JPH111653A - Indian ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an Indian ink compsn. which does not cause the problems of blur, etc., and can be completely erased by such a simple washing as done in the home when attached to clothes by mistake by incorporating an easily erasable colorant, an erasing agent, a fixing agent, and water into the same. SOLUTION: The reasons why this compsn. is excellent in erasability are that a colorant having a long molecular chain and hence inhibited from permeating into fibers is used and that the erasing agent contained generates a wet state on fibers, prevents the micells of the fibers from squeezing, and thus facilitates a dye polymer to flow out. Polyethylene glycol, a linear alkylbenzenesulfonate, a sodium higher alcoholsulfate, a polyoxyethylene deriv., etc., are pref. erasing agents. A water-soluble polymer surfactant of the formula (R is a dye group; n is 15 or higher; and X is 1-16 provided the product of n and X is 30-200) is pref. as the easily erasable colorant. Polyvinylpyrrolidone can be suitably used as the fixing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an ink composition. More specifically, the present invention relates to a black ink composition that can be completely erased by simple washing as generally performed at home even if it accidentally adheres to clothes or the like without causing a problem such as bleeding.

[0002]

2. Description of the Related Art Ink is usually produced by adding a fixing agent such as glue or polyvinyl alcohol to a colorant such as carbon black. Such a fixing agent is added to give viscosity to ink and prevent bleeding on paper, and also improves fixability to a substrate such as paper.

[0003] Therefore, when the ink is accidentally attached to clothes, the fine particles of the colorant of black ink such as carbon black are liable to be caught in the eyes of the fibers, so that they cannot be erased cleanly and stains and dirt adhere to the clothes. Had the problem of doing so. In order to solve this problem, it is conceivable to adjust the raw material, composition, and the like. However, the problem such as excessive bleeding on paper or the like also occurred, and the problem has not been completely solved.

[0004] To solve this problem, many techniques have been disclosed for colorant compositions having excellent erasability, such as inks for washable markers and colorants for fiber sorting which have improved erasability of the colorant itself. A technique for making ink using the ink has been disclosed.

[0005]

However, although these erasable colorants are improved in erasability as compared with conventional colorants, they do not have such erasability that they can be completely erased by washing. That is, when a 40% aqueous solution, which is a commonly marketed form, is used as it is or diluted and used for black ink, depending on the color, concentration, amount of attachment, and the like, it is generally used at home. There is a case where it is difficult to completely erase by washing, and it is necessary to take measures such as extremely increasing the washing temperature or washing for a long time.

[0006] Further, when a black ink composition is prepared using these coloring agents, the erasability can also be improved by changing the composition of the black ink composition, such as by reducing the amount of a fixing agent contained. However, in this case, it is not possible to form a film after writing, and it is difficult to obtain a stable coating film when applied to the target object, such as bleeding is likely to occur, and the original purpose as a black ink composition Caused a problem that it was not possible to demonstrate the performance.

Further, polyvinyl alcohol which has been conventionally used as a fixing agent, depending on the combination of various additives used for exhibiting the performance as ink, etc., may cause gelation of the polyvinyl alcohol, resulting in poor stability over time. Had a problem.

[0008] As described above, at present, a black ink composition which can sufficiently fulfill its original purpose as ink and is erasable by washing generally performed at home has not yet been developed.

An object of the present invention is to provide a black ink composition which can be completely erased by simple washing as is generally done at home even if it accidentally adheres to clothes or the like without causing a problem such as bleeding. The point is to provide.

[0010]

Means for Solving the Problems As a result of intensive studies to solve such problems, the present inventor has found that a black ink composition using a fixing agent is blended with an erasing agent having a certain property to obtain black ink. It has been found that the erasability can be improved while maintaining the performance of. The invention of claim 1 is a black ink composition containing an easily erasable colorant, an erasing agent, a fixing agent, and water.

The excellent erasability of the colorant composition of the present invention is attributable to the fact that the use of a colorant having a long molecular chain suppresses permeation into fibers, and furthermore, the addition of an erasable agent. This is because a wet state is formed on the fiber, the micelle of the fiber is prevented from being squeezed, and the dye polymer that has permeated the fiber is easily flown out. The term "erasing agent" as used in the present invention refers to a substance that is water-soluble, has a low viscosity even when converted to an aqueous solution, and has a surface active effect or a wetting effect.

The reason for the necessity of being water-soluble is that the easily erasable colorant is generally provided as a water-soluble colorant, and that water is used as a solvent in ordinary households for washing. Further, it is presumed that the surfactant having a surfactant effect or a wetting effect promotes the bonding between water as a solvent and the colorant fine particles during washing. The low viscosity is necessary because the colorant composition of the present invention is necessary to secure its writing characteristics when used as black ink or a marker ink, and the colorant composition itself It is not a direct reason to improve erasability.

Preferred examples of the erasing agent include polyoxyethylene derivatives such as polyethylene glycol, linear alkylbenzene sulfonate, sodium higher alcohol sulfate, polyoxyethylene nonylphenyl ether, and polyoxyethylene vitamin monolaurate. These compounds have excellent properties with respect to the conditions required for the above-mentioned erasing agent, and realize excellent erasability when added to an easily erasable colorant to form a colorant composition.

The easily erasable colorant in the present invention corresponds to a colorant which improves its erasability and has a small dyeing power on fibers, and is generally marketed as a washable marker ink and a fiber sorting ink. As an easily erasable colorant that is preferably used, there is an easily erasable colorant represented by the following general formula.

[0015]

Embedded image (However, R is a dye group, n is 15 or more, X is 1 to 16,
The product of n and X is 30 to 200)

That is, a water-soluble polymer surfactant having at least 15 repeating units in the molecule, a compound having a weight average molecular weight of at least 1,000 and having a dye group R bonded to a polymer chain. . The dye group R corresponds to a color-forming portion, and examples thereof include those represented by the following chemical formulas 3 and 4.

[0017]

Embedded image

[0018]

Embedded image

Specific examples of the easily erasable colorant include Milliken, which was originally used as a dye for fiber sorting.
"VERSATINT" (trade name, manufactured by Chemical Company)
Another example is a marker ink manufactured by Milliken Chemical Company, trade name “PALMER”. In the present invention, the use of these easily erasable colorants is desirable, but not particularly limited.

As the fixing agent used in the present invention, polyvinylpyrrolidone can be suitably used. Polyvinylpyrrolidone, even when used as a fixing agent for black ink composition, in combination with other additives, especially the erasing agent used in the present invention, without causing gelation as seen when using polyvinyl alcohol And a stable coating film can be obtained.

Polyvinylpyrrolidone imparts an appropriate viscosity to the ink composition, prevents the ink composition from bleeding into paper and the like, and prevents the colorant composition from separating from the coating film, thereby improving the fixing property on paper. Is to improve. Generally, the viscosity of an aqueous solution of a polymer compound changes according to its molecular weight, for example, the weight average molecular weight. Therefore, it is preferable to determine the blending amount of polyvinylpyrrolidone according to its molecular weight. As described in detail in Examples below, when polyvinyl pyrrolidone having a weight average molecular weight of 10,000 is used, 7 to 15% by weight, and when polyvinyl pyrrolidone having a weight average molecular weight of 40,000 is used, 2 to 7% by weight. % Is preferred.

As the fixing agent used in the present invention, a more preferable one is an anionic or nonionic water-soluble polymer. In particular, it has a hydroxyl group as an essential functional group, and further has at least one of a carboxyalkyloxy group or a salt thereof, an aminocarbonylalkyloxy group, a sulfonylalkyloxy group or a salt thereof.
An anionic or nonionic water-soluble polymer having the above functional group and having a weight average molecular weight of 20,000 to 250,000 is preferably used. This compound has, for example, a structure having a unit represented by the following chemical formula, and is a polymer having a dispersing property, a film forming property, and a binder property. In the following chemical formula, R is not particularly limited,
The weight average molecular weight may be determined within a range of 20,000 to 250,000, and Rs do not need to be all the same.

[0023]

Embedded image (K + l + m + n is 95 mol% or more)

Examples of suitable compounds include the "KEPS" series manufactured by Daiichi Kogyo Seiyaku Co., Ltd. In particular, "KEPS 1205A" and "KEP
When SN-1205 is converted to an aqueous solution, the viscosity is low and optimal.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a black ink composition containing an easily erasable colorant, an erasing agent, a fixing agent and water.

The easily erasable colorant must have a coloring effect, have low dyeing power to fibers, be water-soluble, and have a low viscosity aqueous solution. Specifically, as described above, the product name “VERSATINT” manufactured by Milliken Chemical Co., which was originally used as a fiber sorting dye, and Milliken C
Chemical Company Marker Ink “PA”
LMER "is preferably used, but is not limited thereto.

The amount of the easily erasable colorant is preferably 15 to 95% by weight (hereinafter simply abbreviated as%) based on the whole colorant composition. These colorants are usually 4
Since it is provided as a 0% aqueous solution, it is 6 to 38% in terms of solid content. 15-70 within these ranges
% (Solids 4-28%) is optimal. Excessive mixing in this range results in a high viscosity, which may affect other qualities in some cases. In addition, it is necessary to increase the blending amount of the erasing agent in order to secure the erasability, which may cause a problem in writability. On the other hand, if it is less than these ranges, the concentration will be insufficient.

It is not necessary to use a single colorant as the easily erasable colorant alone, and two or more colorants may be prepared to produce various colors. Specifically, for example, if a mixture of red and yellow inks is used, an orange ink composition can be produced.

As described above, it is necessary that the erasing agent is water-soluble, has a low viscosity even when converted to an aqueous solution, and has a surfactant effect or a wetting effect. Specifically, polyethylene glycol, linear alkyl benzene sulfonate, higher alcohol sodium sulfate, or polyoxyethylene derivatives such as polyoxyethylene nonylphenyl ether and polyoxyethylene vitamin monolaurate are preferable. Among them, polyethylene glycol having a weight average molecular weight of 600 or more and 7000 or less is most suitable.

It is necessary that the amount of these components is about 10% or more. A particularly preferred range is 1
0-30% is optimal. If more than this,
It is not preferable because it has high viscosity and may adversely affect other qualities depending on the application. On the other hand, if the amount is less than this, the erasability will decrease.

The fixing agent is soluble in water or warm water, has a low viscosity of an aqueous solution, has a fixing property and a film forming property, and is soluble in an aqueous solution of an erasing agent such as polyethylene glycol. Need to be stable. Specifically, polyvinylpyrrolidone or a hydroxyl group, a carboxyalkyloxy group or a salt thereof, an aminocarbonylalkyloxy group, a sulfonylalkyloxy group or a salt thereof are combined and blended, and the weight average molecular weight is 20,000 or more and 25 or more.
It is preferable that the number of anionic or nonionic water-soluble polymers is 10,000 or less.

When polyvinylpyrrolidone is used as a fixing agent, it is necessary that the weight-average molecular weight is 40,000 or less, since the aqueous solution needs to have low viscosity. The amount of the compound slightly varies depending on the molecular weight of the polyvinylpyrrolidone to be compounded.
%, When the weight average molecular weight is 40,000, 2 to 7% is preferable. 8-1 especially for 10,000
For 2% and 40,000, 2 to 5% is optimal. If the amount is more than the above range, the viscosity becomes high and the writing character is lost, which is not preferable. If the amount is less than this range, bleeding is not preferable.

An anionic or nonionic water-soluble polymer used as a fixing agent, having a hydroxyl group as an essential functional group, and further having a carboxyalkyloxy group or a salt thereof, an aminocarbonylalkyloxy group, a sulfonylalkyloxy group. At least one of the group or a salt thereof
The compound having the above functional group and having a weight average molecular weight of 20,000 or more and 250,000 or less is not particularly limited.
EPS "series. Above all, it is preferable that the aqueous solution has a low viscosity, specifically, that the 4% aqueous solution has a viscosity of 6 mpa · s or less, and “KEPS 1205A” or “KEPS N-1205” is optimal. The optimal amount of these compounds is 3 to 15%, particularly 4 to 10%. If the amount is more than this range, the viscosity becomes high similarly to polyvinylpyrrolidone, which is not preferable in that brush character characteristics are lost. If the amount is less than this range, bleeding occurs, which is not preferable.

The colorant composition of the present invention may be diluted with water as needed to dissolve the erasing agent. The amount of water is 7
It is preferably at most 5%. If it is added in excess of this range, the concentration becomes insufficient, which is not preferred as a colorant. However, the dye described above (trade name "VERSATIN"
T "(Milliken Chemical Co.) is usually dealt with a 40% aqueous solution, so it may not be necessary to add water at the time of production, and it may be added only to adjust the viscosity of the ink composition. .

The erasable colorant composition of the present invention may optionally contain additives generally used in ink such as bulking agents, preservatives, fungicides, and fragrances. In addition, as a preservative, "Proxel XL-2" (manufactured by Zeneca) can be suitably used, and the addition amount is preferably in the range of 0 to 1%. As a fungicide, "Dencil P" (manufactured by Zeneca) can be exemplified as a preferable one, and the addition amount is preferably about 0 to 1%.

The ink composition of the present invention can be produced, for example, by the following procedure. First, an erasing agent is added to water and stirred for 15 minutes to dissolve. Thereafter, a fixing agent is added, and the mixture is stirred for 30 minutes to be completely dissolved. In these procedures, heating may be performed within a range for dissolving the fixing agent and the erasing agent. After these are completely dissolved, the colorant is added and stirred for 30 minutes. Thereafter, if necessary, various additives are added and completely dissolved.

When water is not added, an erasing agent, a fixing agent and various necessary additives are directly mixed with a commercially available 40% aqueous solution of an easily erasable coloring agent, and the mixture is stirred for 15 minutes. At this time, heating may be performed within the range for dissolving these components.

[0038]

EXAMPLES A black ink composition was prepared using polyvinylpyrrolidone having a weight-average molecular weight of 10,000 as a fixing agent at the compounding amount (% by weight, the same applies hereinafter) shown in Table 1 below. The production procedure was carried out by adding and dissolving polyethylene glycol, which is an erasing agent, and then polyvinylpyrrolidone to water so as to prevent dissolution, and then adding and dissolving a colorant (converted to a solid equivalent). In the description of this example, the indications in the table indicate the following compounds (the same applies hereinafter). Palmer ··· Washable marker ink, trade name “Palmer” (solid content 40%) MILIKEN
CHEMICAL PEG4000: Eraser, polyethylene glycol (weight average molecular weight about 3000) PVP: Fixing agent, polyvinylpyrrolidone KEPS: Fixing agent, trade name "KEPS 1205A"
PVA made by Daiichi Kogyo Seiyaku Co., Ltd. ··· Fixing agent, polyvinyl alcohol (weight 50
0, saponification degree 87%)

[0039]

[Table 1]

Using a polyvinylpyrrolidone having a weight average molecular weight of 40,000 as a fixing agent, ink compositions were prepared in the amounts shown in Table 2 below. The production procedure was carried out by adding and dissolving polyethylene glycol, which is an erasing agent, and then polyvinylpyrrolidone to water so as to prevent dissolution, and then adding and dissolving a colorant.

[0041]

[Table 2]

A black ink composition was produced in the amounts shown in Table 3 below using "KEPS 1205A" (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a fixing agent. The manufacturing procedure is as follows: water is added to polyethylene glycol as an erasing agent, and then to “KEPS 12”.
05A "was added and dissolved so as not to form mamako, and the coloring agent was added and dissolved.

[0043]

[Table 3]

(Comparative Example) A black ink composition was prepared in the amounts shown in Table 4 below using polyvinyl alcohol having a weight of 500 and a saponification degree of 87% as a fixing agent. The production procedure was performed by adding and dissolving polyethylene glycol, which is an erasing agent, and then polyvinyl alcohol to water so as to prevent dissolution, and adding and dissolving a colorant.

[0045]

[Table 4]

The erasability and writability of the above Examples and Comparative Examples were evaluated by the following procedures. (Erasability test) The ink of Examples and Comparative Examples was applied to a cotton-broad test cloth, left at room temperature until dry to the touch, and then dried.
Using a synthetic detergent (manufactured by Kao Corporation, trade name “Attack”) in a washing machine, the laundry was washed at 25 ° C. for 15 minutes (adjusted to 0.2%), and washed with water for 15 minutes. After drying, evaluation was made according to the following criteria. ◎ ・ ・ ・ ・ ・ ・ Completely erased ○ ・ ・ ・ ・ Almost erased × ・ ・ ・ ・ Completely applied marks remain (Bleedability test) Transcribed on calligraphy paper using the inks of Examples and Comparative Examples, and evaluated visually. did. The evaluation criteria were as follows. ◎ ・ ・ ・ ・ No bleeding ○ ・ ・ ・ ・ Slight bleeding but acceptable range × ・ ・ ・ ・ Bleeding is too bad to be used as ink (Viscosity test) The inks of the above Examples and Comparative Examples were measured with an E-type viscometer. The viscosity at ℃ was measured, and the following evaluation was performed. ◎ ・ ・ ・ ・ less than 25mpa ・ s ○ ・ ・ ・ ・ 25 or more and less than 45mpa ・ s × ・ ・ ・ ・ 45mpa ・ s or more (Stability test) The ink compositions of the above Examples and Comparative Examples were visually judged, The stability of the ink composition, such as whether the fixer was not gelled or precipitated, was evaluated. ◎ ・ ・ ・ ・ ・ ・ Good stability × ・ ・ ・ ・ Precipitation precipitation, gelation (concentration test) Test paper applied undiluted to drawing paper (Shiraito Kent paper) and diluted three times with water (water: ink composition) Object =
2: 1) Test papers were prepared, each HVC was measured, and the difference in lightness was compared. The evaluation was performed as follows. ◎ ・ ・ ・ ・ Lightness difference less than 1.5 ○ ・ ・ ・ ・ Lightness difference 1.5 or more and less than 2.5 × ・ ・ ・ ・ Lightness difference 2.5 or more (Fixation test) And a transfer weight (diameter 40 mm, weight 500 g) was placed thereon, pulled at a speed of about 15 cm / sec, and the state of transfer to the half paper was visually evaluated. The evaluation criteria were as follows. ◎ ・ ・ ・ ・ ・ ・ No transfer ○ ・ ・ ・ ・ Slight transfer × ・ ・ ・ ・ Transfer traces can be clearly seen

The results of the above tests are shown in Tables 5 to 8. From this result, it was found that the writing characteristics of the ink composition differed depending on the molecular weight of the fixing agent added to the ink composition. In the case of polyvinylpyrrolidone, the weight average molecular weight was 10
In the case of those having a weight average molecular weight of 40,000, the optimum is 7 to 15%, particularly 8 to 12%.
７7%, especially about 5 was found to be optimal. In these ranges, complete erasure was possible in the erasability test, and the writing characteristics of other ink compositions could be highly evaluated.

[0048]

[Table 5]

[0049]

[Table 6]

[0050]

[Table 7]

[0051]

[Table 8]

When "KEPS" is used as a fixing agent, the amount is optimally about 3 to 15%, particularly about 4 to 10%. In each of these cases, the erasing test and other writing characteristics are used. High evaluation was obtained in the test.

When polyvinyl alcohol is used as a fixing agent, gelation and precipitation are observed in combination with polyethylene glycol as an erasing agent regardless of the amount of the fixing agent, and the properties as a black ink composition are satisfied. I could not get it. Therefore, other evaluations such as an erasability test were not performed.

[0054]

Since the present invention is a black ink composition containing an easily erasable colorant, an erasing agent, a fixing agent and water, it has erroneously adhered to clothes without adversely affecting writing characteristics such as bleeding. Even in such a case, it can be completely erased by simple washing as generally performed at home.

Claims (8)

[Claims] 1. A black ink composition containing an easily erasable coloring agent, an erasing agent, a fixing agent, and water. 2. The ink composition according to claim 1, wherein the easily erasable colorant is a compound represented by the following general formula. Embedded image (However, R is a dye group, n is 15 or more, X is 1 to 16,
The product of n and X is 30 to 200) 3. The ink composition according to claim 1, wherein the fixing agent is polyvinylpyrrolidone. 4. The fixing agent is an anionic or nonionic water-soluble polymer, wherein the water-soluble polymer has a hydroxyl group as an essential functional group, and further has a carboxyalkyloxy group or a salt thereof, and aminocarbonyl. It has at least one functional group of an alkyloxy group, a sulfonylalkyloxy group or a salt thereof, and has a weight average molecular weight of 2
The ink composition according to claim 1, which is a compound of not less than 10,000 and not more than 250,000. 5. The ink composition according to claim 3, which contains 7 to 15% by weight of polyvinylpyrrolidone having a weight average molecular weight of 10,000. 6. The ink composition according to claim 3, which contains 2 to 7% by weight of polyvinylpyrrolidone having a weight average molecular weight of 40,000. 7. The fixing agent according to claim 4 in an amount of 3 to 15% by weight.
The ink composition according to claim 4, which is contained in the ink composition. 8. The ink composition according to claim 1, wherein the erasing agent is at least one of polyethylene glycol, linear alkyl benzene sulfonate, higher alcohol sodium sulfate, and polyoxyethylene derivative.