Modified carbon black, method for preparing the same, and use thereof

Abstract

The application relates to the technical field of modified carbon black for rubber, and discloses a novel modified carbon black and a preparation method and application thereof. The preparation method of the novel modified carbon black comprises the following steps: dissolving cardanol glycidyl ether, a catalyst and a mercapto compound in an organic solvent, then adding carbon black, uniformly stirring, and then performing constant-temperature reaction to obtain a crude product; and the crude product is washed and vacuum-dried to obtain the novel modified carbon black. The novel modified carbon black has multiple active groups and nonpolar long side chains. The long side chain nonpolar groups make it difficult for the carbon black to agglomerate, so that the carbon black can be better dispersed in natural rubber. The double bonds on the long side chains can form crosslinking bonds with the rubber, the interaction force between the carbon black and the rubber is increased in a chemical bond mode, and then the mechanical properties and processing properties of the rubber are improved. In addition, the modified carbon black containing sulfur elements can promote vulcanization of the rubber, improve the vulcanization efficiency, and further improve the mechanical properties and processing properties of the rubber.

Description

Technical Field

[0001] This application relates to the field of modified carbon black for rubber, specifically to a modified carbon black, its preparation method, and its application. Background Technology

[0002] Carbon black is a fine-particle material with carbon as its main component, possessing characteristics such as wear resistance, electrical conductivity, high adsorption capacity, and high-temperature resistance. In the early 20th century, with the rise of the rubber industry, carbon black was discovered to significantly improve the strength, wear resistance, and weather resistance of rubber, while also enhancing its processing properties. Carbon black-filled rubber products are widely used in rubber hoses, seals, and automobile tires, making a significant contribution to the development of the rubber industry. However, carbon black has poor dispersibility and is prone to agglomeration in rubber, which reduces the mechanical and processing properties of the rubber, preventing it from meeting application requirements.

[0003] Currently, the main approach to improving the dispersibility of carbon black is through modification, thereby enhancing the mechanical and processing properties of rubber. However, while the dispersibility of existing modified carbon blacks has been improved, it remains relatively low, resulting in limited improvement in the mechanical and processing properties of rubber.

[0004] There is an urgent need to develop a modified carbon black with high dispersibility to further improve the mechanical and processing properties of rubber. Summary of the Invention

[0005] This application provides a modified carbon black, its preparation method, and its application, aiming to solve the technical problem that the existing modified carbon black has low rubber mechanical properties and processing properties due to its low dispersibility.

[0006] To achieve the above objectives, the present application adopts the following technical solution.

[0007] A first aspect of this application provides a method for preparing modified carbon black, comprising:

[0008] S1, dissolve cashew phenol glycidyl ether, catalyst and mercapto compound in an organic solvent, add carbon black, stir evenly and carry out constant temperature reaction to obtain crude product.

[0009] S2, the crude product is washed and vacuum dried to obtain modified carbon black.

[0010] Preferably, the number of thiol groups contained in the thiol compound is even.

[0011] More preferably, the thiol compound includes at least one of 1,3-propanedithiol, pentaerythritol tetrathiol compound, or dimercaptothiadiazole.

[0012] Preferably, the catalyst comprises at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, or N,N-dimethylaniline.

[0013] Preferably, the organic solvent is at least one selected from anhydrous ethanol, xylene, acetone, diethyl ether, ethyl acetate, and dimethyl sulfoxide.

[0014] Preferably, the temperature of the isothermal reaction is 50~80℃, and the isothermal reaction time is 2~4h.

[0015] Preferably, the mass ratio of the cashew phenol glycidyl ether, the catalyst, and the thiol compound is 1:(0.001~0.01):(0.25~1);

[0016] The mass ratio of carbon black to cashew phenol glycidyl ether is 1:(0.1~0.3).

[0017] Preferably, the amount of carbon black used is 10-25 wt% of the amount of organic solvent used.

[0018] A second aspect of this application provides modified carbon black prepared by the above-described preparation method.

[0019] A third aspect of this application provides the application of the aforementioned modified carbon black in synthetic rubber.

[0020] Compared with the prior art, the beneficial effects of this application are as follows:

[0021] This application utilizes a condensation reaction between the highly reactive epoxy groups of cashew phenol glycidyl ether and the thiol groups of a thiol compound to obtain a compound with multiple active groups and symmetrical long side chains. This compound is then used to modify carbon black through a combination of physical adsorption and chemical reaction. The modified carbon black possesses multiple active groups and non-polar long side chains. The non-polar groups in the long side chains prevent carbon black from agglomerating, thus allowing for better dispersion in natural rubber. Furthermore, the double bonds on the long side chains can form cross-linking bonds with rubber, increasing the interaction force between carbon black and rubber through chemical bonding, thereby improving the mechanical and processing properties of the rubber. In addition, the sulfur-modified carbon black in this application promotes rubber vulcanization, improves vulcanization efficiency, and further enhances the mechanical and processing properties of the rubber. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 Infrared spectra of modified carbon black and unmodified carbon black;

[0024] Figure 2 Thermogravimetric curves of modified carbon black and unmodified carbon black are shown.

[0025] Figure 3 The vulcanization curves are for modified carbon black / natural rubber composites and unmodified carbon black / natural rubber composites.

[0026] Figure 4 The diagram shows the dynamic thermomechanical analysis of modified carbon black / natural rubber composites and unmodified carbon black / natural rubber composites. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0028] In the following description of this embodiment, the terms "including", "comprising", "having", and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0029] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0030] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0031] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0032] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0033] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood as each intermediate value between the upper and lower limits of the specifically disclosed range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0034] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0035] In a first aspect, this application provides a method for preparing modified carbon black, comprising:

[0036] S1, dissolve cashew phenol glycidyl ether, catalyst and mercapto compound in an organic solvent, add carbon black, stir evenly and carry out constant temperature reaction to obtain crude product.

[0037] In this application, the structural formula of the cashew phenol glycidyl ether is shown in formula (1) or formula (2), and its molecular weights are 358.49 and 431.49, respectively.

[0038] (1)

[0039] (2)

[0040] Among them, C 15 H n It is a mixture with the following structure:

[0041]

[0042] In this application, the number of thiol groups contained in the thiol compound is even, preferably two or four; the thiol compound may be any one of 1,3-propanedithiol, pentaerythritol tetrathiol compound, or dimercaptothiadiazole, or a mixture of two or more thereof.

[0043] The catalyst includes at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, or N,N-dimethylaniline;

[0044] The organic solvent is at least one of anhydrous ethanol, xylene, acetone, diethyl ether, ethyl acetate, and dimethyl sulfoxide, preferably a mixture of diethyl ether and anhydrous ethanol or xylene.

[0045] In this application, the preferred carbon black is N330.

[0046] In this application, the isothermal reaction temperature is 50~80℃, and the isothermal reaction time is 2~4h; preferably, the mass ratio of cashew phenol glycidyl ether, catalyst, and mercapto compound is 1:(0.001~0.01):(0.25~1); the mass ratio of carbon black to cashew phenol glycidyl ether is 1:(0.1~0.3). The stirring rate during the isothermal reaction in this application is 200~400rpm.

[0047] In this application, the amount of carbon black used is preferably 10-25 wt% of the amount of organic solvent.

[0048] S2, the crude product is washed and vacuum dried to obtain modified carbon black.

[0049] In this application, the crude product is washed with anhydrous ethanol, the solid phase is collected by filtration, and then dried in a vacuum oven at 80-100°C for 24 hours to obtain the final product.

[0050] This application describes a condensation reaction between the highly reactive epoxy groups of cashew phenol glycidyl ether and the thiol groups of a thiol compound to obtain a compound with multiple active groups and symmetrical long side chains. This compound modifies carbon black through a combination of physical adsorption and chemical reaction. The reaction mechanism between cashew phenol glycidyl ether and the thiol compound is as follows:

[0051]

[0052] The chemical reaction mechanism between the compound obtained by reacting cashew phenol glycidyl ether with a thiol compound and carbon black is as follows:

[0053]

[0054] Among them, C 15 H n The structural formula is shown below:

[0055] .

[0056] The modified carbon black prepared in this application exhibits excellent dispersibility and can be applied to natural rubber and synthetic rubbers such as styrene-butadiene rubber (SBR) to improve their mechanical and processing properties. Specifically, the modified carbon black prepared in this application possesses various active groups and non-polar long side chains. The non-polar groups on the long side chains prevent the carbon black from agglomerating, thus allowing for better dispersion in natural rubber. Furthermore, the double bonds on the long side chains can form cross-linking bonds with the rubber, increasing the interaction force between the carbon black and the rubber through chemical bonding, thereby improving the mechanical and processing properties of the rubber. In addition, the modified carbon black containing sulfur in this application can promote the vulcanization of rubber, improve vulcanization efficiency, and further enhance the mechanical and processing properties of the rubber.

[0057] The present application will be further illustrated by the following examples.

[0058] Example 1

[0059] This embodiment provides a method for preparing modified carbon black, including:

[0060] Weigh out 7.5g carbon black, 15g cashew phenol glycidyl ether, 3.45g dimercaptothiadiazole, 0.25g N,N-dimethylaniline, 0.5g benzoyl peroxide, 10g diethyl ether and 40g anhydrous ethanol respectively.

[0061] Cashew phenol glycidyl ether was poured into a three-necked flask equipped with a thermometer and a condenser. Diethyl ether and anhydrous ethanol were added to the three-necked flask, followed by N,N-dimethylaniline and benzoyl peroxide. After mixing thoroughly, dimercaptothiadiazole was added. Carbon black was then added, and the mixture was stirred at a constant temperature of 80°C and 300 rpm for 2 hours under a nitrogen atmosphere to obtain the crude product.

[0062] The crude product was centrifuged three times with anhydrous ethanol as solvent, and the solid phase was collected and dried in a vacuum oven for 24 hours to obtain modified carbon black.

[0063] Example 2

[0064] This embodiment provides a method for preparing modified carbon black, including:

[0065] Weigh out 7.5g carbon black, 15g cashew phenol glycidyl ether, 1.875g dimercaptothiadiazole, 0.25g N,N-dimethylaniline, 0.5g benzoyl peroxide, 5g diethyl ether and 40g anhydrous ethanol respectively.

[0066] Cashew phenol glycidyl ether was poured into a three-necked flask equipped with a thermometer and a condenser. Diethyl ether and anhydrous ethanol were added to the three-necked flask, followed by N,N-dimethylaniline and benzoyl peroxide. After mixing thoroughly, dimercaptothiadiazole was added. Carbon black was then added, and the mixture was stirred at a constant temperature of 80°C and 300 rpm for 2 hours under a nitrogen atmosphere to obtain the crude product.

[0067] The crude product was centrifuged three times with anhydrous ethanol as solvent, and the solid phase was collected and dried in a vacuum oven for 24 hours to obtain modified carbon black.

[0068] Example 3

[0069] The difference between Example 3 and Example 2 is that the isothermal reaction temperature is 60°C, while the rest is the same as Example 2.

[0070] Example 4

[0071] This embodiment provides a method for preparing modified carbon black, including:

[0072] Weigh out 7.5g carbon black, 15g cashew phenol glycidyl ether, 3.75g pentaerythritol tetramerol compound, 0.5g azobisisobutyronitrile, 5g diethyl ether and 40g xylene respectively;

[0073] Cashew phenol glycidyl ether was poured into a three-necked flask equipped with a thermometer and a condenser. Diethyl ether and anhydrous ethanol were added to the three-necked flask, followed by N,N-dimethylaniline and benzoyl peroxide. After mixing thoroughly, dimercaptothiadiazole was added. Carbon black was then added, and the mixture was stirred at a constant temperature of 60°C and 250 rpm for 3 hours under a nitrogen atmosphere to obtain the crude product.

[0074] The crude product was centrifuged three times with anhydrous ethanol as solvent, and the solid phase was collected and dried in a vacuum oven for 24 hours to obtain modified carbon black.

[0075] Example 5

[0076] This embodiment provides a method for preparing modified carbon black, including:

[0077] Weigh out 7.5g of carbon black, 15g of cashew phenol glycidyl ether, 3.75g of pentaerythritol tetramerol compound, 1g of azobisisobutyronitrile, 5g of diethyl ether and 40g of xylene respectively;

[0078] Cashew phenol glycidyl ether was poured into a three-necked flask equipped with a thermometer and a condenser. Diethyl ether and anhydrous ethanol were added to the three-necked flask, followed by N,N-dimethylaniline and benzoyl peroxide. After mixing thoroughly, dimercaptothiadiazole was added. Carbon black was then added, and the mixture was stirred at a constant temperature of 70°C and 250 rpm for 3 hours under a nitrogen atmosphere to obtain the crude product.

[0079] The crude product was centrifuged three times with anhydrous ethanol as solvent, and the solid phase was collected and dried in a vacuum oven for 24 hours to obtain modified carbon black.

[0080] Comparative Example 1

[0081] This embodiment provides a method for preparing modified carbon black that does not contain mercapto compounds, including:

[0082] Weigh out 7.5g of carbon black, 15g of cashew phenol glycidyl ether, 0.75g of azobisisobutyronitrile, 5g of diethyl ether and 40g of xylene respectively;

[0083] Cashew phenol glycidyl ether was poured into a three-necked flask equipped with a thermometer and a condenser. Diethyl ether and anhydrous ethanol were added to the three-necked flask, followed by N,N-dimethylaniline and benzoyl peroxide. After mixing thoroughly, dimercaptothiadiazole was added. Carbon black was then added, and the mixture was stirred at a constant temperature of 70°C and 250 rpm for 3 hours under a nitrogen atmosphere to obtain the crude product.

[0084] The crude product was centrifuged three times with anhydrous ethanol as solvent, and the solid phase was collected and dried in a vacuum oven for 24 hours to obtain modified carbon black.

[0085] Infrared spectroscopy was performed on the modified carbon black prepared in Example 1 and the unmodified carbon black N330. The test results are as follows: Figure 1 As shown. By Figure 1 It can be seen that the modified carbon black in Example 1 has a wave number of 1670 cm⁻¹. -1 The stretching vibration absorption peak of the carbon-carbon double bond at 1580 cm⁻¹ -1 The increased intensity of the stretching vibration absorption peak of the benzene ring at the carbon black indicates that the compound obtained from the condensation reaction was successfully grafted onto the carbon black.

[0086] Thermogravimetric analysis was performed on the modified carbon black and carbon black N330 prepared in Example 1, and the test results are as follows: Figure 2 As shown. From Figure 2 It can be seen that the modified carbon black in Example 1 has different weight loss curves than the unmodified carbon black. The loading rate of the modified carbon black was calculated to be 15.5%.

[0087] The modified carbon black prepared in Example 1 and Comparative Example 1 were mixed with natural rubber in an internal mixer to prepare natural rubber / carbon black composite materials, with unmodified carbon black as a control. The formulations of the natural rubber / carbon black composite materials are shown in Table 1. Sample 1 used unmodified carbon black N330; in Sample 2, modified carbon black prepared in Example 1 was added to replace part of carbon black N330, keeping the total amount of carbon black constant; in Sample 3, modified carbon black prepared in Comparative Example 1 was added to replace part of carbon black N330, keeping the total amount of carbon black constant.

[0088] Table 1 Formulation of Natural Rubber / Carbon Black Composite Material

[0089]

[0090] The specific preparation method is as follows: Modified carbon black and natural rubber are internally mixed in a mixer at a temperature of 80℃, a speed of 30 rpm, and a mixing time of 8 minutes. After discharge, the mixed rubber and additives are blended on a two-roll mill. The order of addition is: mixed rubber - zinc oxide + hard acid - accelerator - antioxidant - sulfur. The mixture is continuously turned until the additives are evenly dispersed, and then sheeted. The mixed rubber is left to stand at room temperature overnight, and the vulcanization data is tested on a rotorless vulcanizing machine. The mixture is then hot-pressed on a flat vulcanizing machine. After the vulcanized rubber samples were left at room temperature for a period of time, relevant tests were conducted.

[0091] The compound was prepared according to the formulation shown in Table 1. The vulcanization characteristic parameters of the compound are shown in Table 2, and the vulcanization curve of the compound is shown in the figure. Figure 3 As shown in Table 3, the mechanical properties of each sample after vulcanization at 143℃ are as follows, and their dynamic thermomechanical analysis is as follows. Figure 4 As shown.

[0092] Table 2. Vulcanization characteristics of natural rubber compounds

[0093]

[0094] Table 3 Mechanical property test data of natural rubber composite materials

[0095]

[0096] As shown in Table 2, compared with sample 1 using unmodified carbon black, samples 2 and 3 using modified carbon black exhibited shorter positive vulcanization times and higher vulcanization rates. Furthermore, sample 1 using the modified carbon black of Example 2 showed an even shorter positive vulcanization time and faster vulcanization rate compared with sample 3 using the modified carbon black of Comparative Example 1. The sulfur-containing modified carbon black of this application can promote rubber vulcanization, improve vulcanization efficiency, and further enhance the mechanical and processing properties of rubber.

[0097] Depend on Figure 3 It can be seen that the slope of the curve for sample 2 is higher than that for sample 1, indicating that the vulcanization rate of the compound of sample 2 is significantly faster than that of the compound of sample 1. Furthermore, the maximum torque of sample 2 is 2 dN·m higher than that of sample 1, and the difference between the maximum and minimum torques is also 2 dN·m greater for sample 2 than for sample 1, indicating that sample 2 has a higher crosslinking density. This preliminarily suggests that the mechanical properties of sample 2 are higher than those of sample 1.

[0098] As shown in Table 3, compared with sample 1 using unmodified carbon black, samples 2 and 3 using modified carbon black showed improved tensile strength and elongation at break. Furthermore, sample 1 using modified carbon black from Example 2 showed significantly higher tensile strength and elongation at break compared with sample 3 using modified carbon black from Comparative Example 1.

[0099] Compared to sample 1 using unmodified carbon black, sample 1 using the modified carbon black of Example 2 showed a 2.6 MPa increase in tensile strength, a nearly 100% increase in elongation at break, and almost a doubling of tear strength to 84.99 kN / m in the rubber composite material. These data indicate that the condensation reaction between the highly reactive epoxy groups of cashew phenol glycidyl ether and the thiol groups of the thiol compound yields a compound with multiple active groups and symmetrical long side chains. The carbon black modified by this compound possesses various active groups and nonpolar long side chains. The nonpolar groups in the long side chains prevent carbon black from agglomerating, thus allowing for better dispersion in natural rubber. Furthermore, the double bonds on the long side chains can form cross-linking bonds with the rubber, increasing the interaction between carbon black and rubber through chemical bonding, further improving the mechanical and processing properties of the rubber.

[0100] Figure 4 The figures show the dynamic thermomechanical analysis of samples 1 and 2. The loss factor tanδ of the rubber composite at 0℃ is typically used as the criterion for its anti-slip performance, while the loss factor tanδ at 60℃ is used as the criterion for its rolling resistance. Figure 4 It can be seen that the loss factor of the modified carbon black / natural rubber composite material of sample 2 at 60℃ is larger than that of the unmodified carbon black / natural rubber composite material of sample 1, but smaller at 0℃, indicating that the anti-slip performance of the modified carbon black / natural rubber composite material of sample 2 is improved.

[0101] Although this application has been described in detail in this specification with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A method for preparing modified carbon black, characterized in that, include: S1, dissolve cashew phenol glycidyl ether, catalyst and mercapto compound in an organic solvent, add carbon black, stir evenly and carry out constant temperature reaction to obtain crude product. S2, the crude product is washed and vacuum dried to obtain modified carbon black; The thiol compound includes at least one of 1,3-propanedithiol, pentaerythritol tetrathiol compound, or dimercaptothiadiazole.

2. The preparation method according to claim 1, characterized in that, The catalyst includes at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, or N,N-dimethylaniline.

3. The preparation method according to claim 1, characterized in that, The organic solvent is at least one of anhydrous ethanol, xylene, acetone, diethyl ether, ethyl acetate, and dimethyl sulfoxide.

4. The preparation method according to claim 1, characterized in that, The isothermal reaction is carried out at a temperature of 50-80°C for 2-4 hours.

5. The preparation method according to claim 1, characterized in that, The mass ratio of the cashew phenol glycidyl ether, the catalyst, and the thiol compound is 1:(0.001~0.01):(0.25~1); The mass ratio of carbon black to cashew phenol glycidyl ether is 1:(0.1~0.3).

6. The preparation method according to claim 1, characterized in that, The amount of carbon black used is 10-25 wt% of the amount of organic solvent used.

7. Modified carbon black prepared by the preparation method according to any one of claims 1-6.

8. The application of the modified carbon black according to claim 7 in rubber.

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