JP2021191847A - Ink composition for oily marking pen - Google Patents

Abstract

To provide an ink composition for an oily marking pen excellent in writing property on an oil film, and excellent in removable property by an alkali.SOLUTION: The ink composition for an oily marking pen includes: a solvent constituent; a resin constituent; and a dye constituent. The solvent constituent at least includes 2-4 C alcohol. The resin constituent includes an alkali-soluble resin. The dye constituent is composed of only a basic dye.SELECTED DRAWING: None

Description

The present invention relates to an ink composition for an oil-based marking pen.

Oil is applied to the surface of metal processed materials (metal molded products, etc.) used for painting in order to prevent rust. It is difficult for the coating film to adhere to the part where the oil film is formed. Therefore, prior to painting, the oil film formed on the surface of the metal processed material is removed by the degreasing treatment with alkali.

In addition, information such as a lot number may be marked on the metal processed material used for painting. For marking, an opaque oil-based or water-based marking pen or the like is used from the viewpoint of obtaining high visibility.

Generally, the writing property and fixing property of a marking pen on a metal or plastic adherend surface are lower than those of paper or the like. Therefore, there is a demand for an ink composition for a marking pen that can obtain high writability or fixability even on such an adherend surface. For example, Patent Document 1 proposes an oil-based ink for a marking pen containing at least a pigment, an organic solvent, a terpene phenol resin, and fine powdered silicon dioxide.

On the other hand, a technique focusing on suppressing discoloration of ink is also known. For example, Patent Document 2 describes C.I. I. 42660 and / or C.I. I. Soluble in a solvent and at least one solvent among ether alcohols composed of a dye represented by 42655, an alcohol having 2 to 4 carbon atoms, a glycol having 2 to 3 carbon atoms and an alcohol having 1 to 3 carbon atoms. We are proposing alcohol-based inks containing various resins.

Japanese Unexamined Patent Publication No. 2018-053110 Japanese Unexamined Patent Publication No. 11-14066

Since the oil film formed on the surface of the unpainted metal processed material is very thin, it is not possible at a glance to distinguish whether the metal processed material is before the degreasing treatment or after the degreasing treatment.

On the other hand, from the viewpoint of ensuring high adhesiveness to the adherend surface, the oil-based marking pen ink composition contains an oil-soluble resin, and the water-based marking pen ink composition contains a resin emulsion. When the adhesiveness of the marking ink composition is enhanced, the writeability or fixability on the adherend surface can be enhanced. However, resin components such as oil-soluble resins or resin emulsions are difficult to remove by alkaline degreasing treatment. Therefore, apart from the degreasing treatment, it is removed by wiping off the coating film by marking with a solvent.

If the film formed by marking can be removed by alkaline degreasing treatment, the oil film and the film formed by marking can be removed in one step, which is convenient and advantageous in terms of cost. When marking on an oil film, high adhesiveness is required due to the resin component, so that it is more difficult to remove the film by marking by alkaline degreasing treatment.

One aspect of the present invention includes a solvent component, a resin component, and a dye component.
The solvent component contains at least an alcohol having 2 to 4 carbon atoms and contains at least.
The resin component contains an alkali-soluble resin and contains
The dye component relates to an ink composition for an oil-based marking pen, which comprises only a basic dye.

It is possible to provide an ink composition for an oil-based marking pen which is excellent in writability on an oil film and also excellent in removability by an alkali.

[Ink composition for oil-based marking pen]
The ink composition for an oil-based marking pen according to one aspect of the present invention contains a solvent component, a resin component, and a dye component. The solvent component contains at least an alcohol having 2 to 4 carbon atoms. The resin component includes an alkali-soluble resin. The dye component consists only of basic dyes.

By using the alkali-soluble resin, high adhesiveness to the adherend surface of the ink composition for an oil-based marking pen can be ensured, so that excellent writing performance can be ensured. This makes it possible to write with high writability even on a metal adherend surface or an oil film. In addition, high fixability of the ink composition for an oil-based marking pen can be ensured. The amount of the dye component contained in the ink composition for an oil-based marking pen is usually smaller than that of the resin component. However, even when only the alkali-soluble resin is used as the resin component, it is difficult to secure high alkali detergency when the dye component contains a dye other than the basic dye. In the present invention, by using an alkali-soluble resin and using only a basic dye as a dye component, the film formed by marking the ink composition for an oil-based marking pen can be easily removed by an alkali, and the high alkalinity can be obtained. Cleanability can be ensured. Therefore, even when the metal processed material to be subjected to the painting treatment is marked, it can be easily removed by the degreasing treatment with an alkali. The film can be easily removed by using an alkaline aqueous solution having a relatively low concentration of 10% by mass or less or 5% by mass or less.

As described above, the ink composition for an oil-based marking pen of the present invention is excellent in removability with an alkali, and is therefore suitable for use in marking a metal processed material to be subjected to a degreasing treatment with an alkali. ..

If the adhesiveness of the resin component is high, even if the film due to marking can be removed by alkaline degreasing treatment, the component of the film may reattach to the adherend surface and an unintended portion may be colored. From the viewpoint of preventing such a state, the dye component may be composed of only a methine-based basic dye. Dyes generally function as colorants due to the presence of conjugated systems contained within the molecule. The methine-based basic dye has a structure in which methine groups are linked as a conjugated system. Unlike dyes that have only an aromatic ring as a conjugated system, methine-based basic dyes become colorless by breaking the conjugated bonds contained in the molecule when they come into contact with an alkali. Therefore, by using a dye component consisting only of a methine-based basic dye, an ink composition for an oil-based marking pen having excellent decolorizing property due to alkali can be obtained. As a result, when a film is formed by marking on the metal processed material to be coated, even if the constituent components of the film are reattached to the metal processed material when the film is removed by the degreasing treatment with alkali, It is in a decolored state. Therefore, it can be easily determined that the alkaline degreasing treatment of the metal processed material has been completed. Further, even when the dye component is reattached to the metal processing material, it is in a state of being decomposed by alkali. Therefore, even if the dye component bleeds on the surface of the coating film when the metal processed material is applied to the coating, it is colorless and does not affect the coating film. Further, the color can be easily decolorized by using an alkaline aqueous solution having a relatively low concentration such as 10% by mass or less or 5% by mass or less. When the dye component contains a dye other than the methine-based basic dye, the color is not erased by alkali, so it is necessary to remove the dye component remaining on the surface of the metal processing material by wiping after degreasing treatment. When the metal processed material is subjected to the painting process without removing the dye component remaining on the surface of the metal processed material (that is, the dye component that is not decolorized by alkali), the metal processed material bleeds on the surface of the coating film. Therefore, it is necessary to remove all the coating film and repaint. Therefore, in order to ensure the alkaline decolorizing property of the ink composition for an oil-based marking pen, it is preferable to use a dye component consisting only of a methine-based basic dye. By using a dye component consisting only of a methine-based basic dye, it becomes easier to visually determine that the alkaline degreasing treatment of the metal processed material has been completed.

Further, since a volatile organic solvent is usually used in the ink composition for an oil-based marking pen, if the cap of the oil-based marking pen is removed to expose the pen tip, the pen tip tends to dry. Therefore, with an oil-based marking pen, if writing is performed after the pen tip is left exposed for a long period of time, blurring is likely to occur in the handwriting. That is, it is difficult to secure high cap-off performance. In a work environment where marking is performed on an unpainted metalworking material, the work of opening and closing the cap of the oil-based marking pen each time writing is complicated. Therefore, even if the pen tip is left for a while with the cap removed, high cap-off performance is required so that writing can be performed without the pen tip drying. On the other hand, the ink composition for an oil-based marking pen is required to have high fixing property to the adherend surface. However, there is a trade-off relationship between the cap-off property and the fixability of the ink composition for an oil-based marking pen, and it is difficult to achieve both high fixability and excellent cap-off property.

When the ink composition for an oil-based marking pen of the present invention further contains a sucrose fatty acid ester component (preferably a fatty acid glyceride component), it is necessary to ensure excellent cap-off property while ensuring high fixing property. Can be done.

In the present specification, the case where the blurring when writing is suppressed after the tip of the oil-based marking pen is left exposed to the atmosphere is expressed as having excellent cap-off property or high cap-off property. Sometimes. Low cap-off property or low cap-off property means that after leaving the pen tip exposed to the atmosphere, it is relatively easy for blurring to occur when writing. Means. The cap-off property in the present specification is a cap-off property in a general atmospheric atmosphere (for example, an environment of 20 to 25 ° C. and a relative humidity of 50 to 65%).

Hereinafter, the ink composition for an oil-based marking pen of the present invention will be described in more detail.

(Solvent component)
The solvent component contains at least an alcohol having 2 to 4 carbon atoms (hereinafter, may be referred to as a first solvent). Since the solvent component contains the first solvent, excellent color development can be ensured, and even though the above resin having high adhesiveness is used, it can be easily dissolved and has a low viscosity ink composition for an oil-based marking pen. You can get things. The solvent component may contain a second solvent other than the first solvent.

(First solvent)
Specifically, the first solvent is an aliphatic alcohol. The aliphatic alcohol may be a linear alcohol or a branched chain alcohol. As the first solvent, a monohydric alcohol having one hydroxy group is preferable.

Examples of the monohydric alcohol include ethanol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, sec-butyl alcohol and t-butyl alcohol.

The first solvent has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms.

The solvent component may contain one kind of first solvent, or may contain two or more kinds of first solvents. The solvent component preferably contains a first solvent having at least 2 or 3 carbon atoms.

The ratio of the first solvent to the solvent component is, for example, 40% by mass or more. From the viewpoint of ensuring higher color development and suppressing the viscosity of the ink composition for an oil-based marking pen to a lower viscosity, the ratio of the first solvent is preferably 50% by mass or more or 55% by mass or more, preferably 70% by mass. % Or more or 75% by mass or more is more preferable, and 80% by mass or more may be used. When the ratio of the first solvent is in such a range, higher color development can be ensured, higher writeability can be ensured, and bleeding of handwriting can be suppressed. The ratio of the first solvent to the solvent component may be 100% by mass or less, 95% by mass or less, or 90% by mass or less. These lower limit values and upper limit values can be arbitrarily combined. The ratio of the first solvent having 2 to 3 carbon atoms may be adjusted in such a range.

(Second solvent)
Examples of the second solvent include alcohols (including phenol compounds) excluding the first solvent, glycol ethers and the like. As the alcohol, monohydric alcohol is preferable. The solvent may contain one kind of second solvent, or may contain two or more kinds of second solvents. From the viewpoint of easily adjusting the drying rate while ensuring high compatibility with the first solvent, it is preferable to use at least glycol ether as the second solvent.

Examples of the glycol ether include monoethers or diethers of glycol compounds and monoether monoesters of glycol compounds. Examples of the ether include alkyl ether, aryl ether, and aralkyl ether.

Glycol compounds include, for example, polyhydroxyalkanes and polyalkylene glycols. Examples of the polyhydroxyalkane include alkylene glycol (ethylene glycol, propylene glycol, propanediol, butanediol, hexanediol, octanediol, etc.), trimethylolpropane, pentaerythritol and the like. The polyhydroxyalkane has, for example, 1 to 10 carbon atoms and may be 2 to 6 or 2 to 4 carbon atoms.

Examples of the polyalkylene glycol include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol and tetrapropylene glycol. The carbon number of the oxyalkylene unit contained in the polyalkylene glycol is, for example, 2 to 4, and may be 2 or 3. In the polyalkylene glycol, the number of repetitions of the oxyalkylene unit is, for example, 2 to 10, and may be 2 to 6 or 2 to 4.

Of the glycol ethers, monoether is preferable from the viewpoint of easily dissolving other components and easily stabilizing the physical properties of the ink composition for an oil-based marking pen. Further, from the viewpoint of having less odor and high compatibility with the first solvent, alkyl ether and monoalkyl ether monoester are preferable.

Examples of the alkyl constituting the alkyl ether include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, n-hexyl and the like. The number of carbon atoms of the alkyl is, for example, 1 to 10, may be 1 to 6, or may be 1 to 4.

Examples of the acyl group constituting the ester moiety of the monoalkyl ether monoester include an aliphatic acyl group (acetyl, propionyl group, etc.), a benzoyl group and the like. Of these, an aliphatic acyl group having 2 to 4 carbon atoms (particularly, an acetyl group) is preferable.

Specific examples of the alkyl ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol mononormal butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol. Examples thereof include mononormal butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, and diethylene glycol monobutyl ether. Specific examples of the monoalkyl ether monoester include diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monopropyl ether acetate, and diethylene glycol monobutyl ether. Among them, at least one selected from the group consisting of ethylene glycol mononormal butyl ether, propylene glycol monomethyl ether, propylene glycol mononormal butyl ether, and diethylene glycol monomethyl ether is preferable. It is also preferable to use at least propylene glycol monomethyl ether as the second solvent.

Only glycol ether may be used as the second solvent, or glycol ether and another second solvent may be used in combination. The ratio of glycol ether to the solvent component is preferably 5% by mass or more or 10% by mass or more. The proportion of glycol ether is preferably 30% by mass or less, and may be 25% by mass or less or 20% by mass or less. When the ratio of glycol ether is in such a range, it is easy to reduce the viscosity of the ink composition for an oil-based marking pen, and it is easy to balance an appropriate quick-drying property with the suppression of drying of the pen tip. These lower limit values and upper limit values can be arbitrarily combined.

(Resin component)
The resin component includes an alkali-soluble resin. The resin component may further contain a polyvinylamide-based resin. From the viewpoint of ensuring high removability by alkali, it is desirable that the resin component is composed of only an alkali-soluble resin, or only an alkali-soluble resin and a polyvinylamide-based resin. When the resin component contains at least an alkali-soluble resin, high water resistance of the coating film due to marking can be ensured.

In the present specification, the alkali-soluble resin means a resin containing an anionic monomer unit and having an acid value of 30 KOH · mg / g or more.

The alkali-soluble resin may be a homopolymer of a monomer unit having an anionic group (first monomer unit), but is a copolymer containing a first monomer unit and another monomer unit (second monomer unit). May be. The resin component may contain one kind of alkali-soluble resin, or may contain two or more kinds in combination. The anionic group of the alkali-soluble resin may be contained in the ink composition for an oil-based marking pen in the form of an anion, or may be contained in the form of interacting with a methine-based basic dye.

Examples of the anionic group include a carboxy group, an acid anhydride group, a sulfonic acid group, a phosphonic acid group and a phosphinic acid group. The alkali-soluble resin may have one kind of anionic group or may have two or more kinds of anionic groups. Of the anionic groups, a carboxy group, an acid anhydride group and a sulfonic acid group are preferable.

Among the monomers having an anionic group corresponding to the first monomer unit (first monomer), examples of the monomer having a carboxy group include acrylic acid, methacrylic acid, maleic acid, fumaric acid and the like. Examples of the monomer having an acid anhydride group include maleic anhydride and the like. Examples of the monomer having a sulfonic acid group include vinyl sulfonic acid, styrene sulfonic acid, 2-acrylamide-2-methylpropane sulfonic acid and the like. These are merely specific examples, and the first monomer is not limited to these specific examples. The alkali-soluble resin may contain one kind of the first monomer unit, or may contain two or more kinds in combination.

The monomer corresponding to the second monomer unit (second monomer) may be polymerizable with the first monomer. Examples of the second monomer include acrylic monomers, vinyl monomers, olefins, vinyl cyanide (acrylonitrile, methacrylonitrile, etc.) and the like. The alkali-soluble resin may contain one kind of the second monomer unit, or may contain two or more kinds.

Examples of the acrylic monomer include acrylic acid ester, methacrylic acid ester, acrylamide, methacrylamide and the like. The acrylic monomer may have one (meth) acryloyl group in one molecule, or may have two or more (meth) acryloyl groups. Examples of acrylic acid esters and methacrylic acid esters include alkyl (meth) acrylates, hydroxyalkyl (meth) acrylates, cycloalkyl (meth) acrylates, cycloalkenyl (meth) acrylates, aryl (meth) acrylates, and aralkyl (meth) acrylates. Can be mentioned. The number of carbon atoms of the alkyl constituting these esters is, for example, 1 or more and 20 or less, and may be 1 or more and 10 or less or 1 or more and 6 or less. The carbon number of the cycloalkyl or cycloalkenyl is, for example, 4 or more and 8 or less, and may be 5 or more and 8 or less. The aryl has, for example, 6 or more and 20 or less, and may be 6 or more and 14 or less or 6 or more and 10 or less. The carbon number of the aralkyl is, for example, 7 or more and 22 or less, and may be 7 or more and 16 or less or 7 or more and 12 or less. The acryloyl group and the methacryloyl group are collectively referred to as a (meth) acryloyl group. In addition, acrylic acid ester and methacrylic acid ester shall be collectively referred to as (meth) acrylate. The alkali-soluble resin may contain one kind of acrylic monomer unit, or may contain two or more kinds of acrylic monomer units.

Specific examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, n-hexyl (meth) acrylate, and 2-ethylhexyl (meth). Examples thereof include acrylate, 2-hydroxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclohexenyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, and phenethyl (meth) acrylate. These are merely examples, and the (meth) acrylate is not limited to these specific examples.

Vinyl-based monomers include aromatic vinyl (styrene, vinyltoluene, divinylbenzene, etc.), vinyl halide (vinyl chloride, etc.), vinyl ester (vinyl acetate, etc.), vinyl ether (alkyl vinyl ether (propyl vinyl ether, butyl vinyl ether, etc.), etc. ), Vinyl ketone and the like. The vinyl-based monomer may have one vinyl group or two or more vinyl groups. Vinyl-based monomers also include those having a substituent. Examples of the substituent include a hydroxy group, an alkoxy group, a halogen atom and the like. Examples of the substituent on the aromatic ring include an alkyl group and a hydroxyalkyl group. However, the substituent is not limited to these. The alkali-soluble resin may contain one kind of vinyl-based monomer unit, or may contain two or more kinds of vinyl-based monomer units.

Examples of the olefin include α-olefins. The olefin may be chain or cyclic. Specific examples of the chain olefin include ethylene, propylene, 1-butene, and 4-methyl-1-pentene. The number of carbon atoms of the chain olefin is, for example, 2 or more and 16 or less, and may be 2 or more and 12 or less, or 2 or more and 10 or less. Specific examples of the cyclic olefin include norbornene and dicyclopentadiene. However, these are merely examples, and olefins are not limited to these specific examples. The olefin also includes those having a substituent (hydroxy group, alkoxy group, acyl group, halogen atom, etc.). The substituent of the cyclic olefin further includes an alkyl group, a hydroxyalkyl group and the like. However, the substituents are not limited to these. The alkali-soluble resin may contain one kind of olefin unit or may contain two or more kinds of olefin units.

The alkali-soluble resin preferably contains at least an aromatic vinyl unit (particularly, a styrene unit) as the second monomer unit, and may contain an aromatic vinyl unit and a (meth) acrylate unit.

The acid value of the alkali-soluble resin may be 30 KOH · mg / g or more, preferably 40 KOH · mg / g or more, and more preferably 50 KOH · mg / g or more or 60 KOH · mg / g or more. When the alkali-soluble resin has such an acid value, the coating film formed by marking the ink composition for an oil-based marking pen can be more easily removed by the alkali. The acid value of the alkali-soluble resin may be 300 KOH · mg / g or less.

The acid value of the resin can be measured in accordance with "JIS K 2501-2003 Petroleum Products and Lubricating Oil-Neutralization Value Test Method". More specifically, the acid value of the resin can be obtained by the following procedure. First, a predetermined amount of resin is dissolved in a solvent in which xylene and dimethylformamide are mixed at a volume ratio of 1: 1 to prepare a sample for titration. For the titration sample, potentiometric titration is performed using an ethanol solution containing potassium hydroxide at a concentration of 0.1 mol / L, and a titration curve is obtained. With the inflection point on the titration curve as the end point, the acid value is calculated from the concentration of the resin of the titration sample, the titration amount of the ethanol solution to the end point, and the concentration of potassium hydroxide.

The weight average molecular weight (Mw) of the alkali-soluble resin is, for example, 1000 or more and 30,000 or less. When Mw is in such a range, it is possible to secure higher writeability and fixability on the oil film while ensuring high removability of the film by alkali, and to secure high water resistance of the film. can. From the viewpoint of further enhancing the removability of the coating film by alkali, Mw is preferably 1000 or more and 20000 or less.

In the present specification, the weight average molecular weight (Mw) is measured by gel permeation chromatography (GPC) using standard polystyrene. As the standard polystyrene, for example, Mw = 1.01 × 10 ³ , 3.12 × 10 ³ , 5.53 × 10 ³ , 9.49 × 10 ³ , or 1.37 × 10 ⁴ is used.

Examples of the alkali-soluble resin include the John Krill series manufactured by BASF, the Hiros series manufactured by Seiko PMC, and the ARUFON series manufactured by Toagosei Corporation. Specific examples of the alkali-soluble resin include John Krill 67,678,680,682,683,690,52,57,60,61,62,63,70, HPD-962,501,354,6610, and Hi-Loss X-. 1, X-310, RS-1191, VS-1047, YS-1274, X-1, ARUFON UC-3080, UC-3910, UC-3920, UF-5022, but not limited to these. No.

The content of the alkali-soluble resin in the ink composition for an oil-based marking pen is preferably 30% by mass or less, more preferably 25% by mass or less. When the content of the alkali-soluble resin is in such a range, the coating film due to marking can be more easily removed by the alkali. The content of the alkali-soluble resin is, for example, 1% by mass or more. From the viewpoint of ensuring high writability on the oil film, the content of the alkali-soluble resin is preferably 3% by mass or more, more preferably 5% by mass or more. These upper limit values and lower limit values can be arbitrarily combined.

Examples of the polyvinylamide-based resin include a polymer obtained by polymerizing a monomer having a vinyl group and an amide bond and, if necessary, another copolymerizable monomer. The polyvinylamide-based resin preferably contains vinylpyrrolidone as a monomer unit. The polyvinylamide-based resin preferably contains at least polyvinylpyrrolidone. When the resin component contains a polyvinylamide-based resin, excellent color-developing property can be obtained. In addition, it is possible to secure high sensitivity for decolorization and maintain high color development for a long time.

The Mw of the polyvinyl amide-based resin may be, for example, 3000 or more and 100,000 or less, 5000 or more and 70,000 or less, 8000 or more and 50,000 or less, or 10,000 or more and 40,000 or less. When Mw is in such a range, fixability and water resistance can be further enhanced while ensuring high color development property and high removal property of the coating film by alkali by marking.

The content of the polyvinylamide-based resin in the ink composition for an oil-based marking pen is, for example, 0.01% by mass or more. The content of the polyvinylamide resin is preferably 0.05% by mass or more, preferably 0.1, from the viewpoint of ensuring high sensitivity of color development and decolorization and easily maintaining high color development for a long time. More preferably, it is by mass or more or 1% by mass or more. The content of the polyvinylamide-based resin is, for example, 10% by mass or less. From the viewpoint of ensuring higher water resistance, the content of the polyvinylamide resin is preferably 5% by mass or less, more preferably 3% by mass or less, or 2% by mass or less. These lower limit values and upper limit values can be arbitrarily combined.

From the viewpoint of easily ensuring high sensitivity of high water resistance, high color development property and high decolorization property, the resin component preferably contains both an alkali-soluble resin and a polyvinylamide-based resin. In this case, by setting the content of the polyvinylamide-based resin in the ink composition for an oil-based marking pen within the above range, the effect of using the alkali-soluble resin and the polyvinylamide-based resin in combination can be further enhanced. can.

(Dye component)
In the present specification, the fact that the dye component consists only of a basic dye means that the ink composition contains substantially no dye other than the basic dye. Further, in the present specification, the fact that the ink composition does not substantially contain a dye other than the basic dye means that the amount of the dye other than the basic dye is 5 parts by mass or less with respect to 100 parts by mass of the resin component ( It means that the amount is preferably 1 part by mass or less). Dyes other than basic dyes in the ink composition or its coating film may be below the detection limit.

Examples of the basic dye include a methine-based dye, a diarylmethane-based dye, a triarylmethane-based dye, an azo-based dye, an anthraquinone-based dye, and a nitrogen-containing heterocyclic compound. The dye component may contain one kind of basic dye, or may contain two or more kinds in combination.

When the dye component contains only a methine-based basic dye, the conjugated bond in the molecule is broken when it comes into contact with an alkali, so that excellent decolorizing property of the ink composition for an oil-based marking pen can be ensured. ..

The methine-based base dye is a base dye that contains a structure in which methine groups are linked as a conjugated system and whose conjugated bond is cleaved by contact with an alkali.

Specific examples of methine-based basic dyes include Color Index Basic Red 12 to 15, 27, 35, 37, 45, 48, 49, 52, 53, 66, 68, and Basic Yellow 11 to 14,21 to 24,28. , 29,33,35,40,43-45,48,49,51-53, Basic Violet 7,15,16,20,21,27,39,40, BasicBlue 62,63, Basic Orange 27,42 , 44, 46, but are not limited to these. From the viewpoint of high decolorization sensitivity, Basic Red 12 to 15,37, Basic Yellow 11, 13 and Basic Violet 15 are preferable.

The dye component may contain one kind of methine-based basic dye, or may contain two or more kinds of methine-based basic dyes.

Regarding basic dyes other than methine-based dyes, specific examples of triarylmethane-based basic dyes include Basic Blue 5,7,26 and Basic Green 1 of the color index. Specific examples of the azo-based dye include Basic Red 18, Basic Yellow 36, and Basic Blue 54, 65, 66, 67 of the color index.

The content of the basic dye in the ink composition for an oil-based marking pen is, for example, 0.1% by mass or more, preferably 0.2% by mass or more, and 0.5% by mass or more or 1% by mass or more. You may. When the content of the basic dye is in such a range, in addition to obtaining higher color-developing property and high sensitivity of color-developing property, high color-developing property can be maintained for a long time. The content of the methine dye may be in such a range. The content of the basic dye is, for example, 10% by mass or less, preferably 8% by mass or less, and may be 7% by mass or less or 6% by mass or less. When the content of the basic dye is in such a range, the adhesion of the coating film by marking is enhanced, and the water resistance can be improved. When the content of the methine-based basic dye is in such a range, the color can be erased more uniformly. These lower limit values and upper limit values can be arbitrarily combined.

(Pigment component)
The ink composition for an oil-based marking pen may contain a pigment component, if necessary. Some pigments are colored with dyes, and pigment components other than such pigments are used. Examples of the pigment component include coloring pigments, extender pigments, and functional pigments. Examples of the pigment include an inorganic pigment, an organic pigment, and a metal powder pigment. Further, as the pigment, a pearl pigment, white resin particles, or the like may be used. Further, a powder containing these pigments and a resin may be used as a pigment component. As the pigment component, one of these pigments may be used, or two or more of these pigments may be used in combination.

From the viewpoint of ensuring a higher underlying hiding effect, the pigment component preferably contains at least a white pigment (first pigment). The pigment may further contain a pigment (second pigment) other than the white pigment in addition to the first pigment.

Examples of the first pigment include titanium oxide (such as Pigment White 6), zinc oxide, barium sulfate, calcium carbonate, aluminum hydroxide, talc, and white resin particles. As the first pigment, one type may be used alone, or two or more types may be used in combination. From the viewpoint of easily ensuring a higher level of concealment of the substrate, it is preferable to use at least titanium oxide, and titanium oxide and other white pigments may be used in combination. The particles of the first pigment may be coated with at least one of an inorganic component (for example, a metal oxide (alumina, zirconia, and / or titania, etc.)) and an organic component.

Specific examples of the white resin particles include Muticle PP240D (styrene resin) manufactured by Mitsui Kagaku Co., Ltd., Muticle PP110C, PP2000TX (styrene-acrylic copolymer), Low Pake Ultra E, SE manufactured by Roam & Hearth Co., Ltd. Examples thereof include low-pake HP-1055, SN-1055, HP-91, OP-84J and the like. However, these are merely examples, and the white resin particles are not limited to these specific examples.

Examples of the second pigment include chromatic pigments, black pigments, colored resin particles and the like. Each of the chromatic pigment and the black pigment may be an inorganic pigment (for example, carbon black) or an organic pigment. Examples of organic pigments include phthalocyanine pigments, slene pigments, azo pigments, quinacridone pigments, anthracinone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, perinone pigments, perylene pigments, and indolenone. Examples thereof include based pigments and azomethine based pigments. These pigments may be used as a dispersion (pigment dispersion) containing these pigments. Further, a commercially available pigment dispersion may be used as the second pigment.

The ratio of the first pigment to the pigment component is, for example, 30% by mass or more, and may be 50% by mass or more or 60% by mass or more. When the ratio of the white pigment is in such a range, higher hiding power can be ensured. The upper limit of the ratio of the white pigment can be determined according to the color of the desired ink composition, and is, for example, 100% by mass or less. The ratio of titanium oxide contained in the entire content contained in the ink composition may satisfy such a range.

A white inorganic pigment (titanium oxide or the like) and resin particles (white resin particles or the like) may be combined. By using the white inorganic pigment, it is possible to secure higher hiding power of the base. In addition to the white inorganic pigment and the resin particles, pigments other than these may be used in combination.

When the white inorganic pigment and the resin particles are used in combination, the amount of the resin particles (dry solid content) is, for example, 1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the white inorganic pigment (dry solid content). Yes, it may be 5 parts by mass or more and 40 parts by mass or less.

The content of the pigment component in the ink composition for an oil-based marking pen is, for example, 0.1% by mass or more, and may be 1% by mass or more or 5% by mass or more. The content of the pigment component is, for example, 15% by mass or less, and may be 10% by mass or less. These lower limit values and upper limit values can be arbitrarily combined.

(Sucrose fatty acid ester component)
When the ink composition for an oil-based marking pen contains a sucrose fatty acid ester component, a film is formed on the surface of the pen tip even if the oil-based marking pen is left with the cap removed. Therefore, the volatilization of the solvent can be reduced, and when writing is started, the coating film is peeled off and the ink composition for an oil-based marking pen seeps out to the adherend surface, and it is possible to effectively reduce the occurrence of blurring in the handwriting. .. Therefore, the cap-off property can be improved.

Examples of the sucrose fatty acid ester component include sucrose fatty acid ester. The sucrose fatty acid ester may be either a monoester or a polyester. Polyesters include diesters, triesters, tetraesters, pentaesters, hexaesters, hepta esters and octaesters. The polyester may be an ester of sucrose and one kind of fatty acid, or may be an ester of sucrose and two or more kinds of fatty acids.

The sucrose fatty acid ester component may contain one kind of sucrose fatty acid ester, or may contain two or more kinds of sucrose fatty acid esters.

The sucrose fatty acid ester component may include, for example, a monoester and a polyester. From the viewpoint of ensuring higher dispersion stability in the ink composition for an oil-based marking pen, the sucrose fatty acid ester component preferably contains at least a polyester (particularly, a diester and / or a triester).

Examples of fatty acids constituting the sucrose fatty acid ester include saturated fatty acids and unsaturated fatty acids. Examples of the fatty acid include a monovalent aliphatic carboxylic acid having 2 or more carbon atoms. The aliphatic carboxylic acid has, for example, 2 to 30 carbon atoms, may be 2 to 26 or 2 to 22, and may be 5 to 22 or 12 to 20. The number of carbon-carbon unsaturated bonds contained in the unsaturated fatty acid is, for example, 1 to 3, and may be 1 or 2. Fatty acids also include those having one or more substituents. Examples of the substituent include a hydroxy group, an alkoxy group, a halogen atom and the like.

Specific examples of fatty acids include butanoic acid, pentanic acid, hexanoic acid, octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linolenic acid, linolenic acid, behenic acid, and montanic acid. Be done.

From the viewpoint of ensuring higher dispersion stability in the ink composition for an oil-based marking pen, the HLB (Hydrophilic-Lipopicular Balance) of the sucrose fatty acid ester is preferably 8 or less, and may be 1 to 8. The sucrose fatty acid ester having such an HLB contains a large amount of polyester.

The content of the sucrose fatty acid ester in the ink composition for an oil-based marking pen may be 0.05% by mass or more, or 0.1% by mass or more. As described above, even if the content of the sucrose fatty acid ester is very small, high cap-off property can be ensured by combining with the fatty acid glyceride component. From the viewpoint of ensuring higher dispersion stability in the ink composition for an oil-based marking pen, the content of the sucrose fatty acid ester component is preferably 1% by mass or less, and may be 0.5% by mass or less.

(Fatty acid glyceride component)
When the ink composition for an oil-based marking pen contains a fatty acid glyceride component in addition to the sucrose fatty acid ester component, an appropriate composite film is formed on the surface of the pen tip when the oil-based marking pen is left with the cap removed. It is formed. Therefore, the volatilization of the solvent can be reduced, and the film is easily peeled off when writing is started, so that the cap-off property can be further improved.

Examples of the fatty acid glyceride component include fatty acid glycerides. Examples of the fatty acid glyceride include at least one selected from the group consisting of fatty acid monoglyceride, fatty acid diglyceride and fatty acid triglyceride. Of the three hydroxy groups of glycerin, a monoester in which one hydroxy group is esterified with a fatty acid is a fatty acid monoglyceride, and a diester in which each of the two hydroxy groups is esterified with a fatty acid is a fatty acid diglyceride. Fatty acid triglyceride is a triester in which each of the three hydroxy groups of glycerin is esterified with a fatty acid.

As the fatty acid constituting each ester, an aliphatic carboxylic acid having 4 or more and 30 or less carbon atoms is preferable. The number of carbon atoms of the aliphatic carboxylic acid may be 10 or more and 30 or less, 10 or more and 22 or less, or 12 or more and 18 or less. The fatty acid may be a polyvalent fatty acid, but a monovalent fatty acid is preferable. The fatty acid may be either a saturated fatty acid or an unsaturated fatty acid. For fatty acids, explanations and examples of sucrose fatty acid ester components can be referred to.

Each of the fatty acid diglyceride and the fatty acid triglyceride may be an ester of glycerin and one kind of fatty acid, or may be an ester of glycerin and two or more kinds of fatty acids.

The fatty acid glyceride component may contain one kind of fatty acid glyceride or may contain two or more kinds of fatty acid glycerides.

From the viewpoint of ensuring higher dispersion stability in the ink composition for an oil-based marking pen, the fatty acid glyceride component preferably contains at least one selected from the group consisting of fatty acid diglyceride and fatty acid triglyceride, and at least. It is more preferable to contain fatty acid triglyceride. From the same viewpoint, in each of the fatty acid diglyceride and the fatty acid triglyceride, at least one of the three hydroxy groups of glycerin is esterified with a fatty acid having 10 or more and 30 or less carbon atoms (preferably 10 or more and 22 or less or 12 or more and 18 or less). It is preferable to use a fatty acid glyceride component containing at least the fatty acid glyceride. Examples of the fatty acid glyceride include CA340.2 and CA210.2 manufactured by MULTICHEM.

The content of the fatty acid glyceride component in the ink composition for an oil-based marking pen is, for example, 0.3% by mass or more, preferably 0.5% by mass or more. When the content of the fatty acid glyceride component is in such a range, higher cap-off property can be ensured. The content of the fatty acid glyceride component from the viewpoint of suppressing the precipitation of the fatty acid glyceride component in the ink composition for the oil-based marking pen and facilitating the filling of the ink for the oil-based marking pen into the ink container or the core. Is preferably 2.5% by mass or less, more preferably 2% by mass or less.

(Silicone oil)
The ink composition for an oil-based marking pen may contain silicone oil. In this case, the silicone oil migrates to the surface of the coating film while the solvent volatilizes from the coating film of the ink composition for an oil-based marking pen formed by writing on the adherend surface and the viscosity of the coating film increases. do. As a result, the silicone oil bleeds on the surface of the coating film after drying, and acts as a slipping agent (lubricant). Therefore, even if the coating film of the ink composition for an oil-based marking pen is rubbed with a dry film (handwriting), it is slippery and the film is less likely to peel off. Therefore, higher fixability of the ink composition for an oil-based marking pen to the adherend surface can be obtained.

As the silicone oil, one having fluidity at at least room temperature (20 to 30 ° C.) is used. As the silicone oil, it is preferable to use modified silicone oil from the viewpoint of easily ensuring dispersion stability in the ink composition for an oil-based marking pen. Examples of the modified silicone oil include polyether-modified silicone oil, amino-modified silicone oil, mercapto-modified silicone oil, and carboxy-modified silicone oil. The ink composition for an oil-based marking pen may contain one kind of silicone oil, or may contain two or more kinds of silicone oil. Of these silicone oils, a polyether-modified silicone oil is preferable from the viewpoint of easily ensuring high dispersion stability and high scratch resistance of handwriting.

Examples of the polyether-modified silicone oil include polysiloxane having a polyether structure. The polyether-modified silicone oil may have a polyether structure at the end of the molecular chain, may have a side chain, or may have a polyether structure at the end and the side chain.

The HLB (hydrophilic lipophilic oil balance) of the polyether-modified silicone oil is, for example, 7 or less, and may be 5 or less. The lower limit of HLB is not particularly limited, but is usually 3 or more.

From the viewpoint of easily balancing hydrophilicity and hydrophobicity, a polyoxyalkylene structure (repeated structure of oxyalkylene units) is preferable as the polyether structure.

In the polyoxyalkylene structure, the number of repetitions of the oxyalkylene group (oxyalkylene unit) is, for example, 2 to 20, may be 2 to 16, or may be 2 to 10 or 2 to 6. The number of repetitions of the oxyalkylene group is appropriately selected so that the HLB of the modified silicone oil is in the above range, for example.

In the polyoxyalkylene structure, the carbon number of the alkylene is, for example, 1 to 6, and may be 2 to 6 or 2 to 4. The polyether-modified silicone oil preferably contains at least a polyoxyalkylene structure having 2 to 4 carbon atoms (particularly 2 or 3) as the polyether structure.

When the ink composition for an oil-based marking pen contains an alkali-soluble resin, a sucrose fatty acid ester component (and, if necessary, a fatty acid glyceride component), the solvent gradually volatilizes in the coating film formed when writing with an oil-based marking pen. As a result, these components may precipitate on the surface to form a film, which may make it difficult for the solvent to volatilize. This is because the sucrose fatty acid ester component and the fatty acid glyceride component have low solubility in alcohols having 2 to 4 carbon atoms (preferably 2 or 3), which is a trade-off between high cap-off properties. The film formed on the surface of the coating film is easily sticky and may peel off when subjected to a strong impact. For example, when the coating film is touched, the coating film may be peeled off and the oil-based marking pen ink composition in the coating film may adhere. Therefore, in the ink composition for an oil-based marking pen of the present invention, the scratchability of the coating film tends to be low.

When the ink composition for an oil-based marking pen contains a polyether-modified silicone oil containing an oxyethylene unit, the viscosity of the coating film increases with the volatilization of the solvent, and the solid content concentration increases from the surface side of the coating film. , Polyether-modified silicone oil is quickly migrated to the surface of the coating. As a result, the polyether-modified silicone oil bleeds on the surface of the coating film at a relatively early stage, and acts as a slipping agent. Therefore, even if the coating film (handwriting) is rubbed, it is slippery, and even if the coating film is touched, the coating film is suppressed from peeling and adhering, and the drying speed (apparent drying speed) can be shortened. In addition, the fixability of the coating film (handwriting) to the adherend surface can be further enhanced. The reason why the above-mentioned polyether-modified silicone oil is rapidly migrated to the surface of the coating film is that the polyether-modified silicone oil contains oxyethylene units, so that the hydrophilicity is increased and the concentration is increased. This is thought to be because it is easy to separate from oily components (alkali-soluble resin, sucrose fatty acid ester, fatty acid glyceride component, etc.). From the viewpoint that the polyether-modified silicone oil is easily migrated quickly, it is particularly preferable that the polyether-modified silicone oil contains a repeating structure of oxyethylene units. When a polyether-modified silicone oil containing a repeating structure of oxyethylene units is used, it is easy to secure higher fixing property to the adherend surface. From the viewpoint of easily introducing a repeating structure of more oxyethylene units into the molecule to increase hydrophilicity, a polyether-modified silicone oil having a polyether structure (particularly, a repeating structure of oxyethylene units) at least in the side chain is used. It is preferable to use it. Note that the polyether-modified silicone oil containing an oxyethylene unit (particularly, a repeating structure of an oxyethylene unit) has higher hydrophilicity than other polyether-modified silicone oils, but the ink composition for an oil-based marking pen is different. Since it contains the lipophilic component of the above in a well-balanced manner, it is possible to ensure high water resistance of the coating film (stroke).

The polyether-modified silicone oil containing an oxyethylene unit may contain an oxyalkylene unit other than the oxyethylene unit. The carbon number of the alkylene in such an oxyalkylene unit is, for example, 3 to 6, preferably 3 or 4. Polyether-modified silicone oils containing oxyethylene units and oxypropylene units are readily available.

The ratio (EO ratio) of the total number of oxyethylene units to the total number of oxyalkylene units possessed by the polyether-modified silicone oil is, for example, 40% or more. From the viewpoint of obtaining a higher drying rate, the EO ratio is preferably 50% or more. The EO ratio is 100% or less. The total number of oxyalkylene units is the total number of oxyalkylene units contained in one molecule of the polyether-modified silicone oil. The total number of oxyethylene units is the total number of oxyethylene units contained in one molecule of the polyether-modified silicone oil. As the oxyalkylene unit, a polyether-modified silicone oil containing only an oxyethylene unit (EO ratio = 100%) may be used.

Examples of the polyether-modified silicone oil having the above-mentioned EO ratio include TSF4440, 4441, 4445, 4446 (EO ratio: 100%) and TSF4452 (total number of oxyethylene units / oxypropylene unit) manufactured by MOMENTIVE Performance Materials. (= EO / PO) = 50/50 (EO ratio 50%)). All of these polyether-modified silicone oils are side chain type. From the viewpoint of obtaining a higher slipping effect, it is preferable to use a side chain type polyether-modified silicone oil.

The main chain of the polyether-modified silicone oil contains a polysiloxane structure. The polysiloxane structure of silicone oil usually has an organic group in the side chain in addition to the side chain having the polyether structure. Examples of the organic group include an alkyl group (methyl group and the like), an aryl group (phenyl group and the like) and the like. The polysiloxane structure may be a polyalkylsiloxane structure having an alkyl group in the side chain, or a polyarylsiloxane structure having an aryl group in the side chain. Further, the polysiloxane structure may be a polyalkylarylsiloxane structure having an alkyl group and an aryl group in the side chain. These polysiloxane structures also include those in which some side chains are hydrogen atoms. The polyether-modified silicone oil preferably has a polyalkylsiloxane structure from the viewpoint that the viscosity of the ink composition for an oil-based marking pen can be easily controlled to be low and higher writability can be ensured.

The content of silicone oil (or polyether-modified silicone oil) in the ink composition for an oil-based marking pen is, for example, 0.01% by mass or more and 2% by mass or less, and 0.05% by mass or more and 2% by mass or less. It may be 0.05% by mass or more and 1% by mass or less, or 0.1% by mass or more and 1% by mass or less. When the content of the silicone oil (polyether-modified silicone oil or the like) is in such a range, higher cap-off property can be ensured and the drying speed can be accelerated. Further, in addition to facilitating higher fixing property of the ink composition for an oil-based marking pen on the adherend surface, it is easy to secure high writability. The content of the polyether-modified silicone oil containing oxyethylene units in the ink composition for an oil-based marking pen may be in the above range.

Even when the ink composition for an oil-based marking pen contains a sucrose fatty acid ester component and a polyether-modified silicone oil (fatty acid glyceride component if necessary), the cap-off property tends to decrease as the content of the alkali-soluble resin increases. There is. Therefore, from the viewpoint of ensuring higher cap-off property, the content of the alkali-soluble resin in the ink composition for an oil-based marking pen is preferably 20% by mass or less, preferably 15% by mass or less, or 11% by mass or less. May be good. As described above, the lower limit of the content of the alkali-soluble resin in the ink composition for an oil-based marking pen is preferably 3% by mass or more or 5% by mass or more. Further, when the content of the alkali-soluble resin is relatively small as described above, the content of the sucrose fatty acid ester component and the fatty acid glyceride component is relatively large, so that the film tends to be sticky and the drying speed tends to be slow. be. Therefore, it is advantageous to further improve the drying rate by using a polyether-modified silicone oil.

(Additive)
The ink composition for an oil-based marking pen may contain an additive, if necessary. The additive is not particularly limited, and examples thereof include known additives added to an ink composition for an oil-based marking pen. Examples of the additive include, but are not limited to, a viscosity modifier, a structural viscosity imparting agent, a dye solubilizing agent, and a drying property imparting agent.

(others)
When the ink composition for an oil-based marking pen has a low viscosity, the amount of outflow of the ink composition for an oil-based marking pen increases, and high cap-off property can be easily obtained. In the present invention, since the ink composition for an oil-based marking pen contains the above-mentioned components, high fixability can be ensured even if the amount of the resin component is relatively small, so that the viscosity can be easily lowered.

The viscosity of the ink composition for an oil-based marking pen at 20 ° C. is, for example, 10 mPa · s or less, and may be 6 mPa · s or less. The viscosity of the ink composition for an oil-based marking pen at 20 ° C. is, for example, 1 mPa · s or more, and may be 2 mPa · s or more. The viscosity of the ink composition for an oil-based marking pen is measured, for example, using a commercially available E-type rotational viscometer at 20 ° C. under the condition of a rotational speed of 50 rpm.

The ink composition for an oil-based marking pen can be prepared by mixing the constituent components. During the preparation process, the mixture may be heated, if desired. The components may be mixed at once, or a part of the components may be mixed and then the remaining components may be added. The order of addition of the constituents is not particularly limited.

[Example]
Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

<< Examples 1 to 9, Reference Example 1 and Comparative Example 1 >>
(1) Preparation of Ink Composition for Oil-based Marking Pen Prepare an ink composition for oil-based marking pen with the components and amounts shown in Table 1. More specifically, an ink composition for an oil-based marking pen was prepared by adding a resin component and a dye component to the solvent component under stirring and dissolving them.

The following substances were used as the solvent component, the resin component, and the dye component.

(I) Solvent component (i) First solvent (ia) Ethanol (ib) Isopropanol (ii) Second solvent (ia) Propylene glycol monomethyl ether (iib) Ethylene glycol mononormal butyl ether

(II) Resin component (i) Resin 1 (alkali-soluble resin): Styrene-acrylic resin (manufactured by BASF, John Krill 682, acid value 238, Mw1700)
(Ii) Resin 2 (alkali-soluble resin): Styrene-acrylic resin (manufactured by BASF, John Krill 690, acid value 240, Mw16500)
(Iii) Resin 3 (alkali-soluble resin): Styrene-acrylic resin (manufactured by BASF, John Krill 683, acid value 160, Mw8000)
(Iv) Resin 4 (alkali-soluble resin): Styrene-acrylic resin (manufactured by Seiko PMC, Hiros X-1, acid value 110, Mw18000)
(V) Resin 5 (alkali-soluble resin): Acrylic resin (manufactured by Seiko PMC, Hiros X-310, acid value 60, Mw14000)
(Vi) Resin 6 (alkali insoluble resin): Acrylic resin (manufactured by Mitsubishi Chemical Holdings, Dianal BR-100, acid value 0)
(Vii) Resin 7 (polyvinylamide resin): Polyvinylpyrrolidone (manufactured by Tokyo Chemical Industry Co., Ltd., K15, Mw about 10,000)
(Viii) Resin 8 (polyvinylamide resin): Polyvinylpyrrolidone (manufactured by Tokyo Chemical Industry Co., Ltd., K30, Mw about 40,000)

(III) Dye component (i) Dye 1: Methine-based basic dye, C.I. I. Basic Red 14
(Ii) Dye 2: Methine-based basic dye, C.I. I. Basic Red 37
(Iii) Dye 3: Methine-based basic dye, C.I. I. Basic Violet 27
(Iv) Dye 4: Azo-based basic dye, C.I. I. Basic Red 18
(V) Dye 5: Azo-based basic dye, C.I. I. Basic Yellow 36

(2) Preparation of oil-based marking pen An oil-based marking pen is filled with the ink composition for an oil-based marking pen obtained in (1) above in a core for an oil-based marking pen and set in a container of the oil-based marking pen. Was produced.

(3) Evaluation The following evaluation was performed using the oil-based marking pen prepared in (2) above or the ink composition for oil-based marking pen prepared in (1).

(A) Viscosity The viscosity of the ink composition for an oil-based marking pen is measured at a rotation speed of 50 rpm using an E-type rotational viscometer (TVE-type viscometer manufactured by Toki Sangyo Co., Ltd., cone rotor = 1 ° 34'× R24). It was measured under the condition of.

(B) Writability on the oil film An oil film was formed by coating the surface of the steel sheet with rust preventive oil. Writing was performed on the surface of the oil film with an oil-based marking pen, and the repelling of the ink composition for the oil-based marking pen at this time was evaluated according to the following criteria.
A: No repelling of the ink composition for oil-based marking pens is seen.
B: The ink composition for an oil-based marking pen is slightly repelled.
C: The repelling of the ink composition for an oil-based marking pen is remarkable.

(C) Alkaline decolorizing steel sheet was written with an oil-based marking pen and dried. An aqueous solution containing sodium hydroxide at a concentration of 5% by mass was sprayed on the handwriting and left for 1 minute. The state of color development of the handwriting at this time was evaluated according to the following criteria.
A: No color development of handwriting is seen (transparent).
B: The color of the handwriting is slightly seen.
C: The color of the handwriting is as clear as before spraying.

(D) Alkaline cleaning property (removability of film by alkali)
In the above (c), after spraying and leaving for 1 minute, the sprayed portion was lightly wiped with a waste cloth, and the state of the handwriting was observed.
A: The handwriting is completely gone.
B: Handwriting remains, but the original shape cannot be determined.
C: The handwriting can be clearly identified.

(E) Water resistance 1
The steel plate was written with an oil-based marking pen and dried. The steel sheet was immersed in a water bath for 10 minutes. The steel plate was taken out from the water bath and the state of the handwriting was evaluated according to the following criteria.
A: There is no change in the handwriting between before soaking in the water bath.
B: There is a slight change in the handwriting.
C: The change in handwriting is remarkable. Or no handwriting remains.

(F) Color-developing writing on Kent paper with an oil-based marking pen and drying. The color development of the handwriting was evaluated according to the following criteria based on the L * a * b * color system.
A: | a * | + | b * | ≧ 31
B: | a * | + | b * | <31

(G) Quick-drying A steel sheet was written with an oil-based marking pen and dried at 20 ° C. under the condition of 65% RH. The quick-drying property was evaluated according to the following criteria based on the time from writing to the completion of drying.
A: It takes less than 10 seconds to complete the drying.
B: The time until the drying is completed exceeds 10 seconds and is within 30 seconds.
C: It takes more than 30 seconds to complete the drying.

The results are shown in Table 1. In the table, E1 to E9 are Examples 1 to 9, C1 is Comparative Example 1, and R1 is Reference Example 1.

As shown in Table 1, in E1 to E9, the coating film due to marking can be easily removed despite the use of a dilute alkaline aqueous solution having a concentration of 5% by mass. E8 and E9 using dyes other than methine-based basic dyes do not fade even when contacted with an alkaline aqueous solution. On the other hand, in E1 to E7 using a methine-based basic dye, the color can be decolorized by contacting with an alkaline aqueous solution. Further, in E1 to E9, high writing performance on the oil film can be ensured.

On the other hand, in C1 using a resin that is insoluble in alkali, a basic dye was used, but the coating film due to marking could not be removed even by washing with an alkaline aqueous solution.

<< Examples 10 to 25 and Comparative Examples 2 to 6 >>
An ink composition for an oil-based marking pen is prepared with the components and amounts shown in Tables 2 to 4. More specifically, first, the sucrose fatty acid ester component and the fatty acid glyceride component were dissolved in the solvent component as needed. The obtained solution was heated to a temperature of 45 ° C. ± 5 ° C., a resin component was added, and the mixture was stirred and dissolved. The obtained solution was dissolved by adding a dye component and, if necessary, a polyether-modified silicone oil to the solution and stirring the solution while maintaining the temperature at 45 ° C. ± 5 ° C. In this way, an ink composition for an oil-based marking pen was prepared.

Among the components in Tables 2 to 4, the components not listed in Table 1 are as follows.
(I) Solvent component (i) First solvent (ic) n-propyl alcohol (ii) Second solvent (ii) Dipropylene glycol monomethyl ether

(II) Resin component (ix) Resin 9 (oil-soluble resin): Alkylphenol resin (Tamanol 510, manufactured by Arakawa Chemical Industries, Ltd.)
(X) Resin 10 (oil-soluble resin): Water-added ketone resin (TEGO VARIPLUS SK, manufactured by EVONIK)
(Xi) Resin 11 (oil-soluble resin): rosin ester resin (manufactured by Arakawa Chemical Industry Co., Ltd., Marquid 33)
(Xii) Resin 12 (oil-soluble resin): Rosin resin (manufactured by Arakawa Chemical Industries, Ltd., rosin WW)

(III) Dye component (vi) Dye 6: Triarylmethane-based basic dye, C.I. I. Basic Blue 7
(Vii) Dye 7: Triarylmethane-based basic dye, C.I. I. Basic Green 1
(Viii) Dye 8: Azo-based basic dye, C.I. I. Basic Blue 66
(Ix) Dye 9: Oil-soluble dye, Spiron Red CGH (manufactured by Hodogaya Chemical Co., Ltd.)

(IV) Others (i) Sucrose fatty acid ester component (sucrose fatty acid ester, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., DK ester F-50, HLB6)
(Ii) Fatty acid glyceride component (fatty acid triglyceride, manufactured by MULTICHEM, CA340.2)
(Iii) Polyether-modified silicone oil 1 (manufactured by MOMENTIVE Performance Materials, TSF4446, EO / PO = 100/0)
(Iv) Polyether-modified silicone oil 2 (manufactured by MOMENTIVE Performance Materials, TSF4452, EO / PO = 50/50)

Using the prepared oil-based marking pen or the prepared ink composition for an oil-based marking pen, (a) viscosity, (d) alkaline detergency, and (g) quick-drying are evaluated in the same manner as in Examples 1 to 9. , The following evaluation was performed. As for the quick-drying property, the actual drying speed is shown in Tables 2 and 3.

(H) Water resistance 2
The water resistance of the handwriting was evaluated by the same procedure and criteria as in the water resistance 1 except that the immersion time of the steel sheet in the water bath was changed to 1 hour.

(I) Cap-off property in a general atmospheric environment (wet environment) In a constant temperature room at 20 ° C. and a relative humidity of 65%, the cap of the oil-based marking pen was removed and the pen was left in a horizontal position. The cap-off property was evaluated when writing was performed 1 day, 7 days, 14 days, and 28 days after being left unattended. However, the cap-off property was evaluated according to the following criteria when writing on a steel plate.
No blurring is observed in all 5:10 circles, or no blurring occurs in the middle of writing the first circle.
4: No blurring occurs in the middle of writing the second circle.
3: No blurring occurs in the middle of writing the third or fourth circle.
2: No blurring occurs in the middle of writing the 5th to 9th circles.
Cassoulet is observed in all 1:10 circles.

The results of Examples 10 to 25 and Comparative Examples 2 to 6 are shown in Tables 2 to 4. Examples 10 to 25 are E10 to E25, respectively, and Comparative Examples 2 to 6 are C2 to C6, respectively.

As shown in Table 2, when an oil-soluble resin is used instead of the alkali-soluble resin, and when an oil-soluble dye is used instead of the basic dye, high writeability (or fixability) to the adherend surface is used. ) Can be secured. However, in these cases, the handwriting cannot be removed with an aqueous solution containing an alkali (C2 to C6).

As shown in Table 4, when the ink composition for an oil-based marking pen does not contain a sucrose fatty acid ester component, the cap-off property is lowered (E19 to E21, and E23). On the other hand, when the ink composition for an oil-based marking pen contains a sucrose fatty acid ester component (further, a fatty acid glyceride component), high cap-off property can be obtained (E10 to E18, E22, E24, and E25). From the viewpoint of ensuring higher cap-off property, the content of the alkali-soluble resin is preferably 20% by mass or less (comparison between E24 and E25 and E10 and E18). Further, when the ink composition for an oil-based marking pen contains a polyether-modified silicone oil, the drying speed can be increased (comparison between E19 and E20 and E10 and E18). In the examples of Tables 3 and 4, as in the cases of Examples 1 to 9, high alkaline detergency can be obtained and high fixability (or writability) can be obtained.

The ink composition for an oil-based marking pen of the present invention is excellent in writing property on an oil film and also excellent in removal property by alkali. Therefore, the ink composition for an oil-based marking pen is particularly suitable for marking a metal processed material to be subjected to a degreasing treatment with an alkali. However, the use of the ink composition for an oil-based marking pen is not limited to such a use.

Claims (16)

Contains a solvent component, a resin component, and a dye component,
The solvent component contains at least an alcohol having 2 to 4 carbon atoms and contains at least.
The resin component contains an alkali-soluble resin and contains
The dye component is an ink composition for an oil-based marking pen, which comprises only a basic dye. The ink composition for an oil-based marking pen according to claim 1, wherein the content of the alkali-soluble resin is 3% by mass or more and 30% by mass or less. The ink composition for an oil-based marking pen according to claim 1 or 2, wherein the alkali-soluble resin has an acid value of 40 KOH · mg / g or more. The ink composition for an oil-based marking pen according to any one of claims 1 to 3, wherein the alkali-soluble resin has a weight average molecular weight of 1000 or more and 20000 or less. The ink composition for an oil-based marking pen according to any one of claims 1 to 4, wherein the ratio of the alcohol to the solvent component is 50% by mass or more. The ink composition for an oil-based marking pen according to any one of claims 1 to 5, wherein the dye component comprises only a methine-based basic dye. The ink composition for an oil-based marking pen according to claim 6, wherein the content of the methine-based basic dye is 0.1% by mass or more and 10% by mass or less. The ink composition for an oil-based marking pen according to any one of claims 1 to 7, further comprising a sucrose fatty acid ester component. The ink composition for an oil-based marking pen according to claim 8, wherein the content of the sucrose fatty acid ester component is 0.1% by mass or more and 1% by mass or less. The ink composition for an oil-based marking pen according to claim 8 or 9, further comprising a fatty acid glyceride component. The ink composition for an oil-based marking pen according to claim 10, wherein the content of the fatty acid glyceride component is 0.3% by mass or more and 2.5% by mass or less. The ink composition for an oil-based marking pen according to any one of claims 8 to 11, wherein the content of the alkali-soluble resin is 3% by mass or more and 20% by mass or less. The ink composition for an oil-based marking pen according to any one of claims 1 to 12, further comprising a polyether-modified silicone oil. The polyether-modified silicone oil contains a repeating structure of oxyalkylene units and contains at least oxyethylene units as the oxyalkylene units.
The ink composition for an oil-based marking pen according to claim 13, wherein the ratio of the total number of the oxyethylene units to the total number of the oxyalkylene units is 50% or more. The ink composition for an oil-based marking pen according to claim 13 or 14, wherein the content of the polyether-modified silicone oil is 0.01% by mass or more and 2% by mass or less. The ink composition for an oil-based marking pen according to any one of claims 1 to 15, which is used for marking a metal processed material to be subjected to a degreasing treatment with an alkali.