SU763002A1 - Method of obtaining polymer coating - Google Patents

Description

one

The invention relates to the field of zeidite structural materials against corrosion damage and can be used to increase the adhesion of 5 protective polymer coatings to the substrate when applied to the inner and outer surfaces of parts made of heat-resistant materials.

In modern technology, JQ does not apply protective polymeric coatings to increase the adhesive strength of a polymer film to a substrate. Special preparation of the substrate surface is used, the introduction of fillers into the polymer film, and chemical treatment of the polymer film before gluing it to the substrate.

The known methods of increasing the adhesion bond of a polymer film to a JQ substrate are not universal, since they do not ensure the contact of the coating over the entire surface due to the roughness of the substrate.

A known method for producing a coating, creating an adhesive bond between a polymer film and a substrate when applying coatings to sheet material, containers and pipes and concludes in vacuumizing the gap between the metal to be protected and the polymer film, pressing the film under atmospheric pressure to the metal and heating the part to adhere the polymer film to the metal 1.

However, the method involves the use of only film materials, which makes it difficult to use to create an adhesive bond with the surface of parts of complex geometric shape and a polymer film. The use of powdered polymeric materials in this method is completely excluded.

The closest known method is to obtain a polymer coating by applying powdered polytrifluoroethylene to Podilska, followed by heat treatment 2.

However, in the case of using fluoropolymers, the adhesion of the coating to the substrate is low.

The purpose of the invention is to increase the adhesion of the coating to the substrate.

Claims (2)

The goal is achieved by the fact that in the method of obtaining a polymer coating, which includes applying polytrifluoroethylene powder and heat treatment to the substrate, the coated substrate is evacuated and heat treatment is carried out at 2 ° C to 275 ° C before melting the powder, is pressurized with hot air at the specified temperature under excessive pressure 1.5-2 kgf / cm for 1520 minutes The production of polymer coatings can be carried out on parts of complex geometric shape. Polymer powder is deposited on a part using any of the known methods. The part with the precipitated polymer powder is placed in a vacuum device, from which air is pumped out with a vacuum pump. The part is then heated to the melting temperature of the polymer and at this temperature is kept for a certain time in a vacuum device. The holding time of the part is determined by the ability of the polymer particles to melt and form a continuous film and the holding time is determined experimentally. Under the influence of temperature, the polymer particles transfer into a flowing state and form a continuous film on the surface of the part. However, for polymers, only partially filling the hollows of the rough surface of the substrate is characteristic. After the polymer powder is melted, hot air is supplied to the vacuum device under pressure. Hot air is induced by the need to maintain the polymer film in the flowing state until the end of the process of forming the adhesive bond between the coating and the surface of the part. Under the action of air pressure, the polymer melt material deforms and flows into all irregularities of the rough surface of the substrate, which contributes to a significant increase in the adhesion of the coating compared to the coating in a known manner. Example. A protective coating on the basis of polytrifluorochloroethylene is applied to various mg-sized parts of complex geometric shape. Porsnits polymer is deposited on the part in an electrostatic field with a voltage of 2 kV / cm The parts are placed in a vacuum device, air is pumped out from it to a pressure of 10 mm Hg, the parts are heated to 270 + and kept at this temperature for 30 minutes. After this, a vacuum device is pressurized with hot air having a temperature close to 270 ° C. Details with an overpressure of 1.52 kgf / cm are kept in the chamber for another 15-20 minutes. After that, the fluoroplastic coating is quenched in water. The adhesion of the coating thus obtained is 25-30% higher compared to the coating applied in a known manner and is 2700 g / mm. The method of obtaining a polymer coating by applying powdered polytrifluoroethylene and heat treatment to a substrate, characterized in that, in order to increase the adhesion of the coating to the substrate, the latter with applied polytrifluoroethylene is evacuated and the heat treatment is carried out at 260-275 ° C until the spray melts then pressurized with hot air with the specified temperature at an overpressure of 1.5-2 kgf / cm for 15-20 minutes. Sources of information taken into account in the examination 1. US patent 3,929,537, cl. 156-86, pub. 12/30/75. 2. USSR author's certificate number 495217, cl. B 05 D 3/00, 08.29.73 (prototype).