JP2011094079A - Water-based ink composition for ballpoint pen and ballpoint pen incorporated with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based ink composition for a ballpoint pen, which ink composition inhibits ball corrosion due to time passage without causing defects, such as corrosion inhibition effects not sufficiently obtained by precipitation due to long term passage, and which maintains excellent transcript capability; and a ballpoint pen incorporated with the ink composition. <P>SOLUTION: The water-based ink composition for a ballpoint pen includes a colorant, water, and a fatty acid sulfide or its salt. The added amount of the fatty acid sulfide or its salt is 0.1-10 wt.% in the total amount of the ink composition. The ballpoint pen is incorporated with the ink composition. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a water-based ink composition for ballpoint pens. Furthermore, the present invention relates to a water-based ink composition for ballpoint pens that is excellent in ball corrosion resistance and can maintain high writing performance, and a ballpoint pen incorporating the same.

Conventionally, balls such as silicon carbide balls, zirconia balls, cemented carbide balls, etc., which contain silicon carbide, zirconia oxide, tungsten carbide, etc. as the main component and a binder made of metal as other components, have been used as ballpoint pen balls. Has been.
Since the balls mainly use metals such as cobalt, chromium, titanium, and nickel as binders, when used in water-based ballpoint pens, the binders may deteriorate over time due to corrosive components such as dissolved oxygen in the ink. When the binder is lost from the ball, the crystal particles such as silicon carbide, zirconia, and tungsten carbide, which are the main components, drop off, or the eluted binder becomes a metal oxide and becomes insoluble. There may be a so-called corrosion state such as adhesion to the ball surface. Since the corrugation on the surface of the ball becomes large due to the corrosion, the rotation of the ball is obstructed and the writing feel becomes heavy, and the smooth outflow of the ink is obstructed and the handwriting is blurred.
In particular, a cemented carbide ball mainly composed of tungsten carbide has a drawback that it has a high content of metal binders such as cobalt and nickel and is easily corroded with time.
Therefore, as a method for preventing the above-described corrosion over time, a method of adding a sulfide compound or benzotriazole into the ink is disclosed (for example, see Patent Documents 1 and 2).

JP 2004-115684 A Japanese Patent Laid-Open No. 5-98205

  However, the addition of the sulfide compound may cause problems such as generating an odor depending on the structure of the compound or precipitation due to long-term aging, making it difficult to obtain a sufficient corrosion-inhibiting effect. Therefore, as a result, the writing quality is poor and the handwriting is faint, which is insufficient to prevent problems during writing. In addition, benzotriazole has been difficult to obtain a sufficient corrosion-inhibiting effect in the long term.

  The present invention provides a water-based ink composition for ballpoint pens that can suppress ball corrosion over time and maintain excellent writing performance, and a ballpoint pen incorporating the same.

The water-based ink composition for ballpoint pens of the present invention is required to contain a colorant, water and sulfurized fatty acid or a salt thereof.
Furthermore, it is required that the sulfurized fatty acid or a salt thereof is added in the range of 0.1 to 10% by weight in the total amount of the ink composition.
Furthermore, it is a requirement that a ballpoint pen containing the water-based ink composition for ballpoint pens is used, and that a cemented carbide ball mainly composed of tungsten carbide is used for the writing tip.

  According to the present invention, ball corrosion phenomenon such as elution of metallic materials such as cobalt and nickel and accompanying adhesion of insoluble materials to the ball surface can be suppressed for a long time, and the initial writing performance can be maintained. An ink composition for water-based ballpoint pens that can maintain a smooth writing feeling for a long period of time without causing line skipping and a ballpoint pen incorporating the ink composition can be provided.

The above-mentioned sulfurized fatty acid refers to fatty acid sulfides in general, and by adding sulfurized fatty acids and their salts to the ink, the corrosive components in the ink are prevented from acting directly on the ball surface, and the metal elution described above It is possible to suppress the corrosion phenomenon of the ball surface accompanied by a long term.
Examples of the sulfurized fatty acid include sulfides of fatty acids having 8 to 20 carbon atoms. Specifically, sulfurized pelargonic acid, sulfurized lauric acid, sulfurized palmitic acid, sulfurized oleic acid, sulfurized stearic acid, sulfurized nonadecanoic acid, sulfurized Examples include linolenic acid and sulfurized linoleic acid. Further, a hydrocarbon group having 8 to 20 carbon atoms having at least one carboxyl group such as sulfurized distearic acid or a salt thereof is a 1 or more (specifically, an integer of 1 to 8) sulfur atom chain (hydrocarbon group). The di-fatty acid couple | bonded with the both terminal of (including the intervening thing) can be illustrated, and 1 or more types are selected and used from these.
Examples of the salt include alkali metal salts such as lithium, sodium and potassium, amine salts such as alkanolamine and ammonia, alkaline earth metal salts, Zn salts, Al salts, Sn salts and Sb salts.
The sulfurized fatty acid and its salt can be added in an amount of 0.1 to 10% by weight, preferably 0.1 to 5% by weight, based on the total amount of the ink composition.
If it is less than 0.1% 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 corrosion inhibition 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. For example, C.I. I. Pigment Blue 15: 3B [Product Name: S.P. S. Blue GLL, pigment content 22%, manufactured by Sanyo Color Co., Ltd.], C.I. I. Pigment Red 146 [Product Name: S.P. S. Pink FBL, pigment content 21.5%, manufactured by Sanyo Dye 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, luminous pigments, white pigments such as titanium dioxide used in correction pens, metal powders such as aluminum, thermochromic compositions, photochromic compositions, and fragrances Examples thereof include capsule pigments directly or microencapsulated.

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 decolorizable 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, the large hysteresis characteristics described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, JP-A-2005-1369, etc. (ΔH = 8 to 70 ° C.), and the shape of the curve plotting the change in color density due to the temperature change is from the higher temperature side than the color change temperature range, contrary to the case where the temperature is raised from the lower temperature side than the color change temperature range. A microcapsule is a reversible thermochromic composition that changes color by following a path that differs greatly depending on whether it is lowered, and that can store and retain the color development state at a low temperature range or the decolorization state at a high temperature range at a specific temperature range. A heat-erasable microcapsule pigment encapsulated therein can also 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 25% by weight, preferably 2 to 15% 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, as necessary, inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, pH adjusters such as organic basic compounds such as water-soluble amine compounds, rust preventives such as tolyltriazole and saponin, coalic acid, 1,2-benzthiazolin-3-one sodium salt, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, etc. Preservatives or antifungal agents, urea, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, wetting agents such as sodium pyrophosphate, antifoaming agents, fluorine-based surfactants that improve ink permeability Nonionic surfactants may be used.
Furthermore, a lubricant can be added, such as metal soap, polyalkylene glycol fatty acid ester, ethylene oxide addition type cationic surfactant, phosphate ester type surfactant, dicarboxylic acid type surfactant, β-alanine type surfactant, 2,5-dimercapto-1,3,4-thiadiazole and its salts and oligomers, 3-amino-5-mercapto-1,2,4-triazole, thiocarbamate, dimethyldithiocarbamate, N-acyl-L -A condensate of glutamic acid and L-lysine or a salt thereof is used.
Ascorbic acid, erythorbic acid, α-tocopherol, catechins, synthetic polyphenol, kojic acid, alkylhydroxylamine, oxime derivative, α-glucosylrutin, α-lipoic acid, phosphonate, phosphinate, sulfite, sulfoxylate It is also possible to chemically remove bubbles by adding dithionite, thiosulfate, 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 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 based on 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 nets Can be exemplified a salt, further, be added in combination in the ink composition N- alkyl-2-pyrrolidone and anionic surfactant can have stable shear thinning.

Furthermore, when the ink composition is filled in the shaft cylinder (ink storage tube), an ink backflow prevention body (liquid stopper) can be disposed at the rear end of the ink.
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 co-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 filled with the water-based ink composition for the ballpoint pen has conventionally used a general-purpose mechanism. For example, a ball 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, 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 metal pipe or metal material A ball or the like held by a chip formed by cutting can be applied forward by a spring body.

For the balls, general-purpose metal balls obtained by sintering 4a, 5a, 6a group metals or their carbides together with a metal such as cobalt or nickel as a binder are used. A hard alloy ball is preferably used.
Of the 4a, 5a, and 6a metals or their carbides, a cemented carbide ball using tungsten carbide (tungsten carbide) that is chemically stable and has high hardness as a main component is particularly preferably used. In addition, titanium, vanadium, chromium, tantalum, and their carbides may be included as the metals of 4a, 5a, and 6a.
In general, in the case of using cobalt or nickel as the binder, since these metals are easily eluted in water-based ink, the ball surface becomes rough, and further, tungsten carbide is dropped due to the binder elution. The surface becomes rough. As a result, if the ball rotates while in contact with the ball seat, the wear of the seat becomes severe, so the writing feeling is impaired, and the gap between the ball and the ball holding portion in the axial direction (clearance) increases, causing ink outflow. Increasing the amount tends to cause problems such as thick handwriting and line skipping. However, when the water-based ink of the present invention is applied, the elution of the metal material into the ink is suppressed, and the above-described problems are hardly caused.
The balls having a diameter in the range of 0.1 mm to 2.0 mm are preferably used.

The shaft cylinder to which the writing tip is connected directly or via a connecting member is a form capable of containing the water-based ink composition directly or impregnated in an impregnating material (filling), for example, polyethylene, A molded body made of a thermoplastic resin such as polypropylene or polyethylene terephthalate is preferably used in terms of low ink evaporation and productivity, but a metal processed body can also be used. Further, by using a transparent, colored transparent, or translucent molded body, the resin shaft can confirm the ink color, the remaining amount of ink, and the like.
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.
In addition, the said shaft cylinder may accommodate this refill in an outer shaft as a form of the refill for ball-point pens.

The ballpoint pen using the shaft tube can be applied to either a cap type or a retractable type. The retractable ballpoint pen is stored in the outer shaft with the writing tip provided on the ballpoint pen refill exposed to the outside air, and the writing tip protrudes from the opening of the outer shaft by the operation of the retracting mechanism. Anything can be used.
Examples of the operation method of the retracting mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the outer shaft rear end portion or the outer shaft side surface, and by pressing the knock portion, the writing pen tip portion of the ballpoint pen refill is caused to protrude or retract from the outer shaft front end opening portion, or on the outer shaft. By pressing the provided clip portion, a configuration in which the writing tip portion of the ballpoint pen refill is projected and retracted from the outer shaft front end opening portion can be exemplified.
The rotary type has a rotating part at the rear part of the outer shaft, and can be exemplified by a configuration in which the writing tip part of the ballpoint pen refill is projected and retracted from the outer shaft front end opening by turning the rotating part.
The slide type has a slide portion on the side surface of the shaft cylinder, and a configuration in which the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the outer shaft by operating the slide portion, or a clip portion provided on the outer shaft is provided. By sliding, the structure which makes the writing tip part of a ball-point pen refill appear and disappear from the outer-axis front-end opening part can be illustrated.
The retractable ballpoint pen may be a composite retractable ballpoint pen (refill exchange type) in which a plurality of ballpoint pen refills are accommodated in an 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) Orient Chemical Industry Co., Ltd., trade name: Water Pink # 2
(2) Sanyo dye Co., Ltd., trade name: SS Blue GLL
(3) 4.5 parts of 2- (2-chloroanilino) -6-di-n-butylaminofluorane as component (a) and 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, black to colorless Change color)
(4) Made by Sanki Co., Ltd., trade name: Leozan (5) Made by Sanki Co., Ltd., trade name: Kelzan (6) Made by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Prisurf AL
(7) Product name: GS-550, manufactured by DIC Corporation
(8) Thiazolidine

Preparation of ink After adding ingredients other than shear thinning agent to water, mixing and stirring, adding shear thinning agent, stirring at 20 ° C. with a disper at 400 rpm for 1 hour, and filtering. An ink was prepared.

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, the mixture was kneaded with three rolls to obtain an ink backflow preventing body.

Production of Ballpoint Pen A Stainless steel tip holding the ball A (WC-Co cemented carbide ball) mainly composed of tungsten carbide having a diameter of 0.5 mm is used for the ink compositions of Examples and Comparative Examples, which are made of polypropylene. After filling the ball-point pen refill fitted to one end of the pipe and arranging the ink backflow preventive body at the rear end, the ball-point refill was incorporated into an outer shaft (cap type) to prepare a sample ball-point pen A.

Preparation of ballpoint pen B Stainless steel chip (ball press) holding the ball B (WC-Ni-based cemented carbide ball) mainly composed of tungsten carbide having a diameter of 0.5 mm with the ink compositions of the examples and comparative examples. A spring is housed) filled with a ballpoint pen refill fitted to one end of a polypropylene pipe, the ink backflow prevention body is disposed at the rear end, and the ballpoint pen refill is incorporated into an outer shaft (protruding type). Ballpoint pen B was produced.

The following tests were conducted using the ink composition and the sample ballpoint pen.
Ball Corrosion Test Transfer 5 g of each prepared ink to a sample bottle and immerse balls (A: WC-Co type, B: WC-Ni type) mainly composed of tungsten carbide consisting of two types of A and B compositions. And then left in a 70 ° C. environment for 60 days. Then, the state of each ball | bowl surface was confirmed with the optical microscope (1000-times multiplication factor) at room temperature.

Written test Each sample ballpoint pen that was confirmed to be writable was left in a 50 ° C environment for 120 days in a horizontal position, and then handwritten spiral circles were continuously written on the old JIS P3201 writing paper A. The writing feeling and the state of the handwriting were confirmed visually.
The results of the test are shown in the following table.

The evaluation of the test results is as follows.
Ball corrosion test ○: No change from the initial stage.
(Triangle | delta): The glossiness was lost compared with the initial stage.
X: The surface is rough compared with the initial stage, or there is precipitation or deposits.
Writing test ○: Writing was smooth and good handwriting was shown.
(Triangle | delta): There exists a feeling of being caught at the time of writing, and a slight blur and a line jump are seen in a handwriting.
X: Written feeling is poor, many blurs and line jumps are seen in the handwriting, and seat wear is large and cannot be written.

Claims (4)

  A water-based ink composition for ballpoint pens containing a colorant, water, and a sulfurized fatty acid or a salt thereof.   The aqueous ink composition for ballpoint pens according to claim 1, wherein the sulfurized fatty acid or a salt thereof is added in an amount of 0.1 to 10% by weight based on the total amount of the ink composition.   A ballpoint pen incorporating the water-based ink composition for ballpoint pens according to claim 1 or 2.   4. The ballpoint pen according to claim 3, wherein a cemented carbide ball mainly composed of tungsten carbide is used for the writing tip.