A COATING WITH LOW HEAT TRANSMISSION COEFFICIENT,

WATER CLOSET SEAT COMPRISING THIS COATING AND A METHOD FOR APPLYING THIS COATING TO THE WATER CLOSET SEAT

Subject of the Invention

The invention discloses a coating material with low heat transmission coefficient and high mechanical strength; water closet seat coated with this coating material and the method for applying said coating to the water closet seats. Present state of the Art

The fact that the water closet seats give a cold feeling especially in the winter months disturbs the users. Water closet seats used today, which are made of urea formaldehyde, cause the user to get a cold feeling from the surface upon contacting therewith as urea formaldehyde has a high heat transmission coefficient. As the materials with high heat transmission coefficient rapidly transmit heat, the water closet seats produced with the materials having high heat transmission coefficient rapidly transmit the body heat of the user onto the surface of the water closet. Therefore, as the body heat is rapidly transmitted onto the surface of the water closet when the users touch these water closet seats, they feel the cold in their body. Especially during the winter months, this feeling of cold disturbs the users much more. For these reasons, the feeling of cold in the water closet seats is one of the most complained issues in the user surveys.

Several solutions have been produced for eliminating this problem in the present state of the art. Use of systems with electric resistance is one of these solutions. However, the use of electric resistances is not adequate for eliminating said problem as there is no electric connection in the section of the constructions where water closet is connected and the users do not prefer high-voltage products in the bath.

The invention No. JP2013066595 (A), titled "Warm toilet seat" can be given as an example to the present state of the art. The invention given as an example contains a toilet seat having a seating surface and a transparent seat heater disposed on the seating surface. In said invention, with the use of a heater apparatus on the seating surface, the user gets a warm feeling from the toilet seating surface.

Again the invention No. JP2004216076 (A), titled "Human body heating apparatus" can be given as an example to the present state of the art. In the invention given as an example, a warm feeling is provided for the user by sending hot air to the buttocks and waist of said user using the toilet seat. In this invention, a hot air generating device and ports providing hot air transmission are provided. However, an electrical connection is required for the operation of the invention given as an example. Thus, the invention given as an example is totally different from the invention according to the application. The patent No. TR 2007/03325, titled "Bidet water and toilet seat heating system" can be given as an example to the present state of the art. With the invention given as an example, the current central heating system is utilized for heating the toilet seat and the water flowing through the bidet nozzle of the flush toilet and it is aimed to heat the bidet water and the toilet seat by connecting the coils to the system. As seen with the invention given as an example, in order to provide heating of the toilet seat a method different from the invention according to the application is utilized. However, the invention given as an example is disadvantageous because central heating system is required to be installed in the area where the toilet is present. For these reasons, the invention according to the application is different from the invention given as an example. In the invention according to the application, however, instead of the warm feeling of the water closet seat surfaces felt by the users by active heating, the water closet seats are produced by using materials with low heat transmission coefficient and therefore, body temperature of the user is slowly transmitted onto the surface of the water closet seat when contacting with the water closet seat, and it is ensured that the user gets a warm feeling from the surface. As the materials with low heat transmission coefficient transmit the heat slowly, body heat of the users are transmitted from the water closet seat to the surface of the water closet very slowly. Thus, users get a warm feeling from the surface of the water closet. Thanks to the method developed within the scope of the invention and the water closets produced with this method, the safety problems existing in the current heated systems are eliminated. Object of the Invention

The object of the invention is to develop a coating with low heat transmission coefficient which eliminates the feeling of cold disturbing the users when contacting with the water closet seats and a method for applying this coating to the present water closet seats. Detailed Description of the Invention

The invention discloses a coating material with low heat transmission coefficient and high mechanical strength; water closet seat coated with this coating material and the method for applying said coating to the water closet seats.

Aerogels are very light and solid materials having a gel structure which are obtained by changing the liquid structure of gel with gas. Aerogel used in many technologies has a sponge-like structure, but pore sizes thereof are in nano-meter level. Aerogel has much more superior characteristics than the known foams and other insulation materials. High porous nature of the aerogel having many areas of use provides a very large surface coating per unit weight. Therefore, in the invention according to the application, aerogel is used in the water closet seats as a material having low heat transmission coefficient. In the scope of the invention, preferably resorcinol formaldehyde aerogel is used. Resorcinol formaldehyde aerogels desired to be used are synthetized with sol-gel method. For the synthesis first, sol is prepared by mixing resorcinol formaldehyde, catalyst and water in appropriate amounts. The method is explained in detail below.

Resorcinol formaldehyde aerogels (RFA) are synthesized using sol-gel method. The preparation of RFA can be divided into four main steps; Polymerization, Aging, Solvent Exchange and Drying. The aim of the first part of the synthesis is to prepare the resorcinol formaldehyde gel. First resorcinol is dissolved in an appropriate solvent which is commonly water; however organic compounds such as methanol, ethanol or acetone can also be used. Resorcinol is a phenolic tri-functional compound, which is capable of adding formaldehyde in its aromatic ring. In order to activate the aromatic ring of resorcinol, a catalyst usage is required. For that usually a basic catalyst, sodium carbonate ( a ₂ C0 ₃ ) is used. When resorcinol and Na ₂ C0 ₃ are mixed in water medium, resorcinol is deprotonated as shown in Figure 1. With the deprotonation resorcinol becomes reactive towards formaldehyde. Once the formaldehyde is added in to the mixture, a reaction occurs and it leads to the formation of hydroxyl methyl derivatives (-CH ₂ OH) in the ring. The base catalyst further cause the deprotonation of the hydroxyl methylated resorcinol and it leads to very reactive intermediate. Then through the reactions shown in the Figure 2, methylene (-CH ₂ -) and methylene ether (-CH ₂ OCH ₂ -) bridges are formed. With the formation of these bridges, polymer clusters starts to aggregate together. Thus this leads to condensation and formation of the gel. This process is called the polymerization part of the sol-gel process. After this reaction, the container of the reactants are sealed and placed in oven for several days. With the help of the heat provided by the oven, polymerization reaction rate is fastened and completed in several days. This step is usually called the aging step.

Figure 1: RFA synthesis, primary reaction

Figure 2: RFA synthesis secondary part of the polymerization reaction The concentration of the reactants and the amount of solvent used during the synthesis has an effect on the structure of the RFA. 1:2 molar ratio of resorcinol and formaldehyde is used in the reaction based on the stoichiometry of the reaction which is shown in the figure 1. Using excess formaldehyde would lead to occurrence of a dilution effect which causes the particle size to increase. By manipulating the molar ratios of resorcinol (R) to water (W) and resorcinol (R) to catalyst (C), it is possible to obtain aerogels with different densities, pore diameters, porosities and surface areas. Changing these structural properties of the aerogel will lead to a change in the heat capacity and thermal conductivity of the aerogel. Below in table 1, two different synthesis recipes are presented. The change of the physical properties with the change of the reactant conditions can be seen in this table. Both recipe can be used in formation of aerogel.

Table 1: Different synthesis routes ofRF gels

Once the gels are obtained, their pores are filled with water since the water is used as the reaction medium. In order to obtain an aerogel form a gel, the liquid in the pores of the gel must be removed without causing the collapse of the pores. This could be achieved by a process called supercritical drying. Most commonly carbon dioxide is used for supercritical drying. Since the solubility of water is very low in supercritical carbon dioxide, the water in the pores of RF gel is replaced by a liquid which has a high solubility in supercritical C0 ₂ . This step is called solvent exchange step and water is usually replaced with acetone. Once the pores of the gels are filled with acetone, supercritical drying is performed to replace the acetone in the pores with air. At the end of the supercritical drying process, resorcinol formaldehyde aerogel is obtained.

Aerogel is obtained on water closet seat surface in the form of a layer by means of the method developed within the scope of the invention.

In the method developed within the scope of the invention, first so as to provide the gel, which will be formed, to be attached to the surface, water closet seat surface is treated with the chemical groups such as peroxide or acids which can react with resorcinol formaldehyde. Nitric acid solution or hydrogen peroxide solution can be preferred. The prepared aerogel coating solution composition is applied to the surface ready for coating by means of spraying or immersing. Coating solution is preferably added when the solution is close to its gel state and about to gel. After the coating solution is applied to the surface, gelation occurs and aging process is performed. Solvent removal process is then performed so as to obtain the final aerogel coating on the water closet seat surface. For solvent removal process, any one of the methods including heat treatment, supercritical method, drying under room conditions, and vacuum freeze drying methods can be used. Supercritical method is performed after solvent exchange process in which a solvent which will not dissolve the material of closet seat should be used. To give an example; methanol may be one of these solvents and can be used preferably. With the application of the resorcinol formaldehyde aerogel coating solution prepared by sol-gel method to the surface of the water closet seats, feeling of cold disturbing the users is avoided and warm feeling is provided when the surfaces of the water closet seats are contacted.