MXPA98003460A - Sheet to print by jeting it - Google Patents

Abstract

This invention relates to an ink jet sheet having an ink receiving layer filled with particles and a protective overcoating layer filled with particles. The particles of both the ink receptive layer and the protective penetrating layer cause protrusions of the protective penetrating layer

Description

LEAF TO PRINT FOR INK JET TECHNICAL FIELD This invention relates to ink jet printing sheets suitable for use in marking applications and in particular to a printing sheet having a release surface in contact with an adhesive layer. This invention is further related to a method for printing using the printing sheet of this invention.

BACKGROUND OF THE INVENTION Various processes suitable for producing outdoor durable signals are known in the art, for example, by electrostatic printing processes, receivers and transfer methods for marking materials. These processes can produce useful materials in a variety of applications such as advertising, billboards, vehicle marking. However, they suffer from the disadvantage that the machinery requirements for these processes and articles are expensive and the machinery requires a relatively high maintenance and skill of the operator. REF: 27288 The process of inkjet printing is now well known. The examples of its applications are like computer printers for the production of documents and general transparencies. Recently, wide-format ink jet printers have become commercially available and, therefore, the printing of larger items such as large engineering drawings, blueprints and color posters and signs has become feasible. These printers are relatively cheap compared to many other copy production devices, for example, digital electrostatic printers. However, printers have all the usual advantages of computer-directed print production devices, where the image is like a positive photographic transparency, or printed can be scanned using scanning devices known in the art, stored on the disc of the computer, manipulated, re-stored, and printed, etc. In general, inkjet inks are totally or partially water-based and the receivers for these inks are typically simple papers or preferably special ink jet receptors, which are treated or coated to improve its receptor properties or the quality of the images that result from them.

Many ink jet receptor compositions suitable for applications such as overhead transparencies are also known in the art. These are composed of transparent plastic materials such as polyester, which only will not accept aqueous inks and are coated with receptor layers. Typically, these receptor layers are composed of mixtures of water-soluble polymers that can absorb the aqueous mixture of the inkjet ink. Examples of the ink jet receptor compositions used for overhead transparencies are described in U.S. Patent No. 4,935,307 (Iqbal et al.), U.S. Patent No. 5,208,092 (Iqbal), U.S. Patent No. 5,342,688 (Kitchin et al. ), and EPO Publication 0 484 016 Al. A common problem with the images produced with the ink jet is the subsequent dispersion of the dyes, often particularly poor under warm and humid conditions. Therefore, many receiving materials contain media that reacts with, or otherwise immobilizes the colorants after printing. Alternative methods to prevent the dispersion of dyes, are modifying the formulations of the ink.

Another disadvantage with many current inkjet compositions is the color change or fading of the dyes in the images, with the subsequent loss of archival capacity, the change in the image quality over time, and a time of Short life for relatively high quality images in direct sunlight. This is not a problem in applications such as short-term signaling, for example for advertising advertisements. However, these disadvantages make the images unsuitable for long-term applications, such as archival forms, or external durable images and signals. Other ink jet recording materials are described in U.S. Patent No. 5,132,146 (Maruyama et al), and U.S. Patent No. 5,302,437 (Idei et al). There is a need for ink jet receiving materials that provide high density images, with low dyeing of dyes, with dye ink based inks, and which at the same time provide smudge-resistant images with inkjet inks. pigmented ink.

BRIEF DESCRIPTION OF THE INVENTION Briefly, in one aspect of the present invention, there is provided an ink jet sheet comprising a substrate and a layer receiving the image that is in contact with the substrate, wherein the layer receiving the image comprises at least one penetrating protective layer of a composition and at least one ink jet receiving layer of a second composition, and wherein the ink jet receiving layer contains dispersed or particulate particles of a size which causes protrusions of the protective penetrating layer . Optionally, on the side of the substrate opposite the image receiving layer, in sequential order, there is an adhesive layer and a release liner. The sheet is useful in inkjet printing processes to use substrates that can be used in signaling, archiving or other imaging applications. Advantageously, the layer receiving the image (whether comprised of a single layer or multiple layers) can be used with a wide variety of substrates, such as thermoplastic, thermosetting substrates, plastic coated papers, fabrics, plastic coated fabrics , thick or thin substrates, with the proviso that the coated substrates are capable of being loaded in an ink jet printing system.

The printed receiving sheet, whether overlaminated with a protective or coated film, or otherwise treated to provide a durable surface, may be used for commercial signage, filing or imaging applications. An advantage of the present invention is a sheet for printing by inkjet, wherein the substrate and the adhesive are durable for periods of several years in an external environment, where the materials and the images can be exposed to rain, sun , and variations in temperature such as those found in outdoor environments and surfaces in outdoor environments. Typically, the articles of the present invention have some flexibility, so that they can adhere to surfaces that have some curvature or non-uniformity, for example walls or surfaces with screw heads or rivets, without easily tearing the material or cracking or delamination of the layers that receive image, layers on the surface, other coatings or image or "lifting" of the material on the projection. Additionally, a degree of water resistance, additional ion image protection, splash and the like, and a high gloss finish to the printed sheet may be optionally provided, for example by overlaying a clear protective layer.

Finally, the articles of the present invention maintain other desirable properties of a sheet for ideal inkjet printing, such as resistance to dyeing of the dye, and low background color. Good saturation of the color and density in the printed images is also observed. Printed articles do not curl excessively with exposure to moisture or during ink jet printing processes, and printed images exhibit fast ink drying times, followed by printing with good sharpness of the image. As used in this application "colorant" means any substrate that imparts color to another material or mixture and can be either dyes or pigments. "durable" means that the substrates used in the present invention are capable of withstanding the wear and tear associated with pointing, and can be from 2 to 5 years in exterior media, "plastic" means a material that is capable of being formed or molded with or without any heat application, and includes thermoplastic types, thermosetting types, both of which can be flexible, rigid or semi-rigid, brittle or ductile, "stain resistant" as used in this application, means the strength of the ink from ink jet to stain, as described in the following test, print an image with black lines, allowing a minimum of five minutes of time to dry, rub the line with the fingertip with a light to moderate pressure, such like the one that could be used during the normal handling of the images, and to observe if the dispersion of the line occurs.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top plan view of a construction of a layer that receives the two-layer image after printing and overlamination. Figure 2 is a micrograph explored by electron of a sheet for printing by ink jet prepared according to Comparison Example A. Figure 3 is a micrographic scan with electron of a sheet to print by ink jet prepared according to with Example 1. Figure 4 is another micrographic scan with electron of the sheet shown in Figure 3. Figure 5 is another micrograph of the electron scan of a sheet for printing by ink jet of the invention, which has an image printed on it.

DESCRIPTION OF THE PREFERRED MODALITY With reference to Figure 1, there is illustrated an ink jet sheet (1) of the present invention, comprising (a) a layer receiving the image (11-12) in (b) a substrate (10) , wherein the sheet can optionally have (c) an adhesive layer (13), coated or laminated to the substrate (10) on the surface away from the image receiving layer (11-12). The adhesive layer (13) may or may not be reinforced with a release liner (14). In this embodiment (Figure 1), the layer receiving the image (11-12) comprises at least two layers, wherein one layer is a protective penetrating layer (12) and one layer is an ink jet receiving layer (11). ). Once on the ink jet sheet the images have been formed with the ink jet ink (shown as patches of dry ink containing pigment particles) (15) using an ink jet printing process, the printed sheet (1) can be overlaminated with a transparent protective layer (16). The transparent protective layer (16) can be a transparent plastic sheet having on one side a pressure sensitive adhesive or a hot melt adhesive (thermal), or a clear coating, or a processing technique that will affect the surface of the printed sheet (1).

Both the ink jet receiving layer (11) and the penetrating protective layer (12) have particles (17) and (18), respectively, which contribute to the operation of the printed sheet. Typically, a release liner (14) comprises a paper or plastic or other suitable sheet material coated or otherwise treated with a release material, such as a silicone or fluorocarbon type material, on at least one surface in contact with the adhesive layer, so that the adhesive layer adheres to the release layer, but is easily removed from the release liner when desired, so that the adhesive layer is exposed. TO Substrates The substrates are preferably a durable material that resists the deteriorating effects of the exterior signaling means, including large ambient temperature ranges from -60 ° C to + 107 ° C, direct exposure to the sun and is optionally conformable to be fixed to the outer surfaces, where it can adhere on surfaces with some curvature or without uniformity, for example walls or surfaces with screw heads or rivets slightly protruding from the surface, without easily tearing the material or "lifting". However, the invention need not be limited to these, a less durable plastic is useful for indoor signage applications, such as can be used when printed images have been printed with dye-based inkjet inks. The substrates may be clear, translucent or opaque, depending on the application of the invention. Opaque substrates are useful for viewing an image from the image side of the printed sheet under lighting conditions such as artificial lighting or sunlight. Translucent substrates are particularly useful for backlit applications, for example, a light signal. Substrates useful in the practice of the present invention are commercially available and many are designed to be durable on the outside, which is preferred. Non-limiting examples of such substrates include Scotchcal Marking Films * and Scotchcal Short Term Removable Film (STR) * * Series 9000 available from 3M Company, Avery1 Series Long Life Films "" * GL ™, Long Life Films of the Avery Series ** XL, Long Life Movies of the Avery SXMR Series, movies suitable for the FasCalMK or FasFlex "* film range, or any other suitable films for marking, graphic or promotional, available from Fasson, Avery or Meyercord. However, other manufacturers of suitable materials exist and the invention should not be limited to the foregoing. Almost any material composed of a sheet of plastic could be used, depending on the use of the final image, for example, where durability is required for the exterior and with the condition that the lower coating receiving the ink jet can adhere to the surface of the movie well enough. Useful substrates may have a certain surface variety, such as a matte finish as provided with Scotchcal ^ Series 9000 (STR) Short Term Removable Film or a glossy finish such as that provided with Scotchcal 3650 Marking Film. of plastic can be extruded, calendered or molded, or different plastics materials can be used, such as those exemplified by Scotchcal plasticized polyvinyl chloride or Surlyn, a polyolefin. Any suitable plastic material can be used. Non-limiting examples include polyester materials exemplified by MylarMK available from E.I. Du Pont de Nemours &; Company, MelinexM? available from Imperial Chemicals, Inc., and Celanar available from Celanese Corporation. Other examples include polyolefins such as polyethylene and polypropylene, polycarbonates, polymerized acrylates, polystyrene, polysulfones, polyethersulfones, cellulose triacetate, cellophane, poly (vinyl fluoride), polyimides, Teslin "1" available from PPG Indistries, rubber polymers. such as styrene-butadiene copolymers, nitrile or butyl rubbers, polybutadienes Preferred materials for substrates may prefer those which are plasticized polyvinyl chloride or ionomers, although the invention is not limited thereto. Opaque or translucent white materials, but transparent and colored opaque materials, translucent or transparent materials may be useful in special applications.The typical thickness of the substrate (10) is in the range of 0.05 to 0.75 mm. Being outside this range and almost any thickness can be useful, with the condition that the film cula resists tearing or splitting during the printing process and application. Given all considerations any thickness is useful with the condition that the substrate is not too thick to feed from an inkjet printer of choice.

Layer Receiving the Image The layer receiving the image is comprised of at least two layers, so that at least one of the layers functions as an ink jet receiver (11). When the layer receiving the image is comprised of at least two layers, the uppermost layer functions as a penetrating protective layer (12), and the lower covering layer functions as an ink jet receiver (11). Although a layer that receives the image is described as a multi-layer construction, the use of the term "multiple layers" does not necessarily imply that the layers are totally different, that is, there is a discernible demarcation interface, although it can be. There may be, for example, some interlayer mixing, especially at the interface during the coating process. In order to prepare the layers (11) and (12), in general, the typical polymers or binders used in the art hydrophilic or water soluble, or water absorbers, are poly (vinyl pyrrolidone), copolymers of vinyl pyrrolidone for example with ethylene or styrene, polyvinyl alcohol, polyacrylic acids, polymethacrylic acids or copolymers of (1-alkyl) acrylic acid, and inorganic salts such as alkali metal salts derived therefrom, poly (alkylene oxides), and polyglycols , carbohydrates, alkyl derivatives and hydroxyalkyl cellulose, starch and starch derivatives, such as hydroxyalkyl starches, hydroxyalkyl, carboxyalkyl celluloses and their salts, gum arabic, xanthan gum, carrageenan gum, proteins and polypeptides. One or more polymers can be crosslinked using other reagents or catalysts. Preferred constituents of the lower coating layer (11) include copolymers such as those described in EP 0484016 Al, poly (vinyl pyrrolidone), poly (ethylene oxide), and mordants such as those described in U.S. Patent No. 5,342,688 for prevent migration of the dye in the images after printing. However, mordants are not required on the printable sheet designed for use with pigment-based inkjet inks. The preferred constituents of the topcoat layer (12) are hydrophilic or water soluble polymers, gums and surfactants which are less sensitive to moisture and contact fogging than for example is poly (vinyl pyrrolidone). These include poly (vinyl alcohol), the aforementioned particulates, such as corn starch, or modified corn starches or derivatives. The xanthan bomb and surfactants such as the Triton X-100. A similar top coat is described in U.S. Patent No. 4,935,307. It is preferable to use a layer receiving the image having a two-layer construction, wherein both the lower coating layer (11) and the upper coating layer (12) contain a dispersed particle or particulate (17) and (18) , respectively, so that the surface of the sheet for printing by ink jet is rough. As described in Figure 1, the rough surface is characterized by scattered particles and / or particulates such that images printed using pigment-based inkjet inks, in the inkjet printing process are essentially stain resistant. , or not spotless. The filling of the coating layer (11) with particulate matter (17), can achieve a rough receiving surface. Other advantages can also be achieved, such as better grip of the ink jet printer and improved transport of the article of the invention through the printer and prevention of "blocking". Typical thicknesses of the lower coating layer (11) are in the range of about 2 to about 30 u. Desirably, such thicknesses range from about 5 to about 30um, because it is desirable that the particles (17) extend over and otherwise level the surface of the lower coating layer (11). Preferably, such thicknesses vary from about 5 to about 20 u, because it is preferred to provide projections or hills with particles (17) that not only affects the terrain or topology of the lower covering layer (11), but also the soil or top coating layer topology (12). As seen in Figure 1, the protrusions can be caused not only by the particles of the layer that by themselves cause protrusions, but also by smaller particles that "stick together" and cause protrusions, when there is sufficient contracting particles in the layer. Typical thicknesses of the topcoat layer (12) are in the range of about 0.05 to about 4 μm, measured from the lowest valley in the ground or topology of the bottom cover layer (11). As described in detail below, the desired thicknesses of the top coat layer 12 can vary from about 0.05 to about 3 μm. Preferably, such thickness may vary from about 0.05 to about 2 μm. The thicknesses of both layers (11) and (12) are based on the dry coating weights, which are based on coating solutions and coating thicknesses according to techniques known to those skilled in the art. In general, the thickness of the upper covering layer (12) is much thinner than that of the lower covering layer (11). Depending on the printing application, the thicknesses may vary. In relation to each other, the particles and / or particulates (17) contained in the lower coating layer (11), preferably must be larger than the upper coating layer (12) and the thicknesses of the layer ( 11), so that the particles (17) cause projections not only in the layer (11) but also in the layer (12). Preferred materials for such particulate and dispersed particulate material (17) and (18) include materials that are insoluble or of sufficiently low solubility in the remainder of the ink jet coating mixture which is typically aqueous. Preferred materials are those that have some water absorbance. Non-limiting examples of the particulate material include corn starch or modified corn starch, silica, alumina, titanium dioxide or other inorganic oxide or white hydroxide materials, cotton or cotton particles, wool and rayon, and other cellulose particulates or modified cellulose, calcium silicate or calcium carbonate and other white inorganic silicates, sulphides and carbonates, clays, and talc. The size of the dispersed particles or particulates (17) and (18) is typically in the range of 1 to 40 micrometers in diameter, preferably in the range of about 2 to 20 micrometers in diameter. However, the invention is not intended to be limited to this range, with the proviso that there are sufficient particles having sizes large enough to roughen or rough the surface of the lower coating layers and the upper coating (11) and ( 12). The moderate size distribution is a typical range, although it is permissible to use particles or particulates that are outside the previously established range of sizes. The particles and / or particulates (17) and (18) are added in the layers receiving the image (11) and (12) in the range of 10 to 60% by weight of total solids, preferably in the range of 15 to 25% by weight of total solids. In addition, dispersed particles and particulates are generally available in a size distribution, although it is not intended to exclude the use of a particle or particulate of a single size, with the proviso that the size be sufficiently large as described above. Adjuvants for the receptor coatings include, but are not limited to, water-soluble polymers or mixtures of water-soluble polymers that act as absorbents or binders or both, crosslinked materials or other polymers, and optionally other materials such as surfactants, crosslinkers, mordants to prevent fading of the dye or other migration of the dye in the printed image, other means for the prevention of fading of the dye, and dispersions or emulsions. Materials that absorb ultraviolet radiation, free radical scavengers and antioxidants can also be used. The amounts used of any of the adjuvants are those typical for the selected adjuvant and known to those skilled in the art. Referring to the electron scanning micrographs of Figures 2-4, the importance of the particles (17) and (18) for the layers (11) and (12) is shown. Because the ink jet receiving layer (11) contains dispersed particles (17) sized to roughen the surface of the ink jet receiving layer (11), prior to overcoating with the penetrating protective layer (12), the dispersed particles (17) of the ink jet layer (11), also roughens the surface of the protective penetrating layer (12). This rough surface comprises ridges or hills, areas raised above the surrounding receiving surface, which create a terrain or topology that leads to good inkjet printing. Also, the terrain or varied topology provides valleys in which the pigment particles of a pigment-based ink can reside.

Figure 2 (Prior Art) is a scanning electron micrograph with an amplification of 150 of a sheet for printing by ink jet prepared according to Comparative Example A, described later with particles (18) in the layer (12) , but without particles (17) in the layer (11). The surface has a limited number of projections on a uniform surface otherwise. Figure 3 is a scanning electron micrograph with an amplification of 150, of a sheet for printing by ink jet according to Example 1 described below, with particles (18) in the layer (12) and with particles (17). ) in layer (11). The surface has a very rough terrain and a complex topology based on the projections caused not only by the particles (18) in the layer (12), but also the particles (17) in the layer (11). Figure 4 is an electron scanning micrograph with an amplification of 500 of a sheet for printing by ink jet seen in Figure 3. At the center of the micrograph, the particles (18) are visually distinguishable from the particles (17). ) because the jagged edges of the particles (18) contribute "rocky" ridges to the terrain or topology, while the uniform edges of the particles (17), contribute "as hills" overhangs to the terrain or topology. Referring again to Figure 3, it is possible to distinguish the effect of the particles (18) of the particles (17), because the projections on the layer (12) of the particles (17) are more uniform. Referring again to the drawing of Figure 1, the presence of particles (17) and (18) in the layers (11) and (12), respectively, provide unexpected benefits of the sheets for printing by inkjet of the present invention. . An explanation of the effect of the particles (17) and (18) demonstrates these unexpected advantages. In the receiving layer of the ink jet (11) (without the protective penetrating layer (12)), the height of the protrusions above the surrounding surface, caused only by the particles contained therein, does not exceed the diameter of the particle . For purposes of explanation, one can define p as the diameter of the particle of the ink jet receiving layer (17) in nanometers. In a non-spherical particle, this is taken as the maximum distance between two points within or on the surface of the particle (17). Therefore, the height of the ledge above the valleys is < p. If a coating method for the protective penetrating layer (12) provides a uniform coating thickness d on a substrate of uniform thickness, and if this is coated on the ink jet receiving layer (11) containing the particulates (17) with a rough terrain, and if d > p, and the coating flows out, then the dry protective penetrating layer can fill the valleys between the projections, and the layer receiving the image (11-12), will not have an additional roughness of the particles (17) contained in the layer bottom (11), or layers, that is, the ink jet receiving layer (11). Therefore, it is preferred that p > d. If p > d, it is then possible for the particles (17) in the receiving layer of the ink jet (11), to roughen the surface of the protective penetrating layer (12), depending on the height of the projections. The larger the diameter of the particles (17) added to the receiving layer of the ink jet (11), compared to the dry thickness of the protective penetrating layer (12), the rougher the surface of the two-layer construction will be (11-12), with the proviso that the ink jet receiving layer (11), contains a sufficient concentration of particles (17). If the layer receiving the image (11-12) comprises more than one penetrating protective layer (12), then it is desired that the layer or layers receiving the ink jet (11) contain particles (17) of a diameter that exceeds the combined thicknesses of the penetrating layers (11). The terrain or surface topology of the two-layer inkjet receiver should be rougher than the pigment particle size in the pigmented inkjet inkjet ink (15), which resides on the surface of the layer (12). If the external surface is rough (as seen in Figure 3, compared to Figure 2), due to the particulate (17), in the ink jet receiving layer (11), that is, there are raised areas whose diameter in the plane of the surface is of the same order of magnitude as that of the diameter of the particles (17), then at least a part of the pigment particles (after printing and drying the image), in an ink patch dry, it resides under the raised surface of the layer (12). Figure 5 is a scanning electron micrograph with an amplification of 1000, of an inkjet sheet prepared according to Example 1, having dried inkjet ink patches, within which particles reside of pigment. These patches lie on the ledges and valleys caused by both the particles (17) and the particles (18). While not limited to a particular theory, it is believed that the projections caused by the particles (17) provide some protection for at least part of the areas of dry ink to be resistant to abrasion stains, which is particularly valuable when the ink used comprises pigment particles. The dyes diffuse into layers 11 and 12, but the pigment particles reside in layer 12. Other advantages of the ground surface or topology as seen in Figures 3-5, include the prevention of blocking and assistance in Friction feeding the printer. Some roughness on the surface can also be achieved with the particles (18) in the protective penetrating layer (12). However, if the protective penetrating layer (12) is limited to the preferred thicknesses of this invention, then the roughness induced by the particulate of the surface of the layer (12), will be limited to less than the coating solution of the Penetrating protective layer comprises high concentrations of particles (18), compared with other constituents of the penetrating layer that forms the film. Potential problems with this high particle load include difficulties in attaching the particles to the surface of the layer of the image receiving layer (11-12), and the stability of the particle dispersion in the coating solution. the penetrating layer. The roughness of the surface shown in Figures 3-5 is easily achieved if the particles (17) are included in the thicker ink jet receiving layer (11), where the roughness of the surface achieved from the particles of the ink jet receiving layer (17), is distinguishable from those particles (18) in the protective penetrant layer. Referring again to Figure 4, it is visually obvious that the raised (protruding) areas of the particles of the ink jet receiving layer (17) are much more frequent (higher frequency per unit area) than that of the particles of the ink jet. the penetrating protective layer (18), although the particle concentrations of the same starch is 21.5% by weight of the dry protective penetrant layer (12), compared to 16.7% by weight of the dry inkjet receiving layer ( eleven) . This difference is due to the much greater thickness of the ink jet receiving layer (11) than that of the protective penetrating layer (12). The difference in surface roughness of the materials of Example 1 and Comparative Example A is also evident in the gloss measurements included with such examples. An additional advantage can be seen by examining Figure 5 of Example 1, using the preferred particulate, starch, in this system. The particles (17) of the starch of the ink jet receiving layer (11) are wetted with the protective penetrating layer, thus providing no interference with the wettability properties of the dry protective penetrating layer (12). The control of the wettability properties of the medium independently of the absorption properties of the ink jet receiving layer (11) by the use of a protective penetrating layer (12), is one of the most important advantages that are gained with a Two-layer receiver. The addition of a protective penetrant layer such as a penetrating layer to an ink jet receiver, imparts many advantages as indicated in U.S. Patent 4,379,804. The preferred weights of the coating of the dry protective layer (12) are in the range of about 0.05 to about 2 g / m2 (approximately 200 milligrams per square foot).

Assuming densities of 1 g / cm3, this gives preferred thicknesses of the protective penetrating layer (12) of approximately 0.05 to 2 μm. The densities of the polymer can vary between 0.8 and 2.7 grams per cubic centimeter. For example, polyvinyl alcohol, the major constituent of the topcoat in the examples, has a density range of 1.27 to 1.490 (Polymer Handboo, 3rd Edition, J. Brandrup and EH Immergut, iley-Interscience publication of John Wiley and Sons). The average preferred particle size is 2 to 20 μm in diameter, thus exceeding the preferred preferred thickness range of the dry protective penetrant layer. The average particle diameter of the preferred particulate, starch, is about 20 μm, thus far exceeding the range of possible thicknesses of the top coating layer (18) of the preferred range of coating weights. The thickness of the ink jet receiving layer (11), and the concentration of the particles in it, will have a critical effect on the degree of roughness of the surface, that is, the number of protrusions per unit area, and the elevation of the peak of the protrusion of the area or Lower surrounding valley. If the receiving layer of the ink jet (11) were as thin as the protective penetrating layer (12), the frequency of the raised areas of the particulates would be much smaller per unit area on the surface of the two-layer construction. In general, a receiving layer of the ink jet (11) thicker, absorbs more ink. The coating weights of the dry ink jet receiving layer (11) are typically between about 2 to about 30 g / m2. The coating weights of the preferred dry ink jet receiving layer (11) are between about 5 and about 20 g / m2. The particles (17) typically added to the coatings for the layer (11) do not have a uniform size, but are defined in terms of a particle size distribution with an average particle size.

Therefore, it is preferred that p average > d where p refers to the average particle size.

Adhesive layer sensitive to pressure Although it is preferable to use a pressure sensitive adhesive, any adhesive that is particularly suitable to the particular substrate (10) selected, and to the final application, can be used on the sheet for inkjet printing. Such adhesives are those known in the art, and may include adhesives that are highly tacky adhesives, pressure sensitive adhesives, repositionable, and / or positionable adhesives, hot melt adhesives and the like. Furthermore, it is permissible to manufacture an ink jet receiving sheet without the addition of an adhesive layer (13), for example, short-term interior signs loaded into signal boxes.

Overlaminate layer In this application, overlaminate layer (16) refers to any sheet material that can adhere to the surface of any existing covered or uncoated sheet material. "Overlamination" refers to any process to achieve this adhesion, particularly without entrapment of air bubbles, damage or other defects that could spoil the appearance of the finished article or image. The deteriorating effects of ambient humidity can be made slower by the overlamination of a transparent protective coating or sheet, referred to herein as an overlaminate. The overlamination has the additional advantage that the images are protected from scratching, scratching, and the overlaminate can provide a high gloss finish or other desired surface finish or design, and provide a desired degree or gain of optical points. The overlaminate layer (16) can also absorb ultraviolet radiation or protect the underlying layers and image the deteriorating effects of direct sunlight or other sources of radiation. Overlamination is described, for example, in U.S. Patent 4,966,804. After printing an image or design on the receiver layers (11) and (12) of the present invention, the image is preferably overcoated with a colorless transparent or almost colorless material. Suitable overlaminate layers include any suitable clear plastic material, which supports an adhesive on a surface. The adhesive of the overlaminated layer can be a hot melt adhesive, or another thermal adhesive, or a Jl Pressure sensitive adhesive. The surface of the overlaminate layer can provide a high gloss or matt or other surface texture. Preferred overlaminate layers are designed for external graphic applications, and include materials such as those commercially available from 3M Company as Scotchprint Outer Protective Film 8910, Outer Protective Film 8911, and Outer Protective Film 8912. However other films are available or can be manufactured, and the invention is not limited to those exemplified.

Use of the Sheet to Print An example of the printing process used in the present invention comprises feeding the material, either as a sheet or assortment of a roll in an ink jet printer, printing a desired color or monochromic image, recovering the image of the printer, and optionally, overlaminate the image with a layer of overlamination to protect the image and coatings receptors from water, scratches, and other potential sources of image damage, and then remove the release seal (14), and fix the printed image to a wall, next to a vehicle, edge, page or other surface to be displayed.

Advantageously, the articles of the present invention accept inkjet dyes based on pigment, wherein the substrate is comprised of weather-sensitive plastic materials, allowing image options stable to heat or light, under such circumstances, as there are exterior signage means. The ink-jet printing sheet provides usable images, using both dye-based and pigment-based inkjet inks, suitable for use, for example, in wide-format ink jet printers, wherein both narrow images and Wide can be made by the inkjet printing process used in pointing applications. The resulting printed sheet is easily handled without easy staining of the image and can be applied, when an adhesive layer is part of the sheet to print by ink jet, to a wall, next to a vehicle, car or surface to indicate and other applications using techniques well known in the art without the use of other devices such as spray adhesives.

Examples The invention is further illustrated by the following examples, but the particular materials and amounts thereof cited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention. All materials are commercially available or known to those skilled in the art, unless a state is established or evidenced otherwise. In the examples described herein, the density and optical densities were reflection densities measured using a Gretag SPM-50 densitometer, subtracting the density of an unprinted sheet as background. As a reference in the following example, densities were obtained by printing on a Hewlett-Packard HP51631E Special Inkjet Paper using a Hewlett-Packard DesignJet 650C equipped with HP51650 series cartridges (including HP51640A black) as recommended for the printer: 1,365 (blue), 1,154 (magenta), 0.967 (yellow) and 1,247 (black). By reference, the following densities were obtained by printing on a Hewlett-Packard HP51631E Special Inkjet Paper using a Hewlett-Packard DesignJet 650C equipped with the HP51640 series cartridges (including black (HP51640A), 1247 (blue), 1123 (magenta), 0.686 (yellow) and 1242 (black).

Example 1 Ink-jet sheets for ink-jet tubs based on dyes and pigments were prepared by coating the following formulation on a Scotchcal Series 3650 Marking Film available from 3M Company. A formulation was made by thoroughly mixing until homogenous, 810 grams of a 20% aqueous solution of polymer, as described in EP 0484016 Al, 469 grams of solid poly (vinyl pyrrolidone), K90 (available from ISP Technologies Inc.) , 162 grams of Carbowax Polyethylene Glycol 600 (available from Union Carbide Chemicals and Plastics Company Inc.), 108 grams of a 15% solution of mordant (mordant with chloride counterions as described in U.S. Patent No. 5,342,688, and Publication of PCT WO 94/20304, PCT Publication WO 94/20305, and PCT Publication WO / 20306, 3560 grams of deionized water and 1638 grams of ethanol To the mixture were added 167 grams of LOK-SIZE® 30 Corn Starch Cationic (available from AE Staley Manufacturing Company) The solution was mixed using an agitator for four hours, and then homogenized for thirty minutes in a 5 gallon bucket using a Purpose Laboratory mixer. s Multiple high-speed Silverson, fitted with a Disintegration Head.

Before coating, 3.3 grams of 30% aqueous ammonia were thoroughly mixed (available from Aldrich Chemical Company) and then 24.3 grams of Xa to 7 (an aziridine crosslinker available from Hoechst Celanese Corporation). The above formulation was coated on an automated pilot coater, at a speed of 0.10 meters per second on a Scotchcal ™ Series 3650 Marking Film of 0.3048 meters wide, a white vinyl product that can be exposed to the weather, composed of , in order, a white vinyl layer, a layer of pressure sensitive adhesive, and release paper, available from 3M Company. A sheet coater adjusted to a space of 127 micrometers was used, and the dry coating weight was measured at 14.90 grams per square meter. The material was passed at 0.10 meters per second through drying zones, 3.66 meters at 65.6 ° C, 3.66 meters at 79.4JC, 3.66 meters at 93.3 ° C, and 7.32 meters at 121 ° C. In a second pass, an overcoat was overcoated in the product of the above coating operation, in the coated layer previously described, using a pilot coater with a sheet coater fitted to a 76 micrometer space. The top coat similar to that described in US Patent No. 4,935,307 is composed of 66% by weight (of the total mixture) of deionized water. 1.64% by weight of Airvol 540 polyvinyl alcohol (available from Air Products); 31.17% by weight of denatured alcohol; 0.61% by weight of LOK-SIZE® 30 Cationic Corn Starch (available from AE Staley Manufacturing Company), 0.28% by weight of Xantana gum, a polysaccharide gum known as KELTROL TF 1000 (available from Kelco Division of Merck & Co. Inc.), and 0.3% by weight of Triton X-100 surfactant (available from Union Carbide Chemicals and Plastics Company Ine). This coated article was passed at 0.10 meters per second through four drying zones, 3.66 meters at 65.6 ° C, 3.66 meters at 79.4 ° C, 3.66 meters at 93.3 ° C, and 7.32 meters at 93.3 ° C. The images were printed directly on the side of the coated coating of the coated material, using a Hewlett-Packard HP650C Design ink jet printer equipped with the standard 51650 ink cartridges giving excellent densities, fast drying time, resistance to stains of colors including black (printed cartridge HP51640 based on an ink containing an ink based on black pigment). An image was overcoated using the ScotchprintMR 8910 Clear Protective Exterior Film, glossy gloss available from 3M Company, using techniques known in the art, giving a glossy or spill-protected image. The overlaminate also provides additional resistance to the dyeing of the dye from the humid environmental conditions. The examples of optical densities obtained in the non-overlaminated samples, by measurements with a manual Gretag SPM-50 densitometer were 1294 (blue), 0.969 (magenta), 0.654 (yellow), and 1450 (black). This printable sheet was also printed on a large format Encad Novajet printer, equipped with LaserMaster Corp inks (all dye based). Very high densities were obtained, although the drying times were longer - of the order of 10 minutes to dry touch. The optical densities obtained were 1,857 (blue), 1,802 (magenta), 1,044 (yellow), and 1,937 (black). The brightness of the unprinted sheet was measured using a BYK-Gardner micro-TRI-glass gloss meter (available from BK-Gardner Inc. USA, Silver Spring, MD 20910). The average of five readings taken at different positions on the surface of the sheet for printing gave the following readings at various angles: 20 ° - 2.5, 60 ° - 11.9, 85 ° - 6.8.

Example 2 The article produced as follows illustrates a different type of a substrate reinforced with adhesive, allowing short-term removal of the images. An interior coating solution of the same composition as described in Example 1, was coated on a pilot coater at a fabric speed of 0.10 meters per second on a 0.30 meter wide roll of ScotchcalMK Series 9000 (STR) Short Term Removable Film, available from 3M Company, and included in order, from a white vinyl layer, a layer of adhesive, (which allows removal for up to 2 years with little or no adhesive residue from most of the surface) and a release support. The bottom layer was coated on the vinyl using a sheet coater adjusted to a space of approximately 1.27 micrometers, giving a dry coating weight measured at 15.51 grams per square meter. The material was passed at 0.1 meters per second to four drying zones, 3.66 meters at 65.6 ° C, 3.66 meters at 79.4 ° C, 3.66 meters at 93.3 ° C, and 7.32 meters at 121 ° C. The topcoat was as described in Example 1, except that it was further diluted to 1% of the solids with deionized water. In a second pass, the diluted topcoat was overcoated onto the product of the above coating operation, in the above coated layer, using a pilot coater with a sheet coater adjusted to a 127 micrometer space. For the top coating, the speed of ji¬ the fabric was approximately 0.076 meters per second. The top coating was applied using a cross flow sheet. The material was passed at approximately 0.076 meters per second through four drying zones, 3.66 meters at 65.6 ° C, 3.66 meters at 79.4 ° C, 3.66 meters at 93.3 ° C, and 7.32 meters at 121 ° C. The color test patterns were printed on the 21.6 by 27.9 centimeter samples of these materials, using the Hewlett-Packard DesignJet 650C, giving fast drying images with stain resistant images including the white pigment. Printed test patterns and larger full-color images were also printed, using the Hewlett-Packard DesignJet 650C equipped with Hewlett-Packard series 51640 cartridges, giving fast-drying stain-resistant images. Examples of optical densities measured for 100% color areas are: for HP1650 inks (including HP51640A black), printed on the Hewlett-Packard printer DesignJet HP650C: 0.970 (blue), 1.013 (magenta), 0.581 (yellow), and 1.125 (black). Examples of optical densities measured for 100% areas are: for inks printed on the Hewlett-Packard DesignJet HP650C: 1.367 (blue), 0.987 (magenta), 0.991 (yellow), and 1.185 (black).

Example 3 The following example illustrates the printing sheet that acts as receivers for the pigment-based inks only, and therefore does not require any etching method to decrease or prevent the coloration of the dye. A formulation was made by thoroughly mixing to homogeneity, 59.8 grams of a 20% aqueous solution of a copolymer, as described in No. EP 0484016, 34.6 grams of a solid poly (vinyl pyrrolidone) K90, available from ISP Technologies Inc. , 12 grams of Polyethylene Glycol Carbowax 600, available from Union Carbide Chemicals and Plastics Company Inc., and 263 grams of deionized water. 121 grams of ethanol and 12.3 grams of LOK-SIZE® Cationic Corn Starch, (available from A. E. Staley Manufacturing Company) were added to the mixture. The corn starch was homogenized using a L4R Silverson Multi Purpose Laboratory Mixer, equipped with a Disintegration Head for a period of ten minutes. To 50 grams of the above solution, one drop of 30% ammonia (available from Aldrich Chemical Co.) and 0.18 grams of Xama 7 (available from Hoechst Celanese Corporation) were added and mixed thoroughly. The resulting mixture was manually coated using a sheet or a notched bar adjusted to a space setting of approximately 127 micrometers, and dried in an oven at 93.3 ° C for four minutes. The above coatings were overcoated with a topcoat solution described in Example 1, on the sheet using a gap adjustment of approximately 76 micrometers and dried at 93.3 ° C for three minutes. The image areas printed with the Hewlett-Packard DesignJet HP640A in black, were resistant to staining and a sample without overlaminate 8910 (ie, the least protected from the effects of moisture in the air), was placed in an oven / environmental chamber for 90 hours at 40 ° C and 85% humidity, and did not show a black discoloration or other obvious detrimental effects to the black image or leaf areas. Four images were made and three were overlaminated with Scotchprint Outer Clear Protective Film "* 8910, the glossy luster available from 3M Co. using techniques known in the art giving brilliant images.

Example 4 The following procedure illustrates the functionality of different thicknesses of the lower coating. A formulation of the lower coating was made as described on axis 1 (but with twice the amounts of each material). The material was coated on an automated pilot coater, at a fabric speed of 0.10 meters per second, to a 0.30 meter wide roll of the ScothcalMK 3650 Series Marking Film (available from 3M Company). During 15 minutes, a sheet coater adjusted approximately to a space of 51 micrometers was used, and the weight of the dry coating measured to 5.60 grams per square meter. Then, for an additional 15 minutes, the sheet coater was adjusted to approximately 76 micrometers, and the dry coating weight was measured at 9.16 grams per square meter. Then, for another 15 minutes, the sheet coater was adjusted to approximately a 102 micrometer space, and the dry coating weight was measured at 13.3 and again at 13.5 grams per square meter. All material was passed at 0.10 meters per second through four drying zones, 0.37 meters at 65.6 ° C, 3.66 meters at 79.4 ° C, 3.66 meters at 93.3 ° C, and 7.32 meters at 121 ° C. In a second pass, the topcoat (formulation as described in Example 1), was overcoated in the product of the above coating operation, in the coated layer previously described, using the pilot coater with a sheet coater adjusted to a space of 76 micrometers, at a fabric speed of 10 meters per second through four drying zones, 3.66 meters at 65.6 ° C, 3.66 meters at 79.4 ° C, 3.66 meters at 93.3 ° C, and 7.32 meters at 121 ° C. Images of the test pattern were printed, using the Hewlett-Packard DesignJet 650C equipped with Hewlett-Packard series 51640 cartridges, giving stain-resistant fast-drying images at all coating weights. The following table illustrates the optical densities: Example 5 A lower coating formulation containing silica was prepared by thoroughly mixing until homogeneous, 11.95 grams of a 20% aqueous solution of copolymer as described in the 3M patent application no EP 0484016 Al, 6.92 grams of solid poly (vinylpyrrolidone) K90 (available from ISP Technologies Inc.), 2.39 grams of Polyethylene Glycol Carbowax 600 (available from Union Carbide Chemicals and Plastics Company Inc.), 1.59 grams of a 15% aqueous polymeric mordant solution (mordant with chloride counterions as described in Example 1, 52.6 grams of deionized water and 24.2 grams of ethanol The mixture was stirred with an air-operated agitator and 2.46 grams of silica Aerosil 380 (available from Degussa Corporation Silica Division), 0.05 grams of 30% ammonia ( available from Aldrich Chemical Co.) and 0.36 grams of Xama 7, (available from Hoechst Celanese Corporation), were added to the above solution, and mixed thoroughly. The resulting mixture was manually coated using a sheet or a notched bar adjusted to a space setting of approximately 127 micrometers, and dried in an oven at 93.3 ° C for four minutes. The above coatings were overcoated with a solution of the top coat described in Example 1, on the sheet using a space setting of about 51 microns and dried at 93.3 ° C for three minutes. Test patterns were printed on a Hewlett-Packard HP650C, equipped with the HP51650 series ink cartridges and the HP51640A black ink cartridge. Images were obtained with good stain resistance and rapid drying of the ink. The examples of the densities are O 0. 718 (blue), 0.663 (magenta), 0.509 ^ yellow), and 1007 (black).

Comparative Example A The following example illustrates a different mordant, and a lower coating without dispersed particulate. This formulation gives excellent images with dye-based inkjet inks, but the images or parts of the images printed using ink inks based on pigment, remain stainable for an unreasonable time, for example, in excess of 48 hours . A lower coating formulation was made as described in Example 1, with twice the amounts of each material. However, a different mordant was used as in EXAMPLE 1. The mordant used was a 15% solution of mordant with one equivalent of chloride ion and one equivalent of trifluoroacetate ion as described in Example 1. The material was coated on an automated pilot coater at a web speed of 0.043 meters per second on a roll of 0.30 meters wide Marking Film Series 3650 ScotchcalM? (available from 3M Company). A sheet coater adjusted to approximately a 127 micrometer space was used and the dry coating weight was measured at 10.84 grams per square meter.

-D All coated articles were passed at 0.043 meters per second through three heated drying zones, 3.66 meters at 79.4 ° C, 3.66 meters at 121 ° C, and 3.66 meters at 12 ° C. In a second pass, the top coating (formulation as described in Example I), was overcoated in the product of the previous coating operation, in the coated layer described above, using the pilot coater with the sheet coater adjusted to a 51 micrometer space, at a speed of the fabric of 0.043 meters per second, through three heated drying zones, 3.66 meters at 65.6 ° C, 3.66 meters at 79.4 ° C, and 3.66 meters at 93.3 ° C. Test charts were printed directly on the resulting material (on the side of the waterborne coating) on a Hewlett-Packard HP650C DesignJet printer equipped with the 51650 series color cartridges (blue, magenta and yellow) and the 51640A cartridge (for black ink) ). Good images were obtained, but not as good as those obtained with the materials of the type exemplified in examples 1, 2, 3, 4, 5 and 6 with respect to the black areas of the images (ie those areas printed with a pigment-based ink of cartridge HP51640A), could easily be stained using the method described for an unreasonable time after printing, given in 4 / present, as in excess of 48 hours. The examples of the densities obtained are 0.820 (blue), 0.667 (magenta), 0.591 (yellow) and 1.310 (black). The brightness of the nonprinting sheet was measured using a B? K-Gardner micro-TRI-gioss brightness meter (available from B? K-Gardner Inc. USA, Silver Spring, MD 20910). The average of five readings taken at different positions on the surface of the sheet for printing gave the following readings: 20 ° - 45.5, 60 ° - 80.7, 85 ° - 74.5. The brightness was much higher at all angles than those in Example 1 with corn starch particles (17) added to the receiving layer of the ink jet (11).

Example 6 The following example illustrates a different construction of plastic material, adhesive, and a release paper. On the same occasion as that set out in Example 4, the same formulations were coated using the same pilot scale coating apparatus on a fabric approximately 0.41 meters wide, comprising a layer of white Surlyn plastic, a layer of an adhesive removable and release paper as described in U.S. Patent Nos. 5,198,301, 5,196,246 and 4,994,322. The material was coated in a pilot coater 40 automated at a web speed of 0.10 meters per second. Various coating weights were used, but in this example, the space of the sheet coater was adjusted to a space of approximately 102 micrometers. This coated material was shifted to 0.10 meters per second through four drying zones, 3.66 meters at 79.4 ° C, 3.66 meters at 79.4 ° C, 3.66 meters at 93.3 ° C, and 7.32 meters at 93.3 ° C. In a second pass, the topcoat (formulation as described in Example 1 and Example 4) was overcoated in the product of the previous coating operation, in the coated layer previously described, using the pilot coater with the coater of sheet adjusted to a space of 76 micrometers, at a fabric speed of 0.10 meters per second, through four drying zones; 3.66 meters at 79.4 ° C, 3.66 meters at 79.4 ° C, 3.66 meters at 93.3 ° C, and 7.32 meters at 93.3 ° C. Test pattern images were printed using the Hewlett-Packard DesignJet 650C equipped with Hewlett-Packard series 51650 cartridges, giving fast-drying, stain-resistant images. The examples of the obtained densities are 0.978 (blue), 0.834 (magenta), 0.624 (yellow) and 1.117 (black).

Comparative Example B The following exemplifies that the plastic materials with adhesive and release support, without the receiving layers of the invention, do not perform satisfactorily as the ink jet receiving materials with aqueous inkjet inks. Letter size sheets (21.6 X 27.9 centimeters) of the following materials were fed into a Hewlett-Packard HP650C DesignJet inkjet printer. Printing was attempted with the printer equipped with the HP51640 ink cartridge set (with the HP51640A black cartridge), and then with the HP51650 cartridge set (including the HP51640A black cartridge). The materials tested were the Film of Marked Scotchcal ™ 3650 Series, Scotchprint 8620 Marking Film, "Scotchprint Marking 8640" film, all available from 3M Co. and a material comprising a Surlyn plastic coating "white, a layer of adhesive that allows removal, and a release paper, as described in U.S. Patent Nos. 5,198,301, 5,196,246, and 4,994,322.The coating of the latter material to allow receipt of the inkjet ink is described in Example 6.

The inks that form drops on the surface of the plastic, that is to say, that do not penetrate to all or penetrate any major extension, and that did not wet the surface of the plastic, give a discontinuous image and low densities. The lightest touch of the finger caused the image to stain. This continued to be true until after 18 hours of printing. The above observations were true for both dye-based and pigment-based inks HP51640A.

Example 7 and Comparative Example C A roll of film, coated as described in Example 1, was stored in a laboratory for 532 days, together with the roll of film (hence, the same environmental conditions), coated as described in Comparative Example A, which had been coated 17 days earlier than in Example 1, and was stored, therefore, for a total of 549 days. The sheet of this Comparative Example A (without the particles in the ink jet receiving layer (11)), showed some blockage at the edges, and when unrolled, the fibers of the paper backing were bonded to the surface of the Penetrating layer (12). In comparison, the sheet of Example 1 was unrolled in a uniform manner.

Four discs cut from the sheet of Example 1 were stacked in register on four discs of the sheet of Comparative Example A. All discs were of the same diameter (6.6 cm) and approximately circular. The stack was placed on a board in an environmental chamber, maintained at 90 ° F at 90% relative humidity, and a cylindrical weight was placed with the flat side in the stack. The weight was of a diameter greater than that of the discs, and weighed 2,618.7 grams, thus giving a pressure of approximately 196 kilograms per square meter (1.1 pounds per square foot). After 184 hours, the battery was removed, and the disks were separated. In all cases, there was something sticking from one disc to the next. The material of Example 1, separated very easily, and there was no evident impression on the surface of the receiving surface of the ink jet. The four discs of the material of Comparative Example A, were more difficult to separate, impressions were made on the surface of the penetrating layer surface, and in one case, the liner paper was torn by contact with the surface of the layer receiving the image, from the material of Comparative Example A. This test showed the improvement in blocking at high ambient temperature and humidity conditions, obtained by the addition of particulates in the ink jet receiving layer (11).

For an appreciation of the scope of the invention, the claims follow.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following:

Claims (14)

1. A sheet for printing by ink jet, characterized in that it comprises a substrate and a layer that receives the image in contact with the substrate, wherein the layer receiving the image comprises at least one penetrating protective layer, of a composition, and at least an ink jet receiving layer of a second composition, wherein the ink jet receiving layer contains dispersed particles or particulates of a size causing protrusions of the penetrating protective layer.

2. The sheet for printing by ink jet according to claim 1, characterized in that the dispersed particulate is a corn starch or a modified corn starch.

3. The ink jet sheet according to claim 1, characterized in that the protective penetrating layer is thinner than the largest size of the dispersed particulate in the ink jet receiving layer.

4. The sheet for printing by ink jet according to claim 1, characterized in that the substrate is a sheet of plastic based on poly (vinyl chloride), opaque or translucent.

5. The sheet for printing by ink jet according to claim 1, characterized in that it also includes an adhesive layer adjacent to the substrate and on the surface of the substrate opposite the layer receiving the image.

The ink jet sheet according to claim 1, characterized in that the average particle diameter of the dispersed particles or particulates varies from about 1 to 40 μm, wherein the thickness of the penetrating protective layer varies from about 0.05 to about 4 μm, and wherein the thickness of the ink jet receiving layer varies from about 2 to about 30 μm, whereby at least some of the particles or dispersed particulates in the ink jet receiving layer, causes protrusions of the ink jet receiving layer, and causes protrusions of the penetrating protective layer.

The sheet for printing by ink jet according to claim 1, characterized in that the protective penetrating layer has a dry coating weight in the range of about 0.05 to about 4 g / m2.

8. The ink jet printing sheet according to claim 1, characterized in that the ink jet receiving layer has a dry coating weight in the range of about 2 to about 30 g / m2.

9. The ink jet sheet according to claim 8, characterized in that the ink jet receiving layer has a dry coating weight in the range of about 5 to about 20 g / m2.

The sheet for printing by ink jet according to claim 1, characterized in that the projections caused by the particles or dispersed particles in the ink jet receiving layer are visually distinguishable from the projections caused by the particles or dispersed particulates in the protective penetrating layer.

The ink jet sheet according to claim 1, characterized in that the particles or particulates are present in both the ink jet receiving layer and the penetrating protective layer are in the range of 15 to 25 percent by weight of total solids.

12. The sheet for printing by ink jet according to claim 6, characterized in that the protective penetrating layer has a thickness ranging from about 0.05 to about 4 μm, and wherein the receiving layer of the ink jet has a thickness varying from about 2 to about 30 μm.

13. The sheet for printing by ink jet according to claim 1, characterized in that the projections of the ink jet receiving layer cause rough terrain. The sheet for printing by ink jet according to claim 1, characterized in that the projections of the protective penetrating layer are more notched than the projections of the ink jet receiving layer.