CN110577502B - Method for improving yield of rubber accelerator TBBS - Google Patents
Method for improving yield of rubber accelerator TBBS Download PDFInfo
- Publication number
- CN110577502B CN110577502B CN201910870485.2A CN201910870485A CN110577502B CN 110577502 B CN110577502 B CN 110577502B CN 201910870485 A CN201910870485 A CN 201910870485A CN 110577502 B CN110577502 B CN 110577502B
- Authority
- CN
- China
- Prior art keywords
- yield
- butylamine
- tert
- rubber accelerator
- accelerator tbbs
- 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
- C07D—HETEROCYCLIC COMPOUNDS
- C07D277/00—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings
- C07D277/60—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings condensed with carbocyclic rings or ring systems
- C07D277/62—Benzothiazoles
- C07D277/68—Benzothiazoles with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached in position 2
- C07D277/70—Sulfur atoms
- C07D277/76—Sulfur atoms attached to a second hetero atom
- C07D277/80—Sulfur atoms attached to a second hetero atom to a nitrogen atom
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a method for improving the yield of a rubber accelerator TBBS, belonging to the field of fine chemical engineering. The rubber accelerator TBBS is synthesized by taking accelerator MBT, tert-butylamine and sodium hypochlorite as raw materials, taking water as a medium and adding sodium chloride and sodium dodecyl benzene sulfonate into a reaction system. The dispersion of the MBT particles in water is increased by utilizing the dispersion effect of the surfactant, and after the tert-butylamine is added, the contact surface of the MBT particles and the tert-butylamine is increased, so that the synthesis rate of the M-amine salt is improved; NaCl is added to increase the polarity of the reaction environment, so that the M-amine salt is better dissolved in the polar environment and fully contacts with sodium hypochlorite molecules, and the M-amine salt fully participates in the reaction, thereby improving the conversion rate and reducing the consumption of tert-butylamine. The addition of NaCl and the surfactant sodium dodecyl benzene sulfonate greatly improves the product yield, the yield is over 96 percent, and the synthesized material has white appearance, high melting point and high purity.
Description
Technical Field
The invention relates to the field of fine chemical engineering, and particularly relates to a method for improving the yield of a rubber accelerator TBBS.
Background
The vulcanization accelerator TBBS, the chemical name of which is N-tertiary butyl-2-benzothiazole sulfonamide, is used as a post-effective vulcanization accelerator for natural rubber and triene synthetic rubber.
The vulcanization accelerator TBBS is an after-effect vulcanization accelerator which is safe to operate at high temperature, good in scorching performance and high in stretching strength. It conforms to the green environmental protection development concept in the vulcanization process of the accelerator rubber and is called as a standard accelerator. The application amount of the promoter TBBS is larger and larger, and the promoter TBBS has extremely wide development prospect.
The existing method for synthesizing TBBS mainly adopts a sodium hypochlorite oxidation method, the process is relatively complete, and the highest yield of TBBS synthesized by the method can only reach 93%. The key point of the production of the accelerator TBBS is the preparation of the main raw material tert-butylamine. Tert-butylamine is an important lower aliphatic amine, and the synthesis difficulty is determined due to the specificity of the tert-butylamine on the molecular structure, and on the basis of the above, the price of the tert-butylamine is higher, namely the production cost of TBBS is higher, so that the yield of the TBBS is improved, and the production cost can be obviously reduced.
At present, the highest yield of TBBS synthesized by a sodium hypochlorite oxidation method can only reach 93%, scientific researchers are dedicated to improving the yield of TBBS for many years, but still no suitable method is found. How to improve the yield of synthesizing TBBS by the method becomes a technical problem.
Disclosure of Invention
In order to make up for the defects of the prior art, the invention provides a method for improving the yield of the rubber accelerator TBBS.
The technical scheme of the invention is as follows:
a method for improving the yield of a rubber accelerator TBBS is characterized in that an accelerator MBT, tert-butylamine and sodium hypochlorite are used as raw materials, water is used as a medium, and sodium chloride and sodium dodecyl benzene sulfonate are added into a reaction system to synthesize the rubber accelerator TBBS.
As a preferred scheme, the method for improving the yield of the rubber accelerator TBBS comprises the following specific steps: mixing an accelerator MBT, sodium chloride, sodium dodecyl benzene sulfonate and water, adding tert-butylamine while stirring, and dropwise adding sodium hypochlorite for oxidation; and judging the reaction end point, stopping the reaction, filtering, washing with water, and drying to obtain the rubber accelerator TBBS.
The method for producing the rubber accelerator TBBS is simple to operate, and compared with the traditional sodium hypochlorite oxidation process, the yield is greatly improved, and the product purity is also greatly improved.
Preferably, the amount of tert-butylamine, water, sodium dodecyl benzene sulfonate and sodium chloride is 210-265 mL, 200-500 mL, 0.3-1.5 g and 25-50 g, respectively, per mole of the accelerator MBT raw material.
Because MBT is insoluble in water, a reaction system is in a slurry state, and the contact between raw materials is increased by adding sodium dodecyl benzene sulfonate and sodium chloride.
Further: the usage amount of tert-butylamine is 225-240 mL, the usage amount of water is 350-450 mL, the usage amount of sodium dodecyl benzene sulfonate is 0.5-1.0 g, and the usage amount of sodium chloride is 35-45 g per mole of accelerator MBT raw material.
Preferably, starch-KI-ammonium sulfate is used to indicate the end of the oxidation reaction.
Preferably, the reaction temperature is 25-35 ℃.
Preferably, the effective chlorine content of the oxidant sodium hypochlorite is 13-20 g/mL.
Preferably, the mother liquor containing tert-butylamine after filtration is put into the next batch of production.
The filtered tert-butylamine mother liquor is put into the production of the next batch, and at most 24 batches can be circulated, and then new tert-butylamine is reused for feeding. The tert-butylamine mother liquor can be recycled, so that the use amount of tert-butylamine is reduced, the distillation amount of the tert-butylamine mother liquor is reduced, and the treatment amount of waste liquor after distillation is reduced.
Preferably, the sodium chloride is industrial sodium chloride.
The invention has the beneficial effects that:
1. adding sodium dodecyl benzene sulfonate, utilizing the dispersing action of surfactant to increase the dispersion degree of MBT particles in water, after adding tert-butylamine, increasing the contact surface of MBT particles and tert-butylamine, making the reaction more sufficient, thereby increasing the synthesis rate of M-amine salt.
2. The yield can be further increased by adding industrial Nacl, and the polarity of the reaction environment is increased by adding sodium chloride, so that the M-amine salt is better dissolved in the polar environment and better contacted with sodium hypochlorite molecules, the reaction contact rate is improved, the M-amine salt is fully reacted, the conversion rate is improved, and the consumption of tert-butylamine is reduced.
3. The recycling of the tert-butylamine mother liquor reduces the use amount of tert-butylamine, improves the yield, reduces the consumption of raw material tert-butylamine, reduces the distillation amount of the tert-butylamine mother liquor, and reduces the treatment amount of waste liquor after distillation.
4. The method has simple process operation, greatly improves the yield and the product purity compared with the traditional sodium hypochlorite oxidation process.
Detailed Description
Example 1 a method for increasing the yield of rubber accelerator TBBS by adding salt and surfactant:
42g of accelerator MBT, 0.1g of sodium dodecyl benzene sulfonate, 10g of industrial sodium chloride and 100ml of water are added into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, stirring is started, the rotation speed is 90 revolutions per minute, stirring is carried out for 30 minutes, 60ml of tert-butylamine is slowly added, stirring is carried out for 10 minutes, sodium hypochlorite with the effective chlorine content of 15-20g/ml is dropwise added into the three-neck flask at the temperature of t =25-35 ℃, the end point detection is carried out by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, the end point detection is changed to blue-black color, the reaction is stopped, the mixture is filtered, washed and dried to obtain 58.47g of rubber accelerator TBBS, the yield reaches 97.7%, and the melting point reaches.
Example 2 a method for increasing the yield of rubber accelerator TBBS by adding salt and surfactant:
42g of accelerator MBT, 0.1g of sodium dodecyl benzene sulfonate, 10g of industrial sodium chloride and 100ml of water are added into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, stirring is started, the rotation speed is 90 revolutions per minute, stirring is carried out for 30 minutes, 58ml of tert-butylamine mother liquor and 42ml of new tert-butylamine obtained in example 1 are slowly added, stirring is carried out for 10 minutes, sodium hypochlorite with the effective chlorine content of 15-20g/ml is dropwise added into the mixture at the temperature of t =25-35 ℃, an end point detection is carried out by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, bluish black is taken as an end point, the reaction is stopped, and 58.12g of rubber accelerator TBBS product is obtained by filtering, water washing and drying, the yield reaches 97.1%, and the melting point reaches 106.9 ℃.
Example 3 a method of increasing the yield of rubber accelerator TBBS by adding salt and surfactant:
42g of accelerator MBT, 0.1g of sodium dodecyl benzene sulfonate, 10g of industrial sodium chloride and 100ml of water are added into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, stirring is started, the rotation speed is 90 revolutions per minute and is stirred for 30 minutes, 72ml of tert-butylamine mother liquor obtained in the example 2 and 28ml of new tert-butylamine are slowly added, stirring is carried out for 10 minutes, sodium hypochlorite with the effective chlorine content of 15-20g/ml is dropwise added into the mixture at the temperature of t =25-35 ℃, an end point detection is carried out by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, the bluish black is the end point, the reaction is stopped, and 57.59g of rubber accelerator TBBS product is obtained by filtering, water washing and drying, the yield reaches 96.20%, and the melting point reaches 106.7 ℃.
Example 4 a method of increasing the yield of rubber accelerator TBBS by adding salt and surfactant:
42g of accelerator MBT, 0.1g of sodium dodecyl benzene sulfonate, 10g of industrial sodium chloride and 100ml of water are added into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, stirring is started, the rotation speed is 90 revolutions per minute, stirring is carried out for 30 minutes, 67.5ml of tert-butylamine mother liquor obtained in example 3 and 32.5ml of new tert-butylamine are slowly added, stirring is carried out for 10 minutes, sodium hypochlorite with the effective chlorine content of 15-20g/ml is dropwise added into the mixture at the temperature of t =25-35 ℃, an end point detection is carried out by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, the reaction is stopped, filtration, water washing and drying are carried out, 57.77g of rubber accelerator TBBS products are obtained, the yield reaches 96.5%, and the melting point reaches 106.8 ℃.
Example 5 a method of increasing the yield of rubber accelerator TBBS by adding salt and surfactant:
adding 100g of accelerator MBT, 0.3g of sodium dodecyl benzene sulfonate, 28g of industrial sodium chloride and 260ml of water into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, starting stirring at the rotation speed of 80 revolutions per minute for 30 minutes, slowly adding 143ml of tert-butylamine, stirring for 10 minutes, dropwise adding sodium hypochlorite with the effective chlorine content of 15-20g/ml when the temperature t =25-35 ℃, performing end point detection by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, stopping reaction, filtering, washing with water, drying to obtain 138.66g of rubber accelerator TBBS product, wherein the yield reaches 97.3%, and the melting point reaches 106.7 ℃.
Example 6 a method of increasing the yield of rubber accelerator TBBS by adding salt and surfactant:
adding 500g of accelerator MBT, 3g of sodium dodecyl benzene sulfonate, 123g of industrial sodium chloride and 1235ml of water into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, starting stirring at the rotation speed of 100 revolutions per minute for 30 minutes, slowly adding 714ml of tert-butylamine, stirring for 10 minutes, dropwise adding sodium hypochlorite with the effective chlorine content of 15-20g/ml when the temperature t =25-35 ℃, performing end point detection by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, stopping reaction, filtering, washing with water, and drying to obtain 691.91g of rubber accelerator TBBS product, wherein the yield reaches 97.1%, and the melting point reaches 106.2 ℃.
As can be seen from example 6, the quantitative production of the process of the present invention also achieves considerable results, with high product yields and high melting points, and the process of the present invention can be used for quantitative production.
Comparative example 1
The traditional method for preparing the yield of the rubber accelerator TBBS by a sodium hypochlorite oxidation method comprises the following steps:
adding 42g of accelerator MBT and 100ml of water into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, starting stirring at the rotation speed of 90 revolutions per minute for 30 minutes, slowly adding 60ml of tert-butylamine, stirring for 10 minutes, dropwise adding sodium hypochlorite with the effective chlorine content of 15-20g/ml into the three-neck flask at the temperature of t =25-35 ℃, detecting the end point by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, stopping the reaction when the end point is changed to blue black, filtering, washing and drying to obtain 55.54g of a rubber accelerator TBBS product, wherein the yield reaches 92.8%, and the melting point is 105.0 ℃.
That is, comparative example 1 was the same as example 1 except that sodium dodecylbenzenesulfonate and technical-grade sodium chloride as surfactants were not added, as compared with example 1.
The sodium dodecyl benzene sulfonate and the industrial sodium chloride are both beneficial to the contact between the raw materials. Comparative example 1 no sodium dodecylbenzenesulfonate and sodium chloride were used, and the resulting rubber accelerator TBBS product was significantly inferior to the present invention in both yield and melting point.
Compared with the traditional process, the quality (purity) of the product obtained by the method is remarkably improved, and at least 400mL of tert-butylamine can be saved in production of each kilogram of the rubber accelerator TBBS, namely, the cost is saved by 4000 yuan in production of each kilogram of the rubber accelerator TBBS.
Comparative example 2 a method for the yield of rubber accelerator TBBS:
adding 42g of accelerator MBT, 0.1g of sodium dodecyl benzene sulfonate and 100ml of water into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, starting stirring at the rotation speed of 90 revolutions per minute, stirring for 30 minutes, slowly adding 60ml of tert-butylamine, stirring for 10 minutes, dropwise adding sodium hypochlorite with the effective chlorine content of 15-20g/ml into the three-neck flask at the temperature of t =25-35 ℃, detecting the end point by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, stopping the reaction, filtering, washing with water and drying to obtain 56.44g of rubber accelerator TBBS product, wherein the yield reaches 94.3%, and the melting point reaches 105.5 ℃.
That is, comparative example 2 was similar to example 1 except that industrial-grade sodium chloride was not added to example 1.
In comparative example 2, only sodium dodecyl benzene sulfonate is added, and industrial sodium chloride is not added, so that the yield is improved to some extent compared with the yield of the traditional process, but the improvement is not obvious.
Comparative example 3 a process for the yield of rubber accelerator TBBS:
adding 42g of accelerator MBT, 10g of industrial sodium chloride and 100ml of water into a three-neck flask provided with a stirrer, a thermometer and a water bath kettle, starting stirring, rotating at 90 revolutions per minute, stirring for 30 minutes, slowly adding 60ml of tert-butylamine, stirring for 10 minutes, dropwise adding sodium hypochlorite with the effective chlorine content of 15-20g/ml into the three-neck flask at the temperature of t =25-35 ℃, detecting an end point by using a starch-potassium iodide-ammonium sulfate indicator when the end point is approached, stopping the reaction, filtering, washing and drying to obtain 57.28g of rubber accelerator TBBS product, wherein the yield reaches 95.7%, and the melting point reaches 105.5 ℃.
That is, comparative example 3 was similar to example 1 except that sodium dodecylbenzenesulfonate was not added to example 1.
In the comparative example 3, only industrial sodium chloride is added, and sodium dodecyl benzene sulfonate is not added, so that the yield is greatly improved compared with the traditional process, but the improvement effect of the example 1 is still not obvious, and the product purity is not high as that of the example 1.
Claims (8)
1. A method for improving the yield of a rubber accelerator TBBS takes accelerators MBT, tert-butylamine and sodium hypochlorite as raw materials, and is characterized in that: taking water as a medium, and adding sodium chloride and sodium dodecyl benzene sulfonate into a reaction system to synthesize a rubber accelerator TBBS;
the method comprises the following specific steps: mixing an accelerator MBT, sodium chloride, sodium dodecyl benzene sulfonate and water, adding tert-butylamine while stirring, and dropwise adding sodium hypochlorite for oxidation; and judging the reaction end point, stopping the reaction, filtering, washing with water, and drying to obtain the rubber accelerator TBBS.
2. The method for increasing the yield of rubber accelerator TBBS according to claim 1, wherein: the usage amount of tert-butylamine is 210-265 mL, the usage amount of water is 200-500 mL, the usage amount of sodium dodecyl benzene sulfonate is 0.3-1.5 g, and the usage amount of sodium chloride is 25-50 g per mole of accelerator MBT raw material.
3. The method for increasing the yield of rubber accelerator TBBS according to claim 2, wherein: the usage amount of tert-butylamine is 225-240 mL, the usage amount of water is 350-450 mL, the usage amount of sodium dodecyl benzene sulfonate is 0.5-1.0 g, and the usage amount of sodium chloride is 35-45 g per mole of accelerator MBT raw material.
4. The method for increasing the yield of rubber accelerator TBBS according to claim 1, wherein: starch-KI-ammonium sulfate was used to indicate the end of the oxidation reaction.
5. The method for increasing the yield of rubber accelerator TBBS according to claim 1, wherein: the reaction temperature is 25-35 ℃.
6. The method for increasing the yield of rubber accelerator TBBS according to claim 1, wherein: the effective chlorine content of the oxidant sodium hypochlorite is 13-20 g/mL.
7. The method for increasing the yield of rubber accelerator TBBS according to claim 1, wherein: the filtered mother liquor containing tert-butylamine is put into the next batch of production.
8. The method for increasing the yield of rubber accelerator TBBS according to claim 1, wherein: the sodium chloride is industrial sodium chloride.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910870485.2A CN110577502B (en) | 2019-09-16 | 2019-09-16 | Method for improving yield of rubber accelerator TBBS |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910870485.2A CN110577502B (en) | 2019-09-16 | 2019-09-16 | Method for improving yield of rubber accelerator TBBS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110577502A CN110577502A (en) | 2019-12-17 |
| CN110577502B true CN110577502B (en) | 2021-03-23 |
Family
ID=68811573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910870485.2A Active CN110577502B (en) | 2019-09-16 | 2019-09-16 | Method for improving yield of rubber accelerator TBBS |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110577502B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49110664A (en) * | 1973-03-10 | 1974-10-22 | ||
| CN101676274A (en) * | 2008-09-19 | 2010-03-24 | 南化集团研究院 | Method for preparing N-tertiary butyl benzothiazole sulfonamide |
| CN102250038A (en) * | 2011-06-13 | 2011-11-23 | 中国石油化工股份有限公司 | Improve method for preparing N-tert-butylbenzothiazolesulfenamide |
| CN104860829A (en) * | 2015-04-16 | 2015-08-26 | 山东戴瑞克新材料有限公司 | Rubber vulcanization accelerator CBS mother liquor treatment and application method |
| CN105037295A (en) * | 2015-07-22 | 2015-11-11 | 聊城金歌合成材料有限公司 | Method for producing sulfenamide rubber vulcanization accelerator |
| CN106478545A (en) * | 2016-09-30 | 2017-03-08 | 王显权 | The preparation method of N oxygen diethyl support group 2 benzothiazole sulfenamide |
-
2019
- 2019-09-16 CN CN201910870485.2A patent/CN110577502B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49110664A (en) * | 1973-03-10 | 1974-10-22 | ||
| CN101676274A (en) * | 2008-09-19 | 2010-03-24 | 南化集团研究院 | Method for preparing N-tertiary butyl benzothiazole sulfonamide |
| CN102250038A (en) * | 2011-06-13 | 2011-11-23 | 中国石油化工股份有限公司 | Improve method for preparing N-tert-butylbenzothiazolesulfenamide |
| CN104860829A (en) * | 2015-04-16 | 2015-08-26 | 山东戴瑞克新材料有限公司 | Rubber vulcanization accelerator CBS mother liquor treatment and application method |
| CN105037295A (en) * | 2015-07-22 | 2015-11-11 | 聊城金歌合成材料有限公司 | Method for producing sulfenamide rubber vulcanization accelerator |
| CN106478545A (en) * | 2016-09-30 | 2017-03-08 | 王显权 | The preparation method of N oxygen diethyl support group 2 benzothiazole sulfenamide |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110577502A (en) | 2019-12-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100469771C (en) | Method of refining rubber vulcanization accelerant MBT | |
| CN108191672B (en) | Synthetic method of 2, 4-dinitro-6-chloroaniline | |
| CN101717378B (en) | Method for synthesizing rubber vulcanization accelerator DM by oxygen oxidization | |
| CN114853695B (en) | Preparation method of rubber vulcanizing agent 4,4' -dithiodimorpholine | |
| CN111747840A (en) | Preparation method of 1, 4-naphthalenedicarboxylic acid | |
| CN104610193A (en) | Preparation method of rubber vulcanizing accelerator TBBS | |
| CN110577502B (en) | Method for improving yield of rubber accelerator TBBS | |
| CN102923722A (en) | Preparation method for white carbon black | |
| CN102838563A (en) | Synthesis method of rubber vulcanization accelerator TBBS (N-tert-butyl-2-benzothiazolesulfenamide) | |
| CN102827104A (en) | Method for synthesizing rubber vulcanization accelerator CZ by two-step process by using sodium hypochlorite as oxidizer | |
| CN102838562A (en) | Method for synthesizing rubber vulcanization accelerator NS (N-tertiary butyl-2-benzothiazole sulfenamide) through two-step method by taking hydrogen peroxide as oxidant | |
| CN104230844A (en) | Preparation method of vulcanization accelerator CZ | |
| CN102863402A (en) | Preparation method of accelerator CBS | |
| CN105348160A (en) | New green and environmental-protection technology for production of cartap | |
| CN101676274B (en) | Preparation method of N-tert-butylbenzothiazole sulfenamide | |
| CN106316981A (en) | Preparation method of N-cyclohexyl-2-benzothiazolesulfenamide | |
| CN101676273B (en) | Method for directly synthesizing accelerant N-tertiary butyl benzothiazole sulfenamide | |
| WO2023060866A1 (en) | Process for synthesizing accelerator cbs by air oxidation of mbts | |
| CN113980046A (en) | Preparation method of high-purity isooctyl monomethyltrimercaptoacetate tin heat stabilizer | |
| CN1089571A (en) | The preparation method of stable sodium percarbonate | |
| CN111039811A (en) | Process for preparing nonane diacyl amino acid salt | |
| CN107814776A (en) | A kind of continuous preparation method of N- tert-butyl groups benzo thiazolesulfenamide | |
| CN111154287A (en) | Disperse red 60 condensation process | |
| CN108658894A (en) | A kind of synthetic method of thiofide DCBS | |
| CN105503772A (en) | Preparation method for N-tert-butyl benzothiazole sulfenamide |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |