Patent Application
20080080913
Before the present methods, systems and materials are described, it is to be understood that this disclosure is not limited to the particular methodologies, systems and materials described, as these may vary. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope. For example, as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. In addition, the word “comprising” as used herein is intended to mean “including but not limited to.” Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.
Embodiments presented herein may generally be directed to a cleaning agent that may be applied to printed materials to remove residual release agent on printed media prior to the application of adhesives as in a binding process, lamination of the printed material, and/or imprinting the printed material with, for example, metallic leaf MICR encoding, and the like. Without wishing to be bound by theory, the removal of residual release agents from printed material may allow adhesives, laminates, and imprinted material to bind to the printed material more readily thereby improving the quality of the final product.
The cleaning agents, of embodiments, may include at least one solvent, such as water or an organic solvent, and may contain one or more active ingredient broadly defined as surfactants, organic solvents, chelating agents, organic acids and inorganic acids, and transition metals or transition metal salts. Without wishing to be bound by theory, the active ingredients in the cleaning agent may cleave the polymer backbone of release agents freeing the release agent from the printed material, and the solvent may dilute the cleaved release agent allowing it to be washed away from or absorbed into the surface of the printed material. In some embodiments, a surfactant may be provided with the cleaning agent which may interact with the cleaved release agent inhibiting the rebinding of the release agent to the surface of the printed material or sequestering the cleaved particles of release agent allowing them to be more effectively washed away.
The concentration of active ingredients may vary among embodiments depending upon the type of toner, the type of support media, the final product, or combinations of these used in the printed material. In general, the concentration of the active agent may be determined such that the residual release agent is removed without disrupting the printed material by causing, for example, smearing, removal, or loss of color of the fused toner image. It is well within the prevue of the skilled artisan to determine the concentration of the one or more active agent that is most useful and to the dilute or concentrate the cleaning agent accordingly. For example, the cleaning agents of embodiments may be diluted by about 1:2 to 1:25 with water or solvent to accommodate various toner compositions.
Surfactants that may be used in embodiments are well known in the art and may commonly be referred to as soaps or detergents. Generally, a surfactant may include a molecule having a hydrophobic and hydrophilic part that is capable of emulsifying particles and keeping them suspended in solution, so that they may be washed away. Surfactants may be categorized based on their charge and include: anionic surfactants such as, for example, linear alkylbenzene sulfonate, alcohol ethoxysulfates, alkyl sulfates, lautyl sulfate, sodium xylene, sulfonate toluene, sulfonic acid and salts thereof sulfosuccinate salts, phosphonate esters, fatty acids and salts thereof, alkylpolyglucosides, soaps and the like; nonionic surfactants such as, for example, alcohol ethoxylates and the like, cationic surfactants including, but not limited to, quaternary ammonium compounds; and amphoteric surfactants whose charge is dependent on the pH of the cleaning agent such as, for example, midazolines, betaines and the like, all of which may be used in embodiments. The concentration of surfactant may vary in embodiments, and may from about 0.5% to about 10% by weight of the total cleaning agent in some embodiments and from 3% to 7% in other embodiments.
Organic solvents may act, in embodiments, by attacking amines within the polymer backbone of release agents thereby cleaving the backbone and carrying the cleaved release agent away from the surface of the printed materials. Organic solvents are well known in the art and commonly used in cleaning products. Non-limiting examples of organic solvents include, aliphatic and aromatic hydrocarbons which may be saturated or unsaturated, such as, isobutene, toluenes, cyclohexanes and the like; ketones, such as, acetone, N-butyl acetate, methyl ethyl ketone, and the like; alcohols, such as, ethanol, methanol, isopropanol, and the like; ethers, such as, ethyl ether and the like; halogenated hydrocarbons, such as, trichloroethylene, perchloroethylene and the like; phosphates, such as, trisodium phosphate (TSP), and the like; mineral spirits, and combinations thereof In some embodiments, other active ingredients, such as, for example, a chelating agent may be dissolved within organic solvent to enhance the effectiveness of the cleaning agent. The concentration of the organic solvent in a cleaning agent may be up to 100% by volume, in embodiments, and up to 99.5% in other embodiments.
One or more chelating agents may be an active ingredient in a cleaning solution of some embodiments, and in certain embodiments, one or more chelating agents may be used in combination with at least one surfactant. Chelating agents may, generally, be described as compounds that are capable of binding to metal ions. In embodiments, the chelating agent may bind directly to metal ions in release agents causing a breakdown of the release agent and/or effectively removing the release agent from the surface of the printed material. In other embodiments, the chelating agent may bind metal ions in the cleaning agent or on the printed material that may interfere with the action of the at least one surfactant. Therefore, the combination of a chelating agent and a surfactant may be especially effective for removing residual release agent. Chelating agents are well known in the art and include, but are not limited to, ethylenediaminetetraacetic acid (EDTA), sodium citrate, dimethylsulfoxide (DMSO), methylglycine diacetic acid (MGDA), zeolite compounds, and combinations of these and may be from about 1% to about 50% by weight of the total cleaning agent. However, there may be no upper limit to the concentration of chelating agent used in embodiments. In embodiments including the combination of one or more chelating agent and at least one surfactant, the chelating agent may be from about 1% to about 50% and the surfactant may be from about 0.5% to about 10% by weight of the total cleaning agent.
In embodiments, the cleaning agent may contain an organic or inorganic acid which may effectively disrupt the residual release agent without disturbing the fused toner of the printed material. Inorganic acids are well known in the art and include, but are not limited to, boric acid, carbonic acid, chloric acid, hydrochloric acid, nitric acid, sulfuric acid, perchloric acid, hydrofluoric acid, phosphoric acid, pyrophosphoric acid, and combinations thereof. Organic acids useful in embodiments may include those organic acids known in the art to be useful in cleaning agents, such as, aliphatic inonocarboxylic acids, aliphatic dicarboxylic acids, citric acid, acetic acid, oxalic acid, hydroxyacetic acid, benzoic acid, propinoic acid, and the like and combinations thereof Acids of embodiments may be dissolved in water to create an aqueous solution or in an organic solvent, and the acid may make up from about 1% to about 15% by weight of the total solution. The pH of the cleaning agent in which the acid solution is used may be from about 1 to about 5.
In other embodiments, the cleaning agent may contain a transition metal or transition metal salt. Transition metals that may be useful in embodiments include but are not limited to zinc, nickel, copper, boron, chromium, and the like and salts and combinations thereof In some embodiments, the transition metal or transition metal salt may be dissolved in water or an organic solvent to make a cleaning agent that is then applied to the printed material. In other embodiments, a transition metal salt, such as, for example, zinc stearate, may be applied directly to the printed material as a powder. The concentration of the transition metal or transition metal salt in cleaning agents of embodiments may be from about 0.1% to about 25% by weight when the transition metal or transition metal salt is dissolved in a solution or may be up to 100% in a powder.
Cleaning agents of embodiments may further contain one or more auxiliary component, such as, for example; antifoaming, wetting agents, preservatives; colorants; antimicrobial agents, and the like, all of which are well known in the art and available to the skilled artisan.
Referring to
In some embodiments, the cleaning agent may be applied to the printed media and allowed to mix or react 14 with the release agent for an amount of time that is sufficient to physically break down the chemical structure of the release agent. For example, the cleaning agent may be permitted to rest on the media for a time sufficient to allow the media to become dry to the touch, such as by absorption and/or evaporation of the cleaning agent. In some embodiments, if absorption of release agent into the media causes the media to slightly deform, the cleaning agent will be permitted to rest on the media for a time sufficient to allow the deformation to substantially release so that the product appears un-deformed. Smaller segments of the release agent may then be removed 16 with the cleaning agent, such as by washing which may include rinsing or simply allowing the cleaning agent to evaporate or flow off of the printed media, or the release agent may absorb 18 into the substrate of the printed material.
In embodiments including the automatic application of the cleaning agent, an apparatus may be designed that applies the cleaning agent to the printed material after the printed material exits the fuser using a web or brush. The apparatus may be an integral part of the electrostatographic or xerographic machine or may be a stand alone apparatus into which the printed material is placed following the printing process, and in some embodiments, may be added onto a preexisting electrostatographic or xerographic machine so that the printed material is automatically fed into the apparatus following fusing.
In both by-hand and automatic embodiments, mechanical pressure may be applied to the printed material as the cleaning agent is applied. In most embodiments, the mechanical pressure may be light and applied in such a way so as not to disturb the fused toner on the printed image. In other embodiments, the cleaning agent may be applied to the entirety of the printed material. In certain embodiments, such as embodiments where the printed material will receive an adhesive 20, be laminated 22, be bound 24, or be further imprinted 26, the cleaning agent may be applied to the part of the printed material to which adhesive, laminate, or imprinting is to be placed. In some embodiments, the cleaning agent may be applied to substantially only the part or parts of the printed material to which adhesive, laminate, or imprinting is to be placed, so that other portions of the printed material are not substantially contacted by the cleaning agent. For example, the cleaning agent may be applied to the edge of the printed material to which adhesive will be placed during binding, or the portion of the printed material to which a MICR imprint will be placed may be cleaned.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
This application is related to co-pending U.S. patent application Ser. No. 11/424,243, filed Jun. 15, 2006, titled “Pre-Processing Cleaning of Pre-Printed Documents,” the disclosure of which is incorporated herein by reference in its entirety.
