JP4040415B2 - Image forming method using recording medium - Google Patents

Description

【００６９】
【発明の効果】
以上説明したように、本発明の、記録媒体の製造方法を利用した画像記録物の製造方法によれば、インクジェット装置におけるプリントヘッドや液体組成物塗布ローラー表面における固着を発生することなく、被覆層形成後のべとつきもなく、画像品位、耐ガス性、耐擦性に優れた小型化が容易な画像記録物形成方法において、被膜層形成に必要な表面ｐＨが制御され、優れた光沢感、インク吸収性を有する記録媒体の製造方法を提供することが可能である。[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an ink jet recording medium.Recorded images usingIt relates to the manufacturing method.
[0002]
[Prior art]
The ink jet recording method is a method in which micro droplets of ink are ejected by various operating principles and attached to a recording medium such as paper to record images, characters, etc. In other words, it has features such as a large flexibility in recording patterns, no need for development and fixing, and in recent years, it has been rapidly spread in various applications including information equipment as a recording apparatus for various images. Furthermore, images formed by the multi-color ink jet method can obtain a recording that is comparable to multi-color printing by the plate-making method and printing by the color photographic method. Since it is cheaper than multi-color printing or printing, it is being widely applied to the field of full-color image recording.
[0003]
In recent years, a recording medium having a coating layer using an alumina hydrate having a boehmite structure has been proposed, and is disclosed, for example, in JP-A-7-232475 (Patent Document 1).
[0004]
In these recording media using alumina hydrate, since the alumina hydrate has a positive charge, the ink dye is well fixed and an image with good color can be obtained.
[0005]
Furthermore, a recording medium having glossiness and image quality comparable to a silver salt photograph has been proposed by glossing the ink-receiving layer containing alumina hydrate. For example, JP-A-06-79967 (Patent Document) 2) etc. are disclosed. Recording media using these alumina hydrates have advantages such as being preferable to conventional recording media in terms of image quality, particularly in full-color images and glossiness.
[0006]
However, although the recording medium using the dye-based ink and the alumina hydrate as described above has an image quality comparable to or exceeding that of the silver salt print, the formed high-quality image is maintained for a long time. In particular, the present situation is that, in particular, resistance to deterioration (gas resistance) due to substances such as ozone gas in the air does not have satisfactory performance.
[0007]
As a technique aiming at improving image durability comparable to silver salt photography, a method of providing a protective layer on the surface of a recording material after image formation is disclosed. For example, a method of laminating various plastic films as a protective film on an image recording material is disclosed in Japanese Patent Application Laid-Open No. 2001-158092 (Patent Document 3).
[0008]
Japanese Patent Laid-Open No. 10-315448 (Patent Document 4) and the like include fine particles made of a thermoplastic polymer in an ink receiving layer of a recording medium, and printing is performed while maintaining ink absorbability. Thereafter, a method is described in which the fine particles are melted and dissolved with heat or a solvent to form a resin film on the surface to form a protective film.
[0009]
As an example of using the same system as the image forming method as means for forming a coating layer, Japanese Patent Application Laid-Open No. 2000-225695 (Patent Document 5) discloses a liquid composition containing a resin having a film forming function such as an emulsion by an ink jet system. A method of forming by discharging is disclosed.
[0010]
On the other hand, regarding the control of the surface pH of the recording medium, for example, JP-A-11-34484 (Patent Document 6), JP-A-2001-347750 (Patent Document 7) and the like are disclosed.
[0011]
[Patent Document 1]
Japanese Unexamined Patent Publication No. 7-232475
[Patent Document 2]
Japanese Unexamined Patent Publication No. 06-79967
[Patent Document 3]
Japanese Patent Laid-Open No. 2001-158092
[Patent Document 4]
JP-A-10-315448
[Patent Document 5]
JP 2000-225695 A
[Patent Document 6]
Japanese Patent Laid-Open No. 11-34484
[Patent Document 7]
JP 2001-347750 A
[0012]
[Problems to be solved by the invention]
However, in the method described in JP-A-10-315448 (Patent Document 4) and the like, although the gas resistance is surely good, in addition to the image recording apparatus, fine particles made of a laminating apparatus or a thermoplastic polymer are used. It is necessary to provide a separate melting / dissolving device, and there is a problem that the device becomes large
In addition, in the method disclosed in Japanese Patent Application Laid-Open No. 2000-225695 (Patent Document 5), the use of a resin having a self-forming film, such as an emulsion, as an ink jet recording liquid prevents solidification due to long-term standing at the tip of a fine nozzle. May cause.
[0013]
On the other hand, regarding the control of the surface pH of the recording medium, the method described in Japanese Patent Application Laid-Open No. 11-34484 (Patent Document 6) increases the cost by adding the post-treatment of the acid treatment and castability by excessive mixing of the acid to the raw material. Defects may occur. In addition, when silica fine particles are used in the ink receiving layer as in JP-A-2001-347750 (Patent Document 7), a cationic resin must be added as a colorant fixing agent, and light resistance There is a problem in that balancing is difficult.
[0014]
  The present invention has been made for the purpose of solving the above-mentioned problems, and does not cause sticking or nozzle clogging, does not cause stickiness after forming a coating layer, and has a high gloss image even with a downsized apparatus. INK JET RECORDING MEDIUM MANUFACTURING METHOD CAPABLE OF FORMING IMAGE RECORDED MATERIAL FORMABLE FOR FORMATIONFORMING METHOD USING INK JET RECORDING MEDIUMIs to provide.
[0015]
[Means for Solving the Problems]
  The above object is achieved by the present invention described below. That is, the present inventionA method of forming an image recorded matter having a coating layer on at least a part of an image,
  The following general formula:
-COOA
(However, A in the above general formula represents an alkali metal, ammonium or organic ammonium.)
A step of preparing an aqueous liquid composition containing in a dissolved state a polymer having a group having a structure represented by:
  Preparing an image recording material having an image formed by an ink jet recording method on an ink jet recording medium, wherein the surface pH of the image is a pH at which the polymer is insoluble;
  Forming the coating layer by applying the liquid composition to at least a part of the image of the recorded matter and insolubilizing the polymer contained in the liquid composition according to the surface pH of the image; ,
  Have
  The inkjet recording medium isOne or more layers are laminated on a substrate, and an ink receiving layer containing alumina hydrate as the outermost layer is formed.Have andA coating solution containing alumina hydrate is applied and dried to form the ink receiving layer, and then swollen again with a buffer solution. The surface of the ink receiving layer is pressure-bonded to a heated mirror drum and dried. Method for manufacturing inkjet recording medium to be processedProduced by the
It is characterized byIt is a method of forming an image recording.
[0016]
  In the present invention, the polymer contained in a dissolved state in the liquid composition applied to at least a part of the image is insolubilized by the action of the surface pH of the image to form a coating layer. According to this coating layer, it is possible to have an effect of improving the image quality, and it is possible to impart gas resistance and abrasion resistance to the image. In addition, the formation position of the coating layer on the image is not limited to a colored portion by a coloring material such as a dye, and may be only a non-colored portion.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
[0018]
  In the present inventionUsed inThe recording medium is formed by ejecting a recording liquid containing a coloring material by an inkjet recording method to form an image on the recording medium, and then applying a liquid composition onto at least the image of the recording medium to form a transparent coating layer. Used in an image forming method.
[0019]
This liquid composition for forming a coating layer contains a polymer having a carboxylate. This polymer is dissolved in an aqueous medium, and insolubilization is performed by the action of the surface pH of the image to which the liquid composition is applied. As a preferred embodiment, a liquid composition adjusted to a pH higher than the surface pH of the image is applied onto an image having a pH lower than that of the liquid composition, thereby forming a coating layer by insolubilizing the polymer. The method of performing can be mentioned. That is, the polymer in the liquid composition applied on the image is instantly insolubilized on the image, and the polymer and the aqueous medium (solvent component) are separated into solid and liquid, and the aqueous medium component further records the image. By being absorbed in the medium, a coating layer obtained from the polymer insolubilized on the image is formed.
[0020]
Further, the means for applying the liquid composition onto the recording medium is not particularly limited, and it has already been applied by a general coating method such as a roll coater or a reverse coater, or by an inkjet recording method in the same manner as a recording liquid containing a coloring material. It is applied on a recording medium on which an image is formed. In addition, when the ink jet recording method is used, the coating layer forming site by the polymer in the liquid composition may be only the colored portion of the image on the recording medium or the entire surface. Further, it is not always necessary to cover the entire image portion. In some cases, the coloring portion of the color material is not covered, and the purpose may be to protect the surface of the image in the blank portion and to prevent the stain. In particular, by using an ink jet recording method, it is easy to make the coating layer thin and uniform, and further, by adding the nozzle for the liquid composition to the ink jet recording head by the same method as the image forming method. Since it is not necessary to separately provide a unit for forming the coating layer, the size can be reduced.
[0021]
In order to form such a coating layer, the surface pH of the recording medium must be controlled to a value that can insolubilize the polymer of the liquid composition. The surface pH that can be insolubilized may be appropriately selected depending on the polymer used in the liquid composition, but a preferable range is a surface pH of 4.0 to 7.0. If the surface pH exceeds this range, insolubilization of the polymer may be difficult to occur on the recording medium, and a sufficient coating layer may not be formed. Further, if the surface pH is less than this range, the recorded image may be bronzed. More preferably, the surface pH range is increased from 5.4 to 7.0. By adjusting to this range, it is possible to prevent the color change of the recorded image.
[0022]
In the present invention, in order to adjust the surface pH of the recording medium, a coating liquid is applied and dried on a substrate to form an ink receiving layer, and then re-swelled with a buffer solution, and the surface is heated. Press to dry. Known buffers such as Clark-Lubs buffer solution, Kolthoff buffer solution, and Michaelis buffer solution can be used as the buffer solution. Specific examples include acetic acid and sodium acetate, tartaric acid and sodium tartrate, lactic acid and sodium lactate, phosphoric acid and sodium phosphate, citric acid and sodium citrate, and the like. Preferably, from the viewpoint of re-swellability of the alumina hydrate used in the ink receiving layer, an acetic acid and acetate buffer can be used.
[0023]
The temperature of the mirror drum to be bonded is preferably 60 ° C. to 150 ° C., more preferably 70 ° C. to 120 ° C. If the drum temperature does not fall within this range, drying is insufficient or excellent glossiness is difficult to obtain. When the temperature exceeds this range, it becomes difficult to obtain excellent glossiness due to rapid drying of the rewetting liquid.
[0024]
Further, the press pressure at the time of pressure bonding is preferably in the range of 10 kg / cm to 100 kg / cm, more preferably in the range of 15 kg / cm to 80 kg / cm. When the press pressure is less than this range, it is difficult to obtain excellent glossiness. When the press pressure exceeds this range, the pores are collapsed and it is difficult to obtain sufficient absorbability of ink and auxiliary liquid.
[0025]
If the rewetting liquid uses water or hot water instead of a buffer solution, even if the surface pH of the recording medium before the glossing process is set to a desired pH, for example, 4.0 to 7.0, the ink is received at the stage of the glossing process. When the surface of the layer is in contact with water or hot water, the acid component is washed away from the surface of the recording medium, and it becomes difficult to control the surface to a desired surface pH. Also, when the amount of acid to be washed away is predicted and the surface pH of the ink receiving layer before the glossing process is adjusted to be low in advance, or when the rewetting liquid is adjusted to a low pH beforehand with a single acid species, Stable glossiness becomes difficult to obtain due to poor glossing (cracking, etc.) and pH fluctuations of the rewetting liquid during long run.
[0026]
The pH value of the buffer solution in the present invention is preferably adjusted to a range of pH 4.0 to 6.0. When the pH of the buffer exceeds the above range, the surface pH after the gloss treatment may not be controlled to a value of 7.0 or less. On the other hand, when the amount is less than the above range, the pigment used in the ink receiving layer may aggregate and an excellent glossiness may not be obtained.
[0027]
In the present invention, as an auxiliary means for adjusting the pH with the buffer solution, it is preferable to adjust the pH of the coating solution for the ink receiving layer to 4.0 to 6.0. If the pH exceeds this range, it may be necessary to use a relatively low pH buffer in order to adjust the surface pH after glossing to 4.0 to 7.0, and a sufficiently glossy surface cannot be obtained. There is. On the other hand, when the pH is less than this range, the pigment used in the ink receiving layer may aggregate and an excellent glossiness may not be obtained.
[0028]
As the constitution of the recording medium in the present invention, a recording medium provided with a porous ink receiving layer mainly composed of pigment is preferably used.
[0029]
As the substrate, papers such as appropriately sized paper and non-size paper can be used. In particular, the surface pH of the base material is preferably the same as or lower than the surface pH of the recording medium from the viewpoint of storage stability of the recording medium.
[0030]
Furthermore, in consideration of gas intrusion from the back side, a gas sealed with a laminate after performing a glossing treatment is also preferably used.
[0031]
The ink receiving layer of the recording medium in the present invention is preferably formed so that the total pore volume is in the range of 0.35 to 1.0 ml / g, more preferably 0.4 to 0.9 ml / g. When the pore volume of the ink receiving layer is larger than the above range (cracking or dusting occurs in the ink receiving layer), and when the pore volume is smaller than the above range (the ink absorption is poor, especially when performing multicolor printing). In some cases, ink overflows from the ink receiving layer and bleeding tends to occur in the image).
[0032]
The BET specific surface area of the ink receiving layer is 50 to 300 m.²/ g range is preferred, more preferably 100-300m²/ g. If it is smaller than this range, the glossiness of the ink receiving layer is lost, and haze increases, so that the image may appear white. On the other hand, if it is larger than the above range, the ink receiving layer may be easily cracked.
[0033]
The BET specific surface area and pore volume can be determined by a nitrogen adsorption / desorption method after deaeration treatment at 120 ° C. for 24 hours.
[0034]
The material for forming the ink receiving layer having the above physical properties is not particularly limited, but preferred examples include alumina hydrate represented by the following general formula.
[0035]
On the other hand, as the alumina hydrate used for forming the ink receiving layer provided on the substrate, for example,
1) The ink absorption speed is fast and there is no more blur than necessary.
2) High print density and color development,
3) Excellent weather resistance
A material that satisfies the desired characteristics such as the above and that can form the above-described ink receiving layer having the predetermined gloss is used.
[0036]
As such an alumina hydrate, what is represented by the following general formula can be mentioned as a suitable thing.
[0037]
Al₂O_3-n(OH)_2n・ MH₂O
In the formula, n represents an integer of 0, 1, 2, or 3, and m represents a value of 0 to 10, preferably 0 to 5. mH₂Since O represents a detachable water phase that is not involved in the formation of crystal lattice in many cases, m can take a non-integer value. Moreover, when this type of alumina hydrate is calcined, m may reach a value of zero. Note that m and n are not 0 at the same time.
[0038]
The alumina hydrate is adjusted in pore properties during the production process, but in order to satisfy the BET specific surface area and pore volume of the ink receiving layer, the pore volume is 0.3 to 1.0 ml / g. Alumina hydrate is preferably used, more preferably 0.35 to 0.9 ml / g. Alumina hydrate having a pore volume in this range is more suitable for bringing the pore volume of the ink receiving layer within the specified range. Moreover, about BET specific surface area, it is 50-350m.²/ g alumina hydrate is preferably used, more preferably 100 to 250 m²/ g. Alumina hydrate having a BET specific surface area within this range is more suitable for setting the specific surface area of the ink receiving layer within the specified range.
[0039]
The amount of dispersion applied is 0.5 to 60 g / m in terms of dry solid content.², More preferably 5 to 45 g / m²The thickness of the ink receiving layer is, for example, 15 μm to 60 μm, preferably 20 μm to 55 μm, particularly preferably 25 μm to 50 μm, in order to obtain good ink absorbability and resolution. Can do.
[0040]
  Next, in the present inventionLiquidThe body composition will be described. Carboxylates in liquid compositionsAsThe polymer may be any polymer that can be stably dissolved in the liquid composition and insolubilized by the action of the surface pH of the image to form a stable layer. For example, a vinyl copolymer obtained by using one or more acrylic monomers such as acrylic acid, methacrylic acid, maleic acid, maleic acid half ester, and itaconic acid can be added by adding a basic substance. A solubilized one is preferred.
[0041]
The basic substance at this time is not particularly limited, and alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, ammonia water, monoethanolamine, diethanolamine, triethanolamine, monohydrate. Examples thereof include isopropanolamine diisopropanolamine, triisopropanolamine, morpholine, aminomethylpropanol, aminomethylpropanediol, aminoethylpropanediol and the like.
[0042]
The monomer that can be copolymerized with the acrylic acid-based monomer is not particularly limited as long as it can form a polymer having the desired characteristics. At least one kind can be used. That is, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, n- (Meth) acrylate monomers such as hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, further, styrene monomer, Benzyl (meth) acrylate, 2-anthryl (meth) acrylate, 2- (benzoyloxy) ethyl (meth) acrylate, 2- (5-ethyl-2-pyridyl) ethyl (meth) acrylate, [1,1'-biphenyl ] -4-yl (meth) acrylate, 7-oxo-1,3,5-cycloheptatrien-1-yl (meth) acrylate 8-quinolyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, 1-methylhexyl (meth) acrylate, 1-methylheptyl (meth) acrylate, 2-methylpentyl (meth) acrylate, 1 -Cyclohexyl-3-azetidinyl (meth) acrylate, 9-carbazolylmethyl (meth) acrylate, tetrahydro-2H-pyran-2-yl (meth) acrylate, 3-nitrophenyl (meth) acrylate, 1- (3- Perylenyl) ethyl (meth) acrylate, (3-methyloxiranyl) methyl (meth) acrylate, and the like, and at least one selected from these can be used.
[0043]
Examples of the counter ion (A in the present invention) include alkali metals, ammonium, and organic ammonium, and at least one selected from these can be used.
Examples of the alkali metal include lithium, sodium, potassium, rubidium and the like, and examples of the organic ammonium include monoethanolammonium, diethanolammonium, triethanolammonium, monoisopropanolammonium, diisopropanolammonium, triisopropanolammonium, Examples thereof include alkylammonium and alkanolammonium such as monomethylammonium, dimethylammonium, trimethylammonium, monoethylammonium, diethylammonium and triethylammonium.
[0044]
  The carboxylate of the present inventionAsThe acid value of the polymer is preferably 50 or more and 300 or less. If it is less than 50, a problem may occur in terms of adhesion. In particular, when a thermal ink jet is used, it may cause scorching on the heater, and stable ejection properties may not be obtained. On the other hand, if it exceeds 300, insolubilization of the copolymer on the paper surface becomes difficult to occur, the surface pH of the recording medium for forming the coating layer must be extremely lowered, and there is a problem with color and bronze of the image. It may become.
[0045]
The preferred content ratio of the polymer as the carboxylate, the water-soluble organic solvent and water in the liquid composition in the state before the addition of the basic substance for solubilization to the liquid composition is about the polymer Can be selected from the range of 1 to 15% by mass, 0 to 90% by mass for the water-soluble organic solvent, more preferably 5 to 70% by mass, and 9 to 99% by mass for water.
[0046]
In addition, the liquid composition of the present invention can also contain a color material for the purpose of decoration (such as logo placement with a thin blue), etc., but in this case, since the color material is present in the coating layer, Gas resistance (such as a logo) tends to be slightly inferior to the color material present in the ink receiving layer. Accordingly, the color material concentration in the liquid composition is preferably 0.5% or less, more preferably 0.2% or less.
[0047]
Next, the recording liquid containing the color material in the present invention will be described.
[0048]
In the present invention, the components of the coloring material may be known per se, and examples thereof include water-soluble dyes represented by direct dyes, acid dyes, basic dyes, reactive dyes, food dyes and the like. Such a water-soluble dye is generally used in a ratio of about 0.1 to 20% by mass in the recording liquid.
[0049]
The solvent used in the recording liquid used in the present invention is water or a mixed solvent of water and a water-soluble organic solvent, and those listed above as the liquid composition for forming a coating layer are preferably used. The content of the water-soluble organic solvent in the recording liquid is generally in the range of 0 to 95% by mass, preferably 10 to 80% by mass, more preferably 20 to 50% by mass with respect to the total mass of the ink. is there.
[0050]
Further, the recording liquid used in the present invention may include a surfactant, a viscosity adjuster, a surface tension adjuster, a pH adjuster, a fungicide, a rust preventive, and the like as necessary in addition to the above components.
[0051]
【Example】
EXAMPLES Hereinafter, although a manufacture example and an Example demonstrate this invention further, this invention is not limited to these. The physical property values were measured by the following methods.
[0052]
Surface pH
The surface pH of the ink receiving layer of the ink jet recording medium was measured using a pH measurement set for paper (manufactured by Kyoritsu Riken; model MPC) according to Japan TAPPI No 49-2 (coating method).
[0053]
Glossiness
The 20 ° glossiness on the ink receiving side was measured based on JIS-Z-8741 using a digital variable gloss meter (manufactured by Suga Test Instruments Co., Ltd.).
[0054]
* Printing
Using an inkjet recording apparatus (BJF660 manufactured by Canon Inc.) having an on-demand type multi-recording head that discharges ink by applying thermal energy corresponding to the recording signal to the ink, monochrome printing (100%) of color ink having the following composition Thereafter, the liquid composition was solid-printed (200%) by the same method so as to completely cover the portion where the solid-print of each color ink was performed.
[0055]
Ink composition
・ Ink dye (Y, M, C, Bk) 5 parts
・ Ethylene glycol 10 parts
・ Polyethylene glycol 10 parts
・ 75 parts of water
Ink dye
Y: C.I. Acid Yellow 23
M: C.I. Acid Red 52
C: C.I. Direct Blue 199
Bk: C.I. Food Black 2.
[0056]
* Gas resistance test
After forming a black monochromatic image part (100%) on the prepared recording medium by an ink jet recording method, a test sample is formed by discharging a liquid composition for forming a coating layer containing a water-soluble polymer by the ink jet recording method. Was put in an ozone exposure tester (manufactured by Suga Test Instruments Co., Ltd.) and exposed to ozone at a concentration of 3.0ppm for 6 hours under conditions of 23 ° C and 60% RH, and the gas resistance was exposed to ozone. Evaluation was based on the percent change in image density after the test.
Gas resistance (%) = (Image density after ozone exposure test / Image density before ozone exposure test) x 100 (%)
* (Color)
The color of the cyan single color image portion (100%) created above was visually evaluated according to the following criteria. ○: No change in color.
Δ: Slightly reddish.
X: Metallic luster (bronze)
[0057]
(Manufacture of liquid composition)
{Liquid composition A}
A liquid composition A having the following composition was prepared using a styrene-acrylic copolymer A (acid value 200, molecular weight: 10,000) synthesized by a solution polymerization method using a radical initiator. In addition, potassium hydroxide was used as a basic substance, and the addition amount was adjusted so that the pH of the liquid composition was 8.0.
・ Styrene-acrylic copolymer A 3 parts
・ Glycerin 7 parts
・ Diethylene glycol 5 parts
・ 85 parts of water.
[0058]
[Production example]
Disperal HP15 (trade name: manufactured by SASOL) was mixed with pure water as alumina hydrate to obtain a dispersion having a solid content of 22% by mass. Next, 2% of a mixed solution of acetic acid / nitric acid = 1.4 / 0.6 with respect to the solid content was added thereto and stirred for a while. Thereafter, the dispersion was heated to 90 ° C. with stirring, and held at that temperature for 2 hours. Thereafter, the temperature of the dispersion was returned to room temperature, and the coarse particles were separated by a filter to obtain an alumina dispersion A. When this alumina dispersion A was dried and measured by X-ray diffraction, it had a pseudo boehmite structure.
[0059]
Polyvinyl alcohol PVA117 (trade name: manufactured by Kuraray Co., Ltd.) was dissolved in pure water to obtain a 9% by mass solution. The alumina dispersion A and the polyvinyl alcohol solution were mixed and stirred so that the alumina hydrate solid content and the polyvinyl alcohol solid content were 100: 9 in mass ratio, and dispersion B (pH 5. 0) was obtained.
[0060]
[Comparative Example 1]
Base material (basis weight 150g / m², Steecht sizing degree 50 seconds, surface pH 5.4) 5wt% sodium tetraborate aqueous solution in advance with air knife coater 10g / m²After coating, Dispersion B is die coated to a dry thickness of 35g / m²And recording medium A was prepared. Furthermore, 20g / m of polyethylene²The back surface was processed by extrusion lamination, and the recording medium 1 was produced.
[0061]
[Example 1]
The surface of the ink-receiving layer of the recording medium A was subjected to a rewet cast treatment using a pH 4.2 buffer solution (sodium acetate: 0.10 wt% + acetic acid: 0.50 wt%) using a rewet cast coater. Furthermore, 20g / m of polyethylene²The recording medium 2 was obtained by bonding to the back surface by extrusion lamination. The obtained recording medium 2 had excellent gloss.
[0062]
[Example 2]
Base material (basis weight 150g / m²Steecht size 50 seconds, surface pH 6.8) 5wt% sodium tetraborate aqueous solution in advance with air knife coater 10g / m²After applying,
Dispersion B is dried by die coating 35g / m²Then, the recording medium 3 was produced. The surface of the ink receiving layer of the recording medium 3 was subjected to a rewet cast treatment using a pH 5.5 buffer solution (sodium tetraborate: 0.37 wt% / succinic acid: 0.27 wt%) using a rewet cast coater. Furthermore, 20g / m of polyethylene²The recording medium 4 was obtained by sticking to the back surface by extrusion lamination. The obtained recording medium 4 had excellent gloss.
[0063]
[Example 3]
A recording medium 5 was obtained in the same manner as in Example 2 except that the buffer solution of Example 2 was changed to a pH 3.5 buffer solution (potassium hydrogen phthalate: 0.10 wt% / hydrochloric acid: 0.03 wt%). The obtained recording medium 5 had excellent gloss.
[0064]
[Comparative Example 2]
A recording medium 6 was obtained in the same manner as in Example 2 except that the buffer solution in Example 2 was changed to hot water (100 ° C.). Although the obtained recording medium 6 had excellent glossiness, the surface pH was high, and when the liquid composition was applied, a coating layer was not formed, and gasity was inferior.
[0065]
[Comparative Example 3]
A recording medium 7 was obtained in the same manner as in Example 2 except that the buffer solution in Example 2 was changed to an aqueous nitric acid solution having a pH of 2.0. The gloss of the cast surface was somewhat low and defects due to countless fine casting defects were observed. In addition, in the application of the liquid composition, the coating layer was not formed at the minute defect portion, and a gas deterioration site was generated.
[0066]
  [Example 4]
  Dispersion used in Example 2Liquid mixture added during production of alumina dispersion A used to obtain BA recording medium 8 was obtained in the same manner as in Example 2 except that the mixture ratio of acetic acid / nitric acid was changed to 0.5 / 1.5 and the pH of the dispersion was changed to 3.5. The obtained recording medium 8 was found to have a portion where a casting failure occurred in part.
[0067]
Evaluation) ………………………
For the recording media obtained in the above Examples and Comparative Examples, the 20 ° glossiness on the ink receiving layer side was measured based on JIS-Z-8741 using a digital variable gloss meter (manufactured by Suga Test Instruments Co., Ltd.). The results are shown in Table 1. Further, the surface pH value of the glossy surface of the recording medium having the ink receiving layer was measured using a pH measurement set for paper (Kyoritsu Riken Labs; Model MPC), and the results are shown in Table 1. Further, when an image such as a photograph was printed on the glossy surface of the recording medium having an ink receiving layer using an ink jet printer (trade name: manufactured by BJF-870 Canon Inc.), an image corresponding to the photographic information was printed. An image having the texture and image quality of a photograph could be formed. In addition, after discharging the liquid composition A for forming a coating layer containing a water-soluble polymer on the glossy surface of the recording medium on which printing has been performed by the above method by an ink jet recording method, A test was conducted. The results are shown in Table 1.
[0068]
[Table 1]

[0069]
【The invention's effect】
  As explained above, the present inventionMethod of manufacturing recorded image using recording medium manufacturing methodAccording to the above, there is no sticking on the surface of the print head or the liquid composition application roller in the ink jet apparatus, no stickiness after the formation of the coating layer, and easy miniaturization with excellent image quality, gas resistance, and abrasion resistance. In such a method for forming a recorded image, it is possible to provide a method for producing a recording medium in which the surface pH required for forming a coating layer is controlled and the glossiness and ink absorbability are excellent.

Claims (6)

A method of forming an image recorded matter having a coating layer on at least a part of an image,
The following general formula:
-COOA
(However, A in the above general formula represents an alkali metal, ammonium or organic ammonium.)
A step of preparing an aqueous liquid composition containing in a dissolved state a polymer having a group having a structure represented by:
Preparing an image recording having an image formed by an inkjet recording method on an inkjet recording medium, wherein the surface pH of the image is a pH at which the polymer is insoluble;
Forming the coating layer by applying the liquid composition to at least a part of the image of the recorded matter and insolubilizing the polymer contained in the liquid composition according to the surface pH of the image; ,
Have
The inkjet recording medium has one or more layers laminated on a substrate, has an ink receiving layer containing alumina hydrate as the outermost layer , and applied with a coating liquid containing alumina hydrate, After the ink receiving layer was dried and formed, the ink receiving layer was swollen again with a buffer solution, and the surface of the ink receiving layer was pressure-bonded to a heated mirror drum, and the ink-receiving layer was dried by a method for manufacturing an inkjet recording medium . Is,
A method of forming an image recorded matter . The method for forming an image recorded matter according to claim 1, wherein the pH of the buffer solution is in the range of 4.0 to 6.0. 3. The method of forming an image recorded matter according to claim 1, wherein the surface pH of the ink receiving layer is 4.0 to 7.0. 4. The method for forming an image recorded matter according to claim 1, wherein the surface pH of the ink receiving layer is 5.4 to 7.0. 5. The method for forming an image recorded matter according to claim 1, wherein the buffer solution comprises acetic acid and a salt thereof. The method for forming an image recorded matter according to any one of claims 1 to 5, wherein the pH of the coating solution containing alumina hydrate is 4.0 to 6.0.