JPS60115674A - Water based ink for ball point pen - Google Patents

Abstract

PURPOSE:To provide a water based ink having satisfactory lubricating properties and remarkably improved writing performance, containing a dye, water and a water-soluble molybdate. CONSTITUTION:A water based ink contains a dye, water and a water-soluble molybdate. Examples of the water-soluble molybdates are those of sodium, potassium and ammonium. The molybdate is used in a quantity of 0.1-8wt% based on the total quantity of the ink. When the quantity is less than 0.1%, lubricating properties are insufficient, while when the quantity exceeds 8wt%, the viscosity of the ink is increased, the flow characteristics are deterioratd and certain molybdates are poorly dissolved. When a metal salt of naphthenic acid and a phosphate surfactant are used together with the molybdate, writing performance can be further improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-based ink for a ballpoint pen, and more specifically, it contains a water-soluble molybdate as a lubricant. When applied to ballpoint pens, it eliminates numerous defects caused by friction between the ball and the ball seat due to the low lubricity of water-based ink, and also improves handwriting by adding conventional lipophilic lubricants. This invention relates to an improved water-based ink for ballpoint pens that is free from defects such as bleeding.

Conventionally, in ballpoint pens using water-based ink, the ink itself lacks lubricity, so the ball does not rotate smoothly, especially at high speeds ~ -1,7+ -+y
+, + -7-meeting 7h 1 "7 tun -t -y
'nits J Boy History 71-1,000.

The ball catch may wear out due to long-term use.

There were disadvantages such as the writing feeling was significantly deteriorated, the ball rotation became irregular, and furthermore, it became impossible to write before the ink was sufficiently consumed.

Various proposals have been disclosed in an attempt to overcome these drawbacks. For example, in Japanese Patent Application Laid-Open No. 54-81817, water-soluble cutting oil is
Publication No. 4 describes inks containing unsaturated fatty acids. However, in the former case, the surface tension of the ink decreases significantly, causing handwriting to smear on a single sheet of paper, ink scattering due to a drop, or ink dropback making it impossible to write when left upright (when the writing section is left facing upward). In addition, in the latter case, the solubility of the unsaturated fatty acids themselves in water is extremely low, which may cause phase separation within the ink storage body, the occurrence of dark and light writing lines, or the evaporation rate of the unsaturated fatty acids. The drawback was that the drying of handwriting was poor due to the slow speed.

Soluble molybdate ginseng was added to Mokuya A, + J
-, without causing the various defects mentioned above,
It provides sufficient lubricity to the ink and significantly improves the writing performance of ballpoint pens. The water-soluble molybdate used in the present invention is sodium molybdate, potassium molybdate, lithium molybdate, ammonium molybdate, etc., and the amount added is preferably 0.1% to 8% by weight based on the total amount of the ink. is in the range of 0.5 to 5% by weight, and if the amount added is less than 0.1%, the lubricity is poor, and if it is in excess of 8%, it may increase the viscosity of the ink, impairing its flow, and depending on the type of molybdate, Sufficient solubility cannot be obtained. Further, these molybdates can provide good lubricity even when used alone, but it is also possible to use two or more types in combination.

Furthermore, in addition to water-soluble molybdates, conventionally known lubricants 9 such as naphthenic acid metal salts, dithiocarbamates,
Or a phosphoric acid ester/L' selected from phosphoric acid monoesters or diesters of polyoxyethylene alkyl ethers or alkyl aryl ethers and their salts.
By using a surfactant in combination, the writing performance can be further improved.

The coloring agent used in the aqueous ink of the present invention is a dye or pigment that is dissolved or dispersed in an aqueous medium. Examples of the dye include eosin (A, Kogyo, 45880), acid phloxin (A, Kogyo, 45410), erythrosin (c
, Eng., 45480), tartrazine (0,1,1914
0), Sanceratoi x a -h cF (0, engineering, 15
985), Acid Rhodamine (a, Eng, 45]On, Acid Violet 6B (0, Eng, 42640)
, brilliant dove/l'-11'OF(C,1,4
2090), Nige O Shin NB (0,L 504
20) Acidic dyes such as r, Direct Fast Yellow GO (0, I, 29000), Violet BB (0,
Engineering, 27905), Direct Sky Blue 5B (
0,114400), Black G (0,1,18525
Direct dyes such as 5) or Rhodamine B (0, 4)
5170), Rhodamine 6GDN (C0 engineering, 4516
0), Methyl Violet (0, L42535), Victoria Blue BOH (C, Eng.

42595), and pigments include carbon black dyes and azo, anthraquinone, condensed polyazo, thioindico, metal, 7-talocyanine, and perinone OpeIJL.

Examples include quinacridone-based, dioxazine-based, and quinacridone-based organic pigments. These colorants are used in the ink in an amount of 1 to 25% by weight, preferably 2 to 15% by weight.

In addition, ethylene glycol, diethylene glycol, propylene glycol, and butylene glycol are used for the purpose of suppressing ink drying at the pen tip, imparting water resistance to handwriting, or as a solubilizing agent for the dye.

Thiodiethylene glycol, glycerin, ethylene glycol monomethyl ether, polyethylene glycol (
(molecular weight 200 to 1000), N-methyl-2-pyrrolidone, 2-pyrrolidone, triethanolamine, etc., to improve the fluidity of the ink, various surfactants as dispersants for the pigments, and to prevent handwriting from blurring. and polyvinylpyrrolidone, polyvinyl alcohol, and water-soluble acrylic resin as water resistance agents or colloids for the pigments.

Water-soluble resins such as gum arabic and casein, sugars such as glucose, saccharose and dextrin to impart appropriate viscosity to the ink, and preservatives such as phenol, sodium debidroacetate and sodium benzoate may be used.

Next, specific examples of the water-based ink of the present invention will be explained. The parts in the following formulations indicate parts by weight.

Example 1 Ink composition Acid Phloxin (C1 Engineering, 45410) 2.0 parts Eosin GH (0, ■, 45380) 8.5 tt Thiodiethylene glycol ]00〃 Polyethylene glycol (Mounshasha approx. 200)] 0.
Ott Polyvinyl alcohol 05〃 F7-L 05〃 Sodium molybdate 3.0 parts Water 708〃 The above components were mixed and dissolved with stirring while heating to about 70°C to obtain red ink.

Example 2 Ink composition Victoria Blue BOH (0, engineering, 42595) 8.0
Part Methyl Violet (0, Engineering, 42585) 05〃 Diethylene Glycol 100〃 Ethylene Glycol Monomethyl Ether 3.0〃 ]・8-Butylene Glycol 3.0〃Polyvinylpyrrolidone (K-80) 0.5# Potassium Molybdate
5,0〃 Nonionic surfactant (polyoxyethylene lauryl ether) Q, 3 u Sodium dibaidoacetate 1.0〃 Water '1 3.7 1F Mix the above components and stir while heating to about 60°C. It was dissolved to obtain blue ink.

Example 8 Ink composition Water black 100-L (G, ■, 85255
) 80. Part: Ethylene glycol 100 units 19 Glycerin 100 parts Yellow dextrin 3.0 parts Cobalt naphthenate 0.05 parts Ammonium molybdate 1.0 parts Sodium benzoate I, O parts Water 4495 parts The above ingredients were mixed and heated to about 70°C. The mixture was stirred and dissolved to obtain black ink.

Example 4 Ink composition Water black R-45 (1 (C, engineering, 5042o
) 7.0 parts Propylene glycol 8.0 Triethanolamine 80 parts Diethylene glycol 100 Polyvinyl alcohol 05 Phosphate surfactant (polyoxyethylene alkyl ether phosphoric diester) 05 Lithium molybdate 20 Sodium benzoate 1 .9〃Wed 0 9. Q tt The above components were mixed and dissolved with stirring while heating to about 70°C to obtain black ink.

Example 5 Ink composition Red pigment (A, Kogyo, 12815) 9.6 parts Nonionic surfactant (polyoxyethylene nonylphenol ether) 2.4 tt Ethylene glycol 100〃 Sodium molybdate 1, Q tt Polyvinylpyrrolidone (K- 130) 2.0//Water 75°0'' A homogeneous dispersion is prepared by adding the pigment to a medium in which all of the surfactant is dissolved in 18 parts of water and kneading.Separately, add the remaining amount to the remaining amount of water. A vehicle was prepared by dissolving the components, and the dispersion was added to the vehicle while stirring, and stirring was continued to obtain a homogeneous red ink. In order to confirm the effectiveness of the example ink, the following 8 comparisons were made. Created ink.

Comparative Example 1 A red ink was obtained in the same manner as in Example 1 except that sodium molybdate in the ink components was replaced with the same amount of water.

Comparative Example 2 A blue ink was obtained in the same manner as in Example 2 except that potassium molybdate in the ink components was replaced with the same amount of water.

Comparative Example 3 The same amount of ammonium molybdate and cobalt naphthenate in the ink components of Example 8 were added to Nijiroken O'E-8.
60 (water-soluble cutting oil manufactured by Yushiro Kagaku ■), black ink was obtained in the same manner.

Comparative Example 4 A black ink was obtained in the same manner as in Example 4 except that the lithium molybdate and phosphate ester surfactant in the ink components were replaced with the same amount of ricinoleic acid. .

Examples 1 to 4 and Comparative Examples 1 to 4 obtained by the above formulations
Each ink was placed in a ballpoint pen of the type in which a metal tip with a cemented carbide ball of 0.7 a+ diameter and an ink reservoir in the shaft were connected by a fiber bundle processed core. The following tests were conducted using a quantitatively filled sample as a sample, and the results are summarized in Table 1.

Outline of test method (]) Effective writing distance and ink consumption rate Writing with a sample ballpoint pen was performed using a rotating circular writing tester adjusted to a writing speed of 4 m/min, a writing load of 100 g, and a writing angle of 70. Calculate the ink consumption from the measured weight of the ballpoint pen, and the value is 7011y/1
The effective writing distance was determined by setting the point at which the distance became 00 m or less as the end point.

Further, the ink consumption rate is expressed by the following formula.

(2) High-speed followability After writing with a sample ballpoint pen continuously for 500 m using the above-mentioned writing tester, the x-Y printer 5R-
6602 with a writing speed of 20 cm/sec and a length of 85.
280 straight lines of 7 cm were drawn, and the ink followability (presence or absence of line skipping) and the condition of the written lines (presence or absence of bleeding and shading) in high-speed writing were examined.

As seen in Table 1 above, the ink containing the water-soluble molybdate of the present invention is less likely to cause blurring or shading in handwriting, and the effective writing distance of a water-based ballpoint pen and the amount of ink consumed effectively. In addition, the line skipping phenomenon during high-speed writing is not observed. Furthermore, the writing performance can be further improved by using a lubricant such as a naphthenic acid metal salt or a phosphate ester surfactant.

Claims (1)

[Claims] Water-based ink for ballpoint pens containing a colorant, water and water-soluble molybdate as essential ingredients