Method and composition for reducing waste in photo-imaging applications

Abstract

Waste reduction, including hazardous waste reduction in photoimaging processes can be accomplished by improving diffusional resolution of cationic curable compositions. The addition of fluorinated polymers including fluorinated surfactants provides improved diffusional resolution in cationic and/or radical based photoimaging formulations allowing for image accuracy improvements, and reduced product and process waste quantity and disposal cost. These fluorinated surfactants also allow for increased cure speed, and non-hazardous constituent formulations that result in less wasted material and time.

1 . A method of reducing waste from stereolithographic processes comprising: 
 curing a portion of a cationic composition comprising: 
 a photoacid diffusion inhibitor; and/or  
 an oxetane; and  
 a boron-containing, cationic initiator; and/or  
 a photosensitizer having the following chemical formula:  
                     
   wherein R 1 —R 14  are independently H or C 1 -C 8  saturated or unsaturated, branched or unbranched, substituted or unsubstituted hydrocarbyl.    
     
     
         2 . The method of  claim 1 , wherein said cationic composition comprises only non-hazardous materials.  
     
     
         3 . The method of  claim 1 , wherein said cationic composition is antimony-free.  
     
     
         4 . The method of  claim 1 , wherein said waste is hazardous.  
     
     
         5 . The method of  claim 1 , wherein said cationic composition comprises a photoacid diffusion inhibitor.  
     
     
         6 . The method of  claim 5 , wherein the photoacid diffusion inhibitor is present in an amount sufficient to improve the imaging of said composition.  
     
     
         7 . The method of  claim 6 , wherein improving the imaging of said composition includes limiting the diffusion of a photoacid out of a stereolithographic imaging region.  
     
     
         8 . The method of  claim 6 , wherein limiting diffusion of a photoacid includes: 
 forming an association between an activated cationic initiator and said composition using said photoacid diffusion inhibitor.    
     
     
         9 . The method of  claim 6 , wherein improving the imaging includes improving the diffusional resolution of the composition.  
     
     
         10 . The method of  claim 6 , wherein improving the imaging includes improving the layer formation of the composition.  
     
     
         11 . The method of  claim 1 , further comprising: 
 removing excess of said composition from an article formed by curing at least a portion of said composition.    
     
     
         12 . The method of  claim 11 , wherein removing excess of said composition comprises using an air knife or using liquid CO 2 .  
     
     
         13 . A cationic composition for reducing waste production comprising: 
 a photosensitizer having the following chemical formula:                          wherein R 1 —R 14  are independently H or C 1 -C 8  saturated or unsaturated, branched or unbranched, substituted or unsubstituted hydrocarbyl.    
     
     
         14 . The composition of  claim 13 , wherein said composition is antimony-free.  
     
     
         15 . The composition of  claim 13 , further comprising an epoxide.  
     
     
         16 . The composition of  claim 13 , wherein said photosensitizer has no significant absorbance above 400 nm.  
     
     
         17 . The composition of  claim 13 , wherein, said photosensitizer comprises 4-benzoyl -4-methyldiphenyl sulfide.  
     
     
         18 . The composition of  claim 13 , further comprising a free radical initiator.  
     
     
         19 . The composition of  claim 18 , wherein said free radical initiator comprises 2-hydroxy-2-2-methyl-1-phenyl propan-1-one.  
     
     
         20 . A cationic composition for reducing waste production comprising: 
 an oxetane; and    a boron-containing, cationic initiator.    
     
     
         21 . The composition of  claim 20 , wherein said composition is antimony-free.  
     
     
         22 . The composition of  claim 20 , wherein said composition is photocationic.  
     
     
         23 . The composition of  claim 20 , further comprising an epoxide.  
     
     
         24 . The composition of  claim 20 , wherein said cationic initiator comprises (tolylcumyl)iodonium tetrakis(pentafluorphenyl)borate.  
     
     
         25 . The composition of  claim 20 , further comprising a photoacid diffusion inhibitor.  
     
     
         26 . The composition of  claim 25 , wherein said photoacid diffusion inhibitor comprises a fluorinated polymer.  
     
     
         27 . The composition of  claim 25 , wherein said photoacid diffusion inhibitor comprises a fluorinated surfactant.  
     
     
         28 . A cationic high-solids composition for reducing waste production comprising: 
 a photoacid diffusion inhibitor.    
     
     
         29 . The composition of  claim 28 , wherein said photoacid diffusion inhibitor comprises a fluorinated polymer.  
     
     
         30 . The composition of  claim 28 , wherein said photoacid diffusion inhibitor comprises a fluorinated surfactant.  
     
     
         31 . The composition of  claim 28 , wherein said photoacid diffusion inhibitor is 1.0 wt. % or less of said composition.  
     
     
         32 . The composition of  claim 28 , further comprising a cationic initiator.  
     
     
         33 . The composition of  claim 32 , wherein said cationic initiator comprises: phosphorus.  
     
     
         34 . The composition of  claim 32 , wherein said cationic initiator comprises boron.  
     
     
         35 . The composition of  claim 28 , wherein said composition is antimony-free.  
     
     
         36 . The composition of  claim 28 , wherein the composition has an improved diffusional resolution over an identical composition exclusive of the photoacid diffusion inhibitor.  
     
     
         37 . The composition of  claim 28 , further comprising an epoxide.  
     
     
         38 . The composition of  claim 28 , further comprising an acrylate.  
     
     
         39 . The composition of  claim 28 , further comprising an oxetane.  
     
     
         40 . The composition of  claim 28 , further comprising glycidyl epoxide monomers.  
     
     
         41 . The composition of  claim 28 , wherein said composition comprises only non-hazardous materials.  
     
     
         42 . A cationic composition for reducing waste from stereolithographic processes comprising: 
 a photoacid diffusion inhibitor; and/or    an oxetane; and    a boron-containing, cationic initiator; and/or    a photosensitizer having the following chemical formula:                          wherein R 1 —R 14  are independently H or C 1 -C 8  saturated or unsaturated, branched or unbranched, substituted or unsubstituted hydrocarbyl.    
     
     
         43 . A mold or pattern formed from the composition of  claim 28 .  
     
     
         44 . A method of producing molded articles comprising: 
 forming a mold from the composition of  claim 28;  and    forming a thermoplastic film on the mold.    
     
     
         45 . The method of  claim 44 , wherein forming a thermoplastic film on the mold includes using a vacuum molding process.  
     
     
         46 . The composition of  claim 28 , wherein said photoacid diffusion inhibitor contains fluorinated moieties having the following formula C k F m  wherein m has a value of 3-5 and k has a value of 1 or 2.  
     
     
         47 . The composition of  claim 46 , wherein said moieties are part of a repeating group that is repeated at least 5 times.  
     
     
         48 . A stereolithographic composition for reducing waste production comprising: 
 a fluorinated polymer, wherein the stereolithographic composition is non-hazardous.    
     
     
         49 . The composition of  claim 48 , further comprising a cationic initiator.  
     
     
         50 . The composition of  claim 49 , wherein said cationic initiator comprises phosphorous.  
     
     
         51 . The composition of  claim 49 , wherein said cationic initiator comprises boron.  
     
     
         52 . The composition of  claim 48 , wherein the fluorinated polymer is a fluorinated surfactant.  
     
     
         53 . The composition of  claim 48 , wherein the composition is non-hazardous after curing.  
     
     
         54 . A composition comprising a triplet sensitizer for a cationic initiator, wherein said sensitizer has no significant light absorption at wavelengths greater than 400 nm and an extinction coefficient greater than 300 l/mole-cm at wavelengths greater than 348 nm.  
     
     
         55 . A method of forming stereolithographic articles and reducing the production of waste therefrom comprising: 
 forming an article from a cationic composition;    removing excess composition from the formed article using an air knife or liquid CO 2 ;    separating the removed excess composition; and    recycling the removed excess composition.    
     
     
         56 . The method of  claim 55  wherein said cationic composition is non-hazardous.