Composition and method for prolonging shelf life of liquid MDI product

Abstract

The invention discloses a composition and a method for prolonging the shelf life of a liquid MDI product. The composition comprises (a) diphenylmethane diisocyanate (MDI), (b) at least one organophosphoric acid derivative with a structure shown in a formula (I), and (c) at least one metal carbonyl compound with a structure shown in a formula (II). The method provided by the invention can inhibit the formation of the MDI dimer, and especially prominently, can improve the solubility of the MDI dimer in a liquid MDI product, reduce the freezing point of the liquid MDI product, prolong the storage life of the liquid MDI product, and improve the storage and transportation stability and operation convenience of the liquid MDI product.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane, and in particular relates to a composition and method for extending the shelf life of a liquid MDI product. Background Art

[0002] MDI-100, or 4,4'-diphenylmethane diisocyanate, is an important chemical raw material widely used in the manufacture of polyurethane elastomers, adhesives, sealants, coatings, and high-resilience foams. However, MDI-100 faces several challenges during use, the most prominent of which is the formation of dimers. Dimers are cyclic compounds formed by self-polymerization during storage or use. Their presence can lead to a decrease in the active ingredients in MDI-100, reducing its activity, increasing its depolymerization temperature, and even the formation of white insoluble matter during melting. These phenomena not only affect the storage stability of MDI-100 but also seriously affect the quality of polyurethane products. When the dimer content is high, the partial precipitation of dimer can lead to reduced mechanical properties and a poor appearance of polyurethane products, and may even cause cracking and shedding.

[0003] To ensure the storage and transportation stability of MDI-100, it is generally stored and transported in solid form below -5°C or in liquid form around 45°C. Although the shelf life in solid form can reach 6 months, the cumbersome chemical steps reduce the production efficiency of downstream applications and are inconvenient for customers to use. In addition, solid MDI-100 is shipped in barrels, which also poses transportation difficulties when exported overseas. Therefore, MDI-100 is more often stored and transported in liquid form. Due to the impact of the above-mentioned dimer formation on product quality, the shelf life of liquid MDI-100 is only 10 days. Therefore, it is necessary to provide methods to reduce the impact of dimers on MDI-100 and extend its shelf life.

[0004] Chinese invention CN101003498A provides a method for reducing the impurity content by first distillation and then crystallization to obtain high-purity diphenylmethane diisocyanate, effectively reducing the initial dimer content and thus extending the storage period of MDI-100. However, this method does not reduce the dimer formation rate and has limited effect on improving the shelf life.

[0005] Chinese invention CN109180531A provides a method for obtaining an MDI-50 product with an extended shelf life by controlling the isomer ratio and adding a stabilizer. This method achieves an extended shelf life by controlling the isomer ratio in the distillation column, reducing dimer formation in the high-temperature section, and adding a benzoquinone stabilizer during storage. Benzoquinone stabilizers are yellow solids, and their addition to MDI changes its color, affecting downstream applications.

[0006] Chinese invention CN101195675A provides a method for producing an isocyanate product that is storage-stable at room temperature by reacting a diisocyanate with an unsaturated enol by adding a catalyst. This method primarily targets allophanate-modified isocyanates containing reactive unsaturated groups, modifying the composition of the MDI product.

[0007] Currently known methods for stabilizing the quality of MDI products mainly include modifying MDI and adding stabilizers during the photochemical or separation process to improve the quality and performance of its downstream products.

[0008] The current production process for liquid MDI-100 involves separating high-purity 4'4-MDI from crude MDI. This is then mixed with antioxidants in a storage tank, then transported to a heated tank truck. The tank temperature is maintained at 45°C during transport. Once delivered to the customer's site, the product is placed in an insulated tank for storage and immediate use. While liquid MDI-100 is easy to use, its short shelf life limits its transportation range.

[0009] Therefore, it is necessary to provide an MDI composition that extends the shelf life of the product or a method to reduce the formation of MDI dimers and increase the shelf life of liquid MDI-100 products. Summary of the Invention

[0010] The present invention aims to address the problem of a short shelf life of liquid MDI-100 products in the prior art due to the rapid growth rate and easy precipitation of dimers. The present invention utilizes an added additive to hinder the stability of the dimer intermediate, thereby inhibiting the dimer formation rate. After repeated research, the present inventors unexpectedly discovered that by detecting the content and growth rate of MDI dimers during storage using a Fourier transform near-infrared spectrometer, adding an organophosphate derivative and a metal carbonyl compound, and strictly controlling the storage temperature to between 36°C and 39°C, the dimer formation rate is slowed and the saturated solubility of the dimer in MDI is increased. Furthermore, crystallization experiments unexpectedly revealed that this method can lower the freezing point of MDI and increase the operating margin of the liquid MDI-100 product, thereby providing a liquid MDI-100 product with a long shelf life and ease of operation.

[0011] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0012] A composition for extending the shelf life of a liquid MDI product, comprising:

[0013] (a) diphenylmethane diisocyanate (MDI); and

[0014] (b) an organic phosphoric acid derivative comprising at least one structure of formula (I):

[0015]

[0016] wherein X and X' are each independently C or O, and R1 is selected from H or OH; and

[0017] (c) a metal carbonyl compound comprising at least one metal carbonyl compound of formula (II):

[0018] Y m (CO) n (Ⅱ)

[0019] Wherein, m is an integer of 1-6, and n is an integer of 4-16.

[0020] In a specific embodiment, in the organophosphate derivative of formula (I), X and X' are both C; or X and X' are both O; or X is C and X' is O; or X is O and X' is C, preferably X and X' are both O; and / or

[0021] In the metal carbonyl compound of the formula (II), Y is a transition metal element, m is a natural number of 1-6, and n is a natural number of 4-16.

[0022] In a specific embodiment, the organic phosphoric acid derivative of formula (I) does not contain any other heteroatoms as members of the phosphorus-oxygen double bond structure, that is, based on the conventional elements C and H in organic compounds, there are no other heteroatoms except phosphorus and oxygen.

[0023] In a specific embodiment, in addition to the structure of formula (I), the organic phosphoric acid derivative is replaced by 1-2 groups selected from C2-C 18 Alkyl, C2-C 18 Substituted by a haloalkyl, phenyl or benzyl group, wherein the C2-C 18 Alkyl, C2-C 18 The alkyl moiety of a haloalkyl, phenyl or benzyl group may be interrupted by a non-adjacent -O- group.

[0024] In a specific embodiment, the organophosphoric acid derivative is selected from any one or more of di(2-ethylhexyl)phosphate, tris(3-chloropropyl)phosphate, 2-ethylhexyl 2-ethylhexyl phosphate, di(2,4,4-trimethylpentyl)phosphinic acid, diphenyl phosphite, dibenzyl phosphite, diethyl phosphite, diisopropyl phosphite, diisobutyl phosphite, di-tert-butyl phosphite, diisooctyl phosphite, didodecyl phosphite, bis(2-ethylhexyl)phosphite, bis(2,2,2-trifluoroethyl)phosphite, and tris(2,2,2-trifluoroethyl)phosphite;

[0025] Preferably, the organic phosphoric acid derivative comprises diethyl phosphite and 2-ethylhexyl phosphate, or comprises tris(2,2,2-trifluoroethyl)phosphite and di(2,4,4-trimethylpentyl)phosphinic acid.

[0026] In a specific embodiment, the metal Y in the metal carbonyl compound is a transition metal, preferably one or more of tungsten, nickel, osmium, iron, chromium, etc., preferably nickel;

[0027] Preferably, the metal carbonyl compound is selected from one or more of tungsten hexacarbonyl, nickel tetracarbonyl, osmium pentacarbonyl, iron pentacarbonyl, and chromium hexacarbonyl, more preferably nickel tetracarbonyl.

[0028] In a specific embodiment, the organophosphoric acid derivative is present in an effective amount to stabilize diphenylmethane diisocyanate (MDI), preferably in an amount of 100 ppm to 5000 ppm, preferably in a range of 300 ppm to 1000 ppm based on the total weight of the composition.

[0029] In a specific embodiment, the metal carbonyl compound is present in an effective amount to stabilize diphenylmethane diisocyanate (MDI), preferably in an amount of 1 ppm to 500 ppm, preferably in a range of 10 ppm to 100 ppm, based on the total weight of the composition.

[0030] In a specific embodiment, the diphenylmethane diisocyanate (MDI) is liquid MDI-100;

[0031] Preferably, the storage temperature of the liquid MDI-100 product is 33°C-55°C, preferably 36°C-39°C;

[0032] More preferably, the liquid MDI-100 product is prepared via a phosgenation process or via a non-phosgenation process.

[0033] On the other hand, a method for extending the shelf life of a liquid MDI product comprises the steps of adding the aforementioned organophosphate derivative and metal carbonyl compound to the liquid MDI product to form the aforementioned composition for extending the shelf life of the liquid MDI product, preferably adding the organophosphate derivative and metal carbonyl compound to the liquid MDI product during storage or transportation.

[0034] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0035] 1) The present invention simultaneously adds an organophosphate derivative and a metal carbonyl compound to a liquid MDI-100 product. The combined use of the two additives reduces the dimer formation rate in the liquid MDI-100 product while increasing the solubility of the dimer in the liquid MDI-100 product, thereby preventing its rapid precipitation and product deterioration. Furthermore, the present invention unexpectedly reduces the crystallization point of the liquid MDI-100 product, optimizes the insulation temperature during storage and transportation, further reduces the dimer formation rate in the liquid MDI-100 product, and reduces energy consumption during storage and transportation of the liquid MDI-100 product. Furthermore, due to the lowered freezing point of MDI-100, coagulation or precipitation of insoluble matter during loading, unloading, and use can be avoided, thereby improving the operational convenience for customers when receiving and using the product.

[0036] 2) The novelty of this invention lies in the inhibition of the MDI dimerization reaction by the addition of an organophosphate derivative and a metal carbonyl compound, thereby reducing its formation rate. This is because the MDI dimerization reaction contains an ionic intermediate. By complexing with the metal carbonyl compound, the energy barrier of the dimerization reaction is increased, causing the reaction to reverse and dissociate into MDI monomers, making the dimerization reaction more difficult. The addition of the organophosphate derivative also promotes the complexation of the MDI dimerization intermediate with the metal carbonyl compound, increasing the dissociation rate.

[0037] 3) The present invention directly adds an organophosphate derivative and a metal carbonyl compound to a liquid MDI-100 product. After addition, the organic phosphoric acid derivative and the metal carbonyl compound have good compatibility and do not affect the color of the liquid MDI-100 product. At the same time, the added organic phosphoric acid derivative and the metal carbonyl compound do not react with MDI and the antioxidant therein. The invention is applicable to MDI-100 products of different brands and other liquid pure MDI products, and can achieve the above-mentioned effect of extending the shelf life without affecting the application performance and application field of MDI. DETAILED DESCRIPTION

[0038] In order to better further understand the present invention, the present invention provides the following embodiments, which do not limit the content and protection scope of the present invention. Any product that is identical or similar to the present invention and is obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0039] The composition for extending the shelf life of liquid MDI products of the present invention is applicable to all liquid pure MDI products, such as liquid MDI-100, liquid MDI-50, etc., and is described in detail below using liquid MDI-100 as an example.

[0040] A composition for extending the shelf life of a liquid MDI product, comprising:

[0041] (a) diphenylmethane diisocyanate (MDI), and

[0042] (b) an organic phosphoric acid derivative comprising at least one structure of formula (I) as a phosphorus-oxygen double bond structural portion:

[0043]

[0044] wherein X and X' are each independently C or O, and R1 is selected from H, OH; and

[0045] and (c) a metal carbonyl compound comprising at least one structure of formula (II) as a complex structure of a zero-valent transition metal and a carbon monoxide (CO) molecule:

[0046] Y m (CO) n (Ⅱ)

[0047] Wherein, the metal Y is a transition metal element, m is an integer of 1-6, and n is an integer of 4-16.

[0048] In the structure of formula (I) of the organophosphate derivative of the present invention, X and X' are both C; or X and X' are both O; or X is C and X' is O; or X is O and X' is C, preferably X and X' are both O. In the structure of formula (II) of the metal carbonyl compound, Y is a transition metal element, such as tungsten, nickel, osmium, iron, chromium, etc., m is a number from 1 to 6, such as 1, 2, 3, 4, 5, 6, etc., and n is a number from 4 to 16, such as 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, etc.

[0049] Furthermore, in the structure of formula (I) of the organophosphoric acid derivative of the present invention, R1 is H or OH.

[0050] Furthermore, in the present invention, except for the P and O heteroatoms in the structure of formula (I), the organophosphoric acid derivative does not contain any other heteroatoms as members of the phosphorus-oxygen double bond structure.

[0051] Furthermore, in addition to the structure of formula (I), the organic phosphoric acid derivative is replaced by 1-2 groups selected from C2-C 18 Alkyl, C2-C 18 Substituted by a haloalkyl, phenyl or benzyl group, wherein the C2-C 18 Alkyl, C2-C 18 The alkyl moiety of a haloalkyl, phenyl or benzyl group may be interrupted by a non-adjacent -O- group.

[0052] In the context of the present disclosure, the organic moieties mentioned in the definitions of the variables are collective terms like the term halogen for individual enumerations of the individual group members.n -C m In each case it indicates the possible number of carbon atoms in the group.

[0053] "Halogen" or "halo" refers to fluorine, chlorine, bromine and iodine.

[0054] The term "C2-C 18 "Alkyl" (preferably C2-C8 alkyl) refers to a branched or unbranched saturated hydrocarbon group having 2 to 18 carbon atoms, such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl and the like hydrocarbon groups and isomers thereof.

[0055] The term "C2-C 18 "Haloalkyl" (preferably C2-C8 haloalkyl) refers to a straight-chain or branched alkyl group having 2 to 18 carbon atoms (as described above), wherein some or all of the hydrogen atoms in these groups may be replaced by the above-mentioned halogen atoms, for example, chloroethyl, bromoethyl, 1-fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl and the like halogen-substituted hydrocarbon groups and their isomers.

[0056] Furthermore, the organophosphoric acid derivative in the present invention is selected from di(2-ethylhexyl)phosphate, tris(3-chloropropyl)phosphate, 2-ethylhexyl 2-ethylhexyl phosphate, di(2,4,4-trimethylpentyl)phosphinic acid, diphenyl phosphite, dibenzyl phosphite, diethyl phosphite, diisopropyl phosphite, diisobutyl phosphite, di-tert-butyl phosphite, diisooctyl phosphite, didodecyl phosphite, bis(2-ethylhexyl)phosphite, bis(2,2,2-trifluoroethyl)phosphite, tris(2,2,2-trifluoroethyl)phosphite or a mixture thereof.

[0057] The metal carbonyl compound in the present invention is selected from tungsten hexacarbonyl, nickel tetracarbonyl, osmium pentacarbonyl, iron pentacarbonyl, chromium hexacarbonyl or a mixture thereof, preferably nickel tetracarbonyl.

[0058] Furthermore, the composition of the present invention comprises an organophosphoric acid derivative (i) in which R1 is H and an organophosphoric acid derivative (ii) in which R1 is OH, preferably comprising diethyl phosphite as the organophosphoric acid derivative (i) and 2-ethylhexyl 2-ethylhexyl phosphate as the organophosphoric acid derivative (ii), or comprising tris(2,2,2-trifluoroethyl)phosphite as the organophosphoric acid derivative (i) and di(2,4,4-trimethylpentyl)phosphinic acid as the organophosphoric acid derivative (ii).

[0059] Specific examples of the organophosphoric acid derivatives may include:

[0060]

[0061] Specific examples of the metal carbonyl compound may include:

[0062]

[0063] The organophosphoric acid derivative in the present invention is present in an effective amount to stabilize the liquid MDI-100 (taking liquid MDI-100 as an example) product. Preferably, the amount of the organophosphoric acid derivative is 100 ppm to 5000 ppm, for example, 100 ppm, 200 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, 900 ppm, 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm, 3000 ppm, 3500 ppm, 4000 ppm, 4500 ppm, 5000 ppm, etc., based on the total weight of the composition, preferably in the range of 300 ppm to 1000 ppm.

[0064] The metal carbonyl compound in the present invention is present in an effective amount to stabilize the liquid MDI-100 (taking liquid MDI-100 as an example) product. Preferably, the amount of the metal carbonyl compound is 1 ppm to 500 ppm, based on the total weight of the composition, for example, 1 ppm, 3 ppm, 5 ppm, 8 ppm, 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, etc., especially in the range of 10 ppm to 100 ppm.

[0065] Furthermore, the storage temperature of the liquid MDI-100 product of the present invention is 33°C-55°C, for example, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 1°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, etc., preferably 36°C-39°C, which may be lower than 45°C controlled by the conventional method of liquid MDI-100 in the prior art; the method of the present invention can be controlled within a lower temperature range, thereby extending the shelf life while reducing energy consumption.

[0066] The liquid MDI-100 product of the present invention is prepared by a phosgenation method or a non-phosgenation method. The preparation method thereof can refer to the prior art. This is not the key point of the present invention, and the preparation methods of the prior art can be introduced into the present invention.

[0067] Furthermore, the use of the organophosphate derivative and the metal carbonyl compound defined in any one of the items of the present invention in stabilizing an MDI-100 product is preferably to use the organophosphate derivative and the metal carbonyl compound to stabilize the liquid MDI-100 product during storage or transportation.

[0068] The present composition, comprising a special organophosphate derivative and a metal carbonyl compound, can reduce the rate of dimer formation in liquid MDI-100 products, increase the solubility of dimers in the liquid MDI-100 product, prevent the formation of insoluble solids, and extend the shelf life of the liquid MDI-100 product. In particular, the composition can lower the freezing point of MDI-100, preventing blockage and insoluble precipitation caused by crystallization during product handling and use.

[0069] The present invention will be further described below through specific examples. The examples of the present invention are only for illustration of the present invention and do not limit the scope of the present invention.

[0070] In the various embodiments and comparative examples of the present invention, the sources of the main raw materials are as follows. Unless otherwise specified, other raw materials and reagents were purchased through common commercial channels.

[0071] Fresh liquid MDI-100 product, taken from Wanhua Chemical's MDI unit;

[0072] Diethyl phosphite: Inokane, 99%;

[0073] Diphenyl phosphite: Inokane, 99%;

[0074] 2-Ethylhexyl phosphate: Inokane, 99%;

[0075] Tris(2,2,2-trifluoroethyl)phosphite: Adamas, 98%;

[0076] Di(2,4,4-trimethylpentyl)phosphinic acid: Adamas, 98%;

[0077] Di(2-ethylhexyl) phosphate: Macklin, 98%;

[0078] Nickel tetracarbonyl: MacLean, 98%;

[0079] Iron pentacarbonyl: Aladdin, 97%;

[0080] Chromium hexacarbonyl: Aladdin, 98%.

[0081] The main performance of the embodiment of the present invention is tested by the following method:

[0082] Dimer content: The test instrument is a PerkinElmer Spectrum Two infrared spectrometer. The test method is liquid cell quantitative analysis. Take 1g of MDI sample and dissolve it in 10g of dichloromethane for dilution. The sample is poured into the liquid cell and placed in the optical path. The test and data are recorded and processed. The data processing method is the ratio of the dimer characteristic peak to the NCO characteristic peak.

[0083] Product color / HAZEN: tested with BYK LCSIV instrument in accordance with the method specified in GB / T 605-2006.

[0084] Examples 1-6 and Comparative Examples 1-4

[0085] In Examples 1 to 7, an organophosphoric acid derivative and a metal carbonyl compound were used as components (b) and (c). Components (b) and (c) were added to a liquid MDI-100 product in the amounts shown in Table 1 to obtain the compositions of the present invention, which were then stored in an oven at the corresponding temperature.

[0086] Comparative Examples 1 and 2 were blank experiments, and no components (b) and (c) were added. In Comparative Example 3, component (b) was used alone. In Comparative Example 4, component (c) was used alone, and in Comparative Example 5, an inorganic phosphorus compound and component (c) were used. The three compositions of these comparative examples were stored in ovens at the corresponding temperatures. The compositions of Examples 1-7 and Comparative Examples 3-5, as well as the MDI-100 products of Comparative Examples 1-2, were stored at 39°C and 45°C. The initial dimer content in the liquid MDI-100 products, as well as the dimer content after 14 and 28 days, are also shown in Table 1.

[0087] Table 1 Storage experiment test results

[0088]

[0089]

[0090] As can be seen from Table 1, compared with Comparative Examples 1-4, which were stored at 45°C without or with only one additive or with an inorganic phosphorus-containing additive, the addition of the organophosphate derivative and metal carbonyl compound described herein to the MDI-100 product significantly reduced the growth rate of the dimer during storage at the conventional storage temperature of 45°C. If the storage temperature was further adjusted to 36-39°C, the growth rate of the dimer during storage was significantly reduced, and no turbidity was observed even after 28 days of storage. In addition, the inhibitory effect of the organophosphate derivative and metal carbonyl compound selected herein on the dimer reaction rate of MDI-100 is universal. With any combination of different additives, there was no significant difference in the dimer content in the samples after 14 and 28 days of storage, and both were far lower than the dimer content in the comparative examples.

[0091] The compositions of Examples 1-6 and Comparative Examples 2-4 and the MDI-100 product of Comparative Example 1 were placed in an oven and heated to 60° C. After removal, the freezing point of each sample was tested using a paperless recorder. The test method was in accordance with GB / T 13941-2015. The test results are shown in Table 2.

[0092] Table 2 Freezing point test results

[0093]

[0094] As can be seen from Table 2, the freezing points of the comparative examples without, with, or with either a single additive or an inorganic phosphorus-containing additive added are all identical to the 38.1°C stated in the TDS of Wanhua Chemical's MDI-100 series products. This indicates that the addition of either a single additive or an inorganic phosphorus-containing additive has no effect on the freezing point of the MDI-100 product. Furthermore, the test data in Examples 1-6 demonstrate that the combined addition of the organophosphate derivative and metal carbonyl compound described herein can effectively lower the freezing point of the MDI-100 product, thereby reducing storage temperature and improving operational convenience.

[0095] The compositions of Examples 1-6 and Comparative Examples 2-4 and the MDI-100 product of Comparative Example 1 were separately prepared and uniformly placed in an oven and degraded at 110° C. for 4 hours. After removal, the color number after degradation was measured using a colorimeter. The degradation and colorimetry testing methods were in accordance with GB / T 13941-2015. Separately, the degraded samples were uniformly placed at 45° C. for 1 day. The supernatant was filtered and diluted with dichloromethane. The dimer content in the samples was measured using an infrared spectrometer. The test results, i.e., the dimer saturation solubility of the samples at 45° C., were shown in Table 3.

[0096] Table 3 Deterioration color number and dimer saturation solubility test results

[0097]

[0098] As can be seen from Table 3, the color number increases after 4 hours of degradation at 110°C for Examples 1-6 and Comparative Example 1 were not significant and were similar, indicating that the combined addition of the organophosphate derivative and metal carbonyl compound described herein does not affect the initial color number or the degradation color number of the MDI-100 series products. However, as can be seen from Comparative Examples 3 and 4, the use of nickel tetracarbonyl alone or the addition of phosphoric acid both resulted in a significant increase in the degradation color number. This is because nickel tetracarbonyl reacts with the phosphite antioxidant under high temperature and acidic conditions, reducing the phosphite antioxidant content in the MDI-100 product, resulting in a poor antioxidant effect and a significant increase in color number. When metal carbonyl compounds are used in combination with organophosphate derivatives, the organophosphate derivatives can replace the phosphite antioxidant in the MDI-100 product, preventing product degradation and yellowing, which in turn affects the product's application range.

[0099] As can also be seen from Table 3, compared with Comparative Examples 1-4 in which no additive or only one additive was added or an inorganic phosphorus-containing additive was added and the product was stored at 45°C, the simultaneous addition of the organophosphoric acid derivative and the metal carbonyl compound described herein to the MDI-100 product can significantly increase the saturated solubility of the MDI-100 product for the dimer, thereby avoiding product turbidity caused by dimer precipitation.

[0100] In summary, the organophosphate derivative and metal carbonyl compound composition described herein can effectively reduce the dimer formation rate in MDI-100 and increase the dimer solubility in MDI-100, preventing dimer precipitation during prolonged storage that could affect normal product use. Furthermore, the composition significantly lowers the freezing point of MDI-100, facilitating handling during storage, transportation, and production, without affecting other MDI-100 specifications.

[0101] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A composition for extending the shelf life of a liquid MDI product, characterized in that: Include: (a) diphenylmethane diisocyanate (MDI); and (b) an organic phosphoric acid derivative comprising at least one structure of formula (I): wherein X and X' are each independently C or O, and R1 is selected from H or OH; and (c) a metal carbonyl compound comprising at least one metal carbonyl compound of formula (II): Y m (WHAT) n (Ⅱ) Wherein, m is an integer of 1-6, and n is an integer of 4-16.

2. The composition for extending the shelf life of liquid MDI products according to claim 1, characterized in that: In the organophosphate derivative of formula (I), X and X' are both C; or X and X' are both O; or X is C and X' is O; or X is O and X' is C, preferably X and X' are both O; and / or In the metal carbonyl compound of the formula (II), Y is a transition metal element, m is a natural number of 1-6, and n is a natural number of 4-16.

3. The composition for extending the shelf life of a liquid MDI product according to claim 1 or 2, characterized in that: The organic phosphoric acid derivative of formula (I) does not contain any heteroatom as a member of the phosphorus-oxygen double bond structure.

4. The composition for extending the shelf life of a liquid MDI product according to any one of claims 1 to 3, characterized in that: In addition to the structure of formula (I), the organic phosphoric acid derivative is replaced by 1-2 groups selected from C2-C 18 Alkyl, C2-C 18 Substituted by a haloalkyl, phenyl or benzyl group, wherein the C2-C 18 Alkyl, C2-C 18 The alkyl moiety of a haloalkyl, phenyl or benzyl group may be interrupted by a non-adjacent -O- group.

5. The composition for extending the shelf life of a liquid MDI product according to any one of claims 1 to 4, characterized in that: The organic phosphoric acid derivative is selected from any one or more of di(2-ethylhexyl) phosphate, tris(3-chloropropyl) phosphate, 2-ethylhexyl 2-ethylhexyl phosphate, di(2,4,4-trimethylpentyl)phosphinic acid, diphenyl phosphite, dibenzyl phosphite, diethyl phosphite, diisopropyl phosphite, diisobutyl phosphite, di-tert-butyl phosphite, diisooctyl phosphite, didodecyl phosphite, bis(2-ethylhexyl) phosphite, bis(2,2,2-trifluoroethyl) phosphite, and tris(2,2,2-trifluoroethyl) phosphite; Preferably, the organic phosphoric acid derivative comprises diethyl phosphite and 2-ethylhexyl phosphate, or comprises tris(2,2,2-trifluoroethyl)phosphite and di(2,4,4-trimethylpentyl)phosphinic acid.

6. The composition for extending the shelf life of a liquid MDI product according to any one of claims 1 to 5, characterized in that: The metal Y in the metal carbonyl compound is a transition metal; Preferably, the metal carbonyl compound is selected from one or more of tungsten hexacarbonyl, nickel tetracarbonyl, osmium pentacarbonyl, iron pentacarbonyl, and chromium hexacarbonyl, more preferably nickel tetracarbonyl.

7. The composition for extending the shelf life of a liquid MDI product according to any one of claims 1 to 6, characterized in that: The organic phosphoric acid derivative is present in an effective amount to stabilize diphenylmethane diisocyanate (MDI), preferably in an amount of 100 ppm to 5000 ppm, more preferably 300 ppm to 1000 ppm based on the total weight of the composition.

8. The composition for extending the shelf life of a liquid MDI product according to any one of claims 1 to 7, characterized in that: The metal carbonyl compound is present in an effective amount to stabilize diphenylmethane diisocyanate (MDI), preferably in an amount of 1 ppm to 500 ppm, preferably in a range of 10 ppm to 100 ppm, based on the total weight of the composition.

9. The composition for extending the shelf life of a liquid MDI product according to any one of claims 1 to 8, characterized in that: The diphenylmethane diisocyanate (MDI) is liquid MDI-100; Preferably, the storage temperature of the liquid MDI-100 product is 33°C-55°C, preferably 36°C-39°C; More preferably, the liquid MDI-100 product is prepared via a phosgenation process or via a non-phosgenation process.

10. A method for extending the shelf life of a liquid MDI product, characterized in that: The method comprises the steps of adding an organic phosphoric acid derivative and a metal carbonyl compound to a liquid MDI product to form a composition for extending the shelf life of a liquid MDI product as claimed in any one of claims 1 to 9, preferably adding the organic phosphoric acid derivative and the metal carbonyl compound to the liquid MDI product during storage or transportation.

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