JP3037007B2 - Inkjet recording sheet for labels - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet for labels, and more particularly to a method for suppressing bleeding of dots printed with an aqueous ink to obtain good image sharpness and color. And an ink jet recording sheet for labels.

[0002]

2. Description of the Related Art Ink-jet recording is a method in which minute droplets of ink are made to fly and adhere to a recording sheet such as paper by various operating principles to record images and characters. It has features such as easy multi-coloring, great flexibility in recording patterns, and no need for development-fixing.
It is rapidly spreading in various uses as a recording device for various figures and color images including kanji. Furthermore, the image formed by the multi-color ink jet method is compared with the multi-color printing by the plate making method and the printing by the color photographic method,
It is possible to obtain comparable records. In addition, in applications where the number of copies required is small, it is being widely applied to the field of full-color image recording because it is cheaper than the photographic technique.

[0003] Further, with the diversification of needs, recording sheets printed by the ink jet recording method are used for price display labels, product display (barcode) labels, quality display labels, weighing display labels, and advertising. It is increasingly used for label applications such as business labels (stickers). In particular, in the case of a bar code label, the high sharpness of the ink jet sheet can be utilized, and in the case of an advertising label, a good image can be obtained because of its excellent sharpness and color, and the advertising effect is large. It will be.
Further, the fact that an image having excellent image reproducibility such as sharpness and color reproducibility and color reproducibility can be easily obtained at a personal computer level is also a reason why the inkjet recording sheet is frequently used. In particular, labels adhere well to a wide range of adherends and are easy to attach,
It is used in many fields, and the use of the combination of the characteristics of a label and the characteristic that a good image of an ink jet recording sheet can be obtained is expanding. However, even if the ink jet recording sheet is applied to a label, unless the image reproducibility and the color reproducibility, which are features of the ink jet recording method, are excellent, the label ink jet recording sheet has no added value.

If an ink-jet recording sheet obtained by an existing technique is provided with an adhesive layer as it is for label specification, the ink oozes out, resulting in a decrease in sharpness and color due to an enlarged dot diameter. Image reproducibility tends to deteriorate. For this reason, improvements have been made to the formulation of the coating composition for the ink receiving layer, but at present, this problem cannot be avoided. For this reason, ink jet recording sheets for labels are required to suppress the bleeding of dots.Furthermore, with the recent visualization, the demand for ink bleeding has become quite severe. It is the current situation.

[0005]

SUMMARY OF THE INVENTION In view of the foregoing, an object of the present invention is to suppress the bleeding of dots printed with an aqueous ink and to provide an ink jet recording sheet for labels having excellent image sharpness and color. It is to get.

[0006]

The present inventors have conducted various studies on an ink jet recording sheet for a label. As a result, when an adhesive layer is provided on the sheet, the dot size of the printed dot of the ink receiving layer is enlarged. The components in the adhesive layer penetrate through the support to the ink receiving layer,
Further, it has been found that the components cause bleeding of the ink in order to change the receiving ability and the fixing ability of the ink receiving layer with respect to the aqueous ink. Depending on the type of the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer, the component refers to water as a solvent, an organic solvent such as ethyl acetate or toluene, a relatively low molecular weight plasticizer, or a surfactant.

From the above, it is considered that the problem of the ink jet recording sheet for a label described above can be avoided by preventing the penetration of the component from the adhesive layer to the ink receiving layer. That is, the ink jet recording sheet for labels of the present invention is an ink jet recording sheet for labels in which an ink receiving layer is provided on one side of a support mainly composed of wood pulp and an adhesive layer is provided on the other side. Wherein the barrier layer is provided between the support and the ink receiving layer or the adhesive layer, or both.

The ink jet recording sheet for labels according to the present invention has an ink receiving layer on one side and an adhesive layer on the other side with a support interposed therebetween, and the adhesive layer is bonded to a release paper. The barrier layer is provided on the support and the ink receiving layer as shown in FIG. 1, or on the support and the adhesive layer as shown in FIG. 2, and further on both the support and the ink receiving layer and on the support and the adhesive layer as shown in FIG. It was done. In addition, FIG.
3 is a schematic diagram for explaining the ink jet recording sheet for labels of the present invention, and does not limit the thickness, basis weight, coating amount, and the like estimated from these drawings, and the ink receiving layer-barrier Various layers are placed between the layers, between the barrier layer and the support, between the barrier layer and the adhesive layer, and between the adhesive layer and the release paper.
More than two layers may be provided.

The film-forming material of the present invention includes polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, and aqueous solutions such as casein, gelatin, soy protein, and silyl-modified polyvinyl alcohol. Conjugated diene copolymer latex such as maleic anhydride resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer; polymer or copolymer of acrylic ester and methacrylic ester; acrylic acid Acrylic polymer latex such as methacrylic acid or methacrylic acid polymer; vinyl polymer latex such as ethylene vinyl acetate copolymer; or functional group-containing monomer such as carboxyl group of these various polymers Functional group-modified polymer latex Aqueous adhesives such as thermosetting synthetic resin such as melamine resin and urea resin; synthetic resin adhesives such as polymethyl methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, and alkyd resin; For example, one or more types can be used to form a film.

[0010] Among the above-mentioned film-forming materials used for the barrier layer, emulsions or latexes may be used when the barrier layer is coated after the ink-receiving layer is applied. Since water and the like may penetrate into the ink receiving layer, a water-soluble polymer which is unlikely to cause such effects is particularly preferable. Further, the recording sheet is
When a thermoplastic resin such as polyethylene, polystyrene, polyvinyl chloride, or polyamide is provided by extrusion molding or injection molding, the object of the present invention is more reliably achieved. Furthermore,
Thermosetting resins such as urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester resin, alkyd resin, urethane resin, ebonite, or acetophenones, benzophenone, Michler's ketone, benzyl, benzoin, benzyldimethyl ketal, thioxanthone Acrylates and methacrylates by photopolymerization using photoinitiators such as polyester acrylates, epoxy acrylates, and polyester urethane acrylates. A barrier layer may be provided.

The barrier layer is preferably provided on a thickness basis, and the thickness needs to be varied by the roughness of the surface on which the barrier layer is provided or by a coating or impregnating apparatus. Is preferable. When the thickness is less than 0.5 μm, defects are likely to be partially generated in the barrier layer, and when the thickness exceeds 20 μm, the effect on the object of the present invention is not changed so much that it is only uneconomical.

The support according to the present invention includes LBKP, NB
Chemical pulp such as KP, GP, PGW, RMP, TMP,
Mainly wood pulp such as mechanical pulp such as CTMP, CMP and CGP, waste paper pulp such as DIP, etc., and conventionally known pigments, binders, sizing agents, fixing agents, retention improvers, cationizing agents, paper strength agents Base paper manufactured by using various equipment such as fourdrinier paper machine, circular net paper machine, twin wire paper machine, etc. Coated paper such as art paper, coated paper, cast-coated paper, and the like provided with is also included. An ink receiving layer may be directly provided on such base paper and coated paper, or a calendar device such as a machine calendar, a TG calendar, or a soft calendar may be used for the purpose of controlling flattening.

The ink receiving layer according to the present invention comprises a coating composition containing a pigment and a binder as main components, and additives such as a dye fixing agent, a pigment dispersant, a thickener, and a fluidity improver. , Defoamer, foam inhibitor, release agent, foaming agent, penetrant,
A coloring dye, a coloring pigment, a fluorescent whitening agent, an ultraviolet absorber, an antioxidant, a preservative, an antibacterial agent, a waterproofing agent, a wet paper strength enhancer, a dry paper strength enhancer, and the like can also be appropriately compounded. If necessary, a back coat layer may be provided on the surface opposite to the support provided with the ink receiving layer.

As the pigment used in the support, the ink receiving layer and the back coat layer, at least one known white pigment can be used. For example, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate,
Barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina , Lithopone, zeolite, hydrohaloysite, magnesium carbonate, white inorganic pigments such as magnesium hydroxide, styrene-based plastic pigments, acrylic-based plastic pigments,
Organic pigments such as polyethylene, microcapsules, urea resins, and melamine resins can be used.

The binder used for the support, the ink receiving layer, and the back coat layer includes polyvinyl alcohol, vinyl acetate, oxidized starch, etherified starch, cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, and soybean. Protein, silyl-modified polyvinyl alcohol, etc .; conjugated diene copolymer latex such as maleic anhydride resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer; polymer or copolymer of acrylate and methacrylate Acrylic polymer latex such as a polymer or copolymer of acrylic acid and methacrylic acid; vinyl polymer latex such as ethylene-vinyl acetate copolymer; or functional group such as carboxyl group of these various polymers Content simple substance Functional group modified polymer latex; water-based adhesive such as thermosetting synthetic resin such as melamine resin and urea resin; polymethyl methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, alkyd resin And the like, and one or more kinds are used.

As coating or impregnating devices for providing the ink receiving layer, the back coat layer, and the barrier layer, various blade coaters, roll coaters, air knife coaters, bar coaters, rod blade coaters, curtain coaters, short dwell coaters, Various devices such as a size press and a spray can be used on-machine or off-machine. After coating or impregnating each of the ink receiving layer, the back coat layer, and the barrier layer, a machine calendar, T
The finishing may be performed using a calendar such as a G calendar, a super calendar, or a soft calendar. When the barrier layer is provided with a thermoplastic resin, a laminator is generally used.

The pressure-sensitive adhesive layer according to the present invention is formed by providing a pressure-sensitive adhesive on a release-coated surface of a release paper described below, and overlapping the pressure-sensitive adhesive surface with the surface of the recording sheet on which the ink receiving layer is not coated, and pressing Although a method of pressure bonding with a roll or the like is generally performed, an adhesive may be applied to the recording sheet first, and the recording sheet may be bonded to a release paper. As the pressure-sensitive adhesive, a rubber-based or acrylic resin-based pressure-sensitive adhesive can be used. The rubber-based main raw material is natural rubber or styrene-butadiene rubber. In the case of natural rubber, a rosin-based resin or a plasticizer is added, and the coating is usually performed using normal hexane as a solvent. When styrene-butadiene rubber is used as the main raw material, it is melted and applied. In the case of an acrylic resin, it is produced by polymerizing acrylic monomers such as 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate, acrylic acid, and β-hydroxyethyl acrylate. Depending on the polymerization method, an organic solvent such as ethyl acetate or toluene may be used, or an emulsion type obtained by polymerization while emulsifying in water using a surfactant may be used.

Further, in order to improve physical properties such as heat resistance and solvent resistance of the pressure-sensitive adhesive, isocyanate-based materials
A melamine-based or metal-chelate-based crosslinking agent may be used to carry out a crosslinking reaction, or a pigment such as silica, kaolin, clay, calcium carbonate, aluminum hydroxide, zinc oxide, titanium oxide, melamine resin particles, or starch particles. Water soluble polymers, petroleum resins, various paraffin waxes, fatty acids or derivatives thereof, higher alcohols, metal soaps, silicones, antistatic agents, thickeners, dispersants, preservatives, oxidation You may add an inhibitor, an antifoaming agent, etc. These adhesives may be selected according to the use of the ink jet recording sheet for labels.

Apparatuses for providing the adhesive include air knife coaters, blade coaters, bar coaters, roll coaters, slot nozzles, slot dies, rotary screen printers, gravure coaters, offset gravure coaters, hot melt wheels, spiral sprays and the like. Selection may be appropriately made according to the use, such as the type and amount of the adhesive and the necessity of giving a pattern to the applied adhesive.

The base material of the release paper includes high-quality paper, kraft paper, glassine paper, plastic film, and the like. A silicone resin is applied as a release agent on these base materials. In the case of a paper-based substrate, the releasability improves when a thermoplastic resin is laminated on the substrate to obtain a smooth surface.
A silicone resin directly applied to a paper substrate is called a direct type, a thermoplastic resin applied after laminating a thermoplastic resin on a paper substrate is called a poly-laminate type, and a silicone resin applied directly to a plastic film is called a film type.
The criterion for selecting a release paper from among them is that the release paper has an adhesive force that does not peel off during transportation in an ink jet recording apparatus, and an adhesive force that is equal to or less than the peeling force of the labeler at the time of application by an automatic labeler. It is to be. Therefore, it is sufficient to select a release paper suitable for the application, and furthermore, if it is necessary to ensure curl aptitude, as a back surface treatment on the opposite surface of the base material coated with the silicone resin,
It is preferable to laminate a thermoplastic resin or coat a synthetic resin. For special applications, a non-silicone release agent may be used.

The aqueous ink referred to in the present invention is a recording liquid comprising a colorant, a liquid medium, and other additives. Examples of the coloring agent include a direct dye, an acid dye, a basic dye, a reactive dye, and a water-soluble dye such as a food colorant.

As a solvent for the aqueous ink, water and various water-soluble organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, Alkyl alcohols having 1 to 4 carbon atoms such as isobutyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethylene glycol and polypropylene glycol Polyalkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, Alkylene glycols having 2 to 6 alkylene groups such as lene glycol and diethylene glycol; lower alkyl ethers of polyhydric alcohols such as glycerin, ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether and triethylene glycol monomethyl ether; No. Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol, and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether are preferable. Other additives include, for example, P
Examples include an H regulator, a metal sequestering agent, a fungicide, a viscosity modifier, a surface tension modifier, a wetting agent, a surfactant, and a rust inhibitor.

The ink jet recording sheet for a label according to the present invention can be used not only as a label but also as a normal ink jet recording sheet, or used as any recording sheet using a liquid ink at the time of recording. It doesn't matter. For example, a heat-fusible substance, a heat-fusible ink containing a dye or pigment as a main component, applied on a thin support such as a resin film, high-density paper, or synthetic paper, is heated from the back surface, and the ink is heated An image-receiving sheet for thermal transfer recording, which is melted and transferred, an ink-jet recording sheet, which heats and melts a hot-melt ink to form fine droplets, and performs flight recording; an ink-jet recording sheet, which uses an ink in which an oil-soluble dye is dissolved in a solvent; And an image receiving sheet corresponding to a photosensitive pressure-sensitive donor sheet using microcapsules containing a type monomer and a colorless or colored dye / pigment.

A common feature of these recording sheets is that the ink is in a liquid state at the time of recording. The liquid ink permeates or spreads in the depth direction or the horizontal direction of the ink receiving layer of the recording sheet until it hardens, solidifies or fixes. The above-described various recording sheets require absorptivity according to each system, and the ink jet recording sheet of the present invention may be used as the above-described various recording sheets or label recording sheets. In addition, copiers
The ink jet recording sheet for a label according to the present invention may be used as a recording sheet for heating and fixing an electrophotographic toner widely used in a printer or the like, or as a recording sheet for a label.

[0025]

The inventors of the present invention have been studying ink jet recording sheets for labels and have noticed that the provision of an adhesive layer causes a decrease in sharpness and color of an image due to an increase in dot diameter. The enlargement of the dot diameter is a phenomenon in which the aqueous ink printed on the ink receiving layer is diffused in the surface direction without being absorbed in the thickness direction of the ink receiving layer, and the ink oozes out. The reason why such a phenomenon occurs by providing the pressure-sensitive adhesive layer is not clear, but from a physical point of view, the solvent contained in the pressure-sensitive adhesive (mainly water if the water-based, if the solvent-based Ethyl acetate, toluene, etc.) penetrates into the ink receiving layer through the support to change the structure of the ink receiving layer, or from a chemical point of view, the relatively low molecular weight plastic contained in the adhesive. It is conceivable that the agent or the surfactant permeates the ink receiving layer in the same manner as the solvent, and the fixing performance of the printed ink in the ink receiving layer changes.

The bleeding of the ink is self-evident,
It is related to the physical structure and chemical bonding of the ink receiving layer. The former physical structure is related to the thickness of the ink receiving layer and the progress in the plane direction, and the void amount of the ink receiving layer affects the physical structure. In particular, since the ink travels along the wall surface of the void, in the void having a large specific surface area, the ink cannot advance early in the ink receiving layer, and as a result, seepage of the ink is small. However, when a solvent penetrates from the outside, the pigment and the pigment constituting the ink receiving layer, and the voids formed by the pigment and the binder are destroyed, so that the specific surface area is reduced, and it is considered that the ink is likely to bleed. .

It is also considered that a change in the ability of the ink to fix the coloring agent of the ink is caused by mixing a cationic dye fixing agent in the ink receiving layer to suppress the bleeding of the ink. For example, if a plasticizer or a surfactant contained in the pressure-sensitive adhesive penetrates the ink receiving layer and combines with the dye fixing agent, the fixing performance for the printed ink is reduced.
In addition, the influence of a hydrophilic group or a hydrophobic group contained in a plasticizer or a surfactant may be considered. If there is a hydrophilic group in the surface layer of the ink receiving layer, the ink spreads in the surface direction of the ink receiving layer, and the inside of the ink receiving layer becomes hydrophobic. If there is a group, it spreads in the layer,
In any case, it is considered that ink seeps out.

For this reason, in the ink jet recording sheet for labels, it is necessary to provide the barrier layer according to the present invention in order to eliminate the influence of the adhesive. The barrier layer makes it possible to obtain an ink jet recording sheet for labels which does not have a decrease in sharpness or color, which is a characteristic of an ink jet recording sheet, even when an adhesive layer is provided.

[0029]

EXAMPLES The present invention will be described below with reference to examples of the present invention, but the present invention is not limited to these examples.
Further, "parts" and "%" shown in Examples are parts by weight and% by weight unless otherwise specified.

Example 1 A support was prepared by mixing light calcium carbonate / heavy calcium carbonate / talc with respect to 100 parts of wood pulp composed of 70 parts of LBKP (freeness of 400 mlcsf) and 30 parts of NBKP (freeness of 450 mlcsf). 25 parts of a pigment having a ratio of 30/35/35, 0.10 parts of a commercially available alkyl ketene dimer,
After preparing 0.03 part of a commercially available cationic acrylamide, 1.0 part of a commercially available cationized starch, and 0.5 part of a sulfuric acid band, papermaking was performed using a Fourdrinier paper machine with a basis weight of 70 g / m ² .

An ink receiving layer was provided on the surface of the support thus formed. 100 parts of synthetic amorphous silica (Fanseal X37B: manufactured by Tokuyama Soda Co., Ltd.) as an ink receiving layer composition;
Polyvinyl alcohol (PVA117: Kuraray) 3
0 parts, cationic dye fixing agent (SUMIREZ Resin 100
1: Sumitomo Chemical Co., Ltd.), and the solution was prepared to have a solid content of 13%. Using the adjusted ink receiving layer coating liquid, dry coating amount 5 with an air knife coater.
g / m ^{2 on the} surface of the support.

A barrier layer was provided on the back surface of the support provided with the ink receiving layer. The barrier layer is made of polyvinyl alcohol (PVA117: manufactured by Kuraray Co., Ltd.),
Coating was performed using an air knife coater so that the thickness after drying was 4 μm, and after drying, calendering was performed.

Next, a commercially available silicone resin was applied to the glassine paper with a gravure coater so as to be 1.0 g / m ^2, and then a commercially available water-based acrylic emulsion-type pressure-sensitive adhesive was applied to the silicone resin application surface side by dry coating. The solution was applied so as to have a pressure of 20 g / m ^2, and the pressure-sensitive adhesive-coated surface and the barrier layer were adhered with a press roll to obtain an ink jet recording sheet for label of Example 1.

Example 2 A support and an ink receiving layer were obtained in the same manner as in Example 1. The barrier layer was provided on the side of the support opposite to the ink receiving layer. The barrier layer is made of styrene-butadiene latex (062).
3: coated with an air knife coater, dried, and calendered on the back surface of the support provided with the ink receiving layer so that the thickness after drying becomes 4 μm. Was done. Then, the same silicone resin as in Example 1 was applied to glassine paper with a gravure coater so as to be 1.0 g / m ² , and then the same pressure-sensitive adhesive as in Example 1 was applied to the silicone resin-coated surface side in a dry coating amount of 20 g. / M ^2, and the pressure-sensitive adhesive-coated surface and the barrier layer were adhered to each other with a press roll to obtain a label ink jet recording sheet of Example 2.

Example 3 A support and an ink receiving layer were obtained in the same manner as in Example 1. The barrier layer was provided on the side of the support opposite to the ink receiving layer. The barrier layer is made of starch (MS3800: manufactured by Japan Food Processing Co., Ltd.). An air knife coater is used on the back surface of the support provided with the ink receiving layer so that the thickness after drying is 4 μm. After coating and drying, calender treatment was performed. Next, the same silicone resin as in Example 1 was applied to glassine paper with a gravure coater so as to be 1.0 g / m ² , and then the same pressure-sensitive adhesive as in Example 1 was applied to the silicone resin application surface side in a dry coating amount of 20 g / m ^2. the coating is m ^2, by bonding the adhesive coated surface and the barrier layer with a press roll to obtain a label for an ink jet recording sheet of example 3.

Example 4 A support and an ink receiving layer were obtained in the same manner as in Example 1. The barrier layer was provided on the side of the support opposite to the ink receiving layer. The barrier layer is made of a polyethylene resin, and the resin is heated and melted, and is applied by extrusion to the back surface of the support provided with the ink receiving layer so that the thickness after drying becomes 4 μm, and then cooled. Thereafter, a calendar process was performed. Then, the same silicone resin as in Example 1 was added to glassine paper at 1.0 g / m ^2.
After coating with a gravure coater, the same pressure-sensitive adhesive as in Example 1 was applied to the silicone resin-coated surface side in a dry coating amount of 20.
g / m ^2, and the pressure-sensitive adhesive-coated surface and the barrier layer were adhered to each other with a press roll to obtain an ink jet recording sheet for labels of Example 4.

Example 5 A support was obtained in the same manner as in Example 1. The barrier layer was provided between the support and the ink receiving layer. The barrier layer was composed of polyvinyl alcohol (PVA117: manufactured by Kuraray Co., Ltd.), and was coated with an air knife coater so that the thickness after drying was 4 μm, dried, and then applied on the barrier layer. The ink receiving layer was applied under the same composition and application conditions as in Example 1, and calendered. Then, Example 1 was applied to glassine paper.
After applying the same silicone resin as in Example 1 with a gravure coater so as to be 1.0 g / m ² , the same pressure-sensitive adhesive as in Example 1 was applied to the silicone resin-coated surface so as to have a dry coating amount of 20 g / m ^2. Then, the pressure-sensitive adhesive applied surface and the surface of the support not provided with the ink receiving layer were bonded with a press roll to obtain an ink jet recording sheet for label of Example 5.

Example 6 A support was obtained in the same manner as in Example 1. The barrier layer was provided on both sides of the support such that the thickness after drying was 2 μm. The barrier layer is made of polyvinyl alcohol (PVA).
117: manufactured by Kuraray Co., Ltd.), and each of the barrier layers was provided by an air knife coater. Thereafter, the ink receiving layer was applied on one side under the same composition and application conditions as in Example 1, and calendered. Next, the same silicone resin as in Example 1 was applied to glassine paper with a gravure coater so as to be 1.0 g / m ² , and then the same pressure-sensitive adhesive as in Example 1 was applied to the silicone resin application surface side in a dry coating amount of 20 g / m ^2. the coating is m ^2, and bonded to the surface of the adhesive coated surface and the ink receiving layer is not provided with a press roll to obtain a label for an ink jet recording sheet of example 6.

Example 7 A support was obtained in the same manner as in Example 1. The barrier layer was made of styrene-butadiene latex (0623: manufactured by Nippon Synthetic Rubber Co., Ltd.), and was provided before the ink receiving layer was applied. The barrier layer was provided using an air knife coater so that the thickness after drying was 4 μm. Thereafter, an ink receiving layer was applied on the opposite surface on which the barrier layer was provided under the same composition and application conditions as in Example 1, and calendered. Next, the same silicone resin as in Example 1 was applied to glassine paper with a gravure coater so as to be 1.0 g / m ² , and then the same pressure-sensitive adhesive as in Example 1 was applied to the silicone resin application surface side in a dry coating amount of 20 g / m ^2. It was applied so that the m ^2, a surface pressure-sensitive adhesive coated surface and the barrier layer is provided by bonding a press roll to obtain a label for an ink jet recording sheet of example 7.

Example 8 A support, an ink receiving layer and a barrier layer were obtained in the same manner as in Example 1. Thereafter, a calendar process was performed. Then, the same silicone resin as in Example 1 was added to glassine paper at 1.0 g / m ^2.
After coating with a gravure coater, a commercially available solvent-based (ethyl acetate / toluene) acrylic resin type pressure-sensitive adhesive was applied to the silicone resin-coated surface so as to have a dry coating amount of 20 g / m ^2. The pressure-sensitive adhesive-coated surface and the surface provided with the barrier layer were bonded with a press roll to obtain an ink jet recording sheet for a label of Example 8.

Comparative Example 1 A support and an ink receiving layer were obtained in the same manner as in Example 1. Calendar processing was performed without providing a barrier layer. Next, the same silicone resin as in Example 1 was applied to glassine paper with a gravure coater so as to be 1.0 g / m ² , and then the same pressure-sensitive adhesive as in Example 1 was applied to the silicone resin application surface side in a dry coating amount of 20 g / m ^2.
It was applied so that the m ^2, and bonded to the surface of the adhesive coated surface and the ink receiving layer is not provided with a press roll to obtain a label for an ink jet recording sheet of Comparative Example 1.

Comparative Example 2 A support and an ink receiving layer were obtained in the same manner as in Example 1. Calendar processing was performed without providing a barrier layer. Next, the same silicone resin as in Example 1 was applied to glassine paper with a gravure coater so as to be 1.0 g / m ² , and then the same pressure-sensitive adhesive as in Example 10 was applied to the silicone resin application surface side in a dry coating amount of 20 g.
/ M ^2, and the pressure-sensitive adhesive-coated surface and the surface on which the ink receiving layer is not provided were adhered with a press roll to obtain a label ink jet recording sheet of Comparative Example 2.

Comparative Example 3 A support was obtained in the same manner as in Example 1. The ink-receiving layer was formulated in the same manner as in Example 1. The amount of the dried coating was 10 g / m ² , and the solid content of the ink-receiving layer coating composition was 15%. Processing was performed. Next, the same silicone resin as in Example 1 was applied to glassine paper with a gravure coater so as to be 1.0 g / m ² , and then the same pressure-sensitive adhesive as in Example 1 was applied to the silicone resin application surface side in a dry coating amount of 20 g / m ^2. the coating is m ^2, and bonded to the surface of the adhesive coated surface and the ink receiving layer is not provided with a press roll to obtain a label for an ink jet recording sheet of Comparative example 3.

Evaluation was performed using the ink jet recording sheets for labels obtained in Examples 1 to 8 and Comparative Examples 1 to 3, and the results are shown in Table 1. The bleeding of the ink caused by providing the pressure-sensitive adhesive layer was compared with the samples without the pressure-sensitive adhesive layer of each of Examples and Comparative Examples, and the dot diameter (Do) of each label ink jet recording sheet provided with the pressure-sensitive adhesive layer and each Ratio (Do / Dn) to dot diameter (Dn) of each ink jet recording sheet without an adhesive layer corresponding to Examples and Comparative Examples
Was evaluated. This ratio (dot enlargement ratio: Do / Dn) is 1.
If it exceeds 0, it indicates that the dot is enlarged, and 1.2
When the value exceeds, the sharpness and the chromaticity decrease become clear, which affects the subjective image evaluation, and becomes a problem. The dot diameter is
The circle-equivalent diameter defined by the following Equation 1 was used. For the measurement of Do and Dn, each sample was placed in an environment of 20 ° C and 65% RH for 24 hours.
After leaving for a period of time to adjust the humidity, dots are printed with black ink using an ink jet printer (IO-720: manufactured by Sharp Corporation) under the same environment, and measurement is performed using an image analyzer.

The notices in Table 1 have the following meanings. * 1: A barrier layer was provided between the ink receiving layer and the support, and between the adhesive layer and the support. * 2: Indicates that the ink receiving layer was applied after providing the barrier layer. * 3: Indicates that the coating amount of the ink receiving layer is 10 g / m ² .

[0046]

Di = {(4 / π) × Ai} ^1/2 where Di is a circle equivalent diameter (dot diameter), Ai is an actually measured area, and i is an adhesive corresponding to each of Examples and Comparative Examples. It is a variable indicating the presence or absence of the agent layer (equivalent to i = 0 or i = n).

[0048]

[Table 1]

[0049]

As is apparent from the above, according to the present invention, by providing a barrier layer composed of a film-forming material between an ink receiving layer and an adhesive layer in an ink jet recording sheet for labels, ink bleeding is prevented. A small number of ink jet recording sheets for labels can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an ink jet recording sheet for a label in which a barrier layer is provided between an ink receiving layer and a support.

FIG. 2 is a cross-sectional view of an ink jet recording sheet for labels in which a barrier layer is provided between an adhesive layer and a support.

FIG. 3 is a cross-sectional view of an ink jet recording sheet for a label provided with a barrier layer between the ink receiving layer and the support, and between the adhesive layer and the support.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink receiving layer 2 Barrier layer 3 Support 4 Barrier layer 5 Adhesive layer 6 Release paper

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-212846 (JP, A) JP-A-4-341885 (JP, A) Japanese Utility Model sho 59-110666 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B41M 5/00 B44C 1/16-1/17

Claims (3)

(57) [Claims] 1. In a label ink jet recording sheet having an ink receiving layer on one side and an adhesive layer on the other side of a support mainly composed of wood pulp, a barrier layer made of a film-forming material is provided on the support. An ink jet recording sheet for a label, wherein the ink jet recording sheet is provided on one or both of a body and the ink receiving layer or the adhesive layer. 2. The ink-jet recording sheet for labels according to claim 1, wherein the film-forming material comprises a water-soluble polymer. 3. The ink jet recording sheet for labels according to claim 1, wherein the film-forming material is made of a thermoplastic resin.