JP2006008941A - Aqueous ink composition for writing utensils - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous ink composition for writing utensils which gives excellent handwriting free of bleeding and blurring without changing the viscosity of the ink and can impart resistance to drying up. <P>SOLUTION: The aqueous ink composition for writing utensils comprises at least a highly branched cyclic dextrin of a glycan having a moiety of a cyclic structure formed of an α-1,4-glycoside bond and an α-1,6-glycoside bond as a moiety of an inner branched cyclic structure and a moiety of a noncyclic structure bonded to the moiety of the inner branched cyclic structure as a moiety of an outer branched cyclic structure and a degree of polymerization of 50-5,000, water, and a coloring agent. The above highly branched cyclic dextrin is included in an amount of 0.05-20 wt.% based on the entire amount of the ink composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  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.

Conventionally, a pen tip drying inhibitor has been added to water-based inks for writing instruments in order to prevent the ink from drying out at the tip of the pen when left for a long time with the cap removed. ing.
As the nib drying inhibitor, a water-soluble organic solvent, β-cyclodextrin, urea and / or a urea derivative or the like is used (for example, refer to Patent Document 1 or 2).

  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. Inks used in various ballpoint pens are shear thinning agents such as gums such as xanthan gum and succinoglycan, cross-linked acrylic acid polymers, nonionic surfactants having an HLB value of 8 to 12, and associative urethanes. Etc. have been proposed and put to 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.

Accordingly, 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 aforementioned water-soluble organic solvent, β-cyclodextrin, urea and / or derivatives thereof.
Japanese Patent Publication No.62-23793 Japanese Patent Publication No. 5-54875

However, for example, water-soluble organic solvents typified by polyhydric alcohols such as glycerin and ethylene glycol, and β-cyclodextrin in which D-glucopyranose is cyclically linked to α-1,4 have sufficient dry resistance. In order to obtain the properties, a large amount of addition is required, and as a result, various problems such as poor ink followability at high speed writing due to an increase in ink viscosity, poor drying of handwriting, and bleeding of handwriting 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 outage.

  The present invention solves the above-mentioned problem, that is, a water-based ink for a writing instrument capable of providing excellent handwriting without bleeding or blurring and imparting dry-up resistance without changing the viscosity of the ink. A composition is provided.

  The ink composition for a writing instrument of the present invention comprises an inner branched cyclic structure portion which is a cyclic structure portion formed by an α-1,4-glucoside bond and an α-1,6-glucoside bond, and the inner branched cyclic structure portion. A highly branched cyclic dextrin that is a glucan having a degree of polymerization in the range of 50 to 5000, water, and a colorant. Is a requirement. Furthermore, it is a requirement that the highly branched cyclic dextrin is contained in the range of 0.05 to 20% by weight in the total amount of the ink composition.

  According to the present invention, it is possible to provide a water-based ink composition for writing that can impart excellent dry-up resistance and gives a handwriting free from bleeding or blurring without changing the viscosity of the ink.

The highly branched cyclic dextrin used in the present invention is an inner branched cyclic structure portion which is a cyclic structure portion formed by an α-1,4-glucoside bond and an α-1,6-glucoside bond, and the inner branched cyclic dextrin. It is a generic name for a glucan having an outer branched cyclic structure portion that is an acyclic structure portion bonded to the structure portion, and having a polymerization degree in the range of 50 to 5000, 1,4-α-glucan branching enzyme, 4- It is a polymer dextrin having a cyclic structure obtained by allowing branching enzymes such as α-glucanotransferase and cyclodextrin glucanotransferase to act on starch such as waxy corn starch.
By adding the highly branched cyclic dextrin to the water-based ink, excellent dry-up resistance can be imparted.

  The highly branched cyclic dextrin is blended in an amount of 0.05 to 20% by weight, preferably 0.5 to 10% by weight, based on the total amount of the ink composition. If it is less than 0.05% by weight, it is difficult to obtain the effect of dry-up resistance. If it is more than 20% by weight, the viscosity of the ink increases, causing crying or blurring, and good ink ejection properties are hindered. Sometimes.

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.

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.

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.

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 SuperBlue 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 Dye Co., Ltd.].

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.
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.

  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.

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.

  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, ascorbic acid, ascorbic acid derivatives, α-tocopherol, catechin, catechin derivatives, synthetic polyphenols, phosphonates, phosphinates, sulfites, sulfoxylate, dithionite Antioxidants such as salt, thiosulfate, thiourea dioxide, formamidine sulfinic acid and glutathione, wetting agents such as urea and sodium pyrophosphate, fluorinated surfactants and nonionics, anionics that improve ink permeability Further, a cationic surfactant, an antifoaming agent such as dimethylpolysiloxane, a dispersing agent and the like may be used.

  Furthermore, if necessary, a shear thinning agent can be added to give the ink an appropriate viscosity 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.

The ink composition is put into practical use by filling a general-purpose writing instrument such as a marking pen or a ballpoint pen with a tip attached to a writing tip.
When filling the marking pen, the structure and shape of the marking pen itself are not particularly limited. For example, a fiber tip, felt tip, plastic tip is attached to the writing tip, and the fiber bundle contained in the shaft cylinder is used. The ink occlusion body is impregnated with ink, the ink is supplied to the tip of the writing, the ink is directly stored inside the shaft cylinder, and the ink flow rate adjustment member consisting of a comb groove-like ink flow rate adjustment member or fiber bundle is interposed The marking pen of structure is mentioned.
When filling the ball-point pen, the structure and shape of the ball-point pen itself are not particularly limited. For example, an ink occlusion body composed of a fiber bundle housed in the shaft tube is impregnated with ink and supplied to the writing tip. Structure, ink is stored directly inside the shaft cylinder, and there is an ink storage tube filled with the ink composition in the shaft cylinder, with a comb groove-shaped ink flow control member and an ink flow control member consisting of fiber bundles interposed The ink containing tube communicates with a tip having a ball attached to the tip, and a ballpoint pen having a structure in which a liquid stopper for backflow prevention is in close contact with the end surface of the ink. Further, a ballpoint pen or the like that has a writing part exposed in the outside air and is housed in the shaft cylinder and has a retracting mechanism such as a knock type, a rotary type, and a slide type is also included.

The ballpoint pen tip will be described in more detail. A tip formed by holding a ball in a ball holding portion obtained by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, or a metal material is cut by a drill or the like A chip formed by holding the ball in the ball holding part formed by the above, a chip provided with a resin ball receiving seat inside a metal or plastic chip, or a ball held by the chip is moved forward by a spring body Energized items can be applied.
The ball may be made of cemented carbide, stainless steel, ruby, ceramic, resin, rubber, or the like.
In addition, the writing instrument filled with the ink of the present invention includes those provided with a rolling mechanism such as a roller at the tip of the writing for forming a handwriting by the same rolling operation as that of the ball.

For example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon is used as the ink storage tube that stores the ink composition.
Furthermore, by using a transparent, colored transparent, or translucent molded body as the ink containing tube, the ink color, the remaining amount of ink, and the like can be confirmed.
In addition to directly connecting the chip to the ink storage tube, the ink storage tube and the chip may be connected via a connecting member.
The ink storage tube may be a refill type in which the refill is accommodated in the shaft cylinder, or the shaft cylinder itself having a tip mounted on the tip is used as an ink container to directly fill the shaft cylinder with ink. May be.

The back end of the ink composition accommodated in the ink accommodating tube may be filled with an ink backflow prevention body.
The ink backflow prevention body composition is composed of a non-volatile liquid or a hardly volatile liquid.
Specifically, petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples thereof include polyether-modified silicone oil and fatty acid-modified silicone oil, and one or more can be used in combination.

It is preferable to add a gelling agent to the nonvolatile liquid and / or the hardly volatile liquid to increase the viscosity to a suitable viscosity. The surface of the silica is hydrophobized, the surface is methylated fine particle silica, and aluminum silicate. , Swellable mica, hydrophobic thickeners such as bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, fatty acid amide, amide modified Examples include dextrin compounds such as polyethylene wax, hydrogenated castor oil, fatty acid dextrin, and cellulose compounds.
Furthermore, the liquid ink backflow prevention body composition and a solid ink backflow prevention body composition can be used in combination.

  The following table shows examples and comparative examples. However, the present invention is not limited to these examples. In addition, the numerical value in a table | surface represents a weight part.

The raw materials (1) to (8) in Table 1 will be described below.
(1) Product name: FP-10, manufactured by Nippon Shokubai Chemical Industry Co., Ltd.
(2) Product name: Brilliant Blue-FCF-L, manufactured by Daiwa Kasei Co., Ltd.
(3) Sanyo Dye Co., Ltd., trade name: Sandye Super Blue GLL
(4) B. F. Product name: Carbopol 940, manufactured by Goodrich
(5) Product name: NP-10, manufactured by Nikko Chemicals Co., Ltd.
(6) Prisurf A212E, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
(7) Ezaki Glico Co., Ltd., trade name: cluster dextrin (8) Shimizu Minato Sugar Co., Ltd., trade name: DEXIPEARL K100

Preparation of ink After mixing the raw materials other than alkali thickening acrylic emulsion, xanthan gum and succinoglycan in the previous blending amount, stirring with a disper and dissolving, further alkali thickening acrylic emulsion, xanthan gum and succinoglycan The ink for writing instruments was obtained by adding and stirring with a disper.

Preparation of Ink Backflow Preventer Body Into 98 parts of polybutene as a base oil, 2 parts of fatty acid amide as a thickener was added, and then kneaded with three rolls to obtain an ink backflow preventer body.

Preparation of sample ballpoint pen Each ink composition in the previous period was filled in a ballpoint pen refill fitted with one end of a polypropylene pipe with a stainless steel tip holding a 0.7 mm diameter superalloy ball. After filling the ink backflow preventer so as to be in close contact with the sample, a ballpoint pen refill subjected to a centrifugal treatment was incorporated into the ballpoint pen barrel to prepare a sample ballpoint pen.

A cap-off test was conducted by the following method using each sample ballpoint pen.
After assembling, the sample ballpoint pen, which was confirmed to be writable, was left in a temperature-controlled room at 20 ° C. and 60% RH for 2 weeks and 4 weeks with the pen tip exposed, and then JIS P3201 writing paper. Handwritten in A, 12 circles were written continuously in a line, and it was confirmed from what number the circles could be written normally.
The results of the test are shown in the following table.

The evaluation of the test results is as follows.
Cap-off test ○: Writing is smoother than writing.
×: Cannot write within 1 line, or cannot write.

Claims (2)

  An inner branched cyclic structure portion which is a cyclic structure portion formed by an α-1,4-glucoside bond and an α-1,6-glucoside bond, and an outer portion which is an acyclic structure portion bonded to the inner branched cyclic structure portion A water-based ink composition for a writing instrument, comprising a highly branched cyclic dextrin that is a glucan having a branched cyclic structure portion and having a polymerization degree in the range of 50 to 5000, a colorant, and water.   The aqueous ink composition for a writing instrument according to claim 1, wherein the highly branched cyclic dextrin is contained in an amount of 0.05 to 20% by weight in the total amount of the ink composition.