JPS60109894A - Ink jet recording paper - Google Patents

Abstract

PURPOSE:To enhance resistance to light and water, by a method wherein a mixture of a dimethyldiallylammonium chloride polymer having a specified monomer as a component unit with polyethyleneimine is applied to or infiltrated into a base. CONSTITUTION:An aqueous solution of a mixture of 95-50pts.wt. of a dimethyldiallylammonium chloride polymer having a monomer of the formula as a component unit with 5-50pts.wt. of polyethyleneimine is prepared. The solution is sprayed onto the surface of a known ink jet recording paper or is applied to or infiltrated into the surface of a paper in a paper-making step by a size press, a roll coater or the like to obtain an ink jet recording paper. The amount of the mixture applied or infiltrated is preferably 0.1-2.5g/m<2>, whereby sufficient water-resisting and light-resisting effects for images are displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording paper in which recorded images are completely waterproof and have excellent light resistance.

In general, inkjet recording involves ejecting ink under pressure from pores several tens of microns in diameter, and the resulting ink particles record dots on recording paper several millimeters or tens of millimeters apart. Water-based inks with high viscosity and high surface tension are commonly used. In order to ensure ink ejection from the pores, it is difficult to contain pigments, resins, etc. as in normal printing inks. For this reason, it is natural that inkjet recording is inferior in recording quality such as recording density, gloss, light resistance, and water resistance compared to general printing.

However, as the field of use of inkjet recording methods expands, customers' quality requirements for inkjet recordings also become stricter.For example, in addition to recording resolution, density, and color vividness, recording light resistance and water resistance are also required. There is a growing tendency to Naturally, when displaying inkjet-recorded printed matter outdoors, simply storing the recorded matter in a high-humidity environment can cause the recording to bleed and fade, and this tendency is especially common with color inkjet-recorded matter (not observed). ´Reru.

Inkjet inks are generally composed of water-soluble dyes classified as direct dyes, acid dyes, and basic dyes, water, dye solubilizers, wetting agents, etc. Colors other than black are made of three components: yellow, magenta, and cyan. The color is adjusted by mixing one or more of the following.

Although it is possible to add a waterproofing agent directly to the ink in order to make the recording water resistant, this method is difficult from the viewpoint of the above-mentioned ink composition and prevention of ink clogging.

In Japanese Patent Application No. 57-130270, the present inventors proposed dimethyl Schiff 1J Lua:/
We proposed the use of monium chloride polymers and found that coating or impregnating this dimethyldiallylammonium chloride polymer on a support would have a special effect on water resistance not only for black recorded images but also for color recorded images. It showed a lot.

However, the recording paper according to this proposal still has insufficient light resistance of recorded images, and there is still room for improvement. The inventors of the present invention have conducted further studies to eliminate this drawback, and have found that the above drawback can be improved by using polyethyleneimine in combination. That is, inkjet recording paper obtained by coating or impregnating a support with a mixture of dimethyldiallylammonium chloride polymer and HoIJ ethyleneimide has extremely excellent not only water resistance but also light resistance of recorded images. Recognized as demonstrating quality.

The present invention will be explained in detail below. The dimethyldiallylammonium chloride polymer used in the present invention is
Dimethyldiallyl ammonium chloride heavy metal compound, which consists of the monomer shown by the structural formula below, is a hygroscopic white powder and is used as a conductive agent. It is insoluble in organic solvents other than methanol, but is soluble in water. Its characteristic properties are that it dissolves well and its aqueous solution is very stable in both acidic and alkaline conditions.

υ On the other hand, polyethyleneimine is a strong cationic water-soluble liquid, and is an example of a polycationic polymer electrolyte proposed for use in JP-A-56-84992 to improve the water resistance of inkjet recorded images. However, the water-resistant effect of polyethyleneimine cannot be expected much for color recorded images, except for black images. However, when polyethyleneimine is used in combination with the dimethyldiallylammonium chloride polymer, a very remarkable effect is seen not only in improving water resistance but also in improving light resistance.

In the present invention, these mixtures may be used by spraying them in an aqueous solution onto the surface of known inkjet recording paper, or by spraying them on a size press or roll coater during the papermaking process.
It may be applied to or impregnated onto the surface using a coating method such as a coating method, or it may be mixed into a coating material of a known coat type inkjet recording paper and applied using a coating machine such as a blade, an air knife, or a roll coater.

Therefore, the present invention can be applied to all types of recording paper, whether brain type or coated type. White pigments such as fine silica, acid clay, clay, talc, calcium carbonate, diatom, titanium oxide, barium sulfate, etc. are combined with highly water-soluble materials such as oxidized starch, gelatin, casein, polyvinyl alcohol, cellulose II conductor, polyvinylpyrrolitone, etc. Coating with molecular binder. By using it in recording paper, it is possible to obtain inkjet recording paper that has extremely high color image water resistance and also has excellent image light resistance.

The blending ratio of dimethyldiallylammonium chloride polymer and polyethyleneimine is not particularly limited, but if the former ratio is too small, the light resistance will be insufficient, so the solid content ratio should be 95-50:5-50. It is desirable to keep it at a certain level.

In addition, the coating amount or impregnation information is 0.1 to 2.5 g/m
The sufficient water resistance effect and light resistance effect of the image (8) can be achieved at a certain level.

Below, the present invention will be explained according to embodiments.

〔Example〕

In accordance with the treatment of known coated type inkjet recording paper, 81 parts (solid content) of a slurry of white carbon (manufactured by Tokuyama Soda, Tokushir U) as a pigment, and fully phosphorized polyvinyl alcohol (manufactured by Kuraray) as a binder. , 15 parts by weight (solid content) of an aqueous solution of PVAI 17 ),
In addition, 14 parts by weight (solid content) of a mixture of dimethyldiallylammonium chloride polymer (Nittobo Co., Ltd., Pass H-10) and polyethyleneimine (Perdige Mine Dye Chemicals Co., Ltd., Borimin P) in various blending ratios were added, A series of paints with a mold concentration of 15% were prepared. These paints are 6 m2
09 / 7n", on commercially available high-quality paper with a 20-second brush stroke, coated with a wire parser in an amount of 8 to 1297 m.
After applying the inkjet recording paper so as to give an inkjet recording paper of 1'1&11~11!h6χ, it was passed once through a test calender (manufactured by Yuriroll Co., Ltd.) under a linear pressure of 24 !h6χ.

The results of the ml property test for these recording papers are shown in Table 1 and (1) Color density; solid printing in four colors of black, cyan, magenta, and yellow was performed using a Sharp inkjet color image printer 1O-0700Y. Use the 8PI filter below for each part,
Reflection density measured with Mac7 densitometer.

(2) Irradiation time: Fade-o-meter carbon arc irradiation time.

(3) Fading rate: Calculated using the following formula.

When either the I 00 ride polymer or polyethyleneimine is added to the other, there is less fading than when they are used alone.As for water resistance, both recordings were immersed for 24 hours. Almost no discoloration was observed.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the fading rate in Table 1 in relation to the blending ratio.

Claims (1)

[Scope of Claims] (11) An inkjet formed by coating or impregnating a mixture of a dimethyldiallylammonium chloride compound and polyethyleneimine on a support, the constituent unit being a monomer represented by the following structural formula. Recording sheet. (2) The inkjet recording paper according to claim 1, characterized in that the solid proportion of dimethyldiallylammonium chloride polymer and polyethyleneimide in the mixture is 95-50:5-50.