Ceramic binder, ceramic slurry and ceramic chip

Abstract

The invention provides a ceramic binder, which comprises a polymer, and the polymer contains a polar structure unit, a hard structure unit and a flexible structure unit, the glass transition temperature Tg1 of the hard structural unit is above 80 DEG C; the glass transition temperature Tg2 of the flexible structural unit is 0 DEG C or less; in the polymer, the mass ratio of the polar structural unit to the flexible structural unit to the hard structural unit is (1-5): (35-65): (35-65); in the polymer, the hydroxyl content is lower than 0.1 wt%. The adhesive prepared from the ceramic adhesive is good in performance, the viscosity of ceramic slurry is stable, and a ceramic chip subjected to tape casting is high in tensile strength and good in flexibility.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-temperature co-fired ceramics, and particularly relates to a ceramic binder, a ceramic slurry, and a ceramic sheet. Background Art

[0002] Low Temperature Co-fired Ceramics (LTCC), as an important branch in the field of modern electronic packaging, plays an irreplaceable role in the construction of high-frequency, high-speed, and high-density electronic systems due to its excellent electrical properties, mechanical strength, thermal stability, and processability.

[0003] The manufacturing process of LTCC generally includes the following steps: First, the ceramic powder is subjected to ball milling and dispersion treatment, and then a plasticizer and a binder are added, followed by continued ball milling and mixing. After degassing treatment, a ceramic slurry composition with appropriate viscosity is obtained. Then, tape casting is carried out using equipment such as a doctor blade and an inverse roll coater. After removing volatile components such as solvents by heating and other means, the ceramic sheet is peeled off from the base film. A conductive paste for forming internal electrodes is coated on the obtained ceramic sheet by screen printing. The coated ceramic sheets are alternately overlapped in multiple layers and heated and pressed to form a laminate. Subsequently, the adhesive resin components in the laminate are subjected to thermal decomposition treatment (i.e., debinding treatment) to remove these components. After that, through a firing process, a ceramic sintered body is obtained, and external electrodes are sintered on its end faces, and finally a multilayer ceramic capacitor is made.

[0004] In the field of LTCC technology, the glass / ceramic composite system is currently the most widely used system. Among them, the borate glass system mainly composed of B2O3-SiO2 has attracted much attention because it can significantly reduce the sintering temperature. In the traditional preparation process, polyvinyl butyral resin (abbreviated as PVB) is generally selected as the binder. However, when the PVB binder is used in the borate glass system, the stability of the prepared slurry is relatively low, and the key properties such as the tensile strength of the ceramic sheet after tape casting are insufficient.

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

[0006] In order to solve the problem that the existing PVB ceramic binder has low stability and is prone to thickening back when used in the borate glass system mainly composed of B2O3-SiO2, the present invention provides a ceramic binder, a ceramic slurry, and a ceramic sheet.

[0007] The object of the present invention is achieved by the following technical solutions.

[0008] In a first aspect, the present invention provides a ceramic binder, which comprises a polymer containing polar structural units, hard structural units and flexible structural units;

[0009] The glass transition temperature Tg1 of the hard structural units is 80 °C or higher; the glass transition temperature Tg2 of the flexible structural units is 0 °C or lower;

[0010] In the polymer, the mass ratio of the polar structural units, the flexible structural units to the hard structural units is (1-5):(35-65):(35-65);

[0011] In the polymer, the hydroxyl content is less than 0.1 wt%.

[0012] Preferably, the polar structural units include any one or a combination of at least two of carboxylic acid structural units, amide structural units, and sulfonic acid structural units.

[0013] Preferably, the hard structural units include any one or a combination of at least two of acrylate structural units, aromatic vinyl structural units, and nitrile structural units.

[0014] Preferably, the flexible structural units include polyether acrylate structural units.

[0015] Preferably, the weight-average molecular weight of the polyether acrylate structural units is 1000-4000, and / or the glass transition temperature Tg2 of the polyether acrylate structural units is -10 to -90 °C.

[0016] Preferably, the flexible structural units are 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.

[0017] Preferably, the glass transition temperature Tg of the polymer is 0-30 °C; and / or the weight-average molecular weight of the polymer is 150,000-300,000.

[0018] In a second aspect, the present invention provides a ceramic slurry, which comprises ceramic powder and the aforementioned ceramic binder.

[0019] Preferably, the content of B2O3 in the ceramic powder is 20 wt% - 40 wt%; 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% - 35% of the content of B2O3.

[0020] Preferably, the solid content of the ceramic slurry is 45% - 60%, and the viscosity is 1000 - 8000 cp.

[0021] In a third aspect, the present invention provides a ceramic sheet prepared from the aforementioned ceramic slurry.

[0022] When traditional PVB binders are used in borate glass systems, the prepared slurries have low stability, are prone to thickening back, which is not conducive to subsequent processing, and there are also problems with insufficient key properties such as the tensile strength of the ceramic sheet after calendaring. Through a large amount of research and analysis, the inventors of the present invention speculate that the reason may be that the large number of hydroxyl groups in PVB easily interact with B2O3 in the glass powder, resulting in slurry thickening back and performance degradation.

[0023] In the present invention, hard monomers and soft monomers with specific glass transition temperatures are used, combined with polar monomers, and with specific contents among the three. Through polymerization, a polymer with polar structural units, flexible structural units, and hard structural units is obtained. Since none of the monomers used contain hydroxyl groups, the resulting polymer also does not contain hydroxyl groups. The ceramic slurry prepared from this ceramic binder has high stability and improves the problem of thickening back. At the same time, due to the structural units with the above specific glass transition temperatures and content compositions in the polymer, the problems of low tensile strength and toughness of the ceramic sheet can be improved. Specific Embodiments

[0024] In order to make the technical problems, technical solutions, and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the embodiments described here are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to explain the present invention, not to limit the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work fall within the protection scope of the present invention.

[0025] In a first aspect, the present invention provides a ceramic binder comprising 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 °C; the glass transition temperature Tg2 of the flexible structural units is below 0 °C; in the polymer, the mass ratio of polar structural units, flexible structural units, and hard structural units is (1 - 5):(35 - 65):(35 - 65); the hydroxyl content in the polymer is less than 0.1 wt%.

[0026] In the present invention, the polar structural unit includes any one or a combination of at least two of carboxylic acid structural units, amide structural units, and sulfonic acid structural units. Preferably, it is any one or a combination of at least two of amide structural units and carboxylic acid structural units.

[0027] It should be noted that in the present invention, in the above-mentioned carboxylic acid structural units, the -OH group in the carboxyl group is not considered to be the hydroxyl group described above. The spatial structure and charge environment of the -OH group in the carboxyl group are different from those of a conventional simple hydroxyl group (such as the hydroxyl group in PVB). As is well known to those skilled in the art, for polymers, the two can be distinguished directly from the infrared characteristic peaks.

[0028] Specifically, the polar structural unit includes any one or a combination of at least two of acrylic acid structural units, methacrylic acid structural units, acrylamide structural units, methacrylamide structural units, and 2-acrylamide-2-methylpropanesulfonic acid structural units.

[0029] In the present invention, the glass transition temperature Tg1 of the hard structural unit is 80 °C or higher, 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 methyl methacrylate structural units, isobornyl methacrylate structural units, tert-butyl methacrylate structural units, styrene structural units, α-methylstyrene structural units, acrylonitrile structural units, and methacrylonitrile structural units.

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

[0032] According to the present invention, as a preferred case, the above-mentioned flexible structural unit includes polyether acrylate structural units. Specifically, it is preferably that 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.

[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, more preferably -30 to -70 °C.

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

[0036] Specifically, the mass ratio of the polar structural unit, the flexible structural unit, and the hard structural unit 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 the present invention, the above-mentioned polar structural unit, hard structural unit, and flexible structural unit are respectively obtained by polymerizing polar monomers, hard monomers, and soft monomers. Among them, the monomers exist in the polymer obtained by polymerization in the form of the corresponding structural units. The glass transition temperature, mass ratio, molecular weight, etc. of the above various structural units are based on the glass transition temperature, mass ratio to each other, and molecular weight of their corresponding monomers.

[0038] The above various monomers can be obtained by commercial purchase. For example, for the aforementioned soft monomers, monomers with corresponding parameters can be selected and purchased according to the required molecular weight, degree of polymerization, and Tg2.

[0039] In some specific embodiments, the glass transition temperature Tg of the polymer is 0 to 30 °C.

[0040] Specifically, the glass transition temperature Tg of the polymer can be 0 °C, 5 °C, 10 °C, 14 °C, 18 °C, 20 °C, 25 °C, or 30 °C, etc.

[0041] In some specific embodiments, the weight-average molecular weight of the polymer is 150,000 to 300,000.

[0042] Specifically, the weight-average molecular weight of the polymer can be 150,000, 200,000, 225,000, 260,000, 280,000, or 300,000, etc.

[0043] In some specific embodiments, the tensile strength of the polymer film prepared is 20 to 40 MPa, and the elongation at break is 50% to 100%.

[0044] The polymer of the present invention can be prepared by a conventional free radical polymerization method. For example, its preparation method can be:

[0045] Mix the polar monomer, soft monomer, and hard monomer in proportion, add an initiator and a solvent, react at 60 - 70 °C for 3 - 5 h, then raise the temperature to 75 - 80 °C and add the initiator again, and continue to react for 5 - 7 h to obtain the polymer of the ceramic binder. Among them, the initiator can be azobisisobutyronitrile, and the addition amount is 0.5 - 2% of the total mass of the monomers. The solvent can be ethyl acetate, and the addition amount is 1.5 - 2 times the total mass of the monomers.

[0046] It can be understood that in the above polymer and its preparation method provided by the present invention, no monomer or component containing hydroxyl is added. Therefore, the hydroxyl content in the polymer must be lower than 0.1 wt%, and it can be considered that the polymer does not contain hydroxyl.

[0047] In a second aspect, the present invention provides a ceramic slurry, which includes ceramic powder and the aforementioned ceramic binder.

[0048] Preferably, the content of B2O3 in the ceramic powder is 20 wt% - 40 wt%; in the ceramic binder, the flexible structural unit of the polymer includes a polyether acrylate structural unit; the content of the polyether acrylate structural unit is 15% - 35% of the content of B2O3. At this time, it is very beneficial for further improving the tensile strength and elongation at break of the ceramic sheet.

[0049] The preparation method of the ceramic slurry of the present invention:

[0050] a) Initially ball-mill the ceramic powder, solvent, and dispersant for 2 - 4 h. The mass ratio of the raw materials (ceramic powder, solvent, dispersant) to the grinding medium is 1 - 3:1; the content of B2O3 in the ceramic powder is 20 wt% - 40 wt%; the solvent is ethyl acetate, and its addition amount is 75 - 85% of the mass of the ceramic powder; the dispersant is oleic acid, and its addition amount is 0.5 - 2% of the mass of the ceramic powder;

[0051] b) Then add the ceramic binder and plasticizer prepared by the present invention. The addition amount of the ceramic binder (based on the amount of the polymer) is 10 - 20% of the mass of the ceramic powder, and the plasticizer is dioctyl phthalate, and its addition amount is 2 - 4% of the mass of the ceramic powder, and perform secondary ball-milling for 8 - 12 h to obtain the ceramic slurry.

[0052] In some specific embodiments, the solid content of the prepared ceramic slurry is 45% - 60%, and the viscosity is 1000 - 8000 cp.

[0053] In a third aspect, the present invention provides a ceramic sheet, which includes the aforementioned ceramic slurry. Cast the ceramic slurry prepared by the present invention on a fully automatic casting machine to obtain a ceramic sheet.

[0054] In some specific embodiments, the tensile strength of the prepared ceramic sheet is 6-15 MPa, and the elongation at break is 6%-10%.

[0055] The following will further explain and illustrate the specific embodiments of the present invention through examples and comparative examples.

[0056] The reagents, materials, and instruments used in the following description are all conventional reagents, conventional materials, and conventional instruments, which can be obtained commercially. The reagents involved can also be synthesized by conventional synthesis methods. The methods in the examples are all conventional methods in the art unless otherwise specified. The monomers conforming to the present invention can be obtained commercially.

[0057] The glass transition temperature can be detected by a differential scanning calorimeter (DSC) according to GB / T 19466.1-2004. The molecular weight of the polymer can be determined by gel permeation chromatography (GPC).

[0058] Example 1:

[0059] 1) Preparation of ceramic binder:

[0060] In a reaction kettle, 5 parts of acrylic acid, 40 parts of polyethylene glycol monomethyl ether acrylate (Tg2 is -65 °C, weight average molecular weight is 2000, and degree of polymerization is 40), and 55 parts of methyl methacrylate (Tg1 is 105 °C) are mixed, 0.5 part of azobisisobutyronitrile is added, and 200 parts of ethyl acetate are added. The reaction is carried out at 70 °C for 4 h; the temperature is raised to 75 °C, and another 0.5 part of azobisisobutyronitrile is added, and the reaction is continued for 6 h to obtain a ceramic binder containing polymer. Among them, the glass transition temperature of the polymer is 15 °C, and the weight average molecular weight is 15.8 w.

[0061] 2) Preparation of ceramic slurry

[0062] a) In a ball mill tank, the ceramic powder, solvent, and dispersant are initially ball milled for 3 h. The mass ratio of the raw materials (ceramic powder, solvent, dispersant) to the grinding medium is 2:1; the mass ratio of B2O3:SiO2:Al2O3 in the ceramic powder is 3:4:3, and the content of B2O3 in the ceramic powder is 30 wt%; the solvent is ethyl acetate, and its addition amount is 85% of the mass of the ceramic powder; the dispersant is oleic acid, and its addition amount is 1% of the mass of the ceramic powder;

[0063] b) Then, add the ceramic binder and plasticizer prepared in the present invention into the ball milling tank. The addition amount of the ceramic binder (based on the amount of the polymer) is 15% of the mass of the ceramic powder, and the plasticizer is dioctyl phthalate, with an addition amount of 3% of the mass of the ceramic powder. Conduct secondary ball milling for 10 h to obtain a ceramic slurry. The polyether acrylate structural unit in the ceramic binder is 20% of the mass of B2O3 in the ceramic slurry; the solid content of the ceramic slurry is 50.3%, the initial slurry viscosity is 1213 cp, and the viscosity after standing for 24 h is 1219 cp.

[0064] 3) Preparation of ceramic sheets:

[0065] Cast a ceramic sheet with a thickness of 50 μm from the ceramic slurry prepared in the present invention on a fully automatic tape casting machine.

[0066] Example 2:

[0067] Prepare the ceramic binder, ceramic slurry, and ceramic sheet according to the method of Example 1. The main difference between Example 2 and Example 1 is that in the preparation of the ceramic binder, 5 parts of methacrylic acid, 40 parts of polyethylene glycol monomethyl ether acrylate (Tg2 is -63 °C, weight average molecular weight is 1500, and degree of polymerization is 30), and 55 parts of tert-butyl methacrylate (Tg1 is 104 °C) are selected; the glass transition temperature of the ceramic binder is 18 °C, and the weight average molecular weight is 16.8w.

[0068] The remaining operation steps are the same.

[0069] Example 3:

[0070] Prepare the ceramic binder, ceramic slurry, and ceramic sheet according to the method of Example 1. The main difference between Example 3 and Example 1 is that in the preparation of the ceramic binder, 5 parts of acrylamide, 40 parts of polyethylene glycol monomethyl ether acrylate (Tg2 is -68 °C, weight average molecular weight is 4000, and degree of polymerization is 80), and 55 parts of isobornyl methacrylate (Tg1 is 110 °C) are selected; the glass transition temperature of the ceramic binder is 20 °C, and the weight average molecular weight is 24.3w.

[0071] The remaining operation steps are the same.

[0072] Example 4:

[0073] Prepare the ceramic binder, ceramic slurry and ceramic sheet 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, 2 parts of methacrylamide, 50 parts of polypropylene glycol monomethyl ether methacrylate (Tg2 is -66 °C, weight-average molecular weight is 3000, degree of polymerization is 60), and 48 parts of isobornyl methacrylate (Tg1 is 110 °C) are selected; the glass transition temperature of the ceramic binder is -4 °C, and the weight-average molecular weight is 268,000.

[0074] The remaining operation steps are the same.

[0075] Example 5:

[0076] Prepare the ceramic binder, ceramic slurry and ceramic sheet 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, 50 parts of polyethylene glycol monoethyl ether acrylate (Tg2 is -62 °C, molecular weight is 1000, degree of polymerization is 20), 26 parts of styrene (Tg1 is 100 °C) and 20 parts of acrylonitrile (Tg1' is 125 °C) are selected; the glass transition temperature of the ceramic binder is 0 °C, and the molecular weight is 284,000.

[0077] The remaining operation steps are the same.

[0078] Example 6:

[0079] Prepare the ceramic binder, ceramic slurry and ceramic sheet according to the method of Example 1. The main difference between Example 6 and Example 1 is that in the preparation of the ceramic slurry, the ceramic binder (based on the amount of polymer) is 20% of the mass of the ceramic powder, the mass ratio of B2O3:SiO2:Al2O3 in the ceramic powder is 2.5:4.5:3, and the content of B2O3 in the ceramic powder is 25 wt%; the polyether acrylate structural unit in the ceramic binder is 32% of the mass of B2O3 in the ceramic slurry; the solid content of the ceramic slurry is 60%.

[0080] The remaining operation steps are the same.

[0081] Example 7:

[0082] Prepare the ceramic binder, ceramic slurry and ceramic sheet according to the method of Example 1. The main difference between Example 7 and Example 1 is that in the preparation of the ceramic slurry, the ceramic binder (based on the amount of polymer) is 8% of the mass of the ceramic powder, the mass ratio of B2O3:SiO2:Al2O3 in the ceramic powder is 2:4.5:3.5, and the content of B2O3 in the ceramic powder is 20 wt%; the polyether acrylate structural unit in the ceramic binder is 16% of the mass of B2O3 in the ceramic slurry; the solid content of the ceramic slurry is 45%.

[0083] The remaining operation steps are the same.

[0084] Comparative Example 1:

[0085] The difference between Comparative Example 1 and Example 1 is that: PVB resin is selected as the ceramic binder.

[0086] The remaining operation steps are the same.

[0087] Comparative Example 2:

[0088] The difference between Comparative Example 2 and Example 1 is that: it does not contain methoxypolyethylene glycol acrylate.

[0089] The remaining operation steps are the same.

[0090] Comparative Example 3:

[0091] The difference between Comparative Example 3 and Example 1 is that: it does not contain methyl methacrylate.

[0092] The remaining operation steps are the same.

[0093] Comparative Example 4:

[0094] Prepare the ceramic binder, ceramic slurry and ceramic sheet according to the method of Example 1. The main difference between Comparative Example 4 and Example 1 is that: acrylic acid is replaced by 2-hydroxyethyl acrylate.

[0095] The remaining operation steps are the same.

[0096] Performance test:

[0097] Perform performance tests on the ceramic binder, ceramic slurry and ceramic sheet prepared in the above examples and comparative examples.

[0098]

Tensile strength

[0099]

Elongation at break

[0100]

Viscosity

[0101] The performance test results are shown in Table 1.

[0102] Table 1:

[0103]

[0104] From the test results of Examples 1 to 3, 5 and Example 4, it can be seen that when the glass transition temperature of the polymer is above 0 °C, the tensile strength of the ceramic sheet is stronger.

[0105] From the test results of Examples 1 to 3, 6 and Example 7, it can be seen that when the addition amount of the ceramic binder is 10-20% of the mass of the ceramic powder, the tensile strength of the ceramic sheet is stronger.

[0106] From the test results of Examples 1 to 7 and Comparative Example 1, it can be seen that compared with the traditional PVB resin, the tensile strength of the ceramic binder film of the present invention is stronger; the ceramic slurry prepared by the present invention is more stable, and the viscosity does not change significantly after standing for 24 h; the tensile strength and flexibility of the ceramic sheet prepared by the present invention have been significantly improved.

[0107] From the test results of Examples 1 to 7 and Comparative Examples 2 to 3, it can be seen that compared with the binder without flexible structural units or hard structural units, the tensile strength and flexibility of the ceramic binder film of the present invention are stronger; the tensile strength and flexibility of the ceramic sheet prepared by the present invention have been significantly improved.

[0108] From the test results of Examples 1 to 7 and Comparative Example 4, it can be seen that when the polymer contains hydroxyl group-containing structural units, the ceramic slurry will show a phenomenon of thickening back, and the tensile strength of the ceramic sheet will decrease; however, due to the action of the flexible structural units in the polymer, the phenomenon of thickening back of the ceramic slurry is improved compared with the PVB binder slurry.

[0109] From the test results of Examples 1 to 7 and Comparative Example 4, it can be seen that when the polymer does not contain hydroxyl group-containing structural units, it is beneficial to improve the phenomenon of thickening back of the ceramic slurry and increase the tensile strength of the ceramic sheet; moreover, when the polymer contains the flexible structural units of the present invention, even if the polymer contains hydroxyl groups, the phenomenon of thickening back of the ceramic slurry is also improved compared with the PVB binder slurry.

[0110] The present invention has been further described above with the aid of specific embodiments. However, it should be understood that the specific descriptions herein should not be construed as limiting the essence and scope of the present invention. Various modifications made by those of ordinary skill in the art to the above embodiments after reading this specification all fall within the scope protected by the present invention.

Claims

1. A ceramic binder, characterized in that: The ceramic binder includes a polymer, wherein the polymer contains a polar structural unit, a hard structural unit and a flexible structural unit; The glass transition temperature Tg1 of the hard structural unit is above 80°C; the glass transition temperature Tg2 of the flexible structural unit is below 0°C; In the polymer, the mass ratio of the polar structural unit, the flexible structural unit and the hard structural unit is (1-5): (35-65): (35-65); In the polymer, the hydroxyl content is less than 0.1 wt %.

2. The ceramic binder according to claim 1, characterized in that The polar structural unit includes any one of a carboxylic acid structural unit, an amide structural unit, and a sulfonic acid structural unit, or a combination of at least two of them.

3. The ceramic binder according to claim 1, characterized in that The hard structural unit includes any one of an acrylic ester structural unit, an aromatic vinyl structural unit, and a nitrile structural unit, or a combination of at least two of them.

4. The ceramic binder according to claim 1, characterized in that The flexible structural unit includes a polyether acrylate structural unit.

5. The ceramic binder according to claim 4, 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°C.

6. The ceramic binder according to claim 4 or 5, characterized in that: 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.

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

8. A ceramic slurry, characterized in that: The invention comprises ceramic powder and the ceramic binder according to any one of claims 1 to 7.

9. The ceramic slurry according to claim 8, characterized in that: The content of B2O3 in the ceramic powder is 20wt%~40wt%; in the ceramic binder, the flexible structural unit of the polymer includes a polyether acrylate structural unit; the content of the polyether acrylate structural unit is 15%~35% of the B2O3 content.

10. A ceramic sheet, characterized in that: Prepared from the ceramic slurry described in claim 8 or 9.

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