Abstract: A recording medium includes a substrate, a first ink receiving layer and a second ink receiving layer in that order. The first ink receiving layer contains at least one inorganic pigment selected from the group consisting of alumina, hydrated alumina and fumed silica, polyvinyl alcohol, and a boric acid compound. The second ink receiving layer contains fumed silica, particles having an average particle size in a specific range, polyvinyl alcohol, and a boric acid compound. The boric acid compound content in the first ink receiving layer is in a predetermined range, and the boric acid compound content in the second ink receiving layer is in a predetermined range. The particle content in the second ink receiving layer is in a predetermined range.

Abstract: A recording medium including a substrate and an ink receiving layer on the substrate, the ink receiving layer containing inorganic particles and a water-soluble resin. The recording medium has an HM1 of 40 N/mm2 or less and has a rate of change of HM2 to HM1 of 400% or less. HM1 is a Martens hardness when an indenter is pushed at a 500 mN load over 180 seconds from a surface of the recording medium into a 1 ?m depth in a thickness direction thereof. HM2 is a Martens hardness when the indenter is pushed up to a position where the indenter is not in contact with the surface and is then pushed at a 500 mN load over 180 seconds from a pressing starting position into a 1 ?m depth in the thickness direction at the same point as that at which the indenter is first pushed.

Abstract: A recording medium includes a substrate and an ink receiving layer that includes inorganic particles and a binder. The inorganic particles include at least one type of alumina particles selected from fumed alumina particles and hydrated alumina particles. The binder includes a resin having a glass transition temperature of 20° C. or less. The content of the binder in the ink receiving layer is 25% by mass or more of the content of the inorganic particles included in the ink receiving layer.

Abstract: A recording medium includes a substrate and an ink receiving layer that includes inorganic particles and a binder. The inorganic particles include fumed silica particles. The binder includes a resin having a glass transition temperature of 20° C. or less. The content of the binder in the ink receiving layer is 40% by mass or more of the content of the inorganic particles included in the ink receiving layer.

Abstract: A recording medium includes in this order a water-resistant substrate, a first ink receiving layer, and a second ink receiving layer that is the outermost layer. The first ink receiving layer contains a fumed silica and a binder. The second ink receiving layer contains a colloidal silica having an average primary particle diameter of 50 nm or more and 100 nm or less, and a polyvinyl alcohol having a silanol group.

Abstract: A recording medium has a base and an ink receiving layer, in which the ink receiving layer contains colloidal silica, a zirconium compound, an ammonium salt, and hydroxycarboxylic acid and 90% or more of the colloidal silica contained in the ink receiving layer exists in a region of 0 nm or more and 300 nm or less in the depth direction from the outermost surface of the recording medium.

Abstract: A recording medium having a base and an ink receiving layer containing an inorganic particle and at least one compound selected from a compound represented by the following formula (I) and a compound represented by the following formula (II):

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 substrate, a first ink receiving layer and a second ink receiving layer in that order. The first ink receiving layer contains at least one inorganic pigment selected from the group consisting of alumina, hydrated alumina and fumed silica, polyvinyl alcohol, and a boric acid compound. The second ink receiving layer contains fumed silica, particles having an average particle size in a specific range, polyvinyl alcohol, and a boric acid compound. The boric acid compound content in the first ink receiving layer is in a predetermined range, and the boric acid compound content in the second ink receiving layer is in a predetermined range. The particle content in the second ink receiving layer is in a predetermined range.

Abstract: A recording medium including, in the following order, a base, an ink-receiving layer containing inorganic particles, and a protective layer. The protective layer contains colloidal silica, gas phase process silica, and at least one kind of particles selected from resin particles and wet process silica particles. The average particle size of the at least one kind of particles is 1.5 ?m or more.

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 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: 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 has a base and an ink receiving layer, in which the ink receiving layer contains colloidal silica, a zirconium compound, an ammonium salt, and hydroxycarboxylic acid and 90% or more of the colloidal silica contained in the ink receiving layer exists in a region of 0 nm or more and 300 nm or less in the depth direction from the outermost surface of the recording medium.

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.