Anti-falling ceramic material and preparation method thereof

Abstract

The invention relates to an anti-falling ceramic material and a preparation method thereof, and belongs to the technical field of ceramic materials. Acid etching treatment and silane coupling agent grafting treatment are carried out on the surface of the ceramic material, and long-chain alkyl and amido bonds are introduced through an alkene click reaction, so that the interfacial compatibility of ceramic groups and melamine resin (ceramic imitation) is effectively improved, and the flexibility of the melamine resin near the contact surface of the ceramic groups and the melamine resin is improved; according to the present invention, with the melamine resin, when the ceramic material is subjected to the external stress, the local stress can be dispersed to the larger area through the attached melamine resin, the impact action time is prolonged, the local stress concentration and the instantaneous stress peak value of the ceramic material are reduced, and the anti-falling performance of the ceramic group is effectively improved; and the interface bonding part of the ceramic matrix and the melamine resin has good hydrophobic property, can effectively inhibit the hydrolytic aging influence of moisture permeation of the contact surface on the interface, and has good long-term weather resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic materials. Specifically, it relates to a drop-resistant ceramic material and a preparation method thereof. More specifically, it relates to a drop-resistant ceramic utensil and a preparation method thereof. Background Art

[0002] Melamine resin tableware, that is, melamine resin tableware, has the characteristics of being drop-resistant, lightweight, and having a smooth surface. However, the heat resistance of melamine resin is poor, and it may decompose and release formaldehyde when contacting food at a relatively high temperature, which is harmful to health. Ceramic materials have stable chemical properties and excellent heat resistance. They can hold food at any temperature and can also be used for microwave heating. However, the toughness of ceramic materials themselves is poor and they are very fragile. They are prone to crack damage or even breakage when bumped or dropped. In the field of baby tableware, the phenomenon of broken ceramic tableware is particularly common, which not only causes economic losses, but also the sharp ceramic chips generated after breakage may cause harm to children. Although there are fiber (such as carbon fiber, silicon carbide fiber) toughened ceramics in the prior art, the random distribution of short-cut fibers in the reinforcement method will significantly reduce the surface finish of the material, and the preparation cost is relatively high, so it cannot be used for tableware production on a large scale.

[0003] To solve the above technical defects, the present invention combines the two, utilizes the high toughness of melamine resin to resist external mechanical impacts, and at the same time relies on the thermal stability of ceramic materials to ensure the safety of high-temperature food holding. While maintaining the surface texture of ceramics, the crack resistance of ceramic materials is effectively improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a drop-resistant ceramic material and a preparation method thereof to solve the problems mentioned in the above background art.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A preparation method of a drop-resistant ceramic material includes the following steps:

[0007] S1. Etch one side of the ceramic material with hydrofluoric acid, then wash it with deionized water and dry it to obtain the etched ceramic for standby;

[0008] S2. Dissolve the silane coupling agent in an ethanol solution, add glacial acetic acid to the solution to adjust the system pH to 4-5, then uniformly coat the solution on the etched surface of the etched ceramic, and thermally cure to obtain the silanized ceramic;

[0009] S3. Dissolve the amide compound and the photoinitiator in tetrahydrofuran, then add the silanized ceramic to the solution and cure it under ultraviolet light conditions. After the reaction is completed, take out the ceramic and wash it successively with absolute ethanol and deionized water and dry it to obtain the modified ceramic;

[0010] S4. Mix melamine and aqueous formaldehyde solution, add triethanolamine to adjust the pH to 8 - 10, then preheat the solution to obtain a prepolymer. Filter out the prepolymer and add it to a mold with modified ceramics at the bottom, and perform pressure curing to obtain a drop-resistant ceramic material.

[0011] Further, the mass fraction of the hydrofluoric acid is 3 - 10%, and the etching time is 1 - 8 min.

[0012] Further, the silane coupling agent is one of kh - 580 and kh - 590.

[0013] Further, the volume fraction of the ethanol solution is 40 - 90%.

[0014] Further, the mass ratio of the silane coupling agent to the ethanol solution used in S2 is 1 - 5:60 - 100.

[0015] Further, the conditions for thermal curing are curing for 1 - 2 h at a temperature of 80 - 120°C.

[0016] Further, the amide compound is one of erucic acid amide and oleic acid amide.

[0017] Further, the photoinitiator is one of photoinitiator 651 and photoinitiator 1173.

[0018] Further, the mass ratio of the amide compound, photoinitiator, tetrahydrofuran, and silylated ceramics is 5 - 12:0.5 - 1.5:100 - 400:30 - 40.

[0019] Further, the conditions for photocuring are curing for 2 - 6 h under an ultraviolet light intensity of 10 - 50 mW / cm.

[0020] Further, the mass fraction of the aqueous formaldehyde solution is 30 - 40%.

[0021] Further, the mass ratio of melamine to the aqueous formaldehyde solution is 12.6 - 25.2:25 - 52.6.

[0022] Further, the temperature condition for preheating is 70 - 80°C, and the time condition for preheating is 40 - 120 min.

[0023] Further, the conditions for pressure curing are hot pressing and curing for 5 - 15 min at a temperature of 145 - 155°C and a pressure of 10 - 20 MPa to form a shape.

[0024] Further, in S4, the surface in contact with the prepolymer is the etched surface of the modified ceramics.

[0025] An anti-drop ceramic material, one side of the ceramic material is ceramic, the other side is melamine-formaldehyde resin, the contact surface between the ceramic and the melamine-formaldehyde resin is acid-etched, and the ceramic material is prepared by the above preparation method.

[0026] The present invention has at least the following beneficial effects:

[0027] 1) Although the ceramic surface is rich in hydroxyl groups, the dense glaze surface has high chemical inertness and cannot form stable chemical bonding with melamine resin. By modifying the ceramic material, the present invention introduces amide groups that can undergo Mannich reaction with the residual free formaldehyde in the melamine-formaldehyde resin prepolymer on the contact surface between the ceramic material and the melamine-formaldehyde resin, effectively improving the compatibility between the ceramic material and the melamine-formaldehyde resin. When the ceramic matrix is subjected to external stress, the impact force can be dispersed to a larger area through the attached melamine-formaldehyde resin, and the impact action time can be extended, reducing the local stress concentration and instantaneous stress peak of the ceramic material, and improving the anti-drop performance of the ceramic material.

[0028] 2) The modified ceramic surface of the present invention introduces flexible long-chain alkyl groups and sulfur ether bonds, which can effectively reduce the cross-linking density of the melamine-formaldehyde resin in contact with the ceramic surface, enhance the movement ability of the regional molecular chain segments, improve the flexibility of the melamine-formaldehyde resin near the contact surface, and thus have better stress dispersion ability to improve the anti-drop performance of the ceramic matrix.

[0029] 3) The present invention introduces hydrophobic long-chain alkyl groups on the modified ceramic surface, improving the hydrophobicity of the contact surface between the ceramic and the melamine-formaldehyde resin, effectively inhibiting the hydrolysis aging effect of water infiltration on the interface at the contact surface, and improving the long-term weather resistance of the ceramic material. Detailed implementation mode

[0030] It should be understood that the expression "one or more of..." individually includes each of the objects recited after the expression and various different combinations of two or more of the recited objects, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited objects should be understood to have the same meaning, unless otherwise understood from the context.

[0031] The terms "comprising", "having" or "containing", including the use of their grammatical synonyms, should generally be understood as open and non-restrictive, for example, not excluding other unrecited elements or steps, unless specifically stated otherwise or understood from the context.

[0032] It should be understood that as long as the present invention is still operable, the order of steps or the order of performing certain actions is not important. In addition, two or more steps or actions can be carried out simultaneously.

[0033] The use of any and all examples or exemplary language in this document, such as "for example" or "including", is merely intended to better illustrate the present invention and does not limit the scope of the present invention unless a claim is made. Any language in this specification should not be construed as indicating that any unclaimed element is essential for the practice of the present invention.

[0034] Example 1

[0035] A drop-resistant ceramic material, one side of the ceramic material is ceramic, the other side is melamine-formaldehyde resin, the contact surface between the ceramic and the melamine-formaldehyde resin is acid-etched, and the ceramic material is prepared by the following preparation method.

[0036] A preparation method of a drop-resistant ceramic material, comprising the following steps:

[0037] S1. Acid-etch one side of the ceramic material with 3% hydrofluoric acid by mass fraction for 8 min, then wash it with deionized water and dry it to obtain acid-etched ceramic for standby;

[0038] S2. By mass parts, dissolve 1 part of silane coupling agent kh-590 in 60 parts of ethanol solution with a volume fraction of 90%, add glacial acetic acid to the solution to adjust the pH of the system to 4, then uniformly coat the solution on the acid-etched surface of the acid-etched ceramic, and thermally cure it at 80 °C for 2 h to obtain silanized ceramic;

[0039] S3. By mass parts, dissolve 5 parts of oleic acid amide and 0.5 photoinitiator 1173 in 100 parts of tetrahydrofuran, then add 30 parts of silanized ceramic to the solution and cure it under the condition of ultraviolet light intensity of 10 mW / cm² for 6 h. After the reaction is completed, take out the ceramic and wash it with absolute ethanol and deionized water in turn and dry it to obtain modified ceramic;

[0040] S4. By mass parts, mix 12.6 parts of melamine and 25 parts of 30% formaldehyde aqueous solution by mass fraction, add triethanolamine to adjust the pH to 10, then preheat the solution at 70 °C for 120 min to obtain a prepolymer, filter out the prepolymer and add the prepolymer to a mold with modified ceramic at the bottom, and hot-press and cure it at 145 °C and 10 MPa for 15 min to obtain a drop-resistant ceramic material.

[0041] Example 2

[0042] A drop-resistant ceramic material, one side of the ceramic material is ceramic, the other side is melamine-formaldehyde resin, the contact surface between the ceramic and the melamine-formaldehyde resin is acid-etched, and the ceramic material is prepared by the following preparation method.

[0043] A preparation method of a drop-resistant ceramic material, comprising the following steps:

[0044] S1. Etch one side of the ceramic material with hydrofluoric acid with a mass fraction of 6.5% for 4.5 min, then wash with deionized water and dry to obtain the etched ceramic for standby;

[0045] S2. By mass, dissolve 3 parts of silane coupling agent kh-590 in 80 parts of ethanol solution with a volume fraction of 65%, add glacial acetic acid to the solution to adjust the pH of the system to 4.5, then uniformly coat the solution on the etched surface of the etched ceramic, and thermally cure at a temperature of 100 °C for 1.5 h to obtain the silanized ceramic;

[0046] S3. By mass, dissolve 8.5 parts of erucamide and 1 photoinitiator 651 in 250 parts of tetrahydrofuran, then add 35 parts of the silanized ceramic to the solution and cure under ultraviolet light intensity of 30 mW / cm² for 4 h. After the reaction, take out the ceramic and wash and dry it successively with absolute ethanol and deionized water to obtain the modified ceramic;

[0047] S4. By mass, mix 18.9 parts of melamine and 38.8 parts of formaldehyde aqueous solution with a mass fraction of 35%, add triethanolamine to adjust the pH to 9, then preheat the solution at a temperature of 75 °C for 80 min to obtain a prepolymer. Filter out the prepolymer and add the prepolymer to a mold with the modified ceramic placed at the bottom, and hot press and cure at a temperature of 150 °C and a pressure of 15 MPa for 10 min to obtain the drop-resistant ceramic material.

[0048] Example 3

[0049] A drop-resistant ceramic material, one side of the ceramic material is ceramic, the other side is melamine-formaldehyde resin, the contact surface between the ceramic and the melamine-formaldehyde resin is subjected to etching treatment, and the ceramic material is prepared by the following preparation method.

[0050] A preparation method of a drop-resistant ceramic material, comprising the following steps:

[0051] S1. Etch one side of the ceramic material with hydrofluoric acid with a mass fraction of 10% for 1 min, then wash with deionized water and dry to obtain the etched ceramic for standby;

[0052] S2. By mass, dissolve 5 parts of silane coupling agent kh-580 in 100 parts of ethanol solution with a volume fraction of 40%, add glacial acetic acid to the solution to adjust the pH of the system to 5, then uniformly coat the solution on the etched surface of the etched ceramic, and thermally cure at a temperature of 120 °C for 1 h to obtain the silanized ceramic;

[0053] S3. By mass fraction, dissolve 12 parts of erucamide and 1.5 parts of photoinitiator 651 in 400 parts of tetrahydrofuran. Then add 40 parts of silylated ceramic to the solution and cure it for 2 h under the condition of ultraviolet light intensity of 50 mW / cm². After the reaction, take out the ceramic and wash and dry it successively with absolute ethanol and deionized water to obtain the modified ceramic;

[0054] S4. By mass fraction, mix 25.2 parts of melamine and 52.6 parts of 40% formaldehyde aqueous solution, and add triethanolamine to adjust the pH to 8. Then preheat the solution at 80 °C for 40 min to obtain a prepolymer. Filter out the prepolymer and add the prepolymer into a mold with the modified ceramic placed at the bottom. Hot press and cure it at 155 °C and 20 MPa for 5 min to obtain the anti-drop ceramic material.

[0055] Comparative Example 1

[0056] An anti-drop ceramic material, one side of the ceramic material is ceramic, the other side is melamine-formaldehyde resin, the contact surface between the ceramic and the melamine-formaldehyde resin is acid-etched, and the ceramic material is prepared by the following preparation method.

[0057] A preparation method of an anti-drop ceramic material, comprising the following steps:

[0058] S1. Acid-etch one side of the ceramic material with 10% hydrofluoric acid by mass fraction for 1 min, then wash it with deionized water and dry it to obtain the acid-etched ceramic for standby;

[0059] S2. By mass fraction, dissolve 5 parts of silane coupling agent kh-580 in 100 parts of ethanol solution with a volume fraction of 40%, and add glacial acetic acid to adjust the pH of the system to 5. Then evenly coat the solution on the acid-etched surface of the acid-etched ceramic and thermally cure it at 120 °C for 1 h to obtain the silylated ceramic;

[0060] S3. By mass fraction, mix 25.2 parts of melamine and 52.6 parts of 40% formaldehyde aqueous solution, and add triethanolamine to adjust the pH to 8. Then preheat the solution at 80 °C for 40 min to obtain a prepolymer. Filter out the prepolymer and add the prepolymer into a mold with the silylated ceramic placed at the bottom. Hot press and cure it at 155 °C and 20 MPa for 5 min to obtain the anti-drop ceramic material.

[0061] Experimental Example

[0062] Take four samples of the ceramic materials in Examples 1 to 3 and Comparative Example 1 respectively, and refer to the national standard GB / T 38494-2020 "Test Method for Impact Resistance of Ceramics" to conduct impact resistance performance tests. Among them, two samples are used to test the edge impact resistance and the center impact resistance of the ceramic surface respectively. After soaking the other two samples in water for 28 days, test the edge impact resistance and the center impact resistance of the ceramic surface. The test results are shown in Table 1:

[0063] Table 1

[0064]

[0065] As can be seen from Table 1, the ceramic materials of the present invention in Examples 1 to 3 have better impact resistance and water resistance. The reason is that after the ceramic materials of the present invention are treated, they have better compatibility with melamine-formaldehyde resin, and the melamine-formaldehyde resin near the interface has better flexibility, which can more effectively disperse the external stress received by the ceramic groups.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a drop-resistant ceramic material, characterized in that It includes the following steps: Etch one side of the ceramic material with hydrofluoric acid, wash it with water and dry it to obtain the etched ceramic. Then, prepare a silane coupling agent solution, coat the silane coupling agent solution on the etched surface of the etched ceramic, and obtain the silanized ceramic after thermal curing. Then, dissolve the amide compound and the photoinitiator in tetrahydrofuran, add the silanized ceramic to the solution, and obtain the modified ceramic after photocuring, washing and drying. Finally, prepare a melamine resin prepolymer, and press and mold the melamine resin prepolymer on the etched surface of the modified ceramic to obtain the anti-drop ceramic material.

2. The preparation method of an anti-drop ceramic material according to claim 1, characterized in that, The steps for preparing the silane coupling agent are as follows: Dissolve the silane coupling agent kh-580 or kh-590 in an ethanol solution with a volume fraction of 40-90%, then add glacial acetic acid to adjust the pH of the system to 4-5, and the mass ratio of the silane coupling agent to the ethanol solution is 1-5:60-100.

3. The preparation method of an anti-drop ceramic material according to claim 1, characterized in that, The method for preparing the melamine resin prepolymer is as follows: Mix melamine and an aqueous formaldehyde solution, add triethanolamine to adjust the pH to 8-10, and then preheat the solution at a temperature of 75-95°C for 40-120 min to obtain the melamine resin prepolymer.

4. The preparation method of an anti-drop ceramic material according to claim 1, characterized in that, The mass fraction of hydrofluoric acid is 3-10%, and the etching time is 1-8 min.

5. The preparation method of an anti-drop ceramic material according to claim 1, characterized in that, The conditions for thermal curing are curing at a temperature of 80-120°C for 1-2 h.

6. The preparation method of a drop-resistant ceramic material according to claim 1, characterized in that, The amide compound is one of erucamide and oleamide.

7. The preparation method of an anti-drop ceramic material according to claim 1, characterized in that, The photoinitiator is one of photoinitiator 651 and photoinitiator 1173. The conditions for photocuring are curing under ultraviolet light intensity of 10-50 mW / cm² for 2-6 h.

8. The preparation method of a drop-resistant ceramic material according to claim 1, characterized in that, The mass parts ratio of the amide compound, the photoinitiator, tetrahydrofuran, and the silanized ceramic is 5-12:0.5-1.5:100-400:30-40.

9. The preparation method of an anti-drop ceramic material according to claim 1, characterized in that, The conditions for pressure curing are hot pressing at a temperature of 145-155°C and a pressure of 10-20 MPa for 5-15 min for curing and molding.

10. An anti-drop ceramic material, characterized in that, The anti-aging ceramic material is prepared by the preparation method described in any one of claims 1-9.

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