CN110002454A - A kind of honeycomb Si-Al composite membrane compatible with FEVE resin and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of metal surface protection, in particular to a honeycomb Si-Al composite film compatible with FEVE resin and a preparation method thereof. In the invention, the silicon source, the aluminum source, the mineralizer, the organic solvent and the water are stirred and mixed, and the two-dimensional silicon-alumina nanosheets are obtained through reactions such as aging and crystallization. It is coated on the aluminum surface and dried to obtain a Si-Al composite film with a honeycomb microstructure. The honeycomb Si-Al composite film obtained by the invention based on two-dimensional nanosheets has a large specific surface area, provides higher intermolecular force and mechanical anchoring force, improves the compatibility with FEVE resin fluorocarbon powder, and is compatible with post-coating All performance indicators of the layer meet the relevant standard requirements, and the resistance to acetic acid salt spray can reach 2000 hours. After 1000 hours of filiform corrosion test, the filiform corrosion is 0. The honeycomb Si-Al composite film prepared by the invention can replace the fluorocarbon paint by fluorocarbon powder, so as to prevent the volatilization of organic solvents from the source, reduce the VOC emission, and have remarkable application effect.

Description

A honeycomb Si-Al composite film compatible with FEVE resin and preparation method thereof

technical field

The invention relates to the technical field of metal surface protection, in particular to a honeycomb Si-Al composite film compatible with FEVE resin and a preparation method thereof.

Background technique

Aluminum is widely used in automotive, aerospace, architectural decoration and other fields, and is a metal structural material with a large amount. Due to the high chemical activity of aluminum, it is prone to damage such as pitting corrosion, crevice corrosion, stress corrosion and corrosion fatigue, which cannot meet the requirements of use in harsh environments. In order to improve the service life of aluminum materials and meet the requirements of product appearance and decoration, aluminum products must undergo surface treatment before use. Among them, chemical passivation treatment has the advantages of small influence on the fatigue performance of the substrate, convenient operation, low cost, and high production efficiency. It is one of the most widely used surface treatment technologies due to its advantages of high efficiency and wide application range. After the aluminum material is passivated and then painted, it can greatly improve the bonding force between the basic and the coating, and significantly enhance the corrosion protection performance of the aluminum material.

The traditional chemical passivation process of aluminum materials mostly adopts the chromate method, but the hexavalent chromium compound contained in the process formula is a toxic chemical. Improper handling will not only cause great environmental pollution but also seriously endanger human health. At present, new passivation film processes have been developed at home and abroad, such as titanium zirconate system, cobalt salt system, etc. For example, the Chinese patent with publication number CN105803442A discloses a Zr-Ti passivation film for aluminum or aluminum alloy. The treatment agent and its treatment method use zirconate, titanate and the like as raw materials to form a phosphorus-free and chromium-free Zr-Ti passivation film on the surface of aluminum or aluminum alloy, and have good adhesion. However, the current market chrome-free pretreatment film only has good compatibility with class 1 and class 2, and meets the standard requirements in terms of boiling water adhesion, impact resistance, cupping resistance and other properties. However, it is completely incompatible with class 3 ultra-weather-resistant fluorocarbon powder (FEVE resin). Among the various indicators required by the national standard, the boiling water adhesion, impact resistance and cupping cannot meet the requirements, and acetic acid salt spray Much less than 2000 hours, the filiform corrosion is serious, which greatly limits the industrial implementation of VOC emission solutions using fluorocarbon powder instead of fluorocarbon paint.

SUMMARY OF THE INVENTION

In view of the above technical problems, the present invention provides a honeycomb Si-Al composite film compatible with FEVE resin and a preparation method thereof, which improves the compatibility of the aluminum surface with the electrostatically sprayed fluorocarbon powder, so that in the process of processing the aluminum test piece Realize fluorocarbon powder to replace fluorocarbon paint, eliminate volatile organic compounds from the source, and reduce VOC emissions.

In one aspect of the present invention, the present invention proposes a preparation method of a honeycomb Si-Al composite film compatible with FEVE resin, comprising the following steps: (1) mixing a silicon source, an aluminum source, a mineralizer, an organic solvent and Mix with water, and stir at room temperature until a gelatinous substance appears, then transfer to a bath for aging, and then quickly transfer to a PTFE-lined stainless steel reactor for crystallization reaction. After the crystallization reaction, the product is filtered and washed. and drying to obtain two-dimensional silicon-alumina nanosheets; (2) dissolving the two-dimensional silicon-alumina nanosheets obtained in step (1) in an organic solvent, and performing centrifugation; The supernatant liquid is coated on the surface of the aluminum test piece, or the aluminum test piece is immersed in the supernatant liquid after centrifugation in step (2), and then air-dried or heat-dried to obtain a Si-Al composite membrane with a honeycomb microstructure .

The preparation method of the present invention is simple, and at the same time, the source of raw materials is wide, the obtained Si-Al composite film has low activity and good stability, and after electrostatically spraying a layer of fluorocarbon powder based on FEVE resin on the surface of the film layer, according to GB 5237.5-2008 "Aluminum alloy building profiles Part 5: Fluorocarbon paint spray profiles" test, all performance indicators meet the requirements, thus providing a new green technical solution for fluorocarbon powder to replace fluorocarbon paint and eliminate VOC volatilization from the source , with good market prospects.

In another aspect of the present invention, the present invention proposes a honeycomb Si-Al composite film compatible with FEVE resin, prepared by the above preparation method, and the coating is resistant to acetate after being compatible with fluorocarbon powder based on FEVE resin Fog up to 2000 hours, after 1000 hours of filiform corrosion, the filiform corrosion is 0. The Si-Al composite film of the present invention is coated on the surface of aluminum as an inert material, which effectively improves the stability of aluminum and has strong corrosion resistance. Higher strength and mechanical anchoring force, strong adhesion, improved compatibility with FEVE resin fluorocarbon powder, and all performance indicators of the compatible coating meet relevant standards.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

In order to describe the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the drawings that are required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

Fig. 1 is the preparation process flow chart of the honeycomb Si-Al composite film compatible with FEVE resin of the present invention;

Fig. 2 is the scanning electron microscope image of the intermediate product two-dimensional silicon-alumina nanosheet of the honeycomb Si-Al composite film compatible with FEVE resin of the present invention;

Fig. 3 is the scanning electron microscope image of the honeycomb Si-Al composite film compatible with FEVE resin of the present invention;

Fig. 4 is the actual picture of the 2000-hour acetic acid salt spray and 1000-hour filiform corrosion salt spray test after the silicon-aluminum composite film of the present invention and the FEVE resin-based fluorocarbon powder coating;

FIG. 5 is a physical diagram of the high-pressure boiling water adhesion, boiling water adhesion, cupping test and impact test of the coating after the silicon-aluminum composite film of the present invention is coated with FEVE resin-based fluorocarbon powder.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

In one aspect of the present invention, the present invention proposes a preparation method of a honeycomb Si-Al composite film compatible with FEVE resin, as shown in Figure 1, comprising the following steps:

(1) Mix the silicon source, aluminum source, mineralizer, organic solvent and water, and stir at room temperature until a gelatinous substance appears, then transfer to a bath for aging, and then quickly transfer to a PTFE-lined stainless steel The crystallization reaction is carried out in the reaction kettle, and after the crystallization reaction is completed, the product is filtered, washed and dried to obtain two-dimensional silicon-alumina nanosheets. Through aging, crystallization and other processes, the intermediate product two-dimensional silicon-alumina nanosheets are obtained, as shown in FIG.

In some embodiments of the present invention, the molar ratio of silicon source, aluminum source, mineralizer, organic solvent and water is (6-10):1:(0.2-1.2):(18-30):(200- 400). More specifically, in some embodiments of the present invention, the molar ratio of silicon source, aluminum source, mineralizer, organic solvent and water is (7-9):1:(0.6-1.0):(20-25) : (270-320). Preferably, the molar ratio of silicon source, aluminum source, mineralizer, organic solvent and water is 8.75:1:0.72:23.4:298.95.

In some embodiments of the present invention, the silicon source may be, but is not limited to, any one of ethyl orthosilicate, silica sol, and sodium silicate; preferably, the silicon source is ethyl orthosilicate.

In some embodiments of the present invention, the aluminum source can be, but is not limited to, any one of sodium metaaluminate, aluminum nitrate nonahydrate, aluminum phosphate, aluminum sulfate, and aluminum isopropoxide; preferably, the aluminum source is meta-aluminum Sodium.

In some embodiments of the present invention, the mineralizer is one of inorganic alkali or fluoride; preferably, the mineralizer is sodium hydroxide.

The chemical formula of ethyl orthosilicate is Si(OC ₂ H ₅ ) ₄ . It is a colorless liquid, slightly soluble in water, and hydrolyzed slowly in pure water, and can accelerate the hydrolysis in the presence of acid or alkali. In the present invention, under alkaline conditions such as the presence of mineralizers such as sodium hydroxide, ethyl orthosilicate undergoes a hydrolysis and condensation reaction, and tiny, dispersed colloidal particles appear in the reaction system. These colloidal particles pass through van der Waals force, hydrogen bond or The chemical bond forces are connected to each other to form a skeleton structure. The reaction formula of the hydrolysis polycondensation reaction of ethyl orthosilicate is as follows:

Si(OCH ₂ CH ₃ ) ₄ +2H ₂ O→SiO ₂ +4C ₂ H ₅ OH

At the same time, under alkaline conditions, silica reacts with sodium hydroxide to generate sodium silicate, and sodium silicate reacts with sodium metaaluminate to obtain a product containing silicon oxide and aluminum oxide. The reaction formula is as follows:

SiO ₂ +2NaOH→Na ₂ [H ₂ SiO ₄ ]

xNa ₂ [H ₂ SiO ₄ ]+2NaAl(OH) ₄ →Na ₂ O·Al ₂ O ₃ ·xSiO ₂ ·nH ₂ O↓+2xNaOH

In some embodiments of the present invention, the silicon source, the aluminum source, the mineralizer, the organic solvent and the water are mixed and then magnetically stirred for 40-60 min until a colloidal substance appears.

In some embodiments of the present invention, the aging reaction temperature is 50-80° C., and the reaction time is 6-10 h. Preferably, the aging reaction temperature is 60-70°C, and the reaction time is 7-8h.

In some embodiments of the present invention, the crystallization reaction temperature is 100-200° C., and the crystallization time is 96-240 h. Preferably, the crystallization reaction temperature is 150-180°C, and the reaction time is 108-144h.

In some embodiments of the present invention, after the crystallization reaction is completed, the product is filtered with deionized water and washed several times; after thorough cleaning, it is placed in a vacuum drying oven at 100°C for 10 hours to obtain a white powdery product , which are two-dimensional silicon-alumina nanosheets.

(2) Dissolving the two-dimensional silicon-alumina nanosheet obtained in step (1) in an organic solvent, and performing centrifugation treatment. By centrifugation, the two-dimensional silicon-alumina nanosheets in the product are separated from other substances. Of course, during the high-speed centrifugation of the centrifuge, the two-dimensional nanosheets will also be deformed accordingly, so that the product obtained in the supernatant has a deformed, non-complete two-dimensional sheet-like structure.

In some embodiments of the present invention, the rotational speed of the centrifuge is 5000-8000 r/min, and the centrifugation time is 15-30 minutes; preferably, the rotational speed of the centrifuge is 5500-6000 r/min, and the centrifugation time is 20-25 minutes.

In some embodiments of the present invention, the type of the organic solvent is not specifically limited, and those skilled in the art can flexibly select according to the actual situation. In some embodiments of the present invention, the organic solvent may be any one of toluene, ethanol, pentane, chlorobenzene, cyclohexane, and the like.

(3) take the supernatant after centrifugation in step (2) and coat it on the surface of the aluminum test piece, or soak the aluminum test piece in the supernatant liquid after centrifugation in step (2), and then air dry or heat dry, The Si-Al composite film with honeycomb microstructure was obtained. During the process of coating the supernatant of the two-dimensional silicon-alumina nanosheets on the surface of the aluminum specimen and drying, the silicon-alumina nanosheets continued to grow, and finally a Si-Al composite film with a honeycomb microstructure was formed, as shown in Figure 3. Show.

In some embodiments of the present invention, before the supernatant is coated on the aluminum surface, the pretreatment process of grinding and degreasing the aluminum surface is further included. In some embodiments of the present invention, the pretreatment process includes: polishing the aluminum surface with silicon carbide water sandpaper to a surface roughness of less than 10 μm, soaking it in an acidic degreasing and degreasing aqueous solution for 2-6 minutes, and then rinsing it with clean water, After repeating the operation twice, air dry or hot air dry.

In some embodiments of the present invention, the coating thickness of the supernatant on the aluminum test piece or the soaking time of the aluminum test piece in the supernatant is not specifically limited, and those skilled in the art can flexibly choose according to the actual situation.

In another aspect of the present invention, the present invention provides a honeycomb Si-Al composite film compatible with FEVE resin, which is prepared by the above preparation method. The Si-Al composite film of the present invention uses inert materials such as silicon and aluminum as raw materials, and the prepared passivation film has high stability and strong corrosion resistance. The intermolecular force and mechanical bonding force are higher, which improves the adhesion of the aluminum surface to the powder coating, which is helpful for the subsequent treatment process. The corrosion resistance of aluminum materials, the adhesion of powder coatings, impact resistance, toughness and other mechanical properties have been significantly improved.

In some embodiments of the present invention, the FEVE resin-compatible honeycomb Si-Al composite film of the present invention is prepared by the following method:

(1) Mix silicon source, aluminum source, mineralizer, organic solvent and water in a molar ratio of (6-10):1:(0.2-1.2):(18-30):(200-400), and Stir magnetically for 40-60min at room temperature, transfer to a bath for aging after the appearance of jelly, the aging temperature is 50-80℃, and the reaction time is 6-10h; then quickly transfer to a stainless steel reaction kettle lined with PTFE Carry out the crystallization reaction, the crystallization temperature is 100-200 °C, and the time is 96-240 h; after the crystallization reaction is completed, the product is filtered with deionized water and washed several times; after the cleaning is complete, it is placed in a vacuum drying box at 100 °C Dry for 10h to obtain a white powdery product, which is two-dimensional silicon-alumina nanosheets;

(2) dissolving the two-dimensional silicon-alumina nanosheets prepared in step (1) in an organic solvent, and performing centrifugation treatment, the centrifuge rotation speed is 5000-8000r/min, and the centrifugation time is 15-30min;

(3) take the supernatant liquid after centrifugation in step (2) and coat it on the aluminum surface, or soak the aluminum in the supernatant liquid after centrifugation in step (2), and then naturally air dry or heat dry to obtain a honeycomb microscopic Structure of the Si-Al composite film.

The present invention will be described below with reference to specific embodiments. It should be noted that these embodiments are descriptive and do not limit the present invention in any way.

Example 1

A honeycomb Si-Al composite membrane compatible with FEVE resin, prepared by the following method:

(1) 4.43g (21.3mmol) of ethyl orthosilicate, 0.29g (3.55mmol) of sodium metaaluminate, 0.17g (4.26mmol) of sodium hydroxide, 2.94g (63.9mmol) of ethanol and 16.61g (923mmol) of Mix with water and stir magnetically for 40 min at room temperature. After jelly appears, transfer to a bath for aging. The aging temperature is 50 °C and the reaction time is 10 h; After the crystallization reaction, the crystallization temperature was 180 °C, and the time was 108 h; after the crystallization reaction, the product was filtered with deionized water and washed several times; The product is a two-dimensional silicon-alumina nanosheet;

(2) Dissolving the two-dimensional silicon-alumina nanosheets obtained in step (1) in an organic solvent, and performing centrifugation treatment, the centrifuge rotation speed is 5000r/min, and the centrifugation time is 30min;

(3) The supernatant liquid after centrifugation in step (2) is coated on the surface of the aluminum test piece, and then dried by heat to obtain a Si-Al composite film with a honeycomb microstructure.

Example 2

A honeycomb Si-Al composite membrane compatible with FEVE resin, prepared by the following method:

(1) 4.89g (23.52mmol) ethyl orthosilicate, 0.28g (3.36mmol) sodium metaaluminate, 0.13g (3.36mmol) sodium hydroxide, 3.86g (84mmol) ethanol and 24.19g (1344mmol) water Mixed and magnetically stirred at room temperature for 40min. After jelly appeared, it was transferred to a bath for aging. The aging temperature was 60°C and the reaction time was 8h; then it was quickly transferred to a PTFE-lined stainless steel reactor for crystallization. Reaction, crystallization temperature 120 ℃, time 240h; after the crystallization reaction, the product was filtered with deionized water, and washed several times; after thorough cleaning, placed in a vacuum drying box of 100 ℃ for 10 hours to obtain white powder The product is two-dimensional silicon-alumina nanosheets;

(2) Dissolving the two-dimensional silicon-alumina nanosheets obtained in step (1) in an organic solvent, and performing centrifugation treatment, the centrifuge rotation speed is 7000r/min, and the centrifugation time is 25min;

(3) Immerse the aluminum test piece in the supernatant after centrifugation in step (2), and then heat it to dry to obtain a Si-Al composite film with a honeycomb microstructure.

Example 3

A honeycomb Si-Al composite membrane compatible with FEVE resin, prepared by the following method:

(1) 5.84g (28.08mmol) of ethyl orthosilicate, 0.26g (3.12mmol) of sodium metaaluminate, 0.025g (0.624mmol) of sodium hydroxide, 4.31g (93.6mmol) of ethanol and 17.97g (998.4mmol) of ) water, and magnetically stirred at room temperature for 60min. After the jelly appeared, it was transferred to a bath for aging. The aging temperature was 60°C and the reaction time was 7h; Crystallization reaction, crystallization temperature 150 ℃, time 120h; after the crystallization reaction, the product is filtered with deionized water, and washed several times; after cleaning is complete, it is placed in a vacuum drying box at 100 ℃ to dry for 10 hours to obtain white The powder product is to obtain two-dimensional silicon-alumina nanosheets;

(2) dissolving the two-dimensional silicon-alumina nanosheets obtained in step (1) in an organic solvent, and performing centrifugation treatment, the centrifuge rotation speed is 5500r/min, and the centrifugation time is 25min;

(3) Immerse the aluminum test piece in the supernatant after centrifugation in step (2), and then heat it to dry to obtain a Si-Al composite film with a honeycomb microstructure.

Example 4

A honeycomb Si-Al composite membrane compatible with FEVE resin, prepared by the following method:

(1) 5.93g (28.5mmol) of ethyl orthosilicate, 0.23g (2.85mmol) of sodium metaaluminate, 0.068g (1.71mmol) of sodium hydroxide, 2.62g (57mmol) of ethanol and 10.26g (570mmol) of water Mixed and magnetically stirred at room temperature for 50 min. After jelly appeared, it was transferred to a bath for aging. The aging temperature was 70 °C and the reaction time was 7 h; then it was quickly transferred to a PTFE-lined stainless steel reactor for crystallization. Reaction, crystallization temperature 200 ℃, time 96h; after the crystallization reaction, the product was filtered with deionized water, and washed several times; after thorough cleaning, placed in a vacuum drying box of 100 ℃ for 10h to obtain white powder The product is two-dimensional silicon-alumina nanosheets;

(2) Dissolving the two-dimensional silicon-alumina nanosheets obtained in step (1) in an organic solvent, and performing centrifugation treatment, the centrifuge rotation speed is 8000r/min, and the centrifugation time is 15min;

(3) The supernatant after centrifugation in step (2) is coated on the surface of the aluminum test piece, and then air-dried naturally to obtain a Si-Al composite film with a honeycomb microstructure.

Example 5

A honeycomb Si-Al composite membrane compatible with FEVE resin, prepared by the following method:

(1) 6 g (28.8 mmol) of ethyl orthosilicate, 0.27 g (3.29 mmol) of sodium metaaluminate, 0.095 g (2.375 mmol) of sodium hydroxide, 3.55 g (77.17 mmol) of ethanol and 12.8 g (711.1 mmol) of Mix with water and stir magnetically for 45 min at room temperature. After a gelatinous substance appears, transfer to a bath for aging. The aging temperature is 80 °C and the reaction time is 6 h; After the crystallization reaction, the crystallization temperature was 100 °C, and the time was 144 h; after the crystallization reaction, the product was filtered with deionized water and washed several times; The product is a two-dimensional silicon-alumina nanosheet;

(2) Dissolving the two-dimensional silicon-alumina nanosheets obtained in step (1) in an organic solvent, and performing centrifugation treatment, the centrifuge rotation speed is 6000r/min, and the centrifugation time is 20min;

(3) The supernatant after centrifugation in step (2) is coated on the surface of the aluminum test piece, and then air-dried naturally to obtain a Si-Al composite film with a honeycomb microstructure.

Comparative Example 1

According to the method of YS/T 1189-2017 "Chromium-free chemical pretreatment film for aluminum and aluminum alloys", a chromium-free pretreatment film on the surface of existing aluminum alloys in the market was prepared.

Electrostatic spraying was performed on the Si-Al composite films obtained in Examples 1-5 and the chromium-free pretreatment film prepared in Comparative Example 1, and the spraying material was fluorocarbon powder based on FEVE resin. Afterwards, the curing treatment is carried out, the curing temperature is 210°C, and the curing time is 15 minutes. The cured materials were subjected to acid salt spray test, constant temperature condensed water test, SO ₂ resistance test and filiform corrosion test respectively. The specific test conditions are as follows:

(1) Acid salt spray test

The test is based on ISO 9227:2012, the test equipment is Q-FOG/SSP1100 salt spray test chamber, the test time is 2000 hours, the technical requirements are based on QUALICOAT version 14: the foaming level is based on ISO 4628-2: ≤2(S2); Grid penetration area: ≤16mm ² /10cm; single maximum penetration length along the grid: ≤4mm.

(2) Constant temperature condensate test

The test is based on ISO 6270-2:2005, the test equipment is LIEBISCH K300 condensate water test chamber, the test time is 2000 hours, the technical requirements are based on QUALICOAT 14th edition: the foaming level is based on ISO 4628-2: ≤ 2(S2); Maximum penetration length: ≤1mm.

(3) Resistance to SO ₂ test

Test according to DIN EN ISO 3231, test equipment A-SC KBG 400 Co.Liebsche, test duration 24cycles, technical requirements according to QUALICOAT 14th edition: no discoloration or foaming according to ISO 4628-2: ≤2(S2); The maximum penetration length of a single grid: ≤1mm.

(4) Filiform corrosion test

The test is based on DIN EN ISO 4623-2:2004, the test equipment Climate Chamber Co Binder, the test time is 1000 hours, the technical requirements are based on the QUALICOAT 14 edition: the maximum length of filamentous corrosion: L≤4mm, the average length of filamentous corrosion: M≤2mm , the number of filiform corrosion: N≤20/10cm.

(5) Other routine tests are performed in accordance with Quolicoat-2017 or GB5237.5-2018

The test results of Examples 1-5 and Comparative Example 1 are shown in Tables 1-4 and Figures 4-5.

Table 1 Results of acid salt spray test

Table 2 Test results of constant temperature condensate water

group Film thickness/μm Foaming grade Single maximum penetration length/mm Example 1 53 <2 (S2) 0 Example 2 71 <2 (S2) 0 Example 3 59 <2 (S2) 0 Example 4 68 <2 (S2) 0 Example 5 57 <2 (S2) 0 Comparative Example 1 62 >2 3

Table 3 Test results of resistance to SO ₂

group Discoloration or blistering grade Single maximum penetration length/mm Example 1 0(S0) 0 Example 2 0(S0) 0 Example 3 0(S0) 0 Example 4 0(S0) 0 Example 5 0(S0) 0 Comparative Example 1 0(S0) 1

Table 4 Filiform corrosion test results

It can be seen from Table 1-4 and Figure 4-5 that the fluorocarbon powder based on FEVE resin was coated on the surface of the silicon-aluminum composite film prepared in Example 1-5 of the present invention by electrostatic spraying, and acetic acid was applied to it. Salt spray, filiform corrosion, constant temperature condensate and sulfur dioxide resistance tests, and also carried out conventional high pressure boiling water, boiling water adhesion, cupping and impact resistance tests for Example 5, and the results fully met the relevant standards (Quolicoat-2017 and GB5237.5-2018), indicating that the honeycomb silicon-aluminum composite film prepared by the present invention has excellent compatibility with the fluorocarbon powder of FEVE resin, while the existing chromium-free pretreatment film on the surface of aluminum alloy is compatible with FEVE. Fluorocarbon powders for resins are not compatible. Therefore, the present invention provides a brand-new green solution for replacing fluorocarbon paint with fluorocarbon powder, preventing volatilization of organic solvents from the source, and reducing VOC emission, and has broad application prospects.

The present invention has been further described above with the help of specific embodiments, but it should be understood that the specific description herein should not be construed as a limitation on the spirit and scope of the present invention. Various modifications made by the embodiments all belong to the protection scope of the present invention.

Claims (10)

1. a preparation method of a honeycomb Si-Al composite film compatible with FEVE resin, is characterized in that, comprises the following steps: (1) Mix the silicon source, aluminum source, mineralizer, organic solvent and water, and stir at room temperature until a gelatinous substance appears, then transfer to a bath for aging, and then quickly transfer to a PTFE-lined stainless steel The crystallization reaction is carried out in the reaction kettle, and after the crystallization reaction is completed, the product is filtered, washed and dried to obtain two-dimensional silicon-alumina nanosheets; (2) dissolving the two-dimensional silicon-alumina nanosheets obtained in step (1) in an organic solvent, and performing centrifugation; (3) take the supernatant liquid after centrifugation in step (2) and coat it on the surface of the aluminum test piece, or soak the aluminum test piece in the supernatant liquid after centrifugation in step (2), and then dry it naturally or heat it dry, The Si-Al composite film with honeycomb microstructure was obtained. 2. the preparation method of the honeycomb Si-Al composite film compatible with FEVE resin according to claim 1, is characterized in that, the mol ratio of described silicon source, aluminium source, mineralizer, organic solvent and water is ( 6-10):1:(0.2-1.2):(18-30):(200-400). 3 . The preparation method of a honeycomb Si-Al composite film compatible with FEVE resin according to claim 1 , wherein in step (1), the aging reaction temperature is 50-80° C., and the reaction time is 6-10 h. 4 . 4 . The preparation method of a honeycomb Si-Al composite film compatible with FEVE resin according to claim 1 , wherein in step (1), the crystallization reaction temperature is 100-200° C., and the crystallization time is 96-240 h. 5 . 5. the preparation method of the honeycomb Si-Al composite membrane compatible with FEVE resin according to claim 1, is characterized in that, in step (2), centrifugal treatment rotating speed is 5000-8000r/min, and centrifugation time is 15-30min . 6. the preparation method of the honeycomb Si-Al composite film compatible with FEVE resin according to claim 1, is characterized in that, described silicon source is any one in tetraethyl orthosilicate, silica sol, sodium silicate kind. 7. the preparation method of the honeycomb Si-Al composite membrane compatible with FEVE resin according to claim 1, is characterized in that, described aluminium source is sodium metaaluminate, aluminium nitrate nonahydrate, aluminium phosphate, aluminium sulfate, Any of aluminum isopropoxide. 8 . The preparation method of a honeycomb Si-Al composite film compatible with FEVE resin according to claim 1 , wherein the mineralizer is one of inorganic alkali or fluoride. 9 . 9. the preparation method of the honeycomb Si-Al composite film compatible with FEVE resin according to claim 1, is characterized in that, before step (3) covers the supernatant liquid on the aluminum surface, also comprises polishing the aluminum surface , Degreasing pretreatment process. 10. A honeycomb Si-Al composite film compatible with FEVE resin, characterized in that, it is prepared by the preparation method according to any one of claims 1 to 9, and is compatible with fluorocarbon powder based on FEVE resin and then coated The layer is resistant to acetic acid salt spray for 2000 hours, and after 1000 hours of filiform corrosion, the filiform corrosion is 0.