LT6291B - A method of polymeric material surface protection using nanocrystalline oxide coatings - Google Patents

Abstract

The invention describes a method of polymeric material protection using nanocrystalline coatings. The coatings are deposited on pre-formed EPS foam product surfaces by using plasma activation, magnetron sputtering and surface layer oxidation in plasma technologies. Deposited coatings provide improved resistance to direct fire exposure and self cleaning properties. The deposited coatings are hydrophobic. In order to obtain hydrophilic coatings Si or Ti or Si/Ti clusters are deposited on the surface and then fully oxidised in oxygen plasma.

Description

FIELD OF THE INVENTION The invention relates to nanocrystalline thin-layer oxide coatings for polymeric materials (including polystyrene foam (EPS)) for the protection of surfaces against external influences and performance.

TECHNICAL LEVEL

Polymeric materials (EPS) formed on the surface of nanoparticles can change certain surface properties. These properties are usually changed to improve the material's resistance to flame, antibacterial properties, hardness, wear resistance, and appearance change, etc. At the moment, the main ways of nanoparticle formation on polymer materials exist in the world:

Spraying. The most widespread mode of exposure to polymer materials worldwide. Its prevalence is due to the fact that this method is very simple, fast, cheap. This method is mainly used to improve the fire resistance of the polymeric materials, hardness, antibacterial (using T1O2) and other properties. Using this method, the surface of the polymeric materials is usually cleaned and "rolled" to increase the adhesion of the spray materials to the surface of the polymeric materials. Various solvents are used for this, which may in some cases affect the volume of polymeric materials. The main disadvantage of this method is that it is very difficult to cover the surface with the desired thickness (the spray compound is usually unevenly distributed on the surface of the coating) (V. Loddo, G. Marei, G. Palmisano, S. Yurdakal, M. Brazzoli, L. Garavaglia, L Palmisano "Extruded expanded polystyrene sheets coated with T1O2 as new photocatalytic materials for food packaging", Applied Surface Science, Italy, 2012, L. Garavaglia, M. Brazolli "Titanium dioxide-coated expanded polymer sheet with photocatalytic activity, Container and packaging for foodstuffs obtained from such a polymer sheet, EP2418238 A1, 2012; http://eoncoat.com/blog/index.php/2012/12/coating-fire- protection-expanded-polystyrene-foam /).

Electrochemical sol-gel method. Using this method, the EPS is dipped into an ultrasonic bath with special chemicals needed for surface cleaning of polymeric materials. The coatings are formed on the surface of polymeric materials using an electrochemical sol-gel method. Usually this method is used

Si / SiC> 2 coatings on the surface of polymeric materials. For example, EPS with such coatings can be used in catalytic processes, sensors, electronic or optical devices. The main disadvantage of this method is that the surface treatment of polymeric materials has the potential effect on the entire polymeric material structure. Although this method has great potential, it is still in the scientific research phase (X. Wang, R. Xiong, G. Wei, "Preparation of mesoporous silica thin films on polystyrene substrate by electrochemically induced sol-gel techniques", Surface & Coatings Technology, China, 2010).

Magnetic Shot. By forming the coatings on the foam surface, the nanoparticles are deposited from the vapor phase by forming the coating. Using this method, the surface of polymeric materials is activated in the plasma of oxygen prior to the precipitation process. This process is used for surface cleaning of polymeric materials and for better surface adhesion. The advantage of plasma activation against standard chemical methods of surface cleaning of EPAs is that the cleaning of the surface in this way has no effect on the bulk properties of the polymeric materials. Numerous studies have shown that such a method is suitable for the activation of polymeric materials (J. Larrieu, B. Held, H. Martinez, Y. Tison, "Aging of atactic and isotactic polystyrene thin films treated by oxygen pulsed plasma", Surface & Coatings Technology, France, 2004). The other part of the process is magnetron deposition. By forming coatings using this method, the surface of the polymeric materials begins to heat up. For this reason, there is a need for technological solutions to reduce the temperature of polymeric materials (B. Feddes, JGC Volke JA Jansen, AM Vredenberg "Initial deposition of calcium phosphate ceramic, polystyrene and polytetrafluoroethylene by rf magnetron sputtering deposition", Journal of Vacuum Science & Technology, 2003 ; Ch. Anders "Hydrophilic coating of surfaces of polymeric substrates", US005871823A, 1997).

In addition to these methods, there are other methods of surface coating of polymeric materials: latex coating, coating and subsequent emulsion painting, diving into a liquid coating, and the like. (A. Dubey, Y. Peng "Polystyrene foam products with improved adhesion and vvater resistance, and methods of making the sham", CA2843860 A1, 2014; RA Nonvveiler "Method of producing an expanded polystyrene foam having a dense surface", US3309439 A1 , 1964). However, these methods are scarce or uneconomical. Due to poor surface adhesion of polymeric materials, surface treatment of polymeric materials is always required. In most cases, the primary treatment of polymeric materials can affect the entire polymeric material structure. When used for plasma activation, this problem is solved and the effect is only on the surface layer of polymeric materials. OBJECTIVE OF THE INVENTION The object of the present invention is to provide a novel technological solution for protecting polymeric surfaces (EPS) from external influences (direct flame, moisture, microorganism, etc.) using SiO2, TiO2 and combined SiO2 TiO2 nanocrystalline thin coatings obtained from reactive magnetron evaporation. way. The present invention combines surface energy conversion by activation in low temperature (TJ0u ^ 105 K) plasma to improve adhesion of the oxide coatings to the surface to be coated, and to obtain thin oxide coatings in a reactive Ar + 02 gas environment.

DESCRIPTION OF DRAWING DRAWINGS

The invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 provides a general overview of the patent process;

FIG. Figure 2 shows an activation and coating synthesis camera;

FIG. Figure 3 shows a cathode with additives from another material. DESCRIPTION OF THE INVENTION The inventive concept algorithm is shown in FIG. 1. Detailed Description:

We take polymeric (EPS) samples and place in a vacuum chamber (Fig. 2) and perform surface activation. Pressure during activation is 1-10x10'2 mbar. The DC power supply is best suited for activation. The plasma-generating electrode must be at a distance of 3-8 cm from the activated sample, then the power of the pulsed DC plasma source operating in the range of 2 kHz to 20 kHz per 0.2-1 W / cm2 of the respective electrode area. Activation time 20-60 seconds.

Activated specimens shall not be withdrawn from the chamber and the chamber shall be aspirated to a pressure of not more than 7 "10 ″ 4 mbar. After suction, the Ar: 02 gas mixture is fed into the chamber at a ratio of 70 ± 10: 30 ± 10. DC or pulsed DC or RF sources may be used to power the magnetron. The power of the magnetron working surface can vary between 1-3 W / cm2. The distance between the specimen and the substrate depends on the material to be coated: the lower the melting point, the greater the distance, and vice versa. hydrophobic.

If hydrophilic coatings are to be obtained, at the end of the evaporation, the oxygen supply must be completely interrupted and the metal / semiconductor coatings evaporated for 5 seconds. Then turn off the magnetron, interrupt Is feeding, deliver oxygen and initiate RF low temperature plasma in an oxygen environment for 10-30 minutes. as in the case of activation. The metal or semiconductor clusters in the surface layer of the resulting coating will be completely oxidized and removed from the vacuum chamber coating to be hydrophilic.

The combined SiO 2 / TiO 2 coatings can be obtained by using one (Si or Ti) magnetron on which the particles of another material (Ti or Si) are added as shown in FIG. 3. In this way, the use of two magnetrons can be avoided and the TiO2-SiO2 composite coatings obtained.

If it is necessary to arrange continuous production, the main chamber of the existing sluice magnetron evaporation system in which the evaporation is carried out is required, as shown in FIG. 2, and use the technological sequence set forth in points 1 to 3. Activation can be done in a separate camera in both the lock and independent camera. The activated samples remain active for up to 5 days at room temperature and relative humidity of up to 55%.

Claims (2)

DEFINITION DEFINITION A method for protecting surface materials of polymeric materials (EPS) using nanocrystalline oxide coatings, comprising activating EPS surfaces in plasma and subsequently applying nanocrystalline oxide-based coatings to activated surfaces, characterized in that (a) RF or 2 is activated on the surface of the EPS prior to application; -20 kHz pulsed DC or DC power source generated at low temperature (TJu ^ 105 K) plasma, maintaining a pressure of 2-9x10'2 mbar and a distance of 3-8 cm between the sample and the plasma-generating electrode for 20-60 seconds. Area power - 0.2-1 W / cm2; (b) applying a continuous coating of oxide-based (S1O2 or T1O2 or SiO2 / TiO2) coatings on non-EPS beads which are subsequently fused, but on the surface of the already melted expanded polystyrene or one of its copolymer beads; (c) uses a magnetron evaporation method in a reactive Ar: 02 environment for the application with a Ar: 02 gas mixture ratio of 70 ± 10: 30 ± 10, a magnet or DC or RF source for magnetron power supply to maintain the power of the magnetron working surface area between 1 -3 W / cm 2; (d) using hydrophobic nanocrystalline oxide coatings on the surface of the EPS using the reactive magnetron evaporation techniques - DC, pulsed DC, RF, to enhance EPA resistance to direct flame exposure and self-cleaning properties; (e) by using processes for oxidation of metals / semiconductor clusters in plasma, completely stops oxygen supply at the end of evaporation and further evaporates metal / semiconductor coatings for 5 s, then disables magnetron, interrupts or feeds, feeds oxygen and initiates RF low temperature (TJ010 K) plasma in an oxygen environment for 10 to 30 minutes, thereby completely oxidizing the clusters of metals or semiconductors in the surface layer of the resulting coating and producing hydrophilic coatings.