CN1112338C - Method for preparing composite metal oxide ceramic powder material by using organic polymerization auxiliary prosess - Google Patents

Abstract

The present invention relates to a method for preparing a composite metal oxide ceramic powder material by an organic polymerization auxiliary process, which is characterized in that metal oxide or a precursor of the metal oxide is added with an organic polymer monomer comprising at least one simple function group and at least one double function group having the functional group of vinyl or propenyl and organic dispersing agent solution to prepare slurry, a polymerization crosslinking solidification process and a drying process are carried out after a free radical initiator is added, and then a fine grinding process is carried out after ignition under the conversion temperature of a needed phase. The obtained composite metal oxide powder material has the advantages of uniform graininess and high purity. The method for preparing a composite metal oxide ceramic powder material by an organic polymerization auxiliary process has the advantages of simple technology, convenient operation, high efficiency and low production cost and is suitable for bulk production.

Description

The auxiliary method for preparing the complex metal oxides ceramic powder of organic polymer

The present invention relates to complex metal oxides ceramic powder preparation method technical field.

The polynary metal oxide pottery is having wide application as aspects such as catalyzer, high-temperature superconductor, gas detecting element, Solid Oxide Fuel Cell and gas separation membrane materials.

Preparation complex metal oxides stupalith powder is used solid reaction process always at present.According to " inorganic materials physical chemistry " (China Construction Industry Press, 1984) a book chapter 14, and Japanese mountain pass is tall and willow Tian Boming compiles " ceramic process " (skill newspaper hall publication Co., Ltd., 1984) a book introduction, this method is salt mixed grinding, compressing tablet, the high temperature sintering with metal oxide or metal, and then is ground into powder.This method must be ground for a long time so that as far as possible closely contact between the different components, and must long-time heat to promote the carrying out of solid state reaction; For making material reaction thorough, need repeatedly this grinding, compressing tablet and calcination process sometimes, thereby consume energy, take a lot of work, and the powder that obtains often is subjected to the pollution of grinding medium; Simultaneously. because the grain growth in the high-temperature process is not only pulverized difficulty, and the powder sintering poor activity, be unfavorable for the preparation of follow-up ceramic sintered bodies.

Fa Zhan chemical coprecipitation afterwards, such as good that think S. Ruide (Janes S.Reed) work " Principle of Pottery Technology " (Principle of Ceramics Processing, John Wiley $ Sons company, nineteen ninety-five publishes) the 55th page described, the mixing solutions that at first prepares metal-salt, add certain precipitation agent (normally alkali metal hydroxide, ammoniacal liquor, oxalic acid or its ammonium salt solution) again, each metallic element is precipitated out simultaneously with the form of oxyhydroxide or oxalate, and drying, calcination obtain the composite oxides powder again.This method need find all effective coprecipitator of all elements, and generally this is difficult to find; If can not find suitable coprecipitator, the component non-uniform phenomenon will occur, thereby this method application surface is wideless; In addition, also there are shortcomings such as the solution-operated amount is big, drying is difficult, power consumption is taken a lot of work in this method.

Some new chemical preparation process in recent years, relate to organic application, as " chemical communication " (Chem.Lett.) a kind of citric acid compound legal system of the 665th page of report in 1987 be equipped with the perovskite composite oxide ceramics powder, " U.S. pottery can will " (J.Am.Ceram.Soc.) a kind of metal-EDTA inner complex methods of 75 volume 65-69 pages or leaves (1995) reports prepares partially stabilized tetragonal zircite (PTZ) ceramic.These methods are all based on the principle of metal precursor chemical fixation, the organism consumption is very big, its mole dosage often is several times as much as metal, and be Chemical bond, tend to form carbonate in the afterglow process of back, very stable (as the alkaline earth metal carbonate) that has must could decompose by high temperature, for obtaining required composite oxides phase, must improve calcination temperature greatly.These adopt the method for organic additive or sequestrant, and an important condition is that organic additive is removed fully the most at last, if there is not complete burn off, will have CO in the dense ceramic material sintering process ₂Formation, may cause crackle.

The objective of the invention is to overcome the shortcoming of the grinding for a long time of existing general solid reaction process, compressing tablet and above-mentioned chemical method, provide a kind of simple organic polymer the auxiliary method for preparing the complex metal oxides ceramic powder.

The auxiliary method for preparing the complex metal oxides ceramic powder of this organic polymer, it is characterized in that metal oxide or its precursor and organic polymer monomer, organic dispersing agent solution mixing system form slurry, after adding radical initiator, by heating or add catalyzer and make organic polymer monomer polymerization crosslinking curing in the slurry, dry, calcination makes the generation solid state reaction under the invert point of required thing phase, forms compound oxidate ceramic, the levigate powder that obtains.

The precursor of described metal oxide is meant metal nitrate, carbonate and the organic acid salt that can form oxide compound through calcination;

Described organic polymer monomer contains at least a simple function group and at least a bifunctional, described functional group comprises vinyl or propenyl, two kinds of organic polymer monomer N wherein, N '-methylene-bisacrylamide (MBAM) is 0.1-0.4 with the ratio of acrylamide (AM): 1.0; The weight concentration of organic polymer monomer solution is 10--30%; Organic polymer monomer solution consumption accounts for the 35-60% of slurry cumulative volume during pulp preparation; Can adopt ball milling or alr mode with abundant dispersion and mixing in the pulp preparation process; Described solution is solvent with inexpensive water generally, also can select organic solvent for use according to concrete system situation;

Described dispersion agent is the linear macromolecular compound (tensio-active agent) of polyelectrolyte or non-ionic type, comprises polymethyl acrylic acid, polyacrylic acid and its esters, polyvinyl alcohol, polyoxyethylene glycol; The consumption of dispersion agent is the 0.4-2.3% of metal oxide or its precursor weight;

Described polymerization crosslinking solidifies, is after in slurry, adding radical initiator, to be heated to 35-100 ℃, or at room temperature to add catalyst n, and N, N ', N '-Tetramethyl Ethylene Diamine (TEMED) realizes; Described radical initiator is selected ammonium persulphate ((NH for use ₄) ₂S ₂O ₈) or Potassium Persulphate (K ₂S ₂O ₈); The consumption of initiator is generally the 0.1--1% of organic monomer weight; Initiator system of ammonium persulfate is because of it can decompose when the thermal treatment fully, noresidue;

Described drying is generally carried out in room temperature to 110 ℃ temperature; Adopt hot blast or microwave heating can accelerate rate of drying;

Described calcination is meant with dried base substrate that under the invert point of required thing phase by certain temperature schedule, the burn off organism is realized solid state reaction and the process of burning till fully; The required certain temperature schedule of calcination process can determine that this is that those skilled in the art can know according to the hot analytical results of green compact.

Compared with the prior art the inventive method has following advantage:

Because the pulp preparation process of the inventive method is mixed by grinding in the wetting phase that contains organic monomer, organic dispersing agent, feed composition is able to abundant pulverizing, dispersion and evenly mixed, and then is fixed by the high molecular polymer network; The existence of polymer network makes that no streams is moving in the dry calcination process; In the process that the organism calcination is removed, each feed composition is further furthered again closely to be contacted mutually, and interreaction formation composite oxides thing the highest mutually required calcination temperature significantly is lower than existing solid reaction process between feed composition thereby make.

Used total amount of organic seldom is approximately the 3-5% of oxide weight in the inventive method, and is inexpensive, cost is low, and is nontoxic, environmentally safe, thus avoided the shortcoming of existing organic sequestering agent method; Be better than the existing various organic coordination compound methods of development recently greatly.

Because the present invention adopts the organic polymer process that the polymerization of mixtures of metal oxide or its precursor is fixed, organism and ceramic composition are not Chemical bond, and can be subsequently under lower temperature fully calcination remove, the sintered body piece is a porous, be easy to grind, make the ceramic powder purity height of present method preparation, avoided existing organic additive and chelate method to be difficult to organic additive is removed fully, may form the carbonate that is difficult to decompose, and cause shortcomings such as follow-up ceramic sintered bodies crackle.

Because the spatial distribution of organic polymer homogeneous, the homogeneity of polymer network make that the material that is wrapped up is roughly close, thereby the powder particles size distribution that obtains are more even, helps the quality of follow-up ceramic sintered bodies after calcination generation solid state reaction.

Present method related raw material is simple and easy to, and the choice is big; Operation is simple, and saved heavy dry-pressing operation and replaced simple liquid castable than traditional synthesis by solid state reaction, need not specific installation, need not be through the chemosynthesis operation, facility investment and process cost are all low, be applicable to the manufacturing of polycomponent composite oxides powder widely, cost is lower, is fit to produce in enormous quantities.

Embodiment 1: oxygen permeable film material SrCo _0.8Fe _0.2O ₃The preparation of powder

Get SrCO ₃29.53g, 2CoCO ₃3Co (OH) ₂6H ₂O44.95g, Fe ₂O ₃3.194g, polyvinyl alcohol 0.30g, acrylamide (AM) 2.5g, bisacrylamide (MBAM) 0.5g, distilled water 15ml mixes, and ball milling 10 hours is made slurry, adds 10mg initiator ammonium persulfate ((NH ₄) ₂S ₂O ₃)) after be poured into mould, mould that slurry is housed 80 ℃ of heating 40-50 minute, is made that monomer generation polymerization crosslinking solidifies in the slurry, the demoulding 90-110 ℃ of drying 2 hours, is heated to 1000 ℃ then, calcination 5 hours becomes perovskite typed SrCo _0.8Fe _0.2O ₃Pottery obtains oxygen permeable film material SrCo after the pulverizing _0.8Fe _0.2O ₃Powder.

Embodiment 2: oxygen permeable film material La _0.6Sr _0.4Co _0.8Fe _0.2O ₃The preparation of ceramic powder

Get La ₂O ₃19.554g, SrO8.289g, Co ₃O ₄12.78g, Fe ₂O ₃3.194g, polymethyl acrylic acid 1.0g, acrylamide (AM) 3.0g, bisacrylamide (MBAM) 1.2g, distilled water 20ml mixes, and ball milling 15 hours is made slurry, and other is with embodiment 1, but calcination temperature is 1100 ℃.Obtain oxygen permeable film material La _0.6Sr _0.4Co _0.8Fe _0.2O ₃Ceramic powder.

Embodiment 3: composite oxides gas sensitive Cd _1.3In ₂O _4.3The preparation of ceramic powder

Get CdCO ₃22.4g, In ₂O ₃52.3g, polyacrylic acid 0.70g, acrylamide (AM) 2.5g, bisacrylamide (MBAM) 0.25g, distilled water 15ml mixes, ball milling 12 hours is made slurry, adds catalyst n, N, N ', N '-Tetramethyl Ethylene Diamine (TEMED), polyreaction is solidified under room temperature, other is with embodiment 1, but the calcination condition be 800 ℃ 5 hours, obtain the Cd (In to the alcohol sensitivity of spinel structure after the pulverizing _1-xCd _x) ₂O _4-xThe gas sensitive powder.

Embodiment 4: high temperature superconducting oxide YBa ₂Cu ₃O _7-xThe preparation of ceramic powder

Get Y ₂O ₃, BaCO ₃, CuO, be mixed into solid mixture in 1: 2: 3 in molar ratio; Be mixed with solution by per 100 ml water 4.0g polymethyl acrylic acid, 14.0g acrylamide (AM) and 1.4g bisacrylamide (MBAM); Above-mentioned solid mixture and solution are pressed solid-to-liquid ratio=5 (g): 2 (ml) metering proportion, mix, ball milling 20 hours is made slurry; Other step is with embodiment 1, but 850 ℃ of calcinations 5 hours, pulverized the cooling back, grinds, and obtains high temperature superconducting oxide YBa ₂Cu ₃O _7-xCeramic powder material.

Claims (1)

1, the auxiliary method for preparing the complex metal oxides ceramic powder of a kind of organic polymer, it is characterized in that metal oxide or its precursor and organic polymer monomer, organic dispersing agent solution, be mixed and made into slurry, after adding radical initiator, make the monomer polymerization crosslinking curing in the slurry, drying, calcination under the invert point of required thing phase, form compound oxidate ceramic, the levigate powder that obtains; Described organic polymer monomer contains at least a simple function group and at least a bifunctional, and described functional group comprises vinyl or propenyl, two kinds of organic polymer monomer N wherein, and N '-methylene-bisacrylamide is 0.1-0.4 with the ratio of acrylamide: 1; The weight concentration of organic polymer monomer solution is 10-30%; Organic polymer monomer solution consumption accounts for the 35-60% of slurry cumulative volume during pulp preparation; Described dispersion agent is the linear macromolecular compound of polyelectrolyte or non-ionic type; The consumption of dispersion agent is the 0.4-2.3% of metal oxide or its precursor weight; Described radical initiator is selected ammonium persulphate or Potassium Persulphate for use.