CN110590625B - Method for improving rectification yield of thioglycollic acid - Google Patents
Method for improving rectification yield of thioglycollic acid Download PDFInfo
- Publication number
- CN110590625B CN110590625B CN201910947820.4A CN201910947820A CN110590625B CN 110590625 B CN110590625 B CN 110590625B CN 201910947820 A CN201910947820 A CN 201910947820A CN 110590625 B CN110590625 B CN 110590625B
- Authority
- CN
- China
- Prior art keywords
- acid
- thioglycolic acid
- rectification
- thioglycollic
- concentrated solution
- 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.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C319/00—Preparation of thiols, sulfides, hydropolysulfides or polysulfides
- C07C319/26—Separation; Purification; Stabilisation; Use of additives
- C07C319/28—Separation; Purification
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention belongs to the field of fine organic chemical industry, and particularly relates to a method for improving rectification yield of thioglycolic acid, which comprises the steps of obtaining a thioglycolic acid extraction concentrated solution, and carrying out reduced pressure rectification on the thioglycolic acid extraction concentrated solution under the action of a reducing agent and a quinone stabilizer to separate a thioglycolic acid product.
Description
Technical Field
The invention belongs to the field of fine organic chemical industry, and particularly relates to a method for improving the rectification yield of thioglycolic acid.
Background
Thioglycolic acid has the characteristic of reaction between carboxyl and sulfydryl, is an important chemical raw material and chemical intermediate, and is widely used as a hair curling agent, a depilatory, a mineral dressing agent and a synthetic raw material of a plastic rubber additive. With the development of fine chemical engineering, the application field of the fine chemical engineering is continuously expanded, the demand is increased day by day, but because the thioglycolic acid is extremely active, the thioglycolic acid is extremely easy to oxidize in the synthesis and post-treatment processes, and side reactions are extremely easy to generate self-esterification impurities of the thioglycolic acid in the rectification process, so that a large amount of kettle residues are generated, the product yield is reduced, and meanwhile, huge environmental protection pressure is brought.
At present, thioglycolic acid in China basically depends on import. The rectification yield of the thioglycollic acid is low, the production cost is high, and the development of the thioglycollic acid industry is seriously restricted. The concentration of the thioglycollic acid is gradually increased along with the evaporation of the extracting agent in the rectification process of the thioglycollic acid, the temperature of the kettle bottom is increased, and the main side reaction of the thioglycollic acid is intermolecular and intramolecular dehydration polymerization, so that the oxidation product of the thioglycollic acid formed before the rectification working section and the self-esterification impurities generated in the rectification process are main components forming the residue of the thioglycollic acid kettle.
Chinese patent CN106167458B controls the side reaction of thioglycolic acid in the rectification process by adding a phenol stabilizer, and the phenols used by the method are antioxidant series, which can inhibit the oxidation of thioglycolic acid in the rectification process, but have no effect on thioglycolic acid oxidation products formed in the synthesis and post-treatment processes and thioglycolic acid self-esterification impurities formed in the rectification process.
Disclosure of Invention
Aiming at the technical problems, the invention provides a method for improving the rectification yield of thioglycolic acid, which is characterized in that a reducing agent and a stabilizing agent are added in the process of vacuum rectification to reduce the oxidation product of the thioglycolic acid and control the self-esterification reaction of the thioglycolic acid, thereby reducing the quality of kettle residue, improving the product quality and the rectification yield and reducing the production cost.
The technical scheme of the invention is as follows:
a process for increasing the rectifying yield of mercaptoacetic acid includes such steps as adding reducer and stabilizer to the concentrated extracted mercaptoacetic acid solution, vacuum rectifying, and separating out mercaptoacetic acid.
Preferably, the dosage of the reducing agent is 0.01-2% of the mass of the thioglycollic acid extraction concentrated solution.
Preferably, the dosage of the stabilizer is 0.001-1% of the mass of the thioglycollic acid extraction concentrated solution.
Preferably, the reducing agent is one or more of sodium sulfite, sodium thiosulfate, sodium borohydride, aluminum powder, zinc powder, stannous chloride, butyl hydroxy anisole, dibutyl hydroxy toluene and ascorbic acid.
Preferably, the stabilizer is a quinone stabilizer; more preferably, the quinone stabilizer is one or more of methyl hydroquinone, o-benzoquinone, 1, 4-naphthoquinone, tetrachlorobenzoquinone, p-benzoquinone, 2, 6-dimethoxy-p-benzoquinone, alkannin, vitamin K1, o-phenanthrenequinone and 9, 10-anthraquinone.
Preferably, the vacuum distillation control conditions are as follows: the vacuum degree is 0.099-0.05 MPa, and the temperature is 100-205 ℃. The rectification temperature and the vacuum degree are controlled, the energy consumption is reduced, and the oxidation of thioglycollic acid is reduced.
Preferably, the mass fraction of the thioglycolic acid in the thioglycolic acid extraction concentrated solution is 50 to 75 percent.
Preferably, the concentrated solution of thioglycolic acid is obtained by distilling the thioglycolic acid extract under reduced pressure, and the control conditions of the reduced pressure distillation are as follows: the vacuum degree is 0.085-0.02 MPa, and the reduced pressure distillation temperature is 5-50 ℃; further preferably, the temperature of the reduced pressure distillation is 15-25 ℃.
Preferably, the thioglycolic acid reaction liquid is prepared by a sodium sulfide method, the main components are thioglycolic acid, sodium chloride and water, and the method with the authorization publication number of CN102229548B can be adopted for preparation, but the method is not limited to the method.
Preferably, the thioglycollic acid reaction liquid is extracted by adopting an ether extractant to obtain a thioglycollic acid extraction liquid.
According to the invention, in the rectification process, the oxidation of thioglycollic acid is reduced by controlling the temperature and the vacuum degree of reduced pressure rectification, the oxidation products of thioglycollic acid are reduced, and the reducing agent is added to effectively reduce the formed oxidation products of thioglycollic acid in the synthesis and post-treatment processes, so that the content of thioglycollic acid in the extraction concentrated solution of thioglycollic acid is increased, and the self-esterification reaction of thioglycollic acid in the rectification process can be effectively inhibited by adding the quinone stabilizer. The two aspects have synergistic effect, greatly improve the rectification yield of the thioglycolic acid and reduce the production cost of the thioglycolic acid. The method greatly reduces the kettle residue quality of the thioglycollic acid, improves the product yield from 60 percent to more than 98 percent, and reduces the production cost.
Detailed Description
The following further description of the present invention is provided in connection with specific embodiments to enable those skilled in the art to further understand the present invention, and not to limit the present invention, and all techniques based on the principles described herein are within the scope of the present invention.
In the embodiment, the thioglycollic acid extract is thioglycollic acid reaction liquid prepared by a method with an authorization publication number of CN102229548B, and ether extractant is used for extraction to obtain the thioglycollic acid extract.
Example 1
Distilling 1000g of thioglycollic acid extract under reduced pressure at 15 ℃ and a vacuum degree of 0.085MPa to obtain 214.73g of thioglycollic acid extract concentrated solution, measuring the mass fraction of the thioglycollic acid in the concentrated solution to be 64.03%, adding 2.15g of sodium thiosulfate and 2.15g of methyl hydroquinone, carrying out reduced pressure rectification at 148 ℃ under the vacuum degree of 0.092MPa to separate 136.32g of thioglycollic acid finished product, measuring the content of the thioglycollic acid to be 99.71%, and obtaining the rectification yield of 98.86%.
Example 2
And distilling 2500g of thioglycollic acid extract under the vacuum degree of 0.078MPa at 22 ℃ to obtain 503.18g of concentrated solution, wherein the mass fraction of the thioglycollic acid in the concentrated solution is 55.80%, adding 0.50g of zinc powder and 2.52g of p-benzoquinone, and carrying out vacuum rectification at 187 ℃ under the vacuum degree of 0.07Mpa to separate 276.50g of finished thioglycollic acid, wherein the content of the thioglycollic acid is 99.86%, and the rectification yield is 98.34%.
Example 3
Carrying out reduced pressure distillation on 5000g of thioglycollic acid extract liquid at the temperature of 25 ℃ and the vacuum degree of 0.074MPa to obtain 746.43g of concentrated solution, measuring that the mass fraction of the thioglycollic acid in the concentrated solution is 74.96%, adding 4.92g of aluminum powder, 10.00g of sodium sulfite and 0.01g of 1, 4-naphthoquinone into the concentrated solution, carrying out reduced pressure rectification at the temperature of 100 ℃ and the vacuum degree of 0.099MPa to separate 553.87g of finished thioglycollic acid, measuring that the content of the thioglycollic acid is 99.97%, and the rectification yield is 98.96%.
Example 4
Carrying out reduced pressure distillation on 5000g of thioglycolic acid extract at 15 ℃ and a vacuum degree of 0.085MPa to obtain 753.16g of concentrated solution, measuring that the mass fraction of the thioglycolic acid in the concentrated solution is 50.01%, adding a mixture of 0.08g of stannous chloride, 0.25g of chloranil, 0.25g of phenanthrenequinone and 0.25g of vitamin K1, carrying out reduced pressure distillation at 123 ℃ under the vacuum degree of 0.097MPa to separate 377.14g of finished thioglycolic acid, measuring that the content of the thioglycolic acid is 99.69%, and obtaining the distillation yield of 99.82%.
Example 5
1000g of thioglycollic acid extract is subjected to reduced pressure distillation at 20 ℃ and the vacuum degree of 0.08MPa to obtain 206.75g of concentrated solution, the mass fraction of the thioglycollic acid in the concentrated solution is measured to be 69.13%, 0.59g of sodium borohydride and 0.02g of 9, 10-anthraquinone are added into the concentrated solution, the reduced pressure distillation is carried out at 174 ℃ under the vacuum degree of 0.080MPa to separate 140.28g of finished thioglycollic acid, the content of the thioglycollic acid is measured to be 99.87%, and the distillation yield is 98.02%.
Example 6
And distilling 2500g of thioglycolic acid extract under the vacuum degree of 0.078MPa at 22 ℃ to obtain 489.63g of concentrated solution, measuring the thioglycolic acid content in the concentrated solution to be 72.82%, adding 0.82g of butyl hydroxyanisole, 0.82g of dibutyl hydroxytoluene, 0.81g of ascorbic acid mixture, 0.05 o-benzoquinone, 0.05g of 2, 6-dimethoxy-p-benzoquinone and 0.15g of alkannin mixture, rectifying under the vacuum degree of 0.05MPa at 205 ℃ under reduced pressure to separate 351.48g of finished thioglycolic acid, measuring the thioglycolic acid content to be 99.76%, and rectifying at the yield of 98.34%.
Comparative example 1
And distilling 2500g of thioglycollic acid extract under the vacuum degree of 0.08MPa at 20 ℃ to obtain 490.04g of concentrated solution, wherein the mass fraction of the thioglycollic acid in the concentrated solution is 69.19%, and rectifying under the vacuum degree of 0.098MPa at 114 ℃ under reduced pressure to separate 205.94g of finished thioglycollic acid, the content of the thioglycollic acid is 99.16%, and the rectification yield is 60.23%.
Comparative example 2
1000g of thioglycollic acid extract is subjected to reduced pressure distillation at the vacuum degree of 0.078MPa at 22 ℃ to obtain 203.89g of concentrated solution, the mass fraction of the thioglycollic acid in the concentrated solution is measured to be 70.33%, 68.82g of thioglycollic acid finished product is separated by reduced pressure distillation at the vacuum degree of 0.080MPa at 174 ℃, the content of the thioglycollic acid is measured to be 99.28%, and the distillation yield is 47.65%.
Comparative example 3
And carrying out reduced pressure distillation on 5000g of thioglycollic acid extract at 15 ℃ and under the vacuum degree of 0.085MPa to obtain 749.93g of concentrated solution, wherein the mass fraction of thioglycollic acid in the concentrated solution is 54.11%, carrying out reduced pressure rectification at 136 ℃ under the vacuum degree of 0.095MPa to separate 238.38g of finished thioglycollic acid, wherein the content of the thioglycollic acid is 99.53%, and the rectification yield is 58.47%.
Comparative example 4 (example selected from application No. 201610990881.5 as comparative example 4 of the present application)
The production method of mercaptoacetic acid with high yield by a sodium hydrosulfide method is formed by reacting synthetic liquid and a reducing agent in parts by mass as follows: 300 parts of the synthetic solution, 7.0 parts of sodium thiosulfate and 25.0 parts of water are subjected to reduction reaction. Wherein the synthetic liquid is a mixed liquid composed of sodium hydrosulfide and sodium chloroacetate according to a molar ratio of 1.2:1, the mass concentration of the sodium chloroacetate is 45%, and the mass concentration of the sodium hydrosulfide is 30%.
The processing method comprises the following steps:
(1) adding 7.0 parts of sodium thiosulfate 7 into 25.0 parts of water, stirring and dissolving;
(2) adding the solution obtained in the step (1) and 300 parts of synthetic solution into a reactor;
(3) reacting at 69 deg.C for 18min, and cooling to 45 deg.C;
(4) acidifying with 28% hydrochloric acid until pH value reaches 1.4 to obtain thioglycolic acid aqueous solution;
(5) extracting with isopropyl ether, separating out isopropyl ether under normal pressure, and distilling under reduced pressure to collect thioglycollic acid products; the yield of the aqueous thioglycolic acid solution in step (4) was calculated to be 93.4%. The yield of the thioglycolic acid is calculated by utilizing the method for distilling under reduced pressure and is 87 percent.
Comparative example 5 (example selected according to application No. 201610524374.2 as comparative example 5 of the present application)
A method for separating mercaptoacetic acid from a mercaptoacetic acid aqueous solution comprises the steps of concentrating twice and filter pressing twice to obtain a secondary concentrated solution and solid sodium chloride, rectifying the secondary concentrated solution under reduced pressure under the protection of a stabilizing agent to separate a finished product, washing the solid sodium chloride to recover the mercaptoacetic acid carried in the solid sodium chloride, wherein the mercaptoacetic acid aqueous solution is obtained by a sodium hydrosulfide method, and the main components of the mercaptoacetic acid aqueous solution comprise the mercaptoacetic acid, the sodium chloride and water.
A process for separating thioglycolic acid from an aqueous thioglycolic acid solution comprising the steps of:
(1) adding 1500 parts of thioglycolic acid aqueous solution, and performing reduced pressure distillation dehydration to obtain 42.6% of thioglycolic acid;
(2) carrying out filter pressing on the concentrated solution obtained in the step 1), and separating 225g of solid sodium chloride and 360g of filtrate;
(3) concentrating the filtrate obtained in the step 2) for the second time, measuring the content of thioglycollic acid to be 70.2%, and performing filter pressing on the concentrated solution to obtain 213g of filtrate and 55.0g of solid sodium chloride;
(4) combining the solid salts obtained in the steps 2) and 3), washing the solid salts with the aqueous solution of thioglycolic acid before concentration for 2 times according to the mass ratio of 1:1, wherein the content of the thioglycolic acid in the separated solid sodium chloride is 0.19%;
(5) directly adding 0.7g of tert-butyl hydroquinone and 2.3g of tea polyphenol into the concentrated solution of the thioglycolic acid obtained in the step 3), and carrying out vacuum rectification to separate 103.5g of a thioglycolic acid finished product with the mass content of 99.62 percent and calculating the rectification yield of 68.96 percent.
In comparative examples 1 to 3, the control conditions of the vacuum distillation and the vacuum distillation are controlled, but different from the examples of the invention, the reducing agent and the stabilizing agent are not added, so that the distillation yield in the examples of the invention is obviously higher than that in comparative examples 1 to 3; in comparative example 4, a reducing agent is added in the rectification process, but the yield of the final mercaptoacetic acid aqueous solution is 93.4 percent, which is lower than the rectification yield of the application, and the yield of the mercaptoacetic acid obtained by rectification in comparative example 4 is far lower than the yield of the mercaptoacetic acid obtained in the embodiment; in the comparative example 4, the reducing agent is added in the synthesis process, because the water accounts for a large proportion in the aqueous solution, the amount of the reducing agent is large to ensure the reduction effect, and the aqueous solution is subjected to extraction concentration subsequently, the amount of the reducing agent entering an organic phase is limited, the antioxidation effect is greatly reduced, and meanwhile, the reducing agent enters the aqueous phase, so that the composition of wastewater components is complex, and the environmental protection pressure is increased; the rectification purity of the comparative example 5 is equivalent to that of the application, but the rectification yield of the comparative example 5 is far lower than that of the embodiment, the phenolic stabilizer is added into the comparative example 5, and all phenols used in the phenolic stabilizer are antioxidant series, so that the oxidation of thioglycolic acid in the rectification process can be inhibited, but the phenolic stabilizer has no effect on thioglycolic acid oxidation products formed in the synthesis and post-treatment processes and thioglycolic acid self-esterification impurities formed in the rectification process.
The invention reduces the oxidation of thioglycollic acid and the oxidation products of the thioglycollic acid by controlling the temperature and the vacuum degree of reduced pressure distillation in the distillation process, adds a reducing agent to effectively reduce the formed oxidation products of the thioglycollic acid in the synthesis and post-treatment processes, thereby improving the content of the thioglycolic acid in the extraction concentrated solution of the thioglycollic acid, and adds a quinone stabilizer to effectively inhibit the self-esterification reaction of the thioglycollic acid in the distillation process, thereby having synergistic effect in the two aspects, greatly improving the distillation yield of the thioglycollic acid and reducing the production cost of the thioglycollic acid.
Claims (4)
1. A method for improving rectification yield of thioglycolic acid comprises the steps of obtaining a thioglycolic acid extraction concentrated solution, and is characterized in that a reducing agent and a stabilizing agent are added into the thioglycolic acid extraction concentrated solution for vacuum rectification to separate the thioglycolic acid;
the dosage of the reducing agent is 0.01 to 2 percent of the mass of the thioglycollic acid extraction concentrated solution;
the dosage of the stabilizer is 0.001 to 1 percent of the mass of the thioglycollic acid extraction concentrated solution;
the reducing agent is one or more of sodium sulfite, sodium thiosulfate, sodium borohydride, aluminum powder, zinc powder, stannous chloride, butyl hydroxy anisole, dibutyl hydroxy toluene and ascorbic acid;
the stabilizer is one or more of methyl hydroquinone, o-benzoquinone, 1, 4-naphthoquinone, chloranil, p-benzoquinone, 2, 6-dimethoxy p-benzoquinone, alkannin, vitamin K1, o-phenanthrenequinone and 9, 10-anthraquinone;
the vacuum rectification control conditions are as follows: the vacuum degree is 0.099-0.05 MPa, and the temperature is 100-205 ℃.
2. The method for improving the rectification yield of thioglycolic acid according to claim 1, wherein the mass fraction of thioglycolic acid in the thioglycolic acid extraction concentrate is 50% to 75%.
3. The method for improving the rectification yield of thioglycollic acid according to claim 1, wherein the concentrated thioglycollic acid extract is obtained by vacuum distillation of a thioglycollic acid extract, and the control conditions of the vacuum distillation are as follows: the vacuum degree is 0.085-0.02 MPa, and the reduced pressure distillation temperature is 5-50 ℃.
4. The method for improving the rectification yield of mercaptoacetic acid according to claim 3, wherein the temperature of the reduced pressure distillation is 15-25 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910947820.4A CN110590625B (en) | 2019-09-30 | 2019-09-30 | Method for improving rectification yield of thioglycollic acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910947820.4A CN110590625B (en) | 2019-09-30 | 2019-09-30 | Method for improving rectification yield of thioglycollic acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110590625A CN110590625A (en) | 2019-12-20 |
| CN110590625B true CN110590625B (en) | 2021-12-14 |
Family
ID=68865615
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910947820.4A Active CN110590625B (en) | 2019-09-30 | 2019-09-30 | Method for improving rectification yield of thioglycollic acid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110590625B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2594030A (en) * | 1950-03-28 | 1952-04-22 | Gillette Safety Razor Co | Process for producing alpha-mercapto-carboxylic acids |
| DD224843A1 (en) * | 1984-06-25 | 1985-07-17 | Dresden Arzneimittel | METHOD FOR STABILIZING THIOGLYCOLIC ACIDS AND THIOGLYCOLSAEURO SOLUTIONS |
| JPH0272155A (en) * | 1988-09-06 | 1990-03-12 | Daicel Chem Ind Ltd | Purification of thioglycolic acid |
| RO108178B1 (en) * | 1991-11-04 | 1994-02-28 | Inst De Cercetari Pentru Fibre | Thioglicolic acid preparation process |
| CN106167458A (en) * | 2016-07-05 | 2016-11-30 | 山东沾化金嘉利化工科技有限公司 | The method separating TGA from TGA aqueous solution |
| CN106748924A (en) * | 2016-11-10 | 2017-05-31 | 山东沾化金嘉利化工科技有限公司 | The production method of high yield TGA |
-
2019
- 2019-09-30 CN CN201910947820.4A patent/CN110590625B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2594030A (en) * | 1950-03-28 | 1952-04-22 | Gillette Safety Razor Co | Process for producing alpha-mercapto-carboxylic acids |
| DD224843A1 (en) * | 1984-06-25 | 1985-07-17 | Dresden Arzneimittel | METHOD FOR STABILIZING THIOGLYCOLIC ACIDS AND THIOGLYCOLSAEURO SOLUTIONS |
| JPH0272155A (en) * | 1988-09-06 | 1990-03-12 | Daicel Chem Ind Ltd | Purification of thioglycolic acid |
| RO108178B1 (en) * | 1991-11-04 | 1994-02-28 | Inst De Cercetari Pentru Fibre | Thioglicolic acid preparation process |
| CN106167458A (en) * | 2016-07-05 | 2016-11-30 | 山东沾化金嘉利化工科技有限公司 | The method separating TGA from TGA aqueous solution |
| CN106748924A (en) * | 2016-11-10 | 2017-05-31 | 山东沾化金嘉利化工科技有限公司 | The production method of high yield TGA |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110590625A (en) | 2019-12-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106146453B (en) | The preparation method of 1,3- propane sultone | |
| CN109970964B (en) | Preparation method of tertiary alkynol polyether | |
| CN110590625B (en) | Method for improving rectification yield of thioglycollic acid | |
| CN102718634B (en) | Alkylene bialkylphenol compound and preparation method thereof | |
| CN109534970A (en) | A kind of preparation method of high-purity natural benzaldehyde | |
| CN111454129B (en) | Preparation method of high-purity phenoxyethanol | |
| CN113292491A (en) | Preparation method of anti-aging agent AW | |
| CN109320407B (en) | Preparation method of 2-dodecyl-3-hydroxy-1, 4-naphthoquinone | |
| CN112225653B (en) | Green synthesis method of natural benzaldehyde | |
| CN104591989B (en) | The preparation method of 5 [(4 chlorphenyl) methyl] 2,2 cyclopentanone dimethyls | |
| CN101591238A (en) | The preparation method of rosin acrylic acid | |
| CN109988783B (en) | Preparation method of phloretin | |
| CN104387239B (en) | A kind of method improving contraposition nonyl phenol content in nonyl phenol product | |
| CN110229044B (en) | Method for treating florfenicol fluoro technical product | |
| CN103319318A (en) | Recovering and recycling method of excessive methyl catechol in vanillin production process | |
| CN107056592B (en) | Post-treatment method of 2-propoxyl chloroethane crude product | |
| CN106008226A (en) | Synthesis method of diflunisal drug intermediate 2,4-difluoroaniline | |
| CN114014748B (en) | Antioxidant compound, synthesis method and antioxidant containing antioxidant compound | |
| CN105693658A (en) | Stearolactone synthesis process | |
| CN112538036A (en) | Method for producing methyl thioglycolate based on sodium hydrosulfide method | |
| CN110128246A (en) | A kind of preparation method of hydroxytyrosol | |
| CN105330631B (en) | The method that one kettle way prepares n butylphthalide | |
| CN108997138A (en) | A kind of method of solvent-free catalytic hydrogenation production para-fluoroaniline | |
| CN114409532B (en) | Continuous synthesis method of methyl cardiac pavilion | |
| CN115108891B (en) | Preparation method of 3, 5-difluorophenol |
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 | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20200720 Address after: 256500 Boxing Economic Development Zone, Binzhou, Shandong Applicant after: SHANDONG EFIRM BIOCHEMISTRY AND ENVIRONMENTAL PROTECTION Co.,Ltd. Address before: 256500 Boxing Economic Development Zone, Binzhou, Shandong Applicant before: YELLOW RIVER DELTA JINGBO RESEARCH INSTITUTE OF CHEMICAL INDUSTRY Co.,Ltd. |
|
| TA01 | Transfer of patent application right | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 256500 Boxing Economic Development Zone, Shandong, Binzhou Patentee after: Yifeng New Material Co.,Ltd. Address before: 256500 Boxing Economic Development Zone, Shandong, Binzhou Patentee before: SHANDONG EFIRM BIOCHEMISTRY AND ENVIRONMENTAL PROTECTION Co.,Ltd. |
|
| CP01 | Change in the name or title of a patent holder |