JP6265777B2 - Water-based ink composition for writing instruments - Google Patents

Description

  The present invention relates to a water-based ink composition for a writing instrument capable of writing a sharp and clean drawing line with clear tome, honey, and fold and beautiful characters.

Conventionally, a water-based ink composition for a writing instrument utilizing the characteristics of an ink having shear thinning viscosity is known.
Such a water-based ink composition for a writing instrument contains a thickener (gelling agent) that exhibits shear thinning, for example, 1) contains xanthan gum in an amount of 0.20 to 0.45% by weight. 2) Water-based ballpoint pen ink composition (see, for example, Patent Document 1), 2) (b) Colorant as essential component, (b) Glucose / galactose / pyruvic acid or its salt / succinic acid or its salt / acetic acid Organic acid modification having an average molecular weight of about 1 million to about 8 million consisting of basic units having a molar ratio of 5 to 8/1 to 2 / 0.5 to 2 / 0.5 to 2 / 0.5 to 1 A water-based ink composition for a writing instrument comprising a heteropolysaccharide, and (c) an aqueous medium containing water and a water-soluble organic solvent and containing 50% by weight or more of water (for example, see Patent Document 2) is known. Yes.

  The conventional ink composition having shear thinning viscosity has a high ink viscosity when not writing (when not writing), and prevents ink from dropping off (when ink is writing). Is characterized in that the viscosity decreases due to the action of ball rotation, etc., and writing can be performed smoothly, and the shear rate is increased.

  However, the conventional water-based ink composition for a writing instrument having such a viscous behavior has a problem that the writing part has a heavy writing feeling and is easy to blur and blur. In addition, during writing, the viscosity drops drastically, causing problems such as a decrease in the density of the toe portion and cracking of the drawn portion of the halai portion, which tends to make it difficult to obtain sharp and clean characters and drawn lines. was there.

JP 59-74175 (Claims, Examples, etc.) JP-A-6-88050 (Claims, Examples, etc.)

  The present invention is to solve this problem in view of the problems of the prior art described above, and there is no bleeding on the writing lines, no ink breakthrough on the back of the paper, and excellent initial writing performance. An object of the present invention is to provide a water-based ink composition for a writing instrument in which a sharp and clean drawing line with clear tome, honey, and halai and a beautiful character can be written.

（２） 水溶性高分子化合物が分子内にケトン基又はアルデヒド基を有する変性ポリビニルアルコール、分子内にケトン基又はアルデヒド基を有する変性エポキシ樹脂、分子内にイソシアネート基を有するウレタン樹脂から選ばれることを特徴とする上記（１）に記載の筆記具用水性インク組成物。
（３） ジヒドラジド化合物がアジピン酸ジヒドラジド、セバシン酸ジヒドラジド、ドデカンジオヒドラジド、イソフタル酸ジヒドラジドから選ばれることを特徴とする上記（１）に記載の筆記具用水性インク組成物。
（４） 上記（１）〜（３）の何れか一つに記載の筆記具用水性インク組成物を搭載したことを特徴とする筆記具。 As a result of diligent research in view of the above-described conventional problems, the present inventor has found that in a water-based ink composition for writing instruments, a water-soluble polymer compound having at least a specific functional group in the molecule, a specific dihydrazide compound, and It has been found that a water-based ink composition for a writing instrument having the above-mentioned purpose can be obtained by containing the present invention, and the present invention has been completed.
That is, the present invention resides in the following (1) to (4).
(1) A writing instrument comprising a water-soluble polymer compound having at least one functional group of a ketone group, an aldehyde group and an isocyanate group in the molecule, and a dihydrazide compound represented by the following formula (I): Water-based ink composition.

(2) The water-soluble polymer compound is selected from a modified polyvinyl alcohol having a ketone group or an aldehyde group in the molecule, a modified epoxy resin having a ketone group or an aldehyde group in the molecule, and a urethane resin having an isocyanate group in the molecule. The water-based ink composition for a writing instrument as described in the above item (1).
(3) The aqueous ink composition for a writing instrument as described in (1) above, wherein the dihydrazide compound is selected from adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide, and isophthalic acid dihydrazide.
(4) A writing instrument comprising the water-based ink composition for a writing instrument according to any one of (1) to (3) above.

  According to the present invention, there is no blur on the writing lines, no ink penetration on the back of the paper, excellent initial writing performance, clear tome, shine, and fold, sharp and beautiful characters that become beautiful characters Provided is a water-based ink composition for a writing instrument in which a drawn line can be written.

Hereinafter, embodiments of the present invention will be described in detail.
The aqueous ink composition for a writing instrument of the present invention comprises a water-soluble polymer compound having at least a functional group of a ketone group, an aldehyde group and an isocyanate group in the molecule, and a dihydrazide compound represented by the following formula (I): It is characterized by containing.

The water-soluble polymer compound having at least one functional group of ketone group, aldehyde group and isocyanate group used in the present invention includes at least one functional group of ketone group, aldehyde group and isocyanate group in the molecule. Although it will not specifically limit if it is a water-soluble high molecular compound which has this, Preferably, what has any functional group of a ketone group, an aldehyde group, and an isocyanate group in the side chain and / or terminal in a molecule | numerator is preferable.
Examples of water-soluble polymer compounds that can be used include modified polyvinyl alcohol (hereinafter referred to as modified PVA) having a ketone group or an aldehyde group in the molecule, a modified epoxy resin having a ketone group or an aldehyde group in the molecule, and a molecule. Examples thereof include urethane resins having an isocyanate group.
Specifically, modified PVA having a ketone group at the side chain and / or terminal in the molecule, for example, modified PVA (D series such as DF-20) manufactured by Nihon Acetate / Poval, manufactured by Nippon Synthetic Chemical Co., Ltd. Modified PVA (Gosenx series), modified epoxy resin having an aldehyde group at the side chain and / or terminal in the molecule, for example, modified epoxy resin made by Arakawa Chemical Industries (modelix series such as MODEPICS 301), intramolecular The urethane resin having an isocyanate group at its side chain and / or terminal, for example, a urethane resin (Elastoron series) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. and the like. These may be used alone or in combination of two or more.
Further, the mass average molecular weight (Mw) of these water-soluble polymer compounds is preferably 3000 to 150,000.

The content of the water-soluble polymer compound having at least one of a functional group such as a ketone group, an aldehyde group and an isocyanate group in the molecule is preferably 0.1 relative to the total amount of the water-based ink composition for writing instruments. ˜10.0 mass% (hereinafter simply referred to as “%”), more preferably 0.5 to 3.0%.
When the content is less than 0.1%, the effect of the present invention cannot be obtained. On the other hand, when the content exceeds 10%, the followability decreases due to an increase in viscosity, which is not preferable.

The dihydrazide compound used in the present invention is represented by the following formula (I), and serves as a crosslinking agent for a water-soluble polymer compound having a functional group of a ketone group, an aldehyde group or an isocyanate group in the molecule. It exhibits a thickening action due to a chemical bond between any functional group of the ketone group, aldehyde group and isocyanate group in the water-soluble polymer compound and the dihydrazide group in the dihydrazide compound that serves as a crosslinking agent, In the water-based ink composition for writing instruments, rheological properties different from those of the conventional gel ink are developed.

  R in the above (I) is selected from the group consisting of an aromatic ring, a saturated or unsaturated linear or branched hydrocarbon having 2 to 12 carbon atoms, and specifically includes a phenylene group, a naphthylene group, a substituted group. Hydantoin ring, tetramethylene group, heptamethylene group, octamethylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group, pentylene group, neopentylene group, hexylene group, heptylene group, Examples include n-octylene group, 2-ethylhexylene group, nonylene group, decylene group, undecylene group, dodecylene group and the like.

Examples of the dihydrazide compound represented by the above formula (I) include succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, and 1,12-dodecanedicarboxylic acid. Dihydrazide, phthalic acid dihydrazide, terephthalic acid dihydrazide, isophthalic acid dihydrazide, 2,6-naphthalenedicarboxylic acid dihydrazide, 1,4-naphthalenedicarboxylic acid dihydrazide, 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin, dodecane Examples include dihydrazide (dodecanedioic acid dihydrazide), among which adipic acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, dodecanediohydride Disilazide is preferable.
These dihydrazide compounds can use a commercially available thing.

The content of the dihydrazide compound represented by the formula (I) is preferably 0.01 to 2.0%, more preferably 0.05 to 1.0, based on the total amount of the aqueous ink composition for writing instruments. % Is desirable.
If the content is less than 0.01%, the crosslinking reaction does not proceed and the effects of the present invention cannot be obtained. On the other hand, if the content exceeds 2.0%, no further effects are observed. Become.

  In addition, the content ratio of the water-soluble polymer compound having at least one functional group of a ketone group, an aldehyde group and an isocyanate group in the molecule and the dihydrazide compound is 30: 1 from the viewpoint of expressing a good cross-linked state. It is desirable that it is ˜2: 1, more preferably 20: 1 to 3: 1.

  The water-based ink composition for a writing instrument of the present invention comprises a water-soluble polymer compound having at least one functional group of a ketone group, an aldehyde group and an isocyanate group in the molecule, and a dihydrazide compound represented by the formula (I). For example, it is used as an aqueous ink composition for writing instruments such as aqueous ball-point pens.

The aqueous ink composition for a writing instrument of the present invention includes at least the water-soluble polymer compound having at least one functional group of a ketone group, an aldehyde group, and an isocyanate group, a dihydrazide compound represented by the above formula (I), and Contains a colorant and a water-soluble solvent.
Colorants that can be used include pigments and / or water-soluble dyes. There is no restriction | limiting in particular about the kind of pigment, Arbitrary things can be used from the inorganic type and organic type pigment conventionally used for the water-based ink for writing instruments.

Examples of inorganic pigments include carbon black and metal powder.
Examples of organic pigments include azo lakes, insoluble azo pigments, chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dye lakes, nitro pigments, and nitroso pigments. Specifically, phthalocyanine blue (C.I. 74160), phthalocyanine green (C.I. 74260), Hansa Yellow 3G (C.I. 11670), disazo yellow GR (C.I. 21100), permanent red 4R (C.I. 12335), brilliant carmine 6B (C.I. 15850), quinacridone red (C.I. 46500), etc. can be used.
Also, a plastic pigment composed of particles of styrene or acrylic resin can be used. Further, the hollow resin particles having voids inside the particles can be used as white pigments, or resin particles (pseudo pigments) dyed with a basic dye described later having excellent color development and dispersibility.

As the water-soluble dye, any of direct dyes, acid dyes, food dyes, and basic dyes can be used.
Examples of the direct dye include C.I. I. Direct Black 17, 19, 19, 22, 32, 38, 51, 71, C.I. I. Direct yellow 4, 26, 44, 50, C.I. I. Direct Red 1, 4, 23, 31, 37, 39, 75, 80, 81, 83, 225, 226, 227, C.I. I. Direct Blue 1, 15, 71, 86, 106, 119 and the like.
Examples of the acid dye include C.I. I. Acid Black 1, 2, 24, 26, 31, 31, 52, 107, 109, 110, 119, 154, C.I. I. Acid Yellow 7, 17, 19, 23, 25, 29, 38, 42, 49, 61, 72, 78, 110, 127, 135, 141, the same 142, C.I. I. Acid Red 8, 9, 9, 14, 26, 27, 35, 37, 51, 52, 57, 82, 87, 92, 94, 115, 129, 131, 186, 249, 254, 265, 276, C.I. I. Acid Violet 18, 17 and C.I. I. Acid Blue 1, 7, 9, 22, 23, 25, 40, 41, 43, 62, 78, 83, 90, 93, 103, 112, the same 113, 158, C.I. I. Acid Green 3, 9, 16, 25, 27 and the like.
Most of the food dyes are directly contained in the acid dyes or acid dyes. I. Food yellow 3 is mentioned.
Examples of basic dyes include C.I. I. Basic Yellow 1, 2 and 21, C.I. I. Basic Orange 2, 14, 32, C.I. I. Basic Red 1, 2, 9, 9, 14 C.I. I. Basic Brown 12, Basic Black 2, 8 and the like.
Examples of the resin particles dyed with a basic dye include fluorescent pigments obtained by dyeing acrylonitrile copolymer resin particles with a basic fluorescent dye. Specific product names include Sinloi Color SF Series (Sinloihi Co., Ltd.), NKW and NKP Series (Nippon Fluorochemicals Co., Ltd.).

These colorants may be used alone or in combination of two or more, and the content in the total amount of the water-based ink composition for writing instruments is usually 0.5 to 30%, preferably 1 It is in the range of ˜15%.
If the content of this colorant is less than 0.5%, coloring may be weak or the hue of the handwriting may not be known. On the other hand, if it exceeds 30%, writing defects may occur. This is not preferable.

  Examples of the water-soluble solvent that can be used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, 3-butylene glycol, thiodiethylene glycol, and glycerin, ethylene glycol monomethyl ether, and diethylene glycol monomethyl ether. These can be used alone or in combination. The content of the water-soluble solvent is preferably 5 to 40% in the total amount of the water-based ink composition for writing instruments.

  The water-based ink composition for a writing instrument of the present invention includes a water-soluble polymer compound having at least a functional group of a ketone group, an aldehyde group and an isocyanate group in the molecule, and a dihydrazide compound represented by the formula (I). In addition to the colorant and water-soluble solvent, the balance is water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.), and the dispersant, as long as the effects of the present invention are not impaired. Lubricants, pH adjusters, rust inhibitors, preservatives, antibacterial agents, and the like can be appropriately contained.

When a pigment is used as the colorant, it is preferable to use a dispersant. This dispersant acts on the pigment surface to improve the affinity with water and to stably disperse the pigment in water. Nonionic, anionic surfactants and water-soluble resins are used. A water-soluble polymer is preferably used.
Lubricants include nonionics such as fatty acid esters of polyhydric alcohols, higher fatty acid esters of sugars, polyoxyalkylene higher fatty acid esters, and alkyl phosphates, which are also used in pigment surface treatment agents, and alkyl sulfonic acids of higher fatty acid amides. Examples include salts, anionic compounds such as alkyl allyl sulfonates, polyalkylene glycol derivatives, fluorine-based surfactants, polyether-modified silicones, and phosphate esters.

Examples of pH adjusters include ammonia, urea, monoethanolamine, diethanolamine, triethanolamine, sodium tripolyphosphate, sodium carbonate, and alkali metal salts of phosphoric acid and alkali metal hydrates such as sodium hydroxide. Etc.
In addition, as rust preventives, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, saponins, etc., as antiseptics or fungicides, phenol, sodium omadin, sodium benzoate, benzimidazole compounds, etc. Can be mentioned.

The water-based ink composition for a writing instrument of the present invention comprises a water-soluble polymer compound having at least a functional group of a ketone group, an aldehyde group and an isocyanate group in the molecule, a dihydrazide compound represented by the formula (I), and coloring. It is further necessary by mixing agents, water-soluble solvents, and other components as appropriate according to the application of the writing instrument (for ballpoint pen and marking pen), and stirring and mixing with a stirrer such as a homomixer, homogenizer, or disper. Accordingly, a water-based ink composition for writing instruments can be prepared by removing coarse particles in the ink composition by filtration or centrifugation.
For an aqueous ballpoint pen, the aqueous ink composition for a writing instrument can be prepared by filling an aqueous ballpoint pen provided with a ball having a diameter of 0.18 to 2.0 mm.
The aqueous ballpoint pen to be used is not particularly limited as long as it has a ball having a diameter in the above-mentioned range. In particular, the water-based ink composition is filled in an ink storage tube of a polypropylene tube, and a tip stainless tip (ball is A refilled water-based ballpoint pen with a super steel alloy) is desirable.

The method for producing a water-based ink composition for a writing instrument of the present invention can be produced without any particular change compared to other methods for producing a water-based ink composition.
That is, the water-based ink composition for a writing instrument of the present invention comprises the above-described water-soluble polymer compound having at least one functional group of a ketone group, an aldehyde group and an isocyanate group in the molecule, and a dihydrazide represented by the above formula (I). By mixing and stirring each component including a compound or the like with a mixer or the like, it is possible to produce an aqueous ink composition for a writing instrument such as a gel ink aqueous ballpoint pen ink that develops rheological properties different from those of conventional gel inks.
Further, the pH (25 ° C.) of the aqueous ink composition for a writing instrument of the present invention is adjusted to 5 to 10 depending on the pH adjuster or the like from the viewpoints of usability, safety, stability of the ink itself, and matching properties with the ink container. It is preferably adjusted, and more preferably 6 to 9.5.

The water-based ink composition for a writing instrument of the present invention is mounted on a ballpoint pen, a marking pen, or the like having a pen tip such as a ballpoint pen tip, a fiber tip, a felt tip, or a plastic tip.
As the ballpoint pen in the present invention, the water-based ink composition for writing instruments having the above composition is accommodated in a ballpoint pen ink container (refill), and is not compatible with the water-based ink composition housed in the ink container. Examples of the ink follower include substances having a small specific gravity with respect to the water-based ink composition, such as polybutene, silicone oil, mineral oil, and the like.
The structure of the ballpoint pen and the marking pen is not particularly limited. For example, a collector structure (ink holding mechanism) in which the shaft tube itself is used as an ink container and the water-based ink composition for a writing instrument having the above configuration is filled in the shaft tube. It may be a direct liquid ballpoint pen or a marking pen provided.

  In the aqueous ink composition for a writing instrument of the present invention configured as described above, the water-soluble polymer compound having at least one functional group of a ketone group, an aldehyde group and an isocyanate group in the molecule, and the above formula ( By containing the dihydrazide compound represented by I), the chemistry of the functional group of any one of the ketone group, the aldehyde group and the isocyanate group in the water-soluble polymer compound and the dihydrazide group of the dihydrazide compound serving as a crosslinking agent It exerts a thickening action by bonding, and in this way, it develops rheological properties different from conventional gel inks in water-based ink compositions for writing instruments, and as a thickening / gelling agent for water-based ink compositions for writing instruments, A small amount of fine cellulose and xanthan gum, and the type and amount of dihydrazide compounds that serve as crosslinking agents are controlled. This provides a suitable rheology control effect, does not bleed on the writing lines, does not cause ink to penetrate to the back side of the paper, and has excellent initial writing performance, with clear tome, splash, and halai. Thus, a water-based ink composition for a writing instrument capable of writing a sharp and clean drawing line that becomes a beautiful character can be obtained.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to the following Example etc.

[Examples 1 to 9 and Comparative Examples 1 to 4]
Each water-based ballpoint pen ink composition was prepared by a conventional method according to the formulation shown in Table 1 below.
Moreover, about each obtained ink composition for water-based ball-point pens (100 mass% of total quantity), a water-based ball-point pen is produced by the following method, and the following evaluation methods are used for the following: Was evaluated.

(Production of water-based ballpoint pen)
Using a shaft of a ballpoint pen [Mitsubishi Pencil Co., Ltd., trade name: Signo UM-100], an polypropylene ink container having an inner diameter of 4.0 mm and a length of 113 mm and a stainless tip (a cemented carbide ball, a ball diameter of 0.1 mm). 7 mm) and a refill made of a joint connecting the receiving tube and the tip was filled with each ink, and an ink follower made of polybutene was loaded at the rear end of the ink to produce an aqueous ballpoint pen.

(Tome evaluation method)
Using each of the water-based ballpoint pens prepared above, “Ei” was written freehand on the writing test paper, and the blotting of the first stroke and the state of the edge were visually evaluated according to the following evaluation criteria.
Evaluation criteria:
○: There is almost no bleeding and mottling.
Δ: Slight bleeding or blur
X: Bleeding and blurring are severe, and the drawn lines are ugly.

(How to evaluate honey)
Using the water-based ballpoint pens prepared above, the character “Ei” was written freehand on the writing test paper, and the condition of the splash at the end of the second stroke was visually evaluated according to the following evaluation criteria.
Evaluation criteria:
○: The drawn line at the end of the brush is very thin, without blurring, and a beautiful drawn line can be expressed.
(Triangle | delta): The drawn line is somewhat blurred and the drawn line density is light.
X: The drawn line is severely blurred and the drawn line is ugly.

(Halai evaluation method)
Using each of the water-based ballpoint pens prepared above, the letter “Ei” was written freehand on the writing test paper, and the quality of the fifth stroke was visually evaluated according to the following evaluation criteria.
Evaluation criteria:
○: There are no broken lines, and beautiful lines can be expressed.
Δ: There are some cracks in the drawn lines, and the drawn line density is light.
X: The drawing line is broken and the drawing line is ugly.

(First-stroke performance evaluation method)
Using each of the water-based ballpoint pens prepared above, the character “Ei” was written freehand on the writing test paper, and the state of ink ejection performance at the point of the first stroke was visually evaluated according to the following evaluation criteria.
Evaluation criteria:
○: There is almost no blur and the dots are beautiful.
Δ: Slight blurring and light drawing.
X: Scratch is bad and the points are hardly readable.

(Evaluation method for blurring and blurring of drawn lines)
Using the water-based ballpoint pens prepared above, the character “Ei” was written freehand on the writing test paper, and the condition of the splash at the end of the second stroke was visually evaluated according to the following evaluation criteria.
Evaluation criteria:
○: The drawn line at the end of the brush is very thin, and there is no blur or blurring.
(Triangle | delta): The drawn line is somewhat blurred and the drawn line density is light. Or some blur is recognized.
X: The drawn line is severely blurred or blurred, and the drawn line is ugly.

  As is clear from the results of Table 1 above, Examples 1 to 9 according to the present invention have no blur on the writing lines compared to Comparative Examples 1 to 4 that are outside the scope of the present invention. It has been found that the ink composition is a water-based ink composition for writing instruments that has excellent ink writing performance, has excellent initial writing performance, has clear tome, flakes, and folds, and can be used to write sharp and clean lines that form beautiful characters.

  A water-based ink composition for a writing instrument suitable for a water-based ballpoint pen can be obtained.

Claims (3)

A water-soluble polymer compound selected from a modified polyvinyl alcohol having at least a ketone group or an aldehyde group in the molecule, a modified epoxy resin having a ketone group or an aldehyde group in the molecule, and a urethane resin having an isocyanate group in the molecule; A water-based ink composition for a writing instrument comprising the dihydrazide compound represented by (I).

  The aqueous ink composition for a writing instrument according to claim 1, wherein the dihydrazide compound is selected from adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide, and isophthalic acid dihydrazide. A writing instrument comprising the aqueous ink composition for a writing instrument according to claim 1 or 2 mounted thereon.