JP2012045714A - Inkjet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To color a recording medium without decreasing high gloss quality in an inkjet recording medium composed of a base material, a metal film and an ink absorbing layer.SOLUTION: In the inkjet recording medium, a refractive index of a first layer provided in an appreciation surface of the metal layer is different from that of a second layer provided on the appreciation surface of the first layer, and a thickness of the first layer (different refractive layer) is a value, which is a quarter integral number of a wavelength range of a visible light ray.

Description

  The present invention relates to a recording medium having a metallic luster with a high eye-catching effect that can be printed using an ink jet recording printer and having a color.

  In recent years, in order to obtain a printed matter with a high eye-catching effect using an inkjet recording method, development of an inkjet recorded image having a metallic luster has been advanced. As an ink jet recording medium, aluminum is vapor-deposited on a polyethylene terephthalate film, and this is adhered to one side of a recording sheet provided with a recording layer on the opposite side of the film-deposited surface or a support as in Patent Document 1. A metallic glossy recording medium in which a resin layer, a metal foil, and a recording layer are sequentially laminated has been proposed.

  In the ink jet recording medium composed of the base material, the metal film, and the ink receiving layer, high gloss can be obtained by the metal film. However, there are cases where it is felt that the glossiness alone is insufficient to attract people's eyes. In such a case, it has been difficult to adjust the color in a wide range with a metal film. Further, although a colored filter layer may be provided, there is a problem that lightness of the image itself is lowered due to absorption of light by the filter layer, and the metallic luster is also lost.

JP 11-327442 A

  An object of the present invention is to provide an ink jet recording medium having a high metallic luster, a color, and a high brightness and a high catch eye effect.

That is, the means for solving the above object are as follows.
The ink jet recording medium of the first aspect of the invention is an ink jet recording medium having at least a base layer, a metal layer and an ink receiving layer, and a refractive index of a different refractive index layer provided on the viewing side of the metal layer. However, the refractive index is different from the layer provided on the viewing side surface of the different refractive index layer, and the thickness of the different refractive index layer is an integral multiple of 1/4 of the visible light wavelength range. It is characterized by being.

Invention 2 is the invention 1 further comprising:
An ink receptive layer, a transparent base layer and a metal layer are provided in this order from the viewing side of the medium, and a different refractive index layer having a refractive index different from that of the transparent base layer is provided between the transparent base layer and the metal layer. Is provided.

Invention 3 is the invention 1 further comprising:
An ink receiving layer, a metal layer, and a base material layer are provided in this order from the viewing side of the medium, and a different refractive index layer having a refractive index different from that of the ink receiving layer is provided between the ink receiving layer and the metal layer. It is characterized by that.

Invention 4 is the invention 1 further comprising:
An ink receptive layer, a transparent substrate layer, a primer layer and a metal layer are provided in this order from the viewing side of the medium, and a different refractive index layer having a refractive index different from that of the primer layer is provided between the primer layer and the metal layer. It is provided.

Invention 5 is the invention 1 further comprising:
An ink receiving layer, a primer layer, a metal layer and a base material layer are provided in this order from the viewing side of the medium, and a different refractive index layer having a refractive index different from that of the primer layer is provided between the primer layer and the metal layer. It is characterized by that.

In the present invention, visible light has a wavelength range of 360 nm to 830 nm (see JISZ8120). The thickness of the different refractive index layer is desirably 2 μm or less at maximum. If it is thicker than this, the transparency is lowered and gloss is affected.
The difference in refractive index between the first layer and the second layer (that is, two layers having different refractive indices) may be 0.05 or more, more preferably 0.08 or more, and It is particularly preferred that there is one or more.
The thickness can be adjusted by adjusting the water concentration of the coating liquid for the different refractive index layer. If the amount of moisture is increased, the thickness goes in the thinner direction. If the moisture is reduced, the thickness can be increased.

  The two layers having different refractive indexes may be a combination of two layers such as a different refractive index layer and a base material layer, a different refractive index layer and an ink receiving layer, and a different refractive index layer and a primer layer.

  By having an integral multiple of 1/4 of the wavelength of visible light, for example, when the different refractive index layer has a thickness of 95 nm, the path length difference becomes 190 nm in the reciprocation, and the light with a wavelength of 380 nm is weakened. Will be yellowish. Further, when the thickness of the different refractive index layer is 190 nm, the path difference becomes 380 nm, and the light of 380 nm is strengthened, the light of 760 nm is weakened, and the color becomes bluish.

A preferred layer structure is, for example, as follows.
From the viewing side,
Example 1-Ink Receptive Layer, Transparent Substrate Layer, Different Refractive Index Layer and Aluminum Layer In Example 1, the different refractive index layer may contain a primer layer component. Example 2-Ink Receptive Layer, Transparent Substrate Layer, Primer Layer, Different Refractive Index Layer, and Aluminum Layer When the aluminum layer is the outermost layer as in Examples 1 and 2, a protective layer may be provided thereon.
Example 3-Ink Receptive Layer, Different Refractive Index Layer, Aluminum Layer, Base Material Layer In Example 3, the different refractive index layer may contain a primer layer component. Example 4-Ink Receptive Layer, Primer Layer, Different Refractive Index Layer, aluminum layer, base material layer and the like.

The different refractive index layer includes a substance for changing the refractive index. The ink jet recording layer usually contains many polymer materials, and these materials have a refractive index of about 1.5 to 1.55, and silica having a refractive index of about 1.45 is desirable. Titanium dioxide is effective for forming a different refractive index layer having a high refractive index.
As a binder when silica is used for the different refractive index layer, a binder having a low refractive index such as PVA or methacrylic resin may be selected.
When silica is used for the different refractive index layer, the binder of the layer provided on the different refractive index layer is a urethane resin having a relatively high refractive index of about 1.55 to 1.6, 1.6 to 1.7. It is desirable to use a polythiourethane resin or a polythioether polythiourethane resin having an index of refraction. At this time, if only the layer immediately above the different refractive index layer (the second layer) has a high refractive index, interference may occur between this layer and other layers. It is preferable to increase the refractive index in all layers other than the refractive index layer. For example, if urethane resin is used in the entire layer, it is desirable that the refractive index can be increased in layers other than the different refractive index layer.

  The base material used in the present invention includes natural pulp paper, synthetic fiber or so-called synthetic paper made of synthetic resin film, fiber structure (woven fabric, knitted fabric, non-woven fabric), inorganic sheet such as glass fiber sheet, synthetic fiber Resin films, glass, metal surfaces, plates or plywood, laminated plates, etc. can be used without any problem as long as they can be conveyed by a printer and can be recorded, have flexibility and bendability.

  As the transparent substrate, a polyester film, a polyolefin film, a cellulose film, a polyamide film, an aramid film, or the like can be suitably used. Among these, polyethylene terephthalate is particularly desirable.

The metal layer can be provided on the surface of the transparent film by vapor deposition, or can be provided by attaching a metal foil.
The metals used are aluminum, tin, zinc, gold, copper, etc., but aluminum is most desirable in view of cost in order to obtain high glossiness.
The thickness of the metal film is preferably 1 angstrom to 20 μm. When it is thinner than 1 angstrom, the metallic luster peculiar to the metal cannot be obtained, and when it is thicker than 20 μm, the effect of increasing the thickness cannot be obtained.

  The primer layer in this invention is for improving adhesiveness between the said transparent film and the said metal layer. The primer layer is made of a common coating method such as gravure coating method, spray coating method, etc. for organic solvent solution, aqueous solution of resin such as acrylic resin, nitrocellulose resin, urethane resin, melamine resin, epoxy resin, etc. Is applied to a uniform thickness and dried (cured in the case of a thermosetting resin, electron beam curable resin, ultraviolet curable resin, etc.) to form a coating film. The thickness of the primer layer is usually in the range of 0.005 to 2 μm, preferably in the range of 0.01 to 1 μm. The thickness of the primer layer is desirably thinner than the diameter of the fine particles when fine particles are put into the primer layer to form irregularities.

  In order to obtain high glossiness, the ink receiving layer used in the present invention is a dispersion resin such as urethane or acrylic known to create an ink receiving layer having good ink absorbability, water resistance and transparency. In addition, a resin obtained by crosslinking a dispersion resin such as urethane or acrylic with carbodiimide can be used more preferably. In particular, urethane resin is widely used as the resin.

As such an ink receiving layer, for example, those having the following constitution are known.
Ink-receiving layer as disclosed in JP-A-2003-166183, which includes a resin obtained by crosslinking a polyurethane resin having a silanol group with a crosslinking agent selected from polyisocyanate, polyethyleneimine, and carbodiimide resin. 75% by weight of polyurethane resin emulsion in Example 5 (Takelac XW-75-X35 (solid content 30% by weight) manufactured by Takeda Pharmaceutical Co., Ltd.) and 15% by weight of carbodiimide resin (Carbodilite V-02 manufactured by Nisshinbo Industries, Ltd.) % Ink receiving layer,
Ink-receiving layer described in JP-A No. 2004-345110 containing an acrylic polymer and a compound having a carbodiimide group,
An ink receiving layer containing a dispersion resin such as polyester urethane latex and acrylic silicone latex described in JP-A-2009-125958 and carbodiimide.
Further, an ink receiving layer containing two types of water-based urethane resin and water-based acrylic resin described in JP-A-2005-74880 and a crosslinking agent can also be used.
Furthermore, it seems that the dispersion resin and the urethane resin are cross-linked like a combined system of a dispersion resin such as a cationic acrylic silicon emulsion resin having a hydrolyzable silyl group as a crosslinking component and a cationic urethane resin. Those described in JP-A-2006-88341 are also preferable.

Examples of the urethane resin include polyesters and polyethers. Cationic polyether urethane resins are preferred.
Examples of the cationic urethane-based resin include polyester-based and polyether-based resins, but a cationic polyether-based urethane resin is preferable.
The acrylic resin is an acrylic polymer resin such as a polymer or copolymer of acrylic acid ester and methacrylic acid ester, or ethylene such as ethylene-vinyl acetate, ethylene-acryl-vinyl acetate, ethylene-vinyl chloride-vinyl acetate. -Vinyl acetate copolymer resin, acrylic-styrene copolymer resin, etc. can be illustrated. Cationic acrylic / styrene copolymer resins are preferred.
The weight percentage of the cationic acrylic silicone emulsion resin and the cationic urethane resin in the solid content of the ink receiving layer is 5 to 25% for the cationic acrylic silicone emulsion resin and 75 to 95% for the cationic urethane resin. Those are preferred.
Furthermore, it is preferable that the cationic acrylic silicone emulsion resin is 10 to 20% and the cationic urethane resin is 80 to 90%.

As the crosslinking agent, those selected from polyisocyanate, polyethyleneimine, and carbodiimide resin are used.
The carbodiimide resin is a water-soluble or water-dispersible carbodiimide compound obtained by sealing a terminal isocyanate group of a condensation reaction product obtained by decarbonization condensation of diisocyanates or diisocyanates and triisocyanates with a hydrophilic group. .
As diisocyanates and triisocyanates, any of alicyclic isocyanate, aliphatic isocyanate, and aromatic isocyanate may be used, and those having at least two, particularly two, isocyanate groups in the molecule are suitable. Examples of such isocyanates include 4,4′-dicyclohexylmethane diisocyanate (HMDI), tetramethylxylylene diisocyanate (TMXDI), isophorone diisocyanate (is an isocyanate compound having no isocyanate group bonded to a carbon atom of a methylene group in the molecule. IPDI), 2,4,6-triisopropylphenyl diisocyanate (TIDI), 4,4′-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), hydrogenated tolylene diisocyanate (HTDI), etc. Hexamethylene diisocyanate (HDI) and hydrogenated xylylene diisocyanate for alicyclic, aliphatic and aromatic isocyanates having two or more isocyanate groups bonded to carbon atoms of the methylene group H6XDI), xylylene diisocyanate (XDI), 2,2,4-trimethylhexamethylene diisocyanate (TMHDI), 1,12-diisocyanate dodecane (DDI), norbornane diisocyanate (NBDI), and 2,4-bis- (8- And isocyanate octyl) -1,3-dioctylcyclobutane (OCDI).
The compound that seals the terminal isocyanate group is a water-soluble or water-dispersible organic compound having a group capable of reacting with an isocyanate group, and is a monofunctional water-dispersible organic compound such as polyethylene glycol or polypropylene glycol. Examples include alkyl esters or monoalkyl ethers, or monofunctional organic compounds having a cationic functional group (for example, a group containing nitrogen) or an anionic functional group (for example, a group containing a sulfonyl group). Glycol monomethyl ether and polypropylene glycol monomethyl ether are preferred.

Example 1 Preparation of Inkjet Recording Medium 1 On one side of a 100 μm thick polyethylene terephthalate film, a different refractive index layer coating liquid 1 having the following composition was applied with a wire bar so that the thickness was 95 nm and dried. A different refractive index layer was provided. The refractive index of the different refractive index layer after coating and drying is 1.46.
<Non-refractive index layer coating composition 1>
Commercially available non-spherical silica sol 10 parts by weight (manufactured by Nissan Chemical Co., Snowtex UP, SiO ₂ concentration 20% by weight)
1 part by weight of polyvinyl alcohol 10 wt% aqueous solution (degree of saponification 96-98, degree of polymerization about 2600)
Ion-exchanged water 1589 parts by weight Surfactant (Asahi Glass, Surflon 145) 0.0001 part by weight is added and stirred.
Next, an aluminum layer having a thickness of about 500 angstroms is formed on the different refractive index layer by vapor deposition under reduced pressure conditions according to the description in JP-A-9-511955.
Subsequently, the next liquid is apply | coated to the surface opposite to the surface with the aluminum layer of this film, and it is set as an ink receiving layer.

<Ink-receiving layer forming composition 1>
Polyether urethane resin (Daiichi Kogyo Seiyaku Co., Ltd. Superflex 600 solids 25%) 93 parts by weight Carbodiimide (Nisshinbo Chemical Co., Ltd., trade name: Carbodilite V02-L2) 7 parts by weight

The weight ratio is a dry weight ratio.
The above components were sequentially added to ion-exchanged water and stirred, and then an ink receiving layer was provided so that the dried coating film had a thickness of 20 μm. Thus, an inkjet recording medium 1 was obtained.

Example 2 Production of Inkjet Recording Medium 2 A primer layer having the following composition was provided on one side of a 100 μm thick polyethylene terephthalate film so as to have a dry thickness of 0.5 μm.
(Composition 1 for primer layer)
-Polyurethane resin (N-5247 manufactured by Nippon Polyurethane Co., Ltd.) ... 100 parts by weight-Solvent (toluene / methyl ethyl ketone / IPA = 1/1/1) ... 100 parts by weight Next, the difference used in Example 1 on this primer layer. The coating liquid of the refractive index layer coating liquid formulation 1 was applied with a wire bar so that the thickness was 95 nm, and dried to provide a different refractive index layer.
Next, an aluminum layer having a thickness of about 500 angstroms is formed by vapor deposition under reduced pressure conditions on the different refractive index layer according to the description in JP-A-9-511955.
The ink receiving layer forming composition 1 used in Example 1 on the surface opposite to the surface having the aluminum layer of the polyethylene terephthalate film in which the primer layer, the different refractive index layer and the aluminum layer thus obtained were laminated in this order. Was applied so that the dried coating film was 20 μm, and an ink receiving layer was provided to obtain an inkjet recording medium 2.

Example 3 Production of inkjet recording medium 3 Based on the description in JP-A-9-511955, an aluminum layer having a thickness of about 500 angstroms was formed on one side of a polyethylene terephthalate film having a thickness of 100 μm by vapor deposition under reduced pressure conditions. did.
On this, the coating liquid of the different refractive index layer coating composition 1 used in Example 1 was applied with a wire bar so that the thickness was 195 nm, and dried to provide a different refractive index layer. On this different refractive index layer, the ink receiving layer forming composition 1 used in Example 1 was applied such that the dry coating film had a thickness of 20 μm, and an ink receiving layer was provided to obtain an inkjet recording medium 3.

Example 4 Production of Inkjet Recording Medium 4 An inkjet recording medium 4 was obtained in the same manner as in Example 3 except that the thickness of the different refractive index layer in Example 3 was applied to be 390 nm.

Example 5 Production of inkjet recording medium 5 Based on the description in JP-A-9-511955, an aluminum layer having a thickness of about 500 angstroms was formed on one side of a polyethylene terephthalate film having a thickness of 100 μm by vapor deposition under reduced pressure conditions. did.
On this, the coating liquid of the different refractive index layer coating composition 1 used in Example 1 was applied with a wire bar so that the thickness was 195 nm, and dried to provide a different refractive index layer.
Subsequently, the primer layer containing the titanium oxide fine particles of the primer layer composition 1 used in Example 2 was provided so as to have a dry thickness of 0.5 μm.
On this primer layer, the ink receiving layer forming composition 1 used in Example 1 was applied so that the dry coating film had a thickness of 20 μm, and an ink receiving layer was provided to obtain an ink jet recording medium 5.

<Evaluation of inkjet recording medium>
The inkjet recording media of Examples 1 to 5 were cut into A4 size, and photographic images were recorded with an inkjet printer (Epson PM-5000C). The following evaluation was performed on this recorded recording medium.
(1) Evaluation of the color of the recording medium The sensory test was performed on the color of the recording medium of Examples 1 to 5 and the influence on the photographic image.
(2) Evaluation of eye-catching effect Affixed to a white wall under a fluorescent lamp and visually observed from a distance of 10 m. If it is differentiated from the white of the wall and its presence is emphasized, it is judged as an eye catching effect, and if it is assimilated to the white of the wall and its existence is not obvious, it is judged as an inferior eye catching effect.
The results are shown in Table 1.

  As is clear from Table 1, the recording media of Examples 1 to 5 can give a color to a non-image portion without deteriorating the eye catching effect and without affecting the photographic image. The color of the recording medium may be evaluated by measuring the reflection spectrum in the visible region with a spectrophotometer, in addition to the sensory evaluation.

Claims (5)

  In an inkjet recording medium having at least a layer made of a substrate, a metal layer, and an ink receiving layer, the refractive index of the different refractive index layer provided on the viewing side surface of the metal layer is the viewing side of the different refractive index layer. An ink jet recording medium having a refractive index different from that of a layer provided on the surface, and a thickness of the different refractive index layer being an integral multiple of 1/4 of a visible light wavelength range.   In the ink jet recording medium, the ink receiving layer, the transparent base material layer, and the metal layer are provided in this order from the viewing side of the medium, and the transparent base material layer and the refractive index are provided between the transparent base material layer and the metal layer. The inkjet recording medium according to claim 1, wherein different refractive index layers having different values are provided.   In the ink jet recording medium, an ink receiving layer, a metal layer, and a base layer are provided in this order from the viewing side of the medium, and the ink receiving layer and the metal layer are different in refractive index from each other. The inkjet recording medium according to claim 1, further comprising a refractive index layer.   In the ink jet recording medium, an ink receiving layer, a transparent substrate layer, a primer layer, and a metal layer are provided in this order from the viewing side of the medium, and a primer layer and a refractive index are provided between the primer layer and the metal layer. The inkjet recording medium according to claim 1, wherein different different refractive index layers are provided.   In the inkjet recording medium, an ink receiving layer, a primer layer, a metal layer, and a base material layer are provided in this order from the viewing side of the medium, and the refractive index of the primer layer is different from that of the primer layer and the metal layer. The inkjet recording medium according to claim 1, further comprising a different refractive index layer.