Novel modified carbon black as well as preparation method and application thereof

Abstract

The invention relates to the technical field of modified carbon black for rubber, and discloses novel modified carbon black as well as 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 sulfhydryl compound in an organic solvent, adding carbon black, uniformly stirring, and carrying out a constant-temperature reaction to obtain a crude product; and washing and vacuum-drying the crude product to obtain the novel modified carbon black. The novel modified carbon black provided by the invention has various active groups and non-polar long side chains, and the long side chain non-polar groups enable the carbon black not to be easily agglomerated, so that the carbon black can be better dispersed in natural rubber; a double bond on a long side chain can form a cross-linked bond with rubber, and the interaction force between the carbon black and the rubber is increased in a chemical bond manner, so that the mechanical property and the processability of the rubber are improved; in addition, the modified carbon black containing the sulfur element can promote vulcanization of the rubber, the vulcanization efficiency is improved, and the mechanical property and the processability of the rubber are further improved.

Description

Technical Field

[0001] The present application relates to the technical field of modified carbon black for rubber, and in particular to a novel modified carbon black and a preparation method and application thereof. Background Art

[0002] Carbon black is a fine granular material with carbon as the main component, which has the characteristics of wear resistance, conductivity, high adsorption, high temperature resistance, etc. In the early 20th century, with the rise of the rubber industry, carbon black was found to be able to improve the strength, wear resistance and weather resistance of rubber, and at the same time improve the processing performance of rubber; carbon black filled rubber products are widely used in rubber tubes, seals, automobile tires and other fields, making an important 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 properties and processing properties of rubber and cannot meet the use requirements.

[0003] At present, the main method is to improve the dispersibility of carbon black and improve the mechanical properties and processing performance of rubber. However, although the dispersibility of existing modified carbon black has been improved, it is still relatively low, and the improvement of the mechanical properties and processing performance of rubber is limited.

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

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

[0006] In order to achieve the above objectives, the present application adopts the following technical solutions.

[0007] The first aspect of the present application provides a method for preparing a novel modified carbon black, comprising:

[0008] S1, dissolving cardanol glycidyl ether, a catalyst and a thiol compound in an organic solvent, adding carbon black, stirring evenly and reacting at a constant temperature to obtain a crude product;

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

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

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

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

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

[0014] Preferably, the temperature of the isothermal reaction is 50-80° C., and the time of the isothermal reaction is 2-4 hours.

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

[0016] The mass ratio of the carbon black to the cardanol glycidyl ether is 1:(0.1-0.3).

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

[0018] The second aspect of the present application provides a new modified carbon black prepared by the above preparation method.

[0019] The third aspect of the present application provides the use of the above-mentioned novel modified carbon black in synthetic rubber.

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

[0021] The present application obtains a compound having a variety of active groups and symmetrical long side chains by condensing the high-activity epoxy group of cardanol glycidyl ether with the thiol group of a thiol compound, and modifies the carbon black through the dual effects of physical adsorption and chemical reaction. The modified carbon black has a variety of active groups and non-polar long side chains, wherein the long side chain non-polar groups make it difficult for the carbon black to agglomerate, thereby being better dispersed in natural rubber. The double bonds on the long side chains can form cross-linked bonds with the rubber, thereby increasing the interaction force between the carbon black and the rubber by means of chemical bonds, thereby improving the mechanical properties and processing properties of the rubber. In addition, the modified carbon black containing sulfur in the present application can promote the vulcanization of the rubber, improve the vulcanization efficiency, and further improve the mechanical properties and processing properties of the rubber. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0024] Figure 2 The thermal weight loss curves of modified carbon black and unmodified carbon black;

[0025] Figure 3 is the vulcanization curve of modified carbon black / natural rubber composite material and unmodified carbon black / natural rubber composite material;

[0026] Figure 4 Dynamic thermomechanical analysis diagrams of modified carbon black / natural rubber composites and unmodified carbon black / natural rubber composites. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

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

[0029] In the following description of this embodiment, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

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

[0031] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0032] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and 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 the present application.

[0033] Those skilled in the art will appreciate that the numerical ranges in the embodiments of the present application are to be construed as specifically disclosing each intermediate value between the upper and lower limits of the scope. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present application. The upper and lower limits of these smaller ranges may be independently included or excluded in the scope.

[0034] Unless otherwise specified, the technical / scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs. Although this application only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

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

[0036] S1, dissolving cardanol glycidyl ether, a catalyst and a thiol compound in an organic solvent, adding carbon black, stirring evenly and reacting at a constant temperature to obtain a crude product;

[0037] In the present application, the structural formula of the cardanol glycidyl ether is as shown in formula (1) or formula (2), and the molecular weights thereof are 358.49 and 431.49, respectively;

[0038]

[0039]

[0040] Among them, C 15 H n A mixture of the following structure:

[0041]

[0042] In the present application, the number of thiol groups contained in the thiol compound is an even number, preferably 2 or 4; the thiol compound can be selected from any one of 1,3-propanedithiol, pentaerythritol tetrathiol compound or dithiothiadiazole, or a mixture of two or more thereof.

[0043] The catalyst comprises at least one of dibenzoyl peroxide, azobisisobutyronitrile, azobisisoheptylnitrile or N,N-dimethylaniline;

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

[0045] In the present application, the carbon black is preferably N330 carbon black.

[0046] In the present application, the temperature of the isothermal reaction is 50-80°C, and the time of the isothermal reaction is 2-4 hours; preferably, the mass ratio of the cardanol glycidyl ether, the catalyst and the thiol compound is 1:(0.001-0.01):(0.25-1); the mass ratio of the carbon black to the cardanol glycidyl ether is 1:(0.1-0.3). In the isothermal reaction of the present application, the stirring rate is 200-400 rpm.

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

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

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

[0050] The present application uses a condensation reaction between the highly active epoxy group of cardanol glycidyl ether and the thiol group of a thiol compound to obtain a compound having multiple active groups and symmetrical long side chains, and the compound modifies carbon black through the dual effects of physical adsorption and chemical reaction. The mechanism of the reaction between cardanol glycidyl ether and the thiol compound is as follows:

[0051]

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

[0053]

[0054] Among them, C 15 H n The structural formula is as follows:

[0055]

[0056] The new modified carbon black prepared in the present application has good dispersibility and can be applied to natural rubber and synthetic rubber such as styrene-butadiene rubber to improve the mechanical properties and processing properties of rubber. Specifically, the new modified carbon black prepared in the present application has a variety of active groups and non-polar long side chains, among which the long side chain non-polar groups make it difficult for carbon black to agglomerate, so that it can be better dispersed in natural rubber; and the double bonds on the long side chains can form cross-linked bonds with rubber, which increases the interaction between carbon black and rubber by chemical bonds, thereby improving the mechanical properties and processing properties of rubber; in addition, the modified carbon black containing sulfur in the present application can promote the vulcanization of rubber, improve the vulcanization efficiency, and further improve the mechanical properties and processing properties of rubber.

[0057] The present application is further described below by way of examples.

[0058] Example 1

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

[0060] Weigh 7.5 g of carbon black, 15 g of cardanol glycidyl ether, 3.45 g of dithiothiadiazole, 0.25 g of N,N-dimethylaniline, 0.5 g of dibenzoyl peroxide, 10 g of ether and 40 g of anhydrous ethanol respectively;

[0061] Pour cardanol glycidyl ether into a three-necked flask with a thermometer and a condenser, add ether and anhydrous ethanol into the three-necked flask, then add N,N-dimethylaniline and dibenzoyl peroxide in sequence, mix well, then add dithiothiadiazole; then add carbon black, and react at 80°C and 300 rpm under a nitrogen atmosphere for 2 hours with constant temperature stirring to obtain a crude product;

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

[0063] Example 2

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

[0065] Weigh 7.5 g of carbon black, 15 g of cardanol glycidyl ether, 1.875 g of dithiothiadiazole, 0.25 g of N,N-dimethylaniline, 0.5 g of dibenzoyl peroxide, 5 g of ether and 40 g of anhydrous ethanol respectively;

[0066] Pour cardanol glycidyl ether into a three-necked flask with a thermometer and a condenser, add ether and anhydrous ethanol into the three-necked flask, then add N,N-dimethylaniline and dibenzoyl peroxide in sequence, mix well, then add dithiothiadiazole; then add carbon black, and react at 80°C and 300 rpm under a nitrogen atmosphere for 2 hours with constant temperature stirring to obtain a crude product;

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

[0068] Example 3

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

[0070] Example 4

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

[0072] Weigh 7.5 g of carbon black, 15 g of cardanol glycidyl ether, 3.75 g of pentaerythritol tetrathiol compound, 0.5 g of azobisisobutyronitrile, 5 g of ether and 40 g of xylene respectively;

[0073] Pour cardanol glycidyl ether into a three-necked flask with a thermometer and a condenser, add ether and anhydrous ethanol into the three-necked flask, then add N,N-dimethylaniline and dibenzoyl peroxide in sequence, mix well, then add dithiothiadiazole; then add carbon black, and react at 60°C and 250rpm under a nitrogen atmosphere for 3 hours with constant temperature stirring to obtain a crude product;

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

[0075] Example 5

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

[0077] Weigh 7.5 g of carbon black, 15 g of cardanol glycidyl ether, 3.75 g of pentaerythritol tetrathiol compound, 1 g of azobisisobutyronitrile, 5 g of ether and 40 g of xylene respectively;

[0078] Pour cardanol glycidyl ether into a three-necked flask with a thermometer and a condenser, add ether and anhydrous ethanol into the three-necked flask, then add N,N-dimethylaniline and dibenzoyl peroxide in sequence, mix well, then add dithiothiadiazole; then add carbon black, and react at 70°C and 250 rpm under a nitrogen atmosphere for 3 hours with constant temperature stirring to obtain a crude product;

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

[0080] Comparative Example 1

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

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

[0083] Pour cardanol glycidyl ether into a three-necked flask with a thermometer and a condenser, add ether and anhydrous ethanol into the three-necked flask, then add N,N-dimethylaniline and dibenzoyl peroxide in sequence, mix well, then add dithiothiadiazole; then add carbon black, and react at 70°C and 250 rpm under a nitrogen atmosphere for 3 hours with constant temperature stirring to obtain a crude product;

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

[0085] The new modified carbon black prepared in Example 1 and the unmodified carbon black N330 were subjected to infrared spectroscopy test, and the test results are as follows: Figure 1 As shown. Figure 1 It can be seen that the new modified carbon black of Example 1 has a wavelength of 1670 cm -1 The carbon-carbon double bond stretching vibration absorption peak at 1580cm -1 The intensity of the stretching vibration absorption peak of the benzene ring stock at the position increased, which proves that the compound obtained by the condensation reaction was successfully grafted onto carbon black.

[0086] The new modified carbon black and carbon black N330 prepared in Example 1 were subjected to thermogravimetric analysis, and the test results are as follows: Figure 2 As shown. Figure 2 It can be seen that the new modified carbon black in Example 1 has a different weight loss curve from the unmodified carbon black. The loading rate of the new modified carbon black is 15.5% by calculation.

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

[0088] Table 1 Natural rubber / carbon black composite material formula

[0089]

[0090] The specific preparation method is as follows: the modified carbon black and natural rubber are mixed in a mixer at a temperature of 80°C, a mixer speed of 30rpm, and a mixing time of 8min; after the rubber is discharged, the mixed rubber and the additives are blended on a double-roll open mill, and the order of adding materials is: mixed rubber-zinc oxide + hard acid-accelerator-antiaging agent-sulfur, and the mixing is continued until the additives are evenly dispersed and the sheets are produced. The mixed rubber is left at room temperature overnight, the vulcanization data of the mixed rubber is tested on a rotorless vulcanizer, and hot-pressed on a flat vulcanizer (143°C*t90). The vulcanized rubber samples are left at room temperature for a period of time before relevant tests.

[0091] The rubber compound was prepared according to the formula shown in Table 1. The vulcanization characteristic parameters of the rubber compound are shown in Table 2. The vulcanization curve of the rubber compound is shown in Figure 3 After vulcanization at 143°C, the mechanical properties of each sample are shown in Table 3, and the dynamic thermomechanical analysis is shown in Table 3. Figure 4 shown.

[0092] Table 2 Vulcanization characteristic parameters of natural rubber compound

[0093]

[0094] Table 3 Mechanical properties test data of natural rubber composites

[0095]

[0096] As shown in Table 2, compared with Sample 1 using unmodified carbon black, Samples 2 and 3 using modified carbon black have shorter positive vulcanization time and improved vulcanization rate. Compared with Sample 3 using modified carbon black of Comparative Example 1, Sample 1 using modified carbon black of Example 2 has shorter positive vulcanization time and faster vulcanization rate. The modified carbon black containing sulfur element in the present application can promote the vulcanization of rubber, improve the vulcanization efficiency, and further improve the mechanical properties and processing properties of rubber.

[0097] Depend on Figure 3 It can be seen that the slope of the curve of Sample 2 is higher than that of Sample 1, indicating that the vulcanization rate of the sample 2 mix is ​​significantly faster than that of the sample 1 mix, and the maximum torque of Sample 2 is 2dN·m higher than that of Sample 1, and the maximum and minimum torque difference of Sample 2 is also 2dN·m larger than that of Sample 1, indicating that the crosslinking density of Sample 2 is large, which preliminarily indicates that the mechanical properties of Sample 2 are higher than those of Sample 1.

[0098] As shown in Table 3, the tensile strength and elongation at break of samples 2 and 3 using modified carbon black are improved compared with sample 1 using unmodified carbon black. The tensile strength and elongation at break of sample 1 using modified carbon black of Example 2 are higher than those of sample 3 using modified carbon black of Comparative Example 1, which are significantly improved.

[0099] Compared with the sample 1 using the unmodified carbon black, the tensile strength of the rubber composite material of the sample 1 using the modified carbon black of Example 2 is increased by 2.6MPa, the elongation at break is increased by nearly 100%, and the tear strength is nearly doubled, reaching 84.99kN / m. The above data show that the compound having multiple active groups and symmetrical long side chains is obtained by condensation reaction of the high-activity epoxy group of cardanol glycidyl ether with the thiol group of the thiol compound. The carbon black modified by the compound has multiple active groups and non-polar long side chains, wherein the non-polar groups of the long side chains make it difficult for the carbon black to agglomerate, so that it can be better dispersed in the natural rubber; and the double bonds on the long side chains can form cross-linked bonds with the rubber, which increases the interaction between the carbon black and the rubber by chemical bonds, and further improves the mechanical properties and processing properties of the rubber.

[0100] Figure 4 The dynamic thermomechanical analysis diagrams of samples 1 and 2 are shown in Figure 2. The loss factor tanδ of the rubber composite material at 0°C is usually used as a criterion for the anti-skid performance of the composite material, and the loss factor tanδ of the rubber composite material at 60°C is used as a criterion for the rolling resistance of the composite material. Figure 4 It can be seen that the loss factor of the modified carbon black / natural rubber composite material of sample 2 at 60°C is larger than that of the unmodified carbon black / natural rubber composite material of sample 1, but smaller at 0°C, indicating that the anti-skid performance of the modified carbon black / natural rubber composite material of sample 2 is improved.

[0101] Although the present application has been described in detail in general terms and in specific embodiments in this specification, it is obvious to those skilled in the art that some modifications or improvements may be made to the present application. Therefore, these modifications or improvements made without departing from the spirit of the present application are within the scope of protection claimed in the present application.

Claims

1. A method for preparing a novel modified carbon black, characterized in that: include: S1, dissolving cardanol glycidyl ether, a catalyst and a thiol compound in an organic solvent, adding carbon black, stirring evenly and reacting at a constant temperature to obtain a crude product; S2, the crude product is washed and vacuum dried to obtain a new modified carbon black.

2. The preparation method according to claim 1, characterized in that: The number of thiol groups included in the thiol compound is an even number.

3. The preparation method according to claim 2, characterized in that: The mercapto compound includes at least one of 1,3-propanedithiol, pentaerythritol tetrathiol compound or dithiothiadiazole.

4. The preparation method according to claim 1, characterized in that: The catalyst includes at least one of dibenzoyl peroxide, azobisisobutyronitrile, azobisisoheptylnitrile or N,N-dimethylaniline.

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

6. The preparation method according to claim 1, characterized in that: The temperature of the isothermal reaction is 50-80° C., and the time of the isothermal reaction is 2-4 hours.

7. The preparation method according to claim 1, characterized in that: The mass ratio of the cardanol glycidyl ether, the catalyst and the dithiol compound is 1:(0.001-0.01):(0.25-1); The mass ratio of the carbon black to the cardanol glycidyl ether is 1:(0.1-0.3).

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

9. A novel modified carbon black prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the novel modified carbon black according to claim 9 in rubber.

Images