JP2007098673A - Medium for inkjet recording and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium for inkjet recording which has an ink accepting layer having an excellent surface shape. <P>SOLUTION: The medium for inkjet recording comprises forming on a substrate an ink accepting layer containing particulates, a hydrophilic binder and a surfactant of polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether. The surfactant satisfies the conditions that (1) in the case when the rate of solubility in water is 1 mass% or above, the cloud point of the 1-mass% water solution is 30°C or above and the HLB value is 10.5 or above, or that (2) in the case when the rate of solubility in the water is less than 1 mass%, the cloud point of the 10-mass% solution in a mixed solvent of water/diethylene glycol monobutyl ether=75/25 is 30-80°C and the HLB value is 10.5 to less than 15. On the assumption that a virtual compound wherein a hydrophilic group added to a lipophilic group of the surfactant is infinitely long and of which the hydrophilicity is the largest is set as 20 and that a lipophilic compound having no hydrophilic group is set as 0, the HLB value is calculated for each surfactant as a relative value in relation to those values. When the molecular weight of a nonionic surfactant is made M and that of the hydrophilic portion Mw, the HLB value is calculated from Griffin's formula: HLB value=20×Mw/M. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording medium used in an inkjet image recording method and a method for manufacturing the same.

  In recent years, with the rapid development of the information technology (IT) industry, various information processing systems have been developed, and a recording method and a recording apparatus suitable for each information processing system have been developed and put into practical use. Among such recording methods, the inkjet recording method is advantageous in that it can be recorded on various recording materials, the hardware (device) is relatively inexpensive, is compact, and is excellent in low noise. It has been widely used not only in offices but also in so-called home use.

In addition, with the recent increase in resolution of inkjet printers, it is also possible to obtain so-called photographic-like high-quality recorded materials, and along with the further development of hardware (device), various recording sheets for inkjet recording are also available. Improvements have been made.
The characteristics required for a recording sheet for ink jet recording are generally (1) fast drying (fast ink absorption speed), and (2) proper and uniform ink dot diameter (bleeding). (3) Good graininess, (4) High roundness of dots, (5) High color density, (6) High saturation (no dullness) ), (7) The light resistance and water resistance of the print portion are good, (8) The whiteness of the recording sheet is high, (9) The recording sheet has good storage stability (yellowing coloration during long-term storage) (10) hard to deform, good dimensional stability (curl is sufficiently small), (11) good running performance of hardware, Etc. Furthermore, in the use of photo glossy paper used for the purpose of obtaining so-called photographic-like high-quality recorded matter, in addition to the above characteristics, glossiness, surface smoothness, texture of photographic paper similar to silver salt photography, etc. Required.

Further, in the ink jet recording medium as described above, the ink receiving layer formed on the support is generally formed by applying a coating liquid for the ink receiving layer, and the coating liquid has an interface for the purpose of stabilizing the liquid viscosity. For example, it is disclosed that a nonionic surfactant having a cloud point of 60 ° C. or lower is used together with inorganic fine particles and a water-soluble resin (for example, see Patent Document 1). However, the liquid viscosity stability is not yet at a sufficient level, and further improvement has been desired.
JP 2004-230760 A

  An object of the present invention is to solve the above-mentioned conventional drawbacks. That is, an object of the present invention is to provide an ink jet recording medium having an ink receiving layer having a good surface shape, and a method for producing the ink jet recording medium.

Means of the present invention for solving the above-mentioned problems are as follows. That is, the inkjet recording medium of the present invention is
<1> An ink jet recording medium comprising an ink receiving layer containing fine particles, a hydrophilic binder, and a surfactant on a support, wherein the surfactant is polyoxyalkylene decyl. It is an ether or polyoxyalkylene tridecyl ether, and the surfactant satisfies the following (1) or (2).
(1) When the solubility in water is 1% by mass or more, the cloud point of the 1% by mass aqueous solution is 30 ° C. or higher and the HLB value is 10.5 or higher.
(2) When the water solubility is less than 1% by mass, the cloud point of a 10% by mass solution in water / diethylene glycol monobutyl ether = 75/25 mixed solvent is 30 ° C. or higher and 80 ° C. or lower and the HLB value Is 10.5 or more and less than 15.

  <2> The ink jet recording medium according to <1>, wherein the ink receiving layer contains a cationic substance.

  <3> The inkjet recording medium according to <1> or <2>, wherein the surfactant is polyoxyethylene decyl ether or polyoxyethylene tridecyl ether.

  <4> Any one of the above <1> to <3>, wherein the fine particles are vapor-phase method silica or vapor-phase method alumina, and the primary particle diameter of the fine particles is 1 nm or more and 30 nm or less. The ink-jet recording medium described in the item.

  <5> The ink jet recording medium according to any one of <1> to <4>, wherein the ink receiving layer contains at least one water-soluble polyvalent metal salt.

  <6> The ink receiving layer according to any one of <1> to <5>, wherein the ink receiving layer is formed using a coating liquid containing a cation-modified latex having a volume average particle diameter of 0.1 μm or less. The ink-jet recording medium described.

Further, the method for producing the ink jet recording medium of the present invention comprises:
<7> Any of the above <1> to <6>, through a step of applying a coating solution obtained by mixing fine particles, a hydrophilic binder, and a surfactant onto a support to form a coating layer. A method for producing an ink jet recording medium for obtaining the recording medium according to claim 1, wherein the surfactant is polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether. It is a manufacturing method of a medium.

  <8> An aqueous solution (a) in which the surfactant is dissolved, and a fine particle dispersion (b) obtained by mixing the fine particles, a cationic substance, and a hydrophilic binder are mixed in an in-line blend. The method for producing an ink jet recording medium according to <7>, further comprising a step of preparing a coating solution and coating the coating solution on a support to form a coating layer.

  <9> The method for producing an ink jet recording medium according to <7> or <8>, wherein the coating layer is crosslinked and cured to form an ink receiving layer, wherein the crosslinking and curing includes the coating liquid and / or A crosslinking agent is added to the following basic solution and the coating solution is applied to form a coating layer. At the same time or during the drying of the coating layer formed by coating the coating solution, the coating layer is reduced. The ink jet recording medium production method according to any one of the preceding claims, wherein the basic solution having a pH of 7.1 or higher is applied to the coating layer at any time before showing the rate of drying.

  According to the present invention, it is possible to provide an ink jet recording medium having an ink receiving layer having a good surface shape, and a method for producing the ink jet recording medium.

The ink jet recording medium of the present invention is formed by forming an ink receiving layer on a support, and the ink receiving layer contains fine particles, a hydrophilic binder, and a surfactant, Moreover, it is an essential requirement that the surfactant is polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether and satisfies the following (1) or (2).
(1) When the solubility rate with respect to water is 1 mass% or more, the cloud point of 1 mass% aqueous solution is 30 degreeC or more, and HLB value is 10.5 or more.
(2) When the solubility in water is less than 1% by mass, the cloud point of a 10% by mass solution in water / diethylene glycol monobutyl ether = 75/25 mixed solvent is 30 ° C. or higher and 80 ° C. or lower and the HLB value Is 10.5 or more and less than 15.

(Surfactant)
In the present invention, a surfactant of polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether is used from the viewpoint of improving the liquid viscosity stability of the coating liquid for the ink receiving layer and obtaining a good coated surface. In addition, the decyl group or tridecyl group in the surfactant is preferably branched, and from the viewpoint of improving the stability of the coating solution and not causing deterioration of wet heat bleeding, the surfactant is nonionic. It is particularly preferred that

In addition, as described above, the surfactant must satisfy the condition (1) or (2).
Here, the solubility in water of 1% by mass or more means so-called water solubility, whereas the solubility in water of less than 1% by mass means insoluble in water. It means to show.
In addition, the measurement of the solubility rate of the surfactant in water (that is, determination of whether or not it is water-soluble) was carried out by adding 1 g of surfactant to 99 g of ion-exchanged water and at 23 ° C. for 30 minutes. Stirring was carried out, and when it became transparent (determined visually), it was judged to be water-soluble.

(1) When the solubility in water is 1% by mass or more (that is, water-soluble) The cloud point is essential to be 30 ° C. or higher, more preferably 40 ° C. or higher, and 40 to 70 It is particularly preferable that the temperature is C. When the cloud point is less than 30 ° C., the liquid viscosity of the coating solution becomes high and a good coated surface cannot be obtained.
Moreover, it is essential that the HLB value is 10.5 or more, more preferably 12 to 16, and particularly preferably 13 to 14. When the HLB value is less than 10.5, repelling occurs and a good coated surface cannot be obtained.

(2) When the solubility in water is less than 1% by mass (that is, water-insoluble) The cloud point is essential to be 30 ° C. or higher and 80 ° C. or lower, and further 60 to 80 ° C. Preferably, it is 70-80 degreeC. When the cloud point is less than 30 ° C., repelling failure tends to occur during the coating and drying process, and it may be difficult to obtain a good coated surface. On the other hand, when the cloud point exceeds 80 ° C., there is a drawback that sufficient viscosity stability of the coating liquid cannot be obtained, and muscle failure is likely to occur.
Moreover, it is essential that the HLB value is 10.5 or more and less than 15, more preferably 11 to 14, and particularly preferably 12 to 13. When the HLB value is less than 10.5, repelling occurs and a good coated surface cannot be obtained. On the other hand, when the HLB value is 15 or more, the viscosity of the coating solution increases and streaks occur during coating.

-Measurement of cloud point-
Surfactants have two functional groups, a hydrophilic group with a high affinity for water and a hydrophobic group opposite to each other in one molecule. This occurs by hydration of water molecules to the chain ether oxygen. The hydration power due to the hydrogen bond becomes weaker as the temperature rises, and when the temperature rises above a certain temperature, the solubility rapidly decreases and precipitation starts, resulting in cloudiness. This inherent temperature of clouding is called the cloud point.
The cloud point in the present invention was measured by visually checking the temperature at which the aqueous surfactant solution became cloudy. In addition, since it is necessary to perform the measurement in a state in which the surfactant is dissolved, the solvent was changed according to the solubility in water. Specifically, for those having a solubility of 1% by mass or more in water (water-soluble), the measurement is performed with a 1% by mass aqueous solution, while the solubility in water is less than 1% by mass ( For water-insoluble ones, diethylene glycol monobutyl ether / water = 25/75 mixed solvent was used, and a 10% by mass solution of each surfactant was prepared and measured.
Here, specific examples of the water-soluble surfactant include Neugen XL-100, Neugen SD-60, Neugen SD-70, Neugen SD-110, Neugen XL-100, Emulgen 109P, Neugen ET106A and the like. Can do. On the other hand, examples of the water-insoluble surfactant include Neugen TDS-70, Neugen SD-30, Neugen XL-60, Neugen SD-30 and the like.

-Calculation of HLB value-
The HLB value is defined as 20 for a hypothetical compound having an infinitely long hydrophilic group added to the lipophilic group of the surfactant and having the greatest hydrophilicity, and 0 for a lipophilic compound having no hydrophilic group. These are values calculated for each surfactant as relative values thereof, and can generally be calculated by the Griffin equation.
The Griffin equation used for calculating the HLB value is shown below.
When the molecular weight of the nonionic surfactant is M and the molecular weight of the hydrophilic portion is Mw,
HLB value = 20 × Mw / M

The alkylene group in the polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether surfactant is particularly preferably an ethylene group.
Preferable specific examples of the surfactant in the present invention include polyoxyethylene isodecyl ether and polyoxyethylene tridecyl ether, and polyoxyethylene isodecyl ether is more preferable.

  In the present invention, the content of the polyoxyalkylene decyl ether surfactant in the coating liquid for the ink receiving layer is 1 to 50% by mass with respect to the fine particles from the viewpoint of setting the liquid viscosity to a desired low viscosity. Is preferable, and it is more preferable that it is 2-30 mass%.

(Hydrophilic binder)
In order to make the ink receiving layer in the present invention have a porous structure, the present invention includes a hydrophilic binder (water-soluble resin).
Examples of the water-soluble resin used in the present invention include a polyvinyl alcohol resin (polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, and anion-modified polyvinyl) that is a resin having a hydroxy group as a hydrophilic structural unit. Alcohol, silanol-modified polyvinyl alcohol, polyvinyl acetal, etc.], cellulosic resins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxy Propylmethylcellulose, etc.], chitins, chitosans, starch, resins having an ether bond (polyethylene oxide) PEO), polypropylene oxide (PPO), polyethylene glycol (PEG), polyvinyl ether (PVE), etc.], resins having a carbamoyl group [polyacrylamide (PAAM), polyvinylpyrrolidone (PVP), polyacrylic acid hydrazide, etc.), etc. It is done.
Moreover, the polyacrylic acid salt which has a carboxyl group as a dissociable group, maleic acid resin, alginate, gelatins, etc. can be mentioned.

  In the ink-receiving layer in the invention, from the viewpoint of ink absorbability, among the above water-soluble resins, polyvinyl alcohol resins, cellulose resins, resins having an ether bond, resins having a carbamoyl group, resins having a carboxy group And at least one selected from gelatins is more preferable.

Among the above, the water-soluble resin in the present invention is particularly preferably polyvinyl alcohol (PVA).
The degree of saponification of the polyvinyl alcohol (PVA) used in the present invention is preferably 75 to 95 mol%, more preferably 77 to 90 mol%, and particularly preferably 80 to 90 mol% from the viewpoint of color density. Moreover, as a polymerization degree of polyvinyl alcohol (PVA), from a viewpoint of obtaining sufficient film | membrane intensity | strength, 1400-5000 are preferable and 2300-4000 are more preferable. Polyvinyl alcohol having a polymerization degree of less than 1400 and a polymerization degree of 1400 or more may be used in combination.

As the content of the water-soluble resin in the ink receiving layer, the film strength is prevented from being lowered and cracking at the time of drying due to the insufficient content, and the void is blocked by the resin due to the excessive content. From the viewpoint of preventing the ink absorbency from being lowered by decreasing the porosity, the content is preferably 5 to 40% by mass with respect to the total solid content contained in the ink receiving layer, and 10 to 30%. The mass% is more preferable.
The fine particles and the water-soluble resin, which will be described later, mainly constituting the ink receiving layer, may be a single material or a mixed system of a plurality of materials.

  In addition to unmodified polyvinyl alcohol (PVA), the polyvinyl alcohol includes cation-modified PVA, anion-modified PVA, silanol-modified PVA, and other polyvinyl alcohol derivatives. Polyvinyl alcohol may be used alone or in combination of two or more.

The PVA has a hydroxyl group in its structural unit, and this hydroxyl group and the silanol group on the surface of the silica fine particle form a hydrogen bond, and it is easy to form a three-dimensional network structure in which the secondary particle of the silica fine particle is a chain unit. To do. By forming such a three-dimensional network structure, it is considered that an ink receiving layer having a porous structure with a high porosity can be formed.
In the ink jet recording medium obtained by the present invention, the porous ink receiving layer obtained as described above absorbs ink rapidly by capillary action, and forms dots with good roundness without ink bleeding. can do.

(Fine particles)
The ink receiving layer in the invention further contains fine particles as an essential component.
Examples of the fine particles in the present invention include at least one fine particle selected from organic fine particles, silica fine particles, alumina fine particles, and pseudo-boehmite type aluminum hydroxide fine particles. Among these, silica fine particles, alumina fine particles, and pseudo boehmite type aluminum hydroxide fine particles are preferable.

  The fine particles in the present invention preferably have an average primary particle diameter of 50 nm or less, more preferably 30 nm or less, and particularly preferably 15 nm or less. When the average primary particle diameter of the fine particles is 15 nm or less, the ink absorption characteristics can be effectively improved, and at the same time, the glossiness of the ink receiving layer surface can be enhanced. The lower limit of the average primary particle diameter of the fine particles is not particularly limited, but is preferably 1 nm or more.

  Among the above-mentioned fine particles, vapor-phase method silica or vapor-phase method alumina produced by the vapor phase method has a particularly large specific surface area, and therefore has high ink absorption and retention efficiency, and has a low refractive index. If the dispersion is performed up to a small particle size, transparency can be imparted to the ink receiving layer, and there is an advantage that high color density and good color developability can be obtained. Thus, the fact that the receiving layer is transparent means that not only for applications that require transparency, such as OHP, but also when applied to recording sheets such as photo glossy paper, a high color density and good color developability and This is important from the viewpoint of obtaining glossiness.

  In particular, the silica fine particle has a silanol group on the surface thereof, and the particles are likely to adhere to each other by hydrogen bonding of the silanol group, and because of the adhesion effect between the particles via the silanol group and the water-soluble resin, As described above, when the average primary particle diameter is 15 nm or less, the ink receiving layer has a high porosity and a highly transparent structure can be formed, and the ink absorption characteristics can be effectively improved.

  In general, silica fine particles are generally roughly classified into wet method (precipitation method) particles and dry method (gas phase method) particles according to the production method. In the above wet method, a method is mainly used in which activated silica is produced by acid decomposition of a silicate, and this is appropriately polymerized and agglomerated and precipitated to obtain hydrous silica. On the other hand, the gas phase method is a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method), a method in which silica sand and coke are heated and reduced by an arc in an electric furnace and oxidized with air. The method of obtaining anhydrous silica by the (arc method) is the mainstream, and the “gas phase method silica” refers to anhydrous silica fine particles obtained by the gas phase method.

Vapor phase method silica is different from the above hydrous silica in the density of silanol groups on the surface, the presence or absence of vacancies, etc., and shows different properties, but is suitable for forming a three-dimensional structure with high porosity. The reason for this is not clear, but in the case of hydrous silica, the density of silanol groups on the surface of the fine particles is as high as 5 to 8 / nm ^2, and the silica fine particles tend to agglomerate closely (aggregate). In the case of the method silica, the density of silanol groups on the surface of the fine particles is as small as ² to 3 / nm ² , so that it becomes sparse soft agglomeration (flocculate), and as a result, it is estimated that the structure has a high porosity. The

The fine particles in the present invention are preferably amorphous silica or alumina synthesized by a sedimentation method or a gas phase method. In particular, it is preferable to use gas phase method silica or gas phase method alumina having an average primary particle size of 30 nm or less, and the gas phase method silica or gas phase method alumina is 50% by mass or more (preferably 70% by mass or more) of all fine particles. , More preferably 90% by mass or more), a remarkable effect is obtained. In the case of vapor phase method silica, silica fine particles having a density of silanol groups on the fine particle surface of 2 to 3 / nm ² are preferred.

  In the present invention, vapor-phase process alumina has a feature that it has a higher color density and higher gloss than gas-phase process silica. This is presumably because the refractive index of vapor-phase method alumina is higher than that of vapor-phase method silica and the reflection of light on the surface is strong. Vapor phase alumina has the characteristics of spherical particles and excellent ink absorbency compared to alumina hydrate such as pseudoboehmite, and further improves ink absorbency when combined with the present invention. It becomes possible to make it. Although the reason is not clear, vapor-phase method alumina has a feature that microcracks of the ink receiving layer are less likely to occur compared to vapor-phase method silica. Such micro cracks are caused by various factors in the manufacturing process, but when combined with vapor phase alumina, for example, the micro cracks caused by shrinkage of the coating during the drying process are greatly improved. It becomes possible to do.

  In addition, when vapor-phase process alumina is used, the strength of the coating film tends to be higher than when vapor-phase process silica is used, and failure such as scratches is less likely to occur. Furthermore, it is possible to increase the solid content of the pigment dispersion compared to gas phase method silica, so it is possible to increase the solid content of the final coating liquid, and the production with low drying load and high productivity. It also has the advantage that it can be manufactured by the method. When preparing an aqueous dispersion of vapor-phase process alumina, the use of a small amount of an acidic component can further increase the dispersed solid content. As such an acidic component, it is particularly preferable to add a small amount of boric acid when dispersing the pigment.

  In order to increase the pigment dispersion concentration, it is preferable to use a known dispersant. As these dispersants, for example, a cationic polymer having a secondary, tertiary amino group, or quaternary ammonium base, a nonionic or cationic surfactant, and a low molecular weight polyvinyl alcohol are preferably used in combination. .

When vapor phase alumina is used as the fine particles, the preferred amount is 4 to 12 parts by weight, more preferably 5 to 10 parts by weight, and particularly preferably 6 parts by weight with respect to 1 part by weight of the water-soluble binder. It is -9 mass parts, and it becomes possible to obtain sufficient film | membrane intensity | strength with the amount of binders smaller than the case where vapor phase method silica is used.
In the case of an ink-receiving layer having a multilayer structure, it is preferable to include vapor-phase alumina in the outermost layer in order to bring out the characteristics of the vapor-phase alumina.

  In the present invention, the fine particles may be used alone or in combination of two or more. When two or more kinds of fine particles are used in combination, a mode in which precipitation method silica, gas phase method silica, and gas phase method alumina are optionally used in combination is preferable.

  If organic fine particles are used as the fine particles in the present invention, they must be present in the form of particles when the ink receiving layer is formed. Examples of the organic fine particles include polymer fine particles obtained by emulsion polymerization, microemulsion polymerization, soap-free polymerization, seed polymerization, dispersion polymerization, suspension polymerization, and the like. Specifically, polyethylene, polypropylene, polystyrene, Examples include polyacrylate, polyamide, silicon resin, phenol resin, natural polymer powder, latex or emulsion polymer fine particles, and the like. The organic fine particles preferably have a cationized surface. The Tg of the organic fine particles is not particularly limited, but when used alone, it is preferably 40 ° C. or higher, more preferably 80 ° C. or higher.

  In addition, when colloidal silica is used as the fine particles, it is difficult to form an ink-receiving layer having a porous structure with a high porosity due to the small void-forming ability of the colloidal silica itself. By using phase-phase silica and colloidal silica in the same layer, or providing a colloidal silica-containing layer as a multilayer, a high void forming effect can be obtained.

When using fumed silica, primary particle diameter is correlated with the specific surface area measured by substantially the BET method, is preferably a 100m ² / g~400m ² / g, stability and ink absorption of the coating liquid In view of satisfying all the properties and glossiness of the image receiving paper, those having a BET specific surface area of 300 to 350 m ² / g are particularly preferable.

-Content ratio of fine particles and water-soluble resin-
In the present invention, the content ratio of the fine particles (preferably silica fine particles; x) to the water-soluble resin (y) [PB ratio (x / y), the mass of fine particles relative to 1 part by mass of the water-soluble resin] The film structure is also greatly affected. That is, as the PB ratio increases, the porosity, pore volume, and surface area (per unit mass) increase. Specifically, as the PB ratio (x / y), a decrease in film strength and cracking during drying caused by the PB ratio being too large are prevented, and the PB ratio is too small. From the viewpoint of preventing the gap from being easily blocked by the resin and preventing the ink absorbability from being lowered due to a decrease in the void ratio, 1.5 / 1 to 10/1 is preferable.

  Since stress may be applied to the recording medium when passing through the transport system of the ink jet printer, the ink receiving layer needs to have sufficient film strength. Further, when cutting into a sheet, the ink receiving layer needs to have sufficient film strength to prevent cracking and peeling of the ink receiving layer. From such a viewpoint, the PB ratio (x / y) is preferably 6/1 or less, and preferably 3/1 or more from the viewpoint of securing high-speed ink absorbability with an inkjet printer.

For example, a coating solution in which anhydrous silica fine particles having an average primary particle size of 20 nm or less and a water-soluble resin are completely dispersed in an aqueous solution with a PB ratio (x / y) of 3/1 to 6/1 is coated on a support. When the coating layer is dried, a three-dimensional network structure in which the secondary particles of silica fine particles are chain units is formed, the average pore diameter is 30 nm or less, the porosity is 50% to 80%, and the pore specific volume is 0. A translucent porous film having a surface area of 5 ml / g or more and a specific surface area of 100 m ² / g or more can be easily formed.

(latex)
The surfactant of polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether in the present invention may decrease the strength of the film or worsen the wet heat blur after printing. Therefore, it is preferable to use latex in the ink receiving layer in the present invention. Conventionally, it is known to use a cationic polymer in the image-receiving layer for the purpose of improving wet heat bleeding, but in addition to the water-soluble cationic polymer, in the present invention, it is further improved by using a latex together. The occurrence of bleeding can be improved.

The particle diameter of the latex in water is preferably 1 μm or less, more preferably 1 to 100 nm.
Latex includes polystyrene, styrene-butadiene copolymer, acrylonitrile-butadiene, acrylic acid, styrene-acrylic, urethane, methacrylic acid, vinyl chloride, vinyl acetate, ethylene-vinyl acetate latex, etc. Preferably used. Among these, styrene, acrylic acid, methacrylic acid, and urethane latex are preferable, and urethane latex and aqueous dispersion are particularly preferable. These latexes or aqueous dispersions were synthesized by a known polymerization method as described in “Latest Emulsion Application Technology (edited by Motoharu Okikura, Chunichisha, 1991, pp. 88-90)”. Can be used.
The latex is preferably a polyurethane latex having a dispersed particle size of 1 μm or less, preferably 100 nm or less, polymerized and synthesized in a soap-free manner, and most preferably cation-modified.

  The Tg of the latex is not particularly limited, but is preferably 40 ° C. or higher from the viewpoint of improving the strength of the film, and conversely, it is preferably 40 ° C. or lower from the viewpoint of the brittleness improving effect. The cationized polyurethane dispersion is preferably present in the form of a film rather than particles after coating and drying. By forming a film, the haze of the image receiving layer is lowered, and a high color density can be obtained.

The latex resin in the present invention is a colloidal dispersion containing a cationic urethane resin having a volume average particle size of 30 nm or less, and the glass transition temperature of the cationic urethane resin is from the viewpoint of obtaining such a gloss for photographic use. Those having a temperature of less than 50 ° C. are particularly preferred.
When such a colloidal dispersion-like latex resin is used, the viscosity of the coating liquid tends to be promoted by the surfactant, and in particular, the polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether interface in the present invention. The effect of using the activator is remarkably exhibited.

(Cationic substance)
The ink receiving layer in the invention preferably further contains a cationic substance. As the cationic substance, the above-described cation-modified latex is preferably used, and other cationic polymers can also be used.

-Other cationic polymers-
As the other cationic polymer in the present invention, a polymer mordant having a primary to tertiary amino group or a quaternary ammonium base as a cationic group is preferably used, but a cationic non-polymer mordant may also be used. Can be used.
As said other cationic polymer, the homopolymer of the monomer (mordanting monomer) which has a primary-tertiary amino group and its salt, or a quaternary ammonium base, this mordanting monomer, and another monomer (Hereinafter referred to as “non-mordant monomer”) is preferably obtained as a copolymer or condensation polymer. These polymers can be used in any form of water-soluble polymer or water-dispersible latex particles.

  Examples of the monomer (mordant monomer) include trimethyl-p-vinylbenzylammonium chloride, trimethyl-m-vinylbenzylammonium chloride, triethyl-p-vinylbenzylammonium chloride, triethyl-m-vinylbenzylammonium chloride, N , N-dimethyl-N-ethyl-Np-vinylbenzylammonium chloride, N, N-diethyl-N-methyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-Nn-propyl-N -P-vinylbenzylammonium chloride, N, N-dimethyl-Nn-octyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-benzyl-Np-vinylbenzylammonium chloride, N, N-die Ru-N-benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N- (4-methyl) benzyl-Np-vinylbenzylammonium chloride, N, N-dimethyl-N-phenyl-N -P-vinylbenzylammonium chloride;

  Trimethyl-p-vinylbenzylammonium bromide, trimethyl-m-vinylbenzylammonium bromide, trimethyl-p-vinylbenzylammonium sulfonate, trimethyl-m-vinylbenzylammonium sulfonate, trimethyl-p-vinylbenzylammonium acetate, trimethyl-m-vinyl Benzylammonium acetate, N, N, N-triethyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N, N-triethyl-N-2- (3-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride, N, N-diethyl-N-methyl-N-2- (4-vinylphenyl) ethylammonium chloride Tate;

  N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, N, N- Methyl chloride, ethyl chloride, methyl bromide of dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide , Quaternized products of ethyl bromide, methyl iodide or ethyl iodide, or sulfonates, alkyl sulfonates, acetates or alkyl carboxylates substituted with their anions.

  Specifically, for example, monomethyl diallyl ammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium chloride, triethyl-2- (methacryloyloxy) ethylammonium chloride, trimethyl-2- (acryloyloxy) ethylammonium chloride, triethyl- 2- (acryloyloxy) ethylammonium chloride, trimethyl-3- (methacryloyloxy) propylammonium chloride, triethyl-3- (methacryloyloxy) propylammonium chloride, trimethyl-2- (methacryloylamino) ethylammonium chloride, triethyl-2- (Methacryloylamino) ethylammonium chloride, trimethyl-2- (acryloylamino) ethyl Ammonium chloride, triethyl-2- (acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) propylammonium chloride Triethyl-3- (acryloylamino) propylammonium chloride;

N, N-dimethyl-N-ethyl-2- (methacryloyloxy) ethylammonium chloride, N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium chloride, N, N-dimethyl-N-ethyl- 3- (acryloylamino) propylammonium chloride, trimethyl-2- (methacryloyloxy) ethylammonium bromide, trimethyl-3- (acryloylamino) propylammonium bromide, trimethyl-2- (methacryloyloxy) ethylammonium sulfonate, trimethyl-3- And (acryloylamino) propylammonium acetate.
Other examples of the copolymerizable monomer include N-vinylimidazole and N-vinyl-2-methylimidazole.

In addition, allylamine, diallylamine, its derivatives, salts and the like can be used. Examples of such compounds include allylamine, allylamine hydrochloride, allylamine acetate, allylamine sulfate, diallylamine, diallylamine hydrochloride, diallylamine acetate, diallylamine sulfate, diallylmethylamine and salts thereof (for example, Hydrochloride, acetate, sulfate, etc.), diallylethylamine and salts thereof (for example, hydrochloride, acetate, sulfate, etc.), diallyldimethylammonium salt (chloride, acetic acid as counter anions of the salt) Ion sulfate ions, etc.). In addition, since these allylamines and diallylamine derivatives are inferior in polymerizability in the amine form, they are generally polymerized in the form of a salt and desalted as required.
In addition, a unit such as N-vinylacetamide, N-vinylformamide or the like, which is converted into a vinylamine unit by hydrolysis after polymerization, and a salt thereof can also be used.

The non-mordant monomer does not contain a basic or cationic moiety such as a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base, and does not show an interaction with a dye in an inkjet ink. Or the monomer which interaction is substantially small is said.
Examples of the non-mordant monomer include (meth) acrylic acid alkyl ester; (meth) acrylic acid cycloalkyl ester such as cyclohexyl (meth) acrylate; (meth) acrylic acid aryl ester such as phenyl (meth) acrylate; Aralkyl esters such as (meth) benzyl acrylate; Aromatic vinyls such as styrene, vinyl toluene and α-methylstyrene; Vinyl esters such as vinyl acetate, vinyl propionate and vinyl versatic acid; Allyl esters such as allyl acetate Halogen-containing monomers such as vinylidene chloride and vinyl chloride; vinyl cyanide such as (meth) acrylonitrile; olefins such as ethylene and propylene; and the like.

The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl moiety, such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth) Propyl acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, Examples include 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like.
Of these, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, and hydroxyethyl methacrylate are preferable.
The non-mordant monomers can also be used singly or in combination of two or more.

Further, as the other cationic polymer, polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethyleneimine, polyallylamine and derivatives thereof, polyamide-polyamine resin, cationized starch, dicyandiamide formalin condensation , Dimethyl-2-hydroxypropylammonium salt polymer, polyamidine, polyvinylamine, dicyandiamide-formalin polycondensate, dicyanamide-cachinic resin, dicyanamide-diethylenetriamine polycondensate, polyamine-type katine resin, epichlorohydrin dimethylamine addition polymer, dimethyldiallylammonium phosphorus chloride -SO ₂ copolymers, diallylamine salt -SO ₂ co Compounds, mention may be made of quaternary ammonium base-substituted alkyl group having an ester moiety (meth) acrylate-containing polymers, as preferred styryl polymers having a quaternary ammonium base-substituted alkyl group.

  Specific examples of the other cationic polymer include JP-A Nos. 48-28325, 54-74430, 54-124726, 55-22766, 55-142339, and 60-23850. 60-23851, 60-23852, 60-23853, 60-57836, 60-60643, 60-118834, 60-122940, 60-122941, 60-122942, 60-235134, JP-A-1-161236, U.S. Pat.Nos. 2,484,430, 2,548,564, 3,148,061, 3,309,690, 4,115,124, 4,124,386, 4,193,800, Nos. 4,273,853, 4,282,305 and 4,450,224, JP-A-1-1-1 1236, 10-81064, 10-119423, 10-157277, 10-217601, 11-348409, JP-A-2001-138621, 2000-43401, 2000-212235 No. 2000-309157, No. 2001-96897, No. 2001-138627, JP-A-11-91242, No.8-2087, No.8-2090, No.8-2091, No.8-2093 8-1744992, 11-192777, JP-A-2001-301314, JP-B-5-35162, JP-A-5-35163, JP-A-5-35164, JP-A-5-88846, JP-A-7-118333. No. 2000-344990, Japanese Patent No. 2648847, No. 2666177, etc. Those such as the mounting and the like. Among these, a diallyldimethylammonium chloride type polymer or a (meth) acrylate-containing polymer having a quaternary ammonium base in the ester portion is preferable.

  The other cationic polymer is particularly preferably a cationic polymer having a weight average molecular weight of 200000 or less and an I / O value of 3.0 or less from the viewpoint of preventing bleeding with time.

The other cationic polymer mentioned above may be used individually by 1 type, and may use 2 or more types together. Moreover, you may use together another cationic polymer, another organic mordant, and / or an inorganic mordant.
The content of the other cationic polymer contained in the ink receiving layer formed in the present invention is preferably 1 to 30% by mass, and 2 to 15% by mass with respect to the total solid content in the ink receiving layer. Is more preferable, and 3-10 mass% is further more preferable.

(Water-soluble polyvalent metal salt)
The ink jet recording medium of the present invention preferably further contains a water-soluble polyvalent metal salt in the ink receiving layer in order to improve the water resistance and bleeding resistance of the formed image.

Examples of the water-soluble polyvalent metal salt include water-soluble salts of metals selected from calcium, barium, manganese, copper, cobalt, nickel, aluminum, iron, zinc, zirconium, chromium, magnesium, tungsten, and molybdenum.
Specifically, 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 hexahydrate , Zinc sulfate, zirconium acetate, zirconium chloride, zirconium chloride octahydrate, hydroxy zirconium chloride, chromium acetate, chromium sulfate, magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, sodium phosphotungstate Sodium tungsten citrate, 12 tungstophosphoric acid n hydrate, 12 tungstosilicic acid 26 hydrate, molybdenum chloride, 12 molybdophosphoric acid n hydrate, and the like.

  The water-soluble polyvalent metal salt is preferably at least one selected from water-soluble aluminum compounds, zirconium compounds and titanium compounds.

  As an aluminum compound, for example, as an inorganic salt, aluminum chloride or a hydrate thereof, aluminum sulfate or a hydrate thereof, ammonium alum and the like are known. Furthermore, there is a basic polyaluminum hydroxide compound which is an inorganic aluminum-containing cationic polymer. In particular, a basic polyaluminum hydroxide compound is preferable.

The basic polyaluminum hydroxide compound is represented by the following formula 1, 2 or 3, for example, [Al ₆ (OH) ₁₅ ] ³⁺ , [Al ₈ (OH) ₂₀ ] ⁴⁺ , [Al It is a water-soluble polyaluminum hydroxide that stably contains a basic and high-molecular polynuclear condensed ion such as ₁₃ (OH) ₃₄ ] ⁵⁺ , [Al ₂₁ (OH) ₆₀ ] ³⁺ , and the like.

[Al ₂ (OH) _n Cl _6-n ] _m Formula 1
[Al (OH) ₃ ] _n AlCl ₃ Formula 2
Al _n (OH) _m Cl _(3n-m) (0 <m <3n) Formula 3

  These products 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 Purakhem Co., Ltd., Riken Green Co., Ltd. It is marketed under the name of WT and from other manufacturers for the same purpose, and various grades are easily available. In the present invention, these commercially available products can be used as they are, but there are also products having an inappropriately low pH, and in that case, the pH can be appropriately adjusted and used.

  The zirconium compound is not particularly limited and various compounds can be used. For example, zirconyl acetate, zirconium chloride, zirconium oxychloride, hydroxy zirconium chloride, zirconium nitrate, basic zirconium carbonate, zirconium hydroxide, zirconium carbonate and ammonium, Zirconium carbonate / potassium, zirconium sulfate, zirconium fluoride compounds and the like can be mentioned. Zirconyl acetate is particularly preferable.

  Although it does not specifically limit as a titanium compound and various compounds can be used, For example, titanium chloride and titanium sulfate are mentioned.

  Some of these compounds have an inappropriately low pH. In that case, the pH can be appropriately adjusted and used. In the present invention, the term “water-soluble” means that 1% by mass or more dissolves in water at room temperature and normal pressure.

In the present invention, when a water-soluble polyvalent metal salt is used, it is particularly preferable that at least one of them is zirconyl acetate from the viewpoint of imparting a bleeding suppression effect to a wider range of dyes. The content of zirconyl acetate in the ink receiving layer, is preferably 0.3 g / m ² or less, 0.01~0.02g / m ² is more preferable.

  When zirconyl acetate is used, it is preferable from the viewpoint of viscosity stability of the coating solution that zirconyl acetate is previously contained in the fine particle dispersion, and then the dispersion and binder are mixed. More preferably, the dispersion treatment is performed in the presence of zirconyl acetate in advance in the liquid containing the fine particles before the dispersion treatment.

  In the present invention, the content of the water-soluble polyvalent metal salt in the ink receiving layer is preferably from 0.1 to 20% by mass, more preferably from 1 to 10% by mass, based on the fine particles.

  Although the water-soluble polyvalent metal salt can be used alone, it is preferable to use two or more kinds in combination.

(Crosslinking agent)
In the ink receiving layer formed in the present invention, the layer containing the fine particles and the water-soluble resin preferably further contains a cross-linking agent capable of cross-linking the water-soluble resin. An embodiment having a porous structure in which a water-soluble resin is cured by a crosslinking reaction with a crosslinking agent is preferable.

As the cross-linking agent, a suitable one may be selected as appropriate in relation to the water-soluble resin contained in the ink receiving layer, and among them, a boron compound is preferable in that the cross-linking reaction is rapid. Examples of the boron compound include borax, boric acid, borate (for example, orthoborate, InBO ₃ , ScBO ₃ , YBO ₃ , LaBO ₃ , Mg ₃ (BO ₃ ) ₂ , Co ₃ (BO ₃ ) ₂ , diboric acid). Salt (eg, Mg ₂ B ₂ O ₅ , Co ₂ B ₂ O ₅ ), metaborate (eg, LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ , KBO ₂ ), tetraborate (eg, Na _{2 B 4 O 7 · 10H 2 O} ), can be mentioned five borate _{(e.g., KB 5 O 8 · 4H 2} O, Ca 2 B 6 O 11 · 7H 2 O, CsB 5 O 5) or the like. of these, Borax, boric acid and borates are preferred in that a crosslinking reaction can be rapidly caused, and boric acid is particularly preferred, and it is most preferred to use this in combination with polyvinyl alcohol which is a water-soluble resin.

  In the present invention, the crosslinking agent is preferably contained in an amount of 0.05 to 0.50 parts by mass, and 0.08 to 0.30 parts by mass with respect to 1.0 part by mass of the water-soluble resin. More preferably. When the content of the crosslinking agent is within the above range, the water-soluble resin can be effectively crosslinked to prevent cracks and the like.

When gelatin is used as the water-soluble resin, the following compounds other than boron compounds can also be used as a crosslinking agent.
For example, aldehyde compounds such as formaldehyde, glyoxal and glutaraldehyde; ketone compounds such as diacetyl and cyclopentanedione; bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1,3,5- Active halogen compounds such as triazine and 2,4-dichloro-6-S-triazine sodium salt; divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide) ), Active vinyl compounds such as 1,3,5-triacryloyl-hexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin; melamine resins (for example, methylolmelamine, alkylated methylolmelamine) ;Epoxy resin;

  Isocyanate compounds such as 1,6-hexamethylene diisocyanate; Aziridine compounds described in US Pat. Nos. 3,017,280 and 2,983,611; Carboximide compounds described in US Pat. No. 3,100,704; Glycerol triglycidyl Epoxy compounds such as ether; Ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; Halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; 2,3-dihydroxy Dioxane compounds such as dioxane; Titanium lactate, aluminum sulfate, chromium alum, potash alum, metal-containing compounds such as zirconyl acetate and chromium acetate, polyamine compounds such as tetraethylenepentamine, and hydrazide compounds such as adipic acid dihydrazide It is a small molecule or polymer or the like containing an oxazoline group two or more. The above crosslinking agents may be used alone or in combination of two or more.

  In the present invention, the cross-linking agent may be added to the ink-receiving layer coating solution and / or the coating solution for forming the adjacent layer of the ink-receiving layer when forming the ink-receiving layer, or the cross-linking agent in advance. The ink receiving layer coating liquid is coated on the support coated with the coating liquid or the ink receiving layer coating liquid containing no cross-linking agent is coated and dried, and then the cross-linking agent solution is overcoated. A crosslinking agent can be supplied to the layer. From the viewpoint of production efficiency, it is preferable to add a cross-linking agent to the ink receiving layer coating solution or the coating solution for forming the adjacent layer, and to supply the cross-linking agent simultaneously with the formation of the ink receiving layer. In particular, it is preferably contained in the ink-receiving layer coating solution from the viewpoint of improving the image printing density and glossiness. Further, the concentration of the crosslinking agent in the ink receiving layer coating solution is preferably 0.05 to 10% by mass, and more preferably 0.1 to 7% by mass.

  For example, the crosslinking agent can be suitably applied as follows. Here, a boron compound will be described as an example. That is, when the ink receiving layer is a layer obtained by crosslinking and curing the coating layer coated with the ink receiving layer coating liquid (first coating liquid), the crosslinking curing is performed by (1) coating the coating layer by applying the coating liquid. The pH is 7.1 or more at the same time as the formation, or (2) anytime during the drying of the coating layer formed by applying the coating solution and before the coating layer exhibits a reduced rate of drying. The basic solution (second coating solution) is applied to the coating layer. The boron compound as the crosslinking agent may be contained in either the first coating liquid or the second coating liquid, or may be contained in both the first coating liquid and the second coating liquid.

(Other ingredients)
The ink receiving layer in the invention is constituted by containing the following components as required.
That is, for the purpose of suppressing the deterioration of the ink coloring material, various ultraviolet absorbers, antioxidants, anti-fading agents such as singlet oxygen quenchers may be included.
Examples of the ultraviolet absorber include cinnamic acid derivatives, benzophenone derivatives, benzotriazolylphenol derivatives, and the like. For example, α-cyano-phenyl cinnamate butyl, o-benzotriazole phenol, o-benzotriazole-p-chlorophenol, o-benzotriazole-2,4-di-t-butylphenol, o-benzotriazole-2,4 -Di-t-octylphenol etc. are mentioned. A hindered phenol compound can also be used as an ultraviolet absorber, and specifically, a phenol derivative in which one or more of at least 2-position or 6-position is substituted with a branched alkyl group is preferable.

  Moreover, a benzotriazole type ultraviolet absorber, a salicylic acid type ultraviolet absorber, a cyanoacrylate type ultraviolet absorber, an oxalic acid anilide type ultraviolet absorber, etc. can be used. For example, JP-A-47-10537, 58-111942, 58-21284, 59-19945, 59-46646, 59-109055, 63-53544. No. 36, Japanese Patent Publication No. 36-10466, No. 42-26187, No. 48-30492, No. 48-31255, No. 48-41572, No. 48-54965, No. 50-10726. No. 2,719,086, US Pat. No. 3,707,375, US Pat. No. 3,754,919, US Pat. No. 4,220,711, and the like. .

  A fluorescent brightening agent can also be used as an ultraviolet absorber, and examples thereof include a coumarin fluorescent brightening agent. Specifically, it is described in Japanese Patent Publication Nos. 45-4699 and 54-5324.

  Examples of the antioxidant include European Patent Nos. 223739, 309401, 309402, 310551, 310552, 455416, German Patent No. 3435443, and Japanese Patent Laid-Open No. 3435443. 54-48535, 60-107384, 60-107383, 60-125470, 60-125471, 60-125472, 60-287485, 60 -287486, 60-287487, 60-287488, 61-160287, 61-185483, 61-211079, 62-146678, 62- 146680, 62-146679, 62- 82885, JP same 62-262047, JP-same 63-051174, JP-same 63-89877, JP-same 63-88380, JP-same 66-88381, JP-same 63-113536 JP;

  JP-A-63-163351, JP-A-63-203372, JP-A-63-224989, JP-A-63-251282, JP-A-63-267594, JP-A-63-182484, JP-A-1-239282, JP-A-2-262654, JP-A-2-71262, JP-A-3-121449, JP-A-4-291865, JP-A-4-291684, JP-A-5-61166, JP-A-5-119449, 5-188687, 5-188686, 5-110490, 5-110437, 5-170361, JP-A 48-43295, 48-33212, US Those described in Japanese Patent Nos. 4814262 and 4980275 are exemplified.

  Specifically, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2-dihydroquinoline 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2,3 4, -tetrahydroquinoline, nickel cyclohexane acid, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2-ethylhexane, 2-methyl-4-methoxy-diphenylamine, Examples include 1-methyl-2-phenylindole.

  These anti-fading agents may be used alone or in combination of two or more. The anti-fading agent may be water-solubilized, dispersed, emulsified, or contained in microcapsules. The addition amount of the anti-fading agent is preferably 0.01 to 10% by mass of the ink receiving layer coating solution.

  The ink receiving layer in the invention may contain a high boiling point organic solvent for preventing curling. The high-boiling organic solvent is preferably water-soluble, and examples of the water-soluble high-boiling organic solvent include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, glycerin, diethylene glycol monobutyl ether (DEGMBE), and triethylene. Glycol monobutyl ether, glycerin monomethyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol, 1,2,6-hexanetriol, thiodiglycol, triethanol Examples include alcohols such as amines and polyethylene glycol (weight average molecular weight of 400 or less). Diethylene glycol monobutyl ether (DEGMBE) is preferred.

The content of the high-boiling organic solvent in the ink-receiving layer coating solution is preferably 0.05 to 1% by mass, particularly preferably 0.1 to 0.6% by mass.
In addition, for the purpose of improving the dispersibility of the inorganic pigment fine particles, various inorganic salts, pH adjusting agents, and the like may contain acids and alkalis.

  Further, for the purpose of suppressing surface frictional charge and peeling charge, the metal oxide fine particles having electronic conductivity may contain various matting agents for the purpose of reducing the surface frictional characteristics.

[Support etc.]
As the support applied to the present invention, either a transparent support made of a transparent material such as plastic or an opaque support made of an opaque material such as paper can be used. In order to make use of the transparency of the ink receiving layer, it is preferable to use a transparent support or a highly glossy opaque support. In addition, a read-only optical disk such as a CD-ROM or DVD-ROM, a write-once optical disk such as a CD-R or DVD-R, or a rewritable optical disk is used as a support, and an ink receiving layer is provided on the label surface side. You can also.

The material that can be used for the transparent support is preferably a material that is transparent and can withstand radiant heat when used in an OHP or backlight display. Examples of such materials include polyesters such as polyethylene terephthalate (PET); polysulfone, polyphenylene oxide, polyimide, polycarbonate, polyamide, and the like. Of these, polyesters are preferable, and polyethylene terephthalate is particularly preferable.
Although there is no restriction | limiting in particular as thickness of the said transparent support body, 50-200 micrometers is preferable at the point of the ease of handling.

  As the highly glossy opaque support, one having a glossiness of 40% or more on the surface on which the ink receiving layer is provided is preferable. The glossiness is a value determined according to the method described in JIS P-8142 (75-degree specular gloss test method for paper and paperboard). Specifically, the following supports are mentioned.

For example, high gloss paper support such as art paper, coated paper, cast coated paper, baryta paper used for silver salt photographic support, etc .; polyesters such as polyethylene terephthalate (PET), nitrocellulose, cellulose acetate , Cellulose esters such as cellulose acetate butyrate, and plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate, and polyamide are made opaque by adding a white pigment or the like (surface calendering may be applied). Glossy film; or a support in which a polyolefin coating layer containing or not containing a white pigment is provided on the surface of a highly glossy film containing the various paper supports, the transparent support or the white pigment. Etc.
A white pigment-containing foamed polyester film (for example, foamed PET containing polyolefin fine particles and forming voids by stretching) can also be suitably exemplified. Furthermore, resin-coated paper used for silver salt photographic printing paper is also suitable.

Although there is no restriction | limiting in particular also about the thickness of an opaque support body, 50-300 micrometers is preferable at the point of the ease of handling.
In addition, it is preferable to use a surface of the support that has been subjected to corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment or the like in order to improve wettability and adhesion.

Next, a base paper used for a paper support such as resin-coated paper will be described.
The base paper is made from wood pulp as a main raw material and, if necessary, paper using synthetic pulp such as polypropylene or synthetic fibers such as nylon or polyester in addition to wood pulp. As the wood pulp, any of LBKP, LBSP, NBKP, NBSP, LDP, NDP, LUKP, and NUKP can be used, but it is preferable to use more LBKP, NBSP, LBSP, NDP, and LDP with a large amount of short fibers. preferable. However, the ratio of LBSP and / or LDP is preferably 10% by mass to 70% by mass.

As the above-mentioned pulp, chemical pulp (sulfate pulp or sulfite pulp) with few impurities is suitably used, and a pulp whose whiteness is improved by performing a bleaching treatment is also useful.
In the base paper, sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength enhancing agents such as starch, polyacrylamide and polyvinyl alcohol, fluorescent whitening agents, polyethylene glycols A water retaining agent such as a dispersant, a softening agent such as a quaternary ammonium, and the like can be appropriately added.

  The freeness of the pulp used for papermaking is preferably 200 to 500 ml as defined by CSF, and the fiber length after beating is a 24 mesh residual mass% and a 42 mesh residual as defined in JIS P-8207. 30 to 70% of the sum with the mass% of is preferable. The 4 mesh residue is preferably 20% by mass or less.

The basis weight of the base paper is preferably 30 to 250 g, and particularly preferably 50 to 200 g. The thickness of the base paper is preferably 40 to 250 μm. The base paper can be given a high smoothness by calendering at the paper making stage or after paper making. The density of the base paper is generally 0.7 to 1.2 g / m ² (JIS P-8118). Furthermore, the base paper stiffness is preferably 20 to 200 g under the conditions specified in JIS P-8143.

A surface sizing agent may be applied to the surface of the base paper. As the surface sizing agent, a sizing agent similar to the size that can be added to the base paper can be used.
The pH of the base paper is preferably 5 to 9 when measured by a hot water extraction method defined in JIS P-8113.

  The polyethylene covering the front and back surfaces of the base paper is mainly low-density polyethylene (LDPE) and / or high-density polyethylene (HDPE), but some other LLDPE, polypropylene, etc. can also be used. In addition, the aspect which used the hydrotalcite compound as a catalyst deactivator of the catalyst of a high density polyethylene is preferable, As content in a high density polyethylene, 100-2,000 ppm with respect to the quantity of a high density polyethylene Is preferable, and 200 to 1,000 ppm is more preferable. As the antioxidant, it is preferable to use only a secondary antioxidant (particularly a phosphorus-based antioxidant), and the content in the high-density polyethylene to be formed is 100 ppm or more 2 with respect to the high-density polyethylene (HDPE). 1,000 ppm or less is preferable, and 200 ppm or more and 1,000 ppm or less is more preferable.

  In particular, the polyethylene layer on the side on which the ink receiving layer is formed is obtained by adding rutile or anatase type titanium oxide, fluorescent whitening agent, ultramarine blue to polyethylene, as is widely done in photographic paper, Those having improved whiteness and hue are preferred. Here, as a titanium oxide content, about 3-40 mass% is preferable with respect to polyethylene, and 4-30 mass% is more preferable. Although the thickness of a polyethylene layer does not have limitation in particular, 10-50 micrometers is suitable for both front and back layers. Further, an undercoat layer can be provided on the polyethylene layer in order to provide adhesion to the ink receiving layer. As the undercoat layer, aqueous polyester, gelatin and PVA are preferable. Moreover, as thickness of this undercoat layer, 0.01-5 micrometers is preferable.

  Polyethylene-coated paper can be used as glossy paper, or matte or silky surface that can be obtained with ordinary photographic printing paper by applying a so-called molding process when polyethylene is melt-extruded and coated on the base paper surface. Can also be used.

A back coat layer can be provided on the support, and examples of components that can be added to the back coat layer include a white pigment, an aqueous binder, and other components.
Examples of white pigments contained in the backcoat layer include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, and aluminum silicate. , Diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide, white inorganic pigment, styrene And organic pigments such as polyethylene plastic pigments, acrylic plastic pigments, polyethylene, microcapsules, urea resins, and melamine resins.

Examples of the aqueous binder used in the back coat layer include styrene / maleate copolymer, styrene / acrylate copolymer, polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationized starch, casein, gelatin, carboxy Examples thereof include water-soluble polymers such as methyl cellulose, hydroxyethyl cellulose, and polyvinyl pyrrolidone, and water-dispersible polymers such as styrene butadiene latex and acrylic emulsion.
Examples of other components contained in the backcoat layer include an antifoaming agent, an antifoaming agent, a dye, a fluorescent brightening agent, a preservative, and a water-proofing agent.

[Method for producing inkjet recording medium]
The method for producing an ink jet recording medium of the present invention comprises a step of preparing an ink-receiving layer coating solution obtained by mixing the above-described components, and a step of forming an ink-receiving layer on a support using the coating solution. , A method for producing an inkjet recording medium.

The ink receiving layer coating solution includes (a) an aqueous solution in which a polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether surfactant is dissolved, and (b) fine particles, a hydrophilic binder, and optionally a cation. It is preferable to prepare a fine particle dispersion obtained by mixing an active substance by in-line blending.
More preferably, at least one water-soluble polyvalent metal is mixed and dissolved in the aqueous solution (a). From the viewpoint of preventing fine particles from agglomerating, it is preferable that the surfactant is mixed and dissolved in advance with at least one water-soluble polyvalent metal and then mixed with the fine particle dispersion.

  The step of forming the ink receiving layer includes a coating step of coating the coating solution (coating solution mixed and prepared by the in-line blend) containing at least fine particles and a water-soluble binder. A crosslinking agent is added to the coating solution and / or a basic solution having a pH of 7.1 or more, and (1) the coating solution is applied to form a coating layer, or (2) the coating solution is added. The ink is applied by applying the basic solution to the coating layer and crosslinking and curing it at any time during the drying of the coating layer formed by coating and before the coating layer exhibits a decreasing rate of drying. It is preferable to form a receiving layer.

Next, the production of the ink jet recording medium will be further described.
The ink receiving layer in the present invention includes, for example, on a support, at least fine particles, a hydrophilic binder, a polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether surfactant, and if necessary, a cationic substance, A coating layer containing a coating solution (that is, a coating solution (first coating solution) prepared by mixing the aqueous solution of (a) and the fine particle dispersion of (b) by in-line blending). Further, a crosslinking agent is added to the coating solution (first coating solution) and / or a basic solution (second coating solution) having a pH of 7.1 or more, and (1) the coating solution (first coating solution). (2) the coating layer formed by applying the coating solution (first coating solution) is being dried, and the coating layer has a reduced drying rate. At any time before showing, the basic solution (second coating solution) Imparted to the coating layer, a method for crosslinking and curing the coating layer (this is referred to as "Wet on Wet method".) It is preferably formed by.

  The crosslinking agent capable of crosslinking the hydrophilic binder is preferably contained in at least one or both of the first coating liquid and the second coating liquid. As described above, the ink receiving layer obtained by applying a basic solution (second coating solution) to the first coating solution at the same time as (1) or during (2) drying is crosslinked and cured. In addition to having advantages such as ink absorbability and prevention of film cracking, it is particularly preferable for improving the appearance of repelling failure and the like.

  The latex resin is used by being added to at least one of the first coating liquid and the second coating liquid (basic solution), but is sufficiently mixed with the fine particles and the hydrophilic binder in the first coating liquid for a long time. From the viewpoint of effectively preventing bleeding over time, an embodiment in which the first coating liquid (a coating liquid containing fine particles and a water-soluble resin) is included is preferable. At this time, it is not always necessary to include all of the latex resin in the first coating liquid, and it is also effective to include at least a part of the latex resin in the second coating liquid, thereby effectively preventing bleeding over time. Can be prevented. Also preferred is an embodiment in which at least a part of the latex resin is contained in both the first coating liquid and the second coating liquid.

  The mordant is preferably present so that the thickness of the portion where the mordant is present from the surface of the ink receiving layer is 10 to 60% with respect to the total thickness of the ink receiving layer. For example, (1) a method of forming a coating layer containing fine particles, a hydrophilic binder and a crosslinking agent, and applying a mordant-containing solution thereon, (2) a coating solution containing fine particles and a hydrophilic binder, and a mordant-containing solution. It can be formed by any method such as a method of applying multiple layers. The mordant-containing solution may contain inorganic fine particles, a hydrophilic binder, a crosslinking agent, and the like. When configured as described above, since a large amount of mordant is present in a required portion of the ink receiving layer, the ink color material of the ink jet is sufficiently mordanted, the color density and bleeding over time, the gloss of the printed portion, and the characters and images after printing. It is preferable because water resistance and ozone resistance are further improved. Part of the mordant may be contained in the layer initially provided on the support, and in that case, the mordant to be applied later may be the same or different.

In the present invention, when preparing a coating liquid containing fine particles, a hydrophilic binder, and a boron compound (crosslinking agent) as the first coating liquid, it can be prepared, for example, as follows.
That is, silica fine particles having an average primary particle size of 20 nm or less are added to water (for example, 10 to 20% by mass), and a high-speed rotating wet colloid mill (for example, “Clairemix” manufactured by M Technique Co., Ltd.) is used. For example, after being dispersed for 20 minutes (preferably 10 to 30 minutes) under the condition of high-speed rotation of 10000 rpm (preferably 5000 to 20000 rpm), a boron compound (for example, 0.5 to 20 of silica) (Mass%) and dispersion under the same conditions as above, and an aqueous polyvinyl alcohol solution (for example, PVA having a mass of about 1/3 of silica), and further dispersion under the same rotation conditions as above. Can be prepared. The obtained coating solution is a uniform sol, and this is applied to a support by the following coating method to form an ink-receiving layer having a porous structure having a three-dimensional network structure.
If necessary, a pH adjuster, a dispersant, an antifoaming agent, an antistatic agent, and the like can be further added to the first coating liquid.

As dispersion machines used for dispersion, various conventionally known dispersion machines such as a high-speed rotary dispersion machine, a medium stirring type dispersion machine (ball mill, bead mill, sand mill, etc.), an ultrasonic dispersion machine, a colloid mill dispersion machine, and a high-pressure dispersion machine are used. However, in order to efficiently disperse the generated fine particles, a medium stirring type disperser, a colloid mill disperser, or a high pressure disperser (homogenizer) is preferable.
As a disperser applied to the present invention, a medium stirring disperser such as a bead mill is mainly preferably used. From the viewpoint of promoting atomization and high Dm, a high-pressure homogenizer (for example, SUGINO MACHINE Co., Ltd.) is used. It is also used in the same way for manufactured optimizers and the like.

  Moreover, water, an organic solvent, or these mixed solvents can be used as a solvent used for preparation of each coating liquid. Examples of organic solvents that can be used in the coating solution include alcohols such as methanol, ethanol, n-propanol, i-propanol, and methoxypropanol, ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, acetonitrile, ethyl acetate, and toluene. Can be mentioned.

  Moreover, the 2nd coating liquid (basic solution) containing surfactant can be prepared as follows, for example. That is, a mordant (for example, 0.1 to 5.0% by mass) and a surfactant (for example, a total amount of 0.01 to 1.0% by mass) in ion-exchanged water and a crosslinking agent (0 to 0 as necessary). 5.0% by mass) and sufficiently stirred. The pH of the second coating liquid is preferably 8.0 or more, and pH adjustment is carried out using ammonia water, sodium hydroxide, calcium hydroxide, amino group-containing compounds (ethylamine, ethanolamine, diethanolamine, polyallylamine, etc.) and the like. .0 or more can be appropriately performed.

  Application of the first coating liquid (ink receiving layer coating liquid) is, for example, a known coating method such as an extrusion die coater, an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, or a bar coater. Can be done by.

  The second coating liquid (basic solution) is applied to the coating layer simultaneously with or after the first coating liquid (ink-receiving layer coating liquid) is applied. The second coating liquid is applied after the application. It may be applied before the layer exhibits reduced rate drying. That is, it is preferably manufactured by introducing a basic solution after applying the ink-receiving layer coating solution while the coating layer exhibits constant rate drying. The second coating liquid may contain a mordant.

  Here, “before the coating layer comes to show reduced drying” usually refers to a process of several minutes immediately after the application of the ink-receiving layer coating solution, and during this period, It shows the phenomenon of “constant rate drying” in which the content of the solvent (dispersion medium) decreases in proportion to time. The time indicating “constant rate drying” is described in, for example, “Chemical Engineering Handbook” (pages 707 to 712, published by Maruzen Co., Ltd., October 25, 1980).

  As described above, after the application of the first coating liquid, the coating layer is dried until the coating layer exhibits reduced-rate drying. This drying is generally performed at a temperature of 50 to 180 ° C. for 0.5 to 10 minutes (preferably, 0.5-5 minutes). The drying time naturally varies depending on the coating amount, but the above range is usually appropriate.

  As a method of applying the second coating liquid before the reduced rate of drying is exhibited, (1) a method of further applying the second coating liquid on the coating layer, and (2) a method of spraying by a method such as spraying (3) A method of immersing the support on which the coating layer is formed in the second coating liquid.

  In the above method (1), examples of the application method for applying the second coating liquid include curtain flow coaters, extrusion die coaters, air doctor coaters, bread coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, A known coating method such as a bar coater can be used. However, it is preferable to use a method in which the coater does not directly contact the first coating layer that has already been formed, such as an extrusion die coater, a curtain flow coater, or a bar coater.

The coating amount of the second coating solution, 5 to 50 g / m ² is generally, 10 to 30 g / m ² is preferred.

  After the application of the second coating liquid, it is generally heated at a temperature of 40 to 180 ° C. for 0.5 to 30 minutes, and dried and cured. Especially, it is preferable to heat at a temperature of 40 to 150 ° C. for 1 to 20 minutes. For example, when the cross-linking agent contained in the first coating liquid is borax or boric acid, heating at a temperature of 60 to 100 ° C. is preferably performed for 5 to 20 minutes.

  When the basic solution (second coating solution) is applied simultaneously with the application of the ink-receiving layer coating solution (first coating solution), the first coating solution and the second coating solution are supported by the first coating solution. The ink receiving layer can be formed by simultaneous application (multilayer application) on the support so as to come into contact with the substrate, followed by drying and curing.

  Simultaneous coating (multilayer coating) can be performed by a coating method using, for example, an extrusion die coater or a curtain flow coater. After the simultaneous coating, the formed coating layer is dried. In this case, the drying is generally performed by heating the coating layer at a temperature of 40 to 150 ° C. for 0.5 to 10 minutes, preferably at a temperature of 40 It is carried out by heating at -100 ° C for 0.5-5 minutes.

  When simultaneous coating (multilayer coating) is performed using, for example, an extrusion die coater, the two types of coating liquid discharged simultaneously are in the vicinity of the discharge port of the extrusion die coater, that is, before moving onto the support. In that state, it is coated on the support in multiple layers. Since the two-layer coating liquid layered before coating is likely to cause a cross-linking reaction at the interface between the two liquids when transferred to the support, the two liquids to be ejected are mixed in the vicinity of the discharge port of the extrusion die coater. As a result, thickening is likely to occur, which may hinder the application operation. Therefore, when applying simultaneously as described above, it is preferable to apply a triple layer simultaneously with the application of the first coating liquid and the second coating liquid, with a barrier layer liquid (intermediate layer liquid) interposed between the two liquids. .

  The barrier layer liquid can be selected without particular limitation. For example, an aqueous solution containing a trace amount of water-soluble resin, water, and the like can be given. The water-soluble resin is used in consideration of applicability for the purpose of a thickener and the like. For example, a cellulose resin (for example, hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose) And polymers such as polyvinylpyrrolidone and gelatin. Here, the mordant may be contained in the barrier layer solution.

  After the ink receiving layer is formed on the support, the ink receiving layer is subjected to, for example, super calender, gloss calender, etc., and is subjected to calender treatment through the roll nip under heat and pressure, so that surface smoothness, glossiness, It is possible to improve transparency and coating strength. However, the calendering process may cause a decrease in the porosity (that is, the ink absorbability may be decreased), so it is necessary to set the conditions under which the decrease in the porosity is small.

  As roll temperature in the case of performing a calendar process, 30-150 degreeC is preferable and 40-100 degreeC is more preferable. Moreover, as a linear pressure between rolls at the time of a calendar process, 50-400 kg / cm is preferable and 100-200 kg / cm is more preferable.

In the case of inkjet recording, the thickness of the ink receiving layer in the present invention needs to have an absorption capacity sufficient to absorb all of the droplets, and therefore needs to be determined in relation to the porosity in the layer. For example, if the ink amount is 8 nL / mm ² and the porosity is 60%, a film having a layer thickness of about 15 μm or more is required. Considering this point, in the case of ink jet recording, the layer thickness of the ink receiving layer is preferably 10 to 50 μm.

  The pore diameter of the ink receiving layer is preferably 0.005 to 0.030 μm, more preferably 0.01 to 0.025 μm in terms of median diameter. The porosity and pore median diameter can be measured using a mercury porosimeter “Bore Sizer 9320-PC2” manufactured by Shimadzu Corporation.

The ink receiving layer formed in the present invention preferably has a film surface pH of 3 to 6 and more preferably 3 to 5 from the viewpoint of preventing yellowing of the ink receiving layer.
As a method for adjusting the film surface pH of the ink receiving layer, known acids (hydrochloric acid, acetic acid, nitric acid, etc.), bases (NaOH, ammonia, etc.) and salts thereof (ammonium carbonate, etc.) are preliminarily applied to the coating solution. There are a method of adding, a method of sequentially overcoating after forming the ink receiving layer, and the like.
In the present invention, the measurement of the film surface pH of the ink receiving layer is described in J. Org. According to the method for measuring the surface pH of paper defined by TAPPI 49, it can be obtained by measuring after 30 to 40 seconds after dropping 50 μl of pure water having a pH of 6.2 to 7.2 on the ink receiving layer. .

The ink absorbing capacity of the ink-receiving layer (void volume) is preferably from ^{18~40ml / cm 2, 20~30ml / cm} 2 is more preferable.

  In addition, the ink receiving layer is preferably excellent in transparency, as a guide, the haze value when the ink receiving layer is formed on a transparent film support is preferably 30% or less, More preferably, it is 20% or less. The haze value can be measured using a haze meter “HGM-2DP” manufactured by Suga Test Instruments Co., Ltd.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In this example, an ink jet recording sheet is prepared as an example of the ink jet recording medium, and “parts” and “%” in the examples represent mass standards unless otherwise specified. .

[Example 1]
(Production of support)
50 parts of LBKP made of acacia and 50 parts of LBKP made of aspen were beaten to 300 ml of Canadian freeness by a disc refiner to prepare a pulp slurry.
Then, the pulp slurry obtained above was cation modified starch (CAT 0304L manufactured by NSC Japan) 1.3%, 0.15% anionic polyacrylamide (DA4104 manufactured by Seiko PMC), alkyl ketene dimer (Arakawa Chemical Co., Ltd.) per pulp. Sizepine K) 0.29%, epoxidized behenamide 0.29%, polyamide polyamine epichlorohydrin (Arakawa Chemical Co., Ltd .: Arafix 100) 0.32% was added, followed by defoaming agent 0.12% Was added.

In the process of making the pulp slurry prepared as described above with a long paper machine and pressing the felt surface of the web against the drum dryer cylinder through the dryer canvas for drying, the tensile force of the dryer canvas is 1.6 kg / After drying at a setting of cm, 1 g / m ² of polyvinyl alcohol (manufactured by Kuraray Co., Ltd .: KL-118) was applied to both sides of the base paper with a size press and dried to perform calendar treatment. The base paper was made with a basis weight of 166 g / m ² to obtain a base paper (base paper) having a thickness of 160 μm.

After the corona discharge treatment is performed on the wire surface (back surface) side of the obtained base paper, a high-density polyethylene is coated to a thickness of 25 g / m ² using a melt extruder, and the thermoplastic comprising the mat surface A resin layer was formed. The thermoplastic resin layer on the back side is further subjected to corona discharge treatment, and then, as an antistatic agent, aluminum oxide (“Alumina Zil 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (manufactured by Nissan Chemical Industries, Ltd.) Of “Snowtex O”) was dispersed in water at a mass ratio of 1: 2 so that the dry mass was 0.2 g / m ² . Subsequently, the surface was corona-treated and coated with polyethylene having a density of 0.93 g / m ² having 10% by mass of titanium oxide using a melt extruder so as to have a density of 24 g / m ² .

(Preparation of coating liquid A (first liquid) for ink receiving layer)
(1) Gas phase method silica fine particles, (2) ion-exchanged water, (3) “Charol DC-902P”, and (4) “ZA-30” shown in the following composition were mixed to bead mill ( After dispersion using KD-P (produced by Jinmaru Enterprises Co., Ltd.), the dispersion was heated to 45 ° C. and held for 20 hours. Then, the following (5) boric acid aqueous solution, (6) dimethylamine / epichlorohydrin / polyalkylene polyamine polycondensate, (7) polyvinyl alcohol solution, (8) “Superflex 650”, (9 ) Ethanol water was added at 30 ° C. to prepare an ink-receiving layer coating solution A (first solution).

(1) Gas phase method silica fine particles 100 parts (AEROSlL300SF75, manufactured by Nippon Aerosil Co., Ltd.)
(2) Ion-exchanged water 555 parts (3) “Charol DC-902P” 8.7 parts (dispersant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., 51.5% aqueous solution)
(4) Zirconyl acetate 2.7 parts (“ZA-30”, manufactured by Daiichi Rare Element Chemical Industries, Ltd., 50% aqueous solution)
(5) Boric acid (crosslinking agent) aqueous solution (7.5%) 50 parts (6) Dimethylamine / epichlorohydrin / polyalkylene polyamine polycondensate (“SC-505”, Hymo Co., Ltd., 50% aqueous solution) 0. 77 parts (7) Polyvinyl alcohol (water-soluble resin) solution having the following composition 290 parts (8) "Superflex 650" 25 parts (cation-modified polyurethane, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(9) Ethanol water (ethanol content 59%) 75 parts

-Composition of polyvinyl alcohol solution-
Polyvinyl alcohol 20.3 parts ("PVA235", saponification degree 88%, polymerization degree 3500, manufactured by Kuraray Co., Ltd.)
・ Diethylene glycol monobutyl ether 6.0 parts ("Butizenol 20P", manufactured by Kyowa Hakko Co., Ltd.)
・ Ion-exchanged water 263.7 parts

(Preparation of basic solution B (second solution))
The composition shown below was mixed and stirred to obtain a basic solution B.
(1) Boric acid 0.65 parts (2) Zirconyl ammonium carbonate 2.5 parts (Zircosol AC-7 (13% aqueous solution), manufactured by Daiichi Rare Element Chemical Co., Ltd.)
(3) Ammonium carbonate (first grade: manufactured by Kanto Chemical Co., Inc.) 4.0 parts (4) 92.85 parts ion-exchanged water (5) 0.6 parts polyoxyethylene isodecyl ether (Neugen SD-70, No. 1 Manufactured by Kogyo Seiyaku Co., Ltd.)

(Preparation of polyvalent metal salt aqueous solution C for in-line blending)
The composition shown below was mixed and stirred to obtain an aqueous polyvalent metal salt solution C for in-line blending.
(1) Alphain 83 20.0 parts (polyaluminum chloride: manufactured by Daimei Chemical Industry Co., Ltd.)
(2) Neugen SD-60 4.4 parts (polyoxyethylene isodecyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(3) 75.6 parts of ion exchange water

(Preparation of inkjet recording sheet)
After the corona discharge treatment is applied to the front surface of the support, the aqueous solution of the polyvalent metal salt for in-line blending is applied to the coating solution A (first solution) for the ink-receiving layer that is flowed to a coating amount of 173 ml / m ^2. C was inline mixing at a rate of 10.8 ml / m ² of the ink-receiving layer coating liquid a-2 was prepared and subjected to coating. Thereafter, it was dried with a hot air dryer at 80 ° C. (wind speed of 3 to 8 m / sec) until the solid content concentration of the coating layer became 20%. This coating layer showed constant rate drying during this period. Then, before showing the rate-decreasing drying, it was immersed in the basic solution B (second liquid) for 3 seconds to adhere 13 g / m ² on the coating layer, and further dried at 80 ° C. for 10 minutes. (Curing process). This produced the inkjet recording sheet of Example 1 provided with an ink receiving layer having a dry film thickness of 32 μm.

[Example 2]
Example 1 except that Neugen SD-60 in the polyvalent metal salt aqueous solution C for in-line blending of Example 1 was changed to Neugen SD-70 (polyoxyethylene isodecyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). In the same manner as described above, an inkjet recording sheet of Example 2 was produced.

Example 3
Ion so that 4.4 parts Neugen SD-70 in the polyvalent metal salt aqueous solution C for in-line blend of Example 2 is 0.88 parts, and the total amount of polyvalent metal salt aqueous solution C for in-line blend is 100 parts. An inkjet recording sheet of Example 3 was produced in the same manner as Example 2 except that the amount of exchanged water was adjusted.

Example 4
Ion so that 4.4 parts Neugen SD-70 in the polyvalent metal salt aqueous solution C for in-line blend of Example 2 is 1.75 parts, and the total amount of the polyvalent metal salt aqueous solution C for in-line blend is 100 parts. An inkjet recording sheet of Example 4 was produced in the same manner as Example 2 except that the amount of exchanged water was adjusted.

Example 5
Example 1 except that Neugen SD-60 in the polyvalent metal salt aqueous solution C for in-line blending of Example 1 was changed to Neugen SD-110 (polyoxyethylene isodecyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). In the same manner as described above, an inkjet recording sheet of Example 5 was produced.

Example 6
Example 1 except that Neugen SD-60 in the polyvalent metal salt aqueous solution C for in-line blending of Example 1 was changed to Neugen XL-60 (polyoxyalkylene branched decyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) In the same manner as described above, an inkjet recording sheet of Example 6 was produced.

Example 7
Example 1 except that Neugen SD-60 in the polyvalent metal salt aqueous solution C for in-line blending of Example 1 was changed to Neugen XL-100 (polyoxyalkylene branched decyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) In the same manner as described above, an inkjet recording sheet of Example 7 was produced.

Example 8
Except for changing Neugen SD-60 in the polyvalent metal salt aqueous solution C for in-line blending of Example 1 to Neugen TDS-70 (polyoxyethylene tridecyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) In the same manner as in Example 1, an inkjet recording sheet of Example 6 was produced.

[Comparative Example 1]
Neugen SD-70 in the basic solution B of Example 1 and Neugen SD-60 in the polyvalent metal salt aqueous solution C for in-line blending are both Emulgen 109P (polyoxyethylene lauryl ether: manufactured by Kao Corporation) An ink jet recording sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the above was changed.

[Comparative Example 2]
Neugen SD-70 in the basic solution B of Example 1 and Neugen SD-60 in the polyvalent metal salt aqueous solution C for in-line blending were both Neugen SD-30 (polyoxyethylene isodecyl ether: Daiichi Kogyo). An inkjet recording sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that the product was changed to “Pharmaceutical Co., Ltd.”.

[Comparative Example 3]
Neugen SD-70 in the basic solution B of Example 1 and Neugen SD-60 in the polyvalent metal salt aqueous solution C for in-line blending were both Neugen ET-106A (polyoxyalkylene alkyl ether: Daiichi Kogyo Seiyaku Co., Ltd.) An inkjet recording sheet of Comparative Example 3 was produced in the same manner as in Example 1 except that the product was changed to “made by Co., Ltd.”.

<Evaluation>
The following evaluation was performed about the surfactant used in the said Example and comparative example, and its coating solution. Along with the evaluation results, the surfactants used (water-soluble and water-insoluble), the cloud point of each surfactant, the HLB value, the content ratio of the fine particles and each surfactant in the coating liquid A-2 for ink receiving layer Are shown in Tables 1 and 2 below.

[Evaluation of coating solution]
The state of the coating liquid A-2 for ink-receiving layer prepared in each Example and Comparative Example was judged visually.

[Coating fluid viscosity]
The viscosity of the ink receiving layer coating liquid A-2 was measured by the following method.
A B-type viscometer (RB80 viscometer, manufactured by TOKI SANGYO Co., Ltd.) was used as a viscometer, and the temperature of the liquid was set to 30 ° C. and measurement was performed.

[Evaluation of coated surface]
The state of the coating layer formed by coating the coating liquid A-2 for ink-receiving layer was judged visually and evaluated according to the following criteria.
A: There are no streak and dent failures that can be visually identified.
○: There are no streak that can be visually discerned and a dent failure with a diameter of 0.3 mm or more.
△: There is no streak that can be easily discerned visually and a dent failure of 1 mm or more in diameter,
A repelling failure with a diameter of 1 mm or less occurred.
X: A streak that can be easily identified visually or a dent failure with a diameter of 1 mm or more occurs.

Claims (9)

An ink jet recording medium comprising an ink receiving layer containing fine particles, a hydrophilic binder, and a surfactant on a support,
The inkjet recording medium, wherein the surfactant is polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether, and the surfactant satisfies the following (1) or (2).
(1) When the solubility in water is 1% by mass or more, the cloud point of the 1% by mass aqueous solution is 30 ° C. or higher and the HLB value is 10.5 or higher.
(2) When the water solubility is less than 1% by mass, the cloud point of a 10% by mass solution in water / diethylene glycol monobutyl ether = 75/25 mixed solvent is 30 ° C. or higher and 80 ° C. or lower and the HLB value Is 10.5 or more and less than 15.   The ink jet recording medium according to claim 1, wherein the ink receiving layer contains a cationic substance.   The inkjet recording medium according to claim 1 or 2, wherein the surfactant is polyoxyethylene decyl ether or polyoxyethylene tridecyl ether.   The inkjet recording according to any one of claims 1 to 3, wherein the fine particles are vapor-phase method silica or vapor-phase method alumina, and a primary particle diameter of the fine particles is 1 nm or more and 30 nm or less. Media.   The inkjet recording medium according to any one of claims 1 to 4, wherein the ink receiving layer contains at least one water-soluble polyvalent metal salt.   6. The ink jet recording medium according to claim 1, wherein the ink receiving layer is formed using a coating liquid containing a cation-modified latex having a volume average particle diameter of 0.1 [mu] m or less. . It passes through the process of apply | coating the coating liquid formed by mixing microparticles | fine-particles, a hydrophilic binder, and surfactant on a support body, and forming a coating layer, It is described in any one of Claims 1-6. A method for producing an ink jet recording medium for obtaining a recording medium, comprising:
The method for producing an inkjet recording medium, wherein the surfactant is polyoxyalkylene decyl ether or polyoxyalkylene tridecyl ether.   An aqueous solution (a) in which the surfactant is dissolved, and a fine particle dispersion (b) obtained by mixing the fine particles, a cationic substance, and a hydrophilic binder are mixed in an in-line blend to be applied. The method for producing an ink jet recording medium according to claim 7, further comprising the steps of: forming a coating layer by coating the coating solution on a support. The method for producing an inkjet recording medium according to claim 7 or 8, wherein the coating layer is crosslinked and cured to form an ink receiving layer.
The coating layer formed by adding the crosslinking agent to the coating solution and / or the following basic solution and forming the coating layer by coating the coating solution, or by coating the coating solution. The coating layer is subjected to a basic solution having a pH of 7.1 or more applied to the coating layer at any time during the drying of the coating layer and before the coating layer exhibits a reduced rate of drying. A method for producing an inkjet recording medium.