CN113956436B - Light-colored diphenylmethane diisocyanate composition with stable color number in storage process - Google Patents
Light-colored diphenylmethane diisocyanate composition with stable color number in storage process Download PDFInfo
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- CN113956436B CN113956436B CN202111316818.0A CN202111316818A CN113956436B CN 113956436 B CN113956436 B CN 113956436B CN 202111316818 A CN202111316818 A CN 202111316818A CN 113956436 B CN113956436 B CN 113956436B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/72—Polyisocyanates or polyisothiocyanates
- C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
- C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
- C08G18/7657—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings
- C08G18/7664—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups
- C08G18/7671—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups containing only one alkylene bisphenyl group
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/34—Heterocyclic compounds having nitrogen in the ring
- C08K5/3412—Heterocyclic compounds having nitrogen in the ring having one nitrogen atom in the ring
- C08K5/3432—Six-membered rings
- C08K5/3437—Six-membered rings condensed with carbocyclic rings
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Abstract
The present invention relates to a diphenylmethane diisocyanate composition which is light in color and stable in color number during storage. The diphenylmethane diisocyanate composition comprises 2, 2-diphenylmethane diisocyanate, 2, 4-diphenylmethane diisocyanate and 4, 4-diphenylmethane diisocyanate, and the chloromethyl quinoline content in the composition is 1-10ppm. The prepared diphenylmethane diisocyanate composition has stable activity, low color number and good stability, and the isocyanate curing agent prepared by the diphenylmethane diisocyanate composition has low color number.
Description
Technical Field
The invention belongs to the field of isocyanate, and particularly relates to a diphenylmethane diisocyanate composition with light color and stable color number in the storage process.
Background
Diphenylmethane diisocyanate (abbreviated as pure MDI) is widely used in the fields of isocyanate curing agents, polyurethane elastomers, synthetic fiber manufacture, artificial leather, solvent-free paint and the like, and contains isomers such as 4, 4-diphenylmethane diisocyanate, 2-diphenylmethane diisocyanate and the like.
In general, the downstream can adjust the isomer ratio according to the requirements of different fields to achieve the purpose of improving the product performance. Under the general condition, the color number of the product does not influence mechanical properties such as product mechanics, but the consumer needs a product with a low color number, and the color number directly influences the competitiveness of the product.
Thus, there has long been an effort to reduce the color number of MDI products, for example, patent EP0546398A discloses acidifying polymethylene polyphenylene polyamines prior to phosgenation and then producing low color number isocyanate products.
Patent EP446781A describes a process in which polymeric MDA (monomeric and oligomeric polymethylene polyphenylene polyamines) is first treated with hydrogen and subsequently phosgenated to give a lighter colored MDI.
Patent DE19817691.0 describes a process for preparing MDI/PMDI mixtures having a lower content of hydrogen chloride by-products and a lower iodine color value by optimizing the parameters in the phosgenation reaction.
However, the prior art methods do not provide a clear color and stable color number MDI during storage, and there remains a need to develop new methods to obtain better light color MDI products.
Disclosure of Invention
The invention aims to provide a diphenylmethane diisocyanate composition which is light in color and stable in color number during storage.
In the preparation process of the MDI composition, aniline and formaldehyde are subjected to condensation reaction under the catalysis of Lewis acid to generate polyamine. The polyamine and phosgene react in solvent to form solution photochemical liquid, and the photochemical liquid is treated to eliminate solvent to obtain coarse MDI. Crude MDI is subjected to crude separation and rectification to prepare pure MDI and polymeric MDI.
The inventors have surprisingly found in research that the prior art contains a very small amount of chloromethylquinoline (typically 30 ppm) as an impurity in the top fraction of the rectification during phosgenation, which has a molecular weight which is not very different from that of MDI and which cannot be completely removed during the subsequent rectification in the production plant and remains in MDI. Such substances do not develop themselves, only a small increase in the color number of MDI among MDI. However, in downstream, in the reaction of organic polyols to form polyisocyanate composition curing agent systems, chlorinated c=n double bonds resonate to develop color gradually due to changes in chemical environment, while in downstream acidic systems, part of the chloromethylquinoline forms quinoline salts which lead to an increase in color number during storage of the polyisocyanate composition curing agent. Meanwhile, the chloromethyl quinoline substance is slightly alkaline, can react with an acid auxiliary agent in a downstream reaction, improves the reaction activity, and can cause the reduction of the product viscosity due to the excessively low content, so that a qualified product is not obtained. By controlling the content thereof, a diphenylmethane diisocyanate composition having a light color and stable color number during storage can be obtained.
Based on the findings, the invention provides a method for controlling the combined color number of toluene diisocyanate with different ideas, which specifically adopts the following technical scheme:
a diphenylmethane diisocyanate composition having a light color and stable color number during storage, said composition having a chloromethylquinoline content of from 1 to 10ppm, preferably from 3 to 5ppm, based on the total mass of the composition.
In the present invention, the diphenylmethane diisocyanate in the composition comprises 25% to 30% of 2, 2-diphenylmethane diisocyanate, 45% to 55% of 2, 4-diphenylmethane diisocyanate, and 15% to 30% of 4, 4-diphenylmethane diisocyanate.
In the invention, the chloromethyl quinoline has the following structure:
it is another object of the present invention to provide a process for preparing the phenyl methane diisocyanate composition.
A process for preparing the phenyl methane diisocyanate composition by controlling the chloromethylquinoline content in the phenyl methane diisocyanate composition by purification, preferably by one or more of distillation, rectification, chemical reaction, heat treatment and filtration, more preferably by rectification.
In the invention, the purification process conditions are as follows: the temperature of the tower kettle is controlled between 150 and 210 ℃, preferably between 170 and 190 ℃.
In the present invention, the overhead pressure is controlled to be 0.1 to 3.0kPaA, preferably 0.1 to 1.0kPaA, and the overhead reflux ratio is controlled to be 20 to 80%, preferably 50 to 60%.
In the present invention, the side offtake mass ratio is controlled to be 80 to 94%, preferably 88 to 92%, based on the feed mass.
In the present invention, the mass ratio of the overhead fraction produced is controlled to be 1 to 15%, preferably 3 to 7%, based on the mass of the feed.
In one embodiment, the chloromethyl quinoline substance content in the side offtake of the top fraction refining tower can be controlled by adjusting the offtake ratio of the top fraction and the side intermediate product and the temperature of the tower kettle, specifically, the higher the offtake ratio of the top fraction is, the lower the offtake ratio of the side intermediate product is, and the higher the temperature of the tower kettle is, the lower the chloromethyl quinoline substance content in the side intermediate product is.
It is a further object of the present invention to provide the use of a diphenylmethane diisocyanate composition.
Use of a diphenylmethane diisocyanate composition for the preparation of an isocyanate curing agent or polyurethane article which is light colored and stable in color number during storage.
Compared with the prior art, the invention has the beneficial effects that:
(1) The curing agent APHA of the diphenylmethane diisocyanate based polyisocyanate composition prepared by the invention has a color number of less than 15, is stored for 1 year at normal temperature, has a color number increase of less than 10, and is stable in storage.
(2) The adopted purification method is easy to realize and is convenient for industrialized application.
Drawings
FIG. 1 is a mass spectrum of chloromethylquinoline in example 1.
FIG. 2 is a graph showing the peaks of chloromethylquinoline of example 1 in gas chromatography.
Detailed Description
The present invention will be described in detail by way of the following specific examples of the present invention, which should not be construed as limiting the present invention in any sense.
The color number detection adopts a digital display colorimeter, BYK company, germany;
the content of chloromethyl quinoline substances in the diphenyl diisocyanate is quantitatively analyzed by adopting GC, and the analysis method is as follows: and taking gas chromatography of the diphenyl-dimethane diisocyanate sample for direct sample injection analysis, wherein the sample injection amount is 1ul. Chromatographic column: DB-5, the initial temperature of the column temperature box is 150 ℃, and the column temperature box is kept for 0.5min; heating to 250 ℃ at a speed of 5 ℃ per minute, and keeping for 7 minutes; heating to 280 ℃ at a speed of 10 ℃ per minute, and keeping for 2 minutes; the detector type is an ECD detector. The characteristic peak at 6.4min in the chromatogram represents chloromethylquinoline.
The raw material sources are as follows:
diphenylmethane diisocyanate was derived from the Van der Waals chemical (Ningbo) industrial garden MDI plant.
Rectifying device: the rectifying tower has 40 theoretical plates, M252Y-shaped structured packing is adopted as the packing, 25 theoretical plates are arranged at the feeding position, a gas phase process is adopted at 35 theoretical plates at the side line extraction position, and the top fraction is extracted at the 7 th theoretical plate in a liquid phase manner.
Example 1
0.5KG of a mixture containing 25% of 2, 2-diphenylmethane diisocyanate, 55% of 2, 4-diphenylmethane diisocyanate, 20% of 4, 4-diphenylmethane diisocyanate and 60ppm of chloromethylquinoline. The mixture enters a rectifying tower, the temperature of the tower bottom of the rectifying tower is controlled at 150 ℃, the tower top pressure is controlled at 3kPaA, the tower top reflux ratio is controlled at 20%, the side extraction mass ratio is controlled at 80% by taking the feeding mass as a reference, the side extraction mass ratio of the tower top fraction is controlled at 15% by taking the feeding mass as a reference, the side extraction intermediate product is tested, the chloromethylquinoline content is 10ppm, and the final product is obtained after the antioxidant 800ppm BHT is added.
140g of diphenylmethane diisocyanate composition product, 20g of a mixture of trimethylolpropane (mass ratio of the two: 7:1) and 0.1g of catalyst were mixed. Sequentially adding the materials into a 250mL flask, controlling the material reaction temperature to be 75 ℃ and the reaction time to be 4 hours; and (3) curing after the reaction, controlling the curing temperature to be 80 ℃ and curing time to be 2 hours to obtain the curing agent.
APHA color No. 30#, viscosity 3000CP. The temperature is high at 100 ℃ for 72 hours, and the color number is increased to 40#; the color number is increased to 45# after the storage for 1 year at normal temperature.
Example 2
0.5KG of a mixture containing 30% of 2, 2-diphenylmethane diisocyanate, 55% of 2, 4-diphenylmethane diisocyanate, 15% of 4, 4-diphenylmethane diisocyanate and 60ppm of chloromethylquinoline. The mixture enters a rectifying tower, the temperature of the tower bottom of the rectifying tower is controlled at 190 ℃, the tower top pressure is controlled at 0.1kPaA, the tower top reflux ratio is controlled at 60%, the side extraction mass ratio is controlled at 92% by taking the feeding mass as a reference, the side extraction mass ratio is controlled at 3% by taking the feeding mass as a reference, the side extraction intermediate product is obtained by taking the side extraction, the chloromethylquinoline content is tested to be 5ppm, and the final product is obtained after the antioxidant 800ppm BHT is added.
140g of diphenylmethane diisocyanate composition product, 20g of a mixture of trimethylolpropane (mass ratio of the two: 7:1) and 0.1g of catalyst were mixed. Sequentially adding the materials into a 250mL flask, controlling the material reaction temperature to be 75 ℃ and the reaction time to be 4 hours; and (3) curing after the reaction, controlling the curing temperature to be 80 ℃ and curing time to be 2 hours to obtain the curing agent.
APHA color number 20#, viscosity 3000CP. The temperature is high at 100 ℃ for 72 hours, and the color number is increased to 25#; the color number is increased to 28# after the storage for 1 year at normal temperature.
Example 3
0.5KG of a mixture containing 30% of 2, 2-diphenylmethane diisocyanate, 50% of 2, 4-diphenylmethane diisocyanate, 20% of 4, 4-diphenylmethane diisocyanate and 60ppm of chloromethylquinoline. The mixture enters a rectifying tower, the temperature of the tower bottom of the rectifying tower is controlled at 180 ℃, the tower top pressure is controlled at 0.5kPaA, the tower top reflux ratio is controlled at 55%, the side stream extraction mass ratio is controlled at 90% by taking the feeding mass as a reference, the side stream extraction mass ratio is controlled at 5% by taking the feeding mass as a reference, the side stream extraction intermediate is tested, the chloromethylquinoline content is 3ppm, and the final product is obtained after the antioxidant 800ppm BHT is added.
140g of diphenylmethane diisocyanate composition product, 20g of a mixture of trimethylolpropane (mass ratio of the two: 7:1) and 0.1g of catalyst were mixed. Sequentially adding the materials into a 250mL flask, controlling the material reaction temperature to be 75 ℃ and the reaction time to be 4 hours; and (3) curing after the reaction, controlling the curing temperature to be 80 ℃ and curing time to be 2 hours to obtain the curing agent.
APHA color No. 15#, viscosity 3000CP. The temperature is high at 100 ℃ for 72 hours, and the color number is increased to 15#; the color number is increased to 18# after the storage for 1 year at normal temperature.
Example 4
0.5KG of a mixture containing 28% of 2, 2-diphenylmethane diisocyanate, 52% of 2, 4-diphenylmethane diisocyanate, 20% of 4, 4-diphenylmethane diisocyanate and 60ppm of chloromethylquinoline. The mixture enters a rectifying tower, the temperature of the tower bottom of the rectifying tower is controlled at 170 ℃, the tower top pressure is controlled at 1.0kPaA, the tower top reflux ratio is controlled at 50%, the side stream extraction mass ratio is controlled at 88% by taking the feeding mass as a reference, the side stream extraction mass is controlled at 7% by taking the feeding mass as a reference, the side stream extraction intermediate is tested to obtain the final product after the chloromethylquinoline content is 1ppm and the antioxidant 800ppm BHT is added.
140g of diphenylmethane diisocyanate composition product, 20g of a mixture of trimethylolpropane (mass ratio of the two: 7:1) and 0.1g of catalyst were mixed. Sequentially adding the materials into a 250mL flask, controlling the material reaction temperature to be 75 ℃ and the reaction time to be 4 hours; and (3) curing after the reaction, controlling the curing temperature to be 80 ℃ and curing time to be 2 hours to obtain the curing agent.
APHA color number 14#, viscosity 2600CP. The temperature is high at 100 ℃ for 72 hours, and the color number is increased to 16#; the color number is increased to 17# after the storage for 1 year at normal temperature.
Example 5
0.5KG of a mixture containing 25% of 2, 2-diphenylmethane diisocyanate, 45% of 2, 4-diphenylmethane diisocyanate, 30% of 4, 4-diphenylmethane diisocyanate and 60ppm of chloromethylquinoline. The mixture enters a rectifying tower, the temperature of the tower bottom of the rectifying tower is controlled at 210 ℃, the tower top pressure is controlled at 0.1kPaA, the tower top reflux ratio is controlled at 80%, the side stream extraction mass ratio is controlled at 94% by taking the feeding mass as a reference, the overhead fraction extraction mass is controlled at 1% by taking the feeding mass as a reference, the side stream extraction intermediate product is tested to have the chloromethyl quinoline content of 10ppm, and the final product is obtained after the antioxidant of 800ppm BHT is added.
140g of diphenylmethane diisocyanate composition product, 20g of a mixture of trimethylolpropane (mass ratio of the two: 7:1) and 0.1g of catalyst were mixed. Sequentially adding the materials into a 250mL flask, controlling the material reaction temperature to be 75 ℃ and the reaction time to be 4 hours; and (3) curing after the reaction, controlling the curing temperature to be 80 ℃ and curing time to be 2 hours to obtain the curing agent.
APHA color No. 30#, viscosity 3000CP. The temperature is high at 100 ℃ for 72 hours, and the color number is increased to 41#; the color number is increased to 45# after the storage for 1 year at normal temperature.
Comparative example 1
Compared to example 1, the difference is that chloromethylquinoline is not distilled off.
140g of a mixture containing 25%2, 2-diphenylmethane diisocyanate, 55%2, 4-diphenylmethane diisocyanate, 20%4, 4-diphenylmethane diisocyanate, and 60ppm chloromethylquinoline, and 800ppm BHT as an antioxidant. A mixture with 20g of trimethylolpropane (mass ratio of the two 7:1) and 0.1g of catalyst. Sequentially adding the materials into a 250mL flask, controlling the material reaction temperature to be 75 ℃ and the reaction time to be 4 hours; and (3) curing after the reaction, controlling the curing temperature to be 80 ℃ and curing time to be 2 hours to obtain the curing agent.
As can be seen from the comparison of the above examples and comparative examples, the present invention can prepare a curing agent with a light color number by controlling chloromethylquinoline through rectification, and the color number of the curing agent is still stable after high-temperature degradation and long-term storage.
Claims (8)
1. A light-colored diphenylmethane diisocyanate composition having a stable color number during storage, characterized in that the chloromethylquinoline content of the composition is from 1 to 10ppm based on the total mass of the composition;
the chloromethyl quinoline content in the diphenylmethane diisocyanate composition was controlled by rectification.
2. The composition according to claim 1, wherein the chloromethylquinoline content in the composition is 3 to 5ppm based on the total mass of the composition.
3. The composition according to claim 1 or 2, wherein the diphenylmethane diisocyanate in the composition comprises 25% to 30%2, 2' -diphenylmethane diisocyanate, 45% to 55%2, 4' -diphenylmethane diisocyanate, 15% to 30%4, 4' -diphenylmethane diisocyanate.
4. Composition according to claim 1 or 2, characterized in that the chloromethylquinoline has the following structure:
5. a process for preparing the diphenylmethane diisocyanate composition of any of claims 1 to 4, wherein the content of chloromethylquinoline in the diphenylmethane diisocyanate composition is controlled by rectification.
6. The method according to claim 5, wherein the rectification process conditions are: the temperature of the tower kettle is controlled at 150-210 ℃;
and/or, controlling the tower top pressure to be 0.1-3.0kPaA, and controlling the tower top reflux ratio to be 20-80%;
and/or controlling the side offtake mass ratio to be 80-94% based on the feed mass;
and/or controlling the mass ratio of the overhead fraction produced to be 1-15% based on the mass of the feed.
7. The method according to claim 6, wherein the rectification process conditions are: the temperature of the tower kettle is controlled to be 170-190 ℃;
and/or, controlling the tower top pressure to be 0.1-1.0kPaA, and controlling the tower top reflux ratio to be 50-60%;
and/or controlling the side offtake mass ratio to be 88-92% based on the feed mass;
and/or controlling the mass ratio of the overhead fraction produced to be 3-7% based on the mass of the feed.
8. Use of a diphenylmethane diisocyanate composition according to any one of claims 1 to 4, or a diphenylmethane diisocyanate composition prepared by the preparation method according to any one of claims 5 to 7, for preparing an isocyanate curing agent or polyurethane article which is light in color and stable in color number during storage.
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| WO2003027156A1 (en) * | 2001-09-25 | 2003-04-03 | Dainippon Printing Co., Ltd. | Alkali-soluble maleimide copolymer and liquid crystal display comprising the same |
| WO2006072828A2 (en) * | 2005-01-07 | 2006-07-13 | Pfizer Products Inc. | Heteroaromatic quinoline compounds and their use as pde10 inhibitors |
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| CN103881050B (en) * | 2014-02-11 | 2016-02-24 | 万华化学集团股份有限公司 | A kind of preparation method of light polyisocyanate curing agent |
| JP2017088641A (en) * | 2015-11-02 | 2017-05-25 | 三菱化学株式会社 | Method for producing polycarbonate diol |
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| CN107827832B (en) * | 2017-11-22 | 2020-04-10 | 万华化学集团股份有限公司 | Method for preparing IPDI-based polyisocyanate curing agent |
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