JPH01152176A - Water-base ink composition - Google Patents

Abstract

PURPOSE:To provide the above compsn. excellent in absorptivity, storage stability and water resistance which gives an image excellent in light resistance and free of bleeding, by blending a specific hydroxypropylated polyethyleneimine as an essential component with a dye and water as other essential components. CONSTITUTION:Polyethyleneimine having a number-average MW of 300-150,000 is reacted with polypropylene oxide either as such or diluted with a solvent, if necessary, in the presence of a catalyst such as an acid or an alkali at 0-150 deg.C to prepare hydroxypropylated polyethyleneimine (A) having a number- average MW of 500-300,000 and being in the form of polyethyleneimine wherein 50-90% of primary and secondary amine hydrogen atoms are substituted with hydroxypropyl groups. 0.1-100wt.% (based on the component B) of the component A and a direct, acid, mordant, metal complex, vat, disperse or the like dye (B) as essential components are dissolved together with additives (C) such as a lowly volatile org. solvent, a compatibilizing agent, a surfactant, a mildew- proofing agent, an antioxidizing agent and an ultraviolet absorber, if necessary, in water.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to aqueous ink compositions.

Specifically, when recording on various recording materials such as paper, it has excellent water resistance, light resistance, ink absorption, resolution, etc., and is therefore suitable for writing instruments, stamps, printing, ink jets, recorders, etc. The present invention relates to an aqueous ink composition suitable for use in.

(Prior art and problems to be solved by the invention) Water-based ink is highly safe and has good printability;
Widely used. However, conventional water-based inks inherently have poor water resistance, and images formed using these inks frequently smear or begin to melt when they come into contact with water, making them impossible to decipher.

Various attempts have been made to overcome these problems. For example, in JP-A-50-49004, in order to improve the water resistance of water-soluble dyes, a water-soluble reactive binder having a functional group that can chemically bond with both the hydroxyl group of cellulose and the water-soluble dye by heat treatment is proposed. As an agent,
A method has been proposed in which polyamide epichlorohydrin resin, water-soluble jepoxy, polyethylene imine, methylolated acrylamide polymer, etc. are blended into an aqueous ink composition, but this method does not require heat treatment after printing. There were problems such as insufficient light resistance of the formed image. Furthermore, in order to improve water resistance, Japanese Patent Publication No. 55-18753 describes a method using a polyamine having six or less nitrogen atoms per molecule.
JP-A-21710 discloses a method using a polyamine containing no primary amine hydrogen and having 7 or more nitrogen atoms per molecule; A method using hydroxyethylated polyethyleneimine has been proposed.

However, methods using polyamines that do not contain primary amine hydrogen, as disclosed in Japanese Patent Publication No. 55-18753 and Japanese Patent Publication No. 60-21710, have problems such as insufficient water resistance. The methods using hydroxyethylated polyethyleneimine disclosed in Japanese Patent Application Laid-open No. 76066 and Japanese Patent Application Laid-Open No. 119280/1980 have satisfactory water resistance, but have problems such as insufficient ink absorption speed during printing.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of conventional aqueous inks and to provide an aqueous ink composition with improved water resistance, ink absorption, light resistance, and storage stability. It is about providing. Furthermore, the aqueous ink composition is characterized in that it causes few problems in mutagenicity tests.

(Means and effects for solving the problem) As a result of extensive research, the present inventors have discovered that by reacting polyethyleneimine with propylene oxide, 50% to 95St hydroxypropyl of primary and secondary amine hydrogen When an aqueous ink composition containing a hydroxypropylated polyethyleneimine (A) substituted with a group, a dye (B), and water as essential components is used for recording on each Aki recording material, the water resistance of the ink only improves. However, most of the primary and secondary amine hydrogens in polyethyleneimine are hydroxypropylated, which is thought to adversely affect the stability of some dyes. The present invention was achieved based on the discovery that the absorbency of ink is improved.

That is, the present invention provides primary polyethyleneimine and 5g2
Hydroxyzolobylated polyethyleneimine (A
l, dye) and water as essential components f
: This relates to an aqueous ink composition expressed as a percentage.

The hydroxyzolobylated polyethyleneimine (4) used in the present invention is obtained by adding propylene oxide to polyethyleneimine. The reaction conditions are particularly limited, for example, polyethyleneimine and propylene oxide can be synthesized by reacting them until their original temperature or diluting with a solvent as necessary, preferably at a temperature of 0 to 150°C. At this time, a catalyst such as acid or alkali may be used freely.

The polyethyleneimine used here is linear,
Or it may be branched, but the number average molecular weight of polyethyleneimine is 300 to 150.
000 is preferred.

The number of additions of propylene oxide to polyethyleneimine is determined based on practical considerations such as water resistance, ink absorption, storage stability, and light resistance when the resulting hydroxybromolated polyethyleneimine is used as an aqueous ink composition. It can be varied within a certain range. The range of the number of moles of propylene oxide added that does not cause any practical problems is 5Ots of primary and secondary amine hydrogen of polyethyleneimine.
The amount corresponds to ~95es. If the number of moles of propylene oxide added is less than 50 inches, the storage stability and ink absorbability of the ink composition will be poor, and if it is added in excess of 95 inches, water resistance will be poor.

The number average molecular weight of the hydroxypropylated polyethyleneimine compound synthesized by the above method is 500 to 300.0.
00, but if the molecular weight is small, the water resistance of images obtained from the resulting aqueous ink composition will be insufficient, and if the molecular weight is large, problems such as storage stability and increased viscosity of the resulting aqueous ink composition will occur. Therefore, the hydroxyzorobylated polyethyleneimine (3) preferably used in the water-repellent ink composition has a number average molecular weight of 600 to 100.
,000.

The dye (B) binding τ that can be used in the present invention is not particularly limited as long as it is a dye conventionally used in water-based inks, such as direct dyes, acid dyes, mordant dyes, metal complex dyes, vat dyes, disperse dyes, Examples include fluorescent dyes, and dyes such as direct dyes and acid dyes are particularly preferably used.

In the present invention, the amount of hydroxypropylated polyethyleneimine (A) used is 0.1 to 100% based on the dye (B).
Preferably, it is expressed as % by weight.

In addition, the aqueous ink composition of the present invention contains the above-mentioned hydroxybromolated polyethyleneimine (A), dye (6), and water as essential components, but in addition to these, there may be other components conventionally used in aqueous ink compositions. It may also contain appropriate additives such as low-volatile organic solvents, compatibilizers, surfactants, antifungal agents, ultraviolet absorbers, and antioxidants.

(Effects of the Invention) The aqueous ink composition of the present invention comprises hydroxybromolated polyethyleneimine (5) in which 50% to 95% of the primary and secondary amine hydrogens of polyethyleneimine are substituted with hydroxypropyl groups, dye (B) and water as essential components, it not only achieves both water resistance and storage stability, but also has excellent absorbency to various recording materials, and images without bleeding can be obtained. Moreover, the image has excellent light resistance.

Although the mechanism by which this effect occurs is not clear, hydroxybromolated polyethyleneimine (8) contains less primary amines and secondary amines than polyethyleneimine, and it is difficult to absorb into various recording materials. This seems to be due to the excellent properties. However, it goes without saying that this assumption does not limit the present invention in any way.

Therefore, the aqueous ink composition of the present invention having the above characteristics can be used, for example, in writing instruments and stamps.

It can be suitably used as an ink material for printing, inkjet, recording needles, etc.

(Example) The present invention will be described below with reference to Examples, but it is not limited to these examples. In addition, parts and parts shown in Examples mean parts by weight and parts by weight.

Reference Example 1 Epomin 5P-006 (polyethyleneimine manufactured by Nippon Shokubai Chemical Co., Ltd., average molecular weight 600) 344Ii and ion-exchanged water 8021 were placed in a flask equipped with a stirrer, a reflux condenser, a propylene oxide inlet tube, and a thermometer. , and heated to 60C without stirring. Propylene oxide 418 was added into this solution from the propylene oxide introduction tube.
1 was introduced over 2.5 hours. Next, the temperature was raised to 70°C and stirring was continued for 1.5 hours at the same temperature to complete the reaction. Solid content concentration 48.6 cm, viscosity 230 cps (B-type viscometer, 25°C, ÷2.60 rpm), 5% diluted aqueous solution = 11.4 (at 25°C) primary and primary polyethyleneimine An aqueous solution of hydroxybromolated polyethyleneimine (1) in which 90% of secondary amine hydrogens were substituted with hydroxypropyl groups was obtained.

Reference Example 2 In a flask similar to Reference Example 1, Epomin 5P-018 (polyethyleneimine manufactured by Nippon Shokubai Chemical Co., Ltd., average molecular weight 1800) 344.9 and ion exchange water 8021 were placed and heated to 60°C while stirring. . From the propylene oxide introduction pipe into the O-liquid, propylene oxide 3 is added.
72 g were introduced over 2.5 hours. Next, the temperature was raised to 70°C, and stirring was continued at the same temperature for 1.5 hours to complete one reaction. Solid content concentration 47.1 cm, viscosity 260 cps, 5% diluted aqueous solution 0p) 80% of primary and secondary amine hydrogens of polyethyleneimine with i=11.8 t''Hydroxybromole substituted with hydroxypropyl groups An aqueous solution of polyethyleneimine (2) was obtained.

Comparison not reference 1 In reference example 1, the amount of propylene oxide introduced was 51
In the same manner as in Reference Example 1, except that the amount was 1 g, a -
An aqueous solution of comparative hydroxypropylated polyethyleneimine (1') in which 100% of the primary and secondary amine hydrogens of polyethyleneimine of =IL1 (25°C) were replaced with hydroxypropyl groups was obtained.

Comparative Reference Example 2 A solid content concentration of 45.2% and a viscosity of 1 were obtained in the same manner as in Reference Example 1 except that ethylene oxide 317y was used instead of propylene oxide 4181 in Reference Example 1.
00 cps, 5% diluted aqueous solution pH = 11.4 of primary and secondary amine hydrogen of polyethyleneimine.
An aqueous solution of comparative polyethyleneimine (2') in which % was substituted with hydroxyethyl groups was obtained.

Example 1 A black aqueous ink composition (1) was obtained by stirring and mixing the following components at room temperature.

Note (Part) Dye (C, 1, Direct Black 154)
5 hydroxypropylated polyethyleneimine (1 liter aqueous solution 8 ethylene glycol 20 water
67
Examples 2 to 6 and Comparative Examples 1 to 4 A water-based ink composition ( 2
) to (6), and comparative aqueous ink compositions (1) to ( 4) was obtained.

Example 7 Aqueous ink compositions (1) to (6) obtained in Examples 1 to 6
) and comparative aqueous ink compositions (1) to (4) obtained in Comparative Examples 1 to 4 were subjected to performance tests. The results are shown in Table 2.

The performance test was conducted using general high-quality paper with a Steckicht size of 25 seconds and a weight of 60Ii.

1. Absorption speed of ink The time (seconds) from when ink 0.3 μE gold was dropped as a droplet on the above-mentioned general high-quality paper until it was completely absorbed was measured.

2. Immerse the water-resistant ink in running water for 3 minutes after fishing, and measure the Hunter color difference (ΔE) before and after using Nippon Denshoku ND-1001DPfi.
Measured using a color difference meter. The smaller the value, the better the water resistance.

3. After applying light-resistant ink, use Shimadzu Fade Tester CF-2ON
The mold was irradiated at 60°C for 8 hours to test the light resistance using Hunter Color Difference (
Evaluation was made using ΔE). The smaller the value, the better the light resistance.

4. Bleeding When 0.3 μl of the ink was absorbed into the paper, it was evaluated whether the circumference of the ink dot formed a smooth line.

○: Good Δ: Some bleeding ×: Strong bleeding 5. Storage stability The stability of the ink when stored at t-60° C. for 30 days was checked.

Claims (1)

[Claims] 1. Hydroxypropylated polyethyleneimine (A) in which 50% to 95% of the primary and secondary amine hydrogens of polyethyleneimine are substituted with hydroxypropyl groups, dye (
B) and water as essential components.