JP5475943B2 - Water-based ink composition for ballpoint pen and ballpoint pen containing the same - Google Patents

Description

  The present invention relates to a water-based ink composition for ballpoint pens and a ballpoint pen containing the same. More particularly, the present invention relates to a water-based ink composition for ballpoint pens having excellent dry-up resistance performance at the nib and a ballpoint pen containing the same.

In recent years, water-based ink compositions containing water as a main solvent have been widely used as ink compositions accommodated in ballpoint pens in consideration of environmental issues and safety for the human body. Of these, ink compositions having shear thinning viscosity are low. It is possible to eliminate the drawback that the handwriting of a viscous water-based ballpoint pen bleeds.
Examples of the substance that imparts shear thinning to the ink composition (shear thinning imparting agent) include polysaccharides such as xanthan gum (see, for example, Patent Document 1).
However, the shear thinning agent may impair dry-up performance, and attempts to improve dry-up performance by using additives such as wetting agents such as water-soluble organic solvents and solid wetting agents such as urea. However, the effect of preventing drying is insufficient, and the ink viscosity is increased, and writing defects such as fading are likely to occur.
Specifically, when urea is added excessively, the moisture evaporates from the writing tip, the concentration of the water-soluble organic solvent rises, and a so-called flower bloom phenomenon occurs in which solid content is deposited on the writing tip. Appearance deteriorates and blurring occurs. Furthermore, when a large amount of a water-soluble organic solvent or urea is added, when the writing tip is left faced downward in a humid environment, it is liable to cause problems such as drooping.
As described above, although there are many means for improving the dry-up resistance in the ink composition, other performances required for the ballpoint pen, such as blurring and sagging of handwriting, may be caused.
Further, when used for a ballpoint pen (an indented ballpoint pen) that does not require a cap in which the writing tip (ballpoint tip) is always open to the atmosphere when not writing, the dry-up resistance is an important requirement.
JP 59-74175

  The present invention solves the problems of the ink composition applied to the above-described ballpoint pen, that is, a water-based ink composition for ballpoint pens that satisfies dry-up resistance without impairing various writing performances, and The object is to provide a ballpoint pen that houses it.

In the present invention, a pigment , water, a shear thinning agent, a polyalkylene glycol having an average molecular weight of 200 to 20000 as a thickening inhibitor, and a cation formed by dissociation in ink are used. at least consists of a ionic substance is a dicationic is the content of ionic substance in the ink is more than 3 wt% relative to the total amount of the ink composition, the polyalkylene ring recall other than water in the ink composition It is required for the ballpoint pen water-based ink composition characterized by containing no sex organic solvent.
Furthermore, prior Symbol monovalent cations alkali metal ions, selected from ammonium ions, the content of ionic substance in the ink composition is 3-15 wt% relative to the total amount of the ink composition, prior to 1 to 30% by mass of the pigment in the total amount of the ink composition, the shear thinning agent is a polysaccharide, the shear thinning agent is selected from xanthan gum, welan gum, succinoglycan, etc. Is a requirement.
Furthermore, a ballpoint pen that contains a ballpoint pen refill containing the aqueous ink composition for ballpoint pens in a shaft cylinder, a ballpoint pen that contains the aqueous ink composition for ballpoint pens in the shaft cylinder, and a ballpoint pen refill for the aqueous ink composition for ballpoint pens A retractable ball-point pen, etc., which is housed in and retracts from the front end opening of the barrel by the operation of the retracting mechanism, is required.

  In the present invention, since the shear thinning agent, the specific thickening inhibitor, and the ionic substance are used in combination, the ink viscosity does not increase excessively even when water in the ink evaporates. A water-based ink composition for ballpoint pens that has excellent dry-up performance, good initial writing after writing and aging, and can maintain stable writing performance without causing blurring of writing, and can form good writing. And the ball-point pen which accommodated it is obtained.

The present invention has an average molecular weight in addition to water is not such added polyalkylene ring recall other than water-soluble organic solvent 200-20000.
Examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polyethylene glycol / polypropylene glycol block polymer (polyoxyethylene / polyoxypropylene block polymer), and the like.
Specific examples of the polyethylene glycol include Sanyo Chemical Industries, Ltd., trade names: PEG200 (average molecular weight: 200), PEG300 (average molecular weight: 300), PEG400 (average molecular weight: 400), PEG600 (average molecular weight: 600). ), PEG1000 (average molecular weight: 1000), PEG1500 (average molecular weight: 1550), PEG1540 (average molecular weight: 1450), PEG2000 (average molecular weight: 2000), PEG4000S (average molecular weight: 3300), PEG4000N (average molecular weight: 3000), PEG 6000S (average molecular weight: 8300), PEG 6000P (average molecular weight: 8300), PEG 10000 (average molecular weight: 11000), PEG 13000 (average molecular weight: 13000), PEG 20000 (average molecular weight: 2) 000), PEG20000P (average molecular weight: 20000) can be exemplified, of which the average molecular weight is selected and used in more than 300, the effect of a larger thickening inhibitor.
Specific examples of the polypropylene glycol include Sanyo Chemical Industries, Ltd., trade names: Sannix PP-200 (average molecular weight: 200), PP-400 (average molecular weight: 400), PP-950 (average molecular weight: 950). ), PP-1000 (average molecular weight: 1000), PP-1200 (average molecular weight: 1150), PP-2000 (average molecular weight: 2000), PP-3000 (average molecular weight: 3000), PP-4000 (average molecular weight: 4000) ).
Specific examples of the polyethylene glycol / polypropylene glycol block polymer (polyoxyethylene / polyoxypropylene block polymer) include Sanyo Kasei Kogyo Co., Ltd., trade names: New Pole PE-61 (average molecular weight: 1950), PE- 62 (average molecular weight: 2200), PE-64 (average molecular weight: 2900), PE-68 (average molecular weight: 8750), PE-71 (average molecular weight: 2300), PE-74 (average molecular weight: 3400), PE- Examples include 75 (average molecular weight: 4100), PE-78 (average molecular weight: 10250), PE-108 (average molecular weight: 16250), and PE-128 (average molecular weight: 20000).
As the thickening inhibitor is effective any compound of the molecular weight range, the polypropylene glycol is lowered becomes large when the water-soluble average molecular weight, is preferably used a relatively small average molecular weight .
The thickening inhibitor is used in the range of 0.1 to 30% by mass, preferably 0.5 to 20% by mass, more preferably 0.5 to 15% by mass with respect to the total amount of ink. If it is less than 0.1% by mass, the effect of dry-up resistance is small, and if it is more than 30% by mass, the shear thinning agent is poorly swelled in the ink from the beginning and it is difficult to exhibit the desired ink viscosity.

The water-based ink composition for ballpoint pens of the present invention contains the above-mentioned thickening inhibitor and an ionic substance, so that it is not necessary to actively improve anti-drying-up performance by adding a water-soluble organic solvent. capable of expressing a valid thickening inhibiting function Le other than water-soluble organic solvent added such have systems to.
Also, since the total amount of water-soluble organic solvent is less than that of conventional ink compositions, ink accumulates (hangs down) at the writing tip due to the water absorption of the water-soluble organic solvent, impairing the formation of good handwriting, or by mistake It is also possible to prevent defects that contaminate the.

Wherein the ink composition and also contains an ionic substance, and the content of ionic substance in the ink is on more than 3 wt% relative to the total amount of the ink composition.
In the system containing the shear thinning agent and the thickening inhibitor, by containing the ionic substance, the dry-up resistance can be maintained permanently even after the initial stage and after the passage of time.
The ionic substance is ionized in the ink composition to generate a cation and an anion, but a cation having a valence of 2 or more easily reacts with other components in the ink composition to form an insoluble salt. because sometimes cause such thin spots during writing by ionic substances while maintaining an ionized substance to produce monovalent cations is writing performance, excellent is the effect of maintaining the resistance to dry-up performance after aging.
Monovalent cations include alkali metal ions such as lithium ions, sodium ions, and potassium ions, ammonium ions, and aliphatic ammonium ions such as monoalkyl ammonium ions, dialkyl ammonium ions, trialkyl ammonium ions, and tetraalkyl ammonium ions. Aromatic ammonium ions such as ions, pyridinium ions, and anilinium ions are exemplified, and alkali metal ions are preferred.
The ionic substances are shown below.
Examples of inorganic salts include halides, sulfates, nitrates, phosphates, carbonates, etc., specifically sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, potassium iodide. , Lithium sulfate, sodium sulfate, ammonium sulfate, sodium nitrate, potassium nitrate, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, sodium metaphosphate Examples thereof include sodium polyphosphate, potassium polyphosphate, potassium silicate, sodium silicate, sodium carbonate, potassium carbonate, ammonium carbonate and the like. Among the inorganic salts, neutral inorganic salts that do not affect the pH of the ink composition are suitable, and examples thereof include alkali halides.
Examples of organic salts include salts of various low molecular weight organic acids, surfactants, water-soluble resins, water-soluble dyes, and the like.
Examples of the salts of low molecular weight organic acids include carboxylate, sulfonate, sulfate ester salt, phosphate ester salt and the like.
Examples of the carboxylate include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, benzoic acid, p-butylbenzoic acid, p-phenylbenzoic acid and the like. Substituted benzoic acids, α-naphthalene acetic acid, oxalic acid, succinic acid, butane-1,2,3,4-tetracarboxylic acid, terephthalic acid, naphthalenedicarboxylic acid, trimesic acid, lactic acid, malic acid, glycolic acid, glyceric acid And carboxylate obtained from hydroxybutyric acid, hydroxyisobutyric acid, tartaric acid, mevalonic acid, citric acid, isocitric acid, sorbic acid and the like.
Examples of the sulfonate include aliphatic sulfonic acids such as pentane sulfonic acid, hexane sulfonic acid, heptane sulfonic acid, octane sulfonic acid, and dodecane sulfonic acid, and alkylbenzene sulfones such as benzene sulfonic acid, benzene disulfonic acid, and p-toluene sulfonic acid. Acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, naphthalene disulfonic acid such as 1,5-naphthalenesulfonic acid disulfonic acid, naphtholsulfonic acid such as 1-naphthol-3-sulfonic acid, 1-naphthol-2,5 Examples thereof include sulfonates obtained from aromatic sulfonic acids such as naphthol disulfonic acid such as disulfonic acid and aminonaphthol sulfonic acid such as 4-amino-5-hydroxy-2,7-naphthalenesulfonic acid.
Examples of the sulfate salt include salts obtained from monohexyl sulfate, monooctyl sulfate, monodecyl sulfate, monododecyl sulfate and the like.
Examples of the phosphoric acid ester salts include salts obtained from monolauryl phosphoric acid, monostearyl phosphoric acid, monodecyl phosphoric acid, monoisodecyl phosphoric acid and the like.
These salts can be added to the ink as a salt, but when preparing the ink, the organic acid such as carboxylic acid, sulfonic acid, sulfuric acid ester, phosphoric acid ester, alkali hydroxide, aqueous ammonia, various amines, etc. May be neutralized to form a salt directly in the ink.
The surfactant includes a nonionic surfactant and an ionic surfactant, and the ionic surfactant is effective as the ionic substance of the present invention. Examples of the ionic surfactant include anionic surfactants, cationic surfactants, and amphoteric surfactants. Anionic surfactants and amphoteric surfactants are preferable, and an ink composition is more preferably alkaline. Anionic surfactants are used because they are often adjusted to a variety of types and are diverse.
Examples of the anionic surfactant include a carboxylate, a sulfonate, a sulfate ester salt, and a phosphate ester salt. Examples of the carboxylate include a fatty acid soap, an N-acyl amino acid salt, and a polyoxyethylene alkyl ether carboxylic acid. Examples thereof include salts, acylated peptides, and polymer polycarboxylates. Examples of sulfonates include alkylbenzene sulfonate, alkyl naphthalene sulfonate, formalin condensate of naphthalene sulfonate, formalin condensate of melamine sulfonate, dialkyl sulfosuccinate ester salt, alkyl disulphate sulfosuccinate, polyoxyethylene alkyl Examples thereof include sulfosuccinic acid di-salt, alkyl sulfoacetate, α-olefin sulfonate, N-acyl-N-methyl taurate, dimethyl-5-sulfoisophthalate sodium salt, and the like. Sulfate esters include sulfated oils, higher alcohol sulfates, secondary higher alcohol sulfates, polyoxyethylene alkyl ether sulfates, secondary higher alcohol ethoxy sulfates, polyoxyethylene fatty acid alkanolamide sulfates, poly Examples thereof include oxyethylene alkylphenyl ether sulfates, monoglyculates, and sulfate esters of fatty acid alkylol amides. Examples of phosphoric acid ester salts include polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, and alkyl phosphates.
Examples of the cationic surfactant include aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium chloride salts, benzethonium chloride, imidazolinium salts, and the like.
Examples of amphoteric surfactants include carboxybetaine-type amphoteric surfactants, aminocarboxylates, imidazolium betaines, lecithins, and alkylamine oxides.
As the water-soluble resin, those having an ionic group in the molecule are effective. Salts of cellulose derivatives having a carboxyl group such as carboxymethylcellulose, alginates, polyacrylates, styrene-acrylic acid copolymer resins and sulfonic acids -Salts of acrylic acid copolymer resins such as acrylic acid copolymer resins, and salts of maleic acid copolymer resins such as ethylene-maleic acid copolymer resins.
If the water-soluble dye also has an ionic group, it is effective as the ionic material of the present invention, and specifically includes an acid dye, a direct dye, and a basic dye, but the ink composition is adjusted to be alkaline. Of these, acidic dyes and direct dyes are more preferred in view of the fact that they are often used and the variety of types.
In the system using the dye as a colorant, a light ink composition with a low handwriting density or a pastel-like ink composition used in combination with a white pigment has a low dye content and has a sufficient viscosity-inhibiting effect. In some cases, other ionic substances can be used in combination.
The ionic substance is added to a water-based ink composition for ballpoint pens together with a thickening inhibitor so as to exhibit a thickening inhibiting effect. The content of the ionic substance in the ink is 1 with respect to the total amount of the ink composition. It is necessary to be at least mass%, and a practical range is 2 to 15 mass%, preferably 3 to 10 mass%, based on the total amount of the ink composition.
If it exceeds 15% by mass, the initial ink viscosity is not sufficient (not showing a high numerical value). Therefore, in a system using a pigment, the dispersion stability of the pigment is impaired, the handwriting is blurred, or the sag is caused. This causes a problem that it becomes easy.
Two or more kinds of ionic substances can be used in combination.

The colorant, distributed capable Pigments in an aqueous medium may be used all illustrate a specific example below.

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 22%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Red 146 [trade name: Sandye Super Pink FBL, pigment content 24%, 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.].
In addition, as a water-dispersed pigment using a water-soluble resin,
C. I. Pigment Black 7 [Product name: WA color Black
A250, 15% pigment content, 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.].

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 pigment may be used alone or in combination of two or more, and is used in the range of 1 to 30% by mass, preferably 2 to 25% by mass, more preferably 3 to 20% by mass in the ink composition.
Also it can be added to the pigment dispersing agent as needed. Examples of the pigment dispersant include surfactants such as anion and nonion, anionic polymers such as polyacrylic acid and styreneacrylic acid, and nonionic polymers such as polyvinylpyrrolidone and polyvinyl alcohol.
Since an ink composition using a pigment as a colorant has a higher solid content than an ink composition using a dye, when the water in the ink evaporates, the ink viscosity increases and the handwriting tends to be blurred. The ink composition of the present invention is excellent in usefulness as a water-based ink composition for a pigment-based ballpoint pen because it can maintain dry-up resistance even when a pigment is used and hardly causes fading.

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 Rust inhibitor such as nitrite, diisopropylammonium nitrite, 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, fatty acid ester, ethylene oxide addition type cationic activator, phosphoric acid based activator, thiocarbamine Acid salt, dimethyldithio Lubricants such as carbamate, ascorbic acid, ascorbic acid derivative, α-tocopherol, catechin, catechin derivative, synthetic polyphenol, phosphonate, phosphinate, sulfite, sulfoxylate, dithionate, thiosulfate Antioxidants such as thiourea dioxide, formamidinesulfinic acid, glutathione, urea, nonionic surfactants, sorbitol, mannitol, sucrose, glucose, reduced starch hydrolysate, wetting agent such as sodium pyrophosphate, ink Fluorine surfactants, nonionic, anionic, and cationic surfactants that improve the permeability of the liquid, antifoaming agents such as dimethylpolysiloxane, dispersants, and the like may be used.
These compounds contain ionic substances. For compounds that have a thickening inhibitory effect when used in combination with a thickening inhibitor, they can also be used as ionic substances or in combination with the ionic substances described above. Can be used.
In addition, in the ink composition containing the shear thinning agent, the thickening inhibitor, and the ionic substance, the viscosity when water is evaporated by 40% by mass from the total amount of the ink / initial ink viscosity (EMD viscometer, The numerical value (x) indicated by 1 rpm (measured at 20 ° C.) is 2 or less, preferably 0.01 to 1.5, more preferably 0.01 to 1.
When the numerical value (x) is 2 or less, when housed in a ballpoint pen and put to practical use, it has excellent dry-up resistance, good initial writing after time and stable writing performance, and can maintain stable writing performance. .
If the value exceeds 2, the change in the viscosity when the water in the ink is evaporated by 40% by mass and the initial viscosity of the ink is large.

The shear thinning of the ink composition is a rheological characteristic that has a property of being extremely high viscosity and difficult to flow in a static state or when the stress is low, and showing a good fluidity by decreasing the viscosity when the stress increases. It means liquidity also called thixotropic property or pseudoplasticity. Therefore, the ink composition is temporarily destroyed in the three-dimensional structure under high shear stress at the time of writing and the viscosity of the ink is lowered, and the ink at the tip of the writing becomes a low-viscosity ink suitable for writing and transferred to the paper surface. The When not writing, the viscosity of the ink becomes high, so that leakage of the ink can be prevented, and separation and backflow of the ink can be prevented. Also, the ink physical properties can be kept stable over time.
In particular, a ballpoint pen with a ball held at the tip of the writing has a low viscosity suitable for writing under high shear stress during writing, and the gap between the ball and the ball house moves by capillary force and moves on the paper surface. It is necessary to have ink characteristics that can be transferred to, and when not writing, the viscosity of all inks, including the vicinity of the ball, must be increased to prevent ink leakage, ink separation, and backflow. An ink composition having an ink viscosity at 100 rpm measured by an E-type rotational viscometer of 20 to 200 mPa · s (25 ° C.) and a shear thinning index of 0.1 to 0.8 is suitable.
The shear thinning index n can be obtained by assigning a numerical value to the empirical formula T = Kj ⁿ (T: shear stress value, j: shear rate, K is a calculated constant).

As the shear thinning agent, a water-soluble or dispersible substance is effective, and xanthan gum, welan gum, and succinoglycan whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose (average molecular weight) The main component is gum, guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alginic acid alkyl esters, methacrylic acid alkyl ester, which are composed of glucose, glucuronic acid, fucose and rhamnose. A polymer having a molecular weight of 100,000 to 150,000, a thickening polysaccharide having gelling ability extracted from seaweed such as glucomannan, agar and carrageenan, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid heavy Coalescence, inorganic fine particles, Nonionic interfaces having an HLB value of 8 to 12, such as liglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether / polyoxypropylene alkyl ether, polyoxyethylene alkylphenyl ether, fatty acid amide Examples include activators, salts of dialkyl or dialkenyl sulfosuccinic acid, and the like, which can be used alone or in combination.
The shear thinning agent can be used in the range of 0.1 to 20% by mass in the ink composition.
Combined use of the shear thinning agent , a polyalkylene glycol having an average molecular weight of 200 to 20,000 as a thickening inhibitor, and an ionic substance in which the cation formed by dissociation in the ink is a monovalent cation. Thus, when the moisture in the ink is reduced, the shear thinning agent is in a semi-swelled state, and as a result, the ink viscosity hardly increases.
As the shear thinning agent, xanthan gum, welan gum, succinoglycan is preferably used, and the ink stability is excellent.

  In addition, one or more water-soluble resins such as acrylic resin, styrene maleic acid copolymer, and dextrin may be added within a range that does not impair drying resistance.

The water-based ink composition for ballpoint pens of the present invention can contain a sugar mixture containing 40% by mass or more of 10 or more sugars, and can satisfy anti-dripping performance as well as anti-drying performance. .
Monosaccharides and disaccharides do not form a dry film sufficiently, and have high water absorption. Therefore, when applied to a ballpoint pen, dripping tends to occur if the writing tip is left facing downward. In addition, in the case of about 3 to 8 sugars, the water absorption is lower than that of monosaccharides and disaccharides, but sufficient sag prevention performance is not obtained.
Since the saccharide has a lower hygroscopicity as the molecular weight increases and it becomes easier to form a dry film, the use of a saccharide of 10 sugars or more can prevent the ink from dripping while maintaining the cap-off performance.
As the saccharide of 10 sugars or more, a starch saccharified product obtained by enzymatic decomposition of starch or a reduced starch saccharified product obtained by reducing the terminal group of the starch saccharified product can be used.
In addition, when starch is decomposed, saccharides having various degrees of polymerization are generated. Therefore, it is technically difficult to completely isolate only saccharides having 10 or more sugars, and manufacturing costs are also increased. Therefore, in a sugar mixture containing 9 or less saccharides, the above performance can be sufficiently expressed by containing 40% by mass or more of the 10 or more saccharides.
The said sugar mixture is mix | blended in 0.5-10.0 mass% with respect to the ink composition whole quantity, Preferably it is 1.0-8.0 mass%. If it is less than 0.5% by mass, the effect of preventing dripping is difficult to obtain, and if it exceeds 10.0% by mass, the viscosity of the ink increases, which may cause crying or blurring, or impair ink followability during writing.

The ink composition is used by filling a ballpoint pen with a ballpoint tip attached to the writing tip.
The structure and shape of the ballpoint pen itself are not particularly limited. For example, the ballpoint pen has an ink storage tube filled with an ink composition, and the ink storage tube communicates with a ballpoint pen tip holding a ball at the tip. Furthermore, a ballpoint pen in which a ballpoint refill whose ink backflow prevention composition is in close contact with the end face of the ink composition is accommodated in the shaft cylinder can be exemplified.
Furthermore, it has a shaft cylinder filled with the ink composition, the shaft cylinder communicates with a ballpoint pen tip holding a ball at the tip, and the ink backflow preventer composition is in close contact with the end surface of the ink composition. It may be a ballpoint pen.
The ballpoint pen having the structure described above preferably includes a cap.
For the structure of the ballpoint pen tip, a general-purpose mechanism has been effective, and a mechanism for holding a ball in a ball holding portion formed by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, a metal material A chip part is formed by cutting with a drill and the like, a mechanism for holding the ball in the ball holding part, a mechanism for biasing the ball forward by a spring body, or a metal or plastic chip made of resin A mechanism provided with the ball receiving seat can be exemplified.
The ball may be about 0.1 to 3.0 mm in diameter, such as cemented carbide, stainless steel, ruby, ceramic, resin, rubber, etc., preferably 0.15 to 1.5 mm, more preferably 0. 3 to 1.0 mm are used.
For the ink storage tube or the shaft cylinder that stores the ink composition, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon is used.
Furthermore, by using a transparent, colored transparent, or translucent molded body as the ink containing tube or the shaft tube, the ink color, the remaining amount of ink, and the like can be confirmed.
Further, when the water-based ink composition for ballpoint pens is housed in a retractable ballpoint pen, the structure and shape of the retractable ballpoint pen are not particularly limited, and the writing tip provided on the ballpoint pen refill is exposed to the outside air And can be used as long as it has a structure in which the writing tip protrudes from the opening of the shaft cylinder by the operation of the retracting mechanism.
Examples of the operation method of the retracting mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the rear end portion of the shaft tube and the side surface of the shaft tube, and by pressing the knock portion, the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the shaft tube, or on the shaft tube. The structure which makes the writing tip part of a ball-point pen refill appear and disappear from the axial cylinder front-end opening part by pressing the provided clip part can be illustrated.
The rotary type has a rotating part at the rear part of the shaft cylinder, and can be exemplified by a configuration in which the writing tip part of the ballpoint pen refill is projected and retracted from the front end part of the shaft cylinder by turning the rotating part.
The slide type has a slide part on the side surface of the shaft cylinder, and the sliding tip of the writing point of the ballpoint pen refill is projected and retracted from the front end opening of the shaft cylinder by operating the slide, or the clip part provided on the shaft cylinder is slid. By doing so, it is possible to exemplify a configuration in which the writing tip of the ballpoint pen refill is projected and retracted from the opening at the front end of the shaft cylinder.
The retractable ballpoint pen may be a composite retractable ballpoint pen in which a plurality of ballpoint pen refills are accommodated in a shaft cylinder.
The ink storage tube and the shaft cylinder constituting the ballpoint pen refill may be made of resin or metal.

The back end of the ink stored in the ink storage tube or the shaft 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 the formulation of the water-based ink composition for ballpoint pens.
In addition, the numerical value in a table | surface shows the mass%.

The contents of the raw materials in the table are explained according to the note numbers.
(1) C.I. I. Pigment Black 7
(2) C.I. I. Pigment Red 254
(3) C.I. I. Pigment Blue 15: 3
(4) Product name: Epocolor FP-10, manufactured by Nippon Shokubai Co., Ltd.
(5) Product name: Rubytech K-30, manufactured by BASF
(6) Product made by Sanki Co., Ltd., trade name: Kelzan (7) Product made by Sanki Kasei Kogyo Co., Ltd., trade name: PEG400
(8) Sanyo Chemical Industries, Ltd., trade name: PEG 20000
(9) Product name: New Pole PE-68, manufactured by Sanyo Chemical Industries
(10) Sanyo Chemical Industries, Ltd., trade name: SANNICS PP-200
( 11 ) Product name: DEMAL N, manufactured by Kao Corporation
( 12 ) Product name: Jonkrill 61J (active ingredient 30.5%), manufactured by BASF
( 13 ) Product name: Dowfax2A1 (active ingredient 47%), manufactured by The Dow Chemical Company
( 14 ) Product name: Perex OT-P (active ingredient 70%), manufactured by Kao Corporation
( 15 ) Daiichi Kogyo Seiyaku Co., Ltd., trade name: Prisurf M208B, ethanolamine salt of polyoxyethylene octyl ether phosphate

The reversible thermochromic pigments in the table were prepared by the following method.
Preparation of reversible thermochromic pigment A (a) 3- (4-diethylamino-2-hexyloxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) as an electron-donating color-forming organic compound -4-azaphthalide 2.0 parts, (b) 8.0 parts of 1,1-bis (4-hydroxyphenyl) n-decane as an electron-accepting compound, (c) Coloration of (i) and (b) above A reversible thermochromic composition composed of 50.0 parts of -4-benzyloxyphenylethyl laurate as a reaction medium for controlling the reaction is uniformly heated and dissolved, and 30.0 parts of an aromatic isocyanate prepolymer as a wall film material, A solution obtained by mixing 40 parts of ethyl acetate was emulsified and dispersed in 8% polyvinyl alcohol aqueous solution so as to form fine droplets. After stirring at 70 ° C. for about 1 hour, 2.5 parts of a water-soluble aliphatic modified amine was added. While slowly adding 拌 to give a suspension of a reversible thermochromic pigment A and continued for about 6 hours with stirring and further maintained at a liquid temperature of 90 ° C..
The reversible thermochromic pigment was isolated from the suspension by centrifugation to obtain a reversible thermochromic pigment A that changes color from blue to colorless (solid content: 60%, average particle size: 3 μm).
When the reversible thermochromic pigment A is cooled from a colorless state, it begins to develop blue color from 6 ° C., and becomes a completely colored blue state at −2 ° C. When heated from this state, it begins to fade from 56 ° C. and is colorless at 70 ° C. The discoloration behavior that completely disappears was shown. The discoloration behavior could be reproduced repeatedly.
The reversible thermochromic pigment A was cooled in advance to −2 ° C. or less and completely developed to be used as a colorant.
Preparation of reversible thermochromic pigment B Component (a) of the reversible thermochromic composition is 5.0 parts of 2- (2-chloroanilino) -6-di-n-butylaminofluorane, and component (b) is 2, 2-bis (4-hydroxyphenyl) hexafluoropropane (5.0 parts), 1,1-bis (4-hydroxyphenyl) n-decane (10.0 parts), (C) component of capric acid-4-benzyloxyphenylethyl A reversible thermochromic pigment B, which changes color from black to colorless, was obtained in the same manner as the reversible thermochromic pigment A except that the amount was changed to 50.0 parts (solid content: 60%, average particle size: 2 μm).
When the reversible thermochromic pigment B is cooled from a colorless state, it starts to develop a black color from -14 ° C. and becomes a completely colored state at −22 ° C. When heated from this state, it starts to lose its color from 32 ° C. and reaches 58 ° C. It showed a discoloration behavior that resulted in a colorless and completely decolored state. The discoloration behavior could be reproduced repeatedly.
The reversible thermochromic pigment B was cooled in advance to −22 ° C. or less and completely developed to be used as a colorant.

By mixing the formulations shown in Examples 1 to 9 and Comparative Examples 1 to 8 and stirring for 1 hour, a water-based ink composition for ballpoint pens is obtained.

Production of Ballpoint Pen The ink composition of Example 1 and Comparative Example 1 was filled in an ink containing tube fitted with one end of a polypropylene pipe with a stainless steel chip holding a ball having a diameter of 0.4 mm. A ballpoint refill was obtained by filling an ink backflow prevention body in close contact with the ink rear end face.
The ballpoint pen refill was incorporated into a shaft tube to obtain a ballpoint pen.
The ballpoint pen includes a cap.
A stainless steel tip that holds a ball having a diameter of 0.5 mm is filled with the ink composition of Examples 2 and 3 and Comparative Examples 2 and 3 in an ink containing tube fitted to one end of a polypropylene pipe, and A ballpoint pen refill was obtained by filling an ink backflow prevention body in close contact with the rear end surface of the ink.
The ballpoint pen refill was incorporated into a shaft tube to obtain a ballpoint pen.
The ballpoint pen includes a cap.
The ink compositions of Examples 4 to 8 and Comparative Examples 4 to 7 were filled in an ink containing tube fitted with one end of a polypropylene pipe with a stainless steel chip holding a ball having a diameter of 0.7 mm. A ballpoint pen refill was obtained by filling an ink backflow prevention body in close contact with the rear end surface of the ink.
The ballpoint pen refill was incorporated into a shaft tube to obtain a ballpoint pen.
The ballpoint pen includes a cap.

Production of a retractable ballpoint pen The ink composition of Example 9 and Comparative Example 8 was filled in an ink containing tube fitted with one end of a polypropylene pipe with a stainless steel chip holding a ball having a diameter of 0.7 mm. Further, the ink backflow prevention body was filled in close contact with the ink rear end face to obtain a ballpoint pen refill.
The ballpoint pen refill was incorporated in a shaft tube to obtain a retractable ballpoint pen.
The retractable ballpoint pen is housed in the shaft cylinder in a state where the writing tip provided on the ballpoint pen refill is exposed to the outside air, and a retractable mechanism (knock mechanism) provided at the rear end of the shaft cylinder. This is a structure in which the writing tip protrudes from the axial tube opening by operation.
The handwriting obtained by writing with a ballpoint pen containing an ink composition using the reversible thermochromic pigment as a colorant is decolored by rubbing with a friction tool such as SEBS rubber. Can do.

Measurement of x value Each x value of the ink composition [viscosity when water in the ink is evaporated by 40% by mass with respect to the total amount of ink / initial ink viscosity (measured at EMD viscometer, 1 rpm, 20 ° C.)] Was measured.
Dry-up test After the ballpoint pen and the retractable ballpoint pen obtained as described above were left standing at 50 ° C. for 30 days in an inverted state (the writing tip was downward), writing was performed and the state of the handwriting was visually observed.
The ballpoint pen was tested with the cap removed.
Each x value of the ink composition and the dry-up resistance test results are shown in the following table.

The determination results in the table are as follows.
Dry-up resistance test A: A good handwriting that is uniform and not blurred is obtained.
○: Handwriting without blur is obtained.
X: A blur is seen in a handwriting.

Claims (12)

A pigment as a colorant, water, a shear thinning agent, a polyalkylene glycol having an average molecular weight of 200 to 20000 as a thickening inhibitor, and a cation formed by dissociation in ink is a monovalent cation. at least consists of a certain ionic substance, and the content of ionic substance in the ink is more than 3 wt% relative to the total amount of the ink composition, the polyalkylene ring recall other than water-soluble organic solvent in the ink composition A water-based ink composition for ballpoint pens, which is not contained. The aqueous ink composition for ballpoint pens according to claim 1, wherein the monovalent cation is selected from alkali metal ions and ammonium ions. The aqueous ink composition for a ballpoint pen according to claim 1 or 2, wherein the content of the ionic substance in the ink composition is 3 to 15% by mass based on the total amount of the ink composition. The water-based ink composition for ballpoint pens according to claim 1, comprising 1 to 30% by mass of the pigment in the total amount of the ink composition. The water-based ink composition for ballpoint pens according to any one of claims 1 to 4, wherein the shear thinning agent is a polysaccharide. The aqueous ink composition for ballpoint pens according to claim 5, wherein the shear thinning agent is selected from xanthan gum, welan gum, and succinoglycan. A ballpoint pen in which a ballpoint refill containing the water-based ink composition for a ballpoint pen according to any one of claims 1 to 6 is accommodated in a shaft cylinder. The ball-point pen which incorporated the water-based ink composition for ball-point pens in any one of Claim 1 thru | or 6 in the axial cylinder. The ballpoint pen according to claim 7 or 8, wherein an ink backflow prevention body that follows the ink consumption is disposed on the rear end surface of the water-based ink composition for ballpoint pens. The ballpoint pen according to claim 7, further comprising a cap. 7. A retractable type in which the water-based ink composition for a ballpoint pen according to any one of claims 1 to 6 is accommodated in a ballpoint pen refill, and a writing tip portion of the ballpoint pen refill is projected and retracted from a front end opening portion of the barrel by operation of a retractable mechanism. Ballpoint pen. 12. The retractable ballpoint pen according to claim 11, wherein an ink backflow prevention body that follows the ink consumption is disposed on the rear end surface of the water-based ink composition for ballpoint pens.