Example 1: ceramic coating
The coating is prepared by dispersing silicon carbide, silicon tetrachloride or their mixture in a solution composed of polysilazane and aromatic solvent. The coating can provide protective ceramic coating for carbon / carbon composites, graphite and other carbon containing materials. For example, grind the graphite test piece with the size of 3.8 cm × 2.5 cm × 0.5 cm to a smooth surface, clean and dry in vacuum, brush and dry it with the paint fully, dry it for 5 min at 100 ℃, heat it to 150 ℃ at the rate of about 10 ℃ / min, keep it at 150 ℃ for 15-30 min, and then let it cool to room temperature. Then brush another layer of the coating on the test piece, heat it to about 175-186 ℃, keep it at this temperature for at least 15 minutes, cool it, and the thickness of the coating is about 0.08-0.10 mm. The coating sample was heated to 650-700 ℃ and kept at this temperature for 15-30 minutes, then cooled to room temperature, so that the coating could be pyrolyzed into ceramic coating. The effectiveness of the ceramic coating in protecting the graphite surface from thermal degradation can be proved by the following tests: heating the painted specimen in air to 600 ℃ for 1 h, and calculating the number of dents on the surface. The average number of dents per square inch of three painted specimens is only 8-86, but the unpainted graphite test The average number of dents per square inch is 590 ~ 630.

Example 2: antirust coating
The deep drawing steel plate was immersed in 20% concentration of total hydrogen polysiloxane (number average molecular weight is 150-150000) solution for coating, deep drawing was carried out in the air at a rate of 0.3 M / min, dried at room temperature for about 30 min, and then the painted steel plate was placed in an air furnace at 700 ℃ for 10 h, with a heating and cooling rate of 3 ℃ / min. The results show that there is no oxide layer or rust on the coated steel plate.

Example 3: automobile body and hub coating
The coating is made of a total hydrogen polysiloxane or an organic polysiloxane with a molecular weight of 150-150 000. The coating formulation is 35% ~ 40% polysilazane, 0.5% ~ 1% polyacrylate and less than 2.0% flow control additive, and the solvent is butyl acetate. Spray on aluminum parts with spray gun, and the top coat shall be acrylic powder coating or solvent type or water-based varnish. Bake the aluminum piece at 170 ℃ for 20 min. The thickness of the coating is 5 μ m and the surface roughness is 0.09 μ M.

Brake dust test: suspend the brake dust in water, then apply it on the sample plate, store the sample plate at 160 ℃ for 2 hours, wash it with water, wipe it gently, and then evaluate it. The evaluation value is level 1. It can be seen that the coating can prevent the "contamination" of brake powder, has good scratch resistance and corrosion resistance, and its water contact angle is 108 °.

Example 4: coating for metal strip
The polysilazane used are organopolysilazane and polysiloxane, with the average number and molecular weight of 150-150000. The coating can be used for aluminum, zinc and other metal strips. The coating has good acid resistance, alkali resistance, solvent resistance, acid rain resistance, bird contamination resistance and weather resistance. For example, immerse 0.5mm thick aluminum plate in 20% concentration of total hydrogen polysiloxane solution, then exit at 120 cm / min, then preheat to 250 ℃ in forced air drying furnace, and keep at this temperature for 60 s, after cooling, form a clear, transparent and crack free coating. The scratch resistance of the coating was tested first, i.e. the coating was wiped back 5 times with a force of 3N with grade 00 steel wool. The scratch resistance of the coating was very good. After 25 cycles of exposure test, there is no white rust on the coating, and its adhesion (DIN EN ISO 2409-2013) is grade 0.

Example 5: used as permanent anti fingerprint coating
The polysilazane used is a kind of all hydrogen polysilazane, the average molecular weight is 150-150 000, using di-n-butyl ether as solvent and palladium propionate with mass fraction (based on all hydrogen polysilazane) of 0.75% as catalyst, a 20% concentration of all hydrogen polysilazane solution is prepared, which is sprayed on a wire drawing stainless steel (3 cm × 3 cm), ventilated at room temperature for 10 minutes, and then dried After heat treatment (130 ℃, 1H) in the drying box, the film was cured. The thickness of the coating was 2.1 μ M. The coating can also be used for chrome plated plastic substrate, and its coating adhesion (DIN EN ISO 2409-2013) is grade 0; fingerprint resistance performance evaluation is to add fingerprint on the paint substrate, and then wipe it with cotton cloth, and then visually evaluate the ability of fingerprint removal. The results show that the fingerprints on the substrate coated with the coating can be easily removed completely, while the fingerprints on the same substrate without coating can not be removed completely no matter how much force is used. The long-term test of fingerprint resistance also shows that the coating can obtain satisfactory results. The test method is to store the coated substrate and uncoated substrate with fingerprints at room temperature for two weeks, and then wipe the coated and uncoated surfaces with isopropanol respectively to remove the fingerprints left on the surface. As a result, the fingerprints on the coated surface can be easily removed completely, while the fingerprints on the uncoated substrate are still visible. Visible.

Example 6: preparation of hydrophilic coating
The polycarbonate plate (10 cm × 10 cm) was immersed in the solution of n-dibutyl ether with the concentration of 20% of the total hydropolysiloxane by the immersion device with the step motor speed of 20 cm / min. after staying for 10 s, it was withdrawn from the solution at the speed of 20 cm / min, let it drip for a short time, then exposed to air for 10 min, and then immersed in the aqueous solution of BYK lpn-6640 (10% concentration)（ The original solution is 40% and diluted with 3:1 water. After being placed in the solution for 24 hours, the coating is washed with water. The contact angle between the coating and water is determined to be below 10 °. The hydrophilic coating for stainless steel can also be made by the same method, and the contact angle of water is also below 10 °.

Example 7: low oxygen permeability coating
The polyester film sheet with a thickness of 23 μ m was immersed in 5% pdsi-n-alkane solution (the solvent is xylene or di-n-butyl) at a rate of 3 M / min with a deflection roller. In this process, only the front of the membrane is in contact with the total hydrogen polysiloxane solution, and the back of the membrane is covered by a deflection roller. Then, the membrane coated with the film is heated to 60 ℃ for 12 seconds through an infrared drying channel with a length of 60 cm, and the coating is clear and transparent. The results show that the oxygen permeability of the coated membrane is 14 ml / (DM2 · bar), while that of the uncoated membrane is 85 ml / (DM2 · bar).

Example 8: antifouling coating
The coating composed of aromatic hydrocarbon (petroleum solvent oil, paraffin solvent, or alicyclic solvent) solution of 0.5% ~ 10% polysilazane and 4,4 ′ - trimethylene-di (1-methylpiperidine) catalyst (the dosage is less than 0.2%) is applied on the car body, wheel hub, denture, stele and the interior and exterior wall of the house to form a dense and hard coating with long-term, hydrophilic and antifouling properties Effect. The coating can also be used in washrooms, kitchens, washrooms, bathtubs and other places, as well as on signboards, plastic products and glass products, with the effect of stain resistance.

Example 9: anti graffiti coating
Polysilazane coating has high crosslinking density and low surface energy (105 Mn / M), high hardness, good scratch resistance, chemical resistance and corrosion resistance, and can be used in high temperature environment above 600 ℃. Therefore, the coating can especially resist the penetration of ink and color, prevent graffiti and scribble, and is very easy to clean. It can be used in buildings and public transport vehicles. At present, it has been transported by railway in Europe The transmission system is used.

Example 10: heat resistant coating
The heat resistant coating containing polysilazane is a one component coating