Preparation method of rubber self-adhesion detection standard sample

Abstract

The application relates to the technical field of rubber detection, and discloses a preparation method of a rubber self-adhesion detection standard sample. The standard sample is prepared according to the specific mixing method and the formula disclosed in the application, has good stability, and has stable performance in the use process. The formula does not add microcrystalline wax, so that the rubber can be prevented from being separated out in the use process. The preparation method is convenient and fast, and the prepared standard sample is stable and durable.

Description

Technical Field

[0001] This invention relates to the field of rubber testing technology, and more specifically, to a method for preparing a standard sample for testing the self-adhesion of rubber. Background Technology

[0002] During tire manufacturing, one layer of extruded or calendered rubber compound is laid flat on top of another. Before vulcanization, these compounds must be bonded together according to their component layers. Tire compound formulations contain many components with different solubilities. When the temperature changes, some formulation components may separate from the compound, forming frost on the surface. This can damage the self-adhesion of the compound during molding and affect tire manufacturing. The rubber self-adhesion tester uses a butt adhesion test method to measure the adhesion force formed between two rubber sheets after contact and pressing for a certain period of time, thus characterizing the self-adhesion of unvulcanized rubber. To determine the adhesion of different compound formulations, the test wheel of the equipment uses the same standard sample to test different compounds. Through experiments, the self-adhesion of the compound formulation is evaluated to ensure the quality of rubber products and the adhesion and reliability of the rubber compound during use.

[0003] Chinese invention patent (publication number: CN116793949A, publication date: 2023.09.22) discloses an evaluation device and method for the quality of tire steel cord fabric. The device includes: a peel test piece; a thickness gauge for measuring the total thickness of the peel test piece; a vulcanizing mold for vulcanizing the peel test piece, the thickness of the vulcanizing mold being 80%-95% of the total thickness of the sample; a tensile testing machine for performing peel tests on the vulcanized peel test piece and plotting a load curve; and a camera assembly mounted on the tensile testing machine for photographing the adhesion of rubber material on the surface of the steel wires of the peel test piece after peeling. This device uses a peel test piece with a specific structure, which is vulcanized. The tensile testing machine and camera assembly then obtain photographs of the fabric adhesion and the adhesion of rubber material on the surface of the steel wires of the peel test piece after peeling. The quality of the steel cord fabric is evaluated using the fabric adhesion judgment standard and the photographs of the standard scoring sample, which can comprehensively reflect the quality of tire steel cord fabric. To further optimize the evaluation criteria, a standardized and stable standard sample is needed as a reference. However, there is currently no method for preparing such a standard sample. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing a standard sample for testing the self-adhesion of rubber.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a standard sample for testing the self-adhesion of rubber, comprising the following specific steps: 1) Wrap the standard rubber obtained by mixing on the open mill to ensure a smooth surface. Control the thickness of the sheet produced by the open mill within 0.6mm±0.1mm and cut a 200mm×200mm sample. 2) Cut a 250mm×250mm piece of calendered polypropylene coir cloth, and then cut a 250mm×250mm piece of high-temperature resistant cellophane. 3) Place the 200mm×200mm sample between the polypropylene fiber pad and cellophane, and vulcanize it on a flat vulcanizing machine. Vulcanization conditions: vulcanization temperature 100℃, vulcanization time 1min. 4) Cut the vulcanized sample into strips with a width of 12mm ± 0.5mm and a length of 170mm ± 10mm to obtain standard samples.

[0006] Preferably, the standard rubber is prepared by mixing raw materials comprising the following components in 100 parts by weight of rubber component: 100 parts by weight of natural rubber, 55.0 parts by weight of carbon black, 75.0 parts by weight of rubber oil, 12.0 parts by weight of high styrene resin, 6.0 parts by weight of clay, 5.5 parts by weight of activator, 14 parts by weight of phenolic reinforcing resin, 1.0 part by weight of antioxidant, 3.5 parts by weight of vulcanizing agent, 2.51 parts by weight of vulcanization accelerator, and 0.15 parts by weight of scorching inhibitor.

[0007] Preferably, the activator is zinc oxide and stearic acid, wherein zinc oxide is 3.5 parts by weight and stearic acid is 2 parts by weight; The accelerators used are NS and HEXA-65, wherein NS is 0.36 parts by weight and HEXA-65 is 2.15 parts by weight.

[0008] Preferably, the carbon black is N375, the rubber oil is naphthenic oil, the phenolic reinforcing resin is 205 phenolic reinforcing resin, the antioxidant is RD, the vulcanizing agent is 7020, and the scorching inhibitor is CTP.

[0009] Furthermore, the present invention also discloses a method for preparing the standard adhesive, the specific steps of which are as follows: 1) First stage mixing: Add a portion of natural rubber, carbon black, high-styrene, clay, activator, phenolic reinforcing resin, and antioxidant, setting the speed to 53 rpm and the pressure to 5.5 kg / cm². 2 Press the top bolt to 105℃; raise the top bolt, add rubber oil, and set the speed to 58 rpm and the pressure to 5.5 kg / cm. 2 Press the top bolt to 138°C, raise the top bolt to the position, and press the top bolt to 150°C to discharge the glue; 2) Vulcanization section: Add vulcanizing agent, remaining natural rubber, vulcanization accelerator, and anti-scorching agent; press for 25 seconds; set the rotation speed to 30 rpm and the pressure to 4.5 kg / cm².2 Raise the top bolt to the correct position, set the rotation speed to 25 rpm and the pressure to 4.5 kg / cm². 2 Press for 20 seconds; raise the top bolt to its position, set the rotation speed to 30 rpm and the pressure to 4.5 kg / cm². 2 Press for 15 seconds to reach 105℃ to discharge the glue.

[0010] Furthermore, the present invention also discloses a standard sample prepared by the method described.

[0011] Furthermore, the present invention also discloses the comprehensive application of the aforementioned standard sample in the testing of rubber self-adhesion.

[0012] The beneficial effects of this invention are: the standard sample of this invention has good stability and stable performance during use; the formula does not contain microcrystalline wax, which can prevent the exudation of the adhesive during use. Detailed Implementation

[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0014] Example 1 This embodiment provides a method for preparing a standard sample for testing the self-adhesion of rubber.

[0015] Standard rubber formulation: 100 parts by weight of natural rubber, 55.0 parts by weight of N375 carbon black, 75.0 parts by weight of naphthenic oil, 12.0 parts by weight of high-styrene resin, 6.0 parts by weight of kaolin, 3.5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 14 parts by weight of 205 phenolic reinforcing resin, 1.0 part by weight of antioxidant RD, 3.5 parts by weight of 7020 vulcanizing agent, 0.36 parts by weight of vulcanization accelerator NS, 2.15 parts by weight of vulcanization accelerator HEXA-65, and 0.15 parts by weight of scorching inhibitor CTP.

[0016] The specific steps for mixing standard rubber are as follows: 1) First stage mixing: Add a portion of natural rubber, carbon black, high-styrene, clay, activator, phenolic reinforcing resin, and antioxidant, setting the speed to 53 rpm and the pressure to 5.5 kg / cm². 2 Press the top bolt to 105℃; raise the top bolt, add rubber oil, and set the speed to 58 rpm and the pressure to 5.5 kg / cm. 2 Press the top bolt to 138°C, raise the top bolt to the position, and press the top bolt to 150°C to discharge the glue; 2) Vulcanization section: Add vulcanizing agent, remaining natural rubber, vulcanization accelerator, and anti-scorching agent; press for 25 seconds; set the rotation speed to 30 rpm and the pressure to 4.5 kg / cm². 2 Raise the top bolt to the correct position, set the rotation speed to 25 rpm and the pressure to 4.5 kg / cm². 2 Press for 20 seconds; raise the top bolt to its position, set the rotation speed to 30 rpm and the pressure to 4.5 kg / cm². 2 Press for 15 seconds to reach 105℃ to discharge the glue.

[0017] The specific steps for preparing standard samples are as follows: 1) Wrap the standard rubber obtained by mixing on the open mill to ensure a smooth surface. Control the thickness of the sheet produced by the open mill within 0.6mm±0.1mm and cut a 200mm×200mm sample. 2) Cut a 250mm×250mm piece of calendered polypropylene coir cloth, and then cut a 250mm×250mm piece of high-temperature resistant cellophane. 3) Place the 200mm×200mm sample between the polypropylene fiber pad and cellophane, and vulcanize it on a flat vulcanizing machine. Vulcanization conditions: vulcanization temperature 100℃, vulcanization time 1min. 4) Cut the vulcanized sample into strips with a width of 12mm ± 0.5mm and a length of 170mm ± 10mm to obtain standard samples.

[0018] The obtained standard samples were subjected to stability tests, and the test results are shown in Table 1.

[0019] Standard sample stability test method: Use a rubber self-adhesion tester to perform compression and tear test (test conditions: compression speed 20, tear speed 20, compression time 1). Wrap the cut standard sample around the test groove of the test wheel, cut off the excess, tear off the cellophane, put the test wheel back on the test equipment, do not place the test sample on the lower clamp, and test the standard adhesion force (N).

[0020] Table 1 As can be seen from Table 1, the standard test adhesive strength prepared by this invention is stable and can be used to test the self-adhesiveness of rubber.

[0021] Application Example 1 The obtained standard samples were used for rubber self-adhesion testing.

[0022] Rubber self-adhesion testing method: A rubber self-adhesion tester was used for compression-pull-off testing (test conditions: compression speed 20, pull-off speed 20, compression time 1). A pre-cut standard sample was wrapped around the test groove of the test wheel, excess material was cut off, the cellophane was removed, and the test wheel was reinstalled on the testing equipment. The rubber to be tested was placed on the lower clamp, and its adhesive force (N) was measured. Rubber materials from five tire components were used for the test, with 20 batches of rubber material from each component. The test results are shown in Table 2.

[0023] Adhesion standards (N): Upper triangle adhesive ≥8N, lower triangle adhesive ≥6N, pad adhesive ≥15N, transition layer adhesive ≥12N, film adhesive ≥15N.

[0024] Table 2 1 9.76 7.4 15.79 12.17 15.38 2 9.84 6.1 15.44 13.88 15.32 3 8.94 6.32 16.03 11.91 15.79 4 8.29 7.88 16.51 12.99 15.93 5 8.26 8.07 15.78 12.67 16.26 6 8.62 6.68 15.93 12.83 16.26 7 8.47 6.68 16.52 12.46 16.62 8 9.67 6.22 16.64 12.43 16.42 9 9.06 6.61 16.03 13.85 15.24 10 8.54 6.87 15.92 12.35 15.94 11 9.03 6.64 16.12 12.56 15.77 12 9.05 6.23 15.24 13.21 16.02 13 9.02 6.89 16.39 12.41 15.96 14 8.03 6.57 15.44 12.58 15.46 15 8.56 7.21 15.02 13.11 16.01 16 9.12 6.98 16.36 13.24 16.14 17 8.67 6.51 16.82 12.16 15.68 18 9.08 7.19 15.35 12.64 15.24 19 9.89 8.02 16.61 13.21 16.45 20 8.46 6.87 16.84 12.83 16.24 Maximum value 9.89 8.07 16.82 13.88 16.62 Minimum value 8.03 6.10 15.02 11.91 15.24 Range 1.86 1.97 1.8 1.97 1.38 The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A method for preparing a standard sample for testing the self-adhesion of rubber, characterized in that, The specific steps are as follows: 1) Wrap the standard rubber obtained by mixing on the open mill to ensure a smooth surface. Control the thickness of the sheet produced by the open mill within 0.6mm±0.1mm and cut a 200mm×200mm sample. 2) Cut a 250mm×250mm piece of calendered polypropylene coir cloth, and then cut a 250mm×250mm piece of high-temperature resistant cellophane. 3) Place the 200mm×200mm sample between the polypropylene fiber pad and cellophane, and vulcanize it on a flat vulcanizing machine. Vulcanization conditions: vulcanization temperature 100℃, vulcanization time 1min. 4) Cut the vulcanized sample into strips with a width of 12mm ± 0.5mm and a length of 170mm ± 10mm to obtain standard samples.

2. The method for preparing a standard sample according to claim 1, characterized in that, The standard rubber is prepared by mixing raw materials comprising the following components, with a rubber component weight of 100 parts: 100 parts by weight of natural rubber, 55.0 parts by weight of carbon black, 75.0 parts by weight of rubber oil, 12.0 parts by weight of high-styrene resin, 6.0 parts by weight of clay, 5.5 parts by weight of activator, 14 parts by weight of phenolic reinforcing resin, 1.0 part by weight of antioxidant, 3.5 parts by weight of vulcanizing agent, 2.51 parts by weight of vulcanization accelerator, and 0.15 parts by weight of scorching inhibitor.

3. The method for preparing a standard sample according to claim 2, characterized in that, The activator is zinc oxide and stearic acid, wherein zinc oxide is 3.5 parts by weight and stearic acid is 2 parts by weight; The accelerators used are NS and HEXA-65, wherein NS is 0.36 parts by weight and HEXA-65 is 2.15 parts by weight.

4. The method for preparing a standard sample according to claim 2, characterized in that, The carbon black used is N375, the rubber oil is naphthenic oil, the phenolic reinforcing resin is 205 phenolic reinforcing resin, the antioxidant is RD, the vulcanizing agent is 7020, and the anti-scorching agent is CTP.

5. The method for preparing a standard sample according to any one of claims 1-4, characterized in that, The specific steps of the mixing method for the standard rubber are as follows: 1) First stage mixing: Add a portion of natural rubber, carbon black, high-styrene, clay, activator, phenolic reinforcing resin, and antioxidant, setting the speed to 53 rpm and the pressure to 5.5 kg / cm². 2 Press the top bolt to 105℃; raise the top bolt, add rubber oil, and set the speed to 58 rpm and the pressure to 5.5 kg / cm. 2 Press the top bolt to 138°C, raise the top bolt to the position, and press the top bolt to 150°C to discharge the glue; 2) Vulcanization section: Add vulcanizing agent, remaining natural rubber, vulcanization accelerator, and anti-scorching agent; press for 25 seconds; set the rotation speed to 30 rpm and the pressure to 4.5 kg / cm². 2 Raise the top bolt to the correct position, set the rotation speed to 25 rpm and the pressure to 4.5 kg / cm². 2 Press for 20 seconds; raise the top bolt to its position, set the rotation speed to 30 rpm and the pressure to 4.5 kg / cm². 2 Press for 15 seconds to reach 105℃ to discharge the glue.

6. The standard sample prepared by the method according to any one of claims 1-5.

7. The comprehensive application of the standard sample as described in claim 6 in the testing of rubber self-adhesion.

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