rubber oil filled sheet resistance to yellowing by sunlight test method

Abstract

The rubber oil filled film light resistance yellowing test method disclosed in the application, at a certain temperature, accurately weighs rubber oil and rubber particles, places them in a glass container, and oscillates on an oscillator in a test box at a fixed frequency until the transparent glue solution is uniform, carries out constant volume, oscillates again until the transparent glue solution is uniform, and then carries out quantitative gravity coating in the test box, places the glue film on a quartz sheet, and places it for a proper time at a specified temperature and air flow rate, waits until the solvent is completely volatilized, covers the surface with treated release material for standby. The above-mentioned standby test sheet is placed in a simulated sunlight irradiation test box, after irradiation for a specified time, the color difference instrument is used to test the glue film before and after the experiment, and the test result is obtained. The rubber oil filled film light resistance yellowing test method solves the problem that the result obtained by the existing method has low repeatability and it is difficult to evaluate the subtle yellowing difference of the rubber oil filled film.

Description

Technical Field

[0001] This invention belongs to the field of rubber oil application technology, specifically relating to a test method for the resistance of rubber oil-filled films to yellowing under sunlight. Background Technology

[0002] In the application of rubber oil, it is one of the main materials in rubber products and has a significant impact on their resistance to yellowing under sunlight. Currently, the yellowing resistance characteristics of light-colored synthetic rubber and thermoplastic elastomer products are mainly determined using ASTM D1148, "Standard Test Method for Degradation of Rubber - Color Changes of Light-Colored Surfaces by Ultraviolet (UV) or Ultraviolet / Visible Radiation and Heat Exposure," which uses color charts for visual comparison. However, this method cannot distinguish products with similar color changes. While the laboratory's 2013 proposal, "Determination of Yellowing Resistance of Light-Colored Synthetic Rubber and Thermoplastic Elastomers," improved upon ASTM D1148 and can differentiate rubber products with similar color changes, it still presents a series of practical problems when using a colorimeter.

[0003] When evaluating the quality of rubber oils in applications, the testing of the sunlight yellowing resistance of rubber oil-filled film systems often involves traditional methods of granulation, rubber compounding, and high-temperature molding to prepare laboratory samples. However, this approach suffers from excessive material consumption, excessively long testing cycles, and inconsistencies in uniformity. Furthermore, in laboratory research aimed at solving practical application problems, the number of samples required is often limited due to the small quantities of customer-retained samples, internally retained samples, and on-site sampling. Solving practical application problems also requires a shorter testing cycle, which traditional methods struggle to achieve for rapid sample preparation and evaluation, severely impacting the resolution of practical issues. Additionally, traditional methods can cause film deformation during sunlight yellowing resistance testing, significantly affecting subsequent assessments of the degree of yellowing. These challenges result in low repeatability of sunlight yellowing resistance test results for rubber oil-filled films, making it difficult to evaluate subtle differences in yellowing patterns. Summary of the Invention

[0004] The purpose of this invention is to provide a test method for the resistance of rubber oil-filled films to yellowing under sunlight, which solves the problem that the results obtained by existing methods have low repeatability and are difficult to evaluate subtle differences in yellowing of rubber oil-filled films.

[0005] The technical solution adopted in this invention is: a test method for the resistance of rubber oil-filled films to yellowing under sunlight, comprising the following steps:

[0006] Step 1: Weigh the rubber oil and rubber particles to be tested in a glass container with a lid, and record the mass;

[0007] Step 2: Place the glassware in the test chamber, add the solvent to dissolve the rubber oil and rubber particles, cover it with a cover, and then place it on the shaker in the test chamber to shake.

[0008] Step 3: After the adhesive solution is fully dissolved until it is uniform and transparent, add solvent to make up the volume. Place the adjusted volume adhesive solution on a shaker and shake until the adhesive solution is uniform and transparent.

[0009] Step 4: Place a platform calibrated with a level in the test chamber, place a quartz glass slide flat on the platform, transfer a quantitative amount of adhesive solution onto the quartz glass slide, and place it under a fixed air flow rate until the solvent has completely evaporated. Then, cover the surface with release material to obtain a spare sample.

[0010] Step 5: Place the sample in a test chamber that simulates sunlight to obtain the film after the test;

[0011] Step 6: Use a colorimeter to test the film obtained in Step 5 and the sample obtained in Step 4, and calculate the color difference before and after the test.

[0012] The above-mentioned test method for the resistance of rubber oil-filled films to yellowing under sunlight also includes:

[0013] The rubber granules in step 1 are SBC type rubber granules, which can be SEBS, SEPS, SBS, SIS, or any combination of two of them, depending on the specific test formulation.

[0014] In step 1, if SBS granules are used, the optimal ratio of the weighed rubber oil to the granules is 5:3; if SEBS granules are used, the optimal ratio is 4:1; if a mixture of SBS and SEBS is used, the ratio of the rubber oil to the granules should be calculated based on the specific mixing ratio; the situation is similar when using SIS granules and SBS granules, and similar when using SEPS granules and SEBS granules.

[0015] In step 2, the temperature of the test chamber is 25℃-22℃.

[0016] In step 2, toluene is generally the best solvent to use, but any solvent with sufficient solubilizing ability can also be used. The specific amount to be added should be calculated based on the total amount of oil and glue, and it must be ensured that the oil and glue can be completely dissolved.

[0017] After fully dissolving the adhesive in step 3 until the solution is uniform and transparent, add a certain amount of solvent to make up the volume, ensuring that the samples being compared are all in the same solvent ratio and uniform state.

[0018] In step 4, 1 ml of adhesive solution is transferred and coated onto a quartz glass slide. Other transparent materials can also be used, but the materials must meet the requirements of light inertness.

[0019] The placement time in step 4 is generally 24 hours. If the solvent cannot be completely evaporated, the time for the same batch of control samples needs to be extended until the solvent is completely evaporated.

[0020] In step 5, the irradiation temperature is 55℃-22℃. If SBS granules are used as the main evaluation material, the irradiation time is 40h; if SEBS granules are used as the main evaluation material, the irradiation time is 200h; if a mixture of SBS and SEBS granules is used as the main material, the irradiation time should be calculated based on the ratio of SBS granules to SEBS granules; SIS granules are similar to SBS granules, and SEPS granules are similar to SEPS granules.

[0021] After determining the test evaluation granule material in Step 1, subsequent steps need to be carried out according to the characteristics of each material. Generally, SBS granules are used as the evaluation granules. If other materials are used, they should be specifically noted in the results. In Step 4, when transferring a quantitative amount of adhesive solution to coat the quartz glass slide, at least three sets of films should be coated. Depending on the specific situation, the number of sets can be increased. In Step 6, the color value after the test is calculated as the average color value of at least three sets of films.

[0022] The beneficial effects of this invention are as follows: The method for testing the resistance to sunlight yellowing of rubber oil-filled films solves the problems of inconsistent film uniformity, excessively long testing cycles, and small sample quantities in laboratory preparation by using solvent to adjust the volume of rubber oil and rubber particles; it solves the problem of physical structural deformation during film testing by coating the film onto a quartz glass slide; and it eliminates the problem of human visual error by introducing a colorimeter for comparison and calculating the color difference of the film before and after testing. This results in highly repeatable test results for the resistance to sunlight yellowing of rubber oil-filled films, enabling the evaluation of subtle yellowing differences, especially for samples with small test material quantities and short testing cycles. This method is of great significance for solving practical rubber oil application problems and for screening formulation oils in the laboratory. Attached Figure Description

[0023] Figure 1 These are schematic diagrams showing the comparison of yellowing of film before and after light exposure in Embodiments 1-5 of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the glassware used in this invention;

[0025] Figure 3 This is a schematic diagram of the structure of the test chamber with a forced ventilation port and a filtered air inlet used in this invention;

[0026] Figure 4 This is a schematic diagram of the structure of the simulated sunlight test chamber used in this invention. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] This invention provides a method for testing the resistance of rubber oil-filled films to yellowing under sunlight. Under a specific temperature, rubber oil and rubber granules are accurately weighed and placed in a glass container. The container is then vibrated at a fixed frequency on a shaker within a test chamber until a uniform, transparent solution is obtained. The solution is then brought to a final volume and vibrated again until uniformly transparent. A quantitative gravity coating is then applied to a quartz plate within the test chamber. The film is placed at a specified temperature and airflow rate for an appropriate time until the solvent has completely evaporated. Afterward, the surface is covered with a treated release material for later use. The prepared test sheet is then placed in a simulated sunlight irradiation test chamber and exposed to sunlight for a specified duration. The results show the film before and after yellowing. Figure 1 As shown (without * indicating no illumination, * indicating illumination), the films before and after the experiment were tested using a colorimeter to obtain the experimental results. The specific steps include the following:

[0029] Step 1, as follows Figure 2 As shown, weigh the rubber oil and rubber particles to be tested into a glass container with a spout and a lid, accurate to 0.1g, and record the mass. The glass container is made of glass material that can withstand temperatures of not less than 180℃, and the lid is made of solvent-resistant rubber and plastic material with appropriate elasticity. The whole set of equipment is a container for dissolving test materials into liquids of suitable viscosity.

[0030] Step 2, as follows Figure 3 As shown, the test chamber, equipped with a forced ventilation vent and a filtered air inlet, provides an independent space for solvent dissolution of the test materials and offers clean, stable airflow during coating operations. The forced ventilation vent is connected to a harmless exhaust system. At a test chamber temperature of 25℃-22℃, a certain amount of volatile solvent capable of dissolving rubber oil and rubber particles, and which does not chemically react with various materials at the test temperature, is added. The chamber is covered to prevent solvent evaporation and then placed on a shaker for vibration.

[0031] Step 3: After all materials have fully dissolved and the adhesive solution is uniform and transparent, adjust the solvent volume to a fixed ratio. Solvent ratio: The ratio of the mass of the solvent to the total mass of the rubber oil and rubber particles. Place the adjusted adhesive solution on a shaker and shake until the solution is uniform and transparent.

[0032] Step 4: At a test chamber temperature of 25℃-22℃, select a platform calibrated with a level, place the quartz glass slide flat, transfer a quantitative amount of solution, coat it onto the quartz glass slide, and place it for a fixed time under a fixed air flow rate to ensure that the solvent has completely evaporated. Then, attach the surface-treated release material for later use.

[0033] Step 5, as follows Figure 4 As shown, a temperature-controlled simulated sunlight test chamber is used to provide the test sheet with stable irradiance and a constant test temperature, thereby accelerating the aging test process and shortening the test time. The spare sample is placed in the simulated sunlight test chamber and irradiated for a specified time at a temperature of 55℃-22℃, then removed.

[0034] Step 6: Use a colorimeter to test the film after the test and the film before the test, deduct the influence of quartz glass, and use the instrument to calculate the color difference before and after the test.

[0035] The technical principle underlying this invention is to use solvents for mixing various materials instead of thermal mixing, thereby achieving more uniform mixing of small quantities of test materials, avoiding the inhomogeneity of thermal mixing, and also avoiding the problem of excessive material consumption caused by thermal mixing equipment. This achieves control over sample quantity and shortens the test cycle. Simultaneously, using quartz glass sheets as the film support material ensures the stability of the film's mechanical structure under photothermal conditions, preventing changes in the film's structural morphology during simulated sunlight exposure, facilitating subsequent colorimeter testing, and ensuring the reliability and repeatability of the results.

[0036] Through the above methods, the rubber oil-filled film sunlight yellowing test method of the present invention solves the problems of uneven film uniformity, excessive cycle time, and small sample quantity in laboratory preparation by using solvent to fix the rubber oil and rubber particles; by coating the film on the quartz glass slide, the film adheres to the quartz glass sheet, providing strength support for the film. During simulated sunlight irradiation, the physical structure of the film does not change, remaining very flat, which is beneficial for colorimeter detection and solves the problem of film deformation in sunlight resistance testing; by introducing a colorimeter for comparison, the color difference of the test film before and after is calculated, thus solving the problem of human visual error.

[0037] Example 1

[0038] Step 1: Weigh 5.0g of rubber oil and 3.0g of SBS granules into a glass container with a lid, and record the mass. Step 2: At 25℃ in the test chamber, add 15ml of toluene solvent to dissolve the rubber oil and granules. Cover with a lid to prevent solvent evaporation and place on a shaker to vibrate. Step 3: After all materials are fully dissolved and the solution is uniform and transparent, make up to the required volume at a mass ratio of 1:4 (total material mass: solvent mass). Vibrate the solution again on a shaker until it is uniform and transparent. Step 4: At 25℃ in the test chamber, select a platform calibrated with a level, place a quartz glass slide flat, transfer 1ml of solution, and gravity-coat it onto the quartz glass slide. Place under a fixed airflow rate for 24 hours to ensure complete solvent evaporation, then attach a surface-treated release PET film for later use. Step 5: Place the prepared sample in a simulated sunlight test chamber: irradiance: 19×100μW / cm². 2 The film was irradiated at 55℃ for 40 hours and then removed. Step 6: Using a colorimeter, the film after the experiment was compared with the film before the experiment. After deducting the influence of the quartz glass, the color difference before and after the experiment was calculated using the instrument. At least three sets of tests were conducted for each sample, and the average value was taken as the color value.

[0039] Example 2

[0040] Step 1: Weigh 5.0g of rubber oil and 2.0g of SBS granules into a glass container with a lid, and record the mass. Step 2: At 25℃ in the test chamber, add 15ml of toluene solvent to dissolve the rubber oil and granules. Cover with a lid to prevent solvent evaporation and shake on a shaker. Step 3: After all materials are fully dissolved and the solution is uniform and transparent, make up to the required volume at a mass ratio of 1:4 (total material mass: solvent mass). Shake the solution again on a shaker until it is uniform and transparent. Step 4: At 25℃ in the test chamber, select a platform calibrated with a level, place a quartz glass slide flat, transfer 1ml of solution, and gravity-coat it onto the quartz glass slide. Under a fixed airflow rate, place for 24 hours to ensure complete solvent evaporation, then attach a surface-treated release PET film for later use. Step 5: Place the prepared sample in a simulated sunlight test chamber: irradiance: 19×100μW / cm². 2 The film was irradiated at 55℃ for 40 hours and then removed. Step 6: Using a colorimeter, the film after the experiment was compared with the film before the experiment. After deducting the influence of the quartz glass, the color difference before and after the experiment was calculated using the instrument. At least three sets of tests were conducted for each sample, and the average value was taken as the color value.

[0041] Example 3

[0042] Step 1: Weigh 5.0g of rubber oil and 3.0g of SBS granules into a glass container with a lid, and record the mass. Step 2: At 25℃ in the test chamber, add 15ml of toluene solvent to dissolve the rubber oil and granules. Cover with a lid to prevent solvent evaporation and place on a shaker to vibrate. Step 3: After all materials are fully dissolved and the solution is uniform and transparent, make up to the required volume at a mass ratio of 1:4 (total material mass: solvent mass). Vibrate the solution again on a shaker until it is uniform and transparent. Step 4: At 25℃ in the test chamber, select a platform calibrated with a level, place a quartz glass slide flat, transfer 1ml of solution, and gravity-coat it onto the quartz glass slide. Place under a fixed airflow rate for 24 hours to ensure complete solvent evaporation, then attach a surface-treated release PET film for later use. Step 5: Place the prepared sample in a simulated sunlight test chamber: irradiance: 19×100μW / cm². 2 The film was irradiated at 55℃ for 40 hours and then removed. Step 6: Using a colorimeter, the film after the experiment was compared with the film before the experiment. After deducting the influence of the quartz glass, the color difference before and after the experiment was calculated using the instrument. At least three sets of tests were conducted for each sample, and the average value was taken as the color value.

[0043] Example 4

[0044] Step 1: Weigh 5.0g of rubber oil and 3.0g of SBS granules into a glass container with a lid, and record the mass. Step 2: At 25℃ in the test chamber, add 15ml of toluene solvent to dissolve the rubber oil and granules. Cover with a lid to prevent solvent evaporation and place on a shaker to vibrate. Step 3: After all materials are fully dissolved and the solution is uniform and transparent, make up to the required volume at a mass ratio of 1:4 (total material mass: solvent mass). Vibrate the solution again on a shaker until it is uniform and transparent. Step 4: At 25℃ in the test chamber, select a platform calibrated with a level, place a quartz glass slide flat, transfer 1ml of solution, and gravity-coat it onto the quartz glass slide. Place under a fixed airflow rate for 24 hours to ensure complete solvent evaporation, then attach a surface-treated release PET film for later use. Step 5: Place the prepared sample in a simulated sunlight test chamber: irradiance: 19×100μW / cm². 2 The film was irradiated at 55℃ for 40 hours and then removed. Step 6: Using a colorimeter, the film after the experiment was compared with the film before the experiment. After deducting the influence of the quartz glass, the color difference before and after the experiment was calculated using the instrument. At least three sets of tests were conducted for each sample, and the average value was taken as the color value.

[0045] Example 5

[0046] Step 1: Weigh 5.0g of rubber oil and 3.0g of SBS granules into a glass container with a lid, and record the mass. Step 2: At 25℃ in the test chamber, add 15ml of toluene solvent to dissolve the rubber oil and granules. Cover with a lid to prevent solvent evaporation and place on a shaker to vibrate. Step 3: After all materials are fully dissolved and the solution is uniform and transparent, make up to the required volume at a mass ratio of 1:4 (total material mass: solvent mass). Vibrate the solution again on a shaker until it is uniform and transparent. Step 4: At 25℃ in the test chamber, select a platform calibrated with a level, place a quartz glass slide flat, transfer 1ml of solution, and gravity-coat it onto the quartz glass slide. Place under a fixed airflow rate for 24 hours to ensure complete solvent evaporation, then attach a surface-treated release PET film for later use. Step 5: Place the prepared sample in a simulated sunlight test chamber: irradiance: 19×100μW / cm². 2 The film was irradiated at 55℃ for 40 hours and then removed. Step 6: Using a colorimeter, the film after the experiment was compared with the film before the experiment. After deducting the influence of the quartz glass, the color difference before and after the experiment was calculated using the instrument. At least three sets of tests were conducted for each sample, and the average value was taken as the color value.

[0047] Results Analysis

[0048]

[0049] As shown in the table above, calculating the color difference before and after the test can resolve the issue of human visual error. This results in highly repeatable test results for the yellowing resistance of rubber oil-filled films, enabling the evaluation of subtle yellowing differences. This is particularly advantageous for samples with small sample sizes and short testing periods. This approach is significant for solving practical rubber oil application problems and for screening formulation oils in the laboratory.

Claims

1. A test method for the resistance of rubber oil-filled films to yellowing under sunlight, characterized in that, Includes the following steps: Step 1: Weigh the rubber oil and rubber particles to be tested in a glass container with a lid, and record the mass; Step 2: Place the glassware in the test chamber, add the solvent to dissolve the rubber oil and rubber particles, cover it with a cover, and then place it on the shaker in the test chamber to shake. Step 3: After the adhesive solution is fully dissolved until it is uniform and transparent, add solvent to make up the volume. Place the diluted adhesive solution on a shaker and shake it again until the adhesive solution is uniform and transparent. Step 4: Place a platform calibrated with a level in the test chamber, place a quartz glass slide flat on the platform, transfer a quantitative amount of adhesive solution onto the quartz glass slide, and place it under a fixed air flow rate until the solvent has completely evaporated. Then, cover the surface with release material to obtain a spare sample. Step 5: Place the sample in a test chamber that simulates sunlight to obtain the film after the test; Step 6: Use a colorimeter to test the film obtained in Step 5 and the sample obtained in Step 4, and calculate the color difference before and after the test.

2. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, The colloids in step 1 are one or any combination of two of the following: SEBS, SEPS, SBS, or SIS colloids.

3. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, In step 1, the mass ratio of the rubber oil to be tested to the rubber granules is 5:3 or 4:

1.

4. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, The temperature of the test chamber in step 2 is 25℃-22℃.

5. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, The solvent added in step 2 is 15 ml of toluene.

6. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, In step 3, after the adhesive is fully dissolved until it is uniform and transparent, four times the mass of solvent is added to make up the volume.

7. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, In step 4, 1 ml of adhesive solution is transferred and coated onto a quartz glass slide.

8. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, The placement time in step 4 is 24 hours.

9. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, In step 5, the irradiation temperature is 55℃-22℃, and the irradiation time is 40 or 200 hours.

10. The method for testing the resistance of rubber oil-filled films to yellowing under sunlight as described in claim 1, characterized in that, In step 4, when transferring a quantitative amount of adhesive solution onto the quartz glass slide, at least three sets of films are coated. In step 6, the color value after the test is calculated as the average color value of at least three sets of films.

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