JP2006185514A - Manufacturing method of disk-like information medium, and disk-like information medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a disk-like information medium and a disk-like information medium comprising a printable layer which is formed by setting a color material receiving layer on a underlayer, can perform the print of high image quality and can prevent the peeling-off of the color material receiving layer at the edge. <P>SOLUTION: This manufacturing method is for manufacturing a disk-like information medium formed with an underlayer and a printable layer including a color material receiving layer on a substrate. The manufacturing method of the disk-like information medium is characterized by containing a process to set up the underlayer whose a periphery radius is r<SB>a</SB>on the substrate, and a process to set up the color material receiving layer which has a peripheral radius of r<SB>b</SB>and satisfies a relation of r<SB>a</SB>≥r<SB>b</SB>, in this order. The disk-like information medium is obtained by this manufacturing method. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a disc-shaped information medium having a printable layer capable of printing characters, photographs, and the like, and a disc-shaped information medium.

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 with a thickness of about 0.6 mm are bonded together. Pits are formed at a track pitch of 0.74 μm. Then, the linear velocity is kept constant at about 3.5 m / s, and information is reproduced by irradiating laser light with a wavelength of 635 to 650 nm.

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.
On the other hand, in order to achieve high image quality, a printable layer having a color material receiving layer similar to that of an inkjet recording sheet has been proposed. In such a printable layer, a highly opaque underlayer is provided between the colorant receiving layer and the disk substrate. This underlayer is usually composed of a radiation curable resin and is a highly wettable layer, so it has a high affinity with a colorant receiving layer formed using a coating solution containing water, The adhesion between the underlayer and the colorant receiving layer is good.
However, in the printable layer having such a configuration, defects such as cracks may occur at the end of the color material receiving layer. In particular, since the outer peripheral edge of the information medium is likely to be subjected to external stress during use or transport, the outer peripheral edge of the colorant receiving layer is easily peeled off due to this defect. Had a problem.
JP 2002-245671 A

An object of the present invention is to solve the above-described conventional problems and achieve the following objects. That is,
An object of the present invention is to provide a method for producing a disc-shaped information medium having a printable layer and a disc-shaped information medium capable of high-quality printing and preventing peeling at the end of the colorant receiving layer. There is.

Means for solving the above problems are as follows.
That is, the manufacturing method of the disc-shaped information medium of the present invention is a manufacturing method of a disc-shaped information medium having a printable layer including a base layer and a colorant receiving layer on a substrate, and an outer peripheral radius is r _a on the substrate. a step of providing the undercoat layer is, on the underlayer, the outer peripheral radius is r _b, and include the step of providing the colorant-receiving layer satisfies the relationship r _a ≧ r _b, in this order It is characterized by.
Further, when the inner peripheral radius of the underlayer is ra _' and the inner peripheral radius of the colorant receiving layer is rb _' , it is preferable that the relationship rb _' ≧ ra _' is satisfied.
Furthermore, it is preferable to use a die coater in order to form the colorant receiving layer having the above relationship.

The disc-shaped information medium of the present invention is a disc-shaped information medium comprising a printable layer including a base layer and a color material receiving layer on _a substrate, wherein the base layer has an outer peripheral radius ra, and the color material receiving layer When the outer peripheral radius of rb is r _b , the relationship of r _a ≧ r _b is satisfied.
Further, when the inner peripheral radius of the underlayer is ra _' and the inner peripheral radius of the colorant receiving layer is rb _' , it is preferable that the relationship rb _' ≧ ra _' is satisfied.

  In the present invention, the colorant receiving layer preferably contains fine particles, a binder, and a crosslinking agent. In the present invention, the fine particles are at least one selected from the group consisting of vapor phase method silica, pseudoboehmite, and aluminum oxide, the binder is polyvinyl alcohol, and the crosslinking agent is boron. It is preferable that it is a compound and the said color material receiving layer contains a mordant further.

In addition, in the present invention, it is preferable that 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).
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. ]
Among them, the compound represented by the general formula (1) and the compound represented by the general formula (2) are preferably water-soluble, and the R is a saturated hydrocarbon having 1 to 4 carbon atoms. More preferably, it is a group.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the disc-shaped information medium which has a printable layer which can perform a high quality printing, and can prevent peeling in the edge part of a color material receiving layer, and a disc-shaped information medium are provided. be able to.
As a result, the printable layer according to the present invention can perform high-quality printing up to the end portion.

≪Method for manufacturing disc-shaped information medium≫
A method of manufacturing a disc-shaped information medium of the present invention is a method for producing a disc-shaped information medium comprising a printable layer containing a base layer and a colorant receiving layer on the substrate, the outer peripheral radius is r _a on the substrate A step of providing the underlayer (hereinafter referred to as “underlayer forming step”), and the colorant acceptance satisfying the relationship of r _a ≧ r _b and an outer peripheral radius of r _b on the underlayer. And a step of providing a layer (hereinafter referred to as a “coloring material receiving layer forming step”) in this order.
In other words, the printable layer formed by the method for manufacturing a disc-shaped information medium of the present invention has an outer peripheral end of the color material receiving layer that overlaps an outer peripheral end of the base layer or an inner side of the outer peripheral end of the base layer. Will exist.

The positional relationship between the outer peripheral end of the underlayer and the outer peripheral end of the colorant receiving layer in the present invention will be described with reference to FIG. Here, FIG. 1 is an enlarged sectional view showing an outer peripheral end portion of the printable layer in the present invention.
As shown in FIG. 1, the printable layer 40 according to the present invention has a configuration in which a base layer 20 and a color material receiving layer 30 are provided in this order on a substrate 10. The outer peripheral end exists on the inner peripheral side from the outer peripheral end of the foundation layer 20.

In the method for producing a disc-shaped information medium according to the present invention, a color material receiving layer is formed using a base layer having high wettability and a coating solution containing water by providing the color material receiving layer as described above. Since the adhesion developed between the colorant receiving layer works well up to the outer peripheral edge of the colorant receiving layer, it can be prevented from easily peeling even when external stress is applied to the outer peripheral edge of the colorant receiving layer. Can do.
On the other hand, the relationship between the outer peripheral radius r _b of the outer peripheral radius r _a and the colorant receiving layer of the underlayer is r _a <r _b, that is, the outer peripheral end portion of the colorant receiving layer is present on the outer peripheral side of the base layer Then, the end portion comes into contact with the substrate, and since the affinity (adhesion) that is expressed with the base layer cannot be obtained at the contact portion, defects such as cracks are generated, and from the outside The colorant receiving layer easily peels off due to the stress of.

In the present invention, when the inner peripheral radius of the underlayer is ra _' and the inner peripheral radius of the colorant receiving layer is rb _' , it is preferable to satisfy the relationship of rb _' ? _Ra'. . That is, it is a preferable aspect that the inner peripheral end portion of the color material receiving layer overlaps with the inner peripheral end portion of the base layer or exists on the outer peripheral side of the inner peripheral end portion of the base layer.
By adopting this preferred embodiment, the adhesion between the base layer and the color material receiving layer is excellent even at the inner end portion of the color material receiving layer, and the color material receiving layer is peeled off at the inner peripheral edge portion. Can be prevented.

Relationship between the outer peripheral radius r _b of the outer peripheral radius r _a and the colorant receiving layer of the base layer in the present invention will be mandatory to meet the r _a ≧ r _b, the securing of the printing area, from the viewpoint of adhesion , it is preferable that the value of r _a -r _b is in the range of 0 - 0.5 mm, and more preferably in the range of 0～0.2Mm.
Further, _'a, inner radius r _b of the colorant receiving _layer' inner radius r _a of the underlayer relationship with has a secure printing area, from the viewpoint of adhesion, the value of r b _{'-r a'} Is more preferably in the range of 0 to 0.5 mm, and still more preferably in the range of 0 to 0.2 mm.

<Underlayer formation process>
In this step, a base layer is provided on the substrate. Here, the substrate on which the base layer is provided refers to a member having a surface on which the printable layer is provided. The member differs depending on the type of information medium, and is a protective layer in addition to the substrate and the dummy substrate (protective substrate). In some cases.

  As the underlayer in the present invention, it is preferable to increase the opacity because it has a diffusibility close to that of paper and improves the image quality. In particular, when a white underlayer is provided, color reproducibility can be improved. Further, when the base layer has a high glossiness, it is finished like a glossy photo, and when it has a high matteness, it looks like a matte photo. When the underlayer uses various colors, images with various impressions can be formed. Furthermore, in the case of a fluorescent underlayer, a fluorescent image quality can be obtained.

Although the formation method of such a foundation | substrate layer is not ask | required, it is preferable to form by screen-printing radiation curable resin (specifically, for example, ultraviolet curable ink) 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.
Specifically, UV curing resin WhiteNo. 3 is mentioned.
The underlayer obtained using such a material has high wettability. Specifically, specifically, the contact angle of water (FACE CONTACT-ANGLE METER CA-D manufactured by Kyowa Interface Chemical Co., Ltd.) Measurement) is about 30 °.

The layer thickness of the underlayer is preferably from 0.1 to 100 μm, more preferably from 1 to 50 μm, and most preferably from 3 to 20 μm.
In addition, the formation region of the underlayer is preferably in the following range from the viewpoint of the printing region and process stability.
The outer peripheral radius r _a of the underlayer is preferably r _a <r _c , where r _c is the outer peripheral radius of the substrate (surface on which the printable layer is provided), and the value of r _c −r _a is 0.1 to 0.1. It is preferably in the range of 1.5 mm, and more preferably in the range of 0.2 to 0.6 mm.
On the other hand, the inner peripheral radius r _{a ′} of the underlayer is preferably r _{c ′} <r _{a ′} where r _{c ′} is the inner peripheral radius of the substrate (surface on which the printable layer is provided), and r _{z ′} − The value of rc _′ is preferably in the range of 2.0 to 15 mm, and more preferably in the range of 2.0 to 5.0 mm.

<Coloring material receiving layer forming step>
In this step, a colorant receiving layer is provided on the base layer obtained in the base layer forming step.
Relationship between the outer peripheral radius r _a of the outer peripheral radius r _b and the underlying layer of the colorant receiving layer, and, in the colorant receiving layer inner radius r _{b 'and} the underlying layer inner radius r _a' relationship to the above In order to control in such a manner, the method and conditions may be appropriately selected when applying the coating liquid used when forming the colorant receiving layer.
First, each component constituting the color material receiving layer in the present invention will be described, and then a color material receiving layer forming step using the component will be described.

  The colorant-receiving layer in the present invention preferably contains fine particles, a binder, and a crosslinking agent. If necessary, the colorant-receiving layer further contains a compound represented by the general formula (1) and / or the following general formula ( The compound represented by 2) and various additives may be included.

[Fine particles]
As described above, the colorant receiving layer in the present invention preferably 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 surface of the fine particles is large at 5 to 8 / nm ² , and the silica fine particles tend to aggregate closely (aggregate). 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.

  Further, the solid content in the colorant-receiving layer of the vapor phase method silica is preferably 40% by mass or more, and more preferably 50% by mass or more. Thus, when the content of the vapor phase method silica is 50% by mass or more, 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 coloring material receiving layer of the vapor phase method silica is a content calculated based on components other than water in the composition constituting the coloring material receiving layer.

  When forming the colorant receiving layer using the vapor phase silica, the vapor phase silica is preferably dispersed in an aqueous solvent and used as a dispersion. Under the present circumstances, 60 mass% or less is preferable, as for content of the gaseous-phase method silica in a dispersion liquid, 5-60 mass% is more preferable, and 10-50 mass% is especially preferable. Within this range, vapor-phase process silica can be dispersed particularly effectively. For example, thickening or gelation caused by a decrease in the distance between particles of vapor-phase process silica during dispersion can be achieved. It can be effectively suppressed.

  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 diameter 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 > / g is preferable and 200-500 m < ² > / g 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). .

  Further, the solid content in the colorant receiving layer of pseudoboehmite is preferably 50% by mass or more, and more preferably 60% by mass or more. Thus, when content of pseudo boehmite is 60 mass% or more, it becomes possible to form a more favorable porous structure and to obtain a colorant receiving layer having sufficient ink absorbability, which is preferable. Here, the solid content in the colorant-receiving layer of pseudoboehmite is a content calculated based on components other than water in the composition constituting the colorant-receiving layer.

  In addition, when forming a color material receiving layer using the said pseudo boehmite, it is preferable to disperse | distribute pseudo boehmite in an aqueous solvent and to use it as a dispersion liquid. Under the present circumstances, as content of pseudo boehmite in a dispersion liquid, 60 mass% or less is preferable, 5-60 mass% is more preferable, 10-50 mass% is especially preferable. Within this range, pseudoboehmite can be dispersed particularly effectively. For example, thickening and gelation caused by shortening the interparticle distance between pseudoboehmite during dispersion can be effectively suppressed. can do.

When pseudoboehmite (A) and gas phase method silica (S) are used in combination, the content ratio (S: A) is preferably in the range of 95: 5 to 5:95, and 80:20 to 20 : 80 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 the oxyhydrogen reaction, In addition, 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.

  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, when the colorant receiving layer is formed using aluminum oxide, it is preferably dispersed in an aqueous solvent and used as 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.
Moreover, you may add the cationic polymer which has a primary-tertiary amino group, its salt, and a quaternary ammonium base as an aggregation inhibitor to the said dispersion liquid. The addition amount of the anti-aggregation agent is preferably 1 to 10% by mass, and 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.

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 preferably 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 acetal, 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-based resin include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432, Japanese Patent Publication No. 7-29479, Japanese Patent No. 2,537,827, Japanese Patent Publication No. 7-57553, Japanese Patent No. 2 No. 3,502,998, Japanese Patent No. 3,053,231, Japanese Patent Application Laid-Open No. 63-176173, Japanese Patent No. 2604367, Japanese Patent Application Laid-Open No. 7-276787, Japanese Patent Application Laid-Open No. 9-207425, Japanese Patent Application Laid-Open No. 11-58941 JP 2000-135858, JP 2001-205924, JP 2001-287444, JP 62-278080, JP 9-39373, JP 2750433, JP 2000-158801, JP 2001. -213045, JP-A-2001-328345, JP-A-8-324105, JP-A-11-348417, etc. It has been like can be used as.
Examples of water-soluble resins other than polyvinyl alcohol resins include the compounds described in paragraph numbers [0011] to [0014] of JP-A No. 11-165461.

These water-soluble resins as binders may be used alone or in combination of two or more.
In this invention, as content of the said water-soluble resin as a binder, 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. Thus, when using together polyvinyl alcohol-type resin and another water-soluble resin, 50 mass% or more is preferable in all the water-soluble resins, and 70 mass% or more is more preferable.

The polyvinyl alcohol-based resin has a hydroxyl group in its structural unit, and this 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 to form. 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, polyvinyl alcohol resins having a saponification degree of 70 to 99% are more preferable, and polyvinyl alcohol resins having a saponification degree of 80 to 99% are particularly preferable.

(Content ratio between fine particles and water-soluble resin (binder))
In the colorant receiving layer, the mass content ratio [PB ratio (x / y)] of the fine particles (x) and the water-soluble resin (y) as the binder is determined by the film structure and film of the colorant receiving layer. The strength is greatly affected. 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 of the present invention, the mass content ratio [PB ratio (x / y)] prevents a decrease in film strength and cracks during drying caused by the PB ratio being too large, and From the viewpoint of preventing the ink from being lowered due to the porosity being reduced by the PB ratio being too small and the void ratio being reduced, the ratio is reduced to 1.5 / 1 to 10/1. Is preferred.

  When the information medium in the present invention passes through the conveyance system of the ink jet recording printer, stress may be applied to the information medium. Therefore, the colorant receiving layer preferably has sufficient film strength. In consideration of the above, the PB ratio (x / y) is more preferably 4/1 or less, while it is 3/1 or more from the viewpoint of ensuring high-speed ink absorbability in an inkjet recording printer. It is more preferable.

An example of a specific method for forming the colorant receiving layer will be given. For example, a coating solution in which gas phase method silica fine particles 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 3/1 to 4/1 is applied on the underlayer. When the coating layer is dried, a three-dimensional network structure in which secondary particles of silica fine particles are network chains is formed, the average pore diameter is 30 nm or less, the porosity is 50 to 80%, the pore ratio A translucent porous film having a 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 in the invention contains a crosslinking agent that can crosslink the binder. By containing the cross-linking agent in this way, the colorant receiving layer can be a porous layer cured by a cross-linking reaction between the cross-linking agent and the binder.

Boron compounds are preferred for crosslinking polyvinyl alcohol suitable as the water-soluble resin as the binder. 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.

  Moreover, compounds other than the above boron compounds can also be used as a crosslinking agent for the water-soluble resin as a binder. For example, aldehyde compounds such as formaldehyde, glyoxal, succinaldehyde, glutaraldehyde, dialdehyde starch, dialdehyde derivatives of plant gum; diacetyl, 1,2-cyclopentanedione, 3-hexene-2,5-dione, etc. Ketone 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 (Vinylsulfonyl) -2-propanol, N, N′-ethylenebis (vinylsulfonylacetamide), divinylketone, 1,3-bis (acryloyl) urea, 1,3,5-triacryloyl-hexahydro-s- Active vinyl compounds such as triazine; dimethylol urea N-methylol compounds such as methylol dimethyl hydantoin; 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 Epoxy compounds such as polyglycidyl ether, spiroglycol diglycidyl ether, and 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 2,983,611; U.S. Pat. Carbodiimide compounds described in No. 100,704, etc .; ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; halogenated carboxaldehyde compounds such as mucochloric acid and mucophenoxycyclolic acid; Dioxane compounds such as 2,3-dihydroxydioxane; metal-containing compounds such as titanium lactate, aluminum sulfate, chromium alum, potash alum, zirconyl acetate, chromium acetate; polyamine compounds such as tetraethylenepentamine; adipic acid dihydrazide, etc. A hydrazide compound comprising two or more oxazoline groups Low molecule or polymer having: 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 polyhydric acid anhydrides, acid chlorides, bissulfonate compounds; active ester compounds described in US Pat. No. 3,542,558, US Pat. No. 3,251,972, 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.

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 U.S. Pat. Nos. 3,017,280 and 2,983,611; U.S. Pat. No. 3,100,704 Carboximide compounds described in the specification; Epoxy compounds such as glycerol triglycidyl ether; Ethyleneimino compounds such as 1,6-hexamethylene-N, N′-bisethyleneurea; Mucochloric acid and mucophenoxycyclolic acid Halogenated carboxaldehyde compounds such as dioxane; dioxane compounds such as 2,3-dihydroxydioxane; chromium alum, potash alum, zirconium sulfate, chromium acetate and the like. These hardeners may be used alone or in combination of two or more.
When the boron compound and other crosslinking agent (including a hardener) are used in combination, the content of the boron compound in the total crosslinking agent is preferably 50% by mass or more, and more preferably 70% by mass or more.

When the colorant receiving layer is formed, the crosslinking agent in the present invention is preferably dissolved in water and / or an organic solvent and used as a crosslinking agent solution.
As a density | concentration of the crosslinking agent in the said crosslinking agent solution, 0.1-10 mass% is preferable with respect to the mass of a crosslinking agent solution, and 0.5-8 mass% is especially preferable.
As the solvent constituting the crosslinking agent solution, water is generally used, and an aqueous mixed solvent containing an organic solvent miscible with water may be used.
The organic solvent can be arbitrarily used as long as it can dissolve the crosslinking agent. For example, alcohols such as methanol, ethanol, isopropyl alcohol, and glycerin; ketones such as acetone and methyl ethyl ketone; methyl acetate and ethyl acetate An aromatic solvent such as toluene; an ether such as tetrahydrofuran; and a halogenated carbon-based solvent such as dichloromethane.

As one of the methods for applying these crosslinking agent solutions, a coating liquid (coloring material receiving layer coating liquid) for forming a porous coloring material receiving layer containing at least the above-mentioned fine particles and the above binder is applied onto the underlayer. There is a method that is performed at the same time or before the coating layer formed by coating the colorant-receiving layer coating solution 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, at the same time that the coating solution is applied or before the coating layer exhibits a reduced rate of drying, the crosslinking agent penetrates into the coating layer by applying the crosslinking agent solution to the coating layer. By reacting quickly with the binder in the layer and gelling (curing) the binder, the film strength of the coating layer is immediately and greatly improved.

  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 included in the aqueous dispersion composed of the fine particles and the dispersant. A coating solution obtained by adding and redispersing a solution (coloring material-receiving layer coating solution) is applied onto the base layer, and simultaneously with the coating or during the drying of the coating layer formed by the coating. Then, before the coating layer exhibits a decreasing rate of drying, a method of forming a colorant receiving layer by applying a crosslinking agent solution to the coating layer can be used. When using this method, it is preferable to add a crosslinking agent (solution) to both the first solution added to the coating solution and the second solution to be applied later.

[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.

  If this is added directly to the coating liquid for forming the color material receiving layer (color material receiving layer coating liquid), there is a concern that aggregation may occur with the vapor phase silica having an anionic charge. There is no need to worry about the aggregation of the inorganic pigment fine particles if the method of preparing and applying the solution is used. 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 is also used. be able to.
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), the mordant monomer and other monomers (hereinafter, What is obtained as a copolymer or condensation polymer with "non-mordant monomer") is preferred. Further, these polymer mordants can be used in the form of water-soluble polymers or water-dispersible latex particles.

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

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

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

  Specifically, for example, 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.
Other examples of the copolymerizable monomer include N-vinylimidazole and N-vinyl-2-methylimidazole.

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

The (meth) acrylic acid alkyl ester is preferably a (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl moiety, 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, polyethylenimine, 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 1,000 to 200,000 in terms of weight average molecular weight, and more preferably 3,000 to 60,000 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 too high and the 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.

  The content of these mordants is preferably 1 to 20% by mass and more preferably 2 to 10% by mass with respect to the total solid content mass of the colorant receiving layer from the viewpoint of colorability and ink absorbability.

[Compound represented by general formula (1) and compound represented by general formula (2)]
In the present invention, the colorant-receiving layer preferably further contains a compound represented by the following general formula (1) and / or a compound represented by the following general formula (2). The compound represented by the following general formula (1) and the compound represented by 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 compound represented by the general formula (1) and the compound represented by the general formula (2) appropriately inhibit the hydrogen bond between the silanol group on the vapor phase silica surface and the hydroxyl group of polyvinyl alcohol. This is presumably because the drying shrinkage of the colorant receiving layer 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 the above general formula (1) and general formula (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. 1-4 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 still 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 General formula (2), n represents the integer of 1-3 and 2 or 3 is preferable.

  The compound represented by the general formula (1) and the compound represented by the general formula (2) are preferably water-soluble compounds. Here, “water-soluble” means one that is soluble in water by 1% by mass or more.

  Specific examples of the compound represented by the general formula (1) and the compound represented by the general formula (2) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and 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 Ethylene glycol monobutyl ether, propylene glycol Methyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether and the like, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether are preferred.

The compound represented by the general formula (1) and the compound represented by the general formula (2) may contain at least one of them in the colorant receiving layer. Accordingly, the compound represented by the general formula (1) or the compound represented by (2) may be contained alone or in combination of two or more, or the compound represented by the general formula (1) and the general formula (2). You may use together with the compound represented by these. 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.
The total content of the compound represented by the general formula (1) and the compound represented by (2) contained in the colorant receiving layer is preferably 0.1 to 5.0 g / m ² , and 0 More preferably, it is ² to 3.0 g / m ² .

[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 US 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 coating solution when forming the colorant receiving layer.

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.
In addition, the coating liquid in the present invention may contain a surfactant.

[Formation of colorant receiving layer]
In the present invention, the formation method is not particularly limited as long as the relationship between the outer peripheral radius r _b of the formed colorant receiving layer and the outer peripheral radius r _a of the underlayer satisfies r _b > r _a .
For example, as described above, it is preferable that a mordant is introduced into the colorant receiving layer in the course of applying the 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). ) And the coating layer contains a cross-linking agent and a mordant before the coating layer is dried and before the coating layer exhibits a reduced rate of drying. You may use the method formed by the method (WOW method; Wet On Wet method) of apply | coating the solution (crosslinking agent solution) and then crosslinking-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 the present invention, the colorant-receiving layer is a barrier liquid made of a material that does not react with the crosslinking agent, and the coating liquid for the colorant-receiving layer and the crosslinking agent solution (however, at least one of a solution containing the crosslinking agent or a barrier liquid Can be obtained by simultaneously applying and curing in a state of sandwiching a mordant.

  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 vapor phase 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 comprising at least a compound represented by the general formula (1) and / or a compound represented by the general formula (2), vapor phase method silica, and polyvinyl alcohol, For example, 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 After being dispersed for 20 minutes (preferably 10 to 30 minutes) under the condition of high-speed rotation (preferably 5,000 to 20,000 rpm), an aqueous polyvinyl alcohol solution (for example, having a mass of about 1/3 of vapor phase silica) PVA is added, and the compound represented by the general formula (1) and / or the compound represented by the general formula (2) is further added and dispersed under the same rotational conditions as described above. be able to. The obtained coating liquid 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 a substrate 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 crosslinking agent solution, a surfactant, a pH adjuster, an antistatic agent, and the like can be further added to the colorant-receiving layer coating solution.
The colorant receiving layer coating solution is applied by, 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. It can be carried out. Further, a coating method using an extrusion die coater can also be used.
Among these, an extrusion die coater is preferably used because it is easy to form the colorant receiving layer in a predetermined range.

  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 still more preferable. As distance from a workpiece | work (information medium), 1-1000 mm is preferable, 10-200 mm is more preferable, 30-100 mm is still more preferable. As temperature, 10-40 degreeC is preferable, 15-35 degreeC is more preferable, and 20-30 degreeC is still more preferable. As humidity, 5-70% RH is preferable, 10-40% RH is more preferable, 20-50% RH is still 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 6,000 mPa · s, and still more preferably 10 to 3,000 mPa · s. The viscosity of the colorant-receiving layer coating solution is preferably 50 to 10,000 mPa · s, more preferably 100 to 6000 mPa · s, and still more preferably 200 to 3,000 mPa · s, in order to ensure the thickness. The number of rotations is preferably 10 to 1,000 rpm, more preferably 50 to 600 rpm, and still 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 10,000 rpm, more preferably 200 to 5,000 rpm, 300 More preferably, it is set to -3,000 rpm. The length of the nozzle is preferably 1 to 100 mm, more preferably 5 to 50 mm, and still more preferably 10 to 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. As distance from a workpiece | work, 0.5-100 mm is preferable, 1-50 mm is more preferable, and 2-20 mm is still more preferable. As temperature, 10-40 degreeC is preferable, 15-35 degreeC is more preferable, and 20-30 degreeC is still more preferable. As humidity, 5-70% RH is preferable, 10-40% RH is more preferable, 20-50% RH is still more preferable.
In addition, when apply | coating the 2nd liquid (crosslinking agent solution) mentioned later by spin coating, in order to ensure the uniformity of a coating film, the viscosity is preferable 0.1-1,000 mPa * s, 500 mPa · s is more preferable, and 2 to 300 mPa · s is still more preferable.

When applying the colorant-receiving layer coating solution, depending on the type of coating method, for example, when using the above-described spray coating or spin coating, first, for a region having a larger diameter than the base layer By applying and then cleaning and removing the end portions, the formation area of the colorant receiving layer can be controlled as in the present invention.
At this time, ion-exchanged water, alcohol, or a mixed solution thereof is used for washing.
On the other hand, when the colorant receiving layer coating solution is applied using an extrusion die coater, the colorant receiving layer forming region can be controlled by adjusting the length of the slit, which is preferable in the present invention. It is.

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

  Here, “before the coating layer comes to exhibit a decreasing rate of drying” usually means 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 handbook (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 coating layer of the colorant receiving layer may be dried by any drying method such as natural drying, hot air drying, low temperature set drying, infrared / far infrared drying, high frequency drying, oven drying and the like.
In the case of natural drying, the drying time of the coating layer is preferably 0.1 to 10,000 seconds, more preferably 1 to 1000 seconds, and still more preferably 10 to 500 seconds. The drying temperature is preferably 0 to 40 ° C, more preferably 10 to 35 ° C, still more preferably 20 to 30 ° C. The drying humidity is preferably 10 to 70% RH, more preferably 20 to 60% RH, and still more preferably 30 to 50% RH.

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

  In the case of low temperature set drying, the drying temperature of the coating layer is preferably 2 to 25 ° C, more preferably 5 to 15 ° C. The dry humidity is preferably 10 to 50% RH, and more preferably 10 to 30% RH. The temperature / humidity is preferably increased gradually or stepwise from low temperature and low humidity to high temperature and high humidity as the drying progresses. Note that the wind speed is preferably 3 m / s or more in parallel with the coating layer if a reduced drying rate is indicated.

In the case of infrared / far-infrared drying, the drying time of the coating layer is preferably 0.1 to 1000 seconds, more preferably 1 to 500 seconds, and still more preferably 10 to 300 seconds. . The output is preferably 10 to 2000 W, more preferably 50 to 1500 W, and still 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 coating layer is preferably 0.1 to 1,000 seconds, more preferably 1 to 500 seconds, and even more preferably 10 to 300 seconds.

  As a method of applying a crosslinking agent before the coating layer exhibits a reduced rate of drying, (1) a method of further coating a crosslinking agent solution on the coating layer, (2) spraying by a method such as spraying. And (3) a method of immersing the substrate on which the coating layer is formed in the crosslinking agent solution.

  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. Among them, it is preferable to use a method in which the coater does not come into direct contact with an already formed coating layer, such as an extrusion die coater, a curtain flow coater, and a bar coater.

The coating amount of the crosslinking agent solution containing at least a crosslinking agent and a mordant applied on the colorant receiving layer is generally 0.01 to 10 g / m ^{2 in} terms of crosslinking agent, 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, followed by drying and curing. Especially, it is preferable to heat at 40-150 degreeC for 1 to 20 minutes.
For example, when borax or boric acid as a boron compound is used in the crosslinking agent solution, it is preferable to perform heating at 60 to 100 ° C. for 5 to 20 minutes.

Moreover, you may provide the said crosslinking agent solution simultaneously with apply | coating a coloring material receiving layer coating liquid.
In this case, the colorant receiving layer coating solution and the crosslinking agent solution are simultaneously applied (multilayer coating) on the substrate so that both solutions are in contact with the substrate, and then dried and cured to form the colorant receiving layer. be able to.

The simultaneous application (multilayer application) can be performed by, for example, 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 using borax or boric acid as a boron compound in the crosslinking agent solution, it is preferable to heat 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 being transferred onto the substrate. In this state, a multilayer coating is applied on the substrate. Since the two-layer coating liquid layered before coating is likely to cause a crosslinking reaction at the interface between the two liquids when transferred to the substrate, the two liquids to be ejected are mixed near the discharge port of the extrusion die coater. This may increase the viscosity and hinder the application operation. Therefore, at the time of simultaneous coating as described above, a coating solution for the colorant-receiving layer and a crosslinking agent solution containing a crosslinking agent and a mordant, and a barrier layer solution (intermediate layer solution) made of a material that does not react with the crosslinking agent ) 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 crosslinking agent 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 the crosslinking agent, water, and the like can be given. Such a water-soluble resin is used in consideration of coatability for the purpose of a thickener and the like, and examples thereof include polymers such as hydroxypropylmethylcellulose, methylcellulose, hydroxyethylmethylcellulose, polyvinylpyrrolidone, and gelatin.
The barrier layer solution may contain the above mordant.

  Further, the colorant receiving layer in the present invention comprises a compound represented by the above general formula (1) and / or a compound represented by the general formula (2) and a binder in an aqueous dispersion composed of fine particles and a dispersant. A coating solution obtained by adding and redispersing a solution containing a solution (first solution) and a solution containing a crosslinking agent and a mordant (second solution) and redispersing the coating layer It may be formed by a method of forming the coating layer and then curing the coating layer. In this method, the pH of the coating solution for 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.

  Also in this method, a solution containing a compound represented by the general formula (1) and / or a compound represented by the general formula (2) and a binder in an aqueous dispersion composed of fine particles and a dispersant ( The coating solution obtained by adding and redispersing the first solution) and the solution containing the crosslinking agent and mordant (second solution) is a colorant-receiving layer coating solution in the WOW method as described above. It can apply | coat using the method and conditions similar to the time of apply | coating. Among these, an extrusion die coater is preferably used because it is easy to form the colorant receiving layer in a predetermined range.

Specific examples of the curing method and conditions for the coating layer when this method is used include C.I. A. The curing method and its conditions described in the edition of Finchi, “Chemistry and Technology of Water-Soluble Polymers” (1983) can be applied.
Among these, as the curing method, it is preferable to use low temperature set drying.
More specifically, first, the coating layer is dried under low temperature and low pressure until the fluidity of the coating solution on the surface is suppressed. In this case, the drying temperature is preferably 2 to 25 ° C, more preferably 5 to 15 ° C. Moreover, it is preferable to set it as dry humidity 10-50% RH, and it is more preferable to set it as 10-30% RH. When the coating layer changes from the constant rate drying region to the reduction rate drying region, it is preferable that the temperature / humidity is gradually or stepwise increased from low temperature and low humidity to high temperature and low humidity as the drying progresses. As conditions for high temperature and low humidity, the temperature is preferably 20 to 80 ° C, more preferably 30 to 60 ° C. Moreover, it is preferable that the dry humidity in that case shall be 5-30% RH, and it is more preferable to set it as 10-20% RH.
Note that the wind speed is preferably 3 m / s or more in parallel with the coating layer if a reduced drying rate is indicated.

  In forming the colorant-receiving layer in the present invention, as described above, a dispersant can be used in preparing an aqueous dispersion of fine particles. 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 a copolymer or a condensation polymer 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 1,000 to 200,000, and more preferably 3,000 to 60,000 in terms of weight average molecular weight. When the molecular weight is less than 1,000, the dispersibility may be inferior, and when 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 an aqueous dispersion comprising fine particles and a dispersant may be carried out by preparing a fine particle aqueous dispersion in advance and adding the aqueous dispersion to the aqueous dispersant solution, or adding the aqueous dispersant solution to the fine particle aqueous dispersion. Or may be mixed at the same time. Further, instead of the fine particle aqueous dispersion, fine powder particles may be added to the aqueous dispersant solution as described above.
An aqueous dispersion having an average particle diameter of 50 to 300 nm can be obtained by mixing the fine particles and the dispersant and then finely pulverizing the mixed liquid using a disperser. 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.
These dispersers can also be used when preparing an aqueous dispersion that does not use a dispersant.

  Moreover, water, an organic solvent, or these mixed solvents are mentioned as a solvent used for the coating liquid at the time of forming the color material receiving layer in this invention. Examples of the organic solvent 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.

The layer thickness of the color material receiving layer formed as described above needs to have an absorption capacity for absorbing all ink droplets when applied to inkjet recording. It is preferable to be determined according to the porosity of the. For example, when the ink amount is 8 nm / mm ² and the porosity is 60%, the layer thickness of the color material receiving layer needs to be 10 μm or more.
In consideration of these points, the layer thickness of the colorant receiving layer is specifically in the range of 10 to 100 μm from the viewpoint of the absorption capacity of ink droplets and the occurrence of warping or surface wobbling of the information medium. It is preferable to make it into the range of 15-80 micrometers, and it is still more preferable to set it as the range of 20-50 micrometers.

  After forming the color material receiving layer on the base layer as described above, the color material receiving layer is subjected to a calendar process through a roll nip under heat and pressure using, for example, a super calender, a gloss calendar, or the like. It is possible to improve surface smoothness, glossiness, 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 the conditions under which the decrease in the porosity is small.

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

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 pore median diameter 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.).

  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.).

<Intermediate layer forming step>
In this invention, you may have the process of providing an intermediate | middle layer between a base layer and a color material receiving layer. When this 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.
Or you may have the process of providing an intermediate | middle layer between a base layer and a board | substrate. In this case, the intermediate layer can improve the adhesion between the base layer and the substrate or can adjust the warpage of the entire information medium.
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 forming step>
In this invention, you may have the process of providing a surface layer on a color material receiving layer. By this 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 allowing it to permeate 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.

Through the above steps, the printable layer in the present invention can be provided. A disc-shaped information medium (hereinafter, simply referred to as “information medium”) having such a printable layer can be applied to a magnetic medium, an optical medium, a semiconductor medium, etc. In the case of a cartridge storage type, it is preferably removable. In particular, a disc-shaped optical information recording medium (optical disc) is preferable.
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, a bonded type such as a DVD, a type in which a recording layer and a cover layer are formed in this order on a 1.1 mm thick substrate, and a laser beam is incident from the cover layer side There is, but any 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.
Further, the disc-shaped information medium in 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.

  Hereinafter, the process of forming other elements in the method for manufacturing a disc-shaped information medium of the present invention will be described. Here, the substrate and the material of each layer and the method of forming the layer when the disc-shaped information medium is an optical information recording medium (optical disc) will be described, but these are merely examples, and the present invention has this configuration. The medium is not limited.

〔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 provided with irregularities (pregrooves) representing information such as tracking guide grooves or address signals.
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 still more preferably 250 to 350 nm.

In the case of DVD-R or DVD-RW, the pregroove track pitch 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 still more preferably 250 to 350 nm.

In the case of CD-R or CD-RW, the track pitch of the pregroove is preferably in the range of 1.2 to 2.0 μm, more preferably 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 and the like to prepare a coating solution. It forms by apply | coating to the surface side in which the pregroove was formed, forming a coating film, and 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.
When the temperature is lower than 23 ° C., the drying of the solvent becomes slow, and the target dye film thickness (recording layer thickness) cannot be obtained, or the coating and drying time becomes long, and the productivity may decrease.

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 No. 2000-43423, JP-A No. 2000-108513, JP-A No. 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 No. 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 reflection 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 metalloids or stainless steel. These light reflecting substances 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 can prevent 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 a spin coating method 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 optical information recording medium comprising a laminate in which a recording layer, a light reflection layer, a protective layer or an adhesive layer, a protective substrate (dummy substrate), and the like are provided in this order on the substrate is manufactured. .
The disc-shaped information medium according to the present invention is used because the track pitch of the pregroove formed on the substrate and the material constituting the recording layer are appropriately set so that the track pitch is narrower than that of a conventional DVD or the like. The present invention can also be applied to an information medium in which information can be recorded / reproduced with a laser beam having a wavelength smaller than that of the laser beam (for example, a blue-violet laser).

  The thickness of the obtained disc-shaped information medium is preferably 0.3 mm, more preferably 0.5 mm, and still 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 still more preferable. If it is too thin, defects may occur when bent. If it is too thick, the removable property may be inferior.

≪Disc information medium≫
The disc-shaped information medium of the present invention is a disc-shaped information medium comprising a printable layer including a base layer and a color material receiving layer on _a substrate, wherein the base layer has an outer peripheral radius ra, and the color material receiving layer When the outer peripheral radius of rb is r _b , the relationship of r _a ≧ r _b is satisfied.
That is, the disc-shaped information medium of the present invention can be obtained by the above-described method for manufacturing a disc-shaped information medium of the present invention.
Since the disc-shaped information medium of the present invention has excellent adhesion to the base layer even at the outer peripheral end of the color material receiving layer, peeling at the end of the color material receiving layer is prevented.

The disc-shaped information medium of the present invention, inner radius of the underlayer _'is, inner radius of the colorant receiving layer is r _b' r _a case where the relationship of r b _'≧ r _a' It is preferable to satisfy. Thereby, peeling can also be prevented at the inner peripheral end of the color material receiving layer.
For these reasons, the disc-shaped information medium of the present invention has an excellent effect that high-quality printing is possible up to the end.

  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”.

[Examples 1-4, Comparative Examples 1-2]
<< Production of disk-shaped substrate >>
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 had a groove depth: 140 nm, a groove width: 310 nm, and a groove pitch: 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 light reflecting 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 light reflecting layer, and a separately prepared polycarbonate disk-shaped protective substrate (diameter: 120 mm, thickness: 0.6 mm, r _c = 60 mm, r _{c ′} = 7.5 mm) are overlapped with the center aligned, rotated at 5000 rpm for 3 seconds, and UV curable resin (SD640, Dainippon Ink) Chemical Industries Co., Ltd.) was spread over the entire surface, and excess 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 light reflecting layer were formed was bonded to the disc-shaped protective substrate. The thickness of the bonding layer was 25 μm, and it was possible to bond without mixing bubbles.

  Next, a printable layer was formed on the surface of the disk-shaped protective substrate opposite to the laser light incident surface as follows.

UV curable ink (White No. 3, manufactured by Teikoku Ink Manufacturing Co., Ltd.) is printed on the disk-shaped protective substrate by screen printing. After printing, it is cured by irradiating with 80 W / cm ultraviolet light with a metal halide lamp. A base layer (white layer) of 8 μm was repeatedly formed in two layers with a total thickness of 16 μm. As the screen, a Tetron screen having 300 lines / inch mesh, a yarn diameter of 31 μm, and an opening of 38 μm was used.
Forming regions of the base layer, the outer peripheral radius r _a = 59.5 mm, was inner radius r _a '= 10.0mm.

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

-Preparation of coating solution for forming 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. Dispersed. Thereafter, the aqueous dispersion was mixed with a first solution composed of (3) polyoxyethylene lauryl ether, (4) 9% polyvinyl alcohol aqueous solution, and (5) diethylene glycol monobutyl ether, (6) boric acid, (7 A mordant and (8) a second solution comprising ion-exchanged water were added, respectively, and redispersion was performed under the same conditions as above to prepare a coating solution A.
The mass ratio of the silica fine particles to the water-soluble resin (PB ratio / (1) :( 4)) was 3.5: 1, and the pH of the coating solution A was 3.4, indicating acidity.

[Composition of coating liquid A]
(1) Gas phase method silica fine particles (inorganic pigment fine particles) 10.0 parts (average primary particle diameter: 7 nm; Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.)
(2) Ion-exchanged water 55.2 parts [first solution]
(3) Polyoxyethylene lauryl ether (surfactant) 3.5 parts (Emulgen 109P (10%), manufactured by Kao Corporation, HLB value 13.6)
(4) Polyvinyl alcohol 9% aqueous solution (water-soluble resin) 31.7 parts (PVA420, manufactured by Kuraray Co., Ltd., saponification degree 81.8%, polymerization degree 2,000)
(5) 0.5 parts of diethylene glycol monobutyl ether (compound represented by general formula (1))
[Second solution]
(6) Boric acid (6%; crosslinking agent) 10.4 parts (7) Mordant (PAS-F5000; 20% aqueous solution, manufactured by Nittobo Co., Ltd.) 2.5 parts (8) 5.3 parts of ion-exchanged water

-Formation of colorant receiving layer-
After performing the corona discharge treatment on the surface of the underlayer of the information medium, the coating liquid A obtained above was applied onto the underlayer using an extrusion die coater. Here, at the time of application, the length of the slit of the extrusion die coater was adjusted to control the formation region of the colorant receiving layer.
Then, it was dried in a low temperature and low humidity chamber at 5 ° C. and 10% RH until the fluidity of the coating solution on the surface was suppressed. The coating layer showed a constant rate of drying during this period. Immediately after that, it was dried for 10 minutes in a hot air dryer in an environment of 20 ° C. and 20% RH (wind speed: 4 m / sec).
The thickness of the colorant receiving layer after drying was 30 μm.
Thus, colorant receiving layer exhibiting an outer radius r _b and inner radius r _{b 'shown} in the following Table 1 was formed.
As described above, a disc-shaped information medium provided with a printable layer was obtained.

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

[Evaluation of adhesion (confirmation of peeling at end of colorant receiving layer)]
The disk-shaped information media of Examples 1 to 4 and the disk-shaped information media of Comparative Examples 1 to 2 were subjected to a drop test from the end surface three times repeatedly from the position of 3 m on the concrete floor surface, and the color The occurrence of defects in the material receiving layer was confirmed.
The results are shown in Table 1.

As apparent from Table 1, in the disk-shaped information media of Examples 1 to 4 that satisfy both the relationship of r _a ≧ r _{b and} the relationship of r _{b ′} ≧ r _{a ′} , the outer peripheral end and the inner periphery It can be seen that crack peeling does not occur at the end of the colorant receiving layer at any part of the end.

It is an expanded sectional view which shows the outer peripheral edge part of the printable layer in this invention.

Explanation of symbols

10 Substrate (member having a surface on which a printable layer is provided)
20 Underlayer 30 Dye recording layer 40 Printable layer

Claims (4)

A method for producing a disc-shaped information medium comprising a printable layer including a base layer and a colorant receiving layer on a substrate,
A step of providing the undercoat layer outer circumferential radius of r _a on the substrate,
On the underlayer, the outer peripheral radius is r _b, and a step of providing the colorant-receiving layer satisfies the relationship r _a ≧ r _b,
A disc-shaped information medium manufacturing method comprising: 2. The relationship of r _{b ′} ≧ r _{a ′} is satisfied when the inner peripheral radius of the underlayer is r _{a ′} and the inner peripheral radius of the colorant receiving layer is r _{b ′.} A method for producing a disc-shaped information medium according to claim 1. A disc-shaped information medium comprising a printable layer including a base layer and a colorant receiving layer on a substrate,
The outer periphery of the underlying layer radius is r _a, when the outer circumference radius of the colorant receiving layer is r _b, the disc-shaped information medium, characterized by satisfying the relation r _a ≧ r _b. 4. The relationship of r _{b ′} ≧ r _{a ′} is satisfied when the inner peripheral radius of the base layer is r _{a ′} and the inner peripheral radius of the colorant receiving layer is r _{b ′.} Disc-shaped information medium described in 1.

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