Preparation process of reinforced synchronous belt

Abstract

According to the preparation process of the reinforced synchronous belt, modified needle-shaped silicate is added in the preparation of an elastomer, silicate is dissociated into nanofibers under mechanical shearing force, the dispersibility of the nanofibers is improved under the modification of a coupling agent, the interface adhesion of the nanofibers and a rubber matrix is enhanced, and the performance of the elastomer is further improved; according to the scheme, the needle-shaped silicate is subjected to supercritical treatment, so that the dissociation degree of the silicate is improved, the performance of the elastomer is further improved, and the performance of the synchronous belt is synchronously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of synchronous belts, and particularly to a preparation process of reinforced synchronous belts. Background Art

[0002] Synchronous belts are commonly used mechanisms in power transmission. Common synchronous belts such as ethylene propylene diene monomer (EPDM) rubber type. With the increasing demand, EPDM rubber type synchronous belts can no longer meet the requirements. Therefore, market enterprises add different fibers or other fillers, etc. to improve the performance of EPDM rubber. For example, adding silicate, and the silicate dissociates into fibers to improve the performance of EPDM rubber. The defect is that the dissociation degree of silicate is low, and there are still many parts in the undissociated state under mechanical shear force, which limits the performance improvement of EPDM rubber and needs to be improved. Summary of the Invention

[0003] To solve the above at least one technical defect, the present invention provides the following technical solutions:

[0004] This application document discloses a preparation process of reinforced synchronous belts, including the following steps:

[0005] First, the preparation of the elastomer in the synchronous belt. Stir and mix the rubber matrix with modified needle-like silicate, then add expanded carbon black, activator, anti-aging agent, accelerator, paraffin oil and mix, and then add vulcanizing agent for mixing to obtain the elastomer;

[0006] Among them, the preparation of the modified needle-like silicate: The needle-like silicate is subjected to secondary supercritical carbon dioxide treatment, and the pressure of the first supercritical treatment is greater than the pressure in the second supercritical treatment. During the second supercritical treatment, supercritical carbon dioxide is used as the solvent, and silane coupling agent is used as the modifier to modify the needle-like silicate with the silane coupling agent;

[0007] Second, combine the elastomer with the skeleton and covering cloth and vulcanize and mold the synchronous belt.

[0008] Modified needle-like silicate is added in the preparation of the elastomer. The silicate dissociates into nanofibers under mechanical shear force. Under the modification of the coupling agent, the dispersibility of the nanofibers is improved, and the interfacial adhesion with the rubber matrix is enhanced, further improving the performance of the elastomer.

[0009] In this solution, the needle-like silicate is subjected to two supercritical treatments, which helps to improve the dissociation degree of the silicate, thereby further improving the performance of the elastomer and simultaneously improving the performance of the synchronous belt.

[0010] Further, in the first step: by mass, 100 parts of rubber matrix, 15 - 45 parts of modified acicular silicate, 10 - 30 parts of expanded carbon black, 7 - 13 parts of activator, 2 - 5 parts of antioxidant, 2 - 6 parts of accelerator, 3 - 11 parts of paraffin oil, 1 - 4 parts of vulcanizing agent. Under the preferred ratio, the performance of the synchronous belt is excellent.

[0011] Further, the rubber matrix is ethylene propylene diene monomer rubber (EPDM), the activator is one or more of zinc oxide and stearic acid, the antioxidant is a mixture of antioxidant 4010NA and antioxidant RD, and the accelerator is a mixture of vulcanization accelerator TT, vulcanization accelerator CZ, and vulcanization accelerator M.

[0012] Further, in the first supercritical treatment, the pressure is 13 - 14.5 MPa, and in the second supercritical treatment, the pressure is 10 - 12 MPa. The preferred parameters can improve the dissociation degree of the silicate.

[0013] Further, in the first supercritical treatment and the second supercritical treatment, the temperature range is 40 - 100 °C, and the reaction time is 1 - 2 h.

[0014] Further, the skeleton material is carbon fiber wire rope, and the covering cloth is high-strength heat-resistant nylon cloth, which helps to improve the performance of the synchronous belt.

[0015] Further, the vulcanization parameters in the second step: temperature 150 - 170 °C, pressure 10 - 16 MPa, time 20 - 25 min. The preferred vulcanization parameters help to improve the performance of the synchronous belt.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. The present invention designs a preparation method of elastomer. By secondary supercritical modification of silicate, it can help improve the dissociation degree of silicate, thereby increasing the number of nanofibers, and further improving the performance of the elastomer. Correspondingly, the performance of the synchronous belt is improved. Specific Embodiments

[0018] The present invention will be further described below in conjunction with specific embodiments.

[0019] Example 1

[0020] The preparation process of the reinforced synchronous belt includes the following steps:

[0021] First, preparation of the elastomer in the synchronous belt

[0022] Preparation of modified acicular silicate: Add acicular silicate (250 mesh) to the reaction kettle, then add dry ice, stir and heat the temperature to 55 °C, the pressure is 13.5 MPa, the reaction time is 2 h. After the reaction, reduce the pressure of the reaction kettle to atmospheric pressure and maintain it for 10 min at atmospheric pressure.

[0023] Afterwards, the acicular silicate after a single supercritical treatment, triethanolamine, and silane coupling agents (KH550 and KH570 mixed at a mass ratio of 3:5) are added to the reaction kettle according to a mass ratio of 15:2:60. Then, dry ice is added, and it is stirred and heated to a temperature of 55 °C and a pressure of 10.6 MPa for a reaction time of 1.5 h. After the reaction is completed, the pressure in the reaction kettle is reduced to atmospheric pressure, and after cooling, the modified acicular silicate is obtained.

[0024] 100 parts of a rubber matrix (ethylene propylene diene monomer rubber 4045) and 16 parts of the modified acicular silicate are stirred and mixed at a temperature of 140 °C for 20 min. Then, 12 parts of expanded carbon black (KP50), 8 parts of an activator (zinc oxide and stearic acid mixed by mass ratio of 1:1), 2.3 parts of an antioxidant (4010NA and RD mixed at a mass ratio of 2:1), 3 parts of a promoter (vulcanization accelerator TT, vulcanization accelerator CZ, and vulcanization accelerator NOBS mixed at a mass ratio of 1:1:2), and 4 parts of paraffin oil are added and mixed for 20 min. After cooling to 45 °C, 1.5 parts of a vulcanizing agent (sulfur) are added and mixed evenly to obtain a mixed rubber, which is calendered and oriented to obtain an elastomer.

[0025] Second, the elastomer is combined with a skeleton (carbon fiber wire rope) and a cover cloth (high-strength heat-resistant nylon cloth), and vulcanized at 160 °C and 11 MPa for 35 min to prepare a molded synchronous belt.

[0026] Example 2

[0027] The preparation process of the reinforced synchronous belt includes the following steps:

[0028] First, the preparation of the elastomer in the synchronous belt

[0029] Preparation of the modified acicular silicate: Add acicular silicate (250 mesh) to the reaction kettle, then add dry ice, stir and heat to a temperature of 52 °C and a pressure of 13 MPa for a reaction time of 1.8 h. After the reaction is completed, the pressure in the reaction kettle is reduced to atmospheric pressure, and the holding time under atmospheric pressure is 15 min.

[0030] Afterwards, the acicular silicate after a single supercritical treatment, triethanolamine, and silane coupling agents (KH550 and KH570 mixed at a mass ratio of 3:5) are added to the reaction kettle according to a mass ratio of 15:3:58. Then, dry ice is added, and it is stirred and heated to a temperature of 56 °C and a pressure of 10.5 MPa for a reaction time of 1.2 h. After the reaction is completed, the pressure in the reaction kettle is reduced to atmospheric pressure, and after cooling, the modified acicular silicate is obtained.

[0031] Mix 100 parts of a rubber matrix (ethylene propylene diene monomer rubber 4045) with 20 parts of modified acicular silicate at 145 °C for 18 min. Then, sequentially add 15 parts of expanded carbon black (KP50), 8.6 parts of an activator (a 1:1 mass mixture of zinc oxide and stearic acid), 4 parts of an antioxidant (a 2:1 mass ratio mixture of 4010NA and RD), 4 parts of an accelerator (a 1:1:2 mass ratio mixture of vulcanization accelerator TT, vulcanization accelerator CZ, and vulcanization accelerator NOBS), and 5 parts of paraffin oil and mix for 15 min. After cooling to 43 °C, add 1.6 parts of a vulcanizing agent (sulfur) and mix evenly to obtain a kneaded rubber, which is then calendered and oriented to obtain an elastomer.

[0032] Second, combine the elastomer with a skeleton (carbon fiber cord) and a cover cloth (high-strength heat-resistant nylon cloth), and vulcanize at 155 °C and 10 MPa for 30 min to prepare a molded synchronous belt.

[0033] Example 3

[0034] The preparation process of a reinforced synchronous belt includes the following steps:

[0035] First, preparation of the elastomer in the synchronous belt

[0036] Preparation of modified acicular silicate: Add acicular silicate (250 mesh) to a reaction kettle, then add dry ice, stir and heat to 45 °C, with a pressure of 14 MPa and a reaction time of 1.2 h. After the reaction ends, reduce the pressure in the reaction kettle to atmospheric pressure and maintain for 10 min at atmospheric pressure.

[0037] Then, add the acicular silicate after the first supercritical treatment, triethanolamine, and a silane coupling agent (a 3:5 mass ratio mixture of KH550 and KH570) to the reaction kettle in a mass ratio of 14:2:60. Then add dry ice, stir and heat to 56 °C, with a pressure of 11 MPa and a reaction time of 1.5 h. After the reaction ends, reduce the pressure in the reaction kettle to atmospheric pressure, and the modified acicular silicate is obtained after cooling.

[0038] Mix 100 parts of a rubber matrix (ethylene propylene diene monomer rubber 4045) with 26 parts of modified acicular silicate at 145 °C for 20 min. Then, sequentially add 16 parts of expanded carbon black (KP50), 8 parts of an activator (a 1:1 mass mixture of zinc oxide and stearic acid), 3.5 parts of an antioxidant (a 2:1 mass ratio mixture of 4010NA and RD), 4.3 parts of an accelerator (a 1:1:2 mass ratio mixture of vulcanization accelerator TT, vulcanization accelerator CZ, and vulcanization accelerator NOBS), and 8 parts of paraffin oil and mix for 20 min. After cooling to 45 °C, add 2 parts of a vulcanizing agent (sulfur) and mix evenly to obtain a kneaded rubber, which is then calendered and oriented to obtain an elastomer.

[0039] Second, combine the elastomer with the skeleton (carbon fiber cord) and the covering cloth (high-strength heat-resistant nylon cloth), and cure at 160 °C and 11 MPa for 35 min to prepare a synchronous belt.

[0040] Comparative Example 1

[0041] Compared with Example 1, there is no first supercritical treatment process in the preparation of the modified needle-like silicate in this example.

[0042] Detect the performance of the vulcanized elastomer as shown in the following table:

[0043] Table 1

[0044] Tensile strength (MPa) Tear strength (KN / m) Example 1 5.6 25.8 Example 2 6.3 30.1 Example 3 7.6 33.6 Comparative Example 1 3.8 21.3

[0045] It can be seen that the supercritical treatment can increase the dissociation degree of silicate. Under the modification of the coupling agent, the interfacial adhesion performance of the rubber matrix is good, and the performance of the elastomer and the synchronous belt is significantly improved.

[0046] The above is only the preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. The preparation process of the reinforced synchronous belt is characterized in that: The following steps are involved: First, the preparation of the elastomer in the synchronous belt is to stir and mix the rubber matrix with the modified needle-shaped silicate, then add the expanded carbon black, the activator, the antioxidant, the accelerator, and the paraffin oil, and then add the vulcanizing agent and mix to obtain the elastomer; The preparation of the modified needle-shaped silicate comprises: the needle-shaped silicate is subjected to a second supercritical treatment of carbon dioxide, wherein the pressure of the first supercritical treatment is greater than the pressure of the second supercritical treatment, and in the second supercritical treatment, supercritical carbon dioxide is used as a solvent and a silane coupling agent is used as a modifier to modify the needle-shaped silicate with the silane coupling agent; Second, the elastomer is combined with the skeleton and the covering cloth and vulcanized to form the synchronous belt.

2. The process for preparing the reinforced synchronous belt according to claim 1, characterized in that: In the first step: by mass, 100 parts of rubber matrix, 15-45 parts of modified needle silicate, 10-30 parts of expanded carbon black, 7-13 parts of activator, 2-5 parts of antioxidant, 2-6 parts of accelerator, 3-11 parts of paraffin oil, and 1-4 parts of vulcanizer.

3. The process for preparing the reinforced synchronous belt according to claim 1, characterized in that: The rubber matrix is ​​EPDM rubber, the activator is one or more of zinc oxide and stearic acid, the antioxidant is a mixed type of antioxidant 4010NA and antioxidant RD, and the accelerator is a mixed type of vulcanization accelerator TT, vulcanization accelerator CZ, and vulcanization accelerator M.

4. The process for preparing the reinforced synchronous belt according to claim 1, characterized in that: The pressure in the first supercritical treatment is 13-14.5 MPa, and the pressure in the second supercritical treatment is 10-12 MPa.

5. The process for preparing the reinforced synchronous belt according to claim 4, characterized in that: The temperature range in the first supercritical treatment and the second supercritical treatment is 40-100° C., and the reaction time is 1-2 hours.

6. The process for preparing the reinforced synchronous belt according to claim 1, characterized in that: The skeleton material is carbon fiber cord, and the wrapping cloth is high-strength and heat-resistant nylon cloth.

7. The process for preparing the reinforced synchronous belt according to claim 6, characterized in that: The vulcanization parameters in the second step are: temperature 150-170°C, pressure 10-16MPa, and time 20-25min.