramic powder is 20wt%~40wt%; the ceramic binder comprises a polymer, the polymer containing polar structural units, hard structural units and flexible structural units; the glass transition temperature Tg1 of the hard structural units is above 80℃; the glass transition temperature Tg2 of the flexible structural units is below 0℃; the polar structural units include hydroxyl-containing structural units, and simultaneously contain any one or a combination of at least two of carboxylic acid structural units, amide structural units, and sulfonic acid structural units; in the ceramic slurry, the content of hydroxyl-containing structural units in the polymer is 0.2%~1% of the B2O3 content in the ceramic powder.

[0009] Preferably, the content of hydroxyl-containing structural units in the polymer is 0.5~2wt%.

[0010] Preferably, the hydroxyl-containing structural unit is selected from one or more of the 2-hydroxyethyl acrylate structural unit and the 2-hydroxypropyl acrylate structural unit; the carboxylic acid structural unit is selected from one or more of the acrylic acid structural unit and the methacrylic acid structural unit; the amide structural unit is selected from one or more of the acrylamide structural unit and the methacrylamide structural unit; and the sulfonic acid structural unit is selected from the 2-acrylamido-2-methylpropanesulfonic acid structural unit.

[0011] Preferably, the hard structural unit includes any one or a combination of at least two of the following: acrylate structural units, aromatic ethylene structural units, and nitrile structural units.

[0012] Preferably, the flexible structural unit comprises a polyether acrylate structural unit, wherein the weight-average molecular weight of the polyether acrylate structural unit is 1000~4000, and / or the glass transition temperature Tg2 of the polyether acrylate structural unit is -10~-90℃.

[0013] Preferably, the flexible structural unit is selected from one or more of polyethylene glycol monomethyl ether acrylate structural units, polyethylene glycol monoethyl ether acrylate structural units, polyethylene glycol monomethyl ether methacrylate structural units, polyethylene glycol monoethyl ether methacrylate structural units, and polypropylene glycol monomethyl ether methacrylate structural units.

[0014] Preferably, in the polymer, the mass ratio of polar structural units, flexible structural units and hard structural units is (1~5):(35~65):(35~65).

[0015] Preferably, the polymer has a glass transition temperature (Tg) of 0 to 30°C; and / or, the polymer has a weight-average molecular weight of 15w to 30w.

[0016] Preferably, in the ceramic slurry, the mass of the ceramic binder is 10-20% of the mass of the ceramic powder. Preferably, the solid content of the ceramic slurry is 45%-60%, and the viscosity is 1000-8000 cp.

[0017] Secondly, the present invention provides a ceramic sheet prepared from the aforementioned ceramic slurry.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] When traditional PVB binders are used in borate glass systems, the resulting slurry exhibits low stability and is prone to thickening, which is detrimental to subsequent processing and can lead to insufficient tensile strength and other key properties in the cast ceramic sheets. Through extensive research and analysis, the inventors of this invention speculate that the reason may lie in the fact that the abundant hydroxyl groups in PVB readily interact with B2O3 in the glass powder, resulting in slurry thickening and performance degradation.

[0020] In this invention, the content of hydroxyl-containing structural units in the ceramic binder is adjusted to 0.2%~1% of the B2O3 content in the ceramic powder. At the same time, polar structural units such as carboxylic acid structural units, amide structural units, and sulfonic acid structural units are introduced to work together. In addition, hard structural units and flexible structural units with specific glass transition temperatures are combined to improve the phenomenon of thickening of ceramic slurry and to a certain extent improve the problem of low tensile strength and toughness of ceramic sheets. Detailed Implementation

[0021] To make the technical problems solved, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the embodiments described herein are only some, not all, of the embodiments of this invention, and are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the protection scope of this invention.

[0022] In a first aspect, the present invention provides a ceramic slurry, comprising ceramic powder and a ceramic binder; the ceramic powder contains B2O3, and the mass content of B2O3 in the ceramic powder is 20wt%~40wt%; the ceramic binder comprises a polymer, the polymer containing polar structural units, hard structural units and flexible structural units; the glass transition temperature Tg1 of the hard structural units is above 80℃; the glass transition temperature Tg2 of the flexible structural units is below 0℃; the polar structural units include hydroxyl-containing structural units, and simultaneously contain any one or a combination of at least two of carboxylic acid structural units, amide structural units, and sulfonic acid structural units; in the ceramic slurry, the content of hydroxyl-containing structural units in the polymer is 0.2%~1% of the B2O3 content in the ceramic powder.

[0023] In this invention, the content of hydroxyl-containing structural units in the ceramic binder is adjusted to 0.2%~1% of the B2O3 content in the ceramic powder. At the same time, polar structural units such as carboxylic acid structural units, amide structural units, and sulfonic acid structural units are introduced to work together. In addition, hard structural units and flexible structural units with specific glass transition temperatures are combined to improve the phenomenon of thickening of ceramic slurry and to a certain extent improve the problem of low tensile strength and toughness of ceramic sheets.

[0024] Preferably, the content of hydroxyl-containing structural units in the polymer is 0.5~2wt%.

[0025] According to the present invention, the hydroxyl-containing structural unit can be a structural unit formed in a polymer by free radical polymerization of various hydroxyl-containing monomers commonly used in the art. Preferably, the hydroxyl-containing structural unit is selected from one or more of the 2-hydroxyethyl acrylate structural unit and the 2-hydroxypropyl acrylate structural unit.

[0026] In this invention, the polar structural units in the polymer, in addition to hydroxyl-containing structural units, also contain any one or a combination of at least two of carboxylic acid structural units, amide structural units, and sulfonic acid structural units. More preferably, it is a combination of any one or at least two of amide structural units and carboxylic acid structural units.

[0027] At this point, when the content of hydroxyl-containing structural units in the polymer is 0.2% to 1% of the B2O3 content in the ceramic powder, the combined use of multiple polar structural units can improve the phenomenon of thickening of ceramic slurry to a certain extent, and help improve the tensile strength and elongation at break of ceramic sheets.

[0028] Specifically, the carboxylic acid structural unit is selected from one or more of acrylic acid structural units and methacrylic acid structural units. The amide structural unit is selected from one or more of acrylamide structural units and methacrylamide structural units. The sulfonic acid structural unit is selected from 2-acrylamido-2-methylpropanesulfonic acid structural units.

[0029] In this invention, the glass transition temperature Tg1 of the hard structural unit is above 80°C, preferably 80~130°C. Specifically, the hard structural unit includes any one or a combination of at least two of acrylate structural units, aromatic vinyl structural units, and nitrile structural units.

[0030] In some specific embodiments, the hard structural unit includes any one or a combination of at least two of the following: methyl methacrylate structural unit, isobornyl methacrylate structural unit, tert-butyl methacrylate structural unit, styrene structural unit, α-methylstyrene structural unit, acrylonitrile structural unit, and methacrylonitrile structural unit.

[0031] In this invention, the glass transition temperature Tg2 of the flexible structural unit is below 0°C.

[0032] According to the present invention, as a preferred embodiment, the flexible structural unit comprises a polyether-based acrylate structural unit. Specifically, the flexible structural unit is preferably selected from one or more of polyethylene glycol monomethyl ether acrylate, polyethylene glycol monoethyl ether acrylate, polyethylene glycol monomethyl ether methacrylate, polyethylene glycol monoethyl ether methacrylate, and polypropylene glycol monomethyl ether methacrylate.

[0033] To further improve the tensile strength and elongation at break of the ceramic sheet, the weight-average molecular weight of the polyether acrylate structural unit is 1000-4000. More preferably, the degree of polymerization of the polyether acrylate structural unit is 20-80.

[0034] In addition, the glass transition temperature Tg2 of the polyether acrylate structural unit is -10 to -90°C, and more preferably -30 to -70°C.

[0035] In the polymer, the mass ratio of polar structural units, flexible structural units and hard structural units is (1~5):(35~65):(35~65).

[0036] Specifically, the mass ratio of polar structural units, flexible structural units and hard structural units can be 5:35:60, 5:40:55, 5:50:45, 5:60:35, 1:65:34, 2:55:43, 3:47:50, or 4:51:45, etc.

[0037] In this invention, the aforementioned polar structural units, hard structural units, and flexible structural units are obtained by polymerization of polar monomers, hard monomers, and soft monomers, respectively. The monomers exist in the polymer as their corresponding structural units. The glass transition temperature, mass ratio, molecular weight, etc., of each type of structural unit are based on the glass transition temperature, mass ratio, and molecular weight of their respective monomers.

[0038] It should be noted that, in this invention, the content of the aforementioned polar structural units refers to the total content of one or more of the polar structural units other than the hydroxyl-containing structural units. It is understood that when a hard structural unit contains multiple different structural units, the content of the aforementioned hard structural units ranges from the total content of all such structural units.

[0039] The aforementioned monomers can be obtained commercially. For example, for the aforementioned soft monomers, monomers with the corresponding parameters can be selected and purchased based on the required molecular weight, degree of polymerization, and Tg2.

[0040] In some specific embodiments, the glass transition temperature (Tg) of the polymer is 0~30°C.

[0041] Specifically, the glass transition temperature (Tg) of the polymer can be 0℃, 5℃, 10℃, 14℃, 18℃, 20℃, 25℃, or 30℃, etc.

[0042] In some specific embodiments, the weight-average molecular weight of the polymer is 15w to 30w.

[0043] Specifically, the weight-average molecular weight of the polymer can be 15w, 20w, 22.5w, 26w, 28w, or 30w, etc.

[0044] In some specific embodiments, the tensile strength of the polymer film prepared is 20~40 MPa, and the elongation at break is 50%~100%.

[0045] The polymer described in this invention can be prepared by conventional free radical polymerization methods, for example, the preparation method can be:

[0046] Polar monomers, soft monomers, and hard monomers are mixed in a certain proportion, and an initiator and solvent are added. The mixture is reacted at 60-70℃ for 3-5 hours, then the temperature is raised to 75-80℃, and another initiator is added. The reaction continues for another 5-7 hours to obtain the polymer of the ceramic binder. The initiator can be azoisobutyronitrile, and the amount added is 0.5-2% of the total monomer mass. The solvent can be ethyl acetate, and the amount added is 1.5-2 times the total monomer mass.

[0047] Preferably, the B2O3 content in the ceramic powder is 20wt%~40wt%.

[0048] Preferably, in the ceramic slurry, the mass of the ceramic binder is 10-20% of the mass of the ceramic powder.

[0049] In this invention, the content of hydroxyl-containing structural units in the polymer of the ceramic slurry is 0.2% to 1% of the B2O3 content in the ceramic powder. This can, to some extent, improve the phenomenon of slurry thickening.

[0050] In the ceramic binder, the flexible structural units of the polymer include polyether acrylate structural units; the content of the polyether acrylate structural units is 15% to 35% of the B2O3 content. This is highly beneficial for further improving the tensile strength and elongation at break of the ceramic sheet.

[0051] The method for preparing the ceramic slurry of this invention:

[0052] a) Initially ball mill the ceramic powder, solvent, and dispersant for 2-4 hours. The mass ratio of raw materials (ceramic powder, solvent, dispersant) to grinding media is 1-3:1. The B2O3 content in the ceramic powder is 20wt%-40wt%. The solvent is ethyl acetate, which is added at 75-85% of the mass of the ceramic powder. The dispersant is oleic acid, which is added at 0.5-2% of the mass of the ceramic powder.

[0053] b) Add the ceramic binder and plasticizer prepared in this invention. The amount of ceramic binder added (based on the amount of polymer) is 10-20% of the mass of ceramic powder, and the plasticizer is dioctyl phthalate, which is added at 2-4% of the mass of ceramic powder. Perform a second ball milling for 8-12 hours to obtain ceramic slurry.

[0054] The ceramic slurry prepared according to the present invention is used to cast ceramic sheets on a fully automatic casting machine.

[0055] In some specific embodiments, the tensile strength of the ceramic sheet is 6~15 MPa and the elongation at break is 6%~10%.

[0056] Preferably, the solid content of the ceramic slurry is 45% to 60%, and the viscosity is 1000 to 8000 cp.

[0057] Secondly, the present invention provides a ceramic sheet prepared from the aforementioned ceramic slurry.

[0058] The specific embodiments of the present invention will be further explained and described below through examples and comparative examples.

[0059] Unless otherwise specified, all reagents, materials, and instruments used in the following description are conventional reagents, materials, and instruments, all of which are commercially available. The reagents involved can also be synthesized using conventional synthetic methods. Unless otherwise specified, the methods in the examples are conventional methods in the art. Monomers conforming to this invention are commercially available.

[0060] The glass transition temperature can be determined using differential scanning calorimetry (DSC) according to GB / T 19466.1-2004. The molecular weight of the polymer can be determined using gel permeation chromatography (GPC).

[0061] Example 1:

[0062] 1) Preparation of ceramic binder:

[0063] In a reaction vessel, 4 parts of acrylic acid, 1 part of 2-hydroxyethyl acrylate, 40 parts of polyethylene glycol monomethyl ether acrylate (Tg2: -65℃, weight-average molecular weight: 2000, degree of polymerization: 40), and 55 parts of methyl methacrylate (Tg1: 105℃) were mixed, and 0.5 parts of azoisobutyronitrile and 200 parts of ethyl acetate were added. The mixture was reacted at 65℃ for 5 hours. The temperature was then raised to 80℃, and another 0.5 parts of azoisobutyronitrile were added. The reaction was continued for another 5 hours to obtain a ceramic binder containing the polymer. The polymer has a glass transition temperature of 13℃ and a weight-average molecular weight of 16.4 W.

[0064] 2) Preparation of ceramic slurry

[0065] a) In a ball mill jar, the ceramic powder, solvent, and dispersant were initially ball-milled for 3 hours. The mass ratio of raw materials (ceramic powder, solvent, and dispersant) to grinding media was 2:1; the mass ratio of B2O3:SiO2:Al2O3 in the ceramic powder was 3:4:3, and the B2O3 content in the ceramic powder was 30wt%; the solvent was ethyl acetate, which was added at 85% of the mass of the ceramic powder; the dispersant was oleic acid, which was added at 1% of the mass of the ceramic powder.

[0066] b) Add the ceramic binder and plasticizer prepared according to this invention to the ball mill jar. The amount of ceramic binder added (based on the amount of polymer) is 15% of the mass of ceramic powder, and the plasticizer is dioctyl phthalate, which is added at 3% of the mass of ceramic powder. Perform a second ball milling for 10 h to obtain a ceramic slurry. The content of 2-hydroxyethyl acrylate structural units in the ceramic binder is 0.5% of the mass of B2O3 in the ceramic slurry; the solid content of the ceramic slurry is 58.3%, the initial slurry viscosity is 1231 cp, and the viscosity after standing for 24 h is 1246 cp.

[0067] 3) Preparation of ceramic sheets:

[0068] The ceramic slurry prepared according to the present invention is used to cast ceramic sheets with a thickness of 50 μm on a fully automatic casting machine.

[0069] Example 2:

[0070] The ceramic binder, ceramic slurry, and ceramic sheets were prepared according to the method of Example 1. The main difference between Example 2 and Example 1 is that:

[0071] When preparing the ceramic binder, the amount of 2-hydroxyethyl acrylate added is 2 parts, and the amount of acrylic acid added is 3 parts;

[0072] In the preparation of ceramic slurry, the ceramic binder (based on the amount of polymer) accounts for 20% of the mass of ceramic powder, the mass ratio of B2O3:SiO2:Al2O3 in the ceramic powder is 4:3:3, and the content of B2O3 in the ceramic powder is 40wt%; the 2-hydroxyethyl acrylate structural unit in the ceramic binder accounts for 1% of the mass of B2O3 in the ceramic slurry; and the solid content of the ceramic slurry is 60%.

[0073] The remaining steps are the same.

[0074] Example 3:

[0075] The ceramic binder, ceramic slurry, and ceramic sheets were prepared according to the method of Example 1. The main difference between Example 3 and Example 1 is that:

[0076] When preparing the ceramic binder, the amount of 2-hydroxyethyl acrylate added is 0.5 parts, and the amount of acrylic acid added is 4.5 parts;

[0077] In the preparation of ceramic slurry, the ceramic binder (based on the amount of polymer) is 10% of the mass of ceramic powder, the mass ratio of B2O3:SiO2:Al2O3 in the ceramic powder is 2:4:4, and the content of B2O3 in the ceramic powder is 20wt%; the 2-hydroxyethyl acrylate structural unit in the ceramic binder is 0.25% of the mass of B2O3 in the ceramic slurry; and the solid content of the ceramic slurry is 60%.

[0078] Example 4:

[0079] The ceramic binder, ceramic slurry, and ceramic sheets were prepared according to the method of Example 1. The main difference between Example 4 and Example 1 is that in the preparation of the ceramic binder, 4 parts of methacrylic acid, 1 part of 2-hydroxypropyl acrylate, 40 parts of polyethylene glycol monomethyl ether acrylate (Tg2 is -63℃, weight-average molecular weight is 1500, degree of polymerization is 30), and 55 parts of tert-butyl methacrylate (Tg1 is 104℃) were selected; the glass transition temperature of the ceramic binder was 16℃, and the weight-average molecular weight was 17.3 w.

[0080] The remaining steps are the same.

[0081] Example 5:

[0082] The ceramic binder, ceramic slurry, and ceramic sheets were prepared according to the method of Example 1. The main difference between Example 5 and Example 1 is that in the preparation of the ceramic binder, 4 parts of acrylamide, 1 part of 2-hydroxypropyl acrylate, 40 parts of polyethylene glycol monomethyl ether acrylate (Tg2 is -68℃, weight-average molecular weight is 4000, degree of polymerization is 80), and 55 parts of isobornyl methacrylate (Tg1 is 110℃) were selected; the glass transition temperature of the ceramic binder was 18℃, and the weight-average molecular weight was 25.2w.

[0083] The remaining steps are the same.

[0084] Example 6:

[0085] The ceramic binder, ceramic slurry, and ceramic sheets were prepared according to the method of Example 1. The main difference between Example 6 and Example 1 is that in the preparation of the ceramic binder, 1 part of methacrylamide, 1 part of 2-hydroxypropyl acrylate, 50 parts of polypropylene glycol monomethyl ether methacrylate (Tg2 is -66℃, weight-average molecular weight is 3000, degree of polymerization is 60), and 48 parts of isobornyl methacrylate (Tg1 is 110℃) were selected; the glass transition temperature of the ceramic binder was -5℃, and the weight-average molecular weight was 27.3w.

[0086] The remaining steps are the same.

[0087] Example 7:

[0088] The ceramic binder, ceramic slurry, and ceramic sheet were prepared according to the method of Example 1. The main difference between Example 7 and Example 1 is that in the preparation of the ceramic binder, 3 parts of acrylamide, 1 part of 2-hydroxypropyl acrylate, 50 parts of polyethylene glycol monoethyl ether acrylate (Tg2 is -62℃, molecular weight is 1000, degree of polymerization is 20), 26 parts of styrene (Tg1 is 100℃) and 20 parts of acrylonitrile (Tg1' is 125℃) were selected; the glass transition temperature of the ceramic binder was -1℃ and the molecular weight was 29.3w.

[0089] The remaining steps are the same.

[0090] Example 8:

[0091] The difference between Example 8 and Example 1 is that isooctyl acrylate with a glass transition temperature (Tg) of -70 °C is used instead of polyethylene glycol monomethyl ether acrylate in Example 1.

[0092] The remaining steps are the same.

[0093] Comparative Example 1:

[0094] The difference between Comparative Example 1 and Example 1 is that PVB resin was used as the ceramic binder.

[0095] The remaining steps are the same.

[0096] Comparative Example 2:

[0097] The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 does not contain acrylic acid, and the amount of 2-hydroxyethyl acrylate added is 5 parts.

[0098] The remaining steps are the same.

[0099] Performance testing:

[0100] The ceramic binders, ceramic slurries, and ceramic sheets prepared in the above examples and comparative examples were subjected to performance tests.

[0101] [Tensile Strength] The maximum stress that the ceramic sheet can withstand during the tensile process is tested according to GB / T 1040-1992.

[0102]

Elongation at break

[0103] [Viscosity] The viscosity of the slurry was tested using a viscometer. The test procedure was as follows: the viscometer probe was inserted into the slurry, and the measurement was started. The viscosity value at a temperature of 25°C was read. The initial viscosity of the ceramic slurry and the viscosity after standing for 24 hours were tested.

[0104] The performance test results are shown in Table 1.

[0105] Table 1:

[0106] As can be seen from the test results of Examples 1-8 and Comparative Example 1, compared with traditional PVB resin, the ceramic slurry prepared by the ceramic binder of the present invention is more stable, the thickening phenomenon is improved, and the tensile strength and flexibility of the prepared ceramic sheets are significantly improved.

[0107] As can be seen from the test results of Examples 1-8 and Comparative Example 2, compared with the binder that contains only hydroxyl structural units in the polar structural units, the ceramic slurry prepared by the ceramic binder of the present invention is more stable, the thickening phenomenon is improved, and the tensile strength of the prepared ceramic sheet is significantly improved.

[0108] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the nature and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention.

Claims

1. A ceramic slurry, characterized in that, The ceramic slurry includes ceramic powder and ceramic binder; The ceramic powder contains B2O3, and the mass content of B2O3 in the ceramic powder is 20wt%~40wt%. The ceramic binder comprises a polymer containing polar structural units, hard structural units, and flexible structural units; the glass transition temperature Tg1 of the hard structural units is above 80°C; and the glass transition temperature Tg2 of the flexible structural units is below 0°C. The polar structural unit includes a hydroxyl-containing structural unit, and simultaneously contains any one or a combination of at least two of the following: carboxylic acid structural units and amide structural units. The hard structural unit includes any one or a combination of at least two of the following: acrylate structural units, aromatic vinyl structural units, and nitrile structural units; The flexible structural unit includes a polyether-based acrylate structural unit; In the ceramic slurry, the content of hydroxyl-containing structural units in the polymer is 0.2% to 1% of the B2O3 content in the ceramic powder.

2. The ceramic slurry according to claim 1, characterized in that, The polymer contains 0.5 to 2 wt% hydroxyl-containing structural units.

3. The ceramic slurry according to claim 1, characterized in that, The hydroxyl-containing structural unit is selected from one or more of the 2-hydroxyethyl acrylate structural unit and the 2-hydroxypropyl acrylate structural unit; the carboxylic acid structural unit is selected from one or more of the acrylic acid structural unit and the methacrylic acid structural unit; the amide structural unit is selected from one or more of the acrylamide structural unit and the methacrylamide structural unit.

4. The ceramic slurry according to claim 1, characterized in that, The weight-average molecular weight of the polyether acrylate structural unit is 1000~4000, and / or the glass transition temperature Tg2 of the polyether acrylate structural unit is -10~-90℃.

5. The ceramic slurry according to claim 1 or 4, characterized in that, The flexible structural unit is selected from one or more of the following: polyethylene glycol monomethyl ether acrylate structural unit, polyethylene glycol monoethyl ether acrylate structural unit, polyethylene glycol monomethyl ether methacrylate structural unit, polyethylene glycol monoethyl ether methacrylate structural unit, and polypropylene glycol monomethyl ether methacrylate structural unit.

6. The ceramic slurry according to claim 1, characterized in that, In the polymer, the mass ratio of polar structural units, flexible structural units and hard structural units is (1~5):(35~65):(35~65).

7. The ceramic slurry according to claim 1, characterized in that, The polymer has a glass transition temperature (Tg) of 0 to 30°C; and / or, the polymer has a weight-average molecular weight of 15w to 30w.

8. The ceramic slurry according to claim 1, characterized in that, In the ceramic slurry, the mass of the ceramic binder is 10-20% of the mass of the ceramic powder.

9. A ceramic sheet, characterized in that, It is prepared from the ceramic slurry described in any one of claims 1 to 8.

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