CN114085166B - Method for preparing high-purity high-stability isocyanate in high yield - Google Patents
Method for preparing high-purity high-stability isocyanate in high yield Download PDFInfo
- Publication number
- CN114085166B CN114085166B CN202010863112.5A CN202010863112A CN114085166B CN 114085166 B CN114085166 B CN 114085166B CN 202010863112 A CN202010863112 A CN 202010863112A CN 114085166 B CN114085166 B CN 114085166B
- Authority
- CN
- China
- Prior art keywords
- isocyanate
- sulfate
- salt
- additive
- phenylenediamine
- 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
- C07C263/00—Preparation of derivatives of isocyanic acid
- C07C263/10—Preparation of derivatives of isocyanic acid by reaction of amines with carbonyl halides, e.g. with phosgene
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C263/00—Preparation of derivatives of isocyanic acid
- C07C263/18—Separation; Purification; Stabilisation; Use of additives
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C265/00—Derivatives of isocyanic acid
- C07C265/14—Derivatives of isocyanic acid containing at least two isocyanate groups bound to the same carbon skeleton
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to a method for preparing high-purity high-stability isocyanate in high yield. According to the method, the iron compound additive and the organic sulfate salt or the organic sulfate additive are added in the process of preparing the isocyanate by phosgenation of amine or amine salt, so that side reactions are effectively inhibited, and the isocyanate composition which is controllable in hydrolysis chlorine index and stable in storage is obtained by separation on the basis, so that the isocyanate composition with high purity and high stability is obtained.
Description
Technical Field
The invention belongs to the field of isocyanate, and particularly relates to a method for preparing high-purity high-stability isocyanate with high yield.
Background
Isocyanates are generally prepared from amines as starting materials by phosgenation. However, due to the high reactivity of the NCO groups, photochemical reaction processes often occur with side reactions, resulting in a decrease in yield. In addition, the storage process is liable to lose its original characteristics due to occurrence of side reactions, and specifically, the isocyanate forms dimers or multimers due to the self-polymerization of NCO groups, thereby reducing the yield of the reaction process and deteriorating the quality of the storage process. For example, paraphenylene diisocyanate, is extremely prone to dimer formation during phosgenation, and because of the high decomposition temperature of the dimer, recovery is difficult, resulting in yield loss, while the solid state dimer is extremely prone to equipment blockage, thus presenting a safety risk. In addition, the polymerization reaction in the storage process leads to a short storage period of the terephthalyl diisocyanate, and brings much inconvenience to downstream customers.
The liquid phase phosgenation reaction is usually a gas-liquid-solid three-phase reaction, so the reaction time is often long, and side reactions occur to cause yield reduction, so the effective contact of materials in the liquid phase phosgenation process is crucial, and can be improved by gasifying amine or enhancing mixing or increasing the reaction pressure, but higher energy consumption is often generated or higher safety risk exists, so a novel method for enhancing the contact between materials is developed, especially the solubility of solid materials in a solvent is improved, so the contact of the materials is promoted, the probability of side reactions is reduced, and the method is very significant.
Patent CN110114339a reports a side reaction inhibitor for eliminating hydrogen of amine or intermediate carbamoyl chloride during phosgenation, thereby promoting forward reaction and suppressing side reaction, and as a result, appears to suppress the production of monoisocyanate as a by-product. However, this method does not inhibit the occurrence of the isocyanate self-polymerization reaction.
Patent CN101553517 reports a process for preparing modified polyisocyanates by carbodiimidization of liquid polyisocyanates in the presence of phosphole based catalysts to improve the storage stability of the isocyanates. However, this method is not suitable for inhibiting polymerization reactions in the phosgenation process.
In summary, the isocyanate products obtained by the prior art of improved phosgenation still have difficulty in maintaining high stability and cannot maintain high purity during storage.
Disclosure of Invention
The foregoing demonstrates that isocyanates are susceptible to side reactions during phosgenation and storage, resulting in reduced reaction yields and reduced isocyanate quality. The inventors have surprisingly found that the addition of a certain amount of iron salt and a certain amount of organic sulfate or sulfate salt during the photochemical reaction of an amine or amine salt thereof can effectively increase the yield of the reaction and maintain the stability during storage.
The invention aims to provide a method for preparing high-purity high-stability isocyanate in high yield.
In order to achieve the above object, the present invention adopts the following technical scheme:
a process for preparing a high purity, high stability isocyanate, the process comprising the steps of:
s1: mixing an amine and/or amine salt with a solvent;
s2: the S1 is obtained to obtain a mixture, and the mixture reacts with phosgene to obtain isocyanate reaction liquid;
s3: concentrating, separating and purifying the reaction solution of S2 to obtain isocyanate;
wherein, the additive A and the additive B are added in the S1, the additive A is ferric salt, and the additive B is organic sulfate salt and/or organic sulfate.
The ferric ions in the ferric salt have the effect of inhibiting free radical polymerization reaction, the organic sulfate or sulfate salt has the organic matter and inorganic salt structure, the sulfate group with negative charge has good wetting force and emulsifying force, can promote the dissolution contact of gas, liquid and solid phases, and slowly react with phosgene to generate compounds containing active chlorine components, the addition amount of the organic sulfate is changed, the content of the active chlorine components in the obtained isocyanate product is different, the content of the active chlorine components with different contents enables the hydrolysis chlorine content of the isocyanate product to show different levels due to the activity of the active chlorine components, so that the hydrolysis chlorine of the product can be effectively regulated by regulating the addition amount of the organic sulfate or sulfate salt, the stability of the isocyanate product obtained on the basis is greatly improved, and the isocyanate product can maintain high purity in the storage process.
In the invention, the additive A is one or more of ferrous chloride, ferric chloride, ferrous bromide, ferric bromide, ferrous iodide, ferric iodide, ferrous sulfate, pentacarbonyl iron, nine carbonyl iron, ferric acetylacetonate, bis (triphenylphosphine) iron dichloride, ferrocene and ferric chloride diamine; preferably one or more of ferric chloride, ferrous chloride and ferric bromide; preferably, the additive A is added in a proportion of 0.1 to 1% by weight, based on the total mass of the mixture obtained in S1.
In the invention, the organic sulfate salt in the additive B is selected from one or more of nonylphenol polyoxyethylene ether sulfate salt, coco monoethanolamide sulfate salt, octylphenol polyoxyethylene ether sulfate salt, dimer acid polyethylene glycol polyester sulfate salt, imidazoline sulfate salt, coco monoethanolamide sulfate salt, myristic monoethanolamide sulfate salt, alkyl monoethanolamide sulfate salt, sodium lauryl sulfate, sodium cetyl sulfate, sodium stearyl alkyl sulfate, castor oil fatty acid sulfate salt and dihydroxystearic acid sulfate salt, preferably one or more of sodium lauryl sulfate, sodium cetyl sulfate and sodium stearyl alkyl sulfate; the organic sulfate is selected from one or more of disodium laurylsulfosuccinate, disodium laurylsulfosuccinate citrate and disodium laureth sulfosuccinate; preferably, the additive B is added in a proportion of 0.1 to 1% by weight, based on the total mass of the mixture obtained in S1.
In the present invention, the amine or amine salt in S1 includes, but is not limited to, one or more of p-phenylenediamine, naphthalene diamine, hexamethylenediamine, isophorone diamine, 4-diaminodicyclohexylmethane, 4-diaminodiphenylmethane, 4-diaminodiphenyl ether, m-xylylenediamine, hydrogenated m-xylylenediamine, toluenediamine hydrochloride, p-phenylenediamine hydrochloride, and toluenediamine carbonate.
In the invention, the solvent in S1 is chlorobenzene and/or o-dichlorobenzene.
In the invention, the mixture obtained by S1 in S2 is mixed and reacted with phosgene in a molar ratio of 1 (4-6), and the molar amount of the mixture is calculated by the molar amount of amine.
In the invention, the content of isocyanate monomer in the S2 isocyanate reaction solution is more than 99 weight percent, and the sum of the content of dimer and polymer is less than 0.5 weight percent, so as to deduct the total mass of the reaction solution after the solvent.
In the invention, the content of isocyanate in the S3 is more than 99.9 weight percent, the mass content of dimer is 10-500ppm, and the mass content of polymer is 10-400ppm based on the total mass of the obtained isocyanate.
In the present invention, the isocyanate in S3 includes, but is not limited to, one or more of p-phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4-diisocyanato dicyclohexylmethane, 4-diisocyanato diphenylmethane, 4-diisocyanato diphenyl ether, m-phenylene diisocyanate, hydrogenated m-phenylene diisocyanate and toluene diisocyanate.
It is another object of the present invention to provide an isocyanate prepared by the process.
The high-purity high-stability isocyanate prepared by the method.
In the invention, the content of the hydrolytic chlorine of the isocyanate is 10-200ppm, the mass content of the dimer is 10-500ppm, and the mass content of the trimeric polymer is 10-400ppm based on the total mass of the isocyanate.
In the invention, after the isocyanate is stored for 6 months at 50 ℃, the change of the mass percent of isocyanate monomer compared with the initial value is less than or equal to 0.2 percent.
Compared with the prior art, the invention has the following positive effects:
(1) The isocyanate composition has high purity (more than 99.9%), good storage stability and less than 0.2% of purity change after being stored for 6 months at 50 ℃, and greatly improves the application experience of downstream clients.
(2) The isocyanate preparation method is simple, easy to realize industrialized amplification, the purity of the prepared reaction solution is more than 99.5%, the content of dimers and polymers is less than 0.5%, and the reaction yield is greatly improved.
Detailed Description
The invention will be further illustrated with reference to the following examples, which are not intended to limit the same.
The main reagent information adopted by the invention is as follows:
TABLE 1 Main raw material information
| Reagent name | Manufacturer' s | Purity of |
| Para-phenylenediamine | Sigma | ＞99.5％ |
| P-phenylenediamine hydrochloride | Fangzhou Ruiyuan | ＞99.5％ |
| 1, 5-naphthalenediamine | Nantong Haidi | ＞99.0％ |
| Monochlorobenzene | Microphone forest | AR |
| 4-hydroxy TEMPO | Inock | AR |
| O-dichlorobenzene | Microphone forest | AR |
| Ferric chloride | Chinese medicine | AR |
| Ferrous chloride | Chinese medicine | AR |
| Ferric bromide | Chinese medicine | AR |
| Sodium lauryl sulfate | Chinese medicine | AR |
| Cetyl alcohol sodium sulfate | Chinese medicine | AR |
| Sodium stearyl alcohol alkyl sulfate | Chinese medicine | AR |
GPC analysis of the invention for isocyanate, dimer, and multimer content, agilent1260, column chromatography: mesoPore (300X 7.5 mm) 1 root; oligopore (300×7.5 mm) 2 (three columns in series) isocratic tetrahydrofuran elution column temperature: flow rate at 35 ℃): 1.0ml/min time: sample injection amount 40 min: 20ul.
The hydrolysis chlorine analysis is carried out by adopting a GB/T12009.2 method, and a testing instrument is Metrohm905Titrando.
Reaction equipment: 1L jacketed glass reactor, nantongpu, was used.
Example 1
Preparing paraphenylene diisocyanate reaction liquid 1#.
Uniformly mixing 15wt% of p-phenylenediamine, 0.1wt% of ferric trichloride, 0.1wt% of sodium lauryl sulfate and 84.8wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine mixed solution, simultaneously respectively introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (in terms of the p-phenylenediamine, mol/h) of the p-phenylenediamine mixed solution to the feeding speed (in terms of the mol/h) of phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, continuously reacting for 3h until the reaction solution is clarified, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Example 2
Preparing paraphenylene diisocyanate reaction liquid 2#.
Uniformly mixing 15wt% of p-phenylenediamine hydrochloride, 0.2wt% of ferrous chloride, 0.2wt% of sodium lauryl sulfate and 84.6wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine hydrochloride mixed solution, simultaneously respectively introducing the p-phenylenediamine hydrochloride mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (calculated by p-phenylenediamine, per unit mol/h) of the p-phenylenediamine hydrochloride mixed solution to the feeding speed (per unit mol/h) of phosgene to be 1:5, wherein the feeding speed of the mixed solution is 5ml/min, reacting for 1h at 50 ℃ until the feeding of the p-phenylenediamine hydrochloride mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, continuously reacting until the reaction solution is clarified, and stopping introducing phosgene. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Example 3
Preparing paraphenylene diisocyanate reaction liquid 3#.
Uniformly mixing 15wt% of p-phenylenediamine, 0.5wt% of ferric trichloride, 0.5wt% of sodium lauryl sulfate and 84.0wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine mixed solution, simultaneously respectively introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (in terms of p-phenylenediamine, mol/h) of the p-phenylenediamine mixed solution to the feeding speed (in terms of the mol/h) of phosgene to be 1:6, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, and continuously reacting until the reaction solution is clarified, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Example 4
Preparing paraphenylene diisocyanate reaction liquid 4#.
Uniformly mixing 15wt% of p-phenylenediamine, 0.7wt% of ferric bromide, 0.7wt% of sodium cetyl sulfate and 83.6wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine mixed solution, simultaneously respectively introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (in terms of p-phenylenediamine, mol/h) of the p-phenylenediamine mixed solution to the feeding speed (in terms of mol/h) of phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, and continuously reacting until the reaction solution is clarified, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Example 5
Preparing paraphenylene diisocyanate reaction liquid No. 5.
Uniformly mixing 15wt% of p-phenylenediamine, 1wt% of ferric trichloride, 1wt% of sodium stearyl alcohol alkyl sulfate and 83wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine mixed solution, simultaneously respectively introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (calculated by p-phenylenediamine and unit mol/h) of the p-phenylenediamine mixed solution to the feeding speed (calculated by p-phenylenediamine and unit mol/h) of phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, continuously reacting until the reaction solution is clear, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Comparative example 1
In comparison with example 3, the difference is that no ferric trichloride additive was added.
Preparing paraphenylene diisocyanate reaction solution 6#.
Uniformly mixing 15wt% of p-phenylenediamine, 0wt% of ferric trichloride, 0.5wt% of sodium lauryl sulfate and 84.5wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine mixed solution, simultaneously respectively introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (in terms of the p-phenylenediamine, mol/h) of the p-phenylenediamine mixed solution to the feeding speed (in terms of the mol/h) of the phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, continuously reacting for 3h until the reaction solution is clarified, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Comparative example 2
In comparison with example 3, the difference is that no sodium lauryl sulfate additive was added.
Preparing a paraphenylene diisocyanate reaction solution 7#.
Uniformly mixing 15wt% of p-phenylenediamine, 0.5wt% of ferric trichloride, 0wt% of sodium lauryl sulfate and 84.45wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine mixed solution, simultaneously respectively introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (in terms of the p-phenylenediamine, mol/h) of the p-phenylenediamine mixed solution to the feeding speed (in terms of the mol/h) of the phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, continuously reacting for 3h until the reaction solution is clarified, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Comparative example 3
In comparison with example 1 and example 3, the difference is that no iron trichloride or sodium lauryl sulfate additive was added.
Preparing paraphenylene diisocyanate reaction liquid 8#.
Uniformly mixing 15wt% of p-phenylenediamine, 0wt% of ferric trichloride, 0wt% of sodium lauryl sulfate and 85wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine mixed solution, simultaneously respectively introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (calculated by p-phenylenediamine, unit mol/h) of the p-phenylenediamine mixed solution to the feeding speed (calculated by p-phenylenediamine, unit mol/h) of phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, continuously reacting for 3h until the reaction solution is clarified, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Comparative example 4
Compared with example 1 and example 3, the difference is that excessive ferric trichloride and excessive sodium lauryl sulfate additive are added.
Preparing a paraphenylene diisocyanate reaction solution 9#.
Uniformly mixing 15wt% of p-phenylenediamine, 2wt% of ferric trichloride, 2wt% of sodium lauryl sulfate and 81wt% of o-dichlorobenzene at room temperature to obtain a p-phenylenediamine mixed solution, simultaneously respectively introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle, controlling the ratio of the feeding speed (calculated by p-phenylenediamine, unit mol/h) of the p-phenylenediamine mixed solution to the feeding speed (calculated by p-phenylenediamine, unit mol/h) of phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, continuously reacting for 3h until the reaction solution is clarified, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Comparative example 5
Compared with example 1 and example 3, the difference is that insufficient iron trichloride and insufficient sodium lauryl sulfate additive are added.
Preparing paraphenylene diisocyanate reaction solution 10#.
Mixing 15wt% of p-phenylenediamine, 0.05wt% of ferric trichloride, 0.05wt% of sodium lauryl sulfate and 85wt% of o-dichlorobenzene at room temperature uniformly to obtain a p-phenylenediamine mixed solution, simultaneously introducing the p-phenylenediamine mixed solution and phosgene into a reaction kettle respectively, controlling the ratio of the feeding speed (in terms of the p-phenylenediamine, mol/h) of the p-phenylenediamine mixed solution to the feeding speed (in terms of the mol/h) of phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting at 50 ℃ for 1h until the feeding of the p-phenylenediamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, and continuously reacting for 3h until the reaction solution is clarified, and stopping phosgene introducing. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of the terephthalyl diisocyanate, the dimer and the polymer are measured by a GPC analysis method, and the data are summarized in Table 2.
Example 6
Preparing 1, 5-naphthalene diisocyanate reaction liquid 11#.
Uniformly mixing 15wt% of 1, 5-naphthalene diamine, 0.5wt% of ferric trichloride, 0.5wt% of sodium lauryl sulfate and 84wt% of o-dichlorobenzene at room temperature to obtain naphthalene diamine mixed solution, simultaneously introducing the naphthalene diamine mixed solution and phosgene into a reaction kettle respectively, controlling the ratio of the feeding speed (calculated by naphthalene diamine and per unit mol/h) of the naphthalene diamine mixed solution to the feeding speed (per unit mol/h) of phosgene to be 1:4, wherein the feeding speed of the mixed solution is 5ml/min, reacting for 1h at 50 ℃ until the feeding of the naphthalene diamine mixed solution is finished, continuously maintaining the phosgene introducing speed, raising the reaction temperature to 140 ℃, continuously reacting for 3h until the reaction solution is clarified, and stopping introducing phosgene. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of naphthalene diisocyanate, dimer and polymer are measured by GPC analysis method, and the data are summarized in Table 2.
Comparative example 6
In comparison with example 6, the difference is that no iron trichloride or sodium lauryl sulfate additive was added.
Preparing 1,5 naphthalene diisocyanate reaction solution 12#.
15wt% of 1, 5-naphthalene diamine, 0wt% of ferric trichloride, 0wt% of sodium lauryl sulfate and 85wt% of o-dichlorobenzene are uniformly mixed at room temperature to obtain a naphthalene diamine mixed solution, meanwhile, the naphthalene diamine mixed solution and phosgene are respectively introduced into a reaction kettle, the ratio of the feeding speed (calculated by naphthalene diamine and per unit mol/h) of the naphthalene diamine mixed solution to the feeding speed (calculated by naphthalene diamine and per unit mol/h) of phosgene is controlled to be 1:6, wherein the feeding speed of the mixed solution is 5ml/min, the reaction is carried out at 50 ℃ for 1h until the feeding of the naphthalene diamine mixed solution is finished, the phosgene introducing speed is continuously maintained, the reaction temperature is increased to 140 ℃, and the phosgene introducing is stopped after the reaction solution is clarified. Nitrogen is introduced at the speed of 100L/h for 3h to remove the light gas, the reaction liquid is taken for analysis, the contents of naphthalene diisocyanate, dimer and polymer are measured by GPC analysis method, and the data are summarized in Table 2.
Comparative example 7
The photochemical reaction of p-phenylenediamine was carried out according to the procedure of example 1 in patent CN110114339 a.
Preparing a p-phenylene diisocyanate reaction solution 13#.
410g of monochlorobenzene are placed in a 1L flask and cooled to-10℃to-15 ℃. To this was added 0.4g of 4-hydroxy TEMPO and dissolved with stirring. The temperature of the flask was maintained at-10℃to-15℃and 100g of low temperature (-10℃to-15 ℃) liquid phosgene was introduced into the reactor, followed by stirring. From the time of phosgene injection to the end of the reaction, a dry ice-acetone condenser was used to prevent phosgene from leaking to the outside. 70g of p-phenylenediamine was dissolved in 80g of monochlorobenzene and then introduced into the flask using a dropping funnel. The temperature is kept at-10 ℃ to-15 ℃ for cooling. When the introduction of the p-phenylenediamine solution was completed, stirring was carried out at the same temperature for 1 hour. Then, the internal temperature of the flask was heated to 130 ℃. When the internal temperature of the flask reached 130 ℃, a further 30g of liquid phosgene was introduced using a dropping funnel. The flask was kept at 125 ℃ to 135 ℃ and stirred for a further 2 hours until the reaction solution became clear. When the reaction solution became transparent, heating was stopped, the solution was cooled to 80 ℃, and then nitrogen bubbling was performed for phosgene removal. The reaction solution was analyzed, and the contents of terephthalyl isocyanate, dimer and polymer were determined by GPC analysis, wherein the monomer content was 87.5%, the dimer content was 11.5% and the polymer content was 1.0%.
TABLE 2 data on reaction fluids
As shown in the table 2, the addition of 0.1-1wt% of ferric salt and 0.1-1wt% of organic sulfate or sulfate salt in the photochemical process can effectively inhibit side reactions, and the content of dimerization and polymerization products is controlled below 0.5%.
Without adding any one of ferric salt or organic sulfate/sulfate, the occurrence of side reaction cannot be effectively controlled, and byproducts are precipitated in a solid form in the reaction liquid, which would have a risk of blockage in industrialization.
When the addition amount of any one of the iron salt or the organic sulfate/sulfate salt is less than 0.1wt% and/or more than 1wt%, the occurrence of side reactions cannot be effectively controlled.
A p-phenylene diisocyanate reaction solution was prepared according to the procedure of example 1 of patent CN110114339A, in which the monomer content was 87.5%, the dimer content was 11.5%, and the polymer content was 1.0%, and the occurrence of side reactions could not be effectively controlled.
Example 8
P-phenylene diisocyanate having different content of hydrolytic chlorine was prepared.
The reaction solutions 1 to 10# were subjected to solvent removal at 120℃and 10KPaA, respectively, to obtain crude terephthal-isocyanate compositions 1a to 10a, respectively, the crude terephthal-isocyanate compositions 1a to 10a were subjected to rectification separation at 130℃and 1KPaA, 5wt% fraction 1 and 85wt% fraction 2 were collected in this order, and fractions 2 of the crude compositions 1a to 10a were designated as composition 1, composition 2, composition 3, composition 4, composition 5, composition 6, composition 7, composition 8, composition 9 and composition 10, respectively, and the terephthal-isocyanate content, dimer content and multimer content in the compositions 1 to 10 were measured by the above GPC method, and the hydrolysis chlorine content of the isocyanate compositions 1 to 10 was measured by the above hydrolysis chlorine test method, and the results are shown in Table 3.
Example 9
1, 5-naphthalene diisocyanate having different content of hydrolytic chlorine was prepared.
The reaction liquids 11# and 12# were subjected to solvent removal at 120℃under 10KPaA to obtain crude naphthalene diisocyanate compositions 11a and 12a, the crude naphthalene diisocyanate compositions 11a and 12a were subjected to rectification separation at 160℃under 500PaA, 5wt% fraction 1 and 85wt% fraction 2 were collected in this order, the fractions 2 of the crude compositions 11a and 12a were designated as compositions 11 and 12, the naphthalene diisocyanate content, dimer content and multimer content in the compositions 11 to 12 were measured by the GPC method, and the hydrolysis chlorine content of the isocyanate compositions 11 to 12 was measured by the hydrolysis chlorine test method, and the results are shown in Table 3.
TABLE 3 index of isocyanate compositions 1-12
| Composition and method for producing the same | Isocyanate content/% | Dimer content/ppm | Polymer content/ppm | Content of hydrolyzed chlorine/ppm | Color of |
| 1 | 99.96 | 13 | 213 | 10 | White color |
| 2 | 99.96 | 301 | 11 | 40 | White color |
| 3 | 99.96 | 213 | 101 | 100 | White color |
| 4 | 99.93 | 210 | 399 | 140 | White color |
| 5 | 99.94 | 397 | 114 | 200 | White color |
| 6 | 98.98 | 5000 | 5106 | 10 | Yellow colour |
| 7 | 98.65 | 5230 | 5110 | 3 | Yellow colour |
| 8 | 98.66 | 7001 | 6013 | 3 | Yellow colour |
| 9 | 98.89 | 5750 | 5101 | 400 | Yellow colour |
| 10 | 99.88 | 5530 | 5107 | 3 | Yellow colour |
| 11 | 99.95 | 200 | 200 | 17 | White color |
| 12 | 99.06 | 5200 | 4000 | 3 | Yellow colour |
As shown in the table above, the hydrolysis chlorine in the corresponding isocyanate product can be controlled to be at different levels by controlling the addition amount of the organic sulfate or the sulfate salt in the photochemical reaction process, the addition amount of the organic sulfate or the sulfate salt is in the range of 0.1-1wt%, and the hydrolysis chlorine index of the corresponding composition is controlled to be 10-200ppm.
Ferric salt and organic sulfate or sulfate are added, the addition amount of the ferric salt and the sulfate or sulfate is controlled to be a certain level (0.1-1 wt%) and the indexes of the dimer and the polymer of the finally obtained isocyanate composition are in a good range, the mass content of the dimer is 10-500ppm and the mass content of the polymer is 10-400ppm.
The color of the final isocyanate composition obtained without adding any one of iron salt or organic sulfuric acid/sulfuric acid ester salt is yellowish, which can affect the sales of the product.
Example 10
Storage stability test of the terephthal-diisocyanate composition.
The terephthal-isocyanate compositions (compositions 1 to 8) were placed in a transparent glass bottle, the glass bottle was filled with nitrogen gas and sealed, and then, the different terephthal-isocyanate compositions (compositions 1 to 8) were each stored at 50℃for 6 months, resulting in stored compositions, which were designated as composition 1a, composition 2a, composition 3a, composition 4a, composition 5a, composition 6a, composition 7a, composition 8a, respectively, and the terephthal-isocyanate content, dimer, multimer content of the terephthal compositions were tested in the same GPC manner as described above. The color of the composition was visually observed. The results are shown in table 4 below.
TABLE 4 storage stability of compositions 1-8
As demonstrated in the above table, the iron salt and the organic sulfate or sulfate salt were added, and the addition amounts of the iron salt and the organic sulfate or sulfate salt were controlled to a certain level (0.1 to 1 wt%) and the finally obtained isocyanate composition remained unchanged in color after 6 months of storage, with a purity change of less than 0.2%, and therefore, the stability of the composition was very good even when stored for a long period of time.
In the preparation process of the composition 6, only organic sodium sulfate salt is added, no ferric salt is added, and the finally obtained isocyanate contains a certain amount of active chlorine component generated by the organic sulfate photochemical reaction, the hydrolysis chlorine content is 10ppm, the color is not obviously changed after the composition is stored, the purity change is less than 0.2%, and the composition shows better stability, but the isocyanate composition presents yellow color before the composition is stored due to the fact that no ferric salt is added, which is disadvantageous to the sales of products.
The purity of the final p-phenylene diisocyanate composition (composition 7, composition 8) was remarkably reduced without adding the reaction solution of the organic sulfate, the quality of the product was seriously deteriorated, the color of the product was changed to dark yellow after storage for 6 months, and the caking phenomenon occurred.
In summary, in the process of preparing isocyanate by phosgenation of amine or amine salt thereof, the addition amount of iron compound is controlled to be 0.1-1%, and the addition amount of organic sulfate or sulfate salt is controlled to be 0.1-1%, so that side reaction in the photochemical reaction process can be effectively inhibited, the content of hydrolytic chlorine in the product is regulated, and the yield of the reaction and the storage stability of the product are effectively improved.
Those skilled in the art will appreciate that certain modifications and adaptations of the invention are possible and can be made under the teaching of the present specification. Such modifications and adaptations are intended to be within the scope of the present invention as defined in the appended claims.
Claims (11)
1. A process for the preparation of an isocyanate, the process comprising the steps of:
s1: mixing an amine and/or amine salt with a solvent;
s2: the S1 is obtained to obtain a mixture, and the mixture reacts with phosgene to obtain isocyanate reaction liquid;
s3: concentrating, separating and purifying the reaction solution of S2 to obtain isocyanate;
the method is characterized in that an additive A and an additive B are added into S1, wherein the additive A is ferric salt, and the additive B is organic sulfate;
wherein the addition proportion of the additive A is 0.1-1wt%, and the addition proportion of the additive B is 0.1-1wt%, based on the total mass of the mixture obtained in the step S1.
2. The method according to claim 1, wherein the additive a is one or more of ferrous chloride, ferric chloride, ferrous bromide, ferric bromide, ferrous iodide, ferric iodide, ferrous sulfate, ferric acetylacetonate, bis-triphenylphosphine dichloride, ferrocene, and ferric chloride diamine.
3. The method of claim 2, wherein additive a is one or more of ferric chloride, ferrous chloride, and ferric bromide.
4. The preparation method according to claim 1 or 2, wherein the organic sulfate salt in the additive B is selected from one or more of polyoxyethylene nonylphenol ether sulfate salt, monoethanolamide sulfate salt of coco acid, polyoxyethylene octylphenol ether sulfate amine salt, polyethylene glycol dimer acid polyester sulfate salt, imidazoline sulfate salt, monoethanolamide sulfate salt of coco acid, monoethanolamide sulfate salt of myristic acid, alkyl monoethanolamide sulfate salt, sodium laurylsulfate, sodium cetyl sulfate, sodium stearyl alkyl sulfate, castor oil fatty acid sulfate salt, and dihydroxystearic acid sulfate salt.
5. The method according to claim 4, wherein the organic sulfate salt in the additive B is one or more selected from sodium lauryl sulfate, sodium cetyl sulfate and sodium stearyl sulfate.
6. The method of claim 1, wherein the amine or amine salt in S1 comprises one or more of para-phenylenediamine, naphthalene diamine, hexamethylenediamine, isophorone diamine, 4-diaminodicyclohexylmethane, 4-diaminodiphenylmethane, 4-diaminodiphenyl ether, meta-xylylenediamine, hydrogenated meta-xylylenediamine, toluenediamine hydrochloride, para-phenylenediamine hydrochloride, and toluenediamine carbonate;
and/or the solvent in the S1 is chlorobenzene and/or o-dichlorobenzene.
7. The process according to claim 1, wherein the mixture obtained in S2S 1 is mixed with phosgene in a molar ratio of 1 (4-6), the molar amount of the mixture being based on the molar amount of the amine.
8. The preparation method according to claim 1, wherein the S2 isocyanate reaction solution contains more than 99wt% of isocyanate monomer and the sum of dimer and polymer is less than 0.5wt% based on the total mass of the reaction solution after the solvent is removed.
9. The process according to claim 1, wherein the isocyanate content in S3 is greater than 99.9% by weight, the dimer content is from 10 to 500ppm by weight, the polymer content is from 10 to 400ppm by weight, based on the total isocyanate mass obtained;
and/or the isocyanate in the S3 comprises one or more of p-phenylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4-diisocyanatodicyclohexylmethane, 4-diisocyanatodiphenylmethane, 4-diisocyanatodiphenyl ether, m-xylylene diisocyanate, hydrogenated m-xylylene diisocyanate and toluene diisocyanate.
10. The process according to claim 1, wherein the isocyanate in S3 has a content of hydrolysis chlorine of 10 to 200ppm, a content of dimer of 10 to 500ppm and a content of polymer of 10 to 400ppm based on the total mass of isocyanate.
11. The process according to claim 1, wherein the isocyanate in S3 is stored at 50℃for 6 months, and the change in the mass percentage of the isocyanate monomer from the initial value is not more than 0.2%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010863112.5A CN114085166B (en) | 2020-08-25 | 2020-08-25 | Method for preparing high-purity high-stability isocyanate in high yield |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010863112.5A CN114085166B (en) | 2020-08-25 | 2020-08-25 | Method for preparing high-purity high-stability isocyanate in high yield |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114085166A CN114085166A (en) | 2022-02-25 |
| CN114085166B true CN114085166B (en) | 2023-05-05 |
Family
ID=80294855
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010863112.5A Active CN114085166B (en) | 2020-08-25 | 2020-08-25 | Method for preparing high-purity high-stability isocyanate in high yield |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114085166B (en) |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3632827A (en) * | 1968-11-21 | 1972-01-04 | Olin Mathieson | Preparation of aromatic isocyanates |
| DE102004063221A1 (en) * | 2004-12-22 | 2006-07-13 | Lanxess Deutschland Gmbh | Method for reducing hydrolysable chlorine content in organic isocyanates, comprises contacting the isocyanate with water-containing inert gas stream/organic material with cationic exchange effect and releasing the obtained mixture |
| CN101811019B (en) * | 2010-04-19 | 2012-01-18 | 烟台万华聚氨酯股份有限公司 | Dynamic hole jet reactor and method for preparing isocyanate by adopting dynamic hole jet reactor |
| CN105017080B (en) * | 2013-09-26 | 2016-10-12 | 三井化学株式会社 | Double (isocyanatomethyl) hexamethylene of 1,4-, polyisocyantates composition, ocular lens material, spectacle-frame and eyeglass |
| US11118001B2 (en) * | 2016-10-14 | 2021-09-14 | Asahi Kasei Kabushiki Kaisha | Isocyanate composition, method for producing isocyanate composition, and method for producing isocyanate polymer |
| CN114195971B (en) * | 2016-10-14 | 2023-08-25 | 旭化成株式会社 | Polyisocyanate composition, blocked polyisocyanate composition, hydrophilic polyisocyanate composition, coating composition and coating film |
| CN109369457A (en) * | 2018-12-13 | 2019-02-22 | 湖南海利常德农药化工有限公司 | A kind of preparation method of m-xylylene diisocyanate |
-
2020
- 2020-08-25 CN CN202010863112.5A patent/CN114085166B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN114085166A (en) | 2022-02-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5449082B2 (en) | Method for producing methylene dianiline and methylene bis (phenyl isocyanate) | |
| JP4583596B2 (en) | Process for producing a mixture comprising diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanate, wherein both chlorinated by-product content and iodine color number are reduced | |
| US4293687A (en) | Tetraalkylated biscyclohexylamine derivatives | |
| JP4567390B2 (en) | Preparation of a mixture of diphenylmethane series diisocyanates and polyisocyanates having a high content of 4,4'-methylene diphenyl diisocyanate and 2,4'-methylene diphenyl diisocyanate | |
| US4154752A (en) | Preparation of partially carbodiimidized methylenebis (phenyl isocyanate) | |
| CA1248544A (en) | Process for the preparation of polyisocyanates with biuret structure | |
| CN109180531B (en) | Method for obtaining MDI-50 with prolonged shelf life | |
| JPH03294249A (en) | Production of polyarylamine crosslinked with methylene | |
| CA2036538C (en) | Preparation of mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates having a reduced iodine color number | |
| ITMI951445A1 (en) | PROCEDURE FOR THE PRODUCTION OF AROMATIC CARBAMATES | |
| JP2003503383A (en) | Light colored isocyanates, their production and use | |
| US3631198A (en) | Preparation of 1 5-diisocyanato-2-methylpentane | |
| CA1248545A (en) | Process for the production of polyisocyanates which have a biuret structure | |
| CA2137713A1 (en) | Process for the production of diurethanes and their use for the production of diisocyanates | |
| CN114085166B (en) | Method for preparing high-purity high-stability isocyanate in high yield | |
| US4597909A (en) | Process for the production of polyisocyanates | |
| CN116023257B (en) | Continuous production method of high-purity propionyl chloride | |
| CN113444022B (en) | Method for preparing low-color-number long-shelf-life low-temperature-resistant MDI-50 | |
| EP0032011B1 (en) | Modified isocyanate compositions | |
| JPS59172450A (en) | Quality improvement of organic isocyanate | |
| JPS61151179A (en) | Production of hexamethylene isocyanurate compound | |
| US4593117A (en) | Process for the preparation of N- and O-substituted diurethanes and/or polyurethanes | |
| KR20030096039A (en) | Continuous process for the production of mdi allophanates | |
| US4564705A (en) | Bis(aminoneopentyl) aromatics | |
| CN115010694B (en) | Fluoroethylene carbonate and preparation method thereof |
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 |