Method of forming structured sintered articles

Abstract

Disclosed is a method of forming a structured sintered article including providing a mixture comprising a sinterable particulate material and a binder, the binder comprising, as a function of total resin content of the binder, at least 50% by weight of a thermoplastic binder material and at least 5% by weight of a radiation-curable binder material; shaping the mixture with a mold to form a structure; setting the structure by cooling the structure or by allowing the structure to cool; separating the structure from the mold; irradiating the structure so as to at least partially cure the radiation-curable binder material, and debinding and sintering the structure so as to form a structured sintered article. Shaping may include forming a structure having one or more open channels, and sintering may include sintering in together in contact with at least one additional structure so as to cover or enclose the channels.

1 . A method of forming a structured sintered article, the method comprising the steps of:
 providing a mixture comprising a sinterable particulate material and a binder, the binder comprising, as a function of total resin content of the binder, at least 50% by weight of a thermoplastic binder material;   shaping the mixture with a mold so as to form a structure;   setting the structure by cooling the structure or by allowing the structure to cool;   separating the structure from the mold; and   debinding and sintering the structure so as to form a structured sintered article;   
       wherein the binder further comprises at least 5% by weight of a radiation-curable binder material and the method further comprises, after the step of separating the structure from the mold, the step of irradiating the structure so as to at least partially cure the radiation-curable binder material. 
     
     
         2 . The method of  claim 1  wherein the step of irradiating further comprises irradiating the structure sufficiently such that the yield stress of the mixture is at least 8 Pa at a temperature of 100° C. 
     
     
         3 . The method of  claim 1  wherein the step of irradiating comprises irradiating the structure sufficiently such that the yield stress of the mixture is at least 100 Pa at temperatures in the range of 70 to 120° C. 
     
     
         4 . The method of  claim 1  wherein the binder comprises in the range of about 60 to about 90% by weight of a thermoplastic binder material and in the range of about 20 to 40% by weight of a radiation-curable binder material. 
     
     
         5 . The method according to  claim 1  wherein the thermoplastic binder material comprises one or more hydrocarbon waxes, waxy alcohols, or mixtures thereof. 
     
     
         6 . The method according to  claim 1  wherein the radiation-curable binder material is a UV-curable material. 
     
     
         7 . The method according to  claim 6  wherein the UV-curable material comprises one or more acrylates, methacrylates, a vinyls, epoxies, thiols, styrenics, and combinations thereof. 
     
     
         8 . The method of  claim 6  wherein the UV-curable material comprises an acrylated oligomer. 
     
     
         9 . The method of  claim 8  wherein the acrylated oligomer is a polyester acrylate. 
     
     
         10 . The method according to  claim 1  wherein the step of molding the mixture comprises molding the mixture in a silicone-containing mold. 
     
     
         11 . The method according to  claim 1  wherein the step of providing a mixture includes providing a mixture comprising a particulate material transparent to radiation employed in the step of irradiating. 
     
     
         12 . The method according to  claim 1  wherein the particulate material comprises at least one of glass, ceramic, and glass-ceramic. 
     
     
         13 . The method according to  claim 1  wherein the particulate material is a glass. 
     
     
         14 . The method according to  claim 1  wherein the particulate material comprises a metal. 
     
     
         15 - 19 . (canceled)