Disclosure of Invention
The invention aims to provide a phytic acid doped polyaniline/polyphenylene sulfone coating composition and a preparation method thereof. The phytic acid doped polyaniline/polyphenylene sulfone coating composition with excellent corrosion resistance is prepared by firstly preparing phytic acid doped polyaniline and then adding the phytic acid doped polyaniline into the polyphenylene sulfone. The unique redox action of the phytic acid doped polyaniline is utilized to form a form of a passive film with metal, so that the anti-corrosion capability of the polyphenylene sulfone resin is improved; meanwhile, the chelating action between a polyphosphate group carried by the phytic acid and metal is utilized to further promote a passive film formed between the coating and the metal, enhance the adhesive force of the coating and the corrosion resistance of the coating, and play a certain rust inhibiting role in the surface drying period of the coating.
The technical scheme of the invention is as follows:
the preparation method of the phytic acid doped polyaniline comprises the following steps:
(1) weighing a certain amount of N-methylpyrrolidone (NMP), aniline and ammonium persulfate to be added into a phytic acid aqueous solution with the concentration of 0.05-0.2 mol/L, and respectively preparing aniline/N-methylpyrrolidone/phytic acid solution and ammonium persulfate/phytic acid solution; the mass ratio of aniline to ammonium persulfate is 1-2.5: 1, the concentration of aniline in an aniline/N-methyl pyrrolidone/phytic acid solution is 0.05-0.5 g/mL, and the concentration of N-methyl pyrrolidone is 0.01-0.25 g/mL; the structural formula of phytic acid is shown as follows:
(2) stirring the aniline/N-methylpyrrolidone/phytic acid solution prepared in the step (1) at a water bath temperature of 20-40 ℃, wherein the stirring speed is 60-80 r/min, and at the water bath temperature, dropwise adding the prepared ammonium persulfate/phytic acid solution for 3-5 s/drop, and continuously stirring until the dropwise adding of the ammonium persulfate/phytic acid solution is completed;
(3) and (3) fully reacting the product obtained in the step (2) for 4-6 hours at the water bath temperature of the step (2) to form solid-state precipitate of the phytic acid doped polyaniline, filtering under reduced pressure, fully washing the precipitate with ethanol with the mass fraction of 95% and deionized water respectively, and performing vacuum drying at the temperature of 20-40 ℃ for 16-24 hours to obtain the phytic acid doped polyaniline.
The phytic acid doped polyaniline/polyphenylene sulfone coating composition comprises the following components in percentage by mass, calculated by mass and 100%:
wherein, the addition of other pigments, fillers, adjuvants and the like, which are optionally required, to the coating can further improve the decorative and protective properties of the coating composition.
The polyphenylene sulfone resin is a hydroxyl-terminated polyphenylene sulfone resin, and the structural formula of the polyphenylene sulfone resin is shown as follows:
wherein n is an integer of 50 to 130.
The polyphenylene sulfone resin has high hydroxyl terminated end group activity, can generate a crosslinking reaction, enables a coating to be more compact, better prevents the permeation of corrosive media, can generate an action with a metal substrate, enhances the adhesion capability with metal to a certain extent, and further enhances the corrosion resistance of the coating to the metal. The viscosity of the paint formed by the polyphenylene sulfone resin under the molecular weight condition is moderate, the paint is suitable for spraying, and meanwhile, the enough mechanical strength can be ensured. If the molecular weight is too large or too small, the solid content, the leveling property, the film thickness and the like of the paint are greatly changed, so that various performances of the paint are influenced, and even the paint can not be sprayed.
The diluent is prepared from a true solvent and a cosolvent according to a mass ratio of 1-5: 1, the true solvent can be one or more than two of N-methyl pyrrolidone, N-dimethyl acetamide and N, N-dimethyl formamide, and when a plurality of true solvents are used, the true solvents can be mixed and added in any proportion; the cosolvent can be one or more of toluene, xylene, butanone and cyclohexanone, and can be mixed and added at any ratio when used.
The optional other pigment and filler may be one or more of pigments and fillers commonly used in the coating field, such as iron red, cobalt green, carbon black, manganese black, chromium green, pearl powder, graphite, and the like, and may be added selectively according to color.
The optional auxiliary agent can be an anti-settling auxiliary agent and the like commonly used in the coating field, such as one or more than two of organic bentonite and gas-phase silicon dioxide.
The invention relates to a preparation method of a phytic acid doped polyaniline/polyphenylene sulfone coating composition, which is characterized by comprising the following steps: adding film-forming resin polyphenylene sulfone into a diluent at a stirring speed of 2000 r/min-2700 r/min, sequentially adding phytic acid doped polyaniline and other optional pigments, fillers and auxiliaries, raising the rotation speed to 3800 r/min-4500 r/min, and grinding for 4-8 hours to obtain the phytic acid doped polyaniline/polyphenylene sulfone coating composition.
The coating process of the phytic acid doped polyaniline/polyphenylene sulfone coating composition comprises the following steps:
spraying a coating composition with proper viscosity onto metal substrates such as iron, aluminum and the like which are subjected to 80-120-mesh carborundum sand blasting treatment, then cleaned by acetone alcohol and the like, dried at the temperature of 100-120 ℃ and have the surface cleanliness of Sa 2.5 level, baking at the temperature of 100-120 ℃ for 10-30 min, and heating to the temperature of 360-390 ℃ for curing for 5-15 min to obtain the coating.
The coatings produced by the above method require performance testing according to the following criteria and methods:
1. the adhesion of the sample coating is tested with reference to GB/T1720-79 paint film adhesion test.
2. The thickness of the coating of the panels was tested with reference to GB/T1764-1979 "paint thickness determination".
3. The hardness of the sample plate coating is tested by referring to GB/T6739-2006 paint film pencil hardness testing method.
4. The impact resistance of the sample plate coating is tested by referring to GB/T20624.1-2006 paint film impact resistance testing method.
5. The corrosion resistance of the template coating in chemical reagents is tested by referring to GB/T9274-1988 test for liquid medium resistance of colored paint and varnish. Five chemical reagents of sulfuric acid with the mass fraction of 10%, sodium hydroxide with the mass fraction of 10%, sodium chloride with the mass fraction of 3%, toluene and butanone are selected as soaking media, and after the five chemical reagents are soaked for a certain time, whether the coating has a leak point (namely whether the coating is damaged) or not is detected, and whether the coating has the phenomena of light loss, bubbling, falling and the like is observed.
The phytic acid doped polyaniline/polyphenylene sulfone coating composition provided by the invention has the following advantages:
1. the invention utilizes polyphenylene sulfone as film forming material, and compared with conventional film forming resin such as epoxy resin, polyphenylene sulfone has higher chemical stability, stronger impact toughness and higher heat distortion temperature. Meanwhile, the polyphenylene sulfone has strong environmental stress cracking resistance, electrical insulation and radiation resistance. The long-time working temperature of the polyphenylene sulfone reaches up to 180 ℃, so the comprehensive performance of the polyphenylene sulfone is better than that of the conventional film-forming resin such as epoxy resin, and the resin serving as the film-forming resin has more excellent comprehensive performance.
2. The synthesis temperature of the existing phytic acid doped polyaniline is mostly in the temperature range of 0-5 ℃ or even lower, the phytic acid doped polyaniline formed under the temperature condition is mostly porous or latticed polyaniline (the scanning electron microscope picture of which is shown in figure 1 (1)), and the invention forms a polyaniline high molecular polymer with lamellar stacking (the scanning electron microscope picture of which is shown in figure 1 (2)) in the temperature range of 20-40 ℃. The method has the advantages that firstly, the synthesis time is shortened, and the synthesis mode is carried out at normal temperature or at a temperature higher than the normal temperature, so that the method is more suitable for large-scale production of the material, and secondly, the lamellar stacking structure is also beneficial to the application of the filler in the aspect of coating; thirdly, the small amount of N-methyl pyrrolidone promotes aniline to be dissolved in phytic acid aqueous solution, which is beneficial to the full implementation of the synthetic reaction.
3. According to the invention, the phytic acid doped polyaniline is added, so that the corrosion resistance of the polyphenylene sulfone coating can be further enhanced. The phytic acid doped polyaniline can prevent the further occurrence of metal surface corrosion through the self-oxidation-reduction reaction of the polyaniline and the chelation of a large amount of phosphate groups contained in the phytic acid. It is generally considered that when the electrochemical impedance test value is less than 10, the solution is soaked in a solution with a certain concentration for a certain time6When the coating is not protected, the relevant electrochemical soaking test shows that the effective time of the coating is about 80d (the electrochemical impedance test result is shown in figure 2 (1)) based on the condition that the polyphenylene sulfone is soaked in a 3.5% sodium chloride solution under the condition of the same film thickness, and the effective time of the coating is more than 160d based on the polyphenylene sulfone composite coating (the example 5) of the phytic acid doped polyaniline (the electrochemical impedance test result is shown in figure 2 (2)). The integral corrosion resistance of the polyphenylene sulfone coating is improved by about 1 time. The coating formed by the polyphenylene sulfone composite coating of the phytic acid doped polyaniline has good corrosion resistance.
4. According to the invention, through the addition of phytic acid doped polyaniline, polyphosphoric acid groups in a phytic acid molecular structure are utilized to a certain extent to form a certain chelation with iron elements and the like on the surface of metal. In the early stages of drying and film forming of the coating, the polyphosphoric acid groups and surface metals form chelation, the capability of the coating for forming a passivation film is further promoted to a certain extent, and the corrosion resistance of the polyphenylene sulfone coating is improved while the adhesion capability of the coating is enhanced. Meanwhile, the rust inhibitor can also play a certain role in inhibiting rust in the surface drying period of the coating.
Detailed Description
Comparative example 1:
table 1: comparative example 1 proportion data of Components in coating composition
According to the proportion, polyphenylene sulfone resin with logarithmic concentration viscosity of 0.32 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethyl acetamide, toluene and butanone under the condition of stirring speed of 2500r/min, the rotating speed is adjusted to 4000r/min, and the mixture is ground in a sand mill for 6 hours to prepare the coating. The ground coating composition was sprayed with a coating having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and pre-treatment by means of an air spray gun and an air compressor, dried at 120 ℃ for 5min, then heated to 380 ℃ and cured for 10min to obtain a coating, and then cooled to room temperature for testing, the results are shown in table 2.
Table 2: comparative example 1 coating Performance data
Example 1:
diluting phytic acid aqueous solution into 100mL of dilute phytic acid solution with the concentration of 0.10mol/L by using deionized water, then respectively taking 10g N-methyl pyrrolidone, 5g of aniline and 5g of ammonium persulfate, taking 50mL of phytic acid solution with the concentration of 0.10mol/L, adding aniline and N-methyl pyrrolidone to form aniline/N-methyl pyrrolidone/phytic acid solution, and taking the other 50mL of phytic acid solution with the concentration of 0.10mol/L, adding ammonium persulfate to form ammonium persulfate/phytic acid solution. The prepared aniline/N-methyl pyrrolidone/phytic acid solution is put into a 250mL three-neck flask, nitrogen is introduced for protection, a 100 ℃ range thermometer is added for temperature control, stirring is carried out at a water bath temperature of 35 ℃, the stirring speed is controlled at 60r/min, ammonium persulfate/phytic acid solution which is already put into a dropping funnel is added at the water bath temperature, the dropping speed is controlled at 3s 1 drop, and the solution is continuously stirred until the ammonium persulfate/phytic acid solution is dropped. And then continuously reacting for 4 hours at the water bath temperature under the stirring condition to obtain dark green phytic acid doped polyaniline solid precipitate, filtering the dark green solid precipitate under reduced pressure, then fully washing the dark green solid precipitate by using ethanol with the mass fraction of 95% and deionized water, and drying the dark green solid precipitate in vacuum at the temperature of 35 ℃ for 20 hours to obtain the phytic acid doped polyaniline.
Example 2:
diluting phytic acid aqueous solution into 100mL of dilute phytic acid solution with the concentration of 0.05mol/L by using pure water, then respectively taking 5g N-methyl pyrrolidone, 2.5g of aniline and 2g of ammonium persulfate, taking 50mL of phytic acid solution and 0.05mol/L of phytic acid solution, adding aniline to form aniline/N-methyl pyrrolidone/phytic acid solution, and taking the other 25mL of phytic acid solution and 0.05mol/L of ammonium persulfate to form ammonium persulfate/phytic acid solution. The prepared aniline/N-methyl pyrrolidone/phytic acid solution is put into a 250mL three-neck flask, nitrogen is introduced for protection, a 100 ℃ range thermometer is added for temperature control, stirring is carried out at 40 ℃ water bath temperature, the stirring speed is controlled at 80r/min, ammonium persulfate/phytic acid solution which is already put into a dropping funnel is added at the water bath temperature, the dropping speed is controlled at 3s 1 drop, and the solution is continuously stirred until the ammonium persulfate/phytic acid solution is dropped. And then continuously reacting for 3.5 hours at the water bath temperature under the stirring condition to obtain dark green phytic acid doped polyaniline solid precipitate, filtering the dark green solid precipitate under reduced pressure, fully washing the dark green solid precipitate by using ethanol with the mass fraction of 95% and deionized water, and drying the dark green solid precipitate in vacuum for 16 hours at the temperature of 40 ℃ to obtain phytic acid doped polyaniline.
Example 3:
diluting phytic acid aqueous solution into 100mL of dilute phytic acid solution with the concentration of 0.20mol/L by using pure water, then respectively taking 3.75g N-methyl pyrrolidone, 7.5g of aniline and 3.75g of ammonium persulfate, taking 15mL of phytic acid solution and 0.20mol/L of phytic acid solution, adding aniline to form aniline/N-methyl pyrrolidone/phytic acid solution, taking another 50mL of phytic acid solution and 0.20mol/L of ammonium persulfate to form ammonium persulfate/phytic acid solution. The prepared aniline/N-methyl pyrrolidone/phytic acid solution is put into a 250mL three-neck flask, nitrogen is introduced for protection, a 100 ℃ range thermometer is added for temperature control, stirring is carried out at a water bath temperature of 20 ℃, the stirring speed is controlled at 70r/min, ammonium persulfate/phytic acid solution which is already put into a dropping funnel is added at the water bath temperature, the dropping speed is controlled at 4s 1 drop, and the solution is continuously stirred until the ammonium persulfate/phytic acid solution is dropped. And then continuously reacting for 6 hours at the water bath temperature under the stirring condition to obtain dark green phytic acid doped polyaniline solid precipitate, filtering the dark green solid precipitate under reduced pressure, then fully washing the dark green solid precipitate by using ethanol with the mass fraction of 95% and deionized water, and drying the dark green solid precipitate in vacuum for 24 hours at the temperature of 30 ℃ to obtain the phytic acid doped polyaniline.
Example 4:
diluting phytic acid aqueous solution into 100mL of dilute phytic acid solution with the concentration of 0.15mol/L by using pure water, then respectively taking 0.05g N-methyl pyrrolidone, 5g of aniline and 2g of ammonium persulfate, taking 50mL of phytic acid solution and 0.15mol/L of phytic acid solution, adding aniline to form aniline/N-methyl pyrrolidone/phytic acid solution, and taking the other 25mL of phytic acid solution and 0.15mol/L of ammonium persulfate to form ammonium persulfate/phytic acid solution. The prepared aniline/N-methyl pyrrolidone/phytic acid solution is put into a 250mL three-neck flask, nitrogen is introduced for protection, a 100 ℃ range thermometer is added for temperature control, stirring is carried out at 40 ℃ water bath temperature, the stirring speed is controlled at 65r/min, ammonium persulfate/phytic acid solution which is already put into a dropping funnel is added at the water bath temperature, the dropping speed is controlled at 2s 1 drop, and the solution is continuously stirred until the ammonium persulfate/phytic acid solution is dropped. And then continuously reacting for 4 hours at the water bath temperature under the stirring condition to obtain dark green phytic acid doped polyaniline solid precipitate, filtering the dark green solid precipitate under reduced pressure, then fully washing the dark green solid precipitate by using ethanol with the mass fraction of 95% and deionized water, and drying the dark green solid precipitate for 22 hours under vacuum at the temperature of 40 ℃ to obtain the phytic acid doped polyaniline.
Example 5: the component ratios in the coating composition are shown in Table 3, for example.
Table 3: EXAMPLE 5 proportion data of Components in coating compositions
According to the proportion, polyphenylene sulfone resin with logarithmic viscosity density of 0.32 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethylacetamide, toluene and butanone under the condition of stirring speed of 2500r/min, and then phytic acid doped polyaniline, chromic oxide and titanium dioxide prepared in example 1 are sequentially added. After the filler is fully dispersed in the diluent, the rotating speed is adjusted to 4000r/min, and the mixture is ground in a sand mill for 6 hours to prepare the coating. The ground coating composition was sprayed with a coating material having a suitable viscosity by an air spray gun and an air compressor onto a metal substrate which had been subjected to sand blasting and pre-treatment, dried at 120 ℃ for 5min, then heated to 380 ℃ and cured for 10min to obtain a coating layer, and then cooled to room temperature for testing, and the test results are shown in table 4.
Table 4: example 5 coating Performance data
Example 6: the ratios of the components in the coating composition are shown in Table 5, for example.
Table 5: example 6 proportion data of Components in coating composition
According to the proportion, polyphenylene sulfone resin with logarithmic viscosity density of 0.33 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethylacetamide, toluene and butanone under the condition of the stirring rotating speed of 2300r/min, and then phytic acid doped polyaniline, chromic oxide and organic bentonite prepared in the embodiment 1 are added. After the relevant filler was fully dispersed in the diluent, the rotational speed was adjusted to 4200r/min, and the mixture was ground in a sand mill for 5.5 hours to prepare a coating. The ground coating composition was sprayed with a coating having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and pre-treatment using an air spray gun and an air compressor, dried at 100 ℃ for 20min, heated to 360 ℃ and cured for 10min to obtain a coating, and then cooled to room temperature for testing, the test results are shown in table 6:
table 6: example 6 coating Performance data
Example 7: the component ratios in the coating composition are shown in Table 7, for example.
Table 7: example 7 proportion data of Components in coating composition
According to the proportion, under the condition of the stirring speed of 2700r/min, polyphenylene sulfone resin with the logarithmic viscosity number of 0.38 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethylacetamide, toluene and butanone, and then the phytic acid doped polyaniline, chromic oxide and titanium dioxide prepared in the example 1 are sequentially added. After the relevant fillers are fully dispersed in the diluent, the rotating speed is adjusted to 4400r/min, and the mixture is ground in a sand mill for 5 hours to prepare the coating. The ground coating composition was sprayed with a coating material having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and pre-treatment by means of an air spray gun and an air compressor, dried at 110 ℃ for 15min, heated to 375 ℃ and cured for 15min to obtain a coating layer, and then cooled to room temperature for testing, the test results are shown in table 8.
Table 8: example 7 coating Performance data
Example 8: the component ratios in the coating composition are shown in Table 9, for example.
Table 9: example 8 proportion data of Components in coating composition
According to the proportion, under the condition of the stirring speed of 2200r/min, polyphenylene sulfone resin with the logarithmic viscosity number of 0.34 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethylacetamide, toluene and butanone, and then the phytic acid doped polyaniline, chromic oxide, carbon black and organic bentonite prepared in the example 1 are sequentially added. After the relevant filler was fully dispersed in the diluent, the rotational speed was adjusted to 4200r/min, and the mixture was ground in a sand mill for 8 hours to prepare a coating. After the ground coating composition is sprayed on the metal substrate which is subjected to sand blasting treatment and pretreatment by using an air spray gun and an air compressor, the metal substrate is dried for 15min at the temperature of 100 ℃, then the temperature is raised to 380 ℃, the metal substrate is solidified for 5min to obtain a coating, and then the coating is cooled to room temperature for testing, wherein the test results are shown in the table 10:
table 10: example 8 coating Performance data
Example 9: the component ratios in the coating composition are shown in Table 11, for example.
Table 11: example 9 proportion data of Components in coating compositions
According to the proportion, polyphenylene sulfone resin with logarithmic viscosity density of 0.33 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethylacetamide, toluene and butanone under the condition of stirring speed of 2500r/min, and then phytic acid doped polyaniline, titanium dioxide and organic bentonite prepared in example 1 are sequentially added. After the relevant fillers are fully dispersed in the diluent, the rotating speed is adjusted to 4000r/min, and the mixture is ground in a sand mill for 6 hours to prepare the coating. The ground coating composition was sprayed with a coating material having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and pre-treatment using an air spray gun and an air compressor, dried at 100 ℃ for 30min, heated to 370 ℃ and cured for 15min to obtain a coating layer, and then cooled to room temperature for testing, the test results are shown in table 12:
table 12: example 9 coating Performance data
Example 10: the component ratios in the coating composition are shown in Table 13, for example.
Table 13: EXAMPLE 10 proportion data of Components in coating composition
According to the proportion, polyphenylene sulfone resin with logarithmic viscosity density of 0.30 is added into a composite solvent consisting of N-methylpyrrolidone, N-dimethylacetamide, toluene and butanone under the condition of a stirring rotating speed of 2100r/min, and then phytic acid doped polyaniline and organic bentonite prepared in example 1 are sequentially added. After the relevant filler is fully dispersed in the diluent, the rotating speed is adjusted to 3800r/min, and the mixture is ground in a sand mill for 5 hours to prepare the coating. The ground coating composition was sprayed with a coating material having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and pre-treatment by means of an air spray gun and an air compressor, dried at 120 ℃ for 15min, then cured at 385 ℃ for 10min to obtain a coating layer, and then cooled to room temperature for testing, the test results are shown in table 14.
Table 14: example 10 coating Performance data
Example 11: the component ratios in the coating composition are shown in Table 15, for example.
Table 15: example 11 proportion data of Components in coating composition
According to the proportion, under the condition of the stirring speed of 2700r/min, polyphenylene sulfone resin with the logarithmic viscosity number of 0.34 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethyl acetamide, toluene and butanone, and then the phytic acid doped polyaniline, chromic oxide and fumed silica prepared in the example 1 are sequentially added. After the relevant filler is fully dispersed in the diluent, the rotating speed is adjusted to 4100r/min, and the mixture is ground in a sand mill for 8 hours to prepare the coating. The ground coating composition was sprayed with a coating material having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and pre-treatment by means of an air spray gun and an air compressor, dried at 110 ℃ for 10 minutes, heated to 375 ℃ and cured for 10 minutes to obtain a coating layer, and then cooled to room temperature for testing, and the test results are shown in table 16.
Table 16: example 11 coating Performance data
Example 12: the component ratios in the coating compositions are shown in Table 17, for example.
Table 17: example 12 proportion data of Components in coating composition
According to the proportion, polyphenylene sulfone resin with logarithmic viscosity density of 0.34 is added into a composite solvent consisting of N-methylpyrrolidone, N-dimethylacetamide, toluene and butanone under the condition of stirring speed of 2000r/min, and then phytic acid doped polyaniline, carbon black and fumed silica prepared in example 1 are sequentially added. After the relevant fillers are fully dispersed in the diluent, the rotating speed is adjusted to 4500r/min, and the mixture is ground in a sand mill for 7 hours to prepare the coating. The ground coating composition was sprayed with a coating material having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and pre-treatment by means of an air spray gun and an air compressor, dried at 120 ℃ for 15 minutes, then heated to 380 ℃ and cured for 10 minutes to obtain a coating layer, and then cooled to room temperature for testing, and the test results are shown in table 18.
Table 18: example 12 coating Performance data
Example 13: the ratios of the components in the coating composition are shown in Table 19, for example.
Table 19: example 13 proportion data of Components in coating composition
According to the proportion, polyphenylene sulfone resin with logarithmic viscosity density of 0.30 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethylacetamide, toluene and butanone under the condition of the stirring rotating speed of 2300r/min, and then phytic acid doped polyaniline and chromic oxide prepared in the example 1 are sequentially added. After the relevant filler is fully dispersed in the diluent, the rotating speed is adjusted to 3800r/min, and the mixture is ground in a sand mill for 4 hours to prepare the coating. The ground coating composition was sprayed with a coating material having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and pre-treatment by means of an air spray gun and an air compressor, dried at 100 ℃ for 10min, heated to 390 ℃ and cured for 5min to obtain a coating layer, and then cooled to room temperature for testing, and the test results are shown in table 20.
Table 20: example 13 coating Performance data
Example 14: the component ratios in the coating composition are shown in Table 21, for example.
Table 21: example 14 proportion data of Components in coating composition
According to the proportion, polyphenylene sulfone resin with logarithmic viscosity number of 0.38 is added into a composite solvent consisting of N-methyl pyrrolidone, N-dimethylacetamide, toluene and butanone under the condition of the stirring speed of 2600r/min, and then phytic acid doped polyaniline, titanium dioxide and fumed silica prepared in example 1 are sequentially added. After the related fillers are fully dispersed in the diluent, the rotating speed is adjusted to 4300r/min, and the mixture is ground in a sand mill for 8 hours to prepare the coating. The ground coating composition was applied by spraying a coating material having a suitable viscosity onto a metal substrate which had been subjected to sand blasting and had been pretreated by means of an air spray gun and an air compressor, dried at 100 ℃ for 10 minutes, then heated to 370 ℃ and cured for 10 minutes to obtain a coating layer, and then cooled to room temperature for testing, and the test results are shown in table 22.
Table 22: example 14 coating Performance data