JP2009079167A - Water-based ink composition for retractable ballpoint pen and retractable ballpoint pen storing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based ink composition for a retractable ballpoint pen, the composition satisfying conflicting functions of anti-dripping property and dry-up resistance and having excellent writing performances, and to provide a retractable ballpoint pen storing the composition. <P>SOLUTION: The ink composition is housed in a ballpoint pen in which a writing top end of a ballpoint pen refill appears and retracts through a front end opening of the barrel by an operation of a thrusting and retracting mechanism. The composition comprises at least a colorant, water and ι-carrageenan and has electric conductivity of the ink ranging from 6.3 to 50 mS/cm. The retractable ballpoint pen stores the above ink composition in a ballpoint pen refill comprising an ink housing tube to which a ballpoint pen tip enclosing a ball is directly attached or attached via a connecting member, and the pen has an ink backflow preventing part disposed at the rear end of the ink composition. The ballpoint pen tip appears and retracts through the front aperture of the barrel by an operation of the thrusting and retracting mechanism. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water-based ink composition for a retractable ballpoint pen and a retractable ballpoint pen incorporating the same. More specifically, the pendulum ballpoint pen has dry-up resistance that suppresses the occurrence of blurring and inability to write due to drying of the nib even if it is exposed to the outside air for a long period of time, and has excellent drooping prevention performance The present invention relates to a water-based ink composition for use, and a retractable ballpoint pen incorporating the same.

Conventionally, a large number of retractable ballpoint pens have been put on the market in which a water-based ink for ballpoint pens is directly built in an ink storage tube, and a ballpoint pen refill provided with an ink backflow preventer at the rear end of the ink is stored in a shaft cylinder. In the retractable ballpoint pen, if the ink contained therein has a relatively high viscosity, it is possible to prevent the ink from dripping from the pen tip to some extent, but if the ink having a low viscosity is used, the ink tends to droop.
Further, water-based ink for ballpoint pens is important for drying resistance in a state where the pen tip is exposed, and an attempt has been made to increase the amount of urea or its derivative as a pen tip drying inhibitor (for example, see Patent Document 1).
However, since urea and its derivatives have high water absorption performance and express dry resistance, inks with excessive addition of these will absorb water locally at the nib when left under high humidity conditions. Become. For this reason, the ink viscosity at the nib portion decreases due to moisture absorption, and the “dripping” phenomenon in which the ink accumulates in the nib portion or the “bottom-off” phenomenon in which the accumulated ink falls tends to occur.
As described above, although there is a means for improving the dry-up resistance of the ink composition, it does not sufficiently satisfy other writing performance such as sag and dripping. When used for an in-and-out type ball-point pen that does not require a cap that is always open to the atmosphere, it is an important requirement that it has a dry-up resistance and does not cause dripping or dripping.
JP 59-45372 A

  The present invention solves the problems of the ink composition applied to a ballpoint pen that does not require a cap, satisfying the contradictory functions of drooping and drying resistance, and for a retractable ballpoint pen excellent in writing performance An object of the present invention is to provide a water-based ink composition and a retractable ballpoint pen incorporating the same.

The present invention is an ink composition accommodated in a ballpoint pen in which the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening of the shaft cylinder by the operation of the retracting mechanism, and includes at least a colorant, water, and ι-carrageenan. Therefore, a water-based ink composition for an intruding ballpoint pen having an ink conductivity in the range of 6.3 to 50 mS / cm is a requirement.
Furthermore, it is a requirement that the ι-carrageenan is contained in an amount of 0.1 to 1.0% by weight in the total amount of the ink composition.
Further, the water-based ink composition for a pendent ballpoint pen is incorporated in a ballpoint pen refill consisting of an ink containing tube in which a ballpoint pen tip holding a ball is attached directly or via a relay member, and the rear end face of the ink composition An ink backflow prevention body is disposed on the ballpoint pen, and the ballpoint pen tip of the ballpoint pen refill is projected and retracted from the front end opening of the shaft cylinder by the operation of the heightening and retracting mechanism. It is configured so that the ball is pressed against the inner edge of the tip of the tip to make it in close contact when writing, and the ink can flow out by retreating the ball with writing pressure when writing. As a requirement.

  The present invention is excellent in dry-up resistance, good in writing at the beginning and after the lapse of time, and can maintain stable writing performance without causing problems such as blurring or sagging of handwriting, and is continuously good. It is possible to provide a water-based ink composition for a retractable ballpoint pen that is excellent in writing performance for obtaining a good handwriting and a retractable ballpoint pen incorporating the same.

The iota-carrageenan used in the present invention is stably present in water-based inks, and increases the viscosity according to the increase in the ink ion concentration, thereby improving the sag-preventing performance without impairing the drying resistance. It is.
Therefore, it works effectively when the conductivity of the ink, which varies according to the ion concentration of the ink, is in the range of 6.3 to 50 mS / cm.
When the conductivity of the ink is less than 6.3 mS / cm, the viscosity increase rate of ι-carrageenan is low, and it is difficult to obtain a drooping prevention effect. On the other hand, if it exceeds 50 mS / cm, the effect of preventing dripping can be obtained, but the viscosity of the ink itself becomes too high, and there is a possibility that ink ejection failure may occur during writing.
The conductivity of the ink is more preferably in the range of 6.5 to 30 mS / cm. In this case, the ink is optimal because it has a good balance as a writing instrument.
The conductivity can be prepared by adding an ionic substance.

  The ι-carrageenan is blended in the range of 0.1 to 1.0% by weight with respect to the total amount of the ink composition. If it is less than 0.1% by weight, it is difficult to obtain the effect of preventing dripping at the above-mentioned conductivity, and even if added in excess of 1.0% by weight, no improvement in drooping preventing 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 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 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 can 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.

Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, hexylene glycol, 1,3-butanediol, and neoprene. Glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoether Ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, N- methyl-2-pyrrolidone.
The water-soluble organic solvent can be used alone or in combination of two or more.

In addition to the above components, alkali metal salts of alkyd resin, acrylic resin, styrene maleic acid copolymer, cellulose derivative, polyvinyl pyrrolidone, polyvinyl alcohol, λ-carrageenan, methyl cellulose, carboxymethyl cellulose, carboxymethyl cellulose within the category that does not impair drying resistance One or two or more water-soluble polymers such as these can be added.
In addition, a pH adjuster, a rust inhibitor, an antiseptic or an antifungal agent, a lubricant, and a wetting agent can be added as necessary.
Examples of the pH adjusting agent include inorganic salts such as sodium carbonate, sodium phosphate, sodium hydroxide and sodium acetate, and organic basic compounds such as water-soluble amine compounds such as triethanolamine and diethanolamine.
Examples of the rust inhibitor include benzotriazole and derivatives thereof, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, sodium thiosulfate, ethylenediaminetetraacetate, saponin, and dialkylthiourea.
Examples of the preservative or antifungal agent include carboxylic acid, sodium salt of 1,2-benzisothiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2, 3, 5, 6 -Tetrachloro-4- (methylsulfonyl) pyridine and the like.
Examples of the lubricant include higher fatty acids such as oleic acid, nonionic surfactants having a long chain alkyl group, polyether-modified silicone oil, thiophosphite tri (alkoxycarbonylmethyl ester) and thiophosphite tri (alkoxycarbonylethyl). Esters), phosphoric acid monoesters of polyoxyethylene alkyl ethers or polyoxyethylene alkyl aryl ethers, phosphoric acid diesters of polyoxyethylene alkyl ethers or polyoxyethylene alkyl aryl ethers, or metals thereof Examples include salts, ammonium salts, amine salts, alkanolamine salts, and the like.
Examples of the wetting agent include urea, nonionic surfactant, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, sodium pyrophosphate and the like.
In addition, an antifoaming agent such as a fluorine-based surfactant that improves the permeability of the solvent, a nonion, an anion, a cationic surfactant, or dimethylpolysiloxane may be added.

  When the ink composition is incorporated in an ink containing tube and used in a ballpoint pen of a type in which an ink backflow preventer is disposed on the rear end surface of the ink composition, if the gas is mixed in the ink, Bubbles gather to adversely affect ink discharge during writing, and if there are bubbles at the tip of writing, writing may be impossible. -Tocopherol, catechin, catechin derivative, synthetic polyphenol, kojic acid, alkylhydroxylamine, oxime derivative, α-glucosyl rutin, phosphonate, phosphinate, sulfite, sulfoxylate, dithionate, thiosulfate, Add thiourea dioxide, formamidinesulfinic acid, glutathione, etc. to chemistry It is preferable to remove bubbles.

The aqueous ink composition for ballpoint pens of the present invention comprises a shear thinning agent, for example, water soluble or dispersible, xanthan gum, welan gum, or a monosaccharide composed of organic acid-modified heteropolysaccharides of glucose and galactose. A polymer having a molecular weight of 100,000 to 150,000 mainly composed of a certain succinoglycan (average molecular weight of about 1 to 8 million), guar gum, locust bean gum and derivatives thereof, hydroxyethyl cellulose, alkyl alginate, and alkyl ester of methacrylic acid , Glucomannan, thickened polysaccharide with gelling ability extracted from seaweed such as agar and carrageenin, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymer, inorganic fine particles, polyglycerin fatty acid ester, poly Oxyethylene Nonionic surfactants having an HLB value of 8 to 12, such as rubitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether / polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, fatty acid amide, dialkyl or dialkenyl sulfosucci Acid salts and the like can be exemplified, and they can be used alone or in combination.
Furthermore, a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, a mixture of polyvinyl alcohol and an acrylic resin can also be used.
Ink shear thinning is a rheological property that has a high viscosity and is difficult to flow in a static state or when stress is low, and it exhibits low fluidity and good fluidity when stress increases. It means liquidity called pseudo plasticity.

As the viscosity characteristics of the ink of the present invention, the viscosity (20 ° C.) measured with a viscometer is in the range of 1 to 20 mPa · s, and the shear thinning index [shear stress value (T) and shear rate by viscometer] (J) The empirical formula (T = Kj ^n, where K is a calculated constant) derived from rheological measurement of the value, is 0.4-0. A range of 9 is preferred.
When the viscosity exceeds 20 mPa · s, it is difficult to satisfy the ink following ability by writing, and the handwriting when writing at high speed is likely to be blurred.
When the shear thinning index is less than 0.4, the writing feeling is inferior and the ink is difficult to transfer to the ball at the initial writing. Furthermore, the handwriting is difficult to dry, and it is easily contaminated by transferring to a blank portion of the writing surface by finger touch or rubbing between papers.

The structure and shape of the retractable ballpoint pen containing the waterborne ink composition for the retractable ballpoint pen of the present invention is not particularly limited, and the writing tip provided on the ballpoint pen refill is exposed to the outside air in the shaft cylinder. The writing tip protrudes from the shaft tube opening by the operation of the retracting mechanism.
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 rear end portion of the shaft tube and the side surface of the shaft tube, and by pressing the knock portion, the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the shaft tube, or on the shaft tube. 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 shaft cylinder by pressing the provided clip portion can be exemplified.
The rotary type has a rotating part at the rear part of the shaft cylinder, and can be exemplified by a configuration in which the writing tip part of the ballpoint pen refill is projected and retracted from the front end part of the shaft cylinder by turning the rotating part.
The slide type has a slide part on the side surface of the shaft cylinder, and the sliding tip of the writing point of the ballpoint pen refill is projected and retracted from the front end opening of the shaft cylinder by operating the slide, or the clip part provided on the shaft cylinder is slid. By doing so, it is possible to exemplify a configuration in which the writing tip of the ballpoint pen refill is projected and retracted from the opening at the front end of the shaft cylinder.
The retractable ballpoint pen may be a composite ballpoint pen in which a plurality of ballpoint pen refills are accommodated in a shaft cylinder.
The ink storage tube constituting the ballpoint pen refill may be made of resin or metal.

The ball-point pen tip is formed, for example, by cutting a metal to form a ball receiving seat and an ink lead-out portion inside, and providing a plurality of inward protruding portions on the inner surface near the tip of a metal pipe by pressing deformation from the outer surface. It is possible to apply an ink outflow gap extending radially outward from the central portion between the inwardly protruding portions, and the tip, especially the chip formed by pressing deformation, has a comparative contact area with the rear end of the ball. It is small and can give a smooth writing feeling with a low writing pressure.
The ball held by the ballpoint pen tip is 0.1 to 2.0 mm in outer diameter, preferably 0.2 to 1.5 mm, more preferably 0.3 to 0.3 mm, such as cemented carbide, stainless steel, ruby, and ceramic. A 1.0 mm ball is effective, and the moving distance in the radial direction between the inner diameter of the ball holding portion of the chip and the ball is in the range of 10 to 50 μm, and the moving distance in the axial direction of the ball is in the range of 10 to 30 μm. preferable.
The ballpoint pen tip is provided with a resilient member for projecting the rear end of the ball forward in the tip. When not writing, the ball is pressed against the inner edge of the tip of the tip to bring it into close contact, and when writing, it is The ball can be retracted to allow ink to flow out, and ink leakage when not in use can be suppressed.
Examples of the elastic member include a metal thin wire spring, a member provided with a straight portion (rod portion) at one end of the spring, a linear plastic processed body, and the like, and can be pressed by an elastic force of 10 to 40 g. Applied.

The back end of the ink stored in the ballpoint pen refill can be filled with an ink backflow prevention body.
The ink backflow prevention body composition is composed of a non-volatile liquid or a hardly volatile liquid.
Specifically, petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples thereof include polyether-modified silicone oil and fatty acid-modified silicone oil, and one or more can be used in combination.

It is preferable to add a gelling agent to the nonvolatile liquid and / or the hardly volatile liquid to increase the viscosity to a suitable viscosity. The surface of the silica is hydrophobized, the surface is methylated fine particle silica, and aluminum silicate. , Swellable mica, hydrophobic thickeners such as bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, fatty acid amide, amide modified Examples include dextrin compounds such as polyethylene wax, hydrogenated castor oil, fatty acid dextrin, and cellulose compounds.
Furthermore, the liquid ink backflow prevention body composition and a solid ink backflow prevention body composition can be used in combination.

Examples will be described below, but the present invention is not limited to these examples.
The following table shows the composition and conductivity of the water-based ink for ballpoint pens of the examples and comparative examples. In addition, the numerical value of a composition in a table | surface shows a weight part. The conductivity of each ink is a value measured at 25 ° C. using a conductivity meter (manufactured by Yokogawa Electric Corporation, Model SC 82).

The contents of the raw materials in the table will be described along the note numbers.
(1) Daiwa Kasei Co., Ltd., C.I. I. Food Black 2, trade name: Daiwa Black FS-20 (solid content 22%)
(2) Product name: Water Black 181-L (solid content 20%), manufactured by Orient Chemical Co., Ltd.
(3) Eisen Hodogaya Co., Ltd., C.I. I. Acid Red 92, trade name: Phloxine (4) Made by Orient Chemical Co., Ltd., trade name: Water Yellow 6C
(5) Sumitomo Chemical Co., Ltd., C.I. I. Acid Blue 92, trade name: Acid Blue PG
(6) Dainichi Seika Kogyo Co., Ltd., trade name: WA Black 20 (solid content 15%)
(7) Product name: GJ500, manufactured by Mitsubishi Corporation Food Tech Co., Ltd.
(8) Product name: Prisurf AL, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
(9) Product name: Water Black 250-L (solid content 10%), manufactured by Orient Chemical Co., Ltd.

Ballpoint pen refill The ballpoint pen refill consists of a ballpoint pen tip (which contains a ball push spring that bounces the ball forward) and a ballpoint pen tip fixed to the front. A connecting member, an ink containing tube in which the connecting member is fixed to the front end opening, and an ink and an ink backflow prevention body are accommodated therein, and a tail fixed to the rear end opening of the ink containing tube. It consists of a stopper.
The ink was prepared by mixing the inks described in each Example and Comparative Example, stirring at 1000 rpm for 30 minutes with a disper at room temperature, and filtering. The ink backflow preventer is an ink backflow preventer kneaded using polybutene as the base oil and fatty acid amide as the thickener.

Ballpoint Pen The ballpoint pen is formed with a clip on the outer surface of the rear portion of the shaft tube, and each ballpoint pen refill is accommodated in a rearward biased state by a spring (coil spring) inside the shaft tube. By knocking the knock operation portion forward, the ball-point pen tip protrudes from the tip hole of the shaft tube.

The following tests were conducted with each of the ballpoint pens.
Sagging test Using each ballpoint pen, expose the ballpoint pen tip from the barrel, hold the tip downward, and leave it in an atmosphere at a temperature of 20 ° C. and a relative humidity of 60% for 30 minutes. And evaluated according to the following criteria.
Drying resistance test Using each ballpoint pen, the ballpoint pen tip was exposed from the shaft tube and held in a horizontal position, and left in an atmosphere at a temperature of 20 ° C. and a relative humidity of 55 to 75% for 10 days, and then JIS P3201 writing paper. Handwritten in A, 12 circles were written in a row in succession, and the number of rows that can be normally written was visually observed.
Filterability test After mixing each composition of an Example and a comparative example and stirring at 1000 rpm for 30 minutes with a disper at room temperature, No. The state at the time of filtering with 2 filter papers was confirmed.

The test results are shown in the following table.

The contents of the test result evaluation symbols are as follows.
Sag test ○: No ink leakage (sag) was observed.
Δ: Ink droplets are observed at the tip of the chip.
X: Large ink droplets are observed at the tip of the chip, or ink leaking from the tip of the chip is falling.
Drying resistance test ○: Writing is possible within one circle.
×: Cannot be written within one line.
Filterability test ○: Filters well.
X: Cannot be filtered.

Claims (4)

  An ink composition accommodated in a ballpoint pen in which the writing tip portion of the ballpoint pen refill is projected and retracted from the opening at the front end of the barrel by the operation of the intrusion mechanism, comprising at least a colorant, water, and ι-carrageenan. A water-based ink composition for an intruding ballpoint pen having an electrical conductivity in the range of 6.3 to 50 mS / cm.   The water-based ink composition for a retractable ballpoint pen according to claim 1, wherein the ι-carrageenan is contained in an amount of 0.1 to 1.0% by weight based on the total amount of the ink composition.   The water-based ink composition for an intruding ballpoint pen according to claim 1 or 2 is incorporated in a ballpoint pen refill comprising an ink containing tube in which a ballpoint pen tip holding a ball is attached directly or via a relay member, and an ink A retractable ballpoint pen in which an ink backflow preventive body is disposed on the rear end surface of the composition, and the ballpoint pen tip of the ballpoint pen refill appears and disappears from the front end opening of the barrel by the operation of the retracting mechanism.   The ballpoint pen tip is provided with a resilient member that bounces the rear end of the ball forward. When not writing, the ball is pressed against the inner edge of the tip to bring it into close contact, and when writing, the ball is retracted by writing pressure. 4. The retractable ballpoint pen according to claim 3, wherein the ink pendant is configured to be allowed to flow out.