JP2002030241A - Aqueous ink composition for ball-point pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous ink composition for ball-point pens, directly charged into an ink holder having a pen point attached to one end of the holder and a material for preventing the back flow of the ink, capable of maintaining a stable viscosity after stored for a long period, not causing the precipitation of a pigment, having good pigment dispersion stability, and a stable quality. SOLUTION: This ink composition which is used for ball-point pens and comprises a pigment and water, characterized by containing as a thickener a polysaccharide containing at least glucose, fucose, glucuronic acid and rhamnose as constituting monosaccharides.

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 ball-point pen which can be used for a writing instrument in which an ink and an ink backflow preventer are directly connected to an ink storage tube having a pen tip attached to one end, and which has been stored for a long time. The present invention also relates to an aqueous ball-point pen ink composition having little change in viscosity, no sedimentation of pigment, good dispersion stability and stable quality.

[0002]

2. Description of the Related Art In recent years, ball-point pens having both the advantages of an oil-based ball-point pen and the advantages of a water-based ball-point pen have been marketed by directly filling aqueous ink into an ink storage tube to which a pen tip is attached. In a ballpoint pen of this type, the ink is directly filled in the ink storage tube. Therefore, when the pen tip is turned downward, the ink easily leaks naturally from the pen tip. Therefore, in order to prevent this, it is necessary to increase the viscosity of the ink. In addition, improvement of water resistance of handwriting,
When a pigment is used as a coloring material to improve light resistance,
Higher viscosity inks have less sedimentation of the pigment and can be stored for a longer period of time. However, if the viscosity of the ink is high, the ink ejection property from the pen tip becomes poor, which is not preferable. Therefore, various water-soluble polymers have been proposed for the ink used in the water-based ballpoint pen, so that the ink viscosity is reduced by a high shearing force due to the rotation of the ball during writing so that the ink is discharged smoothly. ing. For example, a composition of xanthan gum (Japanese Patent Publication No. 64-8673), a composition of welan gum (Japanese Patent Application Laid-Open No. 4-214782), a composition of succinoglucan (Japanese Patent Application Publication No. 6-88050), and a combination of xanthan gum and locust bingham ( JP-A-2000-
No. 17217). However, xanthan gum has the property of making the dispersion of the pigment somewhat unstable,
When used in a pigment dispersion system for a long time, the pigment may gradually settle due to dispersion destruction. In addition, when xanthan gum is used alone, its thickening effect is insufficient, so it is necessary to add a large amount, and as a result, there is a problem that the addition amount of other components is restricted, and it has been stored for a long time. If
The viscosity of the ink decreases, causing ink leakage, the pigment sedimentation resulting in non-uniform handwriting density during writing, and the sedimented pigment clogs the pen tip, resulting in poor ink followability. Or writing becomes impossible. On the other hand, when locust bean gum is used alone, the effect of thickening is insufficient with a small amount.
In addition, when used in a large amount, there is a risk that the viscosity increases and the ink fluidity is lost. In addition, locust bean gum is generally insoluble in cold water and must be dissolved in hot water, and a strict temperature adjustment is required because a significant difference occurs in viscosity depending on the water temperature during dissolution. Therefore,
There are problems that the ink production becomes complicated and the viscosity of the produced ink becomes unstable. It is difficult for welan gum to maintain the dispersion stability of the pigment, which is a coloring agent, for a long period of time. In some cases, the ink may be clogged, or in a severe case, clogging of the ink may occur at the pen tip due to aggregation of the pigment, making it impossible to write. Similarly, after storing an aqueous ballpoint pen using succinoglucan for a long period of time, the dispersion state of the pigment deteriorates, so when writing, the lightening of the handwriting and conversely the excessive darkening phenomenon occurs, Is clogged.
Therefore, it is still difficult to maintain the dispersion stability of the pigment in the aqueous ballpoint pen using the water-soluble polymer as described above during storage for a long period of time, due to sedimentation of the pigment and aggregation of the viscosity modifier, There are problems such as poor ink followability at the time of writing, heavy writing, fuzziness, and inability to write.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to maintain the viscosity of the ink stably without aggregation of the viscosity modifier even after storage for a long period of time, and without sedimentation of the pigment. An object of the present invention is to provide an aqueous ballpoint pen ink composition having good and stable quality.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on an ink composition for an aqueous ball-point pen containing a pigment, and as a result, formulated a specific polysaccharide-based thickener into the ink composition for an aqueous ball-point pen. By doing so, it was found that an ink composition for a water-based ballpoint pen, which maintains ink viscosity stably, has no sedimentation of pigment, has high ink fluidity, and is excellent in writing quality, has completed the present invention.

[0005] That is, the invention of claim 1 is an aqueous ballpoint pen ink composition comprising at least glucose, fucose, glucuronic acid, a polysaccharide having rhamnose as a constituent monosaccharide, a pigment, and water. .

According to a second aspect of the present invention, in the ink composition for an aqueous ballpoint pen according to the first aspect, the constituent monosaccharides of the polysaccharide are in a molar ratio of fucose: glucose: glucuronic acid: rhamnose = 1: 2: 1-4. : 1-2: 1-2.

According to a third aspect of the present invention, in the ink composition for an aqueous ballpoint pen according to the first aspect, the polysaccharide forms a main chain of glucose, glucuronic acid, and rhamnose, and fucose is bonded to a side chain. A polysaccharide having a certain structure.

According to a fourth aspect of the present invention, there is provided the ink composition for water-based ballpoint pens according to any one of the first to third aspects, wherein the polysaccharide is Alkaline genostras B-16.
It is characterized by being a polysaccharide produced by a strain.

Hereinafter, the present invention will be described in detail.

The polysaccharide used in the ink composition for an aqueous ballpoint pen of the present invention is a polysaccharide substantially containing fucose, glucose, glucuronic acid and rhamnose as constituent monosaccharides, and is preferably represented by the general formula (1). It is a polysaccharide having a repeating chain main chain composed of glucose, glucuronic acid, and rhamnose, and having a structure in which one fucose is branched into one glucose.

[0011]

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The polysaccharide of the present invention is generally obtained as a microorganism-produced polysaccharide. Generally, microorganisms often produce two or more kinds of polysaccharides. Therefore, even if other microorganisms are contained in addition to the polysaccharide used in the present invention, the effect of the polysaccharide of the present invention is hindered. If not, it does not preclude the inclusion of other polysaccharides.

[0013] The microorganism producing the polysaccharide of the present invention is not particularly limited.
Laterus B-16 strain bacteria (FERM BP-2015)
No.).

The compounding amount of the polysaccharide of the present invention is 0.001 to 0.5% by weight, preferably 0.005 to 0.1% by weight in the aqueous ink composition for ballpoint pens. If the blending amount is less than 0.001% by weight, the blended effect cannot be obtained. If the blending amount is more than 0.5% by weight, the effect can be improved, but the effect corresponding to the blending amount can be improved. In some cases, there are few economic benefits.

The polysaccharide of the present invention comprising at least glucose, fucose, glucuronic acid and rhamnose as constituent monosaccharides has a higher viscosity in a small amount and a higher viscosity than conventional synthetic thickeners and natural thickeners. Thixotropy, high water retention and sustained release of water in accordance with the surrounding environment, small effects on viscosity even with the presence of inorganic substances and inorganic salts, small temperature effects on viscosity, and stable viscosity Due to its characteristics, the polysaccharide is used in the aqueous ballpoint pen ink composition of the present invention to improve the dispersion stability and aging stability of dyes, pigments, resin emulsion colorings, etc. This leads to improved stabilization of changes in viscosity. As a result, long-term storability, especially improvement in storage stability in summer, prevention of clogging at the tip of the ink for water-based ball-point pens and improvement of ejection stability, improvement of printing unevenness and color density or bleeding of printed matter, High printing quality such as improved drying of characters can be realized.

The production of the polysaccharide of the present invention is carried out, for example, in the case of Alcaligenes L. strain B-16 bacteria as follows.

Alkagenes strain B-16 bacteria are cultivated by a conventional method for culturing microorganisms. For example, monosaccharides such as fructose, glucose and sucrose, natural polymers such as hemicellulose, starch and corn starch, and olive Oils such as fats and oils, nitrogen sources such as urea, ammonium chloride, ammonium nitrate, inorganic nitrogen sources such as ammonium sulfate, tripton, yeast extract, meat extract, peptone, malt extract, etc. Initial p using a medium supplemented with inorganic salts such as magnesium sulfate and sodium chloride
The aeration and agitation liquid culture is performed for 3 to 10 days at H of 4 to 10 and a culture temperature of 15 to 40 ° C. After the culture, about twice (volume) or more of an organic solvent such as acetone, ethanol, isopropyl alcohol and the like is added to the culture solution, and the culture product is collected as insoluble aggregates.

It has been confirmed that at least two types of polysaccharides are contained in the polysaccharides produced by the Alcaligenes strain B-16 bacterium, and one of the polysaccharides is represented by the above formula ( A polysaccharide having a structure in which one fucose is branched from one glucose in a repeating structure comprising glucose, glucuronic acid, and rhamnose as shown in 1), and the other is represented by the following formula (2): Is a polysaccharide having a repeating structure substantially consisting of fucose and mannose as constituent monosaccharides [see Abstracts of 1998 Annual Meeting of the Japanese Society of Agricultural Chemistry, page 371]. Y. Nohata, J .; Azu
ma, R .; Kurane, Carbohydrate
Research 293 , (1996) 213-22
2).

[0019]

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Even if the polysaccharide represented by the general formula (2) is contained in the polysaccharide of the general formula (1) which is the polysaccharide of the present invention, its effect is not impaired. Without removing the polysaccharides shown
Polysaccharides produced by -16 strain bacteria can be used.

The use of the polysaccharide of the present invention as a mixture with other water-soluble polymers is not impaired as long as the effects of the polysaccharide are not impaired. For example, natural polysaccharides such as pullulan, xanthan gum, welan gum, ramzan gum, guar gum, locust bean gum, pectin, gelatin, casein, starch, cationic starch, dextrin, sodium starch glycolate, and derivatives thereof, and cellulose derivatives. Hydroxyethyl cellulose, carboxymethyl cellulose (CMC),
Hydroxypropylcellulose and the like and derivatives thereof, synthetic polymer polyvinyl alcohol (PVA), polyvinylpyrrolidone, polyvinyl ether, sodium poly (meth) acrylate, polyethylene oxide, methoxyethylene maleic acid copolymer, and the like can be used.

The pigment used in the present invention is used as a main colorant, and those conventionally used in aqueous ballpoint pen ink compositions can be used. Specifically, inorganic pigments such as carbon black, titanium oxide, cobalt blue, iron oxide, ultramarine, navy blue, etc., organic pigments, aluminum powder, gold powder, silver powder, copper powder, tin powder, metal powder pigments such as brass powder, Fluorescent pigments, mica pigments and the like can be used. Further, an aqueous ball-point pen ink composition base of a dispersed pigment obtained by dispersing a pigment in an aqueous medium can also be used.
These can be used alone or in combination.

Further, water is used as a main solvent.

In addition to the above components, various additives conventionally used in aqueous ballpoint pen ink compositions can also be used. For example, prevention of ink drying of the pen tip,
A water-soluble organic solvent may be added for the purpose of preventing freezing of the ink at a low temperature. Specifically, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, 1,3-butylene glycol, thiodiethylene glycol, 1,5-pentanediol, and glycerin; One or more kinds of monomethyl ether, diethylene glycol monomethyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, triethanolamine and the like can be used as a mixture.

In addition, a resin may be added for improving the fixability of the ink on the surface to be written. Examples of the resin include a styrene-acrylic resin emulsion, an acrylic resin emulsion, a styrene-butadiene resin emulsion, an alkali-soluble resin, and a betaine acrylic resin.

Further, conventionally known acid dyes, basic dyes,
A water-soluble dye such as a direct dye can also be used as a complementary colorant. In addition, various additives such as benzothiazoline and omazine preservatives, rust inhibitors such as benzotriazole and various chelating agents, anionic and nonionic surfactants, defoamers and dispersants are also used. it can.

The production of the ink composition for water-based ballpoint pens of the present invention is not particularly limited, and may be carried out by various conventional methods. For example, the above-mentioned components may be mixed with a turbo mixer or a Henschel mixer. It can be easily obtained by stirring and mixing with a stirrer and mixing and grinding with a disperser such as a ball mill.

The ink composition for aqueous ballpoint pens according to the present invention contains at least glucose, fucose, glucuronic acid, and a polysaccharide containing rhamnose as a monosaccharide as a viscosity modifier, whereby the thixotropic property of the ink is improved. As a result, the ink viscosity is stable even when stored for a long period of time, and sedimentation of the pigment can be prevented. Therefore, even if the pen tip is turned down and left as it is after the ballpoint pen is formed, it is possible to prevent the handwriting from being frayed due to the sedimentation of the pigment on the pen tip and to prevent writing.

[0028]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. (Polysaccharides) A-1: According to the method of JP-A-2-291292, Alkaline Genestras strain B-16 (FERM B)
P-2015), and after completion of the culture, about 3
Add twice the volume of isopropyl alcohol, stir and mix,
The precipitated aggregate was filtered and collected, and dried under reduced pressure to obtain polysaccharide A-1. A-2: According to the method disclosed in JP-A-5-301904, Alkaline Genestras B-16 strain (FERM B)
P-2015), 4,000 ml of ion-exchanged water was added to 1,000 ml of the culture, and p-
Prepared to H12. Then Diaion HPA-75
(OH -) ^(Nippon Rensui Co., Ltd.) in a column of 1,000ml performs processing at 8 resin capacity below multi removing the polysaccharide represented by the general formula is a low-molecular component (2) saccharides A- 2
I got A-3: Polysaccharide produced according to Japanese Patent Application No. 2000-41122 (“INCINAME: Alcalage”)
Nes Polysaccharides "(manufactured by Hakuto K.K.) (Others) Aluminum paste:" WXMU75 "trade name, aluminum powder content 60% by weight, Toyo Aluminum Co., Ltd.
Titanium oxide: "Kronos KR380" (trade name) (manufactured by Titanium Industry Co., Ltd.) Colorant-1: "EM Green G" (trade name), green dispersion pigment, 44% by weight of nonvolatile matter (Toyo Ink Co., Ltd.)
Colorant-2: "NKW-2107" (trade name), pink fluorescent pigment, non-volatile content 53% by weight (manufactured by Nippon Fluorescent Chemical Co., Ltd.) Colorant-3: "NKW-2167" (trade name), Purple fluorescent pigment, nonvolatile content 54% by weight (Nippon Fluorescent Chemical Co., Ltd.)
Resin emulsion-1: "Johncryl 450" (trade name), styrene-acrylic resin emulsion (manufactured by Johnson Polymer Co., Ltd.) Resin emulsion-2: "Movinyl DM774" (trade name), acrylic resin emulsion (Hoechst Gosei Co., Ltd.) Resin aqueous solution-1: "John Krill 61J" (trade name),
Ammonium salt of styrene-acrylic acid ester copolymer (manufactured by Johnson Polymer Co., Ltd.) Dispersant-1: Mixture of oleic acid ester of polyoxyethylene diglycerin borate and oleic acid ester of diglycerin borate Dispersion Agent-2: Polyoxyethylene diglycerin borate laurate dispersant-3: "TL10" (trade name) (manufactured by Nikko Chemicals Co., Ltd.) Preservative: 1,2-benzoisothiazolin-3-one ( "Proxel GXL" (trade name) (manufactured by ICI Japan) Defoaming agent: "formclean S" (trade name), silicone emulsion (manufactured by Hakuto Co., Ltd.) Xanthan gum: "Roadpol 23" (trade name) (Rhone Poulin Japan Co., Ltd.) Locust Bean Gum: "Mayprodin 200" (Trade name) (manufactured by May Hall Chemical Co., Ltd.) (Example 1) Polysaccharide A-1 and water were mixed in the following formulation 1 to prepare a dispersion of polysaccharide A-1, and other components were added thereto. Was dispersed with a turbo mixer for 5 minutes, further stirred with a propeller stirrer for 30 minutes, and further subjected to a centrifugal defoamer to remove fine bubbles, thereby obtaining a glossy green ink.

(Formulation 1) Aluminum paste 6.0 parts by weight Colorant-1 12.0 parts by weight Water 64.2 parts by weight Ethylene glycol 6.0 parts by weight Glycerin 6.0 parts by weight Polysaccharide A-1 0.4 Parts by weight Resin emulsion-1 4.0 parts by weight Preservative 0.2 parts by weight Dispersant-1 1.0 part by weight Antifoaming agent 0.2 parts by weight (Example 2) Produced in a similar manner to obtain a glossy pink ink.

(Formulation 2) Aluminum paste 4.0 parts by weight Colorant-2 11.0 parts by weight Water 62.4 parts by weight Propylene glycol 15.0 parts by weight Glycerin 5.0 parts by weight Polysaccharide A-1 0.4 Part by weight Resin emulsion-2 1.0 part by weight Preservative 0.2 part by weight Dispersant-2 1.0 part by weight (Example 3) In the following Formulation 3, the same preparation as in Example 1 was carried out to produce a gloss. A pink ink was obtained.

(Formulation 3) Aluminum paste 4.0 parts by weight Colorant-2 11.0 parts by weight Water 62.4 parts by weight Propylene glycol 15.0 parts by weight Glycerin 5.0 parts by weight Polysaccharide A-2 0.4 Part by weight Resin emulsion-2 1.0 part by weight Preservative 0.2 part by weight Dispersant-2 1.0 part by weight (Example 4) In the following formulation 4, it was produced in the same manner as in Example 1 to obtain a gloss. A pink ink was obtained.

(Formulation 4) Aluminum paste 4.0 parts by weight Colorant-2 11.0 parts by weight Water 62.4 parts by weight Propylene glycol 15.0 parts by weight Glycerin 5.0 parts by weight Polysaccharide A-3 0.4 Parts by weight Resin emulsion-2 1.0 part by weight Preservative 0.2 parts by weight Dispersant-2 1.0 part by weight (Example 5) In the following Formulation 4, using a ball mill instead of the turbo mixer of Example 1 Except for performing the time dispersion treatment, the ink was manufactured in the same manner as in Example 1 to obtain a glossy purple ink.

(Formulation 5) Titanium oxide 20.0 parts by weight Colorant-3 10.0 parts by weight Water 50.3 parts by weight Ethylene glycol 5.0 parts by weight Glycerin 5.0 parts by weight Polysaccharide A-1 0.5 Parts by weight Resin aqueous solution-1 7.0 parts by weight Dispersant-4 2.0 parts by weight Preservative 0.2 parts by weight (Comparative Example 1) Except that the total amount of polysaccharide A-1 of Example 1 was changed to xanthan gum In the same manner as in Example 1, a glossy green ink was obtained. Comparative Example 2 A glossy green ink was obtained in the same manner as in Example 1 except that 0.4 parts by weight of polysaccharide A-1 and 0.4 parts by weight of water were changed to xanthan gum. Was. Comparative Example 3 A glossy green ink was obtained in the same manner as in Example 1 except that the polysaccharide A-1 in Example 1 was changed to 0.32 g of xanthan gum and 0.08 g of locust bean gum. (Comparative Example 4) Same as Example 1 except that 0.4 parts by weight of polysaccharide A-1 and 0.2 parts by weight of water in Example 1 were changed to 0.45 g of xanthan gum and 0.15 g of locust bean gum. Thus, a glossy green ink was obtained. Comparative Example 5 A glossy pink ink was prepared in the same manner as in Example 2 except that 0.4 parts by weight of the polysaccharide A-1 and 0.2 parts by weight of water in Example 2 were changed to 0.6 g of welan gum. I got (Comparative Example 6) A purple ink was prepared in the same manner as in Example 3 except that 0.4 parts by weight of polysaccharide A-1 and 0.2 parts by weight of water in Example 4 were changed to 0.6 g of locust bean gum. Obtained.

The aqueous ink compositions for ballpoint pens obtained from Examples 1 to 4 and Comparative Examples 1 to 4 were tested. The test method is as follows. (Stability Evaluation Test: Ink Viscosity) The ink composition for aqueous ball-point pens prepared by the above method and the viscosity after being left closed for 6 months at room temperature were measured under the following conditions.・ Measurement temperature: 25 ° C. ・ Viscometer used: E-type viscometer (manufactured by Tokimec Co., Ltd.) ・ Rotor used: ST ・ Rotor rotation speed: 1 rotation / min The results are shown in Table 1. (Stability evaluation test: writing test) Using “Hybrid K105” (trade name) manufactured by Pentel Co., Ltd., ink storage in a hollow hollow cylinder made of transparent polypropylene connected to a stainless steel ballpoint pen tip (ball material: cemented carbide). A tube was filled with the ink composition for an aqueous ballpoint pen of the present invention, and filled with an ink backflow preventer to prepare a ballpoint pen for a writing test. Using this ballpoint pen for writing test, put one eye on the commercially available copy paper.
Fifty characters were written, and the number of writable characters without blurring was confirmed. After the test, the ballpoint pen was left for 6 months at room temperature with the tip of the ballpoint pen facing down. Six months later, a similar writing test was performed again. When 150 characters were written and writing was possible without blurring, "150" was described. In the case of less than 150 characters, the writing was cut off in units of 10 characters and evaluated as the number of writing characters. The test results are shown in Table 1.

[0035]

[Table 1]

[0036]

The ink composition for water-based ballpoint pens of the present invention maintains a stable viscosity even after long-term storage, so that there is no sedimentation of the pigment and no decrease in the number of characters that can be written without causing blurring. It is a water-based ink composition for ballpoint pens having high quality.

Claims (4)

[Claims] 1. A polysaccharide having at least glucose, fucose, glucuronic acid and rhamnose as constituent monosaccharides, a pigment,
An aqueous ink composition for a ballpoint pen, comprising water. 2. The constituent monosaccharides of the polysaccharide are fucose: glucose: glucuronic acid: rhamnose = 1 to 2:
The ink composition for an aqueous ball-point pen according to claim 1, wherein the ratio is 1 to 4: 1 to 2: 1 to 2. 3. The polysaccharide is glucose, glucuronic acid,
The aqueous ballpoint pen ink composition according to claim 1, which is a polysaccharide having a structure in which a main chain is composed of rhamnose and fucose is bonded to a side chain. 4. The method according to claim 1, wherein the polysaccharide is alkaligenes latus.
The aqueous ballpoint pen ink composition according to any one of claims 1, 2, 3 and 4, which is a polysaccharide produced by the B-16 strain.