CN118359791A - Hexamethylene diisocyanate composition stable in long-period storage - Google Patents

Abstract

The present invention relates to a long-period storage-stable hexamethylene diisocyanate composition comprising hexamethylene diisocyanate and 0.1 to 500ppm of a halogenated double bond compound. The hexamethylene diisocyanate composition provided by the invention has a storage time of more than 18 months, and the quality of the product is at a good level or above through the Tyndall test of the sample.

Description

Hexamethylene diisocyanate composition stable in long-period storage

Technical Field

The invention relates to the technical field of isocyanate, in particular to a hexamethylene diisocyanate composition with long-period storage stability.

Background

Hexamethylene diisocyanate, which is an aliphatic isocyanate, is generally obtained industrially by reacting hexamethylenediamine with phosgene, and is particularly advantageously carried out in the gas phase. The hexamethylene diisocyanate has higher reactivity due to the isocyanate groups, the product gradually polymerizes with the prolongation of time in the storage process, and even gel precipitation occurs in severe cases, so that the downstream normal use of the product is affected, and particularly, the storage time exceeds 18 months.

It is known to improve isocyanate stability by adding stabilizers. As disclosed in japanese patent JPS50101344a, organic tertiary amines as MDI stabilizers are effective in preventing color number increases; japanese patent JP2004099523 discloses the stabilization of polymeric MDI by tetraalkoxysilanes; chinese patent CN108003072a discloses that acyl-containing compounds can improve the storage stability of XDI. The stabilizing effect of the stabilizers of the abovementioned patent on hexamethylene diisocyanate is generally, especially during long-term storage, and it is still difficult to avoid the abovementioned problems.

Chinese patent CN113072512A discloses a preparation method of polyisocyanate, and the polyisocyanate synthesized by taking the polyisocyanate as a raw material has the characteristic of small turbidity change in the storage process by controlling the content of dichlorohexyl isocyanate in 1, 6-hexamethylene diisocyanate to be less than or equal to 60 mg/kg. This patent gives a means of improving the storage stability of the polyisocyanate product, but does not give a means of improving the stability of the 1, 6-hexamethylene diisocyanate itself.

Chinese patent CN115716906 discloses a hexamethylene diisocyanate composition, wherein the content of cyclic compounds is controlled to be 0.2-500ppm, and thus a polyisocyanate product with low color can be prepared from the composition. This patent gives a method of how to improve the color number, but does not give a teaching of achieving stable long-term storage of hexamethylene diisocyanate.

Disclosure of Invention

In view of the shortcomings of the prior art, the invention provides a hexamethylene diisocyanate composition which is stable in long-period storage, and when the hexamethylene diisocyanate composition is stored for more than 18 months, the Tyndall test of a sample is at a good level or above.

To achieve the purpose, the invention adopts the following technical scheme:

A hexamethylene diisocyanate composition comprising hexamethylene diisocyanate and 0.1 to 500ppm, preferably 0.1 to 450ppm, more preferably 0.2 to 200ppm, still more preferably 0.4 to 100ppm of a halogenated double bond compound based on the weight of the composition; the halogenated double bond compound comprises any one or a combination of at least two of the following compounds:

wherein X represents halogen which is Cl or Br; s is an integer of 1 or 2; m is an integer from 1 to 4; n and P are integers of 1 to 3; It is indicated that halogen X may replace hydrogen in any position within this group, namely: the repeating unit is CH ₂, and X can replace at least any one H of (CH ₂) p or (CH ₂) s.

Preferably, the halogenated double bond compound (I) is selected from one or more of the following specific structural materials:

preferably, the halogenated double bond compound (II) is selected from one or more of the following specific structural substances:

preferably, the halogenated double bond compound (iii) is selected from one or more of the following specific structural materials:

preferably, the halogenated double bond compound (IV) is selected from one or more of the following specific structural materials:

preferably, the halogenated double bond compound (v) is selected from one or more of the following specific structural substances:

The preparation method of the hexamethylene diisocyanate has no specific requirement and can be obtained by any realizable mode in the prior art.

For example, the invention can be realized by the following scheme:

scheme one: directly adding a compound containing the above structure to hexamethylene diisocyanate;

Scheme II: and (3) adding amine compounds corresponding to the structural compounds into hexamethylenediamine, and performing phosgenation reaction to obtain the hexamethylene diisocyanate composition product with the specification.

In some embodiments of the present invention, the second embodiment is employed, and thus one of the preparation methods of the hexamethylene diisocyanate composition of the present invention is to limit the content of the amine compound corresponding to the halogenated double bond compound in the raw hexamethylenediamine to 0.1ppm or more, and the upper limit may be higher than 500ppm. After the amine compound is added, the amine group is converted into an isocyanate group after phosgenation, and the content of the isocyanate group can reach a target interval through a subsequent product refining system, so that the hexamethylene diisocyanate composition is obtained.

According to the Tyndall effect test, microparticles which are not easy to observe in a sample, particularly microparticles with the diameter of 1-100 mu m, can be timely found, so that the quality condition of the sample is timely known at the initial stage of quality change, and the stability of the sample is pre-judged in advance.

As a specific implementation method, the tyndall effect test method is as follows:

1) Weighing 18+ -0.5 g of hexamethylene diisocyanate composition, placing into a 20ml transparent glass bottle, and sealing with nitrogen;

2) Standing the sample obtained in the step 1) for more than 30 min;

3) The middle part of the sample bottle is irradiated by an LED strong light beam visible light source at a position 3-5cm away from the sample bottle; observing the flash points in the sample, wherein the existence of the flash points has the Tyndall effect, and the more the flash points in the sample are, the stronger the Tyndall effect is, and the poorer the storage stability of the sample is.

The judgment standard of the intensity of the Tyndall effect is as follows:

1) The number of flash points is less than or equal to 5, and the product grade is excellent;

2) The number of the flash points is more than 5 and less than or equal to 20, and the product grade is good;

3) The number of flash points is more than 20 and less than or equal to 50, and the product grade is general;

4) The number of flash points is greater than 50 and the product grade is poor.

The invention has the beneficial effects that:

The hexamethylene diisocyanate composition of the present invention having a halogenated double bond compound content of 0.1 to 500ppm has a storage time of 18 months, a good and superior product quality level through the tyndall test of the sample, and has excellent long-period storage stability.

Detailed Description

The invention is further illustrated below in connection with the examples, but the invention is not limited to the examples listed but encompasses any other known modifications within the scope of the claimed invention.

Raw materials and sources:

hexamethylene diisocyanate, wanhua chemical group Co., ltd., purity 99.99%;

Hexamethylenediamine is an industrial grade product of inflight;

phosgene is self-produced by Wanhua chemical group Co., ltd;

FCH Group Reagents for synthesis, purity 98%; FCH Group Reagents for synthesis, purity 98%; Purity 97.5%, CHEMIELIVA PHARMACEUTICAL co., ltd; purity 97%, CHEMIELIVA PHARMACEUTICAL co., ltd; Purity 97%, CHEMIELIVA PHARMACEUTICAL co., ltd.

The test of halogenated double bond compounds in hexamethylene diisocyanate compositions in the following examples and comparative examples was carried out by gas chromatography. Firstly, determining different retention times of the halogenated double bond-containing compound components in gas chromatography by gas chromatography, wherein the content is obtained by adopting an area normalization method, and the testing method is as follows:

The analytical instrument is Agilent 7890B; the chromatographic column model is DB-5 (30 m multiplied by 0.25mm multiplied by 0.25 um); the detector is an FID detector; the temperature of the sample inlet is 260 ℃; the detector temperature was 300 ℃; the temperature program is that the temperature is increased from 50 ℃ to 90 ℃ at 10 ℃/min, kept for 2min, increased to 180 ℃ at 15 ℃/min, kept for 2min, increased to 280 ℃ at 20 ℃/min, and kept for 15min; the sample injection amount is 0.2ul.

The method for testing the tyndall effect of the hexamethylene diisocyanate composition is as follows:

1) Weighing 18+ -0.5 g of hexamethylene diisocyanate composition, placing into a 20ml transparent glass bottle, and sealing with nitrogen;

2) Standing the sample in the step 1) for 30min;

3) The middle part of the sample bottle is irradiated by an LED strong light beam visible light source (SupFire X-R strong light flashlight) at a position 5cm away from the sample bottle;

4) The more flash points in the sample, the stronger the tyndall effect, the poorer the sample storage stability.

The judgment standard of the intensity of the Tyndall effect is as follows:

1) The number of flash points is less than or equal to 5, and the product grade is excellent;

2) The number of the flash points is more than 5 and less than or equal to 20, and the product grade is good;

3) The number of flash points is more than 20 and less than or equal to 50, and the product grade is medium;

4) The number of flash points is greater than 50 and the product grade is poor.

Examples and comparative sample preparation

Hexamethylene diisocyanate compositions of varying amounts of halogenated double bond compounds were prepared.

Using hexamethylene diisocyanate (without halogenated double bond compound, sample 7) with purity of 99.99% as raw material,

AddingThe content was 0.6ppm (sample 1) and 98ppm (sample 2), respectively;

Adding Content 0.3ppm (sample 3);

Adding Content 0.1ppm (sample 4);

Adding The content was 184ppm (sample 5) and 670ppm (sample 8), respectively;

Adding The content was 427ppm (sample 6).

Examples 1 to 6

Examples 1 to 6 were subjected to the tyndall test after long-period storage (sample nitrogen-sealed and stored at room temperature) using the above samples 1 to 6.

Comparative example 1, comparative example 2

Comparative examples 1 and 2 were subjected to the tyndall test after long-period storage (sample nitrogen-sealed and stored at room temperature) using sample 7 and sample 8, respectively.

The results of the above examples and comparative examples are shown in the following table.

Note that: the numbers in the results are the number of flash points of the sample during the Tyndall test, and the characters are described as the quality grade of the product.

According to the Tyndall test results after long-period storage of the samples 1 to 6 in the data in the table, the flash point in the samples, namely the number of microparticles with the diameter of 1-100 μm in the samples is far less than that of the samples 7 and 8, fewer microparticles are formed, and the stable storage period of the samples is greatly improved.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and additions may be made by those skilled in the art without departing from the invention, which modifications and additions are also to be considered as within the scope of the invention.

Claims (9)

1. A hexamethylene diisocyanate composition, characterized in that the hexamethylene diisocyanate composition comprises hexamethylene diisocyanate and 0.1 to 500ppm of a halogenated double bond compound; the halogenated double bond compound comprises any one or at least two of the following compounds:

Wherein X represents halogen which is Cl or Br;

s is an integer of 1 or 2; m is an integer from 1 to 4; n and P are integers of 1 to 3;

it means that halogen X can replace any hydrogen in this group.

2. The composition of claim 1 wherein the halogenated double bond compound is present in an amount of 0.1 ppm to 450ppm.

3. The composition of claim 1 wherein the halogenated double bond compound is present in an amount of 0.2 ppm to 200ppm.

4. The composition of claim 1 wherein the halogenated double bond compound is present in an amount of 0.4 to 100ppm.

5. The composition of claim 1, wherein the halogenated double bond compound (i) is selected from one or more of the following specific structural materials:

6. The composition of claim 1, wherein the halogenated double bond compound (ii) is selected from one or more of the following specific structural materials:

7. The composition of claim 1, wherein the halogenated double bond compound (iii) is selected from one or more of the following specific structural materials:

8. the composition of claim 1, wherein the halogenated double bond compound (iv) is selected from one or more of the following specific structural materials:

9. The composition according to claim 1, wherein the halogenated double bond compound (v) is selected from one or more of the following specific structural substances: