JP2006082453A - Composition for inkjet accepting layer, medium for inkjet, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an accepting layer, and a medium for an inkjet, which enable a high-resolution image to be inexpensively formed by using an inkjet printer, and which can obtain the high-resolution image, so as to obtain printed matter with high designability, incapable of being easily imitated. <P>SOLUTION: The medium for the inkjet is constituted by providing the inkjet accepting layer with elasticity on a base through the use of a composition for the inkjet accepting layer with elasticity, containing latex and an inorganic pigment. The medium is set in the inkjet printer in an extended state, and contracted after output, so that the high-resolution output can be obtained; and laminating is applied to the medium. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet receiving layer composition suitable for image formation by an ink jet method, an ink jet receiving layer using the composition, an ink jet recording medium provided with the receiving layer on a substrate, and the ink jet medium. In particular, the present invention relates to a stretchable ink jet receiving layer (hereinafter sometimes referred to as “receiving layer”) and an ink jet medium (hereinafter also referred to as “media”).

  Currently, in addition to conventional printing methods such as letterpress, lithographic and stencil, electrophotographic laser printers and ink jet methods that draw ink on a substrate are used as image output methods. In particular, laser printers and inkjet printers do not require a plate, so even a small number of drawings can be output immediately, providing printing not only for general households but also for customers and for expiration dates. Individual output such as display is possible.

  As inks for this ink jet printer, solvent inks, UV inks, dye inks, aqueous pigment inks and the like are roughly used. The solvent ink contains a volatile organic solvent, and the organic solvent is volatilized to fix the ink on the medium. The UV ink is fixed to the medium by curing the ultraviolet curable resin in the ink by ultraviolet irradiation. For this reason, solvent ink and UV ink can be output to a wide variety of media regardless of the substrate. On the other hand, dye inks and water-based pigment inks are held and fixed in the receiving layer, so the media that can be used are limited, but they have better color development than solvent inks and UV inks, and form vivid images. I can do it.

  In addition, as an ink jet medium, a receiving layer using silica as an inorganic pigment and using polyvinyl alcohol as a binder is generally used so that ink can be absorbed quickly and bleeding does not occur. (See Patent Document 1).

  In this way, high-quality printing can be easily performed, and when scanners, printers, and peripheral devices become readily available, anyone can easily forge securities and identification cards. I came. For preventing forgery, there have been proposed a printing method in which fluorescent ink is not used for easy output, a method using micro characters to make reading difficult (see Patent Document 2), and the like.

  However, when fluorescent ink is used, this ink may be annoying, and there is an annoyance that it is necessary to replace the ink separately, and a dedicated nozzle is required, which complicates the printer. The micro characters were not worthy of cost.

  In addition, if high-definition output is possible by inkjet, output that is difficult to duplicate, that is, counterfeit becomes possible. However, ink-jet printing has adopted a method in which bubbles are generated by heat into a receiving layer using bubbles or piezo elements, and recently, ink droplets have been applied to minute inks such as micropicoliters. Although high image quality is achieved by spraying, there is a limit to the method of printing an image with high definition by controlling the nozzles or splashing droplets. Further, in the method of transferring by applying printing pressure such as relief printing or offset, since the ink film is pressed and crushed, it is not easy to obtain a high-definition image with a printed matter even if fine processing is performed on the plate.

  Furthermore, when creating a high-definition image, there is a method of performing laser etching using an electron beam. However, in this case, the output cost is high, and it is not suitable for producing a printed matter with high color design. It was. On the other hand, an inkjet printer can output only the required number of copies, which is advantageous in terms of cost. However, when creating a high-definition image, as described above, an output with a certain accuracy or more is required due to the structure of the printer. It was impossible to do. In addition, separately manufacturing a high-precision printer is disadvantageous in terms of cost, and with the improvement of a normal printer, there is a problem that scanning can be easily performed and imitation becomes easy.

JP-A-5-24336 Japanese Unexamined Patent Publication No. 1-222584

  The object of the present invention is to solve the above-mentioned problems of the prior art, and to obtain a printed matter that can form a high-resolution image with an inkjet printer at a low cost, has high designability, and cannot be easily imitated. Therefore, it aims at obtaining the inkjet receptive layer which can obtain a high-definition image, and the medium for inkjet.

  In order to solve the above problems, it is effective to set a stretchable medium in an ink jet printer in a stretched state and shrink the medium after output to obtain a high-definition output.

  However, when drawing on an elastic medium such as rubber by an ink jet printer, the ink repels with dye ink or pigment ink, and the ink cannot be fixed. On the other hand, solvent ink and UV ink can be output regardless of the media, but the color developability is poor and sufficient designability cannot be maintained. When a dye ink or pigment ink having good color developability is used, it is necessary for the receiving layer to absorb the ink and hold the ink. Therefore, the receiving layer for receiving the ink is necessary. However, in general, as a receiving layer for inkjet media, a method of holding silica by binding silica with polyvinyl alcohol as described above is employed. These conventional receptive layers are hardly stretchable and cannot be extended. Further, even when these conventional receiving layers were provided on a highly stretchable base material, the receiving layer peeled off from the base material at the time of extension, and output could not be performed.

  In order to overcome such problems, it is effective to set an ink-jet printer with a stretchable receiving layer extended, and then shrink the receiving layer after output to obtain a high-definition output. .

  For this method, the receiving layer composition is applied to a highly stretchable substrate, and the receiving layer is formed without breaking the receiving layer even if the substrate is extended. I need that.

  The present invention is an ink jet receiving layer composition that satisfies this requirement, that is, a stretchable composition containing latex and an inorganic pigment. Thereby, a receiving layer having elasticity can be produced.

  A high-definition reduced image can be obtained by outputting to the printer in a state where the receiving layer and the medium provided with the receiving layer are stretched, and contracting to the original state after the output.

  In particular, the composition for an inkjet receptive layer having stretchability can enhance the ability to retain inkjet ink when the weight ratio of the inorganic pigment to the weight of the solid content of the latex is 0.2 to 10.

Further, in the relationship between the surface area of the inorganic pigment used in the stretchable ink jet receiving layer composition and the oil absorption amount of the inorganic pigment, the oil absorption amount per 1 m ² of the surface area of the inorganic pigment is 6 μl or more. . As a result, a receiving layer having good ink absorbability can be produced without impeding stretchability.

Ｒは水素原子又はアルキル基
Ｒ１はアルキレン基又は−ＣＯＯＭで置換されたアルキレン基
Ｍは水素原子又はアルカリ金属原子
これにより、伸縮性のあるインクジェット受容層用組成物が良好に作製できる。 The stretchable ink jet receiving layer composition of the present invention is characterized by containing a polycarboxylic acid having the structure of the following general formula I.
Formula I

R is a hydrogen atom or an alkyl group R1 is an alkylene group or an alkylene group M substituted with —COOM is a hydrogen atom or an alkali metal atom. Thus, a stretchable composition for an ink jet receiving layer can be produced satisfactorily.

  The polycarboxylic acid is an acrylic acid / maleic acid copolymer. Thereby, the composition for inkjet receptive layers with elasticity can be produced favorably.

  The stretchable ink jet receiving layer composition of the present invention contains a cationic quaternary amine. Thereby, the composition for inkjet receptive layers with elasticity can be produced favorably.

  In addition, the stretchable ink-jet receiving layer composition of the present invention is characterized by containing a polysiloxane surfactant.

  The stretchable ink jet receiving layer composition of the present invention is characterized by containing a cross-linking agent.

  The present invention also provides an ink jet medium comprising a stretchable ink jet receiving layer comprising the ink jet receiving layer composition as described above.

  Further, the ink jet medium is characterized in that an ink jet receiving layer is provided on a stretchable substrate.

  Further, the present invention provides an image forming method for outputting an image to the ink jet medium by an ink jet printer in a state where the ink jet medium as described above is extended, and shrinking the image by shrinking the ink jet medium after the output. It is.

  Furthermore, after the image is formed by the image forming method, the ink-jet medium is laminated to suppress the extension of the ink-jet receiving layer or the ink-jet medium, and the reduced image is maintained.

  According to the present invention as described above, an ink jet receiving layer having stretchability can be obtained, and by using the ink jet receiving layer having stretchability, high definition that cannot be obtained by a normal printer or conventional media. It was possible to create a high density image. Furthermore, this makes it possible to provide a printed material with high designability and a printed material that can be easily prevented from being duplicated.

Hereinafter, although the concrete form of this invention is shown, this invention is not a thing limited to this.
The stretchable ink jet receiving layer composition of the present invention contains a latex and an inorganic pigment. The ink-jet medium having stretchability of the present invention includes a stretchable receiving layer composed of the composition for ink-jet receiving layer of the present invention.

  The stretchability of the ink jet receiving layer needs to be at least about 1.2 times or more in one direction, that is, an appropriate constant direction, and can be stretched in all directions, and in one direction such as the vertical direction and the horizontal direction. Alternatively, it is desirable that the film can be stretched by 1.5 times or more in the oblique direction, and more desirably, the shrinkage rate can be sufficiently increased and a high-definition image can be obtained if it is 2 times or more. If it is 3 times or more, it becomes difficult to read in a contracted state, and it can be used to prevent forgery. The receiving layer may or may not have the same stretchability in all directions.

In order to absorb the ink in the stretchable receiving layer, an inorganic pigment is added to the receiving layer, that is, the ink jet receiving layer composition. Examples of inorganic pigments include silica, calcium carbonate, magnesium carbonate, titanium dioxide, and the like, and sufficient ink can be absorbed without inhibiting the extension of the receiving layer. The shape of the inorganic pigment is not particularly limited, but it is desirable that the surface area is 50 m ² / g or less. When the surface area is 50 m ² / g or less, the bond with the binder is not so strong, and the extension of the receiving layer is not hindered. More desirably, 20 m ² / g or less can be suitably used.

  Also, the oil absorption amount of the inorganic pigment is not particularly limited, but if the oil absorption amount is 20 ml / 100 g or more, the ink can be absorbed even in a small amount, so that a sufficient amount of ink can be absorbed with a small addition amount of the inorganic pigment. I can do it. In particular, 40 ml / 100 g or more is preferable.

  The surface area and oil absorption of the inorganic pigment can be measured by the following methods. The surface area was measured by a BET method in which molecules having a known adsorption occupation area were adsorbed on the surface of the powder particles at the temperature of liquid nitrogen and the specific surface area of the sample was determined from the amount.

  For the oil absorption, 1 g of inorganic pigment is taken on a glass plate, boiled linseed oil is dropped in small amounts from the burette into the center of the sample, and each is thoroughly kneaded with a spatula. Repeat the dripping and kneading operations, and measure according to the method of JIS (K5101) with the end point when the whole becomes a hard lump-like lump for the first time, and the helix is rolled up with a steel spatula. went.

Since the surface area and the oil absorption amount are in a correlation, if the oil absorption amount per 1 m ² of the surface area of the inorganic pigment is 6 μl or more in the relationship between the surface area (m ² ) and the oil absorption amount (ml), the elongation is good and the absorbency is good. A receiving layer is formed. More preferably, it is 30 μl / m ² or more, and particularly preferably 100 μl / m ² can be suitably used.

  Specifically, as an inorganic pigment, calcium carbonate has good ink absorbability and is familiar with the binder.

  The receiving layer of the present invention, that is, the ink jet receiving layer composition, can use latex as a binder in order to bind an inorganic pigment and to give the receiving layer elasticity. Here, the latex includes natural rubber latex which is a natural product produced by plants, and also includes those in which a high molecular weight material is stably dispersed in an aqueous medium, including an aqueous dispersion of a synthetic polymer. That is, natural latex, synthetic rubber latex synthesized by an emulsion polymerization method, or artificial latex obtained by emulsifying and dispersing solid rubber in water can be used as the latex. Specifically, natural rubber (NR) latex, isoprene rubber (IR), styrene / butadiene copolymer latex (SBR), butadiene / acrylonitrile copolymer latex (NBR), methyl methacrylate / butadiene copolymer latex (MBR), polybutadiene latex, polychloroprene latex (CR), methacrylic acid ester / acrylic acid ester copolymer latex, acrylic acid ester / styrene copolymer latex, vinyl acetate / acrylic copolymer latex, vinyl acetate / There are maleic acid ester copolymer latex, aqueous polyurethane / urethane latex, fluorine rubber (FKM), and the like.

  Of these, natural rubber latex is particularly preferably used, and it is possible to obtain a very strong and flexible coating that is not found in molded products made of solid rubber. These latexes may contain only one kind, but may contain two or more kinds of latexes as appropriate.

  Although binders other than these latexes can be added, it is desirable that 70% by weight or more of the binder is latex. Thereby, the elasticity of the latex can be maintained. The amount of latex added is desirably 2% by weight or more as a latex solid content in the composition for the receiving layer, and if it is 5% by weight or more, sufficient stretchability can be imparted in a dried state. It is desirable because it is possible. Further, the latex content in the receiving layer is preferably 12% by weight or more, more preferably 30% by weight or more when the composition for the receiving layer is applied to a substrate and dried. With these addition amounts, the adhesion to the substrate can be increased and the extension can be made smoothly.

  As for the addition ratio of the latex and the inorganic pigment, it is desirable to add 0.2 to 10 times the weight of the inorganic pigment with respect to the dry weight (weight of the solid content) of the latex. Within this range, the ink can be sufficiently absorbed and retained. Furthermore, in the range of 0.5 to 5 times the amount, it is desirable that even if the thickness of the receiving layer is somewhat uneven, it is possible to suppress the occurrence of cracks during extension.

  The film thickness of the receiving layer can be arbitrarily changed according to the amount and particle size of the inorganic pigment contained in the receiving layer, and can also be adjusted arbitrarily according to the amount of ink discharged and the extension rate of the media or / and the receiving layer. I can do it. When the inorganic pigment has a fine particle size of 2 μm or less, the thickness of the receptor layer can be suppressed and the inorganic pigment can be made thin, and the precipitation of the pigment can be prevented. On the other hand, since the surface area per gram becomes small, the pigment of 2 micrometers or more can suppress the tendency which inhibits extensibility.

  An anti-settling agent may be added so that the inorganic pigment settles when the receptor layer is formed, and the ratio of the inorganic pigment does not change between the upper part and the lower part of the receptor layer. As an anti-settling agent, it may be thickened by a mineral such as bentonite to prevent settling, or a cellulose-based thickener may be used.

  On the other hand, by using a pigment with good sedimentation, forming a layer containing a large amount of binder in the upper layer and forming a layer containing a large amount of pigment formed by the precipitation of inorganic pigment in the lower layer, the substrate and the receiving layer are formed once. It is possible to take a method of manufacturing.

  Further, a hydrophilic polymer may be added in the receiving layer, that is, in the ink jet receiving layer composition, in order to absorb the ink in the stretchable receiving layer. Examples of hydrophilic polymers include gum arabic, starch derivatives such as dextrin, enzyme-modified dextrin, pregelatinized starch, phosphorylated starch, carboxymethyl starch, hydroxyalkyl starch, hydroxypropylated enzyme-degraded dextrin, octenyl succinated starch, carboxymethylcellulose , Carboxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, fiber derivatives such as hydroxyethyl methyl cellulose, alginate, propylene glycol alginate, polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, polyacrylic acid, polystyrene sulfonic acid, vinyl methyl ether / anhydrous Examples thereof include maleic acid copolymers and vinyl acetate / maleic anhydride copolymers.

Ｒは水素原子又はアルキル基
Ｒ１はアルキレン基又は−ＣＯＯＭで置換されたアルキレン基
Ｍは水素原子又はアルカリ金属原子 When a receptor layer is formed using latex, latex agglomeration may occur partially during drying, and uniform film formation may not be possible. This tendency is particularly strong when the amount of the inorganic pigment is larger than the amount of the latex, and it is difficult to produce a homogeneous material even if the film forming conditions are changed. In order to suppress such non-uniform aggregation, an inorganic pigment dispersant can be added to the ink jet receiving layer composition in order to increase the affinity between the pigment and latex and maintain the emulsion in an emulsified state. Examples of inorganic pigment dispersants include polycarboxylic acids, dicarboxylic acids such as maleic acid and fumaric acid, copolymers such as acrylic acid and methacrylic acid, copolymers of olefin and maleic anhydride, naphthalene sulfonate formalin condensate , Polyalkylene glycol acrylate and acrylic copolymer, and the like. In particular, it is desirable to add a polycarboxylic acid having the structure of the following general formula I, and the polycarboxylic acid is particularly a maleic acrylate copolymer. It is desirable that
Formula I

R is a hydrogen atom or an alkyl group R1 is an alkylene group or an alkylene group M substituted with -COOM is a hydrogen atom or an alkali metal atom

  By the addition of these inorganic pigment dispersants, the latex is stably present in the aqueous solution even in the presence of the inorganic pigment, and the homogeneous state can be maintained even during drying. The addition amount of the inorganic pigment dispersant is desirably 0.01 to 5 times the amount of the inorganic pigment, and if it is less than this, a sufficient effect cannot be expected. .

  The receiving layer of the present invention can contain a cationic quaternary amine as an ink fixing agent. Specifically, polydiallyldimethylammonium chloride, polydiallylmethylamine hydrochloride, poly (diallyldimethylammonium chloride / sulfur dioxide), poly (diallyldimethylammonium chloride / acrylamide), poly (diallyldimethylammonium chloride / diallylamine hydrochloride derivative) ), Poly (diallylamine hydrochloride / sulfur dioxide), and the like. These cationic ammonium salts may be added in advance to the composition for the receiving layer, but adverse effects caused by reaction with other substances added to the composition for the receiving layer, such as those in the emulsified state as described above. In order to prevent the harmful effects of coagulation, it is not possible to maintain the emulsified state of the latex by reacting with acrylic acid / maleic acid copolymer etc. when adding acrylic acid / maleic acid copolymer etc. for the purpose of maintaining the latex. After forming the receiving layer, it is desirable to immerse it in a cationic quaternary amine solution and apply it to the receiving layer.

  Furthermore, the receptor layer of the present invention, i.e., the ink jet receptor layer composition, is a cross-linking agent suitable for the type and amount of the latex used, additives and fillers, and a cross-linking agent suitable for the blended cross-linking agent Accelerators can be added. For example, sulfur, sulfur compound, p-quinone dioxime, p, p-dibenzoylquinone dioxime, 4,4′-dithiodimorpholine, poly-p-dinitrosobenzene, N , N′-m-phenylene dimaleimide and ammonium benzoate. In particular, thiosulfate can be used to crosslink the rubber in an emulsion state, and uniform crosslinking can be achieved by adding ammonium thiosulfate. Examples of the vulcanization accelerator as the crosslinking accelerator include aldehyde / ammonia series, aldehyde / amine series, guanidine series, thiazole series, sulfenamide series, thiuram series, dithiocarbamate series, and the like. Examples include 2-mercaptobenzothiazole Na salt (2-MBT-Na).

  In order to improve the adhesion to the substrate, a surfactant may be added to these receiving layers, that is, the ink jet receiving layer composition. Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, but adverse effects caused by reaction with other substances added to the receiving layer composition For example, when an acrylic acid / maleic acid copolymer is added for the purpose of maintaining an emulsified latex as described above, the emulsified state of the latex cannot be maintained due to reaction with the acrylic acid / maleic acid copolymer, etc. In order to prevent harmful effects and the like, it is desirable to use an anionic surfactant or a nonionic surfactant.

  Anionic surfactants include N-alkylsulfosuccinic acid monoamide disodium salts, N-methyl-N-oleyl taurine sodium salts, abietic acid salts, alkane sulfonic acid salts, alkyl naphthalene sulfonic acid salts, alkylphenoxy polyoxyethylene Propyl sulfonates, alkyl sulfate esters, olefin-maleic anhydride copolymer partial saponifications, dialkyl sulfosuccinates, styrene-maleic anhydride copolymer partial saponifications, naphthalene sulfonate formalin condensation Products, hydroxyalkane sulfonates, polyoxyethylene alkyl ether sulfate esters, polyoxyethylene alkyl ether phosphate esters, polyoxyethylene alkylsulfenyl ether salts, polyoxyethylene Lenalkylphenyl ether sulfates, polyoxyethylene alkylphenyl ether phosphates, polyoxyethylene styrylphenyl ether sulfates, sulfates of fatty acid alkyl esters, fatty acid monoglyceride sulfates, fatty acid salts, petroleum sulfonates, Examples include linear alkylbenzene sulfonates, branched alkylbenzene sulfonates, sulfated castor oil, and sulfated beef tallow oil.

  Nonionic surfactants include N, N-bis-2-hydroxyalkylamines, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, trialkylamine oxides, triethanolamine fatty acid esters, propylene glycol. Mono fatty acid esters, pentaerythritol fatty acid partial esters, polyethylene glycol fatty acid esters, polyoxyethylene alkyl amines, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene glycerin fatty acid partial esters, poly Oxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyoxyethylene polyoxypropylene alkyl ethers, polymers Oxyethylene - polyoxypropylene copolymers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene castor oil, polyglycerin fatty acid partial esters, fatty acid diethanol amides. In addition, fluorine-based surfactants, silicon-based surfactants, and the like are also preferably used. By adding these surfactants, the adhesion between the substrate and the receiving layer can be improved, and even if the stretch rate temporarily exceeds the set value, peeling of the receiving layer can be avoided. In particular, surfactants in which a part of polysiloxane is modified with polyalkylene ether among ethylene oxide adducts of acetylene glycol and silicon surfactants have improved affinity with the substrate, and the receiving layer is peeled off from the substrate. No longer.

  Furthermore, additives and fillers used in ordinary receiving layers such as pigment anti-settling agents, stabilizers, softeners, plasticizers, anti-aging agents, and the like can be appropriately added to the ink jet receiving layer composition.

  The receiving layer composed of the ink jet receiving layer composition as described above may be used alone as an ink jet medium, or the ink jet receiving layer composition may be used as a substrate, particularly a stretchable substrate. An ink-jet medium may be formed by coating to form a receiving layer. The base material having elasticity is not particularly limited, but a natural rubber sheet having good elasticity can be proposed. The stretchability of the base material may be appropriately determined according to the stretchability of the receiving layer, but it is necessary to extend at least about 1.2 times in one direction, that is, an appropriate constant direction, in all directions. In addition to being stretchable, it is desirable that the film can be stretched 1.5 times or more in one direction, for example, the longitudinal direction, the lateral direction, or the oblique direction, more preferably 2 times or more, and further preferably 3 times or more. In addition, the stretchability of the substrate may or may not have the same stretchability in all directions, and may not necessarily have the same stretch rate as the stretchability of the receiving layer. .

  The inkjet medium is formed by applying the emulsified ink-jet receiving layer composition to a base material, for example, a 0.1 mm sheet of natural rubber, using a bar coater or a roll coater, and heating the composition. What is necessary is just to provide and form a receiving layer on a base material by coagulating the composition and adhering to the base material.

  In addition, as a method of printing an image on the ink jet medium of the present invention, the ink jet printer can maintain the extension by, for example, pulling and stretching the medium by using energy from the outside and fastening the clip to a hard flat plate. In this case, the ink is supplied to the receiving layer and output, that is, printed, and after the output, the clip is removed and the medium is contracted by releasing the tension to the medium to return to the original size. The contraction in this case is performed by the contraction force and stretchability of the media itself without requiring external energy when the stretched tension is released.

  Furthermore, the base material is configured using a heat-shrinkable resin or the like that does not have stretchability and has only shrinkage due to external energy, and the medium is constructed by providing a stretchable receiving layer on the base material. In addition, after the output, the medium is heated to shrink the substrate, and the substrate is shrunk, and the receiving layer is shrunk to reduce the image to form an image. It is also possible.

  Furthermore, it is recommended to laminate the original media after output, because it becomes impossible to extend and read the reduced image and prevent it from being copied to a third party. Is done. The lamination process is usually performed on the image, that is, on the receiving layer, but may be performed on the back surface of the substrate not provided with the receiving layer. As the laminate, various liquid laminates and film laminates can be used.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples.
In the examples, the composition for inkjet receptive layer described below was applied to a 0.1 mm sheet of natural rubber as a base material using a bar coater, heated at 90 ° C. for 2 hours, and provided with a receptive layer. It was created. The output was extended by about 2 to 5 times in the vertical and horizontal directions using an inkjet printer JV4 manufactured by Mimaki Engineering.

In addition, a comparison was made with media using a receiving layer used in the following normal inkjet output paper.
Comparative Example Silica (particle size 5 μm, surface area 300 m / g, oil absorption 3.3 g / g) 10% by weight
Polyvinyl alcohol (Mw = 22,000) 4% by weight
Polyvinylpyrrolidone (Mw = 8,000) 1.5% by weight
Cationic ammonium (copolymer of quaternary ammonium salt and acrylamide) (PAS-J-81L manufactured by Nittobo Co., Ltd.) 0.5% by weight
The above aqueous solution was applied to a natural rubber sheet at 56 g / m ² and heated at 90 ° C. for 2 hours to provide a receiving layer to prepare a medium.
In this comparative example, the image was formed beautifully in the situation where the media was not stretched, but it was possible to stretch the media up to about 1.1 times in the vertical and horizontal directions. The receptive layer peeled off when extended forcibly.

Silica (particle size 5 μm, surface area 300 m / g, oil absorption 3.3 ml / g) 15% by weight
Acrylic acid / maleic acid copolymer (Kao Corporation, Pois 521) 6% by weight
Natural rubber latex (solid content 60%) 40% by weight
56 g / m ^{2 of the} above aqueous solution was applied to a natural rubber sheet and heated to prepare a medium.
After drying, it was immersed in a 20% aqueous solution of a fixing agent (PAS-J-81L manufactured by Nittobo Co., Ltd.) and dried.
In the situation where the image was not stretched, the image was formed beautifully, and the image could be stretched twice or more in the vertical and horizontal directions, and the ink could be held even when stretched twice.

Compositions 1 to 9 were obtained by changing the types and amounts of inorganic pigments and binders, and a receiving layer was prepared. The composition is shown in Table 1 below. In Table 1, the unit of the compound constituting the composition is% by weight in the ink jet receiving layer composition.

56 g / m ^{2 of the} above composition was applied to a natural rubber sheet and heated to prepare a medium. After drying, it was immersed in a 20% aqueous solution of a fixing agent (PAS-J-81L manufactured by Nittobo Co., Ltd.) and dried. Composition 1 was flexible and could absorb ink well even when extended. Compositions 2 and 3 were able to absorb ink firmly, although the extensibility was weaker than composition 1. Compositions 4, 5, and 6 can be sufficiently retained as the pigment ratio increases even if the ink discharge amount varies. Compositions 7, 8 and 9 have a slightly reduced stretchability due to the large surface area of the pigment, but with the stretch rate shown in Table 1, the receiving layer is not damaged and can retain sufficient ink. It was.

  When the media prepared by providing the receiving layers using all the compositions 1 to 9 were stretched at the stretch rate described in Table 1, respectively, and then output by an ink jet printer, and reduced to the original state, All images with high definition and high density (good color developability) were formed.

Compositions 10 to 18 were obtained by adding polyoxyethylene polyoxypropylene-modified polysiloxane surfactants as surfactants to the compositions 1 to 9 of Example 2 shown in Table 1. Specifically, KF-618 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used. The composition is shown in Table 2. This composition was applied to a natural rubber substrate in the same manner as in Example 2 to prepare a media, which was extended and evaluated. The composition is shown in Table 2 below. In Table 2, the unit of the compound constituting the composition is% by weight in the composition for inkjet receiving layer.

  Compared with the composition described in Table 1 of Example 2, the one added with the polysiloxane-based surfactant is from the base material even if it is extended to about 50% of the extension rate described in Table 1. The receiving layer did not peel off.

A composition 19 to 27 was obtained by adding a crosslinking agent and a crosslinking accelerator to the composition shown in Table 1 of Example 2. As the crosslinking agent, ammonium thiosulfate was used, and as the crosslinking accelerator, 2-mercaptobenzothiazole Na salt (2-MBT-Na) was used. The composition is shown in Table 3. In Table 3, the unit of the compound constituting the composition is% by weight in the ink jet receiving layer composition.

  Compared with the composition described in Table 1 of Example 2, the composition obtained by adding the crosslinking agent and crosslinking accelerator of Example 4 was extended to about 50% increase in the receptive layer extension rate described in Table 1. However, there was no fine crack in the receiving layer.

The composition for the receiving layer prepared with the composition described in Table 1 of Example 2 was applied to a natural rubber sheet at 56 g / m ² and heated to provide a receiving layer to prepare a medium, and then a fixing agent (Nittobo) It was immersed in a 20% aqueous solution of PAS-J-81L) and dried. After extending | stretching to the expansion rate of Table 1, it output with the inkjet printer, and after output, it shrunk | restored and returned to the original magnitude | size. By this operation, a high-definition image was formed, and the following liquid laminate was applied on the image and dried.

As the liquid laminate, 50 g / m ² of JET COART 5002K manufactured by NESCHEN was applied and dried.

  After the lamination process, the high-definition image was maintained as it was, but the receiving layer could not be extended again, and when it was extended forcibly, the image was broken. As a result, the reduced image cannot be expanded and read and prevented from being copied by a third party. Similar results were obtained with various liquid laminates and film laminates.

  The receiving layer of the present invention can be output in a stretched state, and a reduced image can be obtained by returning to the original state. Therefore, a high-definition output can be obtained with a normal inkjet printer, and it can be used for product tags. Can prevent impersonation. Further, when conductive ink is used, a higher density circuit can be created. If this receiving layer is applied to a rubber balloon, an individual design can be output by an ink jet printer, and the user's face can be photographed and output to the balloon.

Claims (12)

  A stretchable ink-jet receiving layer composition comprising a latex and an inorganic pigment.   The composition for an inkjet receiving layer having stretchability according to claim 1, wherein the weight ratio of the inorganic pigment to the weight of the solid content of the latex is 0.2 to 10. The composition for an inkjet receiving layer having stretchability according to claim 1 or 2, wherein the oil absorption amount per 1 m ² of the surface area of the inorganic pigment is 6 µl or more. The composition for an inkjet receiving layer having stretchability according to any one of claims 1 to 3, comprising a polycarboxylic acid having a structure of the following general formula I.
Formula I

R is a hydrogen atom or an alkyl group R1 is an alkylene group or an alkylene group M substituted with -COOM is a hydrogen atom or an alkali metal atom   The composition for an inkjet receiving layer having stretchability according to claim 4, wherein the polycarboxylic acid is an acrylic acid / maleic acid copolymer.   6. The composition for an inkjet receiving layer having stretchability according to claim 1, comprising a cationic quaternary amine.   The composition for inkjet receptive layers having stretchability according to any one of claims 1 to 6, comprising a polysiloxane surfactant.   A composition for an inkjet receiving layer having stretchability according to any one of claims 1 to 7, further comprising a crosslinking agent.   An inkjet medium comprising a stretchable inkjet receiving layer comprising the inkjet receiving layer composition according to any one of claims 1 to 8.   The inkjet medium according to claim 9, wherein the inkjet receiving layer is provided on a stretchable substrate.   Image formation in which the ink-jet medium described in claim 9 or 10 is stretched and output to the ink-jet medium by an ink-jet printer, and the image is reduced by shrinking the ink-jet medium after the output. Method.   An image forming method for maintaining a reduced image by forming an image by the method according to claim 11 and then laminating the ink jet medium to suppress expansion of the ink jet receiving layer or the ink jet medium.