Patent Publication Number: US-2007098963-A1

Title: Toner receiving compositions for electrophotographic toner receiving systems

Description:
BACKGROUND  
      The present disclosure relates generally to toner receiving compositions, and more particularly to toner receiving compositions for electrophotographic toner receiving systems.  
      Electrophotographic printing is widely used for both commercial and personal printing. The desire to produce photo-quality images poses a challenge, as achieving the look of photographs printed using silver halide technology may be difficult. Creating a superior, photo-quality image generally includes obtaining high image resolution and color gamut while minimizing printer/media artifacts. In addition to achieving these effects, it may also be desirable to maximize image toner transfer and to obtain a substantially high media gloss and a uniform gloss appearance for both the media and the toner. In electrophotographic printing devices that may not be capable of achieving a high gloss, it may be preferable to have a media gloss that provides a substantially uniform printed toner/media gloss appearance.  
      In order to achieve the desired effects, printing media are often coated with functional materials on the image receiving side. Such materials may, in some instances, be undesirable for electrophotographic printing methods. In some instances, the materials have difficulty obtaining a high gloss level and/or uniformity between the media and the toner. In other instances, the materials may achieve the high gloss level and/or uniformity; however, they may be unable to maintain such effects under elevated toner fusing temperatures and pressures. Further, it may, in some cases, be relatively problematic to achieve good run-ability or sheet-feeding during high speed color electrophotographic printing when using materials coated to create superior image effects.  
      As such, it would be desirable to provide a toner receiving composition capable of achieving a high and stable gloss level, and/or yielding gloss uniformity between the media and toner.  
     SUMMARY  
      A toner receiving composition for electrophotographic toner receiving systems is disclosed. The composition includes a polymeric binder material and a plurality of organic hollow polymeric particles adhered to the polymeric binder material. The organic hollow polymeric particles are present in an amount equal to or greater than about 50% by weight of total solid weight of the toner receiving composition. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Features and advantages of the present disclosure will become apparent by reference to the following detailed description and drawings, in which like reference numerals correspond to similar, though not necessarily identical components. For the sake of brevity, reference numerals or features having a previously described function may not necessarily be described in connection with other drawings in which they appear.  
       FIG. 1  is a flow diagram depicting embodiment(s) of method(s) of making electrophotographic toner receiving system(s);  
       FIG. 2  is a cross-sectional schematic view of an embodiment of an electrophotographic toner receiving system;  
       FIG. 3  is a cross-sectional schematic view of an embodiment of the electrophotographic toner receiving system having a back coat;  
       FIG. 4  is a cross-sectional schematic view of an embodiment of the electrophotographic toner receiving system having an inorganic layer;  
       FIG. 5  is a cross-sectional schematic view of an embodiment of the electrophotographic toner receiving system having an embodiment of a polymer layer thereon;  
       FIG. 6  is a cross-sectional schematic view of another embodiment of the electrophotographic toner receiving system; and  
       FIG. 7  is a cross-sectional schematic view of an alternate embodiment of the electrophotographic toner receiving system. 
    
    
     DETAILED DESCRIPTION  
      Embodiment(s) of the toner receiving composition and system advantageously achieve a high and stable gloss level when images are printed thereon via an electrophotographic printer. Generally, silver halide glossy photographic prints achieve gloss in the range of 20 gloss units to 70 gloss units when measured at a 20° angle. This range may also be desirable for high gloss media and toner when printing with an electrophotographic printer. Systems incorporating embodiments of the composition may achieve media gloss within this range and may exhibit gloss uniformity when used with an electrophotographic printer that is capable of achieving a toner gloss in this range. If the electrophotographic printer is not capable of achieving the previously described high toner gloss, in order to achieve a desirable photo-like quality, the toner receiving composition may be adjusted to enable a uniform gloss between the media and the toner at a gloss range between about 20 gloss units to about 100 gloss units when measured at a 75° angle. The toner receiving composition may be incorporated on various types of media, thus providing the media with the capability of receiving toner in a manner that yields gloss uniformity between the media and toner. Still further, it is believed that embodiment(s) of the composition and system achieve high image resolution and color gamut, thus providing photo-quality images.  
      It is to be understood that the terms “disposed on”, “deposited on,” or “established on” and the like are broadly defined herein to encompass a variety of divergent layering arrangements and assembly techniques. These arrangements and techniques include, but are not limited to (1) the direct attachment of one material layer to another material layer with no intervening material layers therebetween; and (2) the attachment of one material layer to another material layer with one or more material layers therebetween provided that the one layer being “disposed on,” “deposited on,” or “established on” the other layer is somehow “supported” by the other layer (notwithstanding the presence of one or more additional material layers therebetween). The phrases “directly deposited on,” “deposited directly on,” or “directly established on,” and the like are defined herein to encompass a situation(s) wherein a given material layer is secured to another material layer without any intervening material layers therebetween. Any statement used herein which indicates that one layer of material is on another layer is to be understood as involving a situation wherein the particular layer that is “on” the other layer in question is the outermost of the two layers relative to incoming toner materials being delivered by the printing system of interest (unless specifically defined otherwise). It is to be understood that the characterizations recited above are to be effective regardless of the orientation of the system materials under consideration.  
      Referring now to  FIG. 1 , an embodiment of making an electrophotographic toner receiving system is described. A composition is provided that includes a polymeric binder material and a plurality of organic hollow polymeric particles adhered thereto, wherein the organic hollow polymeric particles are present in an amount equal to or greater than about  50 % by weight of the total solid weight of the toner receiving composition, as shown at reference numeral  13 . The composition is established on a substrate, as shown at reference numeral  15 . The method may also include establishing a back coat on the substrate, as shown at reference numeral  17 . Further, the method may include establishing a polymer layer on the composition, as shown at reference numeral  19 . Still further, the method may include establishing an inorganic layer between the substrate and the composition, as shown at reference numeral  21 . It is to be understood that embodiment(s) of the method will be described in further detail herein in reference to  FIGS. 2 through 7 .  
       FIG. 2  illustrates an embodiment of the toner receiving composition  10  in an embodiment of the electrophotographic in toner receiving system  100 . It is to be understood that the composition  10  is adapted to form a thin-film that acts as a toner receiving layer in the system  100 .  
      In an embodiment, the toner receiving composition  10  is established on a substrate  12 . Non-limitative examples of suitable substrate  12  materials include polymeric films (non-limitative examples of which include polyester white film or polyester transparent film), papers with extruded polymer resins on both sides, polymer coextruded paper stock (cellulosic or the like), fabric paper stock, and/or combinations thereof. In an embodiment, the substrate  12  is paper, photopaper (non-limitative examples of which include polyethylene or polypropylene extruded on one or both sides of paper), metals, and/or the like, and/or combinations thereof. A non-limitative example of a suitable metal material is a metal in foil form made from, for example, at least one of aluminum, silver, tin, copper, alloys thereof, and/or mixtures thereof. Furthermore, the substrate  12  may include first and second opposed faces  14 ,  16  upon which various layer(s) of embodiments of the present disclosure may be established. In an embodiment, the substrate  12  has a thickness, along substantially the entire length, ranging between about 0.025 mm and about 0.5 mm.  
      As depicted in  FIG. 2 , the composition  10  may be established directly on the substrate  12 . The composition  10  includes a polymeric binder material  18  and organic hollow polymeric particles  20  adhered thereto. Generally, the combination of the polymeric binder material  18  and the organic hollow particles  20  forms a composition  10  having at least one glass transition temperature (T g ) less than about 40° C.  
      The polymeric binder material  18  may be present in an amount ranging from about 5% to about 50% based on the weight of the dry coating composition. Any suitable polymeric binder material  18  may be selected as long as it is compatible with the organic hollow polymeric particles  20 . Generally, the polymeric binder material  18  may be water-soluble polymers, water-dispersable polymers, polymeric emulsions, and/or combinations thereof. Specific non-limitative examples of polymeric binder materials  18  include polyvinyl alcohol, starch derivatives, gelatin, cellulose derivatives, acrylamide polymers, acrylic polymers, acrylic copolymers, vinyl acetate latex, polyesters, vinylidene chloride latex, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, styrene-acrylic copolymers, copolymers thereof, and/or the like, and/or combinations thereof.  
      The hollow polymeric particles  20  are present in the composition  10  in an amount equal to or greater than about 50% by weight of the total solid weight of the toner receiving composition  10 . In a non-limitative example, the hollow polymeric particles  20  are present in an amount equal to or greater than about 60% by weight. Generally, each of the organic hollow polymeric particles  20  has a void volume within an outer dimension of the particle  20  that ranges from about 20% to about 70%. Still further, each of the organic hollow particles  20  has an outer diameter ranging from about 0.1 μm to about 10 μm. In an embodiment, the outer diameter of each of the particles  20  ranges from about 0.1 μm to about 4 μm, and in another embodiment, the outer diameter ranges from about 0.1 μm to about 2 μm. Some examples of suitable materials for the hollow particles  20  include, but are not limited to styrene, styrene derivatives, vinyl esters, acrylic acid polymers, ester derivatives of acrylic acid polymers, methacrylic acid polymers, ester derivatives of methacrylic acid polymers, copolymers thereof, and/or combinations thereof.  
      In an embodiment, the ratio of polymeric binder material  18  to organic hollow polymeric particles  20  ranges from about 1:1 to about 1:20.  
      Referring now to  FIG. 3 , an embodiment of the toner receiving system  100  is depicted having a back coat  22  established on the substrate  12 . As shown, the back coat  22  is established on the second face  16  of the substrate  12 . It is to be understood that the back coat  22  may be established on either face  14 , 16  of the substrate  12 , as long as the toner receiving composition  10  and the back coat  22  are on opposed faces  14 ,  16 .  
      In an embodiment, the back coat/coating layer  22  includes inorganic pigments (a non-limitative example of which includes calcium carbonate particles), polymer particles (a non-limitative example of which includes polyethylene beads), polymeric binders, slipping agents (a non-limitative example of which includes polymeric wax), and/or the like, and/or combinations thereof. Generally, the back coat  22  may advantageously assist in controlling the friction between sheets and/or between sheets and pick-up rolls of the printer. Still further, the back coat  22  may form an open structure in the system  100  so that moisture vapor may be released from the coating  22  without causing blistering under high humidity conditions (for example, during fusing). It is to be understood that the back coat  22  may also serve to balance internal stress from layers established on opposed faces  14 ,  16  of the substrate  12 , thus potentially minimizing curling.  
      Referring now to  FIG. 4 , another embodiment of the system  100  is depicted. In this embodiment, an inorganic layer  24  is established between the substrate  12  and the composition  10 . It is to be understood that in an embodiment of the method, the inorganic layer  24  may be established on the substrate  12  prior to the establishment of the composition  10 . It is to be further understood that the inorganic layer  24  may advantageously supply enhanced opacity, brightness, surface smoothness, and/or color hue to the system  100 .  
      The inorganic layer  24  may include from about 5 parts to about 95 parts by weight of the dry layer of inorganic pigments. Non-limitative examples of such pigments include titanium dioxide, hydrated alumina (e.g. aluminum trihydrate), calcium carbonate, barium sulfate, silica, high brightness kaolin clays, calcined clays, alumina, boehmite, talc, zinc oxide, and/or combinations thereof. The inorganic layer  24  may also include a binder. Generally, the binder supplies adhesion force between the substrate  12  and the pigments, and between the pigments themselves. The binder may include, but is not limited to water soluble binders, water dispersable binders, polymeric emulsions exhibiting high binding power for the substrate  12  and the pigments, and/or combinations thereof. Non-limitative examples of binders suitable for the inorganic layer  24  include polyvinyl alcohol, starch derivatives, gelatin, cellulose derivatives, acrylamide polymers, acrylic polymers or copolymers thereof, vinyl acetate latex, polyesters, vinylidene chloride latex, styrene-butadiene, acrylonitrile-butadiene copolymers, styrene acrylic copolymers, copolymers thereof, and/or combinations thereof.  
       FIG. 5  depicts another embodiment of the system  100  having a polymer layer  28  thereon. Generally, the polymer layer  28  may advantageously serve to protect the composition  10  and/or add durability to the system  100 . The polymer layer  28  may also enhance the gloss of the media and/or may tailor the gloss level of the media so as to become more uniform with the gloss of the toner in a particular electrophotographic printing system.  
      In  FIG. 5 , the polymer layer  28  includes a polymeric emulsion of a binder material  30  and organic solid polymeric particles  32 . The organic solid polymeric particles  32  may have any suitable geometry, including, but not limited to spherical particles, or nearly spherical particles in the pre-imaged state. It is to be understood that any suitable binder material  30 , such as those described herein in reference to binders used in other layers, may be used in the polymer layer  28 .  
      Each of the solid particles  32  has a diameter ranging from about 0.1 μm to about 0.6 μm. In a non-limitative example, each of the solid particles  32  has a diameter ranging from about 0.1 μm to about 0.5 μm. Non-limitative examples of organic solid polymeric particles  32  include styrenes, styrene derivatives, vinyl esters, acrylic acid polymers, ester derivatives of acrylic acid polymers, methacrylic acid polymers, ester derivatives of methacrylic acid polymers, copolymers thereof, and/or combinations thereof. An embodiment of the system  100  including the polymer layer  28  may exhibit a media gloss ranging from about 20 gloss units to about 100 gloss units when measured at an angle of 75°.  
      Referring now to  FIG. 6 , an embodiment of the system  100  may include a combination of the layer(s) disclosed herein. In the example embodiment shown, the substrate  12  has a base coat  22  established on its second face  16 , and an inorganic layer  24  established on its first face  14 . The composition  10  is established on the inorganic layer and forms a toner receiving layer. An embodiment of the polymer layer  28  is established on the composition  10 .  
      In an embodiment of the method, the composition  10  is provided and is established on the substrate  12  to form a toner receiving layer. It is to be understood that the composition may be provided by mixing the polymeric binder material  18  with the organic hollow particles  20 . The composition  10  may be homogeneous, heterogeneous, or a combination thereof, where portions of the composition are homogeneous and other portions are heterogeneous.  
      The method may also include establishing the back coat  22  on one of the first or second faces  14 ,  16 , such that it is opposed to the composition  10 . Another embodiment of the method includes establishing the inorganic layer  24  between the composition  10  and the substrate  12 . Still other embodiment(s) of the method include establishing an embodiment of the polymer layer  28  on the composition  10  (i.e. toner receiving layer). It is to be understood that each of the various compositions, coatings, or layers may be established by blade coating processes, rod coating processes, air-knife coating processes, curtain coating processes, slot coating processes, cast coating processes, extrusion coating processes, transfer coating processes, size press processes, jet coating processes, or combinations thereof.  
       FIG. 7  depicts an alternate embodiment of the system  100 ′. In this embodiment, an inorganic layer  24  is established on the substrate  12 . The polymer layer  28  (including the solid particles  32 ) is established on the inorganic layer  24 . It is to be understood that the polymer layer  28  may act as a toner receiving layer.  
      The composition  10  and systems  100 ,  100 ′ are suitable for use in electrophotographic printing. In one non-limitative example, a surface temperature of the fuser of the printer used may range from about 50° C. to about 220° C., or from about 150° C. to about 220° C. It is to be understood that these temperatures may be suitable for deforming the organic hollow polymeric particles  20  of the system  100  to form a thin layer.  
      Embodiment(s) of the toner receiving composition  10  and system  100 ,  100 ′ include, but are not limited to the following advantages. High and stable gloss levels may be achieved when images are printed on embodiment(s) of the system  100 ,  100 ′ via an electrophotographic printer. The toner receiving composition  10  may be incorporated on various types of media, thus providing the media with the capability of receiving toner in a manner that yields gloss uniformity between the media and toner. Still further, embodiment(s) of the composition  10  and system  100 ,  100 ′ may achieve high image resolution and color gamut, thus substantially providing photo-quality images.  
      While several embodiments of the invention have been described in detail, it will be apparent to those skilled in the art that the disclosed embodiments may be modified. Therefore, the foregoing description is to be considered exemplary rather than limiting.