JP2003026983A - Ink composition for oily marking pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition for a marking pen having excellent cap-off performance realizing good writing performance even if a tip end of the pen is allowed to stand in an atmosphere for a long period of time. SOLUTION: The ink composition for an oily marking pen comprises containing at least a coloring agent; an alcoholic solvent; a resin; and N- methylpyrrolidone. It is preferable that a content of N-methylpyrrolidone is 0.5-15% by weight based on a whole amount of the ink composition. It is preferable that paraffin waxes becoming components for inhibiting an evaporation of the ink are contained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for oil-based marking pens that can exhibit good writing performance even when the pen tip is left in the atmosphere for a long period of time.

[0002]

2. Description of the Related Art Hitherto, as a writing instrument, a marking pen or the like has been widely used in which ink is penetrated into a pen tip having a fiber core or a plastic core for writing. The oil-based ink composition used for this marking pen or the like contains various alcohols as the main components of the solvent, and in order to prevent the ink of the pen core, which is the pen tip at the time of cap off, from drying up, benzyl alcohol, propylene glycol derivative, etc. The high boiling point solvent was added as an auxiliary solvent.

However, since these high boiling point solvents have a large viscosity themselves, they may cause writing defects due to an increase in ink viscosity in the pen core, and have a problem in that the effect of preventing dry-up is also low. Is.

On the other hand, Japanese Patent Application Laid-Open No. 9-40900 discloses that
Even when stored for a long period of time, in the handwriting function, a golden metallic luster sufficient for the handwriting appears, and there is no scratching in the writing performance.As a golden ink for writing instruments, brass powder pigment and coumarone-indene resin are used. Those containing a resin and N-alkyl-2-pyrrolidone are known. However, in the publication, the N-alkyl-2-pyrrolidone used for the gold ink for writing instruments is used as a solvent, and dissolves the above-mentioned coumarone-indene resin and the like well, and changes the brass powder pigment with time. The N-alkyl-2-pyrrolidone acts as a solvent that does not have a bad influence such as corrosion and has a different purpose and action from the present invention. There is no description or suggestion of preventing the ink of the pen core from drying up. Therefore, it is apparent that the present invention and the technical contents disclosed in the above publication differ in the purpose of use, the technical idea, and the operation and effect thereof.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art and is intended to solve the problems. Even if the pen tip is left in the atmosphere for a long time, the writing is further excellent. It is an object of the present invention to provide an ink composition for a marking pen, which is excellent in cap-off performance and realizes performance.

[0006]

As a result of intensive studies on the above-mentioned problems of the prior art, the present inventors have found that N-methylpyrrolidone has a good cap-off performance among the substances that impart the cap-off property. The inventors have found that the above can be realized and completed the present invention. That is, the present invention resides in the following (1) to (3). (1) An ink composition for an oil-based marking pen, which contains at least a colorant, an alcohol solvent, a resin, and N-methylpyrrolidone. (2) The ink composition for an oil-based marking pen according to (1) above, wherein the content of N-methylpyrrolidone is 0.5 to 15% by weight based on the total amount of the ink composition. (3) The ink composition for an oil-based marking pen according to the above (1) or (2), which further contains paraffin waxes as a component that suppresses ink evaporation.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The marking pen ink composition of the present invention is characterized by containing at least a colorant, an alcohol solvent, a resin, and N-methylpyrrolidone.

As the colorant used in the present invention, for example,
Examples include oil-soluble dyes and pigments. As the oil-soluble dye, almost any general oil-soluble dye that is soluble in an alcohol solvent can be used. For example, as the dye, Orazole Yellow 2GLN, Orazole Red 3GL, Orazole Blue 2GLN, Neon Zapon Blue FLE,
Spirit Black SP, Bali Fast Red 130
8, Varifast Black 3840, Oil Blue B
A, Oil Yellow 185, Oil Red TR71, Oil Black S, Victoria Blue, Rhodamine 6JHSA, Flex
Yellow 105 and the like, and the pigment is not particularly limited, for example, azo pigment, condensed polyazo pigment,
Phthalocyanine pigments, metal complex pigments, thioindigo pigments, dye lake pigments, organic pigments such as fluorescent pigments and carbon black, inorganic pigments such as titanium oxide, and further processed pigments whose surface is coated with a resin coating, for example, micro Various types of squirrel A type, AS black, AS blue, IK red and the like can also be used. These dyes and / or pigments may be used alone or in combination of two or more, and the content thereof varies depending on the kind of the colorant and other ink components, but is 1 with respect to the total amount of the ink composition.
-30% by weight, preferably 2-15% by weight is desirable.

Examples of the alcohol solvent used in the present invention include ethyl alcohol, n (normal) -propyl alcohol, i (iso) -propyl alcohol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Dipropylene glycol monomethyl ether and the like can be mentioned, and preferably ethyl alcohol, n (normal) -propyl alcohol, from the viewpoint of appropriate drying property and wettability when writing on the non-absorbing surface.
i (iso) -propyl alcohol and propylene glycol monomethyl ether are preferable. These alcohol solvents can be used alone or in combination of two or more, and the content thereof is 50 to 90% by weight, preferably 70 to 85, with respect to the total amount of the ink composition. Weight percent is preferred.

The resin used in the present invention is a resin soluble in an alcohol solvent and is used as an adhesive to the surface to be coated, a viscosity modifier for ink, and a dispersant for a colorant. Various natural resins and synthetic resins that have been used more can be used. , Vinyl resin such as alkyl-phenol resin, vinyl chloride-vinyl acetate copolymer resin, petroleum resin, ketone resin, acrylic resin,
Examples thereof include a condensate of aldehyde and urea, a maleic acid resin, and the like, and these can be used alone or in combination of two or more, and the content thereof is 0.1 to the total amount of the ink composition. 30% by weight, preferably 1-20% by weight
Is desirable.

The N-methylpyrrolidone (also known as 1-methyl-2-pyrrolidone) used in the present invention has an action of suppressing an increase in ink viscosity and evaporation of an alcohol solvent even though it has a high boiling point. Therefore, this N
-When methylpyrrolidone is included in the ink composition for oil-based marking, even if the pen tip is left in the atmosphere for a long period of time, the increase in ink viscosity of the pen tip part is suppressed to prevent the nib dry up. In addition, it is possible to exert excellent writing performance. The content of this N-methylpyrrolidone is preferably 0.5 to 15% by weight based on the total amount of the ink composition, and 3 to 10% by weight is particularly desirable in view of the drying property and cissing of the ink drawn line. If the content of N-methylpyrrolidone is less than 0.5% by weight, the effect of the present invention cannot be exhibited, and if it exceeds 15% by weight, the drying property when writing on the non-absorbing surface is improved. It is not preferable because it worsens and causes cissing.

In the present invention, it is preferable to further include paraffin wax which is a component for suppressing ink evaporation. Specific examples of paraffin waxes that can be used include trade name Paraffin Wax 125F,
Same 130F, Same 135F, Same 140F, Same 150F, Same 155F, HNP-3, HNP-9, HNP-10, H
NP-11, HNP-12, SP-0145, SP-1
035, SP-3040, SP-3035, SP-01
10 [above, manufactured by Nippon Seiro Co., Ltd.], paraffin mp42
~ 44 ° C, 46 ~ 48 ° C, 48 ~ 50 ° C, 50 ~
52 ° C, 52 to 54 ° C, 54 to 56 ° C, 56 to 5
8 ° C, 58-60 ° C, 60-62 ° C, 62-64
℃, the same 64-66 ℃, the same 66-68 ℃, the same 68-70 ℃
[The above are products manufactured by Wako Pure Chemical Industries, Ltd.] and the like, and these can be used alone or in combination of two or more kinds. These paraffin waxes are solid at room temperature (25 ° C) and have a melting point of 40 to 80 ° C.
The average molecular weight (by gas chromatography method) is 300 or more.
Preferably, paraffin waxes having a melting point of 45 ° C. or higher are desirable from the viewpoint that they do not easily dissolve even in the high temperature period of summer and the cap-off performance can be maintained. The content of the paraffin wax is 0.01 to 5% by weight, preferably 0.05 to 2 with respect to the total amount of the ink composition.
% By weight. Paraffin wax content is 0.0
If it is less than 1% by weight, the further effect of the present invention cannot be exhibited, and if it exceeds 5% by weight, the drawn line is hard to dry, which is not preferable. Further, in addition to paraffin waxes, microcrystalline wax, petrowax, glycerin stearate, etc. as a cap-off performance improving agent which is a component that suppresses ink evaporation, together with paraffin waxes, in the above content range (0. 0
1 to 5% by weight).

In the present invention, if necessary, as an additive for other ink compositions for oil-based marking pens, for example, anionic, nonionic or cationic surfactants, preservatives, antifungal agents, A rust preventive agent, a lubricant, a pH adjusting agent and the like may be appropriately contained.

In the present invention, the marking pen to be filled with the ink composition having the above composition is not particularly limited as long as it has a pen tip made of a fiber core or a plastic core. In addition to having an ink tank part that serves as a shaft for directly storing ink, it also has a collector member for temporarily storing ink, and the ink is led from the ink tank part to the pen tip through a relay core (or It has a direct liquid type marking pen that is performed directly, or an ink tank part that serves as a shaft body that directly stores ink, and directs the ink from the ink tank part to the pen tip through the valve mechanism part (or A marking pen that is performed (via a relay core), or an ink absorber that occludes ink in the shaft body, and the ink is inserted from the ink occluder into the pen tip. Derived directly (or via a wick) such as marking pen and the like to be performed.

In the ink composition for an oil-based marking pen of the present invention thus constituted, N-methylpyrrolidone having an action of suppressing increase in ink viscosity and evaporation of alcohol solvent despite having a high boiling point Since it is contained in the oil-based marking ink composition, even if the pen tip of the marking pen is left in a cap-off state in the air for a long period of time, the ink viscosity of the pen tip part increases and alcohol-based solvent The evaporation can be suppressed to prevent the pen tip from drying up, and since the increase in ink viscosity is small, excellent writing performance can be exhibited without causing writing defects. Furthermore, if a paraffin wax is contained, a brittle coating of paraffin wax is formed on the surface of the fiber core or the plastic core, which is the pen tip of the marking pen, without impairing the action and effect of N-methylpyrrolidone. It can be formed, and this coating film further prevents evaporation of the alcohol solvent or the like, which is a volatile component contained in the ink component. In addition, this coating is
A regenerated film that is constantly regenerated on the tip of the pen and that breaks during writing is formed.This effect depends on the content of paraffin waxes, but this effect is due to the ink components for oil-based marking pens filled or occluded in the marking pen. It will be repeated until it is used up.

The ink composition for a marking pen of the present invention can be suitably used for general oil-based markers, underlines, name pens, paint markers, writing pens, erasing pens and the like.

[0017]

EXAMPLES Next, the present invention will be described more specifically and in detail based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Examples 1 to 8 and Comparative Example 1] As a pen tip, a pen core made of an acrylic fiber sliver was used.
The weight was 0.17 g, the length was 33 mm, and the diameter was 4.0 mm (porosity 55%). Further, as the ink for the oil-based marking pen, each ink having the respective composition composition (compounding unit:% by weight) shown in Table 1 below was used.

With the above ink (5.0 g) and pen core,
A batting type marking pen was prepared by occluding the ink in an ink occluding body made of polyester batting. By the following method using each of the marking pens obtained, the evaluation of the writability based on the change with time at the time of cap off, the drying property,
Wettability and stickiness were evaluated. The results are shown in Table 1 below.

[Evaluation Method of Writability at Cap Off] Each marking pen of each Example and Comparative Example was aged in a room at a temperature of 25 ° C. and a humidity of 65% in a cap-off state with the cap of the marking pen removed. Change (4 hours, 12 hours, 18 hours, 24 hours)
The writing performance at 25 ° C. was evaluated according to the following evaluation criteria. Evaluation criteria: ◎: Can be written without blurring ○: Slightly blurring in writing △: Blurring the first line △ △: Blurring the second line ×: Cannot write

[Evaluation Method of Dryability] Each marking pen of each Example and Comparative Example was written on glass in a room at a temperature of 25 ° C. and a humidity of 65% until the ink was dried (the written portion The time until it was not transferred even when laid on paper) was measured. The shorter the measurement time, the better the drying property.

[Evaluation Method of Wettability] Each marking pen of each Example and Comparative Example was written on a polypropylene sheet in a room at a temperature of 25 ° C. and a humidity of 65%, and the wettability of the ink was visually evaluated according to the following evaluation criteria. It was evaluated by. Evaluation criteria: ◎: Good ○: Slightly repelled ×: Repelled

[Evaluation Method of Adhesiveness] Each marking pen of each Example and Comparative Example was written on glass in a room at a temperature of 25 ° C. and a humidity of 65%. After the lapse of 60 minutes after writing, the number of times of rubbing until the writing line was peeled off was measured with a cotton swab. It means that the larger the number of times of rubbing, the better the sticking property.

[0024]

[Table 1]

As is clear from the results shown in Table 1, the ink compositions for oil-based marking pens of Examples 1 to 8, which fall within the scope of the present invention, were exposed to the atmosphere for a longer period of time than Comparative Example 1 which falls outside the scope of the present invention. It was found that even when the pen tip was left inside, good writing performance was realized, and the drying property, wettability and sticking property were excellent. Looking at the examples individually,
Examples 1 to 8 are those in which the content of N-methylpyrrolidone was varied, and in these cases, good writing performance was achieved even when the pen tip was left in the atmosphere for a long time, and drying was performed. It was found that the composition had excellent properties, wettability, and stickiness. In particular, Examples 2, 4, 6 and 8 are prepared by adding paraffin waxes to the ink components of Examples 1, 3, 5 and 7 above. In these cases, Examples 1, 3, 5 were used. It was found that better writing performance can be achieved even when the pen tip is left in the atmosphere for a long time (even after 24 hours in Table 1 but after 36 hours have elapsed) as compared with Nos. 7 and 7. . On the other hand, Comparative Example 1 contained benzyl alcohol, and in this case, it was found that the pen tip portion was immediately dried and thus was inferior in writability.

[0026]

According to the present invention, excellent writing performance can be realized even when the pen tip is left in the atmosphere for a long period of time.
An ink composition for an oil-based marking pen, which is excellent in dryability, wettability, and stickiness is provided.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J039 AB02 AB08 AD05 AD07 AD08                       AD09 AD18 AE01 AE03 AE06                       BA04 BA13 BA35 BB01 BC07                       BC13 BC36 BC39 BC50 BC60                       BE01 BE07 BE12 CA04 CA07                       EA11 GA26

Claims (3)

[Claims] 1. An ink composition for an oil-based marking pen, which contains at least a colorant, an alcohol solvent, a resin, and N-methylpyrrolidone. 2. The ink composition for an oil-based marking pen according to claim 1, wherein the content of N-methylpyrrolidone is 0.5 to 15% by weight based on the total amount of the ink composition. 3. The ink composition for an oil-based marking pen according to claim 1, which further contains paraffin waxes as a component that suppresses ink evaporation.