JP5166098B2 - Water-based ink composition for ballpoint pen and ballpoint pen incorporating the same - Google Patents

Description

  The present invention relates to a water-based ink composition for ballpoint pens. Furthermore, it is related with the water-based ink composition for ball-point pens which was excellent in lubrication performance and was provided with high writing performance, and the ball-point pen which incorporated the same.

Conventionally, in a ballpoint pen incorporating a water-based ink having poor lubricity compared to oil-based ink, wear of the ball seat due to rotation of the ball is likely to occur. As a result, the ink flow path in the ballpoint pen tip may be deformed, resulting in defective ink discharge or leakage. For this reason, there has been a problem that writing feeling is impaired when writing or poor writing is caused.
Therefore, in order to solve the above problem, an attempt has been disclosed in which amino acid-type betaine or the like is added as a lubricant in the ink composition to improve the lubricity of the water-based ink and reduce the wear of the ball seat ( For example, see Patent Document 1).
JP 10-67961 A

However, the amino acid-type betaine has a low lubricating effect and needs to be added in a large amount in order to exert a sufficient effect, but when the carbon number of the alkyl group is large, the solubility in an aqueous medium is poor, There were problems such as precipitation in ink over time. In addition, when added in the range where the precipitation does not occur, the wear of the ball seat cannot be sufficiently suppressed, resulting in ink ejection failure and shortening the writing distance.
In particular, when the ball diameter is as small as 0.4 mm or less, the number of rotations of the ball with respect to the writing distance increases, and therefore wear is more likely to occur. Therefore, a higher lubrication effect is required.

  The present invention suppresses the wear of the ball seat due to the rotation of the ball, so that good ink ejection properties can be ensured over long distance writing, and long-term writing can be performed without impairing the initial writing feeling. A water-based ink composition for a ballpoint pen and a ballpoint pen incorporating the same are provided.

〔式中Ｒ_１、Ｒ_２はそれぞれ独立に炭素数８〜２２の直鎖又は分岐アルキル基のいずれかを表す。〕
更に、前記ジカルボン酸及び／又はその塩が、インキ組成物全量中０．５〜１０重量％の範囲で添加されること、前記インキのｐＨが７〜１３の範囲にあることを要件とする。
更には、前記ボールペン用水性インキ組成物を内蔵したボールペンと、前記ボールペンが、０．４ｍｍ以下のボールを筆記先端部に備えることを要件とする。 The water-based ink composition for ballpoint pens of the present invention is required to contain at least a colorant, water, and a dicarboxylic acid represented by the following general formula (1) and / or a salt thereof.

[In formula, R < ₁ >, R < ₂ > represents either a C8-C22 linear or branched alkyl group each independently. ]
Furthermore, it is required that the dicarboxylic acid and / or salt thereof is added in the range of 0.5 to 10% by weight in the total amount of the ink composition, and the pH of the ink is in the range of 7 to 13.
Furthermore, the ball-point pen in which the water-based ink composition for the ball-point pen is incorporated and the ball-point pen are required to have a ball of 0.4 mm or less at the writing tip.

  According to the present invention, high lubrication performance can be maintained during writing, and wear of the ball seat due to rotation of the ball can be suppressed. An ink composition for water-based ballpoint pens that can be sustained without damage and a ballpoint pen incorporating the ink composition can be provided.

  In the present invention, by adding the dicarboxylic acid represented by the above general formula or a salt thereof to a water-based ink composition for ballpoint pens, it is possible to suppress wear of a ball seat due to rotation of the ball.

As the dicarboxylic acid represented by the general formula, those in which the substituents R ₁ and R ₂ each independently have a linear or branched alkyl group having 8 to 22 carbon atoms can be applied. For example, (R ₁ = R ₂ = C ₁₀ H ₂₁ ), (R ₁ = R ₂ = C ₁₂ H ₂₅ ), (R ₁ = R ₂ = C ₁₄ H ₂₉ ), (R ₁ = R ₂ = C ₁₈ H ₃₇ ), (R ₁ = C ₈ H ₁₇ , R ₂ = C ₁₆ H ₃₃ ), (R ₁ = C ₁₀ H ₂₁ , R ₂ = C ₁₄ H ₂₉ ) and the like are applied. As these salts, sodium salts, potassium salts, calcium salts, ammonium salts and the like are used.
These compounds are considered to reduce the contact resistance between the ball and the seat during writing by forming a film on the surface of the ball or chip (ball seat) in an aqueous medium.

The dicarboxylic acid or a salt thereof can be added in an amount of 0.5 to 10% by weight, preferably 1.0 to 7% by weight, based on the total amount of the ink composition.
If it is less than 0.5% by weight, it is difficult to obtain the desired effect, and even if it is added in excess of 10% by weight, no improvement in wear-inhibiting effect is observed, so no further addition is required.

As the colorant, all dyes and pigments that can be dissolved or dispersed in an aqueous medium can be used, and specific examples thereof will be exemplified below.
As the dye, an acid dye, a basic dye, a direct dye, or the like can be used.
Examples of the acid dye include New Coxin (CI. 16255), Tartrazine (CI. 19140), Acid Blue Black 10B (CI. 20470), Guinea Green (CI. 42085), Brilliant Blue FCF. (CI.42090), Acid Violet 6B (C.I.42640), Soluble Blue (C.I.42755), Naphthalene Green (C.I.44025), Eosin (C.I.45380), Phloxin (C.I. 45410), erythrosine (C.I. 45430), nigrosine (C.I. 50420), acid flavin (C.I. 56205) and the like are used.

  Examples of basic dyes include chrysoidine (C.I. 11270), methyl violet FN (C.I. 42535), crystal violet (C.I. 42555), malachite green (C.I. 42000), Victoria blue FB ( CI 44045), rhodamine B (C.I. 45170), acridine orange NS (C.I. 46005), methylene blue B (C.I. 52015) and the like are used.

  As direct dyes, Congo Red (C.I. 22120), Direct Sky Blue 5B (C.I. 24400), Violet BB (C.I. 27905), Direct Deep Black EX (C.I. 30235), Kaya Las Black G Conch (C.I. 35225), Direct Fast Black G (C.I. 35255), Phthalocyanine Blue (C.I. 74180) and the like are used.

Examples of the pigment include inorganic pigments such as carbon black and ultramarine blue, and organic pigments such as copper phthalocyanine blue and benzidine yellow, as well as water-dispersed pigments that are finely and stably dispersed in an aqueous medium in advance using a surfactant or the like. Products are used, for example
C. I. Pigment Blue 15: 3B [Product Name: S.P. S. Blue GLL, pigment content 22%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Red 146 [Product Name: S.P. S. Pink FBL, pigment content 21.5%, manufactured by Sanyo Color Co., Ltd.]
C. I. Pigment Yellow 81 [Product name: TC Yellow FG, pigment content about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Red220 / 166 [Product name: TC Red FG, pigment content: about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.].
As the fluorescent pigment, a fluorescent pigment in the form of fine particles of a synthetic resin in which various fluorescent dyes are formed into a solid solution in a resin matrix can be used.
Other examples include pearl pigments, gold and silver metallic pigments, luminous pigments, white pigments such as titanium dioxide used in correction pens, metal powders such as aluminum, fragrances, and fragrance capsule pigments.

The colorant may be used singly or in combination of two or more, and is used in the range of 0.01 to 15% by weight, preferably 0.1 to 10% by weight in the ink composition.

Further, if necessary, a conventional general-purpose water-soluble organic solvent compatible with water can be used. Specifically, ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol mono Examples include ethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, and N-methyl-2-pyrrolidone.
In addition, the said water-soluble organic solvent can be used 1 type or in combination of 2 or more types, and is used in 2 to 60 weight%, Preferably it is 5 to 35 weight%.

  Furthermore, a water-soluble resin can be added in order to impart adhesion and viscosity to the paper surface. Examples of the water-soluble resin include alkyd resins, acrylic resins, styrene maleic acid copolymers, cellulose derivatives, polyvinyl pyrrolidone, polyvinyl alcohol, and dextrin. The water-soluble resin can be used alone or in combination of two or more, and is used in the range of 1 to 30% by weight in the ink composition.

In addition, if necessary, pH adjusters such as inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, organic basic compounds such as water-soluble amine compounds, rust preventives such as benzotriazole, tolyltriazole and saponin , Carboxylic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) Preservatives or antifungal agents such as pyridine, urea, nonionic surfactants, sorbitol, mannitol, sucrose, glucose, reduced starch hydrolysates, wetting agents such as sodium pyrophosphate, antifoaming agents, ink permeability Fluorine-based surfactants and nonionic surfactants that improve the viscosity may be used.
Furthermore, polyalkylene glycol fatty acid ester, ethylene oxide addition type cationic surfactant, phosphate ester surfactant, thiocarbamate, dimethyldithiocarbamate, N-acylamino acid, N-acylmethyltaurine, metal soap, etc. These lubricants can also be used in combination.

A shear thinning agent can also be added to the ink composition.
As the shear thinning agent, a water-soluble or dispersible substance is effective, and xanthan gum, welan gum, and succinoglycan whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose (average molecular weight) About 1,000 to 8 million), guar gum, locust bean gum and derivatives thereof, hydroxyethyl cellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000 mainly composed of alkyl esters of methacrylic acid, glucomannan, agar and carrageenan Carbohydrates having gelling ability extracted from seaweed such as benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymers, inorganic fine particles, nonionic surfactants having an HLB value of 8 to 12, and dialkylsulfosuccinic acid Metal salts and amines Etc. can be exemplified, and further, be added in combination in the ink composition N- alkyl-2-pyrrolidone and anionic surfactant can have stable shear thinning.

The ink composition is adjusted to a pH applicable to a general-purpose water-based ballpoint pen, but when a dye is used as a colorant, the pH is 7 to 13 neutral to alkaline region, preferably pH 7.1 to 12 weak alkaline. It is preferable to adjust to the region.
By adjusting to the pH, the color developability of the dye is improved, and the dicarboxylic acid can act more stably.

Furthermore, an ink backflow preventer (liquid stopper) can be disposed at the rear end of the ink composition filled in the ink containing tube.
As the ink backflow preventer, either liquid or solid can be used, and examples of the liquid ink backflow preventer include non-volatile media such as polybutene, α-olefin oligomer, silicone oil, and refined mineral oil. If desired, silica, aluminum silicate, swellable mica, fatty acid amide and the like can be added to the medium. Moreover, a resin molding is mentioned as a solid ink backflow prevention body. The liquid and solid ink backflow preventers can be used in combination.

The structure of the tip end (tip) of the ballpoint pen that is filled with the water-based ink composition for ballpoint pens is effective in a conventional general-purpose mechanism, and a ball holder in which the vicinity of the tip end of a metal pipe is pressed and deformed inward from the outer surface. A chip formed by holding a ball in the holding part, or a chip formed by holding a ball in a ball holding part formed by cutting a metal material with a drill or the like, or cutting a metal pipe or metal material A ball or the like held by a chip formed by processing is urged forward by a spring body can be applied.
Moreover, the said ball | bowl can apply the general purpose thing which consists of a cemented carbide alloy, stainless steel, a ruby, a ceramic, etc., and the thing of the range of diameter 0.1mm-2.0mm, Preferably 0.15mm-1.0mm is suitable. Used for. In particular, when the ball diameter is as small as 0.4 mm or less, the number of rotations of the ball with respect to the writing distance increases, so that the ink of the present application works more suitably.

For example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, or polyethylene terephthalate is preferably used as the shaft cylinder that accommodates the water-based ink composition in terms of low ink evaporation and productivity.
In addition to directly connecting the tip to the shaft tube, the shaft tube and the chip may be connected via a connecting member.
When the ink composition is low in viscosity, the ink composition accommodated in the shaft cylinder includes a method of mounting an ink retaining member at the front of the shaft cylinder and storing the ink composition directly in the shaft cylinder, Examples of the method include impregnating the ink composition into a material body or a fiber processed body.

Furthermore, by using a transparent, colored transparent, or translucent molded body as the shaft tube, it is possible to confirm the ink color, the remaining amount of ink, and the like.
The shaft cylinder may be a ballpoint pen refill that accommodates the refill in an outer cylinder, or the shaft cylinder itself with a tip mounted on the tip is used as an ink container to directly enter the shaft cylinder. You may fill with ink.
Further, the ballpoint pen can be applied to any of a cap type and a retractable type, and the retractable type may be a composite type in which a plurality of ballpoint pen refills are accommodated in the outer shaft.

Examples will be described below, but the present invention is not limited to these examples.
The composition of the water-based ink for ballpoint pens of Examples and Comparative Examples is shown in the following table. In addition, the numerical value of a composition in a table | surface shows a weight part.

The contents of the raw materials in the table will be described along the note numbers.
(1) Made by Orient Chemical Industry Co., Ltd., trade name: Water Black 100L, C.I. I. Direct Black 19 (dye content 20%)
(2) Hodogaya Chemical Co., Ltd., trade name: Eosin, C.I. I. Acid Red 87
(3) Product name: KELZAN, manufactured by Sanki Co., Ltd.
(4) Product name: FZ2163, manufactured by Toray Dow Corning
(5) In the general formula (1), R ₁ = R ₂ = C ₁₂ H ₂₅ , manufactured by Chukyo Yushi Co., Ltd., trade name: Gemisurf α142
(6) In the general formula (1), R ₁ = R ₂ = C ₁₀ H ₂₁ , manufactured by Chukyo Yushi Co., Ltd., trade name: Gemisurf α102
(7) In the general formula (1), R ₁ = R ₂ = C ₁₄ H ₂₉ , manufactured by Chukyo Yushi Co., Ltd., trade name: Gemisurf α182
(8) Sodium salt of dicarboxylic acid in which R ₁ = R ₂ = C ₁₂ H ₂₅ in general formula (1) (9) Nikko Chemicals Co., Ltd., trade name: NIKKOL AM-301 (active ingredient 35%)

Preparation of ink Each component was prepared by adding each component to water, stirring at 400 rpm for 1 hour with a disper at 20 ° C., and filtering.

Preparation of Ink Backflow Preventing Body After adding 1.5 parts of fatty acid amide as a thickener to 98.5 parts of polybutene as a base oil, an ink backflow preventing body was obtained by kneading with 3 rolls.

Preparation of ballpoint pen The same amount of the ink compositions of the above examples and comparative examples were filled in a ballpoint pen refill fitted with one end of a polypropylene pipe with a stainless steel tip holding a cemented carbide ball having a diameter of 0.3 mm. Then, after the ink backflow prevention body was disposed at the rear end, the ballpoint pen refill was incorporated into the outer shaft, and a cap was attached to prepare a sample ballpoint pen.

The following tests were conducted using the sample ballpoint pen.
Abrasion test A sample ball-point pen that has been confirmed to be writable can be worn with an automatic writing tester after the 1500-meter continuous writing of a spiral circle on JIS P3201 writing paper A. The amount of ball sinking in the upward upward state) was measured.
The tester was used under the conditions of a writing load of 50 g, a writing angle of 70 °, and a writing speed of 4 m / min. Moreover, a measured value is an average value of what was tested 5 each.
Written test Using the ball pen after the test, the handwriting state when the hand-written spiral circle was continuously written on the writing paper A by hand was visually confirmed.
The results of the test are shown in the following table.

The evaluation of the test results is as follows.
Written test ○: Good handwriting was obtained.
(Triangle | delta): Many blurs and line jumps were seen in handwriting.
X: Writing is impossible.

Claims (5)

A water-based ink composition for ballpoint pens containing at least a colorant, water, and a dicarboxylic acid represented by the following general formula (1) and / or a salt thereof.

[In formula, R < ₁ >, R < ₂ > represents either a C8-C22 linear or branched alkyl group each independently. ]   The water-based ink composition for ballpoint pens according to claim 1, wherein the dicarboxylic acid and / or salt thereof is added in an amount of 0.5 to 10% by weight based on the total amount of the ink composition.   The aqueous ink composition for ballpoint pens according to claim 1 or 2, wherein the pH of the ink is in the range of 7 to 13.   The ball-point pen which incorporated the water-based ink composition for ball-point pens in any one of the said Claim 1 thru | or 3.   The ball-point pen according to claim 4, wherein the ball-point pen includes a ball of 0.4 mm or less at a writing tip.