JP2002338869A - Water-base ink composition and water-base ballpoint using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-base ink composition which does not corrode a superhard alloy ball at the pen tip of a water-base ballpoint even when the ballpoint is stored for a long time and which does not cause blur or line jumping due to the corrosion of the pen tip; and a water-base ballpoint using the ink. SOLUTION: This water-base ink composition contains an alkali metal silicate and/or an alkali metal borate and is used for a water-base ballpoint having a superhard alloy ball.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous ink composition having improved corrosion resistance of a cemented carbide ball having a pen tip portion, and an aqueous ballpoint pen provided with the same.

[0002]

2. Description of the Related Art A ball provided in a pen point portion of a ballpoint pen is made of a hard sintered alloy having wear resistance to a metal material thereof, and powder of a metal carbide of a group IVa, Va or VIa of the periodic table. Fe, Co, WC-Co-based iron group metal Ni is a sintered bonded alloy and WC-Cr ₃ C ₂ -Co
A cemented carbide such as a system is generally used. However, even if a cemented carbide is used for the ball of the nib, the ball surface will corrode during storage due to the water and corrosive components contained in the ink, and the abrasion resistance of the ball will decrease, and writing will take place. There was a problem that became difficult.

[0003]

In order to solve this problem, it is common practice to add benzotriazole to aqueous ink compositions. However, benzotriazole is not sufficiently soluble in water, and because it is an organic compound, it is easily adsorbed on a plastic ink container or is easily adsorbed on pigments. Even if benzotriazole is contained in the composition, if the composition is stored for a long period of time, corrosion of the pen tip occurs, resulting in burrs and line breaks. Therefore, the problem of difficulty in writing has not been solved.

[0004]

As a result of diligent studies, the present inventors have provided an aqueous ink composition for an aqueous ballpoint pen containing an alkali metal silicate and / or an alkali metal borate, and this aqueous ink composition. It has been found that the use of the water-based ballpoint pen solves the above-mentioned problem without corroding the cemented carbide ball even when stored for a long period of time, leading to the present invention.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention is an aqueous ink composition containing an alkali metal silicate and / or an alkali metal borate.

The aqueous ink composition of the present invention contains an alkali metal silicate and / or an alkali metal borate, and contains both an alkali metal silicate and an alkali metal borate. Or one of them may be included. By containing the alkali metal silicate and the alkali metal borate in the aqueous ink composition, a thin film of silicic acid or boric acid is formed on the ball when the aqueous ink composition contacts the ball, It prevents corrosion of the chip holder.

The alkali metal silicate contained in the aqueous ink composition of the present invention is not particularly limited as long as it is an alkali metal salt of silicic acid. However, it has no toxicity and has good solubility in water. Sodium silicate and potassium silicate are preferred, and sodium silicate is more preferred. The method for producing the alkali metal silicate is not particularly limited as long as it is produced by a known method.

[0008] The composition of the alkali metal silicate is particularly
Without limitation, polysilicic acid (orthosilicic acid,
Meta-silicic acid, para-silicic acid and meso-silicic acid) alkali gold
A genus salt may be used, for example, in the case of sodium silicate
Sodium metasilicate (Na _TwoSiO_Three) Or Ortokei
Sodium acid (Na_FourSiO_Four) And the like, and silicic acid
In the case of potassium, potassium metasilicate (K_TwoSi
O_Three) And potassium hydrogen disilicate (KHSi_TwoO_FiveOr K
_TwoSi_FourO₉・ H_TwoO) and the like.
For thorium or potassium silicate, use water glass (one
General formula: mK_TwoOn SiOn_TwoOr mNa_TwoO ・ nSi
O_Two) Can be used, but insoluble on the ball surface
The composition is sodium metasilicate because it is easy to form a functional film
It is preferred that

The alkali metal borate contained in the aqueous ink composition of the present invention is not particularly limited as long as it is an alkali metal salt of boric acid. However, sodium borate is preferred because of its high solubility in water. It is preferred that The method for producing the alkali metal borate is not particularly limited as long as it is produced by a known method.

The composition of the alkali metal borate may be any alkali metal salt of boric acid. When there are a plurality of compositions, the composition is not particularly limited.
In the case of sodium borate, sodium metaborate (NaBO ₂ ) and sodium diborate (Na ₄ B
₂ O ₅ ), sodium tetraborate (Na ₂ B ₄ O ₇ ), sodium pentaborate (NaB ₅ O ₈ ), sodium hexaborate (Na ₂ B ₆ O ₁₀ ) and sodium octaborate (NaB
₈ O ₁₃ ) or a hydrate thereof, but sodium tetraborate is preferred because an insoluble film is easily formed on the ball surface.

The amount of the alkali metal silicate and / or the alkali metal borate contained in the aqueous ink composition of the present invention is 0.01 to 0.01% based on the total amount of the aqueous ink composition.
1.0% by weight, preferably 0.05 to 0.5% by weight.
More preferably, it is% by weight. When the compounding amount of the alkali metal silicate and / or the alkali metal borate is 1.0
When the amount is more than 0.01% by weight, the coloring agent is apt to aggregate, which is not preferable. On the other hand, when the amount is less than 0.01% by weight, it is difficult to obtain a rust-preventive effect. The alkali metal silicate and / or the alkali metal borate may be one in which one or two or more alkali metal silicates are blended as a composition. One or more of the compositions may be blended.

The water-based ink composition of the present invention contains a coloring agent since it is intended for writing or the like. The coloring agent is not particularly limited as long as it has a coloring effect, but a coloring agent having solubility or dispersibility is preferable. Specifically, acid dyes, direct dyes, water-soluble dyes such as basic dyes, copper phthalocyanine-based pigments, slen-based pigments, azo-based pigments, quinacridone-based pigments, anthraquinone-based pigments, dioxane-based pigments, indigo-based pigments, Use organic pigments such as thioindigo pigments, perinone pigments, perylene pigments, indolenone pigments, azomethine pigments, etc., inorganic pigments such as carbon black and titanium oxide, glitter pigments such as aluminum powder pigments, and colored resin emulsions. be able to. Further, the pigment can be used as a pigment dispersion by dispersing the pigment with a dispersant. Further, the colorant contained in the aqueous ink composition of the present invention can be used alone or in combination of two or more.

The amount of the colorant contained in the aqueous ink composition of the present invention is not particularly limited, but may be 0.5 to 20.0% by weight based on the total amount of the aqueous ink composition. More preferably, it is 1.0 to 15.0% by weight. When the amount of the coloring agent is more than 20.0% by weight based on the total amount of the aqueous ink composition, the viscosity of the ink is increased, the writing property is reduced, and the production cost is increased. If the amount is less than% by weight, it is difficult to obtain a coloring effect, which is not preferable.

The aqueous ink composition of the present invention may contain, if necessary, other components in addition to the above-mentioned alkali metal silicate, alkali metal borate and colorant. As other components, specifically, ethylene glycol, diethylene glycol, triethylene glycol
Glycols such as propylene glycol and polyethylene glycol, polyhydric alcohols such as glycerin, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether and dipropylene glycol monopropyl. Water-soluble organic solvents represented by glycol ethers such as ether, water-soluble acrylic resin, water-soluble maleic resin, water-soluble styrene-acrylic copolymer, water-soluble styrene-maleic acid copolymer, etc. Dispersants, preservatives and fungicides represented by benzoisothiazoline, pentachlorophenol, cresol, etc., lubricants represented by dicarboxylic acid amides, phosphoric esters, N-oleyl sarcosine salts, various interfaces Activator, microbial polysaccharide and its derivatives, water Sexual plant polysaccharides and derivatives thereof,
Includes water-soluble animal polysaccharides and their derivatives, thickeners represented by acrylic synthetic resins, vinyl synthetic resins, cellulosic semi-synthetic resins, etc., anti-agglomeration agents, pH adjusters, pseudoplasticizers, etc. Can be. Further, water may be added for viscosity adjustment or the like.

The method for producing the aqueous ink composition of the present invention comprises:
The method is not particularly limited, and is performed by a known method. For example, after mixing, stirring and dispersing water, a water-soluble organic solvent, a colorant and other components, a water-soluble resin as a thickener is added, and the mixture is stirred, filtered and then defoamed. be able to.

The present invention is also an aqueous ink composition containing an alkali metal silicate and / or an alkali metal borate, an aqueous ballpoint pen provided with a chip holder and a ball made of cemented carbide.

The aqueous ballpoint pen of the present invention comprises an aqueous ink composition containing an alkali metal silicate and / or an alkali metal borate in a ballpoint pen, and holds a ball made of a cemented carbide and the ball at the pen tip. There is no particular limitation as long as it is provided with a chip holder for the ink, and even a batting ballpoint pen using an ink occluding body made of a fiber bundle or the like can be used directly with an ink storage tube for storing an aqueous ink composition. A liquid ballpoint pen may be used. The water-based ball-point pen of the present invention can provide a water-resistant ball-point pen with good writability without rusting and line breakage even when stored for a long period of time, without causing rust in the ball portion at the tip of the chip.
In the water-based ballpoint pen of the present invention, when the tip holder is a stainless steel tip holder, rust prevention of the stainless steel tip holder can be expected.

[0018]

EXAMPLES The present invention will be described below based on examples and comparative examples, but the present invention is not limited to these examples.

With the composition and amount (parts by weight) shown in Table 1,
Sodium silicate or sodium borate, water, a water-soluble organic solvent, a coloring agent, a dispersing resin, a lubricant and an antiseptic / antifungal agent are mixed, stirred and dispersed, and then filtered,
The aqueous ink compositions of Examples and Comparative Examples were obtained. A conventionally known method was used for the dispersion method, filtration, and the like.

[0020]

[Table 1]

The following raw materials were used as the various raw materials in Table 1.

Carbon black (trade name: Monarch 800, manufactured by Cabot Corporation) is used as a coloring agent, and acrylic acid-styrene copolymer (trade name: Joncryl 68) is used as a dispersion resin.
3, Johnson Polymer Co., Ltd.), phosphanol PE510 (trade name, manufactured by Toho Chemical Industry Co., Ltd.) as a lubricant, and sodium metasilicate (Na ₂ Si) as a sodium silicate.
O ₃ ), sodium tetraborate (Na ₂ B ₄ O ₇ ) for sodium borate, diethylene glycol for water-soluble organic solvent A, glycerin for water-soluble organic solvent B,
Proxel XL2 (trade name, manufactured by Zeneca Corporation)
Was used.

[Evaluation of Corrosion Resistance] The aqueous ink compositions of Examples and Comparative Examples were respectively placed in glass bottles with lids.
A tip made of a stainless steel tip holder and a cemented carbide ball having a diameter of 0.5 mm is immersed in an aqueous ink composition in a glass bottle with a lid, and the lid is closed and stored at 70 ° C. for one month. The surface state of the ball was observed with a microscope and evaluated according to the following evaluation criteria. Table 2 shows the results. In the microscopic observation, the microscope showed the product name KH2
700 (manufactured by Hylox Corporation) and observed at a magnification of 250. (Evaluation criteria) 〇: The ball surface has metallic luster. X: The ball surface is corroded and has no metallic luster.

[0024]

[Table 2]

In any of the aqueous ink compositions of Examples 1 to 7, no corrosion was observed on the surface of the ball, and the aqueous ink composition of the present invention had good corrosion resistance to the cemented carbide ball. there were.

[0026]

The aqueous ink composition of the present invention contains an alkali metal silicate and / or an alkali metal borate, so that the hard metal ball of the nib corrodes even after long-term storage. Nothing. Further, the water-based ballpoint pen of the present invention is provided with the water-based ink composition of the present invention, so that the cemented carbide ball does not corrode even during long-term storage, so that there is no fuzz or line break due to pen tip corrosion. Good writability can be maintained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C350 GA03 HA09 NA19 NC01 NC10 4J039 BA04 BA06 BA13 BA22 BA24 BA29 BA32 BA35 BA39 BC60 BE01 BE03 BE04 BE05 CA03 CA05 EA48 GA27

Claims (3)

[Claims] 1. An aqueous ink composition comprising an alkali metal silicate and / or an alkali metal borate. 2. The composition according to claim 1, wherein the amount of the alkali metal silicate and / or the alkali metal borate is 0.01 to 1.0% by weight based on the total amount of the aqueous ink composition. 2. The aqueous ink composition according to item 1. 3. An aqueous ballpoint pen comprising an aqueous ink composition, a chip holder and a ball, wherein the aqueous ink composition contains an alkali metal silicate and / or an alkali metal borate, wherein the ball is made of a cemented carbide ball. An aqueous ballpoint pen characterized by the following.