CN111704152A - Magnesium oxide for moisture-proof fireproof cable and application thereof - Google Patents
Magnesium oxide for moisture-proof fireproof cable and application thereof Download PDFInfo
- Publication number
- CN111704152A CN111704152A CN202010417943.XA CN202010417943A CN111704152A CN 111704152 A CN111704152 A CN 111704152A CN 202010417943 A CN202010417943 A CN 202010417943A CN 111704152 A CN111704152 A CN 111704152A
- Authority
- CN
- China
- Prior art keywords
- magnesium oxide
- moisture
- fireproof cable
- proof fireproof
- proof
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/02—Magnesia
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
- C04B26/30—Compounds having one or more carbon-to-metal or carbon-to-silicon linkages ; Other silicon-containing organic compounds; Boron-organic compounds
- C04B26/32—Compounds having one or more carbon-to-metal or carbon-to-silicon linkages ; Other silicon-containing organic compounds; Boron-organic compounds containing silicon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
- H01B3/10—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances metallic oxides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/28—Protection against damage caused by moisture, corrosion, chemical attack or weather
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/29—Protection against damage caused by extremes of temperature or by flame
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/20—Resistance against chemical, physical or biological attack
- C04B2111/27—Water resistance, i.e. waterproof or water-repellent materials
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/20—Resistance against chemical, physical or biological attack
- C04B2111/28—Fire resistance, i.e. materials resistant to accidental fires or high temperatures
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/90—Electrical properties
- C04B2111/92—Electrically insulating materials
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Inorganic Insulating Materials (AREA)
Abstract
The invention provides magnesium oxide for a moisture-proof fireproof cable and application thereof. The magnesium oxide for the moisture-proof fireproof cable comprises the following components in parts by weight: 95-99 parts of MgO; 0.5-2.0 parts of CaO; fe2O30.3-1.0 part; al (Al)2O30.1-0.6 part; SiO 221.0-4.0 parts; water (LOI) is less than or equal to 0.2 portion. The invention also discloses a preparation method of the magnesium oxide for the moisture-proof fireproof cable and application of the magnesium oxide for the moisture-proof fireproof cable in the field of cables. The magnesium oxide for the moisture-proof fireproof cable has excellent moisture-proof insulating property, and the insulation is still more than or equal to 1000 MOmega under the conditions that the humidity is 80% RH and the time is 5 hours.
Description
Technical Field
The invention relates to a material technology, in particular to magnesium oxide for a moisture-proof fireproof cable and application thereof.
Background
The safety of the electrical lines is of critical importance, whether in a factory or in a building. According to the statistics of relevant departments of the country, the fire caused by an electric line accounts for more than 50% of the causes of the fire. The cable is a main body in the circuit and is a link difficult to protect. Therefore, the cable should not only have the capability of resisting the damage of external flame, but also have the characteristic of not generating fire source by itself. Because the mineral insulated cable is made of inorganic materials, the magnesium oxide insulator can not generate open fire when in overload or short circuit. Therefore, the line formed by the mineral insulated cable can never cause fire. If a fire is caused by other reasons, the cable is not only tested by the big fire of the bear but also continuously impacted by other falling objects in the process of burning. At the moment, whether the cable can ensure the normal starting of fire-fighting equipment, the extinguishing of fire and the evacuation of personnel while generating no smoke and toxic gas is the key for evaluating the fire resistance of the line.
At present, under the conditions that the temperature is 25 ℃, the humidity is 80 percent RH and the temperature is 3 hours, the insulation of the insulated cable made of magnesium oxide is reduced from 500M omega to 0.5M omega. And before the cable is manufactured, the raw materials need to be baked at high temperature, so that moisture in the raw materials is removed, and the process difficulty is increased. The maximum normal working high temperature of the cable can reach 250 ℃, and the working time is short when the temperature is more than or equal to 700 ℃.
Disclosure of Invention
The invention aims to provide a moisture-proof magnesium oxide for a fireproof cable, aiming at the problems that the moisture resistance of the cable insulated by the magnesium oxide is poor and the insulation performance is obviously reduced after the cable is wetted, wherein the material has excellent moisture-proof insulation performance, and the insulation is still more than or equal to 1000 MOmega under the conditions that the humidity is 80% RH and the time is 5 hours.
In order to achieve the purpose, the invention adopts the technical scheme that: the magnesium oxide for the moisture-proof fireproof cable comprises the following components in parts by weight:
further, the magnesium oxide for the moisture-proof fireproof cable comprises the following components in parts by weight:
further, MgO is subjected to high-intensity electromagnetic separation to remove magnetic substances.
Further, the high-intensity electromagnetic field selection intensity is 10000-15000 gauss.
The preparation method of the magnesium oxide for the moisture-proof fireproof cable comprises the following steps: magnesium oxide, kaolin talc, aluminum hydroxide and zirconium silicate are mixed according to the weight ratio of 100: 3-6:2-5:1-3: 10-20; high-hydrogen-content organic silicon resin, high-hydrogen-content organic silicon oil, an aluminate coupling agent and solvent oil are mixed according to the volume ratio of 3-5: 4-6: preparing the solution according to the ratio of 20-30: 60-80; mixing the mixed materials and the solution according to the weight ratio of 80-110: 2-6 to obtain a mixed wet material; and drying the mixed wet material in a low-temperature rotary furnace at 150-300 ℃ for 1-2 hours to obtain the magnesium oxide for the moisture-proof fireproof cable.
Further, the preparation method of the magnesium oxide for the moisture-proof fireproof cable comprises the following steps:
step 1), removing magnetic substances in the fused magnesia by high-strength electromagnetic separation of the fused magnesia particles;
step 2), treating the fused magnesia particles for 60-120 minutes by a high-temperature rotary furnace at 1100-1200 ℃, and removing magnetic substances in the magnesia by high-strength electromagnetic separation;
step 3) placing kaolin into a muffle type rotary kiln, and calcining for 2-4 hours at 700-800 ℃;
step 4), carrying out surface modification treatment on the kaolin subjected to fine classification (fine classification is carried out by adopting an LHB type turbine type airflow classifier) and calcination by using a surface modification machine; obtaining superfine calcined kaolin with d less than or equal to 0.05mm and the content of 90% +/-3%;
step 5) placing the talc in a vertical drier to dry for 1-3 hours at 500-600 ℃; carrying out ultrafine grinding on the talc to 500-1000 meshes;
step 6) baking the aluminum hydroxide powder at 250-350 ℃ for 1-2 hours;
step 7) baking zirconium silicate powder at 750-850 ℃ for 1-3 hours;
step 8), mixing the magnesium oxide, kaolin talc, aluminum hydroxide and zirconium silicate obtained in the step according to the weight ratio of 100: 3-6:2-5:1-3: 10-20;
step 9), mixing the high hydrogen-containing organic silicon resin, the high hydrogen-containing organic silicon oil, the aluminate coupling agent and the solvent oil according to the volume ratio of 3-5: 4-6: preparing the solution according to the ratio of 20-30: 60-80;
step 10) mixing the materials obtained in the step 8) and the solution obtained in the step 9) according to the weight ratio of 80-110: 2-6 to obtain a mixed wet material;
and step 11) drying the mixed wet material in a low-temperature rotary furnace at the temperature of 150-300 ℃ for 1-2 hours to obtain the magnesium oxide for the moisture-proof fireproof cable.
Further, the particle size of the fused magnesia particles in the step 1 is 60-400 meshes, and the fused magnesia particles are prepared by crushing fused magnesia raw materials through a crusher.
Furthermore, the kaolin d in the step 2) is less than or equal to 20mm, the kaolin raw material is crushed by a jaw crusher and finely classified to form fine classification, the d is mainly less than or equal to 20mm, and an LHB type turbine airflow classifier is adopted for fine classification.
Further, the surface modifier in the step 4) comprises 0.05% of organic silicon resin and 0.1% of solvent oil, and the modification method is a chemical coating method.
Further, the d of the talc in the step 5) is less than or equal to 10mm, and the talc is formed by crushing talc raw materials through a hammer crusher.
Further, the content of acid-insoluble substances in the talc in the step 5) is more than or equal to 93.0 percent, and the acid-soluble iron (Fe)2O3) Less than or equal to 0.20 percent, the ignition loss (1200 ℃) less than or equal to 3.00 percent, the magnet absorption less than or equal to 0.03 percent and the water less than or equal to 0.3 percent.
The invention also discloses application of the magnesium oxide for the moisture-proof fireproof cable in the field of cables. The magnesium oxide for the moisture-proof fireproof cable does not need to be baked before use, and the magnesium oxide is filled between a cable core rod and the surface along with the manufacture of the cable, so that the magnesium oxide has the effects of insulation, high temperature resistance and fire resistance. The dosage and the using method are different according to different cable manufacturing processes.
Compared with the prior art, the magnesium oxide for the moisture-proof fireproof cable has the following advantages:
1) the cable manufactured by the magnesium oxide for the moisture-proof fireproof cable can still have the insulation more than or equal to 1000 MOmega under the conditions of 25 ℃ of temperature, 80% RH of humidity and 5 hours.
2) Before the magnesium oxide for the moisture-proof fireproof cable is used for manufacturing the cable, magnesium powder does not need to be baked, the production process is simplified, and the productivity and the working efficiency are improved.
3) The maximum normal working temperature of the cable manufactured by the magnesium oxide for the moisture-proof fireproof cable can reach 280 ℃, and the cable can continue to operate at the temperature close to the melting point of copper and 1083 ℃ in a short period of time. Maintaining circuit integrity provides valuable time for safe evacuation of personnel.
Detailed Description
The invention is further illustrated by the following examples:
example 1
The embodiment discloses magnesium oxide for a moisture-proof fireproof cable, which comprises the following components in parts by weight:
the preparation method of the magnesium oxide for the moisture-proof fireproof cable comprises the following steps:
1. crushing the fused magnesium oxide to 60-400 meshes by a crusher; the granularity of the electric melting magnesium oxide is in an interval range, and the filling effect of a single mesh is not ideal.
2. Carrying out high-strength electromagnetic separation on the electrofused magnesium oxide particles to remove magnetic substances in the electrofused magnesium oxide;
3. treating the fused magnesia particles in a high-temperature rotary furnace at 1100-1200 ℃ for 60 minutes, removing magnetic substances in the magnesia from the obtained fused magnesia through high-strength electromagnetic separation, and cooling for later use;
4. crushing a kaolin raw material by a jaw crusher until d is less than or equal to 20 mm; then fine grading is carried out;
5. directly feeding kaolin into a muffle type rotary kiln to be calcined for 2 hours at 700-800 ℃;
6. carrying out surface modification treatment on the kaolin subjected to fine grading calcination by using a surface modification machine; obtaining superfine calcined kaolin with d less than or equal to 0.05mm and the content of 90% +/-3%;
7. crushing the talc raw material by a hammer crusher until d is less than or equal to 10mm, and drying the talc raw material in a vertical dryer at 500-600 ℃;
8. ultrafine grinding pulvis Talci to obtain 500-1000 mesh powder, acid insoluble substance not less than 93.0%, and acid soluble iron (Fe)2O3) Less than or equal to 0.20 percent, the ignition loss (1200 ℃) is less than or equal to 3.00 percent, the magnet absorption is less than or equal to 0.03 percent, and the water content is less than or equal to 0.3 percent;
9. baking the aluminum hydroxide powder at 250-350 ℃ for 1-2 hours;
10. baking zirconium silicate powder at 750-850 ℃ for 1-3 hours;
11. taking the magnesium oxide obtained in the step 3, the kaolin obtained in the step 6, the talc obtained in the step 8, the aluminum hydroxide obtained in the step 9, and the zirconium silicate obtained in the step 10 according to the weight ratio of 100: 3-6:2-5: stirring uniformly in a container according to the proportion of 1-3: 10-20;
12. high-hydrogen-content organic silicon resin, high-hydrogen-content organic silicon oil, an aluminate coupling agent and solvent oil are mixed according to the volume ratio of 3-5: 4-6: preparing the solution according to the ratio of 20-30: 60-80;
13. adding the solution obtained in the step 12 into the container in the step 11, and uniformly stirring;
14. drying the mixed wet material obtained in the step 13 in a low-temperature rotary furnace at the temperature of 150-300 ℃ for 1-2 hours;
finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (5)
1. The magnesium oxide for the moisture-proof fireproof cable is characterized by comprising the following components in parts by weight:
2. the magnesium oxide for moisture-proof fireproof cable according to claim 1, wherein the magnesium oxide comprises the following components in parts by weight:
3. the magnesium oxide for moisture-proof fireproof cable according to claim 1 or 2, wherein the MgO is subjected to high-intensity electromagnetic separation to remove magnetic substances.
4. The magnesium oxide for moisture-proof fireproof cable as claimed in claim 3, wherein the high-strength electromagnetic magnetic field strength is 10000-15000 gauss.
5. Use of the magnesium oxide for moisture-proof fireproof cable according to any one of claims 1 to 4 in the field of cables.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010417943.XA CN111704152A (en) | 2020-05-18 | 2020-05-18 | Magnesium oxide for moisture-proof fireproof cable and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010417943.XA CN111704152A (en) | 2020-05-18 | 2020-05-18 | Magnesium oxide for moisture-proof fireproof cable and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111704152A true CN111704152A (en) | 2020-09-25 |
Family
ID=72537209
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010417943.XA Pending CN111704152A (en) | 2020-05-18 | 2020-05-18 | Magnesium oxide for moisture-proof fireproof cable and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111704152A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113488273A (en) * | 2021-07-30 | 2021-10-08 | 大石桥市美尔镁制品有限公司 | High-temperature-resistant high-pressure-resistant moisture-proof fireproof cable and preparation method thereof |
| CN113583294A (en) * | 2021-07-30 | 2021-11-02 | 大石桥市美尔镁制品有限公司 | High-temperature-resistant high-pressure-resistant moistureproof magnesium oxide for fireproof cable, and preparation method and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103896552A (en) * | 2014-03-21 | 2014-07-02 | 辽宁华宇镁建材有限公司 | Magnesium chloride fireproof insulation board prepared by utilizing magnesite wastes and preparation method of insulation board |
| CN105776256A (en) * | 2016-03-25 | 2016-07-20 | 久盛电气股份有限公司 | Preparation method for moisture-proof magnesium oxide powder for insulated cables |
| US20170081244A1 (en) * | 2014-03-03 | 2017-03-23 | Krosakiharima Corporation | Unshaped refractory material |
| CN108288528A (en) * | 2018-02-07 | 2018-07-17 | 大石桥市美尔镁制品有限公司 | A kind of magnesia powder insulating materials and a kind of flexible cable |
| CN110256870A (en) * | 2019-07-17 | 2019-09-20 | 辽宁嘉顺化工科技有限公司 | A kind of damp-proof anti-high voltage high temperature electrician preparation process of magnesia and process units |
-
2020
- 2020-05-18 CN CN202010417943.XA patent/CN111704152A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170081244A1 (en) * | 2014-03-03 | 2017-03-23 | Krosakiharima Corporation | Unshaped refractory material |
| CN103896552A (en) * | 2014-03-21 | 2014-07-02 | 辽宁华宇镁建材有限公司 | Magnesium chloride fireproof insulation board prepared by utilizing magnesite wastes and preparation method of insulation board |
| CN105776256A (en) * | 2016-03-25 | 2016-07-20 | 久盛电气股份有限公司 | Preparation method for moisture-proof magnesium oxide powder for insulated cables |
| CN108288528A (en) * | 2018-02-07 | 2018-07-17 | 大石桥市美尔镁制品有限公司 | A kind of magnesia powder insulating materials and a kind of flexible cable |
| CN110256870A (en) * | 2019-07-17 | 2019-09-20 | 辽宁嘉顺化工科技有限公司 | A kind of damp-proof anti-high voltage high temperature electrician preparation process of magnesia and process units |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113488273A (en) * | 2021-07-30 | 2021-10-08 | 大石桥市美尔镁制品有限公司 | High-temperature-resistant high-pressure-resistant moisture-proof fireproof cable and preparation method thereof |
| CN113583294A (en) * | 2021-07-30 | 2021-11-02 | 大石桥市美尔镁制品有限公司 | High-temperature-resistant high-pressure-resistant moistureproof magnesium oxide for fireproof cable, and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111704152A (en) | Magnesium oxide for moisture-proof fireproof cable and application thereof | |
| CN109835927B (en) | High-temperature-resistant and high-hydrophobicity electric-grade magnesium oxide powder and preparation method thereof | |
| CN108584997B (en) | Preparation method of magnesium oxide powder for fireproof cable | |
| CN111718184A (en) | Magnesium oxide powder for calcining high-temperature oven, preparation method and application thereof | |
| CN105618669A (en) | Refractory coating for sand casting of pump body | |
| CN108288528A (en) | A kind of magnesia powder insulating materials and a kind of flexible cable | |
| CN111704395A (en) | Magnesium oxide for moisture-proof fireproof cable and preparation method thereof | |
| CN111960845A (en) | Foamed ceramic material, decorative plate and preparation method | |
| Rakhila et al. | Elaboration and characterization of new ceramic material from clay and phosphogypsum | |
| Adell et al. | Comparison of rapid and slow sintered pulverised fuel ash | |
| CN108455975A (en) | A kind of anti-strong base alumina bubble brick and preparation method thereof | |
| CN101567237A (en) | Ultra high strength outdoor solid core post insulator | |
| CN111302769A (en) | Low-aluminum-magnesium composite unburned brick and preparation method thereof | |
| CN111393174A (en) | Method for manufacturing M47 refractory material by using fly ash | |
| CN110396298A (en) | A kind of fire-proof high-temperature resistant organic silicon rubber material and preparation method thereof | |
| CN112876214A (en) | Microcrystalline foamed ceramic and preparation method and application thereof | |
| CN108793972B (en) | Preparation method of mineral insulated cable magnesium oxide knob insulator | |
| CN104177676A (en) | Rubber for cable insulation outer walls and production method thereof | |
| CN107986304B (en) | Preparation process of nano magnesium oxide | |
| CN113583294A (en) | High-temperature-resistant high-pressure-resistant moistureproof magnesium oxide for fireproof cable, and preparation method and application thereof | |
| CN106747291A (en) | A kind of ceramic macromolecular material ceramic powder and preparation method thereof | |
| CN113488273A (en) | High-temperature-resistant high-pressure-resistant moisture-proof fireproof cable and preparation method thereof | |
| CN115072730A (en) | Energy-saving process for calcining coal series kaolin by double kilns | |
| CN113582677B (en) | Low-temperature sintering ceramic powder and preparation method thereof | |
| CN108281217A (en) | A kind of magnesia powder insulating materials and preparation method thereof and a kind of flexible cable |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200925 |
|
| RJ01 | Rejection of invention patent application after publication |