Abstract: A recording medium has a base, a first ink receiving layer, and a second ink receiving layer that is the outermost layer in the stated order, in which the first ink receiving layer is a layer adjacent to the second ink receiving layer, the first ink receiving layer contains fumed silica, the second ink receiving layer contains colloidal silica and resin particles, and the area in which the colloidal silica exists in the recording medium surface is 10% or more and 70% or less.

Abstract: A recording medium includes a support and an ink-receiving layer. The ink-receiving layer contains alumina particles, silica particles and a binder. A composition analysis of the recording medium performed by X-ray photoelectron spectroscopy while etching is performed from a surface side to a support side provides a ratio of the amount of Si element to the total amount of Al element and Si element at an etching time of 0 minutes of 10 atomic percent or more and 90 atomic percent or less and a ratio of the amount of Si element to the total amount of Al element and Si element at an etching time of 5 minutes of 50 atomic percent or more.

Abstract: A recording medium includes a base and an ink-receiving layer. The ink-receiving layer includes inorganic particles, a binder, poly(diallyldimethylamine hydrochloride), a cationic polymer having a sulfonyl group, and a polyvalent metal.

Abstract: A method for producing a recording medium, including a step of coating one or more ink receiving layers provided on at least one surface of a substrate with an outermost layer coating liquid to form an outermost layer, where an ink receiving layer of the one or more ink receiving layers, which is nearest to the outermost layer contains alumina hydrate and a binder. The outermost layer coating liquid contains monodispersive and spherical cationic colloidal silica particles having an average particle size of 30 nm or more and 60 nm or less, polyvinyl alcohol having a saponification degree of 75% by mol or more and 85% by mol or less and a viscosity-average polymerization degree of 1,500 or more and 2,200 or less, and cationic polyurethane emulsion particles having an average particle size of 10 nm or more and 100 nm or less.

Abstract: A recording medium includes a base, a second ink-receiving layer, and a first ink-receiving layer in this order. The first ink-receiving layer contains gas-phase method silica, a binder, a cationic polymer having a sulfonyl group, and glycol. The second ink-receiving layer contains gas-phase method silica and a binder and (1) does not contain any cationic polymer having a sulfonyl group or (2) contains a cationic polymer having a sulfonyl group in an amount not higher than 0.1 parts by mass based on 100 parts by mass of the gas-phase method silica.

Abstract: A recording medium includes, in sequence, a support, a first ink-receiving layer containing a first inorganic particle and a first binder, a second ink-receiving layer containing a second inorganic particle and a second binder, and a third ink-receiving layer which is an outermost surface layer and contains a third inorganic particle, a third binder, and a particle different from the third inorganic particle and having an average secondary particle size of 1.0 to 20.0 ?m. A mass ratio of a content of the first binder to a content of the first inorganic particle is larger than a mass ratio of a content of the second binder to a content of the second inorganic particle. A content of the particle having the specific average secondary particle size is 0.5% by mass or more with respect to a content of the third inorganic particle.

Abstract: A recording medium includes a support; and an ink-receiving layer, the ink-receiving layer having a lower layer and an upper layer, in which the lower layer contains fine inorganic particles, polyvinyl alcohol, and boric acid, the fine inorganic particles including at least one compound selected from alumina, hydrated alumina, and vapor-phase-process silica, in which the upper layer contains fine inorganic particles, polyvinyl alcohol, and boric acid, the fine inorganic particles including at least one compound selected from alumina and hydrated alumina, in which the lower layer has a boric acid content of 2.0% by mass to 7.0% by mass with respect to polyvinyl alcohol, and in which the upper layer has a boric acid content of 10.0% by mass to 30.0% by mass with respect to polyvinyl alcohol.

Abstract: A recording medium includes an ink-receiving layer on a substrate, in which the ink-receiving layer contains hydrated alumina, a C1-4 alkylsulfonic acid, and a salt of a compound of general formula (1): X1—R1—(S)n—R2—X2, wherein n represents 1 or 2; X1 and X2 each independently represent H, NH2, or COOH, and at least one of X1 and X2 represents NH2 or COOH; R1 and R2 each independently represent alkylene, arylene, or heteroarylene, and they may be bonded to each other to form a ring, upon letting the proportion of the C1-4 alkylsulfonic acid be A percent by mass with respect to hydrated alumina, A is in the range of 1.0 to 2.0, and upon letting the proportion of the salt of the compound of general formula (1) be B percent by mass with respect to hydrated alumina, B is in the range of 0.5 to 5.0.

Abstract: A recording medium includes, in sequence, a support, a first ink-receiving layer, and a second ink-receiving layer, in which a content of a boric acid in the first ink-receiving layer is 2.0% by mass or more and 7.0% by mass or less with respect to a content of a polyvinyl alcohol in the first ink-receiving layer, a content of a boric acid in the second ink-receiving layer is 10.0% by mass or more and 30.0% by mass or less with respect to a content of a polyvinyl alcohol in the second ink-receiving layer, an outermost surface layer of the recording medium has a content of particles of 0.5% by mass or more and 5.0% by mass or less, the particles having an average secondary particle size of 1.0 ?m or more and 20.0 ?m or less with respect to a content of an inorganic pigment.

Abstract: An inkjet recording medium includes a support and an ink-receiving layer which is disposed on the support and which contains an alumina pigment and an alkylsulfonic acid having the carbon number of 1 or more and 4 or less. The ink-receiving layer further contains a polymeric compound, a water-soluble zirconium compound, and boric acid or a borate. The polymeric compound is one obtained by cationizing at least one amino group of a product with acid, the product being obtained by the reaction of at least three compounds, that is, (i) a sulfur-containing organic compound containing two or more active hydrogen atoms, (ii) a polyisocyanate compound containing two or more isocyanate groups, and (iii) an amine compound containing two or more active hydrogen atoms.

Abstract: A recording medium includes, in sequence, a support, a first ink-receiving layer containing a first inorganic particle and a first binder, a second ink-receiving layer containing a second inorganic particle and a second binder, and a third ink-receiving layer which is an outermost surface layer and contains a third inorganic particle, a third binder, and a particle different from the third inorganic particle and having an average secondary particle size of 1.0 to 20.0 ?m. A mass ratio of a content of the first binder to a content of the first inorganic particle is larger than a mass ratio of a content of the second binder to a content of the second inorganic particle. A content of the particle having the specific average secondary particle size is 0.5% by mass or more with respect to a content of the third inorganic particle.

Abstract: A recording medium includes a base and at least one ink-receiving layer. A first ink-receiving layer that is at least one ink-receiving layer contains inorganic particles having an average primary particle size of 1 ?m or less and inorganic particles coated with a metal oxide. The inorganic particles coated with the metal oxide have an average primary particle size of 15.0 ?m or more. When the maximum of a FLOP value of the recording medium is denoted by FLOPMax and the minimum of the FLOP value is denoted by FLOPMin, the FLOPMin is 2.5 or more and a value of FLOPMin/FLOPMax is 0.80 or more and 1.00 or less.

Abstract: A recording medium includes a base and an ink receiving layer. The ink receiving layer contains inorganic particles. The surface of the recording medium has an arithmetic mean roughness of 0.8 ?m or more in accordance with JIS B 0601:2001. The surface of the recording medium includes openings having a width of 30 ?m or less and a length of 500 ?m or less. The number of the openings is 5 or more and 30 or less per 1 mm2 of the surface of the recording medium.

Abstract: An ink jet recording medium including a substrate and an ink receiving layer provided on the substrate and composed of two or more layers of at least an upper layer and a lower layer. The ink receiving layer contains polyvinyl alcohol in an amount of 12.7% by mass or more based on the total mass of the ink receiving layer. The upper layer is a layer most distant from the substrate, contains a pigment and polyvinyl alcohol, the pigment containing 90% by mass or more of alumina hydrate, and has a thickness of 3.0-10.0 ?m. The lower layer is positioned just under the upper layer, contains a pigment and polyvinyl alcohol, the pigment containing 20% by mass or more of silica, and has a thickness 2.5-10 times larger than that of the upper layer and an average pore radius 0.90-1.30 times larger than that of the upper layer.

Abstract: In an ink jet recording medium having at least two ink receiving layers, the total content of boric acid, a borate, and a water-soluble zirconium salt of a lower ink receiving layer located close to a support substrate to the total content of alumina and an alumina hydrate thereof is higher than the total content of boric acid, a borate, and a water-soluble zirconium salt of an upper ink receiving layer located apart from the support substrate to the total content of alumina and an alumina hydrate thereof.

Abstract: A recording medium includes, in sequence, a support, a first ink-receiving layer, and a second ink-receiving layer, in which the first ink-receiving layer contains at least one selected from an alumina, an alumina hydrate, and a fumed silica, a polyvinyl alcohol, and a boric acid, in which a mass ratio of a content of the boric acid in the first ink-receiving layer to a content of the polyvinyl alcohol in the first ink-receiving layer is 2.0% by mass or more and 7.0% by mass or less, in which the second ink-receiving layer contains a fumed silica, a polyvinyl alcohol, and a boric acid, and in which a mass ratio of a content of the boric acid in the second ink-receiving layer to a content of the polyvinyl alcohol in the second ink-receiving layer is 10.0% by mass or more and 30.0% by mass or less.

Abstract: A recording medium includes a base, a second ink-receiving layer, and a first ink-receiving layer in this order. The first ink-receiving layer contains gas-phase method silica, a binder, a cationic polymer having a sulfonyl group, and glycol. The second ink-receiving layer contains gas-phase method silica and a binder and (1) does not contain any cationic polymer having a sulfonyl group or (2) contains a cationic polymer having a sulfonyl group in an amount not higher than 0.1 parts by mass based on 100 parts by mass of the gas-phase method silica.

Abstract: A recording medium includes a base and an ink-receiving layer. The ink-receiving layer includes inorganic particles, a binder, poly(diallyldimethylamine hydrochloride), a cationic polymer having a sulfonyl group, and a polyvalent metal.

Abstract: The invention provides a recording medium having excellent ink absorbency and capable of forming a sharp image thereon. The recording medium has a substrate, and a first layer and an outermost layer provided on the substrate in this order, wherein the first layer contains at least one of alumina and alumina hydrate, the outermost layer contains a pigment and is lower in refractive index than the first layer, and the absolute dry coating amount of the outermost layer is 0.1 g/m2 or more and 0.5 g/m2 or less.

Abstract: An ink jet recording medium including a substrate and two or more ink receiving layers provided on the substrate, wherein a first ink receiving layer that is an outermost ink receiving layer of the two or more ink receiving layers and a second ink receiving layer adjacent to the first ink receiving layer contain an alumina pigment, polyvinyl alcohol and boric acid. The first ink receiving layer contains polyvinyl alcohol in an amount of 7.0-10.5% by mass or less based on the alumina pigment and contains boric acid in an amount of 1.1-1.4% by mass or less based on the alumina pigment. The second ink receiving layer contains polyvinyl alcohol in an amount of 10.5-17.0% by mass or less based on the alumina pigment and contains boric acid in an amount of 1.5-2.5% by mass or less based on the alumina pigment.