Patent Application
20240050932
The present invention relates to a coating composition, a coating and methods of forming the same.
Polysilazane has been widely used for its excellent performance in chemical resistance, higher temperature resistance, hydrophobic properties, and surface hardness. Polysilazanes are thermosetting resin and can be conveniently cured in ambient condition. It can be applied to surface by using conventional solvent-born coating technique such as spray, spin, wipe and dip coating. The cured polysilazne coating may have a thickness of 1-10 μm, and it adheres to the surface via covalence bond. Because of these advantages, polysilazane has been emerged as a leading surface protection coating. There are two types of polysilazane: the in-organic perhydro-polysilazne (PHPS) and the organic polysilazane (OPSZ). For general application, a mixture of PHPS and OPSZ, with suitable composition, is typically used.
Despite these key advantages, the thin polysilazane coating is incapable of providing electrical insulation. In addition, like any other metal or polymer surfaces, a polysilazane coated surface is also subjected to microbial contamination, especially communal and regularly contacted surfaces. Communal surface, or regularly or commonly contacted surface, is contaminated with all kinds of microbial. Such microbial can stay alive and active on the surface up to several hours. It is thus a common source for the spread of the virus during a pandemic. To a certain extent, such contamination aggregates to the spread of virus during a pandemic. The common virus includes influenza A/WSN/33 (H1N1), influenza B/70555, Entero enterovirus 71/4643 (hand-foot-mouth dieses), Covid-19, etc.
Metal, such as copper and aluminium have been known to be a good electrical conductor. Wires and strips made from such material are commonly used as electrical conductors and contacts in many electrical applications such as power generation, power transmission, power distribution, telecommunication, electronic circuitry, electronic appliances and equipment, etc.
Typically, the metal wire or strip is being insulated by a layer of PVC (polyvinyl chloride) or rubber. The layer of PVC or rubber is being coated onto the surface of the metal wire or strip. For electromagnetic applications such as transformers, inductors, motors, speakers, hard disk head actuators, electromagnets, etc, copper wires are insulated (also known as enameled) using a thin layer of polyvinyl formal (formvar), polyurethane, polyamide, polyester, polyester-polyimide, polyamide-polyimide (or amide-imide), and polyimide. For these insulated or enameled wires, the thin insulation layer is typically about 150-200 μm thick, and the operating temperature is typically up to 200° C. This is because the polymer insulation layer may melt at a temperature higher than 200° C. This temperature limitation essentially restricts the electrical load carrying capacity of the copper wire and thus limits the performance of the electromagnetic device.
Furthermore, due to the operating environment of the metal wire or strip, the coating has to be hard to withstand wear and tear and, at the same time, it has to be flexible to allow the copper wire or strip to be laid and be installed in tight-spaced casing of the device.
Therefore, in order to increase the electrical load carrying capacity of the metal wire or strip to improve the performance of the electromagnetic device, a coating that is able to withstand a higher melting temperature, e.g. higher than 200° C., and is able to electrically insulate the metal wire or strip is required. Furthermore, the coating should be relatively hard and yet flexible. In addition, preferably, the manufacturing cost of the metal wire or strip should be relatively low to make it affordable for the wire or strip to be commercially viable.
In addition to the above, it would be beneficial to develop a coating that is able to provide electrical insulation and the abovementioned properties.
Preferably, the coating may be an anti-microbial coating that is thin, durable, and applicable to both indoor and outdoor, and when applied onto these communal surface will help to eliminate or reduce the spread of virus during the pandemic.
According to various embodiments, a coating composition including polysilazane mixed in a suitable solvent, and nanoparticles dispersed therein is provided.
According to various embodiments, the coating composition may consist of polysilazane mixed in a suitable solvent, and nanoparticles dispersed therein
According to various embodiments, the polysilazane may include a mixture of perhydro-polysilazane and organic polysilazane.
According to various embodiments, the mass fraction between perhydro-polysilazane and organic polysilazane may be at least 1 to 10.
According to various embodiments, the mass fraction between perhydro-polysilazane and organic polysilazane may be not more than 1 to 3.
According to various embodiments, the weight percent of polysilazane may be any value selected from a range of about 1% to about 10% of the coating composition.
According to various embodiments, the weight percent of polysilazane may be any value selected from a range of about 2% to about 3% of the coating composition.
According to various embodiments, the nanoparticles may be Al2O3 nanoparticles.
According to various embodiments, the size of the Al2O3 nanoparticles may be any value selected from a range of about 1 nm to about 10 nm.
According to various embodiments, the size of the Al2O3 nanoparticles may be any value selected from a range of about 1 nm to about 5 nm.
According to various embodiments, the weight percent of the Al2O3 nanoparticles may be at least about 2% and not more than about 5% of the coating composition.
According to various embodiments, the weight percent of the Al2O3 nanoparticles may be 2% of the coating composition.
According to various embodiments, the nanoparticles may be TiO2 and Ag nanoparticles.
According to various embodiments, the size of the TiO2 and Ag nanoparticles may be any value selected from a range of about 1 nm to about 10 nm.
According to various embodiments, the size of the TiO2 and Ag nanoparticles may be any value selected from a range of about 1 nm to about 5 nm.
According to various embodiments, the weight percent of the TiO2 and Ag nanoparticles may be at least about 2% and not more than about 5% and at least about 0.1% and not more than about 1% of the coating composition respectively.
According to various embodiments, the solvent may be inert.
According to various embodiments, a method of forming a coating composition is provided. The method includes mixing polysilazane into a suitable solvent, and mixing nanoparticles into the solvent.
According to various embodiments, a method of forming a coating is provided. The method includes applying the abovementioned coating composition onto a substrate, and allowing the coating composition to cure to form the coating.
According to various embodiments, the coating composition may be cured at about 200° C.
According to various embodiments, a coating formed according to the abovemented method is provided.
According to various embodiments, a coating including polysilazane and nanoparticles dispersed therein is provided.
According to various embodiments, a coating consisting of polysilazane and nanoparticles dispersed therein is provided.
Polysilazane 110 may act as a binder to bind the nanoparticles 130. Polysilazane 110 may be composed of organic-polysilazane (OPSZ). Polysilazane 110 may be composed of perhydro-polysilazane (PHPS). Polysilazane 110 may be composed of perhydro-polysilazane and organic-polysilazane. The mass fraction between perhydro-polysilazane and organic polysilazane may be at least 1 to 10. Preferably, the mass fraction may not be more than 1 to 8. Preferably, the mass fraction may not be more than 1 to 5. Preferably, the mass fraction may not be more than 1 to 3.
Coating composition 100 may be composed of polysilazane 110, the nanoparticles 130, and a solvent 120. For example, the coating composition 100 may include a mixture of perhydro-polysilazane and organic-polysilazane in the solvent 120 with the nanoparticles 130 blended and dispersed therein. The weight percent (wt %) of the polysilazane 110 may be any value selected from the range of about 1% to about 10% of the coating composition 100, e.g. about 1% to about 8%, about 1% to 5%. Preferably, the weight percent of the polysilazane 110 may be any value selected from the range of about 2% to about 3% of the coating composition 100 so that the desired thickness of the cured coating may be achieved, e.g. between about 1 μm to about 5 μm. The solvent weight may be at least about 80% of the coating composition 100. Preferably, the solvent weight may be not more than about 99%. Solvent weight may be not more than 90%. Solvent 120 may be inert and may include, but not limited to, di-n-butyl ether, petroleum distillates, and/or alcohols.
Nanoparticles 130 may be Al2O3 nanoparticles. Coating of polysilazane 110 with Al2O3 nanoparticles dispersed therein has good electrical insulating property and is suitable for electrical insulation for wire and strips, etc. Nanoparticles 130 may be TiO2 and Ag nanoparticles. Coating of polysilazane 110 and TiO2 and Ag nanoparticles dispersed therein has anti-microbial property. Nanoparticles 130 may be of the size of any value selected from a range of about 1 nm to about 10 nm, e.g. 2 nm, 4 nm, 6 nm, 8 nm. Preferably, the size of the nanoparticles 130 may be selected from a range of about 1 nm to 8 nm. Preferably, the size of the nanoparticles 130 may be selected from a range of about 4 nm to 6 nm. Preferably, the size of the nanoparticles 130 may be in the range of 1-5 nm. At this range, it is possible to obtain the coating with a smooth surface. Coating composition 100 may consist of Al2O3 nanoparticles and TiO2 and Ag nanoparticles.
The weight percent of the Al2O3 nanoparticles may be at least about 2% and not more than about 5% of the coating composition 100, e.g. about 3% to about 4%. Preferably, the weight percent may be about 2% to achieve the desired effect. Coating may be of a thickness of any value selected between about 2 μm to about 10 μm. Coating with the Al2O3 nanoparticles may achieve a DC breakdown voltage of up to 40 MV/m. Coating with the Al2O3 nanoparticles may withstand a temperature of up to 500° C.
The weight percent of the TiO2 and Ag nanoparticles may be at least about 2% and not more than about 5% and at least about 0.1% and not more than about 1% of the coating composition 100 respectively. Preferably, the weight percent may be a value selected from a range of about 2% to about 3% to achieve the desired effect. Coating may be of a thickness of any value selected between 2 μm and 10 μm. Coating with TiO2 and Ag nanoparticles has photocatalytic characteristic under the UV and visible light respectively. Further, the coating is effective in eradicating virus and bacteria, thus achieving anti-microbial effect.
When the Al2O3 nanoparticles and TiO2 and Ag nanoparticles are mixed into the solvent, the abovementioned weight percent of the Al2O3 nanoparticles and TiO2 and Ag nanoparticles may be applicable.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/SG2020/050705 | 11/30/2020 | WO |
