MXPA00005662A - Coating compositions and inkjet printing media - Google Patents

Abstract

A coating composition comprising:(a) a volatile aqueous liquid medium;(b) binder comprising film-forming water-soluble organic polymer dissolved in the volatile aqueous liquid medium, film-forming water-dispersible organic polymer dispersed in the volatile aqueous liquid medium, or a mixture thereof;and (c) the polymerization reaction product of the hydrolyzate of an aluminum and an organoalkoxysilane of the general formula RxSi(OR')y(OH)z wherein R is an organic radical, R'is a low molecular weight alkyl radical, x is in the range of from 1 to 3, y is in the range of from 1 to 3, z is in the range of from 0 to 2, and (x+y+z)=4. A printing medium comprising a substrate having at least one surface and a coating adhered to the surface wherein the coating is derived from the composition above.

Description

COATING COMPOSITIONS AND PRINTING MEDIA BY INK CHIP When printing substrates coated with an ink-receiving coating with ink-jet printing inks, the inks often migrate from their original locations on the coated substrate frequently, resulting in unsatisfactory images. Said migration is known as "bleeding" or "fogging" and is especially frequent in conditions of high temperature and high humidity, such as, for example, 35 ° C and 80% relative humidity. It has now been found that the shift can be substantially reduced if the coating contains the reaction product of polymerization of the hydrolyzate of an aluminum alkoxide and an organoalkoxysilane. Accordingly, an embodiment of the invention is a coating composition consisting of: (a) a volatile aqueous liquid medium; (b) a binder consisting of a water-soluble, film-forming organic polymer dissolved in the volatile aqueous liquid medium, a hydrodispersible organic film-forming polymer dispersed in the volatile aqueous liquid medium or a mixture thereof; (c) the product of the polymerization reaction of the hydrolyzate of an aluminum alkoxide and an organoalkoxysilane of the general formula: RxSi (0R ') and (0H) 2 where R is an organic radical, R' is an alkyl radical of low molecular weight, x is in the range of 1 to 3, and is in the range of 1 to 3, z is in the range of 0 to 2 and (x + y + z) = 4. Another embodiment of the invention is a printing medium consisting of a substrate having at least one surface and a coating adhered to the surface, wherein the coating consists of: (a) a binder consisting of an organic polymer and (b) the product of the reaction of polymerization of the hydrolyzate of an aluminum alkoxide and an organoalkoxysilane of the general formula: RxSi (0R ') and (0H) z wherein: (1) R is an organic radical, R' is a low molecular weight alkyl radical and x is in the range from 1 to 3, and is in the range of 1 to 3, z is in the range of 0 to 2 and (x + y + z) = 4, and (2) the product of the polymer reaction rization is distributed throughout the binder.

Yet another embodiment of the invention is a printing process consisting of applying droplets of liquid ink to the printing medium of the second embodiment. For reasons of brevity, reference will sometimes be made to the product of the polymerization reaction of the hydrolyzate of an aluminum alkoxide and an organoalkoxysilane as described above as "the hydrolyzate silaneized". The printing means of the invention can be prepared by coating a surface of a substrate with the coating composition of the invention and then substantially removing the aqueous liquid medium. The coating composition may be in the form of an aqueous solution, in which case the volatile aqueous liquid medium is a volatile aqueous solvent for the binder polymer, or the coating composition may be in the form of an aqueous dispersion, in which case the volatile aqueous liquid medium is a volatile aqueous dispersion liquid for at least part of the polymer of the binder.

The volatile aqueous liquid medium is predominantly water. Small amounts of volatile low-boiling miscible organic liquids can be intentionally added for particular purposes. Examples of such volatile, low boiling, water miscible organic liquid solvents include methanol [CAS 67-56-1], ethanol [CAS 64-17-5], 1-propanol [CAS 71-23-8], 2-propanol [CAS 67-63-0], 2-butanol [CAS 78-92-2], 2-methyl-2-propanol [CAS 75-65-0], 2-propanone [CAS 67-64-1] ] and 2-butanone [CAS 78-93-3]. The list of such liquids is by no means exhaustive. It is preferred not to add substantially any volatile organic liquid in volatile water of low boiling point intentionally to the system, in order to minimize organic emissions by drying the coating. In a similar way, organic liquids miscible in water, which are themselves of low, moderate or even insignificant volatility, can be intentionally added for particular purposes, such as, for example, the delay in evaporation. Examples of such organic liquids include 2-methyl-1-propanol [CAS 78-83-1], 1-butanol [CAS 71-36-3], 1,2-ethanediol [CAS 107-21-1] and 1, 2, 3-propanotriol [CAS 56-81-5]. The list of such liquids is by no means exhaustive. It is preferred not to intentionally add substantially any water miscible organic liquid that is of low, moderate or insignificant volatility to the system. Notwithstanding the foregoing, those materials which, although not intentionally added for any specific purpose, are normally present as impurities in one or more of the components of the coating compositions of the invention and which become components of the aqueous liquid medium. Volatile, may be present at low concentrations. In most cases, the water constitutes at least 80 percent by weight of the volatile aqueous liquid medium.Frequently, the water constitutes at least 95 percent by weight of the volatile aqueous liquid medium. Water constitutes substantially all of the volatile aqueous liquid medium The amount of volatile aqueous liquid medium present in the coating composition can vary widely The minimum amount is that which produces a coating composition having a viscosity low enough to be applied as a coating The maximum amount is not governed by any theory, but by practical considerations, such as the cost of the liquid medium, the minimum desired thickness of the coating to be deposited and the cost and time required to remove the volatile aqueous liquid medium. of the applied wet coating Normally, however, the volatile aqueous liquid medium consti it has 60 to 98 weight percent of the coating composition. In many cases, the volatile aqueous liquid medium constitutes 70 to 96 weight percent of the coating composition. Frequently, the volatile aqueous liquid medium constitutes 75 to 95 weight percent of the coating composition. Preferably, the volatile aqueous liquid medium constitutes from 80 to 95 percent by weight of the composition. The organic polymers which can be used in the present invention are numerous and have a wide range of d-water. Examples include water-soluble poly (ethylene oxide), water-soluble poly (vinyl alcohol), water-soluble poly (vinylpyrrolidone), organic polymer water-soluble cellulose, hydrodispersed polymer or a mixture of two or more of them. The water-soluble poly (ethylene oxide) is known. Such materials are ordinarily formed by the polymerization of ethylene oxide [CAS 75-21-8], usually in the presence of a small amount of an "initiator, such" as glycol or low molecular weight triol. Examples of such initiators include ethylene glycol [CAS 107-21-1], diethylene glycol [CAS 111-46-6], triethylene glycol [CAS 112.-27-6], tetraethylene glycol [CAS 112-60-7], propylene glycol [ CAS 57-55-6], trimethylene glycol [CAS 504-63-2], dipropylene glycol [CAS 110-98-5], glycerol [CAS 56-81-5], trimethylolpropane [CAS 77-99-6] already,? -diaminopoly (propylene glycol) [CAS 9046-10-0]. One or more different lower alkylene oxides, such as propylene oxide [CAS 75-56-9] and trimethylene oxide [CAS 503-30-0] can also be used as a comonomer with ethylene oxide, either to form random polymers or block polymers, but they should be used only in small amounts such that they do not cause the resulting polymer to be both insoluble in water and non-dispersible in water. As used herein and in the claims, the term "polyethylene oxide" is intended to include the above copolymers of ethylene oxide with small amounts of lower alkylene oxide, as well as ethylene oxide homopolymers. The poly (ethylene oxide) configuration can be linear, branched, panal or star-shaped. Preferred end groups of the poly (ethylene oxide) are hydroxyl groups, but lower alkoxy end groups, such as methoxy groups, may be present, so long as their type and number do not render the poly (ethylene oxide) polymer unsuitable. for your purpose. In most cases, poly (ethylene oxide) is water-soluble. The preferred poly (ethylene oxide) is a water-soluble ethylene oxide homopolymer produced using a small amount of ethylene glycol-as an initiator. The weight-average molecular weight of the water-soluble poly (ethylene oxide) can vary widely. Normally, it is in the range of 100,000 to 3,000,000, although weighted average molecular weights of less than 100,000 or somewhat greater than 3,000,000 can be used. Often, the weight average molecular weight of the water-soluble poly (ethylene oxide) is in the range of 150,000 to 1,000,000. Frequently, the weight average molecular weight of the water-soluble poly (ethylene oxide) is in the range of 200,000 to 1,000,000. It is preferred from 300,000 to 700,000. Water-soluble polyvinyl alcohol can be broadly classified as one of two types. The first type is hydrosoluble hydrosoluble poly (vinyl alcohol), in which less than 1.5 mole percent of the acetate groups remain in the molecule. The second type is partially hydrolysed water-soluble poly (vinyl alcohol), in which from 1.5 to even 20 mole percent acetate groups remain in the molecule. The water-soluble organic polymer can include any of the types or a mixture of both. The weight-average molecular weight of the water-soluble poly (vinyl alcohol) can vary considerably, but is frequently in the range of 100,000 to 400,000. In many cases, the weight average molecular weight is in the range of 110,000 to 300,000. I know he prefers 120,000 to 200,000. The water-soluble poly (vinylpyrrolidone) is a known material and can be used. Normally, but not necessarily, the weight average molecular weight of poly (vinylpyrrolidone) is in the range of 5,000 to 3,000,000. It is preferred from 10,000 to 1,000,000.

There are many types that can vary widely from water-soluble cellulosic organic polymers that can be employed in the present invention. Of these, the water-soluble cellulose ethers are preferred water-soluble cellulosic organo-polymers. Many of the water-soluble cellulose ethers are also excellent agents for water retention. Examples of water soluble cellulose ethers include methylcellulose hydrosoluble [CAS 9004-67-5], water-soluble carboxymethylcellulose, water-soluble sodium [CAS 9004-32-4], water-soluble ethylmethylcellulose, water-soluble hydroxyethylmethylcellulose [CAS 9032-42-2], water-soluble hydroxypropylmethylcellulose [CAS 9004-65-3], water-soluble hydroxyethylcellulose [CAS 9004-62-0], water-soluble ethylhydroxyethylcellulose, water-soluble sodium carboxymethylhydroxyethylcellulose, water-soluble hydroxypropylcellulose [CAS 9004-64-2], water-soluble hydroxybutylcellulose [CAS 37208-08- 5], water-soluble hydroxybutylmethylcellulose [CAS 9041-56-9] and sodium salt of water-soluble cellulose sulfate [CAS 9005-22-5]. Hydrosoluble hydroxypropylcellulose is preferred. Hydrosoluble hydroxypropylcellulose is a known material and can be purchased commercially at various different weighted-average molecular weights. The weight-average molecular weight of the water-soluble hydroxypropylcellulose used in the present invention can vary widely, but is usually in the range of 100,000 to 1,000,000. Frequently, the weighted average molecular weight is in the range of 100,000 to 500,000. It is preferred from 200,000 to 400,000. Two or more water-soluble hydroxyprocellulose having different weight average molecular weights can be mixed to obtain a water-soluble hydroxypropyl cellulose having a different weight average molecular weight. Similarly, there are many widely varying types of other water-soluble polymers that can be employed in the present invention. Examples include poly (vinylpyridine) water soluble poly (etileni ina) water soluble poly (ethylene imine) ethoxylated soluble, poly (ethyleneimine) soluble epichlorohydrin soluble polyacrylate, polyacrylate water-soluble sodium, poly (acrylamide) soluble, poly (alcohol vin? lic) -modified water soluble carboxy, poly (2-acrylamido-methylpropane-2 soluble soluble acid methyl ether), poly (styrene sulfonate) water-soluble, water-soluble copolymer of vinyl / maleic acid, water-soluble styrene-maleic anhydride copolymer ethylene-maleic anhydride copolymer, water-soluble acrylamide / acrylic acid, poly (diethylenetriamine-co-adipic acid) water-soluble poly ((dimethylamino) ethyl hydrochloride) water soluble poly (im? dazolina) water-soluble quaternized poly (chloride N, N-dimethyl-3, 5-dimethylene piperidinium) water-soluble, poly (vinyl pyridinium halide) water-soluble, water-soluble starch, starch n-do .hidrosoluble oxidized, water-soluble casein, water-soluble gelatin, water-soluble sodium alginate, water-soluble carrageenan, water-soluble dextran, water-soluble gum arabic, water-soluble pectin, water-soluble albumin, agar-agar and water-soluble polymers dispersed in water such as po-li (ethylene -co-acrylic acid) dispersed in water or cationic acrylic polymer dispersed in water. There are many widely varying types of water soluble ethylenically unsaturated organic polymers that can be employed in the present invention. In most cases, ethylenic unsaturation is provided by acryloyl groups, methacryloyl groups, allyl groups, vinyl groups, fumaroyl groups and maleoyl groups. Examples of such polymers, monomers and oligomers which can be used polyacrylates, polymeta-acrylates, polymaleates polyfumarates and soluble soluble poly (ethylene oxide) of low, medium or high molecular weight are included. Of particular importance are water-soluble poly (ethylene oxide) diacrylate [CAS 26570-48-9], water-soluble poly (ethylene oxide) dimethacrylate [CAS 25852-47-5] and water-soluble poly (ethylene oxide) dimaleate [CAS 36247-43-5]. Other examples are water-soluble poly (vinyl alcohols) in which the hydrogens of some of the hydroxyl groups have been replaced by acryloyl or methacryloyl groups. Still other examples include water-soluble or water-dispersible materials formed by chain extension of a central unit with oxy-1,2-ethanediyl groups and termination with acryloyl or methacryloyl groups, as examples of core groups which can be used include diols, triols and prolonged aromatic or aliphatic tetroles with oxy-1,2-ethanediyl, such as, for example, trimethylolpropane, glycerin, bisphenol A, propylene glycol and pentaerythritol - Water-soluble organic polymers containing an ethylenically unsaturated group per molecule In most cases, the ethylenic unsaturation is by acryloyl groups, methacryloyl groups, allyl groups, vinyl groups, fumaroyl groups and maleoyl groups, examples of such polymers include monoacrylates, monomethacrylates, monofumates and water-soluble monomaleats of water-soluble poly (ethylene oxides) and diols, triols and tetr aliphatic or aromatic-prolonged oxi-1,2-ethanediyl oxides described above. Of particular importance are water-soluble poly (ethylene oxide) monoacrylate [CAS 26403-58-7], water-soluble poly (ethylene oxide) monomethacrylate [CAS 25736-86-1] and poly (oxide) monomaleate de._ethylene) water-soluble [CAS 37916-19-1]. As the binder component of the coating or the coating composition, as the case may be, the amount of organic polymer can vary considerably. Normally, the organic polymer constitutes 60 to 100 weight percent of the binder. Frequently, the organic polymer constitutes from 80 to 100 weight percent of the binder. 90 to 100 percent by weight of the binder is preferred.

The binder constitutes from 20 to 90 weight percent of the solids of the coating composition. In many cases, the binder constitutes from 25 to 75 weight percent of the solids of the coating composition. 35 to 70 weight percent is preferred. Similarly, the binder constitutes from 20 to 90 weight percent of the dry coating. Frequently, the binder constitutes from 25 to 75 weight percent of the dry coating. 35 to 70 weight percent is preferred. The polymer constituting all or part of the binder of the coating may or may not be insolubilized upon application of the coating composition to the substrate. As used herein and in the claims, insolubilized organic polymer is an organic polymer that is water-soluble or dispersible in water when applied to the substrate and that is completely or partially insolubilized after said application. The insolubilization can be achieved by the use of an insolubilizer. Insolubilizers generally function as cross-linking agents. Preferably, the insolubilizer reacts with functional groups of at least a portion of the organic polymer to provide the desired degree of inso-lubilization to the total organic polymer of the coating. Many insolubilizers are available that may be "used." Examples of suitable insolubilizers include, but are not limited to, Curesan 199 insolubilizer (PPG Industries, Inc., Pittsburgh, PA), Curesan * 200 insolubilizer (PPG Industries , Inc.), Sequarez 700C insolubilizer (Sequa Chemi-cals, Inc., Chester, SC), Sequarez 700M insolubilizer (Sequa Chemicals, Inc.), Sequarez 755 insolubilizer (Sequa Chemicals, Inc.), Sequarez 770 insolubilizer (Sequa Chemicals , Inc.), Berset 39 insolubilizer (Bercen Inc., Cranston, Rl), Berset 47 insolubilizer (Bercen Inc.), Berset 2185 insolubilizer (Bercen Inc.) and insolubilizer Berset 2586 (Bercen Inc.). In such cases, the weight ratio of the insolubilizer to the binder polymer is usually in the range of 0.05: 100 to 15: 100. F Recently, the weight ratio is in the range of 1: 100 to 10: 100. It is preferred from 2: 100 to 5: 100. These reasons are based on the dry solids of the insolubilizer and on the dry solids of the polymer. The product itself of the polymerization reaction of a hydrolyzate of an aluminum alkoxide and an organoalkoxysilane of the general formula: RxSi (OR ') and (OH) z where R is an organic radical, R' is an alkyl radical of molecular weight, x is in the range of 1 to 3, v is in the range of 1 to 3, z is in the range of 0 to 2 and (x + y + z) = 4, is known and is described in detail , together with the manner in which it can be prepared, in U.S. Patent No. 4,731,264 and in European Patent Application Publication No. 0 263 428 A2, the disclosures of which are herein incorporated by reference in their entirety. To explain it briefly, the hydrolyzate of an aluminum alkoxide is first formed. Normally, the hydrolyzate is in the form of hydrated alumina particles substantially insoluble in water finally divided having the empirical formula A10 (OH). In many cases, the hydrolyzate of an aluminum alkoxide is in the form of substantially water insoluble pseudoboehmite particles finally divided. The preparation of the hydrolyzate of an aluminum alkoxide of the pseudoboeh-mita type is also described by B.E. Yoldas in The American Ceramic Society Bulletin, Vol. 54, No. 3 (March 19751, pages 289-290, in Journal of Applied Chemical Biotechnology, Vol. 23 (1973), pages 803-809, and in Journal of JVIaterials Science, Vol. 10 (1975), pages 1856-1860, whose descriptions are here incorporated in their entirety as a reference., aluminum isopropoxide or secondary aluminum butoxide is hydrolyzed in an excess of water with vigorous stirring at a temperature of 75 ° C to 80 ° C to form a suspension of aluminum monohydroxide. The aluminum monohydroxide is then peptized at temperatures of at least 80 ° C with an acid to form a transparent sun of pseudoboehmite, which exhibits the Tyndall effect when it is illuminated by a narrow beam of light, since the pseudoboehmite of the sun it is not white or colored, it is not a pigment and it does not function as a pigment in the present invention.The acid employed does not form complex with aluminum and has sufficient strength to produce the required loading effect at low concentration.Nitric acid, the acid Hydrochloric acid, perchloric acid, acetic acid, chloroacetic acid and formic acid meet these requirements.The acid concentration is usually in the range of 0.03 to 0.1 mole of acid per mole of aluminum alkoxide. In most cases, the pseudoboehmite is transparent and colorless.Pseudoboehmite particles have a maximum dimension of less than 500 nanometers.Often, pseudoboehm particles Ita have a maximum dimension of less than 100 nanometers. Frequently, the maximum dimension is less than 50 nanometers. Preferably, the maximum dimension is less than 20 nanometers. As used herein and in the claims, the maximum dimension of the pseudoboehmite particles is determined by transmission electron microscopy. After preparation of the alumina sol, an organoalkoxysilane (which may optionally be partially hydrolyzed before) is added. The organoalkoxysilane reacts with the hydrolyzed alumina sol to form a silicon-oxygen-aluminum network. In an aqueous alumina sol, most of the remaining alkoxy groups of the organoalkoxysilane are hydrolyzed to form silanol groups, some of which may condense. Various organoalkoxysilanes according to the present invention can be used. The organoalkoxysilanes of general formula RxSi (OR ') and (OH) z where R is an organic radical, R' is a low molecular weight alkyl radical, x is in the range of 1 to 3, and is in the range of 1. a 3, z is in the range of a 2 and _ (x + y + z) = 4, are themselves known. R is preferably selected from the group consisting of alkyl, vinyl, rae-toxiethyl, phenyl, α-methacryloyloxypropyl, β-glycidyl isopropyl, 3-aminopropyl and mixtures thereof. In most cases, each R 'contains independently from 1 to 6 carbon atoms. Preferably, each R 'is independently methyl, ethyl, n-propyl or isopropyl. Methyl or ethyl is especially preferred. The organoalkoxysilane is preferably added in an amount such that the atomic ratio of silicon to aluminum is from about 10: 1 to 1: 1, more preferably from about 6: 1 to about 3: 1. The reaction between the hydrolyzate of an aluminum alkoxide and the organoalkoxysilane is usually carried out at temperatures in the range of 4 ° C to 80 ° C. Frequently, temperatures are in the range of 10 ° C to 60 ° C. Preference is given to 20 ° C to 30 ° C. The product of the polymerization reaction of a hydrolyzate of an aluminum alkoxide and an organoalkoxysilane is particulate. Particles of the polymerization reaction product have a maximum dimension of less than 500 nanometers Often, the particles of the polymerization reaction product have a maximum dimension of less than 100 nanometers.The maximum dimension is often less than 100 nanometers. of 50 nanometers Preferably the maximum dimension is less than 20 nanometers As used herein and in the claims, the maximum product dimension of the polymerization reaction of a hydrolyzate of an aluminum alkoxide and an organoalkoxysilane is determined by microscopy transmission electronics The quantity of the product of the polymerization reaction of a hydrolyzate of an aluminum alkoxide and an organ or alkoxysilane in the coating or in the solids of the coating composition, as the case may be, it can vary widely. The product of the polymerization reaction constitutes from 2 to 80 weight percent of the coating or solids of the coating composition. In many cases, the product of the polymerization reaction constitutes from 10 to 65 percent by weight of the coating or solids of the coating composition. 15 to 45 weight percent is preferred. As used herein and in the claims, "solids of the coating composition" means the residue remaining after substantially removing the solvent and any other volatile material from the coating composition by drying to form a coating in accordance with good practice of coatings. The product of the polymerization reaction of a hydrolyzate of an aluminum alkoxide and an organoalkoxysilane and the binder together usually constitute from 2 to 40 weight percent of the coating composition. Frequently, said product of the polymerization reaction and the binder together constitute from 4 to 30 weight percent of the coating composition. Often, said product of the polymerization reaction and the binder together constitute from 5 to 25 weight percent of the coating composition. Preferably, said product of the polymerization reaction and the binder together constitute from 5 to 20 weight percent of the coating composition. A material that may possibly be present in the coating composition is a surfactant. For the purposes of the present specification and claims, it is considered that a surfactant is not part of the binder. There are many surfactants and combinations of surfactants available that can be used. Examples of suitable surfactants include, but are not limited to, Fluorad FC-170-C surfactant (3M Company) and Triton X-405 surfactant (Union Carbide Corporation). When used, the amount of surfactant pre-sited in the coating composition can vary considerably. In such cases, the weight ratio of the surfactant to the binder is usually in the range of 0.01: 100 to 10: 100. In many cases, the weight ratio is in the range of 0.1: 100 to 10: 100. Often, the weight ratio is in the range of 0.2: 100 to 5: 100. It is preferred from 0.5: 100 to 2: 100. These reasons are based on the dry solids of the surfactant and the dry solids of the binder.

There are many other conventional adjuvant materials that may optionally be present in the coating composition. These include materials such as lubricants, waxes, plasticizers, antioxidants, organic solvents, lacquers, pigments, free radical initiators, photoinitiators and photosensitizers. The list of such materials is by no means exhaustive. These and other ingredients may be employed in their usual amounts for their usual purposes, insofar as they do not seriously interfere with the good practice of formulating coating compositions. The pH of the coating composition can vary considerably. In most cases, the pH is in the range of 3 to 7. Frequently, the pH is in the range of 3.5 to 6. The coating compositions are usually prepared by simply mixing the various ingredients. The ingredients can be mixed in any order. Although the mixture of liquid and solids is usually carried out at room temperature, elevated temperatures are sometimes used. The maximum temperature that can be used depends on the thermal stability of the ingredients. The coating compositions are generally applied to the surface of the substrate using any conventional technique known in the art. These include spraying, curtain coating, dip coating, vane coating, roller application, size pressing, printing, brushing, dragging, slot die coating and extrusion. The coating is then formed by removing the solvent from the applied coating composition. This can be done by any conventional drying technique. The coating composition can be applied once or multiple times. When the coating composition is applied multiple times, the coating composition is normal, although not necessarily, dried, either partially or totally, between coating applications. Once the coating composition has been applied to the substrate, the solvent is substantially removed, usually by drying. If the coating contains ethylenically unsaturated polymer, all or some of the ethylenically unsaturated groups can be polymerized to form crosslinks in any of a number of ways, such as, for example, by heating, by exposure to actinic radiation, by exposure to ionizing radiation or exposure to plasma. The substrate can be any substrate, at least one surface of which the coating discussed above is capable of carrying. In most cases, the substrate is in the form of a single sheet or in the form of a roll, net, strip, film or sheet of material capable of being cut into sheets. The substrate may be porous in its entirety, may be non-porous in its entirety, or may have porous regions and non-porous regions. Examples of porous substrates include paper, cardboard, wood, cloth, non-woven fabric, felt, non-vitrified ceramic material, microporous polymeric membranes, microporous membranes containing both polymeric and filler particles, porous foam and microporous foam. As examples of substrates that are substantially non-porous throughout, include films or films of organic polymer, such as polyethylene terephthalate, polyethylene, polypropylene, cellulose acetate, polyvinyl chloride and copolymers such as sarán. The sheets or films may be filled or unfilled. The sheets or films can be metallized or non-metallized, as desired. As further examples metal substrates are included, including, but not limited to, metal foils such as aluminum foil and copper foil, yet another example is a porous or microporous foam consisting of a thermoplastic organic polymer., whose foam has been compressed to such an extent that the resulting deformed material is substantially non-porous. Still another example is glass. Base stocks which are normally porous, such as, for example, paper, cardboard, wood, cloth, non-woven fabric, felt, non-vitrified ceramic material, microporous polymer membranes, microporous membranes containing both polymeric and filler particles, porous foam or microporous foam, may be coated or laminated to make one or more surfaces substantially non-porous and thus obtain substrates having at least one substantially non-porous surface. The substrate may be substantially transverse, may be substantially opaque or may be be of intermediate transparency. For some applications, such as upper slides printed by inkjet, the substrate must be sufficiently transparent to be useful for that application. For other applications, such as inkjet printed paper, the transparency of the substrate is not as important. - The thickness of the coating can vary widely, but, in most cases, the thickness of the coating is in the range of 1 to 40 μm. In many cases, the thickness of the coating is in the range of 5 to 40 μm. Often, the thickness is in the range of 8 to 30 μm. It is preferred from 10 to 18 μm. The coating may be substantially transparent, substantially opaque or of intermediate transparency. It can be substantially colorless, it can be highly colored or it can be of an intermediate degree of color. Normally, the coating is substantially transparent and substantially colorless. As used herein and in the claims, a coating is substantially transparent if its light transmission in the visible region is at least 80 percent of the incident light. Frequently, the luminous transmission of the coating is at least 85 percent of the incident light. Preferably, the reverse light transmission is at least 90 percent. Also as used herein and in the claims, a coating is substantially colorless if the light transmission is substantially the same for all wavelengths in the visible region, i.e. 400 to 800 nanometers. Optionally, the coatings described above can be coated with an overcoat consisting of an organic ink-receptive film-forming polymer. The overcoat can be formed by applying a composition containing a liquid medium and an organic film-forming polymer responsive to the ink dissolved or dispersed in the liquid medium and removing the liquid medium, for example by drying. Preferably, the liquid medium is an aqueous solvent and the organic ink-receptive film-forming polymer is water-soluble poly (ethylene oxide) having a weight-average molecular weight in the range of 100,000 to 3,000,000, two of which have been described above with respect to the above described embodiments of the invention Water is an especially preferred aqueous solvent The relative proportions of the liquid medium and the organic film-forming polymer present in the overcoating composition may vary The minimum ratio is that which produces an overcoating composition that has a viscosity low enough to be applied as overcoating.The maximum proportion is not dictated by any theory, but by practical considerations such as the cost of the medium. liquid and the cost and time needed to remove the liquid medium from the overrrevest moist applied. Normally, however, the weight ratio of liquid medium to organic film-forming polymer is from 18: 1 to 50: 1. Frequently, the weight ratio is from 19: 1 to 40: 1. Preferably, the weight ratio is 19: 1 a 24: 1. Occasional ingredients such as those described above may be present in the overcoat composition, when desired. The overcoat composition can be prepared by mixing the ingredients. It can be applied and dried using any of the coating and drying techniques discussed above. When an overcoating composition is to be applied, it may be applied once or multiple times. The invention is further described along with the following example, which is to be considered as illustrative rather than limiting, and where all parts are in parts by weight and all percentages are% by weight, unless otherwise specified. something different. EXAMPLE 1 140 grams ~~ of pseudoboehmite powder Disperal P2 (Condea Chemie GmbH ') (produced by hydrolysis of aluminum alkoxide) was added gradually to 860 grams of a 0.25 percent aqueous solution of nitric acid with stirring. The mixture was stirred until a translucent composition of pseudoboehmite was obtained. A reaction flask was charged with 93.6 grams of the above translucent pseudoboehmite composition and 4 grams of dimethyldiethoxysilane (PCR Inc.). The mixture was stirred for 2 hours at room temperature to form a silanized composition of pseudoboehmite. A solution of poly (ethylene oxide) dissolving 60 grams of poly (ethylene oxide) Alkox E-30 having a weight average molecular weight of about 300,000 to 450,000 (Meisei Chemical Works, Ltd.) in 940 grams was prepared. "Deionized water" The fillers shown in Table 1 were used in the preparation of an aqueous secondary cationic polymer composition Table 1 Ingredients Weight, kilograms Load 1 Methyl ethyl ketone 55, 93 Load 2 Methyl ethyl ketone 28, 67 Starter 1 10.16 Load 3 N-Butyl acrylate 30.44 Methyl methacrylate 87.32 2- (tert-butylamino) ethyl methacrylate 40, 64 [CAS 3775-90-4] Styrene 44.68 Charge 4 Methylethyl ketone 2.27 Charge 5 Methyl ethyl ketone 2, 27 Loading 6 Glacial acetic acid 9, 89 Methyl ethyl ketone 2.27 Charge 7 Deionized water 579, 1 Charge 8 Deionized water 11.1 1 VAZO 67, 2, 2'-azobis (2-methylbutanonitrile) initiator, The du Pont de Nemours and Company, Wilmingto ?, Delaware The load was heated 1 in a reactor with stirring at reflux temperature (80 ° C). The addition of Charge 2 from a catalyst tank to the re-actor was then initiated. The addition of Load 2 was made over a period of 305 minutes. Five minutes after starting the addition of Charge 2, the addition of Charge 3 was started from the monomer tank. The addition of Charge 3 was made over a period of 240 minutes. When the addition of Charge 3 was completed, Charge 4 was added to the monomer tank as a wash and then the wash liquid was added from the monomer tank to the reactor over a period of 10 minutes. After the addition of Charge 2 was complete, Charge 5 was added to the catalyst tank as a wash and the wash liquor from the catalyst tank was then added to the reactor over a period of 10 minutes. The reaction mixture was then stirred at reflux for three hours, while the temperature of the reaction mixture was in the range of 83 ° C to 86 ° C. At the end of the three hour period, the reaction mixture was cooled to temperatures in the range of 48 ° C to 52 ° C. Charge 6 was added over a period of 10 minutes and the reaction mixture was then stirred for 15 minutes. Charge 7 was added to a dilution tank equipped for distillation and heated to temperatures in the range of 48 ° C to 52 ° C. The reaction mixture was dropped from the reactor into the dilution tank as quickly as possible. Charge 8 was added to the reactor as a wash and the wash liquid was also dropped into the dilution tank, the contents of the dilution tank were stirred for 30 minutes at temperatures in the range of 48 ° C to 52 ° C. Over a period of thirty minutes, pressure was reduced- to 71.3 kilopascals, absolute. The temperature was then increased and the liquid removed in vacuo until the solids content of the batch was about 30 weight percent. The resulting product, which was an aqueous composition of secondary cationic polymer, was cooled to about 48 ° C, filtered and then discharged into drums. The fillers shown in Table 2 were used in the preparation of an aqueous quaternary cationic polymer composition. Table 2 Ingredients Weight, grams Load 1 Isopropanol 100", 0 Load 2 Isopropanol 106.5 Primer1 18.2 Load 3 Isopropanol 205, 7 Styrene 182.5 Aqueous quaternary monomer2 243.3 Load 4 Water-deionized 790 1 Starter VAZO * 67 , 2,2'-azobis (2-methylbutanonitrile), Du Pont de Nemours and Company, Wilmington, Delaware 2 [2- (methacryloyloxy) ethyl] trimethylammonium chloride 75%, water 25%, by weight. Load 1 in a reactor with reflux stirring (77 ° C to dO ^ C) At reflux, "Load 2 was added over a period of 3 hours. After adding Load 2, the addition of Load 3 was started. Load 3 was added over a period of 3 hours. Charge 4 was added to the catalyst tank and to the monomer tank as a wash and was used for further additions of deionized water. After completing the additions of Charge 2 and Charge 3, the reaction mixture was stirred at reflux for 4 hours. The reactor was then adjusted for total distillation. Approximately 300 grams of deionized water was added to the reactor, the jacket temperature was lowered and vacuum was applied slowly. The vacuum distillation was started. After collecting 491 grams of distillates, an additional 490 grams of deionized water was added and the distillation was continued in vacuo. After removing most of the isopropanol, the percentage of solids was determined and the product was adjusted to 29.5 percent solids (determined by the weight difference of a sample before and after heating at 110 ° C during one hour) using deionized water. The product, which was an aqueous composition of quaternary-cationic polymer, was filtered through a 5 micron glass fiber filter. To 200 g of the above poly (ethylene oxide) solution were added 50 grams of deionized water, 16.7 grams of the above secondary cationic polymer aqueous composition and 18 grams of the above quaternary cationic polymer aqueous composition. The mixture was stirred until a homogeneous composition was obtained and then the entire above silanized pseudoboehmite composition was added. The mixture was stirred for 30 minutes. At the end of this period, 0.24 grams of Fluo-rad * FC-170C surfactant (3M Company) was added and the mixture was stirred for 5 minutes to form a coating composition. Portions of the coating composition were applied to poly (ethylene terephthalate) transparencies with a Meyer Rod # 120 in an oven at 115 ° C for 4.5 minutes. The dried coatings had a thickness of approximately 12 μm.

The coated transparencies were then printed on the coated side using a Hewlett-Packard 870 ink jet printer. The printed transparencies showed excellent print quality. Although the present invention has been described with respect to specific details of certain embodiments thereof, it is not intended to consider such details as limitations of the scope of the invention, except insofar as they are included in the appended claims.

Claims (26)

1. CLAIMS 1. A coating composition consisting of: (a) a volatile aqueous liquid medium; (b) a binder consisting of a water-soluble, film-forming organic polymer dissolved in the volatile aqueous liquid medium, a dispersible film-dispersing organic polymer dispersed in the 10 volatile aqueous liquid medium or a mixture of these, and (c) the product of the polymerization reaction of the hydrolyzate of an aluminum alkoxide and an organoalkoxysilane of form¬ 15 general mule: RxSi (OR ') and (OH) z where R is an organic radical, R' is a low molecular weight alkyl radical, x is in the range of 1 to 3, and is in the 20 range from 1 to 3, z is in the range of 0 to 2 and (x + y + z) = 4.
2. 2. The coating composition of claim 1, where water constitutes at least 80 percent by weight of the volatile aqueous liquid medium.
3. 3. The coating composition of claim 1, wherein the binder consists of a water-soluble, film-forming organic polymer dissolved in the volatile aqueous liquid medium.
4. 4. The coating composition of claim 3, wherein the water-soluble film-forming organic polymer consists of water-soluble poly (ethylene oxide), water-soluble poly (vinyl alcohol), water-soluble poly (vinylpyrrolidone), water-soluble cellulosic organic polymer or a mix of two or more of these.
5. 5. The coating composition of claim 1, wherein the hydrolyzate is in the form of substantially water-insoluble and finely divided hydrated alumina particles having the empirical formula AlO (OH), the particles of which have a maximum dimension of less than 500 nanometers 6.
6. The coating composition of claim 1, wherein the hydrolyzate is in the form of pseudoboehmite particles substantially insoluble in water and finely divided having a maximum dimension of less than 500 nanometers.
7. The coating composition of claim 6, wherein the pseudoboehmite particles have a maximum dimension of less than 100 nanometers.
8. 8. The coating composition of claim 6, wherein the pseudoboehmite particles have a maximum dimension of less than 50 nanometers.
9. 9. The coating composition of claim 1, wherein R is selected from the group consisting of alkyl, vinyl, methoxyethyl, phenyl, β-glycidyloxypropyl, β-methacryloyloxypropyl, 3-aminopropyl, and mixtures thereof.
10. 10. The coating composition of claim 1, wherein each R 'is independently methyl, ethyl, n-propyl or isopropyl. -
11. 11. The coating composition of claim 1, wherein the product of the polymerization reaction constitutes from 2 to 80 percent by weight of the solids of the coating composition. ~
12. 12. The coating composition of claim 1, wherein the product of the polymerization reaction and the binder together constitute from 2 to 40 weight percent of the coating composition.
13. 13. The coating composition of claim 1, wherein the volatile aqueous liquid medium constitutes 60 to 98 weight percent of the coating composition.
14. 14. A printing medium consisting of a substrate having at least one surface and a coating adhered to the surface, wherein the coating consists of: (a) a binder consisting of an organic polymer and (b) the product of the reaction of polymerization of the hydrolyzate of an aluminum alkoxide and an organoalkoxysilane of general form: RxSi (OR ') and (OH) z where: (1) R is an organic radical, R' is an alkyl radical of low molecular weight lar, x is in the range of 1 to 3, and is in the range of 1 to 3, z is in the range of 0 to 2 and (x + y + z) = 4, and (2) the product of the Polymerization reaction is distributed throughout the binder.
15. 15. The printing medium of claim 14, wherein the organic polymer consists of poly (ethylene oxide), poly (vinyl alcohol), poly (vinylpyrrolidone), organic cellulosic polymer or a mixture of two or more of these.
16. 16. The printing medium of claim 14, wherein the hydrolyzate is in the form of substantially water insoluble and finely divided hydrated alumina particles having the empirical formula Alo (OH), the particles of which have a maximum dimension of less than 500 nanometers .
17. 17. The printing medium of the claim 14, where the hydrolyzate is in the form of pseudoboehmite particles substantially insoluble in water and finely divided having a maximum dimension of less than 500 nanometers.
18. 18. The printing medium of the claim 17, where the pseudoboehmite particles have a maximum dimension of less than 100 nanometers.
19. 19. The printing medium of claim 17, wherein the pseudoboehmite particles have a maximum dimension of less than 50 nanometers.
20. The printing medium of claim 14, wherein R is selected from the group consisting of alkyl, vinyl, methoxyethyl, phenyl, β-glycidyloxypropyl, β-methacryloyloxypropyl, 3-aminopropyl, and mixtures thereof.
21. The printing medium of claim 14, wherein each R 'is independently methyl, ethyl, n-propyl or isopropyl
22. 22. The printing medium of claim 14, wherein the product of the polymerization reaction constitutes a 2 to a 80 weight percent solids of the coating composition
23. 23. The printing medium of claim 14, wherein the thickness of the coating is in the range of 1 to 40 μm
24. 24. The printing medium of claim 14 , where the coating thickness is in the range of 10 to 18 μm.
25. 25. The printing medium of claim 14, wherein the substrate is paper, coated paper or organic polymer.
26. 26. A printing process consisting in applying liquid ink droplets to the printing medium of claim 14.