JP2005093015A - Information media - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information medium having a printable layer which is high in handling safety and high in gloss and with which high sharpness can be obtained. <P>SOLUTION: The information medium has the printable layer including at least an underlayer and a color material receptive layer, wherein the color material receptive layer contains at least fine particles, a binder, and a crosslinking agent and the layer thickness of the underlayer is ≥15 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an information medium having a printable layer capable of printing characters and photographs.

As information media standards widely accepted in the market, there are CD (compact disc) and DVD (digital versatile disc).
CDs include a read-only CD-ROM, a write-once CD-R that can record information only once, and a rewritable CD-RW that can rewrite information any number of times.
In a CD-ROM, for example, pit rows are formed on a transparent substrate having a diameter of 120 mm and a thickness of 1.2 mm with a track pitch of 1.6 μm, a recording capacity of about 650 Mbytes, and a linear velocity of 1.2. Information is reproduced by irradiating with a laser beam having a wavelength of 770 to 790 nm, which is constant at ˜1.4 m / s.

On the other hand, DVDs include DVD-ROM, DVD-R, and DVD-RW as in the case of CD.
The DVD-ROM has a recording density of about 6 to 8 times that of a CD, and has a configuration in which two substrates having a thickness of about 0.6 mm are bonded together, and pits are formed at a track pitch of 0.74 μm. The information is reproduced by irradiating a laser beam having a wavelength of 635 to 650 nm with the linear velocity kept constant at about 3.5 m / s.

In recent years, in such CDs and DVDs, an information medium has been developed in which a printable layer is formed on the surface opposite to the information reproduction surface so that an image can be printed with an ink jet printer (for example, Patent Documents). 1). As a printable layer for such an information medium, an ultraviolet curable resin is generally used. However, a printable layer made of an ultraviolet curable resin has a problem that a high image quality cannot be obtained as compared with an inkjet recording sheet. It was. Specifically, for example, in a printable layer made of an ultraviolet curable resin, even when a base layer is provided, the base layer is as thin as about 10 μm and is sufficiently affected by the color of the dye on the recording layer located on the opposite side. There was a problem that a high brightness could not be obtained. As for high image quality, it has been proposed to define the lightness (L ^* ) and achieve its purpose (see, for example, Patent Documents 2 and 3), but no specific method has been proposed, The effect was not sufficient.
Further, the ultraviolet curable resin has skin irritation, and there is a problem in the safety of the material. Furthermore, the ultraviolet curable resin needs to be stored in a dark room at room temperature, has a short life, has an unpleasant odor, and has a problem in handling.
JP 2002-245671 A JP 2003-59112 A JP 2003-123323 A

An object of the present invention is to solve the conventional problems and achieve the following objects. That is,
An object of the present invention is to provide an information medium having a printable layer that has high handling safety, high gloss, and high image quality.

  Means for solving the above problems are as follows. That is,

<1> An information medium having a printable layer including at least a base layer and a color material receiving layer, wherein the color material receiving layer contains at least fine particles, a binder, and a crosslinking agent, An information medium characterized in that the layer thickness of the formation is 15 μm or more.

<2> The fine particles are at least one selected from gas phase method silica, pseudoboehmite, and aluminum oxide, the binder is polyvinyl alcohol, the crosslinking agent is a boron compound, and The information medium according to <1>, wherein the colorant receiving layer further contains a mordant.

<3> The color material receiving layer further includes a compound represented by the following general formula (1) and / or a compound represented by the following general formula (2): 2>.
RO (CH ₂ CH ₂ O) _n H General formula (1)
[In General Formula (1), R represents a C1-C12 saturated hydrocarbon group, a C1-C12 unsaturated hydrocarbon group, a phenyl group, or an acyl group. n represents an integer of 1 to 3. ]
_{RO (CH 2 CH (CH 3} ) O) n H General Formula (2)
[In General Formula (2), R represents a C1-C12 saturated hydrocarbon group, a C1-C12 unsaturated hydrocarbon group, a phenyl group, or an acyl group. n represents an integer of 1 to 3. ]

<4> The information medium according to <3>, wherein the compound represented by the general formula (1) and the compound represented by the general formula (2) are water-soluble.

<5> The information according to <3> or <4>, wherein, in the general formula (1) and the general formula (2), the R is a saturated hydrocarbon group having 1 to 4 carbon atoms. It is a medium.

<6> The color material-receiving layer is coated with a coating liquid containing the compound represented by the general formula (1) and / or the compound represented by the general formula (2), the fine particles, and the binder. A solution containing the cross-linking agent and the mordant in the coating layer simultaneously with the coating or in the course of drying the coating layer formed by the coating and before the coating layer exhibits a reduced rate of drying. The information medium according to any one of <3> to <5>, wherein the information layer is obtained by curing the coating layer.

<7> The compound represented by the general formula (1) and / or the compound represented by the general formula (2) and the bond to an aqueous dispersion composed of the fine particles and a dispersant. A coating solution obtained by adding and redispersing a solution containing an agent and the crosslinking agent is applied, and at the same time as the application or during the drying of the application layer formed by the application, the application layer is <3> to <5, wherein the coating layer is obtained by curing the coating layer after applying a solution containing the cross-linking agent and the mordant to the coating layer before exhibiting a reduced drying rate. > Is an information medium described in any of the above.

  According to the present invention, it is possible to provide an information medium having a printable layer with high handling safety, high gloss, and high image quality.

  The information medium of the present invention is an information medium having a printable layer including at least a base layer and a color material receiving layer, and the color material receiving layer contains at least fine particles, a binder, and a crosslinking agent. The underlayer has a thickness of 15 μm or more.

The information medium of the present invention can be applied to a magnetic medium, an optical medium, a semiconductor medium, and the like. The form may be a disk shape, a tape shape, or a cartridge storage type. In the case of a cartridge storage type, the information medium may be removable. preferable. In particular, an optical information recording medium (optical disk) is preferable as a disk-shaped medium.
In the case of an optical disc, it may be any one such as a CD, a DVD, an optical disc that is recorded and reproduced with a blue-violet laser.
In the case of a medium for recording with a blue-violet laser, there are a bonded type such as a DVD, and a type in which a recording layer and a cover layer are formed on a 1.1 mm substrate, and laser light is incident from the cover layer side. Either may be sufficient.
The place where the printable layer is formed is basically on the side opposite to the surface on which the laser light is incident, but the printable layer can be formed on the side where the laser light is incident as long as it is an area other than the incident area.
The information medium of the present invention may be any of a ROM type, a rewritable type, and a write-once type, but the write-once type is particularly preferable.

<Printable layer>
The information medium of the present invention has a printable layer including at least a base layer and a color material receiving layer. Hereinafter, each layer of the printable layer will be described.

[Underlayer]
In the present invention, the layer thickness of the underlayer is set to 15 μm or more. Thus, by making the layer thickness of the underlayer 15 μm or more, high smoothness can be obtained and gloss can be increased. More specifically, the gloss at 45 ° can be 30% or more.

  When a base layer having high opacity is provided, it has a diffusibility close to that of paper and image quality is improved. In particular, when a white underlayer is provided, color reproducibility can be improved. If the base layer has a high glossiness, it will look like a glossy photo, and if it has a high matteness, it will look like a matte photo. When the underlayer uses various colors, images with various impressions can be formed. In the case of a fluorescent underlayer, fluorescent image quality can be obtained.

  In the present invention, the layer thickness of the underlayer is 15 μm or more, more preferably 20 μm or more, and still more preferably 25 μm or more. Further, the upper limit of the thickness of the underlayer is preferably 50 μm.

  Although the formation method of the above foundation | substrate layers is not ask | required, it is preferable to form radiation curable resin by screen printing from a viewpoint of productivity. The radiation curable resin is a resin that is cured by electromagnetic waves such as ultraviolet rays, electron beams, X-rays, γ-rays, and infrared rays. Among them, ultraviolet rays and electron beams are preferable. Further, in order to make the base layer have a layer thickness of 15 μm or more, the screen printing / radiation curing process may be performed a plurality of times so that the total layer thickness becomes 15 μm or more. In other words, a plurality of layers less than 15 μm may be stacked to form 15 μm or more.

[Color material receiving layer]
As described above, the colorant receiving layer in the present invention has at least fine particles, a binder, and a crosslinking agent, and further includes a compound represented by the following general formula (1) and / or the following general formula ( The compound represented by 2), a mordant, and various additives may be included.

  Further, the colorant-receiving layer in the present invention is a known various surfactant having the purpose of improving coating suitability and surface quality, and a known surfactant having ionic conductivity for the purpose of suppressing frictional charge or peeling charge on the surface. An antioxidant, an ultraviolet absorber, and a sulfur-containing compound may be used in combination as long as the effects of the present invention are not impaired for the purpose of enhancing the anti-fading property.

(Fine particles)
As described above, the color material receiving layer in the present invention contains fine particles. Examples of the fine particles include vapor phase silica, pseudoboehmite, aluminum oxide, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, boehmite, and the like. Among these, gas phase method silica, pseudoboehmite, and aluminum oxide are preferable.

-Gas phase method silica-
Silica fine particles are generally roughly classified into wet 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 “gas phase method silica” means anhydrous silica fine particles obtained by the gas phase method.

The above-mentioned gas phase method silica is different from the above-mentioned 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 fine particle surface is high at 5 to 8 / nm ² , and the silica fine particles tend to aggregate (aggregate) easily. In the case of the method silica, the density of silanol groups on the surface of the fine particles is 2 to 3 / nm ² , so that it is sparse soft agglomeration (flocculate), resulting in a structure with a high porosity. Is done.

  The above-mentioned vapor phase silica has a particularly large specific surface area, so the ink absorption and retention efficiency is high, and the refractive index is low. It has a feature that it can be applied and a high color density and good color developability can be obtained.

  The average primary particle diameter of the vapor phase silica is preferably 30 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, and most preferably 3 to 10 nm. Since the vapor phase silica is easily adhered to each other by hydrogen bonding with a silanol group, a structure having a large porosity can be formed when the average primary particle diameter is 30 nm or less, and ink absorption characteristics are effectively improved. Can be improved.

  Also, other inorganic pigment fine particles such as hydrous silica fine particles, colloidal silica, titanium dioxide, barium sulfate, calcium silicate, zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, magnesium carbonate, calcium sulfate, boehmite, pseudoboehmite, etc. You may use together. When the other inorganic pigment fine particles and the vapor phase silica are used in combination, the content of the vapor phase silica in the total inorganic pigment fine particles is preferably 50% by mass or more, and more preferably 70% by mass or more.

-Pseudo boehmite-
Pseudoboehmite is represented by Al ₂ O ₃ .xH ₂ O (1 <x <2). In general, the crystal is a layered compound in which a (020) plane forms a huge plane, and its lattice constant d is 0. .67 nm. Here, the pseudo boehmite has a structure containing excess water between (020) plane layers. Pseudoboehmite absorbs and fixes ink well and can improve ink absorbency and aging blur.
In addition, since a smooth layer can be easily obtained, it is preferable to use sol-like pseudoboehmite (pseudoboehmite sol) as a raw material.

The primary average particle size of pseudoboehmite is preferably 50 nm or less, more preferably 30 nm or less, and particularly preferably in the range of 20 to 3 nm. When the average primary particle size of the pseudo boehmite is within the above range, a structure having a large porosity can be formed, and ink absorbability of the colorant receiving layer can be further improved. In addition, the said average primary particle diameter can be measured using an electron microscope, for example. Moreover, as a BET specific surface area of pseudo boehmite, 40-500 m < ² > is preferable and 200-500 m < ² > is still more preferable.

  Furthermore, the aspect ratio of the pseudo boehmite is preferably 3 to 10. About the pore structure of pseudo boehmite, the average pore radius is preferably 1 to 30 nm, and more preferably 2 to 15 nm. The pore volume is preferably 0.3 to 2.0 ml / g (cc / g), more preferably 0.5 to 1.5 ml / g (cc / g). Here, the pore radius and pore volume are measured by a nitrogen adsorption / desorption method, and can be measured by, for example, a gas adsorption / desorption analyzer (for example, trade name “Omni Soap 369” manufactured by Coulter). .

Pseudoboehmite is preferably used by being dispersed in an aqueous solvent. The pseudo boehmite content in the dispersion when used in a dispersed state is preferably 60% by mass or less, more preferably 5 to 60% by mass, and particularly preferably 10 to 50% by mass.
Pseudoboehmite can be dispersed particularly effectively within the above range, and for example, effectively suppresses thickening and gelation caused by the shortened inter-particle distance between pseudoboehmite during dispersion. Can do.

The content ratio (S: A) of the pseudoboehmite (A) and the vapor phase silica (S) used in combination with the pseudoboehmite (A) is preferably in the range of 95: 5 to 5:95, and 80:20 to 20:80. A range is more preferable, and a range of 70:30 to 30:70 is particularly preferable.
When the vapor phase method silica and pseudoboehmite are used in combination within the range of the content ratio, it is possible to effectively prevent aging blur of all the inks of a plurality of colors without depending on the hue, even in the case of forming a multicolor image. A high-resolution and vivid image can be formed and maintained.

-Aluminum oxide-
Examples of the aluminum oxide in the present invention include anhydrous alumina such as α-alumina, δ-alumina, θ-alumina, and χ-alumina, and active aluminum oxide. Among these, preferable alumina fine particles are δ-alumina, and from the viewpoint of the production method, alumina fine particles produced by a gas phase method, that is, in the presence of water generated during an oxyhydrogen reaction, and Vapor phase alumina fine particles obtained by hydrolyzing gaseous metal chloride at a temperature characteristic of such a reaction are preferred because of their large specific surface area.

  As the form of the aluminum oxide, for example, fine particles having a predetermined particle diameter, fine particles, fine particles, powder, fine powder, fine powder and the like can be adopted, and the average primary particle diameter is 200 nm or less. Preferably, it is 5-100 nm, more preferably 5-20 nm. When the average primary particle diameter of the alumina fine particles is within the above range, a structure having a large porosity can be formed, and ink absorbability of the colorant receiving layer can be further improved. In addition, the said average primary particle diameter can be measured using an electron microscope, for example.

  In the present invention, aluminum oxide is preferably used by being dispersed in a dispersion. The content of aluminum oxide in the dispersion is preferably 60% by mass or less, more preferably 5 to 60% by mass, and particularly preferably 10 to 50% by mass. When the content of aluminum oxide is within the above range, aluminum oxide can be more effectively dispersed. When the content of aluminum oxide in the dispersion is at most 60% by mass, for example, thickening or gelation caused by shortening the inter-particle distance between aluminum oxide fine particles in the dispersion, etc. It can be effectively suppressed. In addition, a cationic polymer having primary to tertiary amino groups and salts thereof, and a quaternary ammonium base may be added to the dispersion as an aggregation inhibitor. The addition amount of the aggregation inhibitor is preferably 1 to 10% by mass, more preferably 1 to 5% by mass with respect to the aluminum oxide fine particles. When the addition amount is less than 1% by mass, the dispersibility may be inferior. When the addition amount exceeds 10% by mass, the color density may decrease when printed on the colorant receiving layer, which is not preferable.

  The solid content in the colorant receiving layer of aluminum oxide is preferably 50% by mass or more, and more preferably 60% by mass or more. When the content exceeds 60% by mass, it is possible to form a better porous structure, and it is preferable because a colorant receiving layer having sufficient ink absorbability can be obtained. Here, the solid content in the colorant receiving layer of aluminum oxide is a content calculated based on components other than water in the composition constituting the colorant receiving layer.

In the present invention, aluminum oxide and other fine particles may be used in combination. When the other fine particles and the aluminum oxide are used in combination, the content of aluminum oxide in the present invention in all fine particles is preferably 30% by mass or more, and more preferably 50% by mass or more.
The other fine particles may be either organic fine particles or inorganic fine particles, but inorganic fine particles are preferable from the viewpoint of ink absorbability and image stability.

[Binder]
As described above, in the present invention, the colorant receiving layer contains a binder. As the binder, a water-soluble resin is preferable.

Examples of the water-soluble resin include, for example, a polyvinyl alcohol resin that is a resin having a hydroxyl group as a hydrophilic structural unit [for example, polyvinyl alcohol (PVA), acetoacetyl-modified PVA, cation-modified PVA, anion-modified PVA, silanol-modified PVA, Polyvinyl acetals, etc.], cellulose resins [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, etc.], chitins , Chitosans, starch, resins having an ether bond [eg, polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene Recall (PEG), poly ether (PVE)] and resins having carbamoyl groups [e.g., polyacrylamide (PAAM), polyvinyl pyrrolidone (PVP), polyacrylic acid hydrazide, etc.] and the like.
Further, as the water-soluble resin, polyacrylates having a carboxy group as a dissociable group, maleic acid resins, alginates, gelatins, and the like can also be used.

Among these, polyvinyl alcohol (PVA) resin is particularly preferable. Examples of the polyvinyl alcohol include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432, Japanese Patent Publication No. 7-29479, Japanese Patent No. 2537827, Japanese Patent Publication No. 7-57553, Japanese Patent No. 2502998, and Japanese Patent No. 3053231. JP-A-63-176173, JP-A-2604367, JP-A-7-276787, JP-A-9-207425, JP-A-11-58941, JP-A-2000-135858, JP-A-2001-205924, JP 2001-287444, JP 62-278080, JP 9-39373, JP 2750433, JP 2000-18801, JP 2001-213045, JP 2001-328345, JP 8 -324105, JP-A-11-348417, etc. It can be.
Examples of water-soluble resins other than polyvinyl alcohol resins include compounds described in paragraph numbers [0011] to [0014] of JP-A No. 11-165461.

  These water-soluble resins may be used alone or in combination of two or more. Moreover, in this invention, as content of the said water-soluble resin, 9-40 mass% is preferable with respect to the total solid content mass of a color material receiving layer, and 12-33 mass% is more preferable.

  In addition, the polyvinyl alcohol resin may be used in combination with the other water-soluble resin. When the other water-soluble resin and the polyvinyl alcohol-based resin are used in combination, the content of the polyvinyl alcohol-based resin in the total water-soluble resin is preferably 50% by mass or more, and more preferably 70% by mass or more.

The polyvinyl alcohol has a hydroxyl group in the structural unit. The hydroxyl group and a silanol group on the surface of the silica fine particle form a hydrogen bond to form a three-dimensional network structure in which the secondary particle of the silica fine particle is a chain unit. Make it easier. It is considered that a color material receiving layer having a porous structure with a high porosity can be formed by forming the three-dimensional network structure.
In inkjet recording, the porous colorant-receiving layer obtained as described above can rapidly absorb ink by capillary action and form dots with good roundness without ink blurring.

  From the viewpoint of transparency, PVA having a saponification degree of 70 to 99% is more preferable, and PVA having a saponification degree of 80 to 99% is particularly preferable.

(Content ratio of fine particles to water-soluble resin)
The mass content ratio [PB ratio (x / y)] of the fine particles (x) and the water-soluble resin (y) in the color material receiving layer has a great influence on the film structure and film strength of the color material receiving layer. give. That is, when the mass content ratio [PB ratio] increases, the porosity, pore volume, and surface area (per unit mass) increase, but the density and strength tend to decrease.

  In the colorant receiving layer according to the present invention, the mass content ratio [PB ratio (x / y)] prevents the film strength from being reduced and cracks caused by drying due to the PB ratio being too large, In addition, when the PB ratio is too small, the voids are easily blocked by the resin, and from the viewpoint of preventing the ink absorbability from being lowered due to the decrease in the void ratio, 1.5 / 1 to 10/1. Is preferred.

  Since stress may be applied to the information medium when passing through the conveyance system of the ink jet recording printer, the colorant receiving layer preferably has sufficient film strength. In the case of cutting into a sheet shape, it is preferable that the color material receiving layer has sufficient film strength in order to prevent the color material receiving layer from being cracked or peeled off. In consideration of these cases, the PB ratio (x / y) is more preferably 5/1 or less, while it is 2: 1 or more from the viewpoint of ensuring high-speed ink absorbability in an inkjet recording printer. Is more preferable.

Specifically, for example, a gas phase method silica fine particle having an average primary particle diameter of 20 nm or less and a water-soluble resin are completely dispersed in an aqueous solution at a PB ratio (x / y) of 2/1 to 5/1. When the liquid is coated on a support and the coating layer is dried, a three-dimensional network structure is formed in which secondary particles of silica fine particles are network chains, the average pore diameter is 30 nm or less, and the porosity is 50 to 80. %, A translucent porous film having a pore specific volume of 0.5 ml / g or more and a specific surface area of 100 m ² / g or more can be easily formed.

[Crosslinking agent]
The colorant receiving layer includes a cross-linking agent that can cross-link the binder. By containing a crosslinking agent, it can be set as the porous layer hardened | cured by the crosslinking reaction of a crosslinking agent and a binder.

Boron compounds are preferred for crosslinking the water-soluble resin, particularly polyvinyl alcohol. 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 , two Borate (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. Among them, Of these, borax, boric acid, and borate are preferable, and boric acid is particularly preferable in that a crosslinking reaction can be promptly caused.

Compounds other than the above boron compounds can also be used as a crosslinking agent for the water-soluble resin. For example,
Aldehyde compounds such as formaldehyde, glyoxal, succinaldehyde, glutaraldehyde, dialdehyde starch, dialdehyde derivatives of vegetable gum; ketones such as diacetyl, 1,2-cyclopentanedione, 3-hexene-2,5-dione Compounds; active halogen compounds such as bis (2-chloroethyl) urea, bis (2-chloroethyl) sulfone, 2,4-dichloro-6-hydroxy-s-triazine sodium salt; divinylsulfone, 1,3-bis (vinyl) Sulfonyl) -2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide), divinylketone, 1,3-bis (acryloyl) urea, 1,3,5-triacryloyl-hexahydro-s-triazine, etc. Active vinyl compounds; dimethylolurea, methylol N-methylol compounds such as methylhydantoin; melamine compounds such as trimethylol melamine, alkylated methylol melamine, melamine, benzoguanamine, melamine resin; ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, diglycerin poly Epoxy compounds such as glycidyl ether, spiroglycol diglycidyl ether, polyglycidyl ether of phenol resin;

Isocyanate compounds such as 1,6-hexamethylene diisocyanate and xylylene diisocyanate; aziridine compounds described in U.S. Pat. Nos. 3,017,280 and 2,983611; and U.S. Pat. No. 3,100,704 Carbodiimide compounds; Ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; Halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; 2,3-dihydroxydioxane and the like Dioxane compounds; metal-containing compounds such as titanium lactate, aluminum sulfate, chromium alum, potash alum, zirconyl acetate and chromium acetate; polyamine compounds such as tetraethylenepentamine; hydrazide compounds such as adipic acid dihydrazide; 2 oxazoline groups Including more than Low molecule or polymer having: anhydride of polyvalent acid, acid described in US Pat. No. 2,725,294, US Pat. No. 2,725,295, US Pat. No. 2,726,162, US Pat. No. 3,834,902, etc. Examples include chloride and bissulfonate compounds; active ester compounds described in US Pat. No. 3,542,558, US Pat. No. 3,251972, and the like.
Said crosslinking agent may be used individually by 1 type, and can also be used in combination of 2 or more type.

  The crosslinking agent is applied at the same time as the coating liquid for forming the porous color material receiving layer (color material receiving layer coating liquid) is applied, or by applying the color material receiving layer coating liquid. Preferably, this is done before the coated layer reaches the reduced rate of drying. By this operation, it is possible to effectively prevent the occurrence of cracks that occur during the drying of the coating layer. That is, the boron compound solution (crosslinking agent solution) penetrates into the coating layer at the same time as the coating solution is applied or before the coating layer shows a decreasing rate of drying rate, and the polyvinyl alcohol in the coating layer rapidly. The film strength of the coating layer is immediately and significantly improved by gelling (curing) polyvinyl alcohol.

  In the present invention, the binder and the compound represented by the general formula (1) and / or the compound represented by the general formula (2) are added to the aqueous dispersion composed of the vapor phase silica and the dispersant. A coating solution obtained by adding and redispersing a solution containing (a first solution) is applied to the surface of the underlayer, and simultaneously with the coating or during the drying of the coating layer formed by the coating In addition, a method of forming a colorant receiving layer by applying a solution containing a mordant (second solution) to the coating layer before the coating layer exhibits a decreasing rate of drying can be suitably used. . When using this method, it is preferable to add a crosslinking agent to both the first solution added to the coating solution and the second solution to be applied later.

When gelatin is used in combination with the polyvinyl alcohol, the following compounds, which are known as gelatin hardeners, can be used in combination with a boron compound 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;

Isocyanate compounds such as 1,6-hexamethylene diisocyanate; aziridine compounds described in US Pat. Nos. 3,017,280 and 2,983611; 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; chromium alum, potash alum, zirconium sulfate, chromium acetate and the like. In this case, when using the said boron compound and another crosslinking agent together, 50 mass% or more is preferable and, as for content of the boron compound in all the crosslinking agents, 70 mass% or more is more preferable.
In addition, the said boron compound may be single 1 type, or may combine 2 or more types.

When the boron compound is applied, the solution is prepared by dissolving the boron compound in water and / or an organic solvent.
As a density | concentration of the boron compound in the said boron compound solution, 0.05-10 mass% is preferable with respect to the mass of a boron compound solution, and 0.1-7 mass% is especially preferable.
As a solvent constituting the boron compound solution, water is generally used, and an aqueous mixed solvent containing an organic solvent miscible with water may be used.
As said organic solvent, if a boron compound melt | dissolves, it can be used arbitrarily, For example, alcohol, such as methanol, ethanol, isopropyl alcohol, and glycerol; Ketone, such as acetone and methyl ethyl ketone; Methyl acetate, ethyl acetate, etc. An aromatic solvent such as toluene; an ether such as tetrahydrofuran; and a halogenated carbon-based solvent such as dichloromethane.

(mordant)
In the present invention, a mordant is preferably contained in the colorant receiving layer in order to further improve the water resistance and aging resistance of the formed image.
As the mordant, a cationic polymer (cationic mordant) is preferable. When the mordant is present in the colorant receiving layer, the mordant interacts with a liquid ink having an anionic dye as a colorant to change the colorant. It can stabilize and improve water resistance and aging blur.

  However, if this is added directly to the coating solution for forming the colorant-receiving layer, there is a concern that it will agglomerate with vapor phase silica having an anionic charge, but it is prepared and applied as an independent separate solution. If the method is used, there is no need to worry about aggregation of inorganic pigment fine particles. Therefore, in the present invention, it is preferable to use by containing in a solution (for example, a crosslinking agent solution) different from the above-mentioned vapor-phase process silica.

As the cationic mordant, 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. it can.
Examples of the polymer mordant include a homopolymer of a monomer having a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base (mordant monomer), and the mordant monomer and other monomers (hereinafter, What is obtained as a copolymer or condensation polymer with "non-mordant monomer") is preferred. These polymer mordants can be used in any form of a 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 for their anions.

  Specifically, for example, 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) ethyl Ammonium chloride, trimethyl-2- (acryloylamino) ethylammonium chloride, triethyl-2- ( Acryloylamino) ethylammonium chloride, trimethyl-3- (methacryloylamino) propylammonium chloride, triethyl-3- (methacryloylamino) propylammonium chloride, trimethyl-3- (acryloylamino) propylammonium chloride, triethyl-3- (acryloyl) Amino) 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.
In addition, examples of copolymerizable monomers include N-vinylimidazole and N-vinyl-2-methylimidazole.

The non-mordant monomer does not include 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, for example, 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 a polymer mordant, polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethyleneimine, polyallylamine, polyallylamine hydrochloride, polyamide-polyamine resin, cationized starch, dicyandiamide formalin condensate Dimethyl-2-hydroxypropylammonium salt polymer, polyamidine, polyvinylamine and the like can also be mentioned as preferable examples.

  The molecular weight of the polymer mordant is preferably 1000 to 200000 in terms of weight average molecular weight, and more preferably 3000 to 60000 in terms of weight average molecular weight. When the molecular weight is in the range of 1,000 to 200,000, water resistance does not become insufficient, and it is possible to prevent the viscosity from becoming excessively high and handling suitability from being lowered.

  As the cationic non-polymer mordant, for example, water-soluble metal salts such as aluminum sulfate, aluminum chloride, polyaluminum chloride, and magnesium chloride are preferable.

(Compound represented by general formula (1) and general formula (2))
The information medium of the present invention preferably further contains a compound represented by the following general formula (1) and / or a compound represented by the following general formula (2) in the colorant-receiving layer. The compounds represented by the following general formula (1) and the following general formula (2) are high-boiling solvents.

RO (CH ₂ CH ₂ O) _n H General formula (1)
[In General Formula (1), R represents a C1-C12 saturated hydrocarbon group, a C1-C12 unsaturated hydrocarbon group, a phenyl group, or an acyl group. n represents an integer of 1 to 3. ]
_{RO (CH 2 CH (CH 3} ) O) n H General Formula (2)
[In General Formula (2), R represents a C1-C12 saturated hydrocarbon group, a C1-C12 unsaturated hydrocarbon group, a phenyl group, or an acyl group. n represents an integer of 1 to 3. ]

A colorant receiving layer at the time of forming a three-dimensional network structure (porous structure) by including in the colorant receiving layer the compound represented by the general formula (1) and / or the compound represented by the general formula (2) Drying shrinkage can be suppressed. This is because the compounds represented by the general formula (1) and the general formula (2) moderately inhibit the hydrogen bond between the silanol group on the vapor phase silica surface and the hydroxyl group of polyvinyl alcohol. It is estimated that drying shrinkage is alleviated. As a result, the colorant receiving layer can be prevented from cracking when the three-dimensional network structure is formed, and the production yield and quality of the information medium can be improved.
In addition, by using a fine particle, polyvinyl alcohol, boron compound and mordant in combination with the colorant receiving layer, it is possible to improve glossiness, ink absorptivity, aging resistance, light resistance, printing density (maximum density), and the like. .

In the above general formulas (1) and (2), R represents a saturated hydrocarbon group having 1 to 12 carbon atoms, an unsaturated hydrocarbon group having 1 to 12 carbon atoms, a phenyl group, or an acyl group. 4 saturated hydrocarbon groups are preferred.
The saturated hydrocarbon group has 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. Examples of the saturated hydrocarbon group include an alkyl group and an alicyclic hydrocarbon group. The saturated hydrocarbon group may be substituted with a substituent. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group, and a methyl group, an ethyl group, a propyl group, and a butyl group are preferable.

  The unsaturated hydrocarbon group has 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. Examples of the unsaturated hydrocarbon group include alkenyl groups and alkynyl groups. The unsaturated hydrocarbon group may be substituted with a substituent. Specific examples include a vinyl group, an allyl group, an ethynyl group, a 1,3-butadienyl group, a 2-propynyl group, and the like, and an allyl group is preferable.

  As said acyl group, a C1-C8 acyl group is preferable and a 1-4 acyl group is more preferable. The acyl group may be substituted with a substituent. Specific examples include an acetyl group, a propionyl group, a butyryl group, and a valeryl group, and a butyryl group is preferable.

In the said General Formula (1) and (2), n represents the integer of 1-3 and 2 or 3 is preferable.
As the compounds represented by the general formulas (1) and (2), water-soluble compounds are preferable. Here, “water-soluble” means one that is soluble in water by 1% by mass or more. Specific examples of the compounds represented by the general formulas (1) and (2) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monoallyl ether, Ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monododecyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, propylene glycol Monomethyl ether, pro Glycol monoethyl ether, include propylene glycol monobutyl ether and the like, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether are preferred.

The compounds represented by the general formula (1) and the general formula (2) may contain at least one kind thereof in the colorant receiving layer. Therefore, the compound represented by the general formula (1) or (2) may be contained alone or in combination of two or more, and the compounds represented by the compounds represented by the general formulas (1) and (2) are used in combination. May be. When the compound [x] represented by the general formula (1) and the compound [y] represented by the general formula (2) are used in combination, the mixing ratio (mass ratio; x: y) is not particularly limited. , Preferably 100: 1 to 100: 100, more preferably 100: 10 to 100: 50. Moreover, as total content of the compound represented by General formula (1) and (2) contained in a color material receiving layer, 0.1-5.0 g / m < ² > is preferable and 0.2-3. 0 g / m ² is more preferable.

(Other ingredients)
The color material receiving layer may contain the following components as needed.
For the purpose of suppressing the deterioration of the 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 at least one of 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 Publication No. 223739, Publication No. 309401, Publication No. 309402, Publication No. 310551, Publication No. 310552, Publication No. 4594416, Publication of German Patent No. 3435443, JP-A-54-48535, JP-A-60-107384, JP-A-60-107383, JP-A-60-125470, JP-A-60-125471, JP-A-60-125472, JP-A-60-287485. 60-287486, 60-287487, 60-287488, 61-160287, 61-185483, 61-2111079, 62-146678, 62-146680, 62-146679, 62-282885, 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-4-29185, JP-A-4-291684, JP-A-5-61166, JP-A-5-119449, 5-188687, 5-188686, 5-110490, 5-110437, 5-170361, JP 48-43295, 48-33212, Examples thereof include those described in U.S. Pat. Nos. 4,814,262 and 4,980,275.

  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.

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

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.

(Formation of colorant receiving layer)
As described above, it is preferable that a mordant is introduced into the colorant receiving layer in the course of applying the above-described crosslinking agent solution. That is, the color material receiving layer is a coating liquid containing a compound represented by the general formula (1) and / or a compound represented by the general formula (2), fine particles, and a binder (coloring material receiving layer coating liquid). The coating layer contains a cross-linking agent and a mordant before or after the coating layer is dried and before the coating layer exhibits a reduced drying rate. It is preferably formed by a method (WOW method; Wet On Wet method) of applying a solution (crosslinking agent solution) and then crosslinking and curing the coating layer to which the solution is applied. In this method, the pH of the coating solution for the colorant receiving layer is 8.0 to 10.0, indicating alkalinity.

  In addition, the color material receiving layer of the information medium of the present invention comprises a barrier material made of a material that does not react with the crosslinking agent (the solution containing the crosslinking agent or the barrier solution). The mordant is contained in at least one of them)) and can be obtained by simultaneously applying and curing on the underlayer.

  As described above, in the present invention, the water resistance of the colorant receiving layer can be improved by simultaneously applying the mordant together with the crosslinking agent (boron compound). That is, when the mordant is added to the coating material for the colorant-receiving layer, the mordant is cationic, so that aggregation may occur in the presence of gas phase method silica having an anionic charge on the surface. If the solution containing the coating solution and the coating solution for the colorant receiving layer are prepared independently and applied individually, it is not necessary to consider the aggregation of the vapor phase silica, and the range of mordant selection is expanded.

In the present invention, a coating material for a colorant receiving layer containing at least a compound represented by the general formula (1) and / or a compound represented by the general formula (2), vapor phase silica and polyvinyl alcohol, It can be prepared as follows.
That is, by adding gas phase method silica in water (for example, 10 to 20% by mass) and using a high-speed rotating wet colloid mill (for example, CLEARMIX (M Technique Co., Ltd.)), for example, 10,000 rpm (preferably Is dispersed under high speed rotation conditions of 5000 to 20000 rpm for 20 minutes (preferably 10 to 30 minutes), and then an aqueous polyvinyl alcohol solution (for example, PVA having a mass of about 1/3 that of vapor phase silica). In addition, a compound represented by the general formula (1) and / or a compound represented by the general formula (2) is added, and the mixture is dispersed under the same rotation conditions as described above. The obtained coating solution is a uniform sol, and a porous colorant receiving layer having a three-dimensional network structure can be formed by coating and forming this on the underlayer by the following coating method. As the dispersion treatment method, various conventionally known dispersers such as a high-speed rotating disperser, a medium stirring disperser (ball mill, sand mill, etc.), an ultrasonic disperser, a colloid mill disperser, and a high pressure disperser are used. However, in the present invention, a colloid mill disperser or a high-pressure disperser is preferably used from the viewpoint of efficiently dispersing the formed fine particles.

If necessary, a surfactant, a pH adjuster, an antistatic agent, and the like can be further added to the colorant-receiving layer coating solution.
Application of the colorant receiving layer coating solution is, for example, contact coating such as bar coating, roll coating, blade coating, screen coating, and tampo coating, and non-contact coating such as spray coating, spin coating, curtain coating, and dip coating. Can be performed.

  When applying by spray coating, the pressure is preferably 1.013 to 2026 hPa, more preferably 50.65 to 1013 hPa, and still more preferably 101.3 to 506.5 hPa. The spread angle of the spray is preferably 1 to 120 °, more preferably 10 to 60 °, and still more preferably 20 to 50 °. As a liquid particle size, 0.1-1000 micrometers is preferable, 1-500 micrometers is more preferable, and 10-100 micrometers is further more preferable. The distance from the work (information medium) is preferably 1 to 1000 mm, more preferably 10 to 200 mm, and still more preferably 30 to 100 mm. As temperature, 10-40 degreeC is preferable, 15-35 degreeC is more preferable, and 20-30 degreeC is further more preferable. As humidity, 5-70% RH is preferable, 10-40% RH is more preferable, 20-50% RH is further more preferable.

  When applying by spin coating, the viscosity of the coating solution is preferably 0.1 to 10,000 mPa · s, more preferably 1 to 6000 mPa · s, and still more preferably 10 to 3000 mPa · s. The first liquid (coloring material-receiving layer coating liquid) is preferably 50 to 10,000 mPa · s, more preferably 100 to 6000 mPa · s, and even more preferably 200 to 3000 mPa · s in order to ensure the thickness. The second liquid (crosslinking agent solution) is preferably 0.1 to 1000 mPa · s, more preferably 1 to 500 mPa · s, and still more preferably 2 to 300 mPa · s in order to ensure the uniformity of the coating film. The number of rotations is preferably 10 to 1000 rpm, more preferably 50 to 600 rpm, and even more preferably 100 to 400 at the time of dispensing. At the time of swing-off, the number of rotations is gradually increased, and the method of raising may be step or gentle. Specifically, it is preferably 100 to 10000 rpm, more preferably 200 to 5000 rpm, and more preferably 300 to 3000 rpm. More preferably. As for the shape of a nozzle, it is preferable that length is 1-100 mm, It is more preferable that it is 5-50 mm, It is further more preferable that it is 10-30 mm. The inner diameter of the nozzle is preferably 0.1 to 5 mm, more preferably 0.3 to 3 mm, and still more preferably 0.5 to 2 mm. The wall thickness of the nozzle is preferably 0.1 to 1 mm, and more preferably 0.2 to 0.5 mm. Moreover, you may install a nozzle diagonally along a flow. The distance from the workpiece is preferably 0.5 to 100 mm, more preferably 1 to 50 mm, and even more preferably 2 to 20 mm. As temperature, 10-40 degreeC is preferable, 15-35 degreeC is more preferable, and 20-30 degreeC is further more preferable. As humidity, 5-70% RH is preferable, 10-40% RH is more preferable, 20-50% RH is further more preferable.

  After coating the colorant-receiving layer coating solution, a crosslinking agent solution is applied to the coating layer, but the crosslinking agent solution is applied before the coating layer after coating reaches the reduced rate of drying. May be. That is, after the coating material for the colorant receiving layer is applied, it is preferably manufactured by introducing the boron compound and the mordant while the coating layer exhibits a constant rate of drying.

  Here, “before the coating layer comes to exhibit a reduced rate of drying” usually refers to several minutes immediately after the application of the colorant-receiving layer coating solution, and during this time, the solvent in the coated coating layer The constant rate drying rate which is a phenomenon in which the content of is decreased in proportion to time. About the time which shows this constant rate drying rate, it describes in chemical engineering manual (p.707-712, Maruzen Co., Ltd. issue, October 25, 1980).

  As described above, after application of the colorant-receiving layer coating solution, the coating layer is dried until the coating layer exhibits a reduced rate of drying. Details of the drying conditions will be described below.

The coloring material receiving layer may be dried by any drying method such as natural drying, warm air drying, infrared / far infrared drying, high frequency drying, oven drying, and the like.
In the case of natural drying, the drying time of the first liquid (coloring material receiving layer coating liquid) is preferably 0.1 to 10000 seconds, more preferably 1 to 1000 seconds, and more preferably 10 to 500 seconds. More preferably. The drying time of the second liquid (crosslinking agent solution) is preferably 1 to 10000 minutes, more preferably 5 to 1000 minutes, and even more preferably 10 to 200 minutes. The drying temperature is preferably 0 to 40 ° C, more preferably 10 to 35 ° C, and further preferably 20 to 30 ° C. The drying humidity is preferably 10 to 70% RH, more preferably 20 to 60% RH, and further preferably 30 to 50% RH.

  In the case of warm air drying, the drying time of the first liquid is preferably 0.1 to 5000 seconds, more preferably 1 to 1000 seconds, and further preferably 10 to 500 seconds. The drying temperature is preferably 40 to 200 ° C, more preferably 60 to 150 ° C, and further preferably 80 to 130 ° C. The drying humidity is preferably 0.01 to 50% RH, more preferably 0.1 to 30% RH, and further preferably 1 to 20% RH.

In the case of infrared / far-infrared drying, the drying time of the first liquid is preferably 0.1 to 1000 seconds, more preferably 1 to 500 seconds, and further preferably 10 to 300 seconds. preferable. The drying time of the second liquid is preferably 1 to 2000 seconds, more preferably 10 to 1000 seconds, and further preferably 30 to 500 seconds. The output is preferably 10 to 2000 W, more preferably 50 to 1500 W, and even more preferably 100 to 1000 W.
The drying conditions for high-frequency drying are the same as those for infrared / far-infrared drying.

  In the case of oven drying, the drying time of the first liquid is preferably 0.1 to 1000 seconds, more preferably 1 to 500 seconds, and further preferably 10 to 300 seconds. The drying time of the second liquid is preferably 1 to 2000 seconds, more preferably 10 to 1000 seconds, and further preferably 30 to 500 seconds.

  As a method of giving before the said coating layer comes to show a decreasing rate drying rate, (1) The method of further apply | coating a crosslinking agent solution on a coating layer, (2) The method of spraying by methods, such as spray, ( 3) A method of immersing the substrate on which the coating layer is formed in the crosslinking agent solution, and the like.

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

As a coating amount of the crosslinking agent solution containing at least a boron compound and a mordant provided on the colorant receiving layer, 0.01 to 10 g / m ^{2 in} terms of boron compound is generally used, and 0.05 to 5 g. / M ² is preferred.

After the application of the crosslinking agent solution, it is generally heated at 40 to 180 ° C. for 0.5 to 30 minutes, and dried and cured. Especially, it is preferable to heat at 40-150 degreeC for 1 to 20 minutes.
For example, when borax or boric acid is used as the boron compound contained in the crosslinking agent solution, heating at 60 to 100 ° C. is preferably performed for 5 to 20 minutes.

Moreover, you may provide the said crosslinking agent coating liquid simultaneously with apply | coating a color material receiving layer coating liquid.
In this case, the colorant receiving layer coating solution and the cross-linking agent solution are applied simultaneously (multilayer coating) on the base layer so that the colorant receiving layer coating solution is in contact with the base layer, and then dried and cured. A material receiving layer can be formed.

The simultaneous application (multilayer application) can be performed, for example, by an application method using an extrusion die coater or a curtain flow coater. After the simultaneous application, the formed application layer is dried. In this case, the drying is generally performed by heating the application layer at 40 to 150 ° C. for 0.5 to 10 minutes, preferably 40 to 100. It is carried out by heating at a temperature of 0.5 to 5 minutes.
For example, when borax or boric acid is used as the boron compound contained in the crosslinking agent solution, it is preferably heated at 60 to 100 ° C. for 5 to 20 minutes.

  When the above simultaneous coating (multilayer coating) is performed by, for example, an extrusion die coater, two types of coating liquid discharged at the same time are formed near the discharge port of the extrusion die coater, that is, before moving onto the underlayer. In this state, a multilayer coating is applied on the base layer. Since the two-layer coating liquid layered before coating is likely to cause a crosslinking reaction at the interface between the two liquids when moving to the base layer, the two liquids to be ejected are mixed in the vicinity of the discharge port of the extrusion die coater. This may increase the viscosity and hinder the application operation. Therefore, when simultaneously coating as described above, a barrier layer solution (intermediate layer solution) made of a material that does not react with the crosslinking agent, in addition to the coating solution of the colorant-receiving layer and the crosslinking agent solution containing the boron compound and the mordant. ) Is preferably applied simultaneously between the two liquids.

The barrier layer liquid can be selected without particular limitation as long as it does not react with the boron compound and can form a liquid film. For example, an aqueous solution containing a trace amount of a water-soluble resin that does not react with a boron compound, water, and the like can be given. The water-soluble resin is used in consideration of coatability for the purpose of a thickener and the like, for example, hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose, polyvinylpyrrolidone, gelatin And the like.
The barrier layer solution may contain the above mordant.

  The colorant-receiving layer in the present invention is represented by the compound represented by the general formula (1) and / or the general formula (2) in an aqueous dispersion composed of the vapor phase silica and the dispersant. A coating solution obtained by adding and redispersing a solution containing the compound, the polyvinyl alcohol and the boron compound (first solution) is applied to the surface of the base layer, and formed simultaneously with the coating or by the coating. In the middle of drying of the applied layer, before the applied layer exhibits a decreasing rate of drying, after applying a solution (second solution) containing the boron compound and the mordant to the applied layer, You may form by the method of hardening the said application layer. In the method, the pH of the first solution forming the colorant receiving layer is 2.5 to 4.0, indicating acidity. Use of this method is preferable because glossiness and print density are improved.

  As the dispersant, a cationic polymer can be used. As the cationic polymer, a homopolymer of a monomer having a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base, exemplified as the above-mentioned mordant, Those obtained as copolymers or condensation polymers with other monomers can be suitably used. These dispersants are preferably used in the form of a water-soluble polymer.

  The molecular weight of the dispersant is preferably 1000 to 200000, more preferably 3000 to 60000 in terms of weight average molecular weight. If the molecular weight is less than 1000, the dispersibility may be inferior, and if it exceeds 200,000, the viscosity of the aqueous dispersion may increase. The amount of the dispersant added to the vapor phase silica is preferably 1% to 30%, more preferably 3% to 20%. If the addition amount is less than 1%, the dispersibility may be inferior, and if it exceeds 30%, the color density may decrease when printing on the colorant receiving layer, which is not preferable.

In addition, the preparation of the aqueous dispersant composed of the above-mentioned vapor phase method silica and a dispersant may be performed by preparing a gas phase method silica aqueous dispersion in advance and adding the aqueous dispersion to the aqueous dispersant solution. May be added to the vapor phase silica aqueous dispersion or may be mixed at the same time. Further, instead of vapor phase silica aqueous dispersion, powder vapor phase silica may be used and added to the aqueous dispersant as described above.
After mixing said vapor phase silica and a dispersing agent, the mixed liquid is refined using a disperser, whereby an aqueous dispersion having an average particle diameter of 50 to 300 nm can be obtained. Dispersers used to obtain the aqueous dispersion include various types of conventionally known high-speed rotary dispersers, medium agitating dispersers (such as ball mills and sand mills), ultrasonic dispersers, colloid mill dispersers, and high pressure dispersers. Although a disperser can be used, a colloid mill disperser or a high-pressure disperser is preferable from the viewpoint of efficiently dispersing the formed fine particles.

  Moreover, water, an organic solvent, or these mixed solvents can be used as a solvent in each process. Examples of the organic solvent that can be used for this coating 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. It is done.

  After the colorant receiving layer is formed on the base layer, the colorant 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, thereby providing surface smoothness, glossiness It is possible to improve the degree, transparency and coating strength. However, the calendar process may cause a decrease in the porosity (that is, the ink absorptivity may be decreased), so it is necessary to set 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.

The layer thickness of the colorant-receiving layer needs to be determined in relation to the porosity in the layer because it needs to have an absorption capacity sufficient to absorb all droplets in the case of inkjet recording. For example, if the ink amount is 8 nL / mm ² and the porosity is 60%, a film having a layer thickness of about 1 μm or more is required.
Considering this point, in the case of inkjet recording, the thickness of the colorant receiving layer is preferably 1 to 200 μm, more preferably 5 to 100 μm, and further preferably 10 to 60 μm.

The pore diameter of the colorant 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 the median diameter of the pores can be measured using a mercury porosimeter (trade name: Bore Sizer 9320-PC2, manufactured by Shimadzu Corporation).

The colorant receiving layer is preferably excellent in transparency. As a guideline, the haze value when the colorant receiving layer is formed on the transparent film support is 30% or less. Preferably, it is 20% or less.
The haze value can be measured using a haze meter (HGM-2DP: Suga Test Instruments Co., Ltd.).

As described above, by having the color material receiving layer with fine particles, polyvinyl alcohol, boron compound, and mordant, the color material receiving layer at the time of forming the porous structure without lowering other ink receiving performance Drying shrinkage can be suppressed, film cracking can be prevented, and adhesion between the base layer and the colorant receiving layer can be improved. In addition, when the colorant-receiving layer contains a vapor phase method silica and has a three-dimensional network structure with a porosity of 50 to 80%, it is possible to form a high-resolution and high-density image with good ink absorption and high temperature and high density. It is possible to simultaneously ensure excellent ink receptive performance such as blurring with time in a wet environment is suppressed, and the formed image also exhibits high light resistance and water resistance.
The information medium obtained by the present invention can exhibit a glossiness of 30% or more at 60 °. The glossiness can be measured with a digital variable glossiness meter (UGV-50DP, manufactured by Suga Test Instruments Co., Ltd.).

As described above, the colorant receiving layer of the information medium of the present invention can reduce the amount of ultraviolet rays irradiated to the information medium, and improve recording characteristics such as jitter, unlike those formed by ultraviolet curable resin. Can be made. Moreover, there is no skin irritation like ultraviolet curable resin, and handling safety is high.
Ink jet recording sheets may be cracked or otherwise defective on the surface when bent with a strong force. However, the information medium of the present invention is thicker than the ink jet recording sheet described later, and is resistant to external stress such as bending. And strong.

[Middle layer]
In the information medium of the present invention, an intermediate layer may be provided between the colorant receiving layer and the base layer. When the intermediate layer is a layer having high ink absorbability, the amount of ink that can be received is increased, the color density can be improved during printing, and the image quality can be improved. Alternatively, an intermediate layer may be provided between the base layer and the substrate. In this case, the adhesion between the base layer and the substrate can be improved, and the warp of the entire information medium can be adjusted.

  The thickness of the intermediate layer is preferably 0.1 to 100 μm, more preferably 1 to 50 μm, and most preferably 3 to 20 μm.

[Surface layer]
The information medium of the present invention may have a surface layer on the colorant receiving layer. By the surface layer, the surface strength can be further improved, and the storability of the print can be improved. The surface layer needs to have a property of accepting ink or transmitting it quickly.

  The layer thickness of the surface layer is preferably 0.01 to 100 μm, more preferably 0.1 to 10 μm, and most preferably 0.5 to 5 μm.

  Hereinafter, the substrate and each layer used in the present invention will be described. Note that the layer configuration, materials, and the like are merely examples, and the present invention is not limited to these.

(substrate)
As the substrate, various materials used as substrate materials for conventional optical recording media can be arbitrarily selected and used.
Specifically, glass; acrylic resin such as polycarbonate and polymethyl methacrylate; vinyl chloride resin such as polyvinyl chloride and vinyl chloride copolymer; epoxy resin; amorphous polyolefin; polyester; metal such as aluminum; These may be used together if desired.
Among the above materials, amorphous polyolefin and polycarbonate are preferable, and polycarbonate is particularly preferable from the viewpoints of moisture resistance, dimensional stability, and low price. Further, the thickness of the substrate is preferably 0.5 to 1.2 mm, and more preferably 0.6 to 1.1 mm.

The substrate is formed with unevenness (pregroove) representing information such as a guide groove for tracking or an address signal.
In the case of a medium for recording with a blue-violet laser, the track pitch of the pregroove is preferably in the range of 200 to 800 nm, more preferably 200 to 500 nm, and further preferably 200 to 400 nm.
The depth of the pregroove (groove depth) is preferably in the range of 10 to 180 nm, more preferably 20 to 150 nm.
Furthermore, the half width of the pregroove is preferably in the range of 200 to 400 nm, more preferably 230 to 380 nm, and even more preferably 250 to 350 nm.

In the case of DVD-R or DVD-RW, the track pitch of the pregroove is preferably in the range of 300 to 900 nm, more preferably 350 to 850 nm, and still more preferably 400 to 800 nm.
The depth of the pregroove (groove depth) is preferably in the range of 100 to 160 nm, more preferably 120 to 150 nm, and still more preferably 130 to 140 nm.
Furthermore, the half width of the pregroove is preferably in the range of 200 to 400 nm, more preferably 230 to 380 nm, and even more preferably 250 to 350 nm.

In the case of CD-R or CD-RW, the pregroove track pitch is preferably in the range of 1.2 to 2.0 μm, more preferably in the range of 1.4 to 1.8 μm, More preferably, it is 1.65 μm.
The depth of the pregroove (groove depth) is preferably in the range of 100 to 250 nm, more preferably 150 to 230 nm, and even more preferably 170 to 210 nm.
The half width of the pregroove is preferably in the range of 400 to 650 nm, more preferably 480 to 600 nm, and further preferably 500 to 580 nm.

(Recording layer)
In the case of CD-R or DVD-R, the recording layer is prepared by dissolving a dye as a recording material in a suitable solvent together with a binder or the like to prepare a coating solution. It forms by apply | coating to the surface in which the groove was formed, forming a coating film, and then drying.
The temperature at the time of applying the spin coating method is preferably 23 ° C. or higher, and more preferably 25 ° C. or higher. The upper limit of the temperature is not particularly limited, but the temperature needs to be lower than the flash point of the solvent, and preferably 35 ° C.

Examples of the dye include cyanine dyes, oxonol dyes, metal complex dyes, azo dyes, and phthalocyanine dyes. Among these, phthalocyanine dyes are preferable.
JP-A-4-74690, JP-A-8-127174, 11-53758, 11-334204, 11-334205, 11-334206, 11-334207 The dyes described in JP-A-2000-43423, JP-A-2000-108513, JP-A-2000-158818, and the like are also preferably used.

Examples of the solvent for the coating solution include esters such as butyl acetate, ethyl lactate and 2-methoxyethyl acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chloroform; Amides such as formamide; Hydrocarbons such as methylcyclohexane; Ethers such as tetrahydrofuran, ethyl ether, and dioxane; Alcohols such as ethanol, n-propanol, isopropanol, and n-butanol diacetone alcohol; 2,2,3,3-tetrafluoro Fluorinated solvents such as propanol; Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether; Door can be.
The above solvents can be used alone or in combination of two or more in consideration of the solubility of the recording material used. Various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be further added to the coating solution depending on the purpose.

  In the case of using a binder, examples of the binder include natural organic polymer materials such as gelatin, cellulose derivatives, dextran, rosin, and rubber; hydrocarbon resins such as polyethylene, polypropylene, polystyrene, and polyisobutylene; Vinyl resins such as vinyl chloride, polyvinylidene chloride, polyvinyl chloride / polyvinyl acetate copolymer, acrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resin, butyral resin, And synthetic organic polymers such as rubber derivatives and initial condensates of thermosetting resins such as phenol / formaldehyde resins. When a binder is used in combination as a material for the recording layer, the amount of binder used is generally in the range of 0.01 times to 50 times (mass ratio), preferably 0.1 times the recording substance. The amount is in the range of 5 to 5 times (mass ratio). The concentration of the recording substance in the coating solution thus prepared is generally in the range of 0.01 to 10% by mass, preferably in the range of 0.1 to 5% by mass.

As the coating method, the spin coating method is applied as described above, and conventionally known devices can be used for the device and the like used at that time.
The recording layer may be a single layer or a multilayer, and the layer thickness is generally in the range of 20 to 500 nm, preferably in the range of 30 to 300 nm, and more preferably in the range of 50 to 100 nm.

The recording layer can contain various anti-fading agents in order to improve the light resistance of the recording layer.
As the antifading agent, a singlet oxygen quencher is generally used. As the singlet oxygen quencher, those described in publications such as known patent specifications can be used.
Specific examples thereof include JP-A Nos. 58-175893, 59-81194, 60-18387, 60-19586, 60-19587, and 60-35054. 60-36190, 60-36191, 60-44554, 60-44555, 60-44389, 60-44390, 60-54892, JP-A-60-47069, JP-A-63-209995, JP-A-4-25492, JP-B-1-38680, JP-A-6-26028, etc., German Patent 350399, and Japan Examples include those described in Chemical Society Journal, October 1992, page 1141.

  The amount of the antifading agent such as the singlet oxygen quencher used is usually in the range of 0.1 to 50% by weight, preferably in the range of 0.5 to 45% by weight, based on the amount of the dye. Preferably, it is the range of 3-40 mass%, Most preferably, it is the range of 5-25 mass%.

In the case of CD-RW or DVD-RW, the recording layer is preferably made of a phase change type optical recording material composed of at least Ag, Al, Te, and Sb that can take at least two states of a crystalline state and an amorphous state. . Such a recording layer can be formed by a known method.
A known dielectric layer is formed on the recording layer as necessary.

(Light reflecting layer)
After the recording layer is formed, a light reflecting layer is formed on the recording layer by vapor deposition, sputtering or ion plating of a light reflecting material. In forming the light reflection layer, a mask is usually used, and the formation region of the light reflection layer can be adjusted thereby.

For the light reflection layer, a light reflective material having a high reflectance with respect to laser light is used. The reflectance is preferably 70% or more.
As a light reflective material having a high reflectance, Mg, Se, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Ru, Rh, Pd , Ir, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi, and other metals and semi-metals or stainless steel. These light reflecting materials may be used alone, or may be used in combination of two or more kinds or as an alloy. Among these, Cr, Ni, Pt, Cu, Ag, Au, Al, and stainless steel are preferable. Particularly preferred is Au, Ag, Al or an alloy thereof, and most preferred is Au, Ag or an alloy thereof.
The thickness of the light reflecting layer is generally in the range of 10 to 300 nm, and preferably in the range of 50 to 200 nm.

(Protective layer, protective substrate)
After forming the light reflecting layer, a protective layer is formed on the light reflecting layer.
The protective layer is formed by a spin coating method. By applying the spin coating method, the protective layer can be formed without damaging the recording layer (dissolution of the dye, chemical reaction between the dye and the protective layer material, etc.). The number of rotations during spin coating is preferably 50 to 8000 rpm, more preferably 100 to 5000 rpm, from the viewpoint of uniform layer formation and prevention of damage to the recording layer.
In addition, when a radiation curable resin (ultraviolet curable resin) is used for the protective layer, after the protective layer is formed by spin coating, ultraviolet rays are irradiated from above the protective layer by an ultraviolet irradiation lamp (metal halide lamp). Cure the cured resin.
Further, in order to eliminate the thickness unevenness of the protective layer to be formed, a treatment such as leaving it for a certain period of time before curing the resin may be appropriately performed.

The protective layer prevents moisture from entering and scratching. The material constituting the protective layer is preferably a radiation curable resin, a visible light curable resin, a thermosetting resin, silicon dioxide, or the like, and more preferably a radiation curable resin. Examples of the radiation curable resin include ultraviolet curable resins such as “SD-640” manufactured by Dainippon Ink and Chemicals, Inc. Further, SD-347 (manufactured by Dainippon Ink & Chemicals, Inc.), SD-694 (manufactured by Dainippon Ink & Chemicals, Inc.), SKCD1051 (manufactured by SKC), and the like can be used. The thickness of the protective layer is preferably in the range of 1 to 200 μm, and more preferably in the range of 50 to 150 μm.
In addition, the protective layer is required to have transparency in a layer configuration used as a laser optical path. Here, “transparency” means that the recording light and the reproduction light are so transparent that the light is transmitted (transmittance: 90% or more).

In the case of DVD-R and DVD-RW, instead of the protective layer, an adhesive layer made of an ultraviolet curable resin or the like and a substrate as a protective substrate (thickness: about 0.6 mm, material is the same as the above substrate) are laminated. To do.
That is, after forming the light reflection layer, an ultraviolet curable resin (Dai Nippon Ink Chemical Co., Ltd. SD640 or the like) is applied to a thickness of 20 to 60 μm by spin coating to form an adhesive layer. On the formed adhesive layer, for example, a polycarbonate substrate (thickness: 0.6 mm) as a protective substrate is placed, and the ultraviolet curable resin is cured by being irradiated with ultraviolet rays from the substrate, and bonded together.

As described above, an information medium comprising a laminate in which a recording layer, a light reflection layer, a protective substrate (dummy substrate) with a recording layer, a protective layer, or an adhesive layer provided on the substrate is provided.
The information medium of the present invention has a narrower track pitch than that of a conventional DVD or the like and is used by appropriately setting the track pitch of the pregroove formed on the substrate and the material constituting the recording layer. The present invention can also be applied to an information medium capable of recording / reproducing information with a laser beam having a smaller wavelength.

  The thickness of the information medium of the present invention is preferably 0.3 mm, more preferably 0.5 mm, and even more preferably 0.7 mm as the lower limit. Moreover, as an upper limit, 100 mm is preferable, 20 mm is more preferable, and 5 mm is further more preferable. If it is too thin, defects may occur when bent. If it is too thick, the removable property may be inferior.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In the examples, “parts” and “%” all represent “parts by mass” and “% by mass”.

[Example 1]
<< Production of disk-shaped substrate >>
A polycarbonate resin (resin brand name: Panlite AD5503, Teijin Ltd.) is injected into an injection molding machine equipped with a stamper prepared in advance so as to have a predetermined groove shape at a predetermined track pitch, and a temperature of 115 ° C. To produce a polycarbonate disk-shaped resin substrate. The obtained disk-shaped resin substrate had a diameter of 120 mm and a thickness of 1.2 mm, and a spiral concave groove (pre-groove) was formed on the surface thereof. The track pitch of the concave groove was 1.6 μm, the groove width was 500 nm, and the groove depth was 180 nm.

  A coating solution for forming a recording layer was prepared by dissolving 2.5 g of a cyanine dye represented by the following structural formula in 100 ml of 2,2,3,3-tetrafluoropropanol. This coating solution was applied by spin coating on the surface of the disk-shaped polycarbonate substrate obtained above, on which the pregroove was provided, and a dye recording layer (thickness: 190 nm (groove portion), 110 nm (land portion)) ) Was formed.

  Next, Ag was sputtered on the dye recording layer using a DC magnetron sputtering apparatus to form a reflective layer made of Ag having a thickness of about 120 nm. Further, a UV curable resin (trade name: SD318, manufactured by Dainippon Ink & Chemicals, Inc.) was applied on the reflective layer using a spin coating method while changing the rotational speed between 300 and 4000 rpm. After the application, a protective layer having a thickness of 5 μm was formed by irradiating it with ultraviolet rays using a high pressure mercury lamp and curing it. Through the above steps, a CD-R type information medium (optical disk) composed of a substrate, a dye recording layer, a reflective layer, and a protective layer was produced.

  Next, a printable layer was formed as follows on the protective layer opposite to the incident surface of the recording / reproducing laser beam.

  UV curable ink (White No. 3, manufactured by Teikoku Mfg. Co., Ltd.) is printed on the protective layer on the side opposite to the substrate surface by screen printing. After printing, 80 W / cm of UV light is applied from above using a metal halide lamp. Irradiated and cured, two 8 μm ground layers (white layers) were repeatedly formed to a total thickness of 16 μm. The screen used was a Tetron screen with 300 lines / inch mesh, a thread system of 31 μm, and an opening of 38 μm.

  Next, the following steps were performed to form a colorant receiving layer on the underlayer.

-Preparation of coating solution for colorant receiving layer-
(1) Gas phase method silica fine particles and (2) ion-exchanged water having the following composition are mixed, and using a high-speed rotating colloid mill (CLEAMIX, manufactured by M Technique Co., Ltd.) at a rotational speed of 10,000 rpm for 20 minutes. After the dispersion, the following (3) polyoxyethylene lauryl ether, (4) aqueous ammonia, (5) 9% polyvinyl alcohol aqueous solution, and (6) diethylene glycol monobutyl ether are added, and further dispersed under the same conditions as above, A coating material A for a colorant receiving layer was prepared.
The mass ratio between the silica fine particles and the water-soluble resin (PB ratio / (1) :( 5)) is 3.5: 1, and the pH of the colorant-receiving layer coating solution A is 9.5, which is alkaline. showed that.

[Composition of Color Material Receiving Layer Coating Liquid A]
(1) Gas phase method silica fine particles (inorganic pigment fine particles) 9.9 parts (average primary particle diameter 7 nm; Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.)
(2) Ion-exchanged water 72.6 parts (3) Polyoxyethylene lauryl ether (surfactant) 7.2 parts (Emulgen 109P (10%), manufactured by Kao Corporation, HLB value 13.6)
(4) 17 g / l aqueous ammonia solution (pH adjuster) 5.3 parts (5) Polyvinyl alcohol 9% aqueous solution (water-soluble resin) 31.4 parts (PVA420, manufactured by Kuraray Co., Ltd., saponification degree 81.8%, Degree of polymerization 2000)
(6) 0.6 parts of diethylene glycol monobutyl ether (compound represented by general formula (1))

-Formation of colorant receiving layer-
After the corona discharge treatment is performed on the surface of the base layer of the information medium, the coating material A for the colorant receiving layer obtained above is applied to the surface of the base layer at a coating amount of 100 ml / m ² using a bar coater. Then, 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%. The coating layer showed a constant rate of drying during this period. Immediately after that, the cross-linking agent solution A having the following composition was applied on the applied coating material A for the colorant receiving layer using a bar coater, and further dried at 80 ° C. for 5 minutes. Thus, an information medium of Example 1 in which a colorant receiving layer having a dry film thickness of 30 μm was provided was produced.

[Composition of cross-linking agent solution A]
・ Boric acid (6%; crosslinking agent) 25 parts ・ PAS-F5000 (20%) aqueous solution 7.15 parts (mordant; manufactured by Nittobo Co., Ltd.)
・ Ion-exchanged water 68.98 parts ・ Ammonium chloride (surface pH adjuster) 0.2 parts ・ Ammonia aqueous solution (25%; pH adjuster) 1.67 parts ・ Polyoxyethylene lauryl ether (surfactant) 2 parts ( Emulgen 109P (10%), manufactured by Kao Corporation, HLB value 13.6)

[Example 2]
Polycarbonate substrate (thickness: 0.6 mm, outer diameter: 120 mm, inner diameter: 15 mm, manufactured by Teijin Ltd., trade name “Panlite AD5503” formed with a spiral groove (land) and LPP on the surface by injection molding. ") Was produced. The groove depth was 140 nm, the groove width was 310 nm, and the groove pitch was 740 nm.

  1 g of a dye obtained by mixing the following oxonol dye (A) and oxonol dye (B) in a ratio of 65:35 is dissolved in 100 ml of 2,2,3,3-tetrafluoro-propanol, and a recording layer forming coating solution is obtained. Prepared. This recording layer forming coating solution was applied to the groove surface of the obtained substrate by spin coating while changing the rotational speed from 300 to 3000 rpm, and dried to form a recording layer. The thickness of the recording layer was measured by observing the cross section of the recording layer with an SEM, and found to be 150 nm in the groove and 110 nm in the land portion.

  Next, a reflective layer made of Ag having a thickness of about 150 nm was formed on the recording layer by DC sputtering in an argon atmosphere. The pressure in the chamber was 0.5 Pa.

  Further, a UV curable resin (trade name “SD-318”, manufactured by Dainippon Ink & Chemicals, Inc.) is annularly dispensed on the reflective layer, and a separately prepared polycarbonate disk-shaped protective substrate (diameter: 120 mm). , Thickness: 0.6 mm) with the centers aligned, and rotated for 3 seconds at a rotational speed of 5000 rpm to spread UV curable resin (SD640, manufactured by Dainippon Ink & Chemicals, Inc.) over the entire surface and extra The UV curable resin was shaken off. When the UV curable resin spreads over the entire surface, the UV curable resin was cured by irradiating ultraviolet rays with a high pressure mercury lamp, and the substrate on which the recording layer and the reflective layer were formed was bonded to the disk-shaped protective substrate. The thickness of the bonding layer was 25 μm, and it was possible to bond without mixing bubbles.

  Next, in the same manner as in Example 1, a base layer and a colorant receiving layer were formed on the protective layer on the side opposite to the substrate surface, and an information medium of Example 2 was produced.

[Example 3]
An information medium of Example 3 was manufactured in the same manner as in Example 1 except that the thickness of the base layer was set to 25 μm in the formation of the base layer of Example 1.

[Example 4]
An information medium of Example 4 was fabricated in the same manner as in Example 1 except that the thickness of the foundation layer was set to 50 μm in the formation of the foundation layer of Example 1.

[Comparative Example 1]
Example 1 is the same as Example 1 except that the colorant-receiving layer is replaced with one formed by screen-printing UV-curing resin (UV SP 81019B, Teikoku Ink Manufacturing Co., Ltd.) and UV-curing. Thus, an information medium of Comparative Example 1 was produced.

[Comparative Example 2]
In Example 1, an information medium of Comparative Example 2 was produced in the same manner as in Example 1 except that the thickness of the underlayer was changed to 8 μm.

<Performance evaluation>
The following evaluation was performed about the information medium of Examples 1-4 obtained from the above, and the information medium of Comparative Examples 1-2.

[Measurement of brightness L ^* ]
The lightness L ^* of the printable layer of the information media of Examples 1 to 4 and Comparative Examples 1 to 2 was measured with a color difference meter (CR-300) manufactured by MINOLTA. D65 was used as the light source mode. The measurement results are shown in Table 1.
[printing]
Images were printed on the printable layers of the information media of Examples 1 to 4 and Comparative Examples 1 and 2 using an inkjet printer (manufactured by Seiko Epson Corporation; PM-970C).
[Image quality evaluation]
Subsequently, 10 persons visually evaluated sensory evaluation of the printed image with respect to the printed information media of Examples 1-4 and Comparative Examples 1-2. The case where all 10 people evaluated that it was more beautiful than the conventional product was evaluated as ◯, and the case where it was evaluated as being equal to or less than the conventional product was evaluated as ×. The results are shown in Table 1.

From Table 1, the printable layers of the information media of Examples 1 to 4 all had L ^* of 90 or more and high brightness, whereas the printable layers of the information media of Comparative Examples 1 to 2 were L ^* Was less than 90, and sufficient brightness was not obtained. Regarding the printed image quality, the information media of Examples 1 to 4 have high resolution and a fine texture. Moreover, the hair was able to be printed clearly. On the other hand, the information media of Comparative Examples 1 and 2 had poor print quality, low resolution, and no fine texture.

Claims (7)

An information medium having a printable layer including at least a base layer and a colorant receiving layer,
The colorant receiving layer contains at least fine particles, a binder, and a crosslinking agent;
An information medium, wherein the underlayer has a thickness of 15 μm or more.   The fine particles are at least one selected from vapor phase silica, pseudoboehmite, and aluminum oxide, the binder is polyvinyl alcohol, the crosslinking agent is a boron compound, and the coloring material The information medium according to claim 1, wherein the receiving layer further contains a mordant. The information according to claim 1 or 2, wherein the colorant-receiving layer further contains a compound represented by the following general formula (1) and / or a compound represented by the following general formula (2). Medium.
RO (CH ₂ CH ₂ O) _n H General formula (1)
[In General Formula (1), R represents a C1-C12 saturated hydrocarbon group, a C1-C12 unsaturated hydrocarbon group, a phenyl group, or an acyl group. n represents an integer of 1 to 3. ]
_{RO (CH 2 CH (CH 3} ) O) n H General Formula (2)
[In General Formula (2), R represents a C1-C12 saturated hydrocarbon group, a C1-C12 unsaturated hydrocarbon group, a phenyl group, or an acyl group. n represents an integer of 1 to 3. ]   The information medium according to claim 3, wherein the compound represented by the general formula (1) and the compound represented by the general formula (2) are water-soluble.   The information medium according to claim 3 or 4, wherein, in the general formula (1) and the general formula (2), the R is a saturated hydrocarbon group having 1 to 4 carbon atoms.   The colorant-receiving layer is coated with a coating solution containing the compound represented by the general formula (1) and / or the compound represented by the general formula (2), the fine particles, and the binder; At the same time or during the drying of the coating layer formed by the coating, before the coating layer exhibits a reduced rate of drying, a solution containing the crosslinking agent and the mordant is applied to the coating layer. The information medium according to claim 3, wherein the information medium is obtained by subsequently curing the coating layer.   The colorant-receptive layer comprises an aqueous dispersion composed of the fine particles and a dispersant, a compound represented by the general formula (1) and / or a compound represented by the general formula (2), the binder, and the binder. A coating solution obtained by adding and redispersing a solution containing a crosslinking agent is applied, and at the same time as or during the drying of the coating layer formed by the coating, the coating layer is dried at a reduced rate. 6. The method according to claim 3, wherein the coating layer is obtained by curing the coating layer after applying a solution containing the crosslinking agent and the mordant to the coating layer before the speed is shown. Information media described in 1.