Cutting-resistant rubber material composition and preparation method thereof

Abstract

The invention belongs to the technical field of rubber materials, and provides a cutting-resistant rubber material composition and a preparation method thereof.The cutting-resistant rubber material composition is prepared from natural rubber, butadiene rubber, high-styrene rubber, reinforcing filler, a diene rubber modifier and auxiliaries, and the high-styrene rubber can effectively improve the modulus, cutting resistance and high-temperature performance of the rubber material; the diene rubber modifier is a composite system of a dihydrazide compound, a disulfydryl compound and a tetrazine compound, the whole molecular network structure of the diene rubber can be optimized, the compatibility between different rubbers is enhanced, the compatibility between the diene rubber and a filler is improved, and the modulus and low heat generation of a rubber material are effectively improved; a three-step mixing process is adopted, the cutting-resistant rubber material with good comprehensive performance is prepared by controlling the charging sequence and the mixing process, and the problem that the cutting resistance of the rubber material is insufficient under the complex load condition is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber materials, and particularly relates to a cut-resistant rubber material composition and a preparation method thereof. Background Art

[0002] Track shoe rubber blocks and civilian mining tires are used in harsh conditions, with complex road conditions, and are not resistant to cutting and puncture. They have long suffered from problems such as rapid performance degradation and short life, which seriously affect the performance of related equipment and cause huge economic costs.

[0003] Rubber materials are composite materials with a special microscopic network structure, which are composed of a rubber matrix with long-chain, amorphous structural characteristics, reinforcing fillers (such as carbon black and nano-silica), plasticizers, antioxidants and vulcanizers. The rubber material matrix itself often has poor cut resistance. Traditionally, it mainly relies on the addition of reinforcing fillers to give the rubber material a certain rigidity, thereby having a certain degree of cut resistance. With the development of technology, my country's formula design mainly adopts the addition of cutting and tearing resins, cut-resistant fibers, special structured carbon black, etc. to improve the cut resistance of rubber materials. Studies have found that the rubber materials developed by the above methods are difficult to meet the comprehensive use requirements of high strength, high load-bearing, high temperature resistance, cut and tear resistance, low heat generation, and aging resistance for mining tread rubber and military and civilian track plate grounding rubber blocks under complex load environments.

[0004] Therefore, how to achieve overall optimization of properties such as high load-bearing capacity, high modulus, cut resistance, high temperature resistance, and low heat generation in the compound rubber material through material design is of great significance for meeting the use requirements under harsh working conditions. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a cut-resistant rubber material composition and a preparation method thereof.

[0006] The object of the present invention is achieved in the following way: by using three diene rubbers, namely natural rubber, cis-1,4-butadiene rubber and high-styrene rubber, selecting high-styrene rubber with a combined styrene content of 55-70%, and utilizing its aggregate structure in a wide temperature range to improve the modulus, cut resistance and high-temperature performance of the cut-resistant rubber material, and utilizing cis-1,4-butadiene rubber to improve the processability and compatibility of natural rubber and high-styrene rubber; at the same time, by utilizing three diene rubber modifiers, namely dihydrazide compounds, dithiol compounds and tetrazine compounds, to optimize the overall molecular network structure of the diene rubber, further improve the compatibility between the three rubbers, reduce the amount of reinforcing fillers such as carbon black, improve the compatibility between the diene rubber and the filler, and give the rubber material a high modulus and low heat generation; finally, by a three-step mixing process, the diene rubber is modified by the modifier and the rubber material is evenly mixed by controlling the feeding sequence and the mixing process, so as to prepare a cut-resistant rubber material with good comprehensive performance.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A cut-resistant rubber material composition, comprising:

[0009] Natural rubber 60 parts by weight

[0010] 40 parts by weight of butadiene rubber and high styrene rubber

[0011] Diene rubber modifier 0.6-1.5 parts by weight

[0012] Carbon black reinforcing filler 45-55 parts by weight

[0013] 8 to 20 parts by weight of auxiliary agent;

[0014] The weight ratio of the butadiene rubber to the high styrene rubber is 3:5 to 5:3;

[0015] The high styrene rubber has a combined styrene content of 55-70%;

[0016] The natural rubber is smoked sheet rubber;

[0017] The diene rubber modifier is a composite system of a dihydrazide compound, a bis-mercapto compound, and a tetrazine compound. The dihydrazide compound is preferably sebacic acid dihydrazide or dodecanoic acid dihydrazide. The bis-mercapto compound is preferably bis(2-mercaptoethyl) ether or ethylene bis(thioglycolate). The tetrazine compound is preferably 3,6-bis(3-hydroxyphenyl)-1,2,4,5-tetrazine or 3,6-bis(2-thienyl)-1,2,4,5-tetrazine. The three modifiers are added in the same proportion.

[0018] The auxiliary agent is 3-5 parts of zinc oxide, 2-3 parts of stearic acid, 1-3 parts of antioxidant, 0.5-2 parts of coupling agent, 1-4 parts of sulfur, and 0.5-3 parts of accelerator;

[0019] The carbon black reinforcing filler used is one of carbon black N220, carbon black N330 and carbon black N550;

[0020] The antioxidant is one of antioxidant 4010NA, antioxidant 4020 and antioxidant RD; the accelerator is one of accelerator NS, accelerator CZ and accelerator DM; and the coupling agent is silane coupling agent Si-69.

[0021] The preparation method of the cut-resistant rubber material composition of the present invention comprises a first-stage mixing, a second-stage mixing and a final mixing, and the specific steps are as follows:

[0022] 1) One-stage mixing: put cis-1,2-butadiene rubber, high styrene rubber, half of the antioxidant and tetrazine compound into an internal mixer and mix them at a speed of 30-45 rpm, lift and press the rubber every 30-35 seconds, and when the rubber temperature reaches above 130°C, mix for 80-90 seconds, discharge the rubber, and produce sheets. After standing at room temperature for 4-12 hours, a masterbatch is obtained;

[0023] 2) Second stage mixing: the first stage masterbatch of step 1) and natural rubber, carbon black, dihydrazide compound, dithiol compound, zinc oxide, stearic acid, remaining antioxidant and silane coupling agent are put into an internal mixer, mixed at a speed of 30-40 rpm, and the mass is lifted and pressed every 25-35 seconds. When the temperature of the rubber material reaches above 115° C., the rubber material is mixed for 80-90 seconds, and the rubber material is discharged and sheeted. The second stage masterbatch is obtained after being placed at room temperature for 4-12 hours.

[0024] 3) Final mixing: the second-stage masterbatch, sulfur and accelerator of step 2) are put into an internal mixer, mixed at a speed of 20-30 rpm, and the pressure roller is lifted and pressed once at intervals of 30-35 seconds, 25-30 seconds and 15-20 seconds respectively. When the temperature of the rubber material reaches 100-115° C., the rubber material is discharged and the sheet is removed, and the cut-resistant rubber material composition is obtained after being left to cool.

[0025] The invention adopts three kinds of diene rubbers in combination, adopts high styrene rubber to improve the cut resistance and high temperature resistance of the rubber material, adopts butadiene rubber to improve the processability and compatibility of natural rubber and high styrene rubber; adopts three kinds of modifiers in combination to improve the compatibility of the three kinds of diene rubbers and the compatibility of the diene rubber and filler, improves the modulus of the rubber material and reduces the heat generation; finally, through a three-step mixing process, by controlling the process steps such as the feeding order, the rubber mixing time, the number of times of lifting and pressing the roller, the filler and the modifier are uniformly dispersed in the rubber material, and the problem of material performance degradation caused by excessive mixing can be avoided, thereby realizing the preparation of a track shoe rubber material with high modulus, cut resistance, high temperature resistance and low heat generation, and solving the problem of insufficient cut resistance of the rubber material under complex load conditions.

[0026] The cut-resistant rubber material composition prepared by the formula and preparation method of the present invention is vulcanized on a flat vulcanizer at 145°C for 30 min to obtain a vulcanized rubber sample, and its mechanical properties are tested. The tensile properties of the vulcanized rubber are tested according to GB / T 528-2009, including 100% tensile stress, tensile strength and elongation at break; the compression fatigue heat generation performance of the vulcanized rubber is tested according to GB / T1687.3-2016; the temperature is adjusted according to GB / T2941-2006, and the temperature is adjusted according to GB / T 528-2009 tests the high-temperature tensile strength of vulcanized rubber, the test temperature is 100±1℃; cut resistance: using a rubber dynamic cut resistance tester, the sample speed is 720r / min, the cutting frequency is 120 times / min, and the cutting time is 20min; aging resistance coefficient: the sample is aged in hot air at 100℃*24h, and the product of the tensile strength before aging multiplied by the elongation at break divided by the product of the tensile strength after aging multiplied by the elongation at break is the aging resistance coefficient.

[0027] The test results show that the cut-resistant rubber material composition involved in the present invention has excellent comprehensive performance, among which the material's cut resistance performance has a cutting loss as low as 2.5g, the high temperature resistance is improved to 16.0MPa, and the aging performance is also improved. At the same time, the material can also take into account the load-bearing characteristics such as high modulus and low heat generation. When the cutting loss is not more than 3.0g, the modulus is maintained greater than 4.0MPa and the heat generation is not higher than 20°C.

[0028] The rubber material composition involved in the present invention can be used in mining tire tread rubber and track vehicle track shoe grounding rubber block. The anti-cutting properties of the product are significantly improved, while taking into account the comprehensive use requirements of high strength, high temperature resistance, low heat generation, aging resistance and other properties under complex load environments. DETAILED DESCRIPTION

[0029] The present invention is further described below with reference to specific examples, but is not intended to limit the content of the present invention. Any cut-resistant rubber material composition and preparation method thereof based on the technical solution proposed by the present invention constitute an integral part of the present invention.

[0030] In order to more clearly describe the beneficial effects achieved by the scheme of the present invention, on the basis of the preparation method of the present invention, a rubber material composition is prepared by not adding high styrene rubber, adjusting the ratio of butadiene rubber and high styrene rubber, adjusting the content of diene rubber modifier, etc., and its performance is investigated and compared with the scheme of the present invention, see Comparative Examples 1-8 for details, and the test results are shown in Table 2.

[0031] Example 1

[0032] A cut-resistant rubber material composition, the components of which are as follows, measured by weight: 60 parts of natural rubber (commercially available Indonesian No. 1 smoked sheet rubber), 15 parts of butadiene rubber (BR9000, PetroChina Co., Ltd.), 25 parts of high styrene rubber (JSR0051, with a combined styrene content of 55%, Japan Synthetic Rubber Co., Ltd.), 0.4 parts of sebacic acid dihydrazide, 0.4 parts of ethylene bis(thioglycolate), 0.4 parts of 3,6-bis(2-thienyl)-1,2,4,5-tetrazine, 50 parts of carbon black N220, 5 parts of zinc oxide, 2 parts of stearic acid, 1 part of antioxidant 4020, 0.5 parts of coupling agent si-69, 2.5 parts of sulfur, 1 part of accelerator CZ, and the formula is shown in Table 1.

[0033] Put butadiene rubber, high styrene rubber, 0.5 parts of antioxidant and tetrazine compound into internal mixer and mix them at a speed of 35 rpm. Lift and press the ball every 30 seconds. When the temperature of the rubber reaches 130°C, mix for 90 seconds to discharge the rubber and take out the sheet. After leaving it at room temperature for 8 hours, a masterbatch is obtained.

[0034] Put the first-stage masterbatch, natural rubber, carbon black, dihydrazide compounds, dithiol compounds, zinc oxide, stearic acid, remaining antioxidants and silane coupling agents into an internal mixer and mix them at a speed of 30 rpm. Lift and press the balls every 35 seconds. When the temperature of the rubber material reaches above 115 degrees, mix for 90 seconds, discharge the rubber, and take out the sheets. After standing at room temperature for 8 hours, the second-stage masterbatch is obtained.

[0035] The second-stage masterbatch, sulfur and accelerator are put into an internal mixer and mixed at a speed of 20 rpm. The pressure roller is lifted and pressed once at intervals of 30 seconds, 25 seconds and 15 seconds respectively. When the temperature of the rubber material reaches 100°C, the rubber is discharged and the sheet is removed. After being left to cool, the cut-resistant rubber material composition is obtained.

[0036] The performance test results are shown in Table 2.

[0037] Example 2

[0038] The difference from Example 1 is that a cut-resistant rubber material composition comprises 25 parts by weight of high styrene rubber (NS614, with a combined styrene content of 60%, BASF, Germany), and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0039] Example 3

[0040] The difference from Example 1 is that a cut-resistant rubber material composition comprises 25 parts by weight of high styrene rubber (HS68, with a combined styrene content of 70%, Yantai Shiyuan Rubber Co., Ltd.), and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0041] Example 4

[0042] The difference from Example 1 is that a cut-resistant rubber material composition comprises, by weight, 20 parts of butadiene rubber and 20 parts of high styrene rubber, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0043] Example 5

[0044] The difference from Example 1 is that a cut-resistant rubber material composition comprises, by weight, 25 parts of butadiene rubber and 15 parts of high styrene rubber, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0045] Example 6

[0046] The difference from Example 1 is that a cut-resistant rubber material composition comprises, by weight, 0.2 parts of sebacic acid dihydrazide, 0.2 parts of ethylene bis(thioglycolate), and 0.2 parts of 3,6-bis(2-thienyl)-1,2,4,5-tetrazine, and the remaining components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0047] Example 7

[0048] The difference from Example 1 is that a cut-resistant rubber material composition comprises, by weight, 0.5 parts of sebacic acid dihydrazide, 0.5 parts of ethylene bis(thioglycolate), and 0.5 parts of 3,6-bis(2-thienyl)-1,2,4,5-tetrazine, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0049] Example 8

[0050] The difference from Example 1 is that a cut-resistant rubber material composition comprises, by weight, 0.4 parts of dodecanoic acid dihydrazide, 0.4 parts of bis(2-mercaptoethyl) ether, and 0.4 parts of 3,6-bis(3-hydroxyphenyl)-1,2,4,5-tetrazine, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0051] Example 9

[0052] The difference from Example 1 is that a cut-resistant rubber material composition contains 45 parts of carbon black N220 by weight, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0053] Example 10

[0054] The difference from Example 1 is that a cut-resistant rubber material composition contains 55 parts of carbon black N220 by weight, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0055] Comparative Example 1

[0056] The difference from Example 1 is that a rubber material composition contains 40 parts of butadiene rubber by weight and does not contain high styrene rubber. The other components are the same. The formula is shown in Table 1 and the test results are shown in Table 2.

[0057] Comparative Example 2

[0058] The difference from Example 1 is that a rubber material composition, measured by weight, does not contain sebacic acid dihydrazide, ethylenebis(thioglycolate), and 3,6-bis(2-thienyl)-1,2,4,5-tetrazine, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0059] Comparative Example 3

[0060] The difference from Example 1 is that a rubber material composition does not contain ethylenebis(thioglycolate) and 3,6-bis(2-thienyl)-1,2,4,5-tetrazine by weight, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0061] Comparative Example 4

[0062] The difference from Example 1 is that a rubber material composition, measured by weight, does not contain sebacic acid dihydrazide and 3,6-bis(2-thienyl)-1,2,4,5-tetrazine, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0063] Comparative Example 5

[0064] The difference from Example 1 is that a rubber material composition does not contain sebacic acid dihydrazide and ethylene bis(thioglycolate) by weight, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0065] Comparative Example 6

[0066] The difference from Example 1 is that a rubber material composition, calculated by weight, contains 0.6 parts of sebacic acid dihydrazide, 0.6 parts of ethylene bis(thioglycolate), and 0.6 parts of 3,6-bis(2-thienyl)-1,2,4,5-tetrazine, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0067] Comparative Example 7

[0068] The difference from Example 1 is that a rubber material composition comprises, by weight, 10 parts of butadiene rubber and 30 parts of high styrene rubber, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0069] Comparative Example 8

[0070] The difference from Example 1 is that a rubber material composition comprises, by weight, 30 parts of butadiene rubber and 10 parts of high styrene rubber, and the other components are the same. The formula is shown in Table 1, and the test results are shown in Table 2.

[0071] Table 1 Examples and Comparative Examples

[0072]

[0073] Table 2 Performance comparison of examples and comparative examples

[0074]

[0075]

[0076] Combining Examples 1 to 3 with Comparative Example 1, it can be seen that the addition of high styrene rubber greatly improves the cut resistance of the rubber material, the cutting loss is as low as 2.5g, the high temperature resistance is improved to 16.0MPa, and the aging performance is also improved; by comparing Example 1 with Comparative Examples 2 to 5, it can be seen that the addition of the diene modifier composite system improves the cut resistance, aging performance and high temperature resistance of the rubber material, reduces the compression fatigue temperature rise of the material, and its performance is better than that of the material modified by a single modifier; by comparing Example 1 with Comparative Example 6, when the number of diene rubber modifiers exceeds 1.5 parts (Comparative Example 6 is 1.8 parts), the cut resistance of the material will deteriorate, the cut loss will reach 4.0g, and the cutting performance will be reduced by 35%; by comparing Example 1 with Comparative Examples 7 and 8, when the proportion of high styrene rubber is too large or too small, the aging performance and cut resistance of the material will deteriorate. When the proportion is too large (Comparative Example 7), the heat generation of the material will increase significantly to 23.4°C, and when the proportion is too small (Comparative Example 8), the modulus of the material will be reduced to 3.3MPa.

[0077] It can be seen from the embodiments and comparative examples that the present invention uses a high styrene rubber and diene rubber modifier mixed system to give the rubber material good modulus, high temperature resistance, cut resistance, aging resistance and low heat generation characteristics. The material is used in mining tire tread rubber and track vehicle track shoe grounding rubber blocks, and the product's anti-cutting characteristics are significantly improved, while taking into account the comprehensive use requirements of high strength, high temperature resistance, low heat generation, aging resistance and other properties under complex load environments.

[0078] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A cut-resistant rubber material composition, Features: Its components are: The natural rubber is smoked rubber; the weight ratio of butadiene rubber to high styrene rubber is 3:5 to 5:3; the high styrene rubber has a combined styrene content of 55-70%; the diene rubber modifier is a composite system of dihydrazide compounds, dithiol compounds and tetrazine compounds; the auxiliary agents are zinc oxide, stearic acid, antioxidant, coupling agent, sulfur and accelerator.

2. The cut-resistant rubber material composition according to claim 1, Features: The dihydrazide compound is sebacic acid dihydrazide or dodecanoic acid dihydrazide; the bis-mercapto compound is bis(2-mercaptoethyl) ether or ethylenebis(mercaptoacetate); and the tetrazine compound is 3,6-bis(3-hydroxyphenyl)-1,2,4,5-tetrazine or 3,6-bis(2-thienyl)-1,2,4,5-tetrazine.

3. The cut-resistant rubber material composition according to claim 1 or 2, Features: The mass ratio of the dihydrazide compound, the dithiol compound and the tetrazine compound is 1:1:

1.

4. The cut-resistant rubber material composition according to claim 1, Features: The carbon black reinforcing filler is one of carbon black N220, carbon black N330 and carbon black N550.

5. The cut-resistant rubber material composition according to claim 1, Features: The auxiliary agent is 3-5 parts of zinc oxide, 2-3 parts of stearic acid, 1-3 parts of antioxidant, 0.5-2 parts of coupling agent, 1-4 parts of sulfur and 0.5-3 parts of accelerator.

6. The cut-resistant rubber material composition according to claim 1 or 5, Features: The antioxidant is one of antioxidant 4010NA, antioxidant 4020, and antioxidant RD; the accelerator is one of accelerator NS, accelerator CZ, and accelerator DM; and the coupling agent is silane coupling agent Si-69.

7. A method for preparing the cut-resistant rubber material composition according to claim 1, comprising a first-stage mixing, a second-stage mixing and a final mixing. Features: The specific steps are as follows: 1) One-stage mixing: put cis-1,2-butadiene rubber, high styrene rubber, half of the antioxidant and tetrazine compound into an internal mixer and mix them at a speed of 30-45 rpm, lift and press the balls every 30-35 seconds, and when the temperature of the rubber material reaches above 130°C, mix for 80-90 seconds, discharge the rubber, and take out the sheets. After standing at room temperature for 4-12 hours, a masterbatch is obtained; 2) Second stage mixing: the first stage masterbatch of step 1) and natural rubber, carbon black, dihydrazide compound, dithiol compound, zinc oxide, stearic acid, remaining antioxidant and silane coupling agent are put into an internal mixer, mixed at a speed of 30-40 rpm, and the mass is lifted and pressed every 25-35 seconds. When the temperature of the rubber material reaches above 115° C., the rubber material is mixed for 80-90 seconds, and the rubber material is discharged and sheeted. The second stage masterbatch is obtained after being placed at room temperature for 4-12 hours; 3) Final mixing: the second-stage masterbatch, sulfur and accelerator of step 2) are put into an internal mixer, mixed at a speed of 20-30 rpm, and the pressure roller is lifted and pressed once at intervals of 30-35s, 25-30s and 15-20s respectively. When the temperature of the rubber material reaches 100-115°C, the rubber material is discharged and the sheet is placed to cool, thereby obtaining a cut-resistant rubber material composition.

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