Carboxylated hydrogenated liquid nitrile rubber, preparation method therefor, and vulcanized rubber

Abstract

The present invention relates to the technical field of hydrogenated nitrile rubber, and specifically relates to a carboxylated hydrogenated liquid nitrile rubber, a preparation method therefor, and a vulcanized rubber. The preparation method comprises: in the presence of a solvent, hydrogen, and a catalyst, providing a starting material for a carboxylated hydrogenated liquid nitrile rubber for a contact reaction comprising metathesis and hydrogenation, wherein the starting material for the carboxylated hydrogenated liquid nitrile rubber is selected from carboxylated nitrile rubber, or nitrile rubber and an unsaturated carboxylic acid. The preparation method is simple, has the advantages of mild reaction conditions and a fast reaction rate, and is characterized by controllable product molecular weight.

Description

Carboxyl hydrogenated liquid nitrile rubber and its preparation method, vulcanizate

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411574650.7, filed on November 6, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of hydrogenated nitrile butadiene rubber technology, specifically to a carboxyl-hydrogenated liquid nitrile butadiene rubber, its preparation method, and vulcanizate. Background Technology

[0004] Hydrogenated nitrile butadiene rubber (HNBR) is produced by hydrogenating the unsaturated double bonds in nitrile butadiene rubber (NBR) molecules under high temperature and high pressure. HNBR possesses excellent heat resistance, superior chemical corrosion resistance (such as good resistance to refrigerants, acids, and alkalis), excellent ozone resistance, and high compression set resistance. It also exhibits high strength, high tear resistance, and excellent abrasion resistance, making it one of the most outstanding special rubbers in terms of overall performance. Its superior properties play a crucial role in harsh operating environments such as sealing components and media-resistant pipelines. Currently, the vast majority of commercial HNBR is solid HNBR, typically with a number average molecular weight of over 100,000.

[0005] Liquid hydrogenated nitrile butadiene rubber (LHNBR) is a special type of HNBR product with a number-average molecular weight typically below 10,000, and it exists as a viscous liquid at room temperature. It is a novel low-molecular-weight liquid toughening, plasticizing, and rubber softening agent, and also possesses unique advantages in the coatings field. It has attracted considerable attention as a matrix material for special composite materials such as electromagnetic shielding coatings, oil-resistant coatings, battery corrosion-resistant coatings, sealing components, and damping noise-reducing coatings.

[0006] The mainstream method for preparing liquid nitrile rubber (NBR) is low-temperature emulsion polymerization. This method involves polymerizing various oil-phase monomers in an aqueous medium under the action of an emulsifier. The molecular weight of the polymer is controlled by initiators and chain transfer agents (usually thiols), thus achieving the preparation of liquid NBR. Relevant literature includes CN103626924A, CN1978476A, CN105837754A, and CN118108896A. This process route has a relatively low conversion rate, and generally, extending the polymerization time is used to improve the monomer conversion rate, which reduces production efficiency. At the same time, due to the low conversion rate, unconverted monomers need to be properly collected and treated, requiring high-level post-treatment processes such as tail gas treatment.

[0007] Hydrogenated carboxylated acrylonitrile-butadiene rubber (HXNBR) is HNBR incorporating carboxyl groups. Currently, major global manufacturers of nitrile rubbers produce HXNBR through catalytic hydrogenation of NBR rubber, which is a ternary emulsion copolymer of butadiene, acrylonitrile, and unsaturated carboxylic acids or carboxylic esters. The introduction of carboxyl groups further enhances its oil resistance and effectively improves the tensile strength, elastic modulus, hardness, and adhesion of the rubber material, especially improving the tensile strength of HNBR at high temperatures. In addition, the introduction of carboxyl groups increases the polarity of the HNBR molecular chain, enhancing its compatibility with general-purpose resins such as polyvinyl chloride and phenolic resins, thus broadening the application areas of HNBR.

[0008] Currently, there is limited research on the preparation methods of LHNBR in publicly available information, and the variety of LHNBR products is very limited. Summary of the Invention

[0009] The purpose of this invention is to overcome the problems of limited product variety and insufficient performance improvement of hydrogenated liquid nitrile butadiene rubber in the prior art, and to provide a new carboxyl-based liquid nitrile butadiene rubber, its preparation method, and vulcanizate. This method has the advantages of simple preparation, mild reaction conditions, fast reaction rate, and controllable product molecular weight.

[0010] To achieve the above objectives, the first aspect of the present invention provides a method for preparing carboxyl hydrogenated liquid nitrile butadiene rubber, the method comprising: providing a raw material for carboxyl hydrogenated liquid nitrile butadiene rubber in the presence of a solvent, hydrogen and a catalyst, and subjecting it to a contact reaction including metathesis and hydrogenation, wherein the raw material for providing the carboxyl hydrogenated liquid nitrile butadiene rubber is selected from carboxyl nitrile butadiene rubber, or nitrile butadiene rubber and unsaturated carboxylic acid.

[0011] The second aspect of the present invention provides a carboxyl hydrogenated liquid nitrile rubber prepared by the preparation method described in the first aspect of the present invention.

[0012] A third aspect of the present invention provides a vulcanizate obtained by vulcanizing the carboxyl hydrogenated liquid nitrile rubber described in the second aspect of the present invention.

[0013] Through the above technical solution, the present invention has at least the following beneficial effects:

[0014] 1. The preparation method of carboxyl hydrogenated liquid nitrile rubber in this invention is simple and has the advantages of mild reaction conditions and fast reaction rate. At the same time, the prepared carboxyl hydrogenated liquid nitrile rubber has excellent comprehensive properties, such as good low temperature performance, ozone resistance and weather resistance.

[0015] 2. The carboxyl hydrogenated liquid nitrile rubber prepared by the preparation method of the present invention can be vulcanized directly with sulfur, which solves the problem that HNBR cannot be vulcanized with sulfur system and greatly reduces the processing difficulty.

[0016] 3. The carboxyl hydrogenated liquid nitrile rubber prepared by the preparation method of the present invention has a wide range of applications, considerable economic value and social benefits, and is expected to be applied in fields such as automotive parts, aerospace and high-end sealing materials. Attached Figure Description

[0017] Figure 1 is the infrared spectrum of the carboxyl hydrogenated liquid nitrile rubber in Examples 2 and 4. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] The first aspect of the present invention provides a method for preparing carboxyl hydrogenated liquid nitrile butadiene rubber, the method comprising: providing a raw material for carboxyl hydrogenated liquid nitrile butadiene rubber in the presence of a solvent, hydrogen and a catalyst, and subjecting it to a contact reaction including metathesis and hydrogenation, wherein the raw material for providing the carboxyl hydrogenated liquid nitrile butadiene rubber is selected from carboxyl nitrile butadiene rubber, or nitrile butadiene rubber and unsaturated carboxylic acid.

[0020] In this invention, the molecular weight of solid unsaturated nitrile rubber with a large molecular weight is reduced by metathesis and chain breaking and recombination. Furthermore, the metathesis reaction and hydrogenation reaction occur simultaneously, enabling the one-pot preparation of carboxyl hydrogenated liquid nitrile rubber. This preparation method is simple and has the advantages of mild reaction conditions, fast reaction rate, and controllable product molecular weight. The final carboxyl hydrogenated liquid nitrile rubber has a low glass transition temperature.

[0021] Carboxylated nitrile rubber and nitrile rubber are generally solids. The addition of solvent in this invention is mainly to make the carboxylated nitrile rubber or nitrile rubber form a liquid, which is conducive to the occurrence of contact reaction in this invention.

[0022] According to a specific embodiment of the present invention, nitrile rubber is dissolved in a solvent to obtain a rubber solution. A catalyst and an unsaturated carboxylic acid are added to the rubber solution and hydrogen is introduced to carry out a contact reaction including metathesis and hydrogenation. The solvent is removed to obtain carboxyl hydrogenated liquid nitrile rubber.

[0023] In this invention, there are no special restrictions on the amount of solvent used, as long as it enables the carboxylated nitrile rubber or nitrile rubber to form the corresponding adhesive solution, which is conducive to the occurrence of the contact reaction in this invention. According to one embodiment of the invention, the mass ratio of the carboxylated nitrile rubber or nitrile rubber to the solvent is 0.01-0.15:1.

[0024] According to one embodiment of the present invention, the dissolution conditions include a temperature of 20-60°C, preferably 50-60°C.

[0025] According to one embodiment of the present invention, the dissolution conditions include a time of 1-48 hours, preferably 6-8 hours.

[0026] The carboxylated nitrile butadiene rubber in this invention can be commercially available or prepared using conventional methods in the art. The prepared carboxylated nitrile butadiene rubber can then be used in a specific embodiment of this invention for preparing carboxylated hydrogenated liquid nitrile butadiene rubber. The advantages of this invention are illustrated by using a carboxylated nitrile butadiene rubber with the following characteristics as an example, but this does not constitute a limitation of the invention.

[0027] According to one embodiment of the present invention, the acrylonitrile content in the carboxylated butadiene-acrylonitrile rubber is 30wt%-35wt%, preferably 33wt%-35wt%.

[0028] According to one embodiment of the present invention, the number average molecular weight of the carboxylated nitrile rubber is 80,000-150,000, preferably 102,000-135,000.

[0029] According to one embodiment of the present invention, the carboxyl content in the carboxyl acrylonitrile rubber is 0.1wt%-6wt%, preferably 1.1wt%-3wt%.

[0030] According to one embodiment of the present invention, the Mooney viscosity of the carboxylated nitrile rubber is 50-59, preferably 52-56.

[0031] According to one embodiment of the present invention, the molecular weight distribution index of the carboxylated nitrile rubber is 1.5-10.0, preferably 2.5-6.0.

[0032] The nitrile rubber in this invention can be obtained commercially or prepared using conventional methods in the art. The prepared nitrile rubber can then be used in one specific embodiment of this invention for preparing carboxyl-hydrogenated liquid nitrile rubber. The advantages of this invention are illustrated by nitrile rubber having the following characteristics, but this does not constitute a limitation thereof.

[0033] According to one embodiment of the present invention, the acrylonitrile content in the nitrile rubber is 27wt%-35wt%, preferably 30wt%-35wt%.

[0034] According to one embodiment of the present invention, the number average molecular weight of the nitrile rubber is 80,000-120,000, preferably 90,000-105,000.

[0035] According to one embodiment of the present invention, the Mooney viscosity of the nitrile rubber is 45-55, preferably 50-55.

[0036] According to one embodiment of the present invention, the molecular weight distribution index of the nitrile rubber is 1.0-8.0, preferably 2.5-5.0.

[0037] In this invention, there is no special limitation on the amount of catalyst used, as long as it can promote the contact reaction in this invention. According to one embodiment of the invention, the mass ratio of the carboxylated nitrile rubber or nitrile rubber to the catalyst is 1:0.0002-0.003, preferably 1:0.0003-0.001.

[0038] In the process of preparing carboxyl-hydrogenated liquid nitrile rubber according to the present invention, there are actually two processes: "olefin metathesis" and "hydrogenation of unsaturated double bonds." These two processes are competitive: the olefin metathesis catalyst exhibits metathesis activity after removing some ligands; when the transition metal center combines with hydrogen, it loses its metathesis activity but simultaneously acquires hydrogenation activity. The combination of the transition metal center and hydrogen is a relatively slow process, so macroscopically, the olefin metathesis catalyst simultaneously possesses two functions. That is, the present invention can use a catalyst that can simultaneously achieve olefin metathesis and hydrogenation reactions. According to one embodiment of the present invention, the catalyst is selected from at least one of Grubbs I, Grubbs II, Grubbs III, and Hoveyda-Grubbs II, preferably Hoveyda-Grubbs II.

[0039] The addition of solvent in this invention is mainly to enable the carboxylated nitrile rubber or nitrile rubber to form a glue solution, which is beneficial to the occurrence of the contact reaction in this invention. As long as the purpose of this invention can be achieved, there is no special limitation on the specific type of solvent. According to one embodiment of this invention, the solvent is selected from at least one of methyl ethyl ketone, toluene, butanone, chloroform, trichloromethane, ethyl acetate, butyl butyrate, chlorobenzene, stilbene, toluene, and xylene, preferably at least one of chlorobenzene, toluene, and xylene.

[0040] According to one embodiment of the present invention, the pressure of the hydrogen gas is 6-12 MPa.

[0041] According to one embodiment of the present invention, the conditions for the contact reaction include a temperature of 70-160°C, preferably 120-160°C.

[0042] In this invention, the contact reaction time can be adjusted according to the corresponding temperature. According to one embodiment of the invention, the contact reaction conditions include a time of 1-12 hours, preferably 4-8 hours.

[0043] According to one embodiment of the present invention, the unsaturated carboxylic acid is selected from C3-C4. 10 The unsaturated carboxylic acid is preferably one of methacrylic acid, acrylic acid, butenoic acid, maleic acid, and trans-butenoic acid. Under the action of a catalyst, the two parts of the nitrile rubber and the unsaturated carboxylic acid linked by double bonds undergo exchange to achieve carboxylation.

[0044] According to one embodiment of the present invention, the mass ratio of the unsaturated carboxylic acid to the nitrile rubber is 0.005-0.06:1, for example, 0.005:1, 0.008:1, 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, or any range of two of the above ratios.

[0045] The second aspect of the present invention provides a carboxyl hydrogenated liquid nitrile rubber prepared by the preparation method described in the first aspect of the present invention.

[0046] This invention utilizes an olefin metathesis catalyst to prepare carboxyl hydrogenated liquid nitrile rubber in a one-step process, which can produce a novel liquid nitrile rubber that combines the low glass transition temperature and easy processing of liquid rubber with the high stability of carboxyl hydrogenated nitrile rubber.

[0047] According to one embodiment of the present invention, the carboxyl hydrogenated liquid nitrile rubber contains hydrogenated polybutadiene segments, polyacrylonitrile segments, and modified carboxyl functional groups.

[0048] In this invention, the introduction of carboxyl groups into hydrogenated nitrile butadiene rubber (HNBR) further enhances its oil resistance and effectively improves the tensile strength, elastic modulus, hardness, and adhesion of the rubber material, especially improving the tensile strength of HNBR at high temperatures. Furthermore, the introduction of carboxyl groups increases the polarity of the HNBR molecular chain, enhancing its compatibility with general-purpose resins such as polyvinyl chloride and phenolic resins. Simultaneously, the specific glass transition temperature further broadens the application range of HNBR.

[0049] According to one embodiment of the present invention, the glass transition temperature of the carboxyl hydrogenated liquid nitrile rubber is not higher than -30°C.

[0050] According to one embodiment of the present invention, the glass transition temperature of the carboxyl hydrogenated liquid nitrile rubber is -47 to -30°C.

[0051] The glass transition temperature (Tg) refers to the temperature at which a material transitions from a glassy state to a highly elastic state. When a polymer material is used in an environment below Tg, the material will transition from an elastic state to a glassy state, and its macroscopic properties will become brittle and hard, leading to failure. A lower glass transition temperature means that the material has better low-temperature resistance. The carboxyl hydrogenated liquid nitrile rubber in this invention has superior comprehensive properties within the aforementioned glass transition temperature range.

[0052] In this invention, as long as the objective of the invention can be achieved, the molecular weight distribution of the carboxyl hydrogenated liquid nitrile rubber can be selected within a wide range. According to one embodiment of the invention, the molecular weight distribution index of the carboxyl hydrogenated liquid nitrile rubber is 2.5-6. The carboxyl hydrogenated liquid nitrile rubber of the aforementioned embodiment can be further processed more effectively.

[0053] Liquid hydrogenated nitrile butadiene rubber (NBR) typically has a number-average molecular weight below 10,000 and is a viscous liquid at room temperature. It is a novel type of low-molecular-weight liquid toughening, plasticizing, and rubber softening agent, and also possesses unique advantages in the coatings field, serving as a matrix material for special composite materials such as electromagnetic shielding coatings, oil-resistant coatings, battery corrosion-resistant coatings, sealing components, and damping noise-reducing coatings. In this invention, the molecular weight of the carboxyl-hydrogenated liquid NBR can be selected within a wide range, provided that the objectives of this invention are achieved. According to one embodiment of the invention, the number-average molecular weight of the carboxyl-hydrogenated liquid NBR is 1500-10000. According to another embodiment of the invention, the carboxyl group is located at the end group and / or side group of the main chain.

[0054] According to one embodiment of the present invention, the carboxyl group is selected from -R-COOH; R is H or a C1-C9 alkenyl and / or alkylene group. Examples of C1-C9 alkenyl and / or alkylene groups include methylene, ethylene, ethylpropyl, butylene, etc.

[0055] The controllable hydrogenation saturation of the product allows it to directly undergo vulcanization crosslinking with sulfur, solving the problem that hydrogenated nitrile rubber cannot be vulcanized using sulfur systems, and greatly reducing processing difficulty. Simultaneously, the high hydrogenation saturation further enhances the ozone resistance and weather resistance of carboxyl-hydrogenated liquid nitrile rubber. As long as the objectives of this invention are achieved, the degree of hydrogenation of the hydrogenated polybutadiene segments can be selected within a wide range. According to one embodiment of this invention, the degree of hydrogenation of the hydrogenated polybutadiene segments is 60wt%-100wt%.

[0056] In this invention, the content of polyacrylonitrile segments can be selected within a wide range. According to one embodiment of this invention, based on the mass of carboxyl hydrogenated liquid nitrile rubber, the content of polyacrylonitrile segments is 25-35 wt%.

[0057] In this invention, the content of carboxyl groups can be selected within a wide range. According to one embodiment of this invention, based on the mass of carboxyl hydrogenated liquid nitrile rubber, the content of carboxyl groups is 1.1-4 wt%.

[0058] A third aspect of the present invention provides a vulcanizate obtained by vulcanizing the carboxyl hydrogenated liquid nitrile rubber described in the second aspect of the present invention.

[0059] Due to the high hydrogenation saturation of carboxyl hydrogenated liquid nitrile rubber, it can directly undergo vulcanization crosslinking with sulfur, which can solve the problem that hydrogenated nitrile rubber cannot be vulcanized using sulfur systems, greatly reducing the processing difficulty.

[0060] In this invention, vulcanization is a conventional method, as long as it achieves the purpose of this invention.

[0061] The present invention will be described in detail below through embodiments.

[0062] Evaluation and analysis methods:

[0063] The degree of hydrogenation of the product was tested using Fourier transform infrared spectroscopy, in accordance with the method of SH / T 1762-2008.

[0064] The glass transition temperature test shall be performed in accordance with the method of GB / T 29611-2013.

[0065] The tensile properties of the vulcanized samples were tested using a CMT4104 electronic universal testing machine, following the method in GB / T1040.1-2006, with a tensile rate of 20 mm / min.

[0066] In the following embodiments:

[0067] The raw material XNBR-1 has a bound acrylonitrile content of 35 wt%, a number average molecular weight of 123,000, a carboxyl content of 1.1 wt%, a Mooney viscosity of 56, and a molecular weight distribution index of 3.1. The carboxyl structure is -CH2-COOH.

[0068] The raw material XNBR-2 has a bound acrylonitrile content of 33 wt%, a number average molecular weight of 108,000, a carboxyl content of 3.0 wt%, a Mooney viscosity of 52, and a molecular weight distribution index of 3.0. The carboxyl structure is -CH2-CH2-COOH.

[0069] The raw material XNBR-3 has a bound acrylonitrile content of 27 wt%, a number average molecular weight of 150,000, a carboxyl content of 3.0 wt%, a Mooney viscosity of 65, and a molecular weight distribution index of 2.3. The carboxyl structure is -CH2-CH2-CH2-COOH.

[0070] The raw material NBR-1 has a bound acrylonitrile content of 33 wt%, a number average molecular weight of 96,000, a Mooney viscosity of 54, and a molecular weight distribution index of 3.5.

[0071] The raw material NBR-2 has a bound acrylonitrile content of 27wt%, a number average molecular weight of 125,000, a Mooney viscosity of 64, and a molecular weight distribution index of 2.1.

[0072] Example 1

[0073] First, 70g of XNBR-1 and 900g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 100℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-1.

[0074] Example 2

[0075] First, 70g of XNBR-1 and 500g of chloroform were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 80℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 8MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-2. The infrared spectrum of LHXNBR-2 is shown in Figure 1.

[0076] Example 3

[0077] First, 70g of XNBR-1 and 600g of toluene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 120℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 11MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-3.

[0078] Example 4

[0079] First, 70g of XNBR-1 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction was completed after 6 hours, and the material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-4. The infrared spectrum of LHXNBR-4 is shown in Figure 1.

[0080] Example 5

[0081] First, 70g of XNBR-1 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 160℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-5.

[0082] Example 6

[0083] First, 70g of XNBR-1 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 1000μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-6.

[0084] Example 7

[0085] First, 70g of XNBR-1 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 3000μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-7.

[0086] Example 8

[0087] First, 70g of XNBR-1 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction ended after 2 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-8.

[0088] Example 9

[0089] First, 70g of XNBR-2 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-9.

[0090] Example 10

[0091] First, 70g of XNBR-1 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 4MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-10.

[0092] Example 11

[0093] First, 70g of XNBR-3 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-11.

[0094] Example 12

[0095] First, 70g of NBR-1 and 800g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 700μg / g of Hoveyda-Grubbs II catalyst and 4g of unsaturated carboxylic acid raw material methacrylic acid were added to the reactor, and hydrogen gas was introduced at a pressure of 11MPa. After 5 hours, the reaction was completed, and the material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The hydrogenated gel was then subjected to solvent removal using a rotary evaporator to obtain the product LHXNBR-12.

[0096] Example 13

[0097] First, 70g of NBR-1 and 700g of xylene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst and 2g of unsaturated carboxylic acid raw material methacrylic acid were added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. After 6 hours, the reaction was completed, and the material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-13.

[0098] Example 14

[0099] First, 70g of NBR-1 and 750g of toluene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 700μg / g of Hoveyda-Grubbs II catalyst and 4g of unsaturated carboxylic acid raw material acrylic acid were added to the reactor, and hydrogen gas was introduced at a pressure of 11MPa. After 8 hours, the reaction was completed, and the material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-14.

[0100] Example 15

[0101] First, 70g of NBR-1 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst and 2g of unsaturated carboxylic acid raw material acrylic acid were added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. After 6 hours, the reaction was completed, and the material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The hydrogenated gel was then subjected to solvent removal using a rotary evaporator to obtain the product LHXNBR-15.

[0102] Example 16

[0103] First, 70g of NBR-2 and 750g of toluene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst and 4g of unsaturated carboxylic acid raw material methacrylic acid were added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. After 6 hours, the reaction was completed, and the material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product LHXNBR-16.

[0104] Comparative Example 1

[0105] Compared to Example 4, no hydrogen was added.

[0106] First, 70g of XNBR-1 and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a gel. The solvent was removed from the gel using a rotary evaporator to obtain the product.

[0107] Comparative Example 2

[0108] Compared to Example 14, no unsaturated carboxylic acid raw material was added.

[0109] First, 70g of NBR and 700g of chlorobenzene were added together to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. After the temperature reached 140℃, 500μg / g of Hoveyda-Grubbs II catalyst was added to the reactor, and hydrogen gas was introduced at a pressure of 10MPa. The reaction was completed after 6 hours. The material was cooled to below 20℃ and discharged to obtain a hydrogenated gel. The solvent was removed from the hydrogenated gel using a rotary evaporator to obtain the product.

[0110] Comparative Example 3

[0111] First, the polymerization reactor was evacuated. Then, 130g of deionized water, 3.2g of emulsifier / diffuser N, 0.5g of Na₂CO₃, 0.5g of pH buffer KHCO₃, 16g of acrylonitrile, 4g of methacrylic acid, 4.5g of thiol, and 0.5g of initiator (NH₄)₂S₂O₈ were added sequentially. Next, 30g of butadiene was added, and the reaction temperature was set to 5℃. After 6 hours of reaction, NaNO₂ was added as a terminator to stop the reaction. After the reaction was complete, the product was collected and dried. 70g of the product and 700g of chlorobenzene were added to a 1L hydrogenation reactor. The reactor was purged with nitrogen to replace the air, and then the temperature was raised. Once the temperature reached 140℃, 1500μg / g of RhCl(PPh₃)₃ catalyst was added to the reactor, and 10MPa of hydrogen gas was introduced. After 6 hours, the reaction was completed, and the material was cooled to below 20℃ before being discharged to obtain the hydrogenated gel. The hydrogenated adhesive solution was solvent-removed using a rotary evaporator to obtain the product.

[0112] The test results of the products of each embodiment and comparative example are shown in Table 1.

[0113] Table 1

[0114] Test case

[0115] The vulcanized rubber compound, by weight, comprises: 100 parts raw rubber, 3 parts zinc oxide, 1 part stearic acid, 1 part accelerator (DM), 1.75 parts sulfur, and 10 parts talc. The components of the rubber compound are added to a kneader and mixed at 50°C until evenly dispersed. Then, it is passed through a two-roll mill several times. The obtained rubber compound is vulcanized using a flat vulcanizing mill at 140°C for 30 minutes in the first stage and at 160°C for 60 minutes in the second stage to obtain the vulcanized rubber. The raw rubber is the product from the examples and comparative examples, respectively.

[0116] The mechanical and low-temperature properties of the vulcanized samples (vulcanized rubber) are shown in Table 2.

[0117] Table 2

[0118] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing carboxyl-hydrogenated liquid nitrile rubber, characterized in that, The method includes: providing a raw material of carboxyl hydrogenated liquid nitrile rubber in the presence of a solvent, hydrogen and a catalyst for a contact reaction including metathesis and hydrogenation; The raw material for providing carboxylated hydrogenated liquid nitrile rubber is selected from carboxylated nitrile rubber, or nitrile rubber and unsaturated carboxylic acid.

2. The preparation method according to claim 1, wherein, The number average molecular weight of the carboxylated acrylonitrile rubber is 80,000-150,000; and / or The carboxyl content in the carboxyl-based nitrile rubber is 0.1wt%-6wt%.

3. The preparation method according to claim 1, wherein, The number average molecular weight of the nitrile rubber is 80,000-120,000; and / or The Mooney viscosity of the nitrile rubber is 45-55.

4. The preparation method according to any one of claims 1-3, wherein, The mass ratio of the carboxylated nitrile rubber or nitrile rubber to the solvent is 0.01-0.15:1; and / or The mass ratio of the carboxylated nitrile rubber or nitrile rubber to the catalyst is 1:0.0002-0.003; and / or The mass ratio of the unsaturated carboxylic acid to nitrile rubber is 0.005-0.06:

1.

5. The preparation method according to claim 4, wherein, The mass ratio of the carboxylated nitrile rubber or nitrile rubber to the catalyst is 1:0.0003-0.

001.

6. The preparation method according to any one of claims 1-3, wherein, The catalyst is selected from at least one of Grubbs I, Grubbs II, Grubbs III, and Hoveyda-Grubbs II; and / or The solvent is selected from at least one of methyl ethyl ketone, toluene, butanone, chloroform, trichloromethane, ethyl acetate, butyl butyrate, chlorobenzene, stilbene, toluene, and xylene; and / or The unsaturated carboxylic acid is selected from C3-C4. 10 Unsaturated carboxylic acids.

7. The preparation method according to claim 6, wherein, The unsaturated carboxylic acid is selected from one of methacrylic acid, acrylic acid, butenoic acid, maleic acid, and trans-butenoic acid.

8. The preparation method according to any one of claims 1-3, wherein, The pressure of the hydrogen gas is 6-12 MPa; and / or The conditions for the contact reaction include: a temperature of 70-160°C; and / or a time of 1-12 hours.

9. The preparation method according to claim 8, wherein, The conditions for the contact reaction include: a temperature of 120-160°C; and / or a time of 4-8 hours.

10. A carboxyl hydrogenated liquid nitrile rubber prepared by the preparation method according to any one of claims 1-9.

11. The carboxyl hydrogenated liquid nitrile rubber according to claim 10, wherein, The carboxyl-hydrogenated liquid nitrile rubber contains hydrogenated polybutadiene segments, polyacrylonitrile segments, and modified carboxyl functional groups; and / or The glass transition temperature of the carboxyl hydrogenated liquid nitrile rubber is not higher than -30℃.

12. The carboxyl hydrogenated liquid nitrile rubber according to claim 10, wherein, The glass transition temperature of the carboxyl hydrogenated liquid nitrile rubber is -47 to -30°C; and / or The molecular weight distribution index of the carboxyl hydrogenated liquid nitrile rubber is 2.5-6; and / or The number average molecular weight of the carboxyl hydrogenated liquid nitrile rubber is 1500-10000.

13. The carboxyl hydrogenated liquid nitrile rubber according to claim 11 or 12, wherein, The carboxyl group is selected from -R-COOH; R is H or C1-C9 alkenyl and / or alkylene; and / or The degree of hydrogenation of the hydrogenated polybutadiene segments is 60wt%-100wt%.

14. The carboxyl-hydrogenated liquid nitrile rubber according to any one of claims 11-13, wherein, Based on the mass of carboxyl hydrogenated liquid nitrile rubber: The content of the polyacrylonitrile segments is 25wt%-35wt%; and / or The content of the carboxyl group is 1.1wt%-4wt%.

15. A vulcanizate, characterized in that, The vulcanized rubber is obtained by vulcanizing the carboxyl hydrogenated liquid nitrile rubber according to any one of claims 10-14.

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