Polyphenol-based carbon black in-situ surface modifier, preparation method thereof and product containing polyphenol-based carbon black in-situ surface modifier

Abstract

The invention discloses a polyphenol-based carbon black in-situ surface modifier, a preparation method of the polyphenol-based carbon black in-situ surface modifier and a product containing the polyphenol-based carbon black in-situ surface modifier, and belongs to the technical field of rubber materials. The polyphenol-based carbon black in-situ surface modifier is prepared by carrying out hydroxyl-epoxy group ring-opening reaction through heating stirring and condensation reflux, then the modifier is applied to preparation of a rubber composite material, carbon black and the modifier can form multiple interface interaction through Van der Waals' force, hydrogen bonds, pi-pi conjugation and covalent bonds, and the performance of the composite material is improved. According to the present invention, the carbon black surface in-situ modification is achieved, the dispersion effect of the carbon black in the rubber matrix is significantly improved, and the interface interaction in the composite material is enhanced, such that the mechanical property of the rubber composite material is substantially improved, and the energy loss and the heat generation under the dynamic condition are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber materials, and in particular relates to a polyphenol-based carbon black in-situ surface modifier, a preparation method thereof, and a product containing the same. Background Art

[0002] Carbon black is an irreplaceable reinforcing filler in rubber materials and has played a huge role in promoting the development of the rubber industry. In order to give full play to the reinforcing effect of carbon black in rubber and reduce the hysteresis loss and dynamic heat generation of rubber materials after carbon black filling, improving the dispersion of carbon black in the rubber matrix and enhancing the interfacial interaction between carbon black and rubber are the key. The main methods widely reported to improve the dispersion effect of carbon black in rubber include using carbon black after surface modification pretreatment and directly adding in-situ surface modifiers during rubber processing to modify carbon black in situ. Although the use of carbon black pretreated with surface modification can achieve better results, it usually requires complex pretreatment steps, which is costly and has a long cycle. Therefore, the in-situ modification of carbon black by directly adding modifiers during rubber processing has received increasing attention.

[0003] However, although the method of directly adding modifiers to modify the carbon black surface in situ has obvious advantages such as simple and fast operation and low cost, it also has problems that need to be solved. First, compared with other nanofillers, the content of carbon black surface active functional groups is extremely low, which means that it is difficult to establish a stable interaction between the modifier and carbon black. Secondly, since the proportion of modifiers in the rubber formula is very small, the probability of effective collision between the modifier and the carbon black particles is very low during the short mixing and hot pressing process, resulting in insufficient space and time for in-situ modification. The effect of in-situ surface modification is often not as good as pretreatment modification.

[0004] Therefore, it is necessary to develop an in-situ surface modifier that can meet the needs of in-situ surface modification of carbon black and enhance the interfacial bonding between carbon black and the rubber matrix, so as to prepare high-performance rubber / carbon black composites through a simpler and more efficient modification method. This is still an important topic in the current scientific research and technological development of rubber / carbon black composites. Summary of the invention

[0005] In view of the above technical problems, the present invention proposes a polyphenol-based carbon black in-situ surface modifier, a preparation method thereof, and a product containing the same.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions:

[0008] A method for preparing a polyphenol-based carbon black in-situ surface modifier comprises the following steps:

[0009] The polyphenol compound and the silane coupling agent containing epoxy group are dissolved in water, and a hydroxyl-epoxy ring-opening reaction is carried out by heating, stirring and condensing and refluxing to prepare the polyphenol-based carbon black in-situ surface modifier;

[0010] Wherein, the polyphenolic compounds include any one of tannic acid, gallic acid, catechin, epicatechin, theaflavins, anthocyanins, resveratrol, lignans, coumarin, caffeic acid and curcumin;

[0011] The epoxy-containing silane coupling agent includes any one of γ-glycidyloxypropyltrimethoxysilane, 3-[(2,3)-glycidyloxy]propylmethyldimethoxysilane, [8-(glycidyloxy)-n-octyl]trimethoxysilane and 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane.

[0012] Preferably, the mass ratio of the polyphenol compound to the epoxy-containing silane coupling agent is (2-5):(1-4).

[0013] Preferably, the amount of the polyphenol compound used is 10-60% of the total mass of the polyphenol compound and the epoxy-containing silane coupling agent.

[0014] Preferably, the heating temperature during the heating and stirring process is 20 to 80°C;

[0015] The stirring time is 6 to 48 hours.

[0016] Preferably, after the reaction is completed, a purification step is further included, specifically: the solution obtained by the reaction is centrifuged and washed, and vacuum dried.

[0017] The second technical solution of the present invention:

[0018] A polyphenol-based carbon black in-situ surface modifier is prepared by the above preparation method.

[0019] The third technical solution of the present invention:

[0020] A rubber composite material comprises carbon black, rubber and the above-mentioned polyphenol-based carbon black in-situ surface modifier.

[0021] Beneficial effects: The polyphenol-based carbon black in-situ surface modifier provided by the present invention is applied to rubber composite materials. The carbon black can form multiple interface interactions with the modifier through van der Waals forces, hydrogen bonds, π-π conjugation and covalent bonds, successfully realizing the in-situ modification of the carbon black surface, significantly improving the dispersion effect of carbon black in the rubber matrix and enhancing the interface interaction in the composite material, thereby greatly improving the mechanical properties of the rubber composite material and reducing energy loss and heat generation under dynamic conditions.

[0022] Preferably, the amount of the polyphenol-based carbon black in-situ surface modifier added is 0.5 to 10 wt.% of the amount of carbon black used;

[0023] The carbon black addition amount is 10 to 100 wt.% of the rubber mass.

[0024] Furthermore, the rubber is one or more of natural rubber, styrene-butadiene rubber, and isoprene rubber.

[0025] Preferably, the rubber composite material further comprises the following raw materials:

[0026] Antioxidants, zinc oxide, stearic acid, accelerators and sulphur.

[0027] Further, the antioxidant is one or more of antioxidant RD, antioxidant 4010NA, antioxidant 4010 and antioxidant 4020; and / or

[0028] The accelerator is at least one of accelerator CZ, accelerator M, accelerator DM, accelerator TT and accelerator D.

[0029] Optionally, the antioxidant is added in an amount of 1.5wt% of the rubber; the zinc oxide is added in an amount of 5wt% of the rubber; the stearic acid is added in an amount of 2wt% of the rubber; the accelerator is added in an amount of 2wt% of the rubber; and the sulfur is added in an amount of 1.6wt% of the rubber.

[0030] The fourth technical solution of the present invention:

[0031] The method for preparing the rubber composite material comprises the following steps:

[0032] The above raw materials are directly mixed and hot-pressed to vulcanize to obtain the rubber composite material.

[0033] Preferably, when the mixing is carried out using an internal mixer, the mixing temperature is 60 to 100° C. and the mixing time is 5 to 10 minutes; and / or

[0034] When the mixing is carried out using an open mixing mill, the mixing temperature is 30 to 60° C. and the mixing time is 8 to 10 minutes.

[0035] Compared with the prior art, the present invention has the following advantages and technical effects:

[0036] 1) The in-situ surface modifier of the present invention has a simple synthesis process and can be obtained by a simple one-step reaction, with mild reaction conditions, low cost, and green environmental protection;

[0037] 2) The in-situ surface modifier of the present invention is applied to rubber composite materials, and carbon black can form multiple interface interactions with the modifier through van der Waals forces, hydrogen bonds, π-π conjugation and covalent bonds, successfully realizing in-situ modification of the carbon black surface, significantly improving the dispersion effect of carbon black in the rubber matrix and enhancing the interface interaction in the composite material, thereby greatly improving the mechanical properties of the rubber composite material and reducing energy loss and heat generation under dynamic conditions;

[0038] 3) The in-situ surface modifier of the present invention can be directly applied to traditional rubber formulations, showing great commercial application potential, and is of great significance for the low-energy, low-pollution, and low-cost manufacturing of high-performance and environmentally friendly energy-saving rubber products. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 The surface morphology scanning electron microscope images of the rubber composite materials prepared in Comparative Example 1 (a) and Example 1 (b) are shown. DETAILED DESCRIPTION

[0041] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0042] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. 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 invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0043] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only 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 the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0044] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0045] The term "antioxidant RD" in the embodiments of the present invention has Chinese names 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 2,4-trimethyl-1,2-dihydroquinoline polymer, homopolymer of 2-dihydro-2,2,4-trimethylquinoline; 2,2,4-trimethyl-1,2-dihydroquinoline; aliases include antioxidant TMQ, antioxidant RD, antioxidant 224.

[0046] Antioxidant 4010NA, also known as N-isopropyl-N'-phenyl-p-phenylenediamine, is a light red to purple-red, brown granular substance with a molecular formula of C 15 H 18 N2.

[0047] Antioxidant 4010, Chinese alias: N-cyclohexyl-N'-phenyl-p-phenylenediamine; N-phenyl-N'-cyclohexyl-p-phenylenediamine; Antioxidant CPPD belongs to the p-phenylenediamine rubber antioxidant.

[0048] Antioxidant 4020, Chinese alias: N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine; Antioxidant DMPPD belongs to the p-phenylenediamine rubber antioxidant.

[0049] Accelerator CZ, molecular formula C 13 H 16 N2S2, chemical name is N-cyclohexyl-2-benzothiazolesulfenamide;

[0050] Accelerator M, 2-mercaptobenzothiazole, also known as Accelerator M, is an organic compound with the chemical formula C7H5NS2. It is a light yellow crystalline powder and is mainly used as a sensitive reagent for the determination of gold, bismuth, cadmium, cobalt, mercury, nickel, lead, thallium and zinc and a rubber accelerator.

[0051] Accelerator DM, rubber accelerator DM is an organic substance with the chemical formula C 14 H8N2S4, light yellow needle-shaped crystals, slightly soluble in benzene, dichloromethane, carbon tetrachloride, acetone, ethanol, ether, etc. at room temperature, insoluble in water, ethyl acetate, gasoline and alkali.

[0052] Accelerator TT, Chinese name: Tetramethylthiuram disulfide, molecular formula: C6H 12 N2S4,CAS No.:137-26-8;

[0053] Accelerator D, molecular formula C 13H 13 N3, English name: accelerator D, Chinese alias: diphenylguanidine; accelerator DPG; rubber vulcanization accelerator DPG; 1,3-diphenylguanidine; N,N'-diphenylguanidine; symmetrical diphenylguanidine.

[0054] The embodiment of the present invention discloses a method for preparing a polyphenol-based carbon black in-situ surface modifier, comprising the following steps:

[0055] The polyphenol compound and the epoxy-containing silane coupling agent are dissolved in water, and the mixture is condensed and refluxed at 20 to 80° C., and stirred for reaction for 6 to 48 hours; after the reaction is completed, the reaction solution is centrifuged and washed, and vacuum dried to obtain a polyphenol-based carbon black in-situ surface modifier;

[0056] Among them, the polyphenolic compounds include any one of tannic acid, gallic acid, catechin, epicatechin, theaflavins, anthocyanins, resveratrol, lignans, coumarins, caffeic acid and curcumin;

[0057] The epoxy-containing silane coupling agent includes any one of γ-glycidyloxypropyltrimethoxysilane, 3-[(2,3)-glycidyloxy]propylmethyldimethoxysilane, [8-(glycidyloxy)-n-octyl]trimethoxysilane and 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane;

[0058] In some preferred embodiments, a method for preparing a polyphenol-based carbon black in-situ surface modifier comprises the following steps: adding 150 mL of deionized water into a three-necked flask, then adding 2 g of tannic acid and 1.5 g of γ-glycidyloxypropyltrimethoxysilane, heating and stirring at 80°C, condensing and refluxing, reacting for 8 hours, centrifuging and washing with ether to remove impurities, and finally vacuum drying to obtain purified polyphenol-based carbon black in-situ surface modifier m1 with a yield of 88%.

[0059] In some preferred embodiments, a method for preparing a polyphenol-based carbon black in-situ surface modifier comprises the following steps: adding 120 mL of deionized water into a three-necked flask, then adding 2.5 g of gallic acid and 1.8 g of 3-[(2,3)-epoxypropyloxy]propylmethyldimethoxysilane, heating and stirring at 60°C, condensing and refluxing, reacting for 6 hours, centrifuging and washing with ether to remove impurities, and finally vacuum drying to obtain purified polyphenol-based carbon black in-situ surface modifier m2 with a yield of 83%.

[0060] In some preferred embodiments, a method for preparing a polyphenol-based carbon black in-situ surface modifier comprises the following steps: adding 200 mL of deionized water into a three-necked flask, then adding 4.3 g of curcumin and 3.6 g of 31,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, heating and stirring at 20°C, condensing and refluxing, reacting for 48 hours, centrifuging and washing with ether to remove impurities, and finally vacuum drying to obtain purified polyphenol-based carbon black in-situ surface modifier m3 with a yield of 92%.

[0061] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0062] Unless otherwise specified, the "room temperature" in the present invention refers to 20-30° C. The positive vulcanization time mentioned in the following examples is obtained by testing the mixed rubber in a vulcanizer.

[0063] The "parts" described in the present invention, unless otherwise specified, refer to parts by mass.

[0064] The raw materials used in the present invention are all purchased from the market.

[0065] The technical solution of the present invention is further illustrated by the following embodiments.

[0066] Example 1

[0067] A method for preparing a rubber / carbon black composite material based on a polyphenol-based carbon black in-situ surface modifier, the specific steps are as follows:

[0068] 1g of carbon black in-situ surface modifier (m1), 20g of carbon black, 100g of natural rubber, 5g of zinc oxide, 2g of stearic acid, 1.5g of accelerator CZ, 0.5g of accelerator DM, 1.5g of antioxidant 4020 and 1.6g of sulfur were mixed in an open mill at a mixing temperature of 50°C for 8 minutes, and then hot-press vulcanized at 143°C for 1 minute plus the positive vulcanization time to obtain a rubber composite material (rubber / carbon black composite material).

[0069] Example 2

[0070] The only difference from Example 1 is that m1 is replaced by m2 of equal mass, which is a carbon black in-situ surface modifier. Other conditions are the same as those in Example 1.

[0071] Example 3

[0072] The only difference from Example 1 is that m1 is replaced by m3 of the same mass as the carbon black in-situ surface modifier. Other conditions are the same as those of Example 1.

[0073] Example 4

[0074] The difference from Example 2 is that the amount of carbon black in-situ surface modifier m2 is 1.5 g. Other conditions are the same as those in Example 2.

[0075] Example 5

[0076] The difference from Example 3 is that the amount of carbon black in-situ surface modifier m3 is 1.5 g. Other conditions are the same as those in Example 3.

[0077] Example 6

[0078] The difference from Example 1 is that natural rubber is replaced by styrene-butadiene rubber of equal quality, and the hot pressing temperature is 160° C. The other conditions are the same as those in Example 1.

[0079] Comparative Example 1

[0080] The difference from Example 1 is that the carbon black in-situ surface modifier m1 is not added, and the other conditions are the same as those of Example 1.

[0081] Comparative Example 2

[0082] The difference from Example 6 is that no carbon black in-situ surface modifier m1 is added. Other conditions are the same as those in Example 6.

[0083] The formulas of the rubber / carbon black composite materials prepared in Examples 1-6 and the rubber materials prepared in Comparative Examples 1-2 are shown in Table 1.

[0084] Table 1

[0085]

[0086] Effect verification

[0087] The rubber / carbon black composite materials prepared in Examples 1-6 and the rubber materials prepared in Comparative Examples 1-2 were respectively subjected to performance tests, and the test results are shown in Table 2, wherein the tensile strength, elongation at break and 300% elongation stress were measured according to ISO37-2005, the test temperature was room temperature, and the stretching rate was 500 mm / min; the dynamic temperature rise was measured according to ISO 4666-3:2016; the dynamic energy loss was measured using a dynamic mechanical analyzer (DMA), and the test conditions were that the sample was heated from -80°C to 80°C at 3°C / min in the tensile mode, and the frequency was 1 Hz (the tanδ peak represents the energy loss).

[0088] Table 2

[0089]

[0090] Analysis of the properties of the rubber composite materials obtained from Comparative Example 1 and Examples 1-3 in Table 2 shows that, compared with Comparative Example 1 without the addition of carbon black in-situ surface modifier, after adding different carbon black in-situ surface modifiers, the tensile strength and 300% elongation stress of the natural rubber composite materials are significantly improved, and the fatigue temperature rise (dynamic temperature rise) and energy loss under dynamic strain are significantly reduced. In addition, according to Figure 1 From the surface morphology scanning electron microscopy images of Comparative Example 1 (a) and Example 1 (b), it can be seen that the unmodified carbon black in Comparative Example 1 forms large-sized agglomerates in the rubber, while after modification with an in-situ surface modifier, the agglomeration phenomenon of the carbon black in Example 1 in the rubber matrix is ​​significantly weakened and the dispersion effect is significantly enhanced.

[0091] By comparing the properties of the rubber composite materials obtained by Comparative Example 1 in Table 2 with Examples 2 and 4; or with Examples 3 and 5, it is found that when the same carbon black in-situ surface modifier is used, as the amount increases, the tensile strength of the natural rubber composite material is further improved, and the temperature rise and energy loss under dynamic conditions are further reduced.

[0092] By comparing Comparative Example 2 and Example 6 in Table 2, it is found that after the carbon black in-situ surface modifier is applied to the styrene-butadiene rubber / carbon black composite material, its influence on the comprehensive performance of the composite material is similar to that in the natural rubber / carbon black composite material, and both can significantly improve the comprehensive performance of the rubber composite material.

[0093] In summary, the polyphenol-based carbon black in-situ surface modifier prepared by the present invention can improve the dispersibility of carbon black in rubber, greatly improve the mechanical strength of the rubber composite material, and reduce the energy loss and heat generation of the rubber composite material under dynamic strain.

[0094] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a polyphenol-based carbon black in-situ surface modifier, characterized in that: The following steps are involved: The polyphenol compound and the silane coupling agent containing epoxy group are dissolved in water, and the hydroxyl-epoxy ring-opening reaction is carried out by heating, stirring and condensing and refluxing to prepare the polyphenol-based carbon black in-situ surface modifier.

2. The method for preparing a polyphenol-based carbon black in-situ surface modifier according to claim 1, characterized in that: The polyphenolic compounds include any one of tannic acid, gallic acid, catechin, epicatechin, theaflavins, anthocyanins, resveratrol, lignans, coumarin, caffeic acid and curcumin; The epoxy-containing silane coupling agent includes any one of γ-glycidyloxypropyltrimethoxysilane, 3-[(2,3)-glycidyloxy]propylmethyldimethoxysilane, [8-(glycidyloxy)-n-octyl]trimethoxysilane and 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane.

3. The method for preparing a polyphenol-based carbon black in-situ surface modifier according to claim 1, characterized in that: The amount of the polyphenol compound used is 10-60% of the total mass of the polyphenol compound and the epoxy-containing silane coupling agent.

4. The method for preparing a polyphenol-based carbon black in-situ surface modifier according to claim 1, characterized in that: The heating temperature during the heating and stirring process is 20 to 80°C; The stirring time is 6 to 48 hours.

5. A polyphenol-based carbon black in-situ surface modifier, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 4.

6. A rubber composite material, characterized in that: The raw materials include carbon black, rubber and the polyphenol-based carbon black in-situ surface modifier according to claim 5.

7. A rubber composite material according to claim 6, characterized in that: The amount of the polyphenol-based carbon black in-situ surface modifier added is 0.5 to 10 wt.% of the amount of the carbon black used; The amount of carbon black added is 10 to 100 wt.% of the amount of rubber used.

8. The rubber composite material according to claim 6, characterized in that: The rubber composite material also includes the following raw materials: antioxidant, zinc oxide, stearic acid, accelerator and sulfur.

9. A method for preparing a rubber composite material, characterized in that: The following steps are involved: The raw materials of the rubber composite material according to any one of claims 6 to 8 are directly mixed and hot-pressed and vulcanized to obtain the rubber composite material.

10. The method for preparing a rubber composite material according to claim 9, characterized in that: When the mixing process uses an internal mixer, the mixing temperature is 60 to 100° C. and the mixing time is 5 to 10 minutes; and / or When the mixing process adopts an open mixing mill, the mixing temperature is 30-60° C. and the mixing time is 8-10 minutes.

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