Patent Publication Number: US-2006008589-A1

Title: Method of coating a photo-catalysis on a surface of a coated substrate

Description:
BACKGROUND OF THE INVENTION  
      1. Field of The Invention  
      The present invention relates to a method of coating a photo-catalyst on a surface of a substrate to be coated, and especially to a method of coating a photo-catalyst on a surface of a substrate to be coated at a normal temperature.  
      2. Description of the Related  
      According to the demonstration of technology, a nano-meter TiO 2  has a good absorbency about ultraviolet rays and a high photocatalysis activity. When the nano-meter TiO 2  is illuminated by ultraviolet rays with a wavelength less than 388 nm, the nanometer TiO 2  particles produce large photoelectrons (e−) and photoholes (h+) on a conduction band and a valence band, respectively. The photoelectrons (e−) and photoholes (h+) respectively react with oxygen and water molecule to form a hydroxyl radical for decomposing an organic pollutant to form carbon dioxide (CO 2 ) and water, reducing a heavy-metal ion, and serve as a photocatalytical antibacterial.  
      According to the characteristic of the TiO 2 , the material of TiO 2  can be used to clean an organic waste water and a fountainhead with like benzene, phenol, 12 alkyl benzene sulfonic acid sodium and monocrotophos, oxidize and decompose an organic chemical compound in a pipe network, and purge the water quality for health of human. Furthermore, the material of TiO 2  also can reduce a heavy-metal ion and adapt for photocatalysis antibacterial or increase the color on a ceramics and a glasses product.  
      Referring to  FIG. 1 , the prior art provide a method of coating a photo-catalyst on a surface of a substrate to be coated. The method comprises the steps of: cleaning dirt of the surface of the substrate to be coated by an alcohol or a cleanser, baking the surface of the substrate to be coated to form a dry and clean surface by a heat wind, pouring the colloid solution with 0.20%˜5% TiO 2  into a can of an airbrush, spraying the colloid solution with the TiO 2  on the surface of the substrate to be coated by a shape of micro-foam to form a photo-catalyst layer, wherein the mean diameter of the TiO 2  is about 7 nm, and baking the photo-catalyst layer by the hot wind above 500° C.  
      To sum up, the steps of the method comprises: 
          A. Cleaning the surface of the substrate to be coated;     B. Baking the surface of the substrate to be coated;     C. Spraying the colloid solution with the TiO 2  on the surface of the substrate to be coated by a shape of micro-foam to form a photo-catalyst layer; and     D. Baking the photo-catalyst layer by the hot wind above 500° C.        

      However, it has some defects according the method of prior art, including:  
      1. The content of the colloid solution with TiO 2  only has 0.20%˜5%, so a user must increase the spraying time to increase the TiO 2  content being coated on the substrate.  
      2. Baking the photo-catalyst layer by the hot wind above 500° C. is to increase one step for the method and not an applicable step to a heat-unresistant substrate.  
      3. Baking the photo-catalyst layer by the hot wind is to increase working equipments and working time, so that it also increases the cost.  
      With the employment of unique considerations and application of theories, and based on several years experience in specialized production of all flexible assembly systems and mechanisms, the inventor has come up with an innovative light-emitting diode chip package body.  
     SUMMARY OF THE INVENTION  
      The first object of the present invention is to provide a method of coating a photo-catalyst on a surface. The colloid solution with the TiO 2  has an adhesive for adhering on any substrate without the step of baking. So that the method of the present invention is adapted to a low melting point substrate.  
      The second object of the present invention is to provide a method of coating a photo-catalyst on a surface of. The method does not bake the photo-catalyst layer, so that it will reduce the working time.  
      The third object of the present invention is to provide a method of coating a photo-catalyst on a surface. The method has more content of the colloid solution with TiO 2  for increasing the TiO 2  content on the substrate to be coated without increasing the spraying time.  
      In order to achieve the above objects, the present invention provides a method of coating a photo-catalyst on a surface. The method comprises the steps as follows. A surface is provided. The surface is cleaned. A temperature near the surface is measured. A colloid solution with TiO 2  is provided. Next, a water content of the colloid solution with TiO 2  is regulated according to the temperature by adding water to the colloid solution with TiO 2  to form a mixture. The mixture is poured into a can of an airbrush. Finally, the colloid solution with TiO 2  is sprayed on the surface in a shape of micro-foam.  
      In order to achieve the above objects, the present invention provides a method of coating a photo-catalyst on a surface. The method comprises the steps as follows. First, a surface is provided. A solution is formed by a cleanser and warm water and absorbed by an absorbing body for cleaning dirt of the surface. A temperature near the surface is measured. A colloid solution with TiO 2  is provided. Next, a water content of the colloid solution with TiO 2  is regulated according to the temperature by adding water to the colloid solution with TiO 2  to form a mixture. The mixture is poured into a can of an airbrush. Finally, the colloid solution the TiO 2  is sprayed on the surface away from 30 cm in a shape of micro-foam for fixing the colloid solution with TiO 2  on the surface.  
      In order to achieve the above objects, the present invention provides a method of coating a photo-catalyst on a surface, the method comprising the steps as follows. First, a surface is provided. A solution is formed by a cleanser and warm water and is absorbed by an absorbing body for cleaning dirt of the surface. A temperature near the surface is measured. A colloid solution with TiO 2  is provided. Next, a water content of the colloid solution with TiO 2  is regulated according to the temperature. The water content of the colloid solution with TiO 2 , which includes TiO 2  as 30%, a fast-dry adhesive with acetone as 2˜3%, and water as the rest, (hereinafter also called “Solution”) based on the total weight of the Solution, is not changed when the temperature is under 25° C. But, when the temperature is between 25° C. to 30° C., the Solution should be added with more water which weight is equal to 5% of the Solution; when the temperature is between 30° C. to 40° C., the Solution should be added with more water which weight is equal to 10% of the Solution; when the temperature is over 40° C., the Solution should be added with more water which weight is equal to 15% of the Solution. The mentioned adding of water is for adjusting a solidified time of the fast-dry adhesive. The resulting colloid solution with TiO 2  is poured into a can of an airbrush. Finally, the colloid solution with TiO 2  is sprayed on the surface of the substrate away from 30 cm in a shape of micro-foam for fixing the colloid solution the TiO 2  on the surface.  
      It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. Other advantages and features of the invention will be apparent from the following description, drawings and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which:  
       FIG. 1  is a flow chart illustrating of the method of coating a photo-catalyst on a surface of a substrate to be coated of the prior art;  
       FIG. 2  is a flow chart illustrating of the method of coating a photo-catalyst on a surface of a substrate to be coated of the present invention;  
       FIG. 3  is a schematic view of spraying the colloid solution with TiO 2  on the surface of the substrate to be coated in a shape of micro-foam according to the present invention; and  
       FIG. 3A  is a schematic view of the micro-foam A, as shown in  FIG. 3 , of the present invention.  
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      Referring to  FIGS. 2 and 3 , the present invention provides a method of coating a photo-catalyst on a surface of a substrate to be coated  10 . The method comprises the steps of:  
      1. Cleaning the surface of the substrate to be coated  10 , comprising forming a solution by a cleanser and warm water (about 60° C.) for increasing the cleaning velocity, and absorbing the solution by an absorbing body for cleaning dirt of the surface of the substrate to be coated  10 ;  
      2. Measuring a temperature near the surface of the substrate to be coated  10 ;  
      3. Regulating a water content of the colloid solution with TiO 2  by mixing a water and the colloid solution with TiO 2  to form a uniform mixture according to the temperature. The water content of the colloid solution with TiO 2 , which includes TiO 2  as 30%, a fast-dry adhesive with acetone as 2˜3%, and water as the rest, based on the total weight of the colloid solution with TiO 2  (hereinafter called “Solution”), is not changed when the temperature is under 25° C. But, when the temperature is between 25° C. to 30° C., the Solution should be added with more water which weight is equal to 5% of the Solution; when the temperature is between 30° C. to 40° C., the Solution should be added with more water which weight is equal to 10% of the Solution; when the temperature is over 40° C., the Solution should be added with more water which weight is equal to 15% of the Solution. The mentioned adding of water is for adjusting a solidified time of the fast-dry adhesive. The resulting colloid solution with TiO 2  is poured into a can  31  of an airbrush  30 ; and  
      4. Spraying the colloid solution with TiO 2  on the surface of the substrate to be coated  10  away from 30 cm in a shape of micro-foam for fixing the colloid solution with TiO 2  on the surface of the substrate to be coated  10 , wherein the colloid solution with TiO 2  has a plurality of particles  22  attached on an external wall  21  of the micro-foam thereof. When the micro-foam sprays on the coated substrate, the colloid solution with TiO 2  can contact enough with an external world for developing the photo-catalytic efficiency of the colloid solution with TiO 2 .  
      Referring to  FIG. 3A , the colloid solution with TiO 2  includes TiO 2  as 30%, a fast-dry adhesive with acetone as 2˜3%, and water as the rest, based on the total weight of the colloid solution with TiO 2 .  
      The adhesive has a polyethylene to form an external wall  21 . The colloid solution with TiO 2  has a plurality of particles  22  attached on the external wall  21  of the micro-foam thereof, and the micro-foam covers the air, so that the colloid solution with TiO 2  can contact enough with an external world for developing the efficiency of the colloid solution with TiO 2 .  
      The adhesive is fast-dry type, so that the colloid solution with TiO 2  adheres on the substrate to be coated  10  fast. The TiO 2  particles  22  of the colloid solution with TiO 2  is relatively small, such that the content of TiO 2  particles in a micro-foam is relatively large. Therefore, it is enough for the step of spraying the colloid solution with TiO 2  on the surface of the substrate to be coated  10  to be only proceeded one time. Wherein the step of regulating a water content of the colloid solution with TiO 2  by mixing a water and the colloid solution with TiO 2  allows the sprayer sprays the colloid solution with the TiO 2  on the surface of the substrate to be coated away from about 30 cm, without a need to adjust the spraying distance or a pressure of the sprayer depending on a higher or lower temperature near the surface to be coated.  
      To sum up, the present invention has some advantages comprising:  
      1. The method does not need the baking step, so that the substrate to be coated can be any material;  
      2. The method does not need the baking step, so that it will reduce the working time;  
      3. The colloid solution with TiO 2  has a plurality of TiO 2  particles attached on an external wall of the micro-foam thereof. When the micro-foam is sprayed on the substrate to be coated, the TiO 2  particles can contact enough with an external world for developing the photo-catalytic efficiency of the colloid solution with TiO 2 ; and  
      4. The method only needs one time to spray the colloid solution with TiO 2  on the surface of the substrate to be coated for reducing the working time.  
      Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modification have suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.