Isocyanate composition, modified composition, and polyurethane elastomer

Abstract

The present application discloses an isocyanate composition, a modified composition, and a polyurethane elastomer. The isocyanate composition has an effective coefficient of 3.80 to 5.30, and through the design and control of the effective coefficient, it has excellent reaction activity and can be used in the manufacture of high-performance polyurethane products. The isocyanate composition can improve the stability of polyurethane products, particularly significantly improving the discoloration resistance and weather resistance of polyurethane elastomers, suppressing the increase in color number and yellowing under high-temperature and high-humidity conditions, and enhancing the tensile strength and tear strength of polyurethane elastomers. As a result, the polyurethane elastomer has excellent comprehensive performance in terms of weather resistance, stability, and mechanical properties.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of isocyanates, for example, isocyanate compositions, modified compositions, and polyurethane elastomers.

Background Art

[0002] Polyurethane elastomers (PUR) have characteristics such as high elasticity, high strength, a wide hardness range, and excellent abrasion resistance, and are used in industries such as the automotive industry, machinery industry, medical industry, transportation, sports goods, electronics industry, chemical industry, and coal. Polyurethane elastomers can be classified into TDI (toluene diisocyanate) type, MDI (diphenylmethane diisocyanate) type, PPDI (para-phenylene diisocyanate) type, NDI (naphthalene diisocyanate) type, CHDI (cyclohexane diisocyanate) type, etc. according to the isocyanate used, but the TDI type and the MDI type are the most common.

[0003] As the application scope of polyurethane elastomers expands, the commonly used TDI-type PUR and MDI-type PUR can no longer meet the usage needs, and new polyurethane elastomers have been developed to improve the performance of the elastomers. For example, CN113354788A discloses a polyurethane elastomer excellent in heat resistance and anti-slip properties. The raw materials include 60-65% of polyester polyol, 30-33% of diisocyanate, and 1-9.5% of a mixed chain extender cross-linking agent. The diisocyanate includes a combination of dimethylbiphenyl diisocyanate, p-phenylene diisocyanate, and 1,5-naphthalene diisocyanate. CN104017166A discloses a method for manufacturing a heat-resistant thermoplastic polyurethane elastomer. The steps are as follows: an antioxidant, a catalyst, and molten polyester polyol are added to a reaction kettle, heated, and dehydrated under reduced pressure conditions to form component A. The diisocyanate is heated and melted to form component B. The molten triol and molten diol are uniformly mixed and dehydrated under reduced pressure and heating conditions to form component C. Component A, component B, and component C are simultaneously added to a twin-screw extruder and subjected to a stepwise polymerization reaction to obtain a heat-resistant thermoplastic polyurethane elastomer. The diisocyanate is a mixture composed of 70-100% by mass of trans-1,4-CHDI and 0-30% by mass of cis-1,4-CHDI. CN104817683A discloses a polyurethane elastomer having good mechanical properties and fatigue resistance. Its raw materials include component A and component B. By weight, component A is 100 parts of a high molecular weight diol, 5-20 parts of NDI, 10-30 parts of p-phenylene diisocyanate, or 10-50 parts of 3,3'-dimethyl-4,4'-biphenyl diisocyanate (TODI). Component B is 0-100 parts of a high molecular weight diol, 8-30 parts of a chain extender, and 0.02-0.5 parts of a catalyst. The weight ratio of component A to component B is 100:(8-30).

[0004] Compared with the commonly used MDI and TDI, NDI, PPDI, and CHDI have high melting points and are high-melting-point isocyanates. Moreover, NDI and PPDI have an aromatic structure and a large steric hindrance effect. Therefore, the synthesized polyurethane elastomers have characteristics such as high hardness, excellent resilience, excellent heat resistance, excellent dynamic properties, and excellent abrasion resistance, and can be used in high-dynamic load scenarios. They are popular isocyanate raw materials in the production of new polyurethane elastomers. However, although NDI, PPDI, and CHDI have various advantages, they also have undeniable drawbacks. Due to the high reactivity of the NCO group, it may cause an undesirable increase in color number during the production of polyurethane, that is, obvious yellowing and a decrease in weather resistance, which has a significant impact on the appearance of the polyurethane elastomer and the quality of the product.

[0005] Therefore, in order to improve the properties such as the weather resistance and appearance of polyurethane elastomers, the development of isocyanate raw materials with better properties has become an urgent task.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The following is a summary of the main topics described in detail in this specification. This summary is not intended to limit the scope of protection of the claims.

[0007] The embodiments of the present application can effectively suppress the increase in color number of polyurethane elastomers under high-temperature and high-humidity conditions through the design of the effective coefficient, improve the stability and weather resistance of polyurethane elastomers, and improve the mechanical properties of polyurethane elastomers, and provide an isocyanate composition, a modified composition, and a polyurethane elastomer.

Means for Solving the Problems

[0008] In a first aspect, the embodiments of the present application provide an isocyanate composition with an effective coefficient of 3.80 to 5.30.

[0009] The calculation formula of the effective coefficient is represented by Formula I.

Equation

[0010] The effective coefficient E of the isocyanate composition according to the present application is 3.80 to 5.30. For example, it may be 3.90, 4.00, 4.10, 4.30, 4.50, 4.70, 4.90, 5.00, 5.10, or 5.20, and may also be a specific point value between the above point values. For the convenience of the paper surface and conciseness, in the present application, the specific point values included in the range are not listed comprehensively.

[0011] In the present application, since the isocyanate composition includes a combination of an isocyanate and a chlorine-containing substance, it is named "isocyanate composition", and the chlorine-containing substance includes a combination of a chloro isocyanate and a substance corresponding to the effective coefficient. Through the design and control of the effective coefficient of the present application, the isocyanate composition contains a specific type of chlorine-containing substance at a specific content, thereby having excellent reaction activity and can be used in the production of high-performance polyurethane products. In particular, when the isocyanate composition is used in polyurethane products, especially polyurethane elastomers, it can significantly improve the stability and weather resistance of the polyurethane elastomer, suppress the increase in color number and yellowing under high temperature and high humidity conditions, and increase the tensile strength and tear strength of the polyurethane elastomer, so that the polyurethane elastomer has excellent comprehensive performance in terms of weather resistance, stability, mechanical properties, and appearance.

[0012] Preferably, the isocyanate is a diisocyanate, and more preferably, it contains any one or a combination of at least two of naphthalene diisocyanate (NDI), phenylene diisocyanate (PPDI / MPDI / OPDI), cyclohexane diisocyanate (CHDI), diphenylmethane diisocyanate (MDI), and toluene diisocyanate (TDI).

[0013] In this application, unless otherwise specified, the listed isocyanates include all their isomers. For example, the naphthalene diisocyanate (NDI) is TIFF2025524128000003.tif1853, and the phenylene diisocyanate (PPDI) is TIFF2025524128000004.tif1841, and the cyclohexane diisocyanate (CHDI) is TIFF2025524128000005.tif2140, and the diphenylmethane diisocyanate (MDI) is TIFF2025524128000006.tif2062, and the toluene diisocyanate (TDI) is TIFF2025524128000007.tif2397.

[0014] TIFF2025524128000008.tif94164 TIFF2025524128000009.tif73164

[0015] Preferably, the mass content rate of the isocyanate in the isocyanate composition is 97% or more, for example, 97.5%, 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, 99.92%, 99.95%, 99.98%, 99.99%, etc. More preferably, it is 99% or more, and even more preferably, it is more than 99%.

[0016] Preferably, the chloro isocyanate is a compound in which one NCO group of the isocyanate is substituted with chlorine.

[0017] Preferably, the chloro isocyanate is TIFF2025524128000010.tif138164, or any combination of at least two of them.

[0018] In this application, the notation with “-” attached to the ring structure indicates that the linking site can be at any position on the ring structure where a bond can be formed.

[0019] Preferably, the mass content (B value) of chloro isocyanate in the isocyanate composition is 5 to 2000 ppm, for example, 10 ppm, 20 ppm, 30 ppm, 50 ppm, 80 ppm, 100 ppm, 300 ppm, 500 ppm, 700 ppm, 900 ppm, 1000 ppm, 1100 ppm, 1300 ppm, 1500 ppm, 1700 ppm, or 1900 ppm, and may also be a specific point value between the above point values. For the sake of brevity and convenience of the paper, in this application, the specific point values included in the range are not listed comprehensively, but more preferably it is 10 to 1500 ppm.

[0020] In this application, “ppm” is parts per million, 1 ppm represents one millionth, and the same expression used below has the same meaning.

[0021] Preferably, the substance for the effective coefficient includes any one or a combination of at least two of the following compounds. TIFF2025524128000011.tif39129 (where R is a divalent group obtained by removing the NCO group from the isocyanate).

[0022] Preferably, the R is TIFF2025524128000012.tif68157, or any combination of at least two selected therefrom, where the wavy line represents the linking site of the group.

[0023] Preferably, the mass content of chlorine (A value) in the isocyanate composition is 1 to 1000 ppm, for example, 2 ppm, 5 ppm, 8 ppm, 10 ppm, 30 ppm, 50 ppm, 80 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, 350 ppm, 400 ppm, 450 ppm, 500 ppm, 550 ppm, 600 ppm, 650 ppm, 700 ppm, 750 ppm, 800 ppm, 850 ppm, 900 ppm, or 950 ppm, and specific point values between the above point values. For the sake of brevity of the paper, the specific point values included in the range are not comprehensively listed in this application. More preferably, it is 5 to 500 ppm.

[0024] In the present application, in formula I for calculating the effective coefficient, A is the mass content of chlorine in the isocyanate composition, and is preferably tested by X-ray fluorescence analysis (XRF).

[0025] Preferably, in formula I for calculating the effective coefficient, B is the mass content of chloro isocyanate in the isocyanate composition, and is tested by chromatography-mass spectrometry, and is preferably tested by gas chromatography-mass spectrometry (GCMS).

[0026] In research, it has been found that in the conventional method for evaluating the chlorine content characteristics in isocyanates known in the prior art, it is difficult to accurately control the performance of isocyanates, and in particular, it is impossible to effectively control the performance of polyurethane products / polyurethane elastomers, such as yellowing resistance, stability, and appearance. Specifically, the test method for the total chlorine content described in Standard GB / T 12009.1-1989 is an oxygen cylinder combustion method that converts all chlorine (including bromine) in isocyanate into inorganic chlorine (including bromine), and then titrates it using silver nitrate. The content of all chlorine in isocyanate is evaluated for its characteristics, which includes the bromine content in isocyanate. Standard GB / T 12009.2-2016 measures the hydrolyzable chlorine, specifically the content of chlorine released by reacting isocyanate with alcohol and water. This is the most active chlorine in isocyanate and also includes highly active bromine, and some monochloro isocyanates are also partially hydrolyzed. The content of chlorine (including some bromine) measured by GB / T 12009.1-1989 or GB / T 12009.2-2016 cannot accurately represent the composition information of isocyanate, and therefore, it is also impossible to effectively control the performance of isocyanate, polyurethane products, especially polyurethane elastomers.

[0027] Preferably, as a technical solution of the present application, in the calculation of the effective coefficient E, A is the total chlorine content (excluding bromine) tested by XRF, B is the content of chloro isocyanate tested by chromatography-mass spectrometry, and the A value and the B value are tested by accurate qualitative and quantitative analysis methods. Thereby, the effective coefficient E can accurately characterize poly-chlorine compounds and some hydrolyzed chlorine (excluding hydrolyzed chlorine by monochloro isocyanate) in the isocyanate composition. Therefore, a more accurate and clear chlorine content can be obtained. Such a chlorine content has an important effect on the activity of isocyanate and the performance of polyurethane products (for example, polyurethane elastomers), thereby making it possible to control the performance of the isocyanate composition and further improving the performance of the polyurethane elastomer produced from the isocyanate composition. Particularly, there are remarkable improvement effects regarding weather resistance, stability, mechanical properties, and appearance.

[0028] In addition, in the present application, the substances corresponding to the chloro isocyanate and the effective factor may be generated as by-products in the manufacturing process of isocyanate, or may be artificially added to obtain the required content.

[0029] In the second aspect, the embodiment of the present application provides a method for manufacturing the isocyanate composition according to the first aspect, including the step of reacting an amine compound with phosgene to obtain the isocyanate composition.

[0030] Preferably, the manufacturing method includes step (1) of reacting an amine compound with phosgene to obtain a reaction product, and step (2) of performing a removal treatment including a dephosgenation treatment and / or a solvent removal treatment on the reaction product obtained in step (1) to obtain a crude product, and step (3) of sequentially performing separation and purification on the crude product obtained in step (2) to obtain the isocyanate composition.

[0031] When performing an isocyanation reaction using diamine and phosgene, in order to obtain a specific effective coefficient, preferably, the following parameters may be used. The effective coefficient E of the isocyanate composition may be adjusted by adding chloro isocyanate and / or a substance corresponding to the effective coefficient to the isocyanate.

[0032] Preferably, heavy components and intermediate products are obtained by the separation in step (3), the mixture of the intermediate product and the heavy components is purified to obtain the isocyanate composition, and the mass content of the heavy components in the mixture is 1 to 10%.

[0033] As a preferred technical solution of the present application, the component to be purified is the mixture of the intermediate product and the heavy components, the mass content of the heavy components in the mixture is 1 to 10%, for example, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9%, and specific point values between the above point values may also be used. For the convenience of the paper surface and simplicity, in the present application, the specific point values included in the range are not listed comprehensively, but more preferably 2 to 10%.

[0034] Preferably, the heavy components obtained by the separation may be directly mixed with the intermediate product to obtain a mixture, or the heavy components obtained by the separation may be used as primary heavy components, the primary heavy components are separated again to obtain a heavy component recovery material and residual heavy components, the heavy component recovery material is mixed with the intermediate product, and the mixture is obtained. The mass content of the heavy component recovery material in the mixture is 1 to 10%.

[0035] In another preferred technical solution, the method for producing the isocyanate composition includes a step of mixing the isocyanate obtained by the carbamate decomposition method with the heavy component recovery material to obtain the isocyanate composition. Preferably, the mass content of the heavy component recovery material in the isocyanate composition is 1 to 10% (for example, 2%, 3%, 4%, 5%, 6%, 7%, 8%, or 9%, etc.), and more preferably 1 to 5%.

[0036] As a preferred technical solution of the present application, the method for producing the isocyanate composition is a phosgenation method in which an amine compound is reacted with phosgene to produce isocyanate, and the amine compound includes diamine and / or diamine salt (for example, diamine hydrochloride obtained by reacting diamine with HCl).

[0037] Preferably, examples of the method for reacting the amine compound with phosgene include a method of reacting diamine with phosgene in the gas phase, also called the gas-phase phosgenation method, a method of reacting diamine with phosgene in the liquid phase, also called the liquid-phase phosgenation method or the hot-cold two-stage phosgenation method, and a method of reacting a diamine salt (for example, diamine hydrochloride) with phosgene in a solvent, also called the phosgenation method of diamine hydrochloride. Among these three methods, the hot-cold two-stage phosgenation method is more preferred in the present application.

[0038] Preferably, the amine compound in step (1) is diamine, and the reaction method in step (1) is the hot-cold two-stage phosgenation method.

[0039] Preferably, step (1) specifically includes mixing diamine with a solvent to obtain an amine solution, and introducing phosgene into the amine solution to react to obtain a reaction product, that is, a reaction solution containing diisocyanate.

[0040] Preferably, the solvent is an organic solvent, and exemplified by aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as octane and decane; alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and ethylcyclohexane; halogenated aromatic hydrocarbons such as chlorotoluene, chlorobenzene, dichlorobenzene, dibromobenzene, and trichlorobenzene; nitrogen-containing compounds such as nitrobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, and N,N'-dimethylimidazolinone; ethers such as dibutyl ether, ethylene glycol dimethyl ether, and ethylene glycol diethyl ether; ketones such as heptanone, diisobutyl ketone, methyl isobutyl ketone, and methyl ethyl ketone; fatty acid esters such as ethyl acetate, butyl acetate, amyl acetate, and ethoxyethyl acetate; aromatic carboxylic acid esters such as methyl salicylate, dimethyl phthalate, dibutyl phthalate, and methyl benzoate, etc., but not limited thereto. The solvent may be used alone or in combination of at least two kinds.

[0041] Preferably, the solvent contains halogenated aromatic hydrocarbons, and more preferably is chlorobenzene and / or dichlorobenzene.

[0042] Preferably, the mass content of diamine in the amine solution is 1 to 50 wt.%, for example, 2 wt.%, 5 wt.%, 8 wt.%, 10 wt.%, 12 wt.%, 15 wt.%, 18 wt.%, 20 wt.%, 22 wt.%, 25 wt.%, 28 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, or 48 wt.%, and may be a specific point value between the above point values. For the convenience of space and brevity, in this application, the specific point values included in the range are not listed comprehensively, but more preferably 5 to 40 wt.%.

[0043] Preferably, the molar ratio of the phosgene to the amine compound (diamine) in step (1) is (3 to 50):1. For example, it may be 4:1, 5:1, 8:1, 10:1, 12:1, 15:1, 18:1, 20:1, 22:1, 25:1, 28:1, 30:1, 32:1, 35:1, 38:1, 40:1, 42:1, 45:1, or 48:1, etc. However, more preferably, it is (4 to 40):1, and even more preferably, it is (4 to 30):1.

[0044] Preferably, the reaction in step (1) includes a cold reaction and a heat reaction that are carried out in sequence.

[0045] Preferably, the temperature of the cold reaction is -10°C to 80°C. For example, it may be -5°C, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, or 75°C, and may also be a specific point value between the above point values. For the sake of brevity and the space on the paper, in this application, specific point values included in the range are not listed comprehensively. However, more preferably, it is 0 to 70°C.

[0046] Preferably, the time of the cold reaction is 1 to 20 h. For example, it may be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, or 19 h, and may also be a specific point value between the above point values. For the sake of brevity and the space on the paper, in this application, specific point values included in the range are not listed comprehensively. However, more preferably, it is 2 to 15 h.

[0047] Preferably, the temperature of the heat reaction is 70 to 150°C. For example, it may be 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, or 145°C, and may also be a specific point value between the above point values. For the sake of brevity and the space on the paper, in this application, specific point values included in the range are not listed comprehensively. However, more preferably, it is 80 to 130°C.

[0048] Preferably, the time of the thermal reaction is 1 to 20 h, for example, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, or 19 h, and may also be a specific point value between the above point values. For the sake of brevity on the paper, the present application does not list all the specific point values included in the range. More preferably, it is 2 to 15 h.

[0049] Preferably, the reaction in step (1) is carried out under normal pressure or pressurized conditions.

[0050] Preferably, the pressure (gauge pressure) of the reaction in step (1) is 0 to 0.6 MPa G, for example, 0.0005 MPa G, 0.001 MPa G, 0.003 MPa G, 0.01 MPa G, 0.02 MPa G, 0.03 MPa G, 0.05 MPa G, 0.07 MPa G, 0.09 MPa G, 0.1 MPa G, 0.2 MPa G, 0.3 MPa G, 0.4 MPa G, or 0.5 MPa G, and may also be a specific point value between the above point values. For the sake of brevity on the paper, the present application does not list all the specific point values included in the range. More preferably, it is 0.005 to 0.4 MPa G, and even more preferably 0.01 to 0.2 MPa G.

[0051] Preferably, the reaction (isocyanation step) in step (1) is an intermittent process or a continuous process, preferably a continuous process.

[0052] Here, in the continuous process, the slurry (amine solution) in the stirring tank is continuously sent from the stirring tank to a reaction tank different from the stirring tank, diamine and phosgene are reacted in the reaction tank, and the obtained reaction product (reaction solution containing diisocyanate) is continuously taken out from the reaction tank. The present application does not particularly limit the number of reaction kettles in the continuous process. Exemplarily, it may be 2, 3, 4, 5, or more.

[0053] Optionally, a removal step (solvent removal step and / or phosgene removal step) and a separation and purification step may be performed on the reaction product obtained in step (1).

[0054] Preferably, the phosgene removal treatment in step (2) is carried out in a phosgene removal tower.

[0055] Preferably, the solvent removal treatment in step (2) is carried out in a solvent removal tower.

[0056] Preferably, the separation in step (3) separates intermediate products (light components) from heavy components to remove the heavy components. Examples of the apparatus for the separation include, but are not limited to, a short-path evaporator and a distillation tower, and more preferably a short-path evaporator.

[0057] Preferably, the operating pressure of the short-path evaporator is 0.05 to 4 kPa. For example, it can be 0.08 kPa, 0.1 kPa, 0.3 kPa, 0.5 kPa, 0.8 kPa, 1 kPa, 1.2 kPa, 1.5 kPa, 1.8 kPa, 2 kPa, 2.2 kPa, 2.5 kPa, 2.8 kPa, 3 kPa, 3.2 kPa, 3.5 kPa, or 3.8 kPa, or a specific point value between the above point values. For the sake of brevity in the specification, specific point values within the range are not listed comprehensively in this application. More preferably, it is 0.1 to 2.5 kPa.

[0058] As a preferred technical solution of the present application, the heavy components obtained by the separation contain a rich variety of chlorine-containing substances with relatively high contents. By mixing the heavy components obtained by the separation, or the heavy component recovery material obtained by separating the heavy components again, into the intermediate products (light components) obtained by separation at a predetermined ratio and further purifying it, the types and contents of chlorine-containing substances in the product can be effectively controlled, and the effective coefficient of the isocyanate composition can be made 3.80 to 5.30.

[0059] Preferably, the mass content of the heavy components (heavy component recovery material) in the mixture (materials involved in purification) is 1 to 10%, more preferably 2 to 10%, whereby the effective coefficient of the isocyanate composition is 3.80 to 5.30. If the amount of the heavy components (heavy component recovery material) mixed in is too small, the effective coefficient is too high. When the isocyanate composition is used in the production of polyurethane elastomers, the reaction rate is too fast. As a result, the polymerization becomes non-uniform, the mechanical properties of the polyurethane elastomer deteriorate, and the tensile strength and tear strength decrease. If the amount of the heavy components (heavy component recovery material) mixed in is too high, the effective coefficient is too low, and the isocyanate composition contains a large amount of impurities. As a result, the weather resistance of the polyurethane elastomer deteriorates, and there is obvious yellowing especially under high temperature and high humidity conditions.

[0060] Preferably, the heavy components to be mixed with the intermediate product may be directly mixed into the intermediate product, or may be cyclically separated by a heavy component removal device to obtain a heavy component recovery material and then mixed into the intermediate product.

[0061] Preferably, the purification method is an industrial separation technique known in the art, and illustratively includes, but is not limited to, distillation, rectification, crystallization, etc.

[0062] Preferably, the purification method is rectification.

[0063] Preferably, the rectification is carried out in a rectification column, and the rectification column preferably includes a tray rectification column or a packed rectification column.

[0064] Preferably, the number of theoretical plates of the rectification column is 2 to 40. For example, 3, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, or 38, and specific point values between the above point values may also be used. For the convenience of the paper surface and simplicity, in this application, the specific point values included in the range are not listed comprehensively, but more preferably 5 to 20.

[0065] Preferably, the top pressure of the rectification column is 0.1 to 4 kPa, for example, 0.2 kPa, 0.5 kPa, 0.8 kPa, 1 kPa, 1.2 kPa, 1.5 kPa, 1.8 kPa, 2 kPa, 2.2 kPa, 2.5 kPa, 2.8 kPa, 3 kPa, 3.2 kPa, 3.5 kPa, or 3.8 kPa, and may also be a specific point value between the above point values. For the convenience of space and conciseness, in this application, the specific point values included in the range are not listed comprehensively. More preferably, it is 0.15 to 2.5 kPa.

[0066] Preferably, the top reflux ratio of the rectification column is 0.01 to 40, for example, 0.05, 0.1, 0.5, 1, 3, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, or 38, and may also be a specific point value between the above point values. For the convenience of space and conciseness, in this application, the specific point values included in the range are not listed comprehensively. More preferably, it is 0.1 to 20. In one preferred technical solution of the present application, the method for producing the isocyanate composition includes the following steps. (1) Phosgenation step: A diamine is mixed with a solvent to obtain an amine solution, and phosgene is introduced into the amine solution and reacted to obtain a reaction product. The reaction includes a cold reaction and a heat reaction that are carried out in sequence, and the temperature of the cold reaction is lower than the temperature of the heat reaction. (2) Removal step: The reaction product obtained in step (1) is subjected to a removal treatment including a dephosgenation treatment and / or a desolvent treatment to obtain a crude product. (3a) Separation step: The crude product obtained in step (2) is separated to obtain a heavy component and an intermediate product (light component). (3b) Heavy component recovery step: The intermediate product and the heavy component obtained in step (3a) are mixed to obtain a mixture. The mass content of the heavy component in the mixture is 1 to 10%. Alternatively, the heavy component obtained in step (3a) is further separated to obtain a heavy component recovery material and a remaining heavy component, and the heavy component recovery material is mixed with the intermediate product to obtain a mixture. The mass content of the heavy component recovery material in the mixture is 1 to 10%. (3c) Purification step: Purify the mixture obtained in step (3b) to obtain the isocyanate composition.

[0067] Exemplarily, the manufacturing method is shown in the flowchart in Figure 1 and includes a phosgenation step 10, a removal step 20, a separation step 30, a heavy component recovery step 40, and a purification step 50. Among them, the phosgenation step may be carried out in an intermittent or continuous manner, and the continuous method is carried out continuously using a kettle. By appropriately adjusting the mixing ratio of the heavy component and the intermediate product, the supply ratio of phosgene, the reaction temperature, the reaction pressure, the average residence time, the reflux ratio of the rectification column, etc., the effective coefficient of the isocyanate composition is adjusted. The control of the effective coefficient is mainly realized by the ratio of the heavy component and the intermediate product.

[0068] Specifically, taking the NDI composition as an example, its manufacturing method is as follows. (1) Phosgenation step: Adopt a continuous kettle reaction of 3 or 4 kettles, continuously send an amine solution containing NDA (naphthalenediamine) to the phosgenation reaction kettle, and continuously introduce phosgene by inserting a pipe from the top of each of the first cold reaction kettle, the first hot reaction kettle, and the second hot reaction kettle at the above ratio. Next, while maintaining the inside of the first cold reaction kettle at the above cold reaction temperature and reaction pressure, stir and mix the amine solution and phosgene to carry out a cold reaction between NDA and phosgene (carbonyl chloride) to obtain a cold reaction photochemical solution. Then, continuously send the above cold reaction photochemical solution to the top of the first hot reaction kettle, that is, while continuously supplying the amine solution and phosgene to the first cold reaction kettle, continuously take out the cold reaction photochemical solution from the first cold reaction kettle and send it to the first hot reaction kettle. Next, while maintaining the inside of the first hot reaction kettle at the above hot reaction temperature and reaction pressure, stir and mix the reactants and phosgene in the first hot reaction kettle to carry out a phosgenation reaction. Similarly, while sending the reactants to the second hot reaction kettle, carry out a phosgenation reaction. Thereby, the phosgenation step is continuously carried out to obtain a reaction solution containing NDI. (2) Removal step: It is carried out by a phosgene removal tower and a solvent removal tower. The above reaction solution is continuously fed to the central part of the phosgene removal tower. By the phosgene removal tower, phosgene, hydrogen chloride, etc. are removed from the reaction solution, and then, by the solvent removal tower, the solvent in the reaction solution is removed to obtain a crude NDI product. (3a) Separation step: The above crude NDI product is separated by a short-path evaporator to remove heavy components, and an intermediate product and a primary heavy component are obtained. (3b) Heavy component recovery step: The primary heavy component is recovered by a short-path evaporator to obtain a heavy component recovery material and a residual heavy component, which can be recovered collectively or circulated. The mixture obtained by mixing the heavy component recovery material with the intermediate product is fed to the purification step. The mass content of the heavy component recovery material in the mixture is 1 - 10%. (3c) Purification step: The above mixture is continuously fed to the central part of the rectification tower, and then, under the above-mentioned rectification conditions (bottom temperature, top temperature, top pressure, bottom reflux ratio, top reflux ratio, residence time), low-boiling components are distilled off from the intermediate product, and an NDI composition is withdrawn from below the central part of the tower. Thereby, an NDI composition containing NDI, CNI, and a substance corresponding to the effective coefficient can be continuously produced.

[0069] In the third aspect, the examples of the present application provide a modified composition of isocyanate, the modified composition is obtained by modifying the isocyanate composition described in the first aspect, and the modified composition contains (a) an isocyanurate group, (b) a uretdione group, (c) a biuret group, (d) a urethane group, (e) a urea group, (f) an iminooxadiazinedione group, (g) an allophanate group, (h) a uretonimine group, (i) a carbodiimide group, any one or a combination of at least two of them.

[0070] Those skilled in the art can, if necessary, modify the above-mentioned isocyanate composition by known methods to obtain the modified composition. The modified composition is suitably used as a raw material for isocyanate-based polymers such as polyurethane resins together with an active hydrogen group-containing substance as a polyisocyanate component.

[0071] Specifically, the modified composition containing the isocyanurate group of the group (a) is a trimer of isocyanate, and can be obtained, for example, by reacting an isocyanate composition in the presence of a known isocyanuration catalyst to isocyanurate the isocyanate.

[0072] The modified composition containing the uretdione group of the group (b) can be obtained by heating the isocyanate composition at a temperature of 90 to 200 °C, or by reacting it in the presence of a known uretdionization catalyst to uretdionize (for example, dimerize) the isocyanate.

[0073] The modified composition containing the biuret group of the group (c) can be obtained by reacting the isocyanate composition with, for example, water, a tertiary alcohol (such as tert-butanol), a secondary amine (such as dimethylamine, diethylamine, etc.) and further reacting it in the presence of a known biuretization catalyst.

[0074] The modified composition containing the urethane group of the group (d) can be obtained by reacting the isocyanate composition with a polyol (such as trimethylolpropane).

[0075] The modified composition containing the urea group of the group (e) can be obtained by reacting the isocyanate composition with water, a polyamine (described later), etc.

[0076] The modified composition containing the iminooxadiazinedione group of the group (f) is an asymmetric trimer of isocyanate, and can be obtained by reacting the isocyanate composition in the presence of a known iminooxadiazinedionization catalyst to iminooxadiazinedionize (for example, trimerize) the isocyanate.

[0077] The modified composition containing the allophanate group of the group (g) can be obtained by reacting the isocyanate composition with an alcohol and then further reacting it in the presence of a known allophanatization catalyst.

[0078] The modified composition containing the uretonimine group of the group (h) can be obtained by reacting an isocyanate composition in the presence of a known carbodiimidation catalyst to form a carbodiimide group and then adding an isocyanate to the carbodiimide group.

[0079] The modified composition containing the carbodiimide group of the group (i) can be obtained by reacting an isocyanate composition in the presence of a known carbodiimidation catalyst.

[0080] Note that the modified composition may contain at least one of the above groups (a) to (i), or may contain at least two of them. Such a modified composition can be produced by appropriately using the above reactions in combination. Further, the modified composition may be used alone or in combination of two or more.

[0081] In the fourth aspect, the example of the present application is obtained by reacting an isocyanate-based substance and an active hydrogen group-containing substance, and the isocyanate-based substance includes at least one of the isocyanate composition described in the first aspect and the modified composition described in the third aspect, and provides an isocyanate-based polymer.

[0082] Preferably, the active hydrogen group includes any one or a combination of at least two of a hydroxy group, an amino group, and a thiol group.

[0083] Preferably, the active hydrogen group-containing substance includes any one or a combination of at least two of a polyol, a polyamine, and a polythiol.

[0084] Here, when the active hydrogen group-containing substance is a polyol, the isocyanate-based polymer is a polyurethane; when the active hydrogen group-containing substance is a polyamine, the isocyanate-based polymer is a polyurea; when the active hydrogen group-containing substance is a polythiol, the isocyanate-based polymer is a polythiourethane.

[0085] In the fifth aspect, an embodiment of the present application provides a polyurethane elastomer, wherein the production raw materials include an isocyanate-based substance and a polyol, and the isocyanate-based substance includes the isocyanate composition described in the first aspect and / or the modified composition described in the third aspect.

[0086] Preferably, the polyol is a high molecular weight polyol.

[0087] Preferably, the production raw materials further include a chain extender.

[0088] Preferably, the chain extender includes a low molecular weight polyol and / or a low molecular weight polyamine.

[0089] In the present application, the polyurethane elastomer (PUR) may be a thermoplastic polyurethane elastomer (TPU), a thermosetting polyurethane elastomer (TSU), a calenderable polyurethane elastomer, etc. The polyurethane elastomer includes a soft segment formed by the reaction of an isocyanate-based substance and a polyol (high molecular weight polyol), and a hard segment formed by the reaction of an isocyanate-based substance and a chain extender (low molecular weight polyol and / or low molecular weight polyamine). The polyurethane elastomer can be produced by the reaction of an isocyanate-based substance, a high molecular weight polyol (active hydrogen group-containing substance), a low molecular weight polyol and / or a low molecular weight polyamine (active hydrogen group-containing substance). That is, the isocyanate-based substance (the isocyanate composition and / or the modified composition), the polyol (high molecular weight polyol), and the chain extender (low molecular weight polyol and / or low molecular weight polyamine) are raw materials for producing the polyurethane elastomer.

[0090] In the present application, the isocyanate-based substance includes the isocyanate composition and / or the modified composition, the effective coefficient of the isocyanate composition is 3.80 to 5.30, and the modified composition is obtained by modifying the isocyanate composition having an effective coefficient of 3.80 to 5.30. In the present application, through the design and control of the effective coefficient, the discoloration of the polyurethane elastomer can be effectively suppressed, and the tensile strength and tear strength of the polyurethane elastomer can be improved. Thereby, the polyurethane elastomer has excellent comprehensive performance in terms of discoloration resistance, weather resistance, stability, and mechanical properties.

[0091] Preferably, the polyol is a high molecular weight polyol. Exemplarily, it includes any one or at least a combination of two of polyester polyol, polycarbonate polyol, and polyether polyol, but is not limited thereto. More preferably, it is a polyester polyol.

[0092] Preferably, the polyester polyol includes polycaprolactone polyol and / or adipic acid-based polyester polyol (a polyester polyol having adipic acid as a polybasic acid), and more preferably, it is an adipic acid-based polyester polyol.

[0093] Preferably, the polyether polyol includes polytetramethylene ether glycol.

[0094] Preferably, the chain extender includes a low molecular weight polyol and / or a low molecular weight polyamine, and more preferably, it is a low molecular weight polyol.

[0095] Preferably, the low molecular weight polyol includes ethylene glycol and / or 1,4-butanediol, and more preferably, it is 1,4-butanediol.

[0096] In the present application, the polyurethane elastomer can be produced by known methods such as the one-shot method or the prepolymer method.

[0097] In the case of the one-shot method, for example, an isocyanate-based substance (polyisocyanate component, isocyanate composition and / or modified composition), a polyol (high molecular weight polyol), and a chain extender (low molecular weight polyol and / or low molecular weight polyamine) are reacted together to obtain the polyurethane elastomer.

[0098] In the case of the prepolymer method, for example, first, an isocyanate-based substance (polyisocyanate component, isocyanate composition and / or modified composition) and a polyol (high molecular weight polyol) are reacted to synthesize a prepolymer having isocyanate groups at the molecular terminals, and then the prepolymer and a chain extender (low molecular weight polyol and / or low molecular weight polyamine) are reacted to obtain the polyurethane elastomer.

[0099] Regarding the production method of the polyurethane elastomer, polymerization methods known in the art, such as bulk polymerization, solution polymerization, etc., may be used.

[0100] Also, regarding the production of the polyurethane elastomer, if necessary, known carbamate catalysts such as amines, organometallic compounds (for example, organotin compounds, preferably dibutyltin dichloride, tin octylate, etc.) may be added to the production raw materials.

[0101] Furthermore, if necessary, plasticizers, anti-caking agents, heat stabilizers, light stabilizers, ultraviolet absorbers, NOx yellowing inhibitors, antioxidants, release agents, pigments, dyes, lubricants, nucleating agents, fillers, hydrolysis inhibitors, etc. may be blended with the polyurethane elastomer in appropriate proportions.

[0102] As a preferred technical solution of the present application, the polyurethane elastomer is excellent in discoloration resistance and weather resistance, and is also excellent in mechanical properties (tensile strength and tear strength).

[0103] In particular, the polyurethane elastomer has a color difference Δb of 3.0 or less 240 hours after a high-temperature and high-humidity aging test under irradiation with a xenon lamp. For example, Δb may be 2.95, 2.9, 2.85, 2.8, 2.75, 2.7, 2.65, 2.6, 2.55, 2.5, 2.45, 2.4, 2.35, 2.3, 2.25, 2.2, 2.15, 2.1, 2.05, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, etc., but more preferably, it is less than 3.0.

[0104] Preferably, the polyurethane elastomer produced from the NDI composition has a tensile strength exceeding 41 MPa and can reach 41.3 - 42.5 MPa, and a tear strength exceeding 64 kN / m and can reach 64.1 - 65.2 kN / m.

[0105] Preferably, the polyurethane elastomer produced from the PPDI composition has a tensile strength exceeding 44 MPa and can reach 44.3 - 45.7 MPa, and a tear strength exceeding 119 kN / m and can reach 119.6 - 121.6 kN / m.

[0106] Preferably, the polyurethane elastomer produced from the CHDI composition has a tensile strength exceeding 35 MPa and can reach 35.1 - 36.1 MPa, and a tear strength of 59 kN / m or more, and is 59.0 - 60.1 kN / m.

Advantages of the Invention

[0107] Compared with the related art, the examples of the present application have the following beneficial effects.

[0108] In the isocyanate composition according to the embodiments of the present application, through the design and control of the effective coefficient, it has excellent reaction activity and can be used in the production of high-performance polyurethane products. The isocyanate composition can effectively improve the stability of polyurethane products, particularly significantly improving the discoloration resistance and weather resistance of polyurethane elastomers, suppressing the increase in color number and yellowing under high-temperature and high-humidity conditions. As a result, the color difference Δb of the polyurethane elastomer after 240 h from the high-temperature and high-humidity aging test irradiated with a xenon lamp is less than 3.0. Also, the tensile strength and tear strength of the polyurethane elastomer are improved. Thereby, the polyurethane elastomer has excellent comprehensive properties in terms of weather resistance and mechanical strength and the like.

[0109] Other aspects will become apparent upon reading and understanding the drawings and the detailed description.

Brief Description of the Drawings

[0110] The drawings are provided to further understand the technical solutions of this specification, constitute a part of this specification, and are used to explain the technical solutions of this specification together with the embodiments of the present application, and do not limit the technical solutions of this specification.

[0111]

Figure 1

Modes for Carrying Out the Invention

[0112] Hereinafter, through specific embodiments, the technical solutions of the present application will be further described. It is obvious to those skilled in the art that the above embodiments are only helpful for understanding the present application and should not be regarded as specifically limiting the present application. In the present application, the test methods for components and performance are as follows.

[0113] 1. Measurement of the mass content (B value) of chloro isocyanate in the isocyanate composition: GCMS test Analysis was carried out using gas chromatography-mass spectrometry under the following conditions. The content in this specification is the normalized content. Analytical instrument: Agilent 5977B GCMS Chromatography column: DB-5 chromatography column, specification: 30m × 0.25mm × 0.25μm Column oven temperature: Maintain at 50°C for 2 min, increase the temperature to 80°C at a rate of 5 mL / min, then increase the temperature to 280°C at a rate of 15 mL / min, and maintain for 10 min. Split ratio: Splitless Inlet temperature: 280°C Detection temperature: 300°C Carrier gas: Helium gas Carrier gas flow rate: 1 mL / min (constant flow rate) Injection volume: 1 μL Detection method: For SIM, select the ion scan mode (for NDI, select ions 202 / 168, for PPDI, select ions 152 / 118, for CHDI, select ions 158 / 124).

[0114] 2. Measurement of the mass content (A value) of chlorine in the isocyanate composition: XRF test Instrument: Energy dispersive X-ray fluorescence spectrometry (ED-XRF), model number: MERAK-LE II; Method: Standard addition method Principle and operation: Using chromatographically pure CCl4 standard as the Cl source and ethyl acetate as the diluent, the Cl element in the sample is excited by the X-ray generated by the X-ray tube to generate characteristic X-ray fluorescence. The characteristic X-ray fluorescence intensity has a linear relationship with the element concentration. A calibration curve is prepared, and the extrapolated value is taken as the Cl content in the sample.

[0115] 3. Measurement of the mass content ratio of isocyanate in the isocyanate composition: Test by gas chromatography Analysis was carried out using gas chromatography under the following conditions. The content in this application is the normalized content. Analytical instrument: Agilent 7890B GC Chromatography column: DB-5 chromatography column, specifications: 30m × 0.25mm × 0.25μm Column oven temperature: Maintain at 60°C for 1 min, heat up to 280°C at a rate of 10°C / min, and maintain for 5 min. Separation ratio: 30:1 Inlet temperature: 280°C Detection temperature: 320°C Carrier gas: Nitrogen gas Carrier gas flow rate: 1 mL / min (constant flow rate) Injection volume: 1 μL Detector: FID In the following specific embodiments of the present application, unless otherwise specified, "parts" and "%" are based on mass.

[0116] Example 1 An NDI composition and its manufacturing method, wherein the effective coefficient E of the NDI composition is 5.30, and its manufacturing method is shown in the flowchart in Figure 1. Specifically, it includes the following steps. Phosgenation step: Charge 800 parts by mass of chlorobenzene into a cold reaction kettle, adjust the temperature in the cold reaction kettle to 20°C, and adjust the pressure (gauge pressure) to 0.04 MPaG. Continuously charge a chlorobenzene solution of amine with a concentration of 10.0 wt.% of 1,5-NDA (1,5-naphthalenediamine) into the cold reaction kettle at a rate of 500 parts by mass / h, and continuously introduce phosgene into the kettle at a rate of 626 parts by mass / h. Set the temperature of the cold reaction to 20°C and the time to 2.5 h to obtain a cold reaction photochemical solution. Take out the cold reaction photochemical solution from the cold reaction kettle and send it to a hot reaction kettle. Introduce phosgene into the hot reaction kettle at a rate of parts by mass / h, maintain the temperature in the hot reaction kettle at 110°C, and adjust the pressure (gauge pressure) to 0.2 MPa G to carry out a hot reaction. Set the temperature to 110°C and the time to 4 h, thereby reacting 1,5-NDA with phosgene to produce 1,5-NDI and manufacturing a reaction product containing 1,5-NDI. Removal process: The reaction product obtained in the phosgenation process was continuously sent to a dephosgenation column and a solvent removal column, and dephosgenation treatment and solvent removal treatment were respectively carried out, whereby 130 parts by mass of a crude product of NDI was produced. Separation process: The crude product obtained in the removal process was continuously sent to a short-path evaporator, and 117.2 parts by mass of an intermediate product from which heavy components were removed and 12.8 parts by mass of primary heavy components were obtained. Heavy component recovery process: The primary heavy components were continuously sent to a two-stage short-path evaporator, and 2.39 parts by mass of heavy component recovery material and 10.4 parts by mass of residual heavy components were obtained. Subsequently, the intermediate product with a rate of 117.2 parts by mass / h and the heavy component recovery material with a rate of 2.39 parts by mass / h were mixed to obtain a mixture of 119.6 parts by mass / h. That is, the mass content of the heavy component recovery material in the said mixture was 2%. Purification process: The above-mentioned mixture was continuously sent to a rectification column filled with a packing material corresponding to 5 theoretical plates. Then, light components were removed from the top of the column in the rectification column, and an NDI composition was extracted from the central part of the column to obtain the target product. The rectification conditions in the rectification column are shown below. Bottom temperature: 130 - 140 °C Top temperature: 120 - 130 °C Top pressure: 0 - 50 PaA Residence time: 2 - 4 h Top reflux ratio: 4 Thereby, the said NDI composition was obtained. Here, the mass content of NDI exceeded 99%, the mass content of chlorine (A value) was 7.6 ppm, the mass content of chloro isocyanate CNI (B value) was 15 ppm, and the effective coefficient E was 5.30.

[0117] Examples 2 - 5, Comparative Examples 1 - 2 An NDI composition and a method for producing the same, wherein the effective coefficient E of the NDI composition is shown in Table 1 respectively, and the flow of the production method is the same as that of Example 1, but the parameters of some processes are different. Specifically, they are shown in Table 1 (the processes / parameters not shown in Table 1 are exactly the same as those in Example 1). In Table 1, the "phosgene molar ratio" represents the molar amount of the phosgene when 1 mol of 1,5-NDA is used in the phosgenation step, and the "proportion of the heavy component recovery material" represents the mass content ratio of the heavy component (recovery material) in the mixture in the heavy component recovery step.

[0118]

Table 1

[0119] Examples 6 to 10, Comparative Examples 3 to 4 A PPDI composition and a method for producing the same, wherein the effective coefficient E of the PPDI composition is shown in Table 2 respectively, and the flow of the production method is the same as that of Example 1, but the parameters of some processes are different. Specifically, they are shown in Table 2 (the processes / parameters not shown in Table 2 are exactly the same as those in Example 1). In Table 2, the "phosgene molar ratio" represents the molar amount of the phosgene when 1 mol of 1,4-diaminobenzene is used in the phosgenation step, and the "proportion of the heavy component recovery material" represents the mass content ratio of the heavy component (recovery material) in the mixture in the heavy component recovery step.

[0120]

Table 2

[0121] Examples 11 to 15, Comparative Examples 5 to 6 A CHDI composition and a method for producing the same, wherein the effective coefficient E of the PPDI composition is shown in Table 3 respectively, and the flow of the production method is the same as that of Example 1, but some process parameters are different. Specifically, they are shown in Table 3 (processes / parameters not shown in Table 3 are exactly the same as those in Example 1). In Table 3, the "phosgene molar ratio" is the molar amount of the phosgene when 1 mol of 1,4-diaminocyclohexane is used in the phosgenation step, and the "proportion of heavy component recovery material" represents the mass content rate of the heavy component (recovery material) in the mixture in the heavy component recovery step.

[0122]

Table 3

[0123] Examples 16 to 18 and Comparative Examples 7 to 9 NDI was produced by the method in Example 1 of the related art CN110256296A and used as Comparative Example 7. In this example, NDI was produced by the thermal decomposition method, and since the product did not contain chlorine, there was no effective coefficient. The heavy component recovery material in Example 1 was added to this product at a ratio of 4% (that is, the mass content rate of the heavy component in the obtained mixture was 4%) to obtain Example 16. Similarly, except that the raw material NDA was changed to PPDA, the remaining conditions were the same as those described in Example 1 of CN110256296A to produce PPDI and used as Comparative Example 8. The heavy component recovery material in Example 6 was added to this product at a ratio of 4% (that is, the mass content rate of the heavy component in the obtained mixture was 4%) to obtain Example 17. Except that the raw material NDA was changed to CHDA, the remaining conditions were the same as those described in Example 1 of CN110256296A to produce CHDI and used as Comparative Example 9. The heavy component recovery material in Example 11 was added to this product at a ratio of 4% (that is, the mass content rate of the heavy component in the obtained mixture was 4%) to obtain Example 18.

[0124] Application Example The polyurethane elastomer is specifically a thermoplastic polyurethane elastomer (TPU). Its production raw materials include isocyanate-based substances (polyisocyanate components), high molecular weight polyols, and chain extenders (low molecular weight polyols). The isocyanate-based substances are, respectively, the isocyanate compositions according to Examples 1 to 15 and Comparative Examples 1 to 6. The high molecular weight polyol is an adipic acid-based polyester polyol (manufactured by Mitsui Chemicals, TAKELAC U-2024, number average molecular weight 2000), and the chain extender is 1,4-butanediol (InnoChem reagent). Further, the production raw materials also include a catalyst (tin octylate) and a heat stabilizer (purchased from Ciba Specialty Chemicals, IRGANOX 245). The method for producing the polyurethane elastomer is as follows. (1) 221 parts by mass of an NDI composition (168 parts by mass based on the mass of the PPDI composition and 175 parts by mass based on the mass of the CHDI composition) and 531.2 parts by mass of an adipic acid-based polyester polyol were charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen supply tube, and reacted at 80°C under a nitrogen atmosphere until the NCO group content reached 9.1 wt.% to obtain a prepolymer having isocyanate groups at the molecular terminals. (2) 3.9 parts by mass of a heat stabilizer and 0.07 part by mass of a solution obtained by diluting tin octylate as a catalyst to 4 wt.% with diisononyl adipate (West Asia Reagent Co., Ltd.) were added to the prepolymer obtained in step (1), and using a mechanical stirrer (IKA, RW20 from Germany), stirred at a rotation speed of 600 rpm for about 1 min for mixing. Then, 131.9 parts by mass of 1,4-butanediol previously adjusted to 80°C was added to the system and stirred sufficiently for about 2 min for uniform mixing to obtain a mixed solution. (3) The mixed solution obtained in step (2) was poured into a stainless steel tray previously adjusted to 150°C and reacted at 150°C for 1 h, and then reacted at 100°C for 23 h to obtain an elastomer. (4) Take out the elastomer obtained in step (3) from the tray, and cure it for 7 days under the constant temperature and humidity conditions of room temperature 23°C and relative humidity 55% to obtain the polyurethane elastomer. Evaluation of the performance of the polyurethane elastomer Using an injection molding machine (model number: NEX-140, Taifu Machinery Co., Ltd.), the polyurethane elastomer to be measured (raw material, the mixed solution obtained in step (2) in the application example) was set at a screw speed of 100 rpm, a barrel temperature of 150 - 235°C, a mold temperature of 20°C, an injection time of 10 s, an injection speed of 60 mm / s, and a cooling time of 45 s, and injection molding was carried out to obtain a sheet. Under the constant temperature and humidity conditions of 23°C and relative humidity 55%, the obtained sheet (thickness 2 mm) was cured for 7 days to obtain a polyurethane elastomer sheet for testing. Specifically, the performance was tested as follows. (1) First, use a colorimeter to measure the b value (b1, initial value) of the polyurethane elastomer sheet. Next, conduct a xenon lamp irradiation test, that is, put the polyurethane elastomer sheet into a super xenon lamp climate test chamber (Weibang Instruments), and place it for 240 h under the conditions of temperature 89°C, relative humidity 50%, and xenon lamp illuminance 100 W / m 2 (irradiation wavelength 300 - 400 nm). After taking out the sheet, measure the b value (b2) of the sheet by the same method as above. Calculate the color difference Δb (Δb = |b2 - b1|) of the polyurethane elastomer after 240 h of damp heat aging test under xenon lamp irradiation. (2) Tensile strength: The tensile strength of the elastomer is tested according to the method described in GB / T 528 - 2009. (3) Tear strength: The tear strength of the elastomer is tested according to GB / T 529 - 2008. The above-mentioned test results are shown in Table 4, Table 5, and Table 6.

[0125]

Table 4

[0126]

Table 5

[0127]

Table 6

[0128] As can be seen from the data of the above performance tests, in the present application, by controlling the effective coefficient of the isocyanate composition within the range of 3.80 to 5.30, the polyurethane elastomer produced based on the isocyanate composition has excellent stability and weather resistance, and the color difference Δb is less than 3.0 and as low as 2.53 to 2.95 when aged and treated at high temperature and high humidity for 240 h while irradiating with a xenon lamp. The increase in color number and yellowing under high temperature and high humidity conditions can be suppressed, and the tensile strength and tear strength of the polyurethane elastomer can be increased. Among them, the polyurethane elastomer produced with the NDI composition has a tensile strength of 41.3 to 42.5 MPa and a tear strength of 64.1 to 65.2 kN / m. The polyurethane elastomer produced with the PPDI composition has a tensile strength of 44.3 to 45.7 MPa and a tear strength of 119.6 to 121.6 kN / m. The polyurethane elastomer produced with the CHDI composition has a tensile strength of 35.1 to 36.1 MPa and a tear strength of 59.0 to 60.1 kN / m. Thereby, the polyurethane elastomer can maintain the comprehensive performance of the product such as excellent appearance, weather resistance, and mechanical properties. From the above, it has been found that the isocyanate composition according to the present application is more promising for application to polyurethane elastomers.

[0129] The isocyanate composition, modified composition, and polyurethane elastomer in the present application are described by the above examples. However, the present application is not limited to the steps of the above process, that is, the applicant declares that the present application does not mean that it must be implemented depending on the steps of the above process. For those skilled in the art, it should be obvious that any improvement to the present application, equivalent substitution of the raw materials selected in the present application, addition of auxiliary components, selection of specific forms, etc. are all included within the protection scope and disclosure scope of the present application.

Explanation of reference numerals

[0130] 10 Phosgenation step 20 Removal step 30 Separation step 40 Heavy component recovery step 50 Purification step

Claims

1. The effective coefficient is 3.80 to 5.30, and the calculation formula of the effective coefficient is represented by Formula I, 【Number 1】 where E is the effective coefficient, A is the mass content of chlorine in the isocyanate composition, B is the mass content of chloro isocyanate in the isocyanate composition, M Cl is the relative atomic mass of chlorine, M B is an isocyanate composition that is the relative molecular mass of the chloro isocyanate.

2. The isocyanate composition according to claim 1, wherein the isocyanate is diisocyanate.

3. The isocyanate composition according to claim 2, comprising any one or at least a combination of two of naphthalene diisocyanate, phenylene diisocyanate, cyclohexane diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate.

4. The isocyanate composition according to any one of claims 1 to 3, wherein the mass content rate of isocyanate in the isocyanate composition is 97% or more.

5. The chloro isocyanate is a compound in which one NCO group of the isocyanate is substituted with chlorine, preferably, the chloro isocyanate is 【Chemical 1】 The isocyanate composition according to any one of claims 1 to 4, comprising any one or at least a combination of two of them.

6. The isocyanate composition according to any one of claims 1 to 5, wherein the substance corresponding to the effective coefficient comprises any one or at least a combination of two of the following compounds. 【Chemical 2】 (Here, R is a divalent group obtained by removing the NCO group from the isocyanate, preferably, the R is 【Chemical Formula 3】 Any one or at least a combination of two selected from, where the wavy line represents the connection site of the group.)

7. The A is obtained by X-ray fluorescence analysis, preferably, the B is obtained by chromatography-mass spectrometry, and more preferably, the isocyanate composition according to any one of claims 1 to 6 is obtained by gas chromatography-mass spectrometry.

8. A method for producing the isocyanate composition according to any one of claims 1 to 7, comprising the step of reacting an amine compound with phosgene to obtain the isocyanate composition.

9. Step (1) of reacting an amine compound with phosgene to obtain a reaction product, and Step (2) of performing a removal treatment including a dephosgenation treatment and / or a desolvent treatment on the reaction product obtained in step (1) to obtain a crude product. Step (3) of sequentially performing separation and purification on the crude product obtained in step (2) to obtain the isocyanate composition, and the manufacturing method according to claim 8.

10. Heavy components and intermediate products are obtained by the separation in step (3), the mixture of the intermediate product and the heavy components is purified to obtain the isocyanate composition, and the mass content of the heavy components in the mixture is 1 to 10%, and the manufacturing method according to claim 8.

11. The method of the purification is rectification, and the manufacturing method according to claim 10.

12. Obtained by modifying the isocyanate composition according to any one of claims 1 to 7, An isocyanate modified composition containing any one or a combination of at least two of (a) isocyanurate group, (b) uretdione group, (c) biuret group, (d) urethane group, (e) urea group, (f) iminooxadiazinedione group, (g) allophanate group, (h) uretonimine group, and (i) carbodiimide group.

13. An isocyanate-based polymer formed by reacting an isocyanate-based substance with an active hydrogen group-containing substance, and the isocyanate-based substance includes at least one of the isocyanate composition according to any one of claims 1 to 7 and the modified composition according to claim 12.

14. The manufacturing raw materials include an isocyanate-based substance and a polyol, and the isocyanate-based substance includes the isocyanate composition according to any one of claims 1 to 7 and / or the modified composition according to claim 12, and a polyurethane elastomer.

15. The manufacturing raw materials further include a chain extender, Preferably, the chain extender includes a low molecular weight polyol and / or a low molecular weight polyamine, and the polyurethane elastomer according to claim 14.

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