Inkjet compositions and processes for stretchable substrates

Abstract

Novel inkjet ink compositions for forming an image in a form of an elastic film attached to a surface of a stretchable and/or flexible substrate and processes utilizing same for inkjet printing color images on various substrates such as colored and absorptive or impregnable stretchable materials, which are characterized by heightened efficiency in process time, ink and energy consumption, as well as products having durable, wash-fast and abrasion-fast images printed thereon by the process, are disclosed. The novel ink compositions comprise a first part, which contains a property-adjusting agent and a carrier, and a second part which contains an emulsified property-sensitive proto-elastomeric film-forming agent, a colorant and a carrier, such that the second part congeals upon contact with the property-adjusting agent. The second part is digitally applied to the substrate less than 1 second following the application of the first part to the substrate.

What is claimed is: 
     
         1 . An inkjet composition comprising a proto-elastomeric film-forming agent or binder, a dispersed pigment, a property-sensitive agent and a carrier, wherein said property-sensitive agent is sensitive to an acidic pH such that upon contacting said acidic pH the inkjet composition congeals and subsequently forms an elastic film upon drying/curing which is characterized by an elongation percentage that ranges from 30% to 300%. 
     
     
         2 . The inkjet composition of  claim 1 , being for forming an image in a form of said elastic film attached to a surface of a stretchable and/or flexible substrate. 
     
     
         3 . The inkjet composition of  claim 1 , wherein said film-forming agent or binder is selected from the group consisting of an alkyl-acrylic polymer and/or an emulsion thereof, acrylic-styrene copolymer and/or an emulsion thereof, an alkyl-acrylic copolymer and/or an emulsion thereof, a urethane polymer and/or an emulsion thereof, and any combination thereof. 
     
     
         4 . The inkjet composition of  claim 1 , wherein said dispersant is a property-sensitive polymerizable dispersant. 
     
     
         5 . The inkjet composition of  claim 4 , wherein said dispersant is selected from the group consisting of an acrylate, an acrylic acid salt, an acrylic polymer salt and any combination thereof. 
     
     
         6 . The inkjet composition of  claim 1 , wherein said carrier is an aqueous carrier. 
     
     
         7 . The inkjet composition of  claim 1 , further comprising at least one agent selected from the group consisting of a polymerization catalyst, a crosslinking agent, an amine stabilizer, an alcohol stabilizer, a softener/plasticizer, a surface active agent, a surface tension modifying agent, a viscosity modifying agent, a thickener agent, an anticorrosion agent and any combination thereof. 
     
     
         8 . The inkjet composition of  claim 7 , wherein said crosslinking agent is a formaldehyde-free crosslinking agent. 
     
     
         9 . A multi-part inkjet composition, obtainable by contacting the inkjet composition of  claim 1  with an immobilization composition, wherein said immobilization composition comprises a carrier and an acid. 
     
     
         10 . An image in a form of an elastic film characterized by an elongation percentage that ranges from 30% to 300% when attached to a surface of a stretchable and/or flexible substrate, obtainable by contacting, on the substrate, the inkjet composition of  claim 1  with an immobilization composition, and optionally with a property-sensitive opaque underbase composition and/or optionally with a property-sensitive spot color composition, wherein said immobilization composition comprises a carrier and an acid. 
     
     
         11 . A process of printing an image on a substrate, the process comprising concomitantly applying by means of an inkjet printing machine onto at least a portion of a surface of the substrate, an immobilization composition that comprises a carrier and an acid, and the inkjet composition of  claim 1 , and subsequently drying/curing said inkjet composition on the substrate, wherein said immobilization composition and the inkjet composition are each applied by a separate and discrete component of said printing machine, thereby forming said image, and said image is in a form of an elastic film characterized by an elongation percentage that ranges from 30% to 300%. 
     
     
         12 . The process of  claim 11 , wherein said applying is effected by spraying using a nozzle or by inkjet printing using a printhead. 
     
     
         13 . The process of  claim 11 , wherein a time interval between an application of said immobilization composition and an application of said inkjet composition is less than 10 second. 
     
     
         14 . The process of  claim 13 , wherein said surface is substantially a dark surface. 
     
     
         15 . The process of  claim 11  further comprising flattening protruding fibers in the substrate prior to digitally applying the ink composition. 
     
     
         16 . The process of  claim 15 , wherein flattening protruding fibers is effected by exerting a flattening pressure on a surface of the substrate. 
     
     
         17 . A process of inkjet printing an image on a substrate, the process comprising, prior to printing the image on the substrate by an inkjet printing machine, using a flattening unit on the substrate to thereby effect flattening and/or planarization thereof, wherein said flattening unit is part of said printing machine, and said flattening and/or planarization is effected in said printing machine. 
     
     
         18 . The process of  claim 17 , wherein said printing machine further comprises a wetting unit for wetting the substrate concomitantly or prior to said printing, and at least one inkjet printhead for effecting said printing, wherein said flattening and/or planarization is effected prior to or subsequent to said wetting. 
     
     
         19 . The process of  claim 17 , wherein flattening unit is having a form selected from the group consisting of a downwardly pressing curtain, a mechanical roller, an air knife, a flexible or hard squeegee, and a brushing strip.