Water robustness of inkjet prints using paper precoat and methods thereof

Abstract

To provide a system for improving water fastness of printed documents.SOLUTION: A system for improving water fastness of printed documents includes: a paper transport configured to move paper along a path throughout the system for improving water fastness; a precoat application subsystem that is located along the path of the paper transport and may include a precoat composition applicator adjacent to or in contact with the paper transport; a printhead configured to eject ink onto a surface of the paper in an imagewise fashion; and a dryer. Also described are a method for improving water fastness of printed documents and a water fastness precoat composition for printed documents, including a non-functional silicone fluid, a functional silicone fluid, or a combination thereof.SELECTED DRAWING: None

Description

[Technical field]

[0001] TECHNICAL FIELD The present teachings relate generally to systems and methods for pre-coating paper, and more particularly to inkjet prints using pre-coated paper. [Background technology]

[0002] Digital acoustic ink jet (AIJ) printing is an area of ​​strategic growth for several production class printing systems. Printers or consumers of printed materials making or considering a transition from dry powder (electrophotographic) printing systems to acoustic ink jet printing systems or presses require maintaining existing image quality (IQ) and print permanence and durability properties while reducing running costs per kiloprint (kp). Exemplary printing systems using acoustic ink jet printing methods have significantly improved print image quality that matches or exceeds current electrophotographic printing methods.

[0003] However, one of the disadvantages of AIJ prints versus electrophotographic prints is image durability with respect to water resistance. Since AIJ inks are water-based, prints are not as durable to exposure to water as toner or dry powder prints. This can be especially true for uncoated media or uncoated paper, where there is no barrier coating on the paper. Approximately 80% of media usage areas in production AIJ printing systems use uncoated or uncoated paper media.

[0004] It is therefore desirable to develop or design a method or system for improving the water fastness of AIJ prints on uncoated media, which could be a valuable product feature or add-on that opens new opportunities and uses for aqueous-based inkjet printing systems. Summary of the Invention

[0005] The following presents a simplified summary in order to provide a basic understanding of some aspects of one or more embodiments of the present teachings. This summary is not an extensive overview, and is not intended to identify key or critical elements of the present teachings or to delineate the scope of the disclosure. Rather, its primary purpose is merely to present one or more concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0006] A system for improving waterfastness of a printed document is disclosed. The system includes a paper transport configured to move paper along a path through the system to improve waterfastness, a precoat application subsystem located along the path of the paper transport and may include a precoat composition applicator adjacent to or in contact with the paper transport, a printhead configured to eject ink onto a surface of the paper in an imagewise manner, and a dryer. Implementations of the system for improving waterfastness of a printed document may include where the precoat application subsystem may include one or more rollers positionable to contact the surface of the paper. The precoat application subsystem may include a liquid ejector positionable to eject droplets onto the surface of the paper in an imagewise manner. The system for improving waterfastness of a printed document may include a precoat composition including a silicone fluid. The precoat composition may further include a non-functional silicone fluid or an amine-functional silicone fluid. The precoat composition may include a pendant propylamine, a terminal propylamine, or a combination thereof. The precoat composition may further include a propylmercapto-functional silicone or a fluoro-functional silicone. The precoat composition, also referred to herein as a pretreatment composition, may further have a viscosity of from about 10 cP to about 5000 cP when measured at 25° C. The precoat application subsystem is external to the printhead and dryer. The paper may be in the form of a continuous web or one or more individual sheets.

[0007] A method for improving the waterfastness of a printed document is disclosed. The method for improving the waterfastness of a printed document includes applying a precoat composition to a surface of a paper and printing an image, which may include using an aqueous ink on the surface of the paper. The method for improving the waterfastness of a printed document also includes heating the surface of the paper, the precoat composition, and the aqueous ink. Implementations of the method for improving the waterfastness of a printed document may include where the precoat composition is applied to the surface of the paper using a precoat application subsystem that includes one or more rollers positionable to contact the surface of the paper. The precoat composition applied to the surface of the paper is applied using a precoat application subsystem that may include a liquid ejector positionable to eject droplets imagewise onto the surface of the paper. The method for improving the waterfastness of a printed document may further include a pause of up to 24 hours between applying the precoat composition to the surface of the paper and printing an image onto the surface of the paper using an aqueous ink. The precoat composition may include an amine-functional silicone fluid or a non-functional silicone fluid.

[0008] A water-resistant precoat composition for printed documents includes a non-functional silicone fluid. The composition can include a functional silicone fluid, the functional silicone fluid being present in the water-resistant precoat composition in an amount of about 1% to about 30% by weight, based on the total weight of the water-resistant precoat composition, and the non-functional silicone fluid being present in the water-resistant precoat composition in an amount of about 50% to about 99% by weight, based on the total weight of the water-resistant precoat composition.

[0009] The described features, functions, and advantages may be achieved independently in various implementations or may be combined in yet other implementations, further details of which may be understood with reference to the following description. [Brief description of the drawings]

[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present teachings and, together with the description, serve to explain the principles of the disclosure.

[0011] [Figure 1] FIG. 1 is a schematic diagram of a system and method for pre-coating paper prior to inkjet printing according to the present disclosure. [Diagram 2] 1 is a flow chart illustrating a method for pre-coating paper prior to inkjet printing according to the present disclosure.

[0012] It should be noted that some details of the figures have been simplified and precise structural accuracy, detail, and scale are not maintained, but are drawn to facilitate understanding of the present teachings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Reference will now be made in detail to the exemplary embodiments of the present teachings, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same, similar or like parts.

[0014] The present disclosure provides an in-line paper precoat process using silicone-based fluids to improve the water resistance of prints on uncoated paper after printing with aqueous or water-based inks. A precoat or pretreatment composition containing silicone fluids according to the present disclosure, applied in-line as a precoat using a roll or spray system, coats the paper fibers on the surface of the paper, and since the paper is uncoated, the precoat composition penetrates into the paper fibers. Silicone fluids, sometimes referred to as silicone oils, are hydrophobic and improve the water repellency of prints, which results in the printed paper being more durable against exposure to water. Silicone fluids are currently used in printing, most notably as fuser release fluids. These compositions are non-toxic, inexpensive, can be chemically tailored to include useful functional groups, such as amines, acids, thiols, hydrides, etc., and are well tolerated in existing paper recycling facilities that currently handle toner prints with oil on one or more surfaces of the paper. Various methods of application of a controllable metered amount of the precoat composition onto the paper, such as existing release agent management (RAM) systems including donor rolls, or methods of ejecting the precoat composition or fluid, may also allow for selective digital or variable placement only on the paper surface onto which the ink is jetted. Thus, application of the precoat composition onto one or more surfaces of the paper may be applied either intermittently or continuously. This intermittent or continuous application may be achieved by the application of the precoat composition or by the nature of the medium fed through the printing system. For example, in certain printing systems, the paper or print medium may be a continuous web of paper or may be comprised of cut sheets or individual pieces of paper. In an example of the use of a RAM system, a fluid donor roll may be positionable between the fluid supply and the surface of the paper. In an example, the fluid donor roll may be engaged or moved so as to be partially immersed in the fluid or positioned in contact with the surface of the paper, simultaneously, or moved in such a way that the donor roll is immersed in the fluid supply for a time frame and then contacts the surface of the paper.During some printing operations, the time scale between the precoat step and the printing step may be relatively short, such as on the order of 10-1000 ms. In other instances, the time scale may be longer, for example, when the precoat step and system are separate or not integrated with the printing step and / or operation in a common machine or printing system. In other instances, surface bonding or bonding after printing may be affected by the use of some precoat compositions. These bonding effects may be mitigated by drying or heating the ink with the precoat composition on the surface of the paper. The high temperature of the drying step may initiate a reaction between the precoat composition and the ink composition. Although the exact formula and components of the ink formulation may vary, water-based inks typically include water, co-solvents such as propylene glycol, hexanediol, butanediol, and glycerol, surfactants, pigments, biocides such as Proxel™, pH adjusters such as triethanolamine, and latexes such as styrene acrylate copolymers or emulsified polyurethanes. Exemplary ink components along with the amounts of some typical compositions are shown in Table 1 below. Without being bound to a particular theory, it is hypothesized that one or more components in the precoat composition react with one or more components in the ink to make the image formed by the ink and precoat composition more robust when dried. For example, functional silicone fluid components, such as amine functional, may react and / or crosslink with the latex resin in the ink. In a particular example, the amine functional group of the silicone-based precoat composition may react with the carboxylic acid (-COOH) functional group in the latex component of the ink. Furthermore, the amine group in the precoat composition may additionally have non-covalent H-bond interactions with the ink pigment, ink latex, and paper. Although various latex or resin components may be utilized in the ink formulation, the selection of the precoat components may also be varied based on the ink composition used in the printing system to further improve image durability and water resistance with the precoat composition and method of the present disclosure. [Table 1]

[0015] In other examples, application of the precoat composition may be accomplished in an image-wise manner, such as by selective ejection or spray application. In an illustrative example, the printhead assembly or array, or liquid ejector, may be positionable, i.e., translatable across the lateral dimension of the paper (side to side), or may be movable further away from or closer to the surface of the paper, or may be addressable to activate only certain jets to eject droplets or liquid drops of the precoat composition onto the surface of the paper in an image-wise manner. In this context, image-wise may be defined as applying the precoat formulation to approximately the location on the paper surface that corresponds to the location on the paper where the ink ejector printhead will later print an image in approximately the same location on the same surface of the paper. Each subsequent page, sheet, or section of the continuous paper web may have the same image printed on the surface of the paper, and thus will have the precoat composition applied to the same or similar location on the surface of the paper as the image or ink applied to the surface of the paper. In other examples, each subsequent page, sheet, or section of the continuous paper web may have a different or variable image printed on the surface of the paper, and thus will have a precoat composition applied to variable locations on the surface of the paper that are the same or similar to the variable image or ink applied to the surface of the paper.

[0016] The present disclosure provides a polymer-based fluid or fluid blend comprising a non-functional silicone fluid and an amine-functional or other functional silicone fluid as a water-resistant precoat composition. These fluids alone, blends of one or more of these fluids, or base precoat compositions comprising these fluids and optionally containing other additives or adjuvants, and other examples, can be fabricated by simply mixing the various fluids together at room temperature using an overhead stirrer, with or without additional carriers, solvents, or other materials. The various precoat compositions comprising silicone fluids described herein and their respective components will be completely miscible with each other. The chemical structures of some of the components of one or more exemplary silicone fluid components are shown below: [ka] [ka]

[0017] As mentioned above, non-functional silicone fluids can also be referred to as non-fluorinated non-functional silicone fluids. These non-functional silicone fluids can also be referred to as PDMS, an abbreviation for polydimethylsiloxane. Similarly, functional silicone fluids can also be referred to as non-fluorinated functional silicone fluids. It should be understood by those skilled in the art that non-fluorinated non-functional silicone fluids do not contain any fluorine atoms in their chemical structure or composition, and non-fluorinated functional silicone fluids do not contain any fluorine atoms in their chemical structure or composition. Some precoat compositions can include components that contain fluorine functional groups. In examples, the chemical functionality referred to herein can be pendant or terminal, with respect to when the chemical functionality is attached to a silicone or polydimethylsiloxane polymer chain.

[0018] Additional functional silicone fluids used in the precoat composition can include, but are not limited to, silicone fluids with functional groups, either containing fluorine atoms or not, such as hydride-terminated or hydride-pendant functional silicone fluids, including hydrogenated dimethyl, hydrogenated methyl, or combinations thereof.Additional illustrative examples can include mercapto-terminated or mercapto-pendant functional silicone fluids, including functional groups such as (3-mercaptopropyl)trimethoxy-, (3-mercaptopropyl)triethoxy-, 11-mercaptoundecyltrimethoxy-, s-(octanoyl)mercaptopropyltriethoxy-, (mercaptomethyl)methyldiethoxy-, 3-mercaptopropylmethyldimethoxy-, mercaptopropyltrialkoxy-, such as mercaptopropyltrimethoxy-, 3-mercaptopropyltrimethoxy-, mercaptoundecyltrimethoxy-, (mercaptomethyl)methyldiethoxy-, or combinations thereof. Additional illustrative examples can include amine-terminated or amine pendant functional silicone fluids. The amine functional groups can further include primary amines, secondary amines, tertiary amines, or combinations thereof.

[0019] Examples of amine functional groups include 3-aminopropyltrimethoxy-, 3-aminopropyltriethoxy-, 3-aminopropylmethyldimethoxy-, 3-aminopropylmethyldiethoxy-, 3-aminopropyldimethylethoxy-, 3-(2-aminoethylamino)propyltrimethoxy-, 3-(2-aminoethylamino)propyltriethoxy-, 3-(2-aminoethylamino)propyldimethoxymethyl-, 3-(2-aminoethylamino)propyldiethoxymethyl-, 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxy, and 3-[2-(2-aminoethylamino)ethylamino]propyltriethoxy-. , 3-3-aminopropyltris(2-(2-methoxyethoxy)ethoxy)-, 3-aminopropyltriisopropenyloxy-, 3-aminopropyltri(butanoneoximo)-, 4-aminobutyltriethoxy-, N-2-(aminoethyl)-3-aminopropyltris(2-ethylhexoxy)-, 3-aminopropyldimethylethoxy-, 3-aminopropyldiisopropylethoxy-, p-aminophenyltrimethoxy-, m-aminophenyltrimethoxy-, 3-aminopropylphenyldiethoxy-, 3-aminopropyltriethoxy-, and 3-aminopropyltrimethoxy-, or combinations thereof.

[0020] Additional examples of non-functional silicone fluids may include fluids having repeating units of Si(CH3)2O- as shown generally herein, either in a linear or branched polymer structure, with or without additional chemical functionality. The structure, properties, and behavior of branched silicones are known to those skilled in the art. The precoat compositions described herein may contain additional surfactants or additives to improve performance, but are essentially water-free or contain only trace amounts of water.

[0021] 1 is a schematic diagram of a system and method for pre-coating paper prior to inkjet printing according to the present disclosure. A schematic diagram of a system 100 for improving water fastness of a printed document is shown, the system 100 including a precoat application subsystem 102 including precoat composition applicators 102A, 102B, 102C located along a path 118 of a paper 106 transport adjacent to or in contact with the paper transport 108. The precoat application subsystem 102 is configured to apply a precoat composition 104 to a surface of the paper 106 prior to forming an image on the paper 106 using a water-based ink.

[0022] In one example shown, a donor roll of a RAM-type precoat application subsystem 102A is shown, and as the paper 106 moves between the rollers of the RAM-type precoat application subsystem 102A, the rollers contact the paper transport 108 and the surface of the paper 106, and the precoat composition 104 is applied to the surface of the paper as it passes through the precoat application subsystem 102. In another example, as the paper 106 moves between the spray-type precoat application subsystem 102B and the paper transport 108, a spray-type precoat application subsystem 102B is shown proximate the surface of the paper 106, and the precoat composition 104 is applied to the surface of the paper 106 as it passes through the precoat application subsystem 102. The spray-type precoat application subsystem 102B can be or include an aerosolization head for forming and projecting an aerosolized version of the precoat composition 104 onto the surface of the paper 106 in aerosol or atomized form. One skilled in the art would know that appropriate pressure settings, spray tip configuration, and temperature handling, as well as other attributes, of this spray-type precoat application subsystem 102B are used in a manner consistent with applying a consistent or constant thickness of precoat composition 104 onto the surface of the paper 106. In a third example, a dispenser or jet-type precoat application subsystem 102C is shown for applying the precoat composition 104 to the surface of the paper 106 as the paper 106 passes through the precoat application subsystem 102. In this example, a standard printhead assembly or arrangement may be used and the precoat composition 104 may be applied continuously or only imagewise.

[0023] In the system 100 for improving waterfastness of printed documents, a paper transport moves paper 106 along a path throughout the system 100. Additionally, along the paper transport 108 are printheads 110 that eject one or more colors or types of ink in an image-wise manner onto the surface of the paper. In the example shown in FIG. 1, four separate printheads 110A, 110B, 110C, 110D are shown, each of which deposits or ejects a respective color ink 112A, 112B, 112C, 112D onto the paper 106 on top of the precoat composition 104 previously applied by the precoat application subsystem 102. After printing, the paper 106 is transported along the paper transport 108 proximate a dryer 114, where each color ink 112A, 112B, 112C, 112D on the paper 106 is dried or heated or conditioned to produce a waterfast print 116. In examples, one color may be used, or up to ten colors may be used. In other examples, more than one precoat composition 104 may be used. In examples, the paper path 118 may provide the paper 106 or portions of paper to each station of the system 100 in succession, or there may be pauses between stations. For example, the paper 106 may have the precoat composition 104 applied and may have no images printed on the pre-processed paper for up to 24 hours. Additionally, the precoat application subsystem 102 may be integrated into the same machine as the rest of the system 100, as shown in FIG. 1, or may be separate and external from the printing and drying operations of the system 100, with the precoat application subsystem 102 being external to the printhead 110 and dryer 114.

[0024] In an example, the system for improving the water fastness of a printed document may include a case where one or more donor rolls of a RAM-type precoat application subsystem 102A precoat application subsystem are positionable to contact the surface of the paper. An illustrative example of the system 100 for improving the water fastness of a printed document may include a case where the precoat composition includes a silicone fluid, which may include a non-functional silicone fluid, a functional silicone fluid, such as an amine-functional silicone fluid, or a combination thereof. In an example, the precoat composition may include a pendant propylamine, a terminal propylamine, or a combination thereof, as further described herein. Alternatively, the precoat composition includes a propylmercapto-functional silicone or a fluoro-functional silicone. Consistent with the capabilities of the precoat application subsystem 102 implemented in some formats or delivery types, the precoat composition may have a viscosity of about 10 cP to about 5000 cP, measured at 25° C. In an example, the paper 106 is in the form of a continuous web, or the paper 106 is in the form of one or more individual sheets or separate precut sheets. In the case of a continuous web, the paper 106 may be cut or separated after printing.

[0025] FIG. 2 is a flow chart illustrating a method for pre-coating paper prior to inkjet printing according to the present disclosure. The method for improving the waterfastness of a printed document 200 includes applying a precoat composition to a surface of the paper 202, printing an image composed of water-based ink on the surface of the paper 204, and heating the surface of the paper, the precoat composition, and the water-based ink 206. In an example, the steps of heating the surface of the paper, the precoat composition, and the water-based ink 206 are performed after applying the precoat composition to the surface of the paper 202 and printing an image composed of water-based ink on the surface of the paper 204. In other examples, these steps may be performed in a different order, or one or more of the steps may be repeated at any point in the method for improved waterfastness and durability properties. The method for improving the waterfastness of a printed document 200 includes implementations in which the precoat composition is applied to the surface of the paper using a precoat application subsystem, which further includes one or more rollers positionable to contact the surface of the paper. As previously mentioned, the precoat composition may be applied using a liquid dispenser, or a spray or mist device. It is possible to wait up to 24 hours between applying the precoat composition and printing the image. The precoat composition itself can be comprised of an amine-functional silicone fluid, a non-functional silicone fluid, or a combination of other compositions or materials described herein.

[0026] Important advantages of the present disclosure include improved water resistance durability of uncoated stock prints. Uncoated stock is less expensive and accounts for approximately 80% of media usage for a printer equivalent to the system described herein. The silicone fluid design and delivery system can be easily implemented in such a printing system, and silicone fluid is inexpensive and non-toxic. The compositions and methods of the present disclosure are primarily applicable to uncoated paper or uncoated media, but they should also be applicable to coated paper or coated media. Uncoated paper can be defined as paper manufactured without a surface coating. Uncoated paper can be treated or manufactured for specific properties, but coated paper, known to those skilled in the art, is typically manufactured with a sealant or coating to provide a less porous paper surface compared to uncoated paper. The methods and compositions described herein can work with coated paper as long as there is functional compatibility between the coating and the precoat treatment composition. In the example using uncoated paper, the precoat composition can remain on the top surface of the paper.

[0027] experiment Acoustic inkjet (AIJ) inks are water-based, in other words, they contain water-based components. It has been demonstrated that such inks can be printed on paper that has a hydrophobic silicone fluid deposited thereon. Furthermore, the prints have been shown to be stable and robust with acceptable image quality (IQ). Testing was performed on Lynxjet® uncoated paper available from Domtar (Fort Mill, SC, USA). The Lynxjet® sheet was passed through an iGen fuser to precoat the silicone fluid onto the paper. Both the coated sheet of the precoat or precoat composition and the control uncoated sheet were then printed on an inkjet single dryer printer using the customer's preferred print set and set points.

[0028] The results demonstrated that there was no significant difference between AIJ prints on silicone fluid precoated paper / non-silicone fluid precoated paper. The customer preferred prints were evaluated by an image quality expert in a subjective review and verified that the appearance of the prints was virtually identical when coated with the water-resistant precoat composition and uncoated prints, as shown in Table 2 below. The solid 100% area coverage (AC) ink patch optical density using an Xrite spectrophotometer for the coated and uncoated prints was also similar. Image fastness was measured using a Taber Linear Abrasion Tester using a standard test protocol that included measuring OD and gloss before and after rubbing after 15 rubs at 30 cycles / min. Optical density (OD) was measured using an X-rite Exact portable spectrophotometer. Gloss measurements were made using a BYK Gardner Micro-Tri Gloss Glossmeter. OD and gloss measurements and their meanings are well known to those skilled in the art as they provide a numerical characterization or quantification of how dark and glossy a print patch appears. For each measurement, the respective meter is placed on the patch and the measurement is performed according to the device's instructions. As shown in Table 3 below, there is no significant difference between the prints with and without the precoat composition, indicating that the prints on the paper with the release layer are robust. The potential drawback of silicone fluid on the surface of the paper, such as the customer being unable to bind or write on the page, and post-it notes or tape not sticking, is not seen when printing with water-based ink on top of the silicone fluid-based precoat composition. In these evaluations, the tape adhered very well to the ink patch on top of the paper with the silicone fluid-based precoat composition.

[0029] Image quality analysis and comparison. [Table 2] [Table 3]

[0030] The waterfastness bench test involves applying water to a black band (100% solid area) on the printed image using a foam brush. After a one minute wait period, the band is rubbed five times with a typical cleanroom lint-free cloth wipe. The silicone fluid-containing precoat composition has been demonstrated to significantly improve the waterfastness of the print.

[0031] Precoat Composition Examples Silicone fluid blends were made by mixing various weight ratios of a non-functional fluid (AK300, Wacker Silicones) and an amine-functional fluid (Copy Aid, designated CA-200 or CA-270, Wacker Silicones) and blending them together in a vessel using an overhead stirrer. The Copy Aid series of fluids contain pendant N-(2-aminoethyl)-3-aminopropylamine functional polydimethylsiloxanes with viscosities ranging from 10 to 10,000 cP (measured at 25° C.) based on the grade or molecular weight of the fluid used.

[0032] In the above chemical structures for the non-functional and amine-functional fluids, these silicone fluids have structures where n=100-10000, m=1-1000, and the resulting viscosity of the individual or blended fluids is 10-10,000 cP. Illustrative examples include n as an integer from 10 to 10000, and m as an integer from 1 to 1000, with viscosities from about 10 to about 1000 cP. It should be noted that all viscosity values ​​are reported as measured at room temperature or at or near 25° C.

[0033] Exemplary blend fluids were made as shown in Table 3 below. For the silicone fluids mentioned in Table 4, the chemical compositions of AKF290, polydimethylsiloxane (PDMS)-based non-functional silicone fluid, and polydimethylsiloxane (PDMS)-based functional silicone fluid are shown herein. Fluids designated CA-200 or CA-270 are the amine-functional silicone fluids mentioned above. In describing viscosity, it should be noted that the unit of centistokes (cSt) is considered equivalent to centipoise (cP) by those skilled in the art. It should be noted that all values ​​of viscosity are determined at a temperature of about 20°C to 30°C, nominally 25°C.

[0034] Chemistry (functional group identity and mole %), molecular weight, viscosity, surface tension, etc. can all be optimized to obtain the best deinking. For example, functional groups can be introduced into the release fluid that repel pigments or paper fibers when exposed to deinking conditions. In the following examples, viscosity and other characteristics are representative only and non-limiting, and ranges may be varied or modified based on starting blend materials, lot-to-lot variations, or other compositional attributes of the precoat composition. [Table 4]

[0035] Although the present teachings are described with respect to one or more implementations, changes and / or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. For example, while a process is described as a series of acts or events, it may be understood that the present teachings are not limited by the order of such acts or events. Some acts may occur in different orders and / or simultaneously with other acts or events other than those described herein. Also, not all process steps may be required to implement a methodology in accordance with one or more aspects or embodiments of the present teachings. It may be understood that structural objects and / or processing steps may be added, or existing structural objects and / or processing steps may be removed or modified. Furthermore, one or more of the acts described herein may be performed in one or more separate acts and / or steps. Additionally, to the extent the terms "including," "includes," "having," "has," "with," or variations thereof are used in either the Detailed Description and the Claims, such terms are intended to be inclusive in a manner similar to the term "comprising." The term "at least one" is used to mean that one or more of the listed items may be selected. Additionally, in the discussion and claims herein, the term "on" as used in reference to two materials, one "on" meaning at least some contact between the materials, while "over" means that the materials are in close proximity to one or more additional intervening materials, such that contact is possible, but not required, in some cases. Neither "on" nor "over" implies any directionality when used herein. The term "conformal" describes a coating material in which the angles of the underlying material are maintained by the conformal material. The term "about" indicates that the recited value may be varied slightly unless such variation would result in incompatibility of the process or structure with respect to the embodiment shown.The terms "couple," "coupled," "connect," "connection," "connected," "connected with," and "connecting" refer to "directly connected with" or "connected through one or more intermediate elements or members." Finally, the term "exemplary" or "illustrative" indicates that the description is not meant to be ideal but is used as an example. Other embodiments of the present teachings may be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. It is intended that the specification and examples be considered as merely exemplary, with a true scope and spirit of the present teachings being indicated by the following claims.

Claims

1. 1. A system for improving water fastness of a printed document, comprising: a paper transport configured to move paper along a path through the system to improve water fastness; a precoat application subsystem including a precoat composition applicator located along the path of the paper transport adjacent to or in contact with the paper transport; a printhead configured to eject ink onto a surface of the paper in an image-wise manner; A dryer and 23. A system for improving water fastness of a printed document, comprising:

2. The system for improving water fastness of a printed document of claim 1 , wherein the precoat application subsystem further comprises one or more rollers positionable to contact a surface of the paper.

3. The system for improving water fastness of a printed document of claim 1 , wherein the precoat application subsystem includes a liquid ejector positionable to eject droplets of liquid onto the surface of the paper in an imagewise manner.

4. 10. The system for improving water fastness of a printed document of claim 1, further comprising a precoat composition comprising a silicone fluid.

5. The system for improving the water fastness of a printed document of claim 4 , wherein the precoat composition further comprises a non-functional silicone fluid.

6. The system for improving the water fastness of a printed document of claim 4 , wherein the precoat composition further comprises an amine functional silicone fluid.

7. The system for improving the water fastness of a printed document of claim 6 , wherein the precoat composition further comprises a pendant propylamine, a terminal propylamine, or a combination thereof.

8. The system for improving the water fastness of a printed document of claim 4 , wherein the precoat composition further comprises a propyl mercapto functional silicone.

9. The system for improving the water fastness of a printed document of claim 4 , wherein the precoat composition further comprises a fluorofunctional silicone.

10. 5. The system for improving water fastness of a printed document of claim 4, wherein the precoat composition further has a viscosity of from about 10 cP to about 5000 cP when measured at 25.degree.

11. The system for improving water fastness of printed documents of claim 1 , wherein the precoat application subsystem is external to the printhead and the dryer.

12. The system for improving water fastness of a printed document of claim 1 , wherein the paper is in the form of a continuous web.

13. The system for improving water fastness of a printed document of claim 1 , wherein the paper is in the form of one or more individual sheets.

14. 1. A method for improving the water fastness of a printed document, comprising: applying a precoat composition to a surface of the paper; printing an image composed of water-based ink onto the surface of the paper; heating the surface of the paper, the precoat composition, and the water-based ink; 16. A method for improving the water fastness of a printed document, comprising:

15. 15. The method for improving the water fastness of a printed document of claim 14, wherein the precoat composition is applied to the surface of the paper using a precoat application subsystem further comprising one or more rollers positionable to contact the surface of the paper.

16. 15. The method for improving the water fastness of a printed document of claim 14, wherein the precoat composition is applied to the surface of the paper using a precoat application subsystem including a liquid ejector positionable to eject droplets onto the surface of the paper in an imagewise manner.

17. 15. The method for improving the water fastness of a printed document of claim 14, further comprising resting for up to 24 hours between applying the precoat composition to the surface of the paper and printing the image composed of the water-based ink onto the surface of the paper.

18. The method for improving the water fastness of a printed document of claim 14, wherein the precoat composition comprises an amine functional silicone fluid.

19. The method for improving the water fastness of a printed document of claim 14, wherein the precoat composition comprises a non-functional silicone fluid.

20. 1. A water-resistant precoat composition for a printed document, comprising: a non-functional silicone fluid; a functional silicone fluid; the functional silicone fluid is present in the water-resistant precoat composition in an amount of from about 1% to about 30% by weight, based on the total weight of the water-resistant precoat composition; the non-functional silicone fluid is present in the water-resistant precoat composition in an amount of from about 50% to about 99% by weight, based on the total weight of the water-resistant precoat composition; A water-resistant precoat composition for printed documents.

Images