JP4922016B2 - Printing ink for forming ink receiving layer and ink jet recording medium using the same - Google Patents

Description

  The present invention relates to a printing ink for forming an ink-receiving layer for ink-jet recording and an ink-jet recording medium formed by forming an ink-receiving layer using the ink. The present invention relates to a printing ink for forming an ink receiving layer capable of forming an ink receiving layer excellent in color developability, fixability and water resistance, and an ink jet recording medium using the same.

  2. Description of the Related Art In recent years, in an inkjet recording method that has been widely used, a recording medium in which an ink receiving layer is formed on a support is used in order to quickly absorb and fix the droplets of ejected ink ejected from a nozzle. There are many. In particular, in the case of a support using a resin material such as polyolefin resin, the configuration of the ink receiving layer is important.

  In particular, as an ink-receiving layer of an ink jet recording medium having excellent wettability, dryability, fixability, color developability, water resistance, and bleeding resistance to ejected ink, an emulsifier such as an emulsifier having a number average molecular weight of 1000 or more, polyethyleneimine, etc. Examples thereof include water-soluble polymers having activity or those containing a dispersant (see Patent Document 1 below), but those having more excellent characteristics have been demanded.

  In addition, in order to further improve the drying property, fixing property, and color developability of the ejected ink, an ink receiving layer containing inorganic fine particles such as silica, alumina, alumina hydrate, aluminum oxide, and magnesium oxide can also be mentioned (the following patents). Reference 2).

  However, among the inorganic fine particles, silica contributes to improving the absorbability of the ejected ink, but there is a problem that the fixability of the dye in the ejected ink is not sufficient. Alumina, alumina hydrate, aluminum oxide, and magnesium oxide are Since the surface area is small, there is a problem that the drying property of the ink at the time of forming the receiving layer is not sufficient.

JP-A-9-176560 JP 2002-321445 A

  The present invention relates to a printing ink for forming an ink receiving layer capable of forming an ink receiving layer excellent in concealability, drying property, color developability, fixability, and water resistance to ink ejected for ink jet recording, and an ink jet recording medium using the same. The purpose is to provide.

(1) The ink-receiving layer-forming printing ink for inkjet recording of the present invention is characterized by containing at least magnesium aluminate metasilicate fine powder and a cationic polymer as solid components.

The cationic polymer is polyethyleneimine.

(2) The ink receiving layer for ink jet recording according to (1) , wherein a weight ratio of the magnesium aluminate metasilicate fine powder to the cationic polymer is 1: 2 to 1:10. Printing ink for forming.

(3) The printing ink for forming an ink receiving layer for ink jet recording according to the above (1) or (2), wherein the ink contains starch.

(4) The ink-receiving layer-forming printing ink for ink-jet recording according to any one of (1) to (3) , further comprising inorganic fine particles other than the magnesium aluminate metasilicate fine powder .

(5) An ink jet comprising an ink-receiving layer forming printing ink for ink-jet recording according to any one of (1) to (4) applied to a support to form at least one ink-receiving layer. Recording medium.

(6) An epoxy resin is added to the ink-receiving layer-forming printing ink for ink-jet recording according to any one of (1) to (4) , and is applied to a support to form at least one ink-receiving layer. The inkjet recording medium as described in (5) above, wherein

(7) The inkjet recording medium according to (6) , wherein the epoxy resin is 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate.

  The ink-receiving layer-forming printing ink of the present invention can form an ink-receiving layer that is particularly excellent in concealing property, drying property, color development property, fixing property, and water resistance for ink jet recording ink.

  The printing ink for forming an ink receiving layer of the present invention contains at least magnesium aluminate metasilicate fine powder and a cationic polymer as a solid content.

Metasilicate aluminate magnesium fine powder used in the present invention is represented by the chemical formula _{Al 2 O 3 · MgO · 2SiO} 2 · xH 2 O. The average particle diameter is preferably 1 to 2 μm. Magnesium metasilicate aluminate fine powder has a lower specific gravity than aluminum oxide or magnesium oxide, so it is highly dispersible in water, alcohol, and other solvents used in normal ink-receiving layer-forming printing inks. Since the suspended state can be maintained, the coating property at the time of forming the receiving layer is improved. Further, since the magnesium aluminate metasilicate fine powder has the same specific surface area as silica, the ink-receiving layer is excellent in ink absorbability, and is excellent in drying property and color development property.

  The cationic polymer used in the present invention has a function of reacting with the ink jet recording ink in the ink receiving layer to insolubilize the ink and fix it. Polyethyleneimine is preferably used as the cationic polymer because it is particularly excellent in the fixability of the ejected ink.

  The ink-receiving layer-forming printing ink of the present invention improves the fixability of the ink-receiving layer to the inkjet recording ink by using the above-mentioned magnesium metasilicate aluminate fine powder and the cationic polymer in combination. Even if the recording medium is washed with water, the ink can be prevented from flowing down.

  In the present invention, the mixing ratio of the magnesium metasilicate aluminate fine powder and the cationic polymer is preferably in the range of 1: 2 to 1:10 by weight. If the amount of the magnesium aluminate metasilicate fine powder is too large, the adhesion to the support during the formation of the ink receiving layer will decrease, and if it is too small, the ink receiving layer will be blocked, making it difficult to form the ink receiving layer. .

  The ink-receiving layer-forming printing ink of the present invention preferably contains starch obtained from rice, wheat, potatoes and the like. By containing starch, ink absorbability is improved. The amount of the magnesium metasilicate aluminate fine powder and starch is adjusted to improve the drying property of the ejected ink by the magnesium metasilicate aluminate fine powder. It is also possible to form an ink receiving layer suitable for the method.

  The ink-receiving layer-forming printing ink of the present invention may further contain inorganic fine particles other than the magnesium aluminate metasilicate fine powder, that is, silica, alumina, alumina hydrate, aluminum oxide, magnesium oxide and the like. By changing the ratio of the magnesium aluminate metasilicate fine powder and the other inorganic fine particles, the transparency of the ink receiving layer and the tackiness at the time of forming the ink receiving layer can be adjusted. However, the mixing ratio of the inorganic fine particles other than the magnesium aluminate metasilicate fine powder is at least relative to the total amount of the magnesium metasilicate aluminate fine powder and the other inorganic fine particles in order to effectively express the effect of the present invention. It is preferable that the magnesium aluminate metasilicate fine powder exceeds 6% by weight. The average particle size of the inorganic fine particles other than the magnesium metasilicate aluminate fine powder is preferably in the range of 0.5 to 12 μm.

  The ink-receiving layer-forming printing ink of the present invention is produced by dispersing and dissolving each of the above components in a solvent using a known method in order to apply to a support and form an ink-receiving layer. Examples of the solvent used include solvents such as alcohols generally used for forming the ink receiving layer. A mixed solvent may be used, but IPA is preferably used.

  In addition to the above components, the printing ink for forming an ink receiving layer of the present invention includes a surfactant, an ultraviolet absorber, an antioxidant, a dispersion aid, an antifoaming agent, an antiseptic, as long as the action of the present invention is not impaired. You may add well-known additives, such as an agent, a fluorescent whitening agent, and a pH adjuster.

  The ink-receiving layer forming printing ink for ink-jet recording of the present invention is applied to a support to form at least one ink-receiving layer to obtain an ink-jet recording medium.

  In the ink jet recording medium of the present invention, the ink receiving layer by the printing ink for forming an ink receiving layer for ink jet recording may be a single layer, two layers or more, and two or more ink receiving layers may be provided. During the formation, there may be an ink receiving layer other than the ink receiving layer by the printing ink for forming the ink receiving layer for ink jet recording. Further, when two or more ink receiving layers are formed by the ink receiving layer forming printing ink of the present invention, the blending ratio of each component in the ink receiving layer forming printing ink may be different within the scope of the present invention. .

  In the ink jet recording medium of the present invention, it is preferable that an epoxy resin is added to the ink receiving layer forming printing ink for ink jet recording and then applied to a support to form at least one ink receiving layer. By adding an epoxy resin, the water resistance of the ink receiving layer is improved. From the viewpoint of image clarity, it is preferable to have a multilayer structure in which an ink receiving layer to which no epoxy resin is added is combined with an ink receiving layer to which an epoxy resin is added. In particular, it is preferable to use 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexenecarboxylate as the epoxy resin.

  In the inkjet recording medium of the present invention, the total thickness of the ink receiving layer is preferably 5 to 20 μm in terms of dry thickness. If the total thickness of the ink receiving layer is too small, the ink absorption amount is insufficient, and if it is too large, the adhesion to the support is lowered and the ink receiving layer is difficult to form. Among these, the thickness of the ink receiving layer by the printing ink for forming an ink receiving layer of the present invention is preferably at least 10 μm or more in order to exhibit the function of the present invention.

  In the ink jet recording medium of the present invention, the ink receiving layer is formed on the support by a known coating method such as a gravure coating method, a reverse coating method, a die coating method, or a bar coating method. This is done by applying. Moreover, you may perform surface treatment etc. as needed before application | coating.

  In addition to the ink receiving layer, other layers such as a protective layer and an antistatic layer may be formed on the inkjet recording medium of the present invention.

  Examples of the support used for the ink jet recording medium of the present invention include plastic films such as polyolefin films and polyester films generally used for ink jet recording media, coated paper, non-woven paper, and the like. The effect of the present invention is effectively exhibited when using as a support.

  The present invention will be further described in detail below using test examples and examples, but the present invention is not limited to the scope thereof.

Using each component shown below, each component was mixed by stirring for 10 minutes with a stirrer using a stirrer at a blending ratio shown in Table 1, and printing for ink receiving layer formation in Examples 1 and 2 and Comparative Examples 1 and 2 was performed. An ink was created.

・ Cationic polymer (polyethyleneimine)
“Epomin P-1000” manufactured by Nippon Shokubai Co., Ltd.
・ Magnesium aluminate metasilicate fine powder "Neusilin UFL ₂ " manufactured by Fuji Chemical Industry Co., Ltd.
・ Starch “Micropearl F” manufactured by Shimada Chemical Industries, Ltd.
・ Solvent IPA
"Seridust VP3620" made by polyethylene wax Clariant

Test example 1
In the ink-receiving layer forming printing inks of Examples 1 and 2 and Comparative Examples 1 and 2, 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate (produced by Daicel Chemical Industries, Ltd.) as an epoxy resin , Celoxide 2021P) was added in the formulation shown in Table 1, and was printed on the surface of the transparent polypropylene film surface-treated by corona treatment at 120 l / inch, 50 μm by a gravure coating method, and left at 50 degrees for one day to dry. Curing was performed to form an ink receiving layer having a dry thickness of 12 μm. Furthermore, four-color patterns were printed on the ink receiving layer using an inkjet printer (manufactured by Seiko Epson Corporation, PM770), and the results were visually observed and compared. As a result, in Comparative Example 1 with only the cationic polymer, blocking occurred and it was difficult to form an ink-receiving layer. In Comparative Example 2 in which the cationic polymer and starch were blended, the ejection ink was absorbed faster but bleeding occurred. In addition, the image was not clear due to poor concealability and color developability. On the other hand, Examples 1 and 2 blended with magnesium aluminate metasilicate fine powder were excellent in the concealability and color developability of the discharged ink, and a clear image was obtained.

  In the same manner as in Examples 1 and 2 and Comparative Examples 1 and 2, the components shown above and the components shown in Table 3 as inorganic fine particles were used. In the same manner as in Examples 1 and 2, stirring and mixing were performed to prepare a printing ink for forming an ink receiving layer. Furthermore, the composition shown in Table 2 is 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate (Daicel Chemical Industries, Ltd., Celoxide 2021P) as an epoxy resin in the printing ink for forming the ink receiving layer. In addition, it is printed on the surface of a transparent polypropylene film that has been surface-treated by corona treatment, using a gravure coating method with a direct plate of 120 l / inch and 50 μm, and left to dry and harden at 50 ° C. for one day. The ink receiving layer was formed into an ink jet recording medium. The epoxy resin was added only in the first layer. (Example 3, Comparative Examples 3-6).

Test example 2
For the ink jet recording media of Example 3 and Comparative Examples 3 to 6, each ink of yellow, magenta, cyan, and black was designed as a square with respect to the ink receiving layer using an ink jet printer (manufactured by Seiko Epson Corporation, PM770). In addition, a 1 cm long x 3 cm wide bar code pattern and a 1 cm ² two-dimensional bar code were printed in a black hue. The results were evaluated based on the following test examples.

(1) Concealment The density of the printed pattern printed on the ink receiving layer was measured using a transmission densitometer (Gretag D200-II).

(2) Breathability The barcode pattern printed on the ink receiving layer was visually evaluated based on the following.
○: There is no blur and the print is clear.
Δ: Some bleeding occurs. ×: Bleeding occurs on the entire surface.

2. Whether or not the two-dimensional barcode pattern printed on the ink receiving layer can be read was evaluated based on the following.
○: Can be read.
X: Cannot be read.

(3) Fixing Example An example in which the barcode pattern printed on the ink receiving layer was fixed with the barcode pattern printed surface facing upward using a friction tester for dye fastness test in accordance with JIS-L-0823. 3. Contact the ink-jet recording medium of Comparative Examples 3 to 6 with a white cotton cloth for friction (Kanakin No. 3) applied to a 200 g friction element against the sliding surface of the friction element and pressing and fixing the white cotton cloth with a friction cloth presser. The friction resistance of the printed surface of the barcode pattern was measured by continuously sliding at a stroke of 100 mm at a speed of 10 reciprocations / minute. The adhesion of the black part to the cotton cloth after 10 reciprocations was visually evaluated based on the following criteria.
○: No adhesion.
Δ: Partially adhered.
X: The base is visible.

(4) Drying The gauze was brought into contact with the printing surface 30 seconds and 2 minutes after printing the ejected ink on the ink receiving layer, and the presence or absence of color adhesion was visually evaluated based on the following criteria.
○: No color adhesion after 30 seconds.
Δ: Color adheres after 30 seconds, but not after 2 minutes.
X: Color adheres even after 2 minutes.

(5) Color development (clearness)
The density of the black portion of the printed pattern printed on the ink receiving layer was measured using a spectrophotometer (X-Rite).

(6) Water resistance The ink jet recording medium of Example 3 and Comparative Examples 3 to 6 after printing on the ink receiving layer was washed off with water for 20 seconds, and the occurrence of subsequent black portion bleeding was visually observed based on the following criteria. evaluated.
○: There is almost no bleeding.
Δ: Bleeding has occurred partially. B: Bleeding has occurred on the entire surface.

  The test results are shown in Table 4.

  The ink receiving layer formed by the printing ink for forming the ink receiving layer of the present invention is excellent in the concealing property, drying property, color developing property, fixing property, and water resistance of the ejected ink for ink jet recording. It can be suitably used for forming a receiving layer.

Claims (7)

A printing ink for forming an ink-receiving layer for ink-jet recording, comprising at least magnesium aluminate metasilicate fine powder and polyethyleneimine as a cationic polymer as solid components. Wherein the metasilicate aluminate magnesium fine powder, the weight ratio of the cationic polymer, 1: 2:00 to 1:10 in the ink-receiving layer-forming printing ink for ink jet recording according to claim 1, characterized in that . The printing ink for forming an ink receiving layer for ink jet recording according to claim 1, wherein the ink contains starch. The printing ink for forming an ink receiving layer for ink jet recording according to any one of claims 1 to 3 , further comprising inorganic fine particles other than the magnesium aluminate metasilicate fine powder. An ink jet recording medium comprising: an ink receiving layer forming ink for ink jet recording according to any one of claims 1 to 4 applied to a support to form at least one ink receiving layer. An epoxy resin is added to the ink-receiving layer-forming printing ink for ink-jet recording according to any one of claims 1 to 4 and applied to a support to form at least one ink-receiving layer. The inkjet recording medium according to claim 5 . 7. The ink jet recording medium according to claim 6 , wherein the epoxy resin is 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate.