CN104356007A - Production method of p-aminophenol - Google Patents
Production method of p-aminophenol Download PDFInfo
- Publication number
- CN104356007A CN104356007A CN201410571548.1A CN201410571548A CN104356007A CN 104356007 A CN104356007 A CN 104356007A CN 201410571548 A CN201410571548 A CN 201410571548A CN 104356007 A CN104356007 A CN 104356007A
- Authority
- CN
- China
- Prior art keywords
- aminophenol
- liquid
- crystallization
- mother liquor
- production method
- 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
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a production method of p-aminophenol. The method comprises the steps that methyl alcohol and p-nitrophenol are mixed and dissolved; dissolved material is fed into a hydrogen reactor, a catalyst is also fed into the hydrogen reactor, a hydrogen valve of the hydrogen reactor and a heated steam valve are opened, hydrogen is heated and fed into the hydrogen reactor, and continuous hydrogenation reaction is performed in the condition of the existence of the catalyst; clear liquid enters a continuous crystallizer and then is subjected to heat exchange and cooling crystallization through cooled water and chilled water; crystalline liquid is subjected to solid-liquid separation after crystallization, liquid-phase mother liquor flows into a mother liquor tank, and surplus mother liquor is distilled to recycle methyl alcohol; solid-phase crude products are subjected to pyrosulfite soaking; finished products are subjected to solid-liquid separation; liquid-phase finished mother liquor is reused; solid-phase finished crystal is dried and then packaged and stored.
Description
Technical field
The present invention relates to the method for chemical field material synthesis, specifically refer to a kind of production method of p-aminophenol.
Background technology
P-aminophenol:
Chinese synonym: PAP; Para hydroxybenzene amine; P-aminophenol.
P-aminophenol is at present at China's application more a kind of meticulous organic chemical industry's intermediate, for the synthesis of weak acid yellow 6G, tracid light yellow 5G, DISPERSE NAVY BLUE EXSF 300 3R, SULPHUR BLUE BRN 150 CV, sulphur brilliant green G B, sulfur red brown b3r, the black CLG of reversion etc. on dyestuffs industries.On medicine industry, p-aminophenol is for the synthesis of Paracetamol, clofibrate etc.Also for the preparation of products such as photographic developer, oxidation inhibitor and petroleum additives.
Production method:
1, phenol nitrosation method:
By concentration be 90% phenol solution join in the sulphuric acid soln of 40%, cooling and stir under, add the sodium nitrite solution of 45%, after react, separate out p-Nitrosophenol, filtration.P-Nitrosophenol is joined in the sodium sulfide solution of 10%, be heated to 45 ~ 48 DEG C, after having reacted, add hot water and hydrochloric acid, make pH=7.5, then cool, separate out p-aminophenol, finally use activated carbon decolorizing, and recrystallizing and refining.
2, coupling reduction method:
Take aniline as raw material, react with Sodium Nitrite in hydrochloric acid soln, carry out diazotization, add the sodium hydroxide solution of phenol in this solution again, generate nitrogen benzide crystallization, after filtration, hydrochloric acid soln is dissolved in crystallization, adds iron powder and reduce, generate aniline and p-aminophenol simultaneously, after being separated, recrystallizing and refining.
3, p-NP iron powder reducing method:
Mother liquor on adding in reduction kettle after batch p-aminophenol refining filtering, be heated to 90 DEG C, add the hydrochloric acid of iron powder and 30%, under boiling state, alternately add iron powder and p-NP, reinforced process visual response situation (during as excessive pot), should fill into cold refining filtering mother liquor.Boiling reverts to terminal (, on white filter paper, oozing circle should be colourless for reaction drop).Fill into a certain amount of hot refinement mother liquor, add non-iron-ion in magnesium oxide to reaction solution.Leave standstill 30 minutes, release supernatant liquid, lower floor's iron mud 98 DEG C of crystallization filtrated stocks are pulled an oar, and filter, filtrate is squeezed in the second crystallization kettle.
In the second crystallization kettle, in 4 hours, cool to 60 ~ 65 DEG C, put into the 3rd crystallization kettle and continued to cool to 25 DEG C at 4 hours, maintain 30 minutes, centrifuging.
In refining kettle, be made into the heavy sodium sulfite solution that SO2 content is 4% ~ 5%, add the filter cake that crystallization is filtered, stir 1.5 hours, centrifuging, filter cake carries out negative-pressure air-flow drying, obtains p-aminophenol finished product, and refinement mother liquor recycles when lower batch of reduction.
4, nitrobenzene reduction transposition:
Hydrogenating reduction method: oil of mirbane is Hydrogenation p-aminophenol in sour environment, its process comprises oil of mirbane suction hydrogen generation phenyl and generates N-Phenylhydroxylamine through amine and phenyl through amine transposition, except object product p-aminophenol, also may generate a certain amount of aniline and other a small amount of by product.This method technique is simple, but to equipment and catalyst requirement higher.
5, metal deoxidization:
Metal deoxidization is in dilute sulphuric acid, with metal-powders such as aluminium powder or magnesium powder, oil of mirbane one step is reduced to p-aminophenol.Comparatively early, yield is between 60% ~ 70% in metal deoxidization exploitation.This method technique is simple, but metal wastage is large, and there is the aftertreatment such as recycling problem, is therefore difficult to scale operation.
6, electrolytic reduction:
Electrolytic reduction be temperature at 80 ~ 90 DEG C, make medium with 20% ~ 30% sulfuric acid, add a small amount of tensio-active agent by electrolysis, the nitrobenzene reduction making to be placed on negative electrode generates p-aminophenol.Influence factor mainly contains electrode materials, the composition of electrolysis, the control etc. of voltage and current density.Adopt diaphragm electrolytic cell, pass into nitrogen protection, p-aminophenol can be prevented to be oxidized and reduce the generation of zinin, it is reported that TiO2/Ti makes electrode effect best.This method is simple to operate, flow process is short, product purity is high, it is little to pollute, cost is low.This method has higher technical requirements to the design of reactor and process regulation, and energy consumption is higher.
Summary of the invention
The object of the invention is the defect existed to overcome existing process for producing para-amino-phenol, proposing a kind of production method of p-aminophenol.The method, by processes such as hydrogenating reduction, crystallization, refining, dry packings, solves pollution and the low technical problem of yield.
Realizing method of the present invention is: comprise hydrogenating reduction, crystallization, refining, dry, packaging, wherein
Hydrogenating reduction comprises:
First by 60% methyl alcohol of mol ratio 1: 0.6 and p-NP, undertaken mixing, dissolving by line mixer;
The material dissolved is sent into hydriding reactor by pump according to flow metering, and add catalyzer, catalyzer is modification Raney's nickel, main body is Ni, auxiliary agent is one or more in Mo, Cr, Ti, Fe, Co, Cu, Mn, Ba metal-salt, addition is 2% of Ni mole number, and catalyst levels is the 0.05-20% of p-NP;
Open the hydrogen valve of hydriding reactor and the steam valve of heating, heat and pass into hydrogen, carry out continuous hydrogenation reaction in the presence of a catalyst, react through for some time, qualified hydride enters catalyst settler, returns hydrogenation system at the isolated catalyzer of settling vessel, and settling vessel supernatant liquid is out after decompression, enter ceramic membrane filter system, continuous crystallizer delivered to by the clear liquid after removing catalyzer;
Crystallization comprises:
After clear liquid enters continuous crystallizer, through water coolant, refrigerated water heat exchange cooling crystallization;
Crystallization terminates crystal solution to put to carry out solid, liquid separation to whizzer, liquid phase is that mother liquor flows into mother liquor tank, and a part of Recycling Mother Solution uses, and unnecessary mother liquor is delivered to distillation tower and carried out Distillation recovery methyl alcohol, distillation tower raffinate carries out crystallization and reclaims product, and waste liquid enters sewage work;
Refining, dry, comprising:
Solid phase crude product is sent to refining kettle and carries out burnt sulfurous immersion;
Product after refining carries out Solid-Liquid Separation;
Liquid phase essence Recycling Mother Solution uses;
Solid phase fine work crystal delivers to drying machine, after drying, reaches qualified product and carries out packaging and storing through wrapping machine.
The method also comprises:
Described material by pump according to flow be 5000L/h metering send into hydriding reactor.
Described Heating temperature is 60-180 DEG C; Reaction pressure is 0.5-2.0MPa.
The described time through for some time reaction is 6-8 hour.
Described water coolant is 20 DEG C; Refrigerated water is-5 DEG C.
The beneficial effect that the present invention has:
In p-aminophenol is produced, catalyzer can recycle in Production Flow Chart.
The methyl alcohol used in reaction process also can recycle.
In reaction process, hydrogenation carries out continuously.
In reaction process, crystallisation process is also carry out continuously.
Through actual production test, the p-aminophenol purity adopting the p-aminophenyl phenolic product obtained by the inventive method is more than 98.5%.
Environmental protection, energy-conservation, cost is low, yield is high.
Accompanying drawing explanation
Fig. 1 is process flow sheet of the present invention.
In figure: 1 line mixer, 2 hydriding reactors, 3 settling vessels, 4 ceramic membrane filter systems, 5 continuous crystallizers, 6 whizzers, 7 methanol columns, 8 refining kettles, 9 packagings, 10 mother liquor tanks.
Embodiment
The invention will be further described below:
Embodiment 1:
Be first 60% methyl alcohol and p-NP by the concentration of mol ratio 1: 0.6, undertaken mixing, dissolving by line mixer.To be measured according to flow 5000L/h by pump the material that dissolved and send into hydrogenation unit, add modification Raney's nickel catalyst, main body is Ni, and auxiliary agent is one or more in Mo or Cr or Ti or Fe or Co or Cu or Mn or Ba metal-salt.
Open the hydrogen valve of hydriding reactor and the steam valve of heating, heat and pass into hydrogen, keep temperature of reaction 60-180 DEG C, reaction pressure 0.5-2.0MPa; Carry out continuous hydrogenation reaction in the presence of a catalyst.After reaction in 6-8 hour, qualified hydride enters catalyst settler, returns hydrogenation system at the isolated catalyzer of settling vessel, and settling vessel supernatant liquid is out after decompression, enter ceramic membrane filter system, continuous crystallizer delivered to by the clear liquid after removing catalyzer.
After material enters continuous crystallizer, through 20 DEG C of water coolants ,-5 DEG C of refrigerated water heat exchange cooling crystallizations.Crystallization terminates crystal solution to put to carry out solid, liquid separation to whizzer, and liquid phase is that mother liquor flows into mother liquor tank, and a part of Recycling Mother Solution uses, and unnecessary mother liquor is delivered to distillation tower and carried out Distillation recovery methyl alcohol.Bottom product carries out crystallization and reclaims product, and waste liquid enters sewage work.
Solid phase crude product is sent to refining kettle and carries out burnt sulfurous immersion.Product after refining carries out Solid-Liquid Separation.Liquid phase essence Recycling Mother Solution uses, and solid phase fine work crystal delivers to drying machine, after drying, reaches qualified product and carries out packaging and storing through wrapping machine.
Embodiment 2:
Substantially the same manner as Example 1, be not both modification Raney's nickel catalyst, main body is Ni, auxiliary agent is Mo, Cr or Mo, Ti or Mo, Fe or Mo, Co or Mo, Cu or Mo, Mn or Mo, Ba or Mo, Cr, Ti or Mo, Cr, Fe or Mo, Cr, Co or Mo, Cr, Cu or Mo, Cr, Mn or Mo, Cr, Ba or Mo, Cr, Ti, Fe or Mo, Cr, Ti, Co or Mo, Cr, Ti, Cu or Mo, Cr, Ti, Mn or Mo, Cr, Ti, Ba or Mo, Cr, Ti, Fe, Co or Mo, Cr, Ti, Fe, Cu or Mo, Cr, Ti, Fe, Mn or Mo, Cr, Ti, Fe, Ba or Mo, Cr, Ti, Fe, Co, Cu or Mo, Cr, Ti, Fe, Co, Mn or Mo, Cr, Ti, Fe, Co, Ba or Mo, Cr, Ti, Fe, Co, Cu, Mn or Mo, Cr, Ti, Fe, Co, Cu, Ba or Mo, Cr, Ti, Fe, Co, Cu, Mn, Ba metal-salt.
Feature of the present invention
In p-aminophenol of the present invention is produced, catalyzer can recycle in Production Flow Chart.
The methyl alcohol used in reaction process also can recycle.
In reaction process, hydrogenation carries out continuously.
In reaction process, crystallisation process is also carry out continuously.
Through actual production test, the p-aminophenol purity adopting the p-aminophenyl phenolic product obtained by the inventive method is 98.5%.
Illustrate:
The line mixer that the present invention relates to, hydriding reactor, settling vessel, ceramic membrane filter system, continuous crystallizer etc. are general-purpose equipment; Solid phase fine work is hydrated crystal.
Claims (5)
1. a production method for p-aminophenol, is characterized in that comprising hydrogenating reduction, crystallization, refining, dry, packaging, wherein
Hydrogenating reduction comprises:
First by 60% methyl alcohol of mol ratio 1: 0.6 and p-NP, undertaken mixing, dissolving by line mixer;
The material dissolved is sent into hydriding reactor by pump according to flow metering, and add catalyzer, catalyzer is modification Raney's nickel, main body is Ni, auxiliary agent is one or more in Mo, Cr, Ti, Fe, Co, Cu, Mn, Ba metal-salt, addition is 2% of Ni mole number, and catalyst levels is the 0.05-20% of p-NP;
Open the hydrogen valve of hydriding reactor and the steam valve of heating, heat and pass into hydrogen, carry out continuous hydrogenation reaction in the presence of a catalyst, react through for some time, qualified hydride enters catalyst settler, returns hydrogenation system at the isolated catalyzer of settling vessel, and settling vessel supernatant liquid is out after decompression, enter ceramic membrane filter system, continuous crystallizer delivered to by the clear liquid after removing catalyzer;
Crystallization comprises:
After clear liquid enters continuous crystallizer, through water coolant, refrigerated water heat exchange cooling crystallization;
Crystallization terminates crystal solution to put to carry out solid, liquid separation to whizzer, liquid phase is that mother liquor flows into mother liquor tank, and a part of Recycling Mother Solution uses, and unnecessary mother liquor is delivered to distillation tower and carried out Distillation recovery methyl alcohol, distillation tower raffinate carries out crystallization and reclaims product, and waste liquid enters sewage work;
Refining, dry, comprising:
Solid phase crude product is sent to refining kettle and carries out burnt sulfurous immersion;
Product after refining carries out Solid-Liquid Separation;
Liquid phase essence Recycling Mother Solution uses;
Solid phase fine work crystal delivers to drying machine, after drying, reaches qualified product and carries out packaging and storing through wrapping machine.
2. the production method of p-aminophenol as claimed in claim 1, is characterized in that described material is that hydriding reactor is sent in 5000L/h metering by pump according to flow.
3. the production method of p-aminophenol as claimed in claim 1, is characterized in that described Heating temperature is 60-180 DEG C; Reaction pressure is 0.5-2.0MPa.
4. the production method of p-aminophenol as claimed in claim 1, is characterized in that the described time through for some time reaction is 6-8 hour.
5. the production method of p-aminophenol as claimed in claim 1, is characterized in that described water coolant is 20 DEG C; Refrigerated water is-5 DEG C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410571548.1A CN104356007A (en) | 2014-10-24 | 2014-10-24 | Production method of p-aminophenol |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410571548.1A CN104356007A (en) | 2014-10-24 | 2014-10-24 | Production method of p-aminophenol |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104356007A true CN104356007A (en) | 2015-02-18 |
Family
ID=52523345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410571548.1A Pending CN104356007A (en) | 2014-10-24 | 2014-10-24 | Production method of p-aminophenol |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104356007A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107746380A (en) * | 2017-11-06 | 2018-03-02 | 宁夏中盛新科技有限公司 | A kind of industrialized preparing process of the acetyl-anisidine of 2 amino 4 |
| CN108079994A (en) * | 2016-11-22 | 2018-05-29 | 中国科学院大连化学物理研究所 | A kind of method of p-nitrophenol catalytic hydrogenation para-aminophenol |
| CN108191676A (en) * | 2017-12-29 | 2018-06-22 | 烟台安诺其精细化工有限公司 | The preparation method of para-aminophenol |
| CN111302956A (en) * | 2020-04-14 | 2020-06-19 | 国药集团化学试剂有限公司 | Preparation method of 4-bromo-2-aminophenol |
| WO2020233558A1 (en) * | 2019-05-22 | 2020-11-26 | Solvay Sa | Process for purifying a sodium sulfate residue |
| CN114181098A (en) * | 2021-12-23 | 2022-03-15 | 辽宁世星药化有限公司 | Production method of o-aminophenol |
| CN115734961A (en) * | 2020-04-27 | 2023-03-03 | 伊索美迪克公司 | Continuous synthesis method of acetaminophen |
| RU2797410C1 (en) * | 2023-02-16 | 2023-06-05 | Общество с ограниченной ответственностью "МЕНДЕЛЕЕВСКИЙ ХИМИЧЕСКИЙ ЗАВОД" | Method for obtaining para-aminophenol by reduction of para-nitrosophenol with ammonium sulfide |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101041623A (en) * | 2007-04-26 | 2007-09-26 | 上海华谊丙烯酸有限公司 | Method for preparation of (substituted radical containted) aminophenol by catalytic hydrogenation of (substituted radical containted) nitrophenol |
| CN101607917A (en) * | 2009-06-23 | 2009-12-23 | 泰兴市扬子医药化工有限公司 | The production method of high-quality p-aminophenol |
| CN103360265A (en) * | 2012-04-06 | 2013-10-23 | 浙江龙盛化工研究有限公司 | Method for continuous hydrogenation of dinitrobenzene and recycling of reaction heat thereof |
-
2014
- 2014-10-24 CN CN201410571548.1A patent/CN104356007A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101041623A (en) * | 2007-04-26 | 2007-09-26 | 上海华谊丙烯酸有限公司 | Method for preparation of (substituted radical containted) aminophenol by catalytic hydrogenation of (substituted radical containted) nitrophenol |
| CN101607917A (en) * | 2009-06-23 | 2009-12-23 | 泰兴市扬子医药化工有限公司 | The production method of high-quality p-aminophenol |
| CN103360265A (en) * | 2012-04-06 | 2013-10-23 | 浙江龙盛化工研究有限公司 | Method for continuous hydrogenation of dinitrobenzene and recycling of reaction heat thereof |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108079994A (en) * | 2016-11-22 | 2018-05-29 | 中国科学院大连化学物理研究所 | A kind of method of p-nitrophenol catalytic hydrogenation para-aminophenol |
| CN108079994B (en) * | 2016-11-22 | 2020-12-08 | 中国科学院大连化学物理研究所 | Method for preparing p-aminophenol by catalytic hydrogenation of p-nitrophenol |
| CN107746380A (en) * | 2017-11-06 | 2018-03-02 | 宁夏中盛新科技有限公司 | A kind of industrialized preparing process of the acetyl-anisidine of 2 amino 4 |
| CN107746380B (en) * | 2017-11-06 | 2020-04-07 | 宁夏中盛新科技有限公司 | Industrial production method of 2-amino-4-acetamino anisole |
| CN108191676A (en) * | 2017-12-29 | 2018-06-22 | 烟台安诺其精细化工有限公司 | The preparation method of para-aminophenol |
| WO2020233558A1 (en) * | 2019-05-22 | 2020-11-26 | Solvay Sa | Process for purifying a sodium sulfate residue |
| CN111302956A (en) * | 2020-04-14 | 2020-06-19 | 国药集团化学试剂有限公司 | Preparation method of 4-bromo-2-aminophenol |
| CN115734961A (en) * | 2020-04-27 | 2023-03-03 | 伊索美迪克公司 | Continuous synthesis method of acetaminophen |
| CN114181098A (en) * | 2021-12-23 | 2022-03-15 | 辽宁世星药化有限公司 | Production method of o-aminophenol |
| RU2797410C1 (en) * | 2023-02-16 | 2023-06-05 | Общество с ограниченной ответственностью "МЕНДЕЛЕЕВСКИЙ ХИМИЧЕСКИЙ ЗАВОД" | Method for obtaining para-aminophenol by reduction of para-nitrosophenol with ammonium sulfide |
| RU2801692C1 (en) * | 2023-03-24 | 2023-08-14 | Общество с ограниченной ответственностью "МЕНДЕЛЕЕВСКИЙ ХИМИЧЕСКИЙ ЗАВОД" | Method and unit for obtaining para-aminophenol from phenol by sequential nitrosating and reduction with ammonium sulfide |
| RU2823871C1 (en) * | 2023-12-04 | 2024-07-30 | Общество с ограниченной ответственностью "ДЖИЭСЭМ КЕМИКЭЛ" | Method and apparatus for continuous production of para-aminophenol by reduction of para-nitrosophenol with ammonium sulphide |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104356007A (en) | Production method of p-aminophenol | |
| CN101817766B (en) | Method for preparing m-aminobenzenesulfonic acid by catalyzing and hydrogenating 3-nitrobenzenesulfonic acid | |
| CN102276483A (en) | Production method of oamino pheylmethyl ether | |
| CN110105220B (en) | Method for preparing m-phenylenediamine from meta-oil | |
| CN105566126A (en) | Method for preparing 2-amino-4-nitrophenol through liquid catalytic hydrogenation | |
| CN102020316B (en) | Method for preparing chromic anhydride from potassium chromate | |
| CN111217764B (en) | Method for preparing 6-nitro-1, 2, 4-acid oxygen | |
| CN103113269B (en) | 1,8-dinitro-3,6-naphthalene disulfonate hydrogenation reduction method | |
| CN100494081C (en) | Recovering handling method for amino C acid wastewater | |
| CN107935008A (en) | A kind of processing method of hydrochloric hydrofluoric acid wastewater | |
| CN103435091A (en) | Method for preparing superfine cuprous chloride | |
| CN102675127A (en) | Method and device for preparing 3,4-dichloroaniline without solvent | |
| CN103708518B (en) | Anhydrous aluminum chloride preparation method | |
| CN101830820B (en) | Method for preparing 2,5-diparamethylaniline terephthalic acid (DTTA) | |
| CN112010792A (en) | Production method of high-purity diphenyl sulfone | |
| CN101607917B (en) | Production method of high-quality p-aminophenol | |
| CN109485558A (en) | A kind of method of purification of long-chain biatomic acid | |
| CN110642707B (en) | Purification production method of low-cost environment-friendly sodium salicylate | |
| CN102344382A (en) | Method for preparing 2,5-dimethoxy-4-chloroaniline by hydrogenation reduction | |
| CN112409812A (en) | Preparation method of novel heterocyclic nitrogen-coupled disperse dye | |
| CN101412686A (en) | Method for preparing 2,7-naphthalenedisulfonate with reaction mother liquor for producing 1,6-naphthalene disulfonic acid | |
| CN101823978B (en) | Method for preparing 2, 5-diphenyl amino acid DATA | |
| CN206828284U (en) | The innoxious use processing system of petrochemical industry hazardous waste acid sludge and alkaline residue | |
| CN109455748A (en) | A method of recycling aluminum nitrate from waste acid liquor | |
| CN110981814A (en) | Preparation method of ultraviolet absorbent 2-phenylbenzimidazole |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20150218 |