JP2006291050A - Water-based ink composition for direct liquid-type writing tool and direct liquid-type writing tool having the same contained therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition that, because it has a good wetting property to the surface of a pen wick made of a synthetic resin but yet a surface tension not extremely low, causes neither deterioration in dry-up resistance performances at a pen point nor handwriting bleeding, allows the ink to smoothly flow into and flow out from the pen wick in immediate response to temperature changes or internal pressure changes caused by cap-on and cap-off and causes no ink dropping from the pen tip, and a direct liquid-type writing tool having the same contained therein. <P>SOLUTION: The water-based ink composition to be contained in a writing tool which comprises a penholder, a pen wick made of a synthetic resin accommodated therein, a pen point formed at the tip part of the pen wick, and an ink-guiding wick arranged at the pen wick for guiding an ink from the ink storage part to the pen point, comprises a coloring agent, water and an N-acylmethyltaurine salt. The direct liquid-type writing tool contains the same therein. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a water-based ink composition for a direct liquid writing instrument and a direct liquid writing instrument incorporating the same. More specifically, a water-based ink composition for a direct liquid type writing instrument applied to a writing instrument of a type in which the ink is guided from an ink storage unit directly containing ink to a pen tip via a pen core, and a direct liquid incorporating the same. It relates to a formula writing instrument.

Conventionally, many thin disc bodies have a slight gap (comb groove-like interval) as a writing instrument that houses a pen core that temporarily stores ink in the ink storage section according to changes in internal and external pressures in the shaft cylinder. A slit-shaped ink guide groove that is open and arranged in parallel and passes through the disk body in the axial direction and a ventilation groove that is wider than the groove are provided, and guides ink from the ink storage unit to the pen tip on the axis. There is widely used a writing instrument of a type in which a pen core on which an ink guide core is arranged is accommodated in a shaft cylinder, and ink is guided from an ink storage unit to a pen tip.
Since the pen core applied to the writing instrument is usually a synthetic resin molding and the surface is relatively hydrophobic, when applying water-based ink, various additives are added to the ink to wet the pen core. Attempts have been made to improve the performance (for example, see Patent Documents 1 and 2).
JP-A-3-79682 Japanese Patent Laid-Open No. 5-140498

Although the surfactant described in JP-A-3-79682 can improve wettability by imparting affinity to the pen core, the surface tension of the ink is greatly reduced and the handwriting is reduced. There is a possibility that the ink drips out from the pen tip due to bleeding or a change in temperature inside the writing instrument due to temperature change or attachment / detachment of the cap.
Moreover, although the additive described in JP-A-5-140498 can improve the wettability of the pen core, the ink thickens and the dry-up resistance performance at the pen tip is remarkably deteriorated. It is unsuitable.

  The present invention is a water-based ink applied to a writing instrument provided with the above-described synthetic resin pen core, it is possible to improve the wettability of the pen core, as well as ink drop-off phenomenon from the pen tip due to pressure change inside the writing instrument, An object of the present invention is to provide a water-based ink composition that does not cause handwriting blur and does not cause deterioration of the dry-up resistance performance at the pen tip, and a writing instrument incorporating the same.

The present invention accommodates a synthetic resin pen core that temporarily stores ink in an ink storage section in accordance with a change in internal and external pressure, and a pen tip is provided at the tip of the pen core; and The pen core is a water-based ink composition incorporated in a writing instrument in which an ink guide core for guiding ink from the ink reservoir to the pen tip is disposed, and includes at least a colorant, water, and N-acylmethyl taurine A water-based ink composition for a direct liquid writing instrument containing salt is a requirement.
Furthermore, a direct liquid type writing instrument in which the water-based ink composition for a direct liquid type writing instrument is incorporated in an ink storage part in a shaft cylinder is a requirement.
Furthermore, it is a requirement that a cartridge-type ink storage unit is accommodated in the shaft cylinder, and that a fountain pen-shaped nib is provided.

Since the surface tension is not extremely low in spite of good wettability to the surface of the synthetic resin pen core, the present invention does not cause deterioration in dry-up resistance and pen-bleeding at the pen tip. Ink composition suitable for direct liquid writing instruments that can smoothly flow ink into and out of the pen core in response to changes in internal pressure due to changes and cap removal, and does not cause ink spillage from the pen tip And a writing instrument with it built in.
Furthermore, the writing instrument provided with the metal fountain pen nib containing the ink composition can maintain the formation of relatively thin handwriting because the ink composition has appropriate wettability with respect to the metal. .

  In the present invention, by adding an N-acylmethyl taurine salt to a water-based ink applied to a writing instrument provided with a synthetic resin pen core, the ink spilling phenomenon from the pen tip due to the pressure change inside the writing instrument, and the smearing of the handwriting Further, the wettability of the pen core can be improved without causing deterioration of the dry-up resistance performance.

In general, water-based ink applied to a writing instrument equipped with a pen core causes a drop of ink from the pen tip through the induction core due to a change in atmospheric pressure inside the writing instrument or a surface tension when the surface tension is high. If the pressure is low, problems such as the inability to recover the ink held on the pen core due to a change in atmospheric pressure inside the writing instrument tend to occur.
Therefore, by adding N-acylmethyltaurine salt to the water-based ink, it imparts appropriate wettability to the synthetic resin pen core, and responds quickly to changes in temperature and pressure changes inside the writing instrument due to the attachment / detachment of the cap. The ink can be smoothly put into and out of the pen core. In addition, the surface tension on the pen core does not become extremely high or low, the ink holding function at the pen core is maintained, and the ink spilling phenomenon from the fountain pen tip can be suppressed.

The N-acylmethyl taurine salts can be used alone or in combination of two or more, and can be added in an amount of 0.05 to 5% by weight, preferably 0.1 to 2% by weight, based on the total amount of the ink composition.
If it is less than 0.05% by weight, it is difficult to obtain a desired effect, and even if it is added in excess of 5% by weight, no improvement in wettability is observed, so no further addition is required.
Examples of the N-acylmethyl taurine salt include alkali metal salts such as sodium and potassium such as N-cocoyl imidazole taurine, N-lauroyl methyl taurine, N-myristoyl methyl taurine, N-palmitoyl methyl taurine and N-stearoyl methyl taurine. And amine salts and alkanolamine salts.

As the colorant, all dyes and pigments that can be dissolved or dispersed in an aqueous medium can be used, and specific examples thereof are exemplified below.
As an acid dye,
New coccin (CI. 16255),
Tartrazine (C.I. 19140),
Acid Blue Black 10B (C.I. 20470),
Guinea Green (C.I.42085),
Brilliant blue FCF (C.I.42090),
Acid Violet 6BN (C.I. 43525),
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) or the like is used.

As basic dye,
Chrysoidine (C.I. 11270),
Methyl violet FN (C.I. 42535),
Crystal violet (C.I. 42555),
Malachite green (C.I. 42000),
Victoria Blue FB (C.I. 44045),
Rhodamine B (C.I. 45170),
Acridine orange NS (C.I. 46005),
Methylene blue B (C.I. 52015) or the like is used.

As a direct dye,
Congo Red (C.I. 22120),
Direct Sky Blue 5B (C.I. 24400),
Violet BB (C.I. 27905),
Direct deep black EX (CI 30235),
Caillas Black G Conch (C.I. 35225),
Direct Fast Black G (C.I. 35255),
Phthalocyanine blue (C.I. 74180) or the like is used.

As the pigment, in addition to inorganic pigments such as carbon black and ultramarine blue, organic pigments such as copper phthalocyanine blue and benzidine yellow, surfactants and water-soluble resins have already been used to finely and stably disperse in an aqueous medium. Water-dispersed pigment products and the like are used, for example, as a water-dispersed pigment using a surfactant,
C. I. Pigment Blue 15: 3B [trade name: Sandye Super Blue GLL, pigment content 24%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Red 146 [trade name: Sandye Super Pink FBL, pigment content 21.5%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Yellow 81 [trade name: TC Yellow FG, pigment content about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Red 220/166 [trade name: TC Red FG, pigment content: about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.].
As a water-dispersed pigment using a water-soluble resin,
C. I. Pigment Black 7 [Product name: WA color Black
A250, 15% pigment content, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Green 7 [trade name: WA-S color Green, pigment content 8%, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Violet 23 [trade name: Micropigmo WMVT-5, pigment content 20%, manufactured by Orient Chemical Co., Ltd.]
C. I. Pigment Yellow 83 [trade name: Emacol NS Yellow 4618, pigment content 30%, manufactured by Sanyo Dye Co., Ltd.].
As the fluorescent pigment,
Yellow fluorescent pigment (product name: SF5015 lemon yellow, solid content 30%, manufactured by Sinloihi)
Pink fluorescent pigment (trade name: SF5017 pink, solid content 30%, manufactured by Sinloihi Co., Ltd.)
An orange fluorescent pigment [manufactured by Nippon Fluorescent Chemical Co., Ltd., trade name: Lumicol NKW-3904E, solid content 33.5%] can be mentioned.

Other examples include pearl pigments, metal powder pigments, phosphorescent pigments, white pigments such as titanium dioxide, silica and calcium carbonate, capsule pigments encapsulating thermochromic compositions, capsule pigments encapsulating perfumes and perfumes.
The metallic luster pigment is a metallic luster pigment such as aluminum or brass, and a metallic luster pigment in which the surface of natural mica, synthetic mica, glass piece, alumina, or transparent film piece is coated with a metal oxide such as titanium oxide as a core substance. (Pearl pigment), a metallic luster pigment in which a metal vapor deposition film is formed on a transparent or colored transparent film, and a metallic luster pigment having an iris property obtained by finely cutting an iris film in which a plurality of transparent resin layers are laminated.
The colorant can be used singly 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, when a pigment is used as the colorant, a pigment dispersant can be added as necessary. Examples of the pigment dispersant include surfactants such as anions and nonions, anionic polymers such as polyacrylic acid and styreneacrylic acid, and nonionic polymers such as PVP and PVA.

Furthermore, a water-soluble organic solvent can be added as needed.
Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, and 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 monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, N-methyl-2- Pyrrolidone, and the like.
The water-soluble organic solvent may be used alone or in combination of two or more, and is used in the range of 3 to 30% by 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 to the above components, inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, pH adjusters such as organic basic compounds, benzotriazole and its derivatives, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite as necessary , Anticorrosive agents such as sodium thiosulfate and 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, etc., antiseptic or antifungal agent, metal soap, polyalkylene glycol, fatty acid ester, ethylene oxide addition type cationic activator, phosphoric acid activator, thiocarbamate, Dimethyldi Lubricant such as ocarbamate, ascorbic acid, ascorbic acid derivative, α-tocopherol, catechin, catechin derivative, synthetic polyphenol, phosphonate, phosphinate, sulfite, sulfoxylate, dithionate, thiosulfate Antioxidants such as thiourea dioxide, formamidinesulfinic acid, glutathione, urea, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, wetting agent such as sodium pyrophosphate, antifoaming such as dimethylpolysiloxane Agents, dispersants and the like may be used.

Furthermore, if necessary, a shear thinning agent can be added to give the ink an appropriate viscosity for practical use.
The shear thinning agent can be appropriately selected from conventionally known agents, and specific examples include polysaccharides such as xanthan gum, succinoglycan, welan gum, alkacy gum, guar gum, carrageenan, polyacrylic acid, and cross-linked acrylic. Examples include acids, polyvinyl acetamide, nonionic surfactants, anionic surfactants, and associative urethane emulsions.

  The ink composition is a marking pen having a structure in which various pen nibs are attached to the writing tip, ink is stored directly in the shaft tube, and a comb-shaped ink flow rate adjusting member (pen core) made of synthetic resin is interposed. It can be put into practical use by filling a general-purpose pen-core writing instrument such as a ballpoint pen or a fountain pen.

Among the nibs, as the marking pen tip, for example, a fiber tip, a felt tip, a plastic tip, a brush, etc. can be applied, and as a ball-point pen tip, the vicinity of the tip of a metal pipe is pressed and deformed inward from the outer surface. A chip formed by holding a ball in the ball holding part, a chip formed by holding a ball in a ball holding part formed by cutting a metal material by a drill or the like, and a resin made inside a metal or plastic chip A chip provided with a ball receiving seat or a ball that is held by the chip and biased forward by a spring body can be applied. The ball may be made of cemented carbide, stainless steel, ruby, ceramic, resin, rubber, or the like, and those having a diameter in the range of 0.1 mm to 3.0 mm are preferably used.
Further, as the pen tip in the form of a fountain pen, a metal plate such as a stainless steel plate or a gold alloy plate cut into a taper taper shape, bent or curved, or resin molded into a pen tip shape can be applied. The pen body can be provided with a slit at the center or a ball at the tip.
In particular, when a pen body made of a metal plate piece is used as the nib, the ink composition of the present invention can maintain appropriate wettability with respect to the metal, so that the formation of thin handwriting can be maintained.

Examples will be described below, but the present invention is not limited to these examples.
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) Daiwa Kasei Co., Ltd., trade name: Eosin GH Conch 35% solution (2) Orient Chemical Industry Co., Ltd., trade name: Water Black R510 (acid dye, CI 50420)
(3) Product name: Brilliant Blue FCF-L (acid dye, CI 42090), manufactured by Hodogaya Chemical Co., Ltd.
(4) N-lauroylmethyl taurine sodium salt, manufactured by Nikko Chemicals Co., Ltd., trade name: LMT
(5) Daiichi Kogyo Seiyaku Co., Ltd., trade name: Neugen P

Preparation of ink Add ingredients other than phenol to water, warm to room temperature or in the range of 50 ° C to 60 ° C if necessary, mix and stir, then cool and add phenol to mix uniformly Each ink was prepared.

Preparation of Writing Instruments Each ink composition was filled into an ink storage part of a writing instrument (PVP Corporation, SVP-20NS) having a fountain pen shape pen tip, and a writing instrument was prepared by fitting a cap.

The following tests were conducted using the writing instrument.
Pen core wettability test The pen used when the writing instrument for a sample held in the pen tip downward state is left at 0 ° C. for 1 hour in the cap fitting state and then the cap is removed and the temperature is raised to 40 ° C. with the pen tip downward state. The state of ink flowing into the core comb groove and the presence or absence of ink splatter from the pen tip were observed.

Ink Recovery Test After the pen core wettability test, the ink recovery state from the pen core comb groove to the ink reservoir was observed when cooled to 0 ° C. again.

Cap Attaching / Removing Test The state of ink entering and exiting the pen core comb groove was observed when the cap attaching / detaching operation was continuously repeated in the pen tip downward state.
The results of each test are shown in the following table.

The evaluation of the test results is as follows.
Pen core wettability test ○: Smoothly flowed in and no dropping occurred.
X: The inflow was irregular and a dripping occurred.
Ink recovery test ○: Good recovery was achieved.
X: Not recovered and remained in the pen core comb groove.
Cap attaching / detaching test ○: Ink was put in and out smoothly by attaching and detaching, and no dropping occurred.
X: Ink entry / exit was not performed smoothly, and a drop-out occurred from the pen tip or the air groove.

Claims (5)

  The shaft cylinder contains a synthetic resin pen core that temporarily stores ink in accordance with changes in internal and external pressures, a pen tip is provided at the tip of the pen core, and the pen core Is a water-based ink composition incorporated in a writing instrument in which an ink guide core for guiding ink from the ink reservoir to the nib is disposed, and includes at least a colorant, water, and an N-acylmethyl taurine salt A water-based ink composition for a direct liquid writing instrument.   The water-based ink composition for a direct liquid writing instrument according to claim 1, wherein the N-acylmethyltaurine salt is added in an amount of 0.05 to 5% by weight based on the total amount of the ink composition.   A direct liquid writing instrument comprising the ink storage unit in the shaft cylinder, wherein the aqueous ink composition for a direct liquid writing instrument according to claim 1 or 2 is incorporated.   4. The direct liquid writing instrument according to claim 3, wherein a cartridge type ink storage section is accommodated in the shaft cylinder.   The direct liquid writing instrument according to claim 3 or 4, which has a fountain pen-shaped pen tip.