Method and system for identifying silane modified white carbon black in tire based on XPS method

Abstract

The invention relates to the technical field of tire material analysis, in particular to a method and system for identifying silane modified white carbon black in a tire based on an XPS method. The method comprises the following steps: firing a tire sample at high temperature to remove organic matters, and collecting a Si2p spectrum in ash; separating a Si-O bond peak from an organic silicon peak through peak fitting, and calculating a peak area ratio; and the ratio is compared with pre-established standard database data, so that quantitative determination of the unmodified, partially modified and completely modified states is realized. Compared with traditional TGA, XRD and chemical reaction methods, the method has the advantages of being high in detection sensitivity, easy and convenient to operate, good in repeatability and the like, and reliable data support is provided for tire formula optimization and quality control.

Description

Technical Field

[0001] The present invention relates to the technical field of tire material analysis, and in particular to a method and system for identifying silica modified with silane in tires based on the XPS method. Background Art

[0002] With the rapid development of the automotive industry and the continuous improvement of consumers' requirements for driving safety, energy conservation, and environmental protection, tire performance has become one of the important factors affecting the driving quality of the entire vehicle. As a key functional filler in tires, silica (mainly composed of silicon dioxide, SiO 2 ) plays a crucial role in improving the grip of the tire tread, reducing rolling resistance, and enhancing wet performance. To further improve the comprehensive performance of tires, manufacturers often modify the surface of silica with silane coupling agents to improve its dispersibility in the rubber matrix, thereby enhancing the wear resistance, elasticity, and other mechanical properties of the tires. At the same time, it can also reduce the emission of volatile organic compounds (VOCs) during the production process, meeting modern environmental protection standards.

[0003] Currently, the following several methods are mainly used in the prior art to analyze and identify the modification state of silica in tires: 1. Thermogravimetric analysis (TGA) Thermogravimetric analysis mainly determines the composition and content of materials by monitoring the mass change of samples under high-temperature conditions. For tire samples, TGA can be used to measure the total amount of fillers, but its analysis principle is limited to the macroscopic measurement of the weight loss process of samples, and it is difficult to distinguish the chemical structure and bonding state between silane-modified and unmodified silica. Therefore, in practical applications, TGA has obvious limitations in identifying modified silica.

[0004] 2. X-ray diffraction (XRD) XRD technology can provide crystal structure information of materials, and the diffraction pattern can reflect the crystal morphology and crystallinity of fillers. However, after silica is modified with silane, its basic crystal structure does not change significantly. Therefore, XRD cannot provide sufficient sensitivity and accuracy in detecting the modification effect. In other words, it is difficult to form an obvious difference in the diffraction patterns of silica before and after modification.

[0005] 3. Chemical reaction detection methods Some detection methods attempt to infer the modification state by means of simple chemical reactions, such as using specific acidic or alkaline reagents to react with silica in tire ash and judging from the reaction phenomenon. However, this method is often greatly affected by reaction conditions, reagent concentration, and environmental factors, the operation process is not easy to control, and the repeatability and accuracy of the detection results are insufficient, making it difficult to meet the requirements of industrial detection.

[0006] In summary, the traditional detection methods have obvious deficiencies in accurately distinguishing and quantitatively evaluating silane-modified silica. Therefore, a new method based on more sensitive and accurate analytical means is urgently needed to achieve rapid and accurate judgment of the modified state of silica in tires through fine analysis of chemical bond information in ash, providing effective support for tire formulation optimization and quality control. Summary of the invention

[0007] In order to overcome the shortcomings of traditional thermogravimetric analysis (TGA), X-ray diffraction (XRD) and simple chemical reaction methods that cannot distinguish modified and unmodified white carbon black, the present invention provides a method for identifying silane-modified white carbon black in tires based on the XPS method. The method can quickly and accurately determine whether the white carbon black has been modified by silane by analyzing the Si2p spectral characteristics in the ash.

[0008] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: A method for identifying silane-modified white carbon black in a tire based on an XPS method comprises the following steps: a) Cut a sample from the tread of the tire to be tested, remove organic matter by high-temperature burning, and collect the ash; b) Use X-ray photoelectron spectroscopy (XPS) to test the Si2p spectrum in the ash and record the photoelectron intensity and binding energy; c) performing peak fitting on the Si2p spectrum, separating the Si-O bond peak and the organic silicon peak Organic Si, and calculating the respective peak areas; d) judging whether there is silane-modified white carbon black in the ash by analyzing the area ratio of the Si-O bond peak to the organosilicon peak; e) The presence of silane-modified silica was further verified based on the significance of the Si-O bond peak intensity.

[0009] Preferably, the high temperature calcination in step a) is carried out at a temperature ranging from 600° C. to 800° C., and the calcination time is 2 hours.

[0010] Preferably, the specific conditions of the XPS test in step b) include: The excitation source uses Al Kα light source; The analysis area diameter is 200 to 600 μm; Energy resolution is 0.1 to 0.2 eV; Test vacuum degree is less than 10⁻ 9 mbar.

[0011] Preferably, the characteristic binding energy of the Si-O bond peak is 10 3 ±0.5 eV, while the characteristic binding energy of the organosilicon peak is 10 2 ±0.5 eV.

[0012] Furthermore, the present invention also provides an analysis system for identifying silane-modified silica in tires, which implements the method described above and includes: a) A sample processing module for performing high-temperature burning treatment on tire samples; b) An XPS analysis module for collecting the Si2p spectrum in the ash after burning; c) A data processing module for performing peak fitting processing and peak area calculation on the collected spectrum; d) An analysis result output module for generating a diagnostic report and determining whether there is silane-modified silica.

[0013] Preferably, the sample processing module further includes a temperature and time control unit for precisely controlling the temperature range and burning time of high-temperature burning.

[0014] Preferably, the data processing module is further configured to calibrate the Si-O / Organic Si peak area ratio according to the test data of standard samples to improve the analysis accuracy.

[0015] Preferably, the analysis result output module is also configured with a multi-level determination function, and can generate a diagnostic report reflecting the degree of silane modification according to the numerical value of the Si-O / Organic Si peak area ratio.

[0016] Preferably, the system further includes comparing the Si-O / Organic Si peak area ratio calculated in step d) with a preset threshold, and classifying the tire sample to be tested into three states: unmodified, partially modified, or fully modified according to the comparison result.

[0017] Preferably, the system further includes an integrated database for storing reference spectrum data and threshold information of different tire samples and their corresponding degrees of silane modification, and the data processing module can call the data in this database to assist and optimize the judgment of silane-modified silica.

[0018] Due to the adoption of the above technical solution, the present invention has the following technical effects: 1. High-sensitivity and high-precision detection: By introducing X-ray photoelectron spectroscopy (XPS) technology, the present invention uses fine peak fitting of the Si2p spectrum in the ash to effectively separate and quantitatively analyze the Si-O bond peak and the organosilicon peak, realizing the microscopic analysis of the surface chemical state of silica. Compared with traditional thermogravimetric analysis (TGA) and X-ray diffraction (XRD) methods, the present invention significantly improves the sensitivity and accuracy of detecting silane-modified silica.

[0019] 2. Quantitative determination of the modification degree: By calculating the ratio of the peak areas of Si-O bonds to organosilicon, the present invention can not only qualitatively distinguish modified and unmodified silica, but also quantitatively describe silica with different modification levels, thus providing objective and accurate data support for material formula optimization and process control.

[0020] 3. Simple operation and high repeatability: By adopting standardized sample treatment and high-temperature calcination steps, and combining with the standardized conditions of XPS testing (such as Al Kα excitation source, specific analysis area diameter and energy resolution), the present invention ensures the simplicity of the detection operation and the high repeatability of the results, overcoming the disadvantages of traditional chemical reaction detection methods, such as large environmental interference and cumbersome operation.

[0021] 4. Quick response and potential for on-line detection: Due to the quick response characteristic of XPS analysis, the method of the present invention can complete the detection process in a short time, being suitable for the integrated application of on-line or semi-on-line detection systems, so as to meet the requirements of quality monitoring and instant feedback in the modern tire production process.

[0022] 5. Reducing detection cost and environmental friendliness: The present invention avoids the consumption of a large amount of reagents and complex post-treatment steps in traditional detection means, not only reducing the detection cost, but also reducing the use of chemical reagents, being environmentally friendly and meeting the requirements of green manufacturing.

[0023] 6. Data standardization and intelligent analysis: By integrating a data processing module and a database management system, it is possible to realize the standardized storage and comparison of test data, and at the same time support multi-level determination and automated analysis, providing a reliable basis for quality traceability and determination of different batches of products, and further improving the intelligent level of industrial applications.

[0024] In summary, through the quantitative analysis of XPS spectral data, the present invention not only overcomes the deficiencies of traditional detection methods in terms of sensitivity, accuracy and operation stability, but also realizes the precise and rapid determination of the silane modification state of silica, providing an effective technical means for optimizing the modification effect and quality control of tire materials. Brief Description of the Drawings

[0025] Figure 1 : Si2p spectrum of a common silica sample (58), where the organosilicon peak dominates; Figure 2 : Si2p spectrum of a silane-modified silica sample (58-454), showing a significant Si-O bond peak. Detailed Description of the Invention

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with 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.

[0027] Example 1: Detection of unmodified silica (58) 1. Sample preparation 1 cm² samples were cut from the tread of tires containing unmodified silica.

[0028] 2. High temperature burning treatment The sample was placed in a high temperature furnace and burned at 700° C. for 2 hours to remove organic matter and collect the remaining ash.

[0029] 3. XPS test Al Kα light source was used to test the Si2p spectrum in the sample ash.

[0030] Set the test parameters: the analysis area diameter is 200 to 600 μm; the energy resolution is 0.1 to 0.2 eV; the test vacuum is less than 10⁻ 9 mbar.

[0031] 4. Data processing and analysis The collected Si2p spectrum was subjected to peak fitting processing to separate the Si-O bond peak and the organosilicon peak, and their respective peak areas were calculated.

[0032] The area ratio of the Si-O bond peak to the silicone peak is calculated. If the result is less than the preset threshold (about 0.5), the sample is judged to be unmodified silica.

[0033] 5. Analysis results: The intensity of the Si-O bond peak is low, and the organic silicon peak is dominant; the peak area ratio Si-O / Organic Si=0.3, which is determined to be unmodified silica.

[0034] Example 2: Detection of silane-modified white carbon black (58-454) 1. Sample preparation 1 cm² samples were cut from the tread of tires containing silane-modified silica.

[0035] 2. High temperature burning treatment The samples were calcined at 700°C for 2 hours and the ash was collected.

[0036] 3. XPS test The Al Kα light source was also used to collect the Si2p spectrum of the sample under the specified parameter conditions.

[0037] 4. Data Processing and Analysis Perform peak fitting on the collected spectra to clearly separate the Si-O bond peak and the organosilicon peak, and calculate the peak areas respectively.

[0038] If the calculated Si-O / Organic Si peak area ratio is significantly higher than the preset threshold (reaching 1.5 or higher), the sample is determined to be silane-modified silica.

[0039] 5. Analysis Results: The Si-O bond peak is significantly enhanced and the organosilicon peak exists; the peak area ratio Si-O / Organic Si = 1.5, and it is determined to be silane-modified silica.

[0040] Example 3: Analysis of the Modification Degree of Tire Samples with Different Silane Contents 1. Sample Preparation Cut 1 cm² samples from the treads of tires using different silane modification formulas respectively.

[0041] 2. High-Temperature Calcination Treatment and XPS Testing Perform high-temperature calcination and XPS testing on each sample according to the methods described in Example 1 and Example 2.

[0042] 3. Data Processing and Quantitative Comparison Obtain the area ratio of the Si-O peak to the organosilicon peak by performing peak fitting on the Si2p spectra of each sample.

[0043] Content of the Standard Database: In previous studies, a reference database containing different modification states was established through testing a large number of standard samples. The database records the typical peak area ratios, binding energy ranges, and other relevant parameters in each state.

[0044] Unmodified Silica: The peak area ratio is usually less than 0.5; Partially Modified Silica: The peak area ratio is between 0.5 and 1.5; Fully Modified Silica: The peak area ratio is greater than 1.5.

[0045] Compare the obtained data with the pre-established standard database to achieve quantitative determination of silica with different modification degrees, so as to be able to distinguish states such as "unmodified", "partially modified", and "fully modified", meeting the requirements of tire formula optimization and quality control.

[0046] Comparative Example 1: Thermogravimetric Analysis (TGA) Detection 1. Operating Steps After high-temperature calcination of the same tire sample, monitor the mass change of the sample during heating by TGA to determine the total amount of filler.

[0047] TGA can only reflect the total weight loss of the sample and cannot distinguish the microscopic structure of chemical bonds, resulting in an inability to accurately determine between modified and unmodified silica.

[0048] Comparative Example 2: X-ray diffraction (XRD) analysis 1. Operating steps The burned sample was detected by XRD to obtain the crystal structure information of silica.

[0049] Since the silane modification does not significantly change the crystal structure of silica, there is no obvious difference in the XRD diffraction patterns before and after modification, so the modified state cannot be effectively distinguished.

[0050] Comparative Example 3: Chemical reaction detection method 1. Operating steps The ash sample was placed in a specific acidic or alkaline reagent, and the modification situation was inferred by observing the reaction phenomena (such as color change or precipitation formation).

[0051] The reaction conditions are easily affected by multiple factors such as reagent concentration, temperature, and environment, resulting in poor repeatability of the results and an inability to accurately quantify, making it difficult to meet the requirements of industrial detection.

[0052] Experimental data comparison table Examples / Comparative Examples Method Results Conclusions Example 1 XPS (Sample 58) Si-O / Organic Si ratio is 0.3 Unmodified Example 2 XPS (Sample 58-454) Si-O / Organic Si ratio is 1.5 Silane modification Example 3 XPS With the change of silane content, the peak ratio changes The degree of modification can be distinguished Comparative Example 1 TGA Unable to distinguish The method is invalid Comparative Example 2 XRD Unable to distinguish The method is invalid Comparative Example 3 Simple chemical reaction Unable to determine The method is invalid The above is the description of the embodiments of the present invention. Through the above description of the disclosed embodiments, those skilled in the art can implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for identifying silane-modified white carbon black in tires based on the XPS method, characterized in that: The following steps are involved: a) cutting a sample from the tire tread to be tested, removing organic matter by high-temperature burning, and collecting ash; b) testing the Si2p spectrum in the ash using X-ray photoelectron spectroscopy (XPS), recording the photoelectron intensity and binding energy; c) performing peak fitting on the Si2p spectrum, separating the Si-O bond peak and the organic silicon peak Organic Si, and calculating the respective peak areas; d) determining whether silane-modified white carbon black is present in the ash by analyzing the area ratio of the Si-O bond peak to the organic silicon peak.

2. The method according to claim 1, characterized in that The temperature range of high temperature calcination in step a) is 600° C. to 800° C., and the calcination time is 2 hours.

3. The method according to claim 1, characterized in that The specific conditions of the XPS test in step b) include: The excitation source uses Al Kα light source; The analysis area diameter is 200 to 600 μm; Energy resolution is 0.1 to 0.2 eV; Test vacuum degree is less than 10⁻ 9 mbar.

4. The method according to claim 1, characterized in that: The characteristic binding energy of the Si-O bond peak is 10 3 ±0.5eV, while the characteristic binding energy of the organosilicon peak is 10 2 ±0.5 eV.

5. An analytical system for identifying silane-modified white carbon black in tires, characterized in that: The system implements the method described in any one of claims 1 to 4, comprising: a) a sample processing module for performing high-temperature burning treatment on tire samples; b) an XPS analysis module for collecting Si2p spectra in ash after burning; c) a data processing module for performing peak fitting processing and peak area calculation on the collected spectra; d) an analysis result output module for generating a diagnostic report and determining whether silane-modified white carbon black is present.

6. The system according to claim 5, characterized in that The sample processing module also includes a temperature and time control unit for accurately controlling the temperature range and burning time of high-temperature burning.

7. The system according to claim 5, characterized in that The data processing module is further configured to calibrate the Si-O / Organic Si peak area ratio according to the test data of the standard sample to improve the analysis accuracy.

8. The system according to claim 5, characterized in that The analysis result output module is also equipped with a multi-level judgment function, which can generate a diagnosis report reflecting the degree of silane modification according to the numerical value of the Si-O / Organic Si peak area ratio.

9. The system according to claim 5, characterized in that The method further includes comparing the Si-O / Organic Si peak area ratio calculated in step d) with a preset threshold value, and classifying the tire sample to be tested into three states: unmodified, partially modified or fully modified according to the comparison result.

10. The system according to claim 5, characterized in that It further includes an integrated database for storing reference spectral data and threshold information of different tire samples and corresponding silane modification degrees, and the data processing module can call the data in the database to assist and optimize the judgment of silane-modified white carbon black.

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