KR100493501B1 - Metallic Glossy Water-based Ink for Direct Rechargeable Ballpoint Pen - Google Patents

Abstract

The present invention relates to a metallic luster aqueous ink used in a direct-filling ballpoint pen which directly uses ink in a tube. Based on the total amount of the ink composition, by containing 1 to 20% by weight of the colored metal pigment prepared by adsorbing the colored pigment to the metal powder, 0.1 to 1.0% by weight of a water-soluble or water-dispersible polymer formulation imparting plasticity, and water, An ink having excellent beauty, gloss, stability over time, and writing property is obtained.

Description

Metallic, water-based ink for direct-filling ballpoint pens

The present invention relates to a metallic glossy aqueous ink for a direct-filling ballpoint pen which directly uses ink in a tube.

Inks having metallic luster are already described in Japanese Patent Laid-Open No. 61-123684, Japanese Patent Laid-Open No. 63-95277, and Japanese Patent Laid-Open No. 4-126782. It is. However, since these inks are all very low in viscosity, sedimentation of the metal powder having a high specific gravity cannot be prevented. On the other hand, Japanese Laid-Open Patent Publication No. Hei 7-145339 has a rechargeable plastic resin which is imparted with pseudo-plasticity to a metallic luster aqueous ink using aluminum powder to prevent sedimentation of the aluminum powder. "Metallic glossy water-based ink for ballpoint pens" which can be used by directly filling with a polymer is described. However, only using a coloring pigment as an aluminum powder and a complementary agent is inferior in the beauty and glossiness of an ink. In addition, when aluminum powder is used in an aqueous ink, the surface thereof is often treated with a petroleum solvent or a higher fatty acid to suppress the reaction with water. However, in such a surface state, the reaction cannot be completely suppressed and time elapses. As it becomes unstable.

In addition, JP-A-2-142865 discloses at least one double bond and two carboxyl obtained by thermal polymerization of at least one carboxylic acid having a double bond on the surface of a metal pigment (metal powder). The primary colored metal pigments prepared by chemically adsorbing the colored pigments through a carboxylic acid having a group, or such primary colored metal pigments are further composed of a polymer comprising a radical polymerizable unsaturated carboxylic acid and a monomer having three or more radical polymerizable double bonds. Brightness inks using secondary colored metal pigments prepared by coating are described.

The present inventors purchased the above-mentioned colored metal pigment [trade name: Friendcolor] produced by chemical adsorption of a colored pigment on a metal pigment (metal powder) from Showa Alumin Powder Co., Ltd. and described in the above publication. Tested according to the examples. As a result, it has been found that the above-mentioned bright ink is superior in the beauty or glossiness of the ink as compared to the ink for writing instruments having a metallic luster formed by mixing a conventional dye or pigment and aluminum powder.

However, although the ink for the pen in Example 2 of the above-mentioned publication is described, the water-based ink for the pen in Example 4, and the ink for lettering as Example 5 are described, these inks are used to control the flow of ink from the pen tip. A control member using a capillary mechanism, for example, a pen tip composed of fiber bundles in a sign pen, and an ink for writing instruments having a pen core arranged in the middle of a pen tip and an ink storage tube in other pens. In itself, it cannot be used directly as a filling ink.

There has been no satisfactory metallic luster water-based ink for direct-filling ballpoint pens that is excellent in beauty and luster and stable over time.

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous ink for ballpoint pen, which is useful as a direct filling ink while using the above-mentioned colored metal pigment prepared by adsorbing a colored pigment to a metal powder and having excellent beauty, gloss, and writing properties.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to achieve the said objective, the present inventors prevented the reaction of water and a metal powder, and adds plasticity to ink, and the ink viscosity in the tube (at the time of stopping) of a ballpoint pen By lowering the ink viscosity at the time of writing by increasing the rotation and sliding of the ball generated at the time of writing, it is found that even when the ink is directly filled in the tube, the sedimentation of the colored metal pigment can be prevented and good writing performance can be obtained. The present invention was completed.

That is, the object of the present invention is 1 to 20% by weight of the colored metal pigment prepared by adsorbing the colored pigment to the metal powder, and 0.1 to 1.0% by weight of the water-soluble or water-dispersible polymer formulation to impart pseudoplasticity, based on the total amount of the ink composition. It is achieved by providing a metallic glossy aqueous ink for direct-filling ballpoint pens, characterized in that it contains% and water.

The ink composition of the present invention preferably further contains a moisturizing humectant, a dispersant, an antirust lubricant, and the like.

Since the colored metal pigment mentioned above adsorb | sucks a colored pigment to a metal powder, it is a characteristic that the width | variety of the kind of colored pigment to adsorb | suck is wide, and a wide color tone with strong metal luster is obtained. Moreover, since the metal powder surface is coat | covered with a coloring pigment, reaction of water and a metal powder is also suppressed.

The present invention, based on the total amount of the ink composition, 1 to 20% by weight of the colored metal pigment prepared by adsorbing the colored pigment to the metal powder, 0.1 to 1.0% by weight of water-soluble or water-dispersible polymer formulation to impart plasticity and water It provides a metallic glossy aqueous ink for direct-filling ballpoint pen, characterized in that it comprises in addition to these components 10 to 40% by weight moisturizing agent, 1 to 8% by weight dispersant and 0.2 to 2% by weight of anti-rust lubricant It is preferable to mix. In addition, if necessary, a pH adjusting agent and / or a bacteriostat may be added, and an organic pigment may further be added as a colorant. The metallic glossy aqueous ink for direct-filling ballpoint pen of the present invention is not limited to the ink having the ink composition described above.

The blending amount of the colored metal pigment is in the range of 1 to 20% by weight based on the total amount of the ink composition. The reason for the blending is 20% by weight while the handwriting after writing does not appear to be metallic at all when less than 1% by weight. This is because when the percentage is exceeded, the stability of the ink over time may deteriorate, and the coloring metal pigment may settle, and writing may become impossible as the pen tip is blocked with ink.

The colored metal pigments include, for example, one or more double bonds obtained by thermal polymerization of at least one carboxylic acid having a double bond and two as described in JP-A-2-142865. The carboxylic acid polymer having a carboxyl group (hereinafter referred to as thermal polymerization carboxylic acid) and the metal pigment are stirred in an organic solvent, the filtered cake and the colored pigment are kneaded or stirred mixed in the presence of an organic solvent, followed by an extra organic solvent. It can be prepared by removing. Alternatively, the thermally polymerizable carboxylic acid and the colored pigment are stirred in an organic solvent, the filtered cake and the colored pigment are kneaded or stirred and mixed in the presence of an organic solvent, and then, are dispersed and stirred in an organic solvent, followed by a radical polymerizable double bond. A monomer having three or more and a polymerization initiator can be added to polymerize, and excess organic solvent can be removed therefrom to produce a colored metal pigment. As the colored pigment at this time, any organic pigment or inorganic pigment can be used as long as it does not dissolve in an organic solvent to be used, but a colored pigment that is stably adsorbed to a metal pigment subjected to thermal polymerization carboxylic acid adsorption treatment is required. Specifically, examples of the organic pigments include azo lake pigments, insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, indanthrene pigments, indigo pigments, perinone pigments, perylene pigments, phthalone pigments, and dioxazines. Pigments, quinacridone pigments, isoindolinone pigments, metal complex pigments and the like. Examples of the inorganic pigments include sulfur lead, yellow iron oxide, bengal (red iron oxide), cobalt blue, carbon black, titanium oxide and the like. As a preferable example of a colored metal pigment, what is marketed by Showa Alumin Powder Co., Ltd. (brand name: friend color) is mentioned.

As a water-soluble or water-dispersible polymer formulation which gives pseudo plasticity, synthetic polymers, such as natural polysaccharides, such as guar gum and xanthan gum, and a crosslinking acrylic acid polymer, are mentioned. In general, natural polysaccharides have a smaller yield value compared to synthetic polymers, and therefore are more likely to precipitate colored metal pigments than synthetic polymers. For this reason, when the amount of polysaccharide added to suppress sedimentation increases, the film is formed as the moisture evaporates, so that the ink is solidified at the tip of the pen, which leads to initial writing defects, and therefore, a synthetic polymer is suitable. Crosslinked acrylic acid polymers are most suitable.

The blending amount of the water-soluble or water-dispersible polymer formulation imparting plasticity to the total amount of the ink composition is 0.1 to 1.0% by weight, and the reason for this limitation is that less than 0.1% by weight, no sufficient yield value as an ink is obtained, so that the colored metal pigment This is because if the precipitate precipitates and exceeds 1.0% by weight, the ink viscosity or yield value is too high and the settling of the colored metal pigment can be prevented, but the writing performance such as writing feeling or ink ejection is lowered.

The crosslinkable acrylic acid polymer preferably has a number average molecular weight of 3,000,000 to 5,000,000. The reason for this is that when ink is formed, an ink having excellent stability over time and a high yield value can be formed. If the yield value is low, the colored metal pigment precipitates because the ink fluidizes even if it is subjected to a small shear stress. However, if the yield value is high, the colored metal pigment does not fluidize unless stress above the yield value is applied, so that the settling of the colored metal pigment can be prevented. have. If the molecular weight is less than 3,000,000, the yield value of the ink decreases due to dissociated metal ions over time, so that the colored metal pigment precipitates, and if the molecular weight exceeds 5,000,000, the crosslinkable acrylic acid polymer is uniformly dispersed in the ink. Since it cannot be made, other stability deteriorates over time of the ink.

It is preferable to mix | blend a moisturizing humectant with the aqueous ink for ballpoint pen of this invention in order to prevent the ink of a pen tip from drying out. The amount of the moisturizing humectant settles the colored metal pigment because, on the basis of the total amount of the ink composition, the anti-drying performance of the ink is not sufficiently obtained at less than 10% by weight, and if it exceeds 40% by weight, sufficient yield value is not obtained. There is a possibility that it cannot be sufficiently prevented, 10 to 40% by weight is suitable.

As the moisturizing humectant used in the present invention, ethylene glycol, propylene glycol, glycerin, diethylene glycol, triethylene glycol, dipropylene glycol, thiodiglycol, polyglycerol, polyethylene glycol, polypropylene glycol, methyl cellosolve, butyl cellosolve, Water-soluble organic solvents such as methyl carbitol and ethyl carbitol, and these may be used alone or in mixture of two or more thereof.

It is also desirable to formulate a dispersant in order to improve the stability over time of the ink, in particular the dispersion stability of the colored metal pigment. The blending amount of the dispersant may not be uniformly dispersed at less than 1% by weight based on the total amount of the ink composition, and when the amount is more than 8% by weight, there is a fear that the yield value of the ink may be lowered. Suitable.

As the dispersant, a polymer dispersant and a nonionic surfactant can be used. Specific examples include styrene / acrylic acid copolymer, styrene / acrylic acid / methacrylic acid alkyl ester copolymer, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, and the like.

In addition, since the ink of the present invention is a water-based ink for ballpoint pens, it is preferable to add a lubricant to improve the rotation of the ball. Since a ballpoint pen is made of metal such as stainless steel or brass, a so-called anti-rust lubricant having an antirust effect is suitable. Do. If the amount is less than 0.2% by weight based on the total amount of the ink composition, the lubricity is insufficient, resulting in poor writing and handwriting. If the amount is more than 2% by weight, the yield value of the ink may be lowered. 2% by weight is suitable.

Phosphoric acid ester type surfactant, benzotriazole, a fatty acid, and fatty acid ester are mentioned as a rust preventive lubricant used by this invention, You may mix and use 2 or more types of these rust preventive lubricants.

In addition, in consideration of the stability of the ink, it is preferable to set the pH of the ink in the range of 6 to 8 using a pH adjuster. When the pH is lower than 6, it is difficult to uniformly dissolve and disperse the polymer formulation that imparts pseudoplasticity, the ink becomes unstable with time, and the rust preventing lubricant contained in the ink tends to be deteriorated. It is difficult to obtain writing performance. On the other hand, if the pH is higher than 8, the reactivity of aluminum, such as the base material of the colored metal pigment, becomes high, and thus it becomes difficult to control the reaction with water or a polymer formulation to impart pseudoplasticity, so that it does not become a stable ink over time. There exists a possibility of causing the fluidity | liquid deterioration of ink. As the pH adjusting agent, monoethanolamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethanolamine, N, N-dibutylethanolamine, N, N-methyldiethanolamine and the like can be used. Can be.

In addition, the addition of a bacteriostatic agent is preferable because it can prevent the growth of bacteria and improve the stability over time. Examples of the bacterial growth inhibitors used in the present invention include 1,2-benzoisothiazolin-3-one, sodium benzoate, sodium dehydroacetate, and the like.

In addition, various color tones can be obtained by mixing organic pigments as complementary agents. If the blending amount is less than 1% by weight based on the total amount of the ink composition, the color is not well colored. If the amount is more than 15% by weight, dry solidification at the tip of the pen advances, and initial writing performance (starting- 1 to 15% by weight is preferable because the to-write performance may be significantly reduced. As an organic pigment for complementary colors used in the present invention, Pigment yellow 1, 3, 12, 93, 94 and 109, Pigment blue 15, 16 and 17, Pigment red 3 , 5, 122, 149 and 202, Pigment green 7 and 36, and the like.

Example

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated further in detail based on an Example and a comparative example, this invention is not limited at all by these examples.

Example 1

1.0 weight% of colored metal pigments (trade name: Friend Color F500 RG) sold by Showa Alumin Powder Co., Ltd. as colored metal pigments having a mean particle diameter of 17 µm and a hue of red gold, and ethylene glycol as a moisturizing humectant. 20.0% by weight, 3.0% by weight of styrene / acrylic acid / methacryl alkyl ester copolymer as dispersant, 1.0% by weight of phosphate ester-based surfactant as antirust lubricant, 1,2-benzoisothiazolin-3-one as bacteriostatic agent 0.2% by weight, 1.0% by weight of triethanolamine and 73.4% by weight of ion-exchanged water as a pH adjusting agent are mixed, and mixed for 1 hour under the condition of 60 ° C with a magnetic stirrer.

Subsequently, as a water dispersible polymer formulation to impart pseudoplasticity to the above solution, 0.4% by weight of a crosslinked acrylic acid polymer having a number average molecular weight of 3,000,000 (hereinafter simply referred to as "crosslinked acrylic acid polymer B") was added, A homogeneous stirrer was stirred and uniformly dispersed to prepare an aqueous ink having a red gold metallic luster of the present embodiment, which is used in a direct-filling ballpoint pen. The pH of the ink is 7.

Examples 2 to 10

Except having changed the ink formulation as shown in Table 1 and Table 2, in the same procedure as in Example 1, an aqueous ink having a red gold metallic luster, which is used in a direct-filling ballpoint pen, was prepared. The pH of each ink is seven. In addition, the numbers shown in the table indicate the content (% by weight) of each component in the ink composition.

Note) 1. The crosslinked acrylic acid polymer C used in Example 5 has a number average molecular weight of 5,000,000.

    2. The crosslinked acrylic acid polymer A used in Example 6 has a number average molecular weight of 2,000,000.

    3. The crosslinked acrylic acid polymer D used in Example 7 has a number average molecular weight of 6,500,000.

    4. In Example 8, xanthan gum is used instead of the crosslinkable acrylic acid polymer.

Examples 11-14

Except for adding an organic pigment as a complementary agent and changing the ink formulation as shown in Table 2, a metallic glossy aqueous ink for direct-filling ballpoint pen was prepared in the same procedure as in Example 1. The pH of each ink is seven.

Note 1) In Example 11, Pigment Yellow 3 is added as a complementing agent.

2. Example 12 replaces Friend Color F500 RG with a colored metal pigment (trade name: Friend Color F500 OR) having an average particle diameter of 17 μm and a tint of orange, and adding Pigment Yellow 3 and Pigment Red 3 as complementary agents. do.

3. Example 13 was replaced with pigmented metal pigment (trade name: Friend Color F500 GR) having an average particle diameter of 17 μm and a tint of green, and replacing Pigment Yellow 3 and Pigment Blue 15 as complementary agents. Add.

4. Example 14 changes the friend color F500 RG into the coloring metal pigment (brand name: friend color F500 BL) whose average particle diameter is 17 micrometers, and a hue is blue, and adds pigment blue 15 as a complement agent.

Comparative Examples 1 and 2

A water-based ink having a red gold metallic luster, which is used in a direct-filling ballpoint pen, was used in the same procedure as in Example 1 except that Friend Color F500 RG was used as the coloring metal pigment and the ink formulation was changed as shown in Table 3. Manufacture. The pH of each ink is seven.

Comparative Example 3

An aqueous ink having a silver metallic luster used in a direct-filled ballpoint pen was prepared in the same procedure as in Example 1, except that aluminum powder was used instead of the colored metal pigment and the ink formulation was changed as shown in Table 3. The pH of the ink is 7.

Comparative Examples 4 to 6

Except for changing the ink formulation as shown in Table 3, in the same order as in Example 1, using a friend color F500 RG as the coloring metal pigment in the same manner as in Example 1, a red gold metal, which is used in a direct-filling ballpoint pen An aqueous ink having a gloss is prepared. The pH of each ink is seven.

Note) 1. In Comparative Example 4, xanthan gum was used in place of the crosslinked acrylic acid polymer B.

Exam and evaluation

Each of the Examples 1 to 14 and Comparative Examples 1 to 6, each of the metallic glossy aqueous inks for direct-filling ballpoint pens was evaluated by performing the following tests.

Sedimentation test of colored metal pigments:

Ink (100 cc) is sampled, and the sample is subjected to centrifugal acceleration (G: unit of gravity acceleration) for 10 minutes to observe the state of the ink.

(evaluation)

Below 300 G, colored metal pigments separated and precipitated

From 300 to 400 G, colored metal pigments are separated and settled

At 400-600 G, colored metal pigments are separated and settled (O)

Colored metal pigment is not sedimented and sedimented even at 600 G or more (◎)

Evaluation of stability over time of the ink:

The ink is placed in an airtight glass container at 50 ° C. and 0% RH, left to stand, and then judged by the change in viscosity of the ink and microscopic observation.

(evaluation)

Precipitates formed in ink within one month, or the viscosity change of ink is 30% or more compared to the initial value in the viscosity value of the ink.

Precipitates in the ink in 1 to 2 months or changes in the viscosity of the ink by 30% or more compared to the initial stage in the viscosity value of the ink.

Precipitates in the ink in 2 to 3 months or changes in the viscosity of the ink by 30% or more compared to the initial stage in the viscosity value of the ink.

No precipitates in the ink for more than 3 months and the viscosity change of the ink is less than 30% compared to the initial value in the viscosity value of the ink.

Subsequently, each ink was filled with a refill having a ball pen chip having a ball diameter of 0.7 mm from an ink ball pen (Pilot Co., Ltd., product name: G-1) for use in a commercially available aqueous gel ink composition to prepare a ball pen, and then, Evaluation is performed.

Initial written performance test:

Remove the cap of the ballpoint pen at 50 ° C. and 30% RH, let it lie on its side for 1 month, return to room temperature, and perform a straight line to visually determine the handwriting state.

(evaluation)

I couldn't write after drawing a pen 10 cm or more.

Can write before drawing to 5 to 10 cm and does not break the handwriting or generate a dashed line ································· (△)

Can write before drawing to 3 to 5 cm and does not break the handwriting or generate dashed lines ·································· (O)

Can write before drawing to 3cm, handwriting does not break or generate dashed lines .. ·································· (◎)

Written Performance Test:

In practice, handwriting is performed to visually determine the handwriting state.

(evaluation)

Uneven use due to spots or breaks occurring in the handwriting

Something that is unsatisfactory for real use due to spots or breaks in handwriting ························· ... (△)

Some handwriting that has some stains and tears, but can be used in practice. ····························· (O)

There is no spot and a break in handwriting, and handwriting is good ... (◎)

The evaluation result of each Example and a comparative example is as showing in Table 1, Table 2, and Table 3.

TABLE 1

TABLE 2

TABLE 3

In Comparative Example 1, sedimentation did not occur because the addition amount of the colored metal pigment was small, but the handwriting was faint, the metallic gloss was insufficient, and the characteristics of the crosslinking acrylic acid polymer appeared strongly, resulting in marked breaks and broken lines in the handwriting.

In Comparative Example 2, the added amount of the colored metal pigment is large, and the colored metal pigment cannot be supported by the yield value of the ink, and therefore, it is settled. As a result, clogging of ink occurs at the tip of the pen, making writing impossible.

Comparative Example 3 is an example in which aluminum powder is used as a coloring material in place of a colored metal pigment, but a polymer preparation terminal group which provides a plasticity with a reaction between the aluminum surface and water or with free aluminum ions and pseudoplasticity Reaction proceeded and stability of the ink over time could not be realized. In addition, compared to the colored metal pigments, the beauty or glossiness of the ink was insufficient, and thus the desired writing performance was not obtained.

In Comparative Example 4, since xanthan gum was added in an amount of 1.5% by weight, dissolution and dispersibility in the ink were not sufficient, and it was not stable over time, and ink flowability was also lowered, so that good writing performance was obtained. It wasn't.

In Comparative Example 5, since the addition amount of the crosslinking acrylic acid polymer is small, sufficient yield value as an ink is not obtained, the colored metal pigment precipitates and ink clogging occurs at the pen tip, making writing impossible.

In Comparative Example 6, since the amount of the crosslinking acrylic acid polymer added was large, the viscosity and yield value of the ink were too high, and no precipitation of the colored metal pigment occurred, but the writing performance was not satisfied.

Since the metallic glossy aqueous ink for direct-filling ballpoint pen of the present invention has the above-mentioned constitution, it is easy to obtain a metallic luster and a colorful color tone, and stability and writing property over time than the conventional metallic glossy aqueous ink for direct-filling ballpoint pen. This excellent ink can be obtained.

Claims (6)

Based on the total amount of the ink composition, 1 to 20% by weight of the colored metal pigment prepared by adsorbing the colored pigment to the metal powder, 0.1 to water-soluble or water dispersible polymer formulation to impart pseudo-plasticity A 1.0% by weight, 1 to 15% by weight of an organic pigment as a complementing agent, and water, and a metallic glossy aqueous ink for a direct-filling ballpoint pen. 2. The metallic luster aqueous ink for a direct-filling ballpoint pen according to claim 1, wherein the water-soluble or water-dispersible polymer formulation imparting plasticity is a crosslinkable acrylic acid polymer having a number average molecular weight of 3,000,000 to 5,000,000. The direct charge type according to claim 1, further comprising 10 to 40% by weight of a moisturizing humectant, 1 to 8% by weight of a dispersant, and 0.2 to 2% by weight of an antirust lubricant, based on the total amount of the ink composition. Metallic glossy water-based ink for ballpoint pens. The direct charge type according to claim 2, further comprising 10 to 40% by weight of a moisturizing humectant, 1 to 8% by weight of a dispersant, and 0.2 to 2% by weight of an antirust lubricant, based on the total amount of the ink composition. Metallic glossy water-based ink for ballpoint pens. 4. The metallic glossy aqueous ink for direct-filling ballpoint pen according to claim 3, further comprising a pH adjusting agent, a bacteriostatic agent or both. 5. The metallic glossy aqueous ink for direct-filling ballpoint pen according to claim 4, further comprising a pH adjuster, a bacteriostatic agent or both.