JP4160805B2 - Water-based ink composition for writing instruments - Google Patents

Description

【００４１】
【発明の効果】
本発明は、キャップオフ性を改良するために過剰量の水溶性有機溶剤を含有させたインキ組成物に発生していた粘度上昇や、尿素及び／又は尿素誘導体を配合したインキ組成物の高温下における尿素類の分解によるインキへの悪影響等の問題点を解消し、良好な安定性、優れた耐ドライアップ性を備えた筆記用水性インキ組成物を提供することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water-based ink composition for writing instruments. In more detail, even when left for a long time with the cap removed, the water for writing instruments has excellent dry-up resistance (cap-off performance) that suppresses the occurrence of blurring and inability to write due to drying of the nib. The present invention relates to an ink composition.
[0002]
[Prior art]
Conventionally, water-soluble organic solvents, urea and / or urea derivatives, and the like have been used as pen tip drying inhibitors for water-based inks for writing instruments. In recent years, in order to improve the fastness of handwriting, ink compositions for writing instruments using pigments as colorants have been widely used. However, pigment-based inks dry faster at the pen tip than dye-based inks. Also, there is a drawback that the writing property does not recover even when the cap is attached after drying.
[0003]
In the field of water-based ballpoint pens, there are many so-called “gel ballpoint pens” on the market that have a structure in which shear-thinning ink is directly stored in an ink storage tube and an ink backflow prevention body is provided at the rear end of the ink. The ink used for the ballpoint pen is a shear thinning agent, gums such as xanthan gum and succinoglycan, cross-linked acrylic acid polymers, nonionic surfactants having an HLB value of 8 to 12, associative urethanes, etc. Has been proposed and put into practical use. However, any of these shear thinning agents can easily form a strong dry film when the water evaporates at the pen tip, and thus the dry-up resistance may be significantly deteriorated.
[0004]
Therefore, the shear-thinning water-based ballpoint pen ink requires further improvement in dry-up resistance, and attempts have been made to increase the amount of the water-soluble organic solvent, urea and / or its derivatives.
[0005]
However, for example, water-soluble organic solvents typified by polyhydric alcohols such as glycerin and ethylene glycol need to be added in a large amount in order to obtain sufficient dry-up resistance. Various problems such as poor ink following ability, poor drying of handwriting, bleeding of handwriting, and the like occur.
Although urea and / or urea derivatives have some improvement in dry-up resistance, they decompose when stored in a high temperature environment to generate ammonia, increase the pH of the ink, and perform solid analysis at the nib It may cause performance deterioration of the writing instrument, such as inducing the appearance.
[0006]
The water-soluble organic solvent, urea and / or urea derivatives, etc. have high water-absorbing performance and express dry-up resistance. However, inks with excessive addition of these conventional dry-up resistance-imparting agents are used under high humidity conditions. When the writing instrument is left underneath, there is a problem in the stability of the ink such as locally absorbing moisture at the pen tip.
[0007]
[Problems to be solved by the invention]
The present invention solves the above problems, that is, provides an aqueous ink composition that does not change the viscosity of the ink, provides excellent handwriting without bleeding, and can impart dry-up resistance. To do.
[0008]
[Means for Solving the Problems]
The present invention requires that it comprises at least water, a colorant, and a pantothenic acid salt, and contains the pantothenic acid salt in the range of 0.1 to 20.0% by weight in the ink composition. To do.
[0009]
The pantothenate used in the present invention is a salt of pantothenic acid which is a kind of vitamin B group widely present in nature, an alkali metal such as lithium, sodium and potassium, an alkaline earth metal such as magnesium and calcium, zinc The metal salt which consists of etc. can be used.
By adding the pantothenate to the ink, excellent dry-up resistance can be imparted.
[0010]
The pantothenate is blended in the range of 0.1 to 20.0% by weight, preferably 1.0 to 10.0% by weight, based on the total amount of the ink composition. If it is less than 0.1% by weight, the effect of dry-up resistance is difficult to obtain. If it is more than 20.0% by weight, the added salt cannot be completely dissolved, the solid content in the ink increases, and the viscosity of the ink increases. May cause crying and bloating, and may reduce cap-off performance.
[0011]
As the colorant, all dyes and pigments that can be dissolved or dispersed in an aqueous medium can be used, and specific examples thereof are exemplified below.
As an acid dye,
New coccin (CI. 16255),
Tartrazine (C.I. 19140),
Acid Blue Black 10B (C.I. 20470),
Guinea Green (C.I.42085),
Brilliant blue FCF (C.I.42090),
Acid Violet 6BN (C.I. 43525),
Soluble Blue (C.I. 42755),
Naphthalene green (C.I. 44025),
Eosin (C.I. 45380),
Phloxin (C.I. 45410),
Erythrosine (C.I. 45430),
Nigrosine (C.I. 50420),
Acid flavin (C.I. 56205) or the like is used.
[0012]
As basic dye,
Chrysoidine (C.I. 11270),
Methyl violet FN (C.I. 42535),
Crystal violet (C.I. 42555),
Malachite green (C.I. 42000),
Victoria Blue FB (C.I. 44045),
Rhodamine B (C.I. 45170),
Acridine orange NS (C.I. 46005),
Methylene blue B (C.I. 52015) or the like is used.
[0013]
As a direct dye,
Congo Red (C.I. 22120),
Direct Sky Blue 5B (C.I. 24400),
Violet BB (C.I. 27905),
Direct deep black EX (CI 30235),
Caillas Black G Conch (C.I. 35225),
Direct Fast Black G (C.I. 35255),
Phthalocyanine blue (C.I. 74180) or the like is used.
[0014]
As the pigment, in addition to inorganic pigments such as carbon black and ultramarine blue, organic pigments such as copper phthalocyanine blue and benzidine yellow, surfactants and water-soluble resins have already been used to finely and stably disperse in an aqueous medium. Water-dispersed pigment products and the like are used, for example, as a water-dispersed pigment using a surfactant,
C. I. Pigment Blue 15: 3B [trade name: Sandye Super Blue GLL, pigment content 24%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Red 146 [trade name: Sandye Super Pink FBL, pigment content 21.5%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Yellow 81 [trade name: TC Yellow FG, pigment content about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Red 220/166 [trade name: TC Red FG, pigment content: about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.].
As a water-dispersed pigment using a water-soluble resin,
C. I. Pigment Black 7 (trade name: WA color Black A250, pigment content 15%, manufactured by Dainichi Seika Kogyo Co., Ltd.),
C. I. Pigment Green 7 [trade name: WA-S color Green, pigment content 8%, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Violet 23 [trade name: Micropigmo WMVT-5, pigment content 20%, manufactured by Orient Chemical Co., Ltd.]
C. I. Pigment Yellow 83 [trade name: Emacol NS Yellow 4618, pigment content 30%, manufactured by Sanyo Color Co., Ltd.].
[0015]
As fluorescent pigments, synthetic resin fine particle fluorescent pigments in which various fluorescent dyes are formed into a solid solution in a resin matrix can be used. Other examples include pearl pigments, metal powder pigments, phosphorescent pigments, white pigments such as titanium dioxide, silica and calcium carbonate, capsule pigments encapsulating thermochromic compositions, capsule pigments encapsulating perfumes and perfumes.
The metallic luster pigment is a metallic luster pigment such as aluminum or brass, and a metallic luster pigment in which the surface of natural mica, synthetic mica, glass piece, alumina, or transparent film piece is coated with a metal oxide such as titanium oxide as a core substance. (Pearl pigment), a metallic luster pigment in which a metal vapor deposition film is formed on a transparent or colored transparent film, and a metallic luster pigment having an iris property obtained by finely cutting an iris film in which a plurality of transparent resin layers are laminated.
Furthermore, when a metallic luster pigment such as aluminum or brass is used, a pigment obtained by coating the surface of the metallic luster pigment with a transparent resin or a colored transparent resin is preferably used, and is excellent in stability in the ink composition.
Specific examples of the metallic luster pigment coated with the transparent resin or the like include those obtained by coating both surfaces of a flat metal powder with a transparent or colored transparent resin film.
The colorant can be used singly or in combination of two or more, and is used in the range of 1 to 25% by weight, preferably 2 to 15% by weight in the ink composition.
[0016]
Further, when a pigment is used as the colorant, a pigment dispersant can be added as necessary. Examples of the pigment dispersant include surfactants such as anions and nonions, anionic polymers such as polyacrylic acid and styreneacrylic acid, and nonionic polymers such as PVP and PVA.
[0017]
Furthermore, a water-soluble organic solvent can be added as needed.
Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, and ethylene glycol monomethyl. Ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, N-methyl-2- Pyrrolidone, and the like.
The water-soluble organic solvent may be used alone or in combination of two or more, and is used in the range of 3 to 30% by weight.
[0018]
In addition to the above components, pH adjusters such as inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, organic basic compounds such as water-soluble amine compounds, benzotriazole and its derivatives, tolyltriazole, dicyclohexylammonium as necessary Nitrite, diisopropylammonium nitrite, rust inhibitor such as sodium thiosulfate, saponin, coalic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, paraoxybenzoic acid Preservatives or antifungal agents such as propyl, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, metal soap, polyalkylene glycol, fatty acid ester, ethylene oxide addition type cationic activator, phosphoric acid-based activity Agent, Thioka Lubricants such as bamate and dimethyldithiocarbamate, wetting agents such as urea and sodium pyrophosphate, antifoaming agents, dispersants, and fluorosurfactants and nonionic surfactants that improve ink permeability May be used.
[0019]
When the water-based ink composition for a writing instrument according to the present invention is applied to a ballpoint pen that directly stores ink in an ink storage tube in which a chip is directly or via a connecting member, the ink is added by adding a shear thinning agent. Appropriate viscosity is given for practical use. The shear thinning agent used can be appropriately selected from conventionally known ones. Specific examples thereof include polysaccharides such as xanthan gum, succinoglycan and carrageenan, polyacrylic acid, cross-linked acrylic acid, and polyvinyl acetamide. , Nonionic surfactants, anionic surfactants, associative urethane emulsions and the like.
[0020]
The structure and shape of the writing instrument itself filled with the water-based ink composition for a writing instrument of the present invention are not particularly limited, and conventionally used ones can be applied. For example, fiber tips, felt tips, plastic tips can be used as writing tips. The ink occlusion body consisting of fiber bundles housed in the shaft cylinder is impregnated with ink, and the ink is supplied to the tip of the writing. A structure in which an ink flow rate adjusting member consisting of a member or a fiber bundle is interposed, a marking pen having a structure in which ink is directly stored in the shaft cylinder and a predetermined amount of ink is supplied to the writing tip portion by a valve mechanism, or in the shaft cylinder An ink containing tube filled with the ink composition, the ink containing tube communicating with a tip having a ball mounted on the tip, and an ink back surface for preventing backflow on the ink end surface; Ballpoint pens and the prevention body is closely, writing unit is housed in the barrel in a state of being exposed to the air, knock-type, rotary, ball-point pen or the like having a retractable mechanism sliding the like.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
The water-based ink composition for a writing instrument according to the present invention includes a colorant and pantothenate added to an aqueous medium, and when an additive is further added, the additive is appropriately added, heated as necessary, and stirred. Thus, it is prepared by dissolving or dispersing, and is used by filling in a writing instrument in the form of a marking pen such as a ballpoint pen, a sign pen or a felt pen, a fountain pen or a brush pen.
[0022]
【Example】
Examples are shown below, but the present invention is not limited to these examples. In addition, a numerical value represents a weight part.
[0023]
Example 1
Black pigment 45.0
[Product name: WA Black A250, manufactured by Dainichi Seika Kogyo Co., Ltd .; Pigment 15
%, Diethylene glycol 20%, acrylic resin 6%, water balance]
Glycerin 10.0
Sodium pantothenate 1.0
Water 44.0
Total 100.0
[0024]
The components were stirred with a propeller-type stirrer to obtain a black aqueous ink.
[0025]
Example 2
Black dye 40.0
[Product Name: Water Black 100L, manufactured by Orient Chemical Co., Ltd .; C
. I. (Direct Black 19 20%, Water 80%)
Glycerin 10.0
Potassium pantothenate 3.0
Water 47.0
Total 100.0
[0026]
The components were stirred with a propeller-type stirrer to obtain a black aqueous ink.
[0027]
Example 3
Blue dye 15.0
[Brand name: Brilliant Blue FCF-L, manufactured by Daiwa Kasei Co., Ltd .; I. Acid Blue 9 35% aqueous solution]
Ethylene glycol 3.0
Calcium pantothenate 10.0
Water 72.0
Total 100.0
[0028]
Blue water-based ink was obtained by stirring the said component with a propeller-type stirrer.
[0029]
Example 4
Orange fluorescent pigment 50.0
[Product name: Lumicol NKW-3004, manufactured by Nippon Fluorochemicals Inc .; nonvolatile content: 41.5%]
Glycerin 10.0
Sodium pantothenate 3.0
Water 37.0
Total 100.0
[0030]
The components were stirred with a propeller type stirrer to obtain an orange fluorescent aqueous ink.
[0031]
Example 5
Yellow fluorescent pigment 50.0
[Product name: Lumicol NKW-3005, manufactured by Nippon Fluorochemicals Inc .; nonvolatile content: 42.0%]
Glycerin 10.0
Sodium pantothenate 5.0
Water 35.0
Total 100.0
[0032]
The components were stirred with a propeller stirrer to give a yellow fluorescent aqueous ink.
[0033]
Comparative Example 1
A black aqueous ink was obtained in the same manner as in Example 1 except that sodium pantothenate in the composition of Example 1 was replaced with the same amount of water.
[0034]
Comparative Example 2
A black aqueous ink was obtained in the same manner as in Example 2 except that the same amount of water was used to replace potassium pantothenate in the composition of Example 2.
[0035]
Comparative Example 3
A blue water-based ink was obtained in the same manner as in Example 3 except that the same amount of water was substituted for the calcium pantothenate in the composition of Example 3.
[0036]
Comparative Example 4
An orange fluorescent aqueous ink was obtained in the same manner as in Example 4 except that sodium pantothenate in the composition of Example 4 was replaced with the same amount of water.
[0037]
Comparative Example 5
A yellow fluorescent aqueous ink was obtained in the same manner as in Example 5 except that sodium pantothenate in the composition of Example 5 was replaced with the same amount of water.
[0038]
For each sample, the inks of Examples 1 to 5 and Comparative Examples 1 to 5 obtained by the above blending and preparation methods were filled in a commercially available marking pen [product number: SGR-8SL, manufactured by Pilot Corporation]. A marking pen was prepared and the following performance comparison test was performed.
[0039]
After assembling the dry-up test, the sample marker that was confirmed to be writable was left in the room and in a thermostatic oven at 20 ° C and 65% RH with the pen tip exposed, and then JIS P3201 writing paper A When handwriting was written on the handwriting, the standing time required until an abnormality (scratch, density change, etc.) occurred in the handwriting was confirmed.
The results of the test are shown in the following table.
[0040]
[Table 1]

[0041]
【The invention's effect】
The present invention relates to an increase in viscosity that has occurred in an ink composition containing an excessive amount of a water-soluble organic solvent in order to improve cap-off properties, and the high temperature of an ink composition containing urea and / or a urea derivative. In this way, it is possible to provide a water-based ink composition for writing having good stability and excellent dry-up resistance by eliminating problems such as adverse effects on the ink due to decomposition of ureas.

Claims (2)

A water-based ink composition for a writing instrument, comprising at least water, a colorant, and pantothenate. The aqueous ink composition for a writing instrument according to claim 1, wherein the pantothenate is contained in the ink composition in an amount of 0.1 to 20.0% by weight.