JP2019031645A - Water-based ink composition for ballpoint pen and ballpoint pen incorporating the same - Google Patents

Abstract

A water-based ink composition for ballpoint pens which can exhibit high lubrication effect by water-based ink using polyoxyethylene polyoxypropylene alkyl ether phosphoric acid having high lubricating effect and can suppress aggregation of pigments without worrying about the amount added. Provision of a ballpoint pen with built-in it. A water-based ink composition for a ballpoint pen comprising a colorant, water, a polyoxyethylene polyoxypropylene alkyl ether phosphoric acid represented by formula (1), and an amidoamine compound represented by formula (2). . A ballpoint pen containing the water-based ink composition for ballpoint pens. [Selection figure] None

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 or writing failure is caused.
Therefore, in order to solve the above problem, an attempt to reduce the wear of the ball seat by adding polyoxyethylene polyoxypropylene alkyl ether phosphoric acid to the ink composition and improving the lubricity of the water-based ink is disclosed. (See Patent Document 1).
JP 2014-122253 A

In Document 1, since polyoxyethylene polyoxypropylene alkyl ether phosphoric acid exhibits a higher lubricating effect than conventional lubricants, the number of rotations and the rotation speed of the ball with respect to the writing distance increase, resulting in severe conditions. Even when applied to an extra fine ballpoint pen, good handwriting can be formed without causing seat wear due to writing.
However, when a pigment is used as a colorant, the pigment may agglomerate depending on the amount of polyoxyethylene polyoxypropylene alkyl ether phosphoric acid added when left in an ink state for a long time. In that case, the ink ejection property at the time of writing may not be stable, and the handwriting may be blurred or skipped.

  The present invention aims to further improve the lubricity of a water-based ink using polyoxyethylene polyoxypropylene alkyl ether phosphoric acid having a high lubricating effect, and to solve the above-mentioned problems that occur when a pigment is used. is there. That is, by using the material, it is possible to permanently obtain excellent writing feeling by expressing a higher lubricating effect over a long period of time, and it is possible to suppress aggregation of the pigment without worrying about the amount of addition. Therefore, the present invention provides a water-based ink composition for a ballpoint pen that can maintain a stable ink discharge property and can form good handwriting without blurring or line skipping over a long period of time, and a ballpoint pen incorporating the same.

〔式（１）中、Ｒは炭素数１２〜１８であるアルキル基であり、ａ及びｂは付加モル数を示す整数である。エチレンオキサイドの付加モル数を示すａは、３〜２０の範囲、プロピレンオキサイドの付加モル数を示すｂは、１〜２０の範囲である。〕

〔式（２）中、Ｒ^１は炭素数１１〜１７のアルキル基であり、Ｒ^２は−ＣＨ_２ＣＨ(ＯＨ)ＣＨ_２ＳＯ_３ ⁻又は−Ｏ⁻であり、nは２〜４のいずれかの整数である。〕
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を要件とし、前記ボールペンが直径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 a ballpoint pen of the present invention comprises at least a colorant, water, polyoxyethylene polyoxypropylene alkyl ether phosphoric acid represented by the following general formula (1), and an amidoamine compound represented by the following general formula (2). It is a requirement to contain.

[In Formula (1), R is a C12-C18 alkyl group, and a and b are integers which show addition mole number. “A” indicating the number of added moles of ethylene oxide is in the range of 3 to 20, and “b” indicating the number of added moles of propylene oxide is in the range of 1 to 20. ]

In [formula (2), ^{R 1} is an alkyl group having 11 to 17 carbon atoms, ^{R 2} is _{-CH 2 CH (OH) CH 2} SO 3 - or -O ^- a, n represents any of 2 to 4 Is an integer. ]
Furthermore, it is a requirement that the ballpoint pen contains the water-based ink composition for ballpoint pens, and that the ballpoint pen includes a ball having a diameter of 0.4 mm or less at the writing tip.

  According to the present invention, while exhibiting higher lubricity over a long period of time than when polyoxyethylene polyoxypropylene alkyl ether phosphoric acid is used alone, it is possible to maintain stable ink ejection properties by suppressing the occurrence of pigment aggregation. Therefore, a water-based ink composition for ballpoint pens that can permanently provide a superior writing feeling during writing and can form good handwriting without blurring or line skipping over a long period of time and a ballpoint pen incorporating the same.

In the aqueous ink composition for ballpoint pens, the present invention includes one or more of the amidoamine compounds represented by the general formula (2) together with the polyoxyethylene polyoxypropylene alkyl ether phosphoric acid represented by the general formula (1). In addition to adding polyoxyethylene polyoxypropylene alkyl ether phosphoric acid, a higher lubricating effect can be imparted than when polyoxyethylene polyoxypropylene alkyl ether phosphoric acid is used alone, and the blending amount of polyoxyethylene polyoxypropylene alkyl ether phosphoric acid and It is possible to reliably suppress pigment aggregation that may occur depending on the combination of the types of pigments used.
For this reason, even if a small diameter ball of 0.4 mm or less, which has a narrow ink discharge portion and the ball rotates at a high speed during writing, there is no clogging of aggregates and wear of the ball seat can be suppressed. Writing with excellent feeling and uniform good handwriting can be obtained.

The polyoxyethylene polyoxypropylene alkyl ether phosphoric acid represented by the general formula (1) exhibits high lubricity when added to water-based ink, and a smooth writing feel can be obtained by applying it to a ballpoint pen. It is done.
In the general formula (1), R is an alkyl group, and a substituent having 12 to 18 carbon atoms, such as a lauryl group, a myristyl group, a palmityl group, a cetyl group, a stearyl group, and an oleyl group can be applied. Among them, a myristyl group, a cetyl group, and an oleyl group are particularly preferable because they are highly versatile and can exhibit an effect when added in a small amount.
Moreover, a and b are integers showing the number of added moles, and a showing the number of added moles of ethylene oxide is preferably in the range of 3-20, more preferably in the range of 5-15. B which shows the addition mole number of propylene oxide has the preferable range of 1-20, More preferably, it is the range of 3-8. Those having an added mole number within these ranges are preferably used because they have a high lubricating effect.
In the general formula (1), specifically, a is 10, b is 5, R is a combination of cetyl groups, a is 5 to 8, b is 2, R is a combination of myristyl groups, and a is 5 A combination of ˜8, b = 2 and R = oleyl group is particularly preferred.
Moreover, when adding in ink, it can also be applied as an alkali metal salt or an amine salt.

The polyoxyethylene polyoxypropylene alkyl ether phosphoric acid can be added in an amount of 0.1 to 5% by mass, preferably 0.3 to 3% by mass, based on the total amount of the ink composition.
If it is less than 0.1% by mass, it is difficult to obtain a desired lubricating effect, and even if it exceeds 5% by mass, the effect is not improved, and aggregation may occur depending on the type of pigment. The addition of is not necessary.

The amidoamine compound represented by the general formula (2) includes an amide group as a substituent, a long-chain hydrocarbon group such as R ¹ , and an anionic functional group such as R ² . It exists stably in an aqueous medium and exhibits a high lubricating effect over a long period of time. At that time, higher lubricity can be exhibited over a long period of time in combination with the lubricating effect of polyoxyethylene polyoxypropylene alkyl ether phosphoric acid.
Furthermore, when a pigment is used as a colorant, high dispersion stability can be imparted, so that the ink composition can be determined without worrying about the amount of polyoxyethylene polyoxypropylene alkyl ether phosphoric acid added. it can.
As a result, a water-based ink composition optimal for a ballpoint pen having both high lubricity and ink ejection stability can be obtained.

  The amidoamine compound is preferably in the range of 0.05 to 5% by mass and more preferably in the range of 0.1 to 1% by mass in the total amount of the ink composition. Even in a small amount such as the above range, a high effect can be exhibited.

  In particular, when the amidoamine compound is added in an amount of 0.1 to 20 times, preferably 0.3 to 10 times the polyoxyethylene polyoxypropylene alkyl ether phosphoric acid, the highest lubricating effect can be expected. .

  In the configuration of the present invention, the polyoxyethylene polyoxypropylene alkyl ether phosphoric acid acts preferentially on the ball pen tip ball or the metal surface of the chip body, and the amidoamine compound further comprises polyoxyethylene polyoxypropylene alkyl ether phosphoric acid. By interposing between ink components, a high lubricating effect is exhibited. In particular, when a pigment is used as a colorant, an amidoamine compound is interposed between the polyoxyethylene polyoxypropylene alkyl ether phosphoric acid and the pigment, so that in addition to the lubricating effect, the pigment aggregation can be effectively suppressed. It will be a thing. At this time, if the amount of the amidoamine compound is added more than 20 times, the action of polyoxyethylene polyoxypropylene alkyl ether phosphoric acid on the metal surface may be hindered, making it difficult to obtain a sufficient lubricating effect. On the other hand, if the amount is less than 0.1 times, the effect may be difficult to obtain after a long period of time.

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 general carbon black and ultramarine blue, and organic pigments such as copper phthalocyanine blue and benzidine yellow, as well as finely and stably dispersed in an aqueous medium in advance using a surfactant or the like. Water-dispersed pigment products and the like are used. I. Pigment Blue 15: 3B [Product Name: S.P. S. Blue GLL-E, pigment content 22%, manufactured by Sanyo Dye Co., Ltd.], C.I. I. Pigment Red 22 [Product name: S.P. S. Red 1321-E, pigment content 21.5%, manufactured by Sanyo Color Co., Ltd.], C.I. I. Pigment Yellow 81 [Product name: TC Yellow FG, pigment content about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.], C.I. 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.
In addition, pearl pigments, gold and silver metallic pigments, phosphorescent pigments, white pigments such as titanium dioxide, metal powders such as aluminum, thermochromic compositions, photochromic compositions, perfumes, etc. directly or microcapsules Examples of the capsule pigments are as follows.

The thermochromic composition includes (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reversible thermochromic composition comprising a reaction medium that determines the temperature at which the color reaction occurs. The composition is suitable and is encapsulated in microcapsules and applied as a reversible thermochromic microcapsule pigment.
Examples of the reversible thermochromic composition include those described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-29398, etc., at a predetermined temperature (discoloration point). Discolored before and after, decolored state in the temperature range above the high temperature side discoloration point, color development state in the temperature range below the low temperature side discoloration point, only one specific state exists in the normal temperature range among the two states, The other state is maintained as long as the heat or cold required to develop the state is applied, but when the heat or cold is no longer applied, the hysteresis width returns to the state exhibited in the normal temperature range. A heat decolorable microcapsule pigment in which a reversible thermochromic composition having relatively small characteristics (ΔH = 1 to 7 ° C.) is encapsulated in a microcapsule can be applied.
Furthermore, comparatively large hysteresis characteristics (ΔH = 8 to 50) described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, and the like. ° C), and exhibit large hysteresis characteristics described in JP-A-2006-137886, JP-A-2006-188660, JP-A-2008-45062, JP-A-2008-280523, In other words, the shape of the curve plotting the change in color density due to temperature change differs greatly between when the temperature is raised from the lower temperature side than the color change temperature range and when the temperature is lowered from the higher temperature side than the color change temperature range. The color changes following the path, and the color development state in the low temperature range below the complete color development temperature, or the color erase state in the high temperature range above the complete color erase temperature is in the specific temperature range. Microcapsule pigment was contained a reversible thermochromic composition heated decolorizable having chroma memory property can be applied.
Specifically, as the reversible thermochromic composition having color memory, a complete color development temperature can be obtained only in a freezing room, a cold district, etc., that is, −50 to 0 ° C., preferably −40 to − 5 ° C., more preferably −30 to −10 ° C., and complete decoloring temperature obtained from a frictional heat generated by a friction body, a heating body such as a hair dryer, that is, 50 to 95 ° C., preferably 50 to 90 ° C. More preferably, by specifying the range of 60 to 80 ° C. and specifying the ΔH value of 40 to 100 ° C., it is possible to effectively function to maintain the color exhibited in the normal state (daily life temperature range).

The colorant may be used alone or in combination of two or more, and is used in the range of 1 to 30% by mass, preferably 2 to 25% by mass 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 2-60 mass%, Preferably it is 5-35 mass%.

  Furthermore, it is preferable to add a water-soluble resin 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 mass in the ink composition.

  In addition, 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. In particular, phosphate ester surfactants (phosphate esters) are useful because of their high synergistic effect when used in combination.

In addition, pH adjusters such as inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, organic basic compounds such as water-soluble amine compounds, benzotriazole, tolyltriazole, 2,5-dimercapto- Rust preventives such as 1,3,4-thiadiazole, saponin, coalic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3 , 5,6-tetrachloro-4- (methylsulfonyl) pyridine and other preservatives or antifungal agents, urea, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, wetting agents such as sodium pyrophosphate, Use defoaming agents, fluorine-based surfactants that improve ink permeability, and nonionic surfactants It may be.
Furthermore, ascorbic acids, erythorbic acids, α-tocopherol, catechins, synthetic polyphenols, kojic acid, alkylhydroxylamine, oxime derivatives, α-glucosylrutin, α-lipoic acid, phosphonate, phosphinate, sulfite, sulfoxyl Bubbles can also be removed chemically by adding acid salts, dithionites, thiosulfates, thiourea dioxide or the like.
Further, oligomers of N-vinyl-2-pyrrolidone, oligomers of N-vinyl-2-piperidone, N-vinyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, ε-caprolactam, N-vinyl-ε-caprolactam By adding a thickening inhibitor such as an oligomer, it is possible to enhance the function in the intruding form.

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 Such as carbohydrates having gelling ability extracted from seaweed such as benzylidene sorbitol and benzylidene xylitol or derivatives thereof, cross-linkable acrylic acid polymer, poly N-vinylcarboxylic acid amide, inorganic fine particles, nonion having HLB value of 8-12 Surfactant, dialki Examples thereof include metal salts and amine salts of sulfosuccinic acid, and even when N-alkyl-2-pyrrolidone and an anionic surfactant are used in combination in the ink composition, stable shear thinning can be imparted. .

Viscosity characteristics of the ink composition having the above-described structure include so-called Newtonian ink (shear thinning viscosity) which is applied when using a so-called gel ink having high shear thinning or an ink retaining member. Any ink etc. may be used.
The ink composition of the present invention having high dissolution stability is particularly useful for inks having low viscosity and low shear thinning because the writing instrument structure tends to cause poor writing due to precipitates on the ink retaining member.

  The structure and shape of the ball-point pen filled with the water-based ink composition for ball-point pens are not particularly limited. For example, an ink occlusion body composed of a fiber bundle housed in the shaft tube is impregnated with ink, and the pen tip (ball-point pen tip) ) Ink supply structure, ink is stored directly inside the cylinder, and a comb groove-shaped ink flow rate adjusting member or an ink flow rate adjusting member consisting of a fiber bundle is interposed between the pen tip and the pen tip directly Or a structure in which ink and an ink backflow prevention body (liquid stopper) are housed in a shaft cylinder connected through a connecting member, a structure in which a ballpoint pen refill in which an ink and an ink backflow prevention body are housed in an ink storage tube is contained in the outer shaft, etc. Can be used, and either a cap type or a retractable type can be used. In addition, as a retractable type, the form which accommodates multiple said refills may be sufficient.

  As the ink backflow preventive body applied to the ballpoint pen refill, either liquid or solid can be used, and as the liquid ink backflow preventive body, non-volatile such as polybutene, α-olefin oligomer, silicone oil, refined mineral oil, etc. If necessary, 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 writing tip portion (chip) of the ballpoint pen has been effective in a conventional general-purpose mechanism. The ball holding portion is formed by pressing and deforming the vicinity of the tip end of a metal pipe inward from the outer surface. 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 a chip formed by cutting a metal pipe or metal material A ball or the like that 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 0.15mm-2.0mm, Preferably 0.18mm-1.0mm is suitable. Used for. In particular, when the ball diameter is 0.5 mm or less, the number of rotations of the ball with respect to the writing distance increases, so the ink of the present invention works more suitably. Therefore, as the ball diameter becomes smaller, such as 0.4 mm, 0.38 mm, 0.35 mm, 0.3 mm, 0.28 mm, 0.25 mm, 0.18 mm, etc., the ink of the present invention works very advantageously. .

The shaft cylinder, ink cartridge, and ink storage pipe (refill pipe) for storing the water-based ink composition are, for example, molded articles and metals made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, nylon, polycarbonate, and ABS. The processed body is preferably used in terms of low evaporation property and productivity of ink.
In particular, when a part or the whole of the shaft cylinder, the ink cartridge, and the ink storage tube is made of a resin having transparency, the inside can be visually recognized, so that the remaining amount of ink and the hue can be confirmed. The transparency includes colored transparent, translucent and colored translucent.

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 has a low viscosity, the ink composition accommodated in the shaft cylinder is equipped with an ink retaining member at the front of the axis cylinder, and the ink composition is directly stored in the axis cylinder. Examples thereof include a method of impregnating and storing the ink composition in an ink occlusion body such as a textured body or a fiber processed body (such as a fiber bundle covered with an outer skin).

  In addition, it does not take a form in which the ink is directly incorporated in the shaft cylinder, but in the case of an ink container such as an ink cartridge or an ink containing tube, or a form in which the ink occlusion body is filled with ink and accommodated in the outer shaft. When it takes, it can also be set as the structure which can replace | exchange these ink containers and ink occlusion bodies.

Examples will be described below, but the present invention is not limited to these examples.
The composition of the water base ink for ball-point pens of Examples and Comparative Examples, viscosity, and shear thinning index are shown in the following table. In addition, the numerical value of the composition in a table | surface shows a mass part.
The ink viscosity of each Example and Comparative Example was measured at 60 ° C. using a B-type rotational viscometer (manufactured by Tokyo Keiki Co., Ltd., using a BL adapter) at 20 ° C., or an E-type rotational viscometer [Toki Sangyo Co., Ltd. The measurement at 1 rpm was performed under any possible condition.
In addition, the shear thinning index (n) of the inks of Examples and Comparative Examples was calculated by measuring the ink viscosity at 20 ° C. using an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd.).

The contents of the raw materials in the table will be described along the note numbers.
(1) Sanyo Dye Co., Ltd., trade name: SS BLUE GLL-E
(2) Hodogaya Chemical Co., Ltd., trade name: Phloxine (3) Fuji Dye Co., Ltd., trade name: SP Black 8922
(4) 4.5 parts of 2- (2-chloroanilino) -6-di-n-butylaminofluorane as component (a), 1,1-bis (4'-hydroxyphenyl) n- as component (b) Reversible thermochromic composition comprising 4.5 parts of decane, 7.5 parts of 2,2-bis (4'-hydroxyphenyl) hexafluoropropane, and 50.0 parts of 4-benzyloxyphenylethyl caprate as the component (c) Microcapsule pigment encapsulating a product [T ₁ : −20 ° C., T ₂ : −9 ° C., T ₃ : 40 ° C., T ₄ : 57 ° C., ΔH: 63 ° C., average particle size: 2.5 μm (Coulter method) The color changes from black to colorless.)
(5) POP (5) POE (10) Cetyl ether phosphate (6) POP (2) POE (5) Myristyl ether phosphate (7) POP (2) POE (8) Oleyl ether phosphate (8) POE ( 9) Lauryl ether phosphoric acid (9) In general formula (2), R ¹ is an alkyl group having 11 carbon atoms, R ² is —CH ₂ CH (OH) CH ₂ SO ₃ ^— , and n = 3 compound (10 ) general formula (2) ^{R 1} in the alkyl group of 11 carbon atoms, ^{R 2} is -O ^- a is, n = 3 compound (11) stearyl betaine, commercially available from Kao Corporation under the trade name: AMPHITOL 86B
(12) Product name: Primal ASE-60, manufactured by Rohm & Haas Japan

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.

Production of Ballpoint Pen A Each of the ink compositions of Examples 1, 2, and 5 and Comparative Examples 1, 2, and 5 was directly accommodated inside the shaft tube, and a comb groove-shaped ink flow rate adjusting member was interposed. After assembling a stainless steel cutting tip for holding a cemented carbide ball having a diameter of 0.3 mm, a sample ballpoint pen A was prepared by attaching a cap.

Production of Ballpoint Pen B A stainless steel tip holding a cemented carbide ball having a diameter of 0.3 mm was fitted to one end of a polypropylene pipe with the ink compositions of Examples 3 and 4 and Comparative Examples 3 and 4 and 6 The ball pen refill was filled with 1.0 g, the ink backflow preventer was disposed at the rear end of the ink, the ball pen refill was assembled on the outer shaft, and a cap was attached to prepare a sample ball pen B.

The following tests were conducted using the sample ballpoint pen and ink composition.
Written test A
Whether or not the sampled ballpoint pens (5 each) confirmed to be writable can be completely consumed by continuously writing spiral circles on JIS P3201 writing paper A with an automatic writing tester. confirmed. 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.
The evaluation of the test result is the number of filled inks (number of cut-outs).
Written test B
The writing resistance value was measured when a sample ball-point pen that was confirmed to be writable was written at room temperature using a disc type drawing machine (writing angle 75 °, load 100 g, writing speed 4 m / min). In addition, the obtained value is an average value (unit: g) of five writing resistance value data.
Abrasion test A sample ball-point pen that has been confirmed to be writable is worn by an automatic writing tester after the spiral circle has been continuously written on the JIS P3201 writing paper A for 1000 m (pen) 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.
Ink stability test Each ink composition was sealed in a glass bottle and allowed to stand in a 50 ° C environment for 30 days. Thereafter, the state of the ink inside was visually confirmed at room temperature.
The results of each test are shown in the following table.

The evaluation of the test results is as follows.
Ink stability test ○: No abnormality.
Δ: Some aggregation is observed.
X: A large amount of aggregation is observed.

Claims (3)

A water-based ink composition for ballpoint pens containing at least a colorant, water, a polyoxyethylene polyoxypropylene alkyl ether phosphoric acid represented by the following general formula (1), and an amidoamine compound represented by the following general formula (2).

[In Formula (1), R is a C12-C18 alkyl group, and a and b are integers which show addition mole number. “A” indicating the number of added moles of ethylene oxide is in the range of 3 to 20, and “b” indicating the number of added moles of propylene oxide is in the range of 1 to 20. ]

In [formula (2), ^{R 1} is an alkyl group having 11 to 17 carbon atoms, ^{R 2} is _{-CH 2 CH (OH) CH 2} SO 3 - or -O ^- a, n represents any of 2 to 4 Is an integer. ]   The ball-point pen which incorporated the water-based ink composition for ball-point pens of the said Claim 1.   The ballpoint pen according to claim 2, wherein the ballpoint pen includes a ball having a diameter of 0.4 mm or less at a writing tip portion.