JP2006247979A - Manufacturing method for inkjet roll paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide inkjet roll paper suitable for printing by an inkjet minilabolatory. <P>SOLUTION: An ink absorbing layer mainly containing inorganic particulates with a mean secondary particle diameter of 500 nm or less is applied onto one side of resin-coated paper with a thickness of 200 μm or more and dried; after the resin-coated paper is wound in such a manner that a surface of the ink absorbing layer is directed inward, it is warmed for twenty-four hours or more in an atmosphere at 30°C or higher; and subsequently, a slit with a width of 350 mm or less and a length of 70 m or more is formed; and the resin-coated paper is wound in such a manner that the ink absorbing layer is directed outward. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inkjet roll paper suitable for inkjet minilab printing.

  Inkjet printers are popular in the personal field because of full color, low noise, small size, and low cost. In recent years, with the widespread use of digital cameras, personal printers that can be arbitrarily and easily output at home rather than going to a DPE store or the like and outputting them as color photographs have become popular.

  On the other hand, the so-called minilab, which combines a photographic printer and processor used in DPE stores, etc., has a high environmental load of photographic processing waste liquid, a strong irritating odor of fixing solution, and complicated maintenance. For this reason, there is an increasing tendency to use a dry process ink jet printer (referred to as “inkjet minilab”) that is low environmental load, odorless and maintenance free.

  As a recording material used in an inkjet minilab, an inkjet roll paper in which the recording material is wound up to a length of 50 m or more is usually used in order to cope with a large amount of continuous output. However, the appearance of commercial value may be impaired due to the presence of strong curl with the printed surface facing outward after printing. For example, when recording materials cut into the same size are bundled, it is difficult to pack them, and when a large format is placed flat, it becomes an arch type with the printing surface up.

  Therefore, the inkjet minilab is equipped with a decurler mechanism for correcting the curled wrinkle curl after the recording material passes through the print head part in order to reduce the curled curled curl after the print output, but the effect is still insufficient. There has been a demand for a method for improving the curl after printing on the recording material side.

For example, an ink jet recording material with excellent stability of curl characteristics has been proposed, but no consideration is given to curled curl after print output, and an ink jet recording material can be provided as a cut sheet before printing. This is an object and is completely different from the gist of the present invention. (For example, refer to Patent Document 1). Also, in order to provide a material suitable for printing a long object, the prepared recording material is wound up in a roll shape so that the ink receiving layer is on the outside, and the scrubbed recording material is placed on the outside with the ink receiving layer on the outside. However, the recording material after print output has a problem that the curl with the print surface facing up is severe and the commercial value of the printed matter is impaired. (For example, patent document 2).
JP 2004-291503 A JP 2003-175667 A

  Accordingly, an object of the present invention relates to an inkjet roll paper suitable for printing in an inkjet minilab.

  As a result of intensive studies for achieving the above object, the present inventor has found that the object can be achieved by the following means.

  (1) On one side of a resin-coated paper having a thickness of 200 μm or more, an ink receiving layer mainly containing inorganic fine particles having an average secondary particle diameter of 500 nm or less is applied and dried so that the surface of the ink receiving layer is on the inside. After being wound on, it is heated for 24 hours or more in an atmosphere of 30 ° C. or higher, and then slit to a width of 350 mm or less and a length of 70 m or more, and the ink receiving layer is wound outside. Inkjet roll paper manufacturing method.

(2) The method for producing an inkjet roll paper according to claim 1, wherein the core of the inkjet roll paper has an outer diameter of 100 mm or less.

(3) The method for producing an inkjet roll paper according to (1), wherein the inorganic fine particles are at least one of synthetic silica, alumina, and alumina hydrate.

  According to the present invention, it is possible to realize an ink jet roll paper suitable for printing in an ink jet minilab and having a commercial value as a final printed matter by eliminating the curling curl after printing.

  In the production process of the ink jet recording material, a long roll-shaped support is usually drawn out, and the ink receiving layer is applied and dried by a coating apparatus, and then wound again into a long roll shape having a winding length of about 1000 m to 5000 m. And once stored (this roll is referred to as a jumbo roll for convenience). This jumbo roll is cut into an arbitrary size in a cutting process to become a final product. Although the final product has a roll shape and a sheet shape, the present invention relates to a roll product.

  The present invention is a process of producing a jumbo roll by scraping the recording material produced in the coating and drying process of the ink receiving layer so that the ink receiving layer is inside, and heating it in an atmosphere of 30 ° C. or higher for 24 hours or more. And then slit into a width of 350 mm or less and a length of 70 m or more in parallel with the flow direction, and wound on a winding core so that the ink receiving layer is on the outside, thereby producing an inkjet roll paper as a final product form Is done.

  In the heating step according to the present invention, the heating temperature needs to be 30 ° C. or higher, preferably 35 ° C. or higher, and particularly preferably 35 ° C. to 45 ° C. from the viewpoint of energy required for heating. It is.

  The heating time is 24 hours or more, preferably 48 hours or more, particularly preferably 72 hours or more. The upper limit of the heating time is not particularly set, but is preferably 168 hours or less from the viewpoint of reducing waste of energy required for heating.

  By the heating process according to the present invention, the curl with the ink receiving layer on the inside is primarily caused on the polyolefin resin-coated paper of the recording material. Using this primary curl, the ink jet minilab performs printing continuously for a long time by re-feeding the jumbo roll, slitting it parallel to the flow direction, and rolling it again with the ink receiving layer facing outward. It is possible to provide an ink jet roll paper that is suitable for printing and has a commercial value as a final printed matter by eliminating the curl after printing.

  In the present invention, the length in the flow direction after the slit is required to be at least 70 m or more in an inkjet minilab that outputs a large amount at a time because the workability is reduced if the roll is frequently replaced. On the other hand, if the length is too long, the weight per roll increases and workability becomes difficult, and more space than necessary is imposed on the inkjet minilab. In addition, a plurality of rolls are bundled from the viewpoint of transportation and storage efficiency, but depending on the width of the rolls, the weight per box exceeds the weight that a general person can carry at a time. Therefore, it is preferable to be 70 m or more and 120 m or less.

  The core paper core of the present invention preferably has an outer diameter of 100 mm or less. The outer diameter is such that the primary curl with the ink receiving layer provided on the polyolefin resin-coated paper used as the recording material in the jumbo roll heating process is printed with an ink-jet minilab, and there is almost no wrinkles. Must be a diameter to keep. If the outer diameter is too small, there will be a wrinkle with the ink receiving layer on the outside after printing, and if it is too large, the primary curl with the ink receiving layer provided in the jumbo roll heating process inside will be eliminated. This is insufficient, and after printing with an ink-jet minilab, the ink receiving layer is placed inside and the commercial value is lost. In the present invention, the outer diameter of the roll core of the roll paper is more preferably 74 mm or more and 94 mm or less, and further preferably 79 mm or more and 89 mm or less to maintain the optimum state without impairing the commercial value after printing. Became possible.

  As the inorganic fine particles in the present invention, synthetic silica, alumina, or alumina hydrate is preferably used. In particular, synthetic silica is preferable from the viewpoint of ink absorbability. By using inorganic fine particles having an average primary particle size of 50 nm or less and an average secondary particle size of 500 nm or less, a highly colorable and high-definition printed image can be obtained as an inkjet minilab paper.

  Synthetic silica preferably used in the present invention can be roughly classified into vapor-phase silica and wet-method silica depending on the production method.

  Vapor phase silica is also called a dry method, and is generally produced by flame hydrolysis. Specifically, a method of making silicon tetrachloride by burning with hydrogen and oxygen is generally known, but silanes such as methyltrichlorosilane and trichlorosilane can be used alone or silicon tetrachloride instead of silicon tetrachloride. Can be used in a mixed state. Vapor phase method silica is commercially available as Aerosil from Nippon Aerosil Co., Ltd. and QS type from Tokuyama Co., Ltd., and can be obtained.

  Wet method silica is further classified into precipitation method silica, gel method silica, and sol method silica according to the production method. Precipitated silica is produced by reacting sodium silicate and sulfuric acid under alkaline conditions. The silica particles that have grown in the manufacturing process are aggregated and settled, and then processed through filtration, washing with water, drying, pulverization and classification. The secondary particles of silica produced by this method become loose agglomerated particles, and particles that are relatively easy to grind are obtained. Precipitated silica is commercially available, for example, from Nippon Silica Co., Ltd. as a nip seal, from Tokuyama Co., Ltd. as Toku Seal, and Fine Seal.

  Gel silica is produced by reacting sodium silicate and sulfuric acid under acidic conditions. In this case, the small silica particles dissolve during ripening and reprecipitate so as to bond the primary particles between the primary particles of the large particles, so that the distinct primary particles disappear and are relatively hard agglomerates with an internal void structure Form particles. For example, it is commercially available as Mizusukacil from Mizusawa Chemical Industry Co., Ltd. and as a silo jet from Grace Japan Co., Ltd.

  The sol method silica is also called colloidal silica, and is obtained by heating and aging a silica sol obtained through metathesis of sodium silicate acid or the like through an ion exchange resin layer. For example, it is commercially available from Nissan Chemical Industries as Snowtex. In the present invention, the colloidal silica is not used as the inorganic fine particles of the ink receiving layer, but is used for the colloidal silica-containing layer coated on the ink receiving layer.

  Synthetic silica preferably used in the present invention is gas phase method silica, precipitation method silica, or gel method silica.

  The vapor phase method silica preferably has an average primary particle diameter of 5 to 50 nm. In order to obtain a higher gloss, gas phase method silica having 5 to 20 nm and a specific surface area of 90 to 400 m <2> / g by the BET method is preferable. The BET method referred to in the present invention is one of powder surface area measurement methods by vapor phase adsorption, and is a method for determining the total surface area, that is, the specific surface area of a 1 g sample from the adsorption isotherm. Usually, nitrogen gas is often used as the adsorbed gas, and the most frequently used method is to measure the amount of adsorption from the change in pressure or volume of the gas to be adsorbed. The most prominent expression for expressing the isotherm of multimolecular adsorption is the Brunauer, Emmett, and Teller equation, called the BET equation, which is widely used for determining the surface area. The adsorption amount is obtained based on the BET equation, and the surface area is obtained by multiplying the area occupied by one adsorbed molecule on the surface.

  Vapor phase silica is present in a state where primary particles of several nm to several tens of nm are secondarily aggregated by being linked in a network structure or a chain. The agglomerated particles are preferably dispersed until the average secondary particle diameter is 500 nm or less, more preferably 300 nm or less. The lower limit particle size is about 30 nm. Here, the average particle diameter of the aggregated particles can be obtained by photography using a transmission electron microscope. For simplicity, a laser scattering type particle size distribution meter (for example, LA910, manufactured by Horiba, Ltd.) is used. Thus, it can be measured as the number median diameter.

  A method for dispersing the vapor phase silica will be described. In the present invention, the vapor phase silica is preferably dispersed in the presence of a cationic compound.

  The dispersion process of the vapor phase method silica includes a primary dispersion step in which the vapor phase method silica is added to a dispersion medium and mixed (preliminary dispersion), and a secondary dispersion in which the coarse dispersion obtained in the primary dispersion step is dispersed with a dispersion device It consists of a process.

  The preliminary dispersion in the primary dispersion step can be performed by ordinary propeller stirring, toothed blade type disperser, turbine type stirring, homomixer type stirring, ultrasonic stirring, or the like. As a dispersion apparatus used in the secondary dispersion step, for example, a pressure disperser such as a high pressure homogenizer or an ultra high pressure homogenizer, an ultrasonic disperser, a ball mill, or the like is used. In particular, as a dispersion apparatus used in the secondary dispersion step, a pressure-type disperser such as a high-pressure homogenizer or an ultrahigh-pressure homogenizer is preferable. For example, JP-A-10-310416, JP-A-2000-239536, JP-A-2001-207078. The pressure type dispersion method described in the publication can be used.

  In the present invention, to disperse gas phase method silica in the presence of a cationic compound means that a cationic compound is present at least during dispersion in the secondary dispersion step. Preferably, the cationic compound is added before the start of the secondary dispersion step, and more preferably, the cationic compound is added in advance to the dispersion medium used in the primary dispersion step. More preferably, in the primary dispersion step, gas phase method silica is added in a powder state to a dispersion medium containing a cationic compound and mixed. A flow-type continuous suction mixing and stirring machine can be used as an apparatus for mixing the powder vapor phase process silica with the dispersion medium. By using the vapor phase silica dispersion method described above, it is possible to produce a high concentration silica slurry having a vapor phase silica concentration of 18% by mass or more, and further 19% by mass or more.

  The dispersion medium used for the dispersion of the vapor phase silica is mainly water, but may contain a small amount of an organic solvent (a lower alcohol such as ethanol or a low boiling point solvent such as ethyl acetate). In that case, the organic solvent is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total dispersion medium.

  In the above-described gas phase method silica dispersion step, it is preferable to disperse in a state in which a hydrophilic binder such as polyvinyl alcohol and a crosslinking agent (hardener) such as boric acid are not included. After the vapor phase silica is cationized, a hydrophilic binder such as polyvinyl alcohol or a crosslinking agent such as boric acid may be added and dispersed again with a high-pressure homogenizer or the like.

  In the present invention, the wet method silica preferably used is precipitation method silica and gel method silica, and more preferably precipitation method silica. The average particle diameter (average secondary particle diameter) of these wet process silicas is usually 1 μm or more. In the present invention, these wet process silicas are pulverized until the average particle diameter is 500 nm or less. Preferably, it grind | pulverizes until an average particle diameter becomes 300 nm or less. The lower limit particle size is about 30 nm. This pulverization step is preferably performed in the presence of a cationic compound. The particle diameter of the pulverized wet process silica can be determined by a transmission electron microscope or a laser scattering type particle size distribution meter as described above.

  The pulverization step of the wet process silica includes a primary dispersion step in which silica fine particles are added to a dispersion medium and mixed (preliminary dispersion), and a secondary dispersion step in which the silica in the coarse dispersion obtained in the primary dispersion step is pulverized. . The preliminary dispersion in the primary dispersion step can be performed by ordinary propeller stirring, toothed blade type disperser, turbine type stirring, homomixer type stirring, ultrasonic stirring, or the like. As a wet method silica pulverization method, a wet dispersion method in which silica dispersed in a dispersion medium is mechanically pulverized can be preferably used. As the wet disperser, a media mill such as a ball mill, a bead mill, and a sand grinder, a pressure disperser such as a high pressure homogenizer, and an ultra high pressure homogenizer, an ultrasonic disperser, and a thin film winding disperser can be used. In the present invention, a media mill such as a bead mill is particularly preferably used.

  In the present invention, pulverizing wet-process silica in the presence of a cationic compound means that a cationic compound is present at least in the pulverization step (secondary dispersion step). Preferably, the cationic compound is added before the start of the pulverization step, and more preferably, the cationic compound is added in advance to the dispersion medium used in the primary dispersion step. More preferably, in the primary dispersion step, wet process silica is added in a powder state to a dispersion medium containing a cationic compound and mixed. As a device for mixing the powdered wet process silica with the dispersion medium, a flow type continuous suction mixing and stirring machine can be used.

  The dispersion medium used for the dispersion of the wet process silica is mainly water, but may contain a small amount of an organic solvent (lower alcohol such as ethanol or low boiling point solvent such as ethyl acetate). In that case, the organic solvent is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total dispersion medium.

  It is preferable not to include a hydrophilic binder such as polyvinyl alcohol or a crosslinking agent (hardener) such as boric acid in the above-described wet process silica pulverization step. After the wet process silica is cationized, a hydrophilic binder such as polyvinyl alcohol or a crosslinking agent such as boric acid may be added and dispersed again with a high-pressure homogenizer or the like.

  The wet process silica used in the present invention preferably has an average particle diameter (average secondary particle diameter) of 5 μm or more. By pulverizing silica having a relatively large particle size, dispersion at a higher concentration is possible. The upper limit of the average particle size of the wet method silica used in the present invention is not particularly limited, but the average particle size of the wet method silica is usually 200 μm or less.

  As the wet process silica used in the ink receiving layer of the present invention, precipitated silica is preferable. As described above, precipitated silica is suitable for pulverization because its secondary particles are loosely agglomerated particles.

  In the present invention, a cationic polymer, a water-soluble polyvalent metal compound, or a silane coupling agent is used as the cationic compound used in the dispersion step of the vapor phase method silica and the pulverization step of the wet method silica. Among these cationic compounds, a cationic polymer and a water-soluble polyvalent metal compound are particularly preferable, and a cationic polymer is particularly preferable.

  Examples of the cationic polymer used in the present invention include water-soluble cationic polymers having a quaternary ammonium group, a phosphonium group, or an acid adduct of a primary to tertiary amine. For example, polyethylenimine, polydialkyldiallylamine, polyallylamine, alkylamine epichlorohydrin polycondensate, JP 59-20696, JP 59-33176, JP 59-33177, JP 59-155088 JP-A-60-11389, JP-A-60-49990, JP-A-60-83882, JP-A-60-109894, JP-A-62-198493, JP-A-63-49478, JP-A-63-115780, JP-A-63-280681, JP-A-1-40371, JP-A-6-234268, JP-A-7-125411, JP-A-10-193376, WO99 / 64248, etc. Mention may be made of the cationic polymers described. The mass average molecular weight of the cationic polymer used in the present invention is preferably 100,000 or less, more preferably 50,000 or less, and particularly preferably about 2,000 to 30,000.

  Among the cationic polymers, a cationic polymer having a structural unit of a polydiallylamine derivative is particularly preferable, and a structure represented by the following general formula (1), (2), (3) or (4) is used as a structural unit. Cationic polymer. These cationic polymers are commercially available as Charol DC902P (Daiichi Kogyo Seiyaku), Jetfix 110 (Satoda Chemical), Unisense CP-101 to 103 (Senka), and PAS-H (Nittobo).

In the general formulas (1), (2), (3) and (4), R ₁ and R ₂ each represents a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, or a substituted alkyl group such as a hydroxyethyl group. Y represents a radical polymerizable monomer (for example, sulfonyl, acrylamide and derivatives thereof, acrylic ester, methacrylic ester, etc.). In the general formulas (3) and (4), n / m = 9/1 to 2/8 and l = 5 to 10,000. X represents an anion.

Specific examples of the polydiallylamine derivative represented by the general formula (3) or (4) include those having a SO ₂ group as a repeating unit described in JP-A-60-83882, JP-A-1-9776. Examples thereof include copolymers with acrylamide described in the publication.

  In this invention, the usage-amount of a cationic polymer has the preferable range of 1-10 mass% with respect to a synthetic silica.

  Examples of the water-soluble polyvalent metal compound used in the present invention include calcium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, titanium, chromium, magnesium, tungsten, and molybdenum, and these metals. It can be used as a water-soluble salt. Specifically, for example, calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, manganese ammonium sulfate hexahydrate, chloride chloride Dicopper, ammonium copper (II) chloride dihydrate, copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, nickel chloride hexahydrate, nickel acetate tetrahydrate, nickel sulfate Ammonium hexahydrate, nickel amidosulfate tetrahydrate, aluminum sulfate, aluminum sulfite, aluminum thiosulfate, polyaluminum chloride, aluminum nitrate nonahydrate, aluminum chloride hexahydrate, ferrous bromide, ferric chloride Ferrous, ferric chloride, ferrous sulfate, ferric sulfate, zinc bromide, zinc chloride, zinc nitrate Hydrates, zinc sulfate, zirconium acetate, zirconium nitrate, basic zirconium carbonate, zirconium hydroxide, zirconium carbonate / ammonium, zirconium carbonate / potassium, zirconium sulfate, zirconium fluoride, zirconium chloride, zirconium chloride octahydrate, oxy Zirconium chloride, hydroxy zirconium chloride, titanium chloride, titanium sulfate, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodium phosphotungstate, sodium tungsten citrate, 12 tungstorin Examples include acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphoric acid n hydrate, and the like. Among these, aluminum or a water-soluble salt of a periodic table group IVa element (zirconium, titanium) is preferable. In the present invention, water-soluble means that 1% by mass or more dissolves in water at room temperature and normal pressure.

As a water-soluble aluminum compound other than the above, a basic polyaluminum hydroxide compound is preferably used. The main component of this compound is represented by the following general formula 5, 6 or 7, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [Al ₈ (OH) ₂₀ ] ⁴⁺ , [Al ₁₃ (OH) ₃₄ It is a water-soluble polyaluminum hydroxide containing a basic, high-molecular polynuclear condensed ion such as ⁵⁺ , [Al ₂₁ (OH) ₆₀ ] ³⁺ , etc. stably.

[Al ₂ (OH) _n Cl _6-n ] _m.
[Al (OH) ₃ ] nAlCl ₃ ..General formula 6
Al _n (OH) _m Cl _(3n-m) 0 <m <3n

  These are water treatment agents from Taki Chemical Co., Ltd. under the name of polyaluminum chloride (PAC), from Asada Chemical Co., Ltd. under the name of polyaluminum hydroxide (Paho), and from Riken Green Co., Ltd. It is marketed under the name of Purachem WT and from other manufacturers for the same purpose, and various grades can be easily obtained. In the present invention, these commercially available products can be used as they are. These basic polyaluminum hydroxide compounds are also described in JP-B-3-24907 and JP-B-3-42591.

  The addition amount of the water-soluble polyvalent metal salt compound is preferably in the range of 0.1 to 10% by mass with respect to the synthetic silica.

  As a silane coupling agent used for this invention, it describes in Unexamined-Japanese-Patent No. 2000-233572, The cationic thing can be used among them. The addition amount of the silane coupling agent is preferably in the range of 0.1 to 10% by mass with respect to the inorganic fine particles.

  As the inorganic fine particles used in the present invention, alumina or alumina hydrate can be used in addition to the synthetic silica. As alumina, γ-alumina, which is a γ-type crystal of aluminum oxide, is preferable, and among them, a δ group crystal is preferable. Although γ-alumina can reduce the primary particles to about 10 nm, usually, secondary particles of several thousand to several tens of thousands of nanometers are mixed with ultrasonic waves, high-pressure homogenizers, counter-impact type jet crushers, etc. What grind | pulverized to about 300 nm can be used preferably.

Alumina hydrate is represented by a constitutive formula of Al ₂ O ₃ .nH ₂ O (n = 1 to 3). The case where n is 1 represents an alumina hydrate having a boehmite structure, and the case where n is greater than 1 and less than 3 represents an alumina hydrate having a pseudo boehmite structure. It can be obtained by a known production method such as hydrolysis of an aluminum alkoxide such as aluminum isopropoxide, neutralization of an aluminum salt with an alkali, or hydrolysis of an aluminate.

  The average primary particle diameter of the above-mentioned alumina hydrate is preferably 5 to 50 nm, and in particular, it is preferable to use tabular grains having an average aspect ratio (ratio of average particle diameter to average thickness) of 2 or more and 5 to 30 nm. preferable.

  In the present invention, the inorganic fine particles contain 50% by mass or more, preferably 60% by mass or more, more preferably 65% by mass or more of the inorganic fine particles with respect to the main ratio in the ink receiving layer, that is, the total solid content of the ink receiving layer. In order to improve the ink absorbability, it is further preferable.

  In the present invention, as the hydrophilic binder used together with the inorganic fine particles, various known binders can be used, and a hydrophilic binder that is highly transparent and can obtain higher ink permeability is preferably used. When using a hydrophilic binder, it is important that the hydrophilic binder does not swell during the initial penetration of the ink and block the voids. From this point of view, a hydrophilic binder having a relatively low swellability around room temperature is preferable. Used. Particularly preferred hydrophilic binders are fully or partially saponified polyvinyl alcohol or cation-modified polyvinyl alcohol.

  Particularly preferred among the polyvinyl alcohols are those having a degree of saponification of 80% or more or those completely saponified. Those having an average degree of polymerization of 200 to 5000 are preferred.

  The cation-modified polyvinyl alcohol has a primary to tertiary amino group or a quaternary ammonium group in the main chain or side chain of polyvinyl alcohol as described in, for example, JP-A-61-10383. Polyvinyl alcohol.

  In the present invention, a hardening agent can be used together with the hydrophilic binder. Specific examples of the hardener include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1 , 3,5 triazine, a compound having a reactive halogen as described in US Pat. No. 3,288,775, divinyl sulfone, a compound having a reactive olefin as described in US Pat. No. 3,635,718, N-methylol compounds as described in Japanese Patent No. 2,732,316, isocyanates as described in US Pat. No. 3,103,437, US Pat. Nos. 3,017,280 and 2,983,611 described Aziridines such as carbodiimide compounds as described in US Pat. No. 3,100,704, Epoxy compounds as described in No. 3,091,537, halogen carboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane, chromium alum, zirconium sulfate, boric acid and inorganic cross-linking agents such as borate, etc. Can be used alone or in combination of two or more. Among these, boric acid or borate is particularly preferable.

  The ink receiving layer of each layer in the present invention preferably contains various oil droplets in order to improve the brittleness of the film. Such oil droplets have a solubility in water at room temperature of 0.01% by mass or less. Hydrophobic high boiling organic solvents (eg liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil) and polymer particles (eg styrene, butyl acrylate, divinylbenzene, butyl methacrylate, hydroxyethyl methacrylate) Particles obtained by polymerizing one or more monomers). Such oil droplets can be preferably used in the range of 10 to 50% by mass with respect to the hydrophilic binder.

  In the present invention, in addition to the surfactant and the hardener, the ink receiving layer of each layer further includes a coloring dye, a coloring pigment, a fixing agent for the ink dye, an ultraviolet absorber, an antioxidant, a dispersant for the pigment, Various known additives such as foaming agents, leveling agents, preservatives, optical brighteners, viscosity stabilizers, and pH adjusters can also be added.

  In the present invention, a known coating method can be used as a coating method for each layer constituting the ink receiving layer. For example, there are a slide bead method, a curtain method, an extrusion method, an air knife method, a roll coating method, a Ked bar coating method, and the like.

  In the present invention, the properties required for each layer can be obtained efficiently by coating each layer constituting the ink receiving layer such as a slide bead system almost simultaneously without providing a drying step, from the viewpoint of production efficiency. Is also preferable. That is, by laminating each layer in a wet state, the components contained in each layer are unlikely to penetrate into the lower layer, so that it is expected that the component composition of each layer is maintained well after drying.

  The resin-coated paper used as a support in the present invention will be described in detail. The base paper constituting the resin-coated paper is not particularly limited, and commonly used paper can be used, but smooth base paper such as that used for a photographic support is more preferable. As the pulp constituting the base paper, natural pulp, recycled pulp, synthetic pulp or the like is used alone or in combination of two or more. This base paper is blended with additives such as sizing agent, paper strength enhancer, filler, antistatic agent, fluorescent whitening agent, and dye generally used in papermaking. Further, a surface sizing agent, surface paper strengthening agent, fluorescent brightening agent, antistatic agent, dye, anchor agent and the like may be applied on the surface.

The base paper used in the present invention is preferably one having good surface smoothness such as being compressed by applying pressure during or after paper making, and the basis weight is preferably 30 to 180 g / m ² .

  As the resin layer covering both sides of the base paper used in the present invention, polyolefin resin is used. For example, homopolymers or ethylene-propylene copolymers of olefins such as low density polyethylene, high density polyethylene, polypropylene, polybutene, and polypentene. Examples thereof include copolymers composed of two or more olefins and mixtures thereof, and those having various densities and melt viscosity indices (melt index) can be used alone or in combination.

  The above resin layer contains a white pigment on both sides. Examples of such white pigments include titanium oxide, zinc oxide, talc, and calcium carbonate. A preferred white pigment is titanium oxide, and it is preferable to use rutile type or anatase type titanium oxide as titanium oxide. 1-60 mass% is preferable with respect to polyolefin resin in a resin layer, and, as for content of a white pigment, 2-35 mass% is more preferable.

  In the resin layer, fatty acid amides such as stearic acid amide and arachidic acid amide, fatty acid metal salts such as zinc stearate, calcium stearate, aluminum stearate, and magnesium stearate, oxidation of Irganox 1010, Irganox 1076, etc. Various additives such as inhibitors, cobalt blue, ultramarine blue, cecilian blue, phthalocyanine blue and other blue pigments and dyes, cobalt violet, fast violet, manganese purple and other magenta pigments and dyes, fluorescent whitening agents, UV absorbers, etc. Agents can be added in appropriate combinations.

  A general method for producing a resin-coated paper is produced by a so-called extrusion coating method in which a polyolefin resin heated and melted is cast on a traveling base paper, and both surfaces of the base paper are coated with a resin. Prior to coating the base paper with the resin, it is preferable to subject the base paper to an activation treatment such as corona discharge treatment or flame treatment. The thickness of the resin layer is suitably in the range of 5 to 50 μm.

  As described above, the resin-coated paper is manufactured by extruding a heat-melted resin into a film between a base paper and a cooling roll, pressing and cooling. At this time, the cooling roll is used for forming the surface shape of the resin layer, and the center line average roughness of the surface of the resin layer is obtained by adjusting the surface shape of the cooling roll to be used.

  Various back coat layers can be applied to the above-mentioned resin-coated paper for antistatic properties, transport properties, anti-curling properties, and the like. In the backcoat layer, an inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, latex, a curing agent, a pigment, a surfactant, and the like can be appropriately combined. In addition, it is preferable to previously provide an undercoat layer made of a hydrophilic binder such as gelatin on the surface on which the ink receiving layer is applied.

  The resin-coated paper used in the present invention needs to have a thickness of 200 μm or more in order to give a high-grade feeling and texture similar to those of photographs. Preferably, it is 210-300 micrometers, More preferably, it is 220-280 micrometers.

  When the coating liquid for the ink receiving layer is coated on the support, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, plasma treatment and the like are preferably performed prior to the coating.

  In the present invention, it is preferable to provide a primer layer mainly composed of a natural polymer compound or a synthetic resin on the support surface on which the ink receiving layer is provided.

  The primer layer provided on the support is mainly composed of natural polymer compounds such as gelatin and casein and synthetic resins. Examples of such synthetic resins include acrylic resins, polyester resins, vinylidene chloride, vinyl chloride resins, vinyl acetate resins, polystyrene, polyamide resins, polyurethane resins, and the like.

  The primer layer is provided on the support with a film thickness (dry film thickness) of 0.01 to 5 μm. Preferably it is the range of 0.05-5 micrometers.

  Various back coat layers can be coated on the support in the present invention for writing property, antistatic property, transportability, anticurling property and the like. The backcoat layer can contain an appropriate combination of inorganic antistatic agents, organic antistatic agents, hydrophilic binders, latexes, pigments, curing agents, surfactants, and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the content of this invention is not restricted to an Example. In addition, a part and% show a mass part and the mass%.

A 1: 1 mixture of hardwood bleached kraft pulp (LBKP) and softwood bleached sulfite pulp (NBSP) was beaten to 300 ml with Canadian Standard Freeness to prepare a pulp slurry. As a sizing agent, 0.5% by mass of alkyl ketene dimer with respect to pulp, 1.0% by mass of polyacrylamide with respect to pulp as a strengthening agent, 2.0% by mass of cationized starch with respect to pulp, and polyamide epichlorohydrin resin 0.5% by mass of pulp was added and diluted with water to give a 1% slurry. This slurry was made with a long paper machine to a basis weight of 170 g / m ² , dried and conditioned to obtain a base paper. A polyethylene resin composition in which 10% by mass of anatase-type titanium is uniformly dispersed with respect to 100% by mass of low-density polyethylene having a density of 0.918 g / cm ³ is melted at 320 ° C. on the base paper thus produced, Extrusion coating was carried out to a thickness of 35 μm, and extrusion coating was performed using a cooling roll having a finely roughened surface to form a surface on which the ink receiving layer was applied. On the other side, a blend resin composition of 70 parts by mass of a high density polyethylene resin having a density of 0.962 g / cm ³ and 30 parts by mass of a low density polyethylene resin having a density of 0.918 was similarly melted at 320 ° C. to obtain a thickness. Extrusion coating was carried out to a thickness of 30 μm, and extrusion coating was performed using a cooling roll having a rough surface. The thickness of this resin-coated paper was 230 μm.

Thereafter, the surface on which the ink image-receiving layer is to be coated is subjected to high-frequency corona discharge treatment, and then a primer layer having the following composition is coated and dried so that the gelatin is 50 mg / m ² , so that the ink-receiving layer surface is the outer surface. A support was produced by winding.

(Primer layer)
Lime-processed gelatin 100 parts Sulfosuccinic acid-2-ethylhexyl ester salt 2 parts Chrome alum 10 parts

<Preparation of inkjet recording material>
On the surface provided with the undercoat layer of the support prepared as described above, an ink receiving layer coating solution having the composition described below was applied by a slide bead coater so that the dry coating thickness was 40 μm. As a drying condition, after cooling at 5 ° C. for 30 seconds, a total solid concentration of 90% by mass was dried at 45 ° C. and 10% RH, and then dried at 35 ° C. and 10% RH. The mass ratio of the hydrophilic binder to the inorganic fine particles in the coating liquid was 0.25.

<Production of vapor phase silica dispersion>
After adding 4 parts of dimethyldiallylammonium chloride homopolymer (molecular weight 9,000) and 100 parts of gas phase method silica (average primary particle diameter 7 nm, specific surface area 300 m ² / g) to water to prepare a pre-dispersion liquid, high pressure homogenizer To prepare a silica dispersion having a solid concentration of 20%.

<Ink-receiving layer coating solution>
Gas phase method silica dispersion (as solid content of gas phase method silica) 100 parts polyvinyl alcohol (saponification degree 88%, average polymerization degree 3500) 25 parts boric acid 3 parts water-soluble polyvalent metal compound 3 parts (basic poly water) Aluminum oxide; Purachem WT manufactured by Riken Green Co., Ltd.)
The gas phase method silica solid content concentration was adjusted to 9%.

  When the ink jet recording material was applied, dried and wound up, it was wound up with a length of 2000 m so that the ink receiving layer was on the inside, and a jumbo roll of the recording material was produced. This jumbo roll is heated at 35 ° C. for 24 hours, then slit to 89 mm width and 305 mm width, and the ink receiving layer is wound on a paper core having a length of 100 m and an outer diameter of 88 mm to obtain an ink jet roll paper. It was.

  An ink jet roll paper was obtained in the same manner except that the jumbo roll obtained in Example 1 was heated at 35 ° C. for 144 hours.

(Comparative Example 1)
A roll paper was obtained in the same manner as in Example 1 except that the paper was wound so that the ink receiving layer was on the outside.

(Comparative Example 2)
An inkjet roll paper was obtained in the same manner except that the jumbo roll obtained in Comparative Example 1 was heated at 35 ° C. for 144 hours.

(Comparative Example 3)
An inkjet roll paper was obtained in the same manner except that the jumbo roll was produced without heating in Example 1.

  The obtained ink jet roll papers of Examples 1 and 2 and Comparative Examples 1 to 3 were attached to dDP-621 manufactured by Noritz Steel Machine Co., Ltd., and printed out under the conditions of a temperature of 23 ° C. and a humidity of 50 RH%, and slits were 89 mm wide. The inkjet roll paper cut to a size of 89 mm × 127 mm and the inkjet roll paper slit to a width of 305 mm were cut to a size of 305 mm × 457 mm. After that, the level of the firewood curl of each size was measured as follows.

<Golden carl>
The output sheet was allowed to stand with the printing surface facing down, and the height [mm] of both ends that floated was measured to obtain the level of curl. Since the level of the curled curl differs depending on the outer diameter of the inkjet roll paper, the curled curl of the outermost and innermost sheets was measured. The measurement results are shown in Table 1.

  As is clear from Table 1, Examples 1 and 2 which are the ink jet roll paper of the present invention had almost no creak curl after print output as compared with Comparative Examples 1 to 3, and the commercial value was not impaired. Further, in Comparative Examples 1 to 3, when printing, both ends of the ink-jet roll paper were in physical contact with the ink head, and the images were rubbed and unbearable for viewing. However, such a thing was not observed at all, and the quality excellent in the printing accuracy was obtained. This is because the jumbo roll was made with the ink receiving layer inside, and after curling was temporarily applied, the ink receiving layer was wound around the winding core so that the appropriate curl balance was achieved. It is.

<Handling workability>
Furthermore, 30 sheets of Examples 1 and 2 and Comparative Examples 1 to 3 were output continuously, and the handling workability (number confirmation, bagging work) after the output was investigated. As a result, in Examples 1 and 2, it was possible to work without any trouble, but in Comparative Examples 1 to 3, it was difficult to roll one by one when checking the number of sheets, and when putting them together in a bag In addition, the bag mouth has to be opened more than necessary, and even if it is inserted, when the sheets bundled are pushed into the bag due to tight curl, the bag is often caught and broken.

  From the above, the recording material produced in the ink receiving layer coating and drying step is scraped so that the ink receiving layer is on the inside to produce a jumbo roll, and has a step of heating for 24 hours or more, By slitting in parallel to the flow direction to a width of 350 mm or less and a length of 70 m or more, and spreading on the core so that the ink receiving layer is on the outside, it is suitable for inkjet minilab printing and eliminates wrinkle curling after printing. Thus, an inkjet roll paper having a commercial value as a final printed matter could be provided.

Claims (3)

  An ink receiving layer mainly containing inorganic fine particles having an average secondary particle diameter of 500 nm or less is coated and dried on one side of a resin-coated paper having a thickness of 200 μm or more, and wound so that the surface of the ink receiving layer is on the inside. After that, it is heated for 24 hours or more in an atmosphere of 30 ° C. or higher, then slit to a width of 350 mm or less and a length of 70 m or more, and wound up so that the ink receiving layer is on the outside. Manufacturing method.   The manufacturing method of the inkjet roll paper of Claim 1 whose winding core of the said inkjet roll paper is 100 mm or less in outer diameter. The method for producing an inkjet roll paper according to claim 1, wherein the inorganic fine particles are at least one of synthetic silica, alumina, and alumina hydrate.