JPH06313143A - Ball point pen - Google Patents

Abstract

(57) Abstract: CONSTITUTION colorants, consists of a solvent and additives, viscosity is 1000 mPa · S or more at viscosity 100 mPa · S or less and a shear rate 5s ^-1 at a shear rate of 400 s ^-1 Ink for ballpoint pens, which is characterized by [Effect] The ink for a ball-point pen of the present invention is
Since a direct current phenomenon does not occur, clear lines can be drawn without the transfer of ink blocks at the beginning of writing. Also, the writing feel during writing is good.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ballpoint pen ink and a ballpoint pen using the same.

[0002]

2. Description of the Related Art A ballpoint pen comprises a ball, a pen tip composed of a tip holder, an ink containing tube, a joint for connecting the chip to the containing tube, a pen shaft and the like. In writing with this ballpoint pen, the ink flowing out from the inside of the chip is transferred or penetrates into a recording medium such as paper due to the rotation of the ball of the pen tip, and in particular, the transfer creates a handwriting / drawn line. At that time, excess ink that could not be transferred or penetrated adheres to the outer periphery of the chip holder, and a lump of ink is transferred at the beginning of writing, so that a clear line cannot be obtained, which is a so-called batter phenomenon.

Since the water-based ballpoint pen has a low viscosity of several cps or less, it has an advantage that it can be written with a light writing pressure and has a characteristic that the writing feel is good. However, there are drawbacks such as direct current phenomenon where ink flows slowly from the tip of the pen and reverse flow phenomenon where ink flows out from the tip of the ballpoint pen and ink flows out. Therefore, a method for preventing these phenomena is taken.

On the other hand, since the viscosity of the ink used in the oil-based ballpoint pen is as high as several thousand mPa · S or more, the writing resistance is poor because the resistance when the ball rotates when the ink flows out from the pen tip is large. There are drawbacks.

Recently, a ballpoint pen for medium-viscosity ink has been developed which uses an ink having a viscosity of several mPa · S to several thousand mPa · S, which is an intermediate region between the above-mentioned aqueous and oily properties. However, the writing characteristics, the DC phenomenon, the battering phenomenon, the pen structure, and the like described above are interrelated with each other, and a satisfactory medium-viscosity ballpoint pen has not been obtained.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems with the conventional ballpoint pens, and in particular, in the medium-viscosity ballpoint pens, neither the batter phenomenon nor the direct current phenomenon occurs and the writing feel is excellent. To provide a ballpoint pen and ink for a ballpoint pen.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventor has found that the apparent viscosity at a shear rate of 400 s ⁻¹ or more correlates with the batter phenomenon as the viscosity of the ink and the apparent viscosity at 5 s ⁻¹ or less. It was found that the viscosity correlates with a direct current phenomenon and is not related to the apparent viscosity under other shear rates, and based on this finding, the ink for ballpoint pens and the ballpoint pen of the present invention have been completed.

The ballpoint pen ink of the present invention comprises a coloring agent,
Consists of a solvent and additives, viscosity at a shear rate of 400 s ^-1 viscosity at and a shear rate of 5s ^-1 or less 100 mPa · S is equal to or is 1000 mPa · S or more.

The ballpoint pen of the present invention has a shear rate of 400 s.
^-1 viscosity less than 100mPa · S and shear rate 5s
It is characterized by being filled with an ink having a viscosity at ^-1 of 1000 mPa · S or more.

The ink for a ballpoint pen according to the present invention must have a viscosity of 100 mPa · S or less at a shear rate of 400 s ⁻¹ . This is based on the results of repeated studies on the viscosity at that time, paying attention to the fact that the ink is subjected to a shearing force due to the rotation of the ball and the shearing rate is usually 400 s ⁻¹ or more when written normally. That is, 400s ^-1
Viscosity influences the penetration into writing materials such as paper and is related to the occurrence of the batter phenomenon. If the viscosity is 100 mPa · S or less, the batter phenomenon does not occur, and if it exceeds 100 mPa · S, the batter phenomenon increases. To do. Further, the ink for a ballpoint pen according to the present invention needs to have a viscosity of 1000 cps or more at a shear rate of 5 s ^-1 . This is because the inventor of the idea of the DC behavior viscosity when shear rate without stationary state or as far as close to 0 s ^-1 is related to the DC behavior and the actual to the study of the phenomenon in viscosity measurable 5s ^-1 is It is based. That is, the DC phenomenon does not occur at 1000 mPa · S or more, and the DC phenomenon occurs at less than 1000 cps.

As the colorant used in the ballpoint pen ink of the present invention, it is possible to use dyes and pigments which are usually used in writing instruments and paint inks. The dye may be a basic dye, an acid dye, a direct dye or the like, and may be a solubilized or microencapsulated dye. For example,
Varifast Black # 1802, # 1805, #
3820, Varifast Violet # 1701, Varifast Yellow AUM, Same # 3104, Spyron Violet C-RH, Spyron Black CMHspeci
al, spirone yellow C-GNH, spirone orange GRH, spirone red BEH, auramine, rhodamine, methyl violet, malachite green, crystal violet, Victoria blue BOH and the like. As the pigment, an inorganic pigment or an organic pigment may be used as it is, or a processed pigment or a dispersed toner whose surface is modified with a resin or a surfactant may be used. Examples thereof include titanium oxide, carbon black, phthalocyanine-based, azo-based, anthraquinone-based, quinacridone-based, micro lease color (manufactured by Ciba Geigy), Fuji AS color (manufactured by Fuji Dye Co., Ltd.) and the like. The addition amount is not particularly limited as long as it is an amount depending on the solubility or dispersive power of the colorant or an amount suitable for a desired hue or concentration, but this amount is not preferable as a faint phenomenon of writing characters or drawn lines or poor writing property. It is deeply related, and if the addition amount is too large, the effect is reduced even with the composition of the ink of the present invention, and if it is a small amount, the blurring and the inability to write are extremely reduced, but the coloring of the line drawn as a ballpoint pen is inferior.
Used in the range of up to 40% by weight.

Examples of the solvent for the ballpoint pen ink according to the present invention include water, benzyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin and the like. Examples of glycol ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monophenyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monomethyl ether. . The addition amount is usually in the range of 50 to 95% by weight, but if it is too small, the viscosity increases and the drawing line drying speed becomes slow, which is a problem, but the upper limit is determined by the relationship between the colorant and the additive. Yes Not specified. These solvents are for ensuring the basic performance as a ball-point pen ink, and are necessary not only for dissolving or dispersing the colorant but also for obtaining an appropriate drying property of the drawn line.

The additives for the ballpoint pen ink according to the present invention are selected and blended from auxiliaries commonly used in inks such as resins, antiseptics, rust preventives and lubricants.

For example, as the resin, a resin that is commonly used in ordinary oil-based ballpoint pen inks, such as a ketone resin,
Sulfoamide resin, maleic acid resin, ester gum,
Xylene resin, alkyd resin, phenol resin, rosin, polyvinylpyrrolidone, etc. are used. These resins may be used alone, or may be used by mixing two or more kinds thereof, and the blending amount thereof is based on the total amount of the ink composition.
It is in the range of 0.1 to 20.0% by weight. These resins act to improve the water resistance and adhesion of drawn lines and adjust the viscosity.

As thickeners, "Benton SD-2" and "Benton 27" manufactured by NL Chemicals, "TIXOGEL VZ" and "TIXOGEL E" manufactured by Nissan Gardler Catalyst.
Z ”, organic bentonite such as“ EX-0101 ”manufactured by SUD Chemical,“ Mizukacil P-801 ”manufactured by Mizusawa Chemical Co., Ltd., and silica-based silica such as“ Aerosil 380 ”and“ Aerosil COK84 ”manufactured by Nippon Aerosil Co., Ltd.

Koeisha Oil and Fat Chemical Co., Ltd. "Tarlen VA-"
100 "," VA-500 "," VA-800 ", Ito Oil" ASA T-1 "," T-51 "," T-35 "
A fatty acid polyamide such as 0F ″ is added.

The ball-point pen of the present invention comprises a ball, a pen tip composed of a tip holder, an ink containing tube, a joint for connecting a chip and the containing tube, a pen tip, and the like. It is filled with ink.

[0018]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. The ink evaluation test was performed as follows. The ballpoint pen used for the test has a polypropylene tube with an inner diameter of 2.0 mm and a stainless steel tip (the ball is a cemented carbide and has a diameter of 0.7 mm).
The ballpoint pen was filled with the inks obtained in Examples and Comparative Examples, and the following tests were conducted.

Viscosity: Measured at 25 ° C. by a double cylinder method using a rheometer. Anti-battering property: After filling a ball-point pen with a predetermined ink, the speed is 4.5 m / min and the angle is 60 with a mechanical writing tester.
The amount of ink adhering to the chip holder was observed after writing under conditions of ° and a load of 200 g, and it was evaluated as ⊚ for almost no ink, ○ for slightly ink, Δ for slightly more ink, and × for very much ink. .

Preventing DC phenomenon: 30 ball-point pens filled with a predetermined ink were placed in a thermostat at a temperature of 50 ° C. and a humidity of 80% for 3 days with the tip of the pen facing down, and the degree of DC phenomenon was relatively compared. ∘: almost nothing, ∘: slightly present, ∘: slightly a little, Δ: very much, x. Writing quality: With a ballpoint pen filled with the specified ink, the writing feel when writing freehand is compared relative to each other. Very light writing quality is ◎, light writing quality is ○, slightly heavy writing is △, heavy writing. The writing quality was set to x.

Examples 1 and 2 and Comparative Examples 1 and 2 Ballpoint pen inks were prepared according to the formulations shown in Table 1. Table 1 shows the test results of the ballpoint pen filled with this ink. The pigment (1) in the composition is "Spiron Black GMH Special" (Hodogaya Chemical Co., Ltd.), and the pigment (2) is "Spiron Yellow G-GMH" (Hodogaya Chemical Co., Ltd.). It was used. In addition, organic bentonite is "TIXOGEL
VZ "(manufactured by Nissan Gardler Catalyst Co., Ltd.) was used. As the fatty acid amide," ASA T-1 "(manufactured by Ito Oil Co., Ltd.) was used.

[0022]

[Table 1]

[0023]

INDUSTRIAL APPLICABILITY Since the ink for a ballpoint pen of the present invention does not cause the phenomenon of battering or direct current, a clear line can be drawn without the transfer of a lump of ink at the beginning of writing. Also, the writing feel during writing is good.

Claims (2)

[Claims] 1. A colorant, a solvent, and an additive,
Ballpoint pen ink viscosity at a shear rate of 400 s ^-1 viscosity at and a shear rate of 5s ^-1 or less 100 mPa · S is equal to or is 1000 mPa · S or more. 2. A viscosity of 10 at a shear rate of 400 s ^-1 .
Viscosity below 0 cps and shear rate 5 s ^-1 is 10
A ball-point pen characterized by being filled with ink of 00 mPa · S or more.