Patent Publication Number: US-2020291275-A1

Title: Method for manufacturing non-transparent adhesive and the product thereof

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to the field of adhesives. More particularly, the present invention discloses an opaque adhesive and a method of manufacturing the opaque adhesive. 
     Description of the Prior Art 
     Numerous studies on nanoparticles have been undertaken in academia and industry. It has been found that physicochemical properties of many binders can be adjusted by the addition of inorganic nanoparticles. 
     One technique involves the preparation of a cerium oxide/PMMA hybrid material with high transparency and stability by a sol-gel process. Also, it has been shown that the incorporation of cerium oxide nanoparticles and diamond particles into a UV-cured polyacrylate coating improves the scratch and abrasion resistance of the coating. Additionally, surface functionalized alumina nanoparticle-filled polymer nanocomposites can exhibit enhanced mechanical properties. Further, titanium dioxide in the pigment grade form utilizes the excellent light scattering properties of titanium dioxide in applications requiring white opacity and brightness. 
     Research on the size-dependent optical properties of colloidal semiconductor quantum dots has received increased attention due to the use of colloidal semiconductor quantum dots in light-stable luminescent biotags and LEDs. Colloidal semiconductor quantum dots are typically uniformly dispersed in a transparent film or liquid binder. 
     SUMMARY OF THE INVENTION 
     The present invention provides a color composite adhesive and a method of preparation for the adhesive. The size and degree of mixing is observed utilizing a strain relief (SR)/nanoparticle composite binder through an optical microscopy instrument (Optical Microscope, OM). The present invention utilizes the synthesis of different CdSe quantum dots with different photoluminescence and different TiO 2 , and then incorporates CdSe quantum dots or titanium dioxide nanoparticles into the binder matrix to form various color composite binders. 
     The present invention also provides a method for preparing a colored composite adhesive comprising adding 0.001 to 5 wt. % of titanium oxide (TiO 2 ) or 0.001 to 5 wt. % of CdSe quantum dots to an adhesive matrix to prepare different colors of adhesive. 
     The invention further provides a composite adhesive prepared by the method of the invention. 
     The present invention discloses surface-modified titanium dioxide nanoparticles which are dispersed in the binder. Different types of surface modified titanium dioxide nanoparticles are incorporated into the binder matrix to form a hybrid composite binder. Hybrid composite adhesives have a higher storage module than a pure adhesive system. The storage module can be adjusted by using different forms of titanium dioxide nanoparticles and by changing the solids content of the titanium dioxide. In addition to enhancing the storage module, the present invention also blends the color of the composite adhesive from a transparent hue to a light white color. 
     Furthermore, different sizes of trioctylphosphine oxide (TOPO) modified CdSe quantum dots may further be incorporated into the adhesive matrix to form a color composite binder. Therefore, the size of the color composite adhesive can be observed through the OM. 
     Additionally, mixed SR/nanoparticle composite adhesives generally have better thermal and chemical stability than SR/dye composite adhesives. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross sectional view of the mixing strain relief (SR) assigned gap region filled in a printed circuit board/binder of composite nanoparticles; 
         FIG. 2 ( a )  is an illustration of nano-TiO 2  particles of a TEM image; 
         FIG. 2 ( b )  is an illustration of nano-TiO 2  particles of a high-resolution TEM image; 
         FIG. 3  is a TEM image of rod-shaped TiO 2  nanoparticles; 
         FIG. 4 ( a )  is a chemical structure diagram of an N3 dye; 
         FIG. 4 ( b )  is a chemical structure diagram of a W4 dye; and 
         FIG. 5 ( a ) - 5  ( c ) are illustrations of structures of various TiO 2  particles, (a) spherical TiO 2  particles, (b) rod-shaped TiO 2  particles, (c) another spherical TiO 2  particles, wherein X is oleic acid, and Y A pigment derived from N3 or W4. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following examples are further described in detail, but the present examples are not intended to limit the present invention, and all similar structures and similar modifications of the present invention should be included in the scope of the present invention. 
       FIG. 1  illustrates an elastic printed circuit  1 , a metal frame  2 , a printed circuit board  3 , and a mixing SR/Nano Particle Composite Adhesive  4 . 
     In an embodiment, titanium dioxide nanoparticles having an oleic acid agent, including spherical TiO 2  nanoparticles and rod-shaped TiO 2  nanoparticles, are synthesized by a sol-gel technique, and then the nanoparticles are fused into the binder. The matrix forms an opaque adhesive composition. 
     The precursor of TiO 2  is titanium isopropoxide and the surfactant is oleic acid. The present invention uses different amounts of trimethylamine N-oxide dehydrate (trimethylamine N-oxide dehydrate, TMAO) as a catalyst to synthesize nano TiO 2  spherical particles (excluding TMAO,  FIGS. 2 ( a )  and  2  ( b ) and rod-shaped TiO 2  (including TMAO, as shown in  FIG. 3 ). The synthesized TiO 2  nanoparticles are then modified by small molecules (such as an N3 dye and W4 dye shown in  FIG. 4 ) to partially remove the insulating surface ligand oleic acid. 
     Further, 0.001 to 5 wt. % of titanium dioxide (TiO 2 ) is added to the binder matrix to prepare binders of different colors. 
     The precursor of TiO 2  comprises, but is not limited to, titanium tetrakisisopropoxide, Tetra-n-butyl Titanate, titanium chloride, or titanium butoxide. 
     In other embodiments, titanium dioxide nanoparticles is prepared using a titanium tetrachloride neutralization hydrolysis process, a titanium sulfate hydrolysis process, or a high temperature hydrolysis process, hydrothermal synthesis process. 
     In the method, Cadmium oxide (CdO), tetradecylphosphonic acid mixture (TDPA) and trioctylphosphine oxide (TOPO) are heated to 300 degrees C. under argon, and are converted into a phase solution synthesis of CdSe nanocrystals. After the introduction of a selenium and trioctylphosphine (TOP) solution, the reaction is allowed to react for a few minutes and cooled to room temperature. The synthetic size of CdSe can be adjusted by controlling the reaction time. 
     0.001 to 5 wt. % of CdSe quantum dots is added to the binder matrix to prepare binders of different colors. 
     Preferably, the present invention synthesizes TiO 2  nanoparticles and CdSe nanoparticles (as shown in  FIG. 5 ) using wet chemical methods. In  FIG. 5 , X denotes oleic acid and Y denotes a derived pigment 
     In an embodiment, the adhesive matrix material comprises an acrylate type transparent adhesive having the composition shown in Table 1 below: 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 acrylate adhesive components 
               
            
           
           
               
               
               
            
               
                 Composition 
                 Wt. % 
                 Note 
               
               
                   
               
            
           
           
               
               
               
            
               
                 Acrylate 
                 49 
                 Reactive monomer 
               
               
                 2,2-dimethoxy-2-phenylacetophenone 
                 10 
                 CAS No. 24650428 
               
               
                 N,N-dimethylacrylamide 
                 20 
                 CAS No. 2680037 
               
               
                 Silane couple agent 
                 10 
                 N/A 
               
               
                 Diphenyl(2,4,6- 
                 10 
                 CAS No. 75980608 
               
               
                 trimethylbenzoyl)phosphine oxide 
               
               
                 2-Hydroxyethyl acrylate 
                 &lt;1 
                 CAS No. 818611 
               
               
                   
               
            
           
         
       
     
     It is to be understood that the above described embodiments of the present invention are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any manner. Various changes in the function and arrangement of the elements can be made without departing from the scope of the invention and the legal equivalents thereof