JPH0116437B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an ink composition for a water-based ballpoint pen. Water-based ballpoint pen inks have excellent cap-off properties (the ability to write for long periods of time with the ballpoint pen cap removed);
The pen must have an appropriate viscosity or fluidity to enable smooth writing with a uniform thickness in correspondence with a ball of a given diameter, the ink will not run out even at high writing speeds, and the pen will not run out after writing. It is necessary to have properties such as not leaving any ink scum, having excellent storage stability over a long period of time, and not being corrosive to the metal parts of ballpoint pens. However, these properties include mutually contradictory elements; for example, known inks with excellent cap-off properties tend to have high viscosity and tend to run out. Therefore, there is much room for improvement in the existing inks, and the appearance of new inks is currently desired. As a result of various experiments and research while keeping the above-mentioned current situation in mind, the present inventor has found that when a specific amount of xanthan gum is added to a water-based ballpoint pen ink, an ink having all of the above-mentioned properties can be obtained. , and in this case, the handwriting drying property is slightly reduced, but the inventors have found that the handwriting drying property can be improved by adding a specific amount of a penetrating desiccant, and the present invention has been completed. That is, the present invention uses xanthan gum in an amount of 0.20 to 0.45
The present invention relates to an aqueous ballpoint pen ink composition characterized by containing 0.5 to 10.0% by weight of a penetrating drying agent. The xanthan gum used in the present invention has a molecular weight of
It is a water-soluble polymeric polysaccharide with a weight of about 5 million to 10 million.
The amount of xanthan gum used is 0.20 in the ink composition.
~0.45% by weight. The amount of xanthan gum is 0.20
When the amount is less than 0.45% by weight, it is difficult to write smoothly, while when it is more than 0.45% by weight, the viscosity of the ink increases and the outflow of the ink from the pen tip tends to be inhibited. The content of xanthan gum is more preferably 0.30 to 0.40% by weight in the ink composition. The penetrating drying agent used in the present invention imparts penetrating properties to the ink, thereby improving drying properties and providing smoothness in writing. If a penetrating dryer is not used, part of the ink will penetrate into the writing surface, but the rest will gel again on the writing surface and become difficult to penetrate, so depending on the type of paper, the handwriting may be dry to the touch. It tends to be slow. By adding a penetrating drying agent, even when the ink becomes gelled again, the penetrating property hardly decreases, and the effect of promoting drying is exhibited. Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monophenyl ether, diethylene glycol monoisopropyl ether, Examples include glycol ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, and propylene glycol monomethyl ether, acetates of these glycol ethers, and glycol acetates such as ethylene glycol monoacetate and ethylene glycol diacetate. Among the above, particularly preferred are ethylene glycol monophenyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, and the like. The amount of the penetrating drying agent used is 0.5 to 10.0% by weight, preferably 1.0 to 5.0% by weight in the ink composition. If it is less than 0.5% by weight, the drying properties of handwriting will not be improved, while if it exceeds 10.0% by weight, bleeding onto the paper surface and transfer to the back will likely occur. The components other than the xanthan gum and the penetrating desiccant in the ink composition for an aqueous ballpoint pen of the present invention are not particularly different from the components in known inks for an aqueous ballpoint pen. That is, the ink composition of the present invention:
For example, 5 to 40% by weight of an aqueous medium such as alcohol,
0.1 to 15% by weight of water-soluble or water-dispersible colorants, 0 additives such as surfactants, preservatives, PH regulators, rust preventives, etc.
-10% by weight, 0.20-0.45% xanthan gum and 0.5-10% by weight penetrating desiccant. Examples of components other than xanthan gum and penetrating desiccant are as follows. Aqueous medium component 1 Monohydric alcohol: Alcohol miscible with water such as ethanol and isopropyl alcohol. 2 Dihydric alcohols (i) ethylene glycol, (ii) diethylene glycol, (iii) triethylene glycol,
(iv) 1,3-propanediol, (v) propylene glycol, (vi) 1,3-butylene glycol, (vii) 1,4-butanediol, (viii)
2,3-butylene glycol, (ix) neopentyl glycol, (x) hexylene glycol, () thiodiglycol, etc. 3 Trihydric or higher alcohols (i) Glycerin, (ii) Trimethylolethane, (iii) Trimethylolpropane, (iv) 3-
Methylpentane-1,3,5-triol,
(v) diglycerin, (vi) sorbit et al. 4 Others...pyrrolidone, N-methyl-2-pyrrolidone, dimethylformamide, etc. Colorant 1 Pigment (i) Titanium oxide, (ii) Carbon black,
(iii) Carmine 6B, (iv) CIPigment
Red112, (v) CIPigment Blue15, (vi) CI
Pigment Green7 etc. 2 Acid dyes (indicated by CI number) (i) Acid Red84, (ii) Acid Red92, (iii)
Acid Yellow23, (iv) Acid Blue9, (v)
Acid Violet49, (vi) Acid Blue7, (vii)
Acid Orange56, (viii) Acid Black2, (ix)
Acid Red 18 etc. 3 Direct dyes (indicated by CI number) (i) Direct Black19, (ii) Direct
Black38, (iii) Direct Black154, (iv)
Direct Orange6, (v) Direct Yellow44,
(vi) Direct Yellow87, (vii) Direct Blue71
etc. Additives 1 Nonionic and anionic surfactants (i) Polyethylene glycol oleyl ether, polyethylene glycol nonyl phenyl ether, polyethylene glycol polypropylene glycol ether, 2,4,
7,9-tetramethyl-5-decyl-4,
Nonionic surfactants such as ethylene oxide adducts of 7-diol. (ii) Anionic surfactants such as naphthalene sulfonic acid formalin condensates, dialkyl sulfosuccinates, or their sodium salts. 2 Preservatives (i) Potassium sorbate, (ii) Sodium benzoate, (iii) Sodium pentachlorophenol, (iv) Sodium dehydroacetate, etc. 3 PH adjuster (i) Sodium hydroxide, (ii) Sodium carbonate, (iii) Triethanolamine, etc. 4 Rust inhibitors (i) benzotriazole, (ii) tolyltriazole, (iii) dicyclohexylammonium nitrate, etc. Among the above components, the aqueous medium component such as alcohol is preferably a polyhydric alcohol, and as described above, the amount used is preferably from 5 to 40% by weight of the ink composition. If this amount exceeds 40% by weight, the viscosity increases and there is a tendency to smear when writing, while if it is less than 5% by weight,
The storage stability and cap-off properties of the ink composition deteriorate. The ink composition of the present invention, which contains xanthan gum and a penetrating drying agent as essential components, is not limited to the above composition, and compositions containing components other than the above are also included within the scope of the present invention. be. The ink composition of the present invention is produced, for example, as follows. Gradually add xanthan gum to water being stirred at room temperature, and after completely dissolving it, add aqueous medium components such as polyhydric alcohols, penetrating drying agents such as glycol ethers, coloring agents, and other additives. Dissolve or uniformly disperse. The ink composition of the present invention has excellent storage stability and exhibits appropriate viscosity and fluidity over a long period of time.
Therefore, as shown in FIG.
It has a pen tip part 7 and a ball 9, and has an intermediate hollow part 11.
The so-called “ink-free” system, where the ink storage area is
It is extremely useful as an ink for water-based ballpoint pens. Examples 1 to 12 and Comparative Examples 1 to 4 Ink compositions were prepared using the raw materials shown in Tables 1, 2, and 3. In addition, Table 1, Table 2
In the table and Table 3, "→" indicates "same as on the left".

【table】

【table】

【table】

【table】

[Table] In Tables 1, 2, and 3, all numerical values in the component column indicate weight %, and the meanings of the notes are as follows. (1) Trade name “KELZAN”, manufactured by Sansho Co., Ltd. (2) Trade name “Eosin”, manufactured by Hodogaya Chemical Industry Co., Ltd. (3) Trade name: “Acidophloxin PB”, manufactured by Hodogaya Chemical Industry Co., Ltd. (4) Trade name “Tartrazine”, Hodogaya Chemical Industry
Manufactured by Co., Ltd. (5) Trade name: “Water Blue-#9”, manufactured by Orient Chemical Industry Co., Ltd. (6) The following was used as a penetrating desiccant. Example 1...Ethylene glycol monoacetate. Examples 2, 5 and 10, and Comparative Examples 1 and 2...
Ethylene glycol monophenyl ether. Examples 3, 6, 8, 11 and 12, and Comparative Examples 3 and 4...diethylene glycol monobutyl ether. Example 4...Ethylene glycol diacetate. Examples 7 and 9...Diethylene glycol monobutyl ether acetate. (7) Measured using an ELD type viscometer. (8) Trade name “Water Black 100-L” (dye solid content, approximately 20% by weight), Orient Chemical Industry Co., Ltd.
Made. Next, each of the inks obtained above was placed in a ballpoint pen of the type shown in FIG. 1, and various tests were conducted. The specifications of the ballpoint pen used are as follows. Ball 9...Steel ball with a diameter of 0.4 mm. Pen tip 7...Made of polyacetal, diameter 1.5mm,
It has an ink outlet hole with a length of 7 mm. Ink conductor 5: A polyester fiber bundle processed with resin, having a diameter of 3 mm, a length of 5 mm, and a porosity of 60%. Ink tank 11: Made of polypropylene, the inner diameter is 3 mm, and the length of the tank portion is 80 mm. The test method is as follows. Γ Cap-off property: We investigated how many hours you can write with the cap removed. 48 hours or more
48 to 24 hours was rated △, and 24 hours or less was rated ×. Flowability of Γ ink: The amount of ink flowing out was measured when writing was performed for 100 m at a writing speed of 4 m/min, a writing angle of 75°, and a load of 100 g. 100-200mg, 50-100
mg or 200 to 250 mg is △, and 50 mg or less or 250 mg or more is ×. Γ Shorthand property: The writing speed at which ink breaks were investigated when writing at a writing angle of 75° and a load of 100g.
15m/min or more 〇, 15~10m/min △, 5
m/min or less was marked as x. Γ Ink scum...I investigated whether ink scum would stick to the pen tip during normal writing. No ink scum,
If there was some ink scum, it was rated as △. Γ Handwriting drying property: After writing the letter "V" on high-quality paper, the time (seconds) until it was dry to the touch was measured. Bleeding of Γ ink...When writing the letter "V" on high-quality paper, we checked whether there was any bleeding on the surface of the paper.
No bleeding was rated as ○, slight bleeding was rated as △, and clear bleeding was rated as ×. The test results are shown in Table 4.

【table】 [Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a water-based ballpoint pen suitable for using the ink composition of the present invention. 1...Ballpoint pen body, 3...Backflow prevention part, 5
... Ink conductor, 7 ... Pen tip, 9 ... Ball, 11 ... Ink storage section.

Claims (1)

[Claims] 1. An aqueous ballpoint pen ink composition containing 0.20 to 0.45% by weight of xanthan gum and 0.5 to 10.0% by weight of a penetrating drying agent.