Pretreat compositions

Abstract

The present disclosure is drawn to ink sets, material sets, and 3-dimensional printing systems. An ink set can include a pretreat composition that includes a metal chloride salt, a conductive fusing ink including a transition metal, and a second fusing ink. The second fusing ink can include a fusing agent capable of absorbing electromagnetic radiation to produce heat.

What is claimed is: 
     
         1 . An ink set, comprising:
 a pretreat composition comprising a metal chloride salt;   a conductive fusing ink comprising a transition metal; and   a second fusing ink comprising a fusing agent capable of absorbing electromagnetic radiation to produce heat.   
     
     
         2 . The ink set of  claim 1 , wherein the transition metal is in the form of elemental transition metal particles. 
     
     
         3 . The ink set of  claim 2 , wherein the elemental transition metal particles comprise silver particles, copper particles, gold particles, or combinations thereof. 
     
     
         4 . The ink set of  claim 2 , wherein the elemental transition metal particles are capable of being sintered at a temperature from 20° C. to 350° C. 
     
     
         5 . The ink set of  claim 1 , wherein the fusing agent comprises carbon black, a near-infrared absorbing dye, a near-infrared absorbing pigment, a tungsten bronze, a molybdenum bronze, metal nanoparticles, a conjugated polymer, or combinations thereof. 
     
     
         6 . The ink set of  claim 1 , wherein the metal chloride salt comprises sodium chloride, potassium chloride, or combinations thereof. 
     
     
         7 . The ink set of  claim 1 , wherein the transition metal is in the form of elemental transition metal particles comprising a dispersing agent at surfaces of the elemental transition metal particles, wherein the dispersing agent is capable of being removed from the surfaces by contact with the metal chloride salt. 
     
     
         8 . A material set, comprising:
 a thermoplastic polymer powder having an average particle size from 20 μm to 100 μm;   a pretreat composition comprising a metal chloride salt; and   a conductive fusing ink comprising a transition metal.   
     
     
         9 . The material set of  claim 8 , further comprising a second fusing ink comprising a fusing agent capable of absorbing electromagnetic radiation to produce heat, wherein the second fusing ink provides a lower conductivity than the conductive fusing ink when printed on the thermoplastic polymer powder 
     
     
         10 . The material set of  claim 8 , wherein the transition metal is in the form of elemental transition metal particles. 
     
     
         11 . The material set of  claim 10 , wherein the elemental transition metal particles comprise silver particles, copper particles, gold particles, or combinations thereof. 
     
     
         12 . The material set of  claim 8 , wherein the metal chloride salt comprises sodium chloride, potassium chloride, or combinations thereof. 
     
     
         13 . The material set of  claim 8 , wherein the transition metal is in the form of elemental transition metal particles comprising a dispersing agent at surfaces of the elemental transition metal particles, wherein the dispersing agent is capable of being removed from the surfaces by contact with the metal chloride salt. 
     
     
         14 . A 3-dimensional printing system, comprising:
 a powder bed comprising a thermoplastic polymer powder;   an inkjet printer comprising:
 a first inkjet pen in communication with a reservoir of a pretreat composition to print the pretreat composition onto the powder bed, wherein the pretreat composition comprises a metal chloride salt, 
 a second inkjet pen in communication with a reservoir of a conductive fusing ink to print the conductive fusing ink onto the powder bed, wherein the conductive fusing ink comprises a transition metal, and 
 a third inkjet pen in communication with a reservoir of a second fusing ink to print the second fusing ink onto the powder bed, wherein the second fusing ink comprises a fusing agent capable of absorbing electromagnetic radiation to produce heat; and 
   a fusing lamp to emit electromagnetic radiation sufficient to fuse thermoplastic polymer powder that has been printed with the conductive fusing ink, the second fusing ink, or both.   
     
     
         15 . The system of  claim 14 , wherein the metal chloride salt comprises sodium chloride, potassium chloride, or combinations thereof, and wherein the transition metal is in the form of elemental transition metal particles comprising a dispersing agent at surfaces of the elemental transition metal particles, wherein the dispersing agent is capable of being removed from the surfaces by contact with the metal chloride salt.