JP2003192974A - Ink composition for water-based ballpoint pen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition for a water-based ballpoint pen which has an excellent feeling in writing without impairing the rotation of the ball, excels in antiprecipitation property, gives an excellent line drawing density and pearl touch (color tone), and particularly has excellent performances in that the pearl touch of a drawn line at the beginning of the writing is not impaired because the cohesion of the pearl pigment does not take place even in a prolonged capped-off condition to lead to a thick line drawing density at the beginning of the writing and further in that the edge of the pen does not become hard. <P>SOLUTION: The ink composition contains at least a pearl pigment, a water- soluble organic solvent, a viscosity increasing agent, and pullulan, and is characterized in that the content of the pullulan is 0.05-1.0 wt.% to the total amount of the ink composition. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous ball-point pen ink composition having a pearl luster or a metallic luster. [0002] In the past, various ink compositions using pearl pigments have been proposed in order to obtain pearlescent or metallic luster handwriting. For example, Japanese Patent Application Laid-Open No. Hei 7-118592 discloses that a pearl pigment, a thickening resin, a solvent and water are contained at least and have a viscosity of 10,000 to 150,000 cps.
(ST rotor of E-type viscometer, 1 rpm, 25 ° C.) discloses an aqueous metallic glossy ink for ballpoint pens, and JP-A-11-152438 discloses at least a pearl pigment, a colored pigment bead, and a thickener. And a water-soluble organic solvent and water, and have a viscosity of 2000 to 20000 c. p. (Brookfield viscometer, cone No. 40, number of revolutions: 0.1 rpm, 25 ° C.) is disclosed. However, the pearl pigment particles described in these publications are large scale-like particles,
In some cases, the rotation of the ball of a ballpoint pen is hindered, and the feel of writing is significantly deteriorated. In addition, poor writing is likely to occur due to sedimentation of pearl pigment particles, which poses a serious problem in actual use. Also, in the long-term cap-off state, pearl pigment agglomerates and the drawing line density at the beginning of writing becomes high, so the pearly feeling of the drawing line at the beginning of writing is impaired, and the pen tip solidifies and causes poor writing There is a problem that there is. On the other hand, Japanese Patent Application Laid-Open No. 11-193361 discloses that a water-based ink contains a dye, a pigment, a coloring material such as a fluorescent pigment obtained by coloring resin particles with a dye, a water-soluble organic solvent,
A water-based ink containing at least pullulan and water, which is excellent in drying resistance of an ink discharge portion, does not cause blurring, and is excellent in prevention of bleeding (through-through), is preferably used particularly for an underline marker. Have been. However, this water-based ink has no recognition of problems such as deterioration of writing feel and poor writing due to sedimentation of the pearl pigment particles when pearl pigments, which become giant particles, are applied to ballpoint pens. Things. The pullulan content in the aqueous ink was 0.5% by weight to 10% by weight in Examples 1-4.
In addition, only a case where an oil-soluble dye, an acid dye, or a fluorescent pigment is used as a coloring material is disclosed. for that reason,
In the case of applying pearl pigment, pullulan and thickener which become huge particles for ballpoint pen,
There is no description or suggestion about the effects on the brush feel, sedimentation of pearl pigment particles, drawing line density, and pearl feeling (color tone). SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has been made to solve the problem.
With excellent brush feeling without hindering the rotation of the ball,
It has excellent sedimentation resistance, has excellent drawing line density and pearly feeling (color tone), and can keep the drawing line density constant without impairing the pearly feeling of the drawing line at the beginning of writing at the time of long-term cap-off, An object of the present invention is to provide an ink composition for a water-based ballpoint pen that is excellent in initial brushability. The present inventors have conducted intensive studies on the above-mentioned conventional problems and the like. As a result, at least a pearl pigment, a water-soluble organic solvent, a thickener, Along with including pullulan,
It has been found that by controlling the content of the pullulan in a specific range, the above-mentioned aqueous ink composition for a ballpoint pen can be obtained, and the present invention has been completed.
That is, the aqueous ballpoint pen ink composition of the present invention,
It contains at least a pearl pigment, a water-soluble organic solvent, a thickener and pullulan, and the content of the pullulan is 0.05 to 1.0% by weight based on the total amount of the ink composition. Embodiments of the present invention will be described below in detail. The aqueous ballpoint pen ink composition of the present invention contains at least a pearl pigment, a water-soluble organic solvent, a thickener, and pullulan, and the content of the pullulan is 0.05 to 1. 0% by weight. The pearl pigment used in the present invention includes, for example, those obtained by coating the surface of mica with a metal oxide having a high refractive index such as titanium oxide and iron oxide. In this pearl pigment, light reflected at a boundary between a titanium oxide layer having a high refractive index and mica having a low refractive index provides pearl luster. The pearl pigment thus obtained has acid resistance and alkali resistance and does not generate gas. The average particle size of the pearl pigment used in the present invention is suitably 1 to 60 μm, preferably 5 to 25 μm. If the average particle diameter of the pearl pigment exceeds 60 μm, it will not stably disperse in the ink and will settle. On the other hand, if it is less than 1 μm, the characteristic pearl color tone will not be obtained, which is not preferable. As pearl pigments that can be specifically used, commercially available Iriodin 100 (particle size: 10 to 6)
0 (μm, silver), 103 (particle size: 10 to 60 μm, silver), 111 (particle size: 1 to 15 μm, silver), 119
(Particle size 5-25 μm, silver), 120 (particle size 5-25
μm, silver), 123 (particle size: 5 to 25 μm, silver),
201 (particle size 5-25 μm, gold), 205 (particle size 10-60 μm, gold), 211 (particle size 5-25 μm)
m, red), 215 (particle size: 10-60 μm, red),
219 (particle size 10-60 μm, purple), 221 (particle size 5-25 μm, blue), 223 (particle size 5-25 μm)
m, purple), 225 (particle size: 10-60 μm, blue),
231 (particle size 5 to 25 μm, green), 235 (particle size 10 to 60 μm, green), 300 (particle size 10 to 60 μm)
m (gold), 302 (particle size 5-25 μm, gold), 303 (particle size 10-60 μm, gold), 306 (particle size 10-60 μm, gold), 309 (particle size 10-60 μm)
m, gold), 323 (particle size 5 to 25 μm, gold), 326 (particle size 5 to 25 μm, gold), 500 (particle size 1)
0 to 60 μm, copper color; 502 (particle size: 10 to 60 μm)
m, reddish brown), 504 (particle size 10-60 μm, red), 520 (particle size 10-60 μm, copper color), 52
2 (particle size 10 to 60 μm, reddish brown), 524 (particle size 1
0-60 μm, red) (Merck Japan Co., Ltd.
Manufactured). These pearl pigments can be used alone or in combination of two or more. The content of these pearl pigments is 1 to 20% by weight, preferably 1 to 20% by weight, based on the total amount of the ink composition.
It is desirably 15% by weight, more preferably 2 to 10% by weight. If the content of the pearl pigment is less than 1% by weight, the pearl color tone, which is a characteristic color thereof, does not appear,
On the other hand, if it exceeds 20% by weight, the ink outflow property is impaired, which is not preferable. The pullulan used in the present invention provides an excellent brush feeling without inhibiting the rotation of a ball when an ink containing a pearl pigment is applied to a ballpoint pen, prevents sedimentation of the pearl pigment, and It is included in order to exhibit the drawn line density and pearl (color tone). The pullulan used in the present invention has maltotriose (three glucose molecules are α-1,4 bonds) regularly,
α-1,6-linked natural neutral polysaccharide, for example, obtained by culturing Aureobasidium pullulans, a so-called black yeast, using starch as a raw material. As the pullulan that can be used in the present invention, for example, a commercially available pullulan PF-
20, PF-10 and PI-20 (all made by Hayashibara)
And the like. The content of this pullulan needs to be 0.05 to 1.0% by weight, preferably 0.1 to 0.8% by weight, and more preferably 0 to 1.0% by weight based on the total amount of the ink composition. 0.2 to 0.6% by weight. In the present invention, if the content of pullulan is less than 0.05% by weight, the effects of the present invention cannot be exerted, and particularly, when the cap is off for a long time, the pearly feeling of the drawing line at the start of writing is impaired. Is not obtained, and 1.
If the content exceeds 0% by weight, a hard film is formed and the initial brushability deteriorates, which is not preferable. The thickener used in the present invention imparts gel viscosity to the ink, stably disperses the pearl pigment in the ink,
It is included in order to improve good brush feel, prevent sedimentation of pearl pigment particles, and improve drawing line density and pearl feeling (color tone). Examples of the thickener that can be used in the present invention include, for example, polyacrylic acid, an alkali salt of polymethacrylic acid, an alkali salt of an acrylic acid or methacrylic acid-containing copolymer, and an alkali salt of a copolymer of styrene and maleic acid. , An alkali salt of a copolymer of vinyl acetate and crotonic acid, a vinyl alcohol containing modified polyvinyl alcohol, a copolymer of methyl vinyl ether and maleic acid,
Derivatives of polyalkylene oxide, cross-linked polyacrylic acid resin, methylcellulose, hydroxyethylcellulose,
Carboxymethyl cellulose sodium salt, gum arabic, shellac alkali salt, polyethylene oxide, sodium alginate, tragacanth gum, guar gum, karaya gum, and the like, these thickeners may be used alone or as a mixture of two or more. it can. Preferably, a crosslinked polyacrylic acid resin is used from the viewpoint of excellent moisture retention. Specifically, Hibiswako 104 and Hibiswako 105 manufactured by Wako Pure Chemical Industries, Ltd., and Junron PW110 manufactured by Nippon Pure Chemical Co., Ltd. , Junron PW111, BF
Commercial products such as Carbopol 941 and Carbopol 1342 manufactured by Goodrich Company can be used.
The content of these thickeners is preferably from 0.1 to 0.6% by weight, more preferably from 0.2 to 0.4% by weight, in terms of solid content, based on the total amount of the ink composition. If the content of the thickener is less than 0.1% by weight, the pearl pigment is likely to settle, causing poor writing, and 0.6% by weight.
Exceeding the range is undesirable because the fluidity of the ink is impaired and the ink may not flow out smoothly. The water-soluble organic solvent used in the present invention is:
It is contained for improving the writing taste and the stability over time. Examples of the water-soluble organic solvent that can be used in the present invention include, for example, propylene glycol, glycerin, polyhydric alcohols such as polyethylene glycol, a group consisting of an alkylene oxide adduct of glycerin and an alkylene oxide adduct of trimethylolpropane, and These mixtures and the like can be used. The content of these water-soluble organic solvents is preferably about 1 to 40% by weight based on the total amount of the ink composition. Further, the ink composition of the present invention may contain a pigment and / or a dye other than the pearl pigment, a humectant, a rust inhibitor, a pH adjuster, a lubricant and a preservative as long as the effects of the present invention are not impaired. Agents and the like can be used. The balance of the present invention is adjusted with water (purified water, ion-exchanged water, pure water, deep sea water) and the like. In the present invention, the drawing line density and the pearly feeling (color tone) can be further improved by adding an appropriate amount of a pigment and / or a dye other than the pearl pigment as long as the effects of the present invention are not impaired. As the pigment, azo pigments, phthalocyanine pigments, quinacridone pigments, sulene pigments, anthraquinone pigments, dioxane pigments and the like can be used, and also copolymers of styrene and acrylonitrile and copolymers of acrylic acid. A fluorescent pigment obtained by coloring resin particles of a substance or the like with a dye can also be used. According to the aqueous ballpoint pen ink composition of the present invention thus constituted, the ink composition has an excellent brush feel and excellent sedimentation resistance without inhibiting the rotation of the ball.
It has excellent drawing line density and pearly feeling (color tone). In other words, in the conventional ink composition for a ballpoint pen containing a pearl pigment, the pearl pigment is a scale-like large particle, so that the ball contacts the ball and the seat to hinder the rotation of the ball, which may deteriorate the brush feel. There are also problems such as poor writing due to sedimentation of the pearl pigment particles, and in the long-term cap-off state, pearl pigment agglomerates and the drawing line density at the beginning of writing increases, so the pearl of the drawing line at the beginning of writing There are problems that the feeling is impaired, and that the pen tip is solidified and writing failure may occur.
In the present invention, in order to solve the above-described problems when using a pearl pigment, a water-soluble organic solvent, a thickener and pullulan are contained, and the content of the pullulan is set to a specific range for the first time. It has excellent writing feel, excellent sedimentation resistance, and excellent drawing line density and pearly feeling (color tone) without hindering the rotation of the ball, especially in the long-term cap-off state. An ink for water-based ballpoint pens that has excellent performance without causing aggregation of pearl pigments and increasing the density of drawing lines at the start of writing, without impairing the pearly feeling of the drawing lines at the start of writing and further preventing the pen tip from solidifying. The composition is provided, and when the above-mentioned thickener and pullulan are not contained, or the amount of pullulan is 0.05 to the total amount of the ink composition.
When the content is out of the range of 1.0% by weight or the like, the effects of the present invention cannot be achieved (this point will be further described in Examples and the like which will be described later). Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Examples 1 to 8 and Comparative Examples 1 to 3 Each of the components shown in Table 1 below was blended to prepare an aqueous ball-point pen ink composition (the remainder was adjusted to 100% by weight with purified water). The following methods were used to evaluate the writability (drawing line density, initial brushability) and ink stability. The results are shown in Table 1 below. (Writability test) The inks of the above Examples and Comparative Examples were filled in ballpoint pens having tips and ink tanks, respectively, and centrifuged at 200 G for 3 minutes.
After being left at 10 ° C. for 10 days, “spiral writing” was performed on a writing paper, and the drawing line density and initial writing property were evaluated based on the following evaluation criteria from the drawing line state. (Drawing line density) ◎: within 1 lap to become pearly drawing line from the start of writing ○: within 2 laps to become pearly drawing line after starting to write △: 5 to become pearly drawing line after starting to write Less than or equal to x: 5 or more laps (beginning of writing) to become a pearl-like drawing line from the start of writing. ：: No blurring occurs. ：: Less than 1/8 lap. Δ: Less than 1/4 lap. C: The bleeding is more than 1/2 turn. (Evaluation method of ink stability) The inks of the above Examples and Comparative Examples were transferred to 20 ml sample bottles, sealed, and after one month at room temperature (25 ° C.). Was evaluated organoleptically according to the following evaluation criteria. Evaluation criteria: ○: uniform state x: non-uniform state such as supernatant [Table 1] As is clear from the results shown in Table 1, the writability (drawing line density, first brush) of Examples 1 to 8 which fall within the scope of the present invention are higher than Comparative Examples 1 to 3 which fall outside the scope of the invention. ) And excellent ink stability. Looking specifically at the examples, Examples 1 to 8 have a pullulan amount of 0.05 to
In Example 1, the coloring agent was a mixture of only pearl pigment, Examples 2 to 8 were a mixture of pearl pigment + pigment, and Example 8 was increased. It is a case where the amount of the thickener was increased as compared with Examples 1 to 7, and in these cases, it is understood that the effects of the object of the present invention can be achieved. In particular, it was found that the effects of the present invention were more excellent when the amount of pullulan in Examples 2, 4 to 6 was in the range of 0.2 to 0.6% by weight. On the other hand, when the comparative example is specifically looked at, the comparative example 1
Is the case where no pullulan is contained, and the comparative example is the case where the amount of pullulan is 1.5% by weight. In these cases, it can be seen that the effects of the present invention cannot be achieved. Comparative Example 3
If you add pullulan but not thickener,
Since the pearl pigment was settled by the centrifugal treatment, it was found that it was not feasible as a pen. According to the present invention, the present invention has an excellent brush feel without hindering the rotation of the ball, has excellent sedimentation resistance, and has an excellent drawing line density and pearly feeling (color tone). Especially, even in the long-term cap-off state, pearl pigments do not agglomerate and the drawing line density at the beginning of writing is high, so the pearl feeling of the drawing line at the beginning of writing is not impaired, and the pen tip is further solidified The present invention provides an aqueous ballpoint pen ink composition having excellent performance without causing any problems.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Miyuki Tokairin             5-12 Irie 2-chome, Kanagawa-ku, Yokohama-shi, Kanagawa             No. Mitsubishi Pencil Co., Ltd. Yokohama R & D Center             Inside F term (reference) 4J039 AB01 AB02 AB11 AD03 AD06                       AD09 AD13 AD14 AE07 BD03                       BE01 BE12 BE23 CA06 GA27

Claims (1)

Claims: 1. An ink composition comprising at least a pearl pigment, a water-soluble organic solvent, a thickener, and pullulan, wherein the content of the pullulan is 0.05 to 1.
An aqueous ink composition for a ballpoint pen, which is 0% by weight.