JP3037522B2 - Water-based ballpoint pen ink and water-based ballpoint pen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink used for a water-based ballpoint pen for directly storing ink in an ink container, and more particularly to an ink for a water-based ballpoint pen containing xanthan gum and an improvement of the water-based ballpoint pen.

[0002]

2. Description of the Related Art Conventionally, an ink used for a water-based ballpoint pen that directly stores ink in an ink container, that is, a ballpoint pen that does not have a relay induction core hardened with fibers, is considered to impart thixotropy, plasticity, coagulation, and the like. Have been. The addition of these properties not only prevents shortage or breakage of the line that can not be written due to an insufficient supply of ink during continuous writing, and also prevents writing from being performed on the writing surface due to excessive supply of ink. To suppress the bleeding phenomenon that spreads in an irregular shape in the width direction. One of the most effective examples of imparting plasticity or coagulation to ink based on this idea is Japanese Patent Publication No.
4-8673 and JP-B-1-16437. This is xanthan gum 0.20 to 0.4
The addition of 5% by weight gives the ink a coagulating viscosity.

[0003] In the follow-up test of the prior art by the present inventors, as can be seen in the text of the patent, 0.30-0.
The addition of 40% by weight shows the most favorable co-plastic viscosity. Defining the most preferable co-plastic viscosity by the experiments of the present inventors is as follows: Toki Sangyo Co., Ltd. E type viscometer (ELD, EMD, EHD, etc.)
When measured with a standard cone (1'34 ') / plate of
At 0 revolutions (about 38 sec ^-1 ), the range is 100 to 400 mPa · sec, and at 100 revolutions (about 38 sec ^-1 ), 30 to
The viscosity indicates a range of 60 mPa · sec. When the viscosity at 10 rotations is less than 100 mPa · sec, the ink is excessively supplied at the time of writing, and the effect of suppressing the backflow of the ink at the time of writing is small. Viscosity at 10 rotations is 400mPa · se
If it exceeds c, the ink supply will be insufficient during writing, and it will be easy to cause blurring and line skipping. In particular, it is remarkable at a writing speed of 10 cm / sec or more (about a straight line using a ruler). If the viscosity at 100 rotations is less than 30 mPa · sec, the ink may be excessively supplied during writing. However, if the viscosity setting at low rotation is appropriate, it is often not a problem. Viscosity at 100 rotations is 60 mPa · se
If the value exceeds c, surplus ink accumulates at the pen tip, and the ink drops and stains the paper surface, so-called "bottom" and "dropping" phenomena occur. These experiments by the present inventors are described in
It does not contradict the viscosity data described in JP-A-8673 or the like.
20-0.45% by weight is considered a reasonable setting. However, aqueous ball-point pens filled with an ink containing xanthan gum often have poor writing characteristics such as line breaks, bleeding, and bleeding when stored at room temperature for six months to one year. bad. A possible reason for this is that xanthan gum is an ionic polysaccharide, and as described in JP-B 64-8673 and JP-B 1-16437, xanthan gum is 0.2 to 0.45% by weight, or US Patent No. 5,01
When used at a high concentration of 0.7 to 6% by weight as in JP-A-3,361, it reacts with the ionic material in the ink and adversely affects the temporal stability of the ink.

That is, when a large amount of an ionic polysaccharide such as xanthan gum is used, for example, in an ink system using a pigment, aggregation and sedimentation of the pigment are caused, and in the worst case, a pen cannot be written on a writing surface. It becomes impossible to write.
Even with inks using dyes, since most water-soluble dyes are ionic, there is a concern that precipitation and precipitation of crystals may occur. Further, an ionic compound such as a rust inhibitor, a fungicide, and a lubricant is added to the aqueous ballpoint pen ink. These are selected from those that do not react with the dye or those that do not easily react during the process of developing a long aqueous ink. However, it is not guaranteed that it does not easily react with ionic polysaccharides such as xanthan gum. Therefore, it is necessary to select an ink material that does not easily react with ionic polysaccharides such as xanthan gum.However, it is very difficult to satisfy the performance required for ink, such as writing quality, initial brushability, and line fastness. is there.

[0005] On the other hand, it is considered that there is no problem in storage over time if the ink is thickened by using a nonionic polysaccharide alone. However, specifically, nonionic polysaccharides such as guar gum and locust bean gum have a high viscosity at high shear rates when added in large amounts, and lack viscosity at low shear rates when added in small amounts to be effective. No cohesive plasticity is obtained.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to improve the stability over time, which is a drawback of an aqueous ballpoint pen ink using xanthan gum. .

[0007]

DISCLOSURE OF THE INVENTION As a result of studies, the present inventors have found that the use of specific amounts of nonionic polysaccharides such as xanthan gum and guar gum eliminates the disadvantages of xanthan gum and improves the storage performance of ink. As a result, the ink for aqueous ballpoint pens and the aqueous ballpoint pen of the present invention have been completed.

That is, the present invention resides in the following (1) to (3). (1) In an aqueous ballpoint pen ink containing a colorant, a water-soluble organic solvent, and water, 0.2% by weight or less of xanthan gum and 0.01 to 0.
An aqueous ball-point pen ink containing 5% by weight. (2) The aqueous ballpoint pen ink according to the above (1) or (2), wherein the nonionic polysaccharide is at least one selected from guar gum and derivatives thereof. (3) An aqueous ballpoint pen comprising the ink for an aqueous ballpoint pen according to (1) or (2).

The xanthan gum used in the ink of the present invention is a general name called xanthan gum or suntan gum, and is a polysaccharide produced by Zanthomonas or Campetris isolated from cabbage. Usually, it is a high molecular weight polysaccharide formed by repeating a binding block having two glucoses, two mannoses and one glucuronic acid as constituent units, and glucuronic acid is usually present as a potassium, sodium or calcium salt. The main chain is the same as cellulose at the β-1,4-linkage of D-glucose, and the side chain is composed of two mannoses and one glucuronic acid. Specifically, "KELZ
AN "(trade name of Sanshin Co., Ltd.)," Echo Gum "(trade name of Dainippon Pharmaceutical Co., Ltd.)," Kojin "(trade name of Kojin Co., Ltd.), etc. If the content exceeds 0.2% by weight, it reacts with other ionic ink materials and impurities thereof to cause gelation and formation of crystalline precipitates, which is not preferable. The nonionic polysaccharides used in the ink include guar gum, guar gum derivatives, locust bean gum, etc. Guar gum, also called girl gum, is a mucilage material contained in the embryo part of the seeds of the guar seeds of the leguminous plant guar. Molecular weight: about 20,000, 80% of the composition is D-galactose and D-mannose, 5% protein, 1% fiber, 1% ash, D
-Galactose: D-mannose = 1: 2. Specifically, for example, as guar gum, "guar call"
[San-ei Pharmaceutical Trading Co., Ltd. brand name], "Guapack PM-
1 "," PF-20 "," PC-2 "," T-80 "
[Dainippon Pharmaceutical Co., Ltd. brand name], “JAGUAR CP-
13 "," 8060 "," 8111 "," 8600 "
[Sansei Co., Ltd.], Locust Bean Gum as locust bean gum [San-ei Pharmaceutical Trading Co., Ltd.],
And the like. As a mixture of xanthan gum and guar gum, "MINIT PS" (trade name of Dainippon Pharmaceutical Co., Ltd.) and the like can also be mentioned. The amount used is 0.01 in the ink.
When the amount is less than 0.01% by weight, there is no increase in viscosity due to a synergistic effect with xanthan gum, and the amount is 0.1% by weight.
If it exceeds 5% by weight, the viscosity at a high shear rate increases, which is not preferable.

[0010] In the ink of the present invention, xanthan gum and nonionic polysaccharide are dissolved.
At least 40% by weight of water is required, preferably at least 40% by weight.

The water-soluble organic solvent used in the ink of the present invention includes ethylene glycol, diethylene glycol,
Propylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol, glycerin, diglycerin, 2-pyrrolidone, n-methyl-2-
Examples include pyrrolidone, dimethylformamide, and dimethylimidazolidinone, and one or more selected from these are used.

The coloring agent used in the ink of the present invention may be CIACID YELLOW 1, CIACID RED 27, CIACI
D ORANGE 10, CIACID GREEN 16, CIACID BLUE 9,
CIACID VIOLET 49, FOOD RED 1, FOOD YELLOW 3, FOO
D GREEN 3, FOOD BROWN 3, CIACID BLACK 2, CIACI
Acid dyes such as D BLUE 90, CIBASIC YELLOW 2, CI
Basic dyes such as BASIC RED 1 and CIBASIC BLACK 2;
CIDIRECT YELLOW 1, CIDIRECT ORANGE 29, CIDIR
ECT RED 1, CIDIRECT RED 81, CIDIRECT BLUE 1,
CIDIRECT BLUE 168, CIDIRECT GREEN 1, CIDIREC
T BROWN 2, CIDIRECT BLACK 22, CIDIRECT BLACK 1
And direct dyes such as 54. Inorganic pigments include carbon black, titanium white, titanium black, zinc white, red iron oxide, chromium oxide, iron black, cobalt blue, alumina white, iron oxide yellow, viridian, zinc sulfide, lithoposhi, cadmium yellow, vermilion, gadmium red. , Graphite, molybdenum orange, zinc chromate, strontium chromate, white carbon, clay, talc, ultramarine, sedimentable barium sulfate, barite powder, calcium carbonate, lead white, navy blue, manganese violet, aluminum powder, brass powder, etc. be able to. As organic pigments, CIPIGMENT YELLOW 34, C.
I.PIGMENT RED 104, CIPIGMENT BLUE 27, CIPIGMEN
T VIOLET 1, CIPIGMENT YELLOW 3, CIPIGMENT ORAN
GE 16, CIPIGMENT 23 and the like. These colorants are used alone or in combination of two or more.

The following additives can be added to the ink of the present invention as needed. Preservatives such as ammonia, urea, monoethanolamine, diethanolamine, triethanolamine, sodium tripolyphosphate, alkali metal salts of carbonic acid or phosphoric acid such as sodium carbonate, hydroxides of alkali metal such as sodium hydroxide, etc. As antifungal agents, phenol,
Sodium omazine, sodium pentachlorophenol, 1,2-benzisothiazoline 3-one, 2,3,
Benzotriazole and dicyclohexylammonium nitrite as rust inhibitors such as 5,6-tetrachloro-4 (methylsulfonyl) pyridine, alkali metal salts of benzoic acid such as sodium benzoate, sorbic acid and dehydroacetic acid, and benzimidazole compounds , Diisopropylammonium nitrite, tolyltriazole, etc., as a lubricant or wetting agent, such as polyoxyethylene lauryl ether, such as polyoxyethylene or polyoxypropylene or a derivative of polyoxyethylene polyoxypropylene, tetraglyceryl distearate; Glycerin or polyglycerin derivatives, sorbitan derivatives such as sorbitan monooleate,
Surfactants having a fluorinated alkyl group such as a perfluoroalkyl phosphate, polyether modified silicones such as a polyethylene glycol adduct of dimethylpolysiloxane, and the like. When a pigment is used as a coloring agent, the surfactant exemplified as the above-mentioned wetting agent also has a function as a dispersion stabilizer, but alkylated sulfonates of higher fatty acid amides, alkyl allyl sulfonates, etc. Anionic surfactants, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid,
It is preferable to use a water-soluble polymer such as an acrylic acid copolymer, an acrylic methacrylic acid-based resin, a styrene acrylic resin, a maleic acid resin, and a styrene maleic acid resin as a dispersant.

In the production of the ink of the present invention, no particular attention should be paid to the production method of other water-based ballpoint pen inks. Absent. A simple method for producing the ink of the present invention will be exemplified below. First, when using a dye as a coloring agent, water and a water-soluble organic solvent are mixed at room temperature, and in this case, xanthan gum and a nonionic polysaccharide are added to the solvent and dissolved until the mixture becomes uniform. Next, a dye and optional additives are added. In some cases, it is preferable to add the pH adjuster before the dye, but in general, the blending order does not affect the ink performance. Since the ink of the present invention is used for an aqueous ballpoint pen having a simple structure as shown in FIG. 1, the compounding agent is uniformly dissolved or dissolved so as to prevent clogging around the ball of the pen tip when undissolved matter or dust is mixed. After dispersing, it is desirable to filter. Filtration using ordinary filter paper or filtration under reduced pressure may be used, but pressure filtration is considered to be the most efficient in industrial production. Either one does not affect ink performance. If a filter aid such as celite is used, filtration can be performed more efficiently.

When a pigment or a dye and a pigment are used in combination as a colorant, the preparation procedure is somewhat restricted. This is because the molecular chain of the polysaccharide to be added may be cut by the shearing force applied when dispersing the pigment. In order to avoid this, an ink is prepared, for example, by the following method. To water and a water-soluble organic solvent, a dispersing agent, a pigment, and if necessary, a part or all of additives other than the polysaccharide are added. At this time, the total amount of water and the water-soluble organic solvent is not used in the final blending amount, but the blending amount is such that the pigment can be dispersed most efficiently in the disperser used, such as a three-roll mill, a bead mill, or a kneader. After uniformly dispersing in a disperser, after removing coarse particles and undissolved matter and contaminated solid matter of the pigment by centrifugation or filtration, the remaining water and additives are added, xanthan gum and a nonionic polysaccharide are added, Stir until uniform to obtain ink. Finally, it is preferable to filter once again to remove coarse solids.

In the ink of the present invention, by using a nonionic polysaccharide, a thickening effect can be obtained by a synergistic effect with xanthan gum, and the amount of added xanthan gum can be reduced. Therefore, it is considered that ionicity, which is a disadvantage of xanthan gum, can be used to remove the adverse effect on the ink preservation performance, and that an advantage of using a small amount of the resin can make use of appropriate coagulation properties, thereby obtaining the effects of the present invention.

The water-based ink for a ballpoint pen of the present invention configured as described above is suitably used, for example, in a ballpoint pen having a structure as shown in FIG. That is, the configuration of the ballpoint pen shown in FIG. 1 will be briefly described. 1 is a cap, 2 is a pen tip sealing rubber provided in the cap, 3 is a pen tip, 4 is a ball, 5 is a pen tip 3 Reference numeral 6 denotes a ballpoint pen shaft portion, 7 denotes an ink storage tube, 8 denotes an ink for an aqueous ball-point pen of the present invention filled in the ink storage tube 7, 9 denotes an ink follower, and 10 denotes a tail plug.

[0018]

Next, the present invention will be described in detail with reference to examples.

Example 1 Black dye "Water Black 187" (trade name of Orient Chemical Co., Ltd.) 7 parts by weight propylene glycol 30 xanthan gum [trade name of "KELZAN" Sansei Co., Ltd.] 0.15 guar gum "Guacoal" (San-Ei) 0.15〃 potassium oleate 0.5〃 sodium omadine 0.1 ジ ン urea 1〃 water 61.1 撹 拌 After stirring the above mixture, the mixture was filtered to obtain an aqueous ballpoint pen ink.

Example 2 Black dye “Water Black 187” (trade name of Orient Chemical Co., Ltd.) 7 parts by weight propylene glycol 30 カ リ ウ ム potassium oleate 0.5 ナ ト リ ウ ム sodium omadine 0.1 タ ン xanthan gum [“KELZAN” Sansei Co., Ltd. Name) 0.1 Locust Bean Gum “Locust Coal” (trade name of Sanei Pharmaceutical Trading Co., Ltd.) 0.1 urea 1 〃 water 62.2 撹 拌 The mixture was stirred and filtered to obtain an aqueous ballpoint pen ink.

Example 3 7 parts by weight of carbon black "PRINTEX 25" (trade name of Tegusa) polyvinylpyrrolidone "PVP K-30" (trade name of GAF) 3.5 glycerin 10 triethanolamine 0.3 potassium ricinoleate 0.5 １，２ 1,2-Benzisothiazolin 3-one 0.1 〃 Water 30 〃 After kneading with a bead mill, coarse particles of carbon black are removed. Propylene glycol 15 parts by weight Xanthan gum, guar gum mixture “MINIT PS” (Dainippon Pharmaceutical ) Trade name) 0.2 〃 water 33.4 〃 was added to obtain an aqueous ballpoint pen ink.

Comparative Example 1 Black dye (same as in Example 1) 7 parts by weight Propylene glycol 30 30potassium oleate 0.5 0.5sodium omazine 0.1〃urea 1〃water 61.4〃 Obtained.

Comparative Example 2 Black dye (same as in Example 1) 7 parts by weight Propylene glycol 30 guar gum (same as in Example 1) 0.3 potassium oleate 0.5 sodium omazine 0.1 urea 1 water 61.1 The mixture was stirred and filtered to obtain an ink.

Comparative Example 3 Black dye (same as in Example 1) 7 parts by weight Propylene glycol 30 〃 Xanthan gum (same as in Example 1) 0.3 カ リ ウ ム Potassium oleate 0.5 ナ ト リ ウ ム Sodium omazine 0.1 〃 Urea 1 〃 Water 61.1 〃 The mixture was stirred and filtered to obtain an ink.

Comparative Example 4 Carbon black (same as in Example 3) 7 parts by weight Polyvinylpyrrolidone (same as in Example 3) 3.5 〃 glycerin 10 ト リ triethanolamine 0.3 カ リ ウ ム potassium ricinoleate 0.5 〃 1,2-benzisothiazoline 3- ON 0.1% Water 30% or more was kneaded with a bead mill, coarse particles of carbon black were removed, and propylene glycol 15 parts by weight xanthan gum 0.3% water 33.3% was added to obtain an ink.

Comparative Example 5 Carbon black (same as in Example 3) 7 parts by weight Polyvinylpyrrolidone (same as in Example 3) 3.5 〃 glycerin 10 ト リ triethanolamine 0.3 カ リ ウ ム potassium ricinoleate 0.5 〃 1,2-benzisothiazoline 3- ON 0.1% Water 30% or more was kneaded with a bead mill, and coarse particles of carbon black were removed. Propylene glycol 15 parts by weight guar gum (same as in Example 1) 0.3% Water 33.3% was added to obtain an ink.

With respect to the inks obtained in Examples and Comparative Examples, the viscosity was measured and the presence or absence of precipitates was examined immediately after the production and after 6 months had elapsed (closed in a sample tube and allowed to stand). Table 1 shows the results. Viscosity: Measured at 10 rpm and 100 rpm using an EMD viscometer and an EHD viscometer manufactured by Toki Sangyo Co., Ltd. Ink precipitate: Filtration under reduced pressure was performed using 5A filter paper manufactured by Toyo Roshi Kaisha, Ltd., and the presence or absence of crystal precipitation was observed.

[0028]

[Table 1]

Writing test: Each of the inks obtained in Examples and Comparative Examples was filled in a translucent polypropylene tube having an inner diameter of 3 mm, and a commercially available free-cutting stainless-steel ballpoint pen tip for water-based ballpoint pens (the ball was a cemented carbide alloy) Twenty pens as shown in FIG. 1 were prepared using grease equivalent to tungsten carbide (diameter 0.5 mm) and JIS consistency No. 2 (JIS K-2220), and ten pens were subjected to a writing test immediately after assembling the pens. The remaining 10 tubes were left for 6 months to perform a writing test. Table 2 shows the results. When writing is not possible, "writing is impossible", ink does not flow smoothly,
When an inconvenience such as line skipping or line breakage occurred, it was judged as "writing failure", and when ink was excessively supplied and stained the writing line, it was judged as "insufficient viscosity".

[0030]

[Table 2]

The viscosity immediately after production is 10 rotations (about 40).
sec ^-1 ) in the range of 100 to 400 mPa · sec and 100
Those that show a range of 30 to 60 mPa · sec at the time of rotation (about 40 sec ⁻¹ ) give good results when filled into a pen, and those that are out of either range cause some inconvenience when filled into a pen. .

[0032]

According to the present invention, a water-based ball-point pen which can maintain a long-term stable writing performance by utilizing the characteristics of xanthan gum-improved storage performance of the ink which is a disadvantage of the water-based ball-point pen containing xanthan gum. An ink and an aqueous ballpoint pen are provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an aqueous ballpoint pen according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap 2 Pen tip sealing rubber 3 Pen tip 4 Ball 5 Joint between pen tip and ink storage tube 6 Ballpoint pen shaft 7 Ink storage tube 8 Ink 9 Ink follower 10 Tail plug

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-40585 (JP, A) JP-A-62-501914 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (3)

(57) [Claims] 1. An aqueous ballpoint pen ink containing a colorant, a water-soluble organic solvent and water, wherein xanthan gum is 0.2% by weight or less and nonionic polysaccharide 0.0
An aqueous ball-point pen ink containing 1 to 0.5% by weight. 2. The aqueous ballpoint pen ink according to claim 1, wherein the nonionic polysaccharide is at least one selected from guar gum and derivatives thereof. 3. An aqueous ballpoint pen comprising the ink for an aqueous ballpoint pen according to claim 1.