JP6570946B2 - Water-based ballpoint pen ink composition - Google Patents

Description

  The present invention relates to an aqueous ballpoint pen ink composition that has sufficient lubricity and does not cause ball corrosion or holder wear.

Conventionally, phosphoric acid esters have been conventionally used as writing quality improvers in water-based ballpoint pen inks.
For example, 3 to 10% by weight of a dye, 10 to 40% by weight of a moisturizing wetting agent, 0.6 to 1.0% by weight of a thixotropic property-imparting agent comprising a cross-linked acrylic acid polymer, a phosphate ester-based surfactant, etc. Water-based ballpoint pen ink (for example, refer to Patent Document 1) that is directly supplied to a pen body composed of 0.2 to 2.0% by weight of a rust preventive lubricant and water remaining, and colored as an essential component, water and a colorant An aqueous ink composition for ballpoint pens containing a pigment and further containing a phosphate ester such as an alkali metal salt of a polyoxyethylene alkyl ether phosphate monoester and polyethylene glycol having an average molecular weight of 200 to 1000 (for example, Patent Document 2) For example).

However, it is known that the phosphoric acid ester used in the ink for water-based ballpoint pens in the above-mentioned documents 1 and 2 often promotes corrosion of super steel balls and causes wear of the ball holder. Empirically, there is a problem that a type with a high HLB promotes corrosion, while a type with a low HLB tends to cause wear.
It has been found that the above problems and the like are likely to occur in an ink using a color material (fluorescent pigment) in which resin particles are dyed with a basic dye.

JP 59-74175 (Claims, Examples, etc.) JP-A-6-88050 (Claims, Examples, etc.)

  The present invention has been made in view of the above-described problems of the prior art, and an ink composition for a water-based ballpoint pen that has sufficient lubricity and does not cause ball corrosion or holder wear. The purpose is to provide.

  As a result of intensive studies in view of the above-described conventional problems, the present inventor can obtain the above-described water-based ballpoint pen ink composition by including at least isopropyl phosphate in the water-based ballpoint pen ink composition. As a result, the present invention has been completed.

That is, the present invention resides in the following (1) to (4).
(1) An aqueous ballpoint pen ink composition comprising isopropyl phosphate.
(2) Content of isopropyl phosphate is 0.01-5 mass% with respect to the ink composition for water-based ball-point pens, The ink composition for water-based ball-point pens as described in (1) characterized by the above-mentioned.
(3) A water-based ballpoint pen comprising the water-based ballpoint pen ink composition according to (1) or (2).

  ADVANTAGE OF THE INVENTION According to this invention, while having sufficient lubricity, the ink composition for water-based ball-point pens and a water-based ball-point pen which do not generate | occur | produce corrosion of a ball | bowl and holder wear are provided.

Hereinafter, embodiments of the present invention will be described in detail.
The ink composition for water-based ballpoint pens of the present invention is characterized by containing isopropyl phosphate.

  The isopropyl phosphate used in the present invention is a component that prevents the corrosion of the ball in the water-based ballpoint pen and a component that suppresses wear of the ball holder, and contains isopropyl phosphate in the ink composition for the water-based ballpoint pen. Thus, for the first time, the effects of the present invention are exhibited.

Isopropyl phosphate can be produced in a known manner, for example by esterifying isopropyl alcohol with phosphoric acid or phosphorous pentoxide.
It is also possible to use polyphosphoric acid capable of binding water formed during the esterification process. This process generally produces a mixture of monoesters and diesters, while triesters are generally not formed.

The total content of these isopropyl phosphates is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, particularly preferably 0%, based on the total amount of the ink composition for aqueous ballpoint pens. It is desirable that the content be 1-2% by mass.
When the content is less than 0.01% by mass, the effects of the present invention cannot be exhibited. On the other hand, when the content exceeds 5% by mass, insoluble matter may be generated, which is not preferable.

  In the ink composition for water-based ballpoint pens of the present invention, in addition to isopropyl phosphate, the coloring material, the balance being water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.), and further for water-based ballpoint pens In the range that does not impair the effects of the present invention, for example, water-soluble organic solvents, viscosity modifiers, dispersants, lubricants, rust preventives, antiseptics or fungicides, pH adjusters, etc. It can contain suitably.

Color materials used in the present invention include dyes that dissolve or disperse in water, conventionally known inorganic and organic pigments such as titanium oxide, resin particle pigments containing pigments, and fluorescent dyes in which resin particles are dyed with basic dyes. Uses pseudo-pigments obtained by coloring resin emulsions such as pigments with dyes, white plastic pigments, pigments with a surface coating of silica or mica and a multilayer coating of iron oxide, titanium oxide, etc. as long as the effects of the present invention are not impaired. can do.
Examples of the dye include acid dyes such as eosin, fuoxin, water yellow # 6-C, acid red, water blue # 105, brilliant blue FCF, and nigrosine NB; direct black 154, direct sky blue 5B, violet B00B, and the like. Dyes; basic dyes such as rhodamine and methyl violet can be used.

Examples of inorganic pigments include azo lakes, insoluble azo pigments, chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, and nitroso pigments. More specifically, carbon black, titanium black, zinc white, red pepper, aluminum, chromium oxide, iron black, cobalt blue, iron oxide yellow, viridian, zinc sulfide, lithopone, cadmium yellow, vermilion, cadmium red, yellow lead, Inorganic pigments such as molybdate orange, zinc chromate, strontium chromate, white carbon, clay, talc, ultramarine, precipitated barium sulfate, barite powder, calcium carbonate, lead white, pale white, bituminous, manganese violet, aluminum powder, brass powder , C.I. I. Pigment blue 17, C.I. I. Pigment blue 15, C.I. I. Pigment blue 17, C.I. I. Pigment blue 27, C.I. I. Pigment red 5, C.I. I. Pigment red 22, C.I. I. Pigment red 38, C.I. I. Pigment red 48, C.I. I. Pigment red 49, C.I. I. Pigment red 53, C.I. I. Pigment red 57, C.I. I. Pigment red 81, C.I. I. Pigment red 104, C.I. I. Pigment red 146, C.I. I. Pigment red 245, C.I. I. Pigment yellow 1, C.I. I. Pigment yellow 3, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 34, C.I. I. Pigment yellow 55, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 166, C.I. I. Pigment yellow 167, C.I. I. Pigment orange 5, C.I. I. Pigment orange 13, C.I. I. Pigment orange 16, C.I. I. Pigment violet 1, C.I. I. Pigment violet 3, C.I. I. Pigment violet 19, C.I. I. Pigment violet 23, C.I. I. Pigment violet 50, C.I. I. And CI Pigment Green 7.
These color materials can be used alone or in admixture of two or more.
The content of these coloring materials can be appropriately adjusted within a range of 0.1 to 40% by mass with respect to the total amount of the ink composition for aqueous ballpoint pens.

Examples of water-soluble organic solvents that can be used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, 3-butylene glycol, thiodiethylene glycol, and glycerin, ethylene glycol monomethyl ether, and diethylene glycol monomethyl. Ethers can be used alone or in combination.
The content of these water-soluble organic solvents is preferably 3 to 30% by mass with respect to the total amount of the aqueous ballpoint pen ink composition.

  As the viscosity modifier that can be used, for example, at least one selected from the group consisting of a synthetic polymer, cellulose, and polysaccharide is desirable. Specifically, gum arabic, gum tragacanth, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, welan gum, succinoglycan, diutane gum, dextran, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, starch glycolic acid and Salt thereof, propylene glycol alginate, polyvinyl pyrrolidone, polyvinyl methyl ether, polyacrylic acid and salts thereof, carboxyvinyl polymer, polyethylene oxide, copolymer of vinyl acetate and polyvinyl pyrrolidone, cross-linked acrylic acid polymer and salt thereof, Non-crosslinked acrylic acid polymer and its salt, styrene-acrylic acid copolymer and its salt, etc. are mentioned.

Examples of the dispersant include styrene-maleic acid copolymer and salt thereof, styrene-acrylic acid copolymer and salt thereof, α-methylstyrene-acrylic acid copolymer and salt thereof, and polyacrylic acid polymethacrylic acid copolymer. And at least one of them.
Lubricants include nonionics such as fatty acid esters of polyhydric alcohols, higher fatty acid esters of sugars, polyoxyalkylene higher fatty acid esters, alkyl phosphate esters, etc., which are also used as pigment surface treatment agents, phosphate esters, and higher fatty acid amides. Anionic compounds such as alkyl sulfonates and alkyl allyl sulfonates, polyalkylene glycol derivatives, fluorine-based surfactants, polyether-modified silicones, and the like.
In addition, as rust preventives, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, saponins, etc., as antiseptics or fungicides, phenol, sodium omadin, sodium benzoate, benzimidazole compounds, etc. Can be mentioned.
Examples of pH adjusters include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide and lithium hydroxide, amine compounds such as triethanolamine, diethanolamine, monoethanolamine, dimethylethanolamine, morpholine and triethylamine, ammonia, etc. Is mentioned.

  In order to produce this aqueous ball-point pen ink composition, a conventionally known method can be employed. For example, in addition to isopropyl phosphate, a coloring material, each aqueous component is blended in a predetermined amount, and a homomixer is used. Alternatively, it can be obtained by stirring and mixing with a stirrer such as a disper. Furthermore, if necessary, coarse particles in the ink composition may be removed by filtration or centrifugation.

The ink composition for water-based ballpoint pens of the present invention can be used by being mounted on a ballpoint pen having a pen tip portion such as a metal tip or a resin tip.
The water-based ballpoint pen that can be used is mounted with the ink composition for water-based ballpoint pens having the above composition, and preferably a ballpoint pen tip that rotatably holds a metal ball or the like is inserted directly or via a relay member. It is desirable that the ink composition tube is filled with the ink composition having the above characteristics and an ink follower is provided on the rear end surface of the ink composition. As the ink follower, a substance that is not compatible with the aqueous ballpoint pen ink composition housed in the ink containing tube and has a low specific gravity relative to the aqueous ballpoint pen ink composition, such as polybutene, silicone oil, Mineral oil etc. are mentioned.
The structure of the ballpoint pen is not particularly limited. For example, the ballpoint pen itself is an ink container, and a straight structure provided with a collector structure (ink holding mechanism) in which the ink composition for the aqueous ballpoint pen having the above-described configuration is filled in the shaft cylinder. It may be a liquid ballpoint pen.

  The effect of isopropyl phosphate used in the present invention is very long-lasting to exhibit the effect of the present invention, so a large amount of content is not required, and the period of expression and duration of the effect are long, The stability over time is also excellent.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to the following Example etc.

[Examples 1 to 6 and Comparative Examples 1 to 4]
Each water-based ballpoint pen ink composition was prepared by a conventional method according to the formulation shown in Table 1 below.
About each obtained water-based ball-point pen ink composition (100 mass% of whole quantity), the water-based ball-point pen was produced by the following method, and the following corrosion test and abrasion test were evaluated.
These results are shown in Table 1 below.

(Production of water-based ballpoint pen)
Using a shaft of a ballpoint pen [Mitsubishi Pencil Co., Ltd., trade name: Signo UM-151], an polypropylene ink storage tube having an inner diameter of 3.8 mm and a length of 113 mm and a ballpoint pen tip (holder: made of stainless steel, ball: cemented carbide) Each ink is filled in a refill made up of a ball, a ball diameter of 0.7 mm) and a joint that connects the receiving tube and the tip, and an ink follower made of polybutene is filled in the rear end of the ink, followed by centrifugation (500G, 5 Min)) to produce water-based ballpoint pens (5 each).

[Evaluation method for corrosion test (ball corrosion)]
The ballpoint pen produced as described above was left in a constant temperature bath at 50 ° C. and 80%. Three months later, the ballpoint pen was taken out of the thermostatic bath and left at room temperature for 1 day. Next, the ball pen left for 1 day at room temperature was observed on the ball surface and evaluated according to the following evaluation criteria.
Evaluation criteria:
◯: Good metallic luster, no corrosion observed
Δ: The metallic luster is weak and slight corrosion is observed.
Δ: The metallic luster is further weakened, and corrosion is partially observed.
X: There is no metallic luster and corrosion is recognized on the whole metal surface.

[Evaluation method of wear test (holder wear)]
In the mechanical writing test, 1000 m (final writing) was written in a spiral and evaluated according to the following evaluation criteria.
Writing conditions: 100 gf, writing angle 75 degrees, writing speed 4.5 mm / min
Evaluation criteria:
○: All can be written without problems.
Δ: Scratch, but writing is possible up to the end.
X: Remarkably worn and cannot be written on the way.

Looking at the results in Table 1 above, Comparative Examples 1 to 4 are phosphoric esters that are widely used in conventional water-based ballpoint pen inks, and Comparative Examples 1 and 4 having a low HLB cause wear. In Comparative Examples 2 and 3 having a high HLB type, it can be seen that ball corrosion has occurred.
On the other hand, in the compositions of Examples 1 to 6 using isopropyl phosphate of the present invention, there is no problem seen in Comparative Examples 1 to 4, and there is sufficient lubricity, and the occurrence of ball corrosion and wear. It was found that the ink composition for water-based ballpoint pens was free from water.

  An ink composition for an aqueous ballpoint pen suitable for an aqueous ballpoint pen is obtained.

Claims (3)

  An aqueous ballpoint ink composition comprising isopropyl phosphate.   2. The aqueous ballpoint pen ink composition according to claim 1, wherein the content of isopropyl phosphate is 0.01 to 5 mass% with respect to the total amount of the aqueous ballpoint pen ink composition.   An aqueous ballpoint pen comprising the aqueous ballpoint pen ink composition according to claim 1.