Composition for drop on demand finishing of a textile article

Abstract

A finishing composition is described for deposition by dot-on-demand inkjet technique onto a textile substrate. The composition comprising a dispersion or emulsion of a functional finishing agent in a vehicle, wherein the size of particles in the dispersion or emulsion of the finishing composition is less than about 2 microns. By ensuring sufficient fineness of the particles, effective and reliable droplet deposition may proceed without clogging. Of significance, the composition should not be subject to flocculation or sedimentation during use.

1 . A finishing composition for deposition by drop-on-demand inkjet technique onto a textile substrate, the composition comprising a dispersion or emulsion of a functional finishing agent in a vehicle, wherein the size of particles in the dispersion or emulsion of the finishing composition is less than 2 microns, preferably less than 1 micron, more preferably, less than 0.5 microns and not subject to flocculation or sedimentation. 
   
   
       2 . The finishing composition according to  claim 1 , further comprising a wetting agent, preferably present at from 0.01 to 0.3 wt % in the jetted composition. 
   
   
       3 . The finishing composition according to any preceding claim wherein the surface tension of the composition on deposition is between 28 and 50 dynes/cm. 
   
   
       4 . The finishing composition according to any preceding claim, wherein for piezo-actuation the composition has a viscosity of 2-15 centipoise and for thermal-actuation the viscosity is 1-4 centipoise, as measured at the normal operating temperature of the nozzle. 
   
   
       5 . The finishing composition according to any preceding claim, wherein the total of residual solids in the jetted composition is more than 5 wt %, preferably more than 10 wt % and most preferably more than 15 wt %. 
   
   
       6 . The finishing composition according to any preceding claim, wherein the vehicle is water, preferably present at between 60 and 90 wt % in the jetted composition. 
   
   
       7 . The finishing composition according to any preceding claim, further comprising a co-solvent, preferably present at up to 20 wt % in the jetted composition 
   
   
       8 . The finishing composition according to any preceding claim, further comprising a humectant, preferably present at from 10 to 35 wt % in the jetted composition. 
   
   
       9 . The finishing composition according to any preceding claim, further comprising a viscosity control agent, preferably present at from 2 to 15 wt % in the jetted composition. 
   
   
       10 . The finishing composition according to any preceding claim, further comprising a biocide, preferably present at up to 0.5 wt % in the jetted composition. 
   
   
       11 . The finishing composition according to any preceding claim, further comprising a pH modifier, preferably present at up to 1 wt % in the jetted composition. 
   
   
       12 . The finishing composition according to any preceding claim, further comprising a corrosion inhibitor, preferably present at up to 0.2 wt % in the jetted composition. 
   
   
       13 . The finishing composition according to any of  claims 1  to  4 , wherein the vehicle is a UV curable organic diluent, preferably present at between 75 and 95 wt % in the jetted composition. 
   
   
       14 . The finishing composition according to  claim 13 , further comprising a photo-initiator preferably present at between 3 and 20 wt % in the jetted composition. 
   
   
       15 . The finishing composition according to any preceding claim, wherein the finishing agent is stable to shear up to at least 10 5 /s. 
   
   
       16 . The finishing composition according to any preceding claim, wherein the finishing agent is selected from the group consisting of anti-static, anti-microbial, anti-viral, anti-fungal, medicinal, anti-pilling, non-crease, flame-retardant, water-repellant, UV-protective, deodorant, wear-resistant, slip-resistant, slip enhancing, grip enhancing, stain-resistant, oil resistant, adhesive, stiffening, softening, elasticity-enhancing, pigment-binding, conducting, semi-conducting, photo-sensitive, photo-voltaic and light-emitting agents. 
   
   
       17 . The finishing composition according to any preceding claim, wherein the finishing agent comprises nano-particles carried by a sol-gel. 
   
   
       18 . A method of finishing a textile comprising:
 providing a substantially continuous supply of a textile substrate;   providing an array of drop-on-demand inkjet nozzles;   supplying to the nozzles a finishing composition according to any of the preceding claims;   selectively dispensing the composition from the nozzles in a series of droplets to deposit a predetermined distribution of droplets onto the substrate.   
   
   
       19 . The method according to  claim 18 , whereby the droplets are dispensed from the nozzles at velocities between than 5 m/s and 15 m/s. 
   
   
       20 . The method according to  claim 18  or  claim 19 , whereby the droplets are formed at a frequency of greater than 10 KHz, preferably greater than 20 KHz. 
   
   
       21 . The method according to any of  claims 18  to  20 , wherein the nozzles are of the piezo-electric type and droplets are formed by piezo-electric excitation. 
   
   
       22 . The method according to any of  claims 18  to  20 , wherein the nozzles are of the thermal inkjet type and droplets are formed by localized vaporisation. 
   
   
       23 . The method according to any of  claims 18  to  20 , wherein the nozzles are of the valve-jet type and droplets are formed by periodically opening a valve. 
   
   
       24 . The method according to any of  claims 18  to  23 , wherein more than 30 g/m 2  of wet composition is deposited on the substrate, preferably more then 50 g/m 2 . 
   
   
       25 . A textile article provided with a finish comprising the finishing composition according to any of  claims 1  to  17  or finished according to the method of  claims 18  to  24 .