JPS638465A - Aqueous pigment ink for ball-point pen - Google Patents

Abstract

PURPOSE:The titled ink lessening wear of ball seat in rotation of ball during writing, etc., long writable distance and having small sink of ball, consisting of pigment, a dispersant, water and a wax emulsion. CONSTITUTION:The aimed ink consisting of (A) preferably 3-20wt% pigment (e.g. organic pigment such as azo type pigment, etc., inorganic pigment such as carbon black, etc., metallic powder pigment such as Al powder, etc., fluorescent pigment, etc.), (B) preferably 0.5-20wt% dispersant (e.g. alkylsulfuric ester salt, etc.), (C) water and (D) preferably 0.1-10wt% wax emulsion (e.g. one obtained by dispersing wax of montan wax type with emulsifying agent).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a water-based pigment ink for ballpoint pens. More specifically, the present invention relates to an aqueous pigment ink for ballpoint pens that causes less ball sinking.

(Prior Art) Conventionally, water-soluble dyes have been used as colorants in water-based inks for ballpoint pens.9. In recent years, pigments have also been used to improve the water resistance and weather resistance of handwriting. However, such water-based inks for ballpoint pens have the disadvantage of poor lubricity.

When writing, the ball holder of the ballpoint pen tip wears down on the seat, causing the ball to become buried inside the ballpoint pen tip.
A so-called ball sinking phenomenon occurs, resulting in the inability to write. In order to overcome the above-mentioned drawbacks, for example, Japanese Patent Application Laid-Open No. 76577/1983 discloses adding wax to a water-based ink composition for ballpoint pens in which a water-soluble dye is used as a coloring agent.

(Problems to be Solved by the Invention) However, in the case of adding wax and an emulsifier to the ink to emulsify or solubilize the wax in the ink as in the above-mentioned publication, in the case of an ink using a pigment as a coloring agent,
The wax adsorbs to the pigment, making the pigment dispersion unstable, causing problems such as agglomeration of the pigment and an increase in ink viscosity, and it has not been possible to obtain an ink that eliminates the ball sinking phenomenon.

Therefore, the object of the present invention is to provide an aqueous pigment ink for ballpoint pens using a pigment as a coloring agent.

To provide an ink that does not cause pigment aggregation or increase in ink viscosity and does not cause ball sinking phenomenon.

(Means for Solving the Problems) The gist of the present invention is a water-based pigment ink for ballpoint pens comprising at least a pigment dispersant, water, and Wanox emulsion. below.

The present invention will be described in detail.

Wax emulsion, which is the essence of the present invention, is used to prevent wear of ball seats, and by adding Wanox emulsion, which has been dispersed in water or a solvent compatible with water, to the ink, pigment Adsorption to particles can be prevented, and as a result, pigment aggregation and increase in ink viscosity can be prevented.

The Wanox emulsion used here is made by dispersing one or more natural waxes such as montan wax, beeswax, carnauba wax, and Japanese wax, and petroleum waxes such as paraffin wax, polyethylene wax, and microcrystalline wax using an emulsifier. 11 to 10% by weight is preferably used.

Pigments are used as coloring agents, and include azo, anthraquinone, condensed polyazo, thioindigo, metal complex salts, and phthalocyanine.

Organic pigments such as perinone φ perylene type, dioxazine type, quinacridone type, carbon black.

One or more types of inorganic pigments such as titanium dioxide and iron oxide, metal powder pigments such as brass powder and aluminum powder, and fluorescent pigments can be used in combination, and the amount used is 3 to 20% by weight. preferable.

As a dispersant, use an alkyl sulfate ester salt.

Anionic surfactants such as alkylnaphthalene sulfonates, naphthalene sulfonic acid formalin condensates, polyoxyethylene-alkyl sulfate salts, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene fatty acid esters.

Polyoxygen/ethylene sorbitan fatty acid ester.

Nonionic surfactants such as oxidized carbon dioxide/ethylene oxide/propylene block polymers, cationic surfactants such as alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, etc.

Proteins such as gelati/, albumin, and casein.

Natural rubbers such as gum arabic and gum tragacanth.

Gelcondos such as saponin, methylcellulose.

Cellulose derivatives such as carboquine cellulose and hydroquine methylcellulose, natural polymers such as lignin sulfo/acid, shellac, polyacrylates, and salts of styrene-acrylic acid copolymers.

Salt of vinylnaphthalene/acrylic acid copolymer.

Salt of styrene/maleic acid copolymer, vinyl naphthalene/
11 One or more types of anionic polymers such as salts of maleic acid copolymers, salts of formalin condensates of β-naphthalene sulfo/acid, and nonionic polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyethylene glycol. They can be used in combination, and the amount used is preferably cL5 to 20% by weight based on the total amount of the ink.

In addition to the above, urea can be used as a pen tip drying prevention agent if necessary.
Water-soluble organic solvents such as urea derivatives and glycols, rust preventive agents, antifungal agents, and the like can also be appropriately selected and used.

The method for preparing the ink is as follows: 2. Dispersing the pigment using a commonly known dispersing machine such as a roll mill or a sand mill.
Methods of removing coarse particles such as filtration and centrifugation are used.

The timing of adding Wanx Emulsion is not particularly limited, such as after the dispersion of the pigment, or when diluting the millbase.

(Function) The reason why the ball sinks less and the writable distance becomes longer when the ink of the present invention is used is surmised as follows.

When the ink of the present invention is used, the contact surface between the ball and the ball seat in the ball bench tube.

2.7 particles of wax emulsion are constantly supplied from the ink, and the wax emulsion particles are rolled by writing pressure.
It is thought that it spreads like a film between the ball and the ball seat. This wax film is interposed between the ball and the ball seat.

It is thought that the pigment particles having an abrasive action are less likely to directly rub the ball seating surface, and as a result, the abrasive action of the pigment particles on the ball seating surface is reduced, and the amount of ball sinking is reduced.

(Example) The present invention will be explained in more detail with reference to two examples below. In the examples, "parts" indicate "parts by weight."

(Example 1) Carhonp 5yri (C177265) aO part Sodium salt of butyl acrylate-acrylic acid copolymer 110 parts (weight ratio 4
0:60) Propylene glycol 1α0 parts Ethylene glycol 2α0 parts Water
490 parts JW26 (polyethylene wax emulsion 50 parts John, JW26)
(manufactured by NON ■) (solid content) After mixing the above ingredients and dispersing with a ball mill.

Coarse particles were removed by centrifugation to obtain black ink.

(Example 2) Copper phthalocyanine green aO part (C, 1,
74160) Propylene glycol 1α0 parts Ethylene glycol 1110 parts Styrene/acrylic acid copolymer ammonium salt 2.5 parts Water
64,5
Part Ji-N Wax JW150 (Polyethylene/paraffin wax emulsion 5.0 parts manufactured by Ji-N Son ■) (Solid content) After mixing the above components and dispersing in a sand mill, coarse particles were removed by centrifugation, and green ink was produced. I got it.

(Example 3) Quinacridone Red (CI A6500) 1 (10 parts ethylene glycol 1 α 0 part glycerin 1 α 0 part Shellac GBN (manufactured by Gifu Shellac Manufacturing Co., Ltd., shellac resin) 50 parts Caustic powder
11 parts Emulgen A-60 (manufactured by Kao Soap, nonionic surfactant) α1 part Water
6 &
8 parts John wax JW22 (oxidized microcrystalline wax emulsion 50 parts John, Ji,
(manufactured by Nson ■) (solid content) All of the above components except John Wax JW22 were mixed and dispersed in a sand mill.

Large particles were removed by centrifugation. John Wax JW22 was added to this and mixed and stirred to obtain a red ink.

(Comparative Example 1) A black ink was obtained in the same manner as in Example 1 except that John Wax JW26 was removed from Example 1 and its water was added.

(Comparative Example 2) A green ink was obtained in the same manner as in Example 2, except that John Wax JW150 was removed from Example 2 and its water was added.

(Comparative Example 3) A red ink was obtained in the same manner as in Example 3 except that the Scision Wax JW22 was removed and its water was added.

(Effect of the invention) As described above, Examples 1 to 3. The inks obtained in Comparative Examples 1 to 3 were filled into a writing instrument with a ballpoint pen nib that was a combination of an SU3430 ballpoint tip and a cemented carbide ball with a diameter of Q and six fins, and the writing distance was determined.

The amount of ball sinking was tested and the results are shown in Table 1.

Table 1 (*1) Writing distance: 700. Writing load 100g, writing speed 7 crn/
The distance until the handwriting was interrupted was measured under the condition of see.

(*2) Amount of ball sinking When writing at 600m under the conditions of (*1) Measure the amount of ball exposure and check whether it is the initial measurement amount. The value obtained by subtracting the above is shown.

As described above, the water-based pigment ink for ball-point pens of the present invention is suitable for ball-point pens, with less wear on the ball seat when the ball rotates during writing, and a long writing distance.

Claims (1)

[Claims] A water-based pigment ink for ballpoint pens comprising at least a pigment, a dispersant, water and a wax emulsion.