CN108641358A - A kind of preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity - Google Patents
A kind of preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity Download PDFInfo
- Publication number
- CN108641358A CN108641358A CN201810473751.3A CN201810473751A CN108641358A CN 108641358 A CN108641358 A CN 108641358A CN 201810473751 A CN201810473751 A CN 201810473751A CN 108641358 A CN108641358 A CN 108641358A
- Authority
- CN
- China
- Prior art keywords
- negative permittivity
- preparation
- tube
- carbon nano
- powder
- 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
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/02—Elements
- C08K3/04—Carbon
- C08K3/041—Carbon nanotubes
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0073—Shielding materials
- H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/011—Nanostructured additives
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Nanotechnology (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Electromagnetism (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Carbon And Carbon Compounds (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
The present invention relates to a kind of preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity, the method to prepare novel negative dielectric material, including：The batch mixing in vibrator by carbon nanotube and polyphenylene sulfide powder, is then sieved, and powder hot pressing is prepared into composite material, for testing and using.The preparation method of carbon nano-tube/poly diphenyl sulfide composite material provided by the invention, carbon nanotube are uniformly distributed in matrix polyphenylene sulfide, by the polyphenylene sulfide limitation leakage electrical conduction current of insulation, to reduce dielectric loss.The negative permittivity composite material of preparation keeps 1000 or less in 40MHz 1GHz frequency ranges, negative permittivity absolute value.Composite material simple for process, being prepared by the method with negative permittivity has important practical value and vast market prospect in application fields such as communication, microwave absorption and wireless power transmissions.
Description
Technical field
The preparation method of the present invention relates to a kind of carbon nano-tube/poly diphenyl sulfide composite material with negative permittivity belongs to
In composite material skill field and radio-frequency electromagnetic field of material technology.
Background technology
Dielectric constantεIt is the basic physical parameters for characterizing material electromagnetic performance.When dielectric constant is negative, material will be micro-
Wave is absorbed, is shielded, and decaying, filtering etc. play a significant role in fields.When negative permittivity and negative magnetoconductivity match, material
Many novel electromagnetic performances, such as reversed Doppler effect, inverse Cerenkov effect and negative refraction will be shown, these are solely
It is important that special performance so that material has in fields such as Novel resonator, microstrip antenna, magnetic resonance imaging and wireless power transmissions
Application prospect.
Currently, being broadly divided into two kinds for the realization means of negative permittivity, one is by constructing periodic structure battle array
Row obtain negative permittivity using electric resonance.Another kind is to utilize material intrinsic property, by controlled material object phase composition, micro-
Structure and extra electric field are seen to obtain.The performance that array type bears dielectric material mainly has with the size of structural unit and arrangement mode
It closes, and the object phase composition and microscopic appearance with material itself are unrelated, are a kind of artificial electromagnetic mediums being different from traditional material.By
In its processing cost costliness, manufacture is difficult and application band is specific, therefore limits the application that array type bears dielectric material.It is intrinsic
Negative dielectric material Modulatory character is strong, it is wide to prepare simplicity, application band, becomes new research hotspot in recent years.Studies have shown that passing through
Magnetic metal particle is added in ceramic phase or polymer, negative permittivity and negative magnetoconductivity can be obtained.Due to negative magnetoconductivity
It is mainly realized by the magnetic resonance of magnetic material, therefore the numerical value of negative magnetoconductivity is typically small.On the other hand, due to metal
Middle free electronic concentration is higher so that the negative permittivity absolute value of material is too big, it is difficult to be matched with permeability value, to make
It is poor at impedance matching, it restricts it and is applied on the fields such as microwave absorption, electromagnetic wave attenuation.If it is possible to obtain
Material with weak negative permittivity can have with negative magnetoconductivity values match for the preparation of double negative materials, using with development
There is important impetus.
Polyphenylene sulfide has excellent stability and mechanical performance and electrical insulation capability outstanding.Currently, polyphenylene sulfide
Compound with carbon nanotube is concentrated mainly on mechanical property and conductivity, however the present invention by by carbon nanotube in polyphenylene sulfide
Being uniformly distributed in ether, so as to obtain the product of negative permittivity.
The present invention with carbon nanotube be new functive, prepare the composite material with weak negative permittivity, communication,
The application fields such as microwave absorption and wireless power transmission have important researching value and vast market prospect.
Invention content
The present invention is absolute for unstable, the negative dielectric of dielectric properties that existing negative dielectric material manufacturing cost is high, obtains
Be worth the shortcomings of excessively high, provide that a kind of simple process, manufacturing cost be low and the preparation method of suitable industrialized production, obtain have it is weak
The composite material of negative dielectric.With polyphenylene sulfide（PPS）For matrix, carbon nanotube（CNT）As functive, ground using mechanical oscillation
And hot press forming technology, prepare carbon nano-tube/poly diphenyl sulfide composite material.Concrete technology is as follows：
（1）According to carbon nano-tube/poly diphenyl sulfide（CNT/PPS）Different quality ratio, the polyphenylene sulfide for the corrresponding quality that weighs with scale
Powder and carbon nanotube dust.
（2）By step（1）Load weighted powder is put into vibrating ball grinding jar, is carried out vibratory milling batch mixing at room temperature, is added
Material sequence adds polyphenylene sulfide for carbon nanotube is first added.The good powder of batch mixing is crossed into the screening of 200 mesh, obtains uniform carbon
Nanotube/polyphenylene sulfide powder.
（3）The mixed powder after appropriate sieving is taken to be put into hot-forming in mold, hot pressing temperature is 200 degrees Celsius, heat preservation
Time 10min is thin rounded flakes after demoulding, after the polishing of 1000 mesh sand paper, to be tested as further dielectric properties.
According to the size of mold, the powder of preparation generally has more 15%, prevents the loss of filling not closely, in mixing process
It is too small with finished sheet thickness.
Further, carbon nanotube mass percentage is 20% and 30% in the step (1).
Further, each vibromill period is 2 minutes in the step (2), is carried out 2 to 3 times.Each period is specific
For：5Hz vibrations in 30 seconds, 20Hz vibrations in 1 minute and 30 seconds 5Hz vibrate.
, according to the invention it is preferred to, step（3）In, briquetting pressure 30MPa is pressed into diameter 20mm, and thickness is 2 to 3mm
Thin slice, for dielectric properties test.
The present invention provides a kind of methods preparing negative permittivity material, and achievement, the present invention have compared with the existing technology
Following advantage：
（1）Preparation process is simple, at low cost, and the mass production of product may be implemented, and has market-oriented foreground well.Pass through
Two traditional solid phase powder ball milling mixings, prepared by the mode of tabletting can be obtained the composite material with negative permittivity.
（2）Negative permittivity performance Modulatory character is good, by the mass fraction for changing CNT, you can changes negative permittivity
Numerical value, the regulation and control of negative permittivity performance are simple.
（3）Characteristic with weak negative dielectric.The composite material being prepared, negative permittivity absolute value 5000 hereinafter,
When wherein CNT mass fractions are 20%, in 40MHz-1GHz frequency ranges, negative permittivity numerical value is below 1000 or less.Compared to biography
The metal-base composites of system, carbon nano tube compound material can significantly reduce the numerical value of dielectric constant, the impedance obtained
Match, can apply in electro-magnetic wave absorption and shielding field.
Description of the drawings
Fig. 1 is carbon nano-tube/poly diphenyl sulfide（Mass fraction is respectively 20% and 30%）Permittivity ε it is with frequency change
Collection of illustrative plates.
Specific implementation mode
To keep detailed process of the invention and advantage clearer, it is described in detail below in conjunction with specific embodiment.
Said program is described further below in conjunction with specific embodiment.It should be understood that these embodiments be for illustrate the present invention and
It is not limited to limit the scope of the invention.The implementation condition used in embodiment can further be adjusted according to actual conditions, not noted
Bright implementation condition is usually the condition in routine experiment.
The materials, reagents and the like used in the following examples is commercially available.Wherein, the carbon nanotube used
A diameter of 10-30nm, length are 5 μm.
Embodiment 1
A kind of method that carbon nanotube and polyphenylene sulfide prepare negative permittivity material, including steps are as follows:
（1）It is 1 according to carbon nanotube and polyphenylene sulfide mass ratio:4, with 0.4 gram of carbon nanotube dust of electronic balance weighing and 1.6
Gram polyphenylene sulfide powder.
（2）By step（1）Load weighted powder is put into vibration grinding jar, carries out vibromill batch mixing at room temperature, and charging is suitable
Sequence is that carbon nanotube is first added, and adds polyphenylene sulfide.The good powder of batch mixing is crossed into the screening of 200 mesh, obtains uniform carbon nanometer
Pipe/polyphenylene sulfide powder.
（3）By the mixed powder after sieving, powder is put into mold after stirring evenly, is carried out hot-forming.Wherein, at
Type pressure is 30 MPa, and hot pressing temperature is 200 degrees Celsius, soaking time 10min, is the thin rounded flakes of diameter 20mm after demoulding,
After the polishing of 1000 mesh sand paper, to be tested as further dielectric properties, wherein the mass fraction of carbon nanotube is 20%.
Embodiment 2
A kind of method that carbon nanotube and polyphenylene sulfide prepare negative permittivity material, including steps are as follows:
（1）It is 1 according to carbon nanotube and polyphenylene sulfide mass ratio:4, with 0.6 gram of carbon nanotube dust of electronic balance weighing and 2.4
Gram polyphenylene sulfide powder.
（2）By step（1）Load weighted powder is put into vibration grinding jar, carries out vibromill batch mixing at room temperature, and charging is suitable
Sequence is that carbon nanotube is first added, and adds polyphenylene sulfide.The good powder of batch mixing is crossed into the screening of 200 mesh, obtains uniform carbon nanometer
Pipe/polyphenylene sulfide powder.
（3）By the mixed powder after sieving, powder is put into mold after stirring evenly, is carried out hot-forming.Wherein, at
Type pressure is 30 MPa, and hot pressing temperature is 200 degrees Celsius, soaking time 10min, is the thin rounded flakes of diameter 20mm after demoulding,
After the polishing of 1000 mesh sand paper, to be tested as further dielectric properties, wherein the mass fraction of carbon nanotube is 20%.
Embodiment 3
A kind of method that carbon nanotube and polyphenylene sulfide prepare negative permittivity material, including steps are as follows:
（1）It is 3 according to carbon nanotube and polyphenylene sulfide mass ratio:7, with 0.45 gram of carbon nanotube dust of electronic balance weighing and
1.05 grams of polyphenylene sulfide powders.
（2）By step（1）Load weighted powder is put into vibration grinding jar, carries out vibromill batch mixing at room temperature, and charging is suitable
Sequence is that carbon nanotube is first added, and adds polyphenylene sulfide.The good powder of batch mixing is crossed into the screening of 200 mesh, obtains uniform carbon nanometer
Pipe/polyphenylene sulfide powder.
（3）By the mixed powder after sieving, powder is put into mold after stirring evenly, is carried out hot-forming.Wherein, at
Type pressure is 30 MPa, and hot pressing temperature is 200 degrees Celsius, soaking time 10min, is the thin rounded flakes of diameter 20mm after demoulding,
After the polishing of 1000 mesh sand paper, to be tested as further dielectric properties, wherein the mass fraction of carbon nanotube is 30%.
Embodiment 4
A kind of method that carbon nanotube and polyphenylene sulfide prepare negative permittivity material, including steps are as follows:
（1）It is 3 according to carbon nanotube and polyphenylene sulfide mass ratio:7, with 0.6 gram of carbon nanotube dust of electronic balance weighing and 1.4
Gram polyphenylene sulfide powder.
（2）By step（1）Load weighted powder is put into vibration grinding jar, carries out vibromill batch mixing at room temperature, and charging is suitable
Sequence is that carbon nanotube is first added, and adds polyphenylene sulfide.The good powder of batch mixing is crossed into the screening of 200 mesh, obtains uniform carbon nanometer
Pipe/polyphenylene sulfide powder.
（3）By the mixed powder after sieving, powder is put into mold after stirring evenly, is carried out hot-forming.Wherein, at
Type pressure is 30 MPa, and hot pressing temperature is 200 degrees Celsius, soaking time 10min, is the thin rounded flakes of diameter 20mm after demoulding,
After the polishing of 1000 mesh sand paper, to be tested as further dielectric properties, wherein the mass fraction of carbon nanotube is 30%.
The above-mentioned description to embodiment is in order to which those skilled in the art understand and apply the invention.It is familiar with
The personnel of art technology can easily modify to these embodiments and General Principle described herein is applied to it
In his embodiment without having to go through creative labor.Therefore, the present invention is not limited to embodiment here, those skilled in the art
Announcement according to the present invention, the improvement and modification made to the present invention all should be within protection scope of the present invention.
Claims (7)
1. a kind of preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity, which is characterized in that such as including step
Under:
（1）According to carbon nanotube（CNT）/ polyphenylene sulfide（PPS）Carbon nanotube containing different quality containing in composite material is used
Balance weighs the powder of corrresponding quality；
（2）By step（1）Load weighted powder is put into vibration grinding jar, carries out vibromill batch mixing at room temperature, and charging sequence is
CNT is first added, adds PPS, the good powder of batch mixing is crossed into the screening of 200 mesh, obtains uniform CNT/PPS powders；
（3）It takes the mixed powder after appropriate sieving to be put into hot-forming in mold, is thin rounded flakes after demoulding, 1000 mesh sand paper are beaten
After mill, to be tested as further dielectric properties.
2. the preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity, feature exist as described in claim 1
In carbon nanotube mass percentage is 20%-30% in the step (1).
3. the preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity, feature exist as described in claim 1
In each vibromill period is 2 minutes in the step (2), is carried out 2 to 3 times, each period is specially：30 seconds 5Hz shake
Dynamic, 20Hz vibrations in 1 minute and 30 seconds 5Hz vibrate.
4. the preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity, feature exist as described in claim 1
In in the step (3), hot pressing temperature is 200 DEG C, soaking time 10min.
5. the preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity, feature exist as described in claim 1
In in the step (3), hot-forming condition is:Briquetting pressure 30MPa, natural cooling after pressurize, is pressed into diameter
20mm, the thin rounded flakes that thickness is 2 to 3mm.
6. the negative permittivity material that any methods of claim 1-5 are prepared.
7. application of the negative permittivity material in preparing resonator, filter and microwave attenuation field described in claim 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810473751.3A CN108641358A (en) | 2018-05-17 | 2018-05-17 | A kind of preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810473751.3A CN108641358A (en) | 2018-05-17 | 2018-05-17 | A kind of preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108641358A true CN108641358A (en) | 2018-10-12 |
Family
ID=63756573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810473751.3A Pending CN108641358A (en) | 2018-05-17 | 2018-05-17 | A kind of preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108641358A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109880296A (en) * | 2019-03-01 | 2019-06-14 | 上海海事大学 | A method of reverse-engineering negative dielectric material in metal mesh/epoxy resin composite material |
| CN110760185A (en) * | 2019-09-26 | 2020-02-07 | 金旸（厦门）新材料科技有限公司 | Low-dielectric-constant polyphenylene sulfide composition and preparation method thereof |
| CN113337130A (en) * | 2021-04-12 | 2021-09-03 | 四川大学 | Isolated network composite material containing hybrid nano-filler, preparation method and application thereof |
| WO2024116563A1 (en) * | 2022-11-29 | 2024-06-06 | Dic株式会社 | Method for producing polyarylene sulfide resin composition and molded article |
| WO2024116564A1 (en) * | 2022-11-29 | 2024-06-06 | Dic株式会社 | Polyarylene sulfide resin composition and method for producing molded article |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005232247A (en) * | 2004-02-18 | 2005-09-02 | Toray Ind Inc | Method for producing polyarylene sulfide resin composition |
| CN102382468A (en) * | 2011-09-28 | 2012-03-21 | 深圳市科聚新材料有限公司 | Carbon nano tube reinforced polyphenylene sulfide material and preparation method thereof |
| US20130317159A1 (en) * | 2012-05-22 | 2013-11-28 | Chevron Phillips Chemical Company Lp | Reinforced Poly(Arylene Sulfide) Compositions |
| CN104212170A (en) * | 2014-08-11 | 2014-12-17 | 惠州市昌亿新材料有限公司 | High thermal conductive wear resistant polyphenylene sulfide composite material and preparation method thereof |
-
2018
- 2018-05-17 CN CN201810473751.3A patent/CN108641358A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005232247A (en) * | 2004-02-18 | 2005-09-02 | Toray Ind Inc | Method for producing polyarylene sulfide resin composition |
| CN102382468A (en) * | 2011-09-28 | 2012-03-21 | 深圳市科聚新材料有限公司 | Carbon nano tube reinforced polyphenylene sulfide material and preparation method thereof |
| US20130317159A1 (en) * | 2012-05-22 | 2013-11-28 | Chevron Phillips Chemical Company Lp | Reinforced Poly(Arylene Sulfide) Compositions |
| CN104212170A (en) * | 2014-08-11 | 2014-12-17 | 惠州市昌亿新材料有限公司 | High thermal conductive wear resistant polyphenylene sulfide composite material and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 吴兰峰等: ""聚苯硫醚/碳纳米管复合材料的导电和力学性能"", 《高分子材料科学与工程》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109880296A (en) * | 2019-03-01 | 2019-06-14 | 上海海事大学 | A method of reverse-engineering negative dielectric material in metal mesh/epoxy resin composite material |
| CN109880296B (en) * | 2019-03-01 | 2021-05-14 | 上海海事大学 | Method for reversely designing negative dielectric material in metal mesh/epoxy resin composite material |
| CN110760185A (en) * | 2019-09-26 | 2020-02-07 | 金旸（厦门）新材料科技有限公司 | Low-dielectric-constant polyphenylene sulfide composition and preparation method thereof |
| CN113337130A (en) * | 2021-04-12 | 2021-09-03 | 四川大学 | Isolated network composite material containing hybrid nano-filler, preparation method and application thereof |
| WO2024116563A1 (en) * | 2022-11-29 | 2024-06-06 | Dic株式会社 | Method for producing polyarylene sulfide resin composition and molded article |
| WO2024116564A1 (en) * | 2022-11-29 | 2024-06-06 | Dic株式会社 | Polyarylene sulfide resin composition and method for producing molded article |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108641358A (en) | A kind of preparation method of the carbon nano-tube/poly diphenyl sulfide with negative permittivity | |
| CN107474312B (en) | The preparation method of ceramic filled polytetrafluoroethylglass microwave composite medium substrate | |
| Zhao et al. | Experimental Demonstration of Isotropic Negative Permeability<? format?> in a Three-Dimensional Dielectric Composite | |
| Deng et al. | Microwave characterization of submicrometer-sized nickel hollow sphere composites | |
| Luo et al. | Carbon nanotube/polyolefin elastomer metacomposites with adjustable radio‐frequency negative permittivity and negative permeability | |
| CN108929542B (en) | Polydimethylsiloxane/graphene flexible composite film with negative dielectric constant and preparation method thereof | |
| CN104311024A (en) | Microwave dielectric ceramic material with moderate dielectric constant and high quality factor and preparation method of microwave dielectric ceramic material | |
| Liu et al. | Effects of the absorber, thickness and surface roughness on the electromagnetic wave absorption characteristics of magnesium phosphate cement | |
| CN108529572B (en) | Preparation method of compact hexagonal boron nitride block | |
| Wang et al. | Microwave absorption properties of SiCN ceramics doped with cobalt nanoparticles | |
| CN104844206A (en) | Preparation method of high-performance microwave dielectric ceramic material | |
| CN106747435B (en) | A kind of preparation method for the core-shell structure microwave-medium ceramics that temperature is stable | |
| Guo et al. | Electromagnetic and microwave absorption properties of carbonyl-iron/Fe91Si9 composites in gigahertz range | |
| Liu et al. | Highly tunable negative permittivity of carbon nanofiber/alumina metacomposites at different external temperatures | |
| Drozdov et al. | Electromagnetic properties and EMI shielding effectiveness of polymer composites reinforced with ferromagnetic particles at microwave frequencies | |
| CN110343276A (en) | A kind of graphene with negative dielectric properties/polyvinyl alcohol flexible composite film and preparation method thereof | |
| CN111944267B (en) | Preparation method of boron-doped graphene composite material and application of boron-doped graphene composite material as negative dielectric material | |
| CN104987071A (en) | Low-temperature sintered microwave dielectric ceramic material with middle permittivity | |
| CN107868397A (en) | A kind of composite with weak negative permittivity and preparation method thereof | |
| CN108048034A (en) | A kind of preparation method of electromagnetic shielding material | |
| Wang et al. | Preparation of graphene/flaky carbonyl iron/polyurethane foam composites and research on their microwave absorption properties | |
| CN110066484A (en) | A kind of carbon nanotube-graphite-Kynoar trielement composite material and preparation method thereof with negative dielectric properties | |
| CN104891924B (en) | A kind of gypsum-based microwave-absorbing composite material and preparation method thereof | |
| CN101423645A (en) | Dielectric composite material and preparation method thereof | |
| WO2022148409A1 (en) | Ceramic filter having multiple composite ceramic material structures with different dielectric constants |
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: 20181012 |
|
| RJ01 | Rejection of invention patent application after publication |