Patent Application
20130095333
Surface treatments are used in the production of print media to improve image quality and reduce the drying times after printing. Surface treatment solution may contain soluble multivalent salts such as CaCl2. Surface treatment provides the medium with special functionality which can separate pigmented ink colorants from the ink vehicles and chemically or physically bind the anionically charged ink colorants on the outermost surface of the ink receiving media. Surface treatment provides additional protection from environmental elements such as water, and improves the abrasiveness, creasibility, finish, printability, smoothness, and surface bond strength, while decreasing surface porosity and fuzzing. For example, the surface treatment protects the medium by ensuring that water does not absorb into the medium and displace or otherwise remove or distort the ink printed on the medium.
The accompanying drawings illustrate various examples of the principles described herein and are a part of the specification. The illustrated examples are given merely for illustration, and do not limit the scope of the claims.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.
One drawback of applying surface treatments containing inorganic metallic salts to print media is the corrosion concerns caused by inorganic anions such as, for example, chloride Cl1− within the surface treatment solutions. These inorganic ions are corrosive to many metal objects. These water soluble salts are electrolytic, and inevitably initialize corrosion reactions when brought into contact with the metal surfaces of various machines used to produce the print media as well as metal surfaces of printing devices.
The present disclosure describes a surface treatment solution, associated print media comprising the surface treatment solution, and methods of forming the print media comprising the surface treatment solution. In one example, the surface treatment solution comprises a number of water soluble, multi-valent salts, a number of water dispersible, multi-valent salts, a binder that binds the water dispersible, multi-valent salts to a medium and to the elements within the surface treatment solution, and an organosilane. Print media treated with a mixture of soluble and dispersible organic salt will produce improved image quality while significantly reducing or eliminating soluble multivalent inorganic salts such as CaCl2.
As used in the present specification and in the appended claims, the term “medium,” “media,” “print medium,” or similar language is meant to be understood broadly as any medium upon which ink may be applied. In one example, the medium is made from cellulosic fibers. In another example, the medium is made from synthetic fibers such as, for example, polyamides, polyesters, polyethylene, and polyacrylic fibers. In yet another example, the medium is made from inorganic fibers such as, for example, asbestos, ceramic, and glass fibers. In still another example, the medium may be made of a combination of the above materials. The medium may be formed in any dimension, size, or thickness. Further, the medium may be of any form such as, for example, pulp, wet paper, or dry paper. Further, the medium may comprise a mixture of fibers, for example, wood fibers, non-wood fibers, and recycled fibers. Medium is meant to encompass printing paper such as, for example, inkjet printing paper, and may further include other forms of paper such as, for example, writing paper, drawing paper, and photobase paper, as well as board materials such as, for example, cardboard, poster board, and Bristol board.
The fibers may be produced from chemical pulp, mechanical pulp, thermal mechanical pulp, chemical mechanical pulp, and chemi-thermo-mechanical pulp (CTMP), for example. Examples of wood pulps include, but are not limited to, kraft pulps and sulfite pulps, each of which may or may not be bleached. Examples of softwoods include, but are not limited to, pines, spruces, and hemlocks. Examples of hardwoods include, but are not limited to, birch, maple, oak, poplar and aspen.
The paper medium may further comprise internal starch, inorganic fillers, internal sizing agents, and other additives that provide functional and operational benefits. These additives also may be added to the fiber mixture or pulp stock before it is converted to the paper web. Examples of starch include, but are not limited to, Apollo® cationic corn starch, Astro X® cationic potato starch, Pencat® cationic corn starch, and Topcat® cationic additive all available from Penford Products Co., Cedar Rapids, Iowa, U.S.A.
Examples of fillers that may be incorporated into the fiber mixture of the paper medium include, but are not limited to, carbonates, ground calcium carbonate (GCC), precipitated calcium carbonate (PCC), titanium dioxide, clays, talc, and combinations of the above. Examples of filler include, but are not limited to, Magfil® PCC from Specialty Minerals, Inc. of Bethlehem, Pa., U.S.A., or Omyafil® GCC from Omya North America.
Examples of internal sizing agents include, but are not limited to, fatty acids, alkyl ketene dimer (AKD) emulsification products, alkenyl acid anhydride emulsification products, alkylsuccinic acid anhydride (ASA) emulsification products, and rosin derivatives. Some examples of commercially available ASA and AKD include, but are not limited to, Nalco® 7542 ASA from Nalco Company, Ill., U.S.A., Basoplast® 2030 AKD from BASF, and Hercon® 195 AKD from Hercules Inc. USA.
Examples of retention/drainage aids include, but are not limited to, a polyacrylamide, polyaluminum chloride, microparticles, cationic starch, a flocculant, and a dispersant. In some examples, the paper medium may further comprise an optical brightening agent (OBA) to control the brightness. Some examples of commercially available OBAs may include, but are not limited to, Tinopal® ABP-A from Ciba Specialty Chemicals, High Point, N.C. USA., and Leucophor SAC, SPS, STR, SHR, S liq from Clariant Company, Charleston, N.C., USA. Some examples of commercially available dyes may include, but are not limited to, Irgalite® Violet BL & Irgalite® Blue R-L from Ciba Specialty Chemicals, High Point, N.C. Other agents and additives including, but not limited to, dyes, de-foaming agents, biocides, buffering agents and pitch control agents may be included in the fiber mixture of the paper medium in some examples.
Further, as used in the present specification and in the appended claims, the term “surface treatment” or “surface treatment solution” is meant to be understood broadly as any substance applied to or incorporated into an outermost surface of a medium upon which ink may interact. In one example, surface treatment provides the medium with special functionality which can separate pigmented ink colorants from the ink vehicles and chemically or physically bind the anionically charged ink colorants on the outermost surface of the ink receiving media. In yet another example, the surface treatment provides additional protection from environmental elements such as water, and improves the abrasiveness, creasibility, finish, printability, smoothness, and surface bond strength, while decreasing surface porosity and fuzzing. For example, the surface treatment protects the medium by ensuring that water does not absorb into the medium and displace or otherwise remove or distort the ink printed on the medium.
Further, as used in the present specification and in the appended claims, the term “weight percent” or “wt %” is meant to be understood broadly as the mass fraction (wi) of one substance with mass mi to the mass of the total mixture mtot, multiplied by 100. The mass fraction (wi) is defined by the following equation:
and weight percent is defined by the following equation:
wt %=wi*100 Eq. 2
Further, as used in the present specification and in the appended claims, the term “black color optical density” or “KoD” is meant to be understood broadly as the defined as:
where I is the intensity of light at a specified wavelength λ that has passes through a sample (transmitted light intensity) and I0 is the intensity of the light before it enters the sample or incident light intensity.
Even still further, as used in the present specification and in the appended claims, the term “a number of” or similar language is meant to be understood broadly as any positive number comprising 1 to infinity; zero not being a number, but the absence of a number.
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present systems and methods. It will be apparent, however, to one skilled in the art that the present apparatus, systems, and methods may be practiced without these specific details. Reference in the specification to “an example” or similar language means that a particular feature, structure, or characteristic described in connection with that example is included as described, but may not be included in other examples.
In one example, the surface treatment solution comprises an organic water soluble metallic salt and an organic water dispersible metallic salt. Organic metallic salt are ionic compounds composed of cations and anions with a formula such as (CnH2n+1COO−M+)*(H2O)m where M+ is cation species including Group I metals, Group II metals, Group III metals and transition metals such as, for example, sodium, potassium, calcium, copper, nickel, zinc, magnesium, barium, iron, aluminum and chromium ions. Anion species can include any negatively charged carbon species with a value of n from 1 to 35. The hydrates (H2O) are water molecules attached to salt molecules with a value of m from 0 to 20.
Water soluble is meant to be understood broadly as a species that is readily dissolved in water. Thus, water soluble salts may refer to a salt that has a solubility greater than 15 g/100 g H2O at 1 atm pressure and 20° C. Examples of water soluble salt include, but are not limited to, calcium acetate, calcium acetate hydrate, calcium acetate monohydrate, magnesium acetate, magnesium acetate tetrahydrate, calcium propionate, calcium propionate hydrate, calcium gluconate monohydrate, and calcium formate.
Water dispersible is meant to be understood broadly as a species that does not readily dissolve in water. Thus, water dispersible salts may have the same general chemical formulas as described above, but refer to a salt that has a water solubility less than 10 g/100 g H2O at 1 atm pressure and 20° C. These particles exist in water in a solid state. However, water dispersible salts can be dispersed under various mixing conditions at low or high shear force, or with help of a chemical emulsifier to form a stable emulsion at a not extended time frame of processing, or media manufacture. Examples of water dispersible salts included, but are not limited to, calcium citrate, calcium citrate tetrahydrate, calcium oleate, and calcium oxalate.
In one example, the ratio of water soluble salts to water dispersible salts is from 9:1 to 1:1. In another example, the ratio of water soluble salts to water dispersible salts is from 4:1 to 1:1. When aqueous pigmented ink is jetted on the media (100, 200), cations from water soluble salts will de-stabilize the dispersed pigmented ink by separating the pigments from the ink vehicles. Water dispersible salts function as “fixers” to bond the ink colorant particles printed on the outermost surface of the surface treatment solution (104, 208) to the print media (100, 200). In this manner, the printing quality such as ink density and color gamut are significantly improved. Further, inorganic ions are corrosive to many metal objects, and, because they are electrolytic, inevitably initialize corrosion reactions when brought into contact with the metal surfaces of various machines used to produce the print media as well as metal surfaces of printing devices. Thus, another advantage in using water dispersible salts is the reduction or elimination of potential corrosion in machines used to produce and print on the print media.
In another example, the surface treatment solution compromises at least an organosilane with a general formula of (RO)3SiR′ where R and R′ are any chemical group selected from alkyl groups, aromatic groups, and heteroaromatic groups. The RO groups are hydrolysable in a neutral to acidic environment. The function of organosilane is to modify the surface properties of the dispersible salt particles to make the dispersible salt particles more readily react with both the print medium (102, 202) and ink colorant particles. Examples of organosilanes include, but not limited to, mono amino silanes, diamino silanes, triamino silanes, bis(2-hydroethyl)-3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, bis(triethoxysilylpropyl)disulfide, 3-aminopropyltriethoxysilane, 3-aminopropylsilsesquioxane, bis-(trimethoxysilylpropyl)amine, N-phenyl-3-aminopropyltrimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, N-(trimethyloxysilylpropyl)isothiouronium chloride, N-(triethoxysilpropyl)-O-polyethylene oxide, 3-(triethoxylsilyl)propylsuccinic anhydride, and 3-(2-imidazolin-1-yl)propyltriethoxysilane. Other useful organosilanes include, for example, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl-3-aminopropyltrimethoxysilane, 3-(triethoxysilylpropyl)-diethylenetriamine, poly(ethyleneimine)trimethoxysilane, aminoethylaminopropyl trimethoxysilane, and aminoethylaminoethylaminopropyl trimethoxysilane. In one example, the ratio of dispersible salt to organosilane is from 1:2 to 10:1. In another example, the ratio of dispersible salt to organosilane is from 1:3 to 5:1.
Further, in another example, the surface treatment solution comprises a polymeric binder. The function of a binder is to provide the adhesion between dispersible salt particles and fillers (described below), and between the print medium (102, 202) and the dispersible salt and fillers. The binder may be any kind of natural or synthetic polymer. In one example, the polymers of the binder have neutral or cationic charges. Examples of binders include, but are not limited to, polyvinyl alcohol (PVOH), polyvinyl acetate (PVAc), polyacrylate latex, styrene butadiene latex, styrene acrylate latex, oxidized starch, cationic starch, ethylated starch, and chemically modified starches.
In the examples descried above, the surface treatment solution can include other chemical additives such as, for example, inorganic fillers, pH buffers, deformers, sizing agents such as styrene alkylketene dimer (AKD), alkenylsuccinic anhydride (ASA), styrene-maleic anhydride (SMA), styrene acrylate (SA), and alkyl-substituted urethane copolymers, rheological controllers such as thickeners, OBAs, and color dyes. The following example formulations of surface treatment solutions (104, 208) make reference to Table 1 and
In a first example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 1.00 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2). The water soluble, multi-valent, organic acid salt is used within the surface treatment solution (104, 208) of this example and examples to follow as a crashing agent for pigment-based ink such as, for example, inkjet inks. The water soluble, multi-valent, organic acid salt also provides for better printability including a higher KoD. This formulation resulted in a print medium (102, 202) with a black color optical density (KoD) of 1.19 and a pH of 7.40. In a second example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.90 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2). This formulation resulted in a print medium (102, 202) with a (KoD) of 1.16 and a pH of 7.33.
In a third example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.75 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2). This formulation resulted in a print medium (102, 202) with a KoD of 1.13 and a pH of 6.68. In a fourth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.50 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2). This formulation resulted in a print medium (102, 202) with a KoD of 1.04 and a pH of 7.10.
In a fifth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.90 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2). This fifth example further comprises approximately 0.10 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O). The water dispersible, multi-valent, organic acid salt is used within the surface treatment solution (104, 208) of this example and examples to follow as fixers to bond the ink colorant particles on the outermost surface of the media while reducing or eliminating of potential corrosion to print media production machines and printing devices. This fifth formulation resulted in a print medium (102, 202) with a KoD of 1.20 and a pH of 7.50.
In a sixth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.75 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), and approximately 0.25 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O). This formulation resulted in a print medium (102, 202) with a KoD of 1.33 and a pH of 7.51.
In a seventh example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.50 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), and approximately 0.50 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6H5O7)2.4H2O). This formulation resulted in a print medium (102, 202) with a KoD of 1.07 and a pH of 7.49.
In an eighth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.90 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), and approximately 0.10 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O). This eighth example further comprises approximately 3.0 wt % starch ((C6H10O5)n). The starch is used within the surface treatment solution (104, 208) of this example and examples to follow as a binder to provide adhesion between dispersible salt particles and fillers, and between the print medium (102, 202) and the dispersible salt and fillers. This eighth formulation resulted in a print medium (102, 202) with a KoD of 1.21 and a pH of 7.51.
In a ninth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.75 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.25 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O), and approximately 3.0 wt % starch ((C6H10O5)n). This formulation resulted in a print medium (102, 202) with a KoD of 1.28 and a pH of 7.51.
In a tenth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.50 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.50 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O), and approximately 3.0 wt % starch ((C6H10O5)n). This formulation resulted in a print medium (102, 202) with a KoD of 1.07 and a pH of 7.48.
In an eleventh example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.90 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.10 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O), and approximately 3.0 wt % starch ((C6H10O5)n). This eleventh example further comprises approximately 3.0 wt % of a pigment such as ground calcium carbonate (GCC) (CaCO3). The pigment is used within the surface treatment solution (104, 208) of this example and examples to follow to maintain a specific color of the print medium. This eleventh formulation resulted in a print medium (102, 202) with a KoD of 1.21 and a pH of 7.09.
In a twelfth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.75 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.25 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O), and approximately 3.0 wt % starch ((C6H10O5)n). This twelfth example further comprises approximately 3.0 wt % of a pigment such as, for example, ground calcium carbonate (GCC) (CaCO3). This formulation resulted in a print medium (102, 202) with a KoD of 1.26 and a pH of 6.82.
In a thirteenth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.50 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.50 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O), approximately 3.0 wt % starch ((C6H10O5)n), and approximately 3.0 wt % of a pigment such as, for example, ground calcium carbonate (GCC) (CaCO3). This formulation resulted in a print medium (102, 202) with a KoD of 1.07 and a pH of 7.33
In a fourteenth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.90 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), and approximately 0.10 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O). This fourteenth example further comprises approximately 3.0 wt % of a polyvinyl alcohol ((C2H4O)x). The polyvinyl alcohol is used within the surface treatment solution (104, 208) of this example and examples to follow as a binder to provide adhesion between dispersible salt particles and fillers, and between the print medium (102, 202) and the dispersible salt and fillers. This fourteenth example further comprises approximately 0.15 wt % of an organosilane such as, for example, gamma-aminopropyltriethoxysilane (C9H23NO3Si). The organosilane is used within the surface treatment solution (104, 208) of this example and examples to follow to modify the surface properties of the dispersible salt particles to make the dispersible salt particles more readily react with both the print medium (102, 202) and ink colorant particles. This fourteenth formulation resulted in a print medium (102, 202) with a KoD of 1.41 and a pH of 7.12.
In a fifteenth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.75 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.25 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6H5O7)2.4H2O), approximately 3.0 wt % of a polyvinyl alcohol ((C2H4O)x), and approximately 0.15 wt % of an organosilane such as, for example, gamma-aminopropyltriethoxysilane (C9H23NO3Si). This formulation resulted in a print medium (102, 202) with a KoD of 1.34 and a pH of 7.31.
In a sixteenth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.50 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.50 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O), approximately 3.0 wt % of a polyvinyl alcohol ((C2H4O)x), and approximately 0.15 wt % of an organosilane such as, for example, gamma-aminopropyltriethoxysilane (C9H23NO3Si). This formulation resulted in a print medium (102, 202) with a KoD of 1.27 and a pH of 7.03.
In a seventeenth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.90 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.10 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O), approximately 3.0 wt % of a pigment such as ground calcium carbonate (GCC) (CaCO3), approximately 3.0 wt % of a polyvinyl alcohol ((C2H4O)x), and approximately 0.15 wt % of an organosilane such as, for example, gamma-aminopropyltriethoxysilane (C9H23NO3Si). This seventeenth example further comprises approximately 0.10 wt % of a dispersant such as, for example, a sodium salt of a polyacrylic acid. The dispersant is used within the surface treatment solution (104, 208) of this example and examples to follow to maintain dispersed particles within the surface treatment such as the water dispersible, multi-valent, organic acid salt in suspension. This seventeenth formulation resulted in a print medium (102, 202) with a KoD of 1.27 and a pH of 7.03.
In an eighteenth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.75 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.25 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6H5O7)2.4H2O), approximately 3.0 wt % of a pigment such as ground calcium carbonate (GCC) (CaCO3), approximately 3.0 wt % of a polyvinyl alcohol ((C2H4O)x), approximately 0.10 wt % of a dispersant such as, for example, a sodium salt of a polyacrylic acid, and approximately 0.15 wt % of an organosilane such as, for example, gamma-aminopropyltriethoxysilane (C9H23NO3Si). This formulation resulted in a print medium (102, 202) with a KoD of 1.36 and a pH of 6.93.
In a nineteenth example of a formulation of a surface treatment solution (104, 208), the surface treatment solution comprises approximately 0.50 wt % of a water soluble, multi-valent, organic acid salt such as, for example, calcium acetate hydrate (Ca(C2H3O2)2), approximately 0.50 wt % of a water dispersible, multi-valent, organic acid salt such as, for example, calcium citrate tetrahydrate (Ca3(C6HSO7)2.4H2O), approximately 3.0 wt % of a pigment such as ground calcium carbonate (GCC) (CaCO3), approximately 3.0 wt % of a polyvinyl alcohol ((C2H4O)x), approximately 0.10 wt % of a dispersant such as, for example, a sodium salt of a polyacrylic acid, and approximately 0.15 wt % of an organosilane such as, for example, gamma-aminopropyltriethoxysilane (C9H23NO3Si). This formulation resulted in a print medium (102, 202) with a KoD of 1.29 and a pH of 6.85.
4
indicates data missing or illegible when filed
The specification and figures describe a surface treatment solution, a print medium, and methods of forming a surface treated medium. The surface treatment solution comprises a number of water soluble, multi-valent salts, a number of water dispersible, multi-valent salts, a binder that binds the water dispersible, multi-valent salts to a medium and to the elements within the surface treatment solution, and an organosilane. This surface treatment solution and associated print medium may have a number of advantages, including improved optical density when utilized with pigment-based inks, elimination of print medium degradation, and a more consistent, economical, and precise printing surface. Further, this surface treatment solution and associated print medium may cause the medium to improve in the areas of abrasiveness, creasibility, finish, printability, smoothness, water resistance, and surface bond strength, while decreasing surface porosity and fuzzing.
The preceding description has been presented to illustrate and describe examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the above teaching.
