Partial ammonia esterification modified polycarbodiimide anti-hydrolysis agent and application thereof

Abstract

The invention provides a partial amination modified polycarbodiimide anti-hydrolysis agent, the anti-hydrolysis agent comprises components (1), (2) and (3) with the following general formula structures, and the component (2) and the component (3) are generated by partial amination modification of the component (1) in the reaction process. According to the preparation method, the melting point of the product and the content of carbodiimide functional groups of the product are increased by utilizing an aromatic end group rigid structure, and the compatibility and the dissociation resistance of the hydrolysis-resistant agent product are improved by utilizing the interaction between an ammonia esterification modified reinforced molecular structure and a polyester or polyurethane material. The anti-hydrolysis agent has the characteristics of high carbodiimide functional group content, good compatibility and high activity, and is mainly used in the fields of polyurethane, polyester and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to a polycarbodiimide hydrolysis inhibitor, in particular to a polycarbodiimide hydrolysis inhibitor with partial urethane modification of the aliphatic polymer main skeleton, mainly used in the fields of polyurethane, polyester and the like. BACKGROUND

[0002] The polycarbodiimide compound has the characteristics of reacting with carboxyl at room temperature and can effectively inhibit the hydrolysis of ester groups, and is widely used in the field of hydrolysis inhibitors. The polymeric polycarbodiimide hydrolysis inhibitor has high melting point and long hydrolysis resistance time, and its multi-functional groups can not only inhibit the hydrolysis of ester groups, but also enhance the mechanical properties of the material through intermolecular crosslinking. At present, the Stabaxol P series developed by Germany Lanxess (Lian Chemical) is a representative of the monomer structure, which is an aromatic polycarbodiimide with m-triisopropylbenzene. However, due to the high difficulty in preparation of raw materials and the difficulty in separation, the price is high, which limits the development of polymeric polycarbodiimide.

[0003] The aliphatic polycarbodiimide is a new type of hydrolysis inhibitor developed in recent years, and the representative monomer is generally isophorone diisocyanate (IPDI) or dicyclohexyl methane diisocyanate (HMDI), and the raw material source is wider. However, compared with aromatic products, the aliphatic polycarbodiimide has no obvious advantage in preparation cost and application field, and the aliphatic molecular skeleton leads to lower melting point, easier softening and poorer heat resistance, which is difficult to cope with some higher temperature working conditions, greatly limiting the use range of the product. SUMMARY

[0004] Combining the advantages and disadvantages of aromatic and aliphatic polycarbodiimide, one object of the present application is to provide a partially urethane-modified polycarbodiimide hydrolysis inhibitor, which selects 2,6-diisopropylbenzene with steric hindrance as the end-capping structure of the aliphatic polycarbodiimide polymer skeleton, and increases the content of polycarbodiimide functional groups while improving the melting point of the product by using the rigid structure of the aromatic end group; at the same time, part of the urethane group is introduced for modification, and the urethane modification can enhance the interaction between the molecular structure and the polyester or polyurethane material, thereby realizing better compatibility and anti-freedom of the hydrolysis inhibitor product.

[0005] Another object of the present application is to provide a preparation method and application of the partially urethane-modified polycarbodiimide hydrolysis inhibitor.

[0006] In order to achieve the above-mentioned object of the present application, the following technical scheme is adopted:

[0007] A partially urethane-modified polycarbodiimide hydrolysis inhibitor comprises the following components (1), (2) and (3) with the general structure:

[0008]

[0009] wherein n, m, x = 0-20, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc., R1is one of R2is one or both.

[0010] In one embodiment, the cumulative carbamate groups of component (2) and component (3) are 0.1-50%, such as 0.2%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 10%, 12%, 13%, 15%, 17%, 20%, 22%, 24%, 25%, 28%, 30%, 33%, 35%, 36%, 38%, 40%, 43%, 45%, 48%, 49%, etc., relative to the molar amount of 2,6-diisopropylphenyl end-capping groups in the hydrolysis-resistant agent, preferably 1-30%, based on the carbamate groups in the hydrolysis-resistant agent.

[0011] wherein the molar ratio of carbamate groups and 2,6-diisopropylphenyl end-capping groups in the hydrolysis-resistant agent is determined by integrating the N-H and 2,6-diisopropylphenyl para-hydrogen characteristic in the1H NMR spectrum.

[0012] In one embodiment, the melting point of the hydrolysis-resistant agent is 70-200°C, such as 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, etc., preferably 90-150°C.

[0013] In one embodiment, the color number of the hydrolysis-resistant agent is 50 Hazen or less, such as 49 Hazen, 45 Hazen, 43 Hazen, 40 Hazen, 38 Hazen, 35 Hazen, 30 Hazen, 25 Hazen, 20 Hazen, 15 Hazen, 10 Hazen, 5 Hazen, 1 Hazen, etc., preferably 0-30 Hazen.

[0014] wherein the color number is determined by preparing a 5% by mass solution of the hydrolysis-resistant agent in dichloromethane and testing the platinum-cobalt color.

[0015] The method for preparing the partially urethane-modified polycarbodiimide hydrolysis-resistant agent of the present application is not particularly limited, such as using a pre-urethane method, or using a direct end-capping method, etc. Several exemplary preparation methods are as follows.

[0016] In another aspect, the method for preparing the partially urethanized modified polycarbodiimide hydrolysis resistant agent comprises the following steps:

[0017] (1) urethanization process: a flask is added with aliphatic diisocyanate, antioxidant, and heated to 120-180°C, then urethanization blocking agent is added dropwise, and after the dropwise addition is completed, heating is continued until there is no residual hydroxyl group detected by infrared monitoring;

[0018] (2) polymerization process: the reaction solution of step (1) is added with a catalyst, and then the reaction is continued at 150-210°C, and the reaction progress is monitored by controlling the residual NCO content of the reaction solution, to obtain a polycarbodiimide prepolymer with a degree of polymerization of 1-20;

[0019] (3) blocking process: a certain amount of 2,6-diisopropylbenzene isocyanate is added dropwise to the reaction solution of step (2), and the reaction is continued for 0.2-3h to obtain a modified polycarbodiimide hydrolysis resistant agent.

[0020] In step (1), the aliphatic diisocyanate is isophorone diisocyanate (IPDI) or dicyclohexyl methane diisocyanate (HMDI).

[0021] In step (1), the urethanization blocking agent is cyclohexanol or isooctanol, and the addition ratio is 0-50%, preferably 1-30%, of the target NCO content of the polycarbodiimide prepolymer of step (2).

[0022] In step (1), the antioxidant is one or all of an antioxidant containing a hindered phenol structure or an antioxidant containing a phosphite structure, and the addition mass ratio is 0.001-2% of the mass of the aliphatic diisocyanate.

[0023] In step (2), the catalyst is 3-methyl-1-phenyl-2-cyclophosphorine-1-oxide (MPPO) or 1-methyl-1-oxo-2,3-dihydro-phospholene (MPO), and the addition mass is 0.01-5% of the mass of the aliphatic diisocyanate.

[0024] In step (3), the molar ratio of the amount of 2,6-diisopropylbenzene isocyanate used in the blocking process to the residual NCO content of the polymerization process of step (2) is 1:1.

[0025] In another aspect, the method for preparing the partially urethanized modified polycarbodiimide hydrolysis resistant agent comprises the following steps:

[0026] (1) Polymerization process: add aliphatic diisocyanate, antioxidant, catalyst into a flask, heat to 120-180℃, then start the reaction, monitor the reaction by controlling the NCO residual amount of the reaction solution, obtain the polycarbodiimide prepolymer with polymerization degree of 1-20;

[0027] (2) End-capping process: add a certain amount of 2,6-diisopropylbenzene isocyanate and urethane end-capping agent into the reaction solution of step (1) respectively, obtain the modified polycarbodiimide hydrolysis-resistant agent.

[0028] In step (1), the aliphatic diisocyanate is isophorone diisocyanate (IPDI) or dicyclohexyl methane diisocyanate (HMDI).

[0029] In step (1), the catalyst is 3-methyl-1-phenyl-2-cyclophosphorine-1-oxide (MPPO) or 1-methyl-1-oxo-2,3-dihydro-phospholene (MPO), and the addition amount is 0.01-5% of the mass of the aliphatic diisocyanate.

[0030] In step (1), the antioxidant is one or all of the antioxidants containing hindered phenol structure or the antioxidants containing phosphite structure, and the addition amount is 0.001-2% of the mass of the diisocyanate.

[0031] In step (2), the urethane end-capping agent is cyclohexanol or isooctanol, and the addition amount is 0-50%, preferably 1-30%, of the target NCO content of the polycarbodiimide prepolymer in step (1).

[0032] In step (2), one of 2,6-diisopropylbenzene isocyanate or urethane end-capping agent is preferentially added in the end-capping process, and the other is added after the reaction is completed.

[0033] In step (2), the addition order of 2,6-diisopropylbenzene isocyanate and urethane end-capping agent used in the end-capping process can be reversed, but they cannot be mixed or added at the same time.

[0034] In another aspect, the aforementioned partially urethane-modified polycarbodiimide hydrolysis-resistant agent or the partially urethane-modified polycarbodiimide hydrolysis-resistant agent prepared by the aforementioned preparation method is applied in the field of polyurethane and polyester.

[0035] Compared with the prior art, the present application has the following beneficial effects:

[0036] The present application provides a novel polycarbodiimide hydrolysis-resistant agent, which has the characteristics of high carbodiimide functional group content, high melting point and good compatibility.

[0037] The partially urethane-modified polycarbodiimide antihydrolysis agent of the present invention utilizes the rigid structure of aromatic end groups to increase the product melting point and the content of carbodiimide functional groups in the product; urethane modification enhances the interaction between the molecular structure and polyester or polyurethane materials, thereby improving the compatibility and anti-free radical properties of the antihydrolysis agent product. Detailed Implementation

[0038] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for a better understanding of the invention and do not imply that the invention is limited to these embodiments.

[0039] The main sources of raw materials involved in the following embodiments are as follows:

[0040] Isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), Wanhua Chemical;

[0041] 2,6-Diisopropylphenyl isocyanate, Leyan Reagent;

[0042] Cyclohexanol, isooctyl alcohol, 2,6-di-tert-butyl-p-cresol (BHT), Inokai reagent;

[0043] 3-Methyl-1-phenyl-2-cyclophosphene-1-oxide (MPPO), Bide reagent;

[0044] The main test methods involved in the following embodiments are as follows:

[0045] (1) The NCO content test shall be performed in accordance with standard GB / T 12009.4;

[0046] (2) Test method for color number: Prepare a 5% dichloromethane solution of anti-hydrolysis agent and test its platinum-cobalt color. The test shall be performed in accordance with standard GB / T 6324.6-2014.

[0047] (3) Melting point test method: The test standard shall be in accordance with GB / T 19466.3-2004.

[0048] (4) Test method for the proportion of urethane modification: The ratio of the characteristic hydrogen peak areas of NH and 2,6-diisopropylphenyl in urethane esters is determined by integrating the 1H NMR spectrum.

[0049] Using an AVANCE 600 FT-NMR spectrometer manufactured by Bruker, with deuterated chloroform and deuterated dichloromethane as solvents (the selection criteria for deuterated reagents were that they would not affect the integration results and that the sample could be dissolved), the following parameters were used: sample mass concentration 5%, 600 MHz, 256 iterations, and a chemical shift reference of 0 ppm tetramethylsilane. 1 Qualitative analysis was performed using H nuclear magnetic resonance spectroscopy.

[0050] a: Peak area of ​​the NH structure in the urethane formed by bonding with isocyanate and hydroxyl groups.

[0051] b: Area of ​​the characteristic hydrogen peak at the para-position of 2,6-diisopropylphenyl.

[0052] Example 1

[0053] Add 1000g of isophorone diisocyanate (IPDI) and 2,6-di-tert-butyl-p-cresol (BHT) to a 2L reactor.

[0054] 0.5 g of cyclohexanol was added dropwise to the system at 150 °C. The reaction was continued until no hydroxyl residue was detected by infrared spectroscopy. Then, 2000 mg of 3-methyl-1-phenyl-2-cyclophosphene-1-oxide (MPPO) was added, and the temperature was raised to 170 °C. The reaction was continued, and the NCO content of the reaction system was measured to be 8.9% using the di-n-butylamine method, yielding a polycarbodiimide prepolymer with a degree of polymerization of 4. Subsequently, 365.8 g of 2,6-diisopropylphenyl isocyanate was added dropwise to the reaction solution for end-capping. After reacting for 1 hour, the NCO content was 0, yielding a modified polycarbodiimide anti-hydrolysis agent with an NCN functionality of 4.8.

[0055] Example 2

[0056] Add 1000g of isophorone diisocyanate (IPDI) and 2,6-di-tert-butyl-p-cresol (BHT) to a 2L reactor.

[0057] 0.5 g of cyclohexanol was added dropwise to the system after heating to 150°C. The reaction continued until no hydroxyl residue was detected by infrared spectroscopy. Then, 2000 mg of 3-methyl-1-phenyl-2-cyclophosphene-1-oxide (MPPO) was added and the temperature was raised to 170°C. The reaction continued, and the NCO content of the reaction system was measured to be 5.2% using the di-n-butylamine method, yielding a polycarbodiimide prepolymer with a degree of polymerization of 7. Subsequently, 209 g of 2,6-diisopropylphenyl isocyanate was added dropwise to the reaction solution at 170°C for end-capping. After reacting for 1 hour, the NCO content was 0, yielding a modified NCN-functionality 7.8 polycarbodiimide anti-hydrolysis agent.

[0058] Example 3

[0059] 1000g of dicyclohexylmethane diisocyanate (HMDI) and 0.5g of 2,6-di-tert-butyl-p-cresol (BHT) were added to a 2L reactor. The system was heated to 150℃, and 38.2g of cyclohexanol was added dropwise. After the addition was complete, the reaction was continued until no hydroxyl residue was detected by infrared spectroscopy. Then, 3000mg of 3-methyl-1-phenyl-2-cyclophosphene-1-oxide (MPPO) catalyst was added, and the temperature was raised to 170℃. The reaction was continued, and the NCO content of the reaction system was detected by the di-n-butylamine method. After the NCO content dropped to 7.4%, a polycarbodiimide prepolymer with a degree of polymerization of 4 was obtained. Subsequently, 310g of 2,6-diisopropylphenyl isocyanate was added dropwise to the reaction solution at 170℃ for end-capping. After the reaction was continued for 1 hour, the NCO content was 0, yielding an NCN-modified polycarbodiimide anti-hydrolysis agent with a functionality of 4.8.

[0060] Example 4

[0061] Add 1000g of isophorone diisocyanate (IPDI) and 2,6-di-tert-butyl-p-cresol (BHT) to a 2L reactor.

[0062] 0.5 g of isooctanol was added dropwise to the system after heating to 160°C. The reaction continued until no hydroxyl residue was detected by infrared spectroscopy. Then, 2000 mg of 3-methyl-1-phenyl-2-cyclophosphide-1-oxide (MPPO) was added and the temperature was raised to 170°C. The reaction continued, and the NCO content of the reaction system was measured by the di-n-butylamine method until it decreased to 8.9%, yielding a polycarbodiimide prepolymer with a degree of polymerization of 4. Subsequently, 365.8 g of 2,6-diisopropylphenyl isocyanate was added dropwise to the reaction solution at 170°C for end-capping. After reacting for 1 hour, the NCO content was 0, yielding an NCN-modified polycarbodiimide anti-hydrolysis agent with a functionality of 4.8.

[0063] Example 5

[0064] In a 2L reactor, 1000g of isophorone diisocyanate (IPDI), 2000mg of 3-methyl-1-phenyl-2-cyclophosphide-1-oxide (MPPO), and 0.5g of 2,6-di-tert-butyl-p-cresol (BHT) were added. The system was heated to 170℃ and reacted. The NCO content of the reaction system was measured by the di-n-butylamine method and found to be reduced to 11.1%, yielding a polycarbodiimide prepolymer with a degree of polymerization of 4. Subsequently, 365.8g of 2,6-diisopropylphenyl isocyanate was added for end-capping, and the reaction was continued for 0.5h. Then, 25.7g of cyclohexanol was added, and the reaction was continued until the NCO content was 0, yielding a polycarbodiimide anti-hydrolysis agent with an NCN functionality of 4.8.

[0065] Example 6

[0066] In a 2L reactor, 1000g of isophorone diisocyanate (IPDI), 2000mg of 3-methyl-1-phenyl-2-cyclophosphide-1-oxide (MPPO), and 0.5g of 2,6-di-tert-butyl-p-cresol (BHT) were added. The system was heated to 170℃ and reacted. The NCO content of the reaction system was measured by the di-n-butylamine method and decreased to 11.1%, yielding a polycarbodiimide prepolymer with a degree of polymerization of 4. Subsequently, 25.7g of cyclohexanol was added for end-capping, and the reaction was continued for 0.5h. Then, 365.8g of 2,6-diisopropylphenyl isocyanate was added, and the reaction was continued until the NCO content was 0, yielding a polycarbodiimide anti-hydrolysis agent with an NCN functionality of 4.8.

[0067] Comparative Example 1

[0068] 1000g of isophorone diisocyanate (IPDI), 2g of 3-methyl-1-phenyl-2-cyclophosphine-1-oxide (MPPO), and 0.5g of 2,6-di-tert-butyl-p-cresol (BHT) were added to a 2L reactor. The system was heated to 160℃ and reacted. The NCO content of the reaction system was measured by the di-n-butylamine method and found to be reduced to 11.1%, yielding a polycarbodiimide prepolymer with a degree of polymerization of 4. Subsequently, 225.2g of cyclohexanol was added for end-capping, and the reaction was continued for 1 hour until the NCO content was 0, yielding a polycarbodiimide anti-hydrolysis agent with an NCN functionality of 3.

[0069] The test results are listed in Table 1. As can be seen from Table 1, compared with the fully aliphatic polycarbodiimide in Comparative Example 1, the polycarbodiimide antihydrolysis agent prepared by the partial urethane end-capping modification process in Examples 1-6 of this invention has a slight advantage in color number, higher NCN functionality, and a higher melting point than the product of Comparative Example 1.

[0070] Table 1 Comparison of relevant parameters between the examples and comparative examples.

[0071]

[0072]

[0073] Note: a. NCO content: NCO content of the polycarbodiimide prepolymer during polymerization.

[0074] b. NCN Functionality: NCN functionality of anti-hydrolysis agent products

[0075] c. Colorimetric testing method: Prepare a 5% (w / w) dichloromethane solution of the anti-hydrolysis agent and test its platinum-cobalt colorimetric properties.

[0076] d. Ratio of urethane modification: The ratio of characteristic hydrogens at the para-position of NH and 2,6-diisopropylphenyl in urethane (H 1 NMR, CDCl3)

[0077] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A partially urethaned modified polycarbodiimide hydrolysis resistant agent characterized in that, Component (1), component (2) and component (3) comprising the following general structure: wherein n, m, x = 0-20, R1is each R2is independently one of one or both of the following:

2. The partially urethanized modified polycarbodiimide hydrolysis resistant agent according to claim 1, the cumulative urethane groups of component (2) and component (3) account for 0.1%-50%, preferably 1-30% of the molar amount of 2,6-diisopropyl phenyl end-capping groups in the hydrolysis resistant agent, based on the urethane groups in the hydrolysis resistant agent.

3. The partially urethaned-modified polycarbodiimide hydrolysis resistant agent according to claim 1, characterized by, The melting point of the hydrolysis resistant agent is 70-200℃, preferably 90-150℃.

4. The partially urethaned-modified polycarbodiimide hydrolysis resistant agent according to claim 1, characterized by, The colority of the hydrolysis resistant agent is below 50 Hazen, preferably 0-30 Hazen.

5. The partially urethaned-modified polycarbodiimide hydrolysis resistant agent according to claim 4, characterized by, The testing method of the colority is to prepare a 5% mass fraction dichloromethane solution of the hydrolysis resistant agent and test its platinum-cobalt colority.

6. Process for the preparation of partially urethane-modified polycarbodiimide hydrolysis-resistant agents according to any one of claims 1 to 5, characterized in that, Comprising the following steps: (1) Urethanization process: add aliphatic diisocyanate, antioxidant into a flask, heat to 120-180℃, then add urethanization end-capping agent dropwise, continue heating until infrared monitoring shows no hydroxyl group remains; (2) Polymerization process: add the reaction solution of step (1) into a catalyst, then continue the reaction at 150-210℃, monitor the reaction by controlling the NCO residual amount of the reaction solution, obtain a polycarbodiimide prepolymer with a polymerization degree of 1-20; (3) End-capping process: add 2,6-diisopropyl phenyl isocyanate dropwise into the reaction solution of step (2), continue the reaction for 0.2-3h to obtain the partially urethanized modified polycarbodiimide hydrolysis resistant agent.

7. The preparation method according to claim 6, characterized in that, The aliphatic diisocyanate in step (1) is isophorone diisocyanate (IPDI) or dicyclohexyl methane diisocyanate (HMDI); Preferably, the urethanization end-capping agent is cyclohexanol or isooctanol, and the addition ratio is 0.1-50%, preferably 1-30% of the target NCO content of the polycarbodiimide prepolymer in step (2); More preferably, the antioxidant is one or more of an antioxidant containing a hindered phenol structure or an antioxidant containing a phosphite structure, and the addition mass is 0.001-2% of the mass of the aliphatic diisocyanate.

8. The preparation method according to claim 6, characterized in that, The catalyst in step (2) is 3-methyl-1-phenyl-2-cyclophosphorine-1-oxide (MPPO) or 1-methyl-1-oxo-2,3-dihydro-phospholene (MPO), and the addition mass is 0.01-5% of the mass of the aliphatic diisocyanate; Preferably, the molar ratio of the amount of 2,6-diisopropyl phenyl isocyanate used in the end-capping process in step (3) to the NCO residual amount in the polymerization process in step (2) is 1:

1.

9. Process for the preparation of partially urethane-modified polycarbodiimide hydrolysis-resistant agents according to any one of claims 1 to 5, characterized in that, Comprising the following steps: (1) Polymerization process: add aliphatic diisocyanate, antioxidant, catalyst into a flask, heat to 120-180℃, then start the reaction, monitor the reaction by controlling the NCO residual amount of the reaction solution, obtain a polycarbodiimide prepolymer with a polymerization degree of 1-20; (2) End-capping process: add 2,6-diisopropyl phenyl isocyanate and urethanization end-capping agent into the reaction solution of step (1) respectively, obtain the partially urethanized modified polycarbodiimide hydrolysis resistant agent.

10. Use of the partially urethane-modified polycarbodiimide hydrolysis resistant agent according to any one of claims 1 to 5 in the field of polyurethanes, polyesters.

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