Preparation method of vulcanizing agent BIPB

Abstract

The invention discloses a preparation method of a vulcanizing agent BIPB, and relates to the technical field of vulcanizing agents, and the preparation method comprises the following preparation steps: dissolving AATD in methanol to form an AATD solution, heating, adding aluminum chloride into the AATD solution, uniformly stirring, adding methyl iodide, and uniformly stirring to obtain a mixed solution; filtering, washing and drying the mixed solution to obtain modified AATD; adding the modified AATD into a tert-butyl hydroperoxide solution in a heat preservation state, stirring and heating, dropwise adding a sulfuric acid solution, stirring until the color of a reaction system is changed, and adding water to stop the reaction to obtain a reaction solution; the reaction solution is subjected to standing until complete layering, supernatant is taken and washed with a sodium hydroxide solution and hot water in sequence, finally, low-temperature reduced pressure distillation is performed, the vulcanizing agent BIPB containing the iodo-methylene group is obtained, the strength performance and heat resistance of a vulcanization product can be improved, and then the comprehensive vulcanization performance of the vulcanizing agent BIPB is improved; meanwhile, due to the existence of iodine atoms, a catalyst can be replaced to play a catalytic role, so that the catalyst is more environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of vulcanizing agents, and in particular to a method for preparing a vulcanizing agent BIPB. Background Art

[0002] BIPB [di-(2-tert-butylperoxide)biphenyl] is a highly efficient vulcanizing agent and is widely used in the rubber and plastics industries. There are various methods for its preparation, including the tert-butyl hydroperoxide (TBHP) method, the di-(2-hydroxyisopropyl)benzene method, the di-(isopropenyl)benzene method, etc. These preparation methods have their own characteristics, but all aim to synthesize BIPB with efficient vulcanization performance through chemical reactions.

[0003] In the processing of rubber products, the vulcanizing agent BIPB, as a cross-linking agent, can significantly improve the vulcanization effect of rubber materials. It forms a three-dimensional network structure by initiating chemical reactions between rubber molecular chains, thereby enhancing the hardness, tensile strength, wear resistance and aging resistance of rubber. Therefore, it is widely used in a variety of rubber and plastic materials such as polyethylene (PE), ethylene-vinyl acetate copolymer (EVA), chlorinated polyethylene rubber (CPE), ethylene propylene diene monomer rubber (EPDM), etc.

[0004] However, in practical applications, the traditional BIPB preparation method still has shortcomings in preparation efficiency and vulcanization effect. On the one hand, the structure of BIPB obtained in the preparation process is single, and on the other hand, the traditional preparation method requires the use of a catalyst when obtaining the final product BIPB, which is prone to incomplete separation in the subsequent separation process, resulting in a decrease in the purity of BIPB and affecting its vulcanization performance. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing a vulcanizing agent BIPB to solve the following technical problems:

[0006] How to improve the vulcanization performance of vulcanizing agent BIPB.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] The present invention discloses a method for preparing a vulcanizing agent BIPB, comprising the following preparation steps:

[0009] Step 1: dissolve A,A'-dihydroxy-1,3-diisopropylbenzene (hereinafter collectively referred to as AATD) in methanol to form an AATD solution, heat the AATD solution to 50°C, add aluminum chloride as a catalyst and stir evenly, then dropwise add iodomethane while stirring, and continue stirring for 30-60 minutes after the addition to obtain a mixed solution.

[0010] Preferably, the usage ratio of A,A'-dihydroxy-1,3-diisopropylbenzene to methanol is 1 g:(10-15) mL, more preferably 1 g:12 mL.

[0011] Preferably, the amount of aluminum chloride used is 2%-5% of the amount of A,A'-dihydroxy-1,3-diisopropylbenzene used, and more preferably 3.5%.

[0012] Preferably, the molar ratio of monoiodomethane to A,A'-dihydroxy-1,3-diisopropylbenzene is 1:4.

[0013] In this process, the iodine ion in methyl iodide reacts with the four methyl groups in AATD, so that the iodine ion exchanges with a hydrogen atom in the methyl group to generate methane, and at the same time, AATD carries four iodinated methylene groups. The reaction formula is as follows: Figure 1 shown.

[0014] When the four iodinated methylene groups on the modified AATD undergo vulcanization reaction, the iodine atoms in them have strong electronegativity and reactivity. This activity helps the vulcanizer to react more easily with the vulcanization substrate during the vulcanization process, thereby improving the rate and efficiency of the vulcanization reaction. It can also increase the number of cross-linking points in the vulcanized product, thereby increasing the cross-linking density, and further improving the physical and mechanical properties of the vulcanized product, such as tensile strength, hardness, etc.

[0015] At the same time, the iodinated methylene group can decompose or rearrange at high temperatures to form a more stable chemical structure, thereby also improving the heat resistance of the vulcanized product.

[0016] Step 2: Filter the mixed solution, then wash the filter material repeatedly with clean water, and then dry it to obtain a modified AATD containing an iodinated alkyl group.

[0017] Preferably, the drying temperature is 100-120° C., and the drying time is 1-2 hours.

[0018] Step 3, heat the tert-butyl hydroperoxide solution to 40°C, then add the modified AATD thereto and stir for 10-20 minutes while keeping the temperature, then raise the temperature to 50°C-60°C, dropwise add the sulfuric acid solution and stir until the reaction system changes color, then add water to stop the reaction to obtain a reaction solution;

[0019] Preferably, the molar ratio of tert-butyl hydroperoxide to modified AATD is 2:1.

[0020] Preferably, the mass fraction of the sulfuric acid is 75%.

[0021] Preferably, the mass ratio of the sulfuric acid solution to the tert-butyl hydroperoxide solution is 4:1.

[0022] Preferably, the mass fraction of the tert-butyl hydroperoxide solution is 85%.

[0023] In this process, the reaction equation between modified AATD and tert-butyl hydroperoxide is as follows: Figure 2 shown.

[0024] Due to the presence of iodine atoms in the modified AATD, the iodine atoms can replace the catalyst to play a catalytic role, so that the modified AATD and tert-butyl hydroperoxide can react without adding an additional catalyst, and the reaction rate is significantly improved.

[0025] Step 4: The reaction solution is allowed to stand until it is completely separated, and the upper layer is washed with sodium hydroxide solution and hot water in turn, and finally distilled at low temperature and reduced pressure to obtain the sulfiding agent BIPB.

[0026] Preferably, the temperature of the low-temperature reduced-pressure distillation is 60° C., and the pressure is 1.5 kPa-2.5 kPa, more preferably 2 kPa.

[0027] Beneficial effects of the present invention:

[0028] 1. In the vulcanizing agent BIPB of the present invention, during the preparation process, AATD is first reacted with iodomethane, and the iodide ion undergoes a substitution reaction with the four methyl groups in AATD, so that the iodide ion is exchanged with a hydrogen atom in the methyl group, so that AATD carries four iodinated methylene groups, wherein the iodine atom has a strong electronegativity and reactivity, and this activity helps the vulcanizing agent to react more easily with the vulcanization substrate during the vulcanization process, thereby improving the rate and efficiency of the vulcanization reaction, and can also increase the number of cross-linking points in the vulcanized product, thereby increasing the cross-linking density, and further improving the physical and mechanical properties of the vulcanized product, such as tensile strength, hardness, etc. At the same time, the iodinated methylene group can undergo a decomposition or rearrangement reaction at high temperature to form a more stable chemical structure, so that the heat resistance of the vulcanized product can also be improved, thereby improving the comprehensive vulcanization performance of the vulcanizing agent BIPB.

[0029] 2. In the curing agent BIPB of the present invention, during the preparation process, AATD is first reacted with iodomethane to obtain modified AATD. Due to the presence of iodine atoms in the modified AATD, the iodine atoms can replace the catalyst to play a catalytic role, so that the modified AATD and tert-butyl hydroperoxide react without adding an additional catalyst, and the reaction rate is significantly improved. At the same time, the catalyst cost is saved, and there is no need to separate the catalyst, which is more green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the reaction formula of AATD and methyl iodide in step 1 of the present invention;

[0031] Figure 2It is the reaction formula of modified AATD and tert-butyl hydroperoxide in step three of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0034] Example 1

[0035] Step 1: Dissolve 100 g of AATD (0.62 mol) in a stirring tank containing 1200 mL of methanol and stir evenly to form an AATD solution. Heat the AATD solution to 50° C., add 3.5 g of aluminum chloride thereto and stir evenly, then dropwise add 352 g of iodomethane (2.48 mol) while stirring. After the addition is complete, continue stirring for 50 min to obtain a mixed solution.

[0036] Step 2: Filter the mixed solution, then wash the filter material with clean water repeatedly for 4 times, and then transfer it into an oven and dry it at 110° C. for 1 h to obtain a modified AATD containing an iodinated alkyl group;

[0037] Step 3, 212g of 85% by mass tert-butyl hydroperoxide solution (containing 2mol of tert-butyl hydroperoxide) was heated to 40°C, and then 288g of modified AATD (1mol) was added thereto and stirred for 15min under heat preservation, and then the temperature was raised to 55°C, and 848g of 75% by mass sulfuric acid solution was added dropwise and stirred until the reaction system changed color, and then 200mL of water was added to stop the reaction to obtain a reaction solution;

[0038] Step 4: Allow the reaction solution to stand until it is completely separated, take the upper layer, wash it with sodium hydroxide solution and hot water, and finally perform low-temperature reduced pressure distillation at 60° C. and 2 kPa to obtain the sulfiding agent BIPB.

[0039] Example 2

[0040] Step 1: Dissolve 100 g of AATD (0.62 mol) in a stirring tank containing 1200 mL of methanol and stir evenly to form an AATD solution. Heat the AATD solution to 50° C., add 3.5 g of aluminum chloride thereto and stir evenly, then dropwise add 352 g of iodomethane (2.48 mol) while stirring. After the addition is complete, continue stirring for 30 min to obtain a mixed solution.

[0041] Step 2: Filter the mixed solution, then wash the filter material with clean water repeatedly for 4 times, and then transfer it into an oven and dry it at 100° C. for 2 h to obtain a modified AATD containing an iodinated alkyl group;

[0042] Step 3, 212g of 85% by mass tert-butyl hydroperoxide solution (containing 2mol of tert-butyl hydroperoxide) was heated to 40°C, and then 288g of modified AATD (1mol) was added thereto and stirred for 15min under heat preservation, and then the temperature was raised to 50°C, and 848g of 75% by mass sulfuric acid solution was added dropwise and stirred until the reaction system changed color, and then 200mL of water was added to stop the reaction to obtain a reaction solution;

[0043] Step 4: Allow the reaction solution to stand until it is completely separated, take the upper layer, wash it with sodium hydroxide solution and hot water, and finally perform low-temperature reduced pressure distillation at 60° C. and 1.5 kPa to obtain the sulfiding agent BIPB.

[0044] Example 3

[0045] Step 1: Dissolve 100 g of AATD (0.62 mol) in a stirring tank containing 1200 mL of methanol and stir evenly to form an AATD solution. Heat the AATD solution to 50° C., add 3.5 g of aluminum chloride thereto and stir evenly, then dropwise add 352 g of iodomethane (2.48 mol) while stirring. After the addition is complete, continue stirring for 60 min to obtain a mixed solution.

[0046] Step 2: Filter the mixed solution, then wash the filter material with clean water repeatedly for 4 times, and then transfer it into an oven and dry it at 120° C. for 1 h to obtain a modified AATD containing an iodinated alkyl group;

[0047] Step 3, 212g of 85% by mass tert-butyl hydroperoxide solution (containing 2mol of tert-butyl hydroperoxide) was heated to 40°C, and then 288g of modified AATD (1mol) was added thereto and stirred for 15min under heat preservation, and then the temperature was raised to 60°C, and 848g of 75% by mass sulfuric acid solution was added dropwise and stirred until the reaction system changed color, and then 200mL of water was added to stop the reaction to obtain a reaction solution;

[0048] Step 4: Allow the reaction solution to stand until it is completely separated, take the upper layer, wash it with sodium hydroxide solution and hot water, and finally perform low-temperature reduced pressure distillation at 60° C. and 2.5 kPa to obtain the sulfiding agent BIPB.

[0049] Comparative Example 1

[0050] Step 1, 212g of 85% by mass tert-butyl hydroperoxide solution (containing 2mol of tert-butyl hydroperoxide) and 5.5g of sodium perchlorate are mixed and heated to 40°C, and then 162g of AATD (1mol) is added thereto and stirred for 15min under a heat preservation state, and then the temperature is raised to 60°C, 848g of 75% by mass sulfuric acid solution is added dropwise and stirred until the reaction system changes color, and then 200mL of water is added to stop the reaction to obtain a reaction solution;

[0051] Step 2: Allow the reaction solution to stand until it is completely separated, take the upper layer, wash it with sodium hydroxide solution and hot water, and finally perform low-temperature reduced pressure distillation at 60° C. and 2.5 kPa to obtain the sulfiding agent BIPB.

[0052] The vulcanizing agent BIPB prepared in Examples 1-3 and Comparative Example 1 was tested for application performance respectively, and the testing methods are as follows.

[0053] First, prepare the materials according to the following formula in parts by weight: 100 parts of EPDM rubber, 5 parts of zinc oxide, 1.5 parts of stearic acid, 30 parts of paraffin oil, 25 parts of nano calcium carbonate, 50 parts of carbon black, 20 parts of modified calcined clay, and 5 parts of vulcanizing agent BIPB.

[0054] Then, add the EPDM rubber to the internal mixer and plasticize for 3 minutes, then add zinc oxide, stearic acid, paraffin oil, and add 1 / 2 of the reinforcing filling system (carbon black, modified calcined clay, nano calcium carbonate) after 2 minutes, and then add the remaining 1 / 2 of the reinforcing filling system and plasticizer after 3 minutes for mixing, and discharge the rubber at 125°C; add the vulcanizing agent BIPB on the open mixer, cut the left and right kneading knife 3 times after the powder is eaten, make triangle packages 6 times, and then make 5 large rolls, finally unroll and park for more than 16 hours to obtain the vulcanized rubber sample.

[0055] The rubber samples obtained in Examples 1-3 and Comparative Example 1 were tested for vulcanization performance, strength performance and aging resistance, and the testing method was as follows:

[0056] Vulcanization performance: refer to GB / T16584-1996 test, test conditions 170℃×30min;

[0057] Tensile strength: refer to GB / T 528-2009;

[0058] Shore A hardness: refer to GB / T 531.1-2008;

[0059] Heat resistance: Refer to GB / T 3512-2014, test conditions 110℃×72h.

[0060] The test results are listed in Table 1. Table 1 is as follows:

[0061] Table 1

[0062] <![CDATA[Vulcanization performance (T 10 / min)]]> Tensile strength(MPa) Shore A hardness (degrees) Hot air aging Example 1 4.256 18.5 75 No aging phenomenon Example 2 4.125 17.9 74 No aging phenomenon Example 3 4.123 18.1 74 No aging phenomenon Comparative Example 1 1.021 12.5 64 Slight aging

[0063] By analyzing the data in Table 1, it can be seen that compared with Comparative Example 1, the rubber samples in Examples 1-3 have higher vulcanization performance, tensile strength, hardness and heat resistance, which means that the vulcanizing agent BIPB prepared in Examples 1-3 has stronger vulcanization performance and application effect.

[0064] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a vulcanizing agent BIPB, characterized in that: The method comprises the following preparation steps: Step 1, dissolving A,A'-dihydroxy-1,3-diisopropylbenzene in methanol to form an AATD solution, heating the AATD solution to 50°C, adding aluminum chloride as a catalyst thereto and stirring evenly, then dropping iodomethane while stirring, and continuing to stir for 30-60 minutes after the dropping is complete to obtain a mixed solution; Step 2: filtering the mixed solution, then repeatedly washing the filter material with clean water, and then drying to obtain a modified AATD containing an iodinated alkyl group; Step 3, heat the tert-butyl hydroperoxide solution to 40°C, then add the modified AATD thereto and stir for 10-20 minutes while keeping the temperature, then raise the temperature to 50°C-60°C, dropwise add the sulfuric acid solution and stir until the reaction system changes color, then add water to stop the reaction to obtain a reaction solution; Step 4: The reaction solution is allowed to stand until it is completely separated, and the upper layer is washed with sodium hydroxide solution and hot water in turn, and finally distilled at low temperature and reduced pressure to obtain the sulfiding agent BIPB.

2. The method for preparing the vulcanizing agent B IPB according to claim 1, characterized in that: In step 1, the usage ratio of A,A'-dihydroxy-1,3-diisopropylbenzene to methanol is 1 g:(10-15) mL.

3. The method for preparing the vulcanizing agent B IPB according to claim 1, characterized in that: In step 1, the amount of aluminum chloride used is 2%-5% of the amount of A,A'-dihydroxy-1,3-diisopropylbenzene used.

4. The method for preparing the vulcanizing agent B IPB according to claim 1, characterized in that: In step 1, the molar ratio of monoiodomethane to A,A'-dihydroxy-1,3-diisopropylbenzene is 1:

4.

5. The method for preparing the vulcanizing agent B IPB according to claim 1, characterized in that: In step one and step two, the drying temperature is 100-120° C. and the drying time is 1-2 hours.

6. The method for preparing the vulcanizing agent B IPB according to claim 1, characterized in that: In step three, the molar ratio of tert-butyl hydroperoxide to modified AATD is 2:

1.

7. The method for preparing the vulcanizing agent B IPB according to claim 1, characterized in that: In step three, the mass fraction of the sulfuric acid is 75%, and the mass ratio of the sulfuric acid solution to the tert-butyl hydroperoxide solution is 4:

1.

8. The method for preparing the vulcanizing agent B IPB according to claim 1, characterized in that: In step three, the mass fraction of the tert-butyl hydroperoxide solution is 85%.

9. The method for preparing the vulcanizing agent B IPB according to claim 1, characterized in that: In step 4, the temperature of the low-temperature reduced-pressure distillation is 60° C. and the pressure is 1.5 kPa-2.5 kPa.

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