JP2002096549A - Ink for forming ink-jet ink receiving layer and sheet for recording using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink with which an ink-jet ink receiving layer can be easily formed only at necessary positions of a base material since water resistance of the printed ink is excellent and bleeding of the printed image does not occur and quality of printing is high and printing ink suitability is excellent. SOLUTION: The ink for forming the ink-jet ink receiving layer prepared by compounding a cationic resin whose water solution exhibits alkaline and porous fine particles to a vehicle containing a glycol solvent with a boiling point of at least 100 deg.C as a main ingredient is used. The porous fine particles whose aqueous suspension exhibits alkaline are preferably used as the porous fine particles. In addition, a binder resin is preferably additionally compounded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink for forming an ink-jet ink receiving layer and a recording sheet using the same.

[0002]

2. Description of the Related Art Conventionally, an ink-jet printer using an ink-jet ink has many advantages such as easy colorization, low cost, high resolution, and excellent storability. However, when printing on high-quality paper, the fixability of the ink is inferior, and the printed ink remains on the surface of the base material.Therefore, there is a problem that the guide roll becomes dirty or the printed image becomes dirty when printing is continuously performed. In addition, there were problems that ink jet printing blurred and water resistance was poor. In particular, when used in the information industry field, barcodes printed with ink-jet printing are blurred and difficult to read, mail items printed with ink-jet are exposed to rain outdoors, or accidentally splashed with water. In some cases, there is a problem that the printed content is melted and the printed content becomes invisible.

Since high quality paper has non-uniformity having a size of several millimeters to several centimeters, which is called irregular formation, it is necessary to prevent bleeding of printed images (improve sharpness of images). Recording sheets coated with a porous pigment are commercially available. However, when using a porous pigment, it is necessary to control the distribution of the voids between the porous pigment particles and the voids within the porous pigment particles. To cause "bleeding of the image". Although water-resistant pigment-type inkjet inks are commercially available, they have adverse effects on the head, such as clogging of the head of the inkjet printer and shortening the life of the head, and also have problems such as low print density and difficulty in colorization. Was.

On the other hand, paper (ink-jet paper) or film (OHP film) having an ink-jet ink receiving layer formed thereon has been devised (Japanese Patent Laid-Open No. 6-18313).
No. 5, JP-A-6-297830, Japanese Patent Publication No. Hei 8-297.
22608, JP-A-8-72390, JP-A-8-291496, etc.). However, these inks have improved ink absorbency, but have a problem that the inkjet ink receiving layer is provided on the entire surface of the base material, thereby increasing the cost, and affecting the H liquid, making them unsuitable for offset printing. Was.

[0005]

SUMMARY OF THE INVENTION It is a first object of the present invention to solve the conventional problems, to have excellent ink-jet ink absorbability in an ink-jet ink receiving layer formed on a substrate, and to provide a printed ink-jet ink having a high water resistance. An ink for forming an ink-jet ink receiving layer, which can improve the printability and improve the print quality of the ink-jet printing by preventing bleeding of the printed image. A second object of the present invention is to provide an ink for forming an ink-jet ink-receiving layer that can easily form an ink-jet ink-receiving layer at a predetermined location. It is another object of the present invention to provide a recording sheet having an ink-jet ink receiving layer formed in the above-described manner.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have used a vehicle mainly containing a specific solvent, and a cationic resin whose aqueous solution is alkaline with respect to this vehicle. The inventors have found that the problem can be solved by using an ink for forming an ink-jet ink receiving layer in which porous fine particles are blended, and have completed the present invention.

That is, the ink for forming an ink-jet ink receiving layer according to the first aspect of the present invention comprises a cationic resin and a porous resin whose aqueous solution is alkaline with respect to a vehicle containing a glycol solvent having a boiling point of 100 ° C. or higher as a main component. It is characterized by blending fine particles.

[0008] By using an ink for forming an ink-jet ink receiving layer in which a cationic resin whose aqueous solution is alkaline and a porous fine particle are mixed with a vehicle containing a specific solvent as a main component, a special drying device is not required, and The ink-jet ink receiving layer formed on the base material has excellent ink-jet ink absorbability, does not cause bleeding of a printed image, can improve the water resistance of the printed ink-jet ink, and can improve the print quality of ink-jet printing. Further, since the ink jet ink receiving layer can be easily formed at a required portion of the base material due to the excellent printing ink suitability, the cost can be reduced and the offset printing is not affected.

The ink for forming an ink-jet ink receiving layer according to claim 2 of the present invention is the ink for forming an ink-jet ink receiving layer according to claim 1, wherein the porous fine particles are such that the aqueous suspension is alkaline. Is used. The water resistance of the printed ink-jet ink can be further improved, and the print quality of the ink-jet printing can be further improved by preventing bleeding of a printed image.

[0010] The ink for forming an ink-jet ink receiving layer according to the third aspect of the present invention is the first or second aspect.
The ink for forming an inkjet ink receiving layer according to the above, wherein a vehicle further containing a binder resin is used. The ink-jet ink receiving layer formed on the base material is resistant to rubbing, so that the inorganic porous fine particles do not separate or the ink-jet ink receiving layer does not peel even when rubbed with an OCR reader or the like.

According to a fourth aspect of the present invention, there is provided the recording sheet according to any one of the first to third aspects, which is provided on a predetermined portion of at least one surface of the base material.
And an ink-jet ink receiving layer formed using the ink for forming an ink-jet ink receiving layer according to any one of the above.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS It is essential for the ink for forming an ink-jet ink receiving layer of the present invention to use a vehicle mainly containing a glycol-based solvent having a boiling point of 100 ° C. or higher, and the aqueous solution becomes alkaline with respect to this vehicle. It is prepared by mixing the cationic resin and porous fine particles shown below. The use of such a glycol solvent eliminates the need for a special drying device.

The glycol solvent used in the present invention is a medium- and high-boiling solvent (having a boiling point of 100 ° C. or higher) which can be mixed with water. Specifically, for example, glycol (glycerin, ethylene glycol, diethylene glycol, Triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol)
And glycol derivatives (ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl acetate Butyl ether acetate) and mixtures of two or more of these.

When the cationic resin used in the present invention is dissolved in water at 0.5% by mass at normal temperature, the aqueous solution shows alkalinity of pH 7-14, preferably pH 8-13, particularly preferably 9-12. And an oligomer or polymer of a primary to tertiary amine or quaternary ammonium salt which dissociates when dissolved in water to exhibit a cationic property. Specific examples of particularly preferred cationic resins include, for example, dimethylamine / epichlorohydrin polycondensate, acrylamide / diallylamine copolymer, polyvinylamine copolymer, or a mixture of two or more of these. . As the cationic resin in the present invention, a commercially available resin can be suitably used.

Specific examples of commercially available cationic resins include:
For example, dicyandiamide-based sunfix 70 and polyamine-based sunfixx 55 manufactured by Sanyo Chemical Industries, Ltd.
5,555 US, 555NK, special modified polyamine-based polyfix 700 manufactured by Showa Kogyo Co., Ltd., polyamide epichlorohydrin-based polyfix 301A, Nichia Chemical Industries, Ltd. polyethylene polyamine-based neofix RP-70, A quaternary ammonium salt type Charol DC-902P manufactured by Daiichi Kogyo Seiyaku Co., Ltd. can be mentioned.

The mixing ratio of the cationic resin used in the present invention is not particularly limited since it varies depending on the type of the base sheet such as ink jet ink and paper which are anionic substances. However, it is preferable to blend 5 to 60 parts by mass with respect to 100 parts by mass of a vehicle containing a glycol-based solvent as a main component. If the amount is less than 5 parts by mass, the water resistance may not be improved. If the amount is more than 60 parts by mass, the water resistance is improved, but the printability is deteriorated.

The porous fine particles used in the present invention are not particularly limited, and hydrophilic porous fine particles, hydrophobic porous fine particles and a mixture thereof can be used. However, in the present invention, hydrophilic porous fine particles and / or hydrophobic porous fine particles whose aqueous suspension shows alkalinity can be preferably used. The hydrophilic porous fine particles whose aqueous suspension shows alkalinity are aqueous suspensions of 4% by mass added to water at room temperature and uniformly stirred and mixed at pH 7 to pH 14, preferably pH 8 to pH 13, particularly preferably pH 9 ~ PH
Twelve porous fine particles. The hydrophobic porous fine particles whose aqueous suspension shows alkalinity are aqueous suspensions that are added at 4% by mass to a water / ethanol mixture (mass ratio 1: 1) at room temperature and uniformly stirred and mixed, and have a pH of 7 to 14,
Preferably pH 8 to pH 13, particularly preferably pH 9 to
It is a porous fine particle exhibiting an alkaline pH of 12. The mixture of the hydrophilic porous fine particles and the hydrophobic porous fine particles whose aqueous suspension shows alkalinity has an average value of the respective pHs measured as described above of pH 7.5 to pH 14, preferably pH 8 to pH 13. Particularly preferably pH 9 to p
It is a mixture of H12 hydrophilic porous fine particles and hydrophobic porous fine particles.

Specific examples of the porous fine particles in which the aqueous suspension used in the present invention is alkaline include, for example, silica fine particles and hydrophobic fine particles (Nihon Silica Industry Co., Ni.
psil SS-10F, SS-15, SS-50C, etc.) and hydrophilic ones (Nippon Silica Industry Co., Ltd. Nip
gel AZ-200, Nipsil G-300F,
NA, E-200, etc.). These may be used alone or in combination of two or more.

In the present invention, a vehicle further containing a binder resin can be used if necessary. By further blending the binder resin, the formed inkjet ink receiving layer becomes stronger against abrasion,
Even if rubbed with an OCR reader or the like, it is preferable because the porous fine particles do not separate or the ink jet ink receiving layer does not peel off.

The binder resin used in the present invention is not particularly limited as long as it can be used together with the glycol-based solvent. Specifically, for example, albumin, gelatin, casein, starch, gum arabic, natural resins such as sodium alginate, carboxymethyl cellulose, cellulose derivatives such as hydroxyethyl cellulose, polyamide, polyacrylamide, polyhydroxyethyl methacrylate, polyphenylacetoacetal, Polyethylene imine, polyvinyl pyrrolidone, polyvinyl pyridium halide, melamine resin, polyurethane, polyvinyl alcohol and its derivatives, polyester, polyacrylic acid soda, synthetic resin such as acrylate copolymer, dimethylamine / epichlorohydrin polycondensate, acrylamide Diallylamine copolymer, polyvinylamine copolymer, dicyandiamide, dimethyl
Cationic resin such as a compound containing diallyl ammonium chloride as a main component or a mixture of two or more of these, electron beam curable ink, ultraviolet curable ink, sulfonic acid group, carboxyl group, sulfate group,
Anionic resins such as rosin-modified maleic acid having an anionic group such as a phosphate group can be exemplified.

The amount of the porous fine particles used in the present invention is not particularly limited. However, based on 100 parts by mass of the vehicle, 10 to 60 parts by mass, preferably 20 parts by mass of the porous fine particles are used.
It is desirable that the compounding amount be 50 to 50 parts by mass, more preferably 25 to 45 parts by mass. If the amount is less than 10 parts by mass, water resistance and bleeding of a printed image may not be improved. If the amount is more than 60 parts by mass, the suitability for printing ink may be deteriorated.

Known additives can be added to the ink for forming an ink-jet ink receiving layer of the present invention, if necessary. Examples of the additives include a viscosity adjuster, an antioxidant, a pH adjuster, an antifoaming agent, various stabilizers, and a coloring agent.

The ink for forming an ink-jet ink receiving layer of the present invention is applied to a predetermined portion of at least one surface of a substrate by a coating means such as a gravure coater, flexo, air knife coater or bar coater. Can be formed. Therefore, in the present invention, no special drying device is required.

As the substrate used in the present invention, besides ordinary paper, synthetic paper or a synthetic film of polyethylene, transparent polyethylene terephthalate, polypropylene, vinyl chloride or the like can be used. When using these synthetic films, the surface of the substrate is preferably subjected to a surface treatment such as a mat treatment or a corona treatment. The amount of coating on the substrate surface is not particularly limited, but is, for example, 0.5 to 30 g / m ² , preferably 3 to 20 g / m ² ,
More preferably, it is 5 to 15 g / m ² .

As the ink-jet ink used in the present invention, for example, JP-A-7-228808,
No. 7,228,809 can be used. In particular, at least one anionic selected from the group consisting of anthraquinone, benzoquinone, naphthoxyquinone, xanthene, triphenylmethane, quinoline, indigoid, azine, oxazine, thiazine and methine dyes Ink is preferably used. These specific examples are described in JP-A-7-2288.
No. 09, paragraph No. 0015. As a medium used for this ink, a mixed solvent of water and a water-soluble organic solvent can be used. In addition, a pH adjuster, a viscosity adjuster, a surface tension adjuster and the like can be contained.

FIG. 1 is an explanatory diagram illustrating an embodiment of the recording sheet of the present invention. In FIG. 1, a recording sheet 1 of the present invention has an ink-jet ink receiving layer 3 formed at a predetermined position on the upper surface of a substrate 2 using the ink for forming an ink-jet ink receiving layer of the present invention. Reference numeral 4 denotes printing printed on the inkjet ink receiving layer 3 by an inkjet printer (not shown).

[0027]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to these Examples. (Example 1) 7 parts by mass of rosin-modified maleic acid (trade name: Tespol 1152 (manufactured by Hitachi Chemical Co., Ltd.)) is dissolved in 93 parts by mass of propylene glycol. To 100 parts by mass of the obtained vehicle liquid, 12 parts by mass of synthetic hydrophilic silica fine particles (trade name: NIPGEL AZ-200 (manufactured by Nippon Silica Industry Co., Ltd.)) are kneaded. Subsequently, 12 parts by mass of synthetic hydrophobic silica fine particles (trade name: Nipsil SS-10F (manufactured by Nippon Silica Industry Co., Ltd.)) are kneaded. Further, 24 parts by mass of a polyamine-based cationic resin (trade name: Sanfixus 555 (manufactured by Sanyo Chemical Industries, Ltd.)) whose aqueous solution shows alkalinity as a water resistance improver is dissolved. To this, 12 parts by mass of diethylene glycol and 8 parts by mass of glycerin were added as a roll transferability improver, and a three-roll mill was used to prepare an ink for forming an inkjet ink receiving layer of the present invention. The obtained ink for forming an ink-jet ink receiving layer of the present invention is made of high quality paper (70K
(g continuous mass), offset printing was performed to 3 g / m ² to produce a recording sheet of the present invention having an inkjet ink receiving layer. After printing (black, red, blue, and green dye inks) on the inkjet ink receiving layer of the obtained recording sheet of the present invention with a Cytex inkjet printer, the water resistance and STI grade (% ) (Print quality) was evaluated. Table 1 shows the pH of the aqueous solution of the cationic resin using the evaluation results.

(Evaluation method) <Water resistance> The printed portion is washed away with running water for a certain period of time, or a water droplet is dropped on the printed portion for a certain period of time, and then wiped off to visually determine the state of the ink. When the print completely remained, it was judged as ◎, when the print almost completely remained, as ○, when the print became slightly thinner, as Δ, and when the print became thinner, as ×.

<STI Grade (%) (Print Quality)> A bar code is printed by an ink jet printer, and the read quality is checked with a bar code tester (LASER CHEK).
In II), evaluation was made by measuring the STI grade (%). In general, STI grade 50
% Or more can be evaluated as standard good quality.

Example 2 An ink jet ink of the present invention was prepared in the same manner as in Example 1 except that the cationic resin used in Example 1 was changed to <Trade name: Sanfixus 555US (manufactured by Sanyo Chemical Industries, Ltd.)> After preparing the ink for forming a receiving layer, a recording sheet of the present invention having an ink-jet ink receiving layer is similarly prepared,
Evaluation of TI grade (%) (print quality) was performed. Table 1 shows the pH of the aqueous solution of the cationic resin using the evaluation results.

Example 3 An ink-jet ink of the present invention was prepared in the same manner as in Example 1 except that the cationic resin used in Example 1 was changed to <trade name: Sunfixes 555NK (manufactured by Sanyo Chemical Industries, Ltd.)>. After preparing the ink for forming a receiving layer, a recording sheet of the present invention having an ink-jet ink receiving layer is similarly prepared,
Evaluation of TI grade (%) (print quality) was performed. Table 1 shows the pH of the aqueous solution of the cationic resin using the evaluation results.

Example 4 The procedure of Example 1 was repeated, except that the amount of the cationic resin used in Example 1 was changed to 36 parts by mass, to prepare an ink for forming an ink-jet ink receiving layer of the present invention. The recording sheet of the present invention having an ink-jet ink receiving layer was prepared as described above, and the water resistance and STI grade (%) (print quality) were evaluated. Table 1 shows the pH of the aqueous solution of the cationic resin using the evaluation results.

Example 5 An ink for forming an ink jet ink receiving layer of the present invention was prepared in the same manner as in Example 1 except that the amount of the cationic resin used in Example 1 was changed to 12 parts by mass. The recording sheet of the present invention having an ink-jet ink receiving layer was prepared as described above, and the water resistance and STI grade (%) (print quality) were evaluated. Table 1 shows the pH of the aqueous solution of the cationic resin using the evaluation results.

Comparative Example 1 The procedure of Example 1 was repeated except that the cationic resin used in Example 1 was changed to a polyamine-based cationic resin whose aqueous solution did not show alkalinity (trade name: Sunfixus 555C (manufactured by Sanyo Chemical Industries, Ltd.)). After preparing the ink for forming an ink-jet ink receiving layer of the present invention in the same manner as in Example 1, a recording sheet of the present invention having an ink-jet ink receiving layer is similarly prepared,
Evaluation of TI grade (%) (print quality) was performed. Table 1 shows the pH of the aqueous solution of the cationic resin using the evaluation results.

Comparative Example 2 Synthetic hydrophilic silica fine particles (trade name: NIPGEL AZ-200 (manufactured by Nippon Silica Industry Co., Ltd.)) 24 parts by mass and a polyamine-based cationic resin whose aqueous solution is alkaline as a water resistance improver < Trade name: Sunfixus 555 (manufactured by Sanyo Chemical Industries)> 24 parts by mass of UV varnish <Product name: Silver varnish (T & KT)
The mixture was kneaded with 72 parts by mass using a three-roll mill to obtain an ink for forming an inkjet ink receiving layer for comparison. The obtained ink for forming an ink-jet ink receiving layer was coated on a high quality paper (70 kg) using a resin relief printing plate.
By dry offset printing such that 3 g / m ² on a ream weight) (cured with a high pressure mercury lamp) to make a recording sheet for comparison. Printing (black, red, blue, and green dye inks) was performed on the inkjet receiving layer of the obtained recording sheet with an inkjet printer manufactured by Cytex Corporation, and water resistance and STI grade (%) (print quality) were obtained in the same manner as in Example 1. ) Was evaluated. Table 1 shows the pH of the aqueous solution of the cationic resin using the evaluation results.

Comparative Example 3 60 parts by mass of a rosin-modified phenol resin varnish and 11 parts by mass of linseed oil varnish were mixed.
6 parts by mass of wood wax (baltimic acid glyceride) and 3 parts by mass of a dryer were mixed. In the obtained varnish, synthetic hydrophilic silica fine particles <trade name: NIPGEL G-300 (manufactured by Nippon Silica Industry Co., Ltd.)> 24 parts by mass and a polyamine-based cationic resin whose aqueous solution is alkaline as a water resistance improver <trade name: Sunfixus> 555 (manufactured by Sanyo Kasei Kogyo Co., Ltd.)> And an ink for forming an inkjet ink receiving layer for comparison was prepared using a three-roll mill. The obtained ink was subjected to dry offset printing on a high quality paper (70 kg continuous mass) using a resin relief printing plate at 3 g / m ² to prepare a recording sheet for comparison. After printing (black, red, blue, and green dye inks) on the inkjet ink receiving layer of the obtained recording sheet using an inkjet printer manufactured by Cytex Corporation, water resistance and STI grade (%) were obtained in the same manner as in Example 1.
(Print quality) was evaluated. Table 1 shows the pH of the aqueous solution of the cationic resin using the evaluation results.

[0037]

[Table 1]

The inks for forming the ink-jet ink receiving layer of Examples 1 to 5 have excellent suitability for printing inks and, as shown in Table 1, the water resistance and the water resistance of the prints (black, red, blue and green dye inks) printed by the ink-jet printer. It turns out that it is excellent in STI grade (%) (print quality). In contrast, the inks for forming the inkjet ink receiving layer of Comparative Examples 1 to 3 are inferior in water resistance and STI grade (%) (print quality).

[0039]

The ink for forming an ink-jet ink receiving layer according to the first aspect of the present invention solves various problems of the conventional ink for forming an ink-jet ink receiving layer, and can be used in a vehicle containing a specific glycol-based solvent as a main component. On the other hand, since the aqueous solution used an ink containing a cationic resin showing alkalinity and porous fine particles, no special drying device was required, and the water resistance of the inkjet ink printed on the inkjet ink receiving layer formed on the base material was excellent. No bleeding of the printed image occurs, the printing quality of the printing is high, and
Since the ink-jet ink-receiving layer can be easily formed only at a required portion of the base material because of its excellent printing ink suitability, the cost can be reduced and the offset printing is not affected.

The ink for forming an ink-jet ink receiving layer according to the second aspect of the present invention is the ink for forming an ink-jet ink receiving layer according to the first aspect, wherein the porous fine particles are used as porous fine particles. Is used, the water resistance of the printed ink-jet ink can be further improved, and there is a remarkable effect that the printing quality of the ink-jet printing can be further improved by preventing bleeding of a printed image.

The ink for forming an ink-jet ink receiving layer according to the third aspect of the present invention is the first or second aspect.
In the ink for forming an ink-jet ink receiving layer described in the above, since a vehicle further containing a binder resin was used, the ink-jet ink receiving layer formed on the base material became more resistant to rubbing, and even when rubbed with an OCR reader or the like, inorganic porous material was used. It has a remarkable effect that the fine particles are not separated and the ink-jet ink receiving layer is not separated.

According to a fourth aspect of the present invention, there is provided the recording sheet according to any one of the first to third aspects, which is provided on a predetermined portion of at least one surface of the base material.
Has an inkjet ink receiving layer formed using the ink for forming an inkjet ink receiving layer according to any one of the above, so that the inkjet ink printed on the inkjet ink receiving layer has excellent water resistance, and does not cause bleeding of a printed image. This has a remarkable effect that the printing quality of printing is high.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an embodiment of a recording sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording sheet of this invention 2 Substrate 3 Ink jet ink receiving layer 4 Printing

Claims (4)

[Claims] An ink for forming an ink-jet ink-receiving layer, wherein a cationic resin and an aqueous solution are added to a vehicle containing a glycol-based solvent having a boiling point of 100 ° C. or higher as a main component. . 2. The ink for forming an ink-jet ink receiving layer according to claim 1, wherein the porous fine particles are porous fine particles whose aqueous suspension is alkaline. 3. The method according to claim 1, wherein a vehicle further containing a binder resin is used.
The ink for forming an inkjet ink receiving layer according to the above. 4. An ink-jet ink receiving layer formed by using the ink for forming an ink-jet ink receiving layer according to claim 1 on a predetermined portion of at least one surface of a substrate. Become a recording sheet.