JPH08302265A - Oil based ink for ballpoint pen - Google Patents

Abstract

(57) [Summary] [Structure] An oil-based ink for ballpoint pens, which comprises 5 to 30% by weight of 1,3-dimethyl-2-imidazolidinone. [Effect] From low temperature to high temperature, the writing quality is good, the writing is smooth, and the handwriting is deep.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-based ink for ballpoint pens, and more particularly to an oil-based ink for ballpoint pens that can be written smoothly and darkly in a low temperature environment to a high temperature environment.

[0002]

2. Description of the Related Art Conventional oil-based inks for ballpoint pens are generally composed of organic solvents, colorants, resins, etc.
A relatively viscous material of 000 to 15,000 cps is used. The tip opening of the ballpoint pen tip has a very small gap for ejecting ink due to problems such as ink leakage. Therefore, the amount of ink discharged per unit writing distance is relatively small, and as a result, the writing quality becomes heavy and the coloring agent is used at a high concentration,
The handwriting density was relatively light.

[0003]

In particular, in a low temperature environment such as 5 ° C. or less such as in winter or cold regions, the viscosity of the ink increases and it becomes difficult to eject the ink from the tip opening of the ballpoint pen tip. The above-mentioned problems of heavy writing and thin handwriting are prominent. However, if the ink discharge gap of the ball-point pen tip is set wide in such a low temperature environment, the viscosity of the ink will decrease and ink leakage will occur easily in a high temperature environment of 30 ° C or higher such as in the summer and high temperature areas. There was a problem of becoming.

As a material which can solve such problems, ethylene glycol monophenyl ether, benzyl alcohol, propylene glycol, dipropylene glycol, 1,3 butylene glycol, hexylene glycol, tetralin, propylene glycol monophenyl ether and diethylene glycol. It is well known that propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether, etc. were added by combining various organic solvents with relatively high boiling points. Has been.

However, even with inks added by combining various organic solvents having relatively high boiling points as described above, an appropriate ink discharge amount can be maintained even in a low temperature environment of 5 ° C. or lower, and in a high temperature environment of 30 ° C. or higher. It has not been obtained that ink leakage does not occur as much as possible because the viscosity becomes too small. The present invention provides an oil-based ink for a ballpoint pen that is comfortable to write anytime, anywhere, with good writing quality and rich handwriting even in low temperature regions and seasons, and without ink leakage even in high temperature regions and seasons. The purpose is to get.

[0006]

That is, the present invention provides at least an organic solvent, a colorant, a resin, and 5 to 30% by weight of 1,3-dimethyl-2-imidazolidinone relative to the total amount of the ink. The main point is oil-based ink for ballpoint pens.

Hereinafter, the present invention will be described in detail. In the present invention, the organic solvent can be used without particular limitation as long as it is conventionally used for oil-based ballpoint pens, and examples thereof include ethylene glycol monophenyl ether, benzyl alcohol, propylene glycol, dipropylene glycol, 1,3 butylene glycol, hexylene glycol and tetralin. ,
There are propylene glycol monophenyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether, etc., and these are appropriately selected alone or in combination. The amount of the ink used is preferably 30 to 70% by weight based on the total amount of the ink.

As the colorant, a dye conventionally used in oil-based inks for ballpoint pens is mainly used, but a pigment may be used in combination for the purpose of toning and improving handwriting characteristics. Specific examples thereof include dyes such as Rhodamine B base (C.I. 45170B) and Sordan Red 3R (C.I.
I. 21260), Methyl Violet 2B Base (C.I. 42535B), Victoria Blue F4R
(C.I. 42563B), Nigrosine base LK
(CI.50415), an oily dye manufactured by Orient Chemical Industry Co., Ltd., which is Varifast Yellow # 3104.
(C.I. 13900A), Varifast Yellow #
3105 (C.I. 18690), Orient Spirit Black AB (C.I. 50415), Bali First Black # 3804 (C.I. 12195), Bali First Yellow # 1109, Bali First Orange # 2210, Bali First Red #. 1320, Bali First Blue # 1605, Bali First Violet # 1701, Hodogaya Chemical Co., Ltd. oil dyes, Spiron Black GMH Special, Spiron Yellow C-2GH, Spiron Red C-GH, Spiron Red C-BH, Spyron Blue BPNH, Spyron Blue C-RH, Spyron Violet C-RH, S.I.
P. T. Orange 6 etc. can be illustrated.

As pigments, PRINTEX 95 and 7
5, the same 45, the same P, the same XE2 (above, manufactured by Degussa Japan Co., Ltd.), # 2400B, # 1000, # MCF8.
8, MA100, MA7, MA11, # 50, # 40,
# 30, CF9, # 20B (above, Mitsubishi Kasei Co., Ltd.
Manufactured), RAVEN7000, 2000, 1200,
Carbon black such as 1000, 500, 410, 14 (above, Columbia Carbon Japan Co., Ltd.),
Titanium oxide such as P25 (manufactured by Nippon Aerosil Co., Ltd.), and other inorganic pigments such as black iron oxide, yellow iron oxide, red iron oxide, ultramarine blue, cobalt blue, chrome green and chromium oxide, and Hansa Yellow 10G as an organic pigment. , Same 5G, same 3G, same 4, same GR, same A, benzidine yellow, permanent yellow NCG, tartrazine lake, quinoline yellow, sudan 1, permanent orange, indusren brilliant orange GN, permanent brown FG, para brown, permanent Red 4R, Fire Red, Brilliant Carmine 6B, Bordeaux 5B, Thioindigo Red, First Violet B, Dioxane Violet, Alkaline Blue Lake,
Examples thereof include phthalocyanine blue, indigo, acid green lake, phthalocyanine green and the like. These colorants can be used alone or in combination with other,
Although the amount used varies depending on the color tone and the like, it is preferably 10 to 45% by weight based on the total amount of the ink. Further, a dye, a pigment and a disperse pigment may be mixed and used.

As the resin, any resin used in oil and ballpoint pen inks can be used without particular limitation. As an example, ketone resin, xylene resin, polyethylene oxide, rosin resin, rosin derivative, terpene resin, coumarone-indene resin, polyvinyl butyral,
Examples thereof include polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer, polymethacrylic acid ester, and polyacrylic acid / polymethacrylic acid copolymer.

1,3-Dimethyl-2, which is the essence of the present invention
-Imidazolidinone (hereinafter abbreviated as DMI) may be used by mixing it with an ink solvent in advance, or by a method of adding it later while observing the viscosity and other characteristics of the ink. The amount of addition depends on the type of ink solvent, colorant, resin,
It is not unique because it is affected by the type of surfactant, but the addition of 5% by weight or less dilutes the effect on other ink solvents, and the addition of 30% by weight or more increases the properties of DMI itself. On the contrary, it usually becomes 5 to 30% by weight because it becomes unfavorable because freezing at low temperature occurs.
Is preferred.

In addition to the above components, the oil-based ink for ballpoint pens of the present invention may further contain an antioxidant, an ultraviolet absorber, and
Various additives such as rust preventives and surfactants can be used. Examples of the surfactant include anionic surfactants such as fatty acid salts, higher alcohol sulfate ester salts, fatty acid sulfate ester salts, and alkylallyl sulfonates, decaglycerin fatty acid ester, hexaglycerin fatty acid ester, and polyoxyethylene alkyl ether. Nonionic surfactants such as carboxylic acid, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene hydrogenated castor oil, etc. Agents.

[0013]

[Function] DMI itself has a high melting point of about 8 ° C.,
When added to various solvents, not only the freezing point of the solvent system is lowered but also the fluidity of the ink at low temperatures can be remarkably improved. Moreover, it is hard to volatilize even in a high temperature environment, has excellent stability over time, and has superior lubricity to conventional inks at room temperature, so that an ink with a very smooth writing feel can be obtained. That is, since DMI is easily solvated not only with the ink solvent but also with many colorants and resins, the freezing temperature of the entire ink is remarkably lowered and the fluidity is increased at low temperatures. Therefore, it is considered that the characteristic that the writing can be performed smoothly even in the low temperature environment was obtained. Also, DMI solvent, colorant,
It is considered that a preferable ink was obtained in which the viscosity of the ink decreased gradually even at a high temperature because of good compatibility with the resin, the viscosity did not decrease so much even in a high temperature environment, and the ink did not leak. Furthermore, the good compatibility of DMI enhances the lubricity of the entire ink, and it is considered that an extremely smooth ink with a good writing feel was obtained.

Hereinafter, the present invention will be described in detail with reference to Examples, but "parts" means "parts by weight".

Example 1 Phenyl cellosolve (solvent, ethylene glycol monophenyl ether) 33 parts Benzyl alcohol 11 parts DMI 11 parts Hirac # 901 (ketone resin, Hitachi Chemical Co., Ltd.) 9 parts Polyvinylpyrrolidone 0.9 parts Spyron Black GMH Special (dye, Hodogaya Chemical Co., Ltd.) 8 parts Bali First Violet # 1701 (dye, Orient Chemical Co., Ltd.) 21 parts Spiron Yellow # 530 (dye, Hodogaya Chemical Co., Ltd.) 4 parts) Sorbitan trioleate (surfactant) 2.1 parts The above ingredients were stirred at 80 ° C for 5 hours to obtain a black ink.

Example 2 Phenylcellosolve 20 parts Dipropylene glycol 11 parts DMI 20 parts Hilac # 901 9 parts Polyvinylpyrrolidone 0.9 parts Spyron Black GMH Special 18 parts Spyron Violet C-RH (dye, Hodogaya Chemical Industry ( 13 parts Spyron Yellow C-2GH (dye, Hodogaya Chemical Co., Ltd.) 6 parts Sorbitan trioleate 2.1 parts The above ingredients were stirred for 5 hours at 80 ° C. to obtain a black ink. .

Example 3 Phenylcellosolve 11 parts Benzyl alcohol 22 parts DMI 30 parts Hilac # 901 9 parts Polyvinylpyrrolidone 0.6 parts Varifast Blue # 1607 (dye, manufactured by Orient Chemical Industry Co., Ltd.) 25 parts Sorbitan trioleate 2.4 parts The above ingredients were stirred at 80 ° C. for 5 hours to obtain a blue ink.

Example 4 Phenylcellosolve 33 parts Benzyl alcohol 11 parts DMI 11 parts Polyvinylpyrrolidone 8 parts S.I. P. T. Orange 6 (dye, Hodogaya Chemical Co., Ltd.) 14.7 parts Spyron Yellow C-2GH 3.0 parts Spyron Red C-GH (dye, Hodogaya Chemical Co., Ltd.) 11.7 parts Spyron Red C-BH (Dye, Hodogaya Chemical Co., Ltd.) 0.6 parts Nymeen L-201 (dodecylethanolamine, NOF Corporation) 2.0 parts Nikkor BL-5SS (surfactant, Nikko Chemicals Co., Ltd.) ) 5.0 parts The above ingredients were stirred at 80 ° C for 5 hours to obtain a red ink.

Example 5 Phenyl cellosolve 36 parts Benzyl alcohol 15 parts DMI 5 parts Hirac # 901 (Ketone resin manufactured by Hitachi Chemical Co., Ltd.) 9.5 parts Polyvinylpyrrolidone 0.5 parts Spyron yellow C-2GH 6. 0 part Spyron blue BPNH (dye, Hodogaya Chemical Co., Ltd.) 24.0 parts Glyceryl monoisostearate (surfactant) 4.0 parts The above ingredients are stirred at 80 ° C. for 5 hours to obtain a green ink. It was

Comparative Example 1 A black ink was obtained in the same manner as in Example 1 except that 8.3 parts of phenyl cellosolve and 2.7 parts of benzyl alcohol were added instead of removing DMI. . The specific composition is shown below. Phenyl Cellosolve 41.3 parts Benzyl Alcohol 13.7 parts Hirac # 901 9 parts Polyvinylpyrrolidone 0.9 parts Spyron Black GMH Special 8 parts Balifast Violet # 1701 21 parts Spyron Yellow # 530 4 parts Sorbitan trioleate 2. 1 copy

Comparative Example 2 Instead of removing DMI in Example 2, 12.9 parts of phenyl cellosolve and 7.
A black ink was obtained in the same manner as in Example 2 except that 1 part was added. The specific composition is shown below. Phenyl Cellosolve 32.9 parts Dipropylene glycol 18.1 parts Hilac # 901 9 parts Polyvinylpyrrolidone 0.9 parts Spyron Black GMH Special 18 parts Spyron Violet C-RH 13 parts Spyron Yellow C-2GH 6 parts Sorbitan triole 2.1 parts

Comparative Example 3 A blue ink was obtained in the same manner as in Example 2 except that 10 parts of phenyl cellosolve and 20 parts of benzyl alcohol were added instead of removing DMI. The specific composition is shown below. Phenylcellosolve 21 parts Benzyl alcohol 42 parts Hirac # 901 9 parts Polyvinylpyrrolidone 0.6 parts Varifast Blue # 1607 25 parts Sorbitan trioleate 2.4 parts

Comparative Example 4 A blue ink was obtained in the same manner as in Example 2, except that 8 parts of phenyl cellosolve and 3 parts of benzyl alcohol were added instead of removing DMI. The specific composition is shown below. Phenyl Cellosolve 41 parts Benzyl alcohol 14 parts Polyvinylpyrrolidone 8 parts S.I. P. T. Orange 6 14.7 parts Spyron Yellow C-2GH 3.0 parts Spyron Red C-GH 1.7 parts Spyron Red C-BH 0.6 parts Nymeen L-201 2.0 parts Nikkor BL-5SS 5.0 parts

Comparative Example 5 Instead of removing DM in Example 5, 3 parts of phenyl cellosolve and 2 parts of benzyl alcohol were added to obtain a green ink. The specific composition is shown below. Phenyl Cellosolve 39 parts Benzyl Alcohol 17 parts Hirac # 901 9.5 parts Polyvinylpyrrolidone 0.5 parts Spyron Yellow C-2GH 6.0 parts Spyron Blue BPNH 24.0 parts Glyceryl monoisostearate 4.0 parts

[0025]

The oil-based inks for ball-point pens of Examples 1-5 and Comparative Examples 1-5 are commercially available oil-based ball-point pen bodies BK10.
0 (manufactured by Pentel Co., Ltd.) was filled with 0.25 g, and a test was conducted for writing resistance, handwriting fluff, freeze resistance, handwriting density, and ink leakage reliability. Writing resistance value: A force applied to a ballpoint pen tip when writing on a paper surface with a writing tester was measured as a writing resistance value (friction resistance value). (Unit: gf) Writing load 100 gf, writing angle 70 degrees, writing speed 0.6
m / min, 12 rotations / min (writing while rotating the body of the oil-based ballpoint pen in the axial direction) Writing taste condition 1; measurement at room temperature Writing taste condition 2; 0 ° C Refrigerant storage product measured immediately after being taken out from the refrigerator Writing taste condition 3; Measurement immediately after taking out the stored product in a constant temperature bath at 35 ° C. from the constant temperature bath. In addition, the sensory inspection by a shipping inspector evaluated the writing resistance. Judgment criteria: ◎ Lightly smooth, ○ Smooth, △ Not as heavy but feel resistance, × Writing heavier than commercial products

Bote: Writing load 200 gf, writing angle 7
0 degree, writing speed 4.2m / min, rotation 42 times / min
The number of occurrences of flakes (things in which the writing line does not become a straight line but becomes a bead) was measured at a portion of 100m to 200m of the line written in (1).

Freezing resistance: Each ink was allowed to stand in a freezer at -30 ° C for one week, and the fluidity of the ink was observed. Judgment Criteria: ◎ Good fluidity ○ Flowable △ Few fluidization × Freezing

Handwriting density: A test piece drawn on high-quality paper once in each of the vertical and horizontal directions without gaps was compared with the Y value measured by a color computer, and the smaller the numerical value, the higher the density. (Black only, unit:%) Writing conditions Writing speed = 7 cm / min, Writing load = 0.98 N, Writing angle = 70 degrees

Ink leakage reliability: After leaving it in a constant temperature bath at 50 ° C. and a relative humidity of 30% downward without a cap, ink leakage and the presence or absence of ink adhesion to chips were visually observed. Criteria: ○ No ink leakage, △ Ink droplets on chip, × Ink leakage The results are shown in (Table 1) and (Table 2).

[0030]

[Table 1]

[0031]

[Table 2]

As described above, the oil-based ink for ballpoint pens of the present invention is good in that it has a good writing feel from low temperature to high temperature, is smooth, and has a deep handwriting, and is free from bloating and ink leakage even in a high temperature environment.

Claims (1)

[Claims] 1. An oil-based ink for a ballpoint pen, which comprises at least an organic solvent, a colorant, a resin, and 1,3-dimethyl-2-imidazolidinone in an amount of 5 to 30% by weight based on the total amount of the ink.