JPH1067960A - Water base fluorescent ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water base fluorescent ink having excellent dry resistance at an ink delivery part such as a pen point by mixing a coloring agent colored a resin particle, water and a polyester polyol resin as a dry-preventing agent. SOLUTION: This fluorescent ink is composed of (A) a coloring agent colored a resin particle, (B) water and (C) a polyester polyol resin. As the resin particle constituting the component A, a styrene/acrylonitrile copolymer, etc., is exemplified. Preferably, a particle diameter of the resin particle is 0.05-0.3μm. The component A is obtained by e.g. a method mixing a dye into a monomer at a previous stage in the resin particle is synthesized or a method mixing a dye during polymerization, etc. Preferably, 1-50wt.% of the component A and 0.01-5wt.% of the component B are mixed to the whole weight of the objective ink. A glycol-based solvent such as ethylene glycol or an additive such as a wetting agent such as urea, an antiseptic agent or an antifoaming agent can be mixed into this ink, as necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous fluorescent ink used for writing instruments, recorders, ink jet printing, and the like.
More specifically, the present invention relates to an aqueous fluorescent ink having excellent drying resistance at an ink discharge portion such as a pen tip or an orifice.

[0002]

2. Description of the Related Art Conventionally, aqueous fluorescent inks used for writing instruments, recorders, ink jet printing, and the like generally include at least a coloring material for coloring resin particles, a water-soluble organic solvent, and water. In the above-mentioned ink using water as a main solvent, a phenomenon such as thickening of the ink occurs due to evaporation of the water in the ink, and as a result, the ink discharge from the pen tip is reduced (so-called blurring), and the ink is discharged from the ink discharge hole. In such a case, troubles such as a decrease in ink ejection (so-called "going out") tend to occur. Therefore, in order to prevent the above-mentioned problems from occurring, conventionally, glycol-based solvents such as ethylene glycol, diethylene glycol, triethylene glycol, and thiodiglycol, and high-boiling solvents having hygroscopicity such as glycerin are used as water-soluble organic solvents. Was used. That is, the above-mentioned conventional ink was designed to supplement the water evaporated by the hygroscopicity of the water-soluble organic solvent in order to obtain good drying resistance.

[0003]

However, the water-soluble organic solvent is generally a compound having a high viscosity. On the other hand, ink used for writing instruments, recorders, ink jet printing, and the like is discharged through a capillary such as a pen tip or an orifice. Therefore, there is a limit to the amount of the water-soluble organic solvent that can be used for the ink, and the amount of water used within the limit cannot sufficiently compensate for the evaporated water.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink composition having excellent drying resistance at an ink discharge portion such as a pen tip. An aqueous fluorescent ink comprising at least water, a polyester polyol resin and water.

The details will be described below. The coloring material used in the present invention is obtained by coloring resin particles with a dye.

The resin particles include a copolymer of styrene and acrylonitrile, and a copolymer of acrylic acid. The particle size is preferably 0.05 to 0.3 μm. The dye for coloring the resin particles is, for example, CI.
Direct dyes such as Direct Red 2, CI Direct Yellow 27, CI Acid Red 87, CI Acid Bull-9, CI Acid Yellow-23, CI Acid Red 92, Acid dyes such as CI Acid Black 2; I. Basic Blue 3, CI Basic Blue-45, CI Basic Red 1, CI Basic Red 1: 1, CI Basic Violet 1,
CI Basic Violet 7, CI Basic Violet 11, CI Basic Yellow 40, C.I.
I. Basic dyes such as Basic Green 1; I. Disperse dyes such as Desper Yellow 82; I. And oil-soluble dyes such as Solvent Yellow 44. In order to color the resin particles with the dye, the dye is mixed with the monomer at a stage prior to the synthesis of the resin particles, or the dye is mixed during the polymerization, or the dye is mixed after the synthesis. be able to. One example of a commercially available product is Lumicoll NKW-
3002 (green pigment, styrene-acrylonitrile copolymer colored with CI Basic Yellow 40 and CI Basic Blue 45), NKW-30
04 (orange pigment, styrene-acrylonitrile copolymer was prepared by using CI Basic Yellow 40, CI Basic Violet 11 and CI Basic Red 1:
1), NKW-3005 (yellow pigment,
The styrene-acrylonitrile copolymer was used as a C.I. I. Colored with Basic Yellow 40), NKW-300
7 (pink pigment, styrene-acrylonitrile copolymer colored with CI Basic Violet 11 and CI Basic Red 1: 1), NKW-30
08 (light blue pigment, styrene-acrylonitrile copolymer colored with CI Basic Blue 45) and NKW-3077 (purple pigment, styrene-acrylonitrile copolymer colored with CI Basic Violet 7) NKW-3604 (green pigment, styrene-acrylonitrile copolymer colored with CI Basic Yellow 40 and CI Basic Blue 45), and NKW-3604 (orange pigment, styrene-
The acrylonitrile copolymer was used as C.I. I. Basic Yellow 40, C.I. I. Basic violet 11 and C.I.
I. Basic red 1: 1), NK
W-3605 (yellow pigment, styrene-acrylonitrile copolymer colored with CI Basic Yellow 40), NKW-3607 (pink pigment, styrene-acrylonitrile copolymer with CI Basic Violet 11 and CI Basic Red 1: 1) and NKW-3608 (light blue pigment, styrene-
The acrylonitrile copolymer was used as C.I. I. NKW-3677 (purple pigment, styrene-acrylonitrile copolymer colored with CI Basic Violet 7) (Nippon Fluorescent Chemical Co., Ltd.), Victoria Orange G-21A
(Copolymers of an orange pigment and acrylic acid were used as CI Basic Yellow 40, CI Basic Red 1 and CI Basic Red 1).
I. Basic violet 11), Victoria Yellow G-20 (yellow pigment, copolymer of acrylic acid colored with CI Basic Yellow 40 and CI Desper Yellow 82), Victoria Green G- 24C (yellow-green pigment, a copolymer of acrylic acid colored with CI Basic Yellow 40, CI Despar Yellow 82 and CI Basic Green 1), Victoria Pink G-23 (pink pigment , Acrylic acid copolymers colored with CI Basic Red 1 and CI Basic Violet 11), Victoria Blue G-25 (light blue pigments and acrylic acid copolymers are referred to as CI Basic). Blue 3), Victoria Red G-22 (a copolymer of red pigment and acrylic acid Chic yellow 40,
C. I Desper Yellow 42, C.I. I. Basic Red 1, C.I. I. Basic violet 11 and C.I.
I. Basic Blue 3) (above, manufactured by Mikuni Pigment Co., Ltd.), Cosmo Color S-1000F Series (manufactured by Toyo Soda Co., Ltd.) and the like. These are 1
Species or a mixture of two or more can be used. The amount used is preferably from 1 to 50% by weight based on the total amount of the aqueous fluorescent ink. If the amount is less than 1% by weight, it is difficult to say that the density is sufficient as a handwriting. If the amount is more than 50% by weight, the viscosity of the ink tends to increase, and the ink discharge tends to decrease.

[0007] The polyester polyol resin which is the essence of the present invention is used as an anti-drying agent such as a pen tip. Specifically, it is a polymer compound having a portion having a polyester bond in the main chain and a polyol structure portion having two or more hydroxyl groups, and commercially available products such as PAOGEN PP-15 and EP-15 Daiichi Kogyo Seiyaku Co., Ltd.). The amount used is preferably 0.01 to 5% by weight based on the total amount of the aqueous fluorescent ink. this is,
If the amount is less than 0.01% by weight, the effect cannot be sufficiently obtained, and if the amount is more than 5% by weight, the effect is not improved.

[0008] In addition to the above essential components, if necessary, known solvents such as glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol, and known solvents such as glycerin, polysaccharides, urea, ethylene urea and derivatives thereof. Wetting agents, preservatives, fungicides, rust inhibitors,
Various additives such as alkaline agents, fragrances, antifoaming agents, gloss-imparting agents, dyes for complementary colors, and additives such as water-soluble natural polymer substances and water-soluble synthetic polymer substances, alone or as needed Can be used appropriately in combination.

In order to obtain the ink composition of the present invention, each component is stirred and mixed using a stirrer.

[0010]

The polyester polyol resin used in the aqueous ink composition according to the present invention forms a thin film near the interface of the ink, unlike the conventionally used water-soluble high-boiling solvent having hygroscopicity. It has an effect of suppressing the evaporation of water (including water), so it is assumed that the evaporation of the solvent in the ink from the pen tip is suppressed.

[0011]

The present invention will be described in more detail with reference to the following examples.

Example 1 Lumicoll NKW3002 (manufactured by Nippon Fluorescent Chemical Co., Ltd.) 40.0 parts by weight Glycerin 3.0 parts by weight Thiodiglycol 15.0 parts by weight Glucose 5.0 parts by weight Paogen PP-15 (Daiichi Kogyo) 0.1 part by weight Water 36.9 parts by weight The above components were mixed and stirred with a stirrer for 2 hours to obtain a yellow-green aqueous fluorescent ink.

Example 2 Victoria Pink G-23 (manufactured by Mikuni Pigment Co., Ltd.) 45.0 parts by weight Glycerin 18.0 parts by weight Sorbitan 2.5 parts by weight Glucose 2.5 parts by weight Mergar KM101A (Hoechst Gosei Co., Ltd.) 0.5 parts by weight Paogen PP-15 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight Water 31.0 parts by weight Each of the above components is blended and stirred with a stirrer for 2 hours. A pink aqueous fluorescent ink was obtained.

Example 3 Lumicoll NKW3004 (manufactured by Nippon Fluorescent Chemical Co., Ltd.) 35.0 parts by weight Glycerin 15.0 parts by weight Paogen EP-15 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.8 parts by weight Water 49. 2 parts by weight The above components were mixed and stirred with a stirrer for 2 hours to obtain an orange aqueous fluorescent ink.

Example 4 Lumicoll NKW3608 (manufactured by Nippon Fluorescent Chemical Co., Ltd.) 12.0 parts by weight Diethylene glycol 15.0 parts by weight Proxel GXL (manufactured by ICI Japan Co., Ltd., fungicide) 0.5 part by weight Paogen PP- 15 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 3.5 parts by weight Water 69.0 parts by weight The above components were blended and stirred with a stirrer for 2 hours to obtain a sky blue aqueous fluorescent ink.

Comparative Example 1 Victoria Pink G-23 (manufactured by Mikuni Pigment Co., Ltd.) 45.0 parts by weight Glycerin 18.0 parts by weight Sorbitan 2.5 parts by weight Glucose 2.5 parts by weight Mergar KM101A (Hoechst Gosei Co., Ltd.) 0.5 parts by weight Water 31.5 parts by weight The above components were mixed and stirred with a stirrer for 2 hours to obtain a pink aqueous fluorescent ink.

Comparative Example 2 Lumicoll NKW3004 (manufactured by Nippon Fluorescent Chemical Co., Ltd.) 35.0 parts by weight Glycerin 30.0 parts by weight Paogen EP-15 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.8 parts by weight Water 34. 2 parts by weight The above components were mixed and stirred with a stirrer for 2 hours to obtain an orange aqueous fluorescent ink.

[0018]

The ink compositions obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were tested. Table 1 shows the results.

[0019]

[Table 1]

Writing Test: (Method) Each ink composition was applied to a writing instrument similar to a signal (available from Pentel Co., Ltd.) using a commercially available aqueous fluorescent ink for 2.0 hours.
g, and hand-written on high quality paper immediately after assembly, and the handwriting was observed.

Pen tip drying resistance test: (Method) The writing implement was left sideways with the cap removed from the writing implement at a temperature of 25 ° C. and a humidity of 65%, and handwritten on a high quality paper at regular intervals. And the time until the handwriting was blurred was measured. In Comparative Example 2, the pen tip drying resistance test was not performed because the handwriting was frayed immediately after assembly.

As described in detail above, the ink of the present invention is excellent in the drying resistance of the pen tip and has the excellent features of preventing the occurrence of blurring and the like unlike conventional water-based fluorescent inks.

Claims (1)

[Claims] An aqueous fluorescent ink comprising at least a colorant for coloring resin particles, water, and a polyester polyol resin.