JPH0418472A - Water-based ink composition for ball point pen - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of imparting a desired fastness to drawn line, having excellent aging stability of ink and giving a written mark readable even after exposure to sunlight or wet with water by using a phthalocyanine blue alkali metal salt as a colorant. CONSTITUTION:The objective composition contains at least a phthalocyanine blue alkali metal salt as a colorant. The number of alkali metal atoms to form a salt is preferably <=3 based on one molecule of phthalocyanine blue. The content of the phthalocyanine blue alkali metal salt in the composition is preferably 0.3-8.0wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aqueous ink composition for a ballpoint pen that can impart desired line fastness to written lines and has excellent ink stability over time.

[Conventional technology]

Conventional water-based inks for ballpoint pens contain water and a water-soluble organic solvent such as a polyhydric alcohol or a derivative thereof as main components. There are also inks that use pigment inks or direct dyes as colorants to increase the fastness of drawn lines, or use resins to increase the fixation of dyes.

[Problem to be solved by the invention]

Phthalocyanine blue is known as a blue organic pigment.
In addition, many inks using pigments such as phthalocyanine blue metal salts have been reported, but although they have good line fastness, they are unstable over time. Furthermore, inks that use direct dyes or resins to increase the fastness of drawn lines are stable over time, but have poor line fastness. Therefore, an object of the present invention is to provide a water-based ink composition for a ballpoint pen that has excellent line fastness and stability over time.

[Means to solve the problem]

The present inventors conducted extensive research to solve the above problem, and as a result found that the problem could be solved by using an alkali salt of phthalocyanine blue as a coloring agent, and completed the present invention.

That is, the present invention is an aqueous ink composition for a ballpoint pen containing at least an alkali salt of phthalocyanine blue as a coloring agent.

Here, the alkaline salt of phthalocyanine blue is an inorganic salt such as Na, Li, or the like. Up to four alkali metals can be attached to one molecule of phthalocyanine blue, but
Considering the water resistance of drawn lines, it is preferable to use up to three alkali metals.

The alkaline salt of phthalocyanine blue can be added in an amount of 0.1 to 10.0% by weight in the ink composition.
The content is preferably 0.3 to 8.0% by weight. In addition to the colorant, the water-based ink for ballpoint pens of the present invention contains known non-drying water-soluble organic solvents for the purpose of preventing drying and imparting antifreeze properties, such as
Contains polyhydric alcohols such as ethylene glycol, diethylene glycol, and glycerin, glycol ethers such as methyl cellosolve and butyl cellosolve, and glycol esters such as ethylene glycol monomethyl ether acetate, singly or in combination of two or more. You can let me. These water-soluble organic solvents can be added in an amount of 5 to 50% by weight, preferably 10 to 35% by weight, in the ink composition. Furthermore, if necessary, auxiliary agents commonly used in water-based inks such as lubricants, preservatives, antifungal agents, rust preventives, and pH adjusters may be included.

[Effect]

The salt of phthalocyanine blue with copper is called copper phthalocyanine blue, and as a pigment it has excellent line fastness.

This phthalocyanine blue can be replaced with up to 4 Na salts. If the amount of alkali salt is small, the solubility is slightly inferior, but the solidity of the drawn line is good. Also, if there is a large amount of alkali salt, the solubility will be excellent, but because of the good solubility, the water resistance will be particularly weak.

Therefore, desired line fastness can be obtained by changing the distribution of these alkali salts.

Phthalocyanine Blue 1 to improve the water resistance of drawn lines
Preferably, the molecule has up to three alkali metal atoms.

〔Example〕

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples.

A dye in which the number of Na salts in Phthalocyanine Blue is mainly distributed is called Phthalocyanine Blue A, and a dye in which the number of Na salts in Phthalocyanine Blue is mainly distributed is called Phthalocyanine Blue B1. A dye in which the number of Na salts is mainly distributed is called Phthalocyanine Blue 0, and a dye in which the number of Na salts in phthalocyanine blue is mainly distributed is called Phthalocyanine Blue D.

(Example 1) Water 73.7 (
Weight part) Propylene glycol 2
4.0 Polyoxyethylene alkyl allyl ether 0
．． 2 Phenol 0.
1 Phthalocyanine Blue A2.0 The above blended composition was stirred at 40 to 60°C for 1 hour, then cooled and further filtered to obtain an aqueous blue ink.

(Example 2) Water 67.7 (
Weight part) Glycerin 30
,0 Potassium oleate 0
,2phenol 0.
1 Phthalocyanine Blue 8 2.
0 The above blended composition was treated in the same manner as in Example 1 to obtain a water-based blue ink.

(Example 3) Water 63.5 (
Weight part) Ethylene glycol 2
8.0 Phenol 0.
] Triethanolamine 0.
1 Sodium ricinoleate 0.
4 Phthalocyanine Blue 02.0 The above blended composition was treated in the same manner as in Example 1 to obtain a water-based blue ink.

(Example 4) Water 70.7
(Parts by weight) Propylene glycol
24,0 polyoxyethylene alkyl allyl ether
0.2 Phenol 0.
1 Phthalocyanine Blue D5.0 The above blended composition was treated in the same manner as in Example 1 to obtain a water-based blue ink.

(Comparative example) Water 70.7
(Parts by weight) Propylene glycol
24.0 Polyoxyethylene alkyl allyl ether
0.2 Phenol 0.
1 Edible Blue No. 1 6.0
The above blended composition was treated in the same manner as in Example 1 to obtain a water-based blue ink.

After filling a ballpoint pen with the inks of Examples 1 to 4 and Comparative Example and writing for 10 meters using a writing tester, the lines were stained for 1 hour after writing, soaked in distilled water for 24 hours, taken out, and written. The condition of the wire was visually inspected (water resistance). In addition, it was exposed to ultraviolet fetometer for 80 hours, and the state of the written line was then visually examined (light resistance). Further, the condition of the above ink was visually examined after being left at 0°C and 40°C for one week. The results are shown in Table 1.

Table 1 Note that when the inks were left to stand at 0°C and 40°C, no solubility problems such as precipitation occurred in any of the inks.

It is clear from Table 1 that the inks of each example have better solidity of writing lines and are more stable over time than the inks of the comparative examples.

〔Effect of the invention〕

The aqueous ink composition for ballpoint pens of the present invention improves the fastness of written lines, makes them legible even when exposed to sunlight or wet with water after writing, and enables long-term storage of written materials. It also has the advantage of being stable as an ink and able to withstand storage in a storage container.

Claims (1)

[Scope of Claims] 1. An aqueous ink composition for a ballpoint pen containing at least an alkali salt of phthalocyanine blue as a coloring agent. 2. The aqueous ink composition for a ballpoint pen according to claim 1, wherein the number of alkali metal atoms forming a salt per molecule of phthalocyanine blue is 3 or less.