JP2011252077A - Ink composition for water-based ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition for a water-based ballpoint pen in which feel of writing is good, and abrasion at a ball seat can be suppressed in an ink composition for a water-based ballpoint pen.SOLUTION: The ink composition for a water-based ballpoint pen at least including a colorant, a solvent, and an amine having an aromatic ring is used in order to make good feel of writing or abrasion suppression of a ball seat which is a problem which can not be conventionally solved in an ink composition for a water-based ballpoint pen.

Description

  The present invention relates to an aqueous ballpoint pen ink composition, and more particularly to an aqueous ballpoint pen ink composition containing an amine having an aromatic ring in the ink composition.

  Conventionally, in order to improve the handwriting such as writing quality and blurring, an aqueous ballpoint pen ink composition containing a surfactant as a lubricant and having improved lubricity has been proposed.

  Examples of the former containing a surfactant include those disclosed in JP-A No. 61-235479 “Pigment aqueous ink” using a fluorine-based surfactant, and JP-A No. 2004-346181 “Water-based ballpoint pen ink”. Is a combination of a fluorine-based surfactant and a silicon-based surfactant, and JP-A-10-330678 “Titanium oxide-containing aqueous ink for ballpoint pens” contains a phosphate ester-based surfactant. No. 2003-192972 “Water-based ballpoint pen ink” discloses N-acylamino acids and N-acylmethyltaurines as lubricants.

"Japanese Patent Laid-Open No. 61-235479" "JP 2004-346181 A" "Japanese Patent Laid-Open No. 10-330678" "Japanese Patent Laid-Open No. 2003-192972"

  However, as in Patent Documents 1 to 3, by containing a lubricant such as a surfactant in the water-based ballpoint pen ink composition, it improves writing quality and suppresses wear of the ball seat as compared to the case where it is not contained. However, it is desired to further suppress wear and improve writing quality.

  In particular, as in Patent Documents 1 and 2, fluorine-based surfactants and / or silicon-based surfactants are more susceptible to wear on the ball seat than the phosphate ester surfactants in Patent Document 3, There was also a risk of causing poor writing. Further, in Patent Document 4, N-acylamino acid and N-acylmethyltaurine have a problem that long-term ink aging stability cannot be maintained.

  An object of the present invention is to provide an ink composition for a water-based ballpoint pen that has good writing quality and can suppress wear of a ball seat.

In order to solve the above problems, the present invention
“1. An aqueous ballpoint ink composition containing at least a colorant, a solvent, and an amine having an aromatic ring.
2. 2. The water-based ballpoint pen ink composition according to item 1, wherein the amine having an aromatic ring has a molecular weight of 200 or more.
3. 3. The water-based ballpoint pen ink composition according to item 1 or 2, wherein the amine having an aromatic ring is a quaternary amine.
4). 4. The ink composition for ballpoint pens according to item 3, wherein the quaternary amine is at least one selected from a benzoxonium compound, an alkyldimethylbenzylammonium compound, and an alkyldiethylbenzylammonium compound.
5). The water-based ink composition for ballpoint pens according to any one of Items 1 to 4, wherein the content of the amine having an aromatic ring is 0.1 to 20.0% by mass.
6). 6. The aqueous ballpoint pen ink composition according to any one of items 1 to 5, wherein the aqueous ballpoint pen ink composition has a pH of 4 to 10. "

  The present invention can provide an ink composition for a water-based ballpoint pen that has good writing quality and can suppress wear of a ball seat.

  A feature of the present invention is that an amine having an aromatic ring is contained in an aqueous ballpoint pen ink composition.

  The amine having an aromatic ring used in the present invention is an amine having an aromatic ring such as a benzene ring, a naphthalene ring or an anthracene ring. As a result of diligent research on the lubricity, the inventor of the present invention contains an amine having an aromatic ring in the ink composition for water-based ballpoint pens, so that the writing quality is good and wear of the ball seat can be suppressed. I understood that This has the effect of suppressing metal contact between the ball and the chip body by forming a lubricating film that is easily adsorbed to metal, improving lubricity, good writing, and wear of the ball seat. It is assumed that it suppresses.

  In view of further improving the lubricity of the amine having an aromatic ring, it is preferable to use an amine having an aromatic ring having a molecular weight of 200 or more.

  Examples of the amine having an aromatic ring include primary amines, secondary amines, tertiary amines, and quaternary amines, but it is preferable to use quaternary amines in view of the stability over time.

  Examples of the quaternary amine having an aromatic ring include a benzoxonium compound (Benzoxonium), an alkyldimethylbenzylammonium compound, and an alkyldiethylbenzylammonium compound. In consideration of writing quality and stability over time, a benzoxonium compound (Benzoxonium) ) Is preferred. Specifically, as benzoxonium compounds (Benzoxonium), benzylbistetradecylammonium compounds (Benzylbis (2-hydroxypropyl) tetradecylammonium), benzyldodecylbisammonium compounds (Benzyldodecylbis (2-hydroxypropyl) ammonium), benzyldecylbisammonium compounds (Benzyldecylbis (2-hydroxypropyl) ammonium) and the like, and examples of the alkyldimethylbenzylammonium compound include a tetradecyldimethylbenzylammonium compound, a hexadecyldimethylbenzylammonium compound, an octadecyldimethylbenzylammonium compound, and a palm alkyldimethylbenzylammonium compound. Examples of the alkyldiethylbenzylammonium compound include dodecyldiethylbenzylammonium compound. You may use these individually or in mixture of 2 or more types.

  A quaternary amine having an aromatic ring includes a benzoxonium compound (Benzoxonium), an alkyldimethylbenzylammonium compound, a tetradecyldimethylbenzylammonium compound, a hexadecyldimethylbenzylammonium compound, an octadecyldimethylbenzylammonium compound, an octadecyldimethylbenzylammonium compound, Examples of the cocoalkyldimethylbenzylammonium compound and the alkyldiethylbenzylammonium compound include dodecyldiethylbenzylammonium compound, and benzoxonium compound (Benzoxonium) is preferable in consideration of writing quality and stability over time. You may use these individually or in mixture of 2 or more types.

  Further, if the content of the amine having an aromatic ring is less than 0.1% by mass relative to the total amount of the ink composition, the desired lubricity may not be obtained. Since time may become unstable, 0.1 to 20.0% by mass is preferable with respect to the total amount of the ink composition. More preferably, it is 0.5-10.0 mass% with respect to the ink composition whole quantity, Most preferably, it is 0.5-5.0 mass%.

  Furthermore, in consideration of the stability of amines and colorants having an aromatic ring, if the pH value is a strongly acidic region having a pH value of 3.9 or less and the strongly alkaline region having a pH value of 10.1 or more, the ink aging stability is improved. Since it tends to become unstable, an intermediate region (weakly acidic, neutral, weakly alkaline) having a pH of 4.0 to 10.0 is preferable. Furthermore, when considering the stability over time, the pH value is preferably 5.0 to 9.0.

  Further, the colorant is not particularly limited, such as a dye or a pigment, and can be appropriately selected and used. As the dye, direct dyes, acid dyes, basic dyes, metal-containing dyes, various salt-forming dyes, and the like can be used. Examples of pigments include inorganic, organic, and processed pigments. Specifically, carbon black, aniline black, ultramarine, yellow lead, titanium oxide, iron oxide, phthalocyanine, azo, quinacridone, quinophthalone, selenium , Triphenylmethane, perinone, perylene, glyoxazine, aluminum pigment, pearl pigment, fluorescent pigment, phosphorescent pigment, and complementary color pigment. In addition, a microcapsule pigment in which a colored body in which a pigment is dispersed in a medium as a colored resin particle body is encapsulated or solidified in a shell made of a resin wall film forming substance by a known microencapsulation method may be used. good. Further, colored resin particles in which the pigment is covered with a transparent or translucent resin or the like, or colored resin particles or colorless resin particles colored with a pigment or a dye can also be used. These dyes and pigments may be used alone or in combination of two or more. The content is preferably 1 to 20% by mass relative to the total amount of the ink composition.

  As a solvent used in the present invention, in consideration of water dissolution stability, water evaporation drying prevention, etc., glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, glycerin, methanol, ethanol, 1- Alcohols such as propanol, 2-propanol, isopropanol, isobutanol, t-butanol, propargyl alcohol, allyl alcohol, 3-methyl-1-butyn-3-ol, ethylene glycol monomethyl ether acetate and other higher alcohols; Aqueous ball pens such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 3-methoxybutanol, glycol ethers such as 3-methoxy-3-methylbutanol, etc. Generally a solvent. Examples used as the use ink, these may be used alone or in combination. The content of the solvent is preferably 5.0 to 50.0% by mass with respect to the total amount of the ink composition in consideration of the solubility of the colorant, handwriting drying property, bleeding, and the like.

  In addition, in order to improve the aging stability and lubricity of the colorant, as a pH adjuster and a surfactant, phosphate ester surfactants, fluorine surfactants, silicon surfactants, fatty acids, etc. Antibacterial agents such as 1,2 benzoisothiazolin-3-one, humectants such as urea and sorbit, rust inhibitors such as benzotriazole, and chelating agents such as ethylenediaminetetraacetic acid can be added. In addition, dispersants can be added as appropriate. As water-soluble resins, acrylic resins, alkyd resins, cellulose derivatives, polyvinylpyrrolidone, polyvinyl alcohol, etc., and resin emulsions such as acrylic resins, urethane resins, styrene-butadiene resins. In addition, a shear-thinning agent such as a cross-linked acrylic acid polymer or xanthan gum can be added to adjust the viscosity of the ink such as a polyester resin or a vinyl acetate resin. These can be used alone or in combination of two or more.

Next, an Example is shown and this invention is demonstrated.
Example 1
25.5 parts by weight of water
Solvent (ethylene glycol) 20.0 parts by mass
Amine having an aromatic ring (benzoxonium compound, molecular weight of 200 or more) 2.0 parts by mass
pH adjuster (triethanolamine) 1.5 parts by mass
Moisturizer (urea) 5.0 parts by mass
Moisturizer (Sorbit) 5.0 parts by weight
Antibacterial agent (1,2 benzoisothiazolin-3-one) 0.5 parts by mass
Rust preventive (benzotriazole) 0.5 parts by mass
Colorant (Water Black 191L) 40.0 parts by mass Shear thinning agent (crosslinked acrylic acid polymer) 0.40 parts by mass

  First, a base ink is prepared by heating and stirring a colorant, water, a solvent, an amine having an aromatic ring (benzoxonium compound), a pH adjuster, a moisturizer, a fungicide, and a rust inhibitor with a magnetic hot stirrer. .

Thereafter, while heating the base ink prepared above, a shear thinning agent was added and thoroughly mixed and stirred until a uniform state was obtained using a homogenizer stirrer, followed by filtration using filter paper. 1 aqueous ballpoint pen ink composition was obtained. The ink viscosity of Example 1 was determined using a Brookfield DV-II viscometer (CPE-42 rotor) at 20 ° C. and a shear rate of 380 sec ⁻¹ (rotation speed: 100 rpm). It was 50 mPa · s when measured.

Examples 2-7
As shown in Table 1, water-based ballpoint pen ink compositions of Examples 2 to 7 were obtained in the same procedure as Example 1 except that each component was changed. Table 1 shows the measurement and evaluation results.

Comparative Examples 1-5
As shown in Table 2, blending was carried out in the same procedure as in Example 1 except that each component was changed, and ink compositions for aqueous ballpoint pens of Comparative Examples 1 to 5 were obtained. Table 2 shows the measurement and evaluation results.

Testing and evaluation
The water-based ballpoint pen ink composition and the grease-like ink follower prepared in Examples 1 to 7 and Comparative Examples 1 to 5 are held in an ink containing cylinder (polypropylene), and a ball having a ball diameter of φ0.7 mm is rotatably held. The ballpoint pen refill equipped with the waterballpoint pen tip (stainless steel wire) was filled to prepare an aqueous ballpoint pen. The following tests and evaluations were performed using a writing paper JIS P3201 as a writing test paper.

Written taste: A hand-written sensory test was performed and evaluated.
Very smooth ・ ・ ・ ◎
Smooth thing ○○
Somewhat heavy ・ ・ ・ △
Heavy thing

Abrasion resistance test: The wear of the ball seat after the writing test was measured with a running test machine with a load of 100 gf, a writing angle of 65 °, and 4 m / min.
Ball seat wear of less than 10 μm
Ball seat wear of 10 to 20 μm
Ball seat wear exceeding 20 μm ・ ・ ・ ×

  In Examples 1 to 7, good performance was obtained in both writing quality and abrasion resistance test.

  In Comparative Examples 1 to 5, since an amine having an aromatic ring was not used, writing was heavy, and in the wear resistance test, the ball seats were all worn very badly, and writing was poor or impossible to write.

  In order to prevent the ink from drooping, the ball held rotatably at the tip of the ball-point pen tip is pressed against the inner wall of the tip end edge directly by a coil spring or via a pressing body, and the tip is pressed by the pressing force at the time of writing. It is preferable to provide a valve mechanism for allowing the ink to flow out by providing a gap between the inner wall of the tip edge and the ball, and closing the minute gap at the tip of the tip when not in use.

  Moreover, when using the bare wire of a stainless steel wire for the coil spring, it is preferable to use an amine having an aromatic ring. This is because the compound having an aromatic ring suppresses the wear resistance of the bare wire of the stainless steel wire, and if the tip of the rod shaft portion of the coil spring is worn, the pressing force of the ball is reduced or the wear powder is reduced. This is because there is an effect of suppressing the influence on the writing performance such as causing a writing defect.

  The present invention relates to an aqueous ballpoint pen ink composition, and more specifically, by using an aqueous ballpoint pen ink composition containing at least a colorant, a solvent, and an amine having an aromatic ring, the writing quality is good, and the ball An ink composition for water-based ballpoint pens that can suppress seat wear can be provided. Therefore, it can be widely used as a ballpoint pen, such as a cap type and a knock type.

Claims (6)

An aqueous ballpoint pen ink composition comprising at least a colorant, a solvent, and an amine having an aromatic ring. The water-based ballpoint pen ink composition according to claim 1, wherein the amine having an aromatic ring has a molecular weight of 200 or more. The water-based ballpoint pen ink composition according to claim 1, wherein the amine having an aromatic ring is a quaternary amine. The ink composition for ballpoint pens according to claim 3, wherein the quaternary amine is at least one selected from benzoxonium compounds, alkyldimethylbenzylammonium compounds, and alkyldiethylbenzylammonium compounds. 5. The aqueous ballpoint pen ink composition according to claim 1, wherein the content of the amine having an aromatic ring is 0.1 to 20.0 mass%. The aqueous ballpoint pen ink composition according to any one of claims 1 to 5, wherein the pH of the waterborne ballpoint pen ink composition is 4 to 10.