阅读说明：本技术 一种用于纳米氧化锆陶瓷的分散粘结剂组合及其用途 (Dispersion binder combination for nano zirconia ceramic and application thereof ) 是由 卓建 张廷珂 于 2021-01-25 设计创作，主要内容包括：本发明公开了一种用于纳米氧化锆陶瓷的分散粘结剂组合,其特征在于,包括：A组分,所述A组分为如式1所示的聚合物或如式2所示的聚合物当中的任意一种；B组分,所述B组分为如式3或式4或式5当中任意一种所示的含有脂肪酸酰胺的多羧基化合物；所述B组分的添加量为纳米氧化锆粉的用量的0.8-5％,将所述A组分与所述B组分按量混合后进行分散粘接。本发明还公开了其用途。本发明所制备的纳米氧化锆陶瓷,能够将烧结密度提高6.03-6.07到接近理论密度6.09,提供最佳的强度韧性同时具有出色的烧结过程中的低温收缩均匀性和高温下的形状保持,良品率大幅提高至95％以上。(The invention discloses a dispersion binder combination for nano zirconia ceramics, which is characterized by comprising the following components in percentage by weight: the component A is any one of a polymer shown as a formula 1 or a polymer shown as a formula 2; a component B, wherein the component B is a polycarboxylic compound containing fatty acid amide as shown in any one of a formula 3, a formula 4 or a formula 5; the addition amount of the component B is 0.8-5% of the dosage of the nano zirconia powder, and the component A and the component B are dispersed and bonded after being mixed according to the amount. The invention also discloses the application of the composition. The nano zirconia ceramic prepared by the invention can improve the sintering density by 6.03-6.07 to be close to the theoretical density of 6.09, provides the best strength and toughness, has excellent low-temperature shrinkage uniformity in the sintering process and shape retention at high temperature, and greatly improves the yield to more than 95%.)

1. A dispersed binder composition for nano zirconia ceramics, comprising:

the component A is any one of a polymer shown as a formula 1 or a polymer shown as a formula 2;

r in the formula 1₁Is H or CH₃；

R₂Is H, C₁-C₆Saturated alkanes or phenyl groups;

R₃is H, C₁-C₆Saturated alkanes or phenyl groups;

r in the formula 2₁Is H or CH₃；

R₄Is H, C₁-C₄Saturated alkanes or phenyl groups;

R₅is H, C₁-C₄Saturated alkanes or phenyl groups;

a component B, wherein the component B is a polycarboxylic compound containing fatty acid amide as shown in any one of a formula 3, a formula 4 or a formula 5;

r in the formula 3 is C_8-22Saturated fatty alkyl chain of (a);

r in the formula 4 is C_8-22Saturated fatty alkyl chain of (a);

r in the formula 5 is C_8-22Saturated fatty alkyl chain of (a);

the addition amount of the component A is 1-5% of the amount of the nano zirconia powder;

the addition amount of the component B is 0.8-5% of the dosage of the nano zirconia powder, and the component A and the component B are dispersed and bonded after being mixed according to the amount.

2. The dispersed binder composition for nano zirconia ceramics according to claim 1, wherein the polymer represented by formula 1 is formed by polymerizing penta-cyclooxazoline represented by formula 6;

r in said formula 6₁Is H or CH₃；

R₂Is H, C₁-C₆Saturated alkanes or phenyl groups;

R₃is H, C₁-C₆Saturated alkanes or phenyl groups;

3. the dispersed binder composition for nano zirconia ceramics according to claim 1, wherein the polymer represented by formula 2 is formed by polymerizing six-membered ring oxazoline represented by formula 7,

r in the formula 7₁Is H or CH₃；

R₄Is H, C₁-C₄Saturated alkanes or phenyl groups;

R₅is H, C₁-C₄Saturated alkanes or phenyl groups;

4. use of a dispersion binder combination for nano zirconia ceramics, wherein the dispersion binder is defined in any one of claims 1 to 3 for dispersion and binding of nano zirconia powder, so that the sintered density of ceramics sintered by the nano zirconia powder after dispersion and binding is increased to 6.03 to 6.07.

Technical Field

The invention relates to the field of dispersion and bonding of zirconia ceramics, in particular to a dispersion binder combination for nano zirconia ceramics and application thereof.

Background

Inorganic ceramics, especially zirconia ceramics, have excellent mechanical and electrical properties and are widely used in industry and human life. Compared with metal, the zirconia ceramics has the advantages of better wear resistance, smooth surface, good texture, no oxidation and the like, and is applied to watch chains of watches and ornaments of some high-grade backpacks; zirconia powder and noble metal alloy powder are mixed and fired, and are subjected to a plurality of precise and strict procedures and a plurality of times of machine grinding and polishing, so that the zirconia powder and the noble metal alloy powder can be finally fused into jewelry design. The ceramic is light and wear-resistant, has the property of sensitivity resistance, and is comfortable to wear. The ceramic ornaments are formed by molding and sintering zirconia powder, and have no higher requirements on the mechanical property and molding density of ceramic sintering because the requirement on precision of end use is not high.

The zirconia ceramic material is used in fields requiring high precision, such as automobiles, airplanes and other mechanical equipment, which require small heat conduction coefficient and excellent wear resistance, has higher requirements on the forming in the ceramic sintering process, not only has higher requirements on zirconia powder required by zirconia ceramic, but also has higher requirements on bonding forming agents and other types of auxiliary agents in the forming and sintering processes, and can achieve the effects of uniform forming, shape maintenance in the sintering process and uniform shrinkage forming.

The excellent performances of no-signal shielding, drop resistance, wear resistance, folding resistance, high strength, high toughness, corrosion resistance and wear resistance of the zirconia ceramic can well meet the performance requirements in the electronic field and the field of radio and television communication, and particularly the function of no-signal shielding has better performance advantages when the zirconia ceramic enters the 5G era. This is because the frequency band of 5G is higher and the wavelength is shorter, and the metallic communication devices used in 2G, 3G and 4G all generate larger shielding and interference to the 5G signal, resulting in the phenomenon that the signal becomes worse. Especially in the current society where mobile phones and information communication devices are increasingly important, the mode of increasing boundary plastic components is generally adopted in the 4G stage to ensure the smoothness of signals, but the frequency band of 5G is higher, which causes further deterioration of signals, and a more appropriate mode is to use glass, which is a material that does not generate interference in frequency band, but glass is fragile, has poor resistance, cannot meet the requirements of high strength and long service life, and is easy to damage communication devices. Zirconia ceramics are an ideal choice, do not affect signals, have extremely high hardness and strength, and can achieve relatively excellent toughness at present by modifying the components of zirconia.

However, the zirconia ceramic has a problem that the zirconia molding needs to be dispersed, ground, dried, molded and sintered, particularly in the sintering stage, waste products formed by excessively low sintering density are easily caused, and in addition, the zirconia ceramic needs to use a binder to ensure the shape maintenance in the sintering process and also easily causes deformation of original parts formed by uneven sintering shrinkage, so that the original parts prepared by using the zirconia ceramic at present are very low in precision and thin layers, and the yield is usually lower than 50%. Causing significant waste and high costs.

Patent CN102070336 discloses a preparation method of zirconia ceramics, which uses one of N, N-dimethylacrylamide, hydroxymethyl ammonium acrylate, hydroxyethyl methacrylate or methacrylamide as a monomer of a premixed liquid, then uses N, N-methylene bisacrylamide as a cross-linking agent, then uses a dispersing agent of phosphate or polyacrylate, and is initiated by an initiator, and then is injected into a grinding tool, and is heated to obtain a dry blank, and then is sintered to form ceramics. In this document, the method of preparing a green body by using the water-soluble monomer to initiate pre-crosslinking by free radicals is used, and the green body formed after initiation contains relatively much water, and relatively shrinkage occurs during sintering, so that the preparation of relatively thin and fine green bodies and ceramic parts cannot be performed. According to a lot of experimental data of the authors of the present invention, it was found that the density after sintering is low, often lower than 5.9, after the application to the preparation of the blank by means of isostatic pressing, due to the hardness of the protective layer on the surface of zirconia, which is too high.

Patent CN105045798 discloses a zirconia ceramic mobile phone rear cover machine and a preparation method thereof, and the casting film preparation, isostatic pressing, low-temperature glue discharging and high-temperature sintering processes used in the invention. In the preparation and forming process, organic solvent, dispersant, adhesive and plasticizer are used, mixed in a ball mill, subjected to vacuum defoaming and subjected to tape casting. The applicable organic solvent is one or two of dimethylbenzene, absolute ethyl alcohol, 2-butanone, methanol, toluene, n-butanol, isopropanol and n-hexane, the organic solvent accounts for 20-30 wt% of the slurry, the adhesive is polyvinyl butyral accounting for 5-10 wt% of the slurry, and the plasticizer is phthalate compound accounting for 0.1-1.2 of the adhesive. A large amount of organic solvent is used in the preparation process, the preparation method is not environment-friendly, a large amount of harmful volatile matters are volatilized into the air to cause pollution, and the adhesive is bonded by polyvinyl alcohol, so that the adhesive is softened in the low-temperature adhesive discharge and sintering processes and is easy to deform.

However, the present inventors have conducted a great deal of experiments on the adhesion of polyvinyl alcohols, especially the adhesion of polyvinyl butyral, and found that such adhesion is very likely to cause deformation during the low temperature 180-350 ℃ sintering process, the yield can only be below 50%, the sintering density is between 5.6-5.9, and the above effects of maintaining the sintering density and the sintering shape are difficult to achieve.

The invention aims to overcome the defects of the technology, provides a dispersion binder combination for nano zirconia ceramics, can provide excellent blank forming strength, shape retention of low-temperature sintering and uniform high-temperature sintering shrinkage, and particularly has excellent yield when preparing thin components with high precision requirement.

Disclosure of Invention

In order to overcome the above-mentioned drawbacks of the prior art, the present invention aims to provide a dispersed binder composition for nano zirconia ceramics and its use.

The dispersant binder prepared by the invention is used for the nano zirconia ceramics, can improve the sintering density by 6.03-6.07 to be close to the theoretical density of 6.09, provides the optimal strength and toughness, has excellent low-temperature shrinkage uniformity in the sintering process and shape retention at high temperature, and greatly improves the yield to more than 95%.

In order to realize the purpose of the invention, the technical scheme is that

A dispersed binder composition for a nano zirconia ceramic comprising:

the component A is any one of a polymer shown as a formula 1 or a polymer shown as a formula 2;

said formulaR in 1₁Is H or CH₃；

R₂Is H, C₁-C₆Saturated alkanes or phenyl groups;

R₃is H, C₁-C₆Saturated alkanes or phenyl groups;

r in the formula 2₁Is H or CH₃；

R₄Is H, C₁-C₄Saturated alkanes or phenyl groups;

R₅is H, C₁-C₄Saturated alkanes or phenyl groups;

a component B, wherein the component B is a polycarboxylic compound containing fatty acid amide as shown in any one of a formula 3, a formula 4 or a formula 5;

r in the formula 3 is C_8-22Saturated fatty alkyl chain of (a);

r in the formula 4 is C_8-22Saturated fatty alkyl chain of (a);

r in the formula 5 is C_8-22Saturated fatty alkyl chain of (a);

the addition amount of the component A is 1-5% of the amount of the nano zirconia powder;

the addition amount of the component B is 0.8-5% of the dosage of the nano zirconia powder, and the component A and the component B are dispersed and bonded after being mixed according to the amount.

In a preferred embodiment of the present invention, the polymer represented by formula 1 is formed by polymerizing five-membered ring oxazoline represented by formula 6;

r in said formula 6₁Is H or CH₃；

R₂Is H, C₁-C₆Saturated alkanes or phenyl groups;

R₃is H, C₁-C₆Saturated alkanes or phenyl groups;

in a preferred embodiment of the present invention, the polymer represented by formula 2 is formed by polymerizing six-membered ring oxazoline represented by formula 7,

r in the formula 7₁Is H or CH₃；

R₄Is H, C₁-C₄Saturated alkanes or phenyl groups;

R₅is H, C₁-C₄Saturated alkanes or phenyl groups;

the use of the dispersed binder combination for the nano zirconia ceramics is to use the dispersed binder for dispersing and binding the nano zirconia powder, so that the sintering density of the nano zirconia powder after being dispersed and bound into the zirconia ceramics is improved to 6.03-6.07.

The invention has the beneficial effects that:

the nano zirconia ceramic prepared by the invention can improve the sintering density to 6.03-6.07 to 6.09 which is close to the theoretical density, provides the best strength and toughness, has excellent low-temperature shrinkage uniformity in the sintering process and shape retention at high temperature, and greatly improves the yield to more than 95%.

Detailed Description

The principle of the invention is as follows:

the dispersion binder combination prepared by the invention modifies the nano zirconia powder prepared by a hydrothermal synthesis method, and the zirconia powder after mixing and spray drying can be directly used for forming and sintering zirconia ceramics without adding other binders, such as binders of polyoxyethylene alcohol and polyacrylate. The sintering density and the molding yield can be greatly improved after sintering.

The dispersant and binder combination of the invention can effectively disperse and wrap the nano zirconia powder, and simultaneously has good binding effect in a series of forming processes such as isostatic pressing and the like, so as to ensure that the formed blank has higher strength.

In the low-temperature sintering process, the dispersed binder combination can generate a crosslinking reaction, so that the excellent shape retention effect is kept in the temperature rise process, and the deformation defect caused by softening of the binder due to temperature rise is avoided; with the rise of temperature, the effective crosslinking reaction of the dispersed binder composition of the invention also effectively ensures the shrinkage uniformity of volume in the sintering process, so that the sintered density can approach the theoretical density.

The dispersed binder combination has the beneficial effect that the mould after dry pressing molding is sintered, the molding state of the mould under low-temperature sintering (180 ℃ C. and 350 ℃ C.) can be effectively kept, bending and deformation can not occur, and the sintering density during high-temperature sintering (1200 ℃ C.) can be ensured. Thereby providing high strength and high yield.

The nano zirconia ceramic prepared by the invention can improve the sintering density to 6.03-6.07 to 6.09 which is close to the theoretical density, provides the best strength and toughness, has excellent low-temperature shrinkage uniformity in the sintering process and shape retention at high temperature, and greatly improves the yield to more than 95%.

The invention is further illustrated by the following examples and comparative examples:

example 1

A1L reaction vessel was charged with 107.8 g of octadecylamine, 78.34 g of citric acid, and then 50 g of xylene, heated to 165 ℃ and 170 ℃ with refluxing xylene to bring water to a reaction effluent of 7.0-7.5 g, and the infrared detection reaction was not changed. Then, xylene was distilled off under reduced pressure, cooled to 85 ℃, 50 g of 25% aqueous ammonia was added, 365 g of deionized water was then added, and stirring was carried out at 75 to 85 ℃ for 2 hours to obtain a 30% content ammonium octadecanamide dicarboxylate A1.

Example 2

111 g of dodecylamine and 108 g of nitrilotriacetic acid are added into a 1L reaction bottle, then 120 g of dimethylbenzene is added, and the mixture is heated to 170 ℃ and 180 ℃ to carry out dimethylbenzene reflux with water until the water yield of the reaction reaches 10-11 g, and the infrared detection reaction is not changed. Then, xylene was distilled off under reduced pressure, cooled to 85 ℃ and 75 g of 25% aqueous ammonia was added, then 410 g of deionized water was added and stirred at 75 to 85 ℃ for 2 hours to obtain a 30% content of ammonium dodecanodioate A2.

Example 3

163 g of icosaediamine and 148 g of ethylenediaminetetraacetic acid were added to a1 l reaction vessel, then 250 g of xylene was added, and the reaction was heated to 165-170 ℃ with refluxing xylene with water until the amount of water reached 8.8-9.3 g and the infrared detection reaction did not change. Then, xylene was distilled off under reduced pressure, cooled to 95 ℃ and 100 g of 25% aqueous ammonia was added, then 540 g of deionized water was added, and stirred at 75 to 85 ℃ for 2 hours to obtain a 32% content of ammonium octadecanamide triacetate A3.

Example 4

129 g of n-octylamine and 195 g of citric acid are added into a 1L reaction bottle, then 60 g of dimethylbenzene is added, and the mixture is heated to 165-170 ℃ to carry out dimethylbenzene reflux with water until the water yield of the reaction reaches 17.5-18.5 g, and the infrared detection reaction is not changed. Then, xylene was distilled off under reduced pressure, cooled to 75 ℃ and added with 130 g of 25% aqueous ammonia, then 438 g of deionized water, and stirred at 75-85 ℃ for 2 hours to obtain a 35% content of n-octylenedioic acid ammonium salt A4.

Example 5

89 g of 2-amino-2-methylpropanol, 200 g of methyl methacrylate and then 10 g of p-methoxyphenol were added to the reaction flask, and heating to reflux was started to remove 0.3 g of water from the reaction mass. Then 2.5 g of isopropyl titanate are added, and the reaction is maintained at 75-80 ℃ and methanol and a portion of methyl methacrylate are distilled off and the reaction is maintained for 8 hours. Then the temperature is raised to 110 ℃ until the distillate does not contain methanol under infrared detection, and the heating is stopped. Distillation under reduced pressure was started, and a fraction of 58 to 60 ℃ (24mmHg) was collected. The collected fractions were cooled to below 25 ℃ and 35ppm of p-methoxyphenol was added as a stabilizer to give oxazoline monomer B1.

Example 6

The same preparation process as in example 5 using 103 g of 3-amino-3-methyl-1-butanol, 200 g of methyl methacrylate, 10 g of p-methoxyphenol and 2.5 g of isopropyl titanate gave oxazoline monomer B2.

Example 7

The same preparation process as in example 5 using 61 g of 1-aminoethanol, 200 g of methyl methacrylate, 10 g of p-methoxyphenol and 2.5 g of isopropyl titanate gave oxazoline monomer B3.

Example 8

The same preparation as in example 5 using 75 g of 1-aminopropanol, 200 g of methyl methacrylate, 10 g of p-methoxyphenol and 2.5 g of isopropyl titanate gave oxazoline monomer B4.

Example 9

The same preparation as in example 5 using 89 g of 2-amino-2-methylpropanol, 300 g of ethyl acrylate, 15 g of p-methoxyphenol and 3.5 g of isopropyl titanate gave oxazoline monomer B5.

Example 10

Under the protection of nitrogen, 350 g of deionized water is added into a 1L reaction bottle and then heated to 85 ℃; stirring is started, 30 g of oxazoline monomer B1 is added into a reaction flask under stirring, then 3.0 g of ammonium persulfate is added and dissolved in 10 g of aqueous solution, and the temperature is kept for 5 to 10 minutes at 80 to 85 ℃. When the temperature is not changed any more, a solution of 270 g of oxazoline monomer B1 and 50 g of deionized water and a solution of 0.75 g of ammonium persulfate dissolved in 25 g of deionized water are simultaneously dropped, the temperature is maintained at 85-87 ℃ again in the dropping process, and the dropping time is 240 minutes. After the dropwise addition, the temperature is kept at 85-87 ℃ for 1 hour, then a solution of 0.5 g of ammonium persulfate dissolved in 10 g of deionized water is added, and the temperature is kept for 2 hours. The temperature is reduced to below 40 ℃, and the oxazoline polymer aqueous solution C1 is obtained by filtering through 150-mesh filter cloth.

Example 11

Under the protection of nitrogen, 400 g of deionized water was added into a 1L reaction flask, and then heated to 85 ℃; stirring is started, a mixed solution of 10% oxazoline monomer B2 and 90 g hydroxypropyl acrylate is added into a reaction bottle under stirring, then 2.0 g ammonium persulfate is added and dissolved in 10 g aqueous solution, and the temperature is kept for 5 to 10 minutes at 80 to 85 ℃. When the temperature is not changed any more, the remaining 90 percent of the mixed solution of oxazoline monomer B1 and hydroxypropyl acrylate and a solution of 1.25 g of ammonium persulfate dissolved in 25 g of deionized water are simultaneously dripped, the temperature is kept between 85 ℃ and 87 ℃ in the dripping process, and the dripping time is 240 minutes. After the dropwise addition, the temperature is kept at 85-87 ℃ for 1 hour, then a solution of 0.5 g of ammonium persulfate dissolved in 10 g of deionized water is added, and the temperature is kept for 2 hours. Cooling to below 40 deg.C, and filtering with 150 mesh filter cloth to obtain oxazoline polymer-containing aqueous solution C2.

Example 13

The preparation was carried out as described in example 12, the monomers 294 g of oxazoline B3 and 6 g of acrylamide, and the amount of ammonium persulfate used was 4.25 g, giving an aqueous solution C3 of an oxazoline-containing polymer.

Example 14

Preparation was carried out as in example 12, with the monomers 50 g of oxazoline B4, 60 g of oxazoline B5, 130 g of oxazoline B1 and 60 g of methyl-terminated polyoxyethylene ether (MPEG200) methacrylate, and with the amount of ammonium persulfate used being 3.5 g, to give an aqueous solution C4 of an oxazoline-containing polymer.

Examples 15 to 20

The prepared amidopolyacid ammonium salt A1-A4 and oxazoline-containing C1-C4 were added in various combinations to a 60% content nano-zirconia slurry prepared by a hydrothermal synthesis method (the addition amounts and combinations are shown in Table 1), and then ground in a grinder at 2000rpm for 1 hour, and spray-dried at 115 ℃ to obtain nano-zirconia powder containing amidopolyacid and oxazoline dispersed components. Then carrying out isostatic compaction on the spray-dried nano zirconia powder under the pressure of 150MPa to obtain a blank with the thickness of 1.0-3.0mm, the length of 15cm and the width of 6.5 cm. Then placing the prepared blank into an oven, heating to 380 ℃, sintering for 2 hours, and observing the state of the blank; then, the green body was sintered at 450 ℃ for 2 hours and the state of the green body was observed. Then the temperature is raised to 1200 ℃ and sintering is carried out for 4 hours. And taking out the sintered blank, weighing and calculating the sintering density. Then, polishing, silk weaving and polishing are carried out, a ceramic plate with the thickness of 0.8-2.5mm is prepared, whether bending and deformation exist or not is observed, and the data are listed in table 1.

Table 1:

^*the amounts of A1-A4 and C1-C4 added were based on the mass percentage of the zirconia powder.

Comparative example 1

As in example 15, no oxazoline-containing polymeric component C1 was added.

Comparative example 2

0.5% by weight of ammonium polyacrylate salt was added during the spray drying, and 4.5% polyvinyl butyral rubber powder based on zirconia powder was added during the isostatic pressing.

Comparative example 3

The same as in example 17, except that the amidopolyacid compound used was prepared from n-butylamine and citric acid.

Comparative example 4

Same as example 17 except that the amide carboxylic compound used was a monocarboxylic dodecylamide and succinic anhydride.

The test was compared to examples 15-20 and the data are given in Table 2:

table 2:

as can be seen from tables 1 and 2, the nano zirconia ceramics prepared by the present invention can increase the sintering density to 6.03 to 6.07 to 6.09 close to the theoretical density, provide the best strength and toughness, and have excellent low-temperature shrinkage uniformity during sintering and shape retention at high temperature, and the yield is greatly increased to 95% or more.