JP2002235024A - Aqueous ink composition for writing material and writing material having built-in aqueous ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both an aqueous ink composition for a writing material, with which foam generation in ink is prevented and an excellent handwriting is obtained and the writing material including the ink composition. SOLUTION: The aqueous ink composition comprises a colorant, water, a water-soluble organic solvent and a phosphonate and/or a phosphinate. The writing material includes the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink composition for a writing implement and a writing implement filled with an ink backflow preventive that follows the ink consumption using the composition.

[0002]

2. Description of the Related Art An aqueous ballpoint pen ink composition containing a shear-thinning agent such as a high-molecular-weight polysaccharide has been disclosed as an ink having a shear-thinning property among water-based inks (Japanese Patent Laid-Open Publication No. 4-1992). No. 2144782). This type of ink has a high viscosity at rest when no shear stress is applied, is held stably in the mechanism, and during writing, the ink near the ball is low due to the high shearing force of the high-speed rotating ball. As a result, the ink is ejected from the gap between the ball and the ball housing portion and transferred to the paper. Since the ink transferred to the paper surface is released from the shearing force, it becomes a high-viscosity state again, and does not cause blur of the handwriting, which is a drawback of the conventional aqueous ink composition. Furthermore, since there is no ink leakage due to the above-mentioned shear thinning and no flow rate adjusting member (pen core) for adjusting the ink flow rate is required, a writing implement having a simple structure can be obtained.
The above-described writing implement using the water-based ink exhibiting shear thinning has a simple structure, and since the air does not enter into the inside with the consumption of the ink as in the writing implement using the flow rate adjusting member, the internal pressure is reduced. While it has the advantage of little change and not causing ink dropping, special considerations are required when preparing and filling the ink. This prevents the solvent in the ink from evaporating on the rear end face of the ink, or prevents the ink from flowing backward when the writing tip is in an upright state (upright state). This is because the backflow prevention body (liquid tap) is filled,
Since the ink is present in an airtight space that is cut off from the outside air, if gas is mixed in the ink, the gas collects with the passage of time and bubbles are generated, which has an adverse effect on ink output during writing and also has a negative effect on writing. This is because writing may not be possible if bubbles exist at the tip. Separately from this, as the writing implement of the type in which the ink backflow prevention body is filled, by providing a valve mechanism near the writing tip, it is possible to fill the aqueous ink composition that does not show shear thinning, In the same manner as described above, the presence of air bubbles adversely affects writing performance. In order to solve the above-mentioned problem, defoaming treatment for mechanically removing gas in the ink is mainly performed, but it is difficult to perform sufficient defoaming by this method alone, and gas remains in the ink. There is. Further, when a colorant insoluble in a solvent such as pigment, metal powder, titanium oxide, or the like is used, if a treatment such as centrifugal defoaming is performed, the colorant is unevenly distributed in the ink container. Therefore, a method of chemically removing gas in the ink is considered. For example, an ascorbic acid derivative is added (Japanese Patent Publication No. 7-113101),
α-tocopherol may be added (Japanese Unexamined Patent Publication No.
No. 672) and further attempts to add catechins (JP-A-10-298483).

[0003]

However, among the compounds that chemically remove the gas in the ink, ascorbic acid derivatives are liable to cause the aggregation of the pigment in a system using a pigment as a coloring agent, so that practical use is not possible. Limited.
Further, α-tocopherol is insoluble in water and is separated over time, making it difficult to permanently exhibit a gas removing function. In addition, the catechins are limited in a coloring agent to be applied,
Although good gas removal is possible without causing a problem such as the gas removal function disappearing in a short period of time, catechins are low in purity because of natural extract, and show reducing property. Only a small number of functional groups remove gas, and a large amount must be added to obtain the desired effect. The present invention provides a water-based ink composition for a writing implement that has a wide practicality and can obtain good writing performance by using a specific compound that chemically removes the gas in the ink described above, and a built-in ink composition. It is to provide a writing implement that has been developed.

[0004]

According to the present invention, there is provided an aqueous ink composition comprising at least a coloring agent, water and a water-soluble organic solvent, wherein the aqueous ink for a writing implement comprises a phosphonate and / or a phosphinate. Require composition. Further, the phosphonate and / or phosphinate is contained in the ink composition in an amount of 0.01 to 5% by weight, a shear thinning agent is included, and the ink at 100 rpm by an E-type viscometer is used. 20-200 mP viscosity
a.s (25 ° C.) and a shear thinning index of 0.
It is required to indicate 1 to 0.8. Further, a writing tool in which the ink composition is filled in a writing tool of a type in which an ink backflow preventing body that follows the ink consumption is arranged is required.

The inventor of the present invention has shown that among the above-mentioned compounds for chemically removing gas in ink, there is little effect on various additives, and the compound has a sufficient gas removing function with a small amount of addition. As a result of intensive studies on compounds to be permanently expressed, it has been found that phosphonates and phosphinates exhibit a remarkable long-term gas removal function while maintaining good writing performance.

The above phosphonates and phosphinates are compounds having a reducing property, and exhibit good oxygen absorbing ability when added to an ink composition. Therefore, it is presumed that gas containing oxygen in the ink is prevented from collecting and forming bubbles. The phosphonate is an alkali metal salt, amine salt or alkanolamine salt of phosphonic acid, and specific examples thereof include sodium phosphonate, potassium phosphonate, and ammonium phosphonate. The phosphinate, an alkali metal salt of phosphinic acid, an amine salt, an alkanolamine salt, specifically,
Examples thereof include sodium phosphinate, potassium phosphinate, and ammonium phosphinate.

The phosphonate and / or phosphinate can be added in an amount of 0.01 to 5% by weight, preferably 0.05 to 1% by weight, in the ink composition. If the content is less than 0.01% by weight, it is difficult to obtain the desired effect of suppressing the generation of bubbles, and if it is 5% by weight or less, the desired effect is sufficiently obtained, so that 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 are shown below. As the dye, an acid dye, a basic dye, a direct dye, or the like can be used. As the acid dye, neucoccin (C.I.
I. 16255), tartrazine (CI. 1914)
0), Acid Blue Black 10B (CI.204
70), Guinea Green (CI. 42085), Brilliant Blue FCF (CI. 42090), Acid Violet 6B (CI. 42640), Soluble Blue (CI. 42755), Naphthalene Green (C. .I.44025), eosin (CI.4538)
0), Phloxine (CI. 45410), Erythrosin (CI. 45430), Nigrosine (CI. 50)
420), acid flavin (CI. 56205) and the like.

As the basic dye, chrysoidin (C.I.
I. 11270), methyl violet FN (CI.
42535), crystal violet (C.I.42)
555), malachite green (CI. 4200)
0), Victoria Blue FB (CI.44045),
Rhodamine B (CI. 45170), Acridine Orange NS (CI. 46005), Methylene Blue B
(C.I. 52015) and the like are used.

As a direct dye, Congo Red (C.I.
I. 22120), Direct Sky Blue 5B (C.I.
I. 24400), Violet BB (CI. 279)
05), direct deep black EX (CI.3
0235), Kayalas Black G Conch (CI.35
225), Direct Fast Black G (CI.3)
5255), phthalocyanine blue (CI. 7418)
0) etc. are used.

As the pigment, in addition to inorganic pigments such as carbon black and ultramarine blue, and organic pigments such as copper phthalocyanine blue and benzidine yellow, finely and stably dispersed in an aqueous medium using a surfactant or a resin in advance. Water-dispersed pigment products and the like. I. Pigment Blue 15: 3B [Product name: Sandy Super Blue GLL, pigment content 24%, manufactured by Sanyo Dyeing Co., Ltd.] C.I. I. Pigment Red 146 [Product name: S
andy Super Pink FBL, pigment content 2
1.5%, manufactured by Sanyo Dyeing Co., Ltd.] C.I. I. Pigment Yellow 81 [Product name:
TC YellowFG, pigment content: about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.] I. Pigment Red 220/166 [product name: TC Red FG, pigment content: about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.] and the like. In addition, as the resin for dispersing the pigment, polyamide resin, polyurethane resin, polyester resin, epoxy resin, melamine resin, phenol resin, silicone resin,
Polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polystyrene, acrylic resin, maleic resin, gum arabic, cellulose, dextran, casein, etc., and derivatives thereof, and copolymers of the above resins And the like. As the fluorescent pigment, a fluorescent pigment in the form of fine particles of a synthetic resin in which various fluorescent dyes are made into a solid solution in a resin matrix can be used. Also, white pigments such as titanium dioxide, metal powders such as aluminum, pearl pigments, gold and silver metallic pigments, luminous pigments, fragrances and fragrance capsule pigments can be used. The pigments may be used alone or in combination of two or more, and are used in the ink composition in an amount of 1 to 25% by weight, preferably 2 to 15% by weight.

As the water-soluble organic solvent, a conventional general-purpose solvent compatible with water is used. Ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, Thiodiethylene glycol, hexylene glycol, 1,3-butanediol, neoprene glycol,
Polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether diethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether,
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 2 to 60% by weight, preferably 5 to 60% by weight.
It is used in the range of 35% by weight.

In addition, if necessary, a pH adjuster, a preservative or a fungicide can be added. Examples of the pH adjuster include inorganic salts such as ammonia, 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 preservative or fungicide include sodium salt of carboxylate, 1,2-benzisothiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6 −
Tetrachloro-4- (methylsulfonyl) pyridine and the like. In addition, it is also possible to add a fluorine surfactant for improving the permeability of the solvent, a nonionic, anionic or cationic surfactant, and an antifoaming agent such as dimethylpolysiloxane.

One or more water-soluble resins such as an alkyd resin, an acrylic resin, a styrene-maleic acid copolymer, a cellulose derivative, polyvinylpyrrolidone, polyvinyl alcohol, and dextrin are added in a range that does not hinder the drying resistance. Alternatively, one or more humectants such as urea, nonionic surfactant, sorbite, mannitol, sucrose, glucose, reduced starch hydrolyzate, sodium pyrophosphate and the like can be added.

The term "shear-thinning viscosity" of an ink composition refers to rheological properties in which the composition has an extremely high viscosity and is hard to flow when the ink is in a static state or when the stress is low. Which means a liquid property also called thixotropy or pseudoplasticity. Therefore, the ink composition under high shear stress at the time of writing, the three-dimensional structure is temporarily destroyed, the viscosity of the ink is reduced, the ink at the writing tip becomes a low-viscosity ink suitable for writing,
Transferred to paper. At the time of non-writing, the viscosity of the ink is increased, so that leakage of the ink, separation of the ink, and backflow of the ink can be prevented. In addition, the physical properties of the ink can be kept stable over time. In particular, in a ballpoint pen that holds a ball at the tip of writing, under high shear stress during writing, the ink near the ball has low viscosity suitable for writing, and moves through the gap between the ball and the ball house by capillary force, and It is necessary to have the characteristics of the ink transferred to the ink, and when not writing, the viscosity of all the ink, including the vicinity of the ball, increases, and it is necessary to prevent the leakage of the ink, the separation of the ink, and the backflow. 100 rpm by E-type viscometer
m is 20 to 200 mPa · s (25
C.), and an ink composition having a shear thinning index of 0.1 to 0.8.

As the shear-thinning agent, substances soluble or dispersible in water are effective, and xanthan gum, welan gum, and succinoglycan whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose. (Average molecular weight of about 1 to 8 million), guar gum, locust bean gum and derivatives thereof, hydroxyethylcellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000, and glycomannan, which are mainly composed of alkyl esters of methacrylic acid; Thickening polysaccharides having gelling ability extracted from seaweeds such as agar and carrageenin, benzylidene sorbitol and benzylidene xylitol or derivatives thereof, a crosslinkable acrylic acid polymer, inorganic fine particles,
Polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene castor oil, polyoxyethylene lanolin, lanolin alcohol, beeswax derivative, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene alkyl HLB value of phenyl ether, fatty acid amide, etc. is 8
To 12 nonionic surfactants, salts of dialkyl or dialkenyl sulfosuccinic acid, and the like, and these can be used alone or in combination. Further, N-alkyl-
A mixture of 2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin can also be used. The shear thinning agent can be used in an amount of 0.1 to 20% by weight in the ink composition.

In addition, a rust preventive, a lubricant and the like can be added as required. Examples of the rust preventive include benzotriazole and its derivatives, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, sodium thiosulfate, ethylenediaminetetraacetate, saponin, dialkylthiourea and the like. Examples of the lubricant include metal soap, polyalkylene glycol fatty acid ester, ethylene oxide addition type cationic activator, phosphate ester activator, thiocarbamate, dimethyldithiocarbamate and the like.

In addition, as the lubricant preferably used,
Phosphate ester surfactants described in the following general formula (1) or Japanese Patent Publication No. 1-1508 are exemplified.

[0019]

Embedded image (Wherein, R ₁ represents an alkyl group or alkenyl group of 8 to 18,
Alternatively, a phenyl group, an alkylphenyl group, R ₂
It is OH, OM, R-O- ( CH 2 CH 2 O) shows the _n,
M represents an alkali metal, an amine, or an alkanolamine, and n represents 1 to 30. )

The aqueous ink composition for a writing instrument of the present invention is filled into a marking pen or a ball-point pen having a fiber tip, a felt tip, a plastic tip, and a ball-point pen tip attached to a writing tip.

The structure and shape of the ball-point pen itself are not particularly limited, and conventional ball-point pens can be used. For example, the ball-point pen has an ink container filled with an ink composition in a shaft cylinder. Is a ball-point pen that communicates with a chip having a ball attached to the tip, and a liquid stopper for preventing backflow is in close contact with the end surface of the ink.

The ballpoint pen tip will be described in more detail. A tip holding a ball in a ball holding portion in which the vicinity of the tip of a metal pipe is pressed and deformed inward from the outer surface, or a metal material such as a drill is used. A chip holding a ball in a ball holding portion formed by cutting by the above or a ball held by a chip formed by cutting a metal pipe or a metal material is urged forward by a spring body. Can be applied. Also, the ball is
0.1% of cemented carbide, stainless steel, ruby, ceramic, etc.
Those having a diameter of about 3 to 1.2 mm can be applied.

For the ink containing tube for containing the ink composition, for example, a molded article made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate or the like is suitably used in terms of low ink evaporation and productivity. The ink container preferably has an inner diameter of 2.5 to 10 mm. Further, by using a transparent, colored transparent, or translucent molded body as the ink storage tube, the ink color, the remaining amount of the ink, and the like can be confirmed. In addition to directly connecting the chip to the ink storage tube, the ink storage tube and the chip may be connected via a connection member. In addition, the ink storage tube has a form of refill,
The refill may be housed in the barrel, or the barrel itself with the tip attached to the tip as an ink container.
The shaft cylinder may be directly filled with ink.

The back end of the ink composition contained in the ink containing tube is filled with an ink backflow preventer. As the ink backflow preventive, any liquid or solid can be used.Examples of the liquid ink backflow preventive include non-volatile media such as polybutene and silicone oil.
If desired, silica, aluminum silicate and the like can be added to the medium. In addition, examples of the solid ink backflow preventer include a resin molded product. Further, the liquid and solid ink backflow preventers may be used in combination.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous ink composition for a writing instrument of the present invention comprises a dye or pigment (pigment dispersion), a phosphonate or a phosphinate, if necessary, in a medium comprising water and a water-soluble organic solvent. It is prepared by adding a viscosity reducing agent and various additives, heating and stirring as necessary, dissolving and dispersing, and used by filling in a writing implement in the form of a ballpoint pen, felt-tip pen, felt pen, brush pen, etc. You.

[0026]

EXAMPLES The ink compositions of the present invention and comparative examples, and the viscosities of the inks at 25 ° C. at 1 rpm, 10 rpm, and 100 rpm by an EM-type rotational viscometer and the shear thinning index are shown below. The numbers in the composition indicate parts by weight.

Example 1 Blue pigment 25.0 [manufactured by Sanyo Dyeing Co., Ltd., trade name: SS BLUE GLL] ethylene glycol 15.0 succinoglycan 0.3 (constituent monosaccharide is organic acid-modified hetero of glucose and galactose) Polysaccharide) 1,2-benzisothiazolin-3-one 0.1 [manufactured by Zeneca Corporation, trade name: Proxel XL-2] disodium phosphinate 0.3 water 59.3 total 100.0

The above composition is mixed, stirred at room temperature with a disper for 3 hours, and filtered to obtain a water-based ink composition for writing implements. The ink composition at 25 ° C.
The viscosity at 1 rpm by an EM-type rotational viscometer was 1,400 mPa · s, the viscosity at 10 rpm was 200 mPa · s, the viscosity at 100 rpm was 40 mPa · s, and the shear thinning index was 0.22.
It was 8.

Example 2 Red Dye 5.0 [manufactured by Eisen Co., Ltd., trade name: Phloxine, C.I. I. Acid Red 92, C.I. I. 45410] diethylene glycol 20.0 xanthan gum 0.3 nitrocarbonate 0.3 triethanolamine 0.3 disodium phosphonate 0.5 water 73.6 total 100.0

The above composition is mixed, stirred at room temperature with a disper for 3 hours, and filtered to obtain a water-based ink composition for writing implements. The viscosity of the ink composition at 1 rpm measured by an EM-type rotational viscometer was 1300 mP.
a · s and the viscosity at 10 rpm is 190 mPa
S and the viscosity at 100 rpm is 41 mPa
S and the shear thinning index was 0.249.

Example 3 Pink fluorescent pigment 40.0 [manufactured by Nippon Fluorescent Chemical Co., Ltd., trade name: Lumicol NKW-2117] glycerin 15.0 succinoglycan 0.3 (organic monosaccharide composed of glucose and galactose) Acid-modified heteropolysaccharide) Sodium omadin 0.3 [Permachem Co., Ltd., trade name: Topside 280] Dipotassium phosphinate 0.3 Water 44.1 Total 100.0 The aqueous ink composition for a writing instrument is obtained by stirring with a disper for 3 hours and filtering. The EM of the ink composition at 25 ° C.
The viscosity at 1 rpm by a rotary viscometer is 1200 m
Pa · s and the viscosity at 10 rpm is 144 mP
a · s and the viscosity at 100 rpm is 42 mP.
a · s, and the shear thinning index was 0.272.

Example 4 Aluminum paste 7.0 [Toyo Aluminum Co., Ltd., trade name: 96-2104] Glycerin 15.0 Succinoglycan 0.3 (Constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose.) Body) Sodium omadine 0.3 [Permachem Co., Ltd., trade name: Topside 280] EDTA amine salt 1.0 [Cyrest Co., Ltd., trade name: Cyrest M-50] α-cyclodextrin 0 [manufactured by Saltwater Port Sugar Co., Ltd., trade name: Dexipearl K-100] monosodium phosphinate 0.3 water 73.1 total 100.0

The above composition is mixed, stirred at room temperature with a disper for 3 hours, and filtered to obtain a water-based ink composition for writing implements. The ink composition at 25 ° C.
The viscosity at 1 rpm by an EM-type rotational viscometer was 1,400 mPa · s, the viscosity at 10 rpm was 205 mPa · s, the viscosity at 100 rpm was 44 mPa · s, and the shear thinning index was 0.249.
Met.

Comparative Example 1 A water-based ink composition for a writing implement was obtained in the same manner as in Example 1, except that the disodium phosphinate used in Example 1 was changed to water.

Comparative Example 2 An aqueous ink composition for a writing implement was obtained in the same manner as in Example 2, except that the disodium phosphonate used in Example 2 was changed to water.

Comparative Example 3 An aqueous ink composition for a writing instrument was obtained in the same manner as in Example 3, except that dipotassium phosphinate used in Example 3 was replaced with water.

Comparative Example 4 A water-based ink composition for a writing instrument was obtained in the same manner as in Example 4, except that the monosodium phosphinate used was changed to water.

According to the above-mentioned ink preparation method, inks of Examples and Comparative Examples were prepared, and a stainless steel tip holding a ball having a diameter of 0.5 mm was filled in a ballpoint pen refill fitted to one end of a polypropylene pipe. Further, after filling the ink backflow preventive body in close contact with the rear end face of the ink, the ballpoint pen refill was incorporated into a shaft cylinder to obtain a ballpoint pen.

The initial ballpoint pens obtained as described above and the ballpoint pens left at 50 ° C. for 60 days were visually inspected for the presence or absence of air bubbles in the ink storage tube and the state of the handwriting by a writing test. The results are shown below.

[0040]

[Table 1]

The criteria in the above table are as follows. Handwriting state ：: Good handwriting is obtained. ×: Scatter is seen in the handwriting.

[0042]

According to the ink composition of the present invention, since a phosphonate and / or a phosphinate are incorporated, air bubbles can be removed. Therefore, a writing instrument using the ink can have air bubbles over time. No ink is generated, the ink is smoothly led to the tip of the writing, stable writing performance can be maintained, and good handwriting can be continuously obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C350 GA03 GA04 GA05 GA06 HA08 HA14 HA15 KF03 NA10 4J039 AB01 AB02 AB11 AD03 AD05 AD06 AD08 AD10 AD14 AE04 AE08 AE11 BA04 BA06 BA13 BA18 BA35 BC08 BC09 BC25 BC35 BC38 BC54 BC60 BC79 BD02 BE01 BE03 BE04 BE05 BE12 CA03 CA06 DA01 DA02 EA44 GA27 GA28

Claims (5)

[Claims] 1. An aqueous ink composition for a writing implement comprising a phosphonate and / or a phosphinate in an aqueous ink composition comprising at least a colorant, water and a water-soluble organic solvent. 2. The aqueous ink composition for a writing implement according to claim 1, wherein the phosphonate and / or phosphinate is contained in the ink composition in an amount of 0.01 to 5% by weight. 3. The method according to claim 1, further comprising a shear thinning agent.
Or a water-based ink composition for a writing instrument according to 2 above. 4. The writing implement according to claim 3, wherein the ink viscosity at 100 rpm by an E-type rotational viscometer shows 20 to 200 mPa · s (25 ° C.) and the shear thinning index shows 0.1 to 0.8. Water-based ink composition. 5. A writing implement of the type in which an ink backflow preventive body that follows with the consumption of ink is arranged, wherein the writing implement is filled with the ink composition according to any one of claims 1 to 4.