Method for rapidly screening coating raw materials and application

Abstract

According to the method for rapidly screening the coating raw materials and the application, physical and chemical structures of the raw materials are analyzed through an instrument, a small number of raw materials most similar to the raw materials used in an original formula in structure are screened out, then the types of coatings needing performance testing can be reduced, and efficiency is improved. According to the method, the key physical and chemical structures of the raw materials can be qualitatively and quantitatively analyzed within several hours, so that the raw materials meeting the requirements can be quickly screened out.

Description

Technical Field

[0001] The invention belongs to the technical field of coating materials, and in particular relates to a method for quickly screening coating raw materials and an application thereof. Background Art

[0002] Raw materials are the key factors affecting the performance of coatings. For a mature and excellent coating, the quality and supply of its raw materials should also be stable. However, due to market fluctuations and complex international situations, the quality of raw materials may change, and even the supply chain may have problems. In order to cope with such situations, coating companies sometimes need to replace raw materials. Replacing raw materials in coatings is a rigorous and complex task, which requires not only analyzing the structure and properties of the raw materials themselves, but also analyzing the performance of the replaced coating products. The performance testing of some coatings not only has a long cycle, such as salt spray resistance, UV aging, medium immersion resistance and other tests, which can take months or even years, but also consumes a lot of manpower and material resources. If there are many types of raw materials to choose from, it is very difficult to perform performance tests on each product after the raw materials are replaced. Summary of the invention

[0003] The present invention provides an efficient raw material screening method, which uses instruments to analyze the physical and chemical structures of raw materials, and screens out a few raw materials that are most similar to the raw material structures used in the original formula, thereby reducing the types of coatings that need to be tested for performance and improving efficiency. This method only takes a few hours to perform qualitative and quantitative analysis on the key physical and chemical structures of raw materials, thereby quickly screening out raw materials that meet the requirements.

[0004] One of the purposes of the present invention is to provide a method for rapidly screening coating raw materials, comprising the steps of using an infrared spectrometer-pyrolysis gas chromatograph / mass spectrometer-differential scanning calorimeter to screen organic raw materials and / or using an X-ray fluorescence spectrometer-X-ray diffractometer-laser particle size analyzer-scanning electron microscope to screen inorganic raw materials, wherein the pyrolysis gas chromatograph / mass spectrometer uses multi-stage temperature pyrolysis.

[0005] According to the present invention, the organic raw materials include at least two of amine compounds, polymer resins, ester compounds, phenolic compounds, silane coupling agents, glycidyl ether compounds, organic solvents, reactive diluents, plasticizers, anti-settling agents, and leveling agents. Among them, the organic solvents, reactive diluents, plasticizers, anti-settling agents, and leveling agents can all be components commonly used in the art, for example, the organic solvent is selected from at least one of xylene, butyl acetate, n-butanol, and propylene glycol methyl ether, the reactive diluent is selected from at least one of alkyl glycidyl ether and N-butyl glycidyl ether, the plasticizer is selected from at least one of dibutyl phthalate, chlorinated paraffin, and trimethyl phosphate, the anti-settling agent is selected from at least one of polyamide wax and unsaturated polyester, and the leveling agent is selected from at least one of silicone and acrylate.

[0006] For organic raw materials, first use Fourier infrared spectrometer to analyze the types and contents of their chemical bonds for preliminary analysis; then use thermal pyrolysis gas chromatography / mass spectrometer to analyze the types and contents of their compounds. Thermal pyrolysis can quickly heat and pyrolyze polymer resins and additives, and the generated small molecule pyrolysis products and low molecular weight components are effectively separated in the gas chromatography system. The separated compounds are further tested and analyzed by mass spectrometry; finally, specific physical parameters are analyzed, such as using a thermal gravimetric analyzer or a differential scanning calorimeter to analyze its thermodynamic properties, and finally, a laser particle size analyzer is optionally used to measure the particle size distribution (such as water-based resin emulsion) as needed.

[0007] Specifically, the screening of the organic raw materials comprises the following steps:

[0008] (1-1) Analyzing the organic raw materials using an infrared spectrometer, and comparing the characteristic peaks in the infrared spectrum with the target raw materials;

[0009] (1-2) selecting an organic raw material whose infrared spectrum is not less than 98% similar to that of the target raw material, testing the type and content of organic compounds therein by pyrolysis gas chromatography / mass spectrometry, and comparing the result with that of the target raw material;

[0010] (1-3) Select an organic raw material whose content of the same type of compound in the cracking product differs from that in the target raw material by no more than 3%, test its thermodynamic properties using a thermal gravimetric analyzer or a differential scanning calorimeter, and select an organic raw material whose decomposition temperature and phase transition temperature differ from those of the target raw material by less than 3°C and whose weight loss rate differs by no more than 5%.

[0011] When the organic raw material contains a volatile solvent, first use a gas chromatograph and a gas chromatograph-gas spectrometer to analyze the type and content of the solvent therein, select an organic raw material containing the same type of solvent as the target raw material in a content greater than 0.2%, and the difference between the content of the same type of solvent in the organic raw material and the content in the target raw material is not more than 3%, and then operate according to steps (1-1) to (1-3).

[0012] The test conditions of the pyrolysis gas chromatography / mass spectrometer are:

[0013] The operation of the cracker includes cracking the organic raw material at 250-280°C, 440-470°C, and 620-680°C in sequence. Preferably, the specific operation is: cracking the organic raw material at 250-280°C for 3-5 seconds, analyzing the cracking product, then cracking at 440-470°C for 3-5 seconds, analyzing the cracking product, and then cracking at 620-680°C for 3-5 seconds, analyzing the cracking product;

[0014] The operating conditions of the gas chromatography are: the chromatographic column is DB-5MS; the injection port temperature is 200-300°C; the detector temperature is 200-300°C; the column oven in the gas chromatography adopts multi-stage temperature increase to analyze the pyrolysis products; preferably, the operating conditions of the column oven are: first maintain at 35-55°C for 3-8 minutes, then increase the temperature to 150-220°C at a rate of 3-6°C / min and maintain for 3-8 minutes, and finally increase the temperature to 230-300°C at a rate of 8-14°C / min and maintain for 3-7 minutes;

[0015] The mass spectrometry conditions are as follows: using an EI ion source; ion source temperature 250-350°C; transfer line temperature 150-290°C; ion source energy 40-100 eV; full scan scanning mode; mass scanning range 30 m / z-400 m / z.

[0016] The test conditions of the thermogravimetric analyzer are: in a protective gas atmosphere, heating from -10 to 25°C to 200 to 280°C at a heating rate of 10 to 15°C / min; the protective gas can be commonly used nitrogen or the like.

[0017] The test conditions of the differential scanning calorimeter are as follows: in a protective gas atmosphere, the temperature is increased from -20 to 15°C to 150 to 200°C at a heating rate of 10 to 15°C / min; then the temperature is decreased from 150 to 200°C to -20 to 15°C at a cooling rate of 10 to 15°C / min; then the temperature is increased from -20 to 15°C to 150 to 200°C at a heating rate of 10 to 15°C / min; the protective gas may be commonly used nitrogen or the like.

[0018] The screening of the organic raw materials may also optionally include the steps of particle size testing and / or molecular weight testing, and the organic raw materials whose test results differ from the same kind of components in the target raw materials by no more than 5% are screened.

[0019] According to the present invention, the inorganic raw materials include at least one of titanium dioxide, sericite, fumed silica, mica iron oxide gray, mica iron oxide red, barium sulfate, silicon carbide, zinc phosphate, talc, and calcium carbonate.

[0020] For inorganic raw materials, such as inorganic pigments and fillers, first use an X-ray fluorescence spectrometer to analyze the type and content of the elements. Then use an X-ray diffractometer to analyze the crystal structure, and combine the results of elemental analysis to conduct qualitative and quantitative analysis of the inorganic raw materials. Because the physical structure of inorganic raw materials will also affect the performance of the coating, the scanning electron microscope energy spectrometer and laser particle size analyzer can be used to analyze the microscopic morphology of inorganic pigments and fillers.

[0021] Specifically, the screening of the inorganic raw materials comprises the following steps:

[0022] (2-1) using an X-ray fluorescence spectrometer to analyze the element types and contents of the inorganic raw materials, and selecting elements with a content greater than 0.2% for comparison with the contents of the corresponding elements in the target inorganic raw materials;

[0023] (2-2) selecting an inorganic raw material with an element content difference of no more than 3%, performing phase analysis using an X-ray diffractometer, and selecting an inorganic component with a content greater than 2% in the inorganic raw material for comparison with the target inorganic raw material;

[0024] (2-3) Select inorganic raw materials with the same phase structure and component content difference of no more than 3% to test particle size distribution and aspect ratio, and select inorganic raw materials with average particle size difference of no more than 5% and aspect ratio difference of no more than 8%. The particle size distribution is tested by a laser particle size analyzer; the aspect ratio is tested by a scanning electron microscope.

[0025] The second object of the present invention is to provide the above method for quickly screening coating raw materials for alternative use of raw materials.

[0026] Compared with the prior art, the rapid screening method provided by the present invention has the following advantages:

[0027] (1) The method provided by the present invention can quickly screen out the raw materials to be replaced, and can screen out better alternative raw materials without long-term performance testing;

[0028] (2) The method provided by the present invention conducts qualitative and quantitative analysis of raw materials from the aspects of physical and chemical structure, and screens out a few raw materials with the structures most similar to those used in the original formula, thereby reducing the types of coatings that need to be tested for performance, improving efficiency, and providing more detailed and objective results. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The infrared analysis spectra of curing agents A and B in Comparative Example 1 are shown;

[0030] Figure 2 The thermal decomposition-gas analysis spectra of curing agent A and curing agent B in comparative example 1, curing agent C and curing agent A in example 1;

[0031] Figure 3 It is the reaction temperature diagram of curing agent A and B in comparative example 1;

[0032] Figure 4 The infrared analysis spectra of curing agents A and C in Example 1 are shown;

[0033] Figure 5 is the reaction temperature diagram of curing agent C in Example 1;

[0034] Figure 6 The XRD spectra of the two inorganic fillers in Example 2;

[0035] Figure 7a b to b are the particle size distribution diagrams of two types of mica iron oxide ashes (sample D and sample E) in Example 2;

[0036] Figure 8a ~b are scanning electron microscope images of two types of mica iron oxide ashes (sample D and sample E) in Example 2. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0038] The test instruments and test conditions used in the examples are as follows:

[0039] Instruments: GC-MS / MS, 7000D, Agilent Technologies, USA; Pyrolyzer, EGA / PY-3030D, EGA, Japan; Ultracentrifuge, CS1200, Hitachi, Japan; Fourier transform infrared spectrometer (FT-IR), Nicolet iZ10, Thermo Fisher Scientific, USA; X-ray fluorescence spectrometer, S8tiger, Bruker, Germany; X-ray diffractometer, FRINGE C1600-SY, LANScientific, China; Field emission scanning electron microscope, IT510LA, JEOL; Laser particle size analyzer, LA-960V2, HORBAR, France;

[0040] Reagents: ethyl acetate, chromatographic grade, Aladdin; acetone, analytical grade, Sinopharm reagent; xylene, analytical grade, Sinopharm reagent; commercially available mica iron oxide and epoxy curing agent.

[0041] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0042] Comparative Example 1

[0043] A rapid screening and comparison was conducted on epoxy curing agent A and epoxy curing agent B in the coating.

[0044] (1-1) Epoxy curing agent A and epoxy curing agent B were analyzed and tested by infrared spectrometer for comparison.

[0045] Different types of chemical bonds and functional groups contained in the curing agent can absorb infrared light of different wavelengths, thereby obtaining an infrared spectrum with multiple absorption peaks. The infrared spectrum analysis results are shown in Figure 1 After analysis, it was found that the infrared characteristic peaks of curing agents A and B basically overlap, indicating that they contain the same functional groups and chemical bonds. -1 The characteristic peaks near 910cm indicate the presence of NH stretching vibration. -1 The characteristic peaks near 2925cm indicate the presence of epoxy groups. -1 、2853cm -1 The two strong absorption peaks nearby are methylene-CH 2 , methyl-CH 3 Infrared analysis shows that both curing agents are amine epoxy curing agents, and their infrared similarity is 98.5%.

[0046] (1-2) The types and contents of organic compounds in epoxy curing agent A and epoxy curing agent B were tested by thermal pyrolysis gas chromatography / chromatograph for comparison.

[0047] The test conditions of pyrolysis gas chromatography / mass spectrometer are:

[0048] The operation of the cracker includes cracking the organic raw material at 270°C, 450°C, and 650°C in sequence. Preferably, the specific operation is: cracking the organic raw material at 270°C for 5 seconds and analyzing the cracking product, then cracking at 450°C for 5 seconds and analyzing the cracking product, and then cracking at 650°C for 5 seconds and analyzing the cracking product;

[0049] The operating conditions of the gas chromatography are: the chromatographic column is DB-5MS; the injection port temperature is 280°C; the detector temperature is 260°C; the column oven in the gas chromatography adopts multi-stage temperature increase to analyze the pyrolysis products; preferably, the operating conditions of the column oven are: first maintain at 40°C for 5 minutes, then increase the temperature to 200°C at a rate of 5°C / min and maintain for 5 minutes, and finally increase the temperature to 280°C at a rate of 10°C / min and maintain for 5 minutes;

[0050] The mass spectrometry conditions are as follows: using an EI ion source; ion source temperature of 250°C; transfer line temperature of 190°C; ion source energy of 70 eV; full scan scanning mode; and a mass scanning range of 30 m / z to 400 m / z.

[0051] Figure 2 The thermal cracking-gas chromatography mass spectrometer of curing agents A and B is shown in Figure 1. After analysis, the main compounds that appeared before 14 minutes in the spectrum were small molecular compounds with low boiling points, such as the chromatographic peak near 9.3 minutes for butyl acetate, and the chromatographic peaks of xylene near 10.7 minutes and 11.2 minutes. The peaks of medium molecular weight compounds appeared between 14 and 21 minutes, such as the silane coupling agent near 19.9 minutes and ethylene glycol diglycidyl ether near 20.9 minutes. After 24 minutes, the product peaks of high molecular weight resin after high temperature cracking appeared, such as phenol near 23.7 minutes, cardanol near 24.5 minutes, bisphenol A near 24.9 minutes, and bisphenol A glycidyl ether near 25.8 minutes. Both curing agents A and B contain the above-mentioned compounds, and the content is basically the same. However, the diethylenetriamine around 11.32 min, isophoronediamine around 15.1 min, and meta-xylylenediamine around 15.3 min in Curing Agent B are different from those in Curing Agent A (triethylenetetramine around 14.7 min).

[0052] (1-3) The thermodynamic properties are tested using a differential scanning calorimeter, and an organic raw material is selected whose decomposition temperature and phase transition temperature have a difference of less than 3°C from the target raw material and a weight loss rate difference of no more than 5%.

[0053] The curing agent will be heated to 60°C for curing during use. In order to verify the thermal stability of the curing agent at this temperature, the thermodynamic properties of the two curing agents were analyzed using a differential scanning calorimeter. First, the curing agent was dried to evaporate the solvent, and then the temperature was increased from 15°C to 150°C at a heating rate of 10°C / min under nitrogen protection; then the temperature was decreased from 150°C to 10°C at a cooling rate of 10°C / min; and then the temperature was increased from 10°C to 150°C at a heating rate of 10°C / min. In the last heating process, the reaction temperature of curing agent A and curing agent B was obtained (e.g. Figure 3 As shown). After analysis, it was found that curing agent A had an endothermic reaction peak at 68.9°C, and curing agent B had an endothermic reaction peak at 59.9°C. The thermal stability of the two curing agents was inconsistent, which may be caused by the difference in free amines and other substances. This result is consistent with the obvious difference between the three amine compounds of curing agent B and curing agent A in the pyrolysis gas chromatography-mass spectrometry (Py-GC / MS) analysis results.

[0054] Example 1

[0055] According to the test steps in Comparative Example 1, epoxy curing agent A and epoxy curing agent C in the coating were quickly screened and compared.

[0056] Depend on Figure 2 The results show that the thermal cracking-gas chromatography mass spectrometry of the two curing agents A and C, after analysis, mainly appeared in the spectrum before 14min are small molecular compounds with low boiling points, such as the chromatographic peak near 9.3min is butyl acetate, and the chromatographic peaks of xylene appear near 10.7min and 11.2min. The peaks of medium molecular weight compounds appear from 14 to 21min, such as silane coupling agent near 19.9min, ethylene glycol diglycidyl ether near 20.9min. After 24min, the product peaks of high molecular weight resin after high temperature cracking appear, such as phenol near 23.7min, cardanol near 24.5min, bisphenol A near 24.9min, and bisphenol A glycidyl ether near 25.8min. Both curing agents A and C contain the above-mentioned compounds, and the content is basically the same. In addition, curing agent A and curing agent C only contain one triethylenetetramine, and do not contain other amines such as diethylenetriamine and isophorone diamine.

[0057] Depend on Figure 4 The results show that the infrared characteristic peaks of curing agents A and C are basically the same, indicating that they contain the same functional groups and chemical bonds. -1 The characteristic peaks near 910cm indicate the presence of NH stretching vibration. -1 The characteristic peaks near 2925cm indicate the presence of epoxy groups. -1 、2853cm -1 The two strong absorption peaks nearby are methylene-CH2 , methyl-CH 3 Stretching vibration peak, 1155cm -1 Nearby is the CO stretching vibration peak of phenol. Infrared analysis shows that both curing agents A and C are amine epoxy curing agents, and their infrared similarity is 99.6%.

[0058] Depend on Figure 5 The results show that curing agent A has an endothermic reaction peak at 68.9°C, and curing agent C has an endothermic reaction peak at 67.8°C. The thermal stabilities of the two curing agents are similar, which is consistent with the test results of pyrolysis gas chromatography-mass spectrometry (Py-GC / MS).

[0059] Test Example 1

[0060] Through the rapid screening analysis in Comparative Example 1 and Example 1, curing agent C was screened out as the one that was closest to the original formula curing agent A. Coatings were prepared using curing agents B and C respectively for performance testing and compared with the coating prepared with curing agent A. The performance test results are shown in Table 1 below.

[0061] The test found that the performance of the coating prepared by curing agent C was better than that of the coating prepared by curing agent B, and was close to that of the coating prepared by curing agent A.

[0062] Table 1

[0063]

[0064] Example 2

[0065] A rapid screening and comparison was conducted on two types of mica iron oxide ash (sample D and sample E). Through X-ray fluorescence spectrometer and X-ray diffractometer analysis, it was found that the element types, contents and crystal structures of the two inorganic fillers were basically the same, but further analysis using a laser particle size analyzer and scanning electron microscope revealed that the two fillers had obvious differences in particle size and morphology.

[0066] (2-1) X-ray fluorescence spectrometer was used to analyze the element types and contents of sample D and sample E for comparison.

[0067] First, the element contents of the two mica iron oxide ashes were analyzed using an X-ray fluorescence spectrometer. The analysis results are shown in Table 2 below. The Fe content of samples D and E was 83.71% and 83.51% respectively, the Si content was 6.94% and 6.89% respectively, and the contents of Al, K, Mg, Ca and other elements were also very close. From the results of the elemental analysis, there was no significant difference between the two fillers.

[0068] Table 2 Ash element content of two mica iron oxides, wt%

[0069] Element Type Sample D Sample E Fe 83.71 83.51 Si 6.94 6.89 Al 2.31 2.45 K 1.06 1.08 Mg 0.28 0.29 Ca 0.14 0.15

[0070] (2-2) X-ray diffractometer was used to test sample D and sample E for phase analysis;

[0071] At the same time, the two types of mica iron oxide ash were analyzed by X-ray diffractometer, and the spectra are shown in Figure 6 Through analysis, it was found that both fillers D and E had Fe at 2θ of 31.96°, 33.16°, 35.63°, and 54.08°. 2 O 3 The characteristic peaks of the two fillers are the same, which indicates that the crystal structures of samples D and E are the same.

[0072] (2-3) The particle size distribution and aspect ratio of test sample D and sample E were compared.

[0073] The physical structure of the filler will have a great impact on the anti-corrosion performance of the coating. Therefore, the particle size analysis was performed using a laser particle size analyzer. The particle size distribution diagram of samples D and E is shown in Figure 7a The average particle size, median particle size, and D90 particle size (90% cumulative particle size distribution) of sample D are 23, 20, and 41 μm, and the specific surface area is 3800 cm 2 / cm 3 The average particle size, median particle size, and D90 particle size (the cumulative particle size distribution reaches 90%) of sample E are 32, 29, and 52 μm, and the specific surface area is 2400 cm 2 / cm 3 From the particle size distribution, the particle size of sample D is significantly smaller than that of sample E, and the specific surface area of ​​sample D is 58% higher than that of sample E. The smaller particle size and higher specific surface area of ​​mica iron oxide ash can better prevent corrosive substances from penetrating the coating into the substrate and improve the anti-corrosion performance of the paint film.

[0074] The microstructures of the two types of mica iron oxide ash were further analyzed using scanning electron microscopy. Figure 8a ~b are scanning electron microscope images of samples D and E. Through analysis, it can be found that the particle size of most particles of sample D is between 3-45μm, and the particle size of most particles of sample E is between 5-50μm. And sample D has a flaky structure and a smoother and flatter surface. Sample E has a granular structure. The flaky structure of mica iron oxide ash has a higher specific surface area than the granular structure, which can better prevent corrosive substances from penetrating the paint. And the smoother and flatter surface is conducive to reflecting radiation such as sunlight and improving the weather resistance of the paint. Therefore, compared with sample E, sample D will show better performance in terms of physical structure. The particle size and specific surface area data of the two types of mica iron oxide ash are consistent with the analysis results of the scanning electron microscope and the laser particle size analyzer.

Claims

1. A method for rapidly screening coating raw materials, comprising the steps of using an infrared spectrometer-pyrolysis gas chromatography / mass spectrometer-differential scanning calorimeter to screen organic raw materials and / or using an X-ray fluorescence spectrometer-X-ray diffractometer-laser particle size analyzer-scanning electron microscope to screen inorganic raw materials, wherein: The thermal pyrolysis gas chromatograph / mass spectrometer adopts multi-stage temperature pyrolysis.

2. The method according to claim 1, characterized in that The organic raw materials include at least two of amine compounds, polymer resins, ester compounds, phenolic compounds, silane coupling agents, glycidyl ether compounds, organic solvents, reactive diluents, plasticizers, anti-settling agents, and leveling agents.

3. The method according to claim 1 or 2, characterized in that: The screening of the organic raw materials comprises the following steps: (1-1) Analyzing the organic raw materials using an infrared spectrometer, and comparing the characteristic peaks in the infrared spectrum with the target raw materials; (1-2) selecting an organic raw material whose infrared spectrum is not less than 98% similar to that of the target raw material, testing the type and content of organic compounds therein by pyrolysis gas chromatography / mass spectrometry, and comparing the result with that of the target raw material; (1-3) Select an organic raw material whose content of the same type of compound in the cracking product differs from that in the target raw material by no more than 3%, test its thermodynamic properties using a thermal gravimetric analyzer or a differential scanning calorimeter, and select an organic raw material whose decomposition temperature and phase transition temperature differ from those of the target raw material by less than 3°C and whose weight loss rate differs by no more than 5%.

4. The method according to claim 3, characterized in that: When the organic raw material contains a volatile solvent, first use a gas chromatograph and a gas chromatograph-gas spectrometer to analyze the type and content of the solvent therein, select an organic raw material containing the same type of solvent as the target raw material in a content greater than 0.2%, and the difference between the content of the same type of solvent in the organic raw material and the content in the target raw material is not more than 3%, and then operate according to steps (1-1) to (1-3).

5. The method according to claim 3, characterized in that: The test conditions of the pyrolysis gas chromatography / mass spectrometer are: The operation of the cracker includes cracking the organic raw material at 250-280°C, 440-470°C, and 620-680°C in sequence; The operating conditions of the gas chromatography are: the chromatographic column is DB-5MS; the injection port temperature is 200-300°C; the detector temperature is 200-300°C; the column oven in the gas chromatography adopts multi-stage temperature increase to analyze the pyrolysis products; preferably, the operating conditions of the column oven are: first maintain at 35-55°C for 3-8 minutes, then increase the temperature to 150-220°C at a rate of 3-6°C / min and maintain for 3-8 minutes, and finally increase the temperature to 230-300°C at a rate of 8-14°C / min and maintain for 3-7 minutes; The mass spectrometry conditions are: using an EI ion source; ion source temperature 250-350°C; transfer line temperature 150-290°C; ion source energy 40-100 eV; full scan scanning mode; mass scanning range 30m / z-400m / z; and / or, The test conditions of the thermogravimetric analyzer are: in a protective gas atmosphere, heating from -10 to 25°C to 200 to 280°C at a heating rate of 10 to 15°C / min; and / or, The test conditions of the differential scanning calorimeter are as follows: in a protective gas atmosphere, the temperature is increased from -20 to 15°C to 150 to 200°C at a heating rate of 10 to 15°C / min; then the temperature is decreased from 150 to 200°C to -20 to 15°C at a cooling rate of 10 to 15°C / min; then the temperature is increased from -20 to 15°C to 150 to 200°C at a heating rate of 10 to 15°C / min.

6. The method according to claim 3, characterized in that The screening of the organic raw materials may also optionally include the steps of particle size testing and / or molecular weight testing, and the organic raw materials whose test results differ from the same kind of components in the target raw materials by no more than 5% are screened.

7. The method according to claim 1, characterized in that The inorganic raw materials include at least one of titanium dioxide, sericite, fumed silica, mica iron oxide gray, mica iron oxide red, barium sulfate, silicon carbide, zinc phosphate, talc, and calcium carbonate.

8. The method according to claim 1 or 7, characterized in that: The screening of the inorganic raw materials comprises the following steps: (2-1) using an X-ray fluorescence spectrometer to analyze the types and contents of elements in the inorganic raw materials, and selecting elements with a content greater than 0.2% for comparison with the contents of corresponding elements in the target inorganic raw materials; (2-2) selecting an inorganic raw material with an element content difference of no more than 3%, performing phase analysis using an X-ray diffractometer, and selecting an inorganic component with a content greater than 2% in the inorganic raw material for comparison with the target inorganic raw material; (2-3) Select inorganic raw materials with the same phase structure and component content difference of no more than 3% to test particle size distribution and aspect ratio, and select inorganic raw materials with average particle size difference of no more than 5% and aspect ratio difference of no more than 8%.

9. The method according to claim 8, characterized in that The particle size distribution is measured using a laser particle size analyzer; and / or, The aspect ratio is tested using a scanning electron microscope.

10. A method according to any one of claims 1 to 9, used for rapid screening of coating raw materials for alternative use of raw materials.

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